WorldWideScience

Sample records for binding energy values

  1. Binding energies: New values and impact on the efficiency of chemical desorption

    Science.gov (United States)

    Wakelam, V.; Loison, J.-C.; Mereau, R.; Ruaud, M.

    2017-03-01

    Recent laboratory measurements have confirmed that chemical desorption (desorption of products due to exothermic surface reactions) can be an efficient process. The impact of including this process into gas-grain chemical models entirely depends on the formalism used and the associated parameters. Among these parameters, binding energies are probably the most uncertain ones for the moment. We propose a new model to compute binding energy of species to water ice surfaces. We have also compared the model results using either the new chemical desorption model proposed by Minissale et al. (2016) or the one of Garrod et al. (2007). The new binding energies have a strong impact on the formation of complex organic molecules. In addition, the new chemical desorption model from Minissale produces a much smaller desorption of these species and also of methanol. Combining the two effects, the abundances of CH3OH and COMs observed in cold cores cannot be reproduced by astrochemical models anymore.

  2. Quarkeosynthesis Binding Energy

    Science.gov (United States)

    Webb, Bill

    2009-05-01

    Quarkeosynthesis shows that the binding energy of a nucleus is the difference between the relativistic kinetic energies of its threesome of Jumbo Quarks and that of its building block quarks from neutrons and protons. There is no involvement of a nuclear strong force or gluon material.

  3. Binding energy of two-dimensional biexcitons

    DEFF Research Database (Denmark)

    Singh, Jai; Birkedal, Dan; Vadim, Lyssenko

    1996-01-01

    Using a model structure for a two-dimensional (2D) biexciton confined in a quantum well, it is shown that the form of the Hamiltonian of the 2D biexciton reduces into that of an exciton. The binding energies and Bohr radii of a 2D biexciton in its various internal energy states are derived...... analytically using the fractional dimension approach. The ratio of the binding energy of a 2D biexciton to that of a 2D exciton is found to be 0.228, which agrees very well with the recent experimental value. The results of our approach are compared with those of earlier theories....

  4. Binding energy of protonium ions

    Science.gov (United States)

    Assad Abdel-Raouf, Mohamed

    2009-11-01

    The goal of the present work is to calculate the binding energy of the protonium ions bar PPe+ and bar PPe- using Rayleigh- Ritz variational method. It is indicated that an employment of 21 components of the trial wavefunction yields -0.08793 eV as the ground state energy of these ions. Our result agrees quite well with recently obtained results based on elaborate Monte Carlo approximations. It confirms the possible formation of these ions in laboratory.

  5. 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.

  6. 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...

  7. Binding energy of the barbell exciton

    Science.gov (United States)

    Peeters, F. M.; Golub, J. E.

    1991-02-01

    The exciton binding energy in asymmetric coupled double quantum wells is calculated. As the system is electrically tuned from type I to type II, the exciton binding energy decreases from that of a two-dimensional exciton to the binding energy of a spatially separated electron-hole pair, i.e., the barbell exciton.$-- We compare our theoretical results with a recent experiment and find good agreement.

  8. Atomic Mass and Nuclear Binding Energy for Y-90 (Yttrium)

    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 Y-90 (Yttrium, atomic number Z = 39, mass number A = 90).

  9. Exciton Binding Energy of Monolayer WS2

    Science.gov (United States)

    Zhu, Bairen; Chen, Xi; Cui, Xiaodong

    2015-03-01

    The optical properties of monolayer transition metal dichalcogenides (TMDC) feature prominent excitonic natures. Here we report an experimental approach to measuring the exciton binding energy of monolayer WS2 with linear differential transmission spectroscopy and two-photon photoluminescence excitation spectroscopy (TP-PLE). TP-PLE measurements show the exciton binding energy of 0.71 +/- 0.01 eV around K valley in the Brillouin zone.

  10. 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.

  11. Binding energies of hypernuclei and hypernuclear interactions

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Univ. of Illinois, Chicago, IL; Murali, S.; Usmani, Q.N.

    1996-01-01

    In part 1 the effect of nuclear core dynamics on the binding energies of Λ 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 Λ single-particle energy in terms of basic Λ-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 ΛNN forces are required. Also in this framework they discuss core polarization for medium and heavier hypernuclei

  12. Atomic Mass and Nuclear Binding Energy for Cf-252 (Californium)

    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 Cf-252 (Californium, atomic number Z = 98, mass number A = 252).

  13. Binding energy and formation heat of UO2

    International Nuclear Information System (INIS)

    Almeida, M.R. de; Veado, J.T.; Siqueira, M.L. de

    The Born-Haber cycle is utilized for the calculation of the heat of formation of UO 2 , on the assumption that the binding energy is predominantly ionic in character. The ionization potentials of U and the repulsion energy are two critical values that influence calculations. Calculations of the ionization potentials with non-relativistic Hartree-Fock-Gaspar-Kohn-Sham approximation are presented [pt

  14. Li+-ligand binding energies and the effect of ligand fluorination on the binding energies

    Science.gov (United States)

    Bauschlicher, Charles W.

    2018-02-01

    The Li+-ligand binding energies are computed for seven ligands and their perfluoro analogs using Density Functional Theory. The bonding is mostly electrostatic in origin. Thus the size of the binding energy tends to correlate with the ligand dipole moment, however, the charge-induced dipole contribution can be sufficiently large to affect the dipole-binding energy correlation. The perfluoro species are significantly less strongly bound than their parents, because the electron withdrawing power of the fluorine reduces the ligand dipole moment.

  15. Valuing diversity in energy supply

    International Nuclear Information System (INIS)

    Skea, Jim

    2010-01-01

    There is renewed interest in the role of supply diversity in promoting energy security. This paper explores ways of valuing diversity. A possible incentive mechanism for promoting diversity which takes account of underlying 'disparities' between different technology options is developed. The mechanism provides a way of trading off cost and diversity and results in an 'efficient' cost-diversity frontier by analogy with financial portfolio theory. If all technologies are believed to be equally disparate, the appropriate mechanism is a 'levy' imposed on market share. If the technologies are not equally disparate, the levy needs to be adjusted by technology-specific multipliers that take account of levels of disparity and patterns of market share. The analysis is applied to two stylised situations. In the long-run equilibrium case, the implications of both different patterns of disparity and different values attached to diversity are investigated. The paper also explores the implications of applying such a mechanism to the current Great Britain electricity system. The implications in terms of financial flows, for both the market as a whole and for individual operators, are investigated. Finally, the appropriateness of such a mechanism in the light of other policy goals, and possible future research directions, is discussed. (author)

  16. 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.

  17. How To Deal with Multiple Binding Poses in Alchemical Relative Protein–Ligand Binding Free Energy Calculations

    Science.gov (United States)

    2016-01-01

    Recent advances in improved force fields and sampling methods have made it possible for the accurate calculation of protein–ligand binding free energies. Alchemical free energy perturbation (FEP) using an explicit solvent model is one of the most rigorous methods to calculate relative binding free energies. However, for cases where there are high energy barriers separating the relevant conformations that are important for ligand binding, the calculated free energy may depend on the initial conformation used in the simulation due to the lack of complete sampling of all the important regions in phase space. This is particularly true for ligands with multiple possible binding modes separated by high energy barriers, making it difficult to sample all relevant binding modes even with modern enhanced sampling methods. In this paper, we apply a previously developed method that provides a corrected binding free energy for ligands with multiple binding modes by combining the free energy results from multiple alchemical FEP calculations starting from all enumerated poses, and the results are compared with Glide docking and MM-GBSA calculations. From these calculations, the dominant ligand binding mode can also be predicted. We apply this method to a series of ligands that bind to c-Jun N-terminal kinase-1 (JNK1) and obtain improved free energy results. The dominant ligand binding modes predicted by this method agree with the available crystallography, while both Glide docking and MM-GBSA calculations incorrectly predict the binding modes for some ligands. The method also helps separate the force field error from the ligand sampling error, such that deviations in the predicted binding free energy from the experimental values likely indicate possible inaccuracies in the force field. An error in the force field for a subset of the ligands studied was identified using this method, and improved free energy results were obtained by correcting the partial charges assigned to the

  18. How to deal with multiple binding poses in alchemical relative protein-ligand binding free energy calculations.

    Science.gov (United States)

    Kaus, Joseph W; Harder, Edward; Lin, Teng; Abel, Robert; McCammon, J Andrew; Wang, Lingle

    2015-06-09

    Recent advances in improved force fields and sampling methods have made it possible for the accurate calculation of protein–ligand binding free energies. Alchemical free energy perturbation (FEP) using an explicit solvent model is one of the most rigorous methods to calculate relative binding free energies. However, for cases where there are high energy barriers separating the relevant conformations that are important for ligand binding, the calculated free energy may depend on the initial conformation used in the simulation due to the lack of complete sampling of all the important regions in phase space. This is particularly true for ligands with multiple possible binding modes separated by high energy barriers, making it difficult to sample all relevant binding modes even with modern enhanced sampling methods. In this paper, we apply a previously developed method that provides a corrected binding free energy for ligands with multiple binding modes by combining the free energy results from multiple alchemical FEP calculations starting from all enumerated poses, and the results are compared with Glide docking and MM-GBSA calculations. From these calculations, the dominant ligand binding mode can also be predicted. We apply this method to a series of ligands that bind to c-Jun N-terminal kinase-1 (JNK1) and obtain improved free energy results. The dominant ligand binding modes predicted by this method agree with the available crystallography, while both Glide docking and MM-GBSA calculations incorrectly predict the binding modes for some ligands. The method also helps separate the force field error from the ligand sampling error, such that deviations in the predicted binding free energy from the experimental values likely indicate possible inaccuracies in the force field. An error in the force field for a subset of the ligands studied was identified using this method, and improved free energy results were obtained by correcting the partial charges assigned to the

  19. Free Energy, Value, and Attractors

    Directory of Open Access Journals (Sweden)

    Karl Friston

    2012-01-01

    Full Text Available It has been suggested recently that action and perception can be understood as minimising the free energy of sensory samples. This ensures that agents sample the environment to maximise the evidence for their model of the world, such that exchanges with the environment are predictable and adaptive. However, the free energy account does not invoke reward or cost-functions from reinforcement-learning and optimal control theory. We therefore ask whether reward is necessary to explain adaptive behaviour. The free energy formulation uses ideas from statistical physics to explain action in terms of minimising sensory surprise. Conversely, reinforcement-learning has its roots in behaviourism and engineering and assumes that agents optimise a policy to maximise future reward. This paper tries to connect the two formulations and concludes that optimal policies correspond to empirical priors on the trajectories of hidden environmental states, which compel agents to seek out the (valuable states they expect to encounter.

  20. 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...

  1. Conformational Transitions and Convergence of Absolute Binding Free Energy Calculations

    Science.gov (United States)

    Lapelosa, Mauro; Gallicchio, Emilio; Levy, Ronald M.

    2011-01-01

    The Binding Energy Distribution Analysis Method (BEDAM) is employed to compute the standard binding free energies of a series of ligands to a FK506 binding protein (FKBP12) with implicit solvation. Binding free energy estimates are in reasonably good agreement with experimental affinities. The conformations of the complexes identified by the simulations are in good agreement with crystallographic data, which was not used to restrain ligand orientations. The BEDAM method is based on λ -hopping Hamiltonian parallel Replica Exchange (HREM) molecular dynamics conformational sampling, the OPLS-AA/AGBNP2 effective potential, and multi-state free energy estimators (MBAR). Achieving converged and accurate results depends on all of these elements of the calculation. Convergence of the binding free energy is tied to the level of convergence of binding energy distributions at critical intermediate states where bound and unbound states are at equilibrium, and where the rate of binding/unbinding conformational transitions is maximal. This finding mirrors similar observations in the context of order/disorder transitions as for example in protein folding. Insights concerning the physical mechanism of ligand binding and unbinding are obtained. Convergence for the largest FK506 ligand is achieved only after imposing strict conformational restraints, which however require accurate prior structural knowledge of the structure of the complex. The analytical AGBNP2 model is found to underestimate the magnitude of the hydrophobic driving force towards binding in these systems characterized by loosely packed protein-ligand binding interfaces. Rescoring of the binding energies using a numerical surface area model corrects this deficiency. This study illustrates the complex interplay between energy models, exploration of conformational space, and free energy estimators needed to obtain robust estimates from binding free energy calculations. PMID:22368530

  2. 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}-...

  3. Perturbation method for calculating impurity binding energy in an ...

    Indian Academy of Sciences (India)

    Perturbation method is used to calculate the binding energy within the framework of effective mass approximation and taking into account the effect of dielectric mismatch between the dot and the barrier material. The ground-state binding energy of the donor is computed as a function of dot size for finite confinement.

  4. Perturbation method for calculating impurity binding energy in an ...

    Indian Academy of Sciences (India)

    Nilanjan Sil

    2017-12-18

    Dec 18, 2017 ... Abstract. In the present paper, we have studied the binding energy of the shallow donor hydrogenic impurity, which is confined in an inhomogeneous cylindrical quantum dot (CQD) of GaAs-AlxGa1−xAs. Perturbation method is used to calculate the binding energy within the framework of effective mass ...

  5. Tariff based value of wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Raekkoelaeinen, J.; Vilkko, M.; Antila, H.; Lautala, P. [Tampere Univ. of Technology (Finland)

    1995-12-31

    In this article an approach for determining a value of wind energy is presented. Calculation is based on wholesale tariffs, i.e. the value of wind energy is defined in comparison with other purchase. This approach can be utilised as an aid in the investment planning in defining the benefits of new wind generation capacity. Linear programming optimization method is used. A case study is presented for different wind scenarios. The value of wind energy can vary remarkably depending on timing of power output. (author)

  6. Tariff based value of wind energy

    International Nuclear Information System (INIS)

    Raekkoelaeinen, J.; Vilkko, M.; Antila, H.; Lautala, P.

    1995-01-01

    In this article an approach for determining a value of wind energy is presented. Calculation is based on wholesale tariffs, i.e. the value of wind energy is defined in comparison with other purchase. This approach can be utilised as an aid in the investment planning in defining the benefits of new wind generation capacity. Linear programming optimization method is used. A case study is presented for different wind scenarios. The value of wind energy can vary remarkably depending on timing of power output. (author)

  7. Household energy requirement and value patterns

    International Nuclear Information System (INIS)

    Vringer, Kees; Aalbers, Theo; Blok, Kornelis

    2007-01-01

    For an effective consumer energy policy, it is important to know why some households require more energy than others. The aim of the study described here was to examine whether there is a relationship between the total household energy requirement, on one hand, and value patterns, the motivation to save energy or the problem perception of climate change, on the other. To examine these relationships, we held a consumer survey among 2304 respondent households. We did not find significant differences in the energy requirement of groups of households with different value patterns, taking into account the differences in the socio-economic situation of households. Only for the 'motivation to save energy' we did find that the least motivated group requires 10 GJ more energy than the average and most motivated groups; this is about 4% of the total household energy requirement. This means that a self-regulating energy policy, solely based on the fact that a strategy of internalising environmental responsibility will not be effective in saving energy. There are indications that a social dilemma is one of the reasons why people's consumption patterns do not conform to their value patterns, problem perception or motivation to save energy

  8. Computation of pH-Dependent Binding Free Energies

    Science.gov (United States)

    Kim, M. Olivia; McCammon, J. Andrew

    2015-01-01

    Protein-ligand binding accompanies changes in the surrounding electrostatic environments of the two binding partners and may lead to changes in protonation upon binding. In cases where the complex formation results in a net transfer of protons, the binding process is pH-dependent. However, conventional free energy computations or molecular docking protocols typically employ fixed protonation states for the titratable groups in both binding partners set a priori, which are identical for the free and bound states. In this review, we draw attention to these important yet largely ignored binding-induced protonation changes in protein-ligand association by outlining physical origins and prevalence of the protonation changes upon binding. Following a summary of various theoretical methods for pKa prediction, we discuss the theoretical framework to examine the pH dependence of protein-ligand binding processes. PMID:26202905

  9. Multiple binding modes of ibuprofen in human serum albumin identified by absolute binding free energy calculations

    KAUST Repository

    Evoli, Stefania

    2016-11-10

    Human serum albumin possesses multiple binding sites and transports a wide range of ligands that include the anti-inflammatory drug ibuprofen. A complete map of the binding sites of ibuprofen in albumin is difficult to obtain in traditional experiments, because of the structural adaptability of this protein in accommodating small ligands. In this work, we provide a set of predictions covering the geometry, affinity of binding and protonation state for the pharmaceutically most active form (S-isomer) of ibuprofen to albumin, by using absolute binding free energy calculations in combination with classical molecular dynamics (MD) simulations and molecular docking. The most favorable binding modes correctly reproduce several experimentally identified binding locations, which include the two Sudlow\\'s drug sites (DS2 and DS1) and the fatty acid binding sites 6 and 2 (FA6 and FA2). Previously unknown details of the binding conformations were revealed for some of them, and formerly undetected binding modes were found in other protein sites. The calculated binding affinities exhibit trends which seem to agree with the available experimental data, and drastically degrade when the ligand is modeled in a protonated (neutral) state, indicating that ibuprofen associates with albumin preferentially in its charged form. These findings provide a detailed description of the binding of ibuprofen, help to explain a wide range of results reported in the literature in the last decades, and demonstrate the possibility of using simulation methods to predict ligand binding to albumin.

  10. Structure-function relationships of Na+, K+, ATP, or Mg2+ binding and energy transduction in Na,K-ATPase

    DEFF Research Database (Denmark)

    Jorgensen, Peter L.; Pedersen, Per Amstrup

    2000-01-01

    Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction......Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction...

  11. Using the fast fourier transform in binding free energy calculations.

    Science.gov (United States)

    Nguyen, Trung Hai; Zhou, Huan-Xiang; Minh, David D L

    2018-04-30

    According to implicit ligand theory, the standard binding free energy is an exponential average of the binding potential of mean force (BPMF), an exponential average of the interaction energy between the unbound ligand ensemble and a rigid receptor. Here, we use the fast Fourier transform (FFT) to efficiently evaluate BPMFs by calculating interaction energies when rigid ligand configurations from the unbound ensemble are discretely translated across rigid receptor conformations. Results for standard binding free energies between T4 lysozyme and 141 small organic molecules are in good agreement with previous alchemical calculations based on (1) a flexible complex ( R≈0.9 for 24 systems) and (2) flexible ligand with multiple rigid receptor configurations ( R≈0.8 for 141 systems). While the FFT is routinely used for molecular docking, to our knowledge this is the first time that the algorithm has been used for rigorous binding free energy calculations. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Values in reasoning on energy policy

    International Nuclear Information System (INIS)

    Malaska, P.; Kantola, I.; Kasanen, P.

    1989-01-01

    Energy policy at the present time is a controversial issue with value loaded but hidden assumptions and controdictory views between proponents and opponents. The hidden or even open value contradictions between people acting on the policy formulation as experts or participating in public discussion, hinder attainment of common understanding of the situation and the choices available as well as rational decision making. Diversified subjects of energy issues followed with logical argumentation by different people and with controversial views as presented in public or in the value panel of the research project, have been described and analysed in a novel way in this research. A previously developed cognitive mapping technique has been applied in presenting the logical substructures of argumentation. However, controversality of energy policy does not stem only from the values but equally from other sources of possible contradictory views, such as erraneous or partial data, contingential information or invalid logic. Energy discussion is not devoid of these pitfalls, not necessarily even when the so-called experts express their views and recommendations. The report analyses some important themes. The message of the research, if any, is about how to consider the value arguments in a rational way and how to 'solve' value contradictions for decision making or how to make decisions on energy in a rational way under value contradictions. It is concluded that the remedy is in conscious elaborations on these contradictions and detection of them from other relevant information and furthermore, in the development of communicative rationality instead of and side by side with the more commonly adapted technical rationality

  13. The problem of valuing new energy technologies

    International Nuclear Information System (INIS)

    Awerbuch, Shimon.

    1996-01-01

    A brief editorial outlines the concepts and challenges facing the valuation of modular, renewable energy technologies which are covered in a special issue of ''Energy Policy''. The main problem is the narrowness of the traditional discounted cash flow analysis for valuing such projects when some of the benefits (e.g. flexibility, financial risk, reduction in overhead and indirect costs) are not fully recognized at the outset. (UK)

  14. Values and Technologies in Energy Savings

    DEFF Research Database (Denmark)

    Nørgård, Jørgen Stig

    2000-01-01

    of this saving can cause what is called the rebound effect, which reduces the savings obtained from the technology. Ways to avoid this effect are suggested, and they require value changes, primarly around frugality, consumption, and hard-working. There are indications that some of the necessary changes are well......The chapter is based on the assumption, that technology improvement is not sufficient to achieve a sustainable world community. Changes in people´s values are necessary. A simple model suggest how values, together with basic needs and with the environmental and societal frames, determine people......´s behavioural pattern and lifestyles. Deliberate changes in social values are illustrated by a historical example. From the side of technology the basic principles in the economy of energy savings are briefly described. The marginally profitable energy savings provides an economic saving. The application...

  15. Value of the energy data base

    Energy Technology Data Exchange (ETDEWEB)

    King, D.W.; Griffiths, J.M.; Roderer, N.K.; Wiederkehr, R.R.V.

    1982-03-31

    An assessment was made of the Energy Data Base (EDB) of the Department of Energy's Technical Information Center (TIC). As the major resource containing access information to the world's energy literature, EDB products and services are used extensively by energy researchers to identify journal articles, technical reports and other items of potential utility in their work. The approach taken to assessing value begins with the measurement of extent of use of the EDB. Apparent value is measured in terms of willingness to pay. Consequential value is measured in terms of effect - for searching, the cost of reading which results; and for reading, the savings which result from the application of the information obtained in reading. Resulting estimates of value reflect value to the searchers, the reader, and the reader's organization or funding source. A survey of the 60,000 scientists and eingineers funded by the DOE shows that annually they read about 7.1 million journal articles and 6.6 million technical reports. A wide range of savings values were reported for one-fourth of all article readings and three-fourths of all report readings. There was an average savings of $590 per reading of all articles; there was an average savings of $1280 for technical reports. The total annual savings attributable to reading by DOE-funded scientists and engineers is estimated to be about $13 billion. An investment of $5.3 billion in the generation of information and about $500 million in processing and using information yields a partial return of about $13 billion. Overall, this partial return on investment is about 2.2 to 1. In determining the value of EDB only those searches and readings directly attributable to it are included in the analysis. The values are $20 million to the searchers, $117 million to the readers and $3.6 billion to DOE.

  16. The Business Value of Superior Energy Performance

    Energy Technology Data Exchange (ETDEWEB)

    McKane, Aimee; Scheihing, Paul; Evans, Tracy; Glatt, Sandy; Meffert, William

    2015-08-04

    Industrial facilities participating in the U.S. Department of Energy’s (US DOE) Superior Energy Performance (SEP) program are finding that it provides them with significant business value. This value starts with the implementation of ISO 50001-Energy management system standard, which provides an internationally-relevant framework for integration of energy management into an organization’s business processes. The resulting structure emphasizes effective use of available data and supports continual improvement of energy performance. International relevance is particularly important for companies with a global presence or trading interests, providing them with access to supporting ISO standards and a growing body of certified companies representing the collective knowledge of communities of practice. This paper examines the business value of SEP, a voluntary program that builds on ISO 50001, inviting industry to demonstrate an even greater commitment through third-party verification of energy performance improvement to a specified level of achievement. Information from 28 facilities that have already achieved SEP certification will illustrate key findings concerning both the value and the challenges from SEP/ISO 50001 implementation. These include the facilities’ experience with implementation, internal and external value of third-party verification of energy performance improvement; attractive payback periods and the importance of SEP tools and guidance. US DOE is working to bring the program to scale, including the Enterprise-Wide Accelerator (SEP for multiple facilities in a company), the Ratepayer-Funded Program Accelerator (supporting tools for utilities and program administrators to include SEP in their program offerings), and expansion of the program to other sectors and industry supply chains.

  17. Enzyme activation through the utilization of intrinsic dianion binding energy.

    Science.gov (United States)

    Amyes, T L; Malabanan, M M; Zhai, X; Reyes, A C; Richard, J P

    2017-03-01

    We consider 'the proposition that the intrinsic binding energy that results from the noncovalent interaction of a specific substrate with the active site of the enzyme is considerably larger than is generally believed. An important part of this binding energy may be utilized to provide the driving force for catalysis, so that the observed binding energy represents only what is left over after this utilization' [Jencks,W.P. (1975) Adv. Enzymol. Relat. Areas. Mol. Biol. , , 219-410]. The large ~12 kcal/mol intrinsic substrate phosphodianion binding energy for reactions catalyzed by triosephosphate isomerase (TIM), orotidine 5'-monophosphate decarboxylase and glycerol-3-phosphate dehydrogenase is divided into 4-6 kcal/mol binding energy that is expressed on the formation of the Michaelis complex in anchoring substrates to the respective enzyme, and 6-8 kcal/mol binding energy that is specifically expressed at the transition state in activating the respective enzymes for catalysis. A structure-based mechanism is described where the dianion binding energy drives a conformational change that activates these enzymes for catalysis. Phosphite dianion plays the active role of holding TIM in a high-energy closed active form, but acts as passive spectator in showing no effect on transition-state structure. The result of studies on mutant enzymes is presented, which support the proposal that the dianion-driven enzyme conformational change plays a role in enhancing the basicity of side chain of E167, the catalytic base, by clamping the base between a pair of hydrophobic side chains. The insight these results provide into the architecture of enzyme active sites and the development of strategies for the de novo design of protein catalysts is discussed.

  18. Funnel metadynamics as accurate binding free-energy method

    Science.gov (United States)

    Limongelli, Vittorio; Bonomi, Massimiliano; Parrinello, Michele

    2013-01-01

    A detailed description of the events ruling ligand/protein interaction and an accurate estimation of the drug affinity to its target is of great help in speeding drug discovery strategies. We have developed a metadynamics-based approach, named funnel metadynamics, that allows the ligand to enhance the sampling of the target binding sites and its solvated states. This method leads to an efficient characterization of the binding free-energy surface and an accurate calculation of the absolute protein–ligand binding free energy. We illustrate our protocol in two systems, benzamidine/trypsin and SC-558/cyclooxygenase 2. In both cases, the X-ray conformation has been found as the lowest free-energy pose, and the computed protein–ligand binding free energy in good agreement with experiments. Furthermore, funnel metadynamics unveils important information about the binding process, such as the presence of alternative binding modes and the role of waters. The results achieved at an affordable computational cost make funnel metadynamics a valuable method for drug discovery and for dealing with a variety of problems in chemistry, physics, and material science. PMID:23553839

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

    Science.gov (United States)

    Zhao, Yan-Ping; Li, Ping; Gou, Qing-Quan; Liu, Wei-Na

    2008-12-01

    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 = 5.07a0. 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 and 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.

  20. The economic value of fusion energy

    International Nuclear Information System (INIS)

    Kim, S.H.; Clarke, J.; Edmonds, J.

    1996-01-01

    The potential economic benefit of fusion energy technology is significant and could dwarf the world's total expenditure on fusion energy research and development. However, the realization of these benefits will depend on the economic competitiveness of electricity generation from fusion energy technologies relative to that from other existing fossil fueled and renewable technologies, as well as the time in which fusion energy technologies are available for commercial operation. Utilizing the Second Generation Model, a long-term energy/economics model, the potential economic benefit of fusion energy technology for the United States was assessed. Model scenarios with hypothetical fusion power technologies based on the International Thermonuclear Experimental Reactor (ITER) design with varying cost and time of availability showed that significant economic benefit exists from a competitive fusion technology with cost of electricity (COE) of 0.06 $/kWhr and available in the year 2025. The fusion technology with these characteristics resulted in a total discounted GDP benefit of $105 billion from the year 1995 to 2100. On the other hand, uncompetitive fusion technologies with higher COE of 0.12 and 0.09 $/kWhr had little economic benefits. Moreover, delaying the introduction of all fusion technologies from 2025 to 2050 reduced the economic benefits of fusion technologies by more than 60 percent. Aside from the economic benefit of fusion technologies operating in the United States, the potential economic value of international trade in fusion technologies is likely to be even greater. If the United States could capture just a portion of the global electricity market, the export value of the fusion technology could amount to hundreds of billions of dollars, whereas the cost of importing the technology to the United States will erase any benefits derived from GDP increases

  1. Value of Energy Storage for Grid Applications

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, P.; Jorgenson, J.; Hummon, M.; Jenkin, T.; Palchak, D.; Kirby, B.; Ma, O.; O' Malley, M.

    2013-05-01

    This analysis evaluates several operational benefits of electricity storage, including load-leveling, spinning contingency reserves, and regulation reserves. Storage devices were simulated in a utility system in the western United States, and the operational costs of generation was compared to the same system without the added storage. This operational value of storage was estimated for devices of various sizes, providing different services, and with several sensitivities to fuel price and other factors. Overall, the results followed previous analyses that demonstrate relatively low value for load-leveling but greater value for provision of reserve services. The value was estimated by taking the difference in operational costs between cases with and without energy storage and represents the operational cost savings from deploying storage by a traditional vertically integrated utility. The analysis also estimated the potential revenues derived from a merchant storage plant in a restructured market, based on marginal system prices. Due to suppression of on-/off-peak price differentials and incomplete capture of system benefits (such as the cost of power plant starts), the revenue obtained by storage in a market setting appears to be substantially less than the net benefit provided to the system. This demonstrates some of the additional challenges for storage deployed in restructured energy markets.

  2. Sensitivity Analysis of Grain Surface Chemistry to Binding Energies of Ice Species

    Science.gov (United States)

    Penteado, E. M.; Walsh, C.; Cuppen, H. M.

    2017-07-01

    Advanced telescopes, such as ALMA and the James Webb Space Telescope, are likely to show that the chemical universe may be even more complex than currently observed, requiring astrochemical modelers to improve their models to account for the impact of new data. However, essential input information for gas-grain models, such as binding energies of molecules to the surface, have been derived experimentally only for a handful of species, leaving hundreds of species with highly uncertain estimates. We present in this paper a systematic study of the effect of uncertainties in the binding energies on an astrochemical two-phase model of a dark molecular cloud, using the rate equations approach. A list of recommended binding energy values based on a literature search of published data is presented. Thousands of simulations of dark cloud models were run, and in each simulation a value for the binding energy of hundreds of species was randomly chosen from a normal distribution. Our results show that the binding energy of H2 is critical for the surface chemistry. For high binding energies, H2 freezes out on the grain forming an H2 ice. This is not physically realistic, and we suggest a change in the rate equations. The abundance ranges found are in reasonable agreement with astronomical ice observations. Pearson correlation coefficients revealed that the binding energy of HCO, HNO, CH2, and C correlate most strongly with the abundance of dominant ice species. Finally, the formation route of complex organic molecules was found to be sensitive to the branching ratios of H2CO hydrogenation.

  3. Analysis of experimental positron-molecule binding energies

    International Nuclear Information System (INIS)

    Danielson, J R; Surko, C M; Young, J A

    2010-01-01

    Experiments show that positron annihilation on molecules frequently occurs via capture into vibrational Feshbach resonances. In these cases, the downshifts in the annihilation spectra from the vibrational mode spectra provide measures of the positron-molecule binding energies. An analysis of these binding energy data is presented in terms of the molecular dipole polarizability, the permanent dipole moment, and the number of π bonds in aromatic molecules. The results of this analysis are in reasonably good agreement with other information about positron-molecule bound states. Predictions for other targets and promising candidate molecules for further investigation are discussed.

  4. Calculation of the Relative Change in Binding Free Energy of a Protein-Inhibitor Complex

    Science.gov (United States)

    Bash, Paul A.; Singh, U. Chandra; Brown, Frank K.; Langridge, Robert; Kollman, Peter A.

    1987-01-01

    By means of a thermodynamic perturbation method implemented with molecular dynamics, the relative free energy of binding was calculated for the enzyme thermolysin complexed with a pair of phosphonamidate and phosphonate ester inhibitors. The calculated difference in free energy of binding was 4.21 ± 0.54 kilocalories per mole. This compares well with the experimental value of 4.1 kilocalories per mole. The method is general and can be used to determine a change or ``mutation'' in any system that can be suitably represented. It is likely to prove useful for protein and drug design.

  5. Western values and the Russian energy weapon

    Science.gov (United States)

    Domingues, Bennett K.

    become heavily involved in oil and gas extraction projects in the region, in particular in Kazakhstan. Yet, efforts to transport that energy to western markets without Russian involvement have met with strong resistance. This thesis demonstrates that part of the reason western firms have been less successful than they hoped to be is because western firms, in particular American firms, are so bound by western ethical norms and the statues that codify them, that they have lost their competitive advantage. The thesis concludes with a discussion of the current day balance of energy resources in Europe, noting that Europe is rapidly growing heavily dependent on Russian oil and gas resources. Given the precedents shown in Georgia and Ukraine, it is only a matter of time before Europe grows so dependent on Russian energy that the individual countries will lose their political and economic independence and in turn, their ability to project western values and values-based ideas throughout the world with impunity.

  6. 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...

  7. Nuclear Cartography: Patterns in Binding Energies and Subatomic Structure

    Science.gov (United States)

    Simpson, E. C.; Shelley, M.

    2017-01-01

    Nuclear masses and binding energies are some of the first nuclear properties met in high school physics, and can be used to introduce radioactive decays, fusion, and fission. With relatively little extension, they can also illustrate fundamental concepts in nuclear physics, such as shell structure and pairing, and to discuss how the elements…

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

    International Nuclear Information System (INIS)

    Liu Weina; Li Ping; Gou Qingquan; Zhao Yanping

    2008-01-01

    The formation mechanism for the body-centred regular icosahedral structure of Li 13 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 Li 13 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 = 5.46a 0 . 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 Li 13 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Li 13 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li 2 , 0.494 eV for Li 3 , 0.7878 eV for Li 4 , 0.632 eV for Li 5 , and 0.674 eV for Li 7 calculated by us previously. This means that the Li 13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy

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

    Science.gov (United States)

    Liu, Wei-Na; Li, Ping; Gou, Qing-Quan; Zhao, Yan-Ping

    2008-11-01

    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 Li3, 0.7878 eV for Li4, 0.632 eV for Li5, and 0.674 eV for Li7 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.

  10. Lanthanide 4f-electron binding energies and the nephelauxetic effect in wide band gap compounds

    International Nuclear Information System (INIS)

    Dorenbos, Pieter

    2013-01-01

    Employing data from luminescence spectroscopy, the inter 4f-electron Coulomb repulsion energy U(6, A) in Eu 2+/3+ impurities together with the 5d-centroid energy shift ϵ c (1,3+,A) in Ce 3+ impurities in 40 different fluoride, chloride, bromide, iodide, oxide, sulfide, and nitride compounds has been determined. This work demonstrates that the chemical environment A affects the two energies in a similar fashion; a fashion that follows the anion nephelauxetic sequence F, O, Cl, Br, N, I, S, Se. One may then calculate U(6, A) from well established and accurate ϵ c (1,3+,A) values which are then used as input to the chemical shift model proposed in Dorenbos (2012) [19]. As output it provides the chemical shift of 4f-electron binding energy and therewith the 4f-electron binding energy relative to the vacuum energy. In addition this method provides a tool to routinely establish the binding energy of electrons at the top of the valence band (work function) and the bottom of the conduction band (electron affinity) throughout the entire family of inorganic compounds. How the electronic structure of the compound and lanthanide impurities therein change with type of compound and type of lanthanide is demonstrated. -- Highlights: ► A relationship between 5d centroid shift and 4f-electron Coulomb repulsion energy is established. ► Information on the absolute 4f-electron binding energy of lanthanides in 40 compounds is provided. ► A new tool to determine absolute binding energies of electrons in valence and conduction bands is demonstrated

  11. Magnetic properties and core electron binding energies of liquid water

    Science.gov (United States)

    Galamba, N.; Cabral, Benedito J. C.

    2018-01-01

    The magnetic properties and the core and inner valence electron binding energies of liquid water are investigated. The adopted methodology relies on the combination of molecular dynamics and electronic structure calculations. Born-Oppenheimer molecular dynamics with the Becke and Lee-Yang-Parr functionals for exchange and correlation, respectively, and includes an empirical correction (BLYP-D3) functional and classical molecular dynamics with the TIP4P/2005-F model were carried out. The Keal-Tozer functional was applied for predicting magnetic shielding and spin-spin coupling constants. Core and inner valence electron binding energies in liquid water were calculated with symmetry adapted cluster-configuration interaction. The relationship between the magnetic shielding constant σ(17O), the role played by the oxygen atom as a proton acceptor and donor, and the tetrahedral organisation of liquid water are investigated. The results indicate that the deshielding of the oxygen atom in water is very dependent on the order parameter (q) describing the tetrahedral organisation of the hydrogen bond network. The strong sensitivity of magnetic properties on changes of the electronic density in the nuclei environment is illustrated by a correlation between σ(17O) and the energy gap between the 1a1[O1s] (core) and the 2a1 (inner valence) orbitals of water. Although several studies discussed the eventual connection between magnetic properties and core electron binding energies, such a correlation could not be clearly established. Here, we demonstrate that for liquid water this correlation exists although involving the gap between electron binding energies of core and inner valence orbitals.

  12. Computational scheme for pH-dependent binding free energy calculation with explicit solvent.

    Science.gov (United States)

    Lee, Juyong; Miller, Benjamin T; Brooks, Bernard R

    2016-01-01

    We present a computational scheme to compute the pH-dependence of binding free energy with explicit solvent. Despite the importance of pH, the effect of pH has been generally neglected in binding free energy calculations because of a lack of accurate methods to model it. To address this limitation, we use a constant-pH methodology to obtain a true ensemble of multiple protonation states of a titratable system at a given pH and analyze the ensemble using the Bennett acceptance ratio (BAR) method. The constant pH method is based on the combination of enveloping distribution sampling (EDS) with the Hamiltonian replica exchange method (HREM), which yields an accurate semi-grand canonical ensemble of a titratable system. By considering the free energy change of constraining multiple protonation states to a single state or releasing a single protonation state to multiple states, the pH dependent binding free energy profile can be obtained. We perform benchmark simulations of a host-guest system: cucurbit[7]uril (CB[7]) and benzimidazole (BZ). BZ experiences a large pKa shift upon complex formation. The pH-dependent binding free energy profiles of the benchmark system are obtained with three different long-range interaction calculation schemes: a cutoff, the particle mesh Ewald (PME), and the isotropic periodic sum (IPS) method. Our scheme captures the pH-dependent behavior of binding free energy successfully. Absolute binding free energy values obtained with the PME and IPS methods are consistent, while cutoff method results are off by 2 kcal mol(-1) . We also discuss the characteristics of three long-range interaction calculation methods for constant-pH simulations. © 2015 The Protein Society.

  13. Free energy profiles of cocaine esterase-cocaine binding process by molecular dynamics and potential of mean force simulations.

    Science.gov (United States)

    Zhang, Yuxin; Huang, Xiaoqin; Han, Keli; Zheng, Fang; Zhan, Chang-Guo

    2016-11-25

    The combined molecular dynamics (MD) and potential of mean force (PMF) simulations have been performed to determine the free energy profile of the CocE)-(+)-cocaine binding process in comparison with that of the corresponding CocE-(-)-cocaine binding process. According to the MD simulations, the equilibrium CocE-(+)-cocaine binding mode is similar to the CocE-(-)-cocaine binding mode. However, based on the simulated free energy profiles, a significant free energy barrier (∼5 kcal/mol) exists in the CocE-(+)-cocaine binding process whereas no obvious free energy barrier exists in the CocE-(-)-cocaine binding process, although the free energy barrier of ∼5 kcal/mol is not high enough to really slow down the CocE-(+)-cocaine binding process. In addition, the obtained free energy profiles also demonstrate that (+)-cocaine and (-)-cocaine have very close binding free energies with CocE, with a negligible difference (∼0.2 kcal/mol), which is qualitatively consistent with the nearly same experimental K M values of the CocE enzyme for (+)-cocaine and (-)-cocaine. The consistency between the computational results and available experimental data suggests that the mechanistic insights obtained from this study are reasonable. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Experimental electron binding energies for thulium in different matrices

    Czech Academy of Sciences Publication Activity Database

    Inoyatov, A. K.; Kovalík, Alojz; Filosofov, D. V.; Ryšavý, Miloš; Perevoshchikov, L. L.; Yushkevich, Yu. V.; Zbořil, M.

    2015-01-01

    Roč. 202, JUL (2015), s. 46-55 ISSN 0368-2048 R&D Projects: GA MŠk LG14004; GA ČR(CZ) GAP203/12/1896 Institutional support: RVO:61389005 Keywords : Tm-169 * (169)yb * atomic environment * electron binding energy * chemical shift * natural atomic level width Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.561, year: 2015

  15. Effect of valence nucleons on nuclear binding energy

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, I. (Kossuth Lajos Tudomanyegyetem, Debrecen (HU))

    1991-10-01

    The nucleonic promiscuity factor P = N{sub p}N{sub n}/(N{sub p} + N{sub n}), where N{sub p}(N{sub n}) is the number of valence protons (neutrons) or holes, is shown to be a useful parameter in the description of the mass number dependence of nuclear binding energies. This means that most of the deviation from a smooth mass number dependence is caused by the isoscalar interaction between valence protons and neutrons.

  16. Impurity binding energy for δ-doped quantum well structures

    Indian Academy of Sciences (India)

    Administrator

    Abstract. 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 n-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.

  17. The influence of gravitational binding energy on cosmic expansion dynamics: new perspectives for cosmology

    Science.gov (United States)

    Fahr, Hans-Jörg; Sokaliwska, Michael

    2012-06-01

    Confronted with microwave background observations by WMAP and with consternating supernova locations in the magnitude-redshift diagram modern cosmology feels enforced to call for cosmic vacuum energy as a necessary cosmological ingredient. Most often this vacuum energy is associated with Einstein's cosmological constant Λ or with so-called "dark energy". A positive value of Λ describes an inflationary action on cosmic dynamics which in view of recent cosmological data appears as an absolute need. In this article, however, we question the hypothesis of a constant vacuum energy density since not justifiable on physical grounds. Instead we show that gravitational binding energy of cosmic matter, connected with ongoing structure formation during cosmic expansion, acts similar to vacuum energy, since it reduces the effective gravitating proper mass density. Thus one may be encouraged to believe that actions of cosmic vacuum energy and gravitational binding energy concerning their cosmological effects are closely related to each other, perhaps in some respects even have identical phenomenologies. Based on results presented in this article we propose that the generally wanted action of vacuum energy on cosmic spacetime dynamics inevitably leads to a decay of vacuum energy density. Connected with this decay is a decrease of cosmic binding energy and the generation of new effective gravitating mass in the universe. If this all is adequately taken into account by the energy-momentum tensor of the GR field equations, one is then led to non-standard cosmologies which for the first time can guarantee the conservation of the total energy both in static and expanding universes. We describe the structuring of cosmic matter by a change in time of the 2-point correlation-function. We do show here that cosmic structure formation drives accelerated cosmic expansion and feigns the action of vacuum energy density.

  18. Teaching Children to Value Solar Energy

    Science.gov (United States)

    Hugerat, Muhamad; Saker, Salem; Odeh, Saeed; Agbaria, Adnan

    2011-01-01

    In this educational initiative, we suggest to build a real model of solar village inside the school, which uses only solar energy. These educational initiatives emphasize the importance of energy for a technological society and the advantage of alternative energy sources. In this scientific educational initiative, the pupils in three elementary…

  19. Binding energy and single–particle Energies in the 16 0 region ...

    African Journals Online (AJOL)

    ... single-particle energies in the oxygen region by folding together a Hamiltonian in the rest-frame of the nucleus with two-body correlation functions based on the Njimegen potential. We have found that the binding energies are very sensitive to the core radius rc and that the effects of tensor correlations are non-negligible.

  20. Sampling and energy evaluation challenges in ligand binding protein design.

    Science.gov (United States)

    Dou, Jiayi; Doyle, Lindsey; Jr Greisen, Per; Schena, Alberto; Park, Hahnbeom; Johnsson, Kai; Stoddard, Barry L; Baker, David

    2017-12-01

    The steroid hormone 17α-hydroxylprogesterone (17-OHP) is a biomarker for congenital adrenal hyperplasia and hence there is considerable interest in development of sensors for this compound. We used computational protein design to generate protein models with binding sites for 17-OHP containing an extended, nonpolar, shape-complementary binding pocket for the four-ring core of the compound, and hydrogen bonding residues at the base of the pocket to interact with carbonyl and hydroxyl groups at the more polar end of the ligand. Eight of 16 designed proteins experimentally tested bind 17-OHP with micromolar affinity. A co-crystal structure of one of the designs revealed that 17-OHP is rotated 180° around a pseudo-two-fold axis in the compound and displays multiple binding modes within the pocket, while still interacting with all of the designed residues in the engineered site. Subsequent rounds of mutagenesis and binding selection improved the ligand affinity to nanomolar range, while appearing to constrain the ligand to a single bound conformation that maintains the same "flipped" orientation relative to the original design. We trace the discrepancy in the design calculations to two sources: first, a failure to model subtle backbone changes which alter the distribution of sidechain rotameric states and second, an underestimation of the energetic cost of desolvating the carbonyl and hydroxyl groups of the ligand. The difference between design model and crystal structure thus arises from both sampling limitations and energy function inaccuracies that are exacerbated by the near two-fold symmetry of the molecule. © 2017 The Authors Protein Science published by Wiley Periodicals, Inc. on behalf of The Protein Society.

  1. Measurement of Exciton Binding Energy of Monolayer WS2

    Science.gov (United States)

    Chen, Xi; Zhu, Bairen; Cui, Xiaodong

    Excitonic effects are prominent in monolayer crystal of transition metal dichalcogenides (TMDCs) because of spatial confinement and reduced Coulomb screening. Here we use linear differential transmission spectroscopy and two-photon photoluminescence excitation spectroscopy (TP-PLE) to measure the exciton binding energy of monolayer WS2. Peaks for excitonic absorptions of the direct gap located at K valley of the Brillouin zone and transitions from multiple points near Γ point of the Brillouin zone, as well as trion side band are shown in the linear absorption spectra of WS2. But there is no gap between distinct excitons and the continuum of the interband transitions. Strong electron-phonon scattering, overlap of excitons around Γ point and the transfer of the oscillator strength from interband continuum to exciton states make it difficult to resolve the electronic interband transition edge even down to 10K. The gap between excited states of the band-edge exciton and the single-particle band is probed by TP-PLE measurements. And the energy difference between 1s exciton and the single-particle gap gives the exciton binding energy of monolayer WS2 to be about 0.71eV. The work is supported by Area of excellency (AoE/P-04/08), CRF of Hong Kong Research Grant Council (HKU9/CRF/13G) and SRT on New Materials of The University of Hong Kong.

  2. 2011 EnergyValue Housing Award Report

    Energy Technology Data Exchange (ETDEWEB)

    Sagan, D.; Del Bianco, M.; Wood, A.

    2012-10-01

    This report details the simulation tool(s) and energy modeling methodology followed in making the energy efficiency estimates and documents the estimated performance of the EVHA award winning houses in comparison with the Building America Benchmark and the associated House Simulation Protocols. A summary of each building and its features is included with a brief description of the project and the judges' comments. The purpose of this report is to assess the energy performance of the 2011 EVHA winners as well as align the EVHA Program with the Building America Program.

  3. 2011 EnergyValue Housing Award Report

    Energy Technology Data Exchange (ETDEWEB)

    Sagan, D. [NAHB Research Center, Upper Marlboro, MD (United States); Del Bianco, M. [NAHB Research Center, Upper Marlboro, MD (United States); Wood, A. [NAHB Research Center, Upper Marlboro, MD (United States)

    2012-10-01

    This report details the simulation tool(s) and energy modeling methodology followed in making the energy efficiency estimates, and documents the estimated performance of the EVHA award-winning houses in comparison with the Building America Benchmark and the associated House Simulation Protocols. A summary of each building and its features is included with a brief description of the project and the judges’ comments.

  4. Exciton binding energy in a pyramidal quantum dot

    Science.gov (United States)

    Anitha, A.; Arulmozhi, M.

    2018-05-01

    The effects of spatially dependent effective mass, non-parabolicity of the conduction band and dielectric screening function on exciton binding energy in a pyramid-shaped quantum dot of GaAs have been investigated by variational method as a function of base width of the pyramid. We have assumed that the pyramid has a square base with area a× a and height of the pyramid H=a/2. The trial wave function of the exciton has been chosen according to the even mirror boundary condition, i.e. the wave function of the exciton at the boundary could be non-zero. The results show that (i) the non-parabolicity of the conduction band affects the light hole (lh) and heavy hole (hh) excitons to be more bound than that with parabolicity of the conduction band, (ii) the dielectric screening function (DSF) affects the lh and hh excitons to be more bound than that without the DSF and (iii) the spatially dependent effective mass (SDEM) affects the lh and hh excitons to be less bound than that without the SDEM. The combined effects of DSF and SDEM on exciton binding energy have also been calculated. The results are compared with those available in the literature.

  5. VALUES-ORIENTED PROJECT MANAGEMENT OF RENEWABLE ENERGY

    Directory of Open Access Journals (Sweden)

    Олександр Михайлович ВОЗНИЙ

    2017-03-01

    Full Text Available The value-oriented approach to project management of renewable energy based on classification stage of the life cycle of products of the projects, adapted to the goals and objectives of information modeling, which allowed to formulate stricter requirements information models used at different stages of the power plant is proposed. A classification of the alternative energy projects, which highlighting areas for activities is proposed. The list of stakeholders that have an impact on alternative energy projects and presented their classification is defined. The value of alternative energy projects considered from the standpoint of a utilitarian approach, using the concept of utility and on the basis of this concept proposed classification values of alternative energy projects. Criteria values as indicators for assessing the value of alternative energy projects and their weights determined by pairwise comparison. To take into account the changes of the value criteria over time proposed to use the key control points value, assessed value criteria in various key points of control, defined indicator of the total value of alternative energy projects. The classification of risks and tools for value-oriented risk management in alternative energy projects is proposed. Further study authors plan to link the development of mechanisms for harmonization value alternative energy projects for their stakeholders.

  6. On expectation values for nuclear energy levels

    International Nuclear Information System (INIS)

    De Wet, J.A.

    1978-01-01

    The nuclear model is built up by constructing measured states, including the ground state, from the vacuum state. All states are, however, not accessible from the ground state so that selection rules may be found which at the same time impose even more stringent conditions on the labelling of energy levels. These are the subject of this paper

  7. 1999 Annual Report: Delivering energy value

    International Nuclear Information System (INIS)

    2000-01-01

    Union Gas Limited, a subsidiary of Westcoast Energy Company, is a major Canadian natural gas utility, providing energy delivery and related services to 1.1 million residential, commercial and industrial customers in over 400 communities in northern, southwestern and eastern Ontario. Union Gas also provides natural gas storage and transportation services for other utilities and energy market participants in Ontario, Quebec and the northeastern United States. In 1999 the Company had revenues of 1.5 billion, net income of $ 95 million, and assets totalling $ 3.8 billion. Net income was down from $ 109 million in 1998, due mainly to the impact of the sale of the Company's retail merchandise program to Union Energy, a lower approved rate of return on common equity. Full-time employees number about 2,500. Total throughput for 1999 was 34.6 billion cubic metres of natural gas, up 8.9 per cent from 1998. The Company undertook significant reorganization and restructuring during 1999, to emphasize critical business processes. The reorganization, which saw the divestiture of the retail merchandise programs to an unregulated affiliate, Union Energy, resulted in a flat, flexible and efficient enterprise, more capable of timely response to changing market opportunities and customer needs. Union Gas also filed application with the Ontario Energy Board for rates for the year 2000 and beyond, using the performance-based regulation framework; completed construction of a $ 16 million, 90 km pipeline to make natural gas service available to Parry Sound; Launched 'enoms' a new Internet-based natural gas nominations system; completed the first phase of the $ 17 million Century Pools storage development project, and applied to build the second phase, comprising a $37 million addition to the storage pools at the Mandasumin, Bluewater and Oil City pools; and completed several smaller projects totalling $ 5.2 million to give access to natural gas to 2,300 new customers at various parts of

  8. Valuing the attributes of renewable energy investments

    International Nuclear Information System (INIS)

    Bergmann, Ariel; Hanley, Nick; Wright, Robert

    2006-01-01

    Increasing the proportion of power derived from renewable energy sources is becoming an increasingly important part of many countries's strategies to achieve reductions in greenhouse gas emissions. However, renewable energy investments can often have external costs and benefits, which need to be taken into account if socially optimal investments are to be made. This paper attempts to estimate the magnitude of these external costs and benefits for the case of renewable technologies in Scotland, a country which has set particularly ambitious targets for expanding renewable energy. The external effects we consider are those on landscape quality, wildlife and air quality. We also consider the welfare implications of different investment strategies for employment and electricity prices. The methodology used to do this is the choice experiment technique. Renewable technologies considered include hydro, on-shore and off-shore wind power and biomass. Welfare changes for different combinations of impacts associated with different investment strategies are estimated. We also test for differences in preferences towards these impacts between urban and rural communities, and between high- and low-income households

  9. Experimental support for a desolvation energy term in governing equations for binding equilibria.

    Science.gov (United States)

    Castellano, Brian M; Eggers, Daryl K

    2013-07-11

    This study introduces a new thermodynamic framework for aqueous reaction equilibria that treats water as a coreactant in the development of a general binding equation. The approach features an explicit consideration for the change in hydration that occurs when two solvated surfaces come into contact. As an outcome of this framework, the standard-state free energy of binding is defined by the summation of two terms: the traditional term (-RT ln Ki) plus a desolvation free-energy term that is weighted by the number of complexes formed at equilibrium. The new formalism suggests that the equilibrium ratio, Ki, is not a constant and that the observed concentration dependence of Ki may be used to obtain the molar desolvation energy and the standard-state free energy at infinite dilution. The governing equation is supported by results from isothermal titration calorimetry using the chelation of calcium(II) by EDTA as a model binding reaction. This work may have far-reaching implications for solution thermodynamics, including an explanation for the oft-noted discrepancy between the enthalpy values obtained by calorimetry and those from the van't Hoff approach.

  10. Experimental Support for Desolvation Energy Term in Governing Equations for Binding Equilibria

    Science.gov (United States)

    Castellano, Brian M.; Eggers, Daryl K.

    2013-01-01

    This study introduces a new thermodynamic framework for aqueous reaction equilibria that treats water as a co-reactant in the development of a general binding equation. The approach features an explicit consideration for the change in hydration that occurs when two solvated surfaces come into contact. As an outcome of this framework, the standard state free energy of binding is defined by the summation of two terms, the traditional term (−RTlnKi) plus a desolvation free energy term that is weighted by the number of complexes formed at equilibrium. The new formalism suggests that the equilibrium ratio, Ki, is not a constant and that the observed concentration dependence of Ki may be used to obtain the molar desolvation energy and the standard state free energy at infinite dilution. The governing equation is supported by results from isothermal titration calorimetry using the chelation of calcium(II) by EDTA as a model binding reaction. This work may have far-reaching implications for solution thermodynamics, including an explanation for the oft-noted discrepancy between enthalpy values obtained by calorimetry and the van’t Hoff approach. PMID:23773139

  11. Value at Risk models for Energy Risk Management

    OpenAIRE

    Novák, Martin

    2010-01-01

    The main focus of this thesis lies on description of Risk Management in context of Energy Trading. The paper will predominantly discuss Value at Risk and its modifications as a main overall indicator of Energy Risk.

  12. 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.

  13. 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.

  14. Conservation law of plants' energy value dependence of plants ...

    African Journals Online (AJOL)

    The plants differences in biochemical composition are analyzed, and the conservation law of energy value in plants is obtained. The link between the need for the nutrients and the plants biochemical composition is examined, Liebig's law is specified. Keywords: plant's biochemical composition, biochemistry, energy value in ...

  15. An exploration of possible design options for a binding energy savings target in Europe

    NARCIS (Netherlands)

    Harmsen, Robert; Eichhammer, Wolfgang; Wesselink, Bart

    2014-01-01

    As Europe is not on track in meeting its 2020 energy savings target, there has been quite some debate to make the energy savings target binding instead of indicative. Although the final draft text of the Energy Efficiency Directive left the option of a binding target explicitly open for the period

  16. Experimental Determination of pK[subscript a] Values and Metal Binding for Biomolecular Compounds Using [superscript 31]P NMR Spectroscopy

    Science.gov (United States)

    Swartz, Mason A.; Tubergen, Philip J.; Tatko, Chad D.; Baker, Rachael A.

    2018-01-01

    This lab experiment uses [superscript 31]P NMR spectroscopy of biomolecules to determine pK[subscript a] values and the binding energies of metal/biomolecule complexes. Solutions of adenosine nucleotides are prepared, and a series of [superscript 31]P NMR spectra are collected as a function of pH and in the absence and presence of magnesium or…

  17. Binding affinity of a small molecule to an amorphous polymer in a solvent. Part 1: free energy of binding to a binding site.

    Science.gov (United States)

    Chunsrivirot, Surasak; Diao, Ying; Trout, Bernhardt L

    2011-10-18

    Crystallization is commonly used in a separation and purification process in the production of a wide range of materials in various industries. In industry, crystallization usually starts with heterogeneous nucleation on a foreign surface. The complicated mechanism of heterogeneous nucleation is not well understood; however, we hypothesize that there might be a possible correlation between binding affinity to a surface and enhancement of nucleation. Recent studies show that amorphous polymers can be used to control crystallization, selectively produce pharmaceutical polymorphs, and discover novel pharmaceutical polymorphs. To investigate the possible correlation between the binding affinity of one molecule to key binding sites (local binding) and heterogeneous nucleation activity as well as the possibility of using this binding affinity to help guide the selection of polymers that promote heterogeneous nucleation, we computed the free energy of binding of aspirin to four nonporous cross-linked polymers in an ethanol-water 38 v% mixture. These cross-linked polymers are poly(4-acryloylmorpholine) (PAM), poly(2-carboxyethyl acrylate) (PCEA), poly(4-hydroxylbutyl acrylate) (PHBA), and polystyrene (PS); all of them were cross-linked with divinylbenzene (DVB). These systems were used because their heterogeneous nucleation activities are available in literature, and the ranking is PAM > PCEA > PHBA ≈ PS. We generated three independent surfaces for each polymer and computed the free energy of binding of aspirin to the best binding site that we found on each surface. The average free energies of binding to the best sites of PAM, PCEA, PHBA, and PS are -20.4 ± 1.0, -16.7 ± 1.0, -14.4 ± 1.1, and -13.6 ± 1.1 kcal/mol, respectively. We found that the trend of the magnitudes of the average free energies of binding to the best sites is PAM > PCEA > PHBA ≈ PS. This trend is very similar to that of heterogeneous nucleation activity. Our results suggest the importance of the

  18. Influence of host matrices on krypton electron binding energies and KLL Auger transition energies

    Czech Academy of Sciences Publication Activity Database

    Inoyatov, A. K.; Perevoshchikov, L. L.; Kovalík, Alojz; Filosofov, D. V.; Yushkevich, Yu. V.; Ryšavý, Miloš; Lee, B. Q.; Kibédi, T.; Stuchbery, A. E.; Zhdanov, V. S.

    2014-01-01

    Roč. 197, DEC (2014), s. 64-71 ISSN 0368-2048 R&D Projects: GA ČR(CZ) GAP203/12/1896; GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : Kr-83 * Rb-83 * Sr-83 * electron binding energy * KLL transitions * natural atomic level width * multiconfiguration Dirac-Fock calculations Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.436, year: 2014

  19. Large scale free energy calculations for blind predictions of protein-ligand binding: the D3R Grand Challenge 2015.

    Science.gov (United States)

    Deng, Nanjie; Flynn, William F; Xia, Junchao; Vijayan, R S K; Zhang, Baofeng; He, Peng; Mentes, Ahmet; Gallicchio, Emilio; Levy, Ronald M

    2016-09-01

    We describe binding free energy calculations in the D3R Grand Challenge 2015 for blind prediction of the binding affinities of 180 ligands to Hsp90. The present D3R challenge was built around experimental datasets involving Heat shock protein (Hsp) 90, an ATP-dependent molecular chaperone which is an important anticancer drug target. The Hsp90 ATP binding site is known to be a challenging target for accurate calculations of ligand binding affinities because of the ligand-dependent conformational changes in the binding site, the presence of ordered waters and the broad chemical diversity of ligands that can bind at this site. Our primary focus here is to distinguish binders from nonbinders. Large scale absolute binding free energy calculations that cover over 3000 protein-ligand complexes were performed using the BEDAM method starting from docked structures generated by Glide docking. Although the ligand dataset in this study resembles an intermediate to late stage lead optimization project while the BEDAM method is mainly developed for early stage virtual screening of hit molecules, the BEDAM binding free energy scoring has resulted in a moderate enrichment of ligand screening against this challenging drug target. Results show that, using a statistical mechanics based free energy method like BEDAM starting from docked poses offers better enrichment than classical docking scoring functions and rescoring methods like Prime MM-GBSA for the Hsp90 data set in this blind challenge. Importantly, among the three methods tested here, only the mean value of the BEDAM binding free energy scores is able to separate the large group of binders from the small group of nonbinders with a gap of 2.4 kcal/mol. None of the three methods that we have tested provided accurate ranking of the affinities of the 147 active compounds. We discuss the possible sources of errors in the binding free energy calculations. The study suggests that BEDAM can be used strategically to discriminate

  20. Resonance energy transfer study on the proximity relationship between the GTP binding site and the rifampicin binding site of Escherichia coli RNA polymerase

    International Nuclear Information System (INIS)

    Kumar, K.P.; Chatterji, D.

    1990-01-01

    Terbium(III) upon complexation with guanosine 5'-triphosphate showed remarkable enhancement of fluorescence emission at 488 and 545 nm when excited at 295 nm. Analysis of the binding data yielded a value for the mean K d between Tb(III) and GTP of 0.2 μM, with three binding sites for TB(III) on GTP. 31 P and 1 H NMR measurements revealed that Tb(III) mainly binds the phosphate moiety of GTP. Fluorescence titration of the emission signals of the TbGTP complex with varying concentrations of Escherichia coli RNA polymerase resulted in a K d values of 4 μM between the TbGTP and the enzyme. It was observed that TbGTP can be incorporated in the place of GTP during E. coli RNA polymerase catalyzed abortive synthesis of dinucleotide tetraphosphate at T7A2 promoter. Both the substrate TbGTP and the inhibitor of the initiation of transcription rifampicin bind to the β-subunit of E. coli RNA polymerase. This allows the measurement of the fluorescence excited-state energy transfer from the donor TbGTP-RNA polymerase to the acceptor rifampicin. Both emission bands of Tb(III) overlap with the rifampicin absorption, and the distances at 50% efficiency of energy transfer were calculated to be 28 and 24 angstrom for the 488- and 545-nm emission bands, respectively. The distance between the substrate binding site and the rifampicin binding site on the β-subunit of E. coli RNA polymerase was measured to be around 30 angstrom. This suggest that the nature of inhibition of transcription by rifampicin is essentially noncompetitive with the substrate

  1. An Energy Conservation Approach to Adsorbate-Induced Surface Stress and the Extraction of Binding Energy Using Nanomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Pinnaduwage, Lal A [ORNL; Boiadjiev, Vassil I [ORNL; Fernando, G. W. [University of Connecticut, Storrs; Hawk, J. E. [Oak Ridge National Laboratory (ORNL); Wijewardhana, L.C. R. [University of Cincinnati; Gehl, Anthony C [ORNL

    2008-01-01

    Microcantilevers are ideally-suited for the study of surface phenomena due to their large surface-to-volume ratios, which amplify surface effects. We show that when guest molecules bind to atoms/molecules on a microcantilever surface, the released binding energy is retained in the host surface, leading to a metastable state where the excess energy on the surface is manifested as an increase in surface stress leading to the bending of the microcantilever. When the excess energy is released, the microcantilever relaxes back to the original state, and the relaxation time depends on the particular binding process involved. Such experiments were conducted for three binding processes in vapor phase experiments: physisorption, hydrogen bonding, and chemisorption. To our knowledge, such an energy conservation approach has not been taken into account in adsorbate-induced surface effect investigations. Furthermore, these experiments illustrate that detailed molecular-level information on binding energies can be extracted from this simple micromechanical sensor.

  2. An energy conservation approach to adsorbate-induced surface stress and the extraction of binding energy using nanomechanics

    Science.gov (United States)

    Pinnaduwage, Lal A.; Boiadjiev, Vassil I.; Hawk, John E.; Gehl, Anthony C.; Fernando, Gayanath W.; Rohana Wijewardhana, L. C.

    2008-03-01

    Surface stress induced by molecular adsorption in three different binding processes has been studied experimentally using a microcantilever sensor. A comprehensive free-energy analysis based on an energy conservation approach is proposed to explain the experimental observations. We show that when guest molecules bind to atoms/molecules on a microcantilever surface, the released binding energy is retained in the host surface, leading to a metastable state where the excess energy on the surface is manifested as an increase in surface stress leading to the bending of the microcantilever. The released binding energy appears to be almost exclusively channeled to the surface energy, and energy distribution to other channels, including heat, appears to be inactive for this micromechanical system. When this excess surface energy is released, the microcantilever relaxes back to the original state, and the relaxation time depends on the particular binding process involved. Such vapor phase experiments were conducted for three binding processes: physisorption, hydrogen bonding, and chemisorption. Binding energies for these three processes were also estimated.

  3. An energy conservation approach to adsorbate-induced surface stress and the extraction of binding energy using nanomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Pinnaduwage, Lal A; Boiadjiev, Vassil I; Hawk, John E; Gehl, Anthony C [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6122 (United States); Fernando, Gayanath W [Physics Department, University of Connecticut, Storrs, CT 06269 (United States); Wijewardhana, L C Rohana [Physics Department, University of Cincinnati, Cincinnati, OH 45221 (United States)

    2008-03-12

    Surface stress induced by molecular adsorption in three different binding processes has been studied experimentally using a microcantilever sensor. A comprehensive free-energy analysis based on an energy conservation approach is proposed to explain the experimental observations. We show that when guest molecules bind to atoms/molecules on a microcantilever surface, the released binding energy is retained in the host surface, leading to a metastable state where the excess energy on the surface is manifested as an increase in surface stress leading to the bending of the microcantilever. The released binding energy appears to be almost exclusively channeled to the surface energy, and energy distribution to other channels, including heat, appears to be inactive for this micromechanical system. When this excess surface energy is released, the microcantilever relaxes back to the original state, and the relaxation time depends on the particular binding process involved. Such vapor phase experiments were conducted for three binding processes: physisorption, hydrogen bonding, and chemisorption. Binding energies for these three processes were also estimated.

  4. An accurate redetermination of the sup 1 sup 1 sup 8 Sn binding energy

    CERN Document Server

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

    2002-01-01

    The energy of well-known strong gamma line from sup 1 sup 9 sup 8 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 sub 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 taken into account by a Monte-Carlo simulation. The procedure was used in obtaining B sub n for sup 1 sup 1 sup 8 Sn. The gamma-ray spectrum from thermal neutron radiative capture by sup 1 sup 1 sup 7 Sn has been measured on the IBR-2 pulsed reactor. gamma-rays were detected by a 72 cm sup 3 HPGe detector. For a better determination of B sub n...

  5. 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 fo...

  6. Calculation of Relative Binding Free Energy in the Water-Filled Active Site of Oligopeptide-Binding Protein A

    Directory of Open Access Journals (Sweden)

    Manuela Maurer

    2016-04-01

    Full Text Available The periplasmic oligopeptide binding protein A (OppA represents a well-known example of water-mediated protein-ligand interactions. Here, we perform free-energy calculations for three different ligands binding to OppA, using a thermodynamic integration approach. The tripeptide ligands share a high structural similarity (all have the sequence KXK, but their experimentally-determined binding free energies differ remarkably. Thermodynamic cycles were constructed for the ligands, and simulations conducted in the bound and (freely solvated unbound states. In the unbound state, it was observed that the difference in conformational freedom between alanine and glycine leads to a surprisingly slow convergence, despite their chemical similarity. This could be overcome by increasing the softness parameter during alchemical transformations. Discrepancies remained in the bound state however, when comparing independent simulations of the three ligands. These difficulties could be traced to a slow relaxation of the water network within the active site. Fluctuations in the number of water molecules residing in the binding cavity occur mostly on a timescale larger than the simulation time along the alchemical path. After extensive simulations, relative binding free energies that were converged to within thermal noise could be obtained, which agree well with available experimental data.

  7. Metabolisable energy values of whole palm kernel and palm kernel ...

    African Journals Online (AJOL)

    4.12 Kcal/kg DM. 4.36 and 4.13 Kcal/kg DM, respectively were the corresponding values for broiler chickens. No interaction between ingredients and birds was found but there were interactions among the bioavailable energy systems and the bird types. Keywords: Metabolisable energy, palm kernel layers, broilers.

  8. Values, Perceived Risks and Benefits, and Acceptability of Nuclear Energy

    NARCIS (Netherlands)

    de Groot, Judith I. M.; Steg, Linda; Poortinga, Wouter

    We examined how personal values and perceptions of risks and benefits are associated with the acceptability of nuclear energy (NE). A theoretical model is tested in which beliefs about the risks and benefits of NE mediate the relationship between values and acceptability. The results showed that

  9. From free energy to expected energy: Improving energy-based value function approximation in reinforcement learning.

    Science.gov (United States)

    Elfwing, Stefan; Uchibe, Eiji; Doya, Kenji

    2016-12-01

    Free-energy based reinforcement learning (FERL) was proposed for learning in high-dimensional state and action spaces. However, the FERL method does only really work well with binary, or close to binary, state input, where the number of active states is fewer than the number of non-active states. In the FERL method, the value function is approximated by the negative free energy of a restricted Boltzmann machine (RBM). In our earlier study, we demonstrated that the performance and the robustness of the FERL method can be improved by scaling the free energy by a constant that is related to the size of network. In this study, we propose that RBM function approximation can be further improved by approximating the value function by the negative expected energy (EERL), instead of the negative free energy, as well as being able to handle continuous state input. We validate our proposed method by demonstrating that EERL: (1) outperforms FERL, as well as standard neural network and linear function approximation, for three versions of a gridworld task with high-dimensional image state input; (2) achieves new state-of-the-art results in stochastic SZ-Tetris in both model-free and model-based learning settings; and (3) significantly outperforms FERL and standard neural network function approximation for a robot navigation task with raw and noisy RGB images as state input and a large number of actions. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. Time-Varying Value of Energy Efficiency in Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Mims, Natalie; Eckman, Tom; Schwartz, Lisa C.

    2018-04-02

    Quantifying the time-varying value of energy efficiency is necessary to properly account for all of its benefits and costs and to identify and implement efficiency resources that contribute to a low-cost, reliable electric system. Historically, most quantification of the benefits of efficiency has focused largely on the economic value of annual energy reduction. Due to the lack of statistically representative metered end-use load shape data in Michigan (i.e., the hourly or seasonal timing of electricity savings), the ability to confidently characterize the time-varying value of energy efficiency savings in the state, especially for weather-sensitive measures such as central air conditioning, is limited. Still, electric utilities in Michigan can take advantage of opportunities to incorporate the time-varying value of efficiency into their planning. For example, end-use load research and hourly valuation of efficiency savings can be used for a variety of electricity planning functions, including load forecasting, demand-side management and evaluation, capacity planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service (KEMA 2012). In addition, accurately calculating the time-varying value of efficiency may help energy efficiency program administrators prioritize existing offerings, set incentive or rebate levels that reflect the full value of efficiency, and design new programs.

  11. Time-varying value of electric energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Mims, Natalie A.; Eckman, Tom; Goldman, Charles

    2017-06-30

    Electric energy efficiency resources save energy and may reduce peak demand. Historically, quantification of energy efficiency benefits has largely focused on the economic value of energy savings during the first year and lifetime of the installed measures. Due in part to the lack of publicly available research on end-use load shapes (i.e., the hourly or seasonal timing of electricity savings) and energy savings shapes, consideration of the impact of energy efficiency on peak demand reduction (i.e., capacity savings) has been more limited. End-use load research and the hourly valuation of efficiency savings are used for a variety of electricity planning functions, including load forecasting, demand-side management and evaluation, capacity and demand response planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service. This study reviews existing literature on the time-varying value of energy efficiency savings, provides examples in four geographically diverse locations of how consideration of the time-varying value of efficiency savings impacts the calculation of power system benefits, and identifies future research needs to enhance the consideration of the time-varying value of energy efficiency in cost-effectiveness screening analysis. Findings from this study include: -The time-varying value of individual energy efficiency measures varies across the locations studied because of the physical and operational characteristics of the individual utility system (e.g., summer or winter peaking, load factor, reserve margin) as well as the time periods during which savings from measures occur. -Across the four locations studied, some of the largest capacity benefits from energy efficiency are derived from the deferral of transmission and distribution system infrastructure upgrades. However, the deferred cost of such upgrades also exhibited the greatest range

  12. 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

  13. Conformational Dynamics and Binding Free Energies of Inhibitors of BACE-1: From the Perspective of Protonation Equilibria.

    Directory of Open Access Journals (Sweden)

    M Olivia Kim

    2015-10-01

    Full Text Available BACE-1 is the β-secretase responsible for the initial amyloidogenesis in Alzheimer's disease, catalyzing hydrolytic cleavage of substrate in a pH-sensitive manner. The catalytic mechanism of BACE-1 requires water-mediated proton transfer from aspartyl dyad to the substrate, as well as structural flexibility in the flap region. Thus, the coupling of protonation and conformational equilibria is essential to a full in silico characterization of BACE-1. In this work, we perform constant pH replica exchange molecular dynamics simulations on both apo BACE-1 and five BACE-1-inhibitor complexes to examine the effect of pH on dynamics and inhibitor binding properties of BACE-1. In our simulations, we find that solution pH controls the conformational flexibility of apo BACE-1, whereas bound inhibitors largely limit the motions of the holo enzyme at all levels of pH. The microscopic pKa values of titratable residues in BACE-1 including its aspartyl dyad are computed and compared between apo and inhibitor-bound states. Changes in protonation between the apo and holo forms suggest a thermodynamic linkage between binding of inhibitors and protons localized at the dyad. Utilizing our recently developed computational protocol applying the binding polynomial formalism to the constant pH molecular dynamics (CpHMD framework, we are able to obtain the pH-dependent binding free energy profiles for various BACE-1-inhibitor complexes. Our results highlight the importance of correctly addressing the binding-induced protonation changes in protein-ligand systems where binding accompanies a net proton transfer. This work comprises the first application of our CpHMD-based free energy computational method to protein-ligand complexes and illustrates the value of CpHMD as an all-purpose tool for obtaining pH-dependent dynamics and binding free energies of biological systems.

  14. Ground state energy values and moments of the anharmonic oscillator

    International Nuclear Information System (INIS)

    Seetharaman, M.; Raghavan, Sekhar; Subba Rao, G.

    1981-01-01

    It is shown that a very satisfactory estimate of the energy values (for all values of the anharmonicity) and moments of the ground state of the quartic anharmonic oscillator can be obtained in the variational method, by considering trial wavefunctions which have the correct asymptotic properties. The results derived with a single variational parameter are a considerable improvement over the recent results of C.A. Ginsburg and E.W. Montroll (1978). (author)

  15. The perceived value of using BIM for energy simulation

    Science.gov (United States)

    Lewis, Anderson M.

    Building Information Modeling (BIM) is becoming an increasingly important tool in the Architectural, Engineering & Construction (AEC) industries. Some of the benefits associated with BIM include but are not limited to cost and time savings through greater trade and design coordination, and more accurate estimating take-offs. BIM is a virtual 3D, parametric design software that allows users to store information of a model within and can be used as a communication platform between project stakeholders. Likewise, energy simulation is an integral tool for predicting and optimizing a building's performance during design. Creating energy models and running energy simulations can be a time consuming activity due to the large number of parameters and assumptions that must be addressed to achieve reasonably accurate results. However, leveraging information imbedded within Building Information Models (BIMs) has the potential to increase accuracy and reduce the amount of time required to run energy simulations and can facilitate continuous energy simulations throughout the design process, thus optimizing building performance. Although some literature exists on how design stakeholders perceive the benefits associated with leveraging BIM for energy simulation, little is known about how perceptions associated with leveraging BIM for energy simulation differ between various green design stakeholder user groups. Through an e-survey instrument, this study seeks to determine how perceptions of using BIMs to inform energy simulation differ among distinct design stakeholder groups, which include BIM-only users, energy simulation-only users and BIM and energy simulation users. Additionally, this study seeks to determine what design stakeholders perceive as the main barriers and benefits of implementing BIM-based energy simulation. Results from this study suggest that little to no correlation exists between green design stakeholders' perceptions of the value associated with using

  16. Application of the step-wise regression procedure to the semi-empirical formulae of the nuclear binding energy

    International Nuclear Information System (INIS)

    Eissa, E.A.; Ayad, M.; Gashier, F.A.B.

    1984-01-01

    Most of the binding energy semi-empirical terms without the deformation corrections used by P.A. Seeger are arranged in a multiple linear regression form. The stepwise regression procedure with 95% confidence levels for acceptance and rejection of variables is applied for seeking a model for calculating binding energies of even-even (E-E) nuclei through a significance testing of each basic term. Partial F-values are taken as estimates for the significance of each term. The residual standard deviation and the overall F-value are used for selecting the best linear regression model. (E-E) nuclei are taken into sets lying between two successive proton and neutron magic numbers. The present work is in favour of the magic number 126 followed by 164 for the neutrons and indecisive in supporting the recently predicted proton magic number 114 rather than the previous one, 126. (author)

  17. Evaluation of metabolizable energy values of some feeding stuffs.

    Science.gov (United States)

    Lotfollahian, H; Hosseini, S A

    2007-03-15

    In a trail the Apparent Metabolizable Energy (AME), Apparent Metabolizable Energy corrected to Nitrogen retention (AMEn), True Metabolizable Energy (TME) and True Metabolizable Energy corrected to Nitrogen retention (TMEn) content of some feeding stuffs for poultry were determined with cockerels. The test materials consisted of feed grade Oak (Quercusfaginea), Fig (Ficus carica), Olive (Olea europea) pulp with nucleolus and without nucleolus. The result showed that Oak, Fig, Olive pulp with nucleolus and without nucleolus according to their component can be noticed as an energy sources. Their crude protein was low. The nitrogen- corrected Apparent Metabolizable Energy (AMEn) values for Oak, Fig and Olive pulp with nucleolus and without nucleolus were 2775.04 +/- 29, 2558.7 +/- 35, 1347.05 +/- 64 and 3052.33 +/- 122 Kcal kg(-1) dry matter, respectively. The nitrogen-corrected True Metabolizable Energy (TMEn) value for the respective feeding stuffs were 3177.99 +/- 30, 2999.06 +/- 33, 1537.02 +/- 59 and 3243.34 +/- 126 Kcal kg(-1) dry matter.

  18. Subsite binding energies of an exo-polygalacturonase using isothermal titration calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, Jeffrey A., E-mail: Jeffrey.Mertens@ars.usda.gov [Bioenergy Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, IL 61604 (United States); Hector, Ronald E.; Bowman, Michael J. [Bioenergy Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, IL 61604 (United States)

    2012-01-10

    Highlights: Black-Right-Pointing-Pointer Thermodynamics of (GalpA){sub n} oligomers binding to an exo-polygalacturonase. Black-Right-Pointing-Pointer Energetics of binding (GalpA){sub n} were determined by ITC. Black-Right-Pointing-Pointer Thermodynamic parameters attributable to individual subsites were determined. - Abstract: 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 process that is enthalpically driven and results in extremely tight binding of the substrate to RPG16. Binding energies in combination with prior biochemical data suggests that RPG16 has the potential for five subsites, -1 to +4, with the greatest contribution to binding energies arising from subsite -1/+1. While the enthalpic contribution to binding decreases substantially for subsites +2 to +4, beneficial entropic effects occur in subsites +3 and +4 leading to increased total free energy as the length of oligomer increases. This information will be useful for additional studies in determining the binding contributions of specific amino acids with mutant enzymes.

  19. How to shape a binding energy savings target for Europe that allows for effective evaluation

    NARCIS (Netherlands)

    Harmsen, R.; Wesselink, B.; Eichhammer, W.

    2012-01-01

    This paper considers which design of a binding energy savings target for the EU is the most feasible to both make it work and to ensure it can be evaluated in an efficient and transparent manner. We look at four possible design options. We conclude that a binding target at Member State level

  20. Energy Management in Higher Education: Value for Money Study.

    Science.gov (United States)

    Scottish Higher Education Funding Council, Edinburgh.

    This Value for Money project provides an update of the 1996 "Energy Management Study in the Higher Education Sector: National Report." It reviews the management arrangement for utilities in the higher education (HE) sector, and it identifies key actions and future issues that must be addressed by HE institutions in developing a strategic…

  1. Comparative Energy Values Of Sorghum Distillers Waste, Maize ...

    African Journals Online (AJOL)

    A balance trial aimed at determining the energy values of Sorghum Distiller's Wastes (SDW), Maize cob (MC) and Shea butter Waste (SBW) for barrows was conducted using a 4 x 4 Latin square cross- over experimental design. While feed intake was influenced (P < 0.05) by the test feed ingredients, the weight gained was ...

  2. Metabolisable energy values of some non-conventional feeding ...

    African Journals Online (AJOL)

    A metabolism trial was designed to evaluate dietary energy values (AME, AMEn, TME, TMEn) of eight readily available non-conventional feeding ingredients viz: cassava root meal (CRM); cassava leaf meal (CLM), mango leaf meal (MLM), shrimp waste meal (SWM), full-fat soyabean (FFSB), palm oil sludge (POS), corn cob ...

  3. The value of delay in tidal energy development

    International Nuclear Information System (INIS)

    MacDougall, Shelley L.

    2015-01-01

    Despite robust research, prototype development and demonstration of in-stream tidal energy devices, progress to the commercialization stage has been slow. Some of this can be attributed to a lack readiness or financing. However, when uncertainty is high, a developer may choose to delay a project until more is known. The option to delay has value for a company. This study applies the real option valuation model to an investment in a 10 MW array of in-stream tidal energy conversion devices at the Fundy Ocean Research Centre for Energy (FORCE) in the Bay of Fundy, Nova Scotia, Canada. The values of investing and the option to delay are calculated. A sensitivity analysis of key drivers and scenarios with various input values to the option model are constructed to observe the impact on the 'invest versus delay' decision. The analysis suggests there is value in owning the option to develop, by leasing a FORCE berth, but waiting while uncertainty is resolved. Implications for policy-setting are discussed. - Highlights: • Analyze an invest-vs-delay decision in tidal energy conversion using real options. • Assess whether conditions are conducive to an economically rational decision to delay. • Identify aspects of the decision that can be influenced by government policy.

  4. On the mean value of the energy for resonant states

    International Nuclear Information System (INIS)

    Civitarese, O.; Gadella, M.; Betan, R.Id

    1999-01-01

    In this work we discuss possible definitions of the mean value of the energy for a resonant (Gamow) state. The mathematical and physical aspects of the formalism are reviewed. The concept of rigged Hilbert space is used as a supportive tool in dealing with Gamow-resonances

  5. Energy values of suspended detritus in Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Royan, J.P.; Sumitra-Vijayaraghavan

    Energy content of suspended detritus was determined in Andaman Sea waters during April-May 1988. The caloric content of suspended detritus ranged from 987 to 7040 cal. per gram dry wt with an average value of 5530 cal. per gram dry wt. The results...

  6. Photovoltaics as a terrestrial energy source. Volume 2: System value

    Science.gov (United States)

    Smith, J. L.

    1980-01-01

    Assumptions and techniques employed by the electric utility industry and other electricity planners to make estimates of the future value of photovoltaic (PV) systems interconnected with U.S. electric utilities were examined. Existing estimates of PV value and their interpretation and limitations are discussed. PV value is defined as the marginal private savings accruing to potential PV owners. For utility-owned PV systems, these values are shown to be the after-tax savings in conventional fuel and capacity displaced by the PV output. For non-utility-owned (distributed) systems, the utility's savings in fuel and capacity must first be translated through the electric rate structure (prices) to the potential PV system owner. Base-case estimates of the average value of PV systems to U.S. utilities are presented. The relationship of these results to the PV Program price goals and current energy policy is discussed; the usefulness of PV output quantity goals is also reviewed.

  7. Binding free energy analysis of protein-protein docking model structures by evERdock.

    Science.gov (United States)

    Takemura, Kazuhiro; Matubayasi, Nobuyuki; Kitao, Akio

    2018-03-14

    To aid the evaluation of protein-protein complex model structures generated by protein docking prediction (decoys), we previously developed a method to calculate the binding free energies for complexes. The method combines a short (2 ns) all-atom molecular dynamics simulation with explicit solvent and solution theory in the energy representation (ER). We showed that this method successfully selected structures similar to the native complex structure (near-native decoys) as the lowest binding free energy structures. In our current work, we applied this method (evERdock) to 100 or 300 model structures of four protein-protein complexes. The crystal structures and the near-native decoys showed the lowest binding free energy of all the examined structures, indicating that evERdock can successfully evaluate decoys. Several decoys that show low interface root-mean-square distance but relatively high binding free energy were also identified. Analysis of the fraction of native contacts, hydrogen bonds, and salt bridges at the protein-protein interface indicated that these decoys were insufficiently optimized at the interface. After optimizing the interactions around the interface by including interfacial water molecules, the binding free energies of these decoys were improved. We also investigated the effect of solute entropy on binding free energy and found that consideration of the entropy term does not necessarily improve the evaluations of decoys using the normal model analysis for entropy calculation.

  8. Binding free energy analysis of protein-protein docking model structures by evERdock

    Science.gov (United States)

    Takemura, Kazuhiro; Matubayasi, Nobuyuki; Kitao, Akio

    2018-03-01

    To aid the evaluation of protein-protein complex model structures generated by protein docking prediction (decoys), we previously developed a method to calculate the binding free energies for complexes. The method combines a short (2 ns) all-atom molecular dynamics simulation with explicit solvent and solution theory in the energy representation (ER). We showed that this method successfully selected structures similar to the native complex structure (near-native decoys) as the lowest binding free energy structures. In our current work, we applied this method (evERdock) to 100 or 300 model structures of four protein-protein complexes. The crystal structures and the near-native decoys showed the lowest binding free energy of all the examined structures, indicating that evERdock can successfully evaluate decoys. Several decoys that show low interface root-mean-square distance but relatively high binding free energy were also identified. Analysis of the fraction of native contacts, hydrogen bonds, and salt bridges at the protein-protein interface indicated that these decoys were insufficiently optimized at the interface. After optimizing the interactions around the interface by including interfacial water molecules, the binding free energies of these decoys were improved. We also investigated the effect of solute entropy on binding free energy and found that consideration of the entropy term does not necessarily improve the evaluations of decoys using the normal model analysis for entropy calculation.

  9. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    Abstract. The effect of external magnetic field on the excited state energies in a spher- ical 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 ...

  10. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    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 ...

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

    Science.gov (United States)

    Petukh, Marharyta; Dai, Luogeng; Alexov, Emil

    2016-04-12

    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/.

  12. Nutritional and energy values of sunflower cake for broilers

    Directory of Open Access Journals (Sweden)

    Eveline Berwanger

    2014-12-01

    Full Text Available The study aimed to determine the nutritional and energy values of sunflower cake for broilers through two experiments. The first study evaluated the energy values by the method of total excreta collection, using 100 broiler chicks 21–31 days old, divided into five treatments of 0%, 10%, 20%, 30% and 40% inclusion sunflower cake will reference a diet. The second experiment evaluated the influence of the period and the quantity supplied of sunflower cake on digestibility of amino acids by a forcedfeeding technique. Eighteen cockerels were used, divided into three treatments, which consisted of supplying 15 g of sunflower cake, 30 g of sunflower cake (15 g at intervals of 12 hours and 30 g of sunflower cake (15 g at intervals of 24 hours, and an additional six roosters were fasted for correction of metabolic and endogenous losses. The samples were sent for amino acid analysis by HPLC in the Evonik Laboratory (Germany, and chemical and energy analysis to Unioeste Laboratory. The values of apparent metabolizable energy (AME, metabolization coefficient (AMC, apparent metabolizable energy corrected for nitrogen balance (AMEn, metabolization coefficient corrected for nitrogen balance (AMCn for sunflower cake were 2211.68 kcal.kg-1, 2150.54 kcal.kg-1, 45.47% and 44.73%, respectively. The amount of food provided in the feeding method changed the assessment of true digestibility of amino acids (TDCA, and when only 15 g was used, the values of true digestibility coefficients were underestimated. The lysine, histidine and threonine amino acids were at lower TDCA, and arginine and methionine showed the highest TDCA for sunflower cake.

  13. Public values for energy futures: Framing, indeterminacy and policy making

    International Nuclear Information System (INIS)

    Butler, C.; Demski, C.; Parkhill, K.; Pidgeon, N.; Spence, A.

    2015-01-01

    In the UK there are strong policy imperatives to transition toward low carbon energy systems but how and in what ways such transitional processes might be realised remains highly uncertain. One key area of uncertainty pertains to public attitudes and acceptability. Though there is wide-ranging research relevant to public acceptability, very little work has unpacked the multiple questions concerning how policy-makers can grapple with and mitigate related uncertainties in efforts to enact energy systems change. In this paper, public acceptability is identified as an indeterminate form of uncertainty that presents particular challenges for policy making. We build on our existing research into public values for energy system change to explore how the outcomes of the project can be applied in thinking through the uncertainties associated with public acceptability. Notably, we illustrate how the public values identified through our research bring into view alternative and quite different problem and solution framings to those currently evident within UK policy. We argue that engagement with a wide range of different framings can offer a basis for better understanding and anticipating public responses to energy system change, ultimately aiding in managing the complex set of uncertainties associated with public acceptability. - Highlights: • We argue that public acceptability represents an indeterminate form of uncertainty. • This means alternative approaches to decision-making are required. • We introduce a public value set for energy system change. • We use this as a basis for interrogating current UK policy approaches to transitions. • Incorporating public values in policy can help tackle uncertainty about acceptability.

  14. Generalized Energy-Dependent Q Values for Fission

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R

    2010-03-31

    We extend Madland's parameterization of the energy release in fission to obtain the dependence of the fission Q value for major and minor actinides on the incident neutron energies in the range 0 {le} E{sub n} {le} 20 MeV. Our parameterization is based on the actinide evaluations recommended for the ENDF/B-VII.1 release. This paper describes the calculation of energydependent fission Q values based on the calculation of the prompt energy release in fission by Madland. This calculation was adopted for use in the LLNL ENDL database and then generalized to obtain the prompt fission energy release for all actinides. Here the calculation is further generalized to the total energy release in fission. There are several stages in a fission event, depending on the time scale. Neutrons and gammas may be emitted at any time during the fission event.While our discussion here is focussed on compound nucleus creation by an incident neutron, similar parameterizations could be obtained for incident gammas or spontaneous fission.

  15. Perturbation method for calculating impurity binding energy in an ...

    Indian Academy of Sciences (India)

    Nilanjan Sil

    2017-12-18

    Dec 18, 2017 ... the physical properties in them. As a result, the energy of the electrons in the confined directions become quan- tized and forms a discrete energy spectrum. For such size-quantized electrons, the scattering probability is drastically suppressed [15]. The donor impurity in semiconductor nanoheterostru-.

  16. Using docking and alchemical free energy approach to determine the binding mechanism of eEF2K inhibitors and prioritizing the compound synthesis.

    Science.gov (United States)

    Wang, Qiantao; Edupuganti, Ramakrishna; Tavares, Clint D J; Dalby, Kevin N; Ren, Pengyu

    2015-01-01

    A-484954 is a known eEF2K inhibitor with submicromolar IC50 potency. However, the binding mechanism and the crystal structure of the kinase remains unknown. Here, we employ a homology eEF2K model, docking and alchemical free energy simulations to probe the binding mechanism of eEF2K, and in turn, guide the optimization of potential lead compounds. The inhibitor was docked into the ATP-binding site of a homology model first. Three different binding poses, hypothesis 1, 2, and 3, were obtained and subsequently applied to molecular dynamics (MD) based alchemical free energy simulations. The calculated relative binding free energy of the analogs of A-484954 using the binding pose of hypothesis 1 show a good correlation with the experimental IC50 values, yielding an r (2) coefficient of 0.96 after removing an outlier (compound 5). Calculations using another two poses show little correlation with experimental data, (r (2) of less than 0.5 with or without removing any outliers). Based on hypothesis 1, the calculated relative free energy suggests that bigger cyclic groups, at R1 e.g., cyclobutyl and cyclopentyl promote more favorable binding than smaller groups, such as cyclopropyl and hydrogen. Moreover, this study also demonstrates the ability of the alchemical free energy approach in combination with docking and homology modeling to prioritize compound synthesis. This can be an effective means of facilitating structure-based drug design when crystal structures are not available.

  17. Values, perceived risks and benefits, and acceptability of nuclear energy.

    Science.gov (United States)

    de Groot, Judith I M; Steg, Linda; Poortinga, Wouter

    2013-02-01

    We examined how personal values and perceptions of risks and benefits are associated with the acceptability of nuclear energy (NE). A theoretical model is tested in which beliefs about the risks and benefits of NE mediate the relationship between values and acceptability. The results showed that egoistic values are positively related to the perceived benefits and acceptability of NE. In contrast, altruistic and biospheric values were positively related to the perceived risks of NE. Although it has been argued that NE may help to combat climate change through lower CO(2) emissions, these environmental benefits were not acknowledged by people with strong biospheric values. Furthermore, results confirmed that the more risks respondents perceived, the less they were inclined to accept NE. In contrast, the more a person believed that NE has beneficial consequences, the more acceptable NE was. Finally, as expected, perceived risks and benefits were found to partly mediate the relationship between personal values and acceptability. We discuss the theoretical and practical implications of these findings. © 2012 Society for Risk Analysis.

  18. The Value of Energy Storage for Grid Applications

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jenkin, Thomas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kirby, Brendan [Kirby Consultant; Ma, Ookie [U.S. Department of Energy, Washington, DC (United States); O' Malley, Mark [Univ. College of Dublin (Ireland)

    2013-05-01

    This analysis evaluates several operational benefits of electricity storage, including load-leveling, spinning contingency reserves, and regulation reserves. Storage devices were simulated in a utility system in the western United States, and the operational costs of generation was compared to the same system without the added storage. This operational value of storage was estimated for devices of various sizes, providing different services, and with several sensitivities to fuel price and other factors. Overall, the results followed previous analyses that demonstrate relatively low value for load-leveling but greater value for provision of reserve services. The value was estimated by taking the difference in operational costs between cases with and without energy storage and represents the operational cost savings from deploying storage by a traditional vertically integrated utility. The analysis also estimated the potential revenues derived from a merchant storage plant in a restructured market, based on marginal system prices. Due to suppression of on-/off-peak price differentials and incomplete capture of system benefits (such as the cost of power plant starts), the revenue obtained by storage in a market setting appears to be substantially less than the net benefit provided to the system. This demonstrates some of the additional challenges for storage deployed in restructured energy markets.

  19. ATP binding cassette (ABC) transporters: expression and clinical value in glioblastoma.

    Science.gov (United States)

    Dréan, Antonin; Rosenberg, Shai; Lejeune, François-Xavier; Goli, Larissa; Nadaradjane, Aravindan Arun; Guehennec, Jérémy; Schmitt, Charlotte; Verreault, Maïté; Bielle, Franck; Mokhtari, Karima; Sanson, Marc; Carpentier, Alexandre; Delattre, Jean-Yves; Idbaih, Ahmed

    2018-03-08

    ATP-binding cassette transporters (ABC transporters) regulate traffic of multiple compounds, including chemotherapeutic agents, through biological membranes. They are expressed by multiple cell types and have been implicated in the drug resistance of some cancer cells. Despite significant research in ABC transporters in the context of many diseases, little is known about their expression and clinical value in glioblastoma (GBM). We analyzed expression of 49 ABC transporters in both commercial and patient-derived GBM cell lines as well as from 51 human GBM tumor biopsies. Using The Cancer Genome Atlas (TCGA) cohort as a training dataset and our cohort as a validation dataset, we also investigated the prognostic value of these ABC transporters in newly diagnosed GBM patients, treated with the standard of care. In contrast to commercial GBM cell lines, GBM-patient derived cell lines (PDCL), grown as neurospheres in a serum-free medium, express ABC transporters similarly to parental tumors. Serum appeared to slightly increase resistance to temozolomide correlating with a tendency for an increased expression of ABCB1. Some differences were observed mainly due to expression of ABC transporters by microenvironmental cells. Together, our data suggest that the efficacy of chemotherapeutic agents may be misestimated in vitro if they are the targets of efflux pumps whose expression can be modulated by serum. Interestingly, several ABC transporters have prognostic value in the TCGA dataset. In our cohort of 51 GBM patients treated with radiation therapy with concurrent and adjuvant temozolomide, ABCA13 overexpression is associated with a decreased progression free survival in univariate (p ABC transporters is: (i) detected in GBM and microenvironmental cells and (ii) better reproduced in GBM-PDCL. ABCA13 expression is an independent prognostic factor in newly diagnosed GBM patients. Further prospective studies are warranted to investigate whether ABCA13 expression can be

  20. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    Keywords. Impurity energy; turning point; binding energy. PACS Nos 73.20.Dx; 73.20.Hb; 71.55.-i; 71.55.Eq. 1. Introduction. Because of the recent advances in nanofabrication technology, it is possible to pro- duce quantum dots whose characteristic dimensions are comparable with the elec- tronic de Broglie wavelengths.

  1. Analysis of binding energy activity of TIBO and HIV-RT based on ...

    African Journals Online (AJOL)

    KEN

    2007-02-05

    Feb 5, 2007 ... the structure of TIBO-HIV-RT complex (Ren et al., 1995,. 1999). In this theoretical research, the energy change corresponding to the conformational change within TIBO was investigated. It was observed that change in the beta dihedral angle conformation critically affects the binding energy. Decreased ...

  2. Stocks and energy shocks : the impact of energy accidents on stock market value

    NARCIS (Netherlands)

    Scholtens, B.; Boersen, A.

    We investigate how financial market participants value energy accidents. We employ an event study to look into the response of stock markets to 209 accidents. These accidents were derived from Sovacool's (2008) database on major energy accidents from 1907 to 2007. It appears that the stock market in

  3. Hypernuclear interactions and the binding energies of and hypernuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R.; Usmani, Q.N.

    1988-01-01

    By use of variational calculations a reasonable hadronic description is obtained of the s-shell hypernuclei, of /sub /ZBe, and of the well depth, with N forces which are consistent with p scattering and which are quite strongly spin-dependent, with reasonable TPE NN forces with strongly repulsive dispersive-type NN forces. For the latter we also consider a spin-dependent version which is somewhat favored by our analysis. /sub /ZBe is treated as a 2ed + system and is significantly overbound, approx. =1 MeV, if only ed ed and ed potentials are used. An ed ed potential obtained from the NN forces nicely accounts for this overbinding. The hypernuclei /sub /WHe and /sub / Be are treated as ed + 2 and 2ed + 2 systems. Use of the /sub / Be event gives approx. =1.5 MeV too little binding for /sub /WHe. The S0 potential obtained from /sub / Be is quite strongly attractive, comparable to the N and also to the NN potential without OPE. 18 refs.

  4. Clinical value of determination of TSH-binding inhibiting immunoglobulins (TBII) by a radioreceptor assay

    International Nuclear Information System (INIS)

    Heberling, H.J.; Bierwolf, B.; Lohmann, D.

    1986-01-01

    The clinical value of a commercial kit for determination of TBII was evaluated. 50 patients with untreated Graves' disease, 21 patients with Graves' disease before and during medical therapy, 18 patients after finishing medical therapy and 10 patients after surgical treatment were examined. Besides these, 41 patients with other thyroid diseases and 36 patients without any thyroid disorder were included. In 47 (94%) of 50 patients with untreated Graves' disease TBII were detectable in serum using a TSH standard curve. Binding activities exceeding 10 U/l TSH equivalents were regarded as positive. In other thyroid diseases TBII were negative with the exception of 3 of 22 patient with autonomously functioning thyroid nodules. After 12 months of antithyroid drug treatment of 19 patients the incidence of positive antibody findings was 26%. During follow-up after medical therapy (1-9 years) 7 of 18 patients had increased TBII in correlation with clinical and functional findings. The determination of TBII by TRAK assay proved to be a sensitive and specific method. The assay can be used to differentiate between hyperthyroidism of autoimmune or non-immunogenic origin. Thus the method seems to be helpful for the follow-up under medical treatment of patients with Graves' disease. (author)

  5. 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...... are all incorporated into the binding energy analysis through this parameter. With few exceptions, the agreement of the results from the simple model with full DFT calculations on hundreds of binary surface alloys is remarkable. The scheme should therefore provide a fast and effective method...... for the estimation of oxygen binding energies on a wide variety of transition metal alloys. (c) 2005 Elsevier B.V. All rights reserved....

  6. 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.

  7. A comparison of binding energy and metastable zone width for adipic acid with various additives

    Science.gov (United States)

    Myerson, Allan S.; Jang, Shyh M.

    1995-12-01

    The binding energy of nine alkanoic acids to the major crystal faces of adipic acid were calculated employing molecular modelling techniques. The results indicate that the alkanoic acids bind strongly to the surface when compared to solvents and to adipic acid itself indicating that the alkanoic acids could be potential growth and nucleation inhibitors. The binding energies were found to increase with increasing carbon number to C 14 to decrease from C 14 to C 16 and then to increase again. The effect of the alkanoic acids on the metastable zone width of adipic acid in ethanol solution were measured employing a differential scanning calorimeter. The results showed that each of the nine alkanoic acids increased the metastable zone width. The metastable zone widths were found to increase with increasing carbon number to C 14 to decrease from C 14 to C 16 and to then increase again thus correlating well with the results obtained from binding energies. These results indicate that binding energy calculations appear to provide a valid method to screen impurities as potential nucleation inhibitors.

  8. Binding energies of hypernuclei and Λ-nuclear interactions

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.

    1985-01-01

    Variational Monte Carlo calculations have been made for the s-shell hypernuclei and also of 9 Be hypernuclei with a 2α + Λ model. The well depth is calculated variationally with the Fermi hypernetted chain method. A satisfactory description of all the relevant experimental Λ separation energies and also of the Λp scattering can be obtained with reasonable TPE ΛN and ΛNN forces and strongly repulsive dispersive ΛNN forces which are preferred to be spin dependent. We discuss variational calculations for 6 He and 10 Be hypernuclei with α + 2Λ and 2α + 2Λ models, and the results obtained for the ΛΛ interaction and for 6 He hypernuclei from analysis of 10 Be hypernuclei Coulomb effects and charge symmetry breaking in the A = 4 hypernuclei are discussed. 24 refs., 5 figs

  9. Binding energies of hypernuclei and. lambda. -nuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R.; Usmani, Q.N.

    1985-01-01

    Variational Monte Carlo calculations have been made for the s-shell hypernuclei and also of /sup 9/Be hypernuclei with a 2..cap alpha.. + ..lambda.. model. The well depth is calculated variationally with the Fermi hypernetted chain method. A satisfactory description of all the relevant experimental ..lambda.. separation energies and also of the ..lambda..p scattering can be obtained with reasonable TPE ..lambda..N and ..lambda..NN forces and strongly repulsive dispersive ..lambda..NN forces which are preferred to be spin dependent. We discuss variational calculations for /sup 6/He and /sup 10/Be hypernuclei with ..cap alpha.. + 2..lambda.. and 2..cap alpha.. + 2..lambda.. models, and the results obtained for the ..lambda lambda.. interaction and for /sup 6/He hypernuclei from analysis of /sup 10/Be hypernuclei Coulomb effects and charge symmetry breaking in the A = 4 hypernuclei are discussed. 24 refs., 5 figs.

  10. Binding energy of impurity states in an inverse parabolic quantum well under magnetic field

    International Nuclear Information System (INIS)

    Kasapoglu, E.; Sari, H.; Soekmen, I.

    2007-01-01

    We have investigated the effects of the magnetic field which is directed perpendicular to the well on the binding energy of the hydrogenic impurities in an inverse parabolic quantum well (IPQW) with different widths as well as different Al concentrations at the well center. The Al concentration at the barriers was always x max =0.3. The calculations were performed within the effective mass approximation, using a variational method. We observe that IPQW structure turns into parabolic quantum well with the inversion effect of the magnetic field and donor impurity binding energy in IPQW strongly depends on the magnetic field, Al concentration at the well center and well dimensions

  11. Pressure-dependent shallow donor binding energy in InGaN/GaN square QWWs

    International Nuclear Information System (INIS)

    Ghazi, Haddou El; Jorio, Anouar; Zorkani, Izeddine

    2013-01-01

    Using a variational approach, we perform a theoretical study of hydrostatic pressure effect on the ground-state of axial hydrogenic shallow-donor impurity binding energy in InGaN/GaN square quantum well wire (SQWWs) as a function of the side length within the effective-mass scheme and finite potential barrier. The pressure dependence of wire length, effective mass, dielectric constant and potential barrier are taken into account. Numerical results show that: (i) the binding energy is strongly affected by the wire length and the external applied pressure and (ii) its maximum moves to the narrow wire in particular for height pressure.

  12. Experimental Support for Desolvation Energy Term in Governing Equations for Binding Equilibria

    OpenAIRE

    Castellano, Brian M.; Eggers, Daryl K.

    2013-01-01

    This study introduces a new thermodynamic framework for aqueous reaction equilibria that treats water as a co-reactant in the development of a general binding equation. The approach features an explicit consideration for the change in hydration that occurs when two solvated surfaces come into contact. As an outcome of this framework, the standard state free energy of binding is defined by the summation of two terms, the traditional term (−RTlnKi) plus a desolvation free energy term that is we...

  13. Binding energies of the π-stacked anisole dimer: new molecular beam-laser spectroscopy experiments and CCSD(T) calculations.

    Science.gov (United States)

    Řezáč, Jan; Nachtigallová, Dana; Mazzoni, Federico; Pasquini, Massimiliano; Pietraperzia, Giangaetano; Becucci, Maurizio; Müller-Dethlefs, Klaus; Hobza, Pavel

    2015-04-27

    Among noncovalent interactions, π-π stacking is a very important binding motif governed mainly by London dispersion. Despite its importance, for instance, for the structure of bio-macromolecules, the direct experimental measurement of binding energies in π-π stacked complexes has been elusive for a long time. Only recently, an experimental value for the binding energy of the anisole dimer was presented, determined by velocity mapping ion imaging in a two-photon resonant ionisation molecular beam experiment. However, in that paper, a discrepancy was already noted between the obtained experimental value and a theoretical estimate. Here, we present an accurate recalculation of the binding energy based on the combination of the CCSD(T)/CBS interaction energy and a DFT-D3 vibrational analysis. This proves unambiguously that the previously reported experimental value is too high and a new series of measurements with a different, more sensitive apparatus was performed. The new experimental value of 1800±100 cm(-1) (5.15±0.29 kcal mol(-1)) is close to the present theoretical prediction of 5.04±0.40 kcal mol(-1). Additional calculations of the properties of the cationic and excited states involved in the photodissociation of the dimer were used to identify and rationalise the difficulties encountered in the experimental work. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Ions in size-selected aqueous nanodrops: sequential water molecule binding energies and effects of water on ion fluorescence.

    Science.gov (United States)

    Donald, William A; Leib, Ryan D; Demireva, Maria; Williams, Evan R

    2011-11-23

    The effects of water on ion fluorescence were investigated, and average sequential water molecule binding energies to hydrated ions, M(z)(H(2)O)(n), at large cluster size were measured using ion nanocalorimetry. Upon 248-nm excitation, nanodrops with ~25 or more water molecules that contain either rhodamine 590(+), rhodamine 640(+), or Ce(3+) emit a photon with average energies of approximately 548, 590, and 348 nm, respectively. These values are very close to the emission maxima of the corresponding ions in solution, indicating that the photophysical properties of these ions in the nanodrops approach those of the fully hydrated ions at relatively small cluster size. As occurs in solution, these ions in nanodrops with 8 or more water molecules fluoresce with a quantum yield of ~1. Ce(3+) containing nanodrops that also contain OH(-) fluoresce, whereas those with NO(3)(-) do not. This indirect fluorescence detection method has the advantages of high sensitivity, and both the size of the nanodrops as well as their constituents can be carefully controlled. For ions that do not fluoresce in solution, such as protonated tryptophan, full internal conversion of the absorbed 248-nm photon occurs, and the average sequential water molecule binding energies to the hydrated ions can be accurately obtained at large cluster sizes. The average sequential water molecule binding energies for TrpH(+)(H(2)O)(n) and a doubly protonated tripeptide, [KYK + 2H](2+)(H(2)O)(n), approach asymptotic values of ~9.3 (n ≥ 11) and ~10.0 kcal/mol (n ≥ 25), respectively, consistent with a liquidlike structure of water in these nanodrops.

  15. Determination of the absolute binding free energies of HIV-1 protease inhibitors using non-equilibrium molecular dynamics simulations

    Science.gov (United States)

    Ngo, Son Tung; Nguyen, Minh Tung; Nguyen, Minh Tho

    2017-05-01

    The absolute binding free energy of an inhibitor to HIV-1 Protease (PR) was determined throughout evaluation of the non-bonded interaction energy difference between the two bound and unbound states of the inhibitor and surrounding molecules by the fast pulling of ligand (FPL) process using non-equilibrium molecular dynamics (NEMD) simulations. The calculated free energy difference terms help clarifying the nature of the binding. Theoretical binding affinities are in good correlation with experimental data, with R = 0.89. The paradigm used is able to rank two inhibitors having the maximum difference of ∼1.5 kcal/mol in absolute binding free energies.

  16. Incremental binding free energies of aluminum (III) vs. magnesium (II) complexes

    International Nuclear Information System (INIS)

    Mercero, Jose M.; Mujika, Jon I.; Matxain, Jon M.; Lopez, Xabier; Ugalde, Jesus M.

    2003-01-01

    A sequential ligand addition to the aluminum (III) cation has been studied using the B3LYP functional and a combined all-electron/pseudopotentials basis set. The aluminum complexes are compared with analogous magnesium (II) complexes. Different thermodynamical data, such as incremental binding energies, enthalpies, entropies and free energies, are presented for these addition reactions. While the magnesium (II) cation can only accommodate three negatively charged ligands, aluminum (III) accommodates four even after including bulk solvent effects. The main differences between both cations complexing with the neutral ligands, is that aluminum (III) is not able to form complexes with methanol until the number of methanol ligands is equal to 3. Magnesium (II) prefers to bind methanol and formamide when the number of ligands is small, while aluminum prefers formamide. For the largest complexes both cations prefer to bind water

  17. Analysis of binding energy activity of TIBO and HIV-RT based on ...

    African Journals Online (AJOL)

    Tetrahydro-imidazo[4,5,l-jk][1,4]-benzodiazepin-2 (1 H)one (TIBO) is a noncompetitive non nucleotide antiretroviral drug with a specific allosteric binding site of HIV-1 RT. The conformational analysis shows that the effect of the drug depends on the potential energy which varied due to the beta rotatable dihedral angles (N6 ...

  18. 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.

  19. Absolute binding free energy calculations of CBClip host–guest systems in the SAMPL5 blind challenge

    Science.gov (United States)

    Tofoleanu, Florentina; Pickard, Frank C.; König, Gerhard; Huang, Jing; Damjanović, Ana; Baek, Minkyung; Seok, Chaok; Brooks, Bernard R.

    2016-01-01

    Herein, we report the absolute binding free energy calculations of CBClip complexes in the SAMPL5 blind challenge. Initial conformations of CBClip complexes were obtained using docking and molecular dynamics simulations. Free energy calculations were performed using thermodynamic integration (TI) with soft-core potentials and Bennett’s acceptance ratio (BAR) method based on a serial insertion scheme. We compared the results obtained with TI simulations with soft-core potentials and Hamiltonian replica exchange simulations with the serial insertion method combined with the BAR method. The results show that the difference between the two methods can be mainly attributed to the van der Waals free energies, suggesting that either the simulations used for TI or the simulations used for BAR, or both are not fully converged and the two sets of simulations may have sampled difference phase space regions. The penalty scores of force field parameters of the 10 guest molecules provided by CHARMM Generalized Force Field can be an indicator of the accuracy of binding free energy calculations. Among our submissions, the combination of docking and TI performed best, which yielded the root mean square deviation of 2.94 kcal/mol and an average unsigned error of 3.41 kcal/mol for the ten guest molecules. These values were best overall among all participants. However, our submissions had little correlation with experiments. PMID:27677749

  20. 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. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

  1. Computation of the binding affinities of catechol-O-methyltransferase inhibitors: multisubstate relative free energy calculations.

    Science.gov (United States)

    Palma, P Nuno; Bonifácio, Maria João; Loureiro, Ana Isabel; Soares-da-Silva, Patrício

    2012-04-05

    Alchemical free energy simulations are amongst the most accurate techniques for the computation of the free energy changes associated with noncovalent protein-ligand interactions. A procedure is presented to estimate the relative binding free energies of several ligands to the same protein target where multiple, low-energy configurational substates might coexist, as opposed to one unique structure. The contributions of all individual substates were estimated, explicitly, with the free energy perturbation method, and combined in a rigorous fashion to compute the overall relative binding free energies and dissociation constants. It is shown that, unless the most stable bound forms are known a priori, inaccurate results may be obtained if the contributions of multiple substates are ignored. The method was applied to study the complex formed between human catechol-O-methyltransferase and BIA 9-1067, a newly developed tight-binding inhibitor that is currently under clinical evaluation for the therapy of Parkinson's disease. Our results reveal an exceptionally high-binding affinity (K(d) in subpicomolar range) and provide insightful clues on the interactions and mechanism of inhibition. The inhibitor is, itself, a slowly reacting substrate of the target enzyme and is released from the complex in the form of O-methylated product. By comparing the experimental catalytic rate (k(cat)) and the estimated dissociation rate (k(off)) constants of the enzyme-inhibitor complex, one can conclude that the observed inhibition potency (K(i)) is primarily dependent on the catalytic rate constant of the inhibitor's O-methylation, rather than the rate constant of dissociation of the complex. Copyright © 2012 Wiley Periodicals, Inc.

  2. The effects of electron binding energy corrections on Monte Carlo models in the diagnostic x-ray energy range

    International Nuclear Information System (INIS)

    Sim, L.H.; Van Doorn, T.; Michael, G.J.

    1996-01-01

    Full text: The effects of incorporating electron binding energy corrections for incoherent scatter (BEC) into Monte Carlo models of X-ray transport in the diagnostic energy range have been examined. The inclusion of BEC can significantly increase computing overhead both in terms of data storage and execution time. In a modern PC application, data storage is unlikely to be a significant problem. However, execution time is a major consideration when assessing the relative usefulness of Monte Carlo systems. If the effectiveness of including BEC is barely more than equivocal, as is the case in some of the studies reported here, then a decision to include them requires consideration of the photon energy being modelled and the data being sought. This work seeks to clarify the real significance of inclusion of BEC by examining their effects without the confounding influence of coherent scattering effects. A Monte Carlo computer code has been developed to study a variety of X-ray transport phenomena. Models of radiation dose deposition in a semi-infinite medium, a similar model in tissue using a realistic source spectrum and diverging beam geometry, a simulation of pencil beam bone densitometry measurements, models of barrier penetration by X-rays and models of the angular distribution of scattered radiation have been undertaken. Results of previous studies have been confirmed. Models of radiation dose deposition for 10 keV, 30 keV and 100 keV photons have shown that inclusion of BEC has only a small effect upon values of total depth dose. Differences are of the same order of magnitude as the standard deviation of the results. A larger effect was noted for the values of dose due to scattered photons. This effect reached a maximum of 7% at 30 keV. Similar results were obtained from a model using a realistic source spectrum and diverging beam geometry. In the simulation of bone densitometry measurements the effects are significant (i.e. of the order of 10%). The angular

  3. Binding free energy calculations to rationalize the interactions of huprines with acetylcholinesterase.

    Science.gov (United States)

    Nascimento, Érica C M; Oliva, Mónica; Andrés, Juan

    2018-03-26

    In the present study, the binding free energy of a family of huprines with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation method, based on hybrid quantum mechanics and molecular mechanics potentials. Binding free energy calculations and the analysis of the geometrical parameters highlight the importance of the stereochemistry of huprines in AChE inhibition. Binding isotope effects are calculated to unravel the interactions between ligands and the gorge of AChE. New chemical insights are provided to explain and rationalize the experimental results. A good correlation with the experimental data is found for a family of inhibitors with moderate differences in the enzyme affinity. The analysis of the geometrical parameters and interaction energy per residue reveals that Asp72, Glu199, and His440 contribute significantly to the network of interactions between active site residues, which stabilize the inhibitors in the gorge. It seems that a cooperative effect of the residues of the gorge determines the affinity of the enzyme for these inhibitors, where Asp72, Glu199, and His440 make a prominent contribution.

  4. Accurate Estimation of the Standard Binding Free Energy of Netropsin with DNA

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    2018-01-01

    Full Text Available DNA is the target of chemical compounds (drugs, pollutants, photosensitizers, etc., which bind through non-covalent interactions. Depending on their structure and their chemical properties, DNA binders can associate to the minor or to the major groove of double-stranded DNA. They can also intercalate between two adjacent base pairs, or even replace one or two base pairs within the DNA double helix. The subsequent biological effects are strongly dependent on the architecture of the binding motif. Discriminating between the different binding patterns is of paramount importance to predict and rationalize the effect of a given compound on DNA. The structural characterization of DNA complexes remains, however, cumbersome at the experimental level. In this contribution, we employed all-atom molecular dynamics simulations to determine the standard binding free energy of DNA with netropsin, a well-characterized antiviral and antimicrobial drug, which associates to the minor groove of double-stranded DNA. To overcome the sampling limitations of classical molecular dynamics simulations, which cannot capture the large change in configurational entropy that accompanies binding, we resort to a series of potentials of mean force calculations involving a set of geometrical restraints acting on collective variables.

  5. Precision measurements of high-energy conversion electron lines and determination of neutron binding energies

    International Nuclear Information System (INIS)

    Braumandl, F.

    1979-01-01

    The paper first discusses the energy accuracy of the BILL conversion electron spectrometer at the Grenoble high flux reactor. With an improved temperature stabilisation of the magnets, an energy accuracy of ΔE/E -5 can be reached. After this, highly exact measurements of high-energy conversion electron lines of the 200 Hg, 114 Cd, 165 Dy, 168 Er, 239 U nuclei and the 13 C, 28 Al 3 H and 92 Zr photoelectron lines were carried out. Energy calibration of the spectrometer was carried out in the 1.5 MeV to 6.5 MeV range with intensive high-energy transitions of the 200 Hg nucleus. Systematic calibration errors could be investigated by means of combinations between the calibration lines. A calibration for absolute energies was obtained by comparing low-energy gamma transitions of 200 Hg with the 411.8 keV gold standard. (orig.) [de

  6. Quantum confinement effect and exciton binding energy of layered perovskite nanoplatelets

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2018-02-01

    Full Text Available We report the preparation of monolayer (n = 1, few-layer (n = 2–5 and 3D (n = ∞ organic lead bromide perovskite nanoplatelets (NPLs by tuning the molar ratio of methylammonium bromide (MABr and hexadecammonium bromide (HABr. The absorption spectrum of the monolayer (HA2PbBr4 perovskite NPLs shows about 138 nm blue shift from that of 3D MAPbBr3 perovskites, which is attributed to strong quantum confinement effect. We further investigate the two-photon photoluminescence (PL of the NPLs and measure the exciton binding energy of monolayer perovskite NPLs using linear absorption and two-photon PL excitation spectroscopy. The exciton binding energy of monolayer perovskite NPLs is about 218 meV, which is far larger than tens of meV in 3D lead halide perovskites.

  7. Valence proton-neutron interaction strengths from double binding energy differences

    International Nuclear Information System (INIS)

    Brenner, D.S.; Foy, B.D.; Warner, D.D.; Zamfir, N.V.; Casten, R.F.

    1996-01-01

    Empirical p-n interaction strengths have been extracted from experimental mass data using double-difference binding energy equations. The especially strong interactions for self-conjugate nuclei will be discussed as well as microstructure found for deformed and in doubly magic regions. Valence correlation Schemes provide a basis to comment on the stability of medium mass near-drip-line nuclei and superheavy elements

  8. Prediction of trypsin/molecular fragment binding affinities by free energy decomposition and empirical scores

    Science.gov (United States)

    Benson, Mark L.; Faver, John C.; Ucisik, Melek N.; Dashti, Danial S.; Zheng, Zheng; Merz, Kenneth M.

    2012-05-01

    Two families of binding affinity estimation methodologies are described which were utilized in the SAMPL3 trypsin/fragment binding affinity challenge. The first is a free energy decomposition scheme based on a thermodynamic cycle, which included separate contributions from enthalpy and entropy of binding as well as a solvent contribution. Enthalpic contributions were estimated with PM6-DH2 semiempirical quantum mechanical interaction energies, which were modified with a statistical error correction procedure. Entropic contributions were estimated with the rigid-rotor harmonic approximation, and solvent contributions to the free energy were estimated with several different methods. The second general methodology is the empirical score LISA, which contains several physics-based terms trained with the large PDBBind database of protein/ligand complexes. Here we also introduce LISA+, an updated version of LISA which, prior to scoring, classifies systems into one of four classes based on a ligand's hydrophobicity and molecular weight. Each version of the two methodologies (a total of 11 methods) was trained against a compiled set of known trypsin binders available in the Protein Data Bank to yield scaling parameters for linear regression models. Both raw and scaled scores were submitted to SAMPL3. Variants of LISA showed relatively low absolute errors but also low correlation with experiment, while the free energy decomposition methods had modest success when scaling factors were included. Nonetheless, re-scaled LISA yielded the best predictions in the challenge in terms of RMS error, and six of these models placed in the top ten best predictions by RMS error. This work highlights some of the difficulties of predicting binding affinities of small molecular fragments to protein receptors as well as the benefit of using training data.

  9. Binding energy of a hydrogenic impurity in a coaxial quantum wire with an insulator layer

    Science.gov (United States)

    Kes, H.; Bilekkaya, A.; Aktas, S.; Okan, S. E.

    2017-11-01

    The electronic properties of a coaxial cylindrical quantum well-barrier system constituted about an central insulating wire were determined under an external electric field. The model wire, inside to outside, was considered to be layered as AlAs / GaAs / Alx1 Ga1 -x1 As / GaAs / Alx2 Ga1 -x2 As. Within the framework of the effective mass-approximation, the binding energy of a hydrogenic impurity is calculated by using the combination of the fourth-order Runge-Kutta method and variational approaches. The binding energy exhibits sharp changes depending on the impurity position and the geometrical parameters of the structure such as the well widths of the GaAs wires and the height and thickness of the barrier constituted by Alx1 Ga1 -x1 As . The binding energy of the electron was found to be independent from the impurity position for the specific widths of the well wires. Also, the barrier properties appeared as very effective parameters in controlling the probability distribution of the electron.

  10. 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.

  11. 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. © 2015 The Protein Society.

  12. The Meaning of Green: Values and Energy Policy in Sweden

    International Nuclear Information System (INIS)

    Nilsson, Maans

    2003-01-01

    Values, and the way they are represented, have strong implications for environmental policy. Mapping of how values, perceptions, scientific facts and professional judgments interact and function in the process will contribute to understanding the policy process. However, although a systematic, reasoned and critical examination of values underpinning policy choices and expressions is an essential part of policy analysis, values are rarely scrutinised (Dunn 1994). As a result, their role in environmental policy making is not well understood. This paper addresses this gap by asking: How are values represented in the policy arena and the processes within it? What changes do values undergo over time and as they go through the policy-making process? Value concepts are discussed as a basis to understand and describe the values at play in a process. The paper also draws on theories of the policy process to support the analysis of the empirical material. The analysis is then delimited to a selected set of value issues. The empirical material includes public debate documents such as bills, hearings, motions, presentation, statements and their commentaries. Semi-structured interviews, designed as in-depth interviews with open-ended probing, were held to complernent the material. Respondents were identified in the policy committees, career professionals and representatives of important interest groups

  13. Hybrid density functional-molecular mechanics calculations for core-electron binding energies of glycine in water solution.

    Science.gov (United States)

    Niskanen, Johannes; Arul Murugan, N; Rinkevicius, Zilvinas; Vahtras, Olav; Li, Cui; Monti, Susanna; Carravetta, Vincenzo; Agren, Hans

    2013-01-07

    We report hybrid density functional theory-molecular mechanics (DFT/MM) calculations performed for glycine in water solution at different pH values. In this paper, we discuss several aspects of the quantum mechanics-molecular mechanics (QM/MM) simulations where the dynamics and spectral binding energy shifts are computed sequentially, and where the latter are evaluated over a set of configurations generated by molecular or Car-Parrinello dynamics simulations. In the used model, core ionization takes place in glycine as a quantum mechanical (QM) system modeled with DFT, and the solution is described with expedient force fields in a large molecular mechanical (MM) volume of water molecules. The contribution to the core electronic binding energy from all interactions within and between the two (DFT and MM) parts is accounted for, except charge transfer and dispersion. While the obtained results were found to be in qualitative agreement with experiment, their precision must be qualified with respect to the problem of counter ions, charge transfer and optimal division of QM and MM parts of the system. Results are compared to those of a recent study [Ottoson et al., J. Am. Chem. Soc., 2011, 133, 3120].

  14. Locating Temporal Functional Dynamics of Visual Short-Term Memory Binding using Graph Modular Dirichlet Energy

    Science.gov (United States)

    Smith, Keith; Ricaud, Benjamin; Shahid, Nauman; Rhodes, Stephen; Starr, John M.; Ibáñez, Augustin; Parra, Mario A.; Escudero, Javier; Vandergheynst, Pierre

    2017-02-01

    Visual short-term memory binding tasks are a promising early marker for Alzheimer’s disease (AD). To uncover functional deficits of AD in these tasks it is meaningful to first study unimpaired brain function. Electroencephalogram recordings were obtained from encoding and maintenance periods of tasks performed by healthy young volunteers. We probe the task’s transient physiological underpinnings by contrasting shape only (Shape) and shape-colour binding (Bind) conditions, displayed in the left and right sides of the screen, separately. Particularly, we introduce and implement a novel technique named Modular Dirichlet Energy (MDE) which allows robust and flexible analysis of the functional network with unprecedented temporal precision. We find that connectivity in the Bind condition is less integrated with the global network than in the Shape condition in occipital and frontal modules during the encoding period of the right screen condition. Using MDE we are able to discern driving effects in the occipital module between 100-140 ms, coinciding with the P100 visually evoked potential, followed by a driving effect in the frontal module between 140-180 ms, suggesting that the differences found constitute an information processing difference between these modules. This provides temporally precise information over a heterogeneous population in promising tasks for the detection of AD.

  15. Calculation of the neutron W value for neutron dosimetry below the MeV energy region

    International Nuclear Information System (INIS)

    Endo, S.; Shizuma, K.; Goodhead, D.T.

    2000-01-01

    The effective neutron W value for tissue-equivalent gas in the energy region from 5 keV to 5.7 MeV has been calculated using W values for recoil particles (protons, alpha particles, oxygen, carbon and nitrogen ions), which are produced by incident neutrons. The W value is assumed to be an energy-fluence-average over the W values of the recoil particles. The energy fluence spectra for the recoil particles are calculated by using a continuous slowing-down approximation (CSDA). For the W values of recoil particles in the low-energy region, the recently evaluated data by Siebert et al and Taylor et al were used. Results are presented which show that the effective neutron W value depends strongly on energy in the low-energy region. This result indicates that neutron dose measurements using ionization chambers need a considerable correction of the W value in the low-energy region. (author)

  16. Can the energy gap in the protein-ligand binding energy landscape be used as a descriptor in virtual ligand screening?

    Directory of Open Access Journals (Sweden)

    Arsen V Grigoryan

    Full Text Available The ranking of scores of individual chemicals within a large screening library is a crucial step in virtual screening (VS for drug discovery. Previous studies showed that the quality of protein-ligand recognition can be improved using spectrum properties and the shape of the binding energy landscape. Here, we investigate whether the energy gap, defined as the difference between the lowest energy pose generated by a docking experiment and the average energy of all other generated poses and inferred to be a measure of the binding energy landscape sharpness, can improve the separation power between true binders and decoys with respect to the use of the best docking score. We performed retrospective single- and multiple-receptor conformation VS experiments in a diverse benchmark of 40 domains from 38 therapeutically relevant protein targets. Also, we tested the performance of the energy gap on 36 protein targets from the Directory of Useful Decoys (DUD. The results indicate that the energy gap outperforms the best docking score in its ability to discriminate between true binders and decoys, and true binders tend to have larger energy gaps than decoys. Furthermore, we used the energy gap as a descriptor to measure the height of the native binding phase and obtained a significant increase in the success rate of near native binding pose identification when the ligand binding conformations within the boundaries of the native binding phase were considered. The performance of the energy gap was also evaluated on an independent test case of VS-identified PKR-like ER-localized eIF2α kinase (PERK inhibitors. We found that the energy gap was superior to the best docking score in its ability to more highly rank active compounds from inactive ones. These results suggest that the energy gap of the protein-ligand binding energy landscape is a valuable descriptor for use in VS.

  17. Valuing of research project in energy field with real options

    International Nuclear Information System (INIS)

    De Blasio, N.; Marzo, G.; Turatto, R.

    2008-01-01

    This article presents an application of real options theory for valuing a research project in the field of stranded gas valorisation. After a presentation of the theory, the analysis addresses the use of real options evaluation for generating alternative pathways in order to add new value to the R D projects. It also shows how real option approach may be important for selecting among competitive projects, but also for providing a system for valorisation of decision-maker flexibility [it

  18. Constraining the gravitational binding energy of PSR J0737-3039B using terrestrial nuclear data

    International Nuclear Information System (INIS)

    Newton, W. G.; Li Baoan

    2009-01-01

    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 M max >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.

  19. World Best Practice Energy Intensity Values for SelectedIndustrial Sectors

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Price, Lynn; Neelis, Maarten; Galitsky,Christina; Zhou, Nan

    2007-06-05

    "World best practice" energy intensity values, representingthe most energy-efficient processes that are in commercial use in atleast one location worldwide, are provided for the production of iron andsteel, aluminium, cement, pulp and paper, ammonia, and ethylene. Energyintensity is expressed in energy use per physical unit of output for eachof these commodities; most commonly these are expressed in metric tonnes(t). The energy intensity values are provided by major energy-consumingprocesses for each industrial sector to allow comparisons at the processlevel. Energy values are provided for final energy, defined as the energyused at the production facility as well as for primary energy, defined asthe energy used at the production facility as well as the energy used toproduce the electricity consumed at the facility. The "best practice"figures for energy consumption provided in this report should beconsidered as indicative, as these may depend strongly on the materialinputs.

  20. Value of heart-type fatty acid-binding protein (H-FABP) for ...

    African Journals Online (AJOL)

    Abstract: Objective: The aim of this study is testing the value of H-FABP in the early diagnosis of ACS alone or with routinely used biomarkers such as myoglobin, CK-MB, and cTn I in patients who admitted to emergency department (ED) with complaint of chest pain and suspected acute coronary syndrome. Material and ...

  1. Estimating the true energy value of a wind farm

    International Nuclear Information System (INIS)

    Bass, J.

    1995-01-01

    To assess the true energy yield of a wind farm taking into account real-world effects such as control losses in individual turbines, losses in the distribution network and wake and topographic effects, this report from the Energy Technology Support Unit, has developed a more appropriate methodology for making economic assessments of wind farm projects. Simulations of wind turbines are used to enable control losses to be quantified, and long term performance data from wind turbines in operational United Kingdom wind farms adds to the accuracy of assessment. A model has also been used to estimate performance of a power distribution system for a wind farm, to enable losses associated with wind turbine, wind speed and various distribution layouts to be predicted. Data on wake effects are drawn from a separate study. All these are drawn into an economic simulation model which predicts a wind farm's likely achievement of its target energy yield, thus demonstrating the risk factors involved. (UK)

  2. Mineral Composition and Nutritive Value of Isotonic and Energy Drinks.

    Science.gov (United States)

    Leśniewicz, Anna; Grzesiak, Magdalena; Żyrnicki, Wiesław; Borkowska-Burnecka, Jolanta

    2016-04-01

    Several very popular brands of isotonic and energy drinks consumed for fluid and electrolyte supplementation and stimulation of mental or physical alertness were chosen for investigation. Liquid beverages available in polyethylene bottles and aluminum cans as well as products in the form of tablets and powder in sachets were studied. The total concentrations of 21 elements (Ag, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, Ti, V, and Zn), both essential and toxic, were simultaneously determined in preconcentrated drink samples by inductively coupled plasma-optical emission spectrometry (ICP-OES) equipped with pneumatic and ultrasonic nebulizers. Differences between the mineral compositions of isotonic and energy drinks were evaluated and discussed. The highest content of Na was found in both isotonic and energy drinks, whereas quite high concentrations of Mg were found in isotonic drinks, and the highest amount of calcium was quantified in energy drinks. The concentrations of B, Co, Cu, Ni, and P were higher in isotonic drinks, but energy drinks contained greater quantities of Ag, Cr, Zn, Mn, and Mo and toxic elements, as Cd and Pb. A comparison of element contents with micronutrient intake and tolerable levels was performed to evaluate contribution of the investigated beverages to the daily diet. The consumption of 250 cm(3) of an isotonic drink provides from 0.32% (for Mn) up to 14.8% (for Na) of the recommended daily intake. For the energy drinks, the maximum recommended daily intake fulfillment ranged from 0.02% (for V) to 19.4 or 19.8% (for Mg and Na).

  3. Impact of dietary fiber energy on the calculation of food total energy value in the Brazilian Food Composition Database.

    Science.gov (United States)

    Menezes, Elizabete Wenzel de; Grande, Fernanda; Giuntini, Eliana Bistriche; Lopes, Tássia do Vale Cardoso; Dan, Milana Cara Tanasov; Prado, Samira Bernardino Ramos do; Franco, Bernadette Dora Gombossy de Melo; Charrondière, U Ruth; Lajolo, Franco Maria

    2016-02-15

    Dietary fiber (DF) contributes to the energy value of foods and including it in the calculation of total food energy has been recommended for food composition databases. The present study aimed to investigate the impact of including energy provided by the DF fermentation in the calculation of food energy. Total energy values of 1753 foods from the Brazilian Food Composition Database were calculated with or without the inclusion of DF energy. The energy values were compared, through the use of percentage difference (D%), in individual foods and in daily menus. Appreciable energy D% (⩾10) was observed in 321 foods, mainly in the group of vegetables, legumes and fruits. However, in the Brazilian typical menus containing foods from all groups, only D%foods, when individually considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Attitudes to nuclear energy: beliefs, values and false consensus

    NARCIS (Netherlands)

    van der Pligt, J.; van der Linden, J.; Ester, P.

    1982-01-01

    Surveyed 600 persons (mean age 42.6 yrs) in 4 communities in The Netherlands within 30 miles of a nuclear power plant regarding the use of nuclear energy (NE). Results show a strong relationship between Ss' attitudes toward NE and their perceptions of its possible consequences. Ss for and against NE

  6. The cmc-value of a bolalipid with two phosphocholine headgroups and a C24 alkyl chain: Unusual binding properties of fluorescence probes to bolalipid aggregates.

    Science.gov (United States)

    Kordts, Martin; Kerth, Andreas; Drescher, Simon; Ott, Maria; Blume, Alfred

    2017-09-01

    Bolalipids with a long alkyl chain and two phosphocholine polar groups self-assemble in water into two different types of aggregate structures, namely helical nanofibers at low temperature and two types of micellar aggregates at higher temperature. We tried to determine the critical aggregation concentration (cac) or critical micellar concentration (cmc) of the bolalipid tetracosane-1,24-bis(phosphocholine) (PC-C24-PC) by using different fluorescent probes. The use of pyrene or pyrene derivatives as fluorophores failed, whereas the probes 1,8-ANS and particularly bis-ANS gave consistent results. The structure of the bolalipid aggregates obviously hinders partitioning or binding of pyrene derivatives into the micellar interior, whereas 1,8-ANS and bis-ANS can bind to the surface of the aggregate structures. The observed large increase in fluorescence intensity of bis-ANS indicates that binding to the hydrophobic surface of the aggregates leads to a reduction of the dye mobility. However, binding of bis-ANS is relatively weak, so that the determination of a cac/cmc-value is difficult. Simulations of the intensity curves for PC-C24-PC lead to estimates of the cac/cmc-value of 0.3-1.0×10 -6 M, depending on the structure of the aggregates. Single molecule fluorescence correlation spectroscopy was used to determine the mobility of bis-ANS as a function of concentration of PC-C24-PC. The dye diffusion time and the molecular brightness are lower at low bolalipid concentration, when only free dye is present, and increase at higher concentration when bis-ANS is bound to the aggregates. The experimental cac/cmc-values are higher than those estimated, using an incremental method for the change in Gibbs free energy for micellization with n-alkyl-phosphocholines with only one polar group as a comparison. Apparently, for PC-C24-PC in micellar or fibrous aggregates, more CH 2 groups are exposed to water than in a conventional micelle of an n-alkyl-phosphocholine. Copyright

  7. 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.

  8. Using physics-based pose predictions and free energy perturbation calculations to predict binding poses and relative binding affinities for FXR ligands in the D3R Grand Challenge 2

    Science.gov (United States)

    Athanasiou, Christina; Vasilakaki, Sofia; Dellis, Dimitris; Cournia, Zoe

    2018-01-01

    Computer-aided drug design has become an integral part of drug discovery and development in the pharmaceutical and biotechnology industry, and is nowadays extensively used in the lead identification and lead optimization phases. The drug design data resource (D3R) organizes challenges against blinded experimental data to prospectively test computational methodologies as an opportunity for improved methods and algorithms to emerge. We participated in Grand Challenge 2 to predict the crystallographic poses of 36 Farnesoid X Receptor (FXR)-bound ligands and the relative binding affinities for two designated subsets of 18 and 15 FXR-bound ligands. Here, we present our methodology for pose and affinity predictions and its evaluation after the release of the experimental data. For predicting the crystallographic poses, we used docking and physics-based pose prediction methods guided by the binding poses of native ligands. For FXR ligands with known chemotypes in the PDB, we accurately predicted their binding modes, while for those with unknown chemotypes the predictions were more challenging. Our group ranked #1st (based on the median RMSD) out of 46 groups, which submitted complete entries for the binding pose prediction challenge. For the relative binding affinity prediction challenge, we performed free energy perturbation (FEP) calculations coupled with molecular dynamics (MD) simulations. FEP/MD calculations displayed a high success rate in identifying compounds with better or worse binding affinity than the reference (parent) compound. Our studies suggest that when ligands with chemical precedent are available in the literature, binding pose predictions using docking and physics-based methods are reliable; however, predictions are challenging for ligands with completely unknown chemotypes. We also show that FEP/MD calculations hold predictive value and can nowadays be used in a high throughput mode in a lead optimization project provided that crystal structures of

  9. Using physics-based pose predictions and free energy perturbation calculations to predict binding poses and relative binding affinities for FXR ligands in the D3R Grand Challenge 2.

    Science.gov (United States)

    Athanasiou, Christina; Vasilakaki, Sofia; Dellis, Dimitris; Cournia, Zoe

    2018-01-01

    Computer-aided drug design has become an integral part of drug discovery and development in the pharmaceutical and biotechnology industry, and is nowadays extensively used in the lead identification and lead optimization phases. The drug design data resource (D3R) organizes challenges against blinded experimental data to prospectively test computational methodologies as an opportunity for improved methods and algorithms to emerge. We participated in Grand Challenge 2 to predict the crystallographic poses of 36 Farnesoid X Receptor (FXR)-bound ligands and the relative binding affinities for two designated subsets of 18 and 15 FXR-bound ligands. Here, we present our methodology for pose and affinity predictions and its evaluation after the release of the experimental data. For predicting the crystallographic poses, we used docking and physics-based pose prediction methods guided by the binding poses of native ligands. For FXR ligands with known chemotypes in the PDB, we accurately predicted their binding modes, while for those with unknown chemotypes the predictions were more challenging. Our group ranked #1st (based on the median RMSD) out of 46 groups, which submitted complete entries for the binding pose prediction challenge. For the relative binding affinity prediction challenge, we performed free energy perturbation (FEP) calculations coupled with molecular dynamics (MD) simulations. FEP/MD calculations displayed a high success rate in identifying compounds with better or worse binding affinity than the reference (parent) compound. Our studies suggest that when ligands with chemical precedent are available in the literature, binding pose predictions using docking and physics-based methods are reliable; however, predictions are challenging for ligands with completely unknown chemotypes. We also show that FEP/MD calculations hold predictive value and can nowadays be used in a high throughput mode in a lead optimization project provided that crystal structures of

  10. Validation of tautomeric and protomeric binding modes by free energy calculations. A case study for the structure based optimization of d-amino acid oxidase inhibitors

    Science.gov (United States)

    Orgován, Zoltán; Ferenczy, György G.; Steinbrecher, Thomas; Szilágyi, Bence; Bajusz, Dávid; Keserű, György M.

    2018-02-01

    Optimization of fragment size d-amino acid oxidase (DAAO) inhibitors was investigated using a combination of computational and experimental methods. Retrospective free energy perturbation (FEP) calculations were performed for benzo[d]isoxazole derivatives, a series of known inhibitors with two potential binding modes derived from X-ray structures of other DAAO inhibitors. The good agreement between experimental and computed binding free energies in only one of the hypothesized binding modes strongly support this bioactive conformation. Then, a series of 1-H-indazol-3-ol derivatives formerly not described as DAAO inhibitors was investigated. Binding geometries could be reliably identified by structural similarity to benzo[d]isoxazole and other well characterized series and FEP calculations were performed for several tautomers of the deprotonated and protonated compounds since all these forms are potentially present owing to the experimental pKa values of representative compounds in the series. Deprotonated compounds are proposed to be the most important bound species owing to the significantly better agreement between their calculated and measured affinities compared to the protonated forms. FEP calculations were also used for the prediction of the affinities of compounds not previously tested as DAAO inhibitors and for a comparative structure-activity relationship study of the benzo[d]isoxazole and indazole series. Selected indazole derivatives were synthesized and their measured binding affinity towards DAAO was in good agreement with FEP predictions.

  11. The role of values in public beliefs and attitudes towards commercial wind energy

    International Nuclear Information System (INIS)

    Bidwell, David

    2013-01-01

    Mandates for renewable energy lead to siting disputes, because meeting the mandates requires the development of renewable energy production facilities. Proposals for one common form of renewable energy, commercial wind farms, are frequently met with forceful local opposition. Dissatisfied with simplistic explanations for this opposition (i.e., NIMBY), social scientists have urged a more nuanced understanding of public attitudes towards wind energy and other renewables. Based on a survey of residents of coastal Michigan, this article explores the role of general values and beliefs in shaping attitudes towards the potential development of commercial wind energy projects in or near respondents’ communities. Structural equation modeling reveals that support of commercial wind energy depends largely on a belief that wind farms will provide economic benefits to the community. Underlying values have substantial and important indirect effects on beliefs regarding the likely economic outcomes of wind farm development. Altruistic values buoy wind energy attitudes, while values of traditionalism diminish wind energy support. The pivotal role of values in attitudes towards renewables lends support for more participatory development processes. - Highlights: ► Predictors of attitudes towards commercial wind energy development are examined. ► Support is influenced by beliefs in community economic benefit. ► Underlying values have substantial and important indirect effects on beliefs. ► Altruistic values buoy attitudes towards wind energy. ► Values associated with traditionalism diminish wind energy support

  12. First principle prediction of shallow defect level binding energies and deep level nonradiative recombination rates

    Science.gov (United States)

    Wang, Linwang

    2014-03-01

    Accurate calculation of defect level energies in semiconductors and their carrier capturing rate is an important issue in ab initio prediction of semiconductor properties. In this talk, I will present our result work in ab initio shallow level calculation and deep level caused nonradiative recombination rate calculation. In the shallow acceptor level calculation, a large system up to 64,000 atoms needs to be used to properly describe the weakly bounded hole wave functions. The single particle Hamiltonian of that system is patched from bulk potential and central potential. Furthermore, GW calculation is used to correct the one site potential of the impurity atom. The resulting binding energy agrees excellently with the experiments within 10 meV. To calculate the nonradiative decay rate, the electron-phonon coupling constants in the defect system are calculated all at once using a new variational algorithm. Multiphonon process formalism is used to calculate the nonradiative decay rate. It is found that the transition is induced by the electron and the optical phonon coupling, but the energy conservation is mostly satisfied by the acoustic phonons. The new algorithm allows fast calculation of such nonradiative decay rate for any defect levels, as well as other multiphonon processes in nanostructures. This work was supported by the Director, Office of Science (SC), Basic Energy Science (BES)/Materials Science and Engineering Division (MSED) of the U.S. Department of Energy (DOE) under the contract No. DE-AC02-05CH11231.

  13. The U.S. Department of Energy`s Value Engineering Program: Audit report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    Value Engineering (VE) is defined as the organized analysis of the functions of a program, project, system product, item or equipment, building, facility, service, or supply of an executive agency. This analysis reduces these functions to their most basic elements and then looks for cost-efficient alternatives. VE contributes to the overall management objectives of streamlining operations, improving performance, reliability, quality, safety and reducing life-cycle costs. Further, it can result in the increased use of environmentally-sound and energy-efficient practices and materials. VE benefits have been documented by the General Accounting Office, which reported that VE usually produces a net savings of 3 to 5 percent of project costs. The Department of Energy (Department) used the VE methodology primarily in construction related processes, including design reviews, and reported savings of $31.3 million for Fiscal Year 1996. The VE program was primarily executed by the Department`s management and operating and other prime contractors. The objectives of this review were to assess the effectiveness of the Department`s VE program and test the validity of VE savings reported for FY 1996.

  14. Estimation of the Binding Free Energy of AC1NX476 to HIV-1 Protease Wild Type and Mutations Using Free Energy Perturbation Method.

    Science.gov (United States)

    Ngo, Son Tung; Mai, Binh Khanh; Hiep, Dinh Minh; Li, Mai Suan

    2015-10-01

    The binding mechanism of AC1NX476 to HIV-1 protease wild type and mutations was studied by the docking and molecular dynamics simulations. The binding free energy was calculated using the double-annihilation binding free energy method. It is shown that the binding affinity of AC1NX476 to wild type is higher than not only ritonavir but also darunavir, making AC1NX476 become attractive candidate for HIV treatment. Our theoretical results are in excellent agreement with the experimental data as the correlation coefficient between calculated and experimentally measured binding free energies R = 0.993. Residues Asp25-A, Asp29-A, Asp30-A, Ile47-A, Gly48-A, and Val50-A from chain A, and Asp25-B from chain B play a crucial role in the ligand binding. The mutations were found to reduce the receptor-ligand interaction by widening the binding cavity, and the binding propensity is mainly driven by the van der Waals interaction. Our finding may be useful for designing potential drugs to combat with HIV. © 2015 John Wiley & Sons A/S.

  15. Energy spectrum of two-dimensional tight-binding electrons in a spatially varying magnetic field

    International Nuclear Information System (INIS)

    Oh, G.Y.; Lee, M.H.

    1996-01-01

    The electronic energy spectrum of a two-dimensional lattice in a spatially varying magnetic field is studied within the framework of the tight-binding model by using the scheme of the transfer matrix. It is found that, in comparison with the case of a uniform magnetic field, the energy spectrum exhibits more complicated behavior; band broadening (or gap closing) and band splitting (or gap opening) occur depending on characteristic parameters of the lattice. The origin of these phenomena lies in the existence of direct touching and indirect overlapping between neighboring subbands. Dependence of direct touching and indirect overlapping, and thus the electronic band structure together with the density of states, on characteristic parameters of the lattice is elucidated in detail. copyright 1996 The American Physical Society

  16. Dependence of single-walled carbon nanotube adsorption kinetics on temperature and binding energy.

    Science.gov (United States)

    Rawat, D S; Krungleviciute, V; Heroux, L; Bulut, M; Calbi, M M; Migone, A D

    2008-12-02

    We present results for the isothermal adsorption kinetics of methane, hydrogen, and tetrafluoromethane on closed-ended single-walled carbon nanotubes. In these experiments, we monitor the pressure decrease as a function of time as equilibrium is approached, after a dose of gas is added to the cell containing the nanotubes. The measurements were performed at different fractional coverages limited to the first layer. The results indicate that, for a given coverage and temperature, the equilibration time is an increasing function of E/(k(B)T), where E is the binding energy of the adsorbate and k(B)T is the thermal energy. These findings are consistent with recent theoretical predictions and computer simulations results that we use to interpret the experimental measurements.

  17. Evaluating the Value of Flexibility in Energy Regulation Markets

    DEFF Research Database (Denmark)

    Neupane, Bijay; Pedersen, Torben Bach; Thiesson, Bo

    2015-01-01

    prices. Further, we analyze the benefit for various types of flexibility and market objectives, to detect the type of energy flexibility that maximizes the benefits. Results show that if 3.87% of total demand is flexible, market can reduce the regulation cost by 49% and the regulation volume by 29.4%.......In this paper, we perform an econometric analysis on the benefits of introducing flexibility in the Danish/Nordic regulating power market. The paper investigates the relationships between market power prices and regulation volumes, in order to quantify the effects of flexibility on regulating power...

  18. Photoelectron binding energy shifts observed during oxidation of group IIA, IIIA and IVA elemental surfaces

    International Nuclear Information System (INIS)

    Heide, P.A.W. van der

    2006-01-01

    An extensive re-evaluation of XPS binding energies (BE's) and binding energy shifts (ΔBE's) from metals, oxides and the carbonates of the group II, III and IVA elements (exceptions are Be, Mg and Hf) has been carried out using a substrate specific BE referencing approach. From this, O-1s BE's are found to fall into surface oxide, bulk oxide and carbonate groupings, with bulk oxides showing the lowest BE's followed by surface oxides (+∼1.5 eV) and then carbonates (+∼3.0 eV). The O-1s BE's from the bulk oxides also appear to scale with 1/d, where d is inter-atomic distance. The same is noted in the ΔBE's observed from the metallic counterparts during oxidation of the elemental surfaces. This, and the decreasing BE exhibited by Ca, Sr and Ba on oxidation is explained within the charge potential model as resulting from competing inter- and intra-atomic effects, and is shown to be consistent with partial covalency arguments utilizing Madulung potentials. The ΔBE's also fall into groups according to the elements location in the periodic table, i.e. s, p or d block. These trends open up the possibility of approximating ΔBE's arising from initial and final state effects, and bond distances

  19. Energy renovation of multi-storey buildings with heritage value

    DEFF Research Database (Denmark)

    Harrestrup, Maria

    multi-storey buildings when the buildings undergo various levels of renovation. The investigation aimed at keeping the existing heating system and the existing district heating distribution network. Theoretical investigations showed that low-temperature district heating can be supplied to existing...... on the market today for heritage-valued buildings have still not been documented to the extent needed for the building sector to take responsibility for applying them on a large scale. While old heritage buildings have similar constructional trends, each is unique in its specific design, so solutions...

  20. A comparison of the European renewable energy directive default emission values with actual values from operating biodiesel facilities for sunflower, rape and soya oil seeds in Italy

    International Nuclear Information System (INIS)

    Buratti, C.; Barbanera, M.; Fantozzi, F.

    2012-01-01

    The European Union (EU) set a binding greenhouse gas (GHG) emission reduction target for transportation biofuels and other bioliquids. In this study, the GHG emissions of biodiesel chain from sunflower, rapeseed and soybean were calculated in compliance with the European Union Renewable Energy Directive 2009/28/EC (RED). Input data used for the agricultural step were referred to the Umbrian region for sunflower and rapeseed and to the Veneto region for soybean, while data obtained from the main Italian biodiesel plants were employed for the processing step. Results showed that GHG emissions were higher than default values reported in the RED for sunflower and rapeseed and lower for soybean. Only sunflower biodiesel does not reach the minimum value of GHG saving (35%). The main differences with data used in the RED concern cultivation step, while the processing step has overall the same values of GHG emissions. Finally, three case studies were examined in order to identify possible improvements to make the analyzed supply chains more sustainable. -- Highlights: ► GHG balance of biodiesel from sunflower, rapeseed and soya was analyzed. ► Cultivation has the highest environmental impact for sunflower and rapeseed chains. ► Typical Italian data were adopted for cultivation and processing steps. ► GHG emissions were lower than RED default values for soya biodiesel. ► Cogeneration for the processing plant can greatly increase GHG saving.

  1. 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

    2015-01-08

    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.

  2. Investment, firm value, and risk for a system operator balancing energy grids

    International Nuclear Information System (INIS)

    Dockner, Engelbert J.; Kucsera, Dénes; Rammerstorfer, Margarethe

    2013-01-01

    With the liberalization of energy markets integrated energy companies have separated into entities that specialize in production and/or transmission of energy. Transmission of energy requires balancing the grid to guarantee system security, which is performed by the (independent) system operator (SO). When the SO faces stochastic demand, grid balancing has sizeable consequences on current and future profits, and hence, on firm value and firm risk. We explore these value and risk consequences with and without an investment option to expand transmission capacity. We show that firm value consists of the value of the transmission capacity in place plus the value of a short put and a short call option that are the result of the SO's balancing actions. Firm risk without investment option is non-linear and determined by the short option positions. It is decreasing with increasing energy demand. The existence of an option to expand transmission capacity increases firm value and firm risk. - Highlights: ► Grid balancing under stochastic demand affect current and future revenues, and firm value and firm risk. ► Balancing firm value consists of the value of the transmission capacity plus the value of a short strangle. ► Firm risk without investment option is determined by the short strangle and decreasing with increasing energy demand. ► The existence of an expansion option implies that transmission capacity increases firm value and firm risk

  3. Binding of sodium dodecyl sulfate with linear and branched polyethyleneimines in aqueous solution at different pH values.

    Science.gov (United States)

    Wang, Hao; Wang, Yilin; Yan, Haike; Zhang, Jin; Thomas, Robert K

    2006-02-14

    Isothermal titration microcalorimetry (ITC), conductivity, and turbidity measurements have been carried out to study the interaction of sodium dodecyl sulfate (SDS) with polyethyleneimines (PEI) including linear PEI and branched PEI at different pH values of 3, 7, and 10. In all cases, the polymers show a remarkable affinity toward SDS. At pH 3, the polymer PEI is a strong polycation, and the binding is dominated by electrostatic 1:1 charge neutralization with the anionic surfactant. At pH 7, the electrostatic attraction between SDS and PEI is weak, and the hydrophobic interaction becomes stronger. At the natural pH of 10, PEI is essentially nonionic and binds SDS in the form of polymer-bound surfactant aggregates. The charge neutralization concentration (C1) of SDS for the PEI-SDS complex can be derived from the curves of variation of the enthalpy, conductivity, and turbidity with SDS concentration. There is good agreement between the results from the three methods and all show a decrease with increasing pH. The total interaction enthalpies (deltaH(total)) of PEI with SDS are obtained from the observed enthalpy curves and the difference enthalpy (deltaH*) between the total enthalpy of branched PEI with SDS, and the total enthalpy of linear PEI with SDS can be derived from the obtained deltaH(total). The difference deltaH* increases dramatically as pH increases, which indicates that the interactions are different for linear PEI and branched PEI at high pH values. A schematic map of the different states of aggregation is presented.

  4. Molecular dynamics and MM/GBSA-integrated protocol probing the correlation between biological activities and binding free energies of HIV-1 TAR RNA inhibitors.

    Science.gov (United States)

    Peddi, Saikiran Reddy; Sivan, Sree Kanth; Manga, Vijjulatha

    2018-02-01

    The interaction of HIV-1 transactivator protein Tat with its cognate transactivation response (TAR) RNA has emerged as a promising target for developing antiviral compounds and treating HIV infection, since it is a crucial step for efficient transcription and replication. In the present study, molecular dynamics (MD) simulations and MM/GBSA calculations have been performed on a series of neamine derivatives in order to estimate appropriate MD simulation time for acceptable correlation between ΔG bind and experimental pIC 50 values. Initially, all inhibitors were docked into the active site of HIV-1 TAR RNA. Later to explore various conformations and examine the docking results, MD simulations were carried out. Finally, binding free energies were calculated using MM/GBSA method and were correlated with experimental pIC 50 values at different time scales (0-1 to 0-10 ns). From this study, it is clear that in case of neamine derivatives as simulation time increased the correlation between binding free energy and experimental pIC 50 values increased correspondingly. Therefore, the binding energies which can be interpreted at longer simulation times can be used to predict the bioactivity of new neamine derivatives. Moreover, in this work, we have identified some plausible critical nucleotide interactions with neamine derivatives that are responsible for potent inhibitory activity. Furthermore, we also provide some insights into a new class of oxadiazole-based back bone cyclic peptides designed by incorporating the structural features of neamine derivatives. On the whole, this approach can provide a valuable guidance for designing new potent inhibitors and modify the existing compounds targeting HIV-1 TAR RNA.

  5. Analysis on Binding Energy and Auger Parameter for Estimating Size and Stoichiometry of ZnO Nanorods

    Directory of Open Access Journals (Sweden)

    Santanu Bera

    2012-01-01

    Full Text Available ZnO nanorods prepared through chemical vapor deposition technique are characterized by microscopic and X-ray photoelectron spectroscopy (XPS techniques to correlate the effects of size on the binding energy of Zn 2p3/2 photoelectrons. A positive shift in Zn 2p3/2-binding energy as compared to that in bulk ZnO is assumed to be the effect of size of ZnO tips. The shift in binding energy has been explained in terms of relaxation energy in the photoemission process. Simultaneously, Auger parameter of the nanorods is evaluated for stoichiometric composition. The extra peak in O1s spectrum of nanorods is explained as adsorbed O-bearing species or surface contaminants.

  6. Relation between heat of vaporization, ion transport, molar volume, and cation-anion binding energy for ionic liquids.

    Science.gov (United States)

    Borodin, Oleg

    2009-09-10

    A number of correlations between heat of vaporization (H(vap)), cation-anion binding energy (E(+/-)), molar volume (V(m)), self-diffusion coefficient (D), and ionic conductivity for 29 ionic liquids have been investigated using molecular dynamics (MD) simulations that employed accurate and validated many-body polarizable force fields. A significant correlation between D and H(vap) has been found, while the best correlation was found for -log(DV(m)) vs H(vap) + 0.28E(+/-). A combination of enthalpy of vaporization and a fraction of the cation-anion binding energy was suggested as a measure of the effective cohesive energy for ionic liquids. A deviation of some ILs from the reported master curve is explained based upon ion packing and proposed diffusion pathways. No general correlations were found between the ion diffusion coefficient and molecular volume or the diffusion coefficient and cation/anion binding energy.

  7. Beyond cost-of-energy, the value-of-energy metric and value-centric approaches to design, operations, and maintenance of wind turbines

    Science.gov (United States)

    Fernandes, Kevin

    This thesis is oriented toward developers, owners, operators and investors of renewable energy projects. With increasing demand of renewables, our energy dependence comes down to reducing costs associated with this sector so as to compete with the existing sources. One way of valuing investment potential is to determine and then compare the overall value derived by investing in a particular project. Several engineering and financial levers, one of which is operation and maintenance, affect this value. This thesis provides a useful visual aid to owners and operators by which they can operate and maintain their wind farm so as to achieve maximum value throughout its lifetime. All the necessary components that go into developing a business model of a wind farm project will be discussed. Finally, this tool is valid within the assumptions that are explicitly stated. Real world data and trends are used to provide a practical approach to the optimization.

  8. A Simple PB/LIE Free Energy Function Accurately Predicts the Peptide Binding Specificity of the Tiam1 PDZ Domain

    Directory of Open Access Journals (Sweden)

    Nicolas Panel

    2017-09-01

    Full Text Available PDZ domains generally bind short amino acid sequences at the C-terminus of target proteins, and short peptides can be used as inhibitors or model ligands. Here, we used experimental binding assays and molecular dynamics simulations to characterize 51 complexes involving the Tiam1 PDZ domain and to test the performance of a semi-empirical free energy function. The free energy function combined a Poisson-Boltzmann (PB continuum electrostatic term, a van der Waals interaction energy, and a surface area term. Each term was empirically weighted, giving a Linear Interaction Energy or “PB/LIE” free energy. The model yielded a mean unsigned deviation of 0.43 kcal/mol and a Pearson correlation of 0.64 between experimental and computed free energies, which was superior to a Null model that assumes all complexes have the same affinity. Analyses of the models support several experimental observations that indicate the orientation of the α2 helix is a critical determinant for peptide specificity. The models were also used to predict binding free energies for nine new variants, corresponding to point mutants of the Syndecan1 and Caspr4 peptides. The predictions did not reveal improved binding; however, they suggest that an unnatural amino acid could be used to increase protease resistance and peptide lifetimes in vivo. The overall performance of the model should allow its use in the design of new PDZ ligands in the future.

  9. A Simple PB/LIE Free Energy Function Accurately Predicts the Peptide Binding Specificity of the Tiam1 PDZ Domain.

    Science.gov (United States)

    Panel, Nicolas; Sun, Young Joo; Fuentes, Ernesto J; Simonson, Thomas

    2017-01-01

    PDZ domains generally bind short amino acid sequences at the C-terminus of target proteins, and short peptides can be used as inhibitors or model ligands. Here, we used experimental binding assays and molecular dynamics simulations to characterize 51 complexes involving the Tiam1 PDZ domain and to test the performance of a semi-empirical free energy function. The free energy function combined a Poisson-Boltzmann (PB) continuum electrostatic term, a van der Waals interaction energy, and a surface area term. Each term was empirically weighted, giving a Linear Interaction Energy or "PB/LIE" free energy. The model yielded a mean unsigned deviation of 0.43 kcal/mol and a Pearson correlation of 0.64 between experimental and computed free energies, which was superior to a Null model that assumes all complexes have the same affinity. Analyses of the models support several experimental observations that indicate the orientation of the α 2 helix is a critical determinant for peptide specificity. The models were also used to predict binding free energies for nine new variants, corresponding to point mutants of the Syndecan1 and Caspr4 peptides. The predictions did not reveal improved binding; however, they suggest that an unnatural amino acid could be used to increase protease resistance and peptide lifetimes in vivo . The overall performance of the model should allow its use in the design of new PDZ ligands in the future.

  10. Glucose Sensors Based on Microcapsules Containing an Orange/Red Competitive Binding Resonance Energy Transfer Assay

    Science.gov (United States)

    CHINNAYELKA, SWETHA; McSHANE, and MICHAEL J.

    2015-01-01

    Fluorescent sensing systems offer the potential for noninvasive monitoring with implantable devices, but they require carrier technologies that provide suitable immobilization, accessibility, and biocompatibility while maintaining adequate response characteristics. A recent development towards this goal is a highly specific and sensitive competitive binding assay for glucose using apo-glucose oxidase (apo-GOx) as the recognition element and dextran as the competing ligand; this has been demonstrated as a glucose sensor system by encapsulating the competitive binding assay in semipermeable microcapsule carriers. This paper describes the extension of this sensor design to longer wavelengths in an attempt to increase the applicability to in vivo monitoring. The glucose sensitivity of the tetramethylrhodamine isothiocyanate-dextran (TD) and cyanine Cy5-apo-GOx (CAG) complexes showed five to 10 times greater specificity for β-D-glucose over other sugars. Microcapsules loaded with TD/CAG complexes exhibited a linear, totally reversible response in the range of 0–720 mg/dL, with a sensitivity (percent change in intensity ratio) of 0.06%/(mg/dL). The decrease in sensitivity observed with the use of longer-wavelength dyes is most likely to be compensated with the deeper penetration of light and reduced tissue scattering. These findings imply that the encapsulation of sensing assay elements in microcapsules is a simple and translatable method for the fabrication of stable biosensors, and optimization of resonance energy transfer pairs and assay component preparation will further improve the response to approach clinically relevant performance. PMID:16800748

  11. Interband absorption and exciton binding energy in an inverse parabolic quantum well under the magnetic field

    International Nuclear Information System (INIS)

    Kasapoglu, E.; Soekmen, I.

    2007-01-01

    We have investigated the effects of the magnetic field which is applied perpendicular to the growth direction of the well on the interband absorption and on the binding energy of the excitons in an GaAs/Ga 1-x Al x As inverse parabolic quantum well (IPQW) with different widths as well as different Al concentrations at the well center. The calculations were performed within the effective mass approximation, using a variational method. We observe that IPQW structure turns into parabolic quantum well with the inversion effect of the magnetic field and the effective band gap of the system can be modified by changing Al concentration at the well center, the strength of the magnetic field and well dimensions. This case directly influences the nature of electronic and optical properties in this structure

  12. Estimating Parameter Uncertainty in Binding-Energy Models by the Frequency-Domain Bootstrap

    Science.gov (United States)

    Bertsch, G. F.; Bingham, Derek

    2017-12-01

    We propose using the frequency-domain bootstrap (FDB) to estimate errors of modeling parameters when the modeling error is itself a major source of uncertainty. Unlike the usual bootstrap or the simple χ2 analysis, the FDB can take into account correlations between errors. It is also very fast compared to the Gaussian process Bayesian estimate as often implemented for computer model calibration. The method is illustrated with a simple example, the liquid drop model of nuclear binding energies. We find that the FDB gives a more conservative estimate of the uncertainty in liquid drop parameters than the χ2 method, and is in fair accord with more empirical estimates. For the nuclear physics application, there are no apparent obstacles to apply the method to the more accurate and detailed models based on density-functional theory.

  13. 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.

  14. Scaling Universality between Band Gap and Exciton Binding Energy of Two-Dimensional Semiconductors

    Science.gov (United States)

    Jiang, Zeyu; Liu, Zhirong; Li, Yuanchang; Duan, Wenhui

    2017-06-01

    Using first-principles G W Bethe-Salpeter equation calculations and the k .p theory, we unambiguously show that for two-dimensional (2D) semiconductors, there exists a robust linear scaling law between the quasiparticle band gap (Eg) and the exciton binding energy (Eb), namely, Eb≈Eg/4 , regardless of their lattice configuration, bonding characteristic, as well as the topological property. Such a parameter-free universality is never observed in their three-dimensional counterparts. By deriving a simple expression for the 2D polarizability merely with respect to Eg, and adopting the screened hydrogen model for Eb, the linear scaling law can be deduced analytically. This work provides an opportunity to better understand the fantastic consequence of the 2D nature for materials, and thus offers valuable guidance for their property modulation and performance control.

  15. 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.

  16. 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.

  17. Values, environmental concern, and environmental behavior : A study into household energy use

    NARCIS (Netherlands)

    Poortinga, Wouter; Steg, Linda; Vlek, Charles

    In this study, the role of values in the field of household energy use is investigated by using the concept of quality of life (QOL). Importance judgments on QOL aspects could be summarized into seven clearly interpretable value dimensions. The seven value dimensions and general and specific

  18. [Diagnostic values of prealbumin and retinol-binding protein for liver damage caused by different degrees of neonatal asphyxia].

    Science.gov (United States)

    Zou, Yun-Su; Guo, Yan; Cheng, Rui; Zhou, Xiao-Guang; Cao, Zhao-Lan

    2017-03-01

    To investigate the diagnostic values of prealbumin (PAB) and retinol-binding protein (RBP) for liver damage caused by mild or severe asphyxia. A retrospective analysis was performed on 185 neonates (including 84 premature infants and 101 full-term infants) with asphyxia. Based on the Apgar score, they were divided into two groups: mild asphyxia group (n=150) and severe asphyxia group (n=35). The levels of PAB, RBP, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured and compared. Their diagnostic values for liver damage were evaluated by ROC curve analysis. The premature infants in the severe asphyxia group had significantly higher AST level and significantly lower levels of PAB and RBP than those in the mild asphyxia group (Pasphyxia group had a significantly lower PAB level than those in the mild asphyxia group (Pasphyxia group and in the full-term infants in both mild and severe asphyxia group (Pasphyxia groups also showed a significant improvement in AST level (Pasphyxia in full-term and preterm infants. PAB can be used as an indicator of liver damage caused by asphyxia in neonates, and can be used to assess the degree of asphyxia.

  19. 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

  20. Potential energy surface and binding energy in the presence of an external electric field: modulation of anion-π interactions for graphene-based receptors.

    Science.gov (United States)

    Foroutan-Nejad, Cina; Marek, Radek

    2014-02-14

    Measuring the binding energy or scanning the potential energy surface (PES) of the charged molecular systems in the presence of an external electric field (EEF) requires a careful evaluation of the origin-dependency of the energy of the system and references. Scanning the PES for charged or purely ionic systems for obtaining the intrinsic energy barriers needs careful analysis of the electric work applied on ions by the EEF. The binding energy in the presence of an EEF is different from that in the absence of an electric field as the binding energy is an anisotropic characteristic which depends on the orientation of molecules with respect to the EEF. In this contribution we discuss various aspects of the PES and the concept of binding energy in the presence of an EEF. In addition, we demonstrate that the anion-π bonding properties can be modulated by applying a uniform EEF, which has a more pronounced effect on the larger, more polarizable π-systems. An analogous behavior is presumed for cation-π systems. We predict that understanding the phenomenon introduced in the present account has enormous potential, for example, for separating charged species on the surface of polarizable two-dimensional materials such as graphene or the surface of carbon nanotubes, in desalination of water.

  1. 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......Predicting binding affinities for receptor-ligand complexes is still one of the challenging processes in computational structure-based ligand design. Many computational methods have been developed to achieve this goal, such as docking and scoring methods, the linear interaction energy (LIE) method...

  2. 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

  3. Social values and solar energy policy: the policy maker and the advocate

    Energy Technology Data Exchange (ETDEWEB)

    Shama, A.; Jacobs, K.

    1980-07-01

    Solar energy policy makers and advocates have significantly different hierarchies (clusters) of values upon which they evaluate the adoption of solar technologies. Content analysis, which examines the frequency with which policy makers identify different types of values, indicates that they hold economic values to be of primary importance. Environmental, social, and national security values are also substantial elements of the policy makers' value clusters associated with solar energy. This finding is confirmed by a qualitative analysis of policy makers' values. Advocates, on the other hand, assign almost equal weights (33%) to economic values and social values, slightly less weight to environmental values, and significant attention to ethical and security values as well. These results of frequency analysis are made somewhat more complicated by a qualitative interpretation of the advocates' positions. As part of their more holistic approach, several of the advocates indicated that all values discussed by them are instrumental toward achieving higher-order, ethical and environmental values. In addition, our preliminary investigation indicates that neither group is entirely homogeneous. Testing this and other propositions, as well as obtaining a similar picture of the values which the public associates with solar energy, are topics of future research.

  4. [Prognostic value of lipopolysaccharide binding protein and procalcitonin in patients with severe sepsis and septic shock admitted to intensive care].

    Science.gov (United States)

    García de Guadiana-Romualdo, L M; Rebollo-Acebes, S; Esteban-Torrella, P; Jiménez-Sánchez, R; Hernando-Holgado, A; Ortín-Freire, A; Viqueira-González, M; Trujillo-Santos, J; Jiménez Santos, E; Pedregosa Díaz, J; Albaladejo-Otón, M D; Allegue-Gallego, J M

    2015-05-01

    1) To assess the prognostic value of levels on admission and serial measurements of lipopolysaccharide binding protein (LBP) and procalcitonin (PCT) in relation to in-hospital mortality; and 2) to determine whether the addition of these parameters to severity scores (APACHE II and SOFA) is able to improve prognostic accuracy. A single-center, prospective observational study was carried out. Intensive Care unit of a university hospital. One hundred severe sepsis and septic shock patients were included. Demographic data, APACHE II and SOFA scores, PCT and LBP levels on admission and after 48 hours, and in-hospital mortality. The best area under the curve for predicting in-hospital mortality corresponded to APACHE II on admission and SOFA after 48 h (AUC ROC: 0.75 for both). PCT and LBP levels on admission and LBP clearance were not statistically different between in-hospital survivors and non-survivors. Only PCT clearance was higher among in-hospital survivors than in non-survivors (AUC ROC: 0.66). The combination of severity scores and PCT clearance did not result in superior areas under the curve. LBP and PCT levels on admission and LBP clearance showed no prognostic value in severe sepsis and septic shock patients. Only PCT clearance was predictive of in-hospital mortality. The prognostic accuracy was significantly better for APACHE on admission and SOFA after 48 h than for any of the analyzed biomarkers, and the addition of PCT clearance did not improve their prognostic value. Copyright © 2013 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  5. Enhancing shareholder value: Making a more compelling energy efficiency case to industry by quantifying non-energy benefits

    International Nuclear Information System (INIS)

    Pye, M.; McKane, A.

    1999-01-01

    This paper describes a more compelling case for industry to promote the non-energy benefits of energy efficiency investments. They do this in two ways to actively appeal to chief executive officers' (CEOs') and chief financial officers' (CFOs') primary responsibility: to enhance shareholder value. First, they describe the use of a project-by-project corporate financial analysis approach to quantify a broader range of productivity benefits that stem from investments in energy-efficient technologies, including waste reduction and pollution prevention. Second, and perhaps just as important, they present such information in corporate financial terms. These standard, widely accepted analysis procedures are more credible to industry than the economic modeling done in the past because they are structured in the same way corporate financial analysts perform discounted cashflow investment analyses on individual projects. Case studies including such financial analyses, which quantify both energy and non-energy benefits from investments in energy-efficient technologies, are presented. Experience shows that energy efficiency projects' non-energy benefits often exceed the value of energy savings, so energy savings should be viewed more correctly as part of the total benefits, rather than the focus of the results. Quantifying the total benefits of energy efficiency projects helps companies understand the financial opportunities of investments in energy-efficient technologies. Making a case for investing in energy-efficient technologies based on energy savings alone has not always proven successful. Evidence suggests, however, that industrial decision makers will understand energy efficiency investments as part of a broader set of parameters that affect company productivity and profitability

  6. Comparison of gas-solid chromatography and MM2 force field molecular binding energies for greenhouse gases on a carbonaceous surface.

    Science.gov (United States)

    Rybolt, Thomas R; Bivona, Kevin T; Thomas, Howard E; O'Dell, Casey M

    2009-10-01

    Gas-solid chromatography was used to determine B(2s) (gas-solid virial coefficient) values for eight molecular adsorbates interacting with a carbon powder (Carbopack B, Supelco). B(2s) values were determined by multiple size variant injections within the temperature range of 313-553 K. The molecular adsorbates included: carbon dioxide (CO(2)); tetrafluoromethane (CF(4)); hexafluoroethane (C(2)F(6)); 1,1-difluoroethane (C(2)H(4)F(2)); 1-chloro-1,1-difluoroethane (C(2)H(3)ClF(2)); dichlorodifluoromethane (CCl(2)F(2)); trichlorofluoromethane (CCl(3)F); and 1,1,1-trichloroethane (C(2)H(3)Cl(3)). Two of these molecules are of special interest because they are "super greenhouse gases". The global warming potential, GWP, for CF(4) is 6500 and for C(2)F(6) is 9200 relative to the reference value of 1 for CO(2). The GWP index considers both radiative blocking and molecular lifetime. For these and other industrial greenhouse gases, adsorptive trapping on a carbonaceous solid, which depends on molecule-surface binding energy, could avoid atmospheric release. The temperature variations of the gas-solid virial coefficients in conjunction with van't Hoff plots were used to find the experimental adsorption energy or binding energy values (E(*)) for each adsorbate. A molecular mechanics based, rough-surface model was used to calculate the molecule-surface binding energy (Ecal(*)) using augmented MM2 parameters. The surface model consisted of parallel graphene layers with two separated nanostructures each containing 17 benzene rings arranged in linear strips. The separation of the parallel nanostructures had been optimized in a prior study to appropriately represent molecule-surface interactions for Carbopack B. Linear regressions of E(*) versus Ecal(*) for the current data set of eight molecules and the same surface model gave E(*)=0.926 Ecal(*) and r(2)=0.956. A combined set of the current and prior Carbopack B adsorbates studied (linear alkanes, branched alkanes, cyclic alkanes

  7. Impact of energy efficiency measures on the economic value of buildings

    International Nuclear Information System (INIS)

    Popescu, Daniela; Bienert, Sven; Schuetzenhofer, Christian; Boazu, Rodica

    2012-01-01

    Highlights: → Market driven reasons can strengthen implementation of energy policies in buildings. → Methods that quantify the added value due to energy performance are developed. → Recommendations on how they can be incorporated in the financial analysis are presented. → Case studies on some existing condominiums from Romania are analyzed. → The market sensitivity to energy efficiency measures is also in the focus. -- Abstract: A main objective of energy policies is to make all levels of the society, from governments to citizen, interested in increasing the energy efficiency of buildings. One of the most important barriers in implementation of energy policies is that the cost of potential energy savings, typically considered being the only financial benefit, does not sufficiently motivate investments. The target is therefore to identify further possible drivers pushing positive reaction according to energy saving action. The paper discusses whether a market-based instrument, capturing the increase of the economic value of energy efficient buildings, can be also used. Methods that quantify the added value due to energy performance, including recommendations on how they can be incorporated in the financial analysis of investments in weatherization, are developed. By applying the proposed methods, the payback period of investments in energy efficiency measures depends on two factors: potential energy savings and the added value to the property. Case studies on some existing condominiums from Romania are analyzed and provide evidence to the research question. The market sensitivity to energy efficiency measures, the possibility of an intangible added value as well as the impact to financial investment decisions is subsequently in the focus.

  8. A self-interaction-free local hybrid functional: Accurate binding energies vis-à-vis accurate ionization potentials from Kohn-Sham eigenvalues

    International Nuclear Information System (INIS)

    Schmidt, Tobias; Kümmel, Stephan; Kraisler, Eli; Makmal, Adi; Kronik, Leeor

    2014-01-01

    We present and test a new approximation for the exchange-correlation (xc) energy of Kohn-Sham density functional theory. It combines exact exchange with a compatible non-local correlation functional. The functional is by construction free of one-electron self-interaction, respects constraints derived from uniform coordinate scaling, and has the correct asymptotic behavior of the xc energy density. It contains one parameter that is not determined ab initio. We investigate whether it is possible to construct a functional that yields accurate binding energies and affords other advantages, specifically Kohn-Sham eigenvalues that reliably reflect ionization potentials. Tests for a set of atoms and small molecules show that within our local-hybrid form accurate binding energies can be achieved by proper optimization of the free parameter in our functional, along with an improvement in dissociation energy curves and in Kohn-Sham eigenvalues. However, the correspondence of the latter to experimental ionization potentials is not yet satisfactory, and if we choose to optimize their prediction, a rather different value of the functional's parameter is obtained. We put this finding in a larger context by discussing similar observations for other functionals and possible directions for further functional development that our findings suggest

  9. Nutritive value and energy content of the straw of selected Vicia L. taxa from Tunisia

    Directory of Open Access Journals (Sweden)

    Riccardo Fortina

    2015-07-01

    Full Text Available The chemical composition and energy value of straws of Vicia sativa L. (varieties Languedoc and Mghila, and subspecies amphicarpa and Vicia villosa Roth. (variety Sejenane and accession 2565 were investigated. The plants were grown in a Mediterranean environment, under identical environmental conditions. Total digestible nutrients (TDN and energy values (digestible energy, metabolisable energy, and net energy for lactation were estimated according to the equations developed by the 2001 Dairy National Research Council. Both ether extract (EE or total fatty acids (FA amounts, and digestible neutral detergent fibre (dNDF calculated from chemical analysis or measured using a 48-hour rumen in vitro assay were used for calculations. Significant differences were observed in the chemical composition and energy value of the straws of the considered V. sativa and V. villosa varieties. Within the same variety, the TDN was similar using either EE or FA values for calculation. The energy resulted largely dependent on the dNDF values. Energy was higher when in vitro dNDF was used for calculation in low-NDF straw samples, while the opposite occurred for high-NDF samples.

  10. Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

    KAUST Repository

    Park, Soohyung

    2018-01-03

    Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron–hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

  11. Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

    Science.gov (United States)

    Park, Soohyung; Mutz, Niklas; Schultz, Thorsten; Blumstengel, Sylke; Han, Ali; Aljarb, Areej; Li, Lain-Jong; List-Kratochvil, Emil J. W.; Amsalem, Patrick; Koch, Norbert

    2018-04-01

    Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron-hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

  12. Binding Analysis of Some Classical Acetylcholinesterase Inhibitors: Insights for a Rational Design Using Free Energy Perturbation Method Calculations with QM/MM MD Simulations.

    Science.gov (United States)

    Nascimento, Érica C M; Oliva, Mónica; Świderek, Katarzyna; Martins, João B L; Andrés, Juan

    2017-04-24

    In the present study, the binding free energy of some classical inhibitors (DMT, DNP, GNT, HUP, THA) with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation (FEP) method based on hybrid quantum mechanics and molecular mechanics (QM/MM) potentials. The results highlight the key role of the van der Waals interaction for the inhibition process, since the contribution of this term to the binding free energy is almost as decisive as the electrostatic one. The analysis of the geometrical parameters and the interaction energy per residue along the QM/MM molecular dynamics (MD) simulations highlights the most relevant interactions in the different AChE-ligand systems, showing that the charged residues with a more prominent contribution to the interaction energy are Asp72 and Glu199, although the relative importance depends on the molecular size of the ligand. A correlation between the binding free energy and the number of cation-π interactions present in the systems has been established, DMT being the most potent inhibitor, capable of forming four cation-π interactions. A layer of water molecules surrounding the inhibitors has been observed, which act as bridges along a network formed by the ligands and the residues of the gorge and also between different residues. Although several hydrogen bonds between ligands and AChE do appear, no significant values of BIEs have been recorded. This behavior can be accounted for by the special features of AChE, such as the presence of several subsites of different natures in the gorge or the existence of several water molecules that act as bridges in the electrostatic interactions.

  13. Selective binding of pyrene in subdomain IB of human serum albumin: Combining energy transfer spectroscopy and molecular modelling to understand protein binding flexibility

    Science.gov (United States)

    Ling, Irene; Taha, Mohamed; Al-Sharji, Nada A.; Abou-Zied, Osama K.

    2018-04-01

    The ability of human serum albumin (HSA) to bind medium-sized hydrophobic molecules is important for the distribution, metabolism, and efficacy of many drugs. Herein, the interaction between pyrene, a hydrophobic fluorescent probe, and HSA was thoroughly investigated using steady-state and time-resolved fluorescence techniques, ligand docking, and molecular dynamics (MD) simulations. A slight quenching of the fluorescence signal from Trp214 (the sole tryptophan residue in the protein) in the presence of pyrene was used to determine the ligand binding site in the protein, using Förster's resonance energy transfer (FRET) theory. The estimated FRET apparent distance between pyrene and Trp214 was 27 Å, which was closely reproduced by the docking analysis (29 Å) and MD simulation (32 Å). The highest affinity site for pyrene was found to be in subdomain IB from the docking results. The calculated equilibrium structure of the complex using MD simulation shows that the ligand is largely stabilized by hydrophobic interaction with Phe165, Phe127, and the nonpolar moieties of Tyr138 and Tyr161. The fluorescence vibronic peak ratio I1/I3 of bound pyrene inside HSA indicates the presence of polar effect in the local environment of pyrene which is less than that of free pyrene in buffer. This was clarified by the MD simulation results in which an average of 5.7 water molecules were found within 0.5 nm of pyrene in the binding site. Comparing the fluorescence signals and lifetimes of pyrene inside HSA to that free in buffer, the high tendency of pyrene to form dimer was almost completely suppressed inside HSA, indicating a high selectivity of the binding pocket toward pyrene monomer. The current results emphasize the ability of HSA, as a major carrier of several drugs and ligands in blood, to bind hydrophobic molecules in cavities other than subdomain IIA which is known to bind most hydrophobic drugs. This ability stems from the nature of the amino acids forming the binding

  14. Generating Community, Generating Justice? The production and circulation of value in community energy initiatives

    Directory of Open Access Journals (Sweden)

    Taylor Chase Dotson

    2016-12-01

    Full Text Available In this paper, we explore the potentialities and interconnections between existing and hypothetical community energy systems and the concept of generative justice. New York State’s more recent official energy plan, for instance, includes provisions for community-scale microgrids, and several European nations offer significant financial support to citizens interested in building micro and intermediate-scale renewable energy systems. Such efforts and technologies appear to promise some degree of generative justice, returning much of the value generated by distributed renewable energy back to the community producing it. However, most currently conceived and implemented community energy systems recirculate value in very narrow and limited ways. Building upon an analysis of New York energy policy and on-the-ground cases, we explore community energy’s potential. What kinds of value are being generated by community energy systems and for whom? How could such efforts be more generative of justice across a broad range of values, not just electrons and dollars? Through the attempt to broaden thinking not only about community energy systems but also the concept of generative justice, we connect technological and organizational configurations of community energy systems and the forms of value they have the potential to generate: including, the production of grassroots energy and organizational expertise, the capacity for local and personal autonomy in energy planning and decision-making, and the enhancement of an affective sense and embodied experience of community. Finally, we examine some of the barriers to realizing more generatively just community energy systems. 

  15. Specific interactions and binding energies between thermolysin and potent inhibitors: molecular simulations based on ab initio molecular orbital method.

    Science.gov (United States)

    Hirakawa, Tatsuya; Fujita, Seiya; Ohyama, Tatsuya; Dedachi, Kenichi; Khan, Mahmud Tareq Hassan; Sylte, Ingebrigt; Kurita, Noriyuki

    2012-03-01

    Biochemical functions of the metalloprotease thermolysin (TLN) are controlled by various inhibitors. In a recent study we identified 12 compounds as TLN inhibitors by virtual screening and in vitro competitive binding assays. However, the specific interactions between TLN and these inhibitors have not been clarified. We here investigate stable structures of the solvated TLN-inhibitor complexes by classical molecular mechanics simulations and elucidate the specific interactions between TLN and these inhibitors at an electronic level by using ab initio fragment molecular orbital (FMO) calculations. The calculated binding energies between TLN and the inhibitors are qualitatively consistent with the experimental results, and the FMO results elucidate important amino acid residues of TLN for inhibitor binding. Based on the calculated results, we propose a novel potent inhibitor having a large binding affinity to TLN. Copyright © 2011 Elsevier Inc. All rights reserved.

  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. Binding energies and isomerization in metallocene ions from threshold photoelectron photoion coincidence spectroscopy.

    Science.gov (United States)

    Révész, Agnes; Szepes, László; Baer, Tomas; Sztáray, Bálint

    2010-12-22

    Metallocene ions (Cp(2)M(+), M = Cr, Co, Ni) were studied by threshold photoelectron photoion coincidence spectroscopy (TPEPICO) to investigate the mechanism, energetics, and kinetics of the ionic dissociation processes. The examined energy-selected Cp(2)M(+) ions fragment by losing the neutral cyclopentadienyl ligand. In addition, CH and C(2)H(2) losses appear as minor channels, while the cobaltocene ion also loses an H atom. A possible isomerization pathway has also been observed for Cp(2)Ni(+), yielding a complex with pentafulvalene (C(10)H(8)) with a loss of H(2). In order to determine the 0 K appearance energies for the CpM(+) fragment ions, the asymmetric time-of-flight peak shapes and the breakdown diagrams of the energy-selected metallocene ions were modeled by both the rigid activated complex (RAC) Rice-Ramsperger-Kassel-Marcus (RRKM) theory and the simplified statistical adiabatic channel model (SSACM). The following appearance energies were obtained with SSACM, which is more reliable for loose transition states: 10.57 ± 0.14, 11.01 ± 0.13, and 10.18 ± 0.13 eV for M = Cr, Co, and Ni, respectively. These values combined with the corresponding adiabatic ionization energies yield M-Cp bond dissociation energies in Cp(2)M(+) ions of 5.04 ± 0.16, 5.77 ± 0.15, and 3.96 ± 0.15 eV. Density functional calculations at the B3LYP/6-311G(d,p) level of theory were used to determine the structures of these complexes and to provide parameters necessary for the analysis of the experimental data. The trends in the M-Cp bond energies can be related to the electronic structures of the metallocene ions based on a simple molecular orbital picture.

  18. A Critical Review of Validation, Blind Testing, and Real- World Use of Alchemical Protein-Ligand Binding Free Energy Calculations.

    Science.gov (United States)

    Abel, Robert; Wang, Lingle; Mobley, David L; Friesner, Richard A

    2017-01-01

    Protein-ligand binding is among the most fundamental phenomena underlying all molecular biology, and a greater ability to more accurately and robustly predict the binding free energy of a small molecule ligand for its cognate protein is expected to have vast consequences for improving the efficiency of pharmaceutical drug discovery. We briefly reviewed a number of scientific and technical advances that have enabled alchemical free energy calculations to recently emerge as a preferred approach, and critically considered proper validation and effective use of these techniques. In particular, we characterized a selection bias effect which may be important in prospective free energy calculations, and introduced a strategy to improve the accuracy of the free energy predictions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Binding energy and dynamics of Be acceptor levels in AlAs/GaAs multiple quantum wells

    NARCIS (Netherlands)

    Halsall, M. P.; Zheng, W. M.; Harrison, P.; Wells, J. P. R.; Steer, M. J.; Orlova, E. E.

    2004-01-01

    We report an infrared study of the effect of quantum well confinement on the binding energy and dynamics of shallow Be acceptors in both bulk GaAs and a series of delta-doped AlAs/GaAs multiquantum well samples with well thicknesses of 20,15 and 10 nm. Low temperature far-infrared absorption

  20. Effects due to temperature-dependent nuclear binding energies on the equation of state for hot nuclear matter

    International Nuclear Information System (INIS)

    Benvenuto, O.G.; Civitarese, O.; Reboiro, M.

    1993-01-01

    The influence of finite temperature nuclear effects upon the adiabatic index, for a system of nuclei, nucleons, and leptons, is discussed. It is found that the inclusion of temperature-dependent nuclear binding energies affects the behavior of the adiabats and of the adiabatic index, particularly, at low entropies

  1. Correlation between the binding energy of neutrons in nuclei and anomalous fractionation of isotopes in medico-biological objects

    International Nuclear Information System (INIS)

    Bykovskij, Yu.A.; Timoshin, V.T.; Laptev, I.D.; Manykin, Eh.A.

    1986-01-01

    Laser mass-spectrometry is used to investigate isotope ratio in medico-biological objects (MBO). Anomalous fractionation of carbon, oxygen, silicon, sulphur, potassium and calcium isotopes in MBO is detected. Correlation between neutron binding energy in isotopic nuclei and isotope anomalous fractionation of some elements in MBO is determined

  2. Energy values and chemical composition of spirulina (Spirulina platensis) evaluated with broilers

    OpenAIRE

    Alvarenga,Renata Ribeiro; Rodrigues,Paulo Borges; Cantarelli,Vinícius de Souza; Zangeronimo,Márcio Gilberto; Silva Júnior,José Walter da; Silva,Leonardo Rafael da; Santos,Luziane Moreira dos; Pereira,Luciano José

    2011-01-01

    The objective of this study was to determine the chemical and energy composition of spirulina (Spirulina platensis), the nutrient metabolizability coefficients, and the values of apparent metabolizable energy (AME) and the apparent metabolizable energy corrected for nitrogen balance (AMEn) in broilers. A digestibility trial was carried out by using total excreta collection method, with 90 Cobb 500 lineage chicks, with initial weight of 256 ± 5 g at 11 days of age. Birds were allotted in metab...

  3. Energy Value Housing Award Guide: How to Build and Profit with Energy Efficiency in New Home Construction

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, J. L.

    2001-06-01

    As concern over the environment grows, builders have the potential to fulfill a market niche by building homes that use fewer resources and have lower environmental impact than conventional construction. Builders can increase their marketability and customer satisfaction and, at the same time, reduce the environmental impact of their homes. However, it takes dedication to build environmentally sound homes along with a solid marketing approach to ensure that customers recognize the added value of energy and resource efficiency. This guide is intended for builders seeking suggestions on how to improve energy and resource efficiency in their new homes. It is a compilation of ideas and concepts for designing, building, and marketing energy- and resource-efficient homes based on the experience of recipients of the national Energy Value Housing Award (EVHA).

  4. The value of domestic building energy efficiency — evidence from Ireland

    International Nuclear Information System (INIS)

    Hyland, Marie; Lyons, Ronan C.; Lyons, Seán

    2013-01-01

    Following the transposition of the EU Energy Performance of Buildings Directive into Irish law, all properties offered for sale or to let in Ireland are obliged to have an energy efficiency rating. This paper analyses the effect of energy efficiency ratings on the sale and rental prices of properties in the Republic of Ireland. Using the Heckman selection technique we model the decision to advertise the energy efficiency rating of a property and the effect of energy efficiency ratings on property values. Our results show that energy efficiency has a positive effect on both the sales and rental prices of properties, and that the effect is significantly stronger in the sales segment of the property market. We also analyse the effect of energy efficiency across different market conditions and we find that the effect of the energy rating is generally stronger where market conditions are worse. - Highlights: • We estimate the effect of energy efficiency on property sale and rental prices. • We examine how this effect varies according to market conditions. • Energy efficiency has a significant, positive effect on property values. • The premium is greater for property sales compared to rentals. • The premium for energy efficiency is greater when market conditions are worse

  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. Photodetachment of Isolated Bicarbonate Anion: Electron Binding Energy of HCO3-

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xue B.; Xantheas, Sotiris S.

    2011-04-29

    We report the first direct photodetachment photoelectron spectroscopy of HCO3 in the gas phase under low temperature conditions. The observed photoelectron spectra are complicated due to excitations of manifolds in both vibrational and electronic states. A long and single vibrational progression with a frequency of 530 ± 20 cm-1 is partially resolved in the threshold of the T=20 K, 266 nm spectrum. The adiabatic electron detachment energy (ADE) of HCO3, or in other words the electron affinity (EA) of neutral HCO3, is experimentally determined from the (0-0) transition to be 3.680 ± 0.015 eV. High-level ab initio calculations at the CCSD(T) level of theory produce an anharmonic frequency of 546 cm-1 for HCO3 and a value of 3.62 eV for the (0,0) transition, both in excellent agreement with the experimentally determined values.

  7. The effect of binding energy and resolution in simulations of the common envelope binary interaction

    Science.gov (United States)

    Iaconi, Roberto; De Marco, Orsola; Passy, Jean-Claude; Staff, Jan

    2018-03-01

    The common envelope binary interaction remains one of the least understood phases in the evolution of compact binaries, including those that result in Type Ia supernovae and in mergers that emit detectable gravitational waves. In this work we continue the detailed and systematic analysis of 3D hydrodynamic simulations of the common envelope interaction aimed at understanding the reliability of the results. Our first set of simulations replicate the 5 simulations of Passy et al. (a 0.88 M⊙, 90 R⊙ RGB primary with companions in the range 0.1 to 0.9 M⊙) using a new AMR gravity solver implemented on our modified version of the hydrodynamic code ENZO. Despite smaller final separations obtained, these more resolved simulations do not alter the nature of the conclusions that are drawn. We also carry out 5 identical simulations but with a 2.0 M⊙ primary RGB star with the same core mass as the Passy et al. simulations, isolating the effect of the envelope binding energy. With a more bound envelope all the companions in-spiral faster and deeper though relatively less gas is unbound. Even at the highest resolution, the final separation attained by simulations with a heavier primary is similar to the size of the smoothed potential even if we account for the loss of some angular momentum by the simulation. As a result we suggest that a ˜2.0 M⊙ RGB primary may possibly end in a merger with companions as massive as 0.6 M⊙, something that would not be deduced using analytical arguments based on energy conservation.

  8. Electron momentum distributions and binding energies for the valence orbitals of hydrogen bromide and hydrogen iodide

    International Nuclear Information System (INIS)

    Brion, C.E.; McCarthy, I.E.; Suzuki, I.H.; Weigold, E.; Williams, G.R.J.; Bedford, K.L.; Kunz, A.B.; Weidman, R.

    1981-12-01

    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. High level theoretical study of binding and of the potential energy surface in benzene-hydride system

    Energy Technology Data Exchange (ETDEWEB)

    Coletti, Cecilia, E-mail: ccoletti@unich.it [Dipartimento di Scienze del Farmaco, Universita ' G. d' Annunzio' Chieti-Pescara, Via dei Vestini 31, 66100 Chieti (Italy); Re, Nazzareno [Dipartimento di Scienze del Farmaco, Universita ' G. d' Annunzio' Chieti-Pescara, Via dei Vestini 31, 66100 Chieti (Italy)

    2012-04-04

    Graphical abstract: In-plane minimum geometries for benzene-H{sup -} non-covalent adducts: linear adduct (left) with the hydride ion hydrogen bonded to one aromatic hydrogen; bifurcated adduct (right), with the hydride ion hydrogen bonded to two adjacent aromatic hydrogens. Highlights: Black-Right-Pointing-Pointer Theoretical study on covalent and non-covalent binding in benzene-hydride. Black-Right-Pointing-Pointer Two non-covalent stable adducts were characterized in the in-plane geometry. Black-Right-Pointing-Pointer Significant sections of the potential energy surface were determined. Black-Right-Pointing-Pointer Formation of a very stable C{sub 6}H{sub 7}{sup -} anion upon covalent binding to carbon. - Abstract: High level ab initio calculations were performed on the interaction of the hydride anion with benzene, a system of potential interest for modelling the interactions occurring in hydrogen rich planetary atmospheres. We investigated both non-covalent and covalent binding, exploring the complete basis set limit using highly correlated MP2 and CCSD(T) levels of theory. Two non-covalent minima on the potential energy surface have been characterized, and found to correspond to moderately strong hydrogen bonding interactions. To gain further insight on the nature of binding, the total interaction energy was decomposed into its physically meaningful components and selected sections of the potential energy surface were calculated. Moreover, we found that H{sup -} can easily covalently bind to one of the carbon atoms of benzene to form a stable C{sub 6}H{sub 7}{sup -} anion, a global minimum on the potential energy surface, characterized by a puckered geometry, with a carbon atom bending out of the benzene plane. A slightly less stable planar C{sub 6}H{sub 7}{sup -} structure was also identified, corresponding to the transition state for the flipping motion of the puckered species.

  10. Energy value of soil organic matter and costs of its restoration

    Science.gov (United States)

    Kuczuk, Anna

    2017-10-01

    From the point of view of the sustainable soil management, the most important characteristic of soil organic matter (SOM) is associated with the energy content in it. This paper reports the results of an estimation of SOM resources and its energy value for the arable land in a selected farm. For this purpose, soil samples were taken in two fields from a soil depth profile of 30 cm. The testing regarding humus content were conducted at District Chemical and Agricultural Station in Opole. The study involved the assessment of organic matter content at a depth of 30 cm converted per 1 ha, energy value of the SOM resources and the theoretical energy potential was determined. In addition, an example of crop rotation was provided for the analyzed soils, which could be applicable in the process of restoring SOM resources. The cost of restoring the SOM resource was estimated and this value was compared with the energy value of fuel. The total cost of SOM restoration over the period of five years was equal to 3122.26-7845.86 PLN·ha-1 depending on the value of the lost revenue of commercial production, and simultaneously equal to the value of 6.2-16 Mg thermal coal.

  11. Are automated molecular dynamics simulations and binding free energy calculations realistic tools in lead optimization? An evaluation of the linear interaction energy (LIE) method

    NARCIS (Netherlands)

    Stjernschantz, E.M.; Marelius, J.; Medina, C.; Jacobsson, M.; Vermeulen, N.P.E.; Oostenbrink, C.

    2006-01-01

    An extensive evaluation of the linear interaction energy (LIE) method for the prediction of binding affinity of docked compounds has been performed, with an emphasis on its applicability in lead optimization. An automated setup is presented, which allows for the use of the method in an industrial

  12. Framework for Evaluating the Total Value Proposition of Clean Energy Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Pater, J. E.

    2006-02-01

    Conventional valuation techniques fail to include many of the financial advantages of clean energy technologies. By omitting benefits associated with risk management, emissions reductions, policy incentives, resource use, corporate social responsibility, and societal economic benefits, investors and firms sacrifice opportunities for new revenue streams and avoided costs. In an effort to identify some of these externalities, this analysis develops a total value proposition for clean energy technologies. It incorporates a series of values under each of the above categories, describing the opportunities for recapturing investments throughout the value chain. The framework may be used to create comparable value propositions for clean energy technologies supporting investment decisions, project siting, and marketing strategies. It can also be useful in policy-making decisions.

  13. MODEL OF INTEGRATED VALUE OF PROJECTS IN THE FIELD OF ALTERNATIVE ENERGY

    Directory of Open Access Journals (Sweden)

    Наталія Ігорівна БОРИСОВА

    2015-05-01

    Full Text Available Development of alternative energy sources requires the implementation of complex problems, the solution of which is necessary to apply the project approach. The uniqueness of alternative energy projects (AEP necessitates individual approach to evaluating the effectiveness of each. The paper contains the results of the project management features's analysis in the field of alternative energy, determining the values and developing of the value management integrated conceptual model of AEP. In assessing the effectiveness of AEP considered the socio-economic and commercial aspects. Value management integrated conceptual model of AEP was obtained by combining the classical model of the project management goals with the project values model "Five "E" and two "A". The classical model of the project management goals have been complemented with risk parameters.

  14. From volatility to value: analysing and managing financial and performance risk in energy savings projects

    International Nuclear Information System (INIS)

    Mills, Evan; Kromer, Steve; Weiss, Gary; Mathew, Paul A.

    2006-01-01

    Many energy-related investments are made without a clear financial understanding of their values, risks, and volatilities. In the face of this uncertainty, the investor-such as a building owner or an energy service company-will often choose to implement only the most certain and thus limited energy-efficiency measures. Conversely, commodities traders and other sophisticated investors accustomed to evaluating investments on a value, risk, and volatility basis often overlook energy-efficiency investments because risk and volatility information are not provided. Fortunately, energy-efficiency investments easily lend themselves to such analysis using tools similar to those applied to supply side risk management. Accurate and robust analysis demands a high level of understanding of the physical aspects of energy-efficiency, which enables the translation of physical performance data into the language of investment. With a risk management analysis framework in place, the two groups-energy-efficiency experts and investment decision-makers-can exchange the information they need to expand investment in demand-side energy projects. In this article, we first present the case for financial risk analysis in energy efficiency in the buildings sector. We then describe techniques and examples of how to identify, quantify, and manage risk. Finally, we describe emerging market-based opportunities in risk management for energy efficiency

  15. Measuring the social value of nuclear energy using contingent valuation methodology

    International Nuclear Information System (INIS)

    Jun, Eunju; Joon Kim, Won; Hoon Jeong, Yong; Heung Chang, Soon

    2010-01-01

    As one of the promising energy sources for the next few decades, nuclear energy receives more attention than before as environmental issues become more important and the supply of fossil fuels becomes unstable. One of the reasons for this attention is based on the rapid innovation of nuclear technology which solves many of its technological constraints and safety issues. However, regardless of these rapid innovations, social acceptance for nuclear energy has been relatively low and unchanged. Consequently, the social perception has often been an obstacle to the development and execution of nuclear policy requiring enormous subsidies which are not based on the social value of nuclear energy. Therefore, in this study, we estimate the social value of nuclear energy-consumers' willingness-to-pay for nuclear energy-using the Contingent Valuation Method (CVM) and suggest that the social value of nuclear energy increases approximately 68.5% with the provision of adequate information about nuclear energy to the public. Consequently, we suggest that the social acceptance management in nuclear policy development is important along with nuclear technology innovation.

  16. Binding free-energy calculation is a powerful tool for drug optimization: calculation and measurement of binding free energy for 7-azaindole derivatives to glycogen synthase kinase-3β.

    Science.gov (United States)

    Kitamura, Kunihiro; Tamura, Yunoshin; Ueki, Tomokazu; Ogata, Koji; Noda, Shigeho; Himeno, Ryutaro; Chuman, Hiroshi

    2014-06-23

    Present computational lead (drug)-optimization is lacking in thermodynamic tactics. To examine whether calculation of binding free-energy change (ΔG) is effective for the lead-optimization process, binding ΔGs of 7-azaindole derivatives to the ATP binding site of glycogen synthase kinase-3β (GSK-3β) were calculated. The result was a significant correlation coefficient of r = 0.895 between calculated and observed ΔGs. This indicates that calculated ΔG reflects the inhibitory activities of 7-azaindole derivatives. In addition to quantitative estimation of activity, ΔG calculation characterizes the thermodynamic behavior of 7-azaindole derivatives, providing also useful information for inhibitor optimization on affinity to water molecules.

  17. The impact of Energy Performance Certificates on the rental and capital values of commercial property assets

    International Nuclear Information System (INIS)

    Fuerst, Franz; McAllister, Patrick

    2011-01-01

    This paper focuses on the effect of energy performance ratings on appraised capital values, rental values and equivalent yields of UK commercial property assets. The study is based on a cross-section of 708 commercial property assets. Incorporating a range of potential confounding factors such as unexpired lease term, vacancy rate and tenant credit risk, we use hedonic regression procedures to estimate the effect of EPC rating on rental and capital values. The study finds no evidence of a significant relationship between environmental and/or energy performance and rental and capital values. A small subset of 24 BREEAM-rated assets is also tested for significant price effects but a statistically significant effect is only confirmed for equivalent yields. Similarly, there was no evidence that the EPC rating had any effect on Market Rent or Market Value with only minor effects of EPC ratings on equivalent yields. The preliminary conclusion is that energy labelling is not yet having the effects on Market Values and Market Rents that would be expected if high EPC ratings were associated with substantial cost savings that are fully reflected in capital values and/or were readily available and taken into account by prospective tenants and buyers. - Highlights: → Finds no significant effect of EPC ratings on commercial real estate values. → Expected relationships with other price determinants, e.g. age, location confirmed. → Analysis provides some support for effect of EPC and BREEAM rating on yields.

  18. Energy crops cultivated on the slag from incineration of the sewage sludge energy value assessment

    Science.gov (United States)

    Głowacka, Anna; Tarnowski, Krzysztof; Bering, Sławomira; Mazur, Jacek; Kiper, Justyna; Wołoszyk, Czesław

    2017-11-01

    In 2011-2013, research on the fertilizer value of slag from the incineration of municipal sewage sludge as an alternative source of phosphorus was carried out. The research scheme included 5 variants (in 4 repetitions) fertilization cultivated for grain with mineral fertilizers and ash. (P1, P2 and P3 - consecutive doses of phosphorus from ash) from municipal sewage sludge combustion: NK, NPK, NK+P1, NK+P2 and NK+P3. The obtained results indicate that the average of the three years of research, the value for the straw spring rape heat of combustion was 15.99 MJ/kg d.m., corn straw 16.20 MJ/kg d.m., triticale straw 17.06 MJ/kg d.m. and Miscanthus 17.34 MJ/kg d.m. The highest value of combustion heat for spring rape straw and miscanthus performed for objects fertilized with NK + P3 - 16.08 MJ/kg d.m. (Spring rape) and 17.57 MJ/kg d.m. (Miscanthus); For corn straw objects fertilized with nitrogen and potassium - 16.35 MJ/kg d.m. and triticale straw objects fertilized with NPK and NK + P2 - 17.10 MJ/kg d.m. Straw calorific value of tested plants was lower than the combustion heat by an average of 6.97% (triticale) to 7.38% (spring rape).

  19. Energy- and value added services in the electric power market in Sweden; Energi- och mervaerdestjaenster paa elmarknaden i Sverige

    Energy Technology Data Exchange (ETDEWEB)

    Matsson, Peter

    2000-03-01

    This report tries to give a comprehensive picture of the offerings of energy- and value added services on the deregulated Swedish electric power market. A compilation of the service offerings from some 50 electric utilities is given. Market movements within deregulated sectors are treated with special emphasis on the electric power business.

  20. 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...

  1. Dark energy as consequence of release of cosmological nuclear binding-energy, and its further extension towards a new theory of inflation

    International Nuclear Information System (INIS)

    Gupta, R.C.; Pradhan, Anirudh; Gupta, Sushant

    2012-01-01

    Comparatively recent observations on Type-Ia supernovae and low density (Um = 0.3) measurement of matter including dark matter suggest that the present day universe consists mainly of repulsive-gravity type 'exotic matter' with negative-pressure often said 'dark energy' (Ux = O7). But the nature of dark energy is mysterious and its puzzling questions, such as why, how, where and when about the dark energy, are intriguing. In the present paper the authors attempt to answer these questions while making an effort to reveal the genesis of dark energy, and suggest that the cosmological nuclear binding energy liberated during primordial nucleo-synthesis remains trapped dormant for a long time and then is released free which manifests itself as dark energy in the universe. It is also explained why for dark energy the parameter w = -2/3. Noting that w = 1 for stiff matter and w = 1/3 for radiation; w = -2/3 is for dark energy because '- 1' is due to 'deficiency of stiff- nuclear-matter' and that this binding energy is ultimately released as 'radiation' contributing '+ 1/3', making w = -1+ 1/3 = -2/3. When dark energy is released free at Z = 80, w = -2/3. But as on present day at Z = 0 when radiation strength has diminished to ä ? 0, the parameter w = -1 + ä 1/3 = -1. This, thus almost solves the dark- energy mystery of negative pressure and repulsive-gravity. The proposed theory makes several estimates/predictions which agree reasonably well with the astrophysical constraints and observations. Though there are many candidate-theories, the proposed model of this paper presents an entirely new approach (cosmological nuclear energy) as a possible candidate for dark energy. The secret of acceleration of big-universe is hidden in the small-nucleus. (author)

  2. Determination of the cationic amphiphilic drug-DNA binding mode and DNA-assisted fluorescence resonance energy transfer amplification

    Science.gov (United States)

    Yaseen, Zahid; Banday, Abdul Rouf; Hussain, Mohammed Aamir; Tabish, Mohammad; Kabir-ud-Din

    2014-03-01

    Understanding the mechanism of drug-DNA binding is crucial for predicting the potential genotoxicity of drugs. Agarose gel electrophoresis, absorption, steady state fluorescence, and circular dichroism have been used in exploring the interaction of cationic amphiphilic drugs (CADs) such as amitriptyline hydrochloride (AMT), imipramine hydrochloride (IMP), and promethazine hydrochloride (PMT) with calf thymus or pUC19 DNA. Agarose gel electrophoresis assay, along with absorption and steady state fluorescence studies, reveal interaction between the CADs and DNA. A comparative study of the drugs with respect to the effect of urea, iodide induced quenching, and ethidium bromide (EB) exclusion assay reflects binding of CADs to the DNA primarily in an intercalative fashion. Circular dichroism data also support the intercalative mode of binding. Besides quenching, there is fluorescence exchange energy transfer (FRET) in between CADs and EB using DNA as a template.

  3. Creating prospective value chains for renewable road transport energy sources up to 2050 in Nordic Countries

    DEFF Research Database (Denmark)

    Wessberg, Nina; Leinonen, Anna; Tuominen, Anu

    2013-01-01

    alternative, but partly overlapping technology platforms, namely electricity, biofuels and hydrogen. The approach outlined in the paper combines elements from the fields of system level changes (transitions), value chain analysis and forward looking policy design. It presents a novel, policy relevant......If the Nordic energy and transport sectors are to meet the 2050 energy and climate policy targets, major systemic changes are necessary. Along with new technologies, changes are required also in other societal functions such as business models and consumer habits. The transition requires...... cooperation between public and private actors. This paper discusses the paradigm change towards 2050 Nordic road transport system based on renewable energy. More precisely, it proposes an approach for creation and analysis of prospective value networks up to the year 2050. The value networks arise from three...

  4. Changes in digestible energy values of some agricultural residues treated with gamma irradiation

    International Nuclear Information System (INIS)

    Al-Masri, M.R.; Zarkawi, M.

    1997-07-01

    The effects of different doses of gamma irradiation (0, 5, 20, 50, 100, 150 kGy) on gross energy (GE), in vitro organic matter digestibility (IVOMD) and digestible energy (IVDE), have been evaluated in barley straw, sorghum straw, wheat chaffs, and maize cobs. The results indicate that , there were significant increase in IVOMD and IVDE values, especially, at the dose of 150 kGy. compared with the control, the increase in IVOMD were 22, 21 and 23% for barley straw, sorghum straw, and wheat chaffs, respectively; whereas, the increase was only 12% for maize cobs. Digestible energy values increased by 1165, 1621, 1540, and 1130 MJ/kg dry matter, for barley straw, sorghum straw, wheat chaffs, and maize cobs, respectively. There was no significant effect of gamma irradiation on GE values for the studied agricultural residues. (author)

  5. Value of sensitive in-situ environmental assets in energy resource extraction

    International Nuclear Information System (INIS)

    Thampapillai, Dodo J.

    2011-01-01

    The extraction of energy resources and the preservation of sensitive in-situ environmental assets are invariably mutually exclusive alternatives. The opportunity cost value of preserving the environmental assets can be assessed by recourse to resource rent taxes, and threshold values. The case study analysis carried out in this paper suggests that the preservation of these assets could be justifiable on the grounds of “acceptable sacrifice”. - Highlights: ► Resource rents owed to the state from energy resource extraction can be significant. ► Benefits if mining energy resources are over-stated when the role of sensitive environmental assets is ignored. ► Threshold values could help to resolve conflicts between environmental preservation and resource extraction.

  6. Reshaping the Energy Landscape Transforms the Mechanism and Binding Kinetics of DNA Threading Intercalation.

    Science.gov (United States)

    Clark, Andrew G; Naufer, M Nabuan; Westerlund, Fredrik; Lincoln, Per; Rouzina, Ioulia; Paramanathan, Thayaparan; Williams, Mark C

    2018-02-06

    Molecules that bind DNA via threading intercalation show high binding affinity as well as slow dissociation kinetics, properties ideal for the development of anticancer drugs. To this end, it is critical to identify the specific molecular characteristics of threading intercalators that result in optimal DNA interactions. Using single-molecule techniques, we quantify the binding of a small metal-organic ruthenium threading intercalator (Δ,Δ-B) and compare its binding characteristics to a similar molecule with significantly larger threading moieties (Δ,Δ-P). The binding affinities of the two molecules are the same, while comparison of the binding kinetics reveals significantly faster kinetics for Δ,Δ-B. However, the kinetics is still much slower than that observed for conventional intercalators. Comparison of the two threading intercalators shows that the binding affinity is modulated independently by the intercalating section and the binding kinetics is modulated by the threading moiety. In order to thread DNA, Δ,Δ-P requires a "lock mechanism", in which a large length increase of the DNA duplex is required for both association and dissociation. In contrast, measurements of the force-dependent binding kinetics show that Δ,Δ-B requires a large DNA length increase for association but no length increase for dissociation from DNA. This contrasts strongly with conventional intercalators, for which almost no DNA length change is required for association but a large DNA length change must occur for dissociation. This result illustrates the fundamentally different mechanism of threading intercalation compared with conventional intercalation and will pave the way for the rational design of therapeutic drugs based on DNA threading intercalation.

  7. Binding of Hydrophobic Guests in a Coordination Cage Cavity is Driven by Liberation of "High-Energy" Water.

    Science.gov (United States)

    Metherell, Alexander J; Cullen, William; Williams, Nicholas H; Ward, Michael D

    2018-02-01

    The cavity of an M 8 L 12 cubic coordination cage can accommodate a cluster of ten water molecules in which the average number of hydrogen bonds per water molecule is 0.5 H-bonds less than it would be in the bulk solution. The presence of these "hydrogen-bond frustrated" or "high-energy" water molecules in the cavity results in the hydrophobic effect associated with guest binding being predominantly enthalpy-based, as these water molecules can improve their hydrogen-bonding environment on release. This contrasts with the classical form of the hydrophobic effect in which the favourable entropy change associated with release of ordered molecules from hydrophobic surfaces dominates. For several guests Van't Hoff plots showed that the free energy of binding in water is primarily enthalpy driven. For five homologous pairs of guests related by the presence or absence of a CH 2 group, the incremental changes to ΔH and TΔS for guest binding-that is, ΔΔH and TΔΔS, the difference in contributions arising from the CH 2 group-are consistently 5(±1) kJ mol -1 for ΔΔH and 0(±1) kJ mol -1 for TΔΔS. This systematic dominance of ΔH in the binding of hydrophobic guests is consistent with the view that guest binding is dominated by release of "high energy" water molecules into a more favourable solvation environment, as has been demonstrated recently for some members of the cucurbituril family. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  8. Digestibility, Determination of Metabolizable Energy and Bone Mineralization of Broilers Fed with Nutritionally Valued Phytase

    Directory of Open Access Journals (Sweden)

    FH Litz

    Full Text Available ABSTRACT The objective of this study was to evaluate the effect of using exoenzyme phytase in broiler's diets on digestibility of nutrients, feed energy and tibia bone mineralization. A completely randomized design was used, with the following treatments: sorghum with dicalcium phosphate (SDP, corn with dicalcium phosphate (CDP, sorghum with meat and bone meal (SMBM, sorghum with valued phytase (SVP and sorghum with phytase without valued (SPWV. For digestibility analysis, eighty 15 day old broilers were used, a total of 1400 male Hubbard Flex chickens, which were submitted to total excreta collection to obtain the percentages of food digestibility, crude protein, ether extract, apparent metabolizable energy, calcium and phosphorus while for tibias mineralization. Six birds per treatment were used, where determination of mineral matter, calcium and phosphorus were performed. Metabolizable energy (ME and apparent metabolizable energy corrected for nitrogen (AMEn of the feed were also calculated. Data were subjected to variation analysis and the average compared by 5% Tukey test. There was no difference between treatments for the digestibility at 15-20 day old as well as for the feed energy values, but the diets with phytase had higher phosphorous percentage values for tibia bone mineralization, demonstrating that exogenous phytase enzyme is able to hydrolyze phytate origininated from plant and release the phosphorus for assimilation by animals, acting as a substitute for phosphorus plant sources.

  9. DETERMINING THE VALUE OF SURFACE FREE ENERGY ON THE BASIS OF THE CONTACT ANGLE

    Directory of Open Access Journals (Sweden)

    Mariusz Kłonica

    2017-03-01

    Full Text Available This paper presents the results of tests concerning the value of surface free energy on the basis of measurements of contact angle with measure liquids: distilled water and diiodomethane. The surface of steel-316L samples was modified in an ozone atmosphere, and the concentration of ozone and the conditioning time of the samples in the reaction chamber were changed. The results of tests concerning the measurements of the value of surface free energy were subject to analysis. Also analysed were the components of SFE: the polar and dispersive components. The obtained test results were analysed in statistical terms. The paper ends with conclusions.

  10. The value of producing food, energy, and ecosystem services within an agro-ecosystem

    DEFF Research Database (Denmark)

    Porter, John Roy; Constanza, Robert; Sandhu, Harpinder

    2009-01-01

    Ecosystem Services within an Agro- Ecosystem Agricultural ecosystems produce food, fiber, and nonmarketed ecosystem services (ES). Agriculture also typically involves high negative external costs associated with, for example, fossil fuel use. We estimated, via fieldscale ecological monitoring...... and economic value-transfer methods, the market and nonmarket ES value of a combined food and energy (CFE) agro-ecosystem that simultaneously produces food, fodder, and bioenergy. Such novel CFE agro-ecosystems can provide a significantly increased net crop, energy, and nonmarketed ES compared...... with conventional agriculture, and require markedly less fossil-based inputs. Extrapolated to the European scale, the value of nonmarket ES from the CFE system exceeds current European farm subsidy payments. Such integrated food and bioenergy systems can thus provide environmental value for money for European Union...

  11. Shedding Light on the EOS-Gravity Degeneracy and Constraining the Nuclear Symmetry Energy from the Gravitational Binding Energy of Neutron Stars

    Directory of Open Access Journals (Sweden)

    He Xiao-Tao

    2016-01-01

    Full Text Available 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.

  12. When the lowest energy does not induce native structures: parallel minimization of multi-energy values by hybridizing searching intelligences.

    Directory of Open Access Journals (Sweden)

    Qiang Lü

    Full Text Available BACKGROUND: Protein structure prediction (PSP, which is usually modeled as a computational optimization problem, remains one of the biggest challenges in computational biology. PSP encounters two difficult obstacles: the inaccurate energy function problem and the searching problem. Even if the lowest energy has been luckily found by the searching procedure, the correct protein structures are not guaranteed to obtain. RESULTS: A general parallel metaheuristic approach is presented to tackle the above two problems. Multi-energy functions are employed to simultaneously guide the parallel searching threads. Searching trajectories are in fact controlled by the parameters of heuristic algorithms. The parallel approach allows the parameters to be perturbed during the searching threads are running in parallel, while each thread is searching the lowest energy value determined by an individual energy function. By hybridizing the intelligences of parallel ant colonies and Monte Carlo Metropolis search, this paper demonstrates an implementation of our parallel approach for PSP. 16 classical instances were tested to show that the parallel approach is competitive for solving PSP problem. CONCLUSIONS: This parallel approach combines various sources of both searching intelligences and energy functions, and thus predicts protein conformations with good quality jointly determined by all the parallel searching threads and energy functions. It provides a framework to combine different searching intelligence embedded in heuristic algorithms. It also constructs a container to hybridize different not-so-accurate objective functions which are usually derived from the domain expertise.

  13. When the Lowest Energy Does Not Induce Native Structures: Parallel Minimization of Multi-Energy Values by Hybridizing Searching Intelligences

    Science.gov (United States)

    Lü, Qiang; Xia, Xiao-Yan; Chen, Rong; Miao, Da-Jun; Chen, Sha-Sha; Quan, Li-Jun; Li, Hai-Ou

    2012-01-01

    Background Protein structure prediction (PSP), which is usually modeled as a computational optimization problem, remains one of the biggest challenges in computational biology. PSP encounters two difficult obstacles: the inaccurate energy function problem and the searching problem. Even if the lowest energy has been luckily found by the searching procedure, the correct protein structures are not guaranteed to obtain. Results A general parallel metaheuristic approach is presented to tackle the above two problems. Multi-energy functions are employed to simultaneously guide the parallel searching threads. Searching trajectories are in fact controlled by the parameters of heuristic algorithms. The parallel approach allows the parameters to be perturbed during the searching threads are running in parallel, while each thread is searching the lowest energy value determined by an individual energy function. By hybridizing the intelligences of parallel ant colonies and Monte Carlo Metropolis search, this paper demonstrates an implementation of our parallel approach for PSP. 16 classical instances were tested to show that the parallel approach is competitive for solving PSP problem. Conclusions This parallel approach combines various sources of both searching intelligences and energy functions, and thus predicts protein conformations with good quality jointly determined by all the parallel searching threads and energy functions. It provides a framework to combine different searching intelligence embedded in heuristic algorithms. It also constructs a container to hybridize different not-so-accurate objective functions which are usually derived from the domain expertise. PMID:23028708

  14. A study on value assessment of nuclear energy and quantification model development

    International Nuclear Information System (INIS)

    Jun, Eun Ju

    2009-02-01

    Studies quantifying the contributions of nuclear energy to the countries that operate them are scant. The aim of this study, therefore, is to investigate both qualitatively and quantitatively these benefits, which have proven to be significant. We present estimates of the value of nuclear energy in terms of economics, the environment, security, and social issues, specifically for nuclear energy used in Korea. This study also suggests an approach to quantitatively measure and compare the value of energy ultimately for the generation of electricity from different energy sources Input-Output analysis was used to find out the economic contribution of energy sources. Nuclear energy contributes a similar amount of electricity that coal power plants do but, surprisingly, its value added GDP contribution is almost twice that of coal. Coal, oil, liquefied natural gas (LNG), and nuclear contribute 0.47%, 0.05%, 0.23%, and 0.92% to the value added GDP, respectively. While this may seem small, the four major industries in Korea - primary iron and steel products, semiconductors and related devices, motor vehicles, and petroleum refinery products - contributed 1.3%, 2.1%, 2.2%, and 2.9% to GDP in that same year, respectively. To measure the environmental effect, a carbon-tax scenario was used. Considering both health effects and the carbon-tax scenario, nuclear had the lowest environmental cost at 0.29 won/kWh. Coal had the highest at 24.47 won/kWh, followed by oil at 19.52 won/kWh, and LNG at 12.98 won/kWh. Therefore, if the carbon-tax (or some constraint) is imposed for future and current environmental concerns, nuclear energy's competitiveness will only increase. In spite of the importance of nuclear energy for electricity generation in Korea, the public's attitude towards nuclear energy is not favorable. This negative social perception was defined as the social cost of nuclear energy. To estimate it, a Contingent Valuation Method (CVM) was utilized. This method estimates the

  15. Applying the Water-Energy-Food Nexus to the Charcoal Value Chain

    Directory of Open Access Journals (Sweden)

    Harry K. Hoffmann

    2017-12-01

    Full Text Available Globally, natural resources are increasingly under pressure, especially due to population growth, economic growth and transformation as well as climate change. As a result, the water, energy, and food (WEF nexus approach has emerged to understand interdependencies and commonly manage resources within a multi-scale and multi-level framework. In Sub-Saharan Africa, the high and growing consumption of traditional biomass for cooking purposes - notably fuelwood and charcoal—is both a key source of energy and contributor for food security as well as a pressure on natural resources. Improving the bioenergy value chains is essential for limiting environmental degradation and for securing the livelihoods of millions of people. Although the WEF nexus approach entails large potential to address the complex problems arising along the bioenergy value chains, these are currently not considered. Based on the WEF nexus approach, we analyze the different steps within the charcoal value chain in Sub-Saharan Africa and highlight the respective interdependencies and the potential for improving overall socio-economic and environmental sustainability. We emphasize the water, energy and food related implications of vicious and virtuous production cycles, separated by value chain segments. We discuss the potential and major challenges for implementing more sustainable value chains. Furthermore, we underline the necessity of applying WEF nexus approaches to these value chains in order to optimize environmental and social outcomes.

  16. Lowest excited-state impurity binding energy in InGaN/GaN parabolic QWW: magnetic field effect

    International Nuclear Information System (INIS)

    Haddou El Ghazi; Anouar Jorio; Izeddine Zorkani

    2013-01-01

    In this paper, we have investigated the magnetic field effect on the lowest excited-state binding energy of hydrogenic shallow-donor impurity in wurtzite (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) using the finite-difference method within the quasi-one-dimensional effective potential model. The calculations are performed within the framework of the effective mass approximation. A cylindrical QWW effective radius is taken into account to describe the lateral confinement strength. The numerical results show that: (i) the probability density is the largest on a circularity whose radius is the effective radius and (ii) the lowest excited-state binding energy is the largest when an impurity is located on this circularity while it starts to decrease as the impurity is away from the circularity. (author)

  17. Magnetic field-dependent of binding energy in GaN/InGaN/GaN spherical QDQW nanoparticles

    International Nuclear Information System (INIS)

    El Ghazi, Haddou; Jorio, Anouar; Zorkani, Izeddine

    2013-01-01

    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

  18. Absence of a Scott correction for the total binding energy of noninteracting fermions in a smooth potential well

    International Nuclear Information System (INIS)

    Huxtable, B.D.

    1988-01-01

    It is shown, for V in a particular class of smooth functions, that the total binding energy, E(Z), of Z noninteracting Fermions in the potential well Z 4/3 V(Z 1/3 X) obeys E(Z) = c TF (V)Z 7/3 + O(Z 5/3 ) as Z → ∞. Here c TF (V) is the coefficient predicted by Thomas-Fermi theory. This result is consistent with the conjectured Scott correction, which occurs at order Z 2 , to the total binding energy of an atomic number Z. This correction is thought to arise only because V(x)∼ - |x| -1 near x = 0 in the atomic problem, and so V is not a smooth function

  19. Analytical value of detecting an individual molecular binding event: The case of the surface plasmon resonance biosensor

    Czech Academy of Sciences Publication Activity Database

    Šípová, Hana; Vrba, David; Homola, Jiří

    2012-01-01

    Roč. 84, č. 1 (2012), s. 30-33 ISSN 0003-2700 R&D Projects: GA MŠk(CZ) LH11102 Institutional support: RVO:67985882 Keywords : Binding events * Biosensing * Surface plasmon resonance biosensor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 5.695, year: 2012

  20. Electron binding energies of organic azides: Green’s function and density functional theory versus Hartree Fock calculations

    Science.gov (United States)

    Mateus, Margarida P. S.; Cabral, Benedito J. C.

    2007-11-01

    Theoretical calculations for the electron binding energies (EBEs) of several organic azides including hydrazoic acid, methyl azide, ethyl azide, 2-chloroethyl azide, 2-azidoethanol, azidoacetone, 2-azidoacetic acid, 3-azido-2-butanone, and 2-azidoethyl acetate are reported. EBEs were calculated with ab initio Green's function (GF) and density functional theory (DFT). Complete basis-set extrapolated coupled cluster calculations with single, double, and perturbative triple excitations [CCSD(T)] for the first ionization energy of azides are also reported. It is shown that EBEs from GF and DFT calculations are in better agreement with experiment than Hartree-Fock predictions.

  1. Comparison of metabolisable energy values of different foodstuffs determined in ostriches and poultry

    DEFF Research Database (Denmark)

    Cilliers, S C; Sales, J; Hayes, J P

    1999-01-01

    Apparent (AMEn) and true (TMEn) metabolisable energy values, corrected for nitrogen retention, of wheat bran, saltbush (Atriplex nummularia), common reed (Phragmites australis), lupins, soyabean oil cake meal (SBOCM), sunflower oil cake meal (SFOCM) and fishmeal were compared in 7 successive trials...

  2. Comparison of metabolisable energy values of different foodstuffs determined in ostriches and poultry

    DEFF Research Database (Denmark)

    Cilliers, S C; Sales, J; Hayes, J P

    1999-01-01

    Apparent (AMEn) and true (TMEn) metabolisable energy values, corrected for nitrogen retention, of wheat bran, saltbush (Atriplex nummularia), common reed (Phragmites australis), lupins, soyabean oil cake meal (SBOCM), sunflower oil cake meal (SFOCM) and fishmeal were compared in 7 successive tria...

  3. Amplifying Real Estate Value through Energy&WaterManagement: From ESCO to 'Energy Services Partner'

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Evan

    2004-06-08

    The energy service company (ESCO) business model could become significantly more effective by integrating the energy-efficiency purveyor and their capital into the underlying building ownership and operation partnership, rather than the current model in which the ESCO remains an outsider with higher transaction costs and limited interest and participation in the value created by the cost savings. Resource conservation advocates rarely use the language of real estate to articulate the cost effectiveness of capital improvements aimed at reducing utility costs in commercial and residential income properties. Conventional methods that rely on rarefied academic notions of simple payback time or a narrow definition of return on investment fail to capture a significant component of the true market value created by virtue of reduced operating expenses. Improvements in energy and water efficiency can increase the fundamental profitability of real estate investments by raising Net Operating Income (NOI), and hence returns during the holding period, and, ultimately, proceeds at time of sale. We introduce the concept of an Energy Services Partner, who takes an equity interest in a real estate partnership in exchange for providing the expertise and capital required to reduce utility operating costs. Profit to all partners increases considerably as a result. This approach would also help to address a crisis facing ESCOs today stemming from their considerable liabilities (through guaranteed savings) and negligible offsetting assets.

  4. Environmental value considerations in public attitudes about alternative energy development in Oregon and Washington.

    Science.gov (United States)

    Steel, Brent S; Pierce, John C; Warner, Rebecca L; Lovrich, Nicholas P

    2015-03-01

    The 2013 Pacific Coast Action Plan on Climate and Energy signed by the Governors of California, Oregon, and Washington and the Premier of British Columbia launched a broadly announced public commitment to reduce greenhouse gas emissions through multiple strategies. Those strategies include the development and increased use of renewable energy sources. The initiative recognized that citizens are both a central component in abating greenhouse gas emissions with regard to their energy use behaviors, and are important participants in the public policymaking process at both state and local levels of government. The study reported here examines whether either support or opposition to state government leadership in the development of alternative energy technologies can be explained by environmental values as measured by the New Ecological Paradigm (NEP). The research results are based on mail surveys of randomly selected households conducted throughout Oregon and Washington in late 2009 and early 2010. Findings suggest that younger and more highly educated respondents are significantly more likely than older and less educated respondents to either support or strongly support government policies to promote bioenergy, wind, geothermal, and solar energy. Those respondents with higher NEP scores are also more supportive of government promotion of wind, geothermal, and solar technologies than are those with lower NEP scores. Support for wave energy does not show a statistical correlation with environmental values, maybe a reflection of this technology's nascent level of development. The paper concludes with a consideration of the implications of these findings for environmental management.

  5. Binding Energy and Dissociation Barrier: Experimental Determination of the Key Parameters of the Potential Energy Curve of Diethyl Ether on Si(001).

    Science.gov (United States)

    Reutzel, Marcel; Lipponer, Marcus; Dürr, Michael; Höfer, Ulrich

    2015-10-01

    The key parameters of the potential energy curve of organic molecules on semiconductor surfaces, binding energy of the intermediate state and dissociation barrier, were experimentally investigated for the model system of diethyl ether (Et2O) on Si(001). Et2O adsorbs via a datively bonded intermediate from which it converts via ether cleavage into a covalently attached final state. This thermally activated conversion into the final state was followed in real-time by means of optical second-harmonic generation (SHG) at different temperatures and the associated energy barrier ϵa = 0.38 ± 0.05 eV and pre-exponential factor νa = 10(4±1) s(-1) were determined. From molecular beam experiments on the initial sticking probability, the difference between the desorption energy ϵd and ϵa was extracted and thus the binding energy of the intermediate state was determined (0.62 ± 0.08 eV). The results are discussed in terms of general chemical trends as well as with respect to a wider applicability on adsorbate reactions on semiconductor surfaces.

  6. Functional roles and clinical values of insulin-like growth factor-binding protein-5 in different types of cancers.

    Science.gov (United States)

    Güllü, Gökçe; Karabulut, Sevgi; Akkiprik, Mustafa

    2012-06-01

    Insulin-like growth factor-binding proteins(IGFBPs) are critical regulators of the mitogenic activity of insulin-like growth factors (IGFs). IGFBP5, one of these IGFBPs, has special structural features, including a nuclear transport domain, heparin-binding motif, and IGF/extracellular matrix/acid-labile subunit-binding sites. Furthermore, IGFBP5 has several functional effects on carcinogenesis and even normal cell processes, such as cell growth, death, motility, and tissue remodeling. These biological effects are sometimes related with IGF (IGF-dependent effects) and sometimes not (IGF-independent effects). The functional role of IGFBP5 is most likely determined in a cell-type and tissue-type specific manner but also depends on cell context, especially in terms of the diversity of interacting proteins and the potential for nuclear localization. Clinical findings show that IGFBP5 has the potential to be a useful clinical biomarker for predicting response to therapy and clinical outcome of cancer patients. In this review, we summarize the functional diversity and clinical importance of IGFBP5 in different types of cancers.

  7. On the atomic-number similarity of the binding energies of electrons in filled shells of elements of the periodic table

    Science.gov (United States)

    Karpov, V. Ya.; Shpatakovskaya, G. V.

    2017-03-01

    An expression for the binding energies of electrons in the ground state of an atom is derived on the basis of the Bohr-Sommerfeld quantization rule within the Thomas-Fermi model. The validity of this relation for all elements from neon to uranium is tested within a more perfect quantum-mechanical model with and without the inclusion of relativistic effects, as well as with experimental binding energies. As a result, the ordering of electronic levels in filled atomic shells is established, manifested in an approximate atomic-number similarity. It is proposed to use this scaling property to analytically estimate the binding energies of electrons in an arbitrary atom.

  8. Methods for Analyzing the Economic Value of Concentrating Solar Power with Thermal Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, Paul [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jorgenson, Jennie [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Miller, Mackay [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wang, Caixia [State Grid Energy Research Inst., Beijing (China)

    2015-07-20

    Concentrating solar power with thermal energy storage (CSP-TES) provides multiple quantifiable benefits compared to CSP without storage or to solar photovoltaic (PV) technology, including higher energy value, ancillary services value, and capacity value. This report describes modeling approaches to quantifying these benefits that have emerged through state-level policymaking in the United States as well as the potential applicability of these methods in China. The technical potential for CSP-TES in China is significant, but deployment has not yet achieved the targets established by the Chinese government. According to the 12th Five Year Plan for Renewable Energy (2011-2015), CSP was expected to reach 1 GW by 2015 and 3 GW by 2020 in China, yet as of December 2014, deployment totaled only 13.8 MW. One barrier to more rapid deployment is the lack of an incentive specific to CSP, such as a feed-in tariff. The 13th Five Year Plan for Solar Generation (2016-2020), which is under development, presents an opportunity to establish a feed-in tariff specific to CSP. This report, produced under the auspices of the U.S.-China Renewable Energy Partnership, aims to support the development of Chinese incentives that advance CSP deployment goals.

  9. Chemical composition and metabolizable energy values of corn germ meal obtained by wet milling for layers

    Directory of Open Access Journals (Sweden)

    CS Albuquerque

    2014-03-01

    Full Text Available An experiment was carried out to determine the chemical composition, metabolizable energy values, and coefficients of nutrient digestibility of corn germ meal for layers. The chemical composition of corn germ meal was determined, and then a metabolism assay was performed to determine its apparent metabolizable energy (AME and apparent metabolizable energy corrected for nitrogen (AMEn values and its dry matter and gross energy apparent metabolizability coefficients (CAMDM and CAMGE, respectively. In the 8-day assay (four days of adaptation and four days of total excreta collection, 60 29-week-old white Lohman LSL layers were used. A completely randomized experimental design, with three treatments with five replicates of four birds each, was applied. Treatments consisted of a reference diet and two test diets, containing 20 or 30% corn germ meal. Results were submitted to analysis of variance and means were compared by the Tukey tests at 5% probability level. The chemical composition of corn germ meal was: 96.39% dry matter, 49.48% ether extract, 1.87% ashes, 7243 kcal gross energy/kg, 11.48% protein, 0.19% methionine, 0.21% cystine, 0.48% lysine, 0.40% threonine, 0.72% arginine, 0.35% isoleucine, 0.83% leucine, 0.57% valine, and 0.37% histidine, on as-fed basis. There were no statistical differences in AME, AMEn, CAMDM, and CAMGE values with the inclusion of 20 and 30% corn germ meal in the diets. On dry matter basis, AME, AMEn, CAMDM, and CAMGE values of corn germ meal were: 4,578 and 4,548 kcal/kg, 4,723 and 4,372 kcal/kg, 64.95 and 61.86%, respectively.

  10. Molecular dynamics study of binding energies, mechanical properties, and detonation performances of bicyclo-HMX-based PBXs.

    Science.gov (United States)

    Qiu, Ling; Xiao, Heming

    2009-05-15

    To investigate the effect of polymer binders on the monoexplosive, molecular dynamics simulations were performed to study the binding energies, mechanical properties, and detonation performances of the bicyclo-HMX-based polymer-bonded explosives (PBXs). The results show that the binding energies on different crystalline surfaces of bicyclo-HMX decrease in the order of (010)>(100)>(001). On each crystalline surface, binding properties of different polymers with the same chain segment are different from each other, while those of the polymers in the same content decrease in the sequence of PVDF>F(2311)>F(2314) approximately PCTFE. The mechanical properties of a dozen of model systems (elastic coefficients, various moduli, Cauchy pressure, and Poisson's ratio) have been obtained. It is found that mechanical properties are effectively improved by adding small amounts of fluorine polymers, and the overall effect of fluorine polymers on three crystalline surfaces of bicyclo-HMX changes in the order of (010)>(001) approximately (100). In comparison with the base explosive, detonation performances of the PBXs decrease slightly, but they are still superior to TNT. These suggestions may be useful for the formulation design of bicyclo-HMX-based PBXs.

  11. Identification of potential inhibitors of Fasciola gigantica thioredoxin1: computational screening, molecular dynamics simulation, and binding free energy studies.

    Science.gov (United States)

    Shukla, Rohit; Shukla, Harish; Kalita, Parismita; Sonkar, Amit; Pandey, Tripti; Singh, Dev Bukhsh; Kumar, Awanish; Tripathi, Timir

    2017-07-04

    Fasciola gigantica is the causative organism of fascioliasis and is responsible for major economic losses in livestock production globally. F. gigantica thioredoxin1 (FgTrx1) is an important redox-active enzyme involved in maintaining the redox homeostasis in the cell. To identify a potential anti-fasciolid compound, we conducted a structure-based virtual screening of natural compounds from the ZINC database (n = 1,67,740) against the FgTrx1 structure. The ligands were docked against FgTrx1 and 309 ligands were found to have better docking score. These compounds were evaluated for Lipinski and ADMET prediction, and 30 compounds were found to fit well for re-docking studies. After refinement by molecular docking and drug-likeness analysis, three potential inhibitors (ZINC15970091, ZINC9312362, and ZINC9312661) were identified. These three ligands were further subjected to molecular dynamics simulation (MDS) to compare the dynamics and stability of the protein structure after binding of the ligands. The binding free energy analyses were calculated to determine the intermolecular interactions. The results suggested that the two compounds had a binding free energy of -82.237, and -109.52 kJ.mol -1 for compounds with IDs ZINC9312362 and ZINC9312661, respectively. These predicted compounds displayed considerable pharmacological and structural properties to be drug candidates. We concluded that these two compounds could be potential drug candidates to fight against F. gigantica parasites.

  12. Urban energy generation: The added value of photovoltaics in social housing

    International Nuclear Information System (INIS)

    Bahaj, A.S.; James, P.A.B.

    2007-01-01

    Social housing offers an alternative for low-to-medium income families and keyworkers (teachers, nurses, and police). In the United Kingdom (UK), this fairly priced, rental accommodation is normally owned by housing associations. This paper explores urban energy generation (micro-generation) focussing on photovoltaics (PV) and how its generated electricity can be used to provide added value in terms of demand reduction and contribute to a reduction in fuel poverty. It presents the results associated from in-depth monitoring of nine low-energy social housing units equipped with PV systems commissioned in 2004 in the South of England, UK. We report on energy load profiles and relate these to occupier behaviour and any changes in consumption that occur. The results highlight the impact of micro-generation showing a close correlation between occupant behaviour and energy consumption. Increased energy awareness can lead to changes in the way energy is used, reducing overall consumption but 'education' must be sustained to ensure long-term energy reductions. The financial benefit of operating high demand electrical appliances at the peak of the solar day as opposed to in the evening when overall demand on the central grid is higher is highlighted. The paper also draws conclusions allied to the challenges that PV micro-generation technology presents in the social housing context. (author)

  13. Simulation of value stream mapping and discrete optimization of energy consumption in modular construction

    Science.gov (United States)

    Chowdhury, Md Mukul

    With the increased practice of modularization and prefabrication, the construction industry gained the benefits of quality management, improved completion time, reduced site disruption and vehicular traffic, and improved overall safety and security. Whereas industrialized construction methods, such as modular and manufactured buildings, have evolved over decades, core techniques used in prefabrication plants vary only slightly from those employed in traditional site-built construction. With a focus on energy and cost efficient modular construction, this research presents the development of a simulation, measurement and optimization system for energy consumption in the manufacturing process of modular construction. The system is based on Lean Six Sigma principles and loosely coupled system operation to identify the non-value adding tasks and possible causes of low energy efficiency. The proposed system will also include visualization functions for demonstration of energy consumption in modular construction. The benefits of implementing this system include a reduction in the energy consumption in production cost, decrease of energy cost in the production of lean-modular construction, and increase profit. In addition, the visualization functions will provide detailed information about energy efficiency and operation flexibility in modular construction. A case study is presented to validate the reliability of the system.

  14. The performance of composite forecast models of value-at-risk in the energy market

    International Nuclear Information System (INIS)

    Chiu, Yen-Chen; Chuang, I-Yuan; Lai, Jing-Yi

    2010-01-01

    This paper examines a comparative evaluation of the predictive performance of various Value-at-Risk (VaR) models in the energy market. This study extends the conventional research in literature, by proposing composite forecast models for applying to Brent and WTI crude oil prices. Forecasting techniques considered here include the EWMA, stable density, Kernel density, Hull and White, GARCH-GPD, plus composite forecasts from linearly combining two or more of the competing models above. Findings show Hull and White to be the most powerful approach for capturing downside risk in the energy market. Reasonable results are also available from carefully combining VaR forecasts. (author)

  15. Methodology to determine the technical performance and value proposition for grid-scale energy storage systems :

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Loose, Verne William; Donnelly, Matthew K.; Trudnowski, Daniel J.

    2012-12-01

    As the amount of renewable generation increases, the inherent variability of wind and photovoltaic systems must be addressed in order to ensure the continued safe and reliable operation of the nation's electricity grid. Grid-scale energy storage systems are uniquely suited to address the variability of renewable generation and to provide other valuable grid services. The goal of this report is to quantify the technical performance required to provide di erent grid bene ts and to specify the proper techniques for estimating the value of grid-scale energy storage systems.

  16. Capacity Value of PV and Wind Generation in the NV Energy System

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shuai; Diao, Ruisheng; Samaan, Nader A.; Etingov, Pavel V.

    2014-03-21

    Calculation of photovoltaic (PV) and wind power capacity values is important for estimating additional load that can be served by new PV or wind installations in the electrical power system. It also is the basis for assigning capacity credit payments in systems with markets. Because of variability in solar and wind resources, PV and wind generation contribute to power system resource adequacy differently from conventional generation. Many different approaches to calculating PV and wind generation capacity values have been used by utilities and transmission operators. Using the NV Energy system as a study case, this report applies peak-period capacity factor (PPCF) and effective load carrying capability (ELCC) methods to calculate capacity values for renewable energy sources. We show the connection between the PPCF and ELCC methods in the process of deriving a simplified approach that approximates the ELCC method. This simplified approach does not require generation fleet data and provides the theoretical basis for a quick check on capacity value results of PV and wind generation. The diminishing return of capacity benefit as renewable generation increases is conveniently explained using the simplified capacity value approach.

  17. Measurement of the total solar energy transmittance (g-value) for conventional glazings

    DEFF Research Database (Denmark)

    Duer, Karsten

    1998-01-01

    Three different glazings have been investigated in the Danish experimental setup METSET. (A device for calorimetric measurement of total solar energy transmittance - g-value).The purpose of the measurements is to increase the confidence in the calorimetric measurements. This is done by comparison...... between measurements and calculations. For the investigated types of glazings the g-value can be found with high accuracy by calculations if the relevant optical and thermal data are available. Therefor the calculation results are considered as reference results. The measurements are carried out under...

  18. 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...

  19. Wind energy development and perceived real estate values in Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Chad Walker

    2014-11-01

    Full Text Available This paper focuses on public concerns about real estate value loss in communities in the vicinity of wind turbines. There are some conflicting results in recent academic and non-academic literatures on the issue of property values in general—yet little has been studied about how residents near turbines view the value of their own properties. Using both face-to-face interviews (n = 26 and community survey results (n = 152 from two adjacent communities, this exploratory mixed-method study contextualizes perceived property value loss. Interview results suggest a potential connection between perceived property value loss and actual property value loss, whereby assumed property degradation from turbines seem to lower both asking and selling prices. This idea is reinforced by regression results which suggest that felt property value loss is predicted by health concerns, visual annoyances and community-based variables. Overall, the findings point to the need for greater attention to micro-level local, and interconnected impacts of wind energy development.

  20. Analysis of PV system's values beyond energy - by country and stakeholder

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Polo, A.; Hass, R.; Suna, D.

    2008-03-15

    This report for the International Energy Agency (IEA) made by Task 10 of the Photovoltaic Power Systems (PVPS) programme and PV-Up-Scale analyses, identifies, evaluates and quantifies the major values and benefits of urban scale photovoltaics (PV) based on country and stakeholder specifics. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. The values evaluated and quantified in this report are categorised under the following groups: Avoiding fossil fuels, environmental benefits, benefits for electric utilities, industry development and employment benefits and the customer's individual benefits. The relevance of PV to meeting peak demand is discussed, as are the benefits for architects and building developers.

  1. The value of energy storage in South Korea’s electricity market: A Hotelling approach

    International Nuclear Information System (INIS)

    Shcherbakova, Anastasia; Kleit, Andrew; Cho, Joohyun

    2014-01-01

    Highlights: • We evaluate lifetime economic potential for energy arbitrage in South Korea. • We simulate lifetime energy flows and profits for small price-taking NaS and Li-ion batteries. • We devise optimal battery operating strategy using Hotelling’s depletion rule. • Cumulative profits depend on intraday price differences and social discount rate. • At current electricity prices, neither battery generates enough arbitrage revenue to offset capital costs. - Abstract: In this study we evaluate the economic potential for energy arbitrage by simulating operation and resulting profits of a small price-taking storage device in South Korea’s electricity market. As demand for electricity continues to grow, maintaining a balanced power system at all times has become more challenging in Korea and other developed nations. Along with demand response programs and increased renewable energy utilization, energy storage devices may provide a viable way to contribute to diurnal peak demand shaving. In some parts of the U.S. storage arbitrage has proven to be profitable. Treating a battery’s ability to charge and discharge as a scarce resource, we apply the Hotelling (1931) rule to determine a strategy for maximizing the value of the battery. Results show that present market conditions in South Korea do not provide sufficient economic incentives for energy arbitrage using sodium–sulfur (NaS) or lithium-ion (Li-ion) batteries, with the capital cost of the storage devices exceeding potential revenues

  2. RECOGNITION DYNAMICS OF ESCHERICHIA COLI THIOREDOXIN PROBED USING MOLECULAR DYNAMICS AND BINDING FREE ENERGY CALCULATIONS

    Directory of Open Access Journals (Sweden)

    M. S. Shahul Hameed

    2016-03-01

    Full Text Available E. coli thioredoxin has been regarded as a hub protein as it interacts with, and regulates, numerous target proteins involved in a wide variety of cellular processes. Thioredoxin can form complexes with a variety of target proteins with a wide range of affinity, using a consensus binding surface. In this study an attempt to deduce the molecular basis for the observed multispecificity of E. coli thioredoxin has been made. In this manuscript it has been shown that structural plasticity, adaptable and exposed hydrophobic binding surface, surface electrostatics, closely clustered multiple hot spot residues and conformational changes brought about by the redox status of the protein have been shown to account for the observed multispecificity and molecular recognition of thioredoxin. Dynamical differences between the two redox forms of the enzyme have also been studied to account for their differing interactions with some target proteins.

  3. comets (Constrained Optimization of Multistate Energies by Tree Search): A Provable and Efficient Protein Design Algorithm to Optimize Binding Affinity and Specificity with Respect to Sequence.

    Science.gov (United States)

    Hallen, Mark A; Donald, Bruce R

    2016-05-01

    Practical protein design problems require designing sequences with a combination of affinity, stability, and specificity requirements. Multistate protein design algorithms model multiple structural or binding "states" of a protein to address these requirements. comets provides a new level of versatile, efficient, and provable multistate design. It provably returns the minimum with respect to sequence of any desired linear combination of the energies of multiple protein states, subject to constraints on other linear combinations. Thus, it can target nearly any combination of affinity (to one or multiple ligands), specificity, and stability (for multiple states if needed). Empirical calculations on 52 protein design problems showed comets is far more efficient than the previous state of the art for provable multistate design (exhaustive search over sequences). comets can handle a very wide range of protein flexibility and can enumerate a gap-free list of the best constraint-satisfying sequences in order of objective function value.

  4. Free energy and plaquette expectation value for gluons on the lattice, in three dimensions

    International Nuclear Information System (INIS)

    Panagopoulos, H.; Skouroupathis, A.; Tsapalis, A.

    2006-01-01

    We calculate the perturbative value of the free energy in lattice QCD in three dimensions, up to three loops. Our calculation is performed using the Wilson formulation for gluons in SU(N) gauge theories. The free energy is directly related to the average plaquette. To carry out the calculation, we compute the coefficients involved in the perturbative expansion of the Free Energy up to three loops, using an automated set of procedures developed by us in Mathematica. The dependence on N is shown explicitly in our results. For purposes of comparison, we also present the individual contributions from every diagram. These have been obtained by means of two independent calculations, in order to cross check our results

  5. Roles of binding energy and diffusion length of singlet and triplet excitons in organic heterojunction solar cells

    International Nuclear Information System (INIS)

    Narayan, Monishka Rita; Singh, Jai

    2012-01-01

    The influence of binding energy and diffusion length on the dissociation of excitons in organic solids is studied. The binding energy and excitonic Bohr radius of singlet and triplet excitons are calculated and compared using the dissociation energy of 0.3 eV, which is provided by the lowest unoccupied molecular orbital offset in heterojunction organic solar cells. A relation between the diffusion coefficient and diffusion length of singlet and triplet excitons is derived using the Foerster and Dexter transfer processes and are plotted as a function of the donor-acceptor separation. The diffusion length reduces nearly to a zero if the distance between donor and acceptor is increased to more than 1.5 nm. It is found that the donor-acceptor separation needs to be ≤ 1.5 nm for easy dissociation on singlet excitons leading to better conversion efficiency in heterojunction organic solar cells. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Roles of binding energy and diffusion length of singlet and triplet excitons in organic heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Monishka Rita [Centre for Renewable Energy and Low Emission Technology, Charles Darwin University, Darwin, NT 0909 (Australia); Singh, Jai [School of Engineering and IT, Charles Darwin University, Darwin, NT 0909 (Australia)

    2012-12-15

    The influence of binding energy and diffusion length on the dissociation of excitons in organic solids is studied. The binding energy and excitonic Bohr radius of singlet and triplet excitons are calculated and compared using the dissociation energy of 0.3 eV, which is provided by the lowest unoccupied molecular orbital offset in heterojunction organic solar cells. A relation between the diffusion coefficient and diffusion length of singlet and triplet excitons is derived using the Foerster and Dexter transfer processes and are plotted as a function of the donor-acceptor separation. The diffusion length reduces nearly to a zero if the distance between donor and acceptor is increased to more than 1.5 nm. It is found that the donor-acceptor separation needs to be {<=} 1.5 nm for easy dissociation on singlet excitons leading to better conversion efficiency in heterojunction organic solar cells. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. HypCal, a general-purpose computer program for the determination of standard reaction enthalpy and binding constant values by means of calorimetry.

    Science.gov (United States)

    Arena, Giuseppe; Gans, Peter; Sgarlata, Carmelo

    2016-09-01

    The program HypCal has been developed to provide a means for the simultaneous determination, from data obtained by isothermal titration calorimetry, of both standard enthalpy of reaction and binding constant values. The chemical system is defined in terms of species of given stoichiometry rather than in terms of binding models (e.g., independent or cooperative). The program does not impose any limits on the complexity of the chemical systems that can be treated, including competing ligand systems. Many titration curves may be treated simultaneously. HypCal can also be used as a simulation program when designing experiments. The use of the program is illustrated with data obtained with nicotinic acid (niacin, pyridine-3 carboxylic acid). Preliminary experiments were used to establish the rather different titration conditions for the two sets of titration curves that are needed to determine the parameters for protonation of the carboxylate and amine groups.

  8. Comparison of the Efficiency of the LIE and MM/GBSA Methods to Calculate Ligand-Binding Energies.

    Science.gov (United States)

    Genheden, Samuel; Ryde, Ulf

    2011-11-08

    We have evaluated the efficiency of two popular end-point methods to calculate ligand-binding free energies, LIE (linear interaction energy) and MM/GBSA (molecular mechanics with generalized Born surface-area solvation), i.e. the computational effort needed to obtain estimates of a similar precision. As a test case, we use the binding of seven biotin analogues to avidin. The energy terms used by MM/GBSA and LIE exhibit a similar correlation time (∼5 ps), and the equilibration time seems also to be similar, although it varies much between the various ligands. The results show that the LIE method is more effective than MM/GBSA, by a factor of 2-7 for a truncated spherical system with a radius of 26 Å and by a factor of 1.0-2.4 for the full avidin tetramer (radius 47 Å). The reason for this is the cost for the MM/GBSA entropy calculations, which more than compensates for the extra simulation of the free ligand in LIE. On the other hand, LIE requires that the protein is neutralized, whereas MM/GBSA has no such requirements. Our results indicate that both the truncation and neutralization of the proteins may slow the convergence and emphasize small differences in the calculations, e.g., differences between the four subunits in avidin. Moreover, LIE cannot take advantage of the fact that avidin is a tetramer. For this test case, LIE gives poor results with the standard parametrization, but after optimizing the scaling factor of the van der Waals terms, reasonable binding affinities can be obtained, although MM/GBSA still gives a significantly better predictive index and correlation to the experimental affinities.

  9. Energy Renovation of Buildings Utilizing the U-value Meter, a New Heat Loss Measuring Device

    Directory of Open Access Journals (Sweden)

    Lars Schiøtt Sørensen

    2010-01-01

    Full Text Available A new device with the ability to measure heat loss from building facades is proposed. Yet to be commercially developed, the U-value Meter can be used as stand-alone apparatus, or in combination with thermographic-equipment. The U-value meter complements thermographs, which only reproduce surface temperature and not the heat loss distribution. There is need for a device that measures the heat loss in a quantitative manner. Convective as well as radiative heat losses are captured and measured with a five-layer thermal system. Heat losses are measured in the SI-unit W/m2K. The aim is to achieve more cost-effective building renovation, and provide a means to check the fulfillment of Building Regulation requirements with respect to stated U-values (heat transmission coefficients. In this way it should be possible to greatly reduce energy consumption of buildings.

  10. Improving the energy performance of historic buildings with architectural and cultural values

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2017-01-01

    The thermal performance of solid walls of historic buildings can be improved by external or internal insulation. External insulation is preferred from a technical perspective, but is often disregarded as many such buildings have architectural or cultural values leaving internal insulation.......g. improvement of thermal indoor climate. The paper discusses different motivating factors for improving the thermal performance of solid walls in historic buildings with architectural and cultural values. It is argued that internal insulation, provided that it can be done without resulting in critical moisture......, instead of replacing them with new energy-efficient buildings, because of the architectural and cultural values that they possess. The underlying basis for this study is a 5-year research project, RIBuild, funded by the European Commission, running from 2015 to 2019....

  11. Investigation of value and costs of wind energy in the electric system. Report - Final meeting, Paris, 30 January 2013

    International Nuclear Information System (INIS)

    2013-01-01

    This document contains five Power Point presentations which respectively address: the values and costs of wind energy in the electric system (economic assessment of wind energy in the French electric system), the analysis principles and methods (economic assessment and comparison of two scenarios defined by six different parameters: consumption, energy price, wind energy deployment, evolution of the nuclear fleet, nuclear load factor, potential of demand side management), the analysis of the energy substitution value, the value analysis of the peak management, and the impact on infrastructures and system services

  12. Crystallography aided by atomic core-level binding energies: proton transfer versus hydrogen bonding in organic crystal structures.

    Science.gov (United States)

    Stevens, Joanna S; Byard, Stephen J; Seaton, Colin C; Sadiq, Ghazala; Davey, Roger J; Schroeder, Sven L M

    2011-10-10

    Ionic bond or hydrogen bridge? Brønsted proton transfer to nitrogen acceptors in organic crystals causes strong N1s core-level binding energy shifts. A study of 15 organic cocrystal and salt systems shows that standard X-ray photoelectron spectroscopy (XPS) can be used as a complementary method to X-ray crystallography for distinguishing proton transfer from H-bonding in organic condensed matter. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Calculation of relative free energies for ligand-protein binding, solvation, and conformational transitions using the GROMOS software.

    Science.gov (United States)

    Riniker, Sereina; Christ, Clara D; Hansen, Halvor S; Hünenberger, Philippe H; Oostenbrink, Chris; Steiner, Denise; van Gunsteren, Wilfred F

    2011-11-24

    The calculation of the relative free energies of ligand-protein binding, of solvation for different compounds, and of different conformational states of a polypeptide is of considerable interest in the design or selection of potential enzyme inhibitors. Since such processes in aqueous solution generally comprise energetic and entropic contributions from many molecular configurations, adequate sampling of the relevant parts of configurational space is required and can be achieved through molecular dynamics simulations. Various techniques to obtain converged ensemble averages and their implementation in the GROMOS software for biomolecular simulation are discussed, and examples of their application to biomolecules in aqueous solution are given. © 2011 American Chemical Society

  14. The market value of energy efficiency: What have we learned? What do we still need to learn?

    International Nuclear Information System (INIS)

    Lee, D.; Nevin, R.; Farhar, B.C.

    1998-01-01

    The Environmental Protection Agency (EPA) and the Department of Energy (DOE) at the National Energy Renewable Laboratory (NREL) are investigating the market value of energy efficiency in residential homes. The demonstrated market value for energy efficiency is crucial to the success of EPA's ENERGY STAR Homes Program, providing market information to builders who are deciding whether to construct ENERGY STAR Homes, to lenders who may want to understand the performance of mortgages for energy-efficient homes, and to home owners seeking returns on additional investments in energy-efficient homes. The paper discusses the current dilemma facing the ENERGY STAR Homes Program and the need to demonstrate the value of energy efficiency. The paper presents a brief literature review of past studies on the market value of energy efficiency, as well as a recent analysis on the American Housing Survey. this study suggests that property values increase by $20 to $24 for every $1 reduction in annual fuel bill. Finally, the paper concludes with a summary of a joint research project between EPA and NREL on the market value of ENERGY STAR Homes, and the potential implications of this research

  15. Quantum mechanics/molecular mechanics modeling of photoelectron spectra: the carbon 1s core-electron binding energies of ethanol-water solutions.

    Science.gov (United States)

    Löytynoja, T; Niskanen, J; Jänkälä, K; Vahtras, O; Rinkevicius, Z; Ågren, H

    2014-11-20

    Using ethanol-water solutions as illustration, we demonstrate the capability of the hybrid quantum mechanics/molecular mechanics (QM/MM) paradigm to simulate core photoelectron spectroscopy: the binding energies and the chemical shifts. An integrated approach with QM/MM binding energy calculations coupled to preceding molecular dynamics sampling is adopted to generate binding energies averaged over the solute-solvent configurations available at a particular temperature and pressure and thus allowing for a statistical assessment with confidence levels for the final binding energies. The results are analyzed in terms of the contributions in the molecular mechanics model-electrostatic, polarization, and van der Waals-with atom or bond granulation of the corresponding MM charge and polarizability force-fields. The role of extramolecular charge transfer screening of the core-hole and explicit hydrogen bonding is studied by extending the QM core to cover the first solvation shell. The results are compared to those obtained from pure electrostatic and polarizable continuum models. Particularly, the dependence of the carbon 1s binding energies with respect to the ethanol concentration is studied. Our results indicate that QM/MM can be used as an all-encompassing model to study photoelectron binding energies and chemical shifts in solvent environments.

  16. Amine-hydrogen halide complexes: experimental electric dipole moments and a theoretical decomposition of dipole moments and binding energies.

    Science.gov (United States)

    Brauer, Carolyn S; Craddock, Matthew B; Kilian, Jacob; Grumstrup, Erik M; Orilall, M Christopher; Mo, Yirong; Gao, Jiali; Leopold, Kenneth R

    2006-08-24

    The Stark effect has been observed in the rotational spectra of several gas-phase amine-hydrogen halide complexes and the following electric dipole moments have been determined: H(3)(15)N-H(35)Cl (4.05865 +/- 0.00095 D), (CH(3))(3)(15)N-H(35)Cl (7.128 +/- 0.012 D), H(3)(15)N-H(79)Br (4.2577 +/- 0.0022 D), and (CH(3))(3)(15)N-H(79)Br (8.397 +/- 0.014 D). Calculations of the binding energies and electric dipole moments for the full set of complexes R(n)()(CH(3))(3)(-)(n)()N-HX (n = 0-3; X = F, Cl, Br) at the MP2/aug-cc-pVDZ level are also reported. The block localized wave function (BLW) energy decomposition method has been used to partition the binding energies into contributions from electrostatic, exchange, distortion, polarization, and charge-transfer terms. Similarly, the calculated dipole moments have been decomposed into distortion, polarization, and charge-transfer components. The complexes studied range from hydrogen-bonded systems to proton-transferred ion pairs, and the total interaction energies vary from 7 to 17 kcal/mol across the series. The individual energy components show a much wider variation than this, but cancellation of terms accounts for the relatively narrow range of net binding energies. For both the hydrogen-bonded complexes and the proton-transferred ion pairs, the electrostatic and exchange terms have magnitudes that increase with the degree of proton transfer but are of opposite sign, leaving most of the net stabilization to arise from polarization and charge transfer. In all of the systems studied, the polarization terms contribute the most to the induced dipole moment, followed by smaller but still significant contributions from charge transfer. A significant contribution to the induced moment of the ion pairs also arises from distortion of the HX monomer.

  17. Ligand-induced structural changes in TEM-1 probed by molecular dynamics and relative binding free energy calculations.

    Science.gov (United States)

    Pimenta, A C; Martins, J M; Fernandes, R; Moreira, I S

    2013-10-28

    The TEM family of enzymes has had a crucial impact on the pharmaceutical industry due to their important role in antibiotic resistance. Even with the latest technologies in structural biology and genomics, no 3D structure of a TEM-1/antibiotic complex is known previous to acylation. Therefore, the comprehension of their capability in acylate antibiotics is based on the protein macromolecular structure uncomplexed. In this work, molecular docking, molecular dynamic simulations, and relative free energy calculations were applied in order to get a comprehensive and thorough analysis of TEM-1/ampicillin and TEM-1/amoxicillin complexes. We described the complexes and analyzed the effect of ligand binding on the overall structure. We clearly demonstrate that the key residues involved in the stability of the ligand (hot-spots) vary with the nature of the ligand. Structural effects such as (i) the distances between interfacial residues (Ser70-Oγ and Lys73-Nζ, Lys73-Nζ and Ser130-Oγ, and Ser70-Oγ-Ser130-Oγ), (ii) side chain rotamer variation (Tyr105 and Glu240), and (iii) the presence of conserved waters can be also influenced by ligand binding. This study supports the hypothesis that TEM-1 suffers structural modifications upon ligand binding.

  18. A Correlation between the Activity of Candida antarctica Lipase B and Differences in Binding Free Energies of Organic Solvent and Substrate

    DEFF Research Database (Denmark)

    Banik, Sindrila Dutta; Nordblad, Mathias; Woodley, John

    2016-01-01

    in an inhibitory effect which is also confirmed by the binding free energies for the solvent and substrate molecules estimated from the simulations. Consequently, the catalytic activity of CALB decreases in polar solvents. This effect is significant, and CALB is over 10 orders of magnitude more active in nonpolar...... of the enzyme may be ascribed to binding of solvent molecules to the enzyme active site region and the solvation energy of substrate molecules in the different solvents. Polar solvent molecules interact strongly with CALB and compete with the substrate to bind to the active site region, resulting...

  19. Generalized Extreme Value Distribution Models for the Assessment of Seasonal Wind Energy Potential of Debuncha, Cameroon

    Directory of Open Access Journals (Sweden)

    Nkongho Ayuketang Arreyndip

    2016-01-01

    Full Text Available The method of generalized extreme value family of distributions (Weibull, Gumbel, and Frechet is employed for the first time to assess the wind energy potential of Debuncha, South-West Cameroon, and to study the variation of energy over the seasons on this site. The 29-year (1983–2013 average daily wind speed data over Debuncha due to missing values in the years 1992 and 1994 is gotten from NASA satellite data through the RETScreen software tool provided by CANMET Canada. The data is partitioned into min-monthly, mean-monthly, and max-monthly data and fitted using maximum likelihood method to the two-parameter Weibull, Gumbel, and Frechet distributions for the purpose of determining the best fit to be used for assessing the wind energy potential on this site. The respective shape and scale parameters are estimated. By making use of the P values of the Kolmogorov-Smirnov statistic (K-S and the standard error (s.e analysis, the results show that the Frechet distribution best fits the min-monthly, mean-monthly, and max-monthly data compared to the Weibull and Gumbel distributions. Wind speed distributions and wind power densities of both the wet and dry seasons are compared. The results show that the wind power density of the wet season was higher than in the dry season. The wind speeds at this site seem quite low; maximum wind speeds are listed as between 3.1 and 4.2 m/s, which is below the cut-in wind speed of many modern turbines (6–10 m/s. However, we recommend the installation of low cut-in wind turbines like the Savonius or Aircon (10 KW for stand-alone low energy need.

  20. 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....

  1. A simple method for measuring sex-hormone binding protein (SHBP) - typical values in men and women and in pregnant women

    International Nuclear Information System (INIS)

    Tafurt, C.A.; Estrada, R. de

    1978-01-01

    Assuming that the binding forces between steroid hormones and their binding proteins are similar to those between antigens and their antibodies, the authors describe how to determine SHBP activity by a dilution method analogous to that used for titration of antisera in radioimmunoassay. The method consists of the following stages: (1) plasma dilution; (2) incubation of the dilution with 20,000dis/min of 1,2- 3 H-testosterone; (3) separation of the fraction of tracer bound to the SHBP by precipitation with ammonium sulphate; (4) centrifugation and measurement of the supernatant; and (5) plotting of the results on a graph where the axis of ordinates represents the quotient given by bound steroid over free steroid (U/L) and the abscissa represents the plasma dilutions. The values are expressed as the 50% bound titre. An advantage of the method is the higher sensitivity of the dilution curves in the steepest part where the 50% bound is encountered; it is thus not necessary to use the saturation part of the curves where sensitivity is lost owing to the steeper slope. A further advantage of the method is that there is no need for costly processes such as dialysis. The SHBP values obtained for healthy subjects were as follows: 1/5 for men, 1/93 for women, and 1/360 in pregnant women. These physiological values showed no overlapping. (author)

  2. Energy partitioning and GPP values in a rotating crop in the Spanish Plateau

    Science.gov (United States)

    Sánchez, María Luisa; Pardo, Nuria; Perez, Isidro A.; Garcia, M. Angeles

    2016-04-01

    In order to assess crop ability to act as a CO2 sink and to describe GPP dynamic evolution, in 2008 we installed an eddy correlation station located in an agricultural plot of the Spanish plateau. Continuous measurements of 30-min NEE fluxes and other common variables have been measured over four years. Agricultural practices at the selected plot consisted of annual rotation of non-irrigated rapeseed, wheat, peas, rye. The maximum canopy height of rapeseed, wheat and rye was 1.3, 0.6 and 1.6 m respectively, the values being reached at the end of May. Although no measurements were performed in the pea crop, according to the farmer's information the maximum height was approximately 0.45-0.5 m. The quality of long-term eddy covariance data was evaluated by calculating the energy balance closure. This paper presents and compares the seasonal variation of major components involved in the energy balance as well as GPP for each type of crop. An energy balance closure of 92% was found when using the global dataset. On a four-year basis, the sensible heat flux, H, played the main role in the energy balance with a ratio of 52%. Latent heat flux, LE, accounted for 40% of the energy, with soil heat flux contributing around 8% to the energy balance. These values changed during the period of maximum interest. For this period LE played the main role, using over half of the available energy, 51%, related to evapotranspiration processes. Over the four years of study annual accumulated GPP exhibited a great variability, 1680, 710, 730 and 1410 g C m-2 for rapeseed, wheat, peas and rye, respectively. The influence of crop architecture, phenology and climatic conditions dominated crop-to-crop seasonal evolution. The highest LE contributions to the energy balance were found for rapeseed and rye. Higher GPP were also obtained for denser and higher canopy height crops, rapeseed and rye, yielding annuals almost comparable to C4 plants. Both crops exhibited a marked seasonal variation of

  3. Core-level spectra and binding energies of transition metal nitrides by non-destructive x-ray photoelectron spectroscopy through capping layers

    Energy Technology Data Exchange (ETDEWEB)

    Greczynski, G., E-mail: grzgr@ifm.liu.se [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden); Primetzhofer, D. [Department of Physics and Astronomy, The Ångström Laboratory, Uppsala University, P.O. Box 516, SE-751 20 Uppsala (Sweden); Lu, J.; Hultman, L. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden)

    2017-02-28

    Highlights: • First non-destructive measurements of XPS core level binding energies for group IVb-VIb transition metal nitrides are presented. • All films are grown under the same conditions and analyzed in the same instrument, providing a useful reference for future XPS studies. • Extracted core level BE values are more reliable than those obtained from sputter-cleaned N-deficient surfaces. • Comparison to Ar+-etched surfaces reveals that even mild etching conditions result in the formation of a nitrogen-deficient surface layer. • The N/metal concentration ratios from capped samples are found to be 25-90% higher than those from the corresponding ion-etched surfaces. - Abstract: We present the first measurements of x-ray photoelectron spectroscopy (XPS) core level binding energies (BE:s) for the widely-applicable group IVb-VIb polycrystalline transition metal nitrides (TMN’s) TiN, VN, CrN, ZrN, NbN, MoN, HfN, TaN, and WN as well as AlN and SiN, which are common components in the TMN-based alloy systems. Nitride thin film samples were grown at 400 °C by reactive dc magnetron sputtering from elemental targets in Ar/N{sub 2} atmosphere. For XPS measurements, layers are either (i) Ar{sup +} ion-etched to remove surface oxides resulting from the air exposure during sample transfer from the growth chamber into the XPS system, or (ii) in situ capped with a few nm thick Cr or W overlayers in the deposition system prior to air-exposure and loading into the XPS instrument. Film elemental composition and phase content is thoroughly characterized with time-of-flight elastic recoil detection analysis (ToF-E ERDA), Rutherford backscattering spectrometry (RBS), and x-ray diffraction. High energy resolution core level XPS spectra acquired with monochromatic Al Kα radiation on the ISO-calibrated instrument reveal that even mild etching conditions result in the formation of a nitrogen-deficient surface layer that substantially affects the extracted binding energy

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

    International Nuclear Information System (INIS)

    Heger, Matthias; Suhm, Martin A.; Mata, Ricardo A.

    2014-01-01

    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 −1 upon dimerization, somewhat more than in the anharmonic experiment (−111 cm −1 )

  5. Substitutional disorder, random dipoles and the binding energy of orthorhombic La2-xSrxCuO4

    International Nuclear Information System (INIS)

    Birkholz, M.; Rudert, R.

    1995-01-01

    This study investigates the effect of heterovalent, substitutional disorder on the binding energy of La 2-x Sr x CuO 4 . First, disorder has been found to create crystal electric fields that fluctuate over different lattice sites and induce ionic dipole moments of varying strength and orientation. The strength of these random dipoles will be presented for increasing x. Second, disorder may slightly displace the ions from their average lattice sites. The large thermal parameters obtained from diffraction experiments are discussed in this context. Finally, the polarization energy related to random dipoles was calculated to be on the order of eV and favourizes the positive charge carriers introduced by Sr doping to be associated with the copper ions. It is concluded that the solid exists in a state containing mixed copper valencies (Cu 2+ /Cu 3+ ). (orig.)

  6. The value of electricity storage in energy-only electricity markets

    Science.gov (United States)

    McConnell, D.; Forcey, T.; Sandiford, M.

    2015-12-01

    Price volatility and the prospect of increasing renewable energy generation have raised interest in the potential opportunities for storage technologies in energy-only electricity markets. In this paper we explore the value of a price-taking storage device in such a market, the National Electricity Market (NEM) in Australia. Our analysis suggests that under optimal operation, there is little value in having more than six hours of storage in this market. However, the inability to perfectly forecast wholesale prices, particularly extreme price spikes, may warrant some additional storage. We found that storage devices effectively provide a similar service as peak generators (such as Open Cycle Gas Turbines) and are similarly dependent on and exposed to extreme price events, with revenue for a merchant generator highly skewed to a few days of the year. In contrast to previous studies, this results in the round trip efficiency of the storage being relatively insignificant. Financing using hedging strategies similar to a peak generator effectively reduces the variability of revenue and exposure of storage to extreme prices. Our case study demonstrates that storage may have a competitive advantage over other peaking generators on the NEM, due to its ability to earn revenue outside of extreme peak events. As a consequence the outlook for storage options on the NEM is dependent on volatility, in turn dependent on capacity requirements. Further to this, increased integration of renewable energy may both depend on storage and improve the outlook for storage in technologies in electricity markets.

  7. National and local energy market. Consumer as final step of the value chain

    International Nuclear Information System (INIS)

    Antonioli, B.

    2008-01-01

    Consumer as final step of the value chain - The reorganization of the energy market, together with an increase in the mobility of resources and the evolution of supply, have reduced borders between national and local market, and both regulatory policies and players' strategies have to consider these renewed environment. The goal of this paper is to make some considerations about the dimension and the interactions between national and locals, up-stream and downstream energy markets, both in terms of value chain phases regulation and of the impact on firms' organization and on the industry as a whole. We want to highlight evident problems of coordination of different rules, the necessity to define a clear national industrial policy (not fragmented at local level), as well as the relevance of the end user prices regulation for liberalized market. In particular, this kind of regulation seems to represent a key point of the current discussion between operators and the energy Authority. The end users price regulation present some critical aspects related to its (contested) limited contribution to a real price competition but, on the other side, had to be considered as a strong protection for domestic customers, as well as a way to reduce information asymmetry. [it

  8. [Determination of feeding value on simple food characteristics. 2. Determination of food energy value of green feeds].

    Science.gov (United States)

    Nehring, K

    1975-06-01

    Regression analyses had been made to find interrelationships between the crude fibre content and the EFr content of green feeds. Regression equations were obtained from these analyses which were used to calculate the EFr values, with a sufficient degree of accuracy, from data on the crude fibre content. In these equations the b values were found to be by far more clearly differentiated than in the equations used for calculating digestibility values. These are apparently influenced by the composition of the feeds. The range of variations appears to be only slightly affected when we compare the data with those obtained in calculations made to established the total digestibility values. This is a fact that applies to both the green feeds and their conservation products. Studies investigating the relationships between the content of digestible organic matter (VOS) and EFr (as expressed by the conversion factor (see article) showed that the EFr data could be established, with a fair degree of accuracy, from the VOS values. The f values of the different feeds that were classified into particular groups of feeding-stuffs, were shown to agree fairly well; moreover, they were found to be largely independent of exogenic factors (such as vegetation and N fertilizing). Characteristic differences between the f values of the different conservation products and those of the green feeds were observed although these differences remained within narrow limits (1-3%), so that calculations can be made using only a few factors. When starch equivalents were taken into account it was found that the f values used in calculations for starch equivalents were clearly influenced by feed composition, which, in turn, was influenced by the particular effect of crude values in SE calculations. It is at this point that differences between the two systems of Food Evaluation become particularly apparent. The close relations existing between VOS and EFr values apply, first and foremost, to green feeds

  9. 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.

  10. Binding energy and momentum distribution of nuclear matter using Green's function methods

    International Nuclear Information System (INIS)

    Ramos, A.; Dickhoff, W.H.; Polls, A.

    1991-01-01

    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 v 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

  11. Binding energy and momentum distribution of nuclear matter using Green's function methods

    International Nuclear Information System (INIS)

    Ramos, A.; Dickhoff, W.H.; Polls, A.

    1990-07-01

    The influence of hole-hole (hh) propagation in addition to the conventional particle-particle (pp) propagation on the energy per particle and the momentum distribution is investigated for two central interactions (v 2 and v 2 l=0 ) which are 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 which allows the inclusion of hh 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 pp and hh propagation to all orders. These results can be considered as the contributions of selected Goldstone diagrams (including pp and hh terms on the same footing) to the kinetic and potential energy in which the sp energy is given by the quasi-article 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 pp and hh ladder contributions (using a realistic interaction) will shed light on the question of nuclear saturation at a non-relativistic level which is consistent with the observed depletion of sp orbitals in finite nuclei. (Author) (51 refs., 3 tabs., 15 figs)

  12. Monte Carlo simulations of the cellular S-value, lineal energy and RBE for BNCT

    International Nuclear Information System (INIS)

    Liu Chingsheng; Tung Chuanjong

    2006-01-01

    Due to the non-uniform uptake of boron-containing pharmaceuticals in cells and the short-ranged alpha and lithium particles, microdosimetry provides useful information on the cellular dose and response of boron neutron capture therapy (BNCT). Radiation dose and quality in BNCT may be expressed in terms of the cellular S-value and the lineal energy spectrum. In the present work, Monte Carlo simulations were performed to calculate these microdosimetric parameters for different source-target configurations and sizes in cells. The effective relative biological effectiveness (RBE) of the Tsing Hua Open-pool Reactor (THOR) epithermal neutron beam was evaluated using biological weighting functions that depended on the lineal energy. RBE changes with source-target configurations and sizes were analyzed. (author)

  13. Dynamic Average-Value Modeling of Doubly-Fed Induction Generator Wind Energy Conversion Systems

    Science.gov (United States)

    Shahab, Azin

    In a Doubly-fed Induction Generator (DFIG) wind energy conversion system, the rotor of a wound rotor induction generator is connected to the grid via a partial scale ac/ac power electronic converter which controls the rotor frequency and speed. In this research, detailed models of the DFIG wind energy conversion system with Sinusoidal Pulse-Width Modulation (SPWM) scheme and Optimal Pulse-Width Modulation (OPWM) scheme for the power electronic converter are developed in detail in PSCAD/EMTDC. As the computer simulation using the detailed models tends to be computationally extensive, time consuming and even sometimes not practical in terms of speed, two modified approaches (switching-function modeling and average-value modeling) are proposed to reduce the simulation execution time. The results demonstrate that the two proposed approaches reduce the simulation execution time while the simulation results remain close to those obtained using the detailed model simulation.

  14. Coexistence of a bound state and scattering at the same energy value: a quantum paradox

    International Nuclear Information System (INIS)

    Chabanov, V.M.; Zakhar'ev, B.N.

    1998-01-01

    The example of a multi-channel system which possesses both bound (not quasi-bound !) and scattering states at the same energy value E is demonstrated. A special interaction has ability to confine waves near the origin and simultaneously admit scattering (even with transparency) at the fixed spectral point. These interaction matrices and wave functions can be continued to the whole axis. As another multi-channel peculiarity having no one-channel analogues was found a class of absolutely transparent interaction matrices without bound states

  15. Binding energies of the 1gsub(9/2) and 1hsub(11/2) neutron and average two-body effective interactions anti Vsub(pn) and anti Vsub(nn)

    International Nuclear Information System (INIS)

    Sakai, M.

    1980-01-01

    The binding energies of the single particle or hole orbitals of the 1gsub(9/2) and 1hsub(11/2) neutron shells are given as a simple linear function of the active valence proton and neutron numbers. This function is derived theoretically by the assumption of constant two-body effective interactions anti Vsub(pn) and anti Vsub(nn) in the relevant proton and neutron shell spaces. These values, appearing in the function as the coefficients of the proton and neutron numbers, are determined from the experimental binding energies by a least-squares fit. The good quality of fit between the experimental and fitted binding energies implies the plausibility of the formula and the assumption. The determined anti Vsub(pn) and anti Vsub(nn) have absolute values and signs consistent with those in the literature. The effective interactions in the case of the 1gsub(9/2) hole is found to decrease with increasing mass number. (orig.)

  16. Developing a Novel Hydrogen Sponge with Ideal Binding Energy and High Surface Area for Practical Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Chung, T. C. Mike

    2018-04-19

    This Phase I (5 quarters) research project was to examine the validity of a new class of boron-containing polymer (B-polymer) frameworks, serving as the adsorbents for the practical onboard H2 storage applications. Three B-polymer frameworks were synthesized and investigated, which include B-poly(butyenylstyrene) (B-PBS) framework (A), B-poly(phenyldiacetyene) (B-PPDA) framework (B), and B-poly(phenyltriacetylene) (B-PPTA) framework (C). They are 2-D polymer structures with the repeating cyclic units that spontaneously form open morphology and the B-doped (p-type) π-electrons delocalized surfaces. The ideal B-polymer framework shall exhibit open micropores (pore size in the range of 1-1.5nm) with high surface area (>3000 m2/g), and the B-dopants in the conjugated framework shall provide high surface energy for interacting with H2 molecules (an ideal H2 binding energy in the range of 15-25 kJ/mol). The pore size distribution and H2 binding energy were investigated at both Penn State and NREL laboratories. So far, the experimental results show the successful synthesis of B-polymer frameworks with the relatively well-defined planar (2-D) structures. The intrinsically formed porous morphology exhibits a broad pore size distribution (in the range of 0.5-10 nm) with specific surface area (~1000 m2/g). The miss-alignment between 2-D layers may block some micropore channels and limit gas diffusion throughout the entire matrix. In addition, the 2-D planar conjugated structure may also allow free π-electrons delocalization throughout the framework, which significantly reduces the acidity of B-moieties (electron-deficiency).The resulting 2-D B-polymer frameworks only exhibit a small increase of H2 binding energy in the range of 8-9 KJ/mole (quite constant over the whole sorption range).

  17. Standardized MET Value Underestimates the Energy Cost of Treadmill Running in Men.

    Science.gov (United States)

    Ázara, Helouane M; Farinatti, Paulo T V; Midgley, Adrian W; Vasconcellos, Fabrício; Vigário, Patrícia; Cunha, Felipe A

    2017-11-01

    The main purpose of the present study was to compare the reference metabolic equivalent (MET) value and observed resting oxygen uptake (VO 2 ) for defining cardiorespiratory fitness (VO 2max ) and characterizing the energy cost of treadmill running. A heterogeneous cohort of 114 healthy men volunteered to participate. In Part 1 of the study, 114 men [mean±SD, age: 24±5 years; height: 177.1±7.9 cm; body mass: 75.0±10.0 kg] visited the laboratory twice for assessment of resting and maximal VO 2 values to compare the reference MET value vs. observed resting VO 2 and to investigate the association between resting VO 2 and VO 2max . In Part 2, 14 of the 114 men visited the laboratory once more to perform a 30-min bout of running at 8.0 km∙h -1 /8.3 METs. The mean observed resting VO 2 of 3.26 mL·kg -1 ·min -1 was lower than the reference MET value of 3.5 mL·kg -1 ·min -1 (Pvalues relative to total body mass and fat-free mass were positively correlated (R=0.71 and 0.60, respectively; Pvalue only for those with low VO 2max (P=0.005 to Pvalue considerably overestimated observed resting VO 2 in men with low VO 2max , resulting in underestimations of the maximal MET, exercise intensity prescription, and the energy cost of running. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Dual Energy X-Ray Absorptiometry Body Composition Reference Values from NHANES

    Science.gov (United States)

    Kelly, Thomas L.; Wilson, Kevin E.; Heymsfield, Steven B.

    2009-01-01

    In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA) whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height2, lean mass/height2, appendicular lean mass/height2, %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC) and bone mineral density (BMD) were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass. We developed an obesity classification scheme by using estabbody mass index (BMI) classification thresholds and prevalences in young adults to generate matching classification thresholds for Fat Mass Index (FMI; fat mass/height2). These reference values should be helpful in the evaluation of a variety of adult and childhood abnormalities involving fat, lean, and bone, for establishing entry criteria into clinical trials, and for other medical, research, and epidemiological uses. PMID:19753111

  19. Dual energy X-Ray absorptiometry body composition reference values from NHANES.

    Directory of Open Access Journals (Sweden)

    Thomas L Kelly

    Full Text Available In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height(2, lean mass/height(2, appendicular lean mass/height(2, %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC and bone mineral density (BMD were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass. We developed an obesity classification scheme by using estabbody mass index (BMI classification thresholds and prevalences in young adults to generate matching classification thresholds for Fat Mass Index (FMI; fat mass/height(2. These reference values should be helpful in the evaluation of a variety of adult and childhood abnormalities involving fat, lean, and bone, for establishing entry criteria into clinical trials, and for other medical, research, and epidemiological uses.

  20. Prognostic value of insulinlike growth factor I and its binding protein in patients with alcohol-induced liver disease. EMALD group

    DEFF Research Database (Denmark)

    Møller, Søren; Becker, Povl Ulrik; Juul, A

    1996-01-01

    , and immunoglobulin (Ig) M. When IGF-I or IGFBP-3 were added into this model, a Cox regression analysis showed that either had a significant independent prognostic value. Because IGF-I and IGFBP-3 were closely correlated, they contained almost the same prognostic information. Inclusion of IGF-I gave these results......Insulinlike growth factor I (IGF-I) is a single-polypeptide chain with important anabolic and endocrine activities. The liver is the major source of IGF-I and its binding protein, IGFBP-3. Circulating concentrations of IGF-I and IGFBP-3 are decreased in patients with chronic liver disease...... and correlate with the severity. The aim of this study was to assess the additional prognostic value of IGF-I and IGFBP-3 in patients entered in a large multicenter study (EMALD). Three hundred thirty-seven patients with alcohol-induced liver disease were studied in a randomized placebo-controlled trial...

  1. Evaluation of energy spectral information in nuclear imaging and investigation of protein binding of cationic radionuclides by lactoferrin. Comprehensive progress report, October 1, 1977-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Hoffer, P. B.

    1980-06-10

    Construction of an Anger camera-computer system which allows collection of both the position and energy signals from events detected by the scintillation camera has been completed. The system allows correction of energy response non-uniformity of the detector and facilitates research related to effects of energy discrimination in radionuclide scintigraphy. The system consists of electronic hardware to transmit and digitize the energy signal, software to record and process that signal in conjunction with spatial positioning signals, and additional hardware for recording the processed images so that they can be evaluated by observers. Preliminary results indicate that the system is useful in evaluating clinical images. Assymetric (eccentric) energy windows do improve image quality and are of value in improving detection of lesions on liver scintigraphs. The mechanisms by which Ga-67 is taken up in infection and tumor has been elucidated, and the uptake of radiogallium in microorganisms as a function of its interaction with siderophores was also studied. The primary function of these low molecular weight compounds is to trap ferric ion. However, gallium may be substituted for ferric ion and becomes trapped within the microorganism. The uptake of radiogallium by neutrophils and the role that lactoferrin plays in both intracellular localization of radiogallium and subsequent deposition of the radionuclide at sites of infection were also studied. Investigation of ferric ion analogs reveals definate differences in the affinity of these metals for binding molecules which helps explain their biologic activity. While ferric ion has the strongest affinity for such molecules, gallium has very high affinity for siderophores, moderate affinity for lactoferrin, and lower affinity for transferrin. The relative affinity of indium for these molecules is in approximately the reverse order.

  2. Energy conversion through mass loading of escaping ionospheric ions for different Kp values

    Science.gov (United States)

    Yamauchi, Masatoshi; Slapak, Rikard

    2018-01-01

    Fload. Since Fload significantly increases for increased flux of extreme ultraviolet (EUV) radiation, high EUV flux may significantly enhance this positive feedback. Therefore, the ion escape rate and the energy extraction by mass loading during ancient Earth, when the Sun is believed to have emitted much higher EUV flux than at present, could have been even higher than the currently available highest values based on Kp = 9. This raises a possibility that the ion escape has substantially contributed to the evolution of the Earth's atmosphere.

  3. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on Dietary Reference Values for energy

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived dietary reference values for energy, which are provided as average requirements (ARs) of specified age and sex groups. For children and adults, total energy expenditure (TEE...... ARs for energy may need to be adapted depending on specific objectives and target populations. © European Food Safety Authority, 2013...

  4. Age-related energy values of bakery meal for broiler chickens determined using the regression method.

    Science.gov (United States)

    Stefanello, C; Vieira, S L; Xue, P; Ajuwon, K M; Adeola, O

    2016-07-01

    A study was conducted to determine the ileal digestible energy (IDE), ME, and MEn contents of bakery meal using the regression method and to evaluate whether the energy values are age-dependent in broiler chickens from zero to 21 d post hatching. Seven hundred and eighty male Ross 708 chicks were fed 3 experimental diets in which bakery meal was incorporated into a corn-soybean meal-based reference diet at zero, 100, or 200 g/kg by replacing the energy-yielding ingredients. A 3 × 3 factorial arrangement of 3 ages (1, 2, or 3 wk) and 3 dietary bakery meal levels were used. Birds were fed the same experimental diets in these 3 evaluated ages. Birds were grouped by weight into 10 replicates per treatment in a randomized complete block design. Apparent ileal digestibility and total tract retention of DM, N, and energy were calculated. Expression of mucin (MUC2), sodium-dependent phosphate transporter (NaPi-IIb), solute carrier family 7 (cationic amino acid transporter, Y(+) system, SLC7A2), glucose (GLUT2), and sodium-glucose linked transporter (SGLT1) genes were measured at each age in the jejunum by real-time PCR. Addition of bakery meal to the reference diet resulted in a linear decrease in retention of DM, N, and energy, and a quadratic reduction (P bakery meal did not affect jejunal gene expression. Expression of genes encoding MUC2, NaPi-IIb, and SLC7A2 linearly increased (P bakery meal linearly increased (P bakery meal was included and increased with age of broiler chickens. © 2016 Poultry Science Association Inc.

  5. The composition, heating value and renewable share of the energy content of mixed municipal solid waste in Finland.

    Science.gov (United States)

    Horttanainen, M; Teirasvuo, N; Kapustina, V; Hupponen, M; Luoranen, M

    2013-12-01

    For the estimation of greenhouse gas emissions from waste incineration it is essential to know the share of the renewable energy content of the combusted waste. The composition and heating value information is generally available, but the renewable energy share or heating values of different fractions of waste have rarely been determined. In this study, data from Finnish studies concerning the composition and energy content of mixed MSW were collected, new experimental data on the compositions, heating values and renewable share of energy were presented and the results were compared to the estimations concluded from earlier international studies. In the town of Lappeenranta in south-eastern Finland, the share of renewable energy ranged between 25% and 34% in the energy content tests implemented for two sample trucks. The heating values of the waste and fractions of plastic waste were high in the samples compared to the earlier studies in Finland. These high values were caused by good source separation and led to a low share of renewable energy content in the waste. The results showed that in mixed municipal solid waste the renewable share of the energy content can be significantly lower than the general assumptions (50-60%) when the source separation of organic waste, paper and cardboard is carried out successfully. The number of samples was however small for making extensive conclusions on the results concerning the heating values and renewable share of energy and additional research is needed for this purpose. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Binding energies and energy differences for p-shell nuclei from ab initio calculations with natural orbitals

    Science.gov (United States)

    Fasano, Patrick J.; Caprio, Mark A.; Constantinou, Chrysovalantis; Maris, Pieter; Vary, James P.

    2017-09-01

    Ab initio methods in nuclear theory strive to make quantitative predictions of nuclear observables, starting with the internucleon interaction. In the no-core configuration interaction (NCCI) approach, the nuclear many-body problem is solved in a basis of Slater determinants constructed from single-particle states. NCCI calculations are computationally limited by combinatorial explosion of the many-body basis size; as such, choice of basis greatly influences convergence. Natural orbitals, constructed by diagonalizing the one-body density matrix from an initial many-body calculation, maximize occupation of the lowest single-particle states and thereby reduce the importance of higher-lying many-body basis states. We use natural orbitals to explore energies and energy differences in p-shell nuclei. Supported by the US DOE under Award Nos. DE-FG02-95ER-40934, DE-FG02-91ER-40608, DESC0008485 (SciDAC/NUCLEI), and DE-FG02-87ER40371 and the US NSF under Award No. NSF-PHY05-52843. Computational resources provided by NERSC (DOE Contract DE-AC02-05CH11231).

  7. Comparison between the classical interaction energy and periodic Hartree-Fock binding energies for the interaction between molecules and surfaces

    International Nuclear Information System (INIS)

    Chacon-Taylor, M.R.; McCarthy, M.I.

    1995-01-01

    The energetics of the H 2 O/MgO(001), HCl/MgO(001), and NH 3 /MgO(001) interface were investigated using the ab initio periodic Hartree-Fock LCAO method and a classical interaction energy model. The QM calculations treated a system that was periodic in two dimensions with the adsorbate approaching a three-layer slab of MgO(001). The authors used an approximation to the classical interaction energy, where the surface is represented by its potential, electric field, and electric field derivatives at the positions of the molecule center of mass, and the molecule is described by its charge, electric dipole, electric quadrupole and polarizability. The potential, electric field and electric field gradient are obtained for the clean three-layer slab using the ab initio periodic Hartree-Fock LCAO method (CRYSTAL) and an optimized split valence basis 8-61G on Mg and 8-51G on O. The charge, electric dipole, and electric quadrupole are calculated using ab initio Hartree-Fock theory (GAUSSIAN-92) with a 6-31G* basis set while the SCF polarizability is determined analytically using the same basis set

  8. Hypernuclear interactions and the binding energies of Λ and ΛΛ hypernuclei

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.

    1988-01-01

    By use of variational calculations a reasonable hadronic description is obtained of the s-shell hypernuclei, of /sub Λ/ 9 Be, and of the well depth, with ΛN forces which are consistent with Λp scattering and which are quite strongly spin-dependent, with reasonable TPE ΛNN forces with strongly repulsive dispersive-type ΛNN forces. For the latter we also consider a spin-dependent version which is somewhat favored by our analysis. /sub Λ/ 9 Be is treated as a 2α + Λ system and is significantly overbound, ≅1 MeV, if only αα and αΛ potentials are used. An ααΛ potential obtained from the ΛNN forces nicely accounts for this overbinding. The ΛΛ hypernuclei /sub ΛΛ/ 6 He and /sub ΛΛ/ 10 Be are treated as α + 2Λ and 2α + 2Λ systems. Use of the /sub ΛΛ/ 10 Be event gives ≅1.5 MeV too little binding for /sub ΛΛ/ 6 He. The 1 S 0 ΛΛ potential obtained from /sub ΛΛ/ 10 Be is quite strongly attractive, comparable to the ΛN and also to the NN potential without OPE. 18 refs

  9. Donor impurity binding energies of coaxial GaAs / Alx Ga1 - x As cylindrical quantum wires in a parallel applied magnetic field

    Science.gov (United States)

    Tshipa, M.; Winkoun, D. P.; Nijegorodov, N.; Masale, M.

    2018-04-01

    Theoretical investigations are carried out of binding energies of a donor charge assumed to be located exactly at the center of symmetry of two concentric cylindrical quantum wires. The intrinsic confinement potential in the region of the inner cylinder is modeled in any one of the three profiles: simple parabolic, shifted parabolic or the polynomial potential. The potential inside the shell is taken to be a potential step or potential barrier of a finite height. Additional confinement of the charge carriers is due to the vector potential of the axial applied magnetic field. It is found that the binding energies attain maxima in their variations with the radius of the inner cylinder irrespective of the particular intrinsic confinement of the inner cylinder. As the radius of the inner cylinder is increased further, the binding energies corresponding to either the parabolic or the polynomial potentials attain minima at some critical core-radius. Finally, as anticipated, the binding energies increase with the increase of the parallel applied magnetic field. This behaviour of the binding energies is irrespective of the particular electric potential of the nanostructure or its specific dimensions.

  10. Molecular dynamics simulation, binding free energy calculation and unbinding pathway analysis on selectivity difference between FKBP51 and FKBP52: Insight into the molecular mechanism of isoform selectivity.

    Science.gov (United States)

    Shi, Danfeng; Bai, Qifeng; Zhou, Shuangyan; Liu, Xuewei; Liu, Huanxiang; Yao, Xiaojun

    2018-01-01

    As co-chaperones of the 90-kDa heat shock protein(HSP90), FK506 binding protein 51 (FKBP51) and FK506 binding protein 52 (FKBP52) modulate the maturation of steroid hormone receptor through their specific FK1 domains (FKBP12-like domain 1). The inhibitors targeting FK1 domains are potential therapies for endocrine-related physiological disorders. However, the structural conservation of the FK1 domains between FKBP51 and FKBP52 make it difficult to obtain satisfactory selectivity in FK506-based drug design. Fortunately, a series of iFit ligands synthesized by Hausch et al exhibited excellent selectivity for FKBP51, providing new opportunity for design selective inhibitors. We performed molecular dynamics simulation, binding free energy calculation and unbinding pathway analysis to reveal selective mechanism for the inhibitor iFit4 binding with FKBP51 and FKBP52. The conformational stability evaluation of the "Phe67-in" and "Phe67-out" states implies that FKBP51 and FKBP52 have different preferences for "Phe67-in" and "Phe67-out" states, which we suggest as the determinant factor for the selectivity for FKBP51. The binding free energy calculations demonstrate that nonpolar interaction is favorable for the inhibitors binding, while the polar interaction and entropy contribution are adverse for the inhibitors binding. According to the results from binding free energy decomposition, the electrostatic difference of residue 85 causes the most significant thermodynamics effects on the binding of iFit4 to FKBP51 and FKBP52. Furthermore, the importance of substructure units on iFit4 were further evaluated by unbinding pathway analysis and residue-residue contact analysis between iFit4 and the proteins. The results will provide new clues for the design of selective inhibitors for FKBP51. © 2017 Wiley Periodicals, Inc.

  11. Risk management with substitution options: Valuing flexibility in small-scale energy systems

    Science.gov (United States)

    Knapp, Karl Eric

    Several features of small-scale energy systems make them more easily adapted to a changing operating environment than large centralized designs. This flexibility is often manifested as the ability to substitute inputs. This research explores the value of this substitution flexibility and the marginal value of becoming a "little more flexible" in the context of real project investment in developing countries. The elasticity of substitution is proposed as a stylized measure of flexibility and a choice variable. A flexible alternative (elasticity > 0) can be thought of as holding a fixed-proportions "nflexible" asset plus a sequence of exchange options---the option to move to another feasible "recipe" each period. Substitutability derives value from following a contour of anticipated variations and from responding to new information. Substitutability value, a "cost savings option", increases with elasticity and price risk. However, the required premium to incrementally increase flexibility can in some cases decrease with an increase in risk. Variance is not always a measure of risk. Tools from stochastic dominance are newly applied to real options with convex payoffs to correct some misperceptions and clarify many common modeling situations that meet the criteria for increased variance to imply increased risk. The behavior of the cost savings option is explored subject to a stochastic input price process. At the point where costs are identical for all alternatives, the stochastic process for cost savings becomes deterministic, with savings directly proportional to elasticity of substitution and price variance. The option is also formulated as a derivative security via dynamic programming. The partial differential equation is solved for the special case of Cobb-Douglas (elasticity = 1) (also shown are linear (infinite elasticity), Leontief (elasticity = 0)). Risk aversion is insufficient to prefer a more flexible alternative with the same expected value. Intertemporal

  12. Electron binding energies of aqueous alkali and halide ions: EUV photoelectron spectroscopy of liquid solutions and combined ab initio and molecular dynamics calculations.

    Science.gov (United States)

    Winter, Bernd; Weber, Ramona; Hertel, Ingolf V; Faubel, Manfred; Jungwirth, Pavel; Brown, Eric C; Bradforth, Stephen E

    2005-05-18

    Photoelectron spectroscopy combined with the liquid microjet technique enables the direct probing of the electronic structure of aqueous solutions. We report measured and calculated lowest vertical electron binding energies of aqueous alkali cations and halide anions. In some cases, ejection from deeper electronic levels of the solute could be observed. Electron binding energies of a given aqueous ion are found to be independent of the counterion and the salt concentration. The experimental results are complemented by ab initio calculations, at the MP2 and CCSD(T) level, of the ionization energies of these prototype ions in the aqueous phase. The solvent effect was accounted for in the electronic structure calculations in two ways. An explicit inclusion of discrete water molecules using a set of snapshots from an equilibrium classical molecular dynamics simulations and a fractional charge representation of solvent molecules give good results for halide ions. The electron binding energies of alkali cations computed with this approach tend to be overestimated. On the other hand, the polarizable continuum model, which strictly provides adiabatic binding energies, performs well for the alkali cations but fails for the halides. Photon energies in the experiment were in the EUV region (typically 100 eV) for which the technique is probing the top layers of the liquid sample. Hence, the reported energies of aqueous ions are closely connected with both structures and chemical reactivity at the liquid interface, for example, in atmospheric aerosol particles, as well as fundamental bulk solvation properties.

  13. Study of lysozyme mobility and binding free energy during adsorption on a graphene surface

    International Nuclear Information System (INIS)

    Nakano, C. Masato; Ma, Heng; Wei, Tao

    2015-01-01

    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

  14. 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.

  15. Effects of the atomic environment on the electron binding energies in samarium

    Czech Academy of Sciences Publication Activity Database

    Inoyatov, A. K.; Kovalík, Alojz; Filosofov, D. V.; Ryšavý, Miloš; Vénos, Drahoslav; Yushkevich, Y. V.; Perevoshchikov, L. L.; Zhdanov, V. S.

    2016-01-01

    Roč. 207, FEB (2016), s. 38-49 ISSN 0368-2048 R&D Projects: GA ČR(CZ) GAP203/12/1896; GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : Sm-149 * atomic environment * electron ginding energy * intermediate-valence state * chemical shift * natural atomic level width Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.661, year: 2016

  16. Fast and flexible gpu accelerated binding free energy calculations within the amber molecular dynamics package.

    Science.gov (United States)

    Mermelstein, Daniel J; Lin, Charles; Nelson, Gard; Kretsch, Rachael; McCammon, J Andrew; Walker, Ross C

    2018-03-12

    Alchemical free energy (AFE) calculations based on molecular dynamics (MD) simulations are key tools in both improving our understanding of a wide variety of biological processes and accelerating the design and optimization of therapeutics for numerous diseases. Computing power and theory have, however, long been insufficient to enable AFE calculations to be routinely applied in early stage drug discovery. One of the major difficulties in performing AFE calculations is the length of time required for calculations to converge to an ensemble average. CPU implementations of MD-based free energy algorithms can effectively only reach tens of nanoseconds per day for systems on the order of 50,000 atoms, even running on massively parallel supercomputers. Therefore, converged free energy calculations on large numbers of potential lead compounds are often untenable, preventing researchers from gaining crucial insight into molecular recognition, potential druggability and other crucial areas of interest. Graphics Processing Units (GPUs) can help address this. We present here a seamless GPU implementation, within the PMEMD module of the AMBER molecular dynamics package, of thermodynamic integration (TI) capable of reaching speeds of >140 ns/day for a 44,907-atom system, with accuracy equivalent to the existing CPU implementation in AMBER. The implementation described here is currently part of the AMBER 18 beta code and will be an integral part of the upcoming version 18 release of AMBER. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  17. The composition, heating value and renewable share of the energy content of mixed municipal solid waste in Finland

    International Nuclear Information System (INIS)

    Horttanainen, M.; Teirasvuo, N.; Kapustina, V.; Hupponen, M.; Luoranen, M.

    2013-01-01

    Highlights: • New experimental data of mixed MSW properties in a Finnish case region. • The share of renewable energy of mixed MSW. • The results were compared with earlier international studies. • The average share of renewable energy was 30% and the average LHVar 19 MJ/kg. • Well operating source separation decreases the renewable energy content of MSW. - Abstract: For the estimation of greenhouse gas emissions from waste incineration it is essential to know the share of the renewable energy content of the combusted waste. The composition and heating value information is generally available, but the renewable energy share or heating values of different fractions of waste have rarely been determined. In this study, data from Finnish studies concerning the composition and energy content of mixed MSW were collected, new experimental data on the compositions, heating values and renewable share of energy were presented and the results were compared to the estimations concluded from earlier international studies. In the town of Lappeenranta in south-eastern Finland, the share of renewable energy ranged between 25% and 34% in the energy content tests implemented for two sample trucks. The heating values of the waste and fractions of plastic waste were high in the samples compared to the earlier studies in Finland. These high values were caused by good source separation and led to a low share of renewable energy content in the waste. The results showed that in mixed municipal solid waste the renewable share of the energy content can be significantly lower than the general assumptions (50–60%) when the source separation of organic waste, paper and cardboard is carried out successfully. The number of samples was however small for making extensive conclusions on the results concerning the heating values and renewable share of energy and additional research is needed for this purpose

  18. 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.

  19. Cross calibration of bone mineral density (BMD) values between various dual-energy X-ray absorptiometry (DXA) systems; Special reference to the BMD values in distal radius

    Energy Technology Data Exchange (ETDEWEB)

    Tomomitsu, Tatsushi; Yanagimoto, Shinichi; Mimura, Hiroaki; Akazawa, Yuji (Kawasaki Medical School, Kurashiki, Okayama (Japan). Hospital); Otsuka, Nobuaki; Fukunaga, Masao

    1994-04-01

    The values of bone mineral density (BMD) obtained by different dual energy X-ray absorptiometry systems are known to be non-identical. In this study, the BMD values in the distal radius measured by various DXA instruments were cross-calibrated by in vivo study. The instruments studied were the QDR-1000 (Hologic), DPX-L (Lunar), and DCS-600 (Aloka). Cross calibration was performed by calculating the linear regression formulae of BMD values between different systems. The correlation coefficients (r) were 0.987-0.992. Therefore, highly reliable conversions of BMD values between different systems could be obtained in the distal radius. However, it was shown that the conversion formulae of BMD values in the distal radius were essentially different from those in the lumber vertebrae or proximal femur. (author).

  20. Dual binding in cohesin-dockerin complexes: the energy landscape and the role of short, terminal segments of the dockerin module.

    Science.gov (United States)

    Wojciechowski, Michał; Różycki, Bartosz; Huy, Pham Dinh Quoc; Li, Mai Suan; Bayer, Edward A; Cieplak, Marek

    2018-03-22

    The assembly of the polysaccharide degradating cellulosome machinery is mediated by tight binding between cohesin and dockerin domains. We have used an empirical model known as FoldX as well as molecular mechanics methods to determine the free energy of binding between a cohesin and a dockerin from Clostridium thermocellum in two possible modes that differ by an approximately 180° rotation. Our studies suggest that the full-length wild-type complex exhibits dual binding at room temperature, i.e., the two modes of binding have comparable probabilities at equilibrium. The ability to bind in the two modes persists at elevated temperatures. However, single-point mutations or truncations of terminal segments in the dockerin result in shifting the equilibrium towards one of the binding modes. Our molecular dynamics simulations of mechanical stretching of the full-length wild-type cohesin-dockerin complex indicate that each mode of binding leads to two kinds of stretching pathways, which may be mistakenly taken as evidence of dual binding.

  1. Gauge-invariant expectation values of the energy of a molecule in an electromagnetic field.

    Science.gov (United States)

    Mandal, Anirban; Hunt, Katharine L C

    2016-01-28

    In this paper, we show that the full Hamiltonian for a molecule in an electromagnetic field can be separated into a molecular Hamiltonian and a field Hamiltonian, both with gauge-invariant expectation values. The expectation value of the molecular Hamiltonian gives physically meaningful results for the energy of a molecule in a time-dependent applied field. In contrast, the usual partitioning of the full Hamiltonian into molecular and field terms introduces an arbitrary gauge-dependent potential into the molecular Hamiltonian and leaves a gauge-dependent form of the Hamiltonian for the field. With the usual partitioning of the Hamiltonian, this same problem of gauge dependence arises even in the absence of an applied field, as we show explicitly by considering a gauge transformation from zero applied field and zero external potentials to zero applied field, but non-zero external vector and scalar potentials. We resolve this problem and also remove the gauge dependence from the Hamiltonian for a molecule in a non-zero applied field and from the field Hamiltonian, by repartitioning the full Hamiltonian. It is possible to remove the gauge dependence because the interaction of the molecular charges with the gauge potential cancels identically with a gauge-dependent term in the usual form of the field Hamiltonian. We treat the electromagnetic field classically and treat the molecule quantum mechanically, but nonrelativistically. Our derivation starts from the Lagrangian for a set of charged particles and an electromagnetic field, with the particle coordinates, the vector potential, the scalar potential, and their time derivatives treated as the variables in the Lagrangian. We construct the full Hamiltonian using a Lagrange multiplier method originally suggested by Dirac, partition this Hamiltonian into a molecular term Hm and a field term Hf, and show that both Hm and Hf have gauge-independent expectation values. Any gauge may be chosen for the calculations; but

  2. Towards an ethnography of electrification in rural India : Social relations and values in household energy exchanges

    NARCIS (Netherlands)

    Singh, A.; Strating, Alex T.; Romero Herrera, N.A.; van Dijk, Hylke W.; Keyson, D.V.

    2017-01-01

    Many energy researchers and practitioners envision householders to have an active role in local energy distribution in emerging energy systems. In the energy literature, the dominant view of local energy distribution, grounded in the rational choice perspective, sees exchanges of energy between

  3. Effect of magnetic field and soft potential barrier on off-axis donor binding energy in a nanotube with two quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Jesus D. [Grupo en Teoria de la Materia Condensada, Universidad del Magdalena, Santa Marta (Colombia); Grupo de Fisica Mesoscopica, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia); Rondano, F.J. [Grupo en Teoria de la Materia Condensada, Universidad del Magdalena, Santa Marta (Colombia); Barba-Ortega, J., E-mail: jjbarbao@unal.edu.co [Grupo de Fisica Mesoscopica, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia)

    2012-12-15

    We analyze the effect of the magnetic field parallel to the axis and different potential shape on the ground-state binding energy of the off-axis donors in cylindrical nanotubes containing two GaAs/GaAlAs quantum wells (QWs) in a section of the tube layer. We express the wave function as a product of combinations of s and p subband wave functions and an envelope function that depends only on the electron-ion separation. By using the variational principle we derive a differential equation for the envelope function, which we solve numerically. Two peaks in the curves for the dependence of the ground-state binding energies on the donor distance from the axis are presented and it is shown that the increasing the magnetic field increasing the binding energy while the impurity is located in the QW1, whereas the opposite occurs when the impurity is located in the QW2.

  4. Binding Energy calculation of GSK-3 protein of Human against some anti-diabetic compounds of Momordica charantia linn (Bitter melon).

    Science.gov (United States)

    Hazarika, Ridip; Parida, Pratap; Neog, Bijoy; Yadav, Raj Narain Singh

    2012-01-01

    Diabetes is one of the major life threatening diseases worldwide. It creates major health problems in urban India. Glycogen Synthase Kinase-3 (GSK-3) protein of human is known for phosphorylating and inactivating glycogen synthase which also acts as a negative regulator in the hormonal control of glucose homeostasis. In traditional medicine, Momordica charantia is used as antidiabetic plant because of its hypoglycemic effect. Hence to block the active site of the GSK-3 protein three anti-diabetic compounds namely, charantin, momordenol & momordicilin were taken from Momordica charantia for docking study and calculation of binding energy. The aim of present investigation is to find the binding energy of three major insulin-like active compounds against glycogen synthase kinase-3 (GSK-3), one of the key proteins involved in carbohydrate metabolism, with the help of molecular docking using ExomeTM Horizon suite. The study recorded minimum binding energy by momordicilin in comparison to the others.

  5. The Value of End-Use Energy Efficiency in Mitigation of U.S. Carbon Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, G. Page; Smith, Steven J.; Clarke, Leon E.; Kim, Son H.; Wise, Marshall A.

    2007-11-27

    This report documents a scenario analysis exploring the value of advanced technologies in the U.S. buildings, industrial, and transportation sectors in stabilizing atmospheric greenhouse gas concentrations. The analysis was conducted by staff members of Pacific Northwest National Laboratory (PNNL), working at the Joint Global Change Research Institute (JGCRI) in support of the strategic planning process of the U.S. Department of Energy (U.S. DOE) Office of Energy Efficiency and Renewable Energy (EERE). The conceptual framework for the analysis is an integration of detailed buildings, industrial, and transportation modules into MiniCAM, a global integrated assessment model. The analysis is based on three technology scenarios, which differ in their assumed rates of deployment of new or presently available energy-saving technologies in the end-use sectors. These technology scenarios are explored with no carbon policy, and under two CO2 stabilization policies, in which an economic price on carbon is applied such that emissions follow prescribed trajectories leading to long-term stabilization of CO2 at roughly 450 and 550 parts per million by volume (ppmv). The costs of meeting the emissions targets prescribed by these policies are examined, and compared between technology scenarios. Relative to the reference technology scenario, advanced technologies in all three sectors reduce costs by 50% and 85% for the 450 and 550 ppmv policies, respectively. The 450 ppmv policy is more stringent and imposes higher costs than the 550 ppmv policy; as a result, the magnitude of the economic value of energy efficiency is four times greater for the 450 ppmv policy than the 550 ppmv policy. While they substantially reduce the costs of meeting emissions requirements, advanced end-use technologies do not lead to greenhouse gas stabilization without a carbon policy. This is due mostly to the effects of increasing service demands over time, the high consumption of fossil fuels in the

  6. Energy conversion through mass loading of escaping ionospheric ions for different Kp values

    Directory of Open Access Journals (Sweden)

    M. Yamauchi

    2018-01-01

    K from the solar wind to the current system by the increased Fload. Since Fload significantly increases for increased flux of extreme ultraviolet (EUV radiation, high EUV flux may significantly enhance this positive feedback. Therefore, the ion escape rate and the energy extraction by mass loading during ancient Earth, when the Sun is believed to have emitted much higher EUV flux than at present, could have been even higher than the currently available highest values based on Kp = 9. This raises a possibility that the ion escape has substantially contributed to the evolution of the Earth's atmosphere.

  7. The structure and binding energy of K+endash ether complexes: A comparison of MP2, RI-MP2, and density functional methods

    International Nuclear Information System (INIS)

    Feller, D.; Apra, E.; Nichols, J.A.; Bernholdt, D.E.

    1996-01-01

    The structures and binding energies of several cation:ether complexes (K + :dimethyl ether, K + :dimethoxyethane, K + :12-crown-4 and K + :18-crown-6) were determined with second and fourth order perturbation theory using correlation consistent basis sets. Several of these are the largest correlated calculations yet attempted on crown ethers. The observed systematic convergence to the complete basis set limit provides a standard by which the accuracy of previous studies can be measured and facilitates the calibration of density functional methods. Recent Fouier transform ion cyclotron resonance experiments predicted K + :18-crown-6 binding energies which were significantly smaller than ab initio calculations. None of the potential sources of error examined in the present study were large enough to explain this difference. Although the 6-31+G* basis set used in an earlier theoretical study was smaller than the smallest of the correlation consistent basis sets, with suitable correction for basis set superposition error, it appears capable of yielding binding energies within several kcal/mol of the basis set limit. Perturbation theory calculations exploiting the open-quote open-quote resolution of the identity close-quote close-quote approximation were found to faithfully reproduce binding energies and conformational differences. Although the cation endash ether interaction is dominated by classical electrostatics, the accuracy of density functional techniques was found to be quite sensitive to the choice of functionals. The local density SVWN procedure performed well for binding energies and conformational differences, while underestimating K + O distances by up to 0.08 A. The gradient-corrected Becke endash Lee endash Yang endash Parr functional underestimated the K + :12c4 binding energy by 4 endash 7 kcal/mol or 15%. copyright 1996 American Institute of Physics

  8. Shapley Value-Based Payment Calculation for Energy Exchange between Micro- and Utility Grids

    Directory of Open Access Journals (Sweden)

    Robin Pilling

    2017-10-01

    Full Text Available In recent years, microgrids have developed as important parts of power systems and have provided affordable, reliable, and sustainable supplies of electricity. Each microgrid is managed as a single controllable entity with respect to the existing power system but demands for joint operation and sharing the benefits between a microgrid and its hosting utility. This paper is focused on the joint operation of a microgrid and its hosting utility, which cooperatively minimize daily generation costs through energy exchange, and presents a payment calculation scheme for power transactions based on a fair allocation of reduced generation costs. To fairly compensate for energy exchange between the micro- and utility grids, we adopt the cooperative game theoretic solution concept of Shapley value. We design a case study for a fictitious interconnection model between the Mueller microgrid in Austin, Texas and the utility grid in Taiwan. Our case study shows that when compared to standalone generations, both the micro- and utility grids are better off when they collaborate in power exchange regardless of their individual contributions to the power exchange coalition.

  9. Binding energies and structures of Ca-He2 weakly bound triatomic complexes

    Science.gov (United States)

    López-Durán, David; Rodríguez-Cantano, Rocío; González-Lezana, Tomás; Delgado-Barrio, Gerardo; Villarreal, Pablo; Gianturco, Franco A.

    2012-08-01

    Bound states of 40Ca-nHe2, n=3,4, triatomic complexes are investigated. The potential-energy surface, represented as the addition of atomic-pair interactions, is that recently used to study these systems by Gou and Li, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.85.012510 85, 012510 (2012). The results obtained from three different methods, in fair agreement, profoundly disagree with those reported in the reference above. In addition, we address the feasibility of two Ca-He interactions existing in the literature by analyzing the characteristics of their ground and excited vibrorotational states. To this end, simulated absorption spectra in the region of microwaves are also presented and discussed.

  10. Serum Wisteria Floribunda Agglutinin-Positive Mac-2 Binding Protein Values Predict the Development of Hepatocellular Carcinoma among Patients with Chronic Hepatitis C after Sustained Virological Response.

    Directory of Open Access Journals (Sweden)

    Ryu Sasaki

    Full Text Available Measurement of Wisteria floribunda agglutinin-positive human Mac-2 binding protein (WFA+-M2BP in serum was recently shown to be a noninvasive method to assess liver fibrosis. The aim of this study was to evaluate the utility of serum WFA+-M2BP values to predict the development of hepatocellular carcinoma (HCC in patients who achieved a sustained virological response (SVR by interferon treatment. For this purpose, we retrospectively analyzed 238 patients with SVR who were treated with interferon in our department. Serum WFA+-M2BP values were measured at pre-treatment (pre-Tx, post-treatment (24 weeks after completion of interferon; post-Tx, the time of HCC diagnosis, and the last clinical visit. Of 238 patients with SVR, HCC developed in 16 (6.8% patients. The average follow-up period was 9.1 years. The cumulative incidence of HCC was 3.4% at 5 years and 7.5% at 10 years. The median pre-Tx and post-Tx WFA+-M2BP values were 1.69 (range: 0.28 to 12.04 cutoff index (COI and 0.80 (range: 0.17 to 5.29 COI, respectively. The WFA+-M2BP values decreased significantly after SVR (P 60 years, sex (male, pre-Tx platelet count ( 2.0 COI were associated with the development of HCC after SVR. Conclusion: Post-Tx WFA+-M2BP (> 2.0 COI is associated with the risk for development of HCC among patients with SVR. The WFA+-M2BP values could be a new predictor for HCC after SVR.

  11. Parameterizing the binding properties of dissolved organic matter with default values skews the prediction of copper solution speciation and ecotoxicity in soil.

    Science.gov (United States)

    Djae, Tanalou; Bravin, Matthieu N; Garnier, Cédric; Doelsch, Emmanuel

    2017-04-01

    Parameterizing speciation models by setting the percentage of dissolved organic matter (DOM) that is reactive (% r-DOM) toward metal cations at a single 65% default value is very common in predictive ecotoxicology. The authors tested this practice by comparing the free copper activity (pCu 2+  = -log 10 [Cu 2+ ]) measured in 55 soil sample solutions with pCu 2+ predicted with the Windermere humic aqueous model (WHAM) parameterized by default. Predictions of Cu toxicity to soil organisms based on measured or predicted pCu 2+ were also compared. Default WHAM parameterization substantially skewed the prediction of measured pCu 2+ by up to 2.7 pCu 2+ units (root mean square residual = 0.75-1.3) and subsequently the prediction of Cu toxicity for microbial functions, invertebrates, and plants by up to 36%, 45%, and 59% (root mean square residuals ≤9 %, 11%, and 17%), respectively. Reparametrizing WHAM by optimizing the 2 DOM binding properties (i.e., % r-DOM and the Cu complexation constant) within a physically realistic value range much improved the prediction of measured pCu 2+ (root mean square residual = 0.14-0.25). Accordingly, this WHAM parameterization successfully predicted Cu toxicity for microbial functions, invertebrates, and plants (root mean square residual ≤3.4%, 4.4%, and 5.8%, respectively). Thus, it is essential to account for the real heterogeneity in DOM binding properties for relatively accurate prediction of Cu speciation in soil solution and Cu toxic effects on soil organisms. Environ Toxicol Chem 2017;36:898-905. © 2016 SETAC. © 2016 SETAC.

  12. Diagnostic and prognostic value of factor VIII binding antibodies in acquired hemophilia A: data from the GTH-AH 01/2010 study.

    Science.gov (United States)

    Werwitzke, S; Geisen, U; Nowak-Göttl, U; Eichler, H; Stephan, B; Scholz, U; Holstein, K; Klamroth, R; Knöbl, P; Huth-Kühne, A; Bomke, B; Tiede, A

    2016-05-01

    Essentials Factor VIII (FVIII) binding IgG detected by ELISA could be an alternative to the Bethesda assay. We studied the performance of anti-FVIII IgG ELISA in patients with acquired hemophilia and controls. Anti-FVIII IgG > 99th percentile of controls was highly sensitive and specific. Patients with high anti-FVIII IgG have a lower chance of achieving remission. Background Acquired hemophilia A is a severe bleeding disorder that requires fast and accurate diagnosis as it occurs often unexpectedly in previously healthy men and women of every age. The Nijmegen-modified Bethesda assay is the diagnostic reference standard for detecting neutralizing autoantibodies against factor VIII (FVIII), but is not widely available, not ideal for quantifying the complex type 2 inhibitors seen in acquired hemophilia, and suffers from high inter-laboratory variability. Objectives To assess the diagnostic and prognostic value of FVIII-binding antibodies as detected by ELISA compared with the Nijmegen Bethesda assay. Methods Samples from the time of first diagnosis and clinical data were available from 102 patients with acquired hemophilia enrolled in the prospective GTH-AH 01/2010 study. Controls (n = 102) were matched for gender and age. Diagnostic cut-offs were determined by receiver-operator curve analysis. The prognostic value was assessed in 92 of the 102 patients by Cox regression analysis of time to partial remission. Results Anti-FVIII IgG above the 99th percentile (> 15 arbitrary units per mL) revealed high sensitivity and specificity (both 0.99; 95% confidence interval, 0.95-1.0) for diagnosing acquired hemophilia. The likelihood of achieving partial remission was related to anti-FVIII IgG concentration ( 1050, 0.39). The Bethesda titer was only associated with the likelihood of partial remission when analyzed in the central laboratory, but not when data from local GTH study sites were used. Conclusion Although the Nijmegen-modified Bethesda assay is the reference

  13. An improved theoretical value for Zsub(eff) for low-energy positron-hydrogen-molecule scattering

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Baker, D.J.

    1986-01-01

    The value of Zsub(eff), the effective number of electrons per molecule available to the positron for annihilation, is calculated for low-energy positron-hydrogen-molecule scattering using a scattering wavefunction containing terms in which the positron-electron distance is included linearly as a factor. The results at very low energy are much closer to the experimental value than any that have been obtained previously. (author)

  14. Reproducing kernel potential energy surfaces in biomolecular simulations: Nitric oxide binding to myoglobin

    International Nuclear Information System (INIS)

    Soloviov, Maksym; Meuwly, Markus

    2015-01-01

    Multidimensional potential energy surfaces based on reproducing kernel-interpolation are employed to explore the energetics and dynamics of free and bound nitric oxide in myoglobin (Mb). Combining a force field description for the majority of degrees of freedom and the higher-accuracy representation for the NO ligand and the Fe out-of-plane motion allows for a simulation approach akin to a mixed quantum mechanics/molecular mechanics treatment. However, the kernel-representation can be evaluated at conventional force-field speed. With the explicit inclusion of the Fe-out-of-plane (Fe-oop) coordinate, the dynamics and structural equilibrium after photodissociation of the ligand are correctly described compared to experiment. Experimentally, the Fe-oop coordinate plays an important role for the ligand dynamics. This is also found here where the isomerization dynamics between the Fe–ON and Fe–NO state is significantly affected whether or not this co-ordinate is explicitly included. Although the Fe–ON conformation is metastable when considering only the bound 2 A state, it may disappear once the 4 A state is included. This explains the absence of the Fe–ON state in previous experimental investigations of MbNO

  15. Evaluation of Dynamical Downscaling Resolution Effect on Wind Energy Forecast Value for a Wind Farm in Central Sweden

    DEFF Research Database (Denmark)

    Rosgaard, Martin Haubjerg; Hahmann, Andrea N.; Nielsen, Torben Skov

    2014-01-01

    energy. The present study aims to quantify value added to wind energy forecasts in the 12-48 hour leadtime by downscaling global numerical weather prediction (NWP) data from the National Centers for Environmental Prediction Global Forecast System (GFS) using the limited-area NWP model described...

  16. 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)

    Safarpour, Gh.; Barati, M.; Zamani, A.; Niknam, E.

    2014-01-01

    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

  17. Core-level spectra and binding energies of transition metal nitrides by non-destructive x-ray photoelectron spectroscopy through capping layers

    Science.gov (United States)

    Greczynski, G.; Primetzhofer, D.; Lu, J.; Hultman, L.

    2017-02-01

    We present the first measurements of x-ray photoelectron spectroscopy (XPS) core level binding energies (BE:s) for the widely-applicable group IVb-VIb polycrystalline transition metal nitrides (TMN's) TiN, VN, CrN, ZrN, NbN, MoN, HfN, TaN, and WN as well as AlN and SiN, which are common components in the TMN-based alloy systems. Nitride thin film samples were grown at 400 °C by reactive dc magnetron sputtering from elemental targets in Ar/N2 atmosphere. For XPS measurements, layers are either (i) Ar+ ion-etched to remove surface oxides resulting from the air exposure during sample transfer from the growth chamber into the XPS system, or (ii) in situ capped with a few nm thick Cr or W overlayers in the deposition system prior to air-exposure and loading into the XPS instrument. Film elemental composition and phase content is thoroughly characterized with time-of-flight elastic recoil detection analysis (ToF-E ERDA), Rutherford backscattering spectrometry (RBS), and x-ray diffraction. High energy resolution core level XPS spectra acquired with monochromatic Al Kα radiation on the ISO-calibrated instrument reveal that even mild etching conditions result in the formation of a nitrogen-deficient surface layer that substantially affects the extracted binding energy values. These spectra-modifying effects of Ar+ ion bombardment increase with increasing the metal atom mass due to an increasing nitrogen-to-metal sputter yield ratio. The superior quality of the XPS spectra obtained in a non-destructive way from capped TMN films is evident from that numerous metal peaks, including Ti 2p, V 2p, Zr 3d, and Hf 4f, exhibit pronounced satellite features, in agreement with previously published spectra from layers grown and analyzed in situ. In addition, the N/metal concentration ratios are found to be 25-90% higher than those obtained from the corresponding ion-etched surfaces, and in most cases agree very well with the RBS and ToF-E ERDA values. The N 1 s BE:s extracted from

  18. New Parameters for Higher Accuracy in the Computation of Binding Free Energy Differences upon Alanine Scanning Mutagenesis on Protein-Protein Interfaces.

    Science.gov (United States)

    Simões, Inês C M; Costa, Inês P D; Coimbra, João T S; Ramos, Maria J; Fernandes, Pedro A

    2017-01-23

    Knowing how proteins make stable complexes enables the development of inhibitors to preclude protein-protein (P:P) binding. The identification of the specific interfacial residues that mostly contribute to protein binding, denominated as hot spots, is thus critical. Here, we refine an in silico alanine scanning mutagenesis protocol, based on a residue-dependent dielectric constant version of the Molecular Mechanics/Poisson-Boltzmann Surface Area method. We have used a large data set of structurally diverse P:P complexes to redefine the residue-dependent dielectric constants used in the determination of binding free energies. The accuracy of the method was validated through comparison with experimental data, considering the per-residue P:P binding free energy (ΔΔG binding ) differences upon alanine mutation. Different protocols were tested, i.e., a geometry optimization protocol and three molecular dynamics (MD) protocols: (1) one using explicit water molecules, (2) another with an implicit solvation model, and (3) a third where we have carried out an accelerated MD with explicit water molecules. Using a set of protein dielectric constants (within the range from 1 to 20) we showed that the dielectric constants of 7 for nonpolar and polar residues and 11 for charged residues (and histidine) provide optimal ΔΔG binding predictions. An overall mean unsigned error (MUE) of 1.4 kcal mol -1 relative to the experiment was achieved in 210 mutations only with geometry optimization, which was further reduced with MD simulations (MUE of 1.1 kcal mol -1 for the MD employing explicit solvent). This recalibrated method allows for a better computational identification of hot spots, avoiding expensive and time-consuming experiments or thermodynamic integration/ free energy perturbation/ uBAR calculations, and will hopefully help new drug discovery campaigns in their quest of searching spots of interest for binding small drug-like molecules at P:P interfaces.

  19. Influence of Chirality of Crizotinib on Its MTH1 Protein Inhibitory Activity: Insight from Molecular Dynamics Simulations and Binding Free Energy Calculations.

    Directory of Open Access Journals (Sweden)

    Yuzhen Niu

    Full Text Available As a promising target for the treatment of lung cancer, the MutT Homolog 1 (MTH1 protein can be inhibited by crizotinib. A recent work shows that the inhibitory potency of (S-crizotinib against MTH1 is about 20 times over that of (R-crizotinib. But the detailed molecular mechanism remains unclear. In this study, molecular dynamics (MD simulations and free energy calculations were used to elucidate the mechanism about the effect of chirality of crizotinib on the inhibitory activity against MTH1. The binding free energy of (S-crizotinib predicted by the Molecular Mechanics/Generalized Born Surface Area (MM/GBSA and Adaptive biasing force (ABF methodologies is much lower than that of (R-crizotinib, which is consistent with the experimental data. The analysis of the individual energy terms suggests that the van der Waals interactions are important for distinguishing the binding of (S-crizotinib and (R-crizotinib. The binding free energy decomposition analysis illustrated that residues Tyr7, Phe27, Phe72 and Trp117 were important for the selective binding of (S-crizotinib to MTH1. The adaptive biasing force (ABF method was further employed to elucidate the unbinding process of (S-crizotinib and (R-crizotinib from the binding pocket of MTH1. ABF simulation results suggest that the reaction coordinates of the (S-crizotinib from the binding pocket is different from (R-crizotinib. The results from our study can reveal the details about the effect of chirality on the inhibition activity of crizotinib to MTH1 and provide valuable information for the design of more potent inhibitors.

  20. Comparison of molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) and molecular mechanics-three-dimensional reference interaction site model (MM-3D-RISM) method to calculate the binding free energy of protein-ligand complexes: Effect of metal ion and advance statistical test

    Science.gov (United States)

    Pandey, Preeti; Srivastava, Rakesh; Bandyopadhyay, Pradipta

    2018-03-01

    The relative performance of MM-PBSA and MM-3D-RISM methods to estimate the binding free energy of protein-ligand complexes is investigated by applying these to three proteins (Dihydrofolate Reductase, Catechol-O-methyltransferase, and Stromelysin-1) differing in the number of metal ions they contain. None of the computational methods could distinguish all the ligands based on their calculated binding free energies (as compared to experimental values). The difference between the two comes from both polar and non-polar part of solvation. For charged ligand case, MM-PBSA and MM-3D-RISM give a qualitatively different result for the polar part of solvation.

  1. Investigating the added values of high frequency energy consumption data using data mining techniques

    Science.gov (United States)

    Ni, Ying; Engström, Christopher; Malyarenko, Anatoliy; Wallin, Fredrik

    2014-12-01

    In this paper we apply data-mining techniques to customer classification and clustering tasks on actual electricity consumption data from 350 Swedish households. For the classification task we classify households into different categories based on some statistical attributes of their energy consumption measurements. For the clustering task, we use average daily load diagrams to partition electricity-consuming households into distinct groups. The data contains electricity consumption measurements on each 10-minute time interval for each light source and electrical appliance. We perform the classification and clustering tasks using four variants of processed data sets corresponding to the 10-minute total electricity consumption aggregated from all electrical sources, the hourly total consumption aggregated over all 10-minute intervals during that clock hour, the total consumption over each four-hour intervals and finally the daily total consumption. The goal is to see if there are any differences in using data sets of various frequency levels. We present the comparison results and investigate the added value of the high-frequency measurements, for example 10-minute measurements, in terms of its influence on customer clustering and classification.

  2. A Real Valued Neural Network Based Autoregressive Energy Detector for Cognitive Radio Application.

    Science.gov (United States)

    Onumanyi, A J; Onwuka, E N; Aibinu, A M; Ugweje, O C; Salami, M J E

    2014-01-01

    A real valued neural network (RVNN) based energy detector (ED) is proposed and analyzed for cognitive radio (CR) application. This was developed using a known two-layered RVNN model to estimate the model coefficients of an autoregressive (AR) system. By using appropriate modules and a well-designed detector, the power spectral density (PSD) of the AR system transfer function was estimated and subsequent receiver operating characteristic (ROC) curves of the detector generated and analyzed. A high detection performance with low false alarm rate was observed for varying signal to noise ratio (SNR), sample number, and model order conditions. The proposed RVNN based ED was then compared to the simple periodogram (SP), Welch periodogram (WP), multitaper (MT), Yule-Walker (YW), Burg (BG), and covariance (CV) based ED techniques. The proposed detector showed better performance than the SP, WP, and MT while providing better false alarm performance than the YW, BG, and CV. Data provided here support the effectiveness of the proposed RVNN based ED for CR application.

  3. Bioactive proteins and energy value of okara as a byproduct in hydrothermal processing of soy milk.

    Science.gov (United States)

    Stanojevic, Sladjana P; Barac, Miroljub B; Pesic, Mirjana B; Jankovic, Vanja S; Vucelic-Radovic, Biljana V

    2013-09-25

    The nutritional properties of raw okara obtained as a byproduct from six soybean varieties during hydrothermal cooking (HTC) of soy milk were assessed. The composition and residual activity (rTIA) of trypsin inhibitors (TIs), contents of lectin, proteins, fats, and carbohydrates, and energy values (EV) were correlated with the respective physicochemical properties of soybean and okara. Kunitz (KTI) and Bowman-Birk (BBI) TIs both comprised okara rTIA. TIs content was higher in okara (5.19-14.40%) than in soybean (3.10-12.17%), which additionally enriched okara by cysteine. Contents of KTI (r = 1.00;p < 0.05) and BBI (r = 0.89;p < 0.05) as well as BBI monomeric (r = 0.89;p < 0.05) and polymeric forms (r = 0.95;p < 0.05) in okara and in soybean were strongly correlated. Low urease index activity indicated that okara was heated adequately to inactivate antinutritional factors. The proximate composition of raw okara, advantageous rTIA, and a very low EV (2.74-3.78 kJ/g) qualify this byproduct for potential application in food preparation as a functional ingredient in dietary products.

  4. [Recommended values of energy density in soup or gruel-like foods, for feeding of preschool children].

    Science.gov (United States)

    Araya, H; Alviña, M; Vera, G; Pak, N

    1991-03-01

    The low energy density of the diets has been proposed by several authors as an essential factor which conditions the inadequate energy intake of preschool children of developing countries. However, there are few controlled studies in relation to the volumes which children are able to consume when energy density changes. The objective of this research was to establish recommended values of energy density for preparations with a soup or gruel consistency. The study was carried out in 100 preschool children from 3 to 4 years old who attended a Day Care Center in Santiago, Chile. Six formulas of a mixture of extruded pea-rice with different energy densities and viscosities: 0.8, 1.2 and 1.6 kcal/g and 3,000 and 9,000 cp. were studied. These experimental conditions were obtained modifying the product concentration and adding malt flour. Food consumption was determined at lunch time. Energy adequacy was calculated using the 1985 FAO-OMS-UNU requirements. Children increased significantly their energy intake when energy density of both types of consistency, soup or gruel, was higher. Energy adequacy ranged from 15% when preparations had an energy density of 0.8 kcal/g to 35%, when the preparations had an energy density of 1.6 kcal/g. The formulas which had 1.6 kcal/g fulfilled 100% of the energy requirements of preschool children for lunch time, and should be the recommended energy density for soup or gruels, when they are given as the only food. The energy density of 1.2 kcal/g needs a food complement which supplies 120 kcal, and lower values would be inadequate for preschool children feeding purposes.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Policy options when giving negative externalities market value: Clean energy policymaking and restructuring the Western Australian energy sector

    International Nuclear Information System (INIS)

    McHenry, Mark

    2009-01-01

    Uncertainty surrounds the choice of instruments that internalise fossil-fuel pollution at the local, regional and global level. This work outlines the considerable growth in the Western Australian (WA) energy sector and explores the available options and potential hazards of using specific instruments to internalise externalities. These core options are discussed with respect to liberalising energy markets, providing private investment certainty, and imparting commentary on the developments and consequences of reform in the WA context. As a large energy exporter, providing certainty for the WA energy sector investment and the community is necessary to maintain the current prosperity. Remarkably, in the decades of market reform progress, the absence of one essential element is evident: economic externalities. Policymakers are under increasing pressure to understand economic reform, new energy markets and the multifaceted repercussions they entail. With modern energy reform sitting squarely within the milieu of more efficient governments and climate policy, there are clear economic advantages to internalising negative and positive externalities and other market distortions during energy market developments. Ignoring market failures when commercialising government-owned energy utilities in de-regulated and competitive markets invites continued ad-hoc government interference that generates investment uncertainty in addition to a perplexed electorate

  6. The Value of CO2-Geothermal Bulk Energy Storage to Reducing CO2 Emissions Compared to Conventional Bulk Energy Storage Technologies

    Science.gov (United States)

    Ogland-Hand, J.; Bielicki, J. M.; Buscheck, T. A.

    2016-12-01

    Sedimentary basin geothermal resources and CO2 that is captured from large point sources can be used for bulk energy storage (BES) in order to accommodate higher penetration and utilization of variable renewable energy resources. Excess energy is stored by pressurizing and injecting CO2 into deep, porous, and permeable aquifers that are ubiquitous throughout the United States. When electricity demand exceeds supply, some of the pressurized and geothermally-heated CO2 can be produced and used to generate electricity. This CO2-BES approach reduces CO2 emissions directly by storing CO2 and indirectly by using some of that CO2 to time-shift over-generation and displace CO2 emissions from fossil-fueled power plants that would have otherwise provided electricity. As such, CO2-BES may create more value to regional electricity systems than conventional pumped hydro energy storage (PHES) or compressed air energy storage (CAES) approaches that may only create value by time-shifting energy and indirectly reducing CO2 emissions. We developed and implemented a method to estimate the value that BES has to reducing CO2 emissions from regional electricity systems. The method minimizes the dispatch of electricity system components to meet exogenous demand subject to various CO2 prices, so that the value of CO2 emissions reductions can be estimated. We applied this method to estimate the performance and value of CO2-BES, PHES, and CAES within real data for electricity systems in California and Texas over the course of a full year to account for seasonal fluctuations in electricity demand and variable renewable resource availability. Our results suggest that the value of CO2-BES to reducing CO2 emissions may be as much as twice that of PHES or CAES and thus CO2-BES may be a more favorable approach to energy storage in regional electricity systems, especially those where the topography is not amenable to PHES or the subsurface is not amenable to CAES.

  7. Diagnostic value of soluble receptor-binding cancer antigen expressed on SiSo cells and carcinoembryonic antigen in differentiating malignant from benign pleural effusion.

    Science.gov (United States)

    Dong, Jiahui; Sun, Gengyun; Zhu, Hongbin

    2016-03-01

    Diagnosis of malignant pleural effusion (MPE) remains a major clinical challenge. The aim of this study was to evaluate the diagnostic value of combined detection of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) and carcinoembryonic antigen (CEA) in patients with MPE and benign pleural effusion (BPE). The serum and pleural fluid samples were collected from 53 patients diagnosed with MPE and 49 patients with BPE. Enzyme-linked immunosorbent assay was used to detect the concentration of RCAS1 in serum and pleural effusion. The clinical data and laboratory information, including CEA levels, were gathered from these cases. The concentration of RCAS1 in MPE was significantly higher than that of BPE (P < 0.001). There was no significant difference between the two serum groups. The diagnostic sensitivity and specificity of pleural fluid RCAS1 were 67.92 and 81.63 %, respectively, at the optimized cutoff value of 7.326 U/mL; meanwhile, the sensitivity and specificity of pleural fluid CEA were 83.02 and 91.84 % at the cutoff value of 3.93 ng/mL. The specificity could be elevated to 98.50 % in serial detection, while the sensitivity may be improved to 94.55 % in parallel detection. Serum RCAS1 concentration was only detected in 53 serum samples out of the 102 samples, indicating that serum RCAS1 may not be a better option in differential diagnosis of malignancies compared with serum CEA, of which the diagnostic sensitivity and specificity were 64.15 and 83.67 % at the cutoff value of 3.90 ng/mL. No significant differences were found in pleural fluid RCAS1 concentration in MPE patients with different ages, gender, and pathological types of lung cancers. The detection of RCAS1 concentration in pleural fluid is informative for the diagnosis of MPE. Joint detection of RCAS1 and CEA can improve the diagnostic sensitivity and specificity. However, the diagnostic value of RCAS1 is not higher than that of CEA.

  8. Year rather than farming system influences protein utilization and energy value of vegetables when measured in a rat model.

    Science.gov (United States)

    Jørgensen, Henry; Brandt, Kirsten; Lauridsen, Charlotte

    2008-12-01

    The aim of the study was to measure protein utilization and energy value of dried apple, carrot, kale, pea, and potato prepared for human consumption and grown in 2 consecutive years with 3 different farming systems: (1) low input of fertilizer without pesticides (LIminusP), (2) low input of fertilizers and high input of pesticides (LIplusP), (3) and high input of fertilizers and high input of pesticides (HIplusP). In addition, the study goal was to verify the nutritional values, taking into consideration the physiologic state. In experiment 1, the nutritive values, including protein digestibility-corrected amino acid score, were determined in single ingredients in trials with young rats (3-4 weeks) as recommended by the Food and Agriculture Organization of the United Nations/World Health Organization for all age groups. A second experiment was carried out with adult rats to assess the usefulness of digestibility values to predict the digestibility and nutritive value of mixed diets and study the age aspect. Each plant material was included in the diet with protein-free basal mixtures or casein to contain 10% dietary protein. The results showed that variations in protein utilization and energy value determined on single ingredients between cultivation strategies were inconsistent and smaller than between harvest years. Overall, dietary crude fiber was negatively correlated with energy digestibility. The energy value of apple, kale, and pea was lower than expected from literature values. A mixture of plant ingredients fed to adult rats showed lower protein digestibility and higher energy digestibility than predicted. The protein digestibility data obtained using young rats in the calculation of protein digestibility-corrected amino acid score overestimates protein digestibility and quality and underestimates energy value for mature rats. The present study provides new data on protein utilization and energy digestibility of some typical plant foods that may

  9. Combining substrate dynamics, binding statistics, and energy barriers to rationalize regioselective hydroxylation of octane and lauric acid by CYP102A1 and mutants.

    Science.gov (United States)

    Feenstra, K Anton; Starikov, Eugene B; Urlacher, Vlada B; Commandeur, Jan N M; Vermeulen, Nico P E

    2007-03-01

    Hydroxylations of octane and lauric acid by Cytochrome P450-BM3 (CYP102A1) wild-type and three active site mutants--F87A, L188Q/A74G, and F87V/L188Q/A74G--were rationalized using a combination of substrate orientation from docking, substrate binding statistics from molecular dynamics simulations, and barrier energies for hydrogen atom abstraction from quantum mechanical calculations. Wild-type BM3 typically hydroxylates medium- to long-chain fatty acids on subterminal (omega-1, omega-2, omega-3) but not the terminal (omega) positions. The known carboxylic anchoring site Y51/R47 for lauric acid, and hydrophobic interactions and steric exclusion, mainly by F87, for octane as well as lauric acid, play a role in the binding modes of the substrates. Electrostatic interactions between the protein and the substrate strongly modulate the substrate's regiodependent activation barriers. A combination of the binding statistics and the activation barriers of hydrogen-atom abstraction in the substrates is proposed to determine the product formation. Trends observed in experimental product formation for octane and lauric acid by wild-type BM3 and the three active site mutants were qualitatively explained. It is concluded that the combination of substrate binding statistics and hydrogen-atom abstraction barrier energies is a valuable tool to rationalize substrate binding and product formation and constitutes an important step toward prediction of product ratios.

  10. Decision Analysis Using Value Focused Thinking to Select Renewable Energy Sources

    National Research Council Canada - National Science Library

    Duke, James

    2004-01-01

    The United States is heavily dependent on fossil fuels to produce electricity. Renewable energy can provide an alternative source of energy for electricity production as well as reduce fossil fuel consumption...

  11. Quantum mechanical free energy profiles with post-quantization restraints: Binding free energy of the water dimer over a broad range of temperatures

    Science.gov (United States)

    Bishop, Kevin P.; Roy, Pierre-Nicholas

    2018-03-01

    Free energy calculations are a crucial part of understanding chemical systems but are often computationally expensive for all but the simplest of systems. Various enhanced sampling techniques have been developed to improve the efficiency of these calculations in numerical simulations. However, the majority of these approaches have been applied using classical molecular dynamics. There are many situations where nuclear quantum effects impact the system of interest and a classical description fails to capture these details. In this work, path integral molecular dynamics has been used in conjunction with umbrella sampling, and it has been observed that correct results are only obtained when the umbrella sampling potential is applied to a single path integral bead post quantization. This method has been validated against a Lennard-Jones benchmark system before being applied to the more complicated water dimer system over a broad range of temperatures. Free energy profiles are obtained, and these are utilized in the calculation of the second virial coefficient as well as the change in free energy from the separated water monomers to the dimer. Comparisons to experimental and ground state calculation values from the literature are made for the second virial coefficient at higher temperature and the dissociation energy of the dimer in the ground state.

  12. Quantum mechanical free energy profiles with post-quantization restraints: Binding free energy of the water dimer over a broad range of temperatures.

    Science.gov (United States)

    Bishop, Kevin P; Roy, Pierre-Nicholas

    2018-03-14

    Free energy calculations are a crucial part of understanding chemical systems but are often computationally expensive for all but the simplest of systems. Various enhanced sampling techniques have been developed to improve the efficiency of these calculations in numerical simulations. However, the majority of these approaches have been applied using classical molecular dynamics. There are many situations where nuclear quantum effects impact the system of interest and a classical description fails to capture these details. In this work, path integral molecular dynamics has been used in conjunction with umbrella sampling, and it has been observed that correct results are only obtained when the umbrella sampling potential is applied to a single path integral bead post quantization. This method has been validated against a Lennard-Jones benchmark system before being applied to the more complicated water dimer system over a broad range of temperatures. Free energy profiles are obtained, and these are utilized in the calculation of the second virial coefficient as well as the change in free energy from the separated water monomers to the dimer. Comparisons to experimental and ground state calculation values from the literature are made for the second virial coefficient at higher temperature and the dissociation energy of the dimer in the ground state.

  13. Final Report for Clean, Reliable, Affordable Energy that Reflects the Values of the Pinoleville Pomo Nation

    Energy Technology Data Exchange (ETDEWEB)

    Steele, Lenora [Self-Governance Director; Sampsel, Zachary N [Program Director

    2014-07-21

    This report aims to present and analyze information on the potential of renewable energy power systems and electric vehicle charging near the Pinoleville Pomo Nation in Ukiah, California to provide an environmentally-friendly, cost-effective energy and transportation options for development. For each renewable energy option we examine, solar, wind, microhydro, and biogas in this case, we compiled technology and cost information for construction, estimates of energy capacity, and data on electricity exports rates.

  14. Analysis and monitoring of energy security and prediction of indicator values using conventional non-linear mathematical programming

    Directory of Open Access Journals (Sweden)

    Elena Vital'evna Bykova

    2011-09-01

    Full Text Available This paper describes the concept of energy security and a system of indicators for its monitoring. The indicator system includes more than 40 parameters that reflect the structure and state of fuel and energy complex sectors (fuel, electricity and heat & power, as well as takes into account economic, environmental and social aspects. A brief description of the structure of the computer system to monitor and analyze energy security is given. The complex contains informational, analytical and calculation modules, provides applications for forecasting and modeling energy scenarios, modeling threats and determining levels of energy security. Its application to predict the values of the indicators and methods developed for it are described. This paper presents a method developed by conventional nonlinear mathematical programming needed to address several problems of energy and, in particular, the prediction problem of the security. An example of its use and implementation of this method in the application, "Prognosis", is also given.

  15. Effects of an Intense Laser Field and Hydrostatic Pressure on the Intersubband Transitions and Binding Energy of Shallow Donor Impurities in a Quantum Well

    International Nuclear Information System (INIS)

    Yesilgul, U.; Ungan, F.; Kasapoglu, E.; Sari, H.; Sökmen, I.

    2011-01-01

    We have calculated the intersubband transitions and the ground-state binding energies of a hydrogenic donor impurity in a quantum well in the presence of a high-frequency laser field and hydrostatic pressure. The calculations are performed within the effective mass approximation, using a variational method. We conclude that the laser field amplitude and the hydrostatic pressure provide an important effect on the electronic and optical properties of the quantum wells. According to the results obtained from the present work, it is deduced that (i) the binding energies of donor impurity decrease as the laser field increase, (ii) the binding energies of donor impurity increase as the hydrostatic pressure increase, (iii) the intersubband absorption coefficients shift toward lower energies as the hydrostatic pressure increases, (iv) the magnitude of absorption coefficients decrease and also shift toward higher energies as the laser field increase. It is hopeful that the obtained results will provide important improvements in device applications. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  16. Investigation of the binding free energies of FDA approved drugs against subtype B and C-SA HIV PR: ONIOM approach.

    Science.gov (United States)

    Sanusi, Z K; Govender, T; Maguire, G E M; Maseko, S B; Lin, J; Kruger, H G; Honarparvar, B

    2017-09-01

    Human immune virus subtype C is the most widely spread HIV subtype in Sub-Sahara Africa and South Africa. A profound structural insight on finding potential lead compounds is therefore necessary for drug discovery. The focus of this study is to rationalize the nine Food and Drugs Administration (FDA) HIV antiviral drugs complexed to subtype B and C-SA PR using ONIOM approach. To achieve this, an integrated two-layered ONIOM model was used to optimize the geometrics of the FDA approved HIV-1 PR inhibitors for subtype B. In our hybrid ONIOM model, the HIV-1 PR inhibitors as well as the ASP 25/25' catalytic active residues were treated at high level quantum mechanics (QM) theory using B3LYP/6-31G(d), and the remaining HIV PR residues were considered using the AMBER force field. The experimental binding energies of the PR inhibitors were compared to the ONIOM calculated results. The theoretical binding free energies (?G bind ) for subtype B follow a similar trend to the experimental results, with one exemption. The computational model was less suitable for C-SA PR. Analysis of the results provided valuable information about the shortcomings of this approach. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to provide much improved binding energies for complex enzyme drug interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Combined quantum mechanics/molecular mechanics (QM/MM) simulations for protein-ligand complexes: free energies of binding of water molecules in influenza neuraminidase.

    Science.gov (United States)

    Woods, Christopher J; Shaw, Katherine E; Mulholland, Adrian J

    2015-01-22

    The applicability of combined quantum mechanics/molecular mechanics (QM/MM) methods for the calculation of absolute binding free energies of conserved water molecules in protein/ligand complexes is demonstrated. Here, we apply QM/MM Monte Carlo simulations to investigate binding of water molecules to influenza neuraminidase. We investigate five different complexes, including those with the drugs oseltamivir and peramivir. We investigate water molecules in two different environments, one more hydrophobic and one hydrophilic. We calculate the free-energy change for perturbation of a QM to MM representation of the bound water molecule. The calculations are performed at the BLYP/aVDZ (QM) and TIP4P (MM) levels of theory, which we have previously demonstrated to be consistent with one another for QM/MM modeling. The results show that the QM to MM perturbation is significant in both environments (greater than 1 kcal mol(-1)) and larger in the more hydrophilic site. Comparison with the same perturbation in bulk water shows that this makes a contribution to binding. The results quantify how electronic polarization differences in different environments affect binding affinity and also demonstrate that extensive, converged QM/MM free-energy simulations, with good levels of QM theory, are now practical for protein/ligand complexes.

  18. Clinical value of octamer-binding transcription factor 4 as a prognostic marker in patients with digestive system cancers: A systematic review and meta-analysis.

    Science.gov (United States)

    Chen, Zhiqiang; Zhang, Long; Zhu, Qin; Wang, Xiaowei; Wu, Jindao; Wang, Xuehao

    2017-03-01

    The role of octamer-binding transcription factor 4 (Oct4) has been implicated in the clinical prognosis of various kinds of digestive system cancers, but the results remain controversial. The purpose of this meta-analysis is to assess the potential role of Oct4 as a prognostic marker in digestive system tumors. Relevant articles were retrieved from Pubmed, Web of Science, and Cochrane Library up to July 2016. The software Stata 12.0 was used to analyze the outcomes, including overall survival (OS), disease-free survival, recurrence-free survival, and clinicopathological characteristics. A total of 13 eligible studies with 1538 patients were included. Elevated Oct4 expression was significantly associated with poor OS (pooled hazard ratio [HR] = 2.183, 95% confidence interval [CI]: 1.824-2.612), disease-free survival (pooled HR = 1.973, 95% CI: 1.538-2.532), and recurrence-free survival (pooled HR = 2.209, 95% CI: 1.461-3.338) of digestive system malignancies. Subgroup analyses showed that cancer type, sample size, study quality, and laboratory detection method did not alter the significant prognostic value of Oct4. Additionally, Oct4 expression was found to be an independent predictive factor for OS (HR = 2.068, 95% CI: 1.633-2.619). No significant association was found between Oct4 and clinicopathological features of digestive system malignancies. This study provided evidence of Oct4 and/or its closely related homolog protein as a predictive factor for patients with digestive system cancers. More large-scale clinical studies on the prognostic value of Oct4 are warranted. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  19. Theoretical analysis of the time-resolved binary (e, 2e) binding energy spectra on three-body photodissociation of acetone at 195 nm

    Science.gov (United States)

    Yamazaki, M.; Nakayama, S.; Zhu, C. Y.; Takahashi, M.

    2017-11-01

    We report on theoretical progress in time-resolved (e, 2e) electron momentum spectroscopy of photodissociation dynamics of the deuterated acetone molecule at 195 nm. We have examined the predicted minimum energy reaction path to investigate whether associated (e, 2e) calculations meet the experimental results. A noticeable difference between the experiment and calculations has been found at around binding energy of 10 eV, suggesting that the observed difference may originate, at least partly, in ever-unconsidered non-minimum energy paths.

  20. Acoustic emission energy b-value for local damage evaluation in reinforced concrete structures subjected to seismic loadings

    Science.gov (United States)

    Sagasta, Francisco; Zitto, Miguel E.; Piotrkowski, Rosa; Benavent-Climent, Amadeo; Suarez, Elisabet; Gallego, Antolino

    2018-03-01

    A modification of the original b-value (Gutenberg-Richter parameter) is proposed to evaluate local damage of reinforced concrete structures subjected to dynamical loads via the acoustic emission (AE) method. The modification, shortly called energy b-value, is based on the use of the true energy of the AE signals instead of its peak amplitude, traditionally used for the calculation of b-value. The proposal is physically supported by the strong correlation between the plastic strain energy dissipated by the specimen and the true energy of the AE signals released during its deformation and cracking process, previously demonstrated by the authors in several publications. AE data analysis consisted in the use of guard sensors and the Continuous Wavelet Transform in order to separate primary and secondary emissions as much as possible according to particular frequency bands. The approach has been experimentally applied to the AE signals coming from a scaled reinforced concrete frame structure, which was subjected to sequential seismic loads of incremental acceleration peak by means of a 3 × 3 m2 shaking table. For this specimen two beam-column connections-one exterior and one interior-were instrumented with wide band low frequency sensors properly attached on the structure. Evolution of the energy b-value along the loading process accompanies the evolution of the severe damage at the critical regions of the structure (beam-column connections), thus making promising its use for structural health monitoring purposes.

  1. The conservation nexus: valuing interdependent water and energy savings in Arizona.

    Science.gov (United States)

    Bartos, Matthew D; Chester, Mikhail V

    2014-02-18

    Water and energy resources are intrinsically linked, yet they are managed separately--even in the water-scarce American southwest. This study develops a spatially explicit model of water-energy interdependencies in Arizona and assesses the potential for cobeneficial conservation programs. The interdependent benefits of investments in eight conservation strategies are assessed within the context of legislated renewable energy portfolio and energy efficiency standards. The cobenefits of conservation are found to be significant. Water conservation policies have the potential to reduce statewide electricity demand by 0.82-3.1%, satisfying 4.1-16% of the state's mandated energy-efficiency standard. Adoption of energy-efficiency measures and renewable generation portfolios can reduce nonagricultural water demand by 1.9-15%. These conservation cobenefits are typically not included in conservation plans or benefit-cost analyses. Many cobenefits offer negative costs of saved water and energy, indicating that these measures provide water and energy savings at no net cost. Because ranges of costs and savings for water-energy conservation measures are somewhat uncertain, future studies should investigate the cobenefits of individual conservation strategies in detail. Although this study focuses on Arizona, the analysis can be extended elsewhere as renewable portfolio and energy efficiency standards become more common nationally and internationally.

  2. Quantifying the value that energy efficiency and renewable energy provide as a hedge against volatile natural gas prices

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan; Bachrach, Devra; Golove, William

    2002-05-15

    Advocates of energy efficiency and renewable energy have long argued that such technologies can mitigate fuel price risk within a resource portfolio. Such arguments--made with renewed vigor in the wake of unprecedented natural gas price volatility during the winter of 2000/2001--have mostly been qualitative in nature, however, with few attempts to actually quantify the price stability benefit that these sources provide. In evaluating this benefit, it is important to recognize that alternative price hedging instruments are available--in particular, gas-based financial derivatives (futures and swaps) and physical, fixed-price gas contracts. Whether energy efficiency and renewable energy can provide price stability at lower cost than these alternative means is therefore a key question for resource acquisition planners. In this paper we evaluate the cost of hedging gas price risk through financial hedging instruments. To do this, we compare the price of a 10-year natural gas swap (i.e., what it costs to lock in prices over the next 10 years) to a 10-year natural gas price forecast (i.e., what the market is expecting spot natural gas prices to be over the next 10 years). We find that over the past two years natural gas users have had to pay a premium as high as $0.76/mmBtu (0.53/242/kWh at an aggressive 7,000 Btu/kWh heat rate) over expected spot prices to lock in natural gas prices for the next 10 years. This incremental cost to hedge gas price risk exposure is potentially large enough - particularly if incorporated by policymakers and regulators into decision-making practices - to tip the scales away from new investments in variable-price, natural gas-fired generation and in favor of fixed-price investments in energy efficiency and renewable energy.

  3. Quantifying the value that energy efficiency and renewable energy provide as a hedge against volatile natural gas prices

    International Nuclear Information System (INIS)

    Bolinger, Mark; Wiser, Ryan; Bachrach, Devra; Golove, William

    2002-01-01

    Advocates of energy efficiency and renewable energy have long argued that such technologies can mitigate fuel price risk within a resource portfolio. Such arguments-made with renewed vigor in the wake of unprecedented natural gas price volatility during the winter of 2000/2001-have mostly been qualitative in nature, however, with few attempts to actually quantify the price stability benefit that these sources provide. In evaluating this benefit, it is important to recognize that alternative price hedging instruments are available-in particular, gas-based financial derivatives (futures and swaps) and physical, fixed-price gas contracts. Whether energy efficiency and renewable energy can provide price stability at lower cost than these alternative means is therefore a key question for resource acquisition planners. In this paper we evaluate the cost of hedging gas price risk through financial hedging instruments. To do this, we compare the price of a 10-year natural gas swap (i.e., what it costs to lock in prices over the next 10 years) to a 10-year natural gas price forecast (i.e., what the market is expecting spot natural gas prices to be over the next 10 years). We find that over the past two years natural gas users have had to pay a premium as high as$0.76/mmBtu (0.53/242/kWh at an aggressive 7,000 Btu/kWh heat rate) over expected spot prices to lock in natural gas prices for the next 10 years. This incremental cost to hedge gas price risk exposure is potentially large enough - particularly if incorporated by policymakers and regulators into decision-making practices - to tip the scales away from new investments in variable-price, natural gas-fired generation and in favor of fixed-price investments in energy efficiency and renewable energy

  4. Making It Count: Understanding the Value of Energy Efficiency Financing Programs Funded by Utility Customers

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fadrhonc, Emily Martin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goldman, Charles [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schiller, Steve [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-12-01

    Utility customer-supported financing programs are receiving increased attention as a strategy for achieving energy saving goals. Rationales for using utility customer funds to support financing initiatives

  5. Evaluation of Dynamical Downscaling Resolution Effect on Wind Energy Forecast Value for a Wind Farm in Central Sweden

    DEFF Research Database (Denmark)

    Rosgaard, Martin Haubjerg; Hahmann, Andrea N.; Nielsen, Torben Skov

    2014-01-01

    For any energy system relying on wind power, accurate forecasts of wind fluctuations are essential for efficient integration into the power grid. Increased forecast precision allows end-users to plan day-ahead operation with reduced risk of penalties which in turn supports the feasibility of wind...... energy. The present study aims to quantify value added to wind energy forecasts in the 12-48 hour leadtime by downscaling global numerical weather prediction (NWP) data from the National Centers for Environmental Prediction Global Forecast System (GFS) using the limited-area NWP model described...

  6. Energy Labelling of Glazings and Windows in Denmark: Calculated and Measured Values

    DEFF Research Database (Denmark)

    Duer, Karsten; Svendsen, Svend; Mogensen, Morten Møller

    2002-01-01

    The influence of windows on the energy consumption in buildings is well known and in order to encourage the development and the appropriate use of high performance glazings and windows in Denmark, an Energy Labelling and Rating system is being developed. During this work a need for establishing...

  7. Hydrostatic pressure effects on the {gamma}-X conduction band mixing and the binding energy of a donor impurity in GaAs-Ga{sub 1-x}Al{sub x}As quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Lopez, S.Y. [Facultad de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, C.P. 62210, Cuernavaca (Mexico)

    2007-06-15

    Mixing between {gamma} and X valleys of the conduction band in GaAs-Ga{sub 1-x}Al{sub x}As quantum wells is investigated taken into account the effect of applied hydrostatic pressure. This effect is introduced via the pressure-dependent values of the corresponding energy gaps and the main band parameters. The mixing is considered along the lines of a phenomenological model. Variation of the confined ground state in the well as a function of the pressure is reported. The dependencies of the variationally calculated binding energy of a donor impurity with the hydrostatic pressure and well width are also presented. It is shown that the inclusion of the {gamma}-X mixing explains the non-linear behavior in the photoluminescence peak of confined exciton states that has been observed for pressures above 20 kbar. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Communication: regularizing binding energy distributions and thermodynamics of hydration: theory and application to water modeled with classical and ab initio simulations.

    Science.gov (United States)

    Weber, Valéry; Merchant, Safir; Asthagiri, D

    2011-11-14

    The high-energy tail of the distribution of solute-solvent interaction energies is poorly characterized for condensed systems, but this tail region is of principal interest in determining the excess free energy of the solute. We introduce external fields centered on the solute to modulate the short-range repulsive interaction between the solute and solvent. This regularizes the binding energy distribution and makes it easy to calculate the free energy of the solute with the field. Together with the work done to apply the field in the presence and absence of the solute, we calculate the excess chemical potential of the solute. We present the formal development of this idea and apply it to study liquid water. © 2011 American Institute of Physics

  9. Research on the energy-saving and revenue sharing strategy of ESCOs under the uncertainty of the value of Energy Performance Contracting Projects

    International Nuclear Information System (INIS)

    Qian, Dong; Guo, Ju’e

    2014-01-01

    Under the uncertainty of the value of Energy Performance Contracting Projects (EPCPs), this paper develops a revenue-sharing bargaining model between an Energy Service Company (ESCO) and an Energy-Using Organization (EU). Based on the model the paper analyzes the impacts of energy prices, risk-adjusted discount rates and accidents on the ESCO’s bargaining strategies. The research shows that the greater the probability of adverse circumstances is, the higher is the revenue share (of the EU), and the more disadvantageous is the ESCO’s position in the game. Furthermore, we design a forecast–commitment contract between an ESCO and an EU and analyze the optimal product’s energy savings commitment strategy of the ESCO to cope with uncertain energy savings and contract risk. The research illustrates that by introducing penalties and commitments, the contract can eliminate the impact of the uncertain energy savings on the contract execution to a certain extent; when the EU takes a greater commitment risk, the ESCO is willing to provide a higher commitment, thus enhancing the strategy value of the bilateral relationship and reducing the contract risk. Finally, the policy recommendations about improving shared savings contract standard, third-party energy savings measurement and verification mechanism and arbitration mechanism of EPCs are provided. - Highlights: • We provide a method for determining the revenue-sharing bargaining strategy space in a finite bargaining game of the ESCO. • The increase of the probability of adverse circumstances will increase the revenue share (of the EU). • We design a forecast–commitment contract between an ESCO and an EU. • The forecast–commitment contract can eliminate the impact of the uncertain energy savings on the contract execution to a certain extent. • When the EU takes a greater commitment risk, the ESCO is willing to provide a higher commitment

  10. An Assessment of the Value and Applicability of the Water-Energy Nexus Framework

    Science.gov (United States)

    Gleick, P. H.

    2015-12-01

    There have been major advances in the past decade in thinking about the links between water and energy resources, often called the Water-Energy Nexus. While past resource practices addressed these resource issues separately, both the scientific and the policy communities now acknowledge the close connections between them. Substantial work has been done quantifying and analyzing water requirements of both specific energy systems and integrated scenario projections. Less (albeit some) work has been done evaluating and analyzing the energy and greenhouse gas implications of building and operating water systems. But acknowledging and even quantifying these links is not the same as truly integrating them into decisions about water or energy use, changing policies or infrastructure to account for the connections, or actually advancing sustainable resource management. This talk will review the key scientific findings associated with recent work on the "nexus," including estimates of water requirements for energy systems and energy for water systems, the links with climate change mitigation and adaptation, and examples where work on the nexus has actually produced real change in resource policy.

  11. 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.

  12. Dissociation kinetics of excited ions: PEPICO measurements of Os3(CO)12 — The 7-35 eV single ionization binding energy region

    Science.gov (United States)

    Schalk, Oliver; Josefsson, Ida; Geng, Ting; Richter, Robert; Sa'adeh, Hanan; Thomas, Richard D.; Mucke, Melanie

    2018-02-01

    In this article, we study the photoinduced dissociation pathways of a metallocarbonyl, Os3(CO)12, in particular the consecutive loss of CO groups. To do so, we performed photoelectron-photoion coincidence (PEPICO) measurements in the single ionization binding energy region from 7 to 35 eV using 45-eV photons. Zero-energy ion appearance energies for the dissociation steps were extracted by modeling the PEPICO data using the statistical adiabatic channel model. Upon ionization to the excited ionic states above 13 eV binding energy, non-statistical behavior was observed and assigned to prompt CO loss. Double ionization was found to be dominated by the knockout process with an onset of 20.9 ± 0.4 eV. The oscillator strength is significantly larger for energies above 26.6 ± 0.4 eV, corresponding to one electron being ejected from the Os3 center and one from the CO ligands. The cross section for double ionization was found to increase linearly up to 35 eV ionization energy, at which 40% of the generated ions are doubly charged.

  13. Convergence to Equilibrium in Energy-Reaction-Diffusion Systems Using Vector-Valued Functional Inequalities

    Science.gov (United States)

    Mielke, Alexander; Mittnenzweig, Markus

    2018-04-01

    We discuss how the recently developed energy dissipation methods for reaction diffusion systems can be generalized to the non-isothermal case. For this, we use concave entropies in terms of the densities of the species and the internal energy, where the importance is that the equilibrium densities may depend on the internal energy. Using the log-Sobolev estimate and variants for lower-order entropies as well as estimates for the entropy production of the nonlinear reactions, we give two methods to estimate the relative entropy by the total entropy production, namely a somewhat restrictive convexity method, which provides explicit decay rates, and a very general, but weaker compactness method.

  14. Binding energy of donor impurity states and optical absorption in the Tietz-Hua quantum well under an applied electric field

    Science.gov (United States)

    Al, E. B.; Kasapoglu, E.; Sakiroglu, S.; Duque, C. A.; Sökmen, I.

    2018-04-01

    For a quantum well which has the Tietz-Hua potential, the ground and some excited donor impurity binding energies and the total absorption coefficients, including linear and third order nonlinear terms for the transitions between the related impurity states with respect to the structure parameters and the impurity position as well as the electric field strength are investigated. The binding energies were obtained using the effective-mass approximation within a variational scheme and the optical transitions between any two impurity states were calculated by using the density matrix formalism and the perturbation expansion method. Our results show that the effects of the electric field and the structure parameters on the optical transitions are more pronounced. So we can adjust the red or blue shift in the peak position of the absorption coefficient by changing the strength of the electric field as well as the structure parameters.

  15. The role of corporate reputation and employees' values in the uptake of energy efficiency in office buildings

    International Nuclear Information System (INIS)

    Pellegrini-Masini, Giuseppe; Leishman, Chris

    2011-01-01

    Although office market actors in the United Kingdom show a growing interest in energy efficiency, the pace of takeup of energy efficient office features is slow. Previous studies have highlighted the roles of limited direct financial costs and benefits ('efficiency gaps') and market barriers in limiting the rate of technology adoption. This study provides further evidence on the importance of these factors, but the primary contribution is focused on the role of corporate reputation and on the importance of individuals' values in shaping corporate behaviour. The paper presents a theoretical framework to explain environmental decision making in firms and we present qualitative evidence drawing from sixteen semi-structured individual and group interviews with office market stakeholders in London, Glasgow and Edinburgh. The research finds that companies, despite gradually becoming more energy conscious, still regard energy costs as a negligible part of their business costs. Nevertheless, an increasingly important driver is the reputational gain obtained by corporate businesses implementing sustainable practices. All the interviewees agreed that the pace of change in the office market is slow and that only further policy interventions will accelerate it. - Highlights: → Corporate reputation leads large businesses to seek energy efficient offices. → Investors show growing interest in green offices because of CSR and investment value. → Energy efficiency is not yet a top priority attribute in building choice. → Stakeholders believe that regulation is needed to accelerate the pace of change.

  16. ESTIMATING BASAL ENERGY EXPENDITURE IN LIVER TRANSPLANT RECIPIENTS: THE VALUE OF THE HARRIS-BENEDICT EQUATION

    OpenAIRE

    PINTO, Andressa S.; CHEDID, Marcio F.; GUERRA, Léa T.; ÁLVARES-DA-SILVA, Mario R.; ARAÚJO, Alexandre de; GUIMARÃES, Luciano S.; LEIPNITZ, Ian; CHEDID, Aljamir D.; KRUEL, Cleber R. P.; GREZZANA-FILHO, Tomaz J. M.; KRUEL, Cleber D. P.

    2016-01-01

    ABSTRACT Background: Reliable measurement of basal energy expenditure (BEE) in liver transplant (LT) recipients is necessary for adapting energy requirements, improving nutritional status and preventing weight gain. Indirect calorimetry (IC) is the gold standard for measuring BEE. However, BEE may be estimated through alternative methods, including electrical bioimpedance (BI), Harris-Benedict Equation (HBE), and Mifflin-St. Jeor Equation (MSJ) that carry easier applicability and lower cost....

  17. Binding Energies of the pi-Stacked Anisole Dimer: New Molecular Beam-Laser Spectroscopy Experiments and CCSD(T) Calculations

    Czech Academy of Sciences Publication Activity Database

    Řezáč, Jan; Nachtigallová, Dana; Mazzoni, F.; Pasquini, M.; Pietraperzia, G.; Becucci, M.; Müller-Dethlefs, K.; Hobza, Pavel

    2015-01-01

    Roč. 21, č. 18 (2015), s. 6740-6746 ISSN 0947-6539 R&D Projects: GA ČR GBP208/12/G016 Grant - others:GA MŠk(CZ) ED2.1.00/03.0058 Program:ED Institutional support: RVO:61388963 Keywords : binding energy * noncovalent interactions * pi stacking * laser spectroscopy * CCSD(T) calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.771, year: 2015

  18. Cation-pi interactions with a model for the side chain of tryptophan: structures and absolute binding energies of alkali metal cation-indole complexes.

    Science.gov (United States)

    Ruan, Chunhai; Yang, Zhibo; Hallowita, Nuwan; Rodgers, M T

    2005-12-22

    Threshold collision-induced dissociation techniques are employed to determine bond dissociation energies (BDEs) of mono- and bis-complexes of alkali metal cations, Li+, Na+, K+, Rb+, and Cs+, with indole, C8H7N. The primary and lowest energy dissociation pathway in all cases is endothermic loss of an intact indole ligand. Sequential loss of a second indole ligand is observed at elevated energies for the bis-complexes. Density functional theory calculations at the B3LYP/6-31G level of theory are used to determine the structures, vibrational frequencies, and rotational constants of these complexes. Theoretical BDEs are determined from single point energy calculations at the MP2(full)/6-311+G(2d,2p) level using the B3LYP/6-31G* geometries. The agreement between theory and experiment is very good for all complexes except Li+ (C8H7N), where theory underestimates the strength of the binding. The trends in the BDEs of these alkali metal cation-indole complexes are compared with the analogous benzene and naphthalene complexes to examine the influence of the extended pi network and heteroatom on the strength of the cation-pi interaction. The Na+ and K+ binding affinities of benzene, phenol, and indole are also compared to those of the aromatic amino acids, phenylalanine, tyrosine, and tryptophan to elucidate the factors that contribute to the binding in complexes to the aromatic amino acids. The nature of the binding and trends in the BDEs of cation-pi complexes between alkali metal cations and benzene, phenol, and indole are examined to help understand nature's preference for engaging tryptophan over phenylalanine and tyrosine in cation-pi interactions in biological systems.

  19. Reference binding energies of transition metal carbides by core-level x-ray photoelectron spectroscopy free from Ar+ etching artefacts

    Science.gov (United States)

    Greczynski, G.; Primetzhofer, D.; Hultman, L.

    2018-04-01

    We report x-ray photoelectron spectroscopy (XPS) core level binding energies (BE's) for the widely-applicable groups IVb-VIb transition metal carbides (TMCs) TiC, VC, CrC, ZrC, NbC, MoC, HfC, TaC, and WC. Thin film samples are grown in the same deposition system, by dc magnetron co-sputtering from graphite and respective elemental metal targets in Ar atmosphere. To remove surface contaminations resulting from exposure to air during sample transfer from the growth chamber into the XPS system, layers are either (i) Ar+ ion-etched or (ii) UHV-annealed in situ prior to XPS analyses. High resolution XPS spectra reveal that even gentle etching affects the shape of core level signals, as well as BE values, which are systematically offset by 0.2-0.5 eV towards lower BE. These destructive effects of Ar+ ion etch become more pronounced with increasing the metal atom mass due to an increasing carbon-to-metal sputter yield ratio. Systematic analysis reveals that for each row in the periodic table (3d, 4d, and 5d) C 1s BE increases from left to right indicative of a decreased charge transfer from TM to C atoms, hence bond weakening. Moreover, C 1s BE decreases linearly with increasing carbide/metal melting point ratio. Spectra reported here, acquired from a consistent set of samples in the same instrument, should serve as a reference for true deconvolution of complex XPS cases, including multinary carbides, nitrides, and carbonitrides.

  20. First-Principle Framework for Total Charging Energies in Electrocatalytic Materials and Charge-Responsive Molecular Binding at Gas-Surface Interfaces.

    Science.gov (United States)

    Tan, Xin; Tahini, Hassan A; Seal, Prasenjit; Smith, Sean C

    2016-05-04

    Heterogeneous charge-responsive molecular binding to electrocatalytic materials has been predicted in several recent works. This phenomenon offers the possibility of using voltage to manipulate the strength of the binding interaction with the target gas molecule and thereby circumvent thermochemistry constraints, which inhibit achieving both efficient binding and facile release of important targets such as CO2 and H2. Stability analysis of such charge-induced molecular adsorption has been beyond the reach of existing first-principle approaches. Here, we draw on concepts from semiconductor physics and density functional theory to develop a first principle theoretical approach that allows calculation of the change in total energy of the supercell due to charging. Coupled with the calculated adsorption energy of gas molecules at any given charge, this allows a complete description of the energetics of the charge-induced molecular adsorption process. Using CO2 molecular adsorption onto negatively charged h-BN (wide-gap semiconductor) and g-C4N3 (half metal) as example cases, our analysis reveals that - while adsorption is exothermic after charge is introduced - the overall adsorption processes are not intrinsically spontaneous due to the energetic cost of charging the materials. The energies needed to overcome the barriers of these processes are 2.10 and 0.43 eV for h-BN and g-C4N3, respectively. This first principle approach opens up new pathways for a more complete description of charge-induced and electrocatalytic processes.

  1. The role of extra-atomic relaxation in determining Si2p binding energy shifts at silicon/silicon oxide interfaces

    International Nuclear Information System (INIS)

    Zhang, K.Z.; Greeley, J.N.; Banaszak Holl, M.M.; McFeely, F.R.

    1997-01-01

    The observed binding energy shift for silicon oxide films grown on crystalline silicon varies as a function of film thickness. The physical basis of this shift has previously been ascribed to a variety of initial state effects (Si endash O ring size, strain, stoichiometry, and crystallinity), final state effects (a variety of screening mechanisms), and extrinsic effects (charging). By constructing a structurally homogeneous silicon oxide film on silicon, initial state effects have been minimized and the magnitude of final state stabilization as a function of film thickness has been directly measured. In addition, questions regarding the charging of thin silicon oxide films on silicon have been addressed. From these studies, it is concluded that initial state effects play a negligible role in the thickness-dependent binding energy shift. For the first ∼30 Angstrom of oxide film, the thickness-dependent binding energy shift can be attributed to final state effects in the form of image charge induced stabilization. Beyond about 30 Angstrom, charging of the film occurs. copyright 1997 American Institute of Physics

  2. ESTIMATING BASAL ENERGY EXPENDITURE IN LIVER TRANSPLANT RECIPIENTS: THE VALUE OF THE HARRIS-BENEDICT EQUATION.

    Science.gov (United States)

    Pinto, Andressa S; Chedid, Marcio F; Guerra, Léa T; Álvares-DA-Silva, Mario R; Araújo, Alexandre de; Guimarães, Luciano S; Leipnitz, Ian; Chedid, Aljamir D; Kruel, Cleber R P; Grezzana-Filho, Tomaz J M; Kruel, Cleber D P

    2016-01-01

    Reliable measurement of basal energy expenditure (BEE) in liver transplant (LT) recipients is necessary for adapting energy requirements, improving nutritional status and preventing weight gain. Indirect calorimetry (IC) is the gold standard for measuring BEE. However, BEE may be estimated through alternative methods, including electrical bioimpedance (BI), Harris-Benedict Equation (HBE), and Mifflin-St. Jeor Equation (MSJ) that carry easier applicability and lower cost. To determine which of the three alternative methods for BEE estimation (HBE, BI and MSJ) would provide most reliable BEE estimation in LT recipients. Prospective cross-sectional study including dyslipidemic LT recipients in follow-up at a 735-bed tertiary referral university hospital. Comparisons of BEE measured through IC to BEE estimated through each of the three alternative methods (HBE, BI and MSJ) were performed using Bland-Altman method and Wilcoxon Rank Sum test. Forty-five patients were included, aged 58±10 years. BEE measured using IC was 1664±319 kcal for males, and 1409±221 kcal for females. Average difference between BEE measured by IC (1534±300 kcal) and BI (1584±377 kcal) was +50 kcal (p=0.0384). Average difference between the BEE measured using IC (1534±300 kcal) and MSJ (1479.6±375 kcal) was -55 kcal (p=0.16). Average difference between BEE values measured by IC (1534±300 kcal) and HBE (1521±283 kcal) was -13 kcal (p=0.326). Difference between BEE estimated through IC and HBE was less than 100 kcal for 39 of all 43patients. Among the three alternative methods, HBE was the most reliable for estimating BEE in LT recipients. Estimativa confiável do metabolismo basal em pacientes transplantados de fígado é necessária para adaptar os requerimentos energéticos, melhorar o estado nutricional e prevenir ganho de peso. Calorimetria indireta (CI) é o padrão-ouro para a medição do metabolismo basal. No entanto, ele pode ser estimado utilizando-se métodos alternativos

  3. The economic value of the enterprise for stakeholders in the fuel and energy sector

    Directory of Open Access Journals (Sweden)

    Lorenc Sylwia

    2017-01-01

    Full Text Available The purpose of this article is to present certain trends in the distribution of value created by businesses for groups of stakeholders as part of a conception of sustainable growth. The subject of this analysis is the LW Bogdanka S.A. mining company, which was studied in terms of distribution of value for the period from 2009 to 2015. In this paper, the main stakeholders of the operation were identified as the shareholders, capital providers, employees, suppliers, local governments and the state. A method for measuring distributed value based on cash flow is demonstrated. Identification of the value added by the proposed methodology may assist of decisions related to the continuation or liquidation of operations.

  4. The water energy nexus, an ISO50001 water case study and the need for a water value system

    Directory of Open Access Journals (Sweden)

    Brendan P. Walsh

    2015-06-01

    Full Text Available The world’s current utilisation of water, allied to the forecasted increase in our dependence on it, has led to the realisation that water as a resource needs to be managed. The scarcity and cost of water worldwide, along with water management practices within Europe, are highlighted in this paper. The heavy dependence of energy generation on water and the similar dependence of water treatment and distribution on energy, collectively termed the water–energy nexus, is detailed. A summary of the recently launched ISO14046 Water Footprint Standard along with other benchmarking measures is outlined and a case history of managing water using the Energy Management Standard ISO50001 is discussed in detail. From this, the requirement for a methodology for improvement of water management has been identified, involving a value system for water streams, which, once optimised will improve water management including efficiency and total utilisation.

  5. An all-atom knowledge-based energy function for protein-DNA threading, docking decoy discrimination, and prediction of transcription-factor binding profiles

    Science.gov (United States)

    Xu, Beisi; Yang, Yuedong; Liang, Haojun; Zhou, Yaoqi

    2009-01-01

    How to make an accurate representation of protein-DNA interactions by an energy function is a long-standing unsolved problem in structural biology. Here, we modified a statistical potential based on the distance-scaled, finite ideal-gas reference state (DFIRE) so that it is optimized for protein-DNA interactions. The changes include a volume-fraction correction to account for unmixable atom types in proteins and DNA in addition to the usage of a low-count correction, residue/base-specific atom types, and a shorter cutoff distance for protein-DNA interactions. The new statistical energy functions are tested in threading and docking decoy discriminations and prediction of protein-DNA binding affinities and transcription-factor binding profiles. Results indicate that new proposed energy functions are among the best in existing energy functions for protein-DNA interactions. The new energy functions are available as a web-server called DDNA 2.0 at http://sparks.informatics.iupui.edu. The server version was trained by the entire 212 protein-DNA complexes. PMID:19274740

  6. Ce3+ 5d-centroid shift and vacuum referred 4f-electron binding energies of all lanthanide impurities in 150 different compounds

    International Nuclear Information System (INIS)

    Dorenbos, Pieter

    2013-01-01

    A review on the wavelengths of all five 4f–5d transitions for Ce 3+ in about 150 different inorganic compounds (fluorides, chlorides, bromides, iodides, oxides, sulfides, selenides, nitrides) is presented. It provides data on the centroid shift and the crystal field splitting of the 5d-configuration which are then used to estimate the Eu 2+ inter 4f-electron Coulomb repulsion energy U(6,A) in compound A. The four semi-empirical models (the redshift model, the centroid shift model, the charge transfer model, and the chemical shift model) on lanthanide levels that were developed past 12 years are briefly reviewed. It will be demonstrated how those models together with the collected data of this work and elsewhere can be united to construct schemes that contain the binding energy of electrons in the 4f and 5d states for each divalent and each trivalent lanthanide ion relative to the vacuum energy. As example the vacuum referred binding energy schemes for LaF 3 and La 2 O 3 will be constructed. - Highlights: ► An compilation on all five Ce 3+ 4f–5d energies in 150 inorganic compounds is presented. ► The relationship between the 5d centroid shift and host cation electronegativity id demonstrated. ► The electronic structure scheme of the lanthanides in La 2 O 3 and LaF 3 is presented.

  7. The value of social networks in the diffusion of energy-efficiency innovations in UK households

    International Nuclear Information System (INIS)

    McMichael, Megan; Shipworth, David

    2013-01-01

    The UK Government has policy goals for increasing energy efficiency in existing homes. However, there are doubts that standard technology and behavioural innovations will be adopted widely enough in time to achieve the targets. Diffusion of innovation theory states that the communication of information on innovations through a social system encourages adoption. Social capital theory states that interpersonal communication is a key means of gaining resources, such as information on energy-efficiency innovations, for attaining certain goals. Case study research of three British communities was conducted in 2009 in order to understand the influence of social capital on information diffusion regarding the adoption of household energy-efficiency measures. The findings show that while standard campaigns may account for two-thirds of information-seeking behaviour, they may not be addressing up to one-third of information-seekers who would prefer to speak to people they know. Findings also indicate that seeking information amongst personal contacts is often associated with adoption of energy-efficiency innovations, increasing the likelihood of adoption by up to four times, but that there are important differences between types of innovations and communities. Tailoring campaigns to communities' communication channels is therefore imperative. These findings have important implications for informing community-based energy-efficiency programmes. - Highlights: ► Case study research suggests social capital is important for home energy innovations. ► One-third of respondents indicated a preference for speaking to people they know. ► Those who sought information were up to four times more likely to adopt innovations. ► Results varied by innovation and by each community case study. ► Tailoring campaigns to communities' communication channels is imperative.

  8. Development of a decision aid for energy resource management for the Navajo Nation incorporating environmental cultural values

    Science.gov (United States)

    Necefer, Len Edward

    Decision-making surrounding pathways of future energy resource management are complexity and requires balancing tradeoffs of multiple environmental, social, economic, and technical outcomes. Technical decision aid can provide a framework for informed decision making, allowing individuals to better understand the tradeoff between resources, technology, energy services, and prices. While technical decision aid have made significant advances in evaluating these quantitative aspects of energy planning and performance, they have not been designed to incorporate human factors, such as preferences and behavior that are informed by cultural values. Incorporating cultural values into decision tools can provide not only an improved decision framework for the Navajo Nation, but also generate new insights on how these perspective can improve decision making on energy resources. Ensuring these aids are a cultural fit for each context has the potential to increase trust and promote understanding of the tradeoffs involved in energy resource management. In this dissertation I present the development of a technical tool that explicitly addresses cultural and spiritual values and experimentally assesses their influence on the preferences and decision making of Navajo citizens. Chapter 2 describes the results of a public elicitation effort to gather information about stakeholder views and concerns related to energy development in the Navajo Nation in order to develop a larger sample survey and a decision-support tool that links techno-economic energy models with sociocultural attributes. Chapter 3 details the methods of developing the energy decision aid and its underlying assumptions for alternative energy projects and their impacts. This tool also provides an alternative to economic valuation of cultural impacts based upon an ordinal index tied to environmental impacts. Chapter 4 details the the influence of various cultural, environmental, and economic outcome information provided

  9. Modifications outside the proteinase binding loop in Cucurbita maxima trypsin inhibitor III (CMTI-III) analogues change the binding energy with bovine beta-trypsin.

    Science.gov (United States)

    Jaśkiewicz, A; Lis, K; Rózycki, J; Kupryszewski, G; Rolka, K; Ragnarsson, U; Zbyryt, T; Wilusz, T

    1998-10-02

    Five 26-peptide analogues of the trypsin inhibitor [Pro18]CMTI-III containing Leu or Tyr in position 7 and Val or Tyr in position 27: 1 (Leu7, Tyr27), 2 (Tyr7, Val27), 3 (Tyr7, Tyr27), 4 (Leu7, Val27) and 5 (Leu7, Ala18, Tyr27) were synthesized by the solid-phase method. Analogues 1-4 displayed Ka with bovine beta-trypsin of the same order of magnitude as the wild CMTI-III inhibitor, whereas for analogue 5, this value was lower by about 3 orders of magnitude. This indicated that for the analogues with Pro (but not with Ala) in position 18, the side-chain interactions between positions 7 and 27 did not play a critical role for the stabilization of the active structure. In addition, these results also suggest that Tyr7 is involved in an additional aromatic interaction with position 41 of the enzyme.

  10. Heat Energy From Value-Added Sawdust Briquettes Of Albizia Zygia ...

    African Journals Online (AJOL)

    Choice-Academy

    Introduction raditionally wood in form of fuel wood, twigs and charcoal has been the major source of renewable energy in. Nigeria, accounting for 51% of the total .... The production of briquette at Celina. Industries is through the use of screw press briquetting machine, as shown in cross-section in Fig. 1. The outer surface of ...

  11. Examining Pre-Service Teachers' Use of Atomic Models in Explaining Subsequent Ionisation Energy Values

    Science.gov (United States)

    Wheeldon, Ruth

    2012-01-01

    Chemistry students' explanations of ionisation energy phenomena often involve a number of non-scientific or inappropriate ideas being used to form causality arguments. Research has attributed this to many science teachers using these ideas themselves (Tan and Taber, in "J Chem Educ" 86(5):623-629, 2009). This research extends this work by…

  12. Heat Energy From Value-Added Sawdust Briquettes Of Albizia Zygia ...

    African Journals Online (AJOL)

    The sawdust collected in 30 livestock feed sacs were later transported to Celina Industries where they were densified into briquettes at a pressure of 2000MPa at 4500C and heat intensity of 300% for the production of heat energy and a comparative analysis of the physical properties between the sawdust briquettes and the ...

  13. First-principles investigation on the electronic efficiency and binding energy of the contacts formed by graphene and poly-aromatic hydrocarbon anchoring groups

    KAUST Repository

    Li, Yang

    2015-04-28

    © 2015 AIP Publishing LLC. The electronic efficiency and binding energy of contacts formed between graphene electrodes and poly-aromatic hydrocarbon (PAH) anchoring groups have been investigated by the non-equilibrium Green\\'s function formalism combined with density functional theory. Our calculations show that PAH molecules always bind in the interior and at the edge of graphene in the AB stacking manner, and that the binding energy increases following the increase of the number of carbon and hydrogen atoms constituting the PAH molecule. When we move to analyzing the electronic transport properties of molecular junctions with a six-carbon alkyne chain as the central molecule, the electronic efficiency of the graphene-PAH contacts is found to depend on the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the corresponding PAH anchoring group, rather than its size. To be specific, the smaller is the HOMO-LUMO gap of the PAH anchoring group, the higher is the electronic efficiency of the graphene-PAH contact. Although the HOMO-LUMO gap of a PAH molecule depends on its specific configuration, PAH molecules with similar atomic structures show a decreasing trend for their HOMO-LUMO gap as the number of fused benzene rings increases. Therefore, graphene-conjugated molecule-graphene junctions with high-binding and high-conducting graphene-PAH contacts can be realized by choosing appropriate PAH anchor groups with a large area and a small HOMO-LUMO gap.

  14. Creating a multi-national development platform: Thorium energy and rare earth value chain

    International Nuclear Information System (INIS)

    Kennedy, J.; Kutsch, J.

    2014-01-01

    Rare earths and thorium are linked at the mineralogical level. Changes in thorium regulations and liabilities resulted in the development of excessive market concentrations in the rare earth value chain. High value monazite rare earth resources, a by-product of heavy mineral sands mining, constituted a significant portion of global rare earth supply (and nearly 100% of heavy rare earths) until legislative changes, interpretation and enforcement regarding “source materials” in the early 1980s eliminated these materials from the supply chain.

  15. Valuing the Resilience Provided by Solar and Battery Energy Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    McLaren, Joyce A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mullendore, Seth [Clean Energy Group

    2018-02-05

    This paper explores the impact of valuing resilience on the economics of photovoltaics (PV) and storage systems for commercial buildings. The analysis presented here illustrates that accounting for the cost of grid power outages can change the breakeven point for PV and storage system investment, and increase the size of systems designed to deliver the greatest economic benefit over time. In other words, valuing resilience can make PV and storage systems economical in cases where they would not be otherwise. As storage costs decrease, and outages occur more frequently, PV and storage are likely to play a larger role in building design and management considerations.

  16. Effects of river impoundment on ecosystem services of large tropical rivers: embodied energy and market value of artisanal fisheries.

    Science.gov (United States)

    Hoeinghaus, David J; Agostinho, Angelo A; Gomes, Luiz C; Pelicice, Fernando M; Okada, Edson K; Latini, João D; Kashiwaqui, Elaine A L; Winemiller, Kirk O

    2009-10-01

    Applying the ecosystem services concept to conservation initiatives or in managing ecosystem services requires understanding how environmental impacts affect the ecology of key species or functional groups providing the services. We examined effects of river impoundments, one of the leading threats to freshwater biodiversity, on an important ecosystem service provided by large tropical rivers (i.e., artisanal fisheries). The societal and economic importance of this ecosystem service in developing countries may provide leverage to advance conservation agendas where future impoundments are being considered. We assessed impoundment effects on the energetic costs of fisheries production (embodied energy) and commercial market value of the artisanal fishery of the Paraná River, Brazil, before and after formation of Itaipu Reservoir. High-value migratory species that dominated the fishery before the impoundment was built constituted a minor component of the contemporary fishery that is based heavily on reservoir-adapted introduced species. Cascading effects of river impoundment resulted in a mismatch between embodied energy and market value: energetic costs of fisheries production increased, whereas market value decreased. This was partially attributable to changes in species functional composition but also strongly linked to species identities that affected market value as a result of consumer preferences even when species were functionally similar. Similar trends are expected in other large tropical rivers following impoundment. In addition to identifying consequences of a common anthropogenic impact on an important ecosystem service, our assessment provides insight into the sustainability of fisheries production in tropical rivers and priorities for regional biodiversity conservation.

  17. Reporting on Long-Term Value Creation—The Example of Public Canadian Energy and Mining Companies

    Directory of Open Access Journals (Sweden)

    Petra F. A. Dilling

    2016-09-01

    Full Text Available This study empirically analyzes reporting on long-term value creation for Canadian public mining and energy companies. It represents an important first step in determining the quality of reporting and its determinants for large public companies. In this exploratory empirical study, a reporting quality scoring index was developed to measure disclosure quality of long-term value creation reporting. Content analysis was used to examine financial and sustainability reports for a sample of twenty Canadian public mining and energy companies. Corporate disclosure quality scores were then calculated by assessing the quality of reporting in four main categories. The findings suggest that overall disclosure quality on long-term value creation is still low. Companies disclosing higher quality information on long-term value creation are of bigger size, operate in the basic materials sector, have an independent board, are listed in the Dow Jones Sustainability Index, experience higher stock volatility and use more words related to long-term value creation in their annual financial and non-financial reports. In order to increase and restore stakeholder trust and credibility as well as a tool to maintain stability, it is strongly recommended to introduce adequate mandatory standardization resulting in a set of internationally recognized reporting standards as well as a requirement for external assurance of reports.

  18. A comparison of specific effective energies values obtained for some radioactive element using 3 different decay data banks

    International Nuclear Information System (INIS)

    Nascimento, J.E.C.; Bertelli Neto, L.

    1990-01-01

    The Specific Effective Energies (SEE) are the dose equivalents received by each of the body organs (targets organs) per nuclear transformation of a radionuclide deposited in an organ or tissue (source organ) after an intake of this isotope. The SEE values were calculated on basis of the dosimetric concepts of Publication 30 of the International Comission on Radiological Protection (ICRP). The results were evaluated using two of the three most known decay data banks. This study shows considerables discrepancies in the evaluation of the SEE values for some radionuclides. In theses cases it is recommended the use of the most complete and detailed decay data bank to perform the SEE calculations. (author) [pt

  19. Single-molecule fluorescence resonance energy transfer shows uniformity in TATA binding protein-induced DNA bending and heterogeneity in bending kinetics.

    Science.gov (United States)

    Blair, Rebecca H; Goodrich, James A; Kugel, Jennifer F

    2012-09-25

    TATA binding protein (TBP) is a key component of the eukaryotic RNA polymerase II transcription machinery that binds to TATA boxes located in the core promoter regions of many genes. Structural and biochemical studies have shown that when TBP binds DNA, it sharply bends the DNA. We used single-molecule fluorescence resonance energy transfer (smFRET) to study DNA bending by human TBP on consensus and mutant TATA boxes in the absence and presence of TFIIA. We found that the state of the bent DNA within populations of TBP-DNA complexes is homogeneous; partially bent intermediates were not observed. In contrast to the results of previous ensemble studies, TBP was found to bend a mutant TATA box to the same extent as the consensus TATA box. Moreover, in the presence of TFIIA, the extent of DNA bending was not significantly changed, although TFIIA did increase the fraction of DNA molecules bound by TBP. Analysis of the kinetics of DNA bending and unbending revealed that on the consensus TATA box two kinetically distinct populations of TBP-DNA complexes exist; however, the bent state of the DNA is the same in the two populations. Our smFRET studies reveal that human TBP bends DNA in a largely uniform manner under a variety of different conditions, which was unexpected given previous ensemble biochemical studies. Our new observations led to us to revise the model for the mechanism of DNA binding by TBP and for how DNA bending is affected by TATA sequence and TFIIA.

  20. D3R Grand Challenge 2: blind prediction of protein-ligand poses, affinity rankings, and relative binding free energies

    Science.gov (United States)

    Gaieb, Zied; Liu, Shuai; Gathiaka, Symon; Chiu, Michael; Yang, Huanwang; Shao, Chenghua; Feher, Victoria A.; Walters, W. Patrick; Kuhn, Bernd; Rudolph, Markus G.; Burley, Stephen K.; Gilson, Michael K.; Amaro, Rommie E.

    2018-01-01

    The Drug Design Data Resource (D3R) ran Grand Challenge 2 (GC2) from September 2016 through February 2017. This challenge was based on a dataset of structures and affinities for the nuclear receptor farnesoid X receptor (FXR), contributed by F. Hoffmann-La Roche. The dataset contained 102 IC50 values, spanning six orders of magnitude, and 36 high-resolution co-crystal structures with representatives of four major ligand classes. Strong global participation was evident, with 49 participants submitting 262 prediction submission packages in total. Procedurally, GC2 mimicked Grand Challenge 2015 (GC2015), with a Stage 1 subchallenge testing ligand pose prediction methods and ranking and scoring methods, and a Stage 2 subchallenge testing only ligand ranking and scoring methods after the release of all blinded co-crystal structures. Two smaller curated sets of 18 and 15 ligands were developed to test alchemical free energy methods. This overview summarizes all aspects of GC2, including the dataset details, challenge procedures, and participant results. We also consider implications for progress in the field, while highlighting methodological areas that merit continued development. Similar to GC2015, the outcome of GC2 underscores the pressing need for methods development in pose prediction, particularly for ligand scaffolds not currently represented in the Protein Data Bank (http://www.pdb.org), and in affinity ranking and scoring of bound ligands.

  1. Evaluation of effective energy for QA and QC: measurement of half-value layer using radiochromic film density

    International Nuclear Information System (INIS)

    Gotanda, R.; Takeda, Y.; Gotanda, T.; Oishi Hospital, Hiroshima; Tabuchi, A.; Kawasaki Hospital, Okayama; Yamamoto, K.; Osaka Cancer Prevention and Detection Centre, Osaka; Kuwano, T.; Osaka Medical Center for Cancer and Cardovascular Diseases, Osaka; Yatake, H.; Kaizuka City Hospital, Osaka; Katsuda, T.

    2009-01-01

    The effective energy of diagnostic x-rays is important for quality assurance (QA) and quality control (QC). However, the half-value layer (HVL), which is necessary to evaluate the effective energy, is not ubiquitously monitored because ionization-chamber dosimetry is time-consuming and complicated. To verify the applicability of GAFCHROMIC XR type R (GAF-R) film for HVL measurement as an alternative to monitoring with an ionization chamber, a single-strip method for measuring the HVL has been evaluated. Calibration curves of absorbed dose versus film density were generated using this single-strip method with GAF-R film, and the coefficient of determination (r2) of the straight-line approximation was evaluated. The HVLs (effective energies) estimated using the GAF-R film and an ionization chamber were compared. The coefficient of determination (r2) of the straight-line approximation obtained with the GAF-R film was more than 0.99. The effective energies (HVLs) evaluated using the GAF-R film and the ionization chamber were 43.25 keV (5.10 m m) and 39.86 keV (4.45 mm), respectively. The difference in the effective energies determined by the two methods was thus 8.5%. These results suggest that GAF-R might be used to evaluate the effective energy from the film-density growth without the need for ionization-chamber measurements.

  2. Investigating the interdependence between non-hydroelectric renewable energy, agricultural value added, and arable land use in Argentina

    OpenAIRE

    Ben Jebli, Mehdi; Ben Youssef, Slim

    2017-01-01

    We examine the dynamic relationships between per capita carbon dioxide (CO2) emissions, real gross domestic product (GDP), non-hydroelectric renewable energy (NHRE) consumption, agricultural value added (AVA), and agricultural land (AGRL) use for the case of Argentina over the period 1980-2013 by employing the autoregressive distributed lag (ARDL) bounds approach to cointegration and Granger causality tests. The Wald test confirms the existence of a long-run cointegration between variables. T...

  3. Valuing energy policy attributes for environmental management: Choice experiment evidence from a research institution

    International Nuclear Information System (INIS)

    Komarek, Timothy M.; Lupi, Frank; Kaplowitz, Michael D.

    2011-01-01

    Many governments, firms, institutions and individuals have become increasingly cognizant of their impact on the environment, most notably with respect to global climate change. Coupled with the possibility of future regulations aimed at curbing greenhouse gas emissions, firms and institutions have begun to critically evaluate their own carbon footprint. This paper examines the preferences of stakeholders within a large academic institution for attributes of alternative greenhouse gas (GHG) reduction strategies. The attributes considered by constituents include: the fuel portfolio mix, effort for conserving energy use, carbon emissions reduction, timeframe for emissions reduction to be achieved and cost. We use a choice experiment technique that enables the examination of greenhouse gas reduction program attribute preferences across three constituent groups. The results show that each of the constituent groups have a positive WTP for carbon emissions reductions and prefer investments in reductions in the shorter- rather than longer-term. The results also suggest differences between the constituent groups in their WTP for types of fuels in the fuel portfolio. Finally, we use the results to examine the welfare implications of different combinations of the policy attributes that coincide with alternative GHG program strategies. - Highlights: → We explore preferences for carbon footprint reduction at an academic institution. → Include several pertinent energy policy attributes in a choice experiment. → Find preference heterogeneity between constituent groups for policy attributes. → Find highest willingness to pay for 'green' energy and emissions reduction amount.

  4. The relationship of eating until 80% full with types and energy values of food consumed.

    Science.gov (United States)

    Fukkoshi, Yuko; Akamatsu, Rie; Shimpo, Misa

    2015-04-01

    Eating until one is 80% full is considered a healthy dietary practice in Japan. This study examined the relationship between this behavior and energy intake and types and quantities of foods consumed to examine its beneficial effects. This study relied on dietary records and self-administered questionnaires completed by 330 users of a health-management website in November 2012. ANOVA was performed to examine the relationship between eating until one is 80% full and intake. Men who always ate until they were 80% full consumed less energy than those who did not (mean [SD]; always: 1997.3 [356.7] kcal; rarely/never: 2448.9 [637.1] kcal; p<0.05). Moreover, men who ate until they were 80% full consumed fewer servings of grain dishes (always: 3.7 [0.9] servings; rarely/never: 5.1 [1.9] servings; p<0.05) and more servings of vegetable dishes (always: 5.9 [2.2] servings; rarely/never: 4.0 [2.3] servings, p<0.05) than those who did not. Men who ate until they were 80% full consumed less energy and more vegetable dishes than those who did not, suggesting that eating until one is 80% full is associated with healthy dietary habits among men. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Binding energy and preferred adsorption sites of CO on gold and silver-gold cluster cations: adsorption kinetics and quantum chemical calculations.

    Science.gov (United States)

    Neumaier, Marco; Weigend, Florian; Hampe, Oliver; Kappes, Manfred M

    2008-01-01

    We revisit the reactivity of trapped pure gold (Au(n)+, n cluster cations (Ag(m)Au(n)+, m + n adsorption sites, associated vibrational frequencies) of CO to the noble metal as a function of cluster size and composition. Starting from results for pure gold cluster cations for which an overall decrease of CO binding energy with increasing cluster size was experimentally observed--from about 1.09 +/- 0.1 eV (for n = 6) to below 0.65 +/- 0.1 eV (for n > 26) we demonstrate that metal--CO bond energies correlate with the total electron density and with the energy of the lowest unoccupied molecular orbital (LUMO) on the bare metal cluster cation as obtained by density functional theory (DFT) computations. This is a consequence of the predominantly sigma-donating character of the CO-M bond. Further support for this concept is found by contrasting the predictions of binding energies to the experimental results for small alloy cluster cations (Ag(m)Au(n)+, 4 adsorption sites and pre-screen favorable isomers.

  6. Exergy in the built environment. The added value of exergy in the assessment and development of energy systems for the built environment.

    NARCIS (Netherlands)

    Jansen, S.C.

    2013-01-01

    This doctoral research studied the added value of exergy for the assessment and development of energy systems for the built environment, aiming at a reduced need for high-quality energy input. Currently the analysis and development of energy systems for the built environment is based on the energy

  7. Energy dependence of new thermoluminescent detectors in terms of H{sub p}{sup 10} values

    Energy Technology Data Exchange (ETDEWEB)

    Miljanic, S.; Knezevic, C.; Stuhec, M.; Ranogajec-Komor, M.; Krpan, K.; Vekic, B

    2003-07-01

    The aim of this work was to determine energy dependence characteristics in terms of values of the personal dose equivalent, H{sub p}(10). The following types of thermoluminescent detectors (TLDs) were investigated: (a) two new types based on lithium borate Li{sub 2}B{sub 4}0{sub 7}:Cu,In and Li{sub 2}B{sub 407}:Cu,In,Ag; (b) two types based on the highly sensitive material LiF:Mg,Cu,P, TLD-700H and GR 200A; (c) two well-known types of LiF:Mg,Ti detectors, TLD-100 and TLD-700 and (d) highly sensitive Al{sub 2}0{sub 3}:C detectors. TLDs previously calibrated with {sup 137}Cs gamma rays were simultaneously irradiated with X ray beams in the range of mean energies between 33 and 116 keV. The irradiations were performed with detectors in polymethyl methacrylate (PMMA) holders placed on a 30 cm x 30 cm x 15 cm water phantom with PMMA walls (ISO phantom). Measured energy responses were compared with calculated data for H{sub p}(10) values. The results confirmed the satisfactory tissue equivalent characteristics of all investigated TLDs except Al{sub 2}0{sub 3}:C, which (due to its large energy dependence) is suitable for personal dosimetry only with an appropriate filter. (author)

  8. Value of non-electric applications of nuclear energy beyond market potential

    International Nuclear Information System (INIS)

    Khamis, I.

    2014-01-01

    Providing process steam at different temperatures, Nuclear Power Plants (NPPs) could be coupled to various types of non-electric applications such as seawater desalination, hydrogen production, district heating or cooling, as well as any energy-demanding process heat industrial application. This will not only make nuclear power a more feasible option helping to accelerate its penetration into the the heat and transportation markets, but also helping to improve their overall thermal efficiencies. Typical thermal efficiencies of NPPs are about 33%. All existing reactor types can be coupled to non-electric application based on cogeneration i.e. the production of electricity and process heat. (authors)

  9. Inhibitor and peptide binding to calmodulin characterized by high pressure Fourier transform infrared spectroscopy and Förster resonance energy transfer.

    Science.gov (United States)

    Cinar, Süleyman; Czeslik, Claus

    2018-03-17

    We compare the binding of an inhibitor with that of a natural peptide to Ca 2+ saturated calmodulin (holo-CaM). As inhibitor we have chosen trifluoperazine (TFP) that is inducing a huge conformational change of holo-CaM from the open dumbbell-shaped to the closed globular conformation upon binding. On the other hand, melittin is used as model peptide, which is a well-known natural binding partner of holo-CaM. The experiments are carried out as a function of pressure to reveal the contribution of volume or packing effects to the stability of the calmodulin-ligand complexes. From high-pressure Fourier transform infrared (FTIR) spectroscopy, we find that the holo-CaM/TFP complex has a much higher pressure stability than the holo-CaM/melittin complex. Although the analysis of the secondary structure of holo-CaM (without and with ligand) indicates no major changes up to several kbar, pressure-induced exposure of α-helices to water is most pronounced for holo-CaM without ligand, followed by holo-CaM/melittin and then holo-CaM/TFP. Moreover, structural pressure resistance of the holo-CaM/TFP complex in comparison with the holo-CaM/melittin complex is also clearly visible by higher Ca 2+ affinity. Förster resonance energy transfer (FRET) from the Tyr residues of holo-CaM to the Trp residue of melittin even suggests some partial dissociation of the complex under pressure which points to void volumes at the protein-ligand interface and to electrostatic binding. Thus, all results of this study show that the inhibitor TFP binds to holo-CaM with higher packing density than the peptide melittin enabling a favorable volume contribution to the inhibitor efficiency. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. The value of flow cytometric analysis of platelet glycoprotein expression of CD34+ cells measured under conditions that prevent P-selectin-mediated binding of platelets

    NARCIS (Netherlands)

    Dercksen, M. W.; Weimar, I. S.; Richel, D. J.; Breton-Gorius, J.; Vainchenker, W.; Slaper-Cortenbach, C. M.; Pinedo, H. M.; von dem Borne, A. E.; Gerritsen, W. R.; van der Schoot, C. E.

    1995-01-01

    In the present study, we show by adhesion assays and ultrastructural studies that platelets can bind to CD34+ cells from human blood and bone marrow and that this interaction interferes with the accurate detection of endogenously expressed platelet glycoproteins (GPs). The interaction between these

  11. A new appreciation of nuclear energy's value in the United States and round the world

    International Nuclear Information System (INIS)

    Peterson, S.

    1999-01-01

    The US regulatory system for nuclear power facilities (NRC) must undergo reform both from a safety and economic point of view. Given the current state of affairs, reforms will include plant-specific criteria since there is at present a great difference between the best and worst American nuclear power stations. Generally speaking, however, US reactors have become considerably more reliable since 1985. A number of US public service corporations have already announced that they will be applying for permits to extend the service life of plants and to allow their modification. Total liberalization of the electric energy market in the United States is expected to provide an added impetus in favor of nuclear energy. Since the majority of US nuclear power plants are base-load suppliers, they are very competitive. In the USA, however, the construction of new nuclear power stations based on advanced light-water reactor developments is also being considered. The US Regulatory Commission has already certified three new reactor developments of this type and has granted permission for their construction. (orig./GL) [de

  12. How does Suncor create value : 1998 annual report of Suncor Energy

    International Nuclear Information System (INIS)

    1999-01-01

    A financial and operational review of accomplishments during 1998 from Suncor Energy is presented. Suncor Energy is a leader in oil sands extraction and upgrading technology. Despite low oil prices, Suncor continued to deliver solid results, record production, higher cash flow and significant growth in its growth plans. The company remains on track with its $2 billion Project Millennium oil sands expansion project which is scheduled to begin in the spring of 1999. Natural gas, crude oil and natural gas liquids production continued its upward trend for the eighth year in a row and was responsible for partially offsetting the financial impact of lower crude oil prices. Cash flow from operations increased for the sixth consecutive year. Higher net debt level reflected increased capital spending on growth projects. Share prices declined by 6 per cent in 1998 over year-end 1997, however the decline was moderate compared to a 22 per cent decline in the integrated oil and gas index on the Toronto Stock Exchange. Return on shareholders' equity was 12.9 per cent, compared to 16.9 per cent in 1997. tabs., figs

  13. Founders Energy Ltd. 1998 annual report : fiscally prudent, value driven balanced growth strategy

    International Nuclear Information System (INIS)

    1999-01-01

    Founders Energy Ltd is a growth-oriented junior resource company engaged in the acquisition and development of oil and natural gas properties in Alberta, British Columbia and Saskatchewan. The annual review provides details of the company's operations and relevant financial performance during the 1998 fiscal year. In brief, the company realized significant increases in production and reserves, top quartile findings and development costs. It reported significant increases in leverage to natural gas through exploration success at Pouce Coupe and the acquisition of Opal Energy Inc.. It established new core areas in west-central Alberta, Peace River Arch and west-central Saskatchewan. It achieved a better balanced risk profile through geographical diversification and better balance to exploration and development. It increased undeveloped land area to 160,268 net acres and added 11.5 million barrels of established reserves at a finding cost of $ 6.28 per barrel. Financial highlights include increased gross revenue, increased net income per share, and increased shareholders' equity. tabs., figs

  14. Estimation of value-at-risk for energy commodities via fat-tailed GARCH models

    International Nuclear Information System (INIS)

    Hung, Jui-Cheng; Lee, Ming-Chih; Liu, Hung-Chun

    2008-01-01

    The choice of an appropriate distribution for return innovations is important in VaR applications owing to its ability to directly affect the estimation quality of the required quantiles. This study investigates the influence of fat-tailed innovation process on the performance of one-day-ahead VaR estimates using three GARCH models (GARCH-N, GARCH-t and GARCH-HT). Daily spot prices of five energy commodities (WTI crude oil, Brent crude oil, heating oil 2, propane and New York Harbor Conventional Gasoline Regular) are used to compare the accuracy and efficiency of the VaR models. Empirical results suggest that for asset returns that exhibit leptokurtic and fat-tailed features, the VaR estimates generated by the GARCH-HT models have good accuracy at both low and high confidence levels. Additionally, MRSB indicates that the GARCH-HT model is more efficient than alternatives for most cases at high confidence levels. These findings suggest that the heavy-tailed distribution is more suitable for energy commodities, particularly VaR calculation. (author)

  15. A strategic value management approach for energy and maintenance management in a building

    Science.gov (United States)

    Nawi, Mohd Nasrun Mohd; Dahlan, Nofri Yenita; Nadarajan, Santhirasegaran

    2015-05-01

    Fragmentation process is always been highlighted by the stakeholders in the construction industry as one of the `critical' issue that diminishing the opportunity for stakeholders that involved during the operation and maintenance stage to influence design decisions. Failure of design professionals to consider how a maintenance contractor or facility manager will construct the design thus results in higher operating cost, wastage, defects during the maintenance and operation process. Moving towards team integration is considered a significant strategy for overcoming the issue. Value Management is a style of management dedicated to guiding people and promoting innovation with the aim to improve overall building performance through structured, team-oriented exercises which make explicit, and appraise subsequent decisions, by reference to the value requirements of the clients. Accordingly, this paper discusses the fragmentation issue in more detail including the definition, causes and effects to the maintenance and operation of building and at the same time will highlighted the potential of VM integrated team approach as a strategic management approach for overcoming that issue. It also explores that the team integration strategy alleviates scheduling problems, delays and disputes during the construction process, and, hence, prevent harming the overall building performance.

  16. Just value of the Tactebel energy: an valuation from the main models of pricing asset

    Directory of Open Access Journals (Sweden)

    Renato Campos

    2010-01-01

    Full Text Available This study aimed to determine the current fair value of Tractebel Energia, from the main asset pricing models. The company was taken as the object due to its stable growth and the ease of obtaining data, since it is located in the city of Florianopolis. Nevertheless, the volatility in its shares has been priced aroused interest. Therefore, this study intended to provide subsidy for the decision making of investors regarding the purchase or sale of company stock. For this, the theoretical treat on the concept of asset valuation and the main models available, emphasizing their applications and limitations, which are: assessment book on, discounted dividend model and discounted cash flow. Regarding the methodological aspect, the research fits into exploratory, descriptive, highly quantitative field study and case. Moreover, it was made use of desk research, literature, interview and program Economática. Thus, the analysis of data initially sought to raise the assumptions demanded by each of the models surveyed ad apply them. The results were then compared and adjusted so that there is consistency. He was later adopted an arithmetic mean to assign a fair value to the company. From this average was defined as an acceptance range, depending on the variability of results and uncertainty in the estimates.

  17. Probing ionization potential, electron affinity and self-energy effect on the spectral shape and exciton binding energy of quantum liquid water with self-consistent many-body perturbation theory and Bethe-Salpeter equation.

    Science.gov (United States)

    Ziaei, Vafa; Bredow, Thomas

    2018-04-18

    An accurate theoretical prediction of ionization potential (IP) and electron affinity (EA) is key for understanding of complex photochemical processes in aqueous environments. There have been numerous efforts in literature to accurately predict IP and EA of liquid water, however with often conflicting results depending on the level of theory and the underlying water structures. In a recent study based on hybrid-non-self-consistent many-body perturbation theory (MBPT) Gaiduk et al. [Nature Communications {\\bf 9}, 247 (2018)] predicted an IP of 10.2 eV and EA of 0.2 eV, resulting in an electronic band gap (i.e. electronic gap (IP-EA) as measured by photoelectron spectroscopy) of about 10 eV, redefining the widely cited experimental gap of 8.7 eV in literature. In the present work, we show that GW self-consistency and an implicit vertex correction in MBPT considerably affect recently reported EA value by Gaiduk et al. \\cite{Gaiduk_affinity} by about 1 eV. Furthermore, the choice of pseudo-potential is critical for an accurate determination of the absolute band positions. Consequently, the self-consistent GW approach with an implicit vertex correction based on projector augmented wave (PAW) method on top of quantum water structures predicts an IP of 10.2, an EA of 1.1, a fundamental gap of 9.1 eV and an exciton binding (Eb) energy of 0.9 eV for the first absorption band of liquid water via Bethe-Salpeter equation (BSE). Only within such a self-consistent approach a \\textit{simultanously} accurate prediction of IP, EA, Eg, Eb is possible. © 2018 IOP Publishing Ltd.

  18. Study benefit value of utilization water resources for energy and sustainable environment

    Science.gov (United States)

    Juniah, Restu; Sastradinata, Marwan

    2017-11-01

    Referring to the concept of sustainable development, the environment is said to be sustainable if the fulfillment of three pillars of development that is economic, social and ecological or the environment itself. The environment can sustained in the principle of ecology or basic principles of environmental science, when the three environmental components, namely the natural environment, the artificial environment (the built environment) and the social environment can be aligned for sustainability. The natural environment in this study is the water resources, the artificial environment is micro hydroelectric power generation (MHPG), and the social environment is the community living around the MHPG. The existence of MHPG is intended for the sustainability of special electrical energy for areas not yet reached by electricity derived from the state electricity company (SEC). The utilization of MHPG Singalaga in South Ogan Komering Ulu (OKUS) district is not only intended for economic, ecological, and social sustainability in Southern OKU district especially those who live in Singalaga Village, Kisam Tinggi District. This paper discusses the economic, ecological and social benefits of water resources utilization in Southern OKU District for MHPG Singalaga. The direct economic benefits that arise for people living around MHPG Singalaga is the cost incurred by the community for the use of electricity is less than if the community uses electricity coming from outside the MHPG. The cost to society in the form of dues amounting to IDR 15,000 a month / household. Social benefits with the absorption of manpower to manage the MHPG is chairman, secretary and 3 members, while the ecological benefits of water resources and sustainable energy as well as the community while maintaining the natural vegetation that is located around the MHPG for the continuity of water resources.

  19. Value of focal applied energy quotient in treatment of ureteral lithiasis with shock waves.

    Science.gov (United States)

    Arrabal-Polo, Miguel Angel; Arrabal-Martin, Miguel; Palao-Yago, Francisco; Mijan-Ortiz, Jose Luis; Zuluaga-Gomez, Armando

    2012-08-01

    The treatment of ureteral lithiasis by extracorporeal shock wave lithotripsy (ESWL) is progressively being abandoned owing to advances in endoscopic lithotripsy. The purpose of this paper is to analyze the causes as to why ESWL is less effective-with a measurable parameter: focal applied energy quotient (FAEQ) that allows us to apply an improvement project in ESWL results for ureteral lithiasis. A prospective observational cohort study with 3-year follow-up and enrollment period was done with three groups of cases. In Group A, 83 cases of ureteral lithiasis were treated by endoscopic lithotripsy using Holmiun:YAG laser. In Group B, 81 cases of ureteral lithiasis were treated by ESWL using Doli-S device (EMSE 220F-XXP). In Group C, 65 cases of ureteral lithiasis were treated by ESWL using Doli-S device (EMSE 220F-XXP) (FAEQ >10). Statistical study and calculation of RR, NNT, Chi-square test, Fisher's exact test, and Student's t test were done. Efficiency quotient (EQ) and focal applied energy quotient [FAEQ = (radioscopy seconds/number of shock waves) × ESWL session J] were analyzed. From the results, the success rate of the treatment using Holmium:YAG laser lithotripsy and ESWL is found to be 94 and 48%, respectively, with a statistically significant difference (p 10, we do not observe absolute benefit choosing one or the other. In conclusion, the application of ESWL with FAEQ >10, that is, improving radiologic focalization of the calculus and increasing the number of Joules/SW, makes possible a treatment as safe and equally efficient as Holmium:YAG laser lithotripsy in ureteral lithiasis less than 13 mm.

  20. Investigation of the added value of high-energy electrons in intensity-modulated radiotherapy: four clinical cases

    International Nuclear Information System (INIS)

    Korevaar, Erik W.; Huizenga, Henk; Loef, Johan; Stroom, Joep C.; Leer, Jan Willem H.; Brahme, Anders

    2002-01-01

    Purpose: Intensity-modulated radiotherapy (IMRT) with photon beams is currently pursued in many clinics. Theoretically, inclusion of intensity- and energy-modulated high-energy electron beams (15-50 MeV) offers additional possibilities to improve radiotherapy treatments of deep-seated tumors. In this study the added value of high-energy electron beams in IMRT treatments was investigated. Methods and Materials: In a comparative treatment planning study, conventional treatment plans and various types of IMRT plans were constructed for four clinical cases (cancer of the bladder, pancreas, chordoma of the sacrum, and breast). The conventional plans were used for the actual treatment of the patients. The IMRT plans were optimized using the Orbit optimization code (Loef et al., 2000) with a radiobiologic objective function. The IMRT plans were either photon or combined electron and photon beam plans, with or without dose homogeneity constraints assuming standard or increased radiosensitivities of organs at risk. Results: Large improvements in expected treatment outcome are found using IMRT plans compared to conventional plans, but differences in tumor control probability (TCP) and normal tissue complication probabilities (NTCP) values between IMRT plans with and without electrons are small. However, the use of electrons improves the dose-volume histograms for organs at risk, especially at lower dose levels (e.g., 0-40 Gy). Conclusions: This preliminary study indicates that addition of higher energy electrons to IMRT can only marginally improve treatment outcome for the selected cases. The dose-volume histograms of organs at risk show improvements for IMRT with higher energy electrons, which may reduce tumor induction but does not substantially reduce NTCP

  1. Assessing the economic value of co-optimized grid-scale energy storage investments in supporting high renewable portfolio standards

    International Nuclear Information System (INIS)

    Go, Roderick S.; Munoz, Francisco D.; Watson, Jean-Paul

    2016-01-01

    Highlights: • We present a MILP to co-optimize generation, transmission, and storage investments. • We find significant value in co-optimized storage via investment deferrals. • Operational savings from bulk services are small relative to investment deferrals. • Co-optimized energy storage significantly reduces prices associated with RPS. - Abstract: Worldwide, environmental regulations such as Renewable Portfolio Standards (RPSs) are being broadly adopted to promote renewable energy investments. With corresponding increases in renewable energy deployments, there is growing interest in grid-scale energy storage systems (ESS) to provide the flexibility needed to efficiently deliver renewable power to consumers. Our contribution in this paper is to introduce a unified generation, transmission, and bulk ESS expansion planning model subject to an RPS constraint, formulated as a two-stage stochastic mixed-integer linear program (MILP) optimization model, which we then use to study the impact of co-optimization and evaluate the economic interaction between investments in these three asset classes in achieving high renewable penetrations. We present numerical case studies using the 24-bus IEEE RTS-96 test system considering wind and solar as available renewable energy resources, and demonstrate that up to $180 million/yr in total cost savings can result from the co-optimization of all three assets, relative to a situation in which no ESS investment options are available. Surprisingly, we find that co-optimized bulk ESS investments provide significant economic value through investment deferrals in transmission and generation capacity, but very little savings in operational cost. Finally, we observe that planning transmission and generation infrastructure first and later optimizing ESS investments—as is common in industry—captures at most 1.7% ($3 million/yr) of the savings that result from co-optimizing all assets simultaneously.

  2. Binding affinities of the farnesoid X receptor in the D3R Grand Challenge 2 estimated by free-energy perturbation and docking

    Science.gov (United States)

    Olsson, Martin A.; García-Sosa, Alfonso T.; Ryde, Ulf

    2018-01-01

    We have studied the binding of 102 ligands to the farnesoid X receptor within the D3R Grand Challenge 2016 blind-prediction competition. First, we employed docking with five different docking software and scoring functions. The selected docked poses gave an average root-mean-squared deviation of 4.2 Å. Consensus scoring gave decent results with a Kendall's τ of 0.26 ± 0.06 and a Spearman's ρ of 0.41 ± 0.08. For a subset of 33 ligands, we calculated relative binding free energies with free-energy perturbation. Five transformations between the ligands involved a change of the net charge and we implemented and benchmarked a semi-analytic correction (Rocklin et al., J Chem Phys 139:184103, 2013) for artifacts caused by the periodic boundary conditions and Ewald summation. The results gave a mean absolute deviation of 7.5 kJ/mol compared to the experimental estimates and a correlation coefficient of R 2 = 0.1. These results were among the four best in this competition out of 22 submissions. The charge corrections were significant (7-8 kJ/mol) and always improved the results. By employing 23 intermediate states in the free-energy perturbation, there was a proper overlap between all states and the precision was 0.1-0.7 kJ/mol. However, thermodynamic cycles indicate that the sampling was insufficient in some of the perturbations.

  3. Quantum mechanics capacitance molecular mechanics modeling of core-electron binding energies of methanol and methyl nitrite on Ag(111) surface.

    Science.gov (United States)

    Löytynoja, T; Li, X; Jänkälä, K; Rinkevicius, Z; Ågren, H

    2016-07-14

    We study a newly devised quantum mechanics capacitance molecular mechanics (QMCMM) method for the calculation of core-electron binding energies in the case of molecules adsorbed on metal surfaces. This yet untested methodology is applied to systems with monolayer of methanol/methyl nitrite on an Ag(111) surface at 100 K temperature. It was found out that the studied C, N, and O 1s core-hole energies converge very slowly as a function of the radius of the metallic cluster, which was ascribed to build up of positive charge on the edge of the Ag slab. Further analysis revealed that an extrapolation process can be used to obtain binding energies that deviated less than 0.5 eV against experiments, except in the case of methanol O 1s where the difference was as large as 1.8 eV. Additional QM-cluster calculations suggest that the latter error can be connected to the lack of charge transfer over the QM-CMM boundary. Thus, the results indicate that the QMCMM and QM-cluster methods can complement each other in a holistic picture of molecule-adsorbate core-ionization studies, where all types of intermolecular interactions are considered.

  4. Prognostic Value And Daily Trend Of Interleukin-6, Neutrophil CD64 Expression, C-Reactive Protein And Lipopolysaccharide-Binding Protein In Critically Ill Patients: Reliable Predictors Of Outcome Or Not?

    Directory of Open Access Journals (Sweden)

    Djordjevic Dragan

    2015-10-01

    Full Text Available Background: Severe sepsis and/or trauma complicated by multiple organ dysfunction syndrome are the leading causes of death in critically ill patients. The aim of this prospective single-centre study was to assess the prognostic value and daily trend of interleukin-6 (IL-6, neutrophil CD64 expression, C-reactive protein (CRP and lipopolysaccharide-binding protein (LBP regarding outcome in critically ill patients with severe trauma and/or severe sepsis. Outcome measure was hospital mortality.

  5. Exploring PHD fingers and H3K4me0 interactions with molecular dynamics simulations and binding free energy calculations: AIRE-PHD1, a comparative study.

    Directory of Open Access Journals (Sweden)

    Dimitrios Spiliotopoulos

    Full Text Available PHD fingers represent one of the largest families of epigenetic readers capable of decoding post-translationally modified or unmodified histone H3 tails. Because of their direct involvement in human pathologies they are increasingly considered as a potential therapeutic target. Several PHD/histone-peptide structures have been determined, however relatively little information is available on their dynamics. Studies aiming to characterize the dynamic and energetic determinants driving histone peptide recognition by epigenetic readers would strongly benefit from computational studies. Herein we focus on the dynamic and energetic characterization of the PHD finger subclass specialized in the recognition of histone H3 peptides unmodified in position K4 (H3K4me0. As a case study we focused on the first PHD finger of autoimmune regulator protein (AIRE-PHD1 in complex with H3K4me0. PCA analysis of the covariance matrix of free AIRE-PHD1 highlights the presence of a "flapping" movement, which is blocked in an open conformation upon binding to H3K4me0. Moreover, binding free energy calculations obtained through Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA methodology are in good qualitative agreement with experiments and allow dissection of the energetic terms associated with native and alanine mutants of AIRE-PHD1/H3K4me0 complexes. MM/PBSA calculations have also been applied to the energetic analysis of other PHD fingers recognizing H3K4me0. In this case we observe excellent correlation between computed and experimental binding free energies. Overall calculations show that H3K4me0 recognition by PHD fingers relies on compensation of the electrostatic and polar solvation energy terms and is stabilized by non-polar interactions.

  6. Motif III in superfamily 2 "helicases" helps convert the binding energy of ATP into a high-affinity RNA binding site in the yeast DEAD-box protein Ded1.

    Science.gov (United States)

    Banroques, Josette; Doère, Monique; Dreyfus, Marc; Linder, Patrick; Tanner, N Kyle

    2010-03-05

    Motif III in the putative helicases of superfamily 2 is highly conserved in both its sequence and its structural context. It typically consists of the sequence alcohol-alanine-alcohol (S/T-A-S/T). Historically, it was thought to link ATPase activity with a "helicase" strand displacement activity that disrupts RNA or DNA duplexes. DEAD-box proteins constitute the largest family of superfamily 2; they are RNA-dependent ATPases and ATP-dependent RNA binding proteins that, in some cases, are able to disrupt short RNA duplexes. We made mutations of motif III (S-A-T) in the yeast DEAD-box protein Ded1 and analyzed in vivo phenotypes and in vitro properties. Moreover, we made a tertiary model of Ded1 based on the solved structure of Vasa. We used Ded1 because it has relatively high ATPase and RNA binding activities; it is able to displace moderately stable duplexes at a large excess of substrate. We find that the alanine and the threonine in the second and third positions of motif III are more important than the serine, but that mutations of all three residues have strong phenotypes. We purified the wild-type and various mutants expressed in Escherichia coli. We found that motif III mutations affect the RNA-dependent hydrolysis of ATP (k(cat)), but not the affinity for ATP (K(m)). Moreover, mutations alter and reduce the affinity for single-stranded RNA and subsequently reduce the ability to disrupt duplexes. We obtained intragenic suppressors of the S-A-C mutant that compensate for the mutation by enhancing the affinity for ATP and RNA. We conclude that motif III and the binding energy of gamma-PO(4) of ATP are used to coordinate motifs I, II, and VI and the two RecA-like domains to create a high-affinity single-stranded RNA binding site. It also may help activate the beta,gamma-phosphoanhydride bond of ATP. (c) 2009 Elsevier Ltd. All rights reserved.

  7. Charge transfer, lattice distortion, and quantum confinement effects in Pd, Cu, and Pd-Cu nanoparticles; size and alloying induced modifications in binding energy

    International Nuclear Information System (INIS)

    Sengar, Saurabh K.; Mehta, B. R.; Gupta, Govind

    2011-01-01

    In this letter, effect of size and alloying on the core and valence band shifts of Pd, Cu, and Pd-Cu alloy nanoparticles has been studied. It has been shown that the sign and magnitude of the binding energy shifts is determined by the contributions of different effects; with quantum confinement and lattice distortion effects overlapping for size induced shifts in case of core levels and lattice distortion and charge transfer effects overlapping for alloying induced shifts at smaller sizes. These results are important for understanding gas molecule-solid surface interaction in metal and alloy nanoparticles in terms of valance band positions.

  8. Assessment of the Binding of Protons, Al and Fe to Biochar at Different pH Values and Soluble Metal Concentrations

    Directory of Open Access Journals (Sweden)

    Tan Dang

    2018-01-01

    Full Text Available Biochar can retain large amounts of protons and metals in the drainage water from acid sulfate soils and mine sites. Metal sorption can, however, be influenced by many factors, such as pH and metal composition. This study investigated proton, Al, and Fe retention capacity of eucalyptus biochar (1% w/v at different pH and metal concentrations. In the absence of metals, the biochar had a high proton binding capacity, (up to 0.035 mmol of H+, whereas its capacity to retain hydroxide ions was limited. A batch experiment was carried out at pH 4 and pH 7 with 10−6, 10−5, 10−4, 10−3, and 10−2 M of added Fe or Al. Added metals precipitated considerably prior to addition of the biochar except that Al remained highly soluble at pH 4. The biochar had a high retention capacity for Al and Fe; at high (>1 mM concentrations, over 80% of soluble metals were retained. Metal competition for binding sites of both Al and Fe at different ratios was investigated, but increasing concentrations of one metal did not reduce retention of the other. The results confirmed that biochar has high metal binding capacity under both acidic and neutral conditions.

  9. Algal Pretreatment Improves Biofuels Yield and Value; Highlights in Science, NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-15

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. This research has been highlighted in the Green Chemistry journal article mentioned above and a milestone report, and is based on the work the researchers are doing for the AOP projects Algal Biomass Conversion and Algal Biofuels Techno-economic Analysis. That work has demonstrated an advanced process for algal biofuel production that captures the value of both the algal lipids and carbohydrates for conversion to biofuels.  With this process, as much as 150 GGE/ton of biomass can be produced, 2-3X more than can be produced by terrestrial feedstocks.  This can also reduce the cost of biofuel production by as much as 40%. This also represents the first ever design case for the algal lipid upgrading pathway.

  10. Deeply bound π- states in 207Pb formed in the 208Pb(d,3He) reaction. II. Deduced binding energies and widths and the pion-nucleus interaction

    Science.gov (United States)

    Itahashi, K.; Oyama, K.; Hayano, R. S.; Gilg, H.; Gillitzer, A.; Knülle, M.; Münch, M.; Schott, W.; Kienle, P.; Geissel, H.; Iwasa, N.; Münzenberg, G.; Hirenzaki, S.; Toki, H.; Yamazaki, T.

    2000-08-01

    We find a remarkable agreement of the excitation energy spectrum of the 208Pb(d,3He) reaction measured at Td=600 MeV near the π- production threshold with its theoretical prediction. Their comparison leads us to assign the distinct narrow peak observed at about 5 MeV below the threshold to the formation of bound pionic states π-⊗207Pb of the quasisubstitutional configurations (2p)π-(3p3/2,3p1/2)-1n. A small bump observed on the tail of the peak is assigned to the pionic 1s state. The binding energies (Bnl) and the widths (Γnl) of the pionic orbitals are deduced to be B2p=5.13+/-0.02 (stat)+/-0.12 (syst) MeV and Γ2p=0.43+/-0.06 (stat)+/-0.06 (syst) MeV by decomposing the experimental spectrum into the pionic 1s and 2p components. While B2p and Γ2p are determined with small ambiguity, B1s and Γ1s are strongly correlated with each other, and are affected by the relative 1s/2p cross section ratio assumed, since the 1s component is observed only as an unresolved bump. Thus, we have to allow large uncertainties 6.6 MeVbinding energies and widths are compared with theoretically calculated values based on various optical potential parameter sets, and are jointly used to deduce the effective π- mass in the nuclear medium.

  11. The Value of Energy Efficiency Programs for U.S. Residential and Commercial Buildings in a Warmer World

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Michael J; Dirks, James A; Cort, Katherine A

    2007-06-15

    U.S. residential and commercial buildings currently use about 39 quadrillion Btu (quads) of energy per year and account for 0.6 gigatonnes (GT) of carbon emitted to the atmosphere (38% of U.S. total emissions of 1.6 GT and approximately 9% of the world fossil-fuel related anthropogenic emissions of 6.7 GT). U.S. government buildings-related energy efficiency research and implementation programs are expected to reduce energy consumption in buildings. This has value both in reducing carbon emissions that result in global warming and adapting the U.S. residential and commercial building stock to a potentially warmer world. Analyses conducted by the Intergovernmental Panel on Climate Change (IPCC) show that the world’s climate could warm relative to 1990 by 0.4ºC to 1.2°C by the year 2030 and by 1.4°C to 5.8°C by the end of the 21st century. This paper shows that the effect of the regional projected warming on energy consumption in U.S. residential and commercial buildings is a net decrease ranging from about 5% in 2020 to as much as 20% in 2080, but with an increase of as much as 25% in space cooling. Buildings-related energy efficiency programs should reduce energy consumption in buildings by more than 2 quads in 2020, which would more than offset the growth in space cooling due to climate and growth in building stock combined, and would be worth between $28 and $33 billion.

  12. Shining light on radiation detection and energy transfer : Triazole ligands used for detection of radiation and lanthanide binding

    NARCIS (Netherlands)

    Dijkstra, Peter

    2016-01-01

    Some substances, fluorophores, absorb light and then emit that light again as fluorescence. Apart from absorption of light, some of these substances can also emit light after having absorbed energy from radiation. A substance which can absorb radiation and emit the energy as light is called a

  13. Eigen Value Approach to Generalized Thermoelastic Interactions in an Unbounded Body with Circular Cylindrical Cavity without Energy Dissipation

    Science.gov (United States)

    Chakraborty, S.

    2017-12-01

    The theory of generalized thermoelasticity in the context of the Green-Naghdi model -II (thermoelasticity without energy dissipation) is studied for an infinite circular cylindrical cavity subjected to two different cases of thermoelastic interactions when the radial stress is zero for (a) maintaining constant temperature and (b) temperature is varying exponentially with time. The Laplace transform from time variable is used to the governing equations to formulate a vector matrix differential equation which is then solved by the eigen value approach. Numerical computations for the displacement component, temperature distribution and components of thermal stress have been made and presented graphically.

  14. An Analysis of the Costs, Benefits, and Implications of Different Approaches to Capturing the Value of Renewable Energy Tax Incentives

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark

    2014-04-09

    This report compares the relative costs, benefits, and implications of capturing the value of renewable energy tax benefits in these three different ways – applying them against outside income , carrying them forward in time until they can be fully absorbed internally, or monetizing them through third-party tax equity investors – to see which method is most competitive under various scenarios. It finds that under current law and late-2013 market conditions, monetization makes sense for all but the most tax-efficient project sponsors. In other words, for most project sponsors, bringing in third-party tax equity currently provides net benefits to a project.

  15. The psychology of participation and interest in smart energy systems : Comparing the value-belief-norm theory and the value-identity-personal norm model

    NARCIS (Netherlands)

    van der Werff, Ellen; Steg, Linda

    2016-01-01

    Environmental problems can be reduced if people would participate in smart energy systems. Little is known about which factors motivate people to actually participate in smart energy systems. We tested the factors that influence individuals’ interest and actual participation in smart energy systems.

  16. Binding free energy predictions of farnesoid X receptor (FXR) agonists using a linear interaction energy (LIE) approach with reliability estimation: application to the D3R Grand Challenge 2

    Science.gov (United States)

    Rifai, Eko Aditya; van Dijk, Marc; Vermeulen, Nico P. E.; Geerke, Daan P.

    2018-01-01

    Computational protein binding affinity prediction can play an important role in drug research but performing efficient and accurate binding free energy calculations is still challenging. In the context of phase 2 of the Drug Design Data Resource (D3R) Grand Challenge 2 we used our automated eTOX ALLIES approach to apply the (iterative) linear interaction energy (LIE) method and we evaluated its performance in predicting binding affinities for farnesoid X receptor (FXR) agonists. Efficiency was obtained by our pre-calibrated LIE models and molecular dynamics (MD) simulations at the nanosecond scale, while predictive accuracy was obtained for a small subset of compounds. Using our recently introduced reliability estimation metrics, we could classify predictions with higher confidence by featuring an applicability domain (AD) analysis in combination with protein-ligand interaction profiling. The outcomes of and agreement between our AD and interaction-profile analyses to distinguish and rationalize the performance of our predictions highlighted the relevance of sufficiently exploring protein-ligand interactions during training and it demonstrated the possibility to quantitatively and efficiently evaluate if this is achieved by using simulation data only.

  17. Binding free energy predictions of farnesoid X receptor (FXR) agonists using a linear interaction energy (LIE) approach with reliability estimation: application to the D3R Grand Challenge 2.

    Science.gov (United States)

    Rifai, Eko Aditya; van Dijk, Marc; Vermeulen, Nico P E; Geerke, Daan P

    2018-01-01

    Computational protein binding affinity prediction can play an important role in drug research but performing efficient and accurate binding free energy calculations is still challenging. In the context of phase 2 of the Drug Design Data Resource (D3R) Grand Challenge 2 we used our automated eTOX ALLIES approach to apply the (iterative) linear interaction energy (LIE) method and we evaluated its performance in predicting binding affinities for farnesoid X receptor (FXR) agonists. Efficiency was obtained by our pre-calibrated LIE models and molecular dynamics (MD) simulations at the nanosecond scale, while predictive accuracy was obtained for a small subset of compounds. Using our recently introduced reliability estimation metrics, we could classify predictions with higher confidence by featuring an applicability domain (AD) analysis in combination with protein-ligand interaction profiling. The outcomes of and agreement between our AD and interaction-profile analyses to distinguish and rationalize the performance of our predictions highlighted the relevance of sufficiently exploring protein-ligand interactions during training and it demonstrated the possibility to quantitatively and efficiently evaluate if this is achieved by using simulation data only.

  18. The value of electric energy storage in electricity systems with high shares of wind and solar PV: the case of France in the energy transition

    International Nuclear Information System (INIS)

    Villavicencio, Manuel

    2017-01-01

    The adoption of ambitious targets for variable renewable energies (VRE) such as wind and solar has important effects on the technical and economic operation of power systems. Increasing shares of VRE will in particular require the deployment of more flexible and responsive technologies. Key flexibility providers in the scope are demand side management (DSM) and different forms of electric energy storage (EES) such as pumped hydroelectric (PHS), Li-ion batteries (Li-ion), and compressed air (CAES), among others. It have been previously showed how the value and the deployment of such new flexibility providers depended on the shares of VRE shares introduced into the system (Brijs et al., 2016; Van Stiphout et al., 2015; Villavicencio, 2017). Building on this works, this paper explores the value of storage in the context of a realistic Brownfield model calibrated on the existing French electricity system. In particular, this paper compares the value of storage (a) in a system corresponding to the target of 27% VRE production formulated by the French government in its 2015 Energy Transition Act by 2020 and (b) in a system corresponding to the target of 40% VRE production formulated in the same Act by 2030. The latter case will necessarily reflect the additional target which by 2025 limits the share of nuclear power to 50% of electricity production. In 2020, 4.7 GW of DSM are sufficient to provide the required flexibility and no EES investments will be needed. By 2030, however, in addition to a comparable level of DSM, 3.2 GW of additional EES investments are required. These storage solutions will generate an economic value of euro 350 million per year and will increases overall welfare by euro 670 million per year by 2030. The modeling yields a number of additional policy relevant results. First, limiting nuclear production will open opportunities for alternative base and mid-load providers, mainly gas, implying a threefold increase of CO 2 emissions compared to 2020

  19. [The value of dual-source dual-energy CT with iodine overlay in the diagnosis of acute necrotizing pancreatitis].

    Science.gov (United States)

    Yuan, Yuan; Huang, Zi-Xing; Li, Zhen-Lin; Song, Bin; Deng, Li-Ping

    2012-07-01

    To investigate the clinical value of dual-source computed tomography dual-energy Iodine overlay technique in the imaging diagnosis of acute necrotizing pancreatitis. The imaging data were retrospectively analyzed in 67 cases of acute necrotizing pancreatitis underwent contrast-enhanced dual-source dual-energy CT in portal venous phase. The CT imaging parameters, including the difference of CT value between pancreatic parenchyma and necrotic lesion, contrast-to-noise ratio of pancreatic parenchyma-to-necrosis, area of pancreatic necrosis and score of subjective diagnosis, were measured and assessed on CT images of 80 kV, 140 kV, weighted-average 120 kV as well as Iodine overlay. The differences of CT value between pancreatic parenchyma and necrosis in the images of 80 kV, 140 kV, weighted-average 120 kV and Iodine overlay were (67.40 +/- 20.82) HU, (42.87 +/- 14.99) HU, (48.69 +/- 15.82) HU, (33.01 +/- 10.26) HU, respectively; contrast-to-noise ratios of pancreatic parenchyma-to-necrosis of each group were 8.36 +/- 3.58, 5.85 +/- 2.65, 7.68 +/- 3.51, 10.60 4.34; area of pancreatic necrosis of each group was (3.78 +/- 2.68) cm2, (3.28 +/- 2.59) cm2, (3.37 +/- 2.46) cm2, (2.42 +/- 1.98) cm2; the score of subjective diagnosis of each group was 3.88 +/- 0.33, 3.31 +/- 0.80, 3.58 +/- 0.66, 2.81 +/- 0.76, respectively. The four indexes in the images of Iodine overlay were significantly different from those of another three groups (P overlay was significantly higher than that of another three groups, while the difference of CT value, area of pancreatic necrosis and score of subjective diagnosis were lower. CONCLUSION; Dual-source CT dual-energy Iodine overlay is not helpful to improve subjective judgment in the diagnosis of pancreatic necrosis, but contributes to the display of hypoperfusion area around the necrosis.

  20. Value of monoenergetic dual-energy CT (DECT) for artefact reduction from metallic orthopedic implants in post-mortem studies

    International Nuclear Information System (INIS)

    Filograna, Laura; Magarelli, Nicola; Leone, Antonio; Bonomo, Lorenzo; Guggenberger, Roman; Winklhofer, Sebastian; Thali, Michael John

    2015-01-01

    The aim of this ex vivo study was to assess the performance of monoenergetic dual-energy CT (DECT) reconstructions to reduce metal artefacts in bodies with orthopedic devices in comparison with standard single-energy CT (SECT) examinations in forensic imaging. Forensic and clinical impacts of this study are also discussed. Thirty metallic implants in 20 consecutive cadavers with metallic implants underwent both SECT and DECT with a clinically suitable scanning protocol. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. Image quality of the seven monoenergetic images and of the corresponding SECT image was assessed qualitatively and quantitatively by visual rating and measurements of attenuation changes induced by streak artefact. Qualitative and quantitative analyses showed statistically significant differences between monoenergetic DECT extrapolated images and SECT, with improvements in diagnostic assessment in monoenergetic DECT at higher monoenergies. The mean value of OPTkeV was 137.6 ± 4.9 with a range of 130 to 148 keV. This study demonstrates that monoenergetic DECT images extrapolated at high energy levels significantly reduce metallic artefacts from orthopedic implants and improve image quality compared to SECT examination in forensic imaging. (orig.)

  1. Value of monoenergetic dual-energy CT (DECT) for artefact reduction from metallic orthopedic implants in post-mortem studies

    Energy Technology Data Exchange (ETDEWEB)

    Filograna, Laura [University of Zurich, Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, Zurich (Switzerland); Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Department of Radiological Sciences, Rome (Italy); Magarelli, Nicola; Leone, Antonio; Bonomo, Lorenzo [Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Department of Radiological Sciences, Rome (Italy); Guggenberger, Roman; Winklhofer, Sebastian [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Thali, Michael John [University of Zurich, Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, Zurich (Switzerland)

    2015-09-15

    The aim of this ex vivo study was to assess the performance of monoenergetic dual-energy CT (DECT) reconstructions to reduce metal artefacts in bodies with orthopedic devices in comparison with standard single-energy CT (SECT) examinations in forensic imaging. Forensic and clinical impacts of this study are also discussed. Thirty metallic implants in 20 consecutive cadavers with metallic implants underwent both SECT and DECT with a clinically suitable scanning protocol. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. Image quality of the seven monoenergetic images and of the corresponding SECT image was assessed qualitatively and quantitatively by visual rating and measurements of attenuation changes induced by streak artefact. Qualitative and quantitative analyses showed statistically significant differences between monoenergetic DECT extrapolated images and SECT, with improvements in diagnostic assessment in monoenergetic DECT at higher monoenergies. The mean value of OPTkeV was 137.6 ± 4.9 with a range of 130 to 148 keV. This study demonstrates that monoenergetic DECT images extrapolated at high energy levels significantly reduce metallic artefacts from orthopedic implants and improve image quality compared to SECT examination in forensic imaging. (orig.)

  2. Investigation of naphthofuran moiety as potential dual inhibitor against BACE-1 and GSK-3β: molecular dynamics simulations, binding energy, and network analysis to identify first-in-class dual inhibitors against Alzheimer's disease.

    Science.gov (United States)

    Kumar, Akhil; Srivastava, Gaurava; Srivastava, Swati; Verma, Seema; Negi, Arvind S; Sharma, Ashok

    2017-08-01

    BACE-1 and GSK-3β are potential therapeutic drug targets for Alzheimer's disease. Recently, both the targets received attention for designing dual inhibitors for Alzheimer's disease. Until now, only two-scaffold triazinone and curcumin have been reported as BACE-1 and GSK-3β dual inhibitors. Docking, molecular dynamics, clustering, binding energy, and network analysis of triazinone derivatives with BACE-1 and GSK-3β was performed to get molecular insight into the first reported dual inhibitor. Further, we designed and evaluated a naphthofuran series for its ability to inhibit BACE-1 and GSK-3β with the computational approaches. Docking study of naphthofuran series showed a good binding affinity towards both the targets. Molecular dynamics, binding energy, and network analysis were performed to compare their binding with the targets and amino acids responsible for binding. Naphthofuran series derivatives showed good interaction within the active site residues of both of the targets. Hydrogen bond occupancy and binding energy suggested strong binding with the targets. Dual-inhibitor binding was mostly governed by the hydrophobic interactions for both of the targets. Per residue energy decomposition and network analysis identified the key residues involved in the binding and inhibiting BACE-1 and GSK-3β. The results indicated that naphthofuran series derivative 11 may be a promising first-in-class dual inhibitor against BACE-1 and GSK-3β. This naphthofuran series may be further explored to design better dual inhibitors. Graphical abstract Naphthofuran derivative as a dual inhibitor for BACE-1 and GSK-3β.

  3. Theoretical insight into the binding energy and detonation performance of ε-, γ-, β-CL-20 cocrystals with β-HMX, FOX-7, and DMF in different molar ratios, as well as electrostatic potential.

    Science.gov (United States)

    Feng, Rui-Zhi; Zhang, Shu-Hai; Ren, Fu-de; Gou, Rui-Jun; Gao, Li

    2016-06-01

    Molecular dynamics method was employed to study the binding energies on the selected crystal planes of the ε-, γ-, β-conformation 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (ε-, γ-, β-CL-20) cocrystal explosives with 1,1-diamino-2,2-dinitroethylene (FOX-7), 1,3,5,7-tetranitro- 1,3,5,7-tetrazacyclooctane with β-conformation (β-HMX) and N,N-dimethylformamide (DMF) in different molar ratios. The oxygen balance, density, detonation velocity, detonation pressure, and surface electrostatic potential were analyzed. The results indicate that the binding energies E b (*) and stabilities are in the order of 1:1 > 2:1 > 3:1 > 5:1 > 8:1 (CL-20:FOX-7/β-HMX/DMF). The values of E b (*) and stabilities of the energetic-nonenergetic CL-20/DMF cocrystals are far larger than those of the energetic-energetic CL-20/FOX-7 and CL-20/β-HMX, and those of CL-20/β-HMX are the smallest. For CL-20/FOX-7 and CL-20/β-HMX, the largest E b (*) appears in the cocrystals with the 1:1, 1:2 or 1:3 molar ratio, and the stabilities of the cocrystals with the excess ratio of CL-20 are weaker than those in the cocrystals with the excess ratio of FOX-7 or β-HMX. In CL-20/FOX-7, CL-20 prefers adopting the γ-form, and ε-CL-20 is the preference in CL-20/β-HMX, and ε-CL-20 and β-CL-20 can be found in CL-20/DMF. The CL-20/FOX-7 and CL-20/β-HMX cocrystals with low molar ratios can meet the requirements of low sensitive high energetic materials. Surface electrostatic potential reveals the nature of the sensitivity change upon the cocrystal formation. Graphical Abstract MD method was employed to study the binding energies on the selected crystal planes in the ε-, γ-, β-CL-20 cocrystals with FOX-7, β-HMX and DMF in different molar ratios. Surface electrostatic potential reveals the nature of the sensitivity change in cocrystals.

  4. Economic Value Assessment and Optimal Sizing of an Energy Storage System in a Grid-Connected Wind Farm

    Directory of Open Access Journals (Sweden)

    Dong Gu Choi

    2018-03-01

    Full Text Available This study identifies the optimal management policy of a given energy storage system (ESS installed in a grid-connected wind farm in terms of maximizing the monetary benefits and provides guidelines for defining the economic value of the ESS under optimal management policy and selecting the optimal size of the ESS based on economic value. Considering stochastic models for wind power and electricity price, we develop a finite-horizon periodic-review Markov decision process (MDP model to seek the optimal management policy. We also use a simple optimization model to find the optimal storage capacity and charging/discharging capacity of the ESS. By applying our analytic approach to a real-world grid-connected wind farm located in South Korea, we verify the usefulness of this study. Our numerical study shows that the economic value of the ESS is highly dependent on management policy, wind electricity variability, and electricity price variability. Thus, the optimal size of ESS should be carefully determined based on the locational characteristics and management policy even with limited investments. Furthermore, this study provides a meaningful policy implication regarding how much of a subsidy the government should provide for installing ESS in a wind farm.

  5. Relating the shape of protein binding sites to binding affinity profiles: is there an association?

    Directory of Open Access Journals (Sweden)

    Bitter István

    2010-10-01

    Full Text Available Abstract Background Various pattern-based methods exist that use in vitro or in silico affinity profiles for classification and functional examination of proteins. Nevertheless, the connection between the protein affinity profiles and the structural characteristics of the binding sites is still unclear. Our aim was to investigate the association between virtual drug screening results (calculated binding free energy values and the geometry of protein binding sites. Molecular Affinity Fingerprints (MAFs were determined for 154 proteins based on their molecular docking energy results for 1,255 FDA-approved drugs. Protein binding site geometries were characterized by 420 PocketPicker descriptors. The basic underlying component structure of MAFs and binding site geometries, respectively, were examined by principal component analysis; association between principal components extracted from these two sets of variables was then investigated by canonical correlation and redundancy analyses. Results PCA analysis of the MAF variables provided 30 factors which explained 71.4% of the total variance of the energy values while 13 factors were obtained from the PocketPicker descriptors which cumulatively explained 94.1% of the total variance. Canonical correlation analysis resulted in 3 statistically significant canonical factor pairs with correlation values of 0.87, 0.84 and 0.77, respectively. Redundancy analysis indicated that PocketPicker descriptor factors explain 6.9% of the variance of the MAF factor set while MAF factors explain 15.9% of the total variance of PocketPicker descriptor factors. Based on the salient structures of the factor pairs, we identified a clear-cut association between the shape and bulkiness of the drug molecules and the protein binding site descriptors. Conclusions This is the first study to investigate complex multivariate associations between affinity profiles and the geometric properties of protein binding sites. We found that

  6. Essays in energy policy and planning modeling under uncertainty: Value of information, optimistic biases, and simulation of capacity markets

    Science.gov (United States)

    Hu, Ming-Che

    Optimization and simulation are popular operations research and systems analysis tools for energy policy modeling. This dissertation addresses three important questions concerning the use of these tools for energy market (and electricity market) modeling and planning under uncertainty. (1) What is the value of information and cost of disregarding different sources of uncertainty for the U.S. energy economy? (2) Could model-based calculations of the performance (social welfare) of competitive and oligopolistic market equilibria be optimistically biased due to uncertainties in objective function coefficients? (3) How do alternative sloped demand curves perform in the PJM capacity market under economic and weather uncertainty? How does curve adjustment and cost dynamics affect the capacity market outcomes? To address the first question, two-stage stochastic optimization is utilized in the U.S. national MARKAL energy model; then the value of information and cost of ignoring uncertainty are estimated for three uncertainties: carbon cap policy, load growth and natural gas prices. When an uncertainty is important, then explicitly considering those risks when making investments will result in better performance in expectation (positive expected cost of ignoring uncertainty). Furthermore, eliminating the uncertainty would improve strategies even further, meaning that improved forecasts of future conditions are valuable ( i.e., a positive expected value of information). Also, the value of policy coordination shows the difference between a strategy developed under the incorrect assumption of no carbon cap and a strategy correctly anticipating imposition of such a cap. For the second question, game theory models are formulated and the existence of optimistic (positive) biases in market equilibria (both competitive and oligopoly markets) are proved, in that calculated social welfare and producer profits will, in expectation, exceed the values that will actually be received

  7. Energy spectrum based calculation of the half and the tenth value layers for brachytherapy sources using a semiempirical parametrized mass attenuation coefficient formulism

    International Nuclear Information System (INIS)

    Yue, Ning J.

    2008-01-01

    As different types of radionuclides (e.g., 131 Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically used for years, such as 125 I and 103 Pd, the sources have been manufactured and marketed by several vendors with different designs and structures. Because of the nature of emission of low energy photons for these radionuclides, energy spectra of the sources are very dependent on their individual designs. Though values of the HVL or the TVL in certain commonly used shielding materials are relatively small for these low energy photon emitting sources, the question remains how the variations in energy spectra affect the HVL (or TVL) values and whether these values can be calculated with a relatively simple method. A more fundamental question is whether a method can be established to derive the HVL (TVL) values for any brachytherapy sources and for different materials in a relatively straightforward fashion. This study was undertaken to answer these questions. Based on energy spectra, a well established semiempirical mass attenuation coefficient computing scheme was utilized to derive the HVL (TVL) values of different materials for different types of brachytherapy sources. The method presented in this study may be useful to estimate HVL (TVL) values of different materials for brachytherapy sources of different designs and containing different radionuclides

  8. Daily energy balance in growth hormone receptor/binding protein (GHR−/−) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency

    Science.gov (United States)

    Longo, Kenneth A.; Berryman, Darlene E.; Kelder, Bruce; Charoenthongtrakul, Soratree; DiStefano, Peter S.; Geddes, Brad J.; Kopchick, John

    2009-01-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR −/− mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (Mb) changes and physical activity in 17 month-old female GHR −/− mice and their age-matched wild type littermates. The GHR −/− mice were smaller, consumed more food per unit Mb, had greater EE per unit Mb and had an increase in 24-h EE/Mb that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR −/− mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, Mb and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for Mb and LMA, the GHR −/− mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR −/− mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR −/− mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final three hours of the dark phase. Therefore, we conclude that GHR −/− mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable Mb. Relative to wild type mice, the GHR −/− mice consumed more calories per unit Mb, which offset the disproportionate increase in their daily energy expenditure. While GHR −/− mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

  9. Daily energy balance in growth hormone receptor/binding protein (GHR -/-) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency.

    Science.gov (United States)

    Longo, Kenneth A; Berryman, Darlene E; Kelder, Bruce; Charoenthongtrakul, Soratree; Distefano, Peter S; Geddes, Brad J; Kopchick, John J

    2010-02-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR -/- mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (M(b)) changes and physical activity in 17month-old female GHR -/- mice and their age-matched wild type littermates. The GHR -/- mice were smaller, consumed more food per unit M(b), had greater EE per unit M(b) and had an increase in 24-h EE/M(b) that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR -/- mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, M(b) and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for M(b) and LMA, the GHR -/- mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR -/- mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR -/- mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final 3h of the dark phase. Therefore, we conclude that GHR -/- mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable M(b). Relative to wild type mice, the GHR -/- mice consumed more calories per unit M(b), which offset the disproportionate increase in their daily energy expenditure. While GHR -/- mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Solar Energy Gain and Space-Heating Energy Supply Analyses for Solid-Wall Dwelling Retrofitted with the Experimentally Achievable U-value of Novel Triple Vacuum Glazing

    Directory of Open Access Journals (Sweden)

    Saim Memon

    2017-06-01

    Full Text Available A considerable effort is devoted to devising retrofit solutions for reducing space-heating energy in the domestic sector. Existing UK solid-wall dwellings, which have both heritage values and historic fabric, are being improved but they tend to have meagre thermal performance, partly, due to the heat-loss through glazings. This paper takes comparative analyses approach to envisage space-heating supply required in order to maintain thermal comfort temperatures and attainable solar energy gains to households with the retrofit of an experimentally achievable thermal performance of the fabricated sample of triple vacuum glazing to a UK solid-wall dwelling. 3D dynamic thermal models (timely regimes of heating, occupancy, ventilation and internal heat gains of an externally-insulated solid-wall detached dwelling with a range of existing glazing types along with triple vacuum glazings are modelled. A dramatic decrease of space-heating load and moderate increase of solar gains are resulted with the dwelling of newly achievable triple vacuum glazings (having centre-of-pane U-value of 0.33 Wm-2K-1 compared to conventional glazing types. The space-heating annual cost of single glazed dwellings was minimised to 15.31% (≈USD 90.7 with the retrofit of triple-vacuum glazings. An influence of total heat-loss through the fabric of solid-wall dwelling was analysed with steady-state calculations which indicates a fall of 10.23 % with triple vacuum glazings compared to single glazings.

  11. Diffusion Monte Carlo determination of the binding energy of the sup 4 He nucleus for model Wigner potentials

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, R.F. (Manchester Univ. (United Kingdom). Inst. of Science and Technology); Buendia, E. (Granada Univ. (Spain). Dept. de Fisica Moderna); Flynn, M.F. (Kent State Univ., OH (United States). Dept. of Physics); Guardiola, R. (Valencia Univ. (Spain). Dept. de Fisica Atomica y Nuclear)

    1992-02-01

    The diffusion Monte Carlo method is used to integrate the four-body Schroedinger equation corresponding to the {sup 4}He nucleus for several model potentials of Wigner type. Good importance sampling trial functions are used, and the sampling is large enough to obtain the ground-state energy with an error of only 0.01 to 0.02 MeV. (author).

  12. Stochastic Model Predictive Fault Tolerant Control Based on Conditional Value at Risk for Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Yun-Tao Shi

    2018-01-01

    Full Text Available Wind energy has been drawing considerable attention in recent years. However, due to the random nature of wind and high failure rate of wind energy conversion systems (WECSs, how to implement fault-tolerant WECS control is becoming a significant issue. This paper addresses the fault-tolerant control problem of a WECS with a probable actuator fault. A new stochastic model predictive control (SMPC fault-tolerant controller with the Conditional Value at Risk (CVaR objective function is proposed in this paper. First, the Markov jump linear model is used to describe the WECS dynamics, which are affected by many stochastic factors, like the wind. The Markov jump linear model can precisely model the random WECS properties. Second, the scenario-based SMPC is used as the controller to address the control problem of the WECS. With this controller, all the possible realizations of the disturbance in prediction horizon are enumerated by scenario trees so that an uncertain SMPC problem can be transformed into a deterministic model predictive control (MPC problem. Finally, the CVaR object function is adopted to improve the fault-tolerant control performance of the SMPC controller. CVaR can provide a balance between the performance and random failure risks of the system. The Min-Max performance index is introduced to compare the fault-tolerant control performance with the proposed controller. The comparison results show that the proposed method has better fault-tolerant control performance.

  13. Calculation of Positron Binding Energies and Electron-Positron Annihilation Rates for Atomic Systems with the Reduced Explicitly Correlated Hartree-Fock Method in the Nuclear-Electronic Orbital Framework.

    Science.gov (United States)

    Brorsen, Kurt R; Pak, Michael V; Hammes-Schiffer, Sharon

    2017-01-19

    Although the binding of a positron to a neutral atom has not been directly observed experimentally, high-level theoretical methods have predicted that a positron will bind to a neutral atom. In the present study, the binding energies of a positron to lithium, sodium, beryllium, and magnesium, as well as the electron-positron annihilation rates for these systems, are calculated using the reduced explicitly correlated Hartree-Fock (RXCHF) method within the nuclear-electronic orbital (NEO) framework. Due to the lack of explicit electron-positron correlation, NEO Hartree-Fock and full configuration interaction calculations with reasonable electronic and positronic basis sets do not predict positron binding to any of these atoms. In contrast, the RXCHF calculations predict positron binding energies and electron-positron annihilation rates in qualitative agreement with previous highly accurate but computationally expensive stochastic variational method calculations. These results illustrate that the RXCHF method can successfully describe the binding of a positron to a neutral species with no dipole moment. Moreover, the RXCHF method will be computationally tractable for calculating positron binding to molecular systems. The RXCHF approach offers a balance of accuracy and computational tractability for studying these types of positronic systems.

  14. The relationship between developmental lumbar spinal stenosis and its BMD value : comparison by single energy quantitative CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak Jin; Kim, Kun Il; Song, Keun Sung [Pusan National Univ. Hospital, Pusan (Korea, Republic of)

    1996-03-01

    The purpose of this study is to evaluate the relationship between developmental lumbar spinal stenosis and its BMD value by using the single energy quantitative CT(SEQCT). Eighty normal volunteers(20-60years) were selected as a control group and 28 patients with developmental lumbar spinal stenosis were selected as a disease group. The two groups were divided into a younger (20-39 years) and an older subgroup (40-60 years), and were further divided into male and female subgroups. All the cases showed no evidence of metabolic disease, fracture, herniated nucleus pulposus, degererative spondylosis, infectious disease, tumors or had no history of absolute immobilization of more than two weeks. All underwent lumbar spine CT and SEQCT. we measured bone mineral density(BMD) at the cancellous bone of L1, 2, 3 and obtained the mean and its one standard deviation, and compared the data between each sub-group of the control and the disease group using ANOVA. There was a significant low BMD value in the younger male patient subgroup compared with the control subgroup(p<0.005). Developmental lumbar spinal stenosis in a young male may be a factor of decreasing BMD of the body of the spine.

  15. Small Businesses Save Big: A Guide to Help SBA Lenders Understand and Communicate the Value of Energy Efficiency Investments (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2015-01-01

    Dollars saved through energy efficiency can directly impact your bottom line. Whether you are planning for a major renovation or upgrading individual pieces of building equipment, these improvements can help reduce operating costs, save on utility bills, and boost profits. This fact sheet provides guidelines for SBA lenders to understand the value of financing energy efficiency investments.

  16. Wheat bran reduces concentrations of digestible, metabolizable, and net energy in diets fed to pigs, but energy values in wheat bran determined by the difference procedure are not different from values estimated from a linear regression procedure.

    Science.gov (United States)

    Jaworski, N W; Liu, D W; Li, D F; Stein, H H

    2016-07-01

    . The DE, ME, and NE of wheat bran determined using the difference procedure were 2,168, 2,117, and 896 kcal/kg, respectively, and these values were within the 95% confidence interval of the DE (2,285 kcal/kg), ME (2,217 kcal/kg), and NE (961 kcal/kg) estimated by linear regression. In conclusion, increasing the inclusion of wheat bran in a corn-soybean meal based diet reduced energy and nutrient digestibility and heat production as well as DE, ME, and NE of diets, but values for DE, ME, and NE for wheat bran determined using the difference procedure were not different from values determined using linear regression.

  17. Model for improved correlation of BMD values between abdominal routine Dual energy CT data and DXA scans.

    Science.gov (United States)

    Woisetschläger, Mischa; Spångeus, Anna

    2018-02-01

    Osteoporosis is a common but underdiagnosed and undertreated disease causing severe morbidity and economic burden. The gold standard for detection of osteoporosis is DXA (dual energy x-ray absorptiometry), which is a dedicated examination for osteoporosis. Dual energy CT (DECT) examinations are increasingly used in daily routine for a wide variety of diagnoses. In the present study, we wanted to examine whether vBMD (volume bone mass density) could be evaluated as a side product in non-contrast as well as contrast phases as well as to evaluate a correction model taking known shortcomings for DXA into account. A total of 20 patients, i.e. 79 vertebrae (one excluded due to vertebral fracture), mean age 71 years (range 43-85) with a mean BMI (body mass index) of 26 (range 17-33) were examined with both abdominal/pelvic DECT as well as DXA. Furthermore, aortic calcium was measured as well as the presence of osteoarthritis of the spine (OAS) and osteoarthritis in facet joints (OAF) with a 5-grade scaling system. A significant correlation was found between DXA BMD and vBMD from DECT with no contrast (WNC) (r = 0.424, p = 0.001), and with venous contrast (WVC) (r = 0.402, p < 0.001), but no significant correlation was found with arterial contrast (WAC). Using multivariate linear regression with DXA BMD as dependent, two models were created combining DECT WNC, aortic calciumscore (ACS), OAS and BMI yielding an R 2  = 0.616 (model 1) and replacement of WNC to WVC a R 2  = 0.612 (model 2). The Pearson correlation between DXA and predictive DXA BMD value of model 1 was r = 0.785 (p < 0.001) and model 2 r = 0.782 (p < 0.001). There is a correlation between DXA BMD and DECT in non-contrast and venous contrast scans but not in arterial scans. The correlation is further improved by quantifying the degree of different confounding factors (osteoarthritis of the spine, body mass index and aortic calcium score) and taking these into account in

  18. Cap-proximal nucleotides via differential eIF4E binding and alternative promoter usage mediate translational response to energy stress.

    Science.gov (United States)

    Tamarkin-Ben-Harush, Ana; Vasseur, Jean-Jacques; Debart, Françoise; Ulitsky, Igor; Dikstein, Rivka

    2017-02-08

    Transcription start-site (TSS) selection and alternative promoter (AP) usage contribute to gene expression complexity but little is known about their impact on translation. Here we performed TSS mapping of the translatome following energy stress. Assessing the contribution of cap-proximal TSS nucleotides, we found dramatic effect on translation only upon stress. As eIF4E levels were reduced, we determined its binding to capped-RNAs with different initiating nucleotides and found the lowest affinity to 5'cytidine in correlation with the translational stress-response. In addition, the number of differentially translated APs was elevated following stress. These include novel glucose starvation-induced downstream transcripts for the translation regulators eIF4A and Pabp, which are also translationally-induced despite general translational inhibition. The resultant eIF4A protein is N-terminally truncated and acts as eIF4A inhibitor. The induced Pabp isoform has shorter 5'UTR removing an auto-inhibitory element. Our findings uncovered several levels of coordination of transcription and translation responses to energy stress.

  19. The effect of dielectric constant on binding energy and impurity self-polarization in a GaAs-Ga1- x Al x As spherical quantum dot

    Science.gov (United States)

    Mese, A. I.; Cicek, E.; Erdogan, I.; Akankan, O.; Akbas, H.

    2017-03-01

    The ground state, 1s, and the excited state, 2p, energies of a hydrogenic impurity in a GaAs-Ga1- x Al x As spherical quantum dot, are computed as a function of the donor positions. We study how the impurity self-polarization depends on the location of the impurity and the dielectric constant. The excited state anomalous impurity self-polarization in the quantum dot is found to be present in the absence of any external influence and strongly depends on the impurity position and the radius of the dot. Therefore, the excited state anomalous impurity self-polarization can give information about the impurity position in the system. Also, the variation of E_{b1s} and E_{b2p} with the dielectric constant can be utilized as a tool for finding out the correct dielectric constant of the dot material by measuring the 1s or 2p state binding energy for a fixed dot radius and a fixed impurity position.

  20. A novel construction of complex-valued Gaussian processes with arbitrary spectral densities and its application to excitation energy transfer.

    Science.gov (United States)

    Chen, Xin; Cao, Jianshu; Silbey, Robert J

    2013-06-14

    The recent experimental discoveries about excitation energy transfer (EET) in light harvesting antenna (LHA) attract a lot of interest. As an open non-equilibrium quantum system, the EET demands more rigorous theoretical framework to understand the interaction between system and environment and therein the evolution of reduced density matrix. A phonon is often used to model the fluctuating environment and convolutes the reduced quantum system temporarily. In this paper, we propose a novel way to construct complex-valued Gaussian processes to describe thermal quantum phonon bath exactly by converting the convolution of influence functional into the time correlation of complex Gaussian random field. Based on the construction, we propose a rigorous and efficient computational method, the covariance decomposition and conditional propagation scheme, to simulate the temporarily entangled reduced system. The new method allows us to study the non-Markovian effect without perturbation under the influence of different spectral densities of the linear system-phonon coupling coefficients. Its application in the study of EET in the Fenna-Matthews-Olson model Hamiltonian under four different spectral densities is discussed. Since the scaling of our algorithm is linear due to its Monte Carlo nature, the future application of the method for large LHA systems is attractive. In addition, this method can be used to study the effect of correlated initial condition on the reduced dynamics in the future.

  1. Materialism, Altruism, Environmental Values, Learning Strategies and Sustainable Claim on Purchase Intention of Energy Efficient Vehicle (EEV) - A Literature Review

    Science.gov (United States)

    Syakir Shukor, Muhamad; Sulaiman, Zuraidah; Chin, Thoo Ai; Zakuan, Norhayati; Merlinda Muharam, Farrah

    2017-06-01

    One of the toughest challenges in social marketing is behaviour intervention. Previous research have developed various models and theories to simultaneously examine behaviour changes and their effects. Due to resources scarcity and global warming, automakers have come out with an innovative idea of Energy Efficient Vehicle (EEV) which has been a great improvement in the automotive industry. This invention targets for behavioral change or behavioral adoption for consumers to adjust their preferences from conventional vehicle to EEV. High market growth in automotive industry have encouraged social marketers, policymakers, governments and academics to propose suitable intervention approach in motivating preferences toward EEV. This study will explore the causal model of Environmental Responsible Behaviour (ERB) in measuring the purchase intention of EEV in Malaysia. In specific, this study focuses on two types of EEV - hybrid car and fuel efficient car. This study will hopefully add onto the body of knowledge for value orientation that influences green behaviour. From the practical perspective, this study may provide insights in assisting the stakeholders and automotive industry players on promoting the pro-behaviour toward EEV.

  2. Value of Knowledge to the Cleanup-Stewardship Program of the U.S. Department of Energy

    Energy Technology Data Exchange (ETDEWEB)

    Croff, A.G.

    2001-06-12

    The scientific and technical (S and T) activities of the U.S. Department of Energy Office of Environmental Management (DOE/EM) provide solutions to DOE/EM remediation problems. In many cases, the solution of choice eventually involves deploying a new process or piece of equipment. There has been intensive scrutiny of such deployments over the last few years, and DOE/EM is now in the position of being able to track and depict its progress and plans regarding these solutions. In addition to the well-recognized hardware solutions, many DOE/EM S and T activities result in improved knowledge or understanding of a particular situation or phenomenon that does not lead to a deployment but which nevertheless has proven to be very valuable. However, in many cases, the value of knowledge (VOK) is unrecognized, and it is certain that some key decision makers do not fully appreciate the VOK. The need to inform others concerning the VOK resulted in the preparation of this paper, the purposes of which are to provide conceptual background on the definition of VOK and why it is valuable to DOE/EM, cite examples of how knowledge has benefited and will benefit DOE/EM, and provide recommendations on the actions that the DOE/EM Office of Science and Technology (OST) should undertake to ensure that DOE/EM's VOK contributions are routinely recognized in the future.

  3. [Clinical value of toes periungual green-coloured voxels of dual-energy CT gout detecting technology].

    Science.gov (United States)

    Li, Huixia; Qu, Jin; Zhan, Ying; Lei, Xinwei

    2015-10-20

    To evaluate the clinical value of dual-energy CT(DECT) in the detection of green-coloured voxels in toenails in patients with gout using DECT. A total of 53 patients with gout could be included in the study composed of 45 men and 8 women, and 33 individuals without gout were regarded as control group. There were no significant differences in gender and age between two groups. DECT were performed for the both feet, DE (80 kV and 140 kV) datasets were reconstructed via gout-recognition software, the pseudo-color images group as the postprocessed group.Imagings were reviewed independently by two senior radiologists. Chi-square test was used for statistical analysis with the SPSS 17.0 software. In the gout group, DECT scans revealed a total of 266 areas of green-coloured voxels in 53 patients (relevance ratio 50.2% (266/530)); in the control group, 27 areas of green-coloured voxels were detected in 33 patients (relevance ratio 8.2% (27/330)), the differences had statistical significance (Pgreen-coloured voxels were detected only in the nail groove in 8 patients which compared with 2 the control group, the differences had statistical significance (Pgreen-coloured voxels of monosodium urate in the toenails, with a great potential in clinical diagnosis.

  4. Investigation of level energies and B(E2) values for rotation-aligned bands in Hg isotopes

    International Nuclear Information System (INIS)

    Mertin, D.; Tischler, R.; Kleinrahm, A.; Kroth, R.; Huebel, H.; Guenther, C.

    1978-01-01

    High spin states in 191 192 193 195 197 199 Hg were investigated by observing γ-rays and conversion electrons in the compound reactions 192 194 198 Pt(α,xn) and 192 Pt ( 3 He,4n). In 197 Hg the decoupled band built on the 13/2 + state and the semi-decoupled negative-parity band are observed up to Isup(π)=41/2 + and 33/2 - , respectively. A careful investigation of 199 Hg revealed no new high spin states above the previously known levels with Isup(π)=25/2 + and 31/2 - . Half-lives were determined for the 10 + , 7 - , 8 - and 16 - states in 192 Hg, the 33/2 states in 191 193 Hg and the 25/2 - states in 191 193 195 197 Hg. The systematics of the level energies and B(E2) values for the positive parity ground and 13/2 + bands and the negative-parity semi-decoupled bands in 190-200 Hg is discussed. (Auth.)

  5. Binding matrix: a novel approach for binding site recognition.

    Science.gov (United States)

    Kim, Jan T; Gewehr, Jan E; Martinetz, Thomas

    2004-06-01

    Recognition of protein-DNA binding sites in genomic sequences is a crucial step for discovering biological functions of genomic sequences. Explosive growth in availability of sequence information has resulted in a demand for binding site detection methods with high specificity. The motivation of the work presented here is to address this demand by a systematic approach based on Maximum Likelihood Estimation. A general framework is developed in which a large class of binding site detection methods can be described in a uniform and consistent way. Protein-DNA binding is determined by binding energy, which is an approximately linear function within the space of sequence words. All matrix based binding word detectors can be regarded as different linear classifiers which attempt to estimate the linear separation implied by the binding energy function. The standard approaches of consensus sequences and profile matrices are described using this framework. A maximum likelihood approach for determining this linear separation leads to a novel matrix type, called the binding matrix. The binding matrix is the most specific matrix based classifier which is consistent with the input set of known binding words. It achieves significant improvements in specificity compared to other matrices. This is demonstrated using 95 sets of experimentally determined binding words provided by the TRANSFAC database.

  6. An Assessment of Direct on-Farm Energy Use for High Value Grain Crops Grown under Different Farming Practices in Australia

    Directory of Open Access Journals (Sweden)

    Tek Maraseni

    2015-11-01

    Full Text Available Several studies have quantified the energy consumption associated with crop production in various countries. However, these studies have not compared the energy consumption from a broad range of farming practices currently in practice, such as zero tillage, conventional tillage and irrigated farming systems. This study examines direct on-farm energy use for high value grain crops grown under different farming practices in Australia. Grain farming processes are identified and “typical” farming operation data are collected from several sources, including published and unpublished literature, as well as expert interviews. The direct on-farm energy uses are assessed for 27 scenarios, including three high value grain crops―wheat, barley and sorghum―for three regions (Northern, Southern and Western Australia under three farming conditions with both dryland (both for conventional and zero-tillage and irrigated conditions. It is found that energy requirement for farming operations is directly related to the intensity and frequency of farming operations, which in turn is related to tillage practices, soil types, irrigation systems, local climate, and crop types. Among the three studied regions, Western Australia requires less direct on-farm energy for each crop, mainly due to the easily workable sandy soils and adoption of zero tillage systems. In irrigated crops, irrigation energy remains a major contributor to the total on-farm energy demand, accounting for up to 85% of total energy use.

  7. Unbinding pathway energy of glyphosate from the EPSPs enzyme binding site characterized by Steered Molecular Dynamics and Potential of Mean Force.

    Science.gov (United States)

    Ferreira, Moacir F; Franca, Eduardo F; Leite, Fábio L

    2017-03-01

    The quantification of herbicides in the environment, like glyphosate, is extremely important to prevent contamination. Nanobiosensors stands out in the quantization process, because of the high selectivity, sensitivity and short response time of the method. In order to emulate the detection of glyphosate using a specific nanobiossensor through an Atomic Force Microscope (AFM), this work carried out Steered Molecular Dynamics simulations (SMD) in which the herbicide was unbinded from the active site of the enzyme 5- enolpyruvylshikimate 3 phosphate synthase (EPSPS) along three different directions.After the simulations, Potential of Mean Force calculations were carried, from a cumulant expansion of Jarzynski's equation to obtain the profile of free energy of interaction between the herbicide and the active site of the enzyme in the presence of shikimate-3 substrate phosphate (S3P). The set of values for external work, had a Gaussian distribution. The PMF values ranged according to the directions of the unbindong pahway of each simulation, displaying energy values of 10.7, 14.7 and 19.5KJmol -1 . The results provide a theoretical support in order to assist the construction of a specific nanobiossensor to quantify the glyphosate herbicide. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A economia solidária e o valor das relações sociais vinculantes Solidarity economics and the value of binding social relations

    Directory of Open Access Journals (Sweden)

    Luiz Inácio Germany Gaiger

    2008-06-01

    Full Text Available A questão de fundo do artigo diz respeito às possibilidades contidas na economia solidária para configurar vínculos não determinados pelo cálculo utilitário e materializar um regime singular entre distintos princípios operantes na vida econômica. Para isso, apóia-se em pesquisas empíricas que demonstram a tendência da economia solidária a desenvolver relações portadoras de vínculos sociais, a partir dos quais se entrelaçam indissociavelmente a vida econômica e a vida social. Os valores emanados em tais experiências conduzem à ampliação da reciprocidade social e a envolvimentos na esfera pública, convertendo a economia solidária em agente político impulsionador de novos espaços de deliberação política, cuja perspectiva é a adoção de um sistema de regulação que garanta a coexistência de diferentes lógicas econômicas, em condições mínimas de equilíbrio. Em conclusão do artigo, argumenta-se que essa visão plural da economia requer a superação da antinomia utilitarismo-altruísmo, em favor de uma concepção híbrida das relações sociais.The fundamental topic of this article is the possibility for solidarity economics to establish ties not defined by utilitarian calculations and to create a unique economic regime with distinct operating principles. To do so, it is supported by empiric studies that show the trend for solidarity economics to develop relations that carry social ties that inseparably intertwine economic and social life. The values emanating from these experiences lead to the expansion of social reciprocity and to involvements in the public sphere, converting solidarity economics into a political agent that stimulates new spaces for political deliberation. The aim is to create a system that guarantees the coexistence of different economic logics, which offer the basic conditions for equilibrium. In conclusion, the article argues that this plural vision of economics requires overcoming the

  9. Calculating the Na⁺ translocating V-ATPase catalytic site affinity for substrate binding by homology modeled NtpA monomer using molecular dynamics/free energy calculation.

    Science.gov (United States)

    Muhammed, Zahed; Arai, Satoshi; Saijo, Shinya; Yamato, Ichiro; Murata, Takeshi; Suenaga, Atsushi

    2012-07-01

    Vacuolar ATPase (V-ATPase) of Enterococcus hirae is composed of a soluble catalytic domain (V₁; NtpA₃-B₃-D-G) and an integral membrane domain (V₀; NtpI-K₁₀) connected by a central and two peripheral stalks (NtpC, NtpD-G and NtpE-F). Recently nucleotide binding of catalytic NtpA monomer has been reported (Arai et al.). In the present study, we calculated the nucleotide binding affinity of NtpA by molecular dynamics (MD) simulation/free energy calculation using MM-GBSA approach based on homology modeled structure of NtpA monomer docked with ATP analogue, adenosine 5'-[β, γ-imido] triphosphate (AMP-PNP). The calculated binding free energies showed qualitatively good agreement with experimental data. The calculation was cross-validated further by the rigorous method, thermodynamic integration (TI) simulation. Finally, the interaction between NtpA and nucleotides at the atomic level was investigated by the analyses of components of free energy and the optimized model structures obtained from MD simulations, suggesting that electrostatic contribution is responsible for the difference in nucleotide binding to NtpA monomer. This is the first observation and suggestion to explain the difference of nucleotide binding properties in V-ATPase NtpA subunit, and our method can be a valuable primary step to predict nucleotide binding affinity to other subunits (NtpAB, NtpA₃B₃) and to explore subunit interactions and eventually may help to understand energy transduction mechanism of E. hirae V-ATPase. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Growth hormone (GH) provocative retesting of 108 young adults with childhood-onset GH deficiency and the diagnostic value of insulin-like growth factor I (IGF-I) and IGF-binding protein-3

    DEFF Research Database (Denmark)

    Juul, A; Kastrup, K W; Pedersen, S A

    1997-01-01

    Serum levels of total insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) reflect the endogenous GH secretion in healthy children and exhibit little diurnal variation, which makes them good diagnostic markers for screening of GH deficiency (GHD) in short children, although some...... controversy still exists. In adults, the diagnostic value of IGF-I and IGFBP-3 suspected of GHD has been reported in only a few studies. We performed a GH provocative test, using oral clonidine, in 108 patients who had previously been treated with GH during childhood (73 men and 35 women). Basal IGF......-I and IGFBP-3 levels were compared to those in 1237 healthy controls (312 controls > 18 yr) as well as to peak GH levels. Seventy-nine patients had peak GH values below a cut-off value of 7.5 micrograms/L (34 with isolated GHD), whereas 29 patients had a normal GH response (28 with previous isolated GHD), i...

  11. Efficiently "pumping out" value-added resources from wastewater by bioelectrochemical systems: A review from energy perspectives.

    Science.gov (United States)

    Zou, Shiqiang; He, Zhen

    2017-12-15

    Bioelectrochemical systems (BES) can accomplish simultaneous wastewater treatment and resource recovery via interactions between microbes and electrodes. Often deemed as "energy efficient" technologies, BES have not been well evaluated for their energy performance, such as energy production and consumption. In this work, we have conducted a review and analysis of energy balance in BES with parameters like normalized energy recovery, specific energy consumption, and net energy production. Several BES representatives based on their functions were selected for analysis, including direct electricity generation in microbial fuel cells, hydrogen production in microbial electrolysis cells, nitrogen recovery in BES, chemical production in microbial electrosynthesis cells, and desalination in microbial desalination cells. Energy performance was normalized to water volume (kWh m -3 ), organic removal (kWh kg COD -1 ), nitrogen recovery (kWh kg N -1 ), chemical production (kWh kg -1 ), or removed salt during desalination (kWh kg -1 ). The key operating factors such as pumping system (recirculation/feeding pumps) and external power supply were discussed for their effects on energy performance. This is an in-depth analysis of energy performance of various BES and expected to encourage more thinking, analysis, and presentation of energy data towards appropriate research and development of BES technology for resource recovery from wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The influence of Aspergillus niger inoculum dosage on nutritive value and metabolizable energy of apu-apu meal (Pistia stratiotes L.) on broiler chicken

    Science.gov (United States)

    Gloria, J.; Tafsin, M.; Hanafi, N. D.; Daulay, A. H.

    2018-02-01

    Apu-apu lives at tropical and subtropical fresh waterways. The apu-apu meals ultization as feed still limited. The problem of ultization apu-apu meals as ingredients is a high crude fiber and need a treatment to decrease crude fiber. This study aim to find out the influence of Aspergillus niger inoculums dosage on apu-apu meal (Pistia stratiotes L.) on metabolizable energy on broiler chicken. This research used completely randomize design (CRD). The treatments consists of Aspergillus niger inoculum dosage (CFU/g) such as P0 (0), P1 (104 CFU/g), P2 (106 CFU/g), and P3 (108 CFU/g). The variable were observed : apparent metabolizable energy (AME), true metabolizable energy (TME), apparent metabolizable energy nitrogen corrected (AMEn) and true metabolizable energy nitrogen corrected (TMEn).The results showed that the dosage of Aspergillus niger increase nutritive value of Aspergillus niger. Dosage of Aspergillus niger also influence (P<0.05) metabolizable energy of apu-apu meals. Dosage 108 CFU/g had metabolizable energy significantly higher than other treatments. Conclusion of this research is the Aspergillus niger at the dosage 108 CFU/g increased nutritive value and metabolizable energy of apu-apu meal.

  13. Economic Radar of the Sustainable Energy Sector in the Netherlands. Employment, production, investments, innovation, value added, trade. Trends and references 2009/2010

    Energy Technology Data Exchange (ETDEWEB)

    Vuik, J.; Zult, D.; Van Rossum, M.

    2012-06-15

    This monitor of the sustainable energy sector published by Statistics Netherlands (CBS) in 2012 is a follow-up to the study conducted in 2011. This 2012 study was commissioned by the Ministry of Economic Affairs, Agriculture and Innovation (ELI). Detailed economic indicators for the sustainable energy sector are presented for 2008 and 2009. Efforts for the compilation of more recent economic indicators are discussed, and the results for these more up-to-date figures are presented. The relevance of monitoring the sustainable energy sector lies in evaluating economic opportunities of the Netherlands in the global transformation towards a renewable energy supply and demand system and more attention for energy conservation. Several geopolitical, economic and enviro