Skyrmions with low binding energies

Directory of Open Access Journals (Sweden)

Mike Gillard

2015-06-01

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

Binding energy effects in cascade evolution and sputtering

International Nuclear Information System (INIS)

Robinson, M.T.

1995-06-01

The MARLOWE model was extended to include a binding energy dependent on the local crystalline order, so that atoms are bound less strongly to their lattice sites near surfaces or associated damage. Sputtering and cascade evolution were studied on the examples of self-ion irradiations of Cu and Au monocrystals. In cascades, the mean binding energy is reduced ∼8% in Cu with little dependence on the initial recoil energy; in Au, it is reduced ∼9% at 1 keV and ∼15% at 100 keV. In sputtering, the mean binding energy is reduced ∼8% in Cu and ∼15% in Au with little energy dependence; the yields are increased about half as much. Most sites from which sputtered atoms originate are isolated in both metals. Small clusters of such sites occur in Cu, but there are some large clusters in Au, especially in [111] targets. There are always more large clusters with damage-dependent binding than with a constant binding energy, but only a few clusters are compact enough to be regarded as pits

Implicit ligand theory for relative binding free energies

Science.gov (United States)

Nguyen, Trung Hai; Minh, David D. L.

2018-03-01

Implicit ligand theory enables noncovalent binding free energies to be calculated based on an exponential average of the binding potential of mean force (BPMF)—the binding free energy between a flexible ligand and rigid receptor—over a precomputed ensemble of receptor configurations. In the original formalism, receptor configurations were drawn from or reweighted to the apo ensemble. Here we show that BPMFs averaged over a holo ensemble yield binding free energies relative to the reference ligand that specifies the ensemble. When using receptor snapshots from an alchemical simulation with a single ligand, the new statistical estimator outperforms the original.

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.

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

On binding energy of trions in bulk materials

Science.gov (United States)

Filikhin, Igor; Kezerashvili, Roman Ya.; Vlahovic, Branislav

2018-03-01

We study the negatively T- and positively T+ charged trions in bulk materials in the effective mass approximation within the framework of a potential model. The binding energies of trions in various semiconductors are calculated by employing Faddeev equation in configuration space. Results of calculations of the binding energies for T- are consistent with previous computational studies and are in reasonable agreement with experimental measurements, while the T+ is unbound for all considered cases. The mechanism of formation of the binding energy of trions is analyzed by comparing contributions of a mass-polarization term related to kinetic energy operators and a term related to the Coulomb repulsion of identical particles.

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....

Transformation of cooperative free energies between ligation systems of hemoglobin: resolution of the carbon monoxide binding intermediates.

Science.gov (United States)

Huang, Y; Ackers, G K

1996-01-23

A strategy has been developed for quantitatively "translating" the distributions of cooperative free energy between different oxygenation analogs of hemoglobin (Hb). The method was used to resolve the cooperative free energies of all eight carbon monoxide binding intermediates. These parameters of the FeCOHb system were determined by thermodynamic transformation of corresponding free energies obtained previously for all species of the Co/FeCO system, i.e., where cobalt-substituted hemes comprise the unligated sites [Speros, P. C., et al. (1991) Biochemistry 30, 7254-7262]. Using hybridized combinations of normal and cobalt-substituted Hb, ligation analog systems Co/FeX (X = CO, CN) were constructed and experimentally quantified. Energetics of cobalt-induced structural perturbation were determined for all species of both the "mixed metal" Co/Fe system and also the ligated Co/FeCN system. It was found that major energetic perturbations of the Co/Fe hybrid species originate from a pure cobalt substitution effect on the alpha subunits. These perturbations are transduced to the beta subunit within the same dimeric half-tetramer, resulting in alteration of the free energies for binding at the nonsubstituted (Fe) sites. Using the linkage strategy developed in this study along with the determined energetics of these couplings, the experimental assembly free energies for the Co/FeCO species were transformed into cooperative free energies of the 10 Fe/FeCO species. The resulting values were found to distribute according to predictions of a symmetry rule mechanism proposed previously [Ackers, G. K., et al. (1992) Science 255, 54-63]. Their distribution is consistent with accurate CO binding data of normal Hb [Perrella, M., et al. (1990b) Biophys. Chem. 37, 211-223] and also with accurate O2 binding data obtained under the same conditions [Chu, A. H., et al. (1984) Biochemistry 23, 604-617].

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.

The perspectives of fusion energy: The roadmap towards energy production and fusion energy in a distributed energy system

DEFF Research Database (Denmark)

Naulin, Volker; Juul Rasmussen, Jens; Korsholm, Søren Bang

2014-01-01

at very high temperature where all matter is in the plasma state as the involved energies are orders of magnitude higher than typical chemical binding energies. It is one of the great science and engineering challenges to construct a viable power plant based on fusion energy. Fusion research is a world...... The presentation will discuss the present status of the fusion energy research and review the EU Roadmap towards a fusion power plant. Further the cost of fusion energy is assessed as well as how it can be integrated in the distributed energy system......Controlled thermonuclear fusion has the potential of providing an environmentally friendly and inexhaustible energy source for mankind. Fusion energy, which powers our sun and the stars, is released when light elements, such as the hydrogen isotopes deuterium and tritium, fuse together. This occurs...

Predicting accurate absolute binding energies in aqueous solution

DEFF Research Database (Denmark)

Jensen, Jan Halborg

2015-01-01

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

Elemental distribution imaging by energy-filtering transmission electron microscopy (EFTEM) and its applications

International Nuclear Information System (INIS)

Kurata, Hiroki

1996-01-01

EFTEM is new microscopy with the object of visualizing high resolution quantitative elemental distribution. The measurement principles and the present state of EFTEM studies are explained by the examples of measurement of the elemental distributions. EFTEM is a combination of the transmission electron microscope with the electron energy loss spectroscopy (EFLS). EFTEM method sets the slit in the specific energy field and put the electron passing the slit back in the microscopic image. The qualitative elemental analysis is obtained by observing the position of the absorption end of core electronic excitation spectrum and the quantitative one by determining the core electronic excitation strength of the specific atom depend on filtering with energy selector slit. The binding state and the local structure in the neighborhood of excited atom is determined by the fine structure of absorption end. By the chemical mapping method, the distribution image of chemical binding state is visualized by the imaging chemical map obtained by filtering the specific peak strength of fine structure with the narrow energy selector slit. The fine powder of lead chromate (PbCrO 4 ) covered with silica glass was shown as a typical example of the elemental distribution image of core electronic excitation spectrum. The quantitative analysis method of elemental distribution image is explained. The possibility of single atom analysis at nanometer was shown by the example of nanotube observed by EFTEM. (S.Y.)

Measurements of energy losses, distributions of energy loss and additivity of energy losses for 50 to 150 keV protons in hydrogen and nine hydrocarbon gases

International Nuclear Information System (INIS)

Thorngate, J.H.

1976-05-01

Measurements of energy-loss distributions were made for 51, 102, and 153 keV protons traversing hydrogen, methane, ethyne (acetylene), ethene (ethylene), ethane, propyne (methyl acetylene), propadiene (allene), propene (propylene), cyclopropane and propane. The objectives were to test the theories of energy-loss distribution in this energy range and to see if the type of carbon bonding in a hydrocarbon molecule affects the shape of the distribution. Stopping powers and stopping cross sections were also measured at these energies and at 76.5 and 127.5 keV to determine effects of chemical binding. All of the measurements were made at the gas density required to give a 4 percent energy loss. The mean energy, second central moment (a measure of the width of the distribution), and the third central moment (a measure of the skew) were calculated from the measured energy-loss distributions. Stopping power values, calculated using the mean energy, compared reasonably well with those calculated from the Bethe stopping power theory. For the second and third central moments, the best agreement between measurement and theory was when the classical scattering probability was used for the calculations, but even these did not agree well. In all cases, variations were found in the data that could be correlated to the type of carbon binding in the molecule. The differences were statistically significant at a 99 percent confidence interval for the stopping powers and second central moments measured with 51 keV protons. Similar trends were noted at other energies and for the third central moment, but the differences were not statistically significant at the 99 percent confidence interval

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.

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

Integrating water exclusion theory into βcontacts to predict binding free energy changes and binding hot spots

Science.gov (United States)

2014-01-01

Background Binding free energy and binding hot spots at protein-protein interfaces are two important research areas for understanding protein interactions. Computational methods have been developed previously for accurate prediction of binding free energy change upon mutation for interfacial residues. However, a large number of interrupted and unimportant atomic contacts are used in the training phase which caused accuracy loss. Results This work proposes a new method, βACV ASA , to predict the change of binding free energy after alanine mutations. βACV ASA integrates accessible surface area (ASA) and our newly defined β contacts together into an atomic contact vector (ACV). A β contact between two atoms is a direct contact without being interrupted by any other atom between them. A β contact’s potential contribution to protein binding is also supposed to be inversely proportional to its ASA to follow the water exclusion hypothesis of binding hot spots. Tested on a dataset of 396 alanine mutations, our method is found to be superior in classification performance to many other methods, including Robetta, FoldX, HotPOINT, an ACV method of β contacts without ASA integration, and ACV ASA methods (similar to βACV ASA but based on distance-cutoff contacts). Based on our data analysis and results, we can draw conclusions that: (i) our method is powerful in the prediction of binding free energy change after alanine mutation; (ii) β contacts are better than distance-cutoff contacts for modeling the well-organized protein-binding interfaces; (iii) β contacts usually are only a small fraction number of the distance-based contacts; and (iv) water exclusion is a necessary condition for a residue to become a binding hot spot. Conclusions βACV ASA is designed using the advantages of both β contacts and water exclusion. It is an excellent tool to predict binding free energy changes and binding hot spots after alanine mutation. PMID:24568581

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 ...

Core electron binding energy shifts of AlBr3 and Al2Br6 vapor

International Nuclear Information System (INIS)

Mueller, Astrid M.; Plenge, Juergen; Leone, Stephen R.; Canton, Sophie E.; Rude, Bruce S.; Bozek, John D.

2006-01-01

The Al 2p and Br 3d inner-shell photoelectron spectra of aluminum tribromide monomer and dimer vapor were measured at 90 and 95 eV photon energy, respectively, to determine the core electron binding energies of the atoms in the two molecular species. While AlBr 3 has three identical Br atoms, Al 2 Br 6 exhibits four terminal and two bridging Br atoms. The species are identified by their distinct valence photoelectron spectra. Comparison of the observed Al 2p 1/2 and Al 2p 3/2 electron binding energies of AlBr 3 with those of Al 2 Br 6 shows that there is a chemical shift of (0.15 ± 0.03) eV to lower energy in the dimer. In Al 2 Br 6 , an assignment is proposed in which the Br 3d 3/2 and Br 3d 5/2 binding energies of terminal Br atoms are (1.18 ± 0.03) eV lower than those of bridging Br atoms. This assignment assumes that both types of Br atoms have similar cross-sections for ionization. With this result, the Br 3d 3/2 and Br 3d 5/2 binding energies of Br atoms in AlBr 3 are (0.81 ± 0.03) eV lower than those of bridging Br atoms of the dimer but (0.37 ± 0.03) eV higher than those of terminal Br atoms of the dimer. The obtained chemical shifts are considered in terms of the binding relations and electron density distributions in both molecules. Chemical shifts that are larger than a few hundred millielectron volts, as observed in the Al 2 Br 6 /AlBr 3 system, offer potential to study the dissociation dynamics of the dimer in a femtosecond visible or ultraviolet-pump/XUV-probe experiment

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.

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.

Polaron binding energy and effective mass in the GaAs film

International Nuclear Information System (INIS)

Wu Zhenhua; Yan Liangxing; Tian Qiang; Li Hua; Liu Bingcan

2012-01-01

The binding energy and effective mass of a polaron in a GaAs film deposited on the Al 0.3 Ga 0.7 As substrate are studied theoretically by using the fractional-dimensional space approach. Our calculations show that the polaron binding energy and mass shift decrease monotonously with increasing the film thickness. For the film thicknesses with L w ≤ 70Å and the substrate thicknesses with L b ≤ 200Å, the different values of the substrate thickness influence the polaron binding energy and mass shift in the GaAs film. The polaron binding energy and mass shift increase monotonously with increasing the substrate thickness. For the film thickness with L w ≥ 70Å or the substrate thicknesses with L b ≤ 200Å, the different values of the substrate thickness have no significant influence on the polaron binding energy and mass shift in the GaAs film deposited on the Al 0.3 Ga 0.7 As substrate.

Eel calcitonin binding site distribution and antinociceptive activity in rats

International Nuclear Information System (INIS)

Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.

1986-01-01

The distribution of binding site for [ 125 I]-eel-calcitonin (ECT) to rat central nervous system, studied by an autoradiographic technique, showed concentrations of binding in the diencephalon, the brain stem and the spinal cord. Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei. The density of grains in the reticular formation and in the nucleus tractus spinalis nervi trigemini was more moderate. In the spinal cord, grains were scattered throughout the dorsal horns. Binding of the ligand was displaced equally by cold ECT and by salmon CT(sCT), indicating that both peptides bind to the same receptors. Human CT was much weaker than sCT in displacing [ 125 I]-ECT binding. The administration of ECT into the brain ventricles of rats dose-dependently induced a significant and long-lasting enhancement of hot-plate latencies comparable with that obtained with sCT. The antinociceptive activity induced by ECT is compatible with the topographical distribution of binding sites for the peptide and is a further indication that fish CTs are active in the mammalian brain

Distribution of [3H]diadenosine tetraphosphate binding sites in rat brain

International Nuclear Information System (INIS)

Miras-Portugal, M.T.; Palacios, J.M.; Torres, M.; Cortes, R.; Rodriguez-Pascual, F.

1997-01-01

The distribution of the diadenosine tetraphosphate high-affinity binding sites has been studied in rat brain by an autoradiographic method using [ 3 H]diadenosine tetraphosphate as the ligand. The binding characteristics are comparable to those described in studies performed on rat brain synaptosomes. White matter is devoid of specific binding. The range of binding site densities in gray matter varies from 3 to 15 fmol/mg of tissue, exhibiting a widespread but heterogeneous distribution. The highest densities correspond to the seventh cranial nerve, medial superior olive, pontine nuclei, glomerular and external plexiform layers of the olfactory bulb, and the granule cell layer of the cerebellar cortex. Intermediate density levels of binding correspond to different cortical areas, several nuclei of the amygdala, and the oriens and pyramidal layers of the hippocampal formation.The localization of diadenosine tetraphosphate binding sites in the brain may provide information on the places where diadenosine polyphosphate compounds can be expected to function in the central nervous system. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

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...

Changes in the zero-point energy of the protons as the source of the binding energy of water to A-phase DNA.

Science.gov (United States)

Reiter, G F; Senesi, R; Mayers, J

2010-10-01

The measured changes in the zero-point kinetic energy of the protons are entirely responsible for the binding energy of water molecules to A phase DNA at the concentration of 6  water molecules/base pair. The changes in kinetic energy can be expected to be a significant contribution to the energy balance in intracellular biological processes and the properties of nano-confined water. The shape of the momentum distribution in the dehydrated A phase is consistent with coherent delocalization of some of the protons in a double well potential, with a separation of the wells of 0.2 Å.

Changes in the Zero-Point Energy of the Protons as the Source of the Binding Energy of Water to A-Phase DNA

International Nuclear Information System (INIS)

Reiter, G. F.; Senesi, R.; Mayers, J.

2010-01-01

The measured changes in the zero-point kinetic energy of the protons are entirely responsible for the binding energy of water molecules to A phase DNA at the concentration of 6 water molecules/base pair. The changes in kinetic energy can be expected to be a significant contribution to the energy balance in intracellular biological processes and the properties of nano-confined water. The shape of the momentum distribution in the dehydrated A phase is consistent with coherent delocalization of some of the protons in a double well potential, with a separation of the wells of 0.2 Angst .

Alternate Energy Sources for Thermalplastic Binding Agent Consolidation

Energy Technology Data Exchange (ETDEWEB)

Frame, B.J.

1999-01-01

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

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.

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.

Study of dissociative collisions of hydrogen-line ions by mean of angular and energy distributions

International Nuclear Information System (INIS)

Martinez, H.; Urquijo, J. de; Cisneros, C.; Alvarez, J.

1988-01-01

Angular and energy distribution of fragments produced in a collision, employed in conjunction with the 'step-model' that means excitation and binary dissociation, are used to determine the binding energy of H 3 (D 3 ) and HD + 2 and also to identify the principal channels in the dissociation processes. (A.C.A.S.) [pt

Pharmacokinetics of warfarin in rats: role of serum protein binding and tissue distribution

International Nuclear Information System (INIS)

Cheung, W.K.

1985-01-01

The purpose of this study was to explore the role of serum protein binding and tissue distribution in the non-linear pharmacokinetics of warfarin in rats. The first phase of the research was an attempt to elucidate the causes of intersubject differences in serum protein binding of warfarin in rats. It was found that the distribution of S-warfarin between blood and liver, kidneys, muscle, or fatty tissue was non-linear. Based on the tissue distribution data obtained, a physiologically-based pharmacokinetic model was developed to describe the time course of S-warfarin concentrations in the serum and tissues of rats. The proposed model was able to display the dose-dependent pharmacokinetics of warfarin in rats. Namely a lower clearance and a smaller apparent volume of distribution with increasing dose, which appear to be due to the presence of capacity-limited, high-affinity binding sites for warfarin in various tissues. To determine if the binding of warfarin to the high-affinity binding sites in the liver of rats is reversible, concentrations of S-warfarin in the liver and serum of rats were monitored for a very long time after an intravenous injection of a 1 mg/kg dose. In another study in rats, non-radioactive warfarin was found to be able to displace tissue-bound C 14 -warfarin which was administered about 200 hours before the i.v. injection of the non-radioactive warfarin, showing that the binding of warfarin to the high-affinity binding sites in the body is persistent and reversible

Distribution of [{sup 3}H]diadenosine tetraphosphate binding sites in rat brain

Energy Technology Data Exchange (ETDEWEB)

Miras-Portugal, M.T. [Departamento de Bioquimica, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid (Spain); Palacios, J.M. [Laboratorios Almirall, Research Center, Cardener 68, 08024 Barcelona (Spain); Torres, M. [Departamento de Bioquimica, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid (Spain); Cortes, R. [Departamento de Neuroquimica, Centro de Investigacion y Desarrollo, CSIC Jordi Girona 18-26, 08034 Barcelona (Spain); Rodriguez-Pascual, F. [Departamento de Bioquimica, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid (Spain)

1997-01-06

The distribution of the diadenosine tetraphosphate high-affinity binding sites has been studied in rat brain by an autoradiographic method using [{sup 3}H]diadenosine tetraphosphate as the ligand. The binding characteristics are comparable to those described in studies performed on rat brain synaptosomes. White matter is devoid of specific binding. The range of binding site densities in gray matter varies from 3 to 15 fmol/mg of tissue, exhibiting a widespread but heterogeneous distribution. The highest densities correspond to the seventh cranial nerve, medial superior olive, pontine nuclei, glomerular and external plexiform layers of the olfactory bulb, and the granule cell layer of the cerebellar cortex. Intermediate density levels of binding correspond to different cortical areas, several nuclei of the amygdala, and the oriens and pyramidal layers of the hippocampal formation.The localization of diadenosine tetraphosphate binding sites in the brain may provide information on the places where diadenosine polyphosphate compounds can be expected to function in the central nervous system. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

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.

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

Science.gov (United States)

Maurer, Manuela; de Beer, Stephanie B A; Oostenbrink, Chris

2016-04-15

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.

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.

Distributed Energy Implementation Options

Energy Technology Data Exchange (ETDEWEB)

Shah, Chandralata N [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-13

This presentation covers the options for implementing distributed energy projects. It distinguishes between options available for distributed energy that is government owned versus privately owned, with a focus on the privately owned options including Energy Savings Performance Contract Energy Sales Agreements (ESPC ESAs). The presentation covers the new ESPC ESA Toolkit and other Federal Energy Management Program resources.

Quantitative autoradiographic distribution of L-[3H]glutamate-binding sites in rat central nervous system

International Nuclear Information System (INIS)

Greenamyre, J.T.; Young, A.B.; Penney, J.B.

1984-01-01

Quantitative autoradiography was used to determine the distribution of L-[3H]glutamate-binding sites in the rat central nervous system. Autoradiography was carried out in the presence of Cl- and Ca2+ ions. Scatchard plots and Hill coefficients of glutamate binding suggested that glutamate was interacting with a single population of sites having a K-D of about 300 nM and a capacity of 14.5 pmol/mg of protein. In displacement studies, ibotenate also appeared to bind to a single class of non-interacting sites with a KI of 28 microM. However, quisqualate displacement of [3H]glutamate binding revealed two well-resolved sites with KIS of 12 nM and 114 microM in striatum. These sites were unevenly distributed, representing different proportions of specific glutamate binding in different brain regions. The distribution of glutamate-binding sites correlated very well with the projection areas of putative glutamatergic pathways. This technique provides an extremely sensitive assay which can be used to gather detailed pharmacological and anatomical information about L-[3H]glutamate binding in the central nervous system

Distribution of PASTA domains in penicillin-binding proteins and serine/threonine kinases of Actinobacteria.

Science.gov (United States)

Ogawara, Hiroshi

2016-09-01

PASTA domains (penicillin-binding protein and serine/threonine kinase-associated domains) have been identified in penicillin-binding proteins and serine/threonine kinases of Gram-positive Firmicutes and Actinobacteria. They are believed to bind β-lactam antibiotics, and be involved in peptidoglycan metabolism, although their biological function is not definitively clarified. Actinobacteria, especially Streptomyces species, are distinct in that they undergo complex cellular differentiation and produce various antibiotics including β-lactams. This review focuses on the distribution of PASTA domains in penicillin-binding proteins and serine/threonine kinases in Actinobacteria. In Actinobacteria, PASTA domains are detectable exclusively in class A but not in class B penicillin-binding proteins, in sharp contrast to the cases in other bacteria. In penicillin-binding proteins, PASTA domains distribute independently from taxonomy with some distribution bias. Particularly interesting thing is that no Streptomyces species have penicillin-binding protein with PASTA domains. Protein kinases in Actinobacteria possess 0 to 5 PASTA domains in their molecules. Protein kinases in Streptomyces can be classified into three groups: no PASTA domain, 1 PASTA domain and 4 PASTA domain-containing groups. The 4 PASTA domain-containing groups can be further divided into two subgroups. The serine/threonine kinases in different groups may perform different functions. The pocket region in one of these subgroup is more dense and extended, thus it may be involved in binding of ligands like β-lactams more efficiently.

Distributed coordination of energy storage with distributed generators

NARCIS (Netherlands)

Yang, Tao; Wu, Di; Stoorvogel, Antonie Arij; Stoustrup, Jakob

2016-01-01

With a growing emphasis on energy efficiency and system flexibility, a great effort has been made recently in developing distributed energy resources (DER), including distributed generators and energy storage systems. This paper first formulates an optimal DER coordination problem considering

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.

An experimental and theoretical investigation of the valence orbital momentum distributions and binding energy spectra of nitrogen

International Nuclear Information System (INIS)

Cook, J.P.D.; Pascual, R.; Weigold, E.

1989-05-01

A detailed electron momentum spectrosocpy (EMS) and a manybody theoretical study of the complete valence region of N 2 was carried out. The 1500eV EMS momentum distributions show that they provide a sensitive test for orbital wavefunctions of SCF calculations, and of correlation effects. The outermost 3σ g orbital is more sharply peaked at the origin than predicted by the orbital wavefunction. The inner valence 2σ g orbital is severely split, with spectroscopic strength ranging from 34eV to over 60eV in binding energy. The results of the present extended basis 1p Green's function calculations, as well as those of several previous manybody calculations, are only in semiquantitative agreement with this. There is a 2σ u pole at 25eV with a pole strength of approximately 0.067 in agreement with the results of manybody calculations. There is significant 2σ u and or 1π u strength and little 2σ g strength in the region 26-34eV. Poles observed at 29 and 32eV, previously attributed to the 2σ g orbital, are shown to be largely 2σ u in character. The manybody calculations predict too much 2σ g strength in the region 26-34eV. 29 refs., 1 tab., 16 figs

Exciton binding energy in GaAsBiN spherical quantum dot heterostructures

Science.gov (United States)

Das, Subhasis; Dhar, S.

2017-03-01

The ground state exciton binding energies (EBE) of heavy hole excitons in GaAs1-x-yBixNy - GaAs spherical quantum dots (QD) are calculated using a variational approach under 1s hydrogenic wavefunctions within the framework of effective mass approximation. Both the nitrogen and the bismuth content in the material are found to affect the binding energy, in particular for larger nitrogen content and lower dot radii. Calculations also show that the ground state exciton binding energies of heavy holes increase more at smaller dot sizes as compared to that for the light hole excitons.

Towards accurate free energy calculations in ligand protein-binding studies.

Science.gov (United States)

Steinbrecher, Thomas; Labahn, Andreas

2010-01-01

Cells contain a multitude of different chemical reaction paths running simultaneously and quite independently next to each other. This amazing feat is enabled by molecular recognition, the ability of biomolecules to form stable and specific complexes with each other and with their substrates. A better understanding of this process, i.e. of the kinetics, structures and thermodynamic properties of biomolecule binding, would be invaluable in the study of biological systems. In addition, as the mode of action of many pharmaceuticals is based upon their inhibition or activation of biomolecule targets, predictive models of small molecule receptor binding are very helpful tools in rational drug design. Since the goal here is normally to design a new compound with a high inhibition strength, one of the most important thermodynamic properties is the binding free energy DeltaG(0). The prediction of binding constants has always been one of the major goals in the field of computational chemistry, because the ability to reliably assess a hypothetical compound's binding properties without having to synthesize it first would save a tremendous amount of work. The different approaches to this question range from fast and simple empirical descriptor methods to elaborate simulation protocols aimed at putting the computation of free energies onto a solid foundation of statistical thermodynamics. While the later methods are still not suited for the screenings of thousands of compounds that are routinely performed in computational drug design studies, they are increasingly put to use for the detailed study of protein ligand interactions. This review will focus on molecular mechanics force field based free energy calculations and their application to the study of protein ligand interactions. After a brief overview of other popular methods for the calculation of free energies, we will describe recent advances in methodology and a variety of exemplary studies of molecular dynamics

BFEE: A User-Friendly Graphical Interface Facilitating Absolute Binding Free-Energy Calculations.

Science.gov (United States)

Fu, Haohao; Gumbart, James C; Chen, Haochuan; Shao, Xueguang; Cai, Wensheng; Chipot, Christophe

2018-03-26

Quantifying protein-ligand binding has attracted the attention of both theorists and experimentalists for decades. Many methods for estimating binding free energies in silico have been reported in recent years. Proper use of the proposed strategies requires, however, adequate knowledge of the protein-ligand complex, the mathematical background for deriving the underlying theory, and time for setting up the simulations, bookkeeping, and postprocessing. Here, to minimize human intervention, we propose a toolkit aimed at facilitating the accurate estimation of standard binding free energies using a geometrical route, coined the binding free-energy estimator (BFEE), and introduced it as a plug-in of the popular visualization program VMD. Benefitting from recent developments in new collective variables, BFEE can be used to generate the simulation input files, based solely on the structure of the complex. Once the simulations are completed, BFEE can also be utilized to perform the post-treatment of the free-energy calculations, allowing the absolute binding free energy to be estimated directly from the one-dimensional potentials of mean force in simulation outputs. The minimal amount of human intervention required during the whole process combined with the ergonomic graphical interface makes BFEE a very effective and practical tool for the end-user.

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).

Exciton binding energy in a pyramidal quantum dot

Indian Academy of Sciences (India)

A ANITHA

2018-03-27

Mar 27, 2018 ... screening function on exciton binding energy in a pyramid-shaped quantum dot of ... tures may generate unique properties and they show .... where Ee is the ground-state energy of the electron in ... Figure 1. The geometry of the pyramidal quantum dot. base and H is the height of the pyramid which is taken.

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...

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

A = 4 0+ - 1+ binding-energy difference

International Nuclear Information System (INIS)

Gibson, B.F.; Lehman, D.R.

1982-01-01

The A = 4 Λ-hypernuclei provide a rich source of information about the s-wave properties of the fundamental hyperon-nucleon (YN) force as well as offer a unique opportunity to investigate the complications that arise in calculations of the properties of bound systems in which one baryon (here the Λ) with a given isospin couples strongly to another (the Σ) with a different isospin. The Λ 4 H - Λ 4 He isodoublet ground-state energies are not consistent with a charge symmetry hypothesis for the YN interaction. The (spin-flip) excitation energies are quite sensitive to the ΛN - ΣN coupling of the YN interaction. In particular, when one represents the free YN interaction in terms of one-channel effective ΛN potentials, the resulting 0 + (ground) state and 1 + (excited) spin-flip state are inversely ordered in terms of binding energies, the 1 + state being more bound. It is the Σ suppression that results from the reduced strength of the ΛN - ΣN off-diagonal coupling potential when the trinucleon core is restricted to isospin-1/2 which we study here. We find this spin-isospin suppression of the Λ-Σ conversion, which is due to the composite nature of the nuclear cores of the Λ 4 H and Λ 4 He hypernuclei, to be a significant factor in understanding the 0 + - 1 + binding energy relationship

Distribution of cyclophilin B-binding sites in the subsets of human peripheral blood lymphocytes.

Science.gov (United States)

Denys, A; Allain, F; Foxwell, B; Spik, G

1997-08-01

Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein, mainly associated with the secretory pathway and released in biological fluids. We have recently demonstrated that both free CyPB and CyPB-CsA complex specifically bind to peripheral blood T lymphocytes and are internalized. These results suggest that CyPB might promote the targeting of the drug into sensitive cells. Peripheral blood lymphocytes are subdivided in several populations according to their biological functions and sensitivity to CsA. We have investigated the binding of CyPB to these different subsets using a CyPB derivatized by fluorescein through its single cysteine which retains its binding properties. We have confirmed that only T cells were involved in the interaction with CyPB. The ligand binding was found to be heterogeneously distributed on the different T-cell subsets and surface-bound CyPB was mainly associated with the CD4-positive cells. No significant difference was noted between the CD45RA and CD45RO subsets, demonstrating that CyPB-binding sites were equally distributed between native and memory T cells. CD3 stimulation of T lymphocytes led to a decrease in the CyPB-binding capacity, that may be explained by a down-regulation of the CyPB-receptor expression upon T-cell activation. Finally, we demonstrated that CyPB-receptor-positive cells, isolated on CyPB sulphydryl-coupled affinity matrices, are more sensitive to CyPB-complexed CsA than mixed peripheral blood lymphocytes, suggesting that CyPB potentiates CsA activity through the binding of the complex. Taken together, our results demonstrate that CyPB-binding sites are mainly associated with resting cells of the helper T lymphocyte, and that CyPB might modulate the distribution of CsA through the drug targeting to sensitive cells.

Towards Automated Binding Affinity Prediction Using an Iterative Linear Interaction Energy Approach

Directory of Open Access Journals (Sweden)

C. Ruben Vosmeer

2014-01-01

Full Text Available Binding affinity prediction of potential drugs to target and off-target proteins is an essential asset in drug development. These predictions require the calculation of binding free energies. In such calculations, it is a major challenge to properly account for both the dynamic nature of the protein and the possible variety of ligand-binding orientations, while keeping computational costs tractable. Recently, an iterative Linear Interaction Energy (LIE approach was introduced, in which results from multiple simulations of a protein-ligand complex are combined into a single binding free energy using a Boltzmann weighting-based scheme. This method was shown to reach experimental accuracy for flexible proteins while retaining the computational efficiency of the general LIE approach. Here, we show that the iterative LIE approach can be used to predict binding affinities in an automated way. A workflow was designed using preselected protein conformations, automated ligand docking and clustering, and a (semi-automated molecular dynamics simulation setup. We show that using this workflow, binding affinities of aryloxypropanolamines to the malleable Cytochrome P450 2D6 enzyme can be predicted without a priori knowledge of dominant protein-ligand conformations. In addition, we provide an outlook for an approach to assess the quality of the LIE predictions, based on simulation outcomes only.

The universal statistical distributions of the affinity, equilibrium constants, kinetics and specificity in biomolecular recognition.

Directory of Open Access Journals (Sweden)

Xiliang Zheng

2015-04-01

Full Text Available We uncovered the universal statistical laws for the biomolecular recognition/binding process. We quantified the statistical energy landscapes for binding, from which we can characterize the distributions of the binding free energy (affinity, the equilibrium constants, the kinetics and the specificity by exploring the different ligands binding with a particular receptor. The results of the analytical studies are confirmed by the microscopic flexible docking simulations. The distribution of binding affinity is Gaussian around the mean and becomes exponential near the tail. The equilibrium constants of the binding follow a log-normal distribution around the mean and a power law distribution in the tail. The intrinsic specificity for biomolecular recognition measures the degree of discrimination of native versus non-native binding and the optimization of which becomes the maximization of the ratio of the free energy gap between the native state and the average of non-native states versus the roughness measured by the variance of the free energy landscape around its mean. The intrinsic specificity obeys a Gaussian distribution near the mean and an exponential distribution near the tail. Furthermore, the kinetics of binding follows a log-normal distribution near the mean and a power law distribution at the tail. Our study provides new insights into the statistical nature of thermodynamics, kinetics and function from different ligands binding with a specific receptor or equivalently specific ligand binding with different receptors. The elucidation of distributions of the kinetics and free energy has guiding roles in studying biomolecular recognition and function through small-molecule evolution and chemical genetics.

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.

Energy Management of Smart Distribution Systems

Science.gov (United States)

Ansari, Bananeh

Electric power distribution systems interface the end-users of electricity with the power grid. Traditional distribution systems are operated in a centralized fashion with the distribution system owner or operator being the only decision maker. The management and control architecture of distribution systems needs to gradually transform to accommodate the emerging smart grid technologies, distributed energy resources, and active electricity end-users or prosumers. The content of this document concerns with developing multi-task multi-objective energy management schemes for: 1) commercial/large residential prosumers, and 2) distribution system operator of a smart distribution system. The first part of this document describes a method of distributed energy management of multiple commercial/ large residential prosumers. These prosumers not only consume electricity, but also generate electricity using their roof-top solar photovoltaics systems. When photovoltaics generation is larger than local consumption, excess electricity will be fed into the distribution system, creating a voltage rise along the feeder. Distribution system operator cannot tolerate a significant voltage rise. ES can help the prosumers manage their electricity exchanges with the distribution system such that minimal voltage fluctuation occurs. The proposed distributed energy management scheme sizes and schedules each prosumer's ES to reduce the electricity bill and mitigate voltage rise along the feeder. The second part of this document focuses on emergency energy management and resilience assessment of a distribution system. The developed emergency energy management system uses available resources and redundancy to restore the distribution system's functionality fully or partially. The success of the restoration maneuver depends on how resilient the distribution system is. Engineering resilience terminology is used to evaluate the resilience of distribution system. The proposed emergency energy

Metastable decay and binding energies of van der Waals cluster ions

International Nuclear Information System (INIS)

Ernstberger, B.; Krause, H.; Neusser, H.J.

1991-01-01

In this work the appearance potentials for the metastable decay channel of a series of van der Waals dimer ions are presented. Ionization and metastable dissociation is achieved by resonance-enhanced two-photon absorption in a linear reflectron time-of-flight mass spectrometer. From the appearance potentials the binding energy of the neutral dimers is obtained and from the additionally measured ionization potentials binding energies of the dimer cations are achieved. The contribution of charge transfer resonance interaction to the binding in cluster ions is evaluated by investigation of several homo- and heterodimers of aromatic components and the heterodimer benzene/cyclohexane as an example for a dimer consisting of an aromatic and a nonaromatic component. (orig.)

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

International Nuclear Information System (INIS)

Haddad, S.

2011-04-01

The effect of the isovector coupling channel on the macroscopic part of the nuclear binding energy is determined utilizing the relativistic density dependent Thomas-Fermi approach for the calculation of the macroscopic part of the nuclear binding energy, and the dependency of this effect on the numbers of neutrons and protons is studied. The isovector coupling channel leads to increased nuclear binding energy, and this effect sharpens with growing excess of the number of neutrons on the number of protons. (author)

Exciton binding energy in wurtzite InGaN/GaN quantum wells

International Nuclear Information System (INIS)

Park, Seoung-Hwan; Kim, Jong-Jae; Kim, Hwa-Min

2004-01-01

The internal field and carrier density effects on the exciton binding energies in wurtzite (WZ) InGaN/GaN quantum-well (QW) structures are investigated using the multiband effective-mass theory, and are compared with those obtained from the at-band model and with those of GaN/AlGaN QW structures. The exciton binding energy is significantly reduced with increasing sheet carrier density, suggesting that excitons are nearly bleached at densities around 10 12 cm -2 for both InGaN/GaN and GaN/AlGaN QW structures. With the inclusion of the internal field, the exciton binding energy is substantialy reduced compared to that of the at-band model in the investigated region of the wells. This can be explained by a decrease in the momentum matrix element and an increase in the inverse screening length due to the internal field. The exciton binding energy of the InGaN/GaN structure is smaller than that of the GaN/AlGaN structure because InGaN/GaN structures have a smaller momentum matrix element and a larger inverse screening length than GaN/AlGaN structures.

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.

Hydrostatic-pressure effects on the donor binding energy in GaAs-(Ga, Al)As quantum dots

International Nuclear Information System (INIS)

Perez-Merchancano, S T; Paredes-Gutierrez, H; Silva-Valencia, J

2007-01-01

The binding energy of shallow hydrogenic impurities in a spherical quantum dot under isotropic hydrostatic pressure is calculated using a variational approach within the effective mass approximation. The binding energy is computed as a function of hydrostatic pressure, dot size and impurity position. The results show that the impurity binding energy increases with the pressure for any position of the impurity. Also, we have found that the binding energy depends on the location of the impurity and the pressure effects are less pronounced for impurities on the edge

Estimating Atomic Contributions to Hydration and Binding Using Free Energy Perturbation.

Science.gov (United States)

Irwin, Benedict W J; Huggins, David J

2018-05-08

We present a general method called atom-wise free energy perturbation (AFEP), which extends a conventional molecular dynamics free energy perturbation (FEP) simulation to give the contribution to a free energy change from each atom. AFEP is derived from an expansion of the Zwanzig equation used in the exponential averaging method by defining that the system total energy can be partitioned into contributions from each atom. A partitioning method is assumed and used to group terms in the expansion to correspond to individual atoms. AFEP is applied to six example free energy changes to demonstrate the method. Firstly, the hydration free energies of methane, methanol, methylamine, methanethiol, and caffeine in water. AFEP highlights the atoms in the molecules that interact favorably or unfavorably with water. Finally AFEP is applied to the binding free energy of human immunodeficiency virus type 1 protease to lopinavir, and AFEP reveals the contribution of each atom to the binding free energy, indicating candidate areas of the molecule to improve to produce a more strongly binding inhibitor. FEP gives a single value for the free energy change and is already a very useful method. AFEP gives a free energy change for each "part" of the system being simulated, where part can mean individual atoms, chemical groups, amino acids, or larger partitions depending on what the user is trying to measure. This method should have various applications in molecular dynamics studies of physical, chemical, or biochemical phenomena, specifically in the field of computational drug discovery.

Role of codeposited impurities during growth. II. Dependence of morphology on binding and barrier energies

Science.gov (United States)

Sathiyanarayanan, Rajesh; Hamouda, Ajmi Bh.; Pimpinelli, A.; Einstein, T. L.

2011-01-01

In an accompanying article we showed that surface morphologies obtained through codeposition of a small quantity (2%) of impurities with Cu during growth (step-flow mode, θ = 40 ML) significantly depends on the lateral nearest-neighbor binding energy (ENN) to Cu adatom and the diffusion barrier (Ed) of the impurity atom on Cu(0 0 1). Based on these two energy parameters, ENN and Ed, we classify impurity atoms into four sets. We study island nucleation and growth in the presence of codeposited impurities from different sets in the submonolayer (θ⩽ 0.7 ML) regime. Similar to growth in the step-flow mode, we find different nucleation and growth behavior for impurities from different sets. We characterize these differences through variations of the number of islands (Ni) and the average island size with coverage (θ). Further, we compute the critical nucleus size (i) for all of these cases from the distribution of capture-zone areas using the generalized Wigner distribution.

DEM - distribution energy management

Energy Technology Data Exchange (ETDEWEB)

Seppaelae, A; Kekkonen, V; Koreneff, G [VTT Energy, Espoo (Finland); and others

1998-08-01

The electricity market was de-regulated in Finland at the end of 1995 and the customers can now freely choose their power suppliers. The national grid and local distribution network operators are now separated from the energy business. The network operators transmit the electric power to the customers on equal terms regardless from whom the power is purchased. The Finnish national grid is owned by one company Finnish Power Grid PLC (Fingrid). The major shareholders of Fingrid are the state of Finland, two major power companies and institutional investors. In addition there are about 100 local distribution utilities operating the local 110 kV, 20 kV and 0.4 kV networks. The distribution utilities are mostly owned by the municipalities and towns. In each network one energy supplier is always responsible for the hourly energy balance in the network (a `host`) and it also has the obligation to provide public energy prices accessible to any customer in the network`s area. The Finnish regulating authorities nominate such a supplier who has a dominant market share in the network`s area as the supplier responsible for the network`s energy balance. A regulating authority, called the Electricity Market Centre, ensures that the market is operating properly. The transmission prices and public energy prices are under the Electricity Market Centre`s control. For domestic and other small customers the cost of hourly metering (ca. 1000 US$) would be prohibitive and therefore the use of conventional energy metering and load models is under consideration by the authorities. Small customer trade with the load models (instead of the hourly energy recording) is scheduled to start in the first half of 1998. In this presentation, the problems of energy management from the standpoint of the energy trading and distributing companies in the new situation are first discussed. The topics covered are: the hourly load data management, the forecasting and estimation of hourly energy demands

Energy distributions of neutral species ejected from well-characterized surfaces measured by means of multiphoton resonance ionization spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, D.; Ishigami, R.; Dhole, S.D.; Morita, K. E-mail: k-morita@mail.nucl.nagoya-u.ac.jp

2000-04-01

The energy distributions of neutral atoms ejected from the polycrystalline Cu target, the Si(1 1 1)-7x7 surface, and the Si(1 1 1)-''5 x 5''-Cu surface by 5 keV Ar{sup +} ion bombardment have been measured with very high efficiency by means of the multi-photon resonance ionization spectroscopy, in order to obtain the surface binding energies. The energy distributions for Cu from polycrystalline Cu target, Si from the Si(1 1 1)-7x7 surface, and Cu from the Si(1 1 1)-''5 x 5''-Cu surface have been found to have a peak at energies of around 3.0, 5.0 and 1.5 eV, and the function shapes of high energy tails to be proportional to E{sup -1.9}, E{sup -1.2} and E{sup -1.3}, respectively. Based on the linear collision cascade theory, the surface binding energies are determined to be 5.7, 6.0 and 2.0 eV, and the power factor m in the power law approximation to the Thomas-Fermi potential are determined to be 0.1, 0.4 and 0.3 for Cu from the Cu polycrystalline, Si from the Si(1 1 1)-7x7 surface, and Cu from the Si(1 1 1)-''5 x 5''-Cu surface, respectively. In conclusion, the results indicate that the energy distributions of ejected particles are well characterized by the linear collision cascade theory developed by Sigmund.

Methods for Distributed Optimal Energy Management

DEFF Research Database (Denmark)

Brehm, Robert

The presented research deals with the fundamental underlying methods and concepts of how the growing number of distributed generation units based on renewable energy resources and distributed storage devices can be most efficiently integrated into the existing utility grid. In contrast to convent......The presented research deals with the fundamental underlying methods and concepts of how the growing number of distributed generation units based on renewable energy resources and distributed storage devices can be most efficiently integrated into the existing utility grid. In contrast...... to conventional centralised optimal energy flow management systems, here-in, focus is set on how optimal energy management can be achieved in a decentralised distributed architecture such as a multi-agent system. Distributed optimisation methods are introduced, targeting optimisation of energy flow in virtual......-consumption of renewable energy resources in low voltage grids. It can be shown that this method prevents mutual discharging of batteries and prevents peak loads, a supervisory control instance can dictate the level of autarchy from the utility grid. Further it is shown that the problem of optimal energy flow management...

Atom-solid binding energy shifts for K 2p and Rb 3d sublevels

International Nuclear Information System (INIS)

Holappa, M.; Aksela, S.; Patanen, M.; Urpelainen, S.; Aksela, H.

2011-01-01

Highlights: → Binding energy shifts between atom and solid. K 2p and Rb 3d sublevels were studied. → Simultaneous measurements give accurate results. → Results can be used as a reference for cluster studies. - Abstract: Binding energy shifts between free and solid state atoms for K 2p and Rb 3d photolines have been determined by measuring the vapor and solid state spectra simultaneously in similar experimental conditions applying synchrotron radiation excited photoelectron spectroscopy. This method has the important benefit that the work function is not needed to correct for different reference energy levels, therefore much more accurate values for binding energy shifts are obtained.

Autonomy-oriented mechanisms for efficient energy distribution

Energy Technology Data Exchange (ETDEWEB)

Liu, Jiming; Shi, Benyun

2010-09-15

Due to the uneven geographical availability of energy resources, it is essential for the energy suppliers and consumers in different countries/regions to most efficiently, economically, as well as reliably distribute energy resources. In this paper, starting from a specific energy distribution problem, we present a decentralized behavior-based paradigm that draws on the methodology of autonomy-oriented computing. The goal is twofold: (i) to characterize the underlying mechanism of the energy distribution systems, (ii) to provide scalable solutions for efficient energy distribution. We conjecture that efficient energy trading markets can emerge from appropriate behavior-based mechanisms, which can autonomously improve energy distribution efficiency.

Ion Binding Energies Determining Functional Transport of ClC Proteins

Science.gov (United States)

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

2014-06-01

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

Binding Energy, Vapor Pressure and Melting Point of Semiconductor Nanoparticles

International Nuclear Information System (INIS)

H. H. Farrell; C. D. Van Siclen

2007-01-01

Current models for the cohesive energy of nanoparticles generally predict a linear dependence on the inverse particle diameter for spherical clusters, or, equivalently, on the inverse of the cube root of the number of atoms in the cluster. Although this is generally true for metals, we find that for the group IV semiconductors, C, Si and Ge, this linear dependence does not hold. Instead, using first principles, density functional theory calculations to calculate the binding energy of these materials, we find a quadratic dependence on the inverse of the particle size. Similar results have also been obtained for the metallic group IV elements Sn and Pb. This is in direct contradiction to current assumptions. Further, as a consequence of this quadratic behavior, the vapor pressure of semiconductor nanoparticles rises more slowly with decreasing size than would be expected. In addition, the melting point of these nanoparticles will experience less suppression than experienced by metal nanoparticles with comparable bulk binding energies. This non-linearity also affects sintering or Ostwald ripening behavior of these nanoparticles as well as other physical properties that depend on the nanoparticle binding energy. The reason for this variation in size dependence involves the covalent nature of the bonding in semiconductors, and even in the 'poor' metals. Therefore, it is expected that this result will hold for compound semiconductors as well as the elemental semiconductors

Analysis of oxygen binding-energy variations for BaO on W

Science.gov (United States)

Haas, G. A.; Shih, A.; Mueller, D.; Thomas, R. E.

Interatomic Auger analyses have been made of different forms of BaO layers on W substrates. Variations in Auger spectroscopy energies of the Ba4dBa5pO2p interatomic Auger transition were found to be largely governed by the O2p binding energy of the BaO adsorbate. This was illustrated by comparing results of the Auger data values with values derived from O2p binding energies using ultraviolet photoelectron spectroscopy. Very good agreement was observed not only for the W substrate but also for the W substrate which showed two oxygen-induced electronics state. Variations in binding energy were noted for different states of BaO lattice formation and for different amounts of oxidation, ranging from the transition of Ba to BaO and continuing to the BaO 2 stoichiometry and beyond. Effects were also reported for adsorbate alignment and thermal activation (i.e., reduction) of the oxidized state. An empirical relationship was found suggesting that the more tightly bound the O2p states of the BaO adsorbate were, the lower its work function would be. This link between binding energy and work function was observed to be valid not only for cases of poisoning by oxidation, but held as well during reactivation by the subsequent reduction of the oxide. In addition, this relationship also appeared to predict the low work function obtained through the introduction of substances such as Sc to the BaO-W system. Possible qualitative reasons which might contribute to this are discussed in terms of enhanced dipole effects and shifts in band structure.

Energy Storage and Distributed Energy Generation Project, Final Project Report

Energy Technology Data Exchange (ETDEWEB)

Schwank, Johannes; Mader, Jerry; Chen, Xiaoyin; Mi, Chris; Linic, Suljo; Sastry, Ann Marie; Stefanopoulou, Anna; Thompson, Levi; Varde, Keshav

2008-03-31

This report serves as a Final Report under the “Energy Storage and Distribution Energy Generation Project” carried out by the Transportation Energy Center (TEC) at the University of Michigan (UM). An interdisciplinary research team has been working on fundamental and applied research on: -distributed power generation and microgrids, -power electronics, and -advanced energy storage. The long-term objective of the project was to provide a framework for identifying fundamental research solutions to technology challenges of transmission and distribution, with special emphasis on distributed power generation, energy storage, control methodologies, and power electronics for microgrids, and to develop enabling technologies for novel energy storage and harvesting concepts that can be simulated, tested, and scaled up to provide relief for both underserved and overstressed portions of the Nation’s grid. TEC’s research is closely associated with Sections 5.0 and 6.0 of the DOE "Five-year Program Plan for FY2008 to FY2012 for Electric Transmission and Distribution Programs, August 2006.”

Institutional distributed energy interconnection barriers

International Nuclear Information System (INIS)

Castelaz, S.A.

2002-01-01

This PowerPoint presentation provided an introduction to Encorp Inc., a leading provider of network technology and infrastructure management solutions for the distributed energy market. Encorp develops and markets software and hardware technology solutions for communications, control and networking of distributed energy. It is developing and implementing real-time, distributed energy-focused solutions for a wide variety of applications through new products and services which are technology neutral, and easily networked. Encorp controls more than 500 MW of distributed power with a total of 127 customers. This paper reviewed 3 barriers (regulatory, contractual/tariffs, and business practices) based on US experience. The challenge remaining is to determine if microgrids can be used effectively, and to determine the limitations of bi-directional power flows. The key issues regarding how end-users can share the costs and maximize on the benefits of distributed energy resources include: standby service charges, departing load charges, regulatory uncertainty, rate class degradation, lack of incentives for utility cost reduction, and lack of ability to create experimental tariffs. tabs., figs

Evaluation of two typical distributed energy systems

Science.gov (United States)

Han, Miaomiao; Tan, Xiu

2018-03-01

According to the two-natural gas distributed energy system driven by gas engine driven and gas turbine, in this paper, the first and second laws of thermodynamics are used to measure the distributed energy system from the two parties of “quantity” and “quality”. The calculation results show that the internal combustion engine driven distributed energy station has a higher energy efficiency, but the energy efficiency is low; the gas turbine driven distributed energy station energy efficiency is high, but the primary energy utilization rate is relatively low. When configuring the system, we should determine the applicable natural gas distributed energy system technology plan and unit configuration plan according to the actual load factors of the project and the actual factors such as the location, background and environmental requirements of the project. “quality” measure, the utilization of waste heat energy efficiency index is proposed.

Systematic studies of binding energy dependence of neutron-proton momentum correlation function

International Nuclear Information System (INIS)

Wei, Y B; Ma, Y G; Shen, W Q; Ma, G L; Wang, K; Cai, X Z; Zhong, C; Guo, W; Chen, J G; Fang, D Q; Tian, W D; Zhou, X F

2004-01-01

Hanbury Brown-Twiss (HBT) results of the neutron-proton correlation function have been systematically investigated for a series of nuclear reactions with light projectiles with the help of the isospin-dependent quantum molecular dynamics model. The relationship between the binding energy per nucleon of the projectiles and the strength of the neutron-proton HBT at small relative momentum has been obtained. Results show that neutron-proton HBT results are sensitive to the binding energy per nucleon

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

Science.gov (United States)

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

2018-05-01

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.

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

Science.gov (United States)

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

2018-05-01

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.

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

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.

Converging ligand‐binding free energies obtained with free‐energy perturbations at the quantum mechanical level

Science.gov (United States)

Olsson, Martin A.; Söderhjelm, Pär

2016-01-01

In this article, the convergence of quantum mechanical (QM) free‐energy simulations based on molecular dynamics simulations at the molecular mechanics (MM) level has been investigated. We have estimated relative free energies for the binding of nine cyclic carboxylate ligands to the octa‐acid deep‐cavity host, including the host, the ligand, and all water molecules within 4.5 Å of the ligand in the QM calculations (158–224 atoms). We use single‐step exponential averaging (ssEA) and the non‐Boltzmann Bennett acceptance ratio (NBB) methods to estimate QM/MM free energy with the semi‐empirical PM6‐DH2X method, both based on interaction energies. We show that ssEA with cumulant expansion gives a better convergence and uses half as many QM calculations as NBB, although the two methods give consistent results. With 720,000 QM calculations per transformation, QM/MM free‐energy estimates with a precision of 1 kJ/mol can be obtained for all eight relative energies with ssEA, showing that this approach can be used to calculate converged QM/MM binding free energies for realistic systems and large QM partitions. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:27117350

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

Cooper-pair size and binding energy for unconventional superconducting systems

Science.gov (United States)

Dinóla Neto, F.; Neto, Minos A.; Salmon, Octavio D. Rodriguez

2018-06-01

The main proposal of this paper is to analyze the size of the Cooper pairs composed by unbalanced mass fermions from different electronic bands along the BCS-BEC crossover and study the binding energy of the pairs. We are considering an interaction between fermions with different masses leading to an inter-band pairing. In addiction to the attractive interaction we have an hybridization term to couple both bands, which in general acts unfavorable for the pairing between the electrons. We get first order phase transitions as the hybridization breaks the Cooper pairs for the s-wave symmetry of the gap amplitude. The results show the dependence of the Cooper-pair size as a function of the hybridization for T = 0 . We also propose the structure of the binding energy of the inter-band system as a function of the two-bands quasi-particle energies.

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...... for well widths less than 8 nm. In the quantum wires an increase of 30% is found in the smallest quantum wire structures compared to the corresponding quantum well value. A simple analytical model taking into account the quantum confinement in these low-dimensional systems is used to explain...

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

Evaluation of binding energies by using quantum mechanical methods

International Nuclear Information System (INIS)

Postolache, Cristian; Matei, Lidia; Postolache, Carmen

2002-01-01

Evaluation of binding energies (BE) in molecular structure is needed for modelling chemical and radiochemical processes by quantum-chemical methods. An important field of application is evaluation of radiolysis and autoradiolysis stability of organic and inorganic compounds as well as macromolecular structures. The current methods of calculation do not allow direct determination of BE but only of total binding energies (TBE) and enthalpies. BEs were evaluated indirectly by determining the homolytic dissociation energies. The molecular structures were built and geometrically optimized by the molecular mechanics methods MM+ and AMBER. The energy minimizations were refined by semi-empirical methods. Depending on the chosen molecular structure, the CNDO, INDO, PM3 and AM1 methods were used. To reach a high confidence level the minimizations were done for gradients lower than 10 -3 RMS. The energy values obtained by the difference of the fragment TBLs, of the transition states and initial molecular structures, respectively, were associated to the hemolytic fragmentation energy and BE, respectively. In order to evaluate the method's accuracy and to establish the application fields of the evaluation methods, the obtained values of BEs were compared with the experimental data taken from literature. To this goal there were built, geometrically optimized by semi-empirical methods and evaluated the BEs for 74 organic and inorganic compounds (alkanes, alkene, alkynes, halogenated derivatives, alcohols, aldehydes, ketones, carboxylic acids, nitrogen and sulfur compounds, water, hydrogen peroxide, ammonia, hydrazine, etc. (authors)

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/.

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.

Effect of binding in cyclic phosphorylation-dephosphorylation process and in energy transformation.

Science.gov (United States)

Sarkar, A; Beard, D A; Franza, B R

2006-07-01

The effects of binding on the phosphorylation-dephosphorylation cycle (PDPC) - one of the key components of the signal transduction processes - is analyzed based on a mathematical model. The model shows that binding of proteins, forming a complex, diminishes the ultrasensitivity of the PDPC to the differences in activity between kinase and phosphatase in the cycle. It is also found that signal amplification depends upon the strength of the binding affinity of the protein (phosphorylated or dephosphorylated) to other proteins . It is also observed that the amplification of signal is not only dependent on phosphorylation potential but also on binding properties and resulting adjustments in binding energies.

Photoelectron spectroscopy on the charge reorganization energy and small polaron binding energy of molecular film

Energy Technology Data Exchange (ETDEWEB)

Kera, Satoshi, E-mail: kera@ims.ac.jp [Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan); Department of Nanomaterial Science, Graduate School of Advanced Integration Science, Chiba University, Inage-ku, Chiba 263-8522 (Japan); Ueno, Nobuo [Department of Nanomaterial Science, Graduate School of Advanced Integration Science, Chiba University, Inage-ku, Chiba 263-8522 (Japan)

2015-10-01

Understanding of electron-phonon coupling as well as intermolecular interaction is required to discuss the mobility of charge carrier in functional molecular solids. This article summarizes recent progress in direct measurements of valence hole-vibration coupling in ultrathin films of organic semiconductors by using ultraviolet photoelectron spectroscopy (UPS). The experimental study of hole-vibration coupling of the highest occupied molecular orbital (HOMO) state in ordered monolayer film by UPS is essential to comprehend hole-hopping transport and small-polaron related transport in organic semiconductors. Only careful measurements can attain the high-resolution spectra and provide key parameters in hole-transport dynamics, namely the charge reorganization energy and small polaron binding energy. Analyses methods of the UPS HOMO fine feature and resulting charge reorganization energy and small polaron binding energy are described for pentacene and perfluoropentacene films. Difference between thin-film and gas-phase results is discussed by using newly measured high-quality gas-phase spectra of pentacene. Methodology for achieving high-resolution UPS measurements for molecular films is also described.

In vitro membrane binding and protein binding (IAM MB/PB technology to estimate in vivo distribution: applications in early drug discovery

Directory of Open Access Journals (Sweden)

Klara Livia Valko

2017-03-01

Full Text Available The drug discovery process can be accelerated by chromatographic profiling of the analogs to model in vivo distribution and the major non-specific binding. A balanced potency and chromatographically determined membrane and protein binding (IAM MB/PB data enable selecting drug discovery compounds for further analysis that have the highest probability to show the desired in vivo distribution behavior for efficacy and reduced chance for toxicity. Although the basic principles of the technology have already appeared in numerous publications, the lack of standardized procedures limited its widespread applications especially in academia and small drug discovery biotech companies. In this paper, the standardized procedures are described that has been trademarked as Regis IAM MB/PB Technology®. Comparison between the Drug Efficiency Index (DEI=pIC50-logVdu+2 and generally used Ligand Lipophilicity Efficiency (LLE has been made, demonstrating the advantage of measured IAM and HSA binding over calculated log P. The power of the proposed chromatographic technology is demonstrated using the data of marketed drugs.

Research on the Orientation and Application of Distributed Energy Storage in Energy Internet

Science.gov (United States)

Zeng, Ming; Zhou, Pengcheng; Li, Ran; Zhou, Jingjing; Chen, Tao; Li, Zhe

2018-01-01

Energy storage is indispensable resources to achieve a high proportion of new energy power consumption in electric power system. As an important support to energy Internet, energy storage system can achieve a variety of energy integration operation to ensure maximum energy efficiency. In this paper, firstly, the SWOT analysis method is used to express the internal and external advantages and disadvantages of distributed energy storage participating in the energy Internet. Secondly, the function orientation of distributed energy storage in energy Internet is studied, based on which the application modes of distributed energy storage in virtual power plant, community energy storage and auxiliary services are deeply studied. Finally, this paper puts forward the development strategy of distributed energy storage which is suitable for the development of China’s energy Internet, and summarizes and prospects the application of distributed energy storage system.

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

Protection of Distribution Systems with Distributed Energy Resources

DEFF Research Database (Denmark)

Bak-Jensen, Birgitte; Browne, Matthew; Calone, Roberto

of 17 months of work of the Joint Working Group B5/C6.26/CIRED “Protection of Distribution Systems with Distributed Energy Resources”. The working group used the CIGRE report TB421 “The impact of Renewable Energy Sources and Distributed Generation on Substation Protection and Automation”, published...... by WG B5.34 as the entry document for the work on this report. In doing so, the group aligned the content and the scope of this report, the network structures considered, possible islanding, standardized communication and adaptive protection, interface protection, connection schemes and protection...... are listed (chapter 3). The first main part of the report starts with a summary of the backgrounds on DER and current practices in protection at the distribution level (chapter 4). This chapter contains an analysis of CIGRE TB421, protection relevant characteristics of DER, a review of current practices...

Polaron binding energy in polymers: poly[methyl(phenyl)silylene

Czech Academy of Sciences Publication Activity Database

Nožár, Juraj; Nešpůrek, Stanislav; Šebera, Jakub

2012-01-01

Roč. 18, č. 2 (2012), s. 623-629 ISSN 1610-2940 R&D Projects: GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40500505 Keywords : polaron * polaron binding energy * polysilane Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.984, year: 2012

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 ...

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 ...

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

Science.gov (United States)

Kalescky, Robert; Kraka, Elfi; Cremer, Dieter

2014-02-01

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

Electricity End Uses, Energy Efficiency, and Distributed Energy Resources Baseline

Energy Technology Data Exchange (ETDEWEB)

Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Morrow, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Deason, Jeff [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schiller, Steven R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leventis, Greg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Smith, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leow, Woei Ling [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levin, Todd [Argonne National Lab. (ANL), Argonne, IL (United States); Plotkin, Steven [Argonne National Lab. (ANL), Argonne, IL (United States); Zhou, Yan [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

2017-01-01

This report was developed by a team of analysts at Lawrence Berkeley National Laboratory, with Argonne National Laboratory contributing the transportation section, and is a DOE EPSA product and part of a series of “baseline” reports intended to inform the second installment of the Quadrennial Energy Review (QER 1.2). QER 1.2 provides a comprehensive review of the nation’s electricity system and cover the current state and key trends related to the electricity system, including generation, transmission, distribution, grid operations and planning, and end use. The baseline reports provide an overview of elements of the electricity system. This report focuses on end uses, electricity consumption, electric energy efficiency, distributed energy resources (DERs) (such as demand response, distributed generation, and distributed storage), and evaluation, measurement, and verification (EM&V) methods for energy efficiency and DERs.

Charge compensation and binding energy referencing in XPS analysis

International Nuclear Information System (INIS)

Metson, J.B.

1999-01-01

Full text: The past decade has seen a number of significant advances in the capabilities of commercial X-ray Photoelectron spectrometers. Of note have been the near universal adoption of monochromatised X-ray sources, very useful advances in spatial resolution, particularly in spectroscopy, and radical developments in sample handling and automation. However one of the most significant advances has been the development of several relatively new concepts in charge compensation. Throughout the evolution of XPS, the ability to compensate for surface charging and accurately determine binding energies, particularly with electrically inhomogenous samples, has remained one of the most intractable problems. Beginning perhaps with the Kratos, 'in the lens' electrostatic mirror/electron source coupled with a magnetic snorkel lens, a number of concepts have been advanced which take a quite different conceptual approach to charge compensation. They differ in a number of quite fundamental ways to the electron flood type compensators widely used and absolutely essential with instruments based on monochromatised sources. The concept of the local return of secondary electrons to their point of emission, largely negates the problems associated with differential charging across different regions of the surface, and suggests the possibility of overcoming one of the central limitations of XPS, that is the inability to compare absolute binding energies of species in different electrical as well as chemical environments. The general status of charge compensation and the use of internal binding energy references in XPS will be reviewed, along with some practical examples of where these techniques work, and where there is clearly still room for further development. Copyright (1999) Australian X-ray Analytical Association Inc

Energy efficiency optimization in distribution transformers considering Spanish distribution regulation policy

International Nuclear Information System (INIS)

Pezzini, Paola; Gomis-Bellmunt, Oriol; Frau-Valenti, Joan; Sudria-Andreu, Antoni

2010-01-01

In transmission and distribution systems, the high number of installed transformers, a loss source in networks, suggests a good potential for energy savings. This paper presents how the Spanish Distribution regulation policy, Royal Decree 222/2008, affects the overall energy efficiency in distribution transformers. The objective of a utility is the maximization of the benefit, and in case of failures, to install a chosen transformer in order to maximize the profit. Here, a novel method to optimize energy efficiency, considering the constraints set by the Spanish Distribution regulation policy, is presented; its aim is to achieve the objectives of the utility when installing new transformers. The overall energy efficiency increase is a clear result that can help in meeting the requirements of European environmental plans, such as the '20-20-20' action plan.

Energy Efficiency in Grocery Distribution in Denmark

DEFF Research Database (Denmark)

Jørgensen, Kaj

1997-01-01

Evaluation of the development of the energy efficiency of grocery distribution from 1960 to the present in Denmark, covering both the distribution to the shops and the shopping transport (distribution from shops to individual homes)......Evaluation of the development of the energy efficiency of grocery distribution from 1960 to the present in Denmark, covering both the distribution to the shops and the shopping transport (distribution from shops to individual homes)...

Distributed Wind Energy in Idaho

Energy Technology Data Exchange (ETDEWEB)

Gardner, John [Boise State Univ., ID (United States); Johnson, Kathryn [Colorado School of Mines, Golden, CO (United States); Haynes, Todd [Boise State Univ., ID (United States); Seifert, Gary [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2009-01-31

This project is a research and development program aimed at furthering distributed wind technology. In particular, this project addresses some of the barriers to distributed wind energy utilization in Idaho.

Energy efficiency optimization in distribution transformers considering Spanish distribution regulation policy

Energy Technology Data Exchange (ETDEWEB)

Pezzini, Paola [Centre d' Innovacio en Convertidors Estatics i Accionaments (CITCEA-UPC), E.T.S. Enginyeria Industrial Barcelona, Universitat Politecnica Catalunya, Diagonal, 647, Pl. 2, 08028 Barcelona (Spain); Gomis-Bellmunt, Oriol; Sudria-Andreu, Antoni [Centre d' Innovacio en Convertidors Estatics i Accionaments (CITCEA-UPC), E.T.S. Enginyeria Industrial Barcelona, Universitat Politecnica Catalunya, Diagonal, 647, Pl. 2, 08028 Barcelona (Spain); IREC Catalonia Institute for Energy Research, Josep Pla, B2, Pl. Baixa, 08019 Barcelona (Spain); Frau-Valenti, Joan [ENDESA, Carrer Joan Maragall, 16 07006 Palma (Spain)

2010-12-15

In transmission and distribution systems, the high number of installed transformers, a loss source in networks, suggests a good potential for energy savings. This paper presents how the Spanish Distribution regulation policy, Royal Decree 222/2008, affects the overall energy efficiency in distribution transformers. The objective of a utility is the maximization of the benefit, and in case of failures, to install a chosen transformer in order to maximize the profit. Here, a novel method to optimize energy efficiency, considering the constraints set by the Spanish Distribution regulation policy, is presented; its aim is to achieve the objectives of the utility when installing new transformers. The overall energy efficiency increase is a clear result that can help in meeting the requirements of European environmental plans, such as the '20-20-20' action plan. (author)

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…

Making the most of distributed energy

International Nuclear Information System (INIS)

Malkamaeki, M.

2004-01-01

Distributed energy production is on the threshold of a new area, and offers a growing number of options for meeting energy needs that cannot be met effectively by larger, base load-type infrastructure. Distributed energy generation can offer a more cost- effective approach, depending on things such as location, load requirements, and fuel availability. It can also make it possible to generate energy at times when grid power is not available or is likely to be overloaded, and in locations not covered by an existing grid net-work. Perhaps most interesting from a technological point of view is the fact that distributed power opens up the opportunity to use fuels that have not been utilised up until now, for a variety of reasons

Gas-Fired Distributed Energy Resource Technology Characterizations

Energy Technology Data Exchange (ETDEWEB)

Goldstein, L.; Hedman, B.; Knowles, D.; Freedman, S. I.; Woods, R.; Schweizer, T.

2003-11-01

The U. S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) is directing substantial programs in the development and encouragement of new energy technologies. Among them are renewable energy and distributed energy resource technologies. As part of its ongoing effort to document the status and potential of these technologies, DOE EERE directed the National Renewable Energy Laboratory to lead an effort to develop and publish Distributed Energy Technology Characterizations (TCs) that would provide both the department and energy community with a consistent and objective set of cost and performance data in prospective electric-power generation applications in the United States. Toward that goal, DOE/EERE - joined by the Electric Power Research Institute (EPRI) - published the Renewable Energy Technology Characterizations in December 1997.As a follow-up, DOE EERE - joined by the Gas Research Institute - is now publishing this document, Gas-Fired Distributed Energy Resource Technology Characterizations.

Molecular dynamics simulations and free energy calculations of netropsin and distamycin binding to an AAAAA DNA binding site

Science.gov (United States)

Dolenc, Jožica; Oostenbrink, Chris; Koller, Jože; van Gunsteren, Wilfred F.

2005-01-01

Molecular dynamics simulations have been performed on netropsin in two different charge states and on distamycin binding to the minor groove of the DNA duplex d(CGCGAAAAACGCG)·d(CGCGTTTTTCGCG). The relative free energy of binding of the two non-covalently interacting ligands was calculated using the thermodynamic integration method and reflects the experimental result. From 2 ns simulations of the ligands free in solution and when bound to DNA, the mobility and the hydrogen-bonding patterns of the ligands were studied, as well as their hydration. It is shown that even though distamycin is less hydrated than netropsin, the loss of ligand–solvent interactions is very similar for both ligands. The relative mobilities of the ligands in their bound and free forms indicate a larger entropic penalty for distamycin when binding to the minor groove compared with netropsin, partially explaining the lower binding affinity of the distamycin molecule. The detailed structural and energetic insights obtained from the molecular dynamics simulations allow for a better understanding of the factors determining ligand–DNA binding. PMID:15687382

Molecular dynamics simulations and free energy calculations of netropsin and distamycin binding to an AAAAA DNA binding site.

Science.gov (United States)

Dolenc, Jozica; Oostenbrink, Chris; Koller, Joze; van Gunsteren, Wilfred F

2005-01-01

Molecular dynamics simulations have been performed on netropsin in two different charge states and on distamycin binding to the minor groove of the DNA duplex d(CGCGAAAAACGCG).d(CGCGTTTTTCGCG). The relative free energy of binding of the two non-covalently interacting ligands was calculated using the thermodynamic integration method and reflects the experimental result. From 2 ns simulations of the ligands free in solution and when bound to DNA, the mobility and the hydrogen-bonding patterns of the ligands were studied, as well as their hydration. It is shown that even though distamycin is less hydrated than netropsin, the loss of ligand-solvent interactions is very similar for both ligands. The relative mobilities of the ligands in their bound and free forms indicate a larger entropic penalty for distamycin when binding to the minor groove compared with netropsin, partially explaining the lower binding affinity of the distamycin molecule. The detailed structural and energetic insights obtained from the molecular dynamics simulations allow for a better understanding of the factors determining ligand-DNA binding.

Modelling distributed energy resources in energy service networks

CERN Document Server

Acha, Salvador

2013-01-01

Focuses on modelling two key infrastructures (natural gas and electrical) in urban energy systems with embedded technologies (cogeneration and electric vehicles) to optimise the operation of natural gas and electrical infrastructures under the presence of distributed energy resources

Binding energies of double-Λ hypernuclei and ΛΛ G-matrix

International Nuclear Information System (INIS)

Himeno, Hiroyuki; Sakuda, Toshimi; Nagata, Sinobu; Yamamoto, Yasuo.

1993-01-01

Binding energies of double-Λ hypernuclei ΛΛ 10 Be, ΛΛ 13 B and ΛΛ 6 He are calculated on the basis of G-matrix theory in finite nuclei. The core + Λ + Λ three-body model is adopted and the G-matrix for ΛΛ interaction is treated consistently with the model space. As the bare interaction the Nijmegen model D and model F are used. It is discussed that the consistency of the interaction with the model space is very important to calculate reliably the binding energies. It is shown that if the new event of double-Λ hypernuclei is interpreted as ΛΛ 13 B, model D reproduces the experimental data very well, whereas model F does not. (author)

Hawai‘i Distributed Energy Resource Technologies for Energy Security

Energy Technology Data Exchange (ETDEWEB)

None, None

2012-09-30

HNEI has conducted research to address a number of issues important to move Hawai‘i to greater use of intermittent renewable and distributed energy resource (DER) technologies in order to facilitate greater use of Hawai‘i's indigenous renewable energy resources. Efforts have been concentrated on the Islands of Hawai‘i, Maui, and O‘ahu, focusing in three areas of endeavor: 1) Energy Modeling and Scenario Analysis (previously called Energy Road mapping); 2) Research, Development, and Validation of Renewable DER and Microgrid Technologies; and 3) Analysis and Policy. These efforts focused on analysis of the island energy systems and development of specific candidate technologies for future insertion into an integrated energy system, which would lead to a more robust transmission and distribution system in the state of Hawai‘i and eventually elsewhere in the nation.

Relative Binding Free Energy Calculations in Drug Discovery: Recent Advances and Practical Considerations.

Science.gov (United States)

Cournia, Zoe; Allen, Bryce; Sherman, Woody

2017-12-26

Accurate in silico prediction of protein-ligand binding affinities has been a primary objective of structure-based drug design for decades due to the putative value it would bring to the drug discovery process. However, computational methods have historically failed to deliver value in real-world drug discovery applications due to a variety of scientific, technical, and practical challenges. Recently, a family of approaches commonly referred to as relative binding free energy (RBFE) calculations, which rely on physics-based molecular simulations and statistical mechanics, have shown promise in reliably generating accurate predictions in the context of drug discovery projects. This advance arises from accumulating developments in the underlying scientific methods (decades of research on force fields and sampling algorithms) coupled with vast increases in computational resources (graphics processing units and cloud infrastructures). Mounting evidence from retrospective validation studies, blind challenge predictions, and prospective applications suggests that RBFE simulations can now predict the affinity differences for congeneric ligands with sufficient accuracy and throughput to deliver considerable value in hit-to-lead and lead optimization efforts. Here, we present an overview of current RBFE implementations, highlighting recent advances and remaining challenges, along with examples that emphasize practical considerations for obtaining reliable RBFE results. We focus specifically on relative binding free energies because the calculations are less computationally intensive than absolute binding free energy (ABFE) calculations and map directly onto the hit-to-lead and lead optimization processes, where the prediction of relative binding energies between a reference molecule and new ideas (virtual molecules) can be used to prioritize molecules for synthesis. We describe the critical aspects of running RBFE calculations, from both theoretical and applied perspectives

Binding Energy and Lifetime of Excitons in InxGa1-xAs/GaAs Quantum Wells

DEFF Research Database (Denmark)

Orani, D.; Polimeni, A.; Patane, A.

1997-01-01

We report a systematic study of exciton binding energies and lifetimes in InGaAs/GaAs quantum wells. The experimental binding energies have been deduced from photoluminescence excitation measurements taking into account the contribution of the 2s state of the exciton and the line broadening...

Notes for lectures in China: distribution of the oscillator strength over the entire range of excitation energy for atoms, molecules, and solids

International Nuclear Information System (INIS)

Inokuti, M.

1984-01-01

Consider the intensity of absorption of a photon (i.e., the photoabsorption cross section) as a function of photon energy E. Apart from some intensity related to pure nuclear motion and spins, the (electronic) absorption begins at several eV (i.e., in the visible region or the near ultraviolet region). It becomes stronger at tens of eV's (i.e., in the far ultraviolet), and gradually diminishes at higher E. However, the intensity enhances again as E becomes comparable to an inner-shell binding energy. This repeats throughout the x-ray region until E greatly exceeds the K-shell binding energy. I shall discuss the gross variation of the absorption intensity with E. This intensity, suitably normalized, is the oscillator-strength distribution df/dE

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.

Distributed Energy Planning for Climate Resilience

Energy Technology Data Exchange (ETDEWEB)

Stout, Sherry R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hotchkiss, Elizabeth L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Day, Megan H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lee, Nathan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Holm, Alison [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-05-01

At various levels of government across the United States and globally climate resilient solutions are being adopted and implemented. Solutions vary based on predicted hazards, community context, priorities, complexity, and available resources. Lessons are being learned through the implementation process, which can be replicated regardless of level or type of government entity carrying out the resiliency planning. Through a number of analyses and technical support across the world, NREL has learned key lessons related to resilience planning associated with power generation and water distribution. Distributed energy generation is a large factor in building resilience with clean energy technologies and solutions. The technical and policy solutions associated with distributed energy implementation for resilience fall into a few major categories, including spatial diversification, microgrids, water-energy nexus, policy, and redundancy.

Relativistic deformed mean-field calculation of binding energy differences of mirror nuclei

International Nuclear Information System (INIS)

Koepf, W.; Barreiro, L.A.

1996-01-01

Binding energy differences of mirror nuclei for A=15, 17, 27, 29, 31, 33, 39 and 41 are calculated in the framework of relativistic deformed mean-field theory. The spatial components of the vector meson fields and the photon are fully taken into account in a self-consistent manner. The calculated binding energy differences are systematically smaller than the experimental values and lend support to the existence of the Okamoto-Nolen-Schiffer anomaly found decades ago in nonrelativistic calculations. For the majority of the nuclei studied, however, the results are such that the anomaly is significantly smaller than the one obtained within state-of-the-art nonrelativistic calculations. (author). 35 refs

Distributed Energy Technology Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Distributed Energy Technologies Laboratory (DETL) is an extension of the power electronics testing capabilities of the Photovoltaic System Evaluation Laboratory...

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.

Non-abelian binding energies from the lightcone bootstrap

Energy Technology Data Exchange (ETDEWEB)

Li, Daliang [Department of Physics, Yale University,New Haven, CT 06511 (United States); Department of Physics and Astronomy, Johns Hopkins University,Baltimore, MD 21218 (United States); Meltzer, David [Department of Physics, Yale University,New Haven, CT 06511 (United States); Poland, David [Department of Physics, Yale University,New Haven, CT 06511 (United States); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States)

2016-02-23

We analytically study the lightcone limit of the conformal bootstrap for 4-point functions containing scalars charged under global symmetries. We show the existence of large spin double-twist operators in various representations of the global symmetry group. We then compute their anomalous dimensions in terms of the central charge C{sub T}, current central charge C{sub J}, and the OPE coefficients of low dimension scalars. In AdS, these results correspond to the binding energy of two-particle states arising from the exchange of gravitons, gauge bosons, and light scalar fields. Using unitarity and crossing symmetry, we show that gravity is universal and attractive among different types of two-particle states, while the gauge binding energy can have either sign as determined by the representation of the two-particle state, with universal ratios fixed by the symmetry group. We apply our results to 4D N=1 SQCD and the 3D O(N) vector models. We also show that in a unitary CFT, if the current central charge C{sub J} stays finite when the global symmetry group becomes infinitely large, such as the N→∞ limit of the O(N) vector model, then the theory must contain an infinite number of higher spin currents.

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.

Distributed energy store railguns experiment and analysis

International Nuclear Information System (INIS)

Holland, L.D.

1984-01-01

Electromagnetic acceleration of projectiles holds the potential for achieving higher velocities than yet achieved by any other means. A railgun is the simplest form of electromagnetic macroparticle accelerator and can generate the highest sustained accelerating force. The practical length of conventional railguns is limited by the impedance of the rails because current must be carried along the entire length of the rails. A railgun and power supply system called the distributed energy store railgun was proposed as a solution to this limitation. The distributed energy store railgun used multiple current sources connected to the rails of a railgun at points distributed along the bore. These current sources (energy stores) are turned on in sequence as the projectile moves down the bore so that current is fed to the railgun from behind the armature. In this system the length of the rails that carry the full armature current is less than the total length of the railgun. If a sufficient number of energy stores is used, this removes the limitation on the length of a railgun. An additional feature of distributed energy store type railguns is that they can be designed to maintain a constant pressure on the projectile being accelerated. A distributed energy store railgun was constructed and successfully operated. In addition to this first demonstration of the distributed energy store railgun principle, a theoretical model of the system was also constructed

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

Calculation of positron binding energies using the generalized any particle propagator theory

International Nuclear Information System (INIS)

Romero, Jonathan; Charry, Jorge A.; Flores-Moreno, Roberto; Varella, Márcio T. do N.; Reyes, Andrés

2014-01-01

We recently extended the electron propagator theory to any type of quantum species based in the framework of the Any-Particle Molecular Orbital (APMO) approach [J. Romero, E. Posada, R. Flores-Moreno, and A. Reyes, J. Chem. Phys. 137, 074105 (2012)]. The generalized any particle molecular orbital propagator theory (APMO/PT) was implemented in its quasiparticle second order version in the LOWDIN code and was applied to calculate nuclear quantum effects in electron binding energies and proton binding energies in molecular systems [M. Díaz-Tinoco, J. Romero, J. V. Ortiz, A. Reyes, and R. Flores-Moreno, J. Chem. Phys. 138, 194108 (2013)]. In this work, we present the derivation of third order quasiparticle APMO/PT methods and we apply them to calculate positron binding energies (PBEs) of atoms and molecules. We calculated the PBEs of anions and some diatomic molecules using the second order, third order, and renormalized third order quasiparticle APMO/PT approaches and compared our results with those previously calculated employing configuration interaction (CI), explicitly correlated and quantum Montecarlo methodologies. We found that renormalized APMO/PT methods can achieve accuracies of ∼0.35 eV for anionic systems, compared to Full-CI results, and provide a quantitative description of positron binding to anionic and highly polar species. Third order APMO/PT approaches display considerable potential to study positron binding to large molecules because of the fifth power scaling with respect to the number of basis sets. In this regard, we present additional PBE calculations of some small polar organic molecules, amino acids and DNA nucleobases. We complement our numerical assessment with formal and numerical analyses of the treatment of electron-positron correlation within the quasiparticle propagator approach

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.

Impact of domain knowledge on blinded predictions of binding energies by alchemical free energy calculations

Science.gov (United States)

Mey, Antonia S. J. S.; Jiménez, Jordi Juárez; Michel, Julien

2018-01-01

The Drug Design Data Resource (D3R) consortium organises blinded challenges to address the latest advances in computational methods for ligand pose prediction, affinity ranking, and free energy calculations. Within the context of the second D3R Grand Challenge several blinded binding free energies predictions were made for two congeneric series of Farsenoid X Receptor (FXR) inhibitors with a semi-automated alchemical free energy calculation workflow featuring FESetup and SOMD software tools. Reasonable performance was observed in retrospective analyses of literature datasets. Nevertheless, blinded predictions on the full D3R datasets were poor due to difficulties encountered with the ranking of compounds that vary in their net-charge. Performance increased for predictions that were restricted to subsets of compounds carrying the same net-charge. Disclosure of X-ray crystallography derived binding modes maintained or improved the correlation with experiment in a subsequent rounds of predictions. The best performing protocols on D3R set1 and set2 were comparable or superior to predictions made on the basis of analysis of literature structure activity relationships (SAR)s only, and comparable or slightly inferior, to the best submissions from other groups.

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.

Distribution and binding of [14C]acrylamide to macromolecules in SENCAR and BALB/c mice following oral and topical administration

International Nuclear Information System (INIS)

Carlson, G.P.; Weaver, P.M.

1985-01-01

To determine if differences in acrylamide distribution or its binding to DNA could be responsible for the reported higher incidence of skin papillomas observed after oral administration compared to topical application, [ 14 C]acrylamide was administered by topical application and oral intubation to male SENCAR and BALB/mice. Portions of lung, liver, stomach, testes, and skin were removed, and 14 C was measured at 15 min, 30 min, 1, 6, 12, 24, and 48 hr. Binding to DNA, RNA, and protein was measured at 6 and 48 hr. Following oral administration, few strain differences in distribution or binding were noted. After topical application, SENCAR mice generally showed higher tissue concentrations than did the BALB/c mice at the early time periods but not at the later ones. Comparing the two routes, comparable concentrations were observed in all tissues except the skin where the amount of [ 14 C]acrylamide after topical application was approximately 100 times that observed after oral administration. At 48 hr, binding to DNA was sevenfold higher after topical than after oral administration. The effect of route on papilloma formation cannot be explained, therefore, on the basis of either a difference in distribution or binding to DNA in the target organ. The binding of acrylamide to DNA in skin was similar in both SENCAR and BALB/c mice indicating that the much greater susceptibility of the SENCAR mice to tumorigenesis cannot be explained simply on the basis of distribution or macromolecular binding

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

Simple method for determining binding energies of fullerene and complex atomic negative ions

Science.gov (United States)

Felfli, Zineb; Msezane, Alfred

2017-04-01

A robust potential which embeds fully the vital core polarization interaction has been used in the Regge pole method to explore low-energy electron scattering from C60, Eu and Nb through the total cross sections (TCSs) calculations. From the characteristic dramatically sharp resonances in the TCSs manifesting negative ion formation in these systems, we extracted the binding energies for the C60, Euand Nbanions they are found to be in outstanding agreement with the measured electron affinities of C60, Eu and Nb. Common among these considered systems, including the standard atomic Au is the formation of their ground state negative ions at the second Ramsauer-Townsend (R-T) minima of their TCSs. Indeed, this is a signature of all the fullerenes and complex atoms considered thus far. Shape resonances, R-T minima and binding energies of the resultant anions are presented. This work was supported by U.S. DOE, Basic Energy Sciences, Office of Energy Research.

Interpretation of Ocular Melanin Drug Binding Assays. Alternatives to the Model of Multiple Classes of Independent Sites.

Science.gov (United States)

Manzanares, José A; Rimpelä, Anna-Kaisa; Urtti, Arto

2016-04-04

Melanin has a high binding affinity for a wide range of drugs. The determination of the melanin binding capacity and its binding affinity are important, e.g., in the determination of the ocular drug distribution, the prediction of drug effects in the eye, and the trans-scleral drug delivery. The binding parameters estimated from a given data set vary significantly when using different isotherms or different nonlinear fitting methods. In this work, the commonly used bi-Langmuir isotherm, which assumes two classes of independent sites, is confronted with the Sips isotherm. Direct, log-log, and Scatchard plots are used, and the interpretation of the binding curves in the latter is critically analyzed. In addition to the goodness of fit, the emphasis is placed on the physical meaning of the binding parameters. The bi-Langmuir model imposes a bimodal distribution of binding energies for the sites on the melanin granules, but the actual distribution is most likely continuous and unimodal, as assumed by the Sips isotherm. Hence, the latter describes more accurately the distribution of binding energies and also the experimental results of melanin binding to drugs and metal ions. Simulations are used to show that the existence of two classes of sites cannot be confirmed on the sole basis of the shape of the binding curve in the Scatchard plot, and that serious doubts may appear on the meaning of the binding parameters of the bi-Langmuir model. Experimental results of melanin binding to chloroquine and metoprolol are used to illustrate the importance of the choice of the binding isotherm and of the method used to evaluate the binding parameters.

Photoionization cross section and binding energy of single dopant in hollow cylindrical core/shell quantum dot

Science.gov (United States)

Feddi, E.; El-Yadri, M.; Dujardin, F.; Restrepo, R. L.; Duque, C. A.

2017-02-01

In this study, we have investigated the confined donor impurity in a hollow cylindrical-shell quantum dot. The charges are assumed to be completely confined to the interior of the shell with rigid walls. Within the framework of the effective-mass approximation and by using a simple variational approach, we have computed the donor binding energy as a function of the shell sizes in order to study the behavior of the electron-impurity attraction for a very small thickness. Our results show that the binding energy of a donor impurity placed at the center of cylindrical core/shell dots depends strongly on the shell size. The binding energy increases when the shell-wideness becomes smaller and shows the same behavior as in a simple cylindrical quantum dot. A special case has been studied, which corresponds to the ratio between the inner and outer radii near to one (a/b → 1) for which our model gives a non-significant behavior of the impurity binding energy. This fact implies the existence of a critical value (a/b) for which the binding energy of the donor impurity tends to the limit value of 4 effective Rydbergs as in a 2D quantum well. We also analyse the photoionization cross section considering only the in-plane incident radiation polarization. We determine its behavior as a function of photon energy, shell size, and donor position. The measurement of photoionization in such systems would be of great interest to understand the optical properties of carriers in quantum dots.

Free energies of binding from large-scale first-principles quantum mechanical calculations: application to ligand hydration energies.

Science.gov (United States)

Fox, Stephen J; Pittock, Chris; Tautermann, Christofer S; Fox, Thomas; Christ, Clara; Malcolm, N O J; Essex, Jonathan W; Skylaris, Chris-Kriton

2013-08-15

Schemes of increasing sophistication for obtaining free energies of binding have been developed over the years, where configurational sampling is used to include the all-important entropic contributions to the free energies. However, the quality of the results will also depend on the accuracy with which the intermolecular interactions are computed at each molecular configuration. In this context, the energy change associated with the rearrangement of electrons (electronic polarization and charge transfer) upon binding is a very important effect. Classical molecular mechanics force fields do not take this effect into account explicitly, and polarizable force fields and semiempirical quantum or hybrid quantum-classical (QM/MM) calculations are increasingly employed (at higher computational cost) to compute intermolecular interactions in free-energy schemes. In this work, we investigate the use of large-scale quantum mechanical calculations from first-principles as a way of fully taking into account electronic effects in free-energy calculations. We employ a one-step free-energy perturbation (FEP) scheme from a molecular mechanical (MM) potential to a quantum mechanical (QM) potential as a correction to thermodynamic integration calculations within the MM potential. We use this approach to calculate relative free energies of hydration of small aromatic molecules. Our quantum calculations are performed on multiple configurations from classical molecular dynamics simulations. The quantum energy of each configuration is obtained from density functional theory calculations with a near-complete psinc basis set on over 600 atoms using the ONETEP program.

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.

The influence of drug distribution and drug-target binding on target occupancy : The rate-limiting step approximation

NARCIS (Netherlands)

Witte, de W.E.A.; Vauquelin, G.; Graaf, van der P.H.; Lange, de E.C.M.

2017-01-01

The influence of drug-target binding kinetics on target occupancy can be influenced by drug distribution and diffusion around the target, often referred to as "rebinding" or "diffusion-limited binding". This gives rise to a decreased decline of the drug-target complex concentration as a result of a

Hydrostatic pressure and conduction band non-parabolicity effects on the impurity binding energy in a spherical quantum dot

International Nuclear Information System (INIS)

Sivakami, A.; Mahendran, M.

2010-01-01

The binding energy of a shallow hydrogenic impurity in a spherical quantum dot under hydrostatic pressure with square well potential is calculated using a variational approach within the effective mass approximation. The effect of conduction band non-parabolicity on these energies is also estimated. The binding energy is computed for GaAs spherical quantum dot as a function of dot size, hydrostatic pressure both in the presence and absence of the band non-parabolicity effect. Our results show that (i) the hydrostatic pressure increases the impurity binding energy when dot radius increases for a given pressure, (ii) the hydrostatic pressure with the band non-parabolicity effect effectively increases the binding energy such that the variation is large for smaller dots and (iii) the maximum contribution by the non-parabolicity effect is about 15% for narrow dots. Our results are in good agreement with Perez-Merchancano et al. [J. Phys. Condens. Matter 19 (2007) 026225] who have not considered the conduction band non-parabolicity effect.

Interaction Entropy: A New Paradigm for Highly Efficient and Reliable Computation of Protein-Ligand Binding Free Energy.

Science.gov (United States)

Duan, Lili; Liu, Xiao; Zhang, John Z H

2016-05-04

Efficient and reliable calculation of protein-ligand binding free energy is a grand challenge in computational biology and is of critical importance in drug design and many other molecular recognition problems. The main challenge lies in the calculation of entropic contribution to protein-ligand binding or interaction systems. In this report, we present a new interaction entropy method which is theoretically rigorous, computationally efficient, and numerically reliable for calculating entropic contribution to free energy in protein-ligand binding and other interaction processes. Drastically different from the widely employed but extremely expensive normal mode method for calculating entropy change in protein-ligand binding, the new method calculates the entropic component (interaction entropy or -TΔS) of the binding free energy directly from molecular dynamics simulation without any extra computational cost. Extensive study of over a dozen randomly selected protein-ligand binding systems demonstrated that this interaction entropy method is both computationally efficient and numerically reliable and is vastly superior to the standard normal mode approach. This interaction entropy paradigm introduces a novel and intuitive conceptual understanding of the entropic effect in protein-ligand binding and other general interaction systems as well as a practical method for highly efficient calculation of this effect.

Semiphenomenological studies of the ground state binding energies of hypernuclei

International Nuclear Information System (INIS)

Mian, M.

1987-01-01

We show that the binding energies of /sub Λ/ 5 He and p-shell hypernuclei can be satisfactorily explained in the folding model approach using a density dependent effective ΛN interaction. Our analysis predicts a very reasonable value of the range of the ΛN interaction. The calculated value of B/sub Λ/ of /sub Λ/ 7 Li using the cluster model density for 6 Li and the best fit parameters of this potential supports the view that 6 Li possesses an α-d cluster structure. Using this potential we also determine the average size parameter (a 0 ) of the oscillator shell model density of nucleons in Nnot =Z core nuclei from fitting the B/sub Λ/ values of the corresponding hypernuclei. The effect of different forms of density distribution of core nuclei on the values of potential parameters is investigated and is found to be very small. As regards the form of density dependence, a rho/sup 2/3/ form is found to be the most appropriate for this purpose and is used throughout this work. Other forms do not give a satisfactory account of the data

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.

Determination analysis of energy conservation standards for distribution transformers

Energy Technology Data Exchange (ETDEWEB)

Barnes, P.R.; Van Dyke, J.W.; McConnell, B.W.; Das, S.

1996-07-01

This report contains information for US DOE to use in making a determination on proposing energy conservation standards for distribution transformers as required by the Energy Policy Act of 1992. Potential for saving energy with more efficient liquid-immersed and dry-type distribution transformers could be significant because these transformers account for an estimated 140 billion kWh of the annual energy lost in the delivery of electricity. Objective was to determine whether energy conservation standards for distribution transformers would have the potential for significant energy savings, be technically feasible, and be economically justified from a national perspective. It was found that energy conservation for distribution transformers would be technically and economically feasible. Based on the energy conservation options analyzed, 3.6-13.7 quads of energy could be saved from 2000 to 2030.

Thermal Distribution System | Energy Systems Integration Facility | NREL

Science.gov (United States)

Thermal Distribution System Thermal Distribution System The Energy Systems Integration Facility's . Photo of the roof of the Energy Systems Integration Facility. The thermal distribution bus allows low as 10% of its full load level). The 60-ton chiller cools water with continuous thermal control

Hydrostatic pressure and temperature effects on the binding energy and optical absorption of a multilayered quantum dot with a parabolic confinement

International Nuclear Information System (INIS)

Ortakaya, Sami; Kirak, Muharrem

2016-01-01

The influence of hydrostatic pressure, temperature, and impurity on the electronic and optical properties of spherical core/shell/well/shell (CSWS) nanostructure with parabolic confinement potential is investigated theoretically. The energy levels and wave functions of the structure are calculated by using shooting method within the effective-mass approximation. The numerical results show that the ground state donor binding energy as a function layer thickness very sensitively depends on the magnitude of pressure and temperature. Also, we investigate the probability distributions to understand clearly electronic properties. The obtained results show that the existence of the pressure and temperature has great influence on the electronic and optical properties. (paper)

77 FR 10997 - Energy Conservation Program: Energy Conservation Standards for Distribution Transformers; Correction

Science.gov (United States)

2012-02-24

... Conservation Program: Energy Conservation Standards for Distribution Transformers; Correction AGENCY: Office of... standards for distribution transformers. It was recently discovered that values in certain tables of the...,'' including distribution transformers. The Energy Policy Act of 1992 (EPACT 1992), Public Law 102-486, amended...

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

Cost allocation model for distribution networks considering high penetration of distributed energy resources

DEFF Research Database (Denmark)

Soares, Tiago; Pereira, Fábio; Morais, Hugo

2015-01-01

The high penetration of distributed energy resources (DER) in distribution networks and the competitive environment of electricity markets impose the use of new approaches in several domains. The network cost allocation, traditionally used in transmission networks, should be adapted and used...... in the distribution networks considering the specifications of the connected resources. The main goal is to develop a fairer methodology trying to distribute the distribution network use costs to all players which are using the network in each period. In this paper, a model considering different type of costs (fixed......, losses, and congestion costs) is proposed comprising the use of a large set of DER, namely distributed generation (DG), demand response (DR) of direct load control type, energy storage systems (ESS), and electric vehicles with capability of discharging energy to the network, which is known as vehicle...

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

Electro-optic measurement of terahertz pulse energy distribution

NARCIS (Netherlands)

Sun, J.H.; Gallacher, J.G.; Brussaard, G.J.H.; Lemos, N.; Issac, R.; Huang, Z.X.; Dias, J.M.; Jaroszynski, D.A.

2009-01-01

An accurate and direct measurement of the energy distribution of a low repetition rate terahertz electromagnetic pulse is challenging because of the lack of sensitive detectors in this spectral range. In this paper, we show how the total energy and energy density distribution of a terahertz

Small Distributed Renewable Energy Generation for Low Voltage Distribution Networks

Directory of Open Access Journals (Sweden)

Chindris M.

2016-08-01

Full Text Available Driven by the existing energy policies, the use of renewable energy has increased considerably all over the world in order to respond to the increasing energy consumption and to reduce the environmental impact of the electricity generation. Although most policy makers and companies are focusing on large applications, the use of cheap small generation units, based on local renewable resources, has become increasingly attractive for the general public, small farms and remote communities. The paper presents several results of a research project aiming to identify the power quality issues and the impact of RES based distributed generation (DG or other non-linear loads on low voltage (LV distribution networks in Romania; the final goal is to develop a Universal Power Quality Conditioner (UPQC able to diminish the existing disturbances. Basically, the work analyses the existing DG technologies and identifies possible solutions for their integration in Romania; taking into account the existent state of the art, the attention was paid on small systems, using wind and solar energy, and on possibility to integrate them into suburban and rural LV distribution networks. The presence of DG units at distribution voltage level means the transition from traditional passive to active distribution networks. In general, the relatively low penetration levels of DG does not produce problems; however, the nowadays massive increase of local power generation have led to new integration challenges in order to ensure the reliability and quality of the power supply. Power quality issues are identified and their assessment is the key element in the design of measures aiming to diminish all existing disturbances.

Distribution of basic fibroblast growth factor binding sites in various tissue membrane preparations from adult guinea pig

International Nuclear Information System (INIS)

Ledoux, D.; Mereau, A.; Dauchel, M.C.; Barritault, D.; Courty, J.

1989-01-01

In order to localize a rich source of basic FGF receptor, we examined the distribution of basic FGF binding sites in brain, stomach, lung, spleen, kidney, liver and intestine membrane preparations from adult guinea pig. Comparative binding studies using iodinated basic FGF showed that a specific binding was detected in all the membrane preparations tested. Scatchard plots from iodinated basic FGF competition experiment with native basic FGF in various membrane preparations, suggested the presence of one class of binding sites in some tissues such as liver, kidney, spleen, lung, stomach, and intestine with an apparent dissociation constant (appKD) value ranging from 4 to 7.5 nM and the existence of a second class of higher affinity sites in brain membranes with appKD value of 15 pM. Characterization of these basic FGF high affinity interaction sites was performed using a cross-linking reagent. These results show for the first time that specific interaction sites for basic FGF are widely distributed, suggesting that this growth factor might play a role in the physiological functions of a number of adult organs

Structure-based prediction of free energy changes of binding of PTP1B inhibitors

Science.gov (United States)

Wang, Jing; Ling Chan, Shek; Ramnarayan, Kal

2003-08-01

The goals were (1) to understand the driving forces in the binding of small molecule inhibitors to the active site of PTP1B and (2) to develop a molecular mechanics-based empirical free energy function for compound potency prediction. A set of compounds with known activities was docked onto the active site. The related energy components and molecular surface areas were calculated. The bridging water molecules were identified and their contributions were considered. Linear relationships were explored between the above terms and the binding free energies of compounds derived based on experimental inhibition constants. We found that minimally three terms are required to give rise to a good correlation (0.86) with predictive power in five-group cross-validation test (q2 = 0.70). The dominant terms are the electrostatic energy and non-electrostatic energy stemming from the intra- and intermolecular interactions of solutes and from those of bridging water molecules in complexes.

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.

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.

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}-...

Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

Energy Technology Data Exchange (ETDEWEB)

Cheng, Xiaofei [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036 (China); Deng, Ping; Cui, Hongguang [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); Wang, Aiming, E-mail: aiming.wang@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada)

2015-11-15

Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

International Nuclear Information System (INIS)

Cheng, Xiaofei; Deng, Ping; Cui, Hongguang; Wang, Aiming

2015-01-01

Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

Binding energies and chemical shifts of least bound core electron excitations in cubic Asub(N)Bsub(8-N) semiconductors

International Nuclear Information System (INIS)

Bechstedt, F.; Enderlein, R.; Wischnewski, R.

1981-01-01

Core electron binding energies Esup(B) with respect to the vacuum level and their chemical shifts are calculated for the least bound core levels of cations and anions of cubic Asub(N)Bsub(8-N) semiconductors. Starting from the HF-binding energy of the free atom absolute values of Esup(B) are obtained by adding core level shifts and relaxation energies. Core level shifts are calculated by means of an electrostatic model with ionic and bond charges according to Phillips' bond charge model. For the calculation of relaxation energies the linear dielectric theory of electronic polarization is applied. Valence and core electrons, and diagonal and non-diagonal screening are taken into account. The theoretical results for chemical shifts of binding energies are compared with experimental values from XPS-measurements corrected by work function data. Good agreement is obtained in all cases within the error limit of about one eV. Chemical and atomic trends of core level shifts, relaxation energies, and binding energies are discussed in terms of changes of atomic and solid state parameters. Chemical shifts and relaxation energies are predicted for various ternary Asub(N)Bsub(8-N) compounds. (author)

Solute-vacancy binding in aluminum

International Nuclear Information System (INIS)

Wolverton, C.

2007-01-01

Previous efforts to understand solute-vacancy binding in aluminum alloys have been hampered by a scarcity of reliable, quantitative experimental measurements. Here, we report a large database of solute-vacancy binding energies determined from first-principles density functional calculations. The calculated binding energies agree well with accurate measurements where available, and provide an accurate predictor of solute-vacancy binding in other systems. We find: (i) some common solutes in commercial Al alloys (e.g., Cu and Mg) possess either very weak (Cu), or even repulsive (Mg), binding energies. Hence, we assert that some previously reported large binding energies for these solutes are erroneous. (ii) Large binding energies are found for Sn, Cd and In, confirming the proposed mechanism for the reduced natural aging in Al-Cu alloys containing microalloying additions of these solutes. (iii) In addition, we predict that similar reduction in natural aging should occur with additions of Si, Ge and Au. (iv) Even larger binding energies are found for other solutes (e.g., Pb, Bi, Sr, Ba), but these solutes possess essentially no solubility in Al. (v) We have explored the physical effects controlling solute-vacancy binding in Al. We find that there is a strong correlation between binding energy and solute size, with larger solute atoms possessing a stronger binding with vacancies. (vi) Most transition-metal 3d solutes do not bind strongly with vacancies, and some are even energetically strongly repelled from vacancies, particularly for the early 3d solutes, Ti and V

Distributed Wireless Power Transfer With Energy Feedback

Science.gov (United States)

Lee, Seunghyun; Zhang, Rui

2017-04-01

Energy beamforming (EB) is a key technique for achieving efficient radio-frequency (RF) transmission enabled wireless energy transfer (WET). By optimally designing the waveforms from multiple energy transmitters (ETs) over the wireless channels, they can be constructively combined at the energy receiver (ER) to achieve an EB gain that scales with the number of ETs. However, the optimal design of EB waveforms requires accurate channel state information (CSI) at the ETs, which is challenging to obtain practically, especially in a distributed system with ETs at separate locations. In this paper, we study practical and efficient channel training methods to achieve optimal EB in a distributed WET system. We propose two protocols with and without centralized coordination, respectively, where distributed ETs either sequentially or in parallel adapt their transmit phases based on a low-complexity energy feedback from the ER. The energy feedback only depends on the received power level at the ER, where each feedback indicates one particular transmit phase that results in the maximum harvested power over a set of previously used phases. Simulation results show that the two proposed training protocols converge very fast in practical WET systems even with a large number of distributed ETs, while the protocol with sequential ET phase adaptation is also analytically shown to converge to the optimal EB design with perfect CSI by increasing the training time. Numerical results are also provided to evaluate the performance of the proposed distributed EB and training designs as compared to other benchmark schemes.

Tailored ion energy distributions on plasma electrodes

International Nuclear Information System (INIS)

Economou, Demetre J.

2013-01-01

As microelectronic device features continue to shrink approaching atomic dimensions, control of the ion energy distribution on the substrate during plasma etching and deposition becomes increasingly critical. The ion energy should be high enough to drive ion-assisted etching, but not too high to cause substrate damage or loss of selectivity. In many cases, a nearly monoenergetic ion energy distribution (IED) is desired to achieve highly selective etching. In this work, the author briefly reviews: (1) the fundamentals of development of the ion energy distribution in the sheath and (2) methods to control the IED on plasma electrodes. Such methods include the application of “tailored” voltage waveforms on an electrode in continuous wave plasmas, or the application of synchronous bias on a “boundary electrode” during a specified time window in the afterglow of pulsed plasmas

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

Distributed optimal coordination for distributed energy resources in power systems

DEFF Research Database (Denmark)

Wu, Di; Yang, Tao; Stoorvogel, A.

2017-01-01

Driven by smart grid technologies, distributed energy resources (DERs) have been rapidly developing in recent years for improving reliability and efficiency of distribution systems. Emerging DERs require effective and efficient coordination in order to reap their potential benefits. In this paper......, we consider an optimal DER coordination problem over multiple time periods subject to constraints at both system and device levels. Fully distributed algorithms are proposed to dynamically and automatically coordinate distributed generators with multiple/single storages. With the proposed algorithms...

Distributed Energy Resource (DER) Cybersecurity Standards

Energy Technology Data Exchange (ETDEWEB)

Saleem, Danish [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnson, Jay [Sandia National Laboratories

2017-11-08

This presentation covers the work that Sandia National Laboratories and National Renewable Energy Laboratory are doing for distributed energy resource cybersecurity standards, prepared for NREL's Annual Cybersecurity & Resilience Workshop on October 9-10, 2017.

Subcellular distribution of calcium-binding proteins and a calcium-ATPase in canine pancreas

International Nuclear Information System (INIS)

Nigam, S.K.; Towers, T.

1990-01-01

Using a 45Ca blot-overlay assay, we monitored the subcellular fractionation pattern of several Ca binding proteins of apparent molecular masses 94, 61, and 59 kD. These proteins also appeared to stain blue with Stains-All. Additionally, using a monoclonal antiserum raised against canine cardiac sarcoplasmic reticulum Ca-ATPase, we examined the subcellular distribution of a canine pancreatic 110-kD protein recognized by this antiserum. This protein had the same electrophoretic mobility as the cardiac protein against which the antiserum was raised. The three Ca binding proteins and the Ca-ATPase cofractionated into the rough microsomal fraction (RM), previously shown to consist of highly purified RER, in a pattern highly similar to that of the RER marker, ribophorin I. To provide further evidence for an RER localization, native RM were subjected to isopycnic flotation in sucrose gradients. The Ca binding proteins and the Ca-ATPase were found in dense fractions, along with ribophorin I. When RM were stripped of ribosomes with puromycin/high salt, the Ca binding proteins and the Ca-ATPase exhibited a shift to less dense fractions, as did ribophorin I. We conclude that, in pancreas, the Ca binding proteins and Ca-ATPase we detect are localized to the RER (conceivably a subcompartment of the RER) or, possibly, a structure intimately associated with the RER

External electric field effect on the binding energy of a hydrogenic donor impurity in InGaAsP/InP concentric double quantum rings

Science.gov (United States)

Hu, Min; Wang, Hailong; Gong, Qian; Wang, Shumin

2018-04-01

Within the framework of effective-mass envelope-function theory, the ground state binding energy of a hydrogenic donor impurity is calculated in the InGaAsP/InP concentric double quantum rings (CDQRs) using the plane wave method. The effects of geometry, impurity position, external electric field and alloy composition on binding energy are considered. It is shown that the peak value of the binding energy appears in two rings with large gap as the donor impurity moves along the radial direction. The binding energy reaches the peak value at the center of ring height when the donor impurity moves along the axial direction. The binding energy shows nonlinear variation with the increase of ring height. With the external electric field applied along the z-axis, the binding energy of the donor impurity located at zi ≥ 0 decreases while that located at zi < 0 increases. In addition, the binding energy decreases with increasing Ga composition, but increases with the increasing As composition.

(+)- and (-)-N-allylnormetazocine binding sites in mouse brain: in vitro and in vivo characterization and regional distribution

International Nuclear Information System (INIS)

Compton, D.R.; Bagley, R.B.; Katzen, J.S.; Martin, B.R.

1987-01-01

In vivo and in vitro binding studies, both in whole brain and in selected areas, indicate that non-identical (+)- and (-)-NANM sites exist in the mouse brain, and each exhibits a different regional distribution. The in vivo binding of (+)- 3 H-NANM was found to be saturable at pharmacologically relevant doses, and represents a relatively small (10 - 22%) portion of total brain (+)- 3 H-NANM concentrations. The in vivo binding of (+)- 3 H-NANM was selectively displaced by (+)-NANM and PCP, and more sensitive to haloperidol and (+)-ketocyclazocine than the (-)- 3 H-NANM site. The in vivo binding of (-)- 3 H-NANM was selectively displaced by (-)-NANM, and more sensitive to naloxone and (-) ketocyclazocine than the (+)- 3 H-NANM site, and insensitive to PCP. This study indicates that the investigation of NANM binding sites is possible using in vivo binding techniques, and that each isomer apparently binds, in the mouse brain, to a single class of distinct sites. 32 references, 4 figures, 2 tables

Orbital momentum profiles and binding energy spectra for the complete valence shell of molecular fluorine

Energy Technology Data Exchange (ETDEWEB)

Zheng, Y.; Brion, C.E. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemistry; Brunger, M.J.; Zhao, K.; Grisogono, A.M.; Braidwood, S.; Weigold, E. [Flinders Univ. of South Australia, Adelaide, SA (Australia). Electronic Structure of Materials Centre; Chakravorty, S.J.; Davidson, E.R. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry; Sgamellotti, A. [Univ di Perugia (Italy). Dipartimento di Chimica; von Niessen, W. [Technische Univ. Braunschweig (Germany). Inst fuer Physikalische

1996-01-01

The first electronic structural study of the complete valence shell binding energy spectrum of molecular fluorine, encompassing both the outer and inner valence regions, is reported. These binding energy spectra as well as the individual orbital momentum profiles have been measured using an energy dispersive multichannel electron momentum spectrometer at a total energy of 1500 eV, with an energy resolution of 1.5 eV and a momentum resolution of 0.1 a.u. The measured binding energy spectra in the energy range of 14-60 eV are compared with the results of ADC(4) many-body Green`s function and also direct-Configuration Interaction (CI) and MRSD-CI calculations. The experimental orbital electron momentum profiles are compared with SCF theoretical profiles calculated using the target Hartree-Fock approximation with a range of basis sets and with Density Functional Theory predictions in the target Kohn-Sham approximation with non-local potentials. The truncated (aug-cc-pv5z) Dunning basis sets were used for the Density Functional Theory calculations which also include some treatment of correlation via the exchange and correlation potentials. Comparisons are also made with the full ion-neutral overlap amplitude calculated with MRSD-CI wave functions. Large, saturated basis sets (199-GTO) were employed for both the high level SCF near Hartree-Fock limit and MRSD-CI calculations to investigate the effects of electron correlation and relaxation. 66 refs., 9 tabs., 9 figs.

Orbital momentum profiles and binding energy spectra for the complete valence shell of molecular fluorine

International Nuclear Information System (INIS)

Zheng, Y.; Brion, C.E.; Brunger, M.J.; Zhao, K.; Grisogono, A.M.; Braidwood, S.; Weigold, E.; Chakravorty, S.J.; Davidson, E.R.; Sgamellotti, A.; von Niessen, W.

1996-01-01

The first electronic structural study of the complete valence shell binding energy spectrum of molecular fluorine, encompassing both the outer and inner valence regions, is reported. These binding energy spectra as well as the individual orbital momentum profiles have been measured using an energy dispersive multichannel electron momentum spectrometer at a total energy of 1500 eV, with an energy resolution of 1.5 eV and a momentum resolution of 0.1 a.u. The measured binding energy spectra in the energy range of 14-60 eV are compared with the results of ADC(4) many-body Green's function and also direct-Configuration Interaction (CI) and MRSD-CI calculations. The experimental orbital electron momentum profiles are compared with SCF theoretical profiles calculated using the target Hartree-Fock approximation with a range of basis sets and with Density Functional Theory predictions in the target Kohn-Sham approximation with non-local potentials. The truncated (aug-cc-pv5z) Dunning basis sets were used for the Density Functional Theory calculations which also include some treatment of correlation via the exchange and correlation potentials. Comparisons are also made with the full ion-neutral overlap amplitude calculated with MRSD-CI wave functions. Large, saturated basis sets (199-GTO) were employed for both the high level SCF near Hartree-Fock limit and MRSD-CI calculations to investigate the effects of electron correlation and relaxation. 66 refs., 9 tabs., 9 figs

Measuring Intermolecular Binding Energies by Laser Spectroscopy.

Science.gov (United States)

Knochenmuss, Richard; Maity, Surajit; Féraud, Géraldine; Leutwyler, Samuel

2017-02-22

The ground-state dissociation energy, D0(S0), of isolated intermolecular complexes in the gas phase is a fundamental measure of the interaction strength between the molecules. We have developed a three-laser, triply resonant pump-dump-probe technique to measure dissociation energies of jet-cooled M•S complexes, where M is an aromatic chromophore and S is a closed-shell 'solvent' molecule. Stimulated emission pumping (SEP) via the S0→S1 electronic transition is used to precisely 'warm' the complex by populating high vibrational levels v" of the S0 state. If the deposited energy E(v") is less than D0(S0), the complex remains intact, and is then mass- and isomer-selectively detected by resonant two-photon ionization (R2PI) with a third (probe) laser. If the pumped level is above D0(S0), the hot complex dissociates and the probe signal disappears. Combining the fluorescence or SEP spectrum of the cold complex with the SEP breakoff of the hot complex brackets D0(S0). The UV chromophores 1-naphthol and carbazole were employed; these bind either dispersively via the aromatic rings, or form a hydrogen bond via the -OH or -NH group. Dissociation energies have been measured for dispersively bound complexes with noble gases (Ne, Kr, Ar, Xe), diatomics (N2, CO), alkanes (methane to n-butane), cycloalkanes (cyclopropane to cycloheptane), and unsaturated compounds (ethene, benzene). Hydrogen-bond dissociation energies have been measured for H2O, D2O, methanol, ethanol, ethers (oxirane, oxetane), NH3 and ND3.

Distributed Energy Resources Test Facility

Data.gov (United States)

Federal Laboratory Consortium — NREL's Distributed Energy Resources Test Facility (DERTF) is a working laboratory for interconnection and systems integration testing. This state-of-the-art facility...

Energy conservation in electric distribution

International Nuclear Information System (INIS)

Lee, Chong-Jin.

1994-01-01

This paper discusses the potential for energy and power savings that exist in electric power delivery systems. These savings translate into significant financial and environmental benefits for electricity producers and consumers as well as for society in general. AlliedSignal's knowledge and perspectives on this topic are the result of discussions with hundreds of utility executives, government officials and other industry experts over the past decade in conjunction with marketing our Amorphous Metal technology for electric distribution transformers. Amorphous metal is a technology developed by AlliedSignal that significantly reduces the energy lost in electric distribution transformers at an incremental cost of just a few cents per kilo-Watt-hour. The purpose of this paper is to discuss: Amorphous Metal Alloy Technology; Energy Savings Opportunity; The Industrial Barriers and Remedies; Worldwide Demand; and A Low Risk Strategy. I wish this presentation will help KEPCO achieve their stated aims of ensuring sound development of the national economy and enhancement of public life through the economic and stable supply of electric power. AlliedSignal Korea Ltd. in conjunction with AlliedSignal Amorphous Metals in the U.S. are here to work with KEPCO, transformer manufacturers, industry, and government agencies to achieve greater efficiency in power distribution

Distributed energy store railgun

International Nuclear Information System (INIS)

Marshall, R.A.

1991-01-01

This paper reports that when the limiting case of a distributed energy store railgun is analyzed, i.e., the case where the space between adjacent energy stores become indefinitely small, three important results are obtained. First, the shape of the current pulse delivered by each store is sinusoidal and an exponential tail. Second, the rail-to-rail voltage behind the rear-most active store approaches zero. Third, it is not possible to choose parameters in such a way that capacitor crowbars can be eliminated

Capacity of Distribution Feeders for Hosting Distributed Energy Resources

DEFF Research Database (Denmark)

Papathanassiou, S.; Hatziargyriou, N.; Anagnostopoulos, P.

The last two decades have seen an unprecedented development of distributed energy resources (DER) all over the world. Several countries have adopted a variety of support schemes (feed-in tariffs, green certificates, direct subsidies, tax exemptions etc.) so as to promote distributed generation (DG...... standards of the networks. To address this need in a timely and effective manner, simplified methodologies and practical rules of thumbs are often applied to assess the DER hosting capacity of existing distribution networks, avoiding thus detailed and time consuming analytical studies. The scope...

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.

Distribution in rat tissues of modulator-binding protein of particulate nature

International Nuclear Information System (INIS)

Sobue, K.; Muramoto, Y.; Kakiuchi, S.; Yamazaki, R.

1979-01-01

Studies on Ca 2+ -activatable cyclic nucleotide phosphodiesterase led to the discovery of a protein modulator that is required for the activation of this enzyme by Ca 2+ . Later, this protein has been shown to cause the Ca 2+ -dependent activation of several enzymes that include phosphodiesterase, adenylate cyclase, a protein kinase from muscles, phosphorylase b kinase, actomyosin ATPase, membranous ATPase from erythrocytes and nerve synapses. Thus, modulator protein appears to be an intracellular mediator of actions of Ca 2+ . The present work shows the distribution of this particulate modulator-binding component in rat tissues. This paper also describes the labeling of modulator protein with tritium without deteriorating its biological activities and application of this 3 H-modulator protein to the determination of the Ca ++ dependent binding of modulator protein with membranous protein. This technique proves to be useful in studying enzymes or proteins whose functions are regulated by Ca ++ /modulator protein system. (Auth.)

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

Hydrogenic-Donor Impurity Binding Energy Dependence of the Electric Field in GaAs/AlxGa1−xAs Quantum Rings

Directory of Open Access Journals (Sweden)

Guangxin Wang

2013-01-01

Full Text Available Using a variational method with two-parameter trial wave function and the effective mass approximation, the binding energy of a donor impurity in GaAs/AlxGa1−xAs cylindrical quantum ring (QR subjected to an external field is calculated. It is shown that the donor impurity binding energy is highly dependent on the QR structure parameters (radial thickness and height, impurity position, and external electric field. The binding energy increases inchmeal as the QR parameters (radial thickness and height decrease until a maximum value for a central impurity and then begins to drop quickly. The applied electric field can significantly modify the spread of electronic wave function in the QR and shift electronic wave function from the donor position and then leads to binding energy changes. In addition, results for the binding energies of a hydrogenic donor impurity as functions of the impurity position and applied electric field are also presented.

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.

Binding energy and dephasing of biexcitons in In0.18Ga0.82As/GaAs single quantum wells

DEFF Research Database (Denmark)

Borri, Paola; Langbein, Wolfgang Werner; Hvam, Jørn Märcher

1999-01-01

Biexciton binding energies and biexciton dephasing in In0.18Ga0.82As/GaAs single quantum wells have been measured by time-integrated and spectrally resolved four-wave mixing. The biexciton binding energy increases from 1.5 to 2.6 meV for well widths increasing from 1 to 4 nm. The ratio between...... exciton and biexciton binding energy changes from 0.23 to 0.3 with increasing inhomogeneous broadening, corresponding to increasing well width. From the temperature dependence of the exciton and biexciton four-wave mixing signal decay, we have deduced the acoustic-phonon scattering of the exciton...

Fast Reliability Assessing Method for Distribution Network with Distributed Renewable Energy Generation

Science.gov (United States)

Chen, Fan; Huang, Shaoxiong; Ding, Jinjin; Ding, Jinjin; Gao, Bo; Xie, Yuguang; Wang, Xiaoming

2018-01-01

This paper proposes a fast reliability assessing method for distribution grid with distributed renewable energy generation. First, the Weibull distribution and the Beta distribution are used to describe the probability distribution characteristics of wind speed and solar irradiance respectively, and the models of wind farm, solar park and local load are built for reliability assessment. Then based on power system production cost simulation probability discretization and linearization power flow, a optimal power flow objected with minimum cost of conventional power generation is to be resolved. Thus a reliability assessment for distribution grid is implemented fast and accurately. The Loss Of Load Probability (LOLP) and Expected Energy Not Supplied (EENS) are selected as the reliability index, a simulation for IEEE RBTS BUS6 system in MATLAB indicates that the fast reliability assessing method calculates the reliability index much faster with the accuracy ensured when compared with Monte Carlo method.

Enhanced distributed energy resource system

Science.gov (United States)

Atcitty, Stanley [Albuquerque, NM; Clark, Nancy H [Corrales, NM; Boyes, John D [Albuquerque, NM; Ranade, Satishkumar J [Las Cruces, NM

2007-07-03

A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

Energy Policy Case Study - California: Renewables and Distributed Energy Resources

Energy Technology Data Exchange (ETDEWEB)

Homer, Juliet S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bender, Sadie R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-09-19

The purpose of this document is to present a case study of energy policies in California related to power system transformation and renewable and distributed energy resources (DERs). Distributed energy resources represent a broad range of technologies that can significantly impact how much, and when, electricity is demanded from the grid. Key policies and proceedings related to power system transformation and DERs are grouped into the following categories: 1.Policies that support achieving environmental and climate goals 2.Policies that promote deployment of DERs 3.Policies that support reliability and integration of DERs 4.Policies that promote market animation and support customer choice. Major challenges going forward are forecasting and modeling DERs, regulatory and utility business model issues, reliability, valuation and pricing, and data management and sharing.

Reactive Power from Distributed Energy

Energy Technology Data Exchange (ETDEWEB)

Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

2006-12-15

Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

Reactive Power from Distributed Energy

International Nuclear Information System (INIS)

Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

2006-01-01

Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

Practical scaling law for photoelectron angular distributions

International Nuclear Information System (INIS)

Guo Dongsheng; Zhang Jingtao; Xu Zhizhan; Li Xiaofeng; Fu Panming; Freeman, R.R.

2003-01-01

A practical scaling law that predicts photoelectron angular distributions (PADs) is derived using angular distribution formulas which explicitly contain spontaneous emission. The scaling law is used to analyze recent PAD measurements in above-threshold ionization, and to predict results of future experiments. Our theoretical and numerical studies show that, in the non-relativistic regime and long-wavelength approximation, the shapes of PADs are determined by only three dimensionless numbers: (1) u p ≡U p /(ℎ/2π)ω, the ponderomotive number (ponderomotive energy in units of laser photon energy); (2) ε b ≡E b /(ℎ/2π)ω, the binding number (atomic binding energy in units of the laser photon energy); (3) j, the absorbed-photon number. The scaling law is shown to be useful in predictions of results from strong-field Kapitza-Dirac effect measurements; specifically, the application of this scaling law to recently reported Kapitza-Dirac diffraction is discussed. Possible experimental tests to verify the scaling law are suggested

Taxonomy for Evaluation of Distributed Control Strategies for Distributed Energy Resources

DEFF Research Database (Denmark)

Han, Xue; Heussen, Kai; Gehrke, Oliver

2017-01-01

Distributed control strategies applied to power distribution control problems are meant to offer robust and scalable integration of distributed energy resources (DER). However, the term “distributed control” is often loosely applied to a variety of very different control strategies. In particular....... For such comparison, a classification is required that is consistent across the different aspects mentioned above. This paper develops systematic categories of control strategies that accounts for communication, control and physical distribution aspects of the problem, and provides a set of criteria that can...

Estimation of photon energy distribution in gamma calibration field

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Shimizu, Shigeru; Yamaguchi, Yasuhiro

1997-03-01

Photon survey instruments used for radiation protection are usually calibrated at gamma radiation fields, which are traceable to the national standard with regard to exposure. Whereas scattered radiations as well as primary gamma-rays exit in the calibration field, no consideration for the effect of the scattered radiations on energy distribution is given in routine calibration works. The scattered radiations can change photon energy spectra in the field, and this can result in misinterpretations of energy-dependent instrument responses. Construction materials in the field affect the energy distribution and magnitude of the scattered radiations. The geometric relationship between a gamma source and an instrument can determine the energy distribution at the calibration point. Therefore, it is essential for the assurance of quality calibration to estimate the energy spectra at the gamma calibration fields. Then, photon energy distributions at some fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (JAERI) were estimated by measurements using a NaI(Tl) detector and Monte Carlo calculations. It was found that the use of collimator gives a different feature in photon energy distribution. The origin of scattered radiations and the ratio of the scattered radiations to the primary gamma-rays were obtained. The results can help to improve the calibration of photon survey instruments in the JAERI. (author)

Contribution of charge symmetry breaking interactions in binding energy difference of mirror nuclei

International Nuclear Information System (INIS)

Asghari, M.

2006-01-01

Nolen-Schiffer Anomaly in mirror nuclei due to the NN interactions with isospin mixing between T=0 and T=1 mesons of the same spin and parity are investigated. With the computation of coulomb energy along with the charge symmetry breaking effects provide a reasonably accurate description of binding energy differences between 39 Ca- 39 K , 41 Sc- 41 Ca mirror nuclei

Synthesis of 4,4-ditritio-(+)-nicotine: comparative binding and distribution studies with natural enantiomer

Energy Technology Data Exchange (ETDEWEB)

Vincek, W.C.; Martin, B.R.; Aceto, M.D.; Tripathi, H.L.; May, E.L.; Harris, L.S.

1981-11-01

The preparation of 4,4-ditritio-(+)-nicotine (Vb) (specific activity 10.3 Ci/mmole)from (+)-nicotine (Ib) via (-) 4,4-dibromocotinine (IIIb) is described. Although Ib is 10-30 times less potent than (-)-nicotine (Ia) in the CNS, its binding affinity for the crude mitochondrial or nuclear fraction of whole rat brain is only three times less than that of Ia. However, distribution studies showed that the maximum brain levels of (-)-(3H) nicotine are nearly twice those of (+)-(3H)-nicotine following administration of a 2-micrograms/kg dose. Binding affinity and disposition of the stereoisomers account for a portion of the pharmacological stereospecificity of nicotine.

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.

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

Multiple protonation equilibria in electrostatics of protein-protein binding.

Science.gov (United States)

Piłat, Zofia; Antosiewicz, Jan M

2008-11-27

All proteins contain groups capable of exchanging protons with their environment. We present here an approach, based on a rigorous thermodynamic cycle and the partition functions for energy levels characterizing protonation states of the associating proteins and their complex, to compute the electrostatic pH-dependent contribution to the free energy of protein-protein binding. The computed electrostatic binding free energies include the pH of the solution as the variable of state, mutual "polarization" of associating proteins reflected as changes in the distribution of their protonation states upon binding and fluctuations between available protonation states. The only fixed property of both proteins is the conformation; the structure of the monomers is kept in the same conformation as they have in the complex structure. As a reference, we use the electrostatic binding free energies obtained from the traditional Poisson-Boltzmann model, computed for a single macromolecular conformation fixed in a given protonation state, appropriate for given solution conditions. The new approach was tested for 12 protein-protein complexes. It is shown that explicit inclusion of protonation degrees of freedom might lead to a substantially different estimation of the electrostatic contribution to the binding free energy than that based on the traditional Poisson-Boltzmann model. This has important implications for the balancing of different contributions to the energetics of protein-protein binding and other related problems, for example, the choice of protein models for Brownian dynamics simulations of their association. Our procedure can be generalized to include conformational degrees of freedom by combining it with molecular dynamics simulations at constant pH. Unfortunately, in practice, a prohibitive factor is an enormous requirement for computer time and power. However, there may be some hope for solving this problem by combining existing constant pH molecular dynamics

Smart Distribution Boxes, Complete Energy Management

Energy Technology Data Exchange (ETDEWEB)

Platise, Uros

2010-09-15

Present households demand side management implementations are turning conventional appliances into smart ones to support auto demand (AutoDR) response function. Present concept features a direct link between the power meters and appliances. In this paper new concept and example of implementation of a so-called Smart Distribution Box (SmartDB) is represented for complete energy and power management. SmartDBs, as an intermediate layer, are extending smart grid power meter functionality to support AutoDR with fast and guaranteed response times, distributed power sources, and besides provide full control over energy management and extra safety functions to the consumers.

Theoretical investigation of stark effect on shallow donor binding energy in InGaN spherical QD-QW

International Nuclear Information System (INIS)

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

2013-01-01

In this paper, a simultaneous study of electric field and impurity's position effects on the ground-state shallow-donor binding energy in GaN|InGaN|GaN spherical quantum dot-quantum well (SQD-QW) as a function of the ratio of the inner and the outer radius is reported. The calculations are investigated using variational approach within the framework of the effective-mass approximation. The numerical results show that: (i) the binding energy is strongly affected by the external electric field and the SQD-QW dimension, (ii) a critical value of spherical system's radius is obtained constituting the limit of three dimension confinement and spherical thin layer confinement and (iii) the Stark shift increases with increasing electric field and it is more pronounced around the position of the impurity corresponding to the binding energy maxima than in the spherical layer extremities

Beta 1- and beta 2-adrenergic 125I-pindolol binding sites in the interpeduncular nucleus of the rat: Normal distribution and the effects of deafferentation

International Nuclear Information System (INIS)

Battisti, W.P.; Artymyshyn, R.P.; Murray, M.

1989-01-01

The plasticity of the beta 1- and beta 2-adrenergic receptor subtypes was examined in the interpeduncular nucleus (IPN) of the adult rat. The beta-adrenergic receptor antagonist 125I-pindolol (125I-PIN) was used in conjunction with the selective subtype antagonists ICI 118,551 and ICI 89,406 to determine the subnuclear distribution of beta 1- and beta 2-adrenergic receptors in this nucleus and to correlate the receptor distribution with the distribution of both noradrenergic afferents from the locus coeruleus (LC) and non-noradrenergic afferents from the fasiculus retroflexus (FR). The density of these binding sites was examined following lesions that decreased (LC lesions) or increased (FR lesions) the density of the noradrenergic projection in the IPN. Quantitative radioautography indicated that beta 1-labeled binding sites account for the larger percentage of binding sites in the IPN. The beta 1-binding sites are densest in those subnuclei that receive a noradrenergic projection from the LC: the central, rostral, and intermediate subnuclei. beta 1-binding sites are algo homogeneously distributed throughout the lateral subnuclei, where there is no detectable noradrenergic innervation. beta 2-binding sites have a more restricted distribution. They are concentrated in the ventral half of the lateral subnuclei, where they account for 70% of total 125I-PIN binding sites. beta 2-binding sites are also present along the ventral border of the IPN. Some of this labeling extends into the central and intermediate subnuclei. Bilateral lesions of the LC, which selectively remove noradrenergic innervation to the IPN, result in an increase in the beta 1-binding sites. Bilateral lesions of the FR, which remove the major cholinergic and peptidergic input from the IPN, elicit an increase in noradrenergic projections and a decrease in beta 1-binding sites

Probability distributions in conservative energy exchange models of multiple interacting agents

International Nuclear Information System (INIS)

Scafetta, Nicola; West, Bruce J

2007-01-01

Herein we study energy exchange models of multiple interacting agents that conserve energy in each interaction. The models differ regarding the rules that regulate the energy exchange and boundary effects. We find a variety of stochastic behaviours that manifest energy equilibrium probability distributions of different types and interaction rules that yield not only the exponential distributions such as the familiar Maxwell-Boltzmann-Gibbs distribution of an elastically colliding ideal particle gas, but also uniform distributions, truncated exponential distributions, Gaussian distributions, Gamma distributions, inverse power law distributions, mixed exponential and inverse power law distributions, and evolving distributions. This wide variety of distributions should be of value in determining the underlying mechanisms generating the statistical properties of complex phenomena including those to be found in complex chemical reactions

Evaluating Maximum Wind Energy Exploitation in Active Distribution Networks

DEFF Research Database (Denmark)

Siano, Pierluigi; Chen, Peiyuan; Chen, Zhe

2010-01-01

The increased spreading of distributed and renewable generation requires moving towards active management of distribution networks. In this paper, in order to evaluate maximum wind energy exploitation in active distribution networks, a method based on a multi-period optimal power flow (OPF......) analysis is proposed. Active network management schemes such as coordinated voltage control, energy curtailment and power factor control are integrated in the method in order to investigate their impacts on the maximization of wind energy exploitation. Some case studies, using real data from a Danish...... distribution system, confirmed the effectiveness of the proposed method in evaluating the optimal applications of active management schemes to increase wind energy harvesting without costly network reinforcement for the connection of wind generation....

Photoelectron angular distribution parameters for elements Z=55 to Z=100 in the photoelectron energy range 100-5000 eV

CERN Document Server

Trzhaskovskaya, M B; Yarzhemsky, V G

2002-01-01

Presented here are parameters of the angular distribution of photoelectrons along with the subshell photoionization cross sections for all atoms with 55<=Z<=100 and for atomic shells with binding energies lower than 2000 eV. The parameters are given for nine photoelectron energies in the range 100-5000 eV. Relativistic calculations have been carried out within the quadrupole approximation by the use of the central Dirac-Fock-Slater potential. The effect of the hole resulting in the atomic subshell after photoionization has been taken into account in the framework of the frozen orbital approximation.

Assessment of energy supply and continuity of service in distribution network with renewable distributed generation

International Nuclear Information System (INIS)

Abdullah, M.A.; Agalgaonkar, A.P.; Muttaqi, K.M.

2014-01-01

Highlights: • Difficulties in assessing distribution network adequacy with DG are addressed. • Indices are proposed to assess adequacy of energy supply and service continuity. • Analytical methodology is developed to assess the proposed indices. • Concept of joint probability distribution of demand and generation is applied. - Abstract: Continuity of electricity supply with renewable distributed generation (DG) is a topical issue for distribution system planning and operation, especially due to the stochastic nature of power generation and time varying load demand. The conventional adequacy and reliability analysis methods related to bulk generation systems cannot be applied directly for the evaluation of adequacy criteria such as ‘energy supply’ and ‘continuity of service’ for distribution networks embedded with renewable DG. In this paper, new indices highlighting ‘available supply capacity’ and ‘continuity of service’ are proposed for ‘energy supply’ and ‘continuation of service’ evaluation of generation-rich distribution networks, and analytical techniques are developed for their quantification. A probability based analytical method has been developed using the joint probability of the demand and generation, and probability distributions of the proposed indices have been used to evaluate the network adequacy in energy supply and service continuation. A data clustering technique has been used to evaluate the joint probability between coincidental demand and renewable generation. Time sequential Monte Carlo simulation has been used to compare the results obtained using the proposed analytical method. A standard distribution network derived from Roy Billinton test system and a practical radial distribution network have been used to test the proposed method and demonstrate the estimation of the well-being of a system for hosting renewable DG units. It is found that renewable DG systems improve the ‘energy supply’ and �

Aftershock Energy Distribution by Statistical Mechanics Approach

Science.gov (United States)

Daminelli, R.; Marcellini, A.

2015-12-01

The aim of our work is to research the most probable distribution of the energy of aftershocks. We started by applying one of the fundamental principles of statistical mechanics that, in case of aftershock sequences, it could be expressed as: the greater the number of different ways in which the energy of aftershocks can be arranged among the energy cells in phase space the more probable the distribution. We assume that each cell in phase space has the same possibility to be occupied, and that more than one cell in the phase space can have the same energy. Seeing that seismic energy is proportional to products of different parameters, a number of different combinations of parameters can produce different energies (e.g., different combination of stress drop and fault area can release the same seismic energy). Let us assume that there are gi cells in the aftershock phase space characterised by the same energy released ɛi. Therefore we can assume that the Maxwell-Boltzmann statistics can be applied to aftershock sequences with the proviso that the judgment on the validity of this hypothesis is the agreement with the data. The aftershock energy distribution can therefore be written as follow: n(ɛ)=Ag(ɛ)exp(-βɛ)where n(ɛ) is the number of aftershocks with energy, ɛ, A and β are constants. Considering the above hypothesis, we can assume g(ɛ) is proportional to ɛ. We selected and analysed different aftershock sequences (data extracted from Earthquake Catalogs of SCEC, of INGV-CNT and other institutions) with a minimum magnitude retained ML=2 (in some cases ML=2.6) and a time window of 35 days. The results of our model are in agreement with the data, except in the very low energy band, where our model resulted in a moderate overestimation.

Role of Electrostatics in Protein-RNA Binding: The Global vs the Local Energy Landscape.

Science.gov (United States)

Ghaemi, Zhaleh; Guzman, Irisbel; Gnutt, David; Luthey-Schulten, Zaida; Gruebele, Martin

2017-09-14

U1A protein-stem loop 2 RNA association is a basic step in the assembly of the spliceosomal U1 small nuclear ribonucleoprotein. Long-range electrostatic interactions due to the positive charge of U1A are thought to provide high binding affinity for the negatively charged RNA. Short range interactions, such as hydrogen bonds and contacts between RNA bases and protein side chains, favor a specific binding site. Here, we propose that electrostatic interactions are as important as local contacts in biasing the protein-RNA energy landscape toward a specific binding site. We show by using molecular dynamics simulations that deletion of two long-range electrostatic interactions (K22Q and K50Q) leads to mutant-specific alternative RNA bound states. One of these states preserves short-range interactions with aromatic residues in the original binding site, while the other one does not. We test the computational prediction with experimental temperature-jump kinetics using a tryptophan probe in the U1A-RNA binding site. The two mutants show the distinct predicted kinetic behaviors. Thus, the stem loop 2 RNA has multiple binding sites on a rough RNA-protein binding landscape. We speculate that the rough protein-RNA binding landscape, when biased to different local minima by electrostatics, could be one way that protein-RNA interactions evolve toward new binding sites and novel function.

Risø energy report 4. The future energy system - distributed production and use

DEFF Research Database (Denmark)

Larsen, Hans Hvidtfeldt; Sønderberg Petersen, Leif

2005-01-01

technologies or fuel cells. Furthermore the following developments are expected: -closer link between supply and end-use -closer link between the various energy carriers distributed through grids such aselectricity, heat, natural gas and maybe hydrogen in the future -increased energy trade across national...... and the distribution of energy through grids such as those used for natural gas, electricity, districtheating and hydrogen. The focus is on industrialised countries, but the report also deals with specific points relevant to developing countries, such as isolated energy systems. The transport sector is discussed only...

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...

Theoretical investigation of stark effect on shallow donor binding energy in InGaN spherical QD-QW

Energy Technology Data Exchange (ETDEWEB)

El Ghazi, Haddou, E-mail: hadghazi@gmail.com [Solid State Physics Laboratory, Faculty of Science, Dhar EL Mehrez, BP 1796 Fes-Atlas (Morocco); Mathématiques spéciales, CPGE Kénitra, Chakib Arsalane Street (Morocco); Jorio, Anouar; Zorkani, Izeddine [Solid State Physics Laboratory, Faculty of Science, Dhar EL Mehrez, BP 1796 Fes-Atlas (Morocco)

2013-08-01

In this paper, a simultaneous study of electric field and impurity's position effects on the ground-state shallow-donor binding energy in GaN|InGaN|GaN spherical quantum dot-quantum well (SQD-QW) as a function of the ratio of the inner and the outer radius is reported. The calculations are investigated using variational approach within the framework of the effective-mass approximation. The numerical results show that: (i) the binding energy is strongly affected by the external electric field and the SQD-QW dimension, (ii) a critical value of spherical system's radius is obtained constituting the limit of three dimension confinement and spherical thin layer confinement and (iii) the Stark shift increases with increasing electric field and it is more pronounced around the position of the impurity corresponding to the binding energy maxima than in the spherical layer extremities.

Energy Distribution and Economic Growth

DEFF Research Database (Denmark)

Dalgaard, Carl-Johan Lars; Strulik, Holger

2011-01-01

This research examines the physical constraints on the growth process. In order to run, maintain and build capital energy is required to be distributed to geographically dispersed sites where investments are deemed profitable. We capture this aspect of physical reality by a network theory....../2 and 3/4, depending on the efficiency of the network. Together with an energy conservation equation, capturing instantaneous aggregate demand for electricity, we are able to provide a metabolic-energetic founded law of motion for capital per capita that is mathematically isomorphic to the one emanating...... of electricity distribution. The model leads to a supply relation according to which feasible electricity consumption per capita rises with the size of the economy, as measured by capital per capita. Specifically, the relation is a simple power law with an exponent assigned to capital that is bounded between 1...

Evaluations of the electron energy distribution in multidipole plasmas

International Nuclear Information System (INIS)

Taylor, G.R.; Kessel, M.A.; Sealock, J.W.

1980-01-01

In a previous paper a preliminary evaluation of the electron energy distribution in multidipole plasmas was presented. A polynominal regression technique for evaluating the distribution function from Langmuir probe current-voltage characteristics was described. This paper presents an extension of that analysis and the evaluations of the electron energy distributions in multidipole argon and hydrogen plasmas

Simulation and energy analysis of distributed electric heating system

Science.gov (United States)

Yu, Bo; Han, Shenchao; Yang, Yanchun; Liu, Mingyuan

2018-02-01

Distributed electric heating system assistssolar heating systemby using air-source heat pump. Air-source heat pump as auxiliary heat sourcecan make up the defects of the conventional solar thermal system can provide a 24 - hour high - efficiency work. It has certain practical value and practical significance to reduce emissions and promote building energy efficiency. Using Polysun software the system is simulated and compared with ordinary electric boiler heating system. The simulation results show that upon energy request, 5844.5kW energy is saved and 3135kg carbon - dioxide emissions are reduced and5844.5 kWhfuel and energy consumption is decreased with distributed electric heating system. Theeffect of conserving energy and reducing emissions using distributed electric heating systemis very obvious.

Poor energy poor: Energy saving obligations, distributional effects, and the malfunction of the priority group

International Nuclear Information System (INIS)

Moser, Simon

2013-01-01

The European Union’s Energy Efficiency Directive forces the Member States to install energy efficiency obligation schemes. In a first step, this paper identifies the distributional effects caused by this policy instrument which occur when energy efficiency measures are implemented (phase of delivery) and when its costs are passed on to the society (phase of financing). In the phase of delivery, suppliers prefer to implement measures at the property of those customers which enable them to minimise their costs, i.e. enterprises with large energy savings potentials and high-income households who can contribute a greater share of the costs. In the phase of financing, distributional effects occur when the costs of the scheme are passed on from the obliged suppliers to their customers, primarily affecting less competitive customers, i.e. households and small enterprises. In the British scheme, the so-called priority group was installed in order to decrease distributional effects and to support energy poor households. In a second step, this paper evaluates approaches to reduce energy poverty and indicates ineffectiveness, high transaction costs and incoherency with the aims of the obligation scheme. Alternative approaches to tackle energy poverty are briefly described. - Highlights: • The paper discusses distributional effects of energy efficiency obligations. • Significant distributional effects occur when measures are implemented. • Significant distributional effects occur when costs are passed on to the customers. • Suppliers face problems to identify energy poor households. • The priority group contradicts the scheme’s intention of cost minimisation

The congruence energy: A contribution to nuclear masses and deformation energies

International Nuclear Information System (INIS)

Myers, W.D.; Swiatecki, W.J.

1995-06-01

The difference between measured binding energies and those calculated using a shell- and pairing-corrected Thomas-Fermi model can be described approximately by C(I) = -10exp(-4.2|I|) MeV. The authors' interpretation of this extra binding is in terms of the granularity of quantal nucleonic density distributions, which leads to a stronger interaction for a neutron and proton with congruent nodal structures of their wave functions. The predicted doubling of this congruence energy in fission is supported by an analysis of measured fission barriers and by a study of wave functions in a dividing Hill-Wheeler box potential. A semi-empirical formula for the shape-dependent congruence energy is described

Interconnection of Distributed Energy Resources

Energy Technology Data Exchange (ETDEWEB)

Reiter, Emerson [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-19

This is a presentation on interconnection of distributed energy resources, including the relationships between different aspects of interconnection, best practices and lessons learned from different areas of the U.S., and an update on technical advances and standards for interconnection.

Distributed continuous energy scheduling for dynamic virtual power plants

International Nuclear Information System (INIS)

Niesse, Astrid

2015-01-01

This thesis presents DynaSCOPE as distributed control method for continuous energy scheduling for dynamic virtual power plants (DVPP). DVPPs aggregate the flexibility of distributed energy units to address current energy markets. As an extension of the Virtual Power Plant concept they show high dynamics in aggregation and operation of energy units. Whereas operation schedules are set up for all energy units in a day-ahead planning procedure, incidents may render these schedules infeasible during execution, like deviation from prognoses or outages. Thus, a continuous scheduling process is needed to ensure product fulfillment. With DynaSCOPE, software agents representing single energy units solve this problem in a completely distributed heuristic approach. Using a stepped concept, several damping mechanisms are applied to allow minimum disturbance while continuously trying to fulfill the product as contracted at the market.

Energy and Reserve under Distributed Energy Resources Management—Day-Ahead, Hour-Ahead and Real-Time

Directory of Open Access Journals (Sweden)

Tiago Soares

2017-11-01

Full Text Available The increasing penetration of distributed energy resources based on renewable energy sources in distribution systems leads to a more complex management of power systems. Consequently, ancillary services become even more important to maintain the system security and reliability. This paper proposes and evaluates a generic model for day-ahead, intraday (hour-ahead and real-time scheduling, considering the joint optimization of energy and reserve in the scope of the virtual power player concept. The model aims to minimize the operation costs in the point of view of one aggregator agent taking into account the balance of the distribution system. For each scheduling stage, previous scheduling results and updated forecasts are considered. An illustrative test case of a distribution network with 33 buses, considering a large penetration of distribution energy resources allows demonstrating the benefits of the proposed model.

Autoradiographic analysis of the in vivo distribution of 3H-imipramine and 3H-desipramine in brain: Comparison to in vitro binding patterns

International Nuclear Information System (INIS)

Duncan, G.E.; Paul, I.A.; Fassberg, J.B.; Powell, K.R.; Stumpf, W.E.; Breese, G.R.

1991-01-01

Using high resolution autoradiographic techniques, the distribution of radioactivity in forebrain and brainstem was assessed after 4 injection of 3H-impramine or 3H-desipramine. Results were compared with regional binding of the drugs to brain sections in vitro. Similar topographic binding of 3H-imipramine and 3H-desipramine was observed in vitro among brain regions, except in the paraventricular nucleus of the hypothalamus and locus coeruleus, where binding was greater for 3H-desipramine. For both 3H-desipramine and 3H-imipramine, some brain regions that exhibited high binding in vitro also showed high accumulation after in vivo injection. However, certain regions that contained high densities of binding sites for the antidepressant drugs as measured by in vitro binding showed very low accumulation of radioactivity after in vivo treatment. Such regions included the dentate gyrus of the hippocampus, layer 1 of piriform cortex, caudate-putamen, pontine and midbrain central gray, and cerebellar granular layer. Compared to in vitro binding of the drugs, the distribution of imipramine and desipramine in vivo appears more anatomically selective. For imipramine, primary sites of action in vivo, as indicated by the topographic distribution in brain, appear to be the locus coeruleus, hippocampus, lateral septal nucleus, and amygdala. For desipramine, the greatest accumulation in vivo was found in the locus coeruleus, paraventricular nucleus of the hypothalamus, and anterior thalamic nuclei

Distributed energy store railguns experiment and analysis

Science.gov (United States)

Holland, L. D.

1984-02-01

Electromagnetic acceleration of projectiles holds the potential for achieving higher velocities than yet achieved by any other means. A railgun is the simplest form of electromagnetic macroparticle accelerator and can generate the highest sustained accelerating force. The practical length of conventional railguns is limited by the impedance of the rails because current must be carried along the entire length of the rails. A railgun and power supply system called the distributed energy store railgun was proposed as a solution to this limitation. A distributed energy storage railgun was constructed and successfully operated. In addition to this demonstration of the distributed energy store railgun principle, a theoretical model of the system was also constructed. A simple simulation of the railgun system based on this model, but ignoring frictional drag, was compared with the experimental results. During the process of comparing results from the simulation and the experiment, the effect of significant frictional drag of the projectile on the sidewalls of the bore was observed.

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.

Stark effect-dependent of ground-state donor binding energy in InGaN/GaN parabolic QWW

International Nuclear Information System (INIS)

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

2013-01-01

Using the finite-difference method within the quasi-one-dimensional effective potential model and effective mass approximation, the ground-state binding energy of hydrogenic shallow-donor impurity in wurtzite (WZ) (In,Ga)N/GaN parabolic transversal-section quantum-well wires (PQWWs) subjected to external electric field is investigated. An effective radius of a cylindrical QWW describing the strength of the lateral confinement is introduced. The results show that (i) the position of the largest electron probability density in x–y plane is located at a point and it is pushed along the negative sense by the electric field directed along the positive sense, (ii) the ground-state binding energy is largest for the impurity located at this point and starts to decrease when the impurity is away from this point, (iii) the ground-state binding energy decreases with increase in the external electric field and effective radius, and (iv) the Stark-shift increases with the increase of the external electric field and the effective radius

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.

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

Energy Technology Data Exchange (ETDEWEB)

Karpov, V. Ya. [Bruk Institute of Electronic Control Machines (Russian Federation); Shpatakovskaya, G. V., E-mail: shpagalya@yandex.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation)

2017-03-15

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.

Empirical analysis for Distributed Energy Resources' impact on future distribution network

DEFF Research Database (Denmark)

Han, Xue; Sandels, Claes; Zhu, Kun

2012-01-01

There has been a large body of statements claiming that the large scale deployment of Distributed Energy Resources (DERs) will eventually reshape the future distribution grid operation in various ways. Thus, it is interesting to introduce a platform to interpret to what extent the power system...... operation will be alternated. In this paper, quantitative results in terms of how the future distribution grid will be changed by the deployment of distributed generation, active demand and electric vehicles, are presented. The analysis is based on the conditions for both a radial and a meshed distribution...... network. The input parameters are based on the current and envisioned DER deployment scenarios proposed for Sweden....

Simultaneous effects of hydrostatic pressure and electric field on impurity binding energy and polarizability in coupled InAs/GaAs quantum wires

International Nuclear Information System (INIS)

Tangarife, E.; Duque, C.A.

2011-01-01

This work is concerned with the theoretical study of the combined effects of applied electric field and hydrostatic pressure on the binding energy and impurity polarizability of a donor impurity in laterally coupled double InAs/GaAs quantum-well wires. Calculations have been made in the effective mass and parabolic band approximations and using a variational method. The results are reported for different configurations of wire and barriers widths, impurity position, and electric field and hydrostatic pressure strengths. Our results show that for symmetrical structures the binding energy is an even function of the impurity position along the growth direction of the structure. Also, we found that for hydrostatic pressure strength up to 38 kbar, the binding energy increases linearly with hydrostatic pressure, while for larger values of hydrostatic pressure the binding energy has a non-linear behavior. Finally, we found that the hydrostatic pressure can increase the coupling between the two parallel quantum-well wires. -- Research highlights: → Binding energy for donor impurity in coupled wires strongly depends on the confinement potential. → Polarizability for donor impurity in coupled wires strongly depends on the confinement potential. → Binding energy strongly depends on the direction of the applied electric field. → Polarizability strongly depends on the direction of the applied electric field. → The coupling between the two parallel wires increases with the hydrostatic pressure.

Energy efficient distributed computing systems

CERN Document Server

Lee, Young-Choon

2012-01-01

The energy consumption issue in distributed computing systems raises various monetary, environmental and system performance concerns. Electricity consumption in the US doubled from 2000 to 2005.  From a financial and environmental standpoint, reducing the consumption of electricity is important, yet these reforms must not lead to performance degradation of the computing systems.  These contradicting constraints create a suite of complex problems that need to be resolved in order to lead to 'greener' distributed computing systems.  This book brings together a group of outsta

Transverse-energy distribution in proton-nucleus collisions at high energy

International Nuclear Information System (INIS)

Liu, F.H.

2001-01-01

Based on the model of nuclear-collision geometry, the independent N - N collision picture and participant contribution picture are used to describe the transverse-energy distribution in p-A collisions at high energy. In the independent N - N collision picture, the energy loss of leading proton in each p-N collision is considered. The calculated results are in agreement with the experimental data of p-Al, p-Cu, p-U collisions at 200 GeV/c. (author)

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.

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.

Influence of carbamazepin and diclofenac on the radio-T3/T4-distribution and the maximal binding capacity of thyroid hormone binding proteins

International Nuclear Information System (INIS)

Sternad, H.; Albrecher, B.; Langsteger, W.; Eber, O.

1993-01-01

Marked changes in plasma thyroid function parameters due to medication have been described in literature. We, therefore, studied the influence of routine administration of carbamazepine and diclofenac upon the radio T3/T4 distribution to specific thyroid transport proteins as well as their maximal binding capacity (MBC) for T4. Both drugs have been found to lead to changes in T3 and T4 distribution but not to any influence upon MBC. The parameters of thyroid function mostly revealed reduced FT3 and FT4 values while bTSH was affected only by carbamazepine administration. (authors)

Risoe energy report 4: The future energy system - distributed production and use

International Nuclear Information System (INIS)

Larsen, Hans; Soenderberg Petersen, L.

2005-10-01

The world is facing major challenges in providing energy services to meet the future needs of the developed world and the growing needs of developing countries. These challenges are exacerbated by the need to provide energy services with due respect to economic growth, sustainability and security of supply. Today, the world's energy system is based mainly on oil, gas and coal, which together supply around 80% of our primary energy. Only around 0.5% of primary energy comes from renewable sources such as wind, solar and geothermal. Despite the rapid development of new energy technologies, the world will continue to depend on fossil fuels for several decades to come - and global primary energy demand is forecasted to grow by 60% between 2002 and 2030. The expected post Kyoto targets call for significant CO 2 reductions, increasing the demand to decouple the energy and transport systems from fossil fuels. There is a strong need for closer links between electricity, heat and other energy carriers, including links to the transport sector. On a national scale Denmark has three main characteristics. Firstly, it has a diverse and distributed energy system based on the power grid, the district heating grid and the natural gas grid. Secondly, renewable energy, especially wind power, plays an increasingly important role in the Danish energy system. Thirdly, Denmark's geographical location allows it to act as a buffer between the energy systems of the European continent and the Nordic countries. Energy systems can be made more robust by decentralising both power generation and control. Distributed generation (DG) is characterised by a variety of energy production technologies integrated into the electricity supply system, and the ability of different segments of the grid to operate autonomously. The use of a more distributed power generation system would be an important element in the protection of the consumers against power interruptions and blackouts, whether caused by

Fitting theories of nuclear binding energies

International Nuclear Information System (INIS)

Bertsch, G.F.; Sabbey, B.; Uusnaekki, M.

2005-01-01

In developing theories of nuclear binding energy such as density-functional theory, the effort required to make a fit can be daunting because of the large number of parameters that may be in the theory and the large number of nuclei in the mass table. For theories based on the Skyrme interaction, the effort can be reduced considerably by using the singular value decomposition to reduce the size of the parameter space. We find that the sensitive parameters define a space of dimension four or so, and within this space a linear refit is adequate for a number of Skyrme parameters sets from the literature. We find no marked differences in the quality of the fit among the SLy4, the BSk4, and SkP parameter sets. The root-mean-square residual error in even-even nuclei is about 1.5 MeV, half the value of the liquid drop model. We also discuss an alternative norm for evaluating mass fits, the Chebyshev norm. It focuses attention on the cases with the largest discrepancies between theory and experiment. We show how it works with the liquid drop model and make some applications to models based on Skyrme energy functionals. The Chebyshev norm seems to be more sensitive to new experimental data than the root-mean-square norm. The method also has the advantage that candidate improvements to the theories can be assessed with computations on smaller sets of nuclei

Multi-objective optimal dispatch of distributed energy resources

Science.gov (United States)

Longe, Ayomide

This thesis is composed of two papers which investigate the optimal dispatch for distributed energy resources. In the first paper, an economic dispatch problem for a community microgrid is studied. In this microgrid, each agent pursues an economic dispatch for its personal resources. In addition, each agent is capable of trading electricity with other agents through a local energy market. In this paper, a simple market structure is introduced as a framework for energy trades in a small community microgrid such as the Solar Village. It was found that both sellers and buyers benefited by participating in this market. In the second paper, Semidefinite Programming (SDP) for convex relaxation of power flow equations is used for optimal active and reactive dispatch for Distributed Energy Resources (DER). Various objective functions including voltage regulation, reduced transmission line power losses, and minimized reactive power charges for a microgrid are introduced. Combinations of these goals are attained by solving a multiobjective optimization for the proposed ORPD problem. Also, both centralized and distributed versions of this optimal dispatch are investigated. It was found that SDP made the optimal dispatch faster and distributed solution allowed for scalability.

Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition

DEFF Research Database (Denmark)

Green, M R; Couchman, J R

1985-01-01

, the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing......Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map...... whether EGF-R1 could recognize molecules unrelated to the EGF receptor, the EGF binding and EGF-R1 recognition profiles were compared on cultures of SVK14 cells, a SV40 transformed human keratinocyte cell line. EGF binding and EGF-R1 monoclonal antibody distribution on these cells was found to be similar...

4He binding energy calculation including full tensor-force effects

Science.gov (United States)

Fonseca, A. C.

1989-09-01

The four-body equations of Alt, Grassberger, and Sandhas are solved in the version where the (2)+(2) subamplitudes are treated exactly by convolution, using one-term separable Yamaguchy nucleon-nucleon potentials in the 1S0 and 3S1-3D1 channels. The resulting jp=1/2+ and (3/2+ three-body subamplitudes are represented in a separable form using the energy-dependent pole expansion. Converged bound-state results are calculated for the first time using the full interaction, and are compared with those obtained from a simplified treatment of the tensor force. The Tjon line that correlates three-nucleon and four-nucleon binding energies is shown using different nucleon-nucleon potentials. In all calculations the Coulomb force has been neglected.

Energy management in a microgrid with distributed energy resources

International Nuclear Information System (INIS)

Zhang, Linfeng; Gari, Nicolae; Hmurcik, Lawrence V.

2014-01-01

Highlights: • A performance metric is proposed with the consideration of price, environment effect, and service quality. • Models of a microgrid and a microgrid network are designed with distribute energy resources and storage. • Different cases in MG operation are discussed. - Abstract: A smart grid power system with renewable energy resources and distributed energy storage shows significant improvement in the power system’s emission reduction, reliability, efficiency, and security. A microgrid is a smart grid in a small scale which can be stand-alone or grid-tied. Multi microgrids form a network with energy management and operational planning through two-way power flow and communication. To comprehensively evaluate the performance of a microgrid, a performance metric is proposed with consideration of the electricity price, emission, and service quality, each of them is given a weighting factor. Thus, the performance metric is flexible according to the consumers’ preference. With the weighting factors set in this paper, this performance metric is further applied on microgrids operated as stand-alone, grid-tied, and networked. Each microgrid consists of a solar panel, a hydrogen fuel cell stack, an electrolyzer, a hydrogen storage tank, and a load. For a stand-alone system, the load prediction lowers down the daily electricity consumption about 5.7%, the quantity of H 2 stored fluctuates in a wide range, and overall performance indexes increase with the solar panel size. In a grid-tied MG, the load prediction has a significant effect on the daily consumed electricity which drops 25% in 4 days, some day-time loads are shifted to the night time, and the capacity of hydrogen tank is lower than that in a stand-alone MG. In a network with multiple MGs, the control of the power distribution strongly affects the MG’s performance. However, the overall performance index instead of any specific index increases with the MG’s power generated from renewable energy

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 cations (Ag(m)Au(n)+, m + n carbon monoxide as studied in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The experimental results are discussed in terms of ab initio computations which provide a comprehensive picture of the chemical binding behaviour (like binding energy, 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 < m + n < 7) as a function of composition. Here, binding energy drops with increasing silver content, while CO still binds always in a head-on fashion to a gold atom. Finally we show how the CO stretch frequency of Ag(m)Au(n)CO+ may be used to identify possible adsorption sites and pre-screen favorable isomers.

Binding and distribution studies in the SENCAR mouse of compounds demonstrating a route-dependent tumorigenic effect

International Nuclear Information System (INIS)

Carlson, G.P.; Fossa, A.A.; Morse, M.A.; Weaver, P.M.

1986-01-01

Previous investigators have determined that benzo(a)pyrene [B(a)P] was much more effective in causing skin papillomas if applied topically than when administered orally in the initiation-promotion assay in SENCAR mouse. Conversely, urethane and acrylamide caused a higher percentage of mice to develop papillomas and induced more tumors per mouse when given orally. In an attempt to understand the reason for this discrepancy in route dependency, 3 H-benzo(a)pyrene, 14 C-acrylamide were administered as single doses orally or topically to male SENCAR mice. Distribution in skin, stomach, liver, and lung was determined for time periods up to 48 hr. The binding of these compounds to DNA, RNA, and protein in these tissues was determined 6 and 48 hr after administration. For all three compounds, high concentrations were found in the skin following topical application, but very little material reached this target organ following oral administration. In contrast, the internal organs generally contained more material after oral administration. The binding of label compounds to DNA, RNA, and protein generally reflected the distribution data, thus more compound was bound in the stomach, liver, and lung after oral administration compared to topical application, whereas the opposite was true for the skin. This finding was particularly evident for B(a)P. The results suggest that differences in distribution to the skin and binding to macromolecules following oral or topical administration cannot explain the greater tumorigenicity of urethane and acrylamide after oral administration in the SENCAR mouse

Technologies for Distributed Energy Resources. Federal Energy Management Program (FEMP) Technical Assistance Fact Sheet

International Nuclear Information System (INIS)

Pitchford, P.; Brown, T.

2001-01-01

This four-page fact sheet describes distributed energy resources for Federal facilities, which are being supported by the U.S. Department of Energy's (DOE's) Federal Energy Management Program (FEMP). Distributed energy resources include both existing and emerging energy technologies: advanced industrial turbines and microturbines; combined heat and power (CHP) systems; fuel cells; geothermal systems; natural gas reciprocating engines; photovoltaics and other solar systems; wind turbines; small, modular biopower; energy storage systems; and hybrid systems. DOE FEMP is investigating ways to use these alternative energy systems in government facilities to meet greater demand, to increase the reliability of the power-generation system, and to reduce the greenhouse gases associated with burning fossil fuels

Effects of fissioning nuclei distributions on fragment mass distributions for high energy fission

Directory of Open Access Journals (Sweden)

Rossi P C R

2012-02-01

Full Text Available We study the effects of fissioning nuclei mass- and energy-distributions on the formation of fragments for fission induced by high energy probes. A Monte Carlo code called CRISP was used for obtaining mass distributions and spectra of the fissioning nuclei for reactions induced by 660 MeV protons on 241Am and on 239Np, by 500 MeV protons on 208Pb, and by Bremsstrahlung photons with end-point energies at 50 MeV and 3500 MeV on 238U. The results show that even at high excitation energies, asymmetric fission may still contribute significantly to the fission cross section of actinide nuclei, while it is the dominante mode in the case of lead. However, more precise data for high energy fission on actinide are necessary in order to allow definite conclusions.

Exploring Distributed Energy Alternatives to Electrical Distribution Grid Expansion in Souhern California Edison Service Territory

Energy Technology Data Exchange (ETDEWEB)

Stovall, Therese K [ORNL; Kingston, Tim [Gas Technology Institute

2005-12-01

Distributed energy (DE) technologies have received much attention for the energy savings and electric power reliability assurances that may be achieved by their widespread adoption. Fueling the attention have been the desires to globally reduce greenhouse gas emissions and concern about easing power transmission and distribution system capacity limitations and congestion. However, these benefits may come at a cost to the electric utility companies in terms of lost revenue and concerns with interconnection on the distribution system. This study assesses the costs and benefits of DE to both consumers and distribution utilities and expands upon a precursory study done with Detroit Edison (DTE)1, by evaluating the combined impact of DE, energy-efficiency, photovoltaics (a use of solar energy), and demand response that will shape the grid of the future. This study was funded by the U.S. Department of Energy (DOE), Gas Research Institute (GRI), American Electric Power (AEP), and Gas Technology Institute's (GTI) Distributed Energy Collaborative Program (DECP). It focuses on two real Southern California Edison (SCE) circuits, a 13 MW suburban circuit fictitiously named Justice on the Lincoln substation, and an 8 MW rural circuit fictitiously named Prosper on the Washington Substation. The primary objectives of the study were threefold: (1) Evaluate the potential for using advanced energy technologies, including DE, energy-efficiency (EE), demand response, electricity storage, and photovoltaics (PV), to reshape electric load curves by reducing peak demand, for real circuits. (2) Investigate the potential impact on guiding technology deployment and managing operation in a way that benefits both utilities and their customers by: (a) Improving grid load factor for utilities; (b) Reducing energy costs for customers; and (c) Optimizing electric demand growth. (3) Demonstrate benefits by reporting on a recently installed advanced energy system at a utility customer site

Coordination-resolved local bond relaxation, electron binding-energy shift, and Debye temperature of Ir solid skins

Energy Technology Data Exchange (ETDEWEB)

Bo, Maolin [Key Laboratory of Low-Dimensional Materials and Application Technologies, Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105 (China); Wang, Yan [Key Laboratory of Low-Dimensional Materials and Application Technologies, Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105 (China); School of Information and Electronic Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201 (China); Huang, Yongli, E-mail: huangyongli@xtu.edu.cn [Key Laboratory of Low-Dimensional Materials and Application Technologies, Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105 (China); Yang, Xuexian [Department of Physics, Jishou University, Jishou, Hunan 416000 (China); Yang, Yezi [Key Laboratory of Low-Dimensional Materials and Application Technologies, Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105 (China); Li, Can [Center for Coordination Bond Engineering, School of Materials Science and Engineering, China Jiliang University, Hangzhou 330018 (China); Sun, Chang Q., E-mail: ecqsun@ntu.edu.sg [Key Laboratory of Low-Dimensional Materials and Application Technologies, Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105 (China); NOVITAS, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2014-11-30

Highlights: • Cohesive energy of the representative bond determines the core-level shift. • XPS derives the energy level of an isolated atom and its bulk shift. • XPS derives the local bond length, bond energy, binding energy density. • Thermal XPS resolves the Debye temperature and atomic cohesive energy. - Abstract: Numerical reproduction of the measured 4f{sub 7/2} energy shift of Ir(1 0 0), (1 1 1), and (2 1 0) solid skins turns out the following: (i) the 4f{sub 7/2} level of an isolated Ir atom shifts from 56.367 eV to 60.332 eV by 3.965 eV upon bulk formation; (ii) the local energy density increases by up to 130% and the atomic cohesive energy decreases by 70% in the skin region compared with the bulk values. Numerical match to observation of the temperature dependent energy shift derives the Debye temperature that varies from 285.2 K (Surface) to 315.2 K (Bulk). We clarified that the shorter and stronger bonds between under-coordinated atoms cause local densification and quantum entrapment of electron binding energy, which perturbs the Hamiltonian and the core shifts in the skin region.

Multiplicity distributions in high energy collisions

International Nuclear Information System (INIS)

Giovannini, A.; Lupia, S.; Ugoccioni, R.

1992-01-01

We discuss the important phases in the evolution of our understanding of multiplicity distributions in high energy collisions with particular emphasis to intermittent behavior and shoulder structure problem. (orig.)

Multiplicity distributions in high energy collisions

Energy Technology Data Exchange (ETDEWEB)

Giovannini, A.; Lupia, S.; Ugoccioni, R. (Dipt. di Fisica Teorica, Univ. Turin (Italy) INFN, Turin (Italy))

1992-03-01

We discuss the important phases in the evolution of our understanding of multiplicity distributions in high energy collisions with particular emphasis to intermittent behavior and shoulder structure problem. (orig.).

Smart Control of Energy Distribution Grids over Heterogeneous Communication Networks

DEFF Research Database (Denmark)

Olsen, Rasmus Løvenstein; Iov, Florin; Hägerling, Christian

2014-01-01

The expected growth in distributed generation will significantly affect the operation and control of todays distribution grids. Being confronted with short time power variations of distributed generations, the assurance of a reliable service (grid stability, avoidance of energy losses) and the qu......The expected growth in distributed generation will significantly affect the operation and control of todays distribution grids. Being confronted with short time power variations of distributed generations, the assurance of a reliable service (grid stability, avoidance of energy losses...

Distribution of epidermal growth factor binding sites in the adult rat anterior pituitary gland

International Nuclear Information System (INIS)

Chabot, J.G.; Walker, P.; Pelletier, G.

1986-01-01

The distribution of epidermal growth (EGF) binding sites was studied in the pituitary gland using light and electron microscope autoradiography which was performed at different time intervals (2 to 60 min) after intravenous (IV) injection of [ 125 I]EGF into adult rats. At the light microscopic level, the labeling was found over cells of the anterior pituitary gland. The time-course study performed by light microscope autoradiography showed that the maximal values were reached at the 2 min time interval. At this time interval, most silver grains were found at the periphery of the target cells. After, the number of silver grains decreased progressively and the localization of silver grains in the cytoplasm indicated the internalization of [ 125 I]EGF. Electron microscope autoradiography showed that labeling was mostly restricted to mammotrophs and somatotrophs. Control experiments indicated that the autoradiographic labeling was due specific interaction of [ 125 I]EGF with its binding site. These results indicate that EGF binding sites are present in at least two anterior pituitary cell types and suggest that EGF can exert a physiological role in the pituitary gland

Free energy distribution function of a random Ising ferromagnet

International Nuclear Information System (INIS)

Dotsenko, Victor; Klumov, Boris

2012-01-01

We study the free energy distribution function of a weakly disordered Ising ferromagnet in terms of the D-dimensional random temperature Ginzburg–Landau Hamiltonian. It is shown that besides the usual Gaussian 'body' this distribution function exhibits non-Gaussian tails both in the paramagnetic and in the ferromagnetic phases. Explicit asymptotic expressions for these tails are derived. It is demonstrated that the tails are strongly asymmetric: the left tail (for large negative values of the free energy) is much slower than the right one (for large positive values of the free energy). It is argued that at the critical point the free energy of the random Ising ferromagnet in dimensions D < 4 is described by a non-trivial universal distribution function which is non-self-averaging

A test of Wigner's spin-isospin symmetry from double binding energy differences

International Nuclear Information System (INIS)

Van Isacker, P.; Warner, D.D.; Brenner, D.S.

1995-01-01

It is shown that the anomalously large double binding energy differences for even-even N = Z nuclei are a consequence of Wigner's SU(4) symmetry. These, and similar quantities for odd-mass and odd-odd nuclei, provide a simple and distinct signature of this symmetry in N ≅ Z nuclei. (authors). 16 refs., 2 figs., 1 tab

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 ...

Binding energies of sd-shell nuclei with a realistic effective Hamiltonian

International Nuclear Information System (INIS)

Dalton, B.J.; Vary, J.P.; Baldridge, W.J.

1977-01-01

The nuclear shell model with a second-order effective Hamiltonian derived within Brueckner theory from the free nucleon-nucleon interaction is shown to yield accurate binding energies of nuclei with 16 < A < 40. This agreement is obtained by choosing the spectrum of low-lying unoccupied orbitals in a justified manner and, when necessary, by employing a statistical method to approximate the lowest eigenvalue of very large shell-model diagonalizations

Universal binding energy relation for cleaved and structurally relaxed surfaces.

Science.gov (United States)

Srirangarajan, Aarti; Datta, Aditi; Gandi, Appala Naidu; Ramamurty, U; Waghmare, U V

2014-02-05

The universal binding energy relation (UBER), derived earlier to describe the cohesion between two rigid atomic planes, does not accurately capture the cohesive properties when the cleaved surfaces are allowed to relax. We suggest a modified functional form of UBER that is analytical and at the same time accurately models the properties of surfaces relaxed during cleavage. We demonstrate the generality as well as the validity of this modified UBER through first-principles density functional theory calculations of cleavage in a number of crystal systems. Our results show that the total energies of all the relaxed surfaces lie on a single (universal) energy surface, that is given by the proposed functional form which contains an additional length-scale associated with structural relaxation. This functional form could be used in modelling the cohesive zones in crack growth simulation studies. We find that the cohesive law (stress-displacement relation) differs significantly in the case where cracked surfaces are allowed to relax, with lower peak stresses occurring at higher displacements.

77 FR 7281 - Energy Conservation Program: Energy Conservation Standards for Distribution Transformers

Science.gov (United States)

2012-02-10

... Electrical Efficiencies for all Liquid-Immersed Distribution Transformer Equipment Classes (Compliance... ``customers.'' Customers refer to electric utilities in the case of liquid-immersed transformers, and to... for Determining Energy Efficiency for Distribution Transformers'' published by the National Electrical...

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.

Effects of distributing wind energy generation over Europe

Energy Technology Data Exchange (ETDEWEB)

Giebel, G [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

1999-03-01

Using data from 60 meteorological stations distributed all over Europe in conjunction with the National Grid Model (NGM) from the Rutherford Appleton Laboratory, the effects of the large-scale distribution of wind energy generation are studied. In some regions of Europe, wind energy already covers a significant proportion of the electricity demand. But the intermittence of the wind resource is always a limiting factor when penetration levels are high. Studies for single countries have shown that distributing the generation over a large area reduces the variability of the output and hence makes wind energy more appealing to utilities, since the stability requirement of the network are easier to fulfil. The data are analysed in terms of absolute highs and lows, temporal and spatial correlations. To assess the financial benefits, the NGM is used to evaluate the match of electricity demand and generation as well as the possibel savings of fossil fuel in an electricity grid incorporating various capacities of wind energy generation. To assess the value of wind energy on a trans-national scale, the European plant mix is modelled, and the NGM is used to simulate the scheduling of these plants in the presence of different penetrations of wind energy. (au) EU-JOULE-3. 11 refs.

Optimal Operation of Energy Storage in Power Transmission and Distribution

Science.gov (United States)

Akhavan Hejazi, Seyed Hossein

In this thesis, we investigate optimal operation of energy storage units in power transmission and distribution grids. At transmission level, we investigate the problem where an investor-owned independently-operated energy storage system seeks to offer energy and ancillary services in the day-ahead and real-time markets. We specifically consider the case where a significant portion of the power generated in the grid is from renewable energy resources and there exists significant uncertainty in system operation. In this regard, we formulate a stochastic programming framework to choose optimal energy and reserve bids for the storage units that takes into account the fluctuating nature of the market prices due to the randomness in the renewable power generation availability. At distribution level, we develop a comprehensive data set to model various stochastic factors on power distribution networks, with focus on networks that have high penetration of electric vehicle charging load and distributed renewable generation. Furthermore, we develop a data-driven stochastic model for energy storage operation at distribution level, where the distribution of nodal voltage and line power flow are modelled as stochastic functions of the energy storage unit's charge and discharge schedules. In particular, we develop new closed-form stochastic models for such key operational parameters in the system. Our approach is analytical and allows formulating tractable optimization problems. Yet, it does not involve any restricting assumption on the distribution of random parameters, hence, it results in accurate modeling of uncertainties. By considering the specific characteristics of random variables, such as their statistical dependencies and often irregularly-shaped probability distributions, we propose a non-parametric chance-constrained optimization approach to operate and plan energy storage units in power distribution girds. In the proposed stochastic optimization, we consider

Energy Inputs Uncertainty: Total Amount, Distribution and Correlation Between Different Forms of Energy

Science.gov (United States)

Deng, Yue

2014-01-01

Describes solar energy inputs contributing to ionospheric and thermospheric weather processes, including total energy amounts, distributions and the correlation between particle precipitation and Poynting flux.

Polarizability and binding energy of a shallow donor in spherical quantum dot-quantum well (QD-QW)

Science.gov (United States)

Rahmani, K.; Chrafih, Y.; M’Zred, S.; Janati, S.; Zorkani, I.; Jorio, A.; Mmadi, A.

2018-03-01

The polarizability and the binding energy is estimated for a shallow donor confined to move in inhomogeneous quantum dots (CdS/HgS/CdS). In this work, the Hass variational method within the effective mass approximation in used in the case of an infinitely deep well. The polarizability and the binding energy depend on the inner and the outer radius of the QDQW, also it depends strongly on the donor position. It’s found that the stark effect is more important when the impurity is located at the center of the (QDQW) and becomes less important when the donor moves toward the extremities of the spherical layer. When the electric field increases, the binding energy and the polarizability decreases. Its effects is more pronounced when the impurity is placed on the center of the spherical layer and decrease when the donor move toward extremities of this spherical layer. We have demonstrated the existence of a critical value {≤ft( {{{{R_1}} \\over {{R_2}}}} \\right)cri} which can be used to distinguish the tree dimension confinement from the spherical surface confinement and it’s may be important for the nanofabrication techniques.

Risoe energy report 4: The future energy system - distributed production and use

Energy Technology Data Exchange (ETDEWEB)

Larsen, Hans; Soenderberg Petersen, L.

2005-10-01

The world is facing major challenges in providing energy services to meet the future needs of the developed world and the growing needs of developing countries. These challenges are exacerbated by the need to provide energy services with due respect to economic growth, sustainability and security of supply. Today, the world's energy system is based mainly on oil, gas and coal, which together supply around 80% of our primary energy. Only around 0.5% of primary energy comes from renewable sources such as wind, solar and geothermal. Despite the rapid development of new energy technologies, the world will continue to depend on fossil fuels for several decades to come - and global primary energy demand is forecasted to grow by 60% between 2002 and 2030. The expected post Kyoto targets call for significant CO{sub 2} reductions, increasing the demand to decouple the energy and transport systems from fossil fuels. There is a strong need for closer links between electricity, heat and other energy carriers, including links to the transport sector. On a national scale Denmark has three main characteristics. Firstly, it has a diverse and distributed energy system based on the power grid, the district heating grid and the natural gas grid. Secondly, renewable energy, especially wind power, plays an increasingly important role in the Danish energy system. Thirdly, Denmark's geographical location allows it to act as a buffer between the energy systems of the European continent and the Nordic countries. Energy systems can be made more robust by decentralising both power generation and control. Distributed generation (DG) is characterised by a variety of energy production technologies integrated into the electricity supply system, and the ability of different segments of the grid to operate autonomously. The use of a more distributed power generation system would be an important element in the protection of the consumers against power interruptions and blackouts, whether

Exploring the binding energy profiles of full agonists, partial agonists, and antagonists of the α7 nicotinic acetylcholine receptor.

Science.gov (United States)

Tabassum, Nargis; Ma, Qianyun; Wu, Guanzhao; Jiang, Tao; Yu, Rilei

2017-09-01

Nicotinic acetylcholine receptors (nAChRs) belong to the Cys-loop receptor family and are important drug targets for the treatment of neurological diseases. However, the precise determinants of the binding efficacies of ligands for these receptors are unclear. Therefore, in this study, the binding energy profiles of various ligands (full agonists, partial agonists, and antagonists) were quantified by docking those ligands with structural ensembles of the α7 nAChR exhibiting different degrees of C-loop closure. This approximate treatment of interactions suggested that full agonists, partial agonists, and antagonists of the α7 nAChR possess distinctive binding energy profiles. Results from docking revealed that ligand binding efficacy may be related to the capacity of the ligand to stabilize conformational states with a closed C loop.

Multi-agent based distributed control architecture for microgrid energy management and optimization

International Nuclear Information System (INIS)

Basir Khan, M. Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

2016-01-01

Highlights: • A new multi-agent based distributed control architecture for energy management. • Multi-agent coordination based on non-cooperative game theory. • A microgrid model comprised of renewable energy generation systems. • Performance comparison of distributed with conventional centralized control. - Abstract: Most energy management systems are based on a centralized controller that is difficult to satisfy criteria such as fault tolerance and adaptability. Therefore, a new multi-agent based distributed energy management system architecture is proposed in this paper. The distributed generation system is composed of several distributed energy resources and a group of loads. A multi-agent system based decentralized control architecture was developed in order to provide control for the complex energy management of the distributed generation system. Then, non-cooperative game theory was used for the multi-agent coordination in the system. The distributed generation system was assessed by simulation under renewable resource fluctuations, seasonal load demand and grid disturbances. The simulation results show that the implementation of the new energy management system proved to provide more robust and high performance controls than conventional centralized energy management systems.

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.

Design and Realization of Online Monitoring System of Distributed New Energy and Renewable Energy

Science.gov (United States)

Tang, Yanfen; Zhou, Tao; Li, Mengwen; Zheng, Guotai; Li, Hao

2018-01-01

Aimed at difficult centralized monitoring and management of current distributed new energy and renewable energy generation projects due to great varieties, different communication protocols and large-scale difference, this paper designs a online monitoring system of new energy and renewable energy characterized by distributed deployment, tailorable functions, extendible applications and fault self-healing performance. This system is designed based on international general standard for grid information data model, formulates unified data acquisition and transmission standard for different types of new energy and renewable energy generation projects, and can realize unified data acquisition and real-time monitoring of new energy and renewable energy generation projects, such as solar energy, wind power, biomass energy, etc. within its jurisdiction. This system has applied in Beijing. At present, 576 projects are connected to the system. Good effect is achieved and stability and reliability of the system have been validated.

Energy flow models for the estimation of technical losses in distribution network

International Nuclear Information System (INIS)

Au, Mau Teng; Tan, Chin Hooi

2013-01-01

This paper presents energy flow models developed to estimate technical losses in distribution network. Energy flow models applied in this paper is based on input energy and peak demand of distribution network, feeder length and peak demand, transformer loading capacity, and load factor. Two case studies, an urban distribution network and a rural distribution network are used to illustrate application of the energy flow models. Results on technical losses obtained for the two distribution networks are consistent and comparable to network of similar types and characteristics. Hence, the energy flow models are suitable for practical application.

First calculation of the deuteron binding energy

International Nuclear Information System (INIS)

Schaegger, B.

2012-01-01

No universal constant characterizing the nuclear force has yet been found as for gravity and electromagnetism. The neutron is globally neutral with a zero net charge. The charges contained in a neutron may be separated by the electric field of a nearby proton and therefore being attracted by electrostatic induction in the same way as a rubbed plastic pen attracts small pieces of paper. There is also a magnetic force that may repel the nucleons like magnets in the proper relative orientation. In the deuteron, the heavy hydrogen nucleus, the induced electrostatic attraction is equilibrated by the magnetic repulsion between the opposite and colinear moments of the nucleons. Equilibrium is calculated by minimizing the electromagnetic interaction potential, giving a binding energy of 1.6 MeV, not much lower than the experimental value, 2.2 MeV. No fitting parameter is used: it is a true ab initio calculation

Community energy storage and distribution SCADA improvements

International Nuclear Information System (INIS)

Riggins, M.

2010-01-01

The mission of American Electric Power (AEP) is to sustain the real time balance of energy supply and demand. Approximately 2.5 percent of energy generated in the United States (USA) is stored as pumped hydro, compressed air, or in batteries and other devices. This power point presentation discussed the use of SCADA for improving community energy storage (CES) and distribution systems. CES is a distributed fleet of small energy units connected to the transformers in order to serve houses or small commercial loads. CES is operated as a fleet offering multi-megawatt (MW) multi-hour storage. The benefits of CES include backup power, flicker mitigation, and renewable integration. Benefits to the electricity grid include power factor correct, ancillary services, and load leveling at the substation level. SCADA is being used to determine when emergency load reductions are required or when emergency inspections on fans, oil pumps or other devices are needed. An outline of AEP's monitoring system installation plan was also included. tabs., figs.

Towards Integrating Distributed Energy Resources and Storage Devices in Smart Grid.

Science.gov (United States)

Xu, Guobin; Yu, Wei; Griffith, David; Golmie, Nada; Moulema, Paul

2017-02-01

Internet of Things (IoT) provides a generic infrastructure for different applications to integrate information communication techniques with physical components to achieve automatic data collection, transmission, exchange, and computation. The smart grid, as one of typical applications supported by IoT, denoted as a re-engineering and a modernization of the traditional power grid, aims to provide reliable, secure, and efficient energy transmission and distribution to consumers. How to effectively integrate distributed (renewable) energy resources and storage devices to satisfy the energy service requirements of users, while minimizing the power generation and transmission cost, remains a highly pressing challenge in the smart grid. To address this challenge and assess the effectiveness of integrating distributed energy resources and storage devices, in this paper we develop a theoretical framework to model and analyze three types of power grid systems: the power grid with only bulk energy generators, the power grid with distributed energy resources, and the power grid with both distributed energy resources and storage devices. Based on the metrics of the power cumulative cost and the service reliability to users, we formally model and analyze the impact of integrating distributed energy resources and storage devices in the power grid. We also use the concept of network calculus, which has been traditionally used for carrying out traffic engineering in computer networks, to derive the bounds of both power supply and user demand to achieve a high service reliability to users. Through an extensive performance evaluation, our data shows that integrating distributed energy resources conjointly with energy storage devices can reduce generation costs, smooth the curve of bulk power generation over time, reduce bulk power generation and power distribution losses, and provide a sustainable service reliability to users in the power grid.

Transmitted ion energy loss distributions to detect cluster formation in silicon

International Nuclear Information System (INIS)

Selen, L.J.M.; Loon, A. van; IJzendoorn, L.J. van; Voigt, M.J.A. de

2002-01-01

The energy loss distribution of ions transmitted through a 5.7±0.2 μm thick Si crystal was measured and simulated with the Monte Carlo channeling simulation code FLUX. A general resemblance between the measured and simulated energy loss distributions was obtained after incorporation of an energy dependent energy loss in the simulation program. The energy loss calculations are used to investigate the feasibility to detect the presence of light element dopant clusters in a host crystal from the shape of the energy loss distribution, with transmission ion channeling. A curved crystal structure is used as a model for a region in the host crystal with clusters. The presence of the curvature does have a large influence on the transmitted energy distribution, which offers the possibility to determine the presence of dopant clusters in a host crystal with transmission ion channeling

Kinetic energy distributions of sputtered neutral aluminum clusters: Al--Al6

International Nuclear Information System (INIS)

Coon, S.R.; Calaway, W.F.; Pellin, M.J.; Curlee, G.A.; White, J.M.

1992-01-01

Neutral aluminum clusters sputtered from polycrystalline aluminum were analyzed by laser postionization time-of-flight (TOF) mass spectrometry. The kinetic energy distributions of Al through Al 6 were measured by a neutrals time-of-flight technique. The interpretation of laser postionization TOF data to extract velocity and energy distributions is presented. The aluminum cluster distributions are qualitatively similar to previous copper cluster distribution measurements from our laboratory. In contrast to the steep high energy tails predicted by the single- or multiple- collision models, the measured cluster distributions have high energy power law dependences in the range of E -3 to E -4.5 . Correlated collision models may explain the substantial abundance of energetic clusters that are observed in these experiments. Possible influences of cluster fragmentation on the distributions are discussed

Influence of chemical disorder on the electronic level spacing distribution of the Ag{sub 5083} nanoparticle: A tight-binding study

Energy Technology Data Exchange (ETDEWEB)

Medrano, L.R., E-mail: leonardoms20@gmail.com [Faculty of Physical Sciences, National University of San Marcos, P.O. Box 14-0149, Lima 14 (Peru); Landauro, C.V., E-mail: clandauros@unmsm.edu.pe [Faculty of Physical Sciences, National University of San Marcos, P.O. Box 14-0149, Lima 14 (Peru)

2013-03-01

In the present work we study, employing a tight-binding Hamiltonian, the influence of chemical disorder on the electronic level spacing distribution of a silver nanoparticle containing 5083 atoms (∼ 5.5 nm). This nanoparticle was obtained by molecular dynamics simulations with a tight-binding atomic potential. The results indicate that in the absence of disorder the level spacing distributions are similar to those expected for systems belonging to the Gaussian Orthogonal Ensemble. Whereas, after increasing the chemical disorder, the electronic level spacing distribution and the Σ{sub 2} statistics tend to the corresponding form for the Poisson Ensemble, i.e., the silver nanoparticle acquires an insulating character which is expected for strongly disordered systems. Hence, this kind of disorder produces the localization of the electronic states of the nanoparticle.

Autoradiographic localization of benzomorphan binding sites in rat brain

Energy Technology Data Exchange (ETDEWEB)

Crain, B.J.; Kwenjen Chang; McNamara, J.O.; Valdes, F.

1985-07-17

The benzomorphan subpopulation of opiate binding sites was labeled by (TH)diprenorphine in the presence of unlabeled ligands selected to quench and delta opiate binding sites. The distribution of benzomorphan binding sites was then localized autoradiographically. The distribution differs from the distributions of , delta and kappa opiate binding and is quite similar to the distribution of US -endorphin immunoreactivity. These observations support the hypothesis, based on biochemical studies in brain membranes, that benzomorphan binding sites may represent the ligand recognition sites of putative epsilon receptors. (Auth.). 34 refs.; 3 figs.

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)

Transition to distributed energy generation in Finland: Prospects and barriers

International Nuclear Information System (INIS)

Ruggiero, Salvatore; Varho, Vilja; Rikkonen, Pasi

2015-01-01

Small-scale distributed energy generation is expected to play an important role in helping Finland increase its energy self-sufficiency. However, the overall strategy to date for promoting distributed energy remains unclear. It is not yet well understood which factors promote the growth of the distributed energy sector and what barriers need to be removed. In this article we present the results of a questionnaire directed at a panel of 26 experts from the distributed energy value chain and 15 semi-structured interviews with industry and non-industry representatives. We investigated, from a sociotechnical transition perspective, the possibilities and challenges of the transition to distributed energy in Finland through 2025. The results show that a shift to a prosperous future for distributed energy is possible if permit procedures, ease of grid connection, and taxation laws are improved in the electricity sector and new business concepts are introduced in the heat sector. In contrast to other European countries, the transition in Finland is expected to take place through a market-based approach favoring investment-focused measures. We conclude that incentive-based schemes alone, whatever they may be, will be insufficient to create significant growth in Finland without institutional change, removal of barriers, and the engagement of key actors. - Highlights: • We examine the possibilities and challenges of the transition to DE in Finland. • Technological niches are emerging both in the heat and electricity sector. • Business model innovation is evident only in the electricity sector. • Removing barriers and developing new business models will accelerate the transition.

Accurate core-electron binding energy shifts from density functional theory

International Nuclear Information System (INIS)

Takahata, Yuji; Marques, Alberto Dos Santos

2010-01-01

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

Advanced Distribution Network Modelling with Distributed Energy Resources

Science.gov (United States)

O'Connell, Alison

The addition of new distributed energy resources, such as electric vehicles, photovoltaics, and storage, to low voltage distribution networks means that these networks will undergo major changes in the future. Traditionally, distribution systems would have been a passive part of the wider power system, delivering electricity to the customer and not needing much control or management. However, the introduction of these new technologies may cause unforeseen issues for distribution networks, due to the fact that they were not considered when the networks were originally designed. This thesis examines different types of technologies that may begin to emerge on distribution systems, as well as the resulting challenges that they may impose. Three-phase models of distribution networks are developed and subsequently utilised as test cases. Various management strategies are devised for the purposes of controlling distributed resources from a distribution network perspective. The aim of the management strategies is to mitigate those issues that distributed resources may cause, while also keeping customers' preferences in mind. A rolling optimisation formulation is proposed as an operational tool which can manage distributed resources, while also accounting for the uncertainties that these resources may present. Network sensitivities for a particular feeder are extracted from a three-phase load flow methodology and incorporated into an optimisation. Electric vehicles are the focus of the work, although the method could be applied to other types of resources. The aim is to minimise the cost of electric vehicle charging over a 24-hour time horizon by controlling the charge rates and timings of the vehicles. The results demonstrate the advantage that controlled EV charging can have over an uncontrolled case, as well as the benefits provided by the rolling formulation and updated inputs in terms of cost and energy delivered to customers. Building upon the rolling optimisation, a

Magnetic field effect on the ground-state binding energy in InGaN/GaN parabolic QWW

International Nuclear Information System (INIS)

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

2013-01-01

Within the framework of the effective mass scheme, the ground-state binding energy of hydrogenic shallow-donor impurity in wurtzite (WZ) (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) subjected to magnetic field is investigated. The finite-difference method within the quasi-one-dimensional effective potential model is used. A cylindrical QWW effective radius is introduced to describe the lateral confinement strength. The results show that: (i) the binding energy is the largest for the impurity located at a point corresponding to the largest electron probability density and (ii) it increases with increasing external magnetic field

Magnetic field effect on the ground-state binding energy in InGaN/GaN parabolic QWW

Energy Technology Data Exchange (ETDEWEB)

El Ghazi, Haddou, E-mail: hadghazi@gmail.com [LPS, Faculty of sciences, Dhar EL Mehrez, B.P 1796 Atlas Fez (Morocco); Specials Mathematics, CPGE Kénitra, Chakib Arsalane Street, Kénitra (Morocco); Jorio, Anouar; Zorkani, Izeddine [LPS, Faculty of sciences, Dhar EL Mehrez, B.P 1796 Atlas Fez (Morocco)

2013-07-15

Within the framework of the effective mass scheme, the ground-state binding energy of hydrogenic shallow-donor impurity in wurtzite (WZ) (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) subjected to magnetic field is investigated. The finite-difference method within the quasi-one-dimensional effective potential model is used. A cylindrical QWW effective radius is introduced to describe the lateral confinement strength. The results show that: (i) the binding energy is the largest for the impurity located at a point corresponding to the largest electron probability density and (ii) it increases with increasing external magnetic field.

The Design of Distributed Micro Grid Energy Storage System

Science.gov (United States)

Liang, Ya-feng; Wang, Yan-ping

2018-03-01

Distributed micro-grid runs in island mode, the energy storage system is the core to maintain the micro-grid stable operation. For the problems that it is poor to adjust at work and easy to cause the volatility of micro-grid caused by the existing energy storage structure of fixed connection. In this paper, an array type energy storage structure is proposed, and the array type energy storage system structure and working principle are analyzed. Finally, the array type energy storage structure model is established based on MATLAB, the simulation results show that the array type energy storage system has great flexibility, which can maximize the utilization of energy storage system, guarantee the reliable operation of distributed micro-grid and achieve the function of peak clipping and valley filling.

Energy system analysis of fuel cells and distributed generation

DEFF Research Database (Denmark)

Mathiesen, Brian Vad; Lund, Henrik

2007-01-01

This chapter introduces Energy System Analysis methodologies and tools, which can be used for identifying the best application of different Fuel Cell (FC) technologies to different regional or national energy systems. The main point is that the benefits of using FC technologies indeed depend...... on the energy system in which they are used. Consequently, coherent energy systems analyses of specific and complete energy systems must be conducted in order to evaluate the benefits of FC technologies and in order to be able to compare alternative solutions. In relation to distributed generation, FC...... technologies are very often connected to the use of hydrogen, which has to be provided e.g. from electrolysers. Decentralised and distributed generation has the possibility of improving the overall energy efficiency and flexibility of energy systems. Therefore, energy system analysis tools and methodologies...

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.

Hybrid Hydrogen and Mechanical Distributed Energy Storage

Directory of Open Access Journals (Sweden)

Stefano Ubertini

2017-12-01

Full Text Available Effective energy storage technologies represent one of the key elements to solving the growing challenges of electrical energy supply of the 21st century. Several energy storage systems are available, from ones that are technologically mature to others still at a research stage. Each technology has its inherent limitations that make its use economically or practically feasible only for specific applications. The present paper aims at integrating hydrogen generation into compressed air energy storage systems to avoid natural gas combustion or thermal energy storage. A proper design of such a hybrid storage system could provide high roundtrip efficiencies together with enhanced flexibility thanks to the possibility of providing additional energy outputs (heat, cooling, and hydrogen as a fuel, in a distributed energy storage framework. Such a system could be directly connected to the power grid at the distribution level to reduce power and energy intermittence problems related to renewable energy generation. Similarly, it could be located close to the user (e.g., office buildings, commercial centers, industrial plants, hospitals, etc.. Finally, it could be integrated in decentralized energy generation systems to reduce the peak electricity demand charges and energy costs, to increase power generation efficiency, to enhance the security of electrical energy supply, and to facilitate the market penetration of small renewable energy systems. Different configurations have been investigated (simple hybrid storage system, regenerate system, multistage system demonstrating the compressed air and hydrogen storage systems effectiveness in improving energy source flexibility and efficiency, and possibly in reducing the costs of energy supply. Round-trip efficiency up to 65% can be easily reached. The analysis is conducted through a mixed theoretical-numerical approach, which allows the definition of the most relevant physical parameters affecting the system

Big Pylons: Mixed signals for transmission. Spatial planning for energy distribution

International Nuclear Information System (INIS)

Ritchie, Heather; Hardy, Maelíosa; Lloyd, M. Greg; McGreal, Stanley

2013-01-01

The effective delivery of a sustainable energy future raises many challenges in relation to energy distribution where a new understanding of spatial planning is needed in relation to energy production, consumption and storage. Understanding the emergent low carbon energy economy in terms of its production, distribution and consumption characteristics has prompted a deliberate spatial planning interest. This paper examines issues relating to spatial planning, regulation, political legitimacy and accountability in the current and future systems for energy distribution. In particular it examines the Beauly Denny public inquiry in Scotland as a case study in terms of demonstrating the changing state–market–civil relations in an energy transition context with differentiated values and interests. The case study highlights implications for the regulation in the public interest of highly contested spaces, places and development schemes, together with a synopsis of government structure and change that is influencing the future of spatial planning and energy distribution in particular. - Highlights: • We examine links between spatial planning and regulation of energy distribution. • We examine the Beauly Denny public inquiry in Scotland. • We highlight challenges surrounding the development of a resilient energy system. • We highlight links between spatial planning and infrastructural development

Foundational Report Series: Advanced Distribution Management Systems for Grid Modernization, DMS Integration of Distributed Energy Resources and Microgrids

Energy Technology Data Exchange (ETDEWEB)

Singh, Ravindra [Argonne National Lab. (ANL), Argonne, IL (United States); Reilly, James T. [Reilly Associates, Pittston, PA (United States); Wang, Jianhui [Argonne National Lab. (ANL), Argonne, IL (United States); Lu, Xiaonan [Argonne National Lab. (ANL), Argonne, IL (United States); Kang, Ning [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-03-01

Deregulation of the electric utility industry, environmental concerns associated with traditional fossil fuel-based power plants, volatility of electric energy costs, Federal and State regulatory support of “green” energy, and rapid technological developments all support the growth of Distributed Energy Resources (DERs) in electric utility systems and ensure an important role for DERs in the smart grid and other aspects of modern utilities. DERs include distributed generation (DG) systems, such as renewables; controllable loads (also known as demand response); and energy storage systems. This report describes the role of aggregators of DERs in providing optimal services to distribution networks, through DER monitoring and control systems—collectively referred to as a Distributed Energy Resource Management System (DERMS)—and microgrids in various configurations.

Distributed Electrical Energy Systems: Needs, Concepts, Approaches and Vision

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yingchen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Jun [University of Denver; Gao, Wenzhong [University of Denver; Zheng, Xinhu [University of Minnesota; Yang, Liuqing [Colorado State University; Hao, Jun [University of Denver; Dai, Xiaoxiao [University of Denver

2017-09-01

Intelligent distributed electrical energy systems (IDEES) are featured by vast system components, diversifled component types, and difficulties in operation and management, which results in that the traditional centralized power system management approach no longer flts the operation. Thus, it is believed that the blockchain technology is one of the important feasible technical paths for building future large-scale distributed electrical energy systems. An IDEES is inherently with both social and technical characteristics, as a result, a distributed electrical energy system needs to be divided into multiple layers, and at each layer, a blockchain is utilized to model and manage its logic and physical functionalities. The blockchains at difierent layers coordinate with each other and achieve successful operation of the IDEES. Speciflcally, the multi-layer blockchains, named 'blockchain group', consist of distributed data access and service blockchain, intelligent property management blockchain, power system analysis blockchain, intelligent contract operation blockchain, and intelligent electricity trading blockchain. It is expected that the blockchain group can be self-organized into a complex, autonomous and distributed IDEES. In this complex system, frequent and in-depth interactions and computing will derive intelligence, and it is expected that such intelligence can bring stable, reliable and efficient electrical energy production, transmission and consumption.

Energy distribution in dissociations of polyatomic molecules

International Nuclear Information System (INIS)

Koernig, S.A.

1989-01-01

In this thesis studies are reported of fragmentation processes in polyatomic molecules. In order to find out which dessocaciation reactions take place, how they are brought about by the internal energy of the reactant, and to investigate the structure of the dissociating 'transition state', the fragment mass and the corresponding kinetic energy release (KER) are determined by differential translational spectroscopy using a position and time sensitive two-particle coincidence detector. The results are interpreted using the statistical theory of unimolecular dissociation. It turns out that the standard assumptions of the theory, especially in calculating KER-distributions, are not realistic in all molecules considered. Dissociation is induced by the neutralization with alkali metal vapour. In ch. 2 the experimental method and the analysis of the data (dissociation pathways, branching ratios and ε-d-distributions) are introduced and exemplified by measurements of cyclohexane, which represents the upper limit in precursor and fragment mass accessible in the apparatus. In ch. 3 a study is reported of the molecules methylchloride (CH 3 Cl) and the acetylradical (CH 3 CO). In spite of their similar geometric structures, completely different dissociation mechanisms have been found. Methylchloride dissociates via a repulsive state; acetyl radicals show energy scrambling. The energy distribution from dissociating acetyl exemplifies dynamical effects in the dissociation. In ch. 4 an investigation of a number of prototype hydrocarbons is presented. The dissociation pathways of several small linear alkanes indicate that neutralization takes place to unknown repulsive potentials, of which the position and steepness are determined from the kinetic energy release. (author). 118 refs.; 40 figs.; 5 tabs

Hydrogenic impurity binding energy in vertically coupled Ga1-xAlxAs quantum-dots under hydrostatic pressure and applied electric field

International Nuclear Information System (INIS)

Duque, C.M.; Barseghyan, M.G.; Duque, C.A.

2009-01-01

This work deals with a theoretical study, using a variational method and the effective mass approximation, of the ground state binding energy of a hydrogenic donor impurity in a vertically coupled multiple quantum dot structure under the effects of hydrostatic pressure and in-growth direction applied electric field. The low dimensional structure consists of three cylindrical shaped GaAs quantum dots coupled by Ga 1-x Al x As barriers. For the hydrostatic pressure has been considered the Γ-X crossover in the Ga 1-x Al x As material. As a general, the results show that: (1) the binding energy as a function of the impurity position has a similar shape to that shown by the electron wave function without the Coulomb interaction, (2) the presence of the electric field changes dramatically the binding energy profile destroying (favoring) the symmetry in the structures, and (3) depending on the impurity position the binding energy can increase or decrease with the hydrostatic pressure mainly due to increases or decreases of the carrier-wave function symmetry by changing the height of the potential barrier.

Total-energy Assisted Tight-binding Method Based on Local Density Approximation of Density Functional Theory

Science.gov (United States)

Fujiwara, Takeo; Nishino, Shinya; Yamamoto, Susumu; Suzuki, Takashi; Ikeda, Minoru; Ohtani, Yasuaki

2018-06-01

A novel tight-binding method is developed, based on the extended Hückel approximation and charge self-consistency, with referring the band structure and the total energy of the local density approximation of the density functional theory. The parameters are so adjusted by computer that the result reproduces the band structure and the total energy, and the algorithm for determining parameters is established. The set of determined parameters is applicable to a variety of crystalline compounds and change of lattice constants, and, in other words, it is transferable. Examples are demonstrated for Si crystals of several crystalline structures varying lattice constants. Since the set of parameters is transferable, the present tight-binding method may be applicable also to molecular dynamics simulations of large-scale systems and long-time dynamical processes.

Network Capacity Assessment of CHP-based Distributed Generation on Urban Energy Distribution Networks

Science.gov (United States)

Zhang, Xianjun

The combined heat and power (CHP)-based distributed generation (DG) or dis-tributed energy resources (DERs) are mature options available in the present energy market, considered to be an effective solution to promote energy efficiency. In the urban environment, the electricity, water and natural gas distribution networks are becoming increasingly interconnected with the growing penetration of the CHP-based DG. Subsequently, this emerging interdependence leads to new topics meriting serious consideration: how much of the CHP-based DG can be accommodated and where to locate these DERs, and given preexisting constraints, how to quantify the mutual impacts on operation performances between these urban energy distribution networks and the CHP-based DG. The early research work was conducted to investigate the feasibility and design methods for one residential microgrid system based on existing electricity, water and gas infrastructures of a residential community, mainly focusing on the economic planning. However, this proposed design method cannot determine the optimal DG sizing and siting for a larger test bed with the given information of energy infrastructures. In this context, a more systematic as well as generalized approach should be developed to solve these problems. In the later study, the model architecture that integrates urban electricity, water and gas distribution networks, and the CHP-based DG system was developed. The proposed approach addressed the challenge of identifying the optimal sizing and siting of the CHP-based DG on these urban energy networks and the mutual impacts on operation performances were also quantified. For this study, the overall objective is to maximize the electrical output and recovered thermal output of the CHP-based DG units. The electricity, gas, and water system models were developed individually and coupled by the developed CHP-based DG system model. The resultant integrated system model is used to constrain the DG's electrical

Creating hourly distributions at national level for various energy demands and renewable energy supplies

DEFF Research Database (Denmark)

Connolly, David; Drysdale, Dave; Hansen, Kenneth

2015-01-01

being recorded over longer time horizons, for example over one day. In this paper, a methodology is presented for creating hourly distributions for energy systems analysis tools. On the demand side, hourly distributions are developed for electricity, heating, cooling, and transport while the supply side...... includes wind, solar (photovoltaic and thermal), and wave power. Distributions are not created for dispatchable plants, such as coal, gas, and nuclear thermal plants, since their output is usually determined by the energy modelling tool rather than by a dependent resource. The methodologies are purposely...

Microgrid Enabled Distributed Energy Solutions (MEDES) Fort Bliss Military Reservation

Science.gov (United States)

2014-02-01

FINAL REPORT Microgrid Enabled Distributed Energy Solutions (MEDES) Fort Bliss Military Reservation ESTCP Project EW-201140 FEBRUARY...TITLE AND SUBTITLE Microgrid Enabled Distributed Energy Solutions (MEDES) 5a. CONTRACT NUMBER W912HQ-11-C-0082 Fort Bliss, Texas...Lockheed Martin’s Intelligent Microgrid Solution can provide more energy security while also lowering electric utility costs and greenhouse gas emissions

What do we learn from transverse energy distributions?

International Nuclear Information System (INIS)

Baym, G.; Friedman, G.; Heiselberg, H.

1990-01-01

Transverse energy measurements provide a wealth of information on the physics of ultrarelativistic heavy-ion collisions. To begin with they tell one the degree to which the colliding nuclei transfer energy and stop each other. With information about the space-time dynamics of the collisions, transverse energy data enables one to estimate the evolving energy density in the collision volume, a quantity needed to assess the likelihood of quark-gluon plasma formation. Furthermore, since the transverse energy distribution is to a large extent determined by the geometry of the collision, transverse energy is a useful indicator of centrality of collisions. It also provides considerable evidence for the rescattering of secondaries in the medium. Finally, fluctuations in the tails of the transverse energy distributions are an important probe of the independence of or possible coherence among the nucleon-nucleon subcollisions that constitute the first stage of heavy-ion collisions. Since the experimental talks in this workshop have done a rather complete job of presenting the transverse energy data from both BNL and CERN, the focus, as the authors discuss these topics in turn, will be on the theoretical interpretation of the data

Energy distribution extraction of negative charges responsible for positive bias temperature instability

International Nuclear Information System (INIS)

Ren Shang-Qing; Yang Hong; Wang Wen-Wu; Tang Bo; Tang Zhao-Yun; Wang Xiao-Lei; Xu Hao; Luo Wei-Chun; Zhao Chao; Yan Jiang; Chen Da-Peng; Ye Tian-Chun

2015-01-01

A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of nMOSFET during positive bias temperature instability (PBTI) stress based on the recovery measurement. In our case, the extracted energy distribution of negative charges shows an obvious dependence on energy, and the energy level of the largest energy density of negative charges is 0.01 eV above the conduction band of silicon. The charge energy distribution below that energy level shows strong dependence on the stress voltage. (paper)

Influence of Distributed Residential Energy Storage on Voltage in Rural Distribution Network and Capacity Configuration

Science.gov (United States)

Liu, Lu; Tong, Yibin; Zhao, Zhigang; Zhang, Xuefen

2018-03-01

Large-scale access of distributed residential photovoltaic (PV) in rural areas has solved the voltage problem to a certain extent. However, due to the intermittency of PV and the particularity of rural residents’ power load, the problem of low voltage in the evening peak remains to be resolved. This paper proposes to solve the problem by accessing residential energy storage. Firstly, the influence of access location and capacity of energy storage on voltage distribution in rural distribution network is analyzed. Secondly, the relation between the storage capacity and load capacity is deduced for four typical load and energy storage cases when the voltage deviation meets the demand. Finally, the optimal storage position and capacity are obtained by using PSO and power flow simulation.

The broadband spectral energy distributions of SDSS blazars

Science.gov (United States)

Li, Huai-Zhen; Chen, Luo-En; Jiang, Yun-Guo; Yi, Ting-Feng

2015-07-01

We compiled the radio, optical and X-ray data of blazars from the Sloan Digital Sky Survey database, and presented the distribution of luminosities and broadband spectral indices. The distribution of luminosities shows that the averaged luminosity of flat spectrum radio quasars (FSRQs) is larger than that of BL Lacertae (BL Lac) objects. On the other hand, the broadband spectral energy distribution reveals that FSRQs and low energy peaked BL Lac objects have similar spectral properties, but high energy peaked BL Lac objects have a distinct spectral property. This may be due to the fact that different subclasses of blazars have different intrinsic environments and are at different cooling levels. Even so, a unified scheme is also revealed from the color-color diagram, which hints that there are similar physical processes operating in all objects under a range of intrinsic physical conditions or beaming parameters. Supported by the National Natural Science Foundation of China.

Universal binding energy relation for cleaved and structurally relaxed surfaces

International Nuclear Information System (INIS)

Srirangarajan, Aarti; Datta, Aditi; Gandi, Appala Naidu; Ramamurty, U; Waghmare, U V

2014-01-01

The universal binding energy relation (UBER), derived earlier to describe the cohesion between two rigid atomic planes, does not accurately capture the cohesive properties when the cleaved surfaces are allowed to relax. We suggest a modified functional form of UBER that is analytical and at the same time accurately models the properties of surfaces relaxed during cleavage. We demonstrate the generality as well as the validity of this modified UBER through first-principles density functional theory calculations of cleavage in a number of crystal systems. Our results show that the total energies of all the relaxed surfaces lie on a single (universal) energy surface, that is given by the proposed functional form which contains an additional length-scale associated with structural relaxation. This functional form could be used in modelling the cohesive zones in crack growth simulation studies. We find that the cohesive law (stress–displacement relation) differs significantly in the case where cracked surfaces are allowed to relax, with lower peak stresses occurring at higher displacements. (paper)

The congruence energy: a contribution to nuclear masses, deformation energies and fission barriers

International Nuclear Information System (INIS)

Myers, W.D.; Swiatecki, W.J.

1997-01-01

The difference between measured binding energies and those calculated using a shell- and pairing-corrected Thomas-Fermi model can be described approximately by C(I)=-10 exp(-4.2 vertical stroke I vertical stroke) MeV, where I=(N-Z)/A. Our interpretation of this extra binding is in terms of the granularity of quantal nucleonic density distributions, which leads to a stronger interaction for a neutron and proton with congruent nodal structures of their wave functions. The predicted doubling of this congruence energy in fission is supported by an analysis of measured fission barriers and by a study of wave functions in a dividing Hill-Wheeler box potential. A semi-empirical formula for the shape-dependent congruence energy is described. (orig.)

Subcellular distribution of folate and folate binding protein in renal proximal tubules

International Nuclear Information System (INIS)

Sharkey, C.; Hjelle, J.T.; Selhub, J.

1986-01-01

High affinity folate binding protein (FBP) found in brush border membranes derived from renal cortices is thought to be involved in the renal conservation of folate. To examine the mechanisms of folate recovery, the subcellular distribution of FBP and 3 H-folate in rabbit renal proximal tubules (PT) was examined using analytical cell fractionation techniques. Tubules contain 3.41 +/- 0.32 picomoles FBP/mg protein (X +/- S.D.; n = 5). Postnuclear supernates (PNS) of PT were layered atop Percoll-sucrose gradients, centrifuged, fractions collected and assayed for various marker enzymes and FBP. Pooled fractions from such gradients were subsequently treated with digitonin and centrifuged in a stoichiometric manner with the activity of the microvillar enzyme, alanylaminopeptidase (AAP); excess FBP distributed with more buoyant particles. Infusion of 3 H-folate into rabbit kidneys followed by tubule isolation and fractionation revealed a time dependent shift in distribution of radiolabel from the AAP-rich gradient fractions to a region containing more buoyant particles; radiolevel was not associated with lysosomal markers. EM-radioautography revealed grains over intracellular vesicles. These results are consistent with the hypothesis that folate is recovered by a process involving receptor-mediated endocytosis or transcytosis

Distributed energy resources in grid interactive AC microgrids

DEFF Research Database (Denmark)

Wang, Xiongfei; Guerrero, Josep; Chen, Zhe

2010-01-01

Increased penetration of distributed energy resources (DER) and large-scale deployment of renewable energy sources are challenging the entire architecture of traditional power system. Microgrid, featuring higher flexibility and reliability, becomes an attractive candidate for the configuration...

Anisotropic Lithium Insertion Behavior in Silicon Nanowires: Binding Energy, Diffusion Barrier, and Strain Effect

KAUST Repository

Zhang, Qianfan; Cui, Yi; Wang, Enge

2011-01-01

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.

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.

A method for predicting individual residue contributions to enzyme specificity and binding-site energies, and its application to MTH1.

Science.gov (United States)

Stewart, James J P

2016-11-01

A new method for predicting the energy contributions to substrate binding and to specificity has been developed. Conventional global optimization methods do not permit the subtle effects responsible for these properties to be modeled with sufficient precision to allow confidence to be placed in the results, but by making simple alterations to the model, the precisions of the various energies involved can be improved from about ±2 kcal mol -1 to ±0.1 kcal mol -1 . This technique was applied to the oxidized nucleotide pyrophosphohydrolase enzyme MTH1. MTH1 is unusual in that the binding and reaction sites are well separated-an advantage from a computational chemistry perspective, as it allows the energetics involved in docking to be modeled without the need to consider any issues relating to reaction mechanisms. In this study, two types of energy terms were investigated: the noncovalent interactions between the binding site and the substrate, and those responsible for discriminating between the oxidized nucleotide 8-oxo-dGTP and the normal dGTP. Both of these were investigated using the semiempirical method PM7 in the program MOPAC. The contributions of the individual residues to both the binding energy and the specificity of MTH1 were calculated by simulating the effect of mutations. Where comparisons were possible, all calculated results were in agreement with experimental observations. This technique provides fresh insight into the binding mechanism that enzymes use for discriminating between possible substrates.

Modeling Shear Induced Von Willebrand Factor Binding to Collagen

Science.gov (United States)

Dong, Chuqiao; Wei, Wei; Morabito, Michael; Webb, Edmund; Oztekin, Alparslan; Zhang, Xiaohui; Cheng, Xuanhong

2017-11-01

Von Willebrand factor (vWF) is a blood glycoprotein that binds with platelets and collagen on injured vessel surfaces to form clots. VWF bioactivity is shear flow induced: at low shear, binding between VWF and other biological entities is suppressed; for high shear rate conditions - as are found near arterial injury sites - VWF elongates, activating its binding with platelets and collagen. Based on parameters derived from single molecule force spectroscopy experiments, we developed a coarse-grain molecular model to simulate bond formation probability as a function of shear rate. By introducing a binding criterion that depends on the conformation of a sub-monomer molecular feature of our model, the model predicts shear-induced binding, even for conditions where binding is highly energetically favorable. We further investigate the influence of various model parameters on the ability to predict shear-induced binding (vWF length, collagen site density and distribution, binding energy landscape, and slip/catch bond length) and demonstrate parameter ranges where the model provides good agreement with existing experimental data. Our results may be important for understanding vWF activity and also for achieving targeted drug therapy via biomimetic synthetic molecules. National Science Foundation (NSF),Division of Mathematical Sciences (DMS).

An integrated economic and distributional analysis of energy policies

Energy Technology Data Exchange (ETDEWEB)

Labandeira, Xavier [Facultade de CC. Economicas, University of Vigo, 36310 Vigo (Spain); Labeaga, Jose M. [Instituto de Estudios Fiscales, Avda. Cardenal Herrera Oria 378, 28035 Madrid (Spain); Rodriguez, Miguel [Facultade de CC. Empresariais e Turismo, University of Vigo, 32004 Ourense (Spain)

2009-12-15

Most public policies, particularly those in the energy sphere, have not only efficiency but also distributional effects. However, there is a trade-off between modelling approaches suitable for calculating those impacts on the economy. For the former most of the studies have been conducted with general equilibrium models, whereas partial equilibrium models represent the main approach for distributional analysis. This paper proposes a methodology to simultaneously carry out an analysis of the distributional and efficiency consequences of changes in energy taxation. In order to do so, we have integrated a microeconomic household demand model and a computable general equilibrium model for the Spanish economy. We illustrate the advantages of this approach by simulating a revenue-neutral reform in Spanish indirect taxation, with a large increase of energy taxes that serve an environmental purpose. The results show that the reforms bring about significant efficiency and distributional effects, in some cases counterintuitive, and demonstrate the academic and social utility of this approximation. (author)

An integrated economic and distributional analysis of energy policies

International Nuclear Information System (INIS)

Labandeira, Xavier; Labeaga, Jose M.; Rodriguez, Miguel

2009-01-01

Most public policies, particularly those in the energy sphere, have not only efficiency but also distributional effects. However, there is a trade-off between modelling approaches suitable for calculating those impacts on the economy. For the former most of the studies have been conducted with general equilibrium models, whereas partial equilibrium models represent the main approach for distributional analysis. This paper proposes a methodology to simultaneously carry out an analysis of the distributional and efficiency consequences of changes in energy taxation. In order to do so, we have integrated a microeconomic household demand model and a computable general equilibrium model for the Spanish economy. We illustrate the advantages of this approach by simulating a revenue-neutral reform in Spanish indirect taxation, with a large increase of energy taxes that serve an environmental purpose. The results show that the reforms bring about significant efficiency and distributional effects, in some cases counterintuitive, and demonstrate the academic and social utility of this approximation. (author)

An accurate redetermination of the 118Sn binding energy

International Nuclear Information System (INIS)

Borzakov, S.B.; Panteleev, Ts.Ts.; Telezhnikov, S.A.; Chrien, R.E.; Faikow-Stanczyk, H.; Grigor'ev, Yu.V.; Pospisil, S.; Smotritskij, L.M.

2001-01-01

The energy of well-known strong γ-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,γ)-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 was taken into account by a Monte Carlo simulation. The procedure was used in obtaining of B n for 118 Sn and 64 Cu. The γ-ray spectrum from thermal neutron radiative capture by 117 Sn has been measured on the IBR-2 pulsed reactor. γ-rays were detected by a 72 cm 2 HPGe-detector. B n for 64 Cu was obtained from two γ-spectra. One spectrum was measured on the IBR-2 by the same detector. The other spectrum was measured with a pair spectrometer at the Brookhaven High Flux Beam Reactor. From these two spectra B n for 64 Cu was determined equal to 7915.52(8) keV. The mean value of two most precise results of B n for 118 Sn was determined to be 9326.35(9) keV. The B n for 57Fe was determined to be 7646.08(9) keV

Comparison of experimental and theoretical binding and transition energies in the actinide region

International Nuclear Information System (INIS)

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

1977-01-01

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

[3]tetrahydrotrazodone binding. Association with serotonin binding sites

International Nuclear Information System (INIS)

Kendall, D.A.; Taylor, D.P.; Enna, S.J.

1983-01-01

High (17 nM) and low (603 nM) affinity binding sites for [ 3 ]tetrahydrotrazodone ([ 3 ] THT), a biologically active analogue of trazodone, have been identified in rat brain membranes. The substrate specificity, concentration, and subcellular and regional distributions of these sites suggest that they may represent a component of the serotonin transmitter system. Pharmacological analysis of [ 3 ]THT binding, coupled with brain lesion and drug treatment experiments, revealed that, unlike other antidepressants, [ 3 ] THT does not attach to either a biogenic amine transporter or serotonin binding sites. Rather, it would appear that [ 3 ]THT may be an antagonist ligand for the serotonin binding site. This probe may prove of value in defining the mechanism of action of trazodone and in further characterizing serotonin receptors

High-energy tail distributions and resonant wave particle interaction

Science.gov (United States)

Leubner, M. P.

1983-01-01

High-energy tail distributions (k distributions) are used as an alternative to a bi-Lorentzian distribution to study the influence of energetic protons on the right- and left-hand cyclotron modes in a hot two-temperature plasma. Although the parameters are chosen to be in a range appropriate to solar wind or magnetospheric configurations, the results apply not only to specific space plasmas. The presence of energetic particles significantly alters the behavior of the electromagnetic ion cyclotron modes, leading to a wide range of unstable frequencies and increased growth rates. From the strongly enhanced growth rates it can be concluded that high-energy tail distributions should not show major temperature anisotropies, which is consistent with observations.

Resolving runaway electron distributions in space, time, and energy

Science.gov (United States)

Paz-Soldan, C.; Cooper, C. M.; Aleynikov, P.; Eidietis, N. W.; Lvovskiy, A.; Pace, D. C.; Brennan, D. P.; Hollmann, E. M.; Liu, C.; Moyer, R. A.; Shiraki, D.

2018-05-01

Areas of agreement and disagreement with present-day models of runaway electron (RE) evolution are revealed by measuring MeV-level bremsstrahlung radiation from runaway electrons (REs) with a pinhole camera. Spatially resolved measurements localize the RE beam, reveal energy-dependent RE transport, and can be used to perform full two-dimensional (energy and pitch-angle) inversions of the RE phase-space distribution. Energy-resolved measurements find qualitative agreement with modeling on the role of collisional and synchrotron damping in modifying the RE distribution shape. Measurements are consistent with predictions of phase-space attractors that accumulate REs, with non-monotonic features observed in the distribution. Temporally resolved measurements find qualitative agreement with modeling on the impact of collisional and synchrotron damping in varying the RE growth and decay rate. Anomalous RE loss is observed and found to be largest at low energy. Possible roles for kinetic instability or spatial transport to resolve these anomalies are discussed.

Experimental energy-dependent nuclear spin distributions

International Nuclear Information System (INIS)

Egidy, T. von; Bucurescu, D.

2009-01-01

A new method is proposed to determine the energy-dependent spin distribution in experimental nuclear-level schemes. This method compares various experimental and calculated moments in the energy-spin plane to obtain the spin-cutoff parameter σ as a function of mass A and excitation energy using a total of 7202 levels with spin assignment in 227 nuclei between F and Cf. A simple formula, σ 2 =0.391 A 0.675 (E-0.5Pa ' ) 0.312 , is proposed up to about 10 MeV that is in very good agreement with experimental σ values and is applied to improve the systematics of level-density parameters.

Comparison of Measured Dark Current Distributions with Calculated Damage Energy Distributions in HgCdTe

Science.gov (United States)

Marshall, C. J.; Marshall, P. W.; Howe, C. L.; Reed, R. A.; Weller, R. A.; Mendenhall, M.; Waczynski, A.; Ladbury, R.; Jordan, T. M.

2007-01-01

This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distributions were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described in [1]. The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Carlo code MCNPX [2]) produce a pronounced skewing of the damage energy distribution. While the nuclear elastic component (also calculated using the MCNPX) contributes only a small fraction of the total nonionizing damage energy, its inclusion in the shape of the damage across the array is significant. The Coulombic contribution was calculated using MRED [3-5], a Geant4 [4,6] application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.

Benchmark calculations with correlated molecular wave functions. VII. Binding energy and structure of the HF dimer

International Nuclear Information System (INIS)

Peterson, K.A.; Dunning, T.H. Jr.

1995-01-01

The hydrogen bond energy and geometry of the HF dimer have been investigated using the series of correlation consistent basis sets from aug-cc-pVDZ to aug-cc-pVQZ and several theoretical methods including Moller--Plesset perturbation and coupled cluster theories. Estimates of the complete basis set (CBS) limit have been derived for the binding energy of (HF) 2 at each level of theory by utilizing the regular convergence characteristics of the correlation consistent basis sets. CBS limit hydrogen bond energies of 3.72, 4.53, 4.55, and 4.60 kcal/mol are estimated at the SCF, MP2, MP4, and CCSD(T) levels of theory, respectively. CBS limits for the intermolecular F--F distance are estimated to be 2.82, 2.74, 2.73, and 2.73 A, respectively, for the same correlation methods. The effects of basis set superposition error (BSSE) on both the binding energies and structures have also been investigated for each basis set using the standard function counterpoise (CP) method. While BSSE has a negligible effect on the intramolecular geometries, the CP-corrected F--F distance and binding energy differ significantly from the uncorrected values for the aug-cc-pVDZ basis set; these differences decrease regularly with increasing basis set size, yielding the same limits in the CBS limit. Best estimates for the equilibrium properties of the HF dimer from CCSD(T) calculations are D e =4.60 kcal/mol, R FF =2.73 A, r 1 =0.922 A, r 2 =0.920 A, Θ 1 =7 degree, and Θ 2 =111 degree

Signatures of van der Waals binding: A coupling-constant scaling analysis

Science.gov (United States)

Jiao, Yang; Schröder, Elsebeth; Hyldgaard, Per

2018-02-01

The van der Waals (vdW) density functional (vdW-DF) method [Rep. Prog. Phys. 78, 066501 (2015), 10.1088/0034-4885/78/6/066501] describes dispersion or vdW binding by tracking the effects of an electrodynamic coupling among pairs of electrons and their associated exchange-correlation holes. This is done in a nonlocal-correlation energy term Ecnl, which permits density functional theory calculation in the Kohn-Sham scheme. However, to map the nature of vdW forces in a fully interacting materials system, it is necessary to also account for associated kinetic-correlation energy effects. Here, we present a coupling-constant scaling analysis, which permits us to compute the kinetic-correlation energy Tcnl that is specific to the vdW-DF account of nonlocal correlations. We thus provide a more complete spatially resolved analysis of the electrodynamical-coupling nature of nonlocal-correlation binding, including vdW attraction, in both covalently and noncovalently bonded systems. We find that kinetic-correlation energy effects play a significant role in the account of vdW or dispersion interactions among molecules. Furthermore, our mapping shows that the total nonlocal-correlation binding is concentrated to pockets in the sparse electron distribution located between the material fragments.

Leak detection for city gas pipelines based on instantaneous energy distribution characteristics

Energy Technology Data Exchange (ETDEWEB)

Zhigang, Chen [Deijing University of Civil Engineering and Architecture, Beijing, (China)

2010-07-01

Many natural gas pipelines are used in our cities. The development of efficient leakage detection systems is fundamental for safety issues avoidance. This paper investigated a new solution to the leak detection problem in city gas pipelines based on instantaneous energy distribution. In a theoretical approach, the Hilbert-Huang transform (HHT) was used to provide the instantaneous energy distribution feature of an unstable pressure signal. The signal noise was eliminated thanks to the instantaneous energy contribution. A leakage detection model with instantaneous energy distribution (IED) was then established. The correlation coefficients of instantaneous energy distribution were through correlation analysis. It was found that in different pipeline states, the instantaneous energy distribution characteristics are different. A strong correlation of IED signal characteristics was found of the two ends of a city gas pipeline in the same operation. The test results demonstrated the reliability and validity of the method.

Distribution of primaquine in human blood: Drug-binding to alpha 1-glycoprotein

International Nuclear Information System (INIS)

Kennedy, E.; Frischer, H.

1990-01-01

To clarify the distribution of the antimalarial primaquine in human blood, we measured the drug separately in the liquid, cellular, and ultrafiltrate phases. Washed red cells resuspended at a hematocrit of 0.4 were exposed to a submaximal therapeutic level of 250 ng/ml of carbon 14-labeled primaquine. The tracer was recovered quantitatively in separated plasma and red cells. Over 75% of the total labeled drug was found in red cells suspended in saline solution, but only 10% to 30% in red cells suspended in plasma. The plasma effect was not mediated by albumin. Studies with alpha 1-acid glycoprotein (AGP), tris(2-butoxyethyl)phosphate, an agent that displaces AGP-bound drugs, and cord blood known to have decreased AGP established that primaquine binds to physiologic amounts of the glycoprotein in plasma. Red cell primaquine concentration increased linearly as AGP level fell and as the free drug fraction rose. We suggest that clinical blood levels of primaquine include the red cell fraction or whole blood level because (1) erythrocytic primaquine is a sizable and highly variable component of the total drug in blood; (2) this component reflects directly the free drug in plasma, and inversely the extent of binding to AGP; (3) the amount of free primaquine may influence drug transport into specific tissues in vivo; and (4) fluctuations of AGP, an acute-phase reactant that increases greatly in patients with malaria and other infections, markedly affect the partition of primaquine in blood. Because AGP binds many basic drugs, unrecognized primaquine-drug interactions may exist

Uncertainty analysis for secondary energy distributions

International Nuclear Information System (INIS)

Gerstl, S.A.W.

1978-01-01

In many transport calculations the integral design parameter of interest (response) is determined mainly by secondary particles such as gamma rays from (n,γ) reactions or secondary neutrons from inelastic scattering events or (n,2n) reactions. Standard sensitivity analysis usually allows to calculate the sensitivities to the production cross sections of such secondaries, but an extended formalism is needed to also obtain the sensitivities to the energy distribution of the generated secondary particles. For a 30-group standard cross-section set 84% of all non-zero table positions pertain to the description of secondary energy distributions (SED's) and only 16% to the actual reaction cross sections. Therefore, any sensitivity/uncertainty analysis which does not consider the effects of SED's is incomplete and neglects most of the input data. This paper describes the methods of how sensitivity profiles for SED's are obtained and used to estimate the uncertainty of an integral response due to uncertainties in these SED's. The detailed theory is documented elsewhere and implemented in the LASL sensitivity code SENSIT. SED sensitivity profiles have proven particularly valuable in cross-section uncertainty analyses for fusion reactors. Even when the production cross sections for secondary neutrons were assumed to be without error, the uncertainties in the energy distribution of these secondaries produced appreciable uncertainties in the calculated tritium breeding rate. However, complete error files for SED's are presently nonexistent. Therefore, methods will be described that allow rough error estimates due to estimated SED uncertainties based on integral SED sensitivities

Assessment of grid-friendly collective optimization framework for distributed energy resources

Energy Technology Data Exchange (ETDEWEB)

Pensini, Alessandro; Robinson, Matthew; Heine, Nicholas; Stadler, Michael; Mammoli, Andrea

2015-11-04

Distributed energy resources have the potential to provide services to facilities and buildings at lower cost and environmental impact in comparison to traditional electric-gridonly services. The reduced cost could result from a combination of higher system efficiency and exploitation of electricity tariff structures. Traditionally, electricity tariffs are designed to encourage the use of ‘off peak’ power and discourage the use of ‘onpeak’ power, although recent developments in renewable energy resources and distributed generation systems (such as their increasing levels of penetration and their increased controllability) are resulting in pressures to adopt tariffs of increasing complexity. Independently of the tariff structure, more or less sophisticated methods exist that allow distributed energy resources to take advantage of such tariffs, ranging from simple pre-planned schedules to Software-as-a-Service schedule optimization tools. However, as the penetration of distributed energy resources increases, there is an increasing chance of a ‘tragedy of the commons’ mechanism taking place, where taking advantage of tariffs for local benefit can ultimately result in degradation of service and higher energy costs for all. In this work, we use a scheduling optimization tool, in combination with a power distribution system simulator, to investigate techniques that could mitigate the deleterious effect of ‘selfish’ optimization, so that the high-penetration use of distributed energy resources to reduce operating costs remains advantageous while the quality of service and overall energy cost to the community is not affected.

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

Ion energy and angular distributions in inductively coupled Argon RF discharges

International Nuclear Information System (INIS)

Woodworth, J.R.; Riley, M.E.; Meister, D.C.

1996-03-01

We report measurements of the energies and angular distributions of positive ions in an inductively coupled argon plasma in a GEC reference cell. Use of two separate ion detectors allowed measurement of ion energies and fluxes as a function of position as well as ion angular distributions on the discharge centerline. The inductive drive on our system produced high plasma densities (up to 10 12 /cm 3 electron densities) and relatively stable plasma potentials. As a result, ion energy distributions typically consisted of a single feature well separated from zero energy. Mean ion energy was independent of rf power and varied inversely with pressure, decreasing from 29 eV to 12 eV as pressure increased form 2.4 m Torr to 50 mTorr. Half-widths of the ion angular distributions in these experiments varied from 5 degrees to 12.5 degrees, or equivalently, transverse temperatures varied form 0.2 to 0.5 eV with the distributions broadening as either pressure or RF power were increased

A Multiagent-based Consensus Algorithm for Distributed Coordinated Control of Distributed Generators in the Energy Internet

DEFF Research Database (Denmark)

Sun, Qiuye; Han, Renke; Zhang, Huaguang

2015-01-01

With the bidirectional power flow provided by the Energy Internet, various methods are promoted to improve and increase the energy utilization between Energy Internet and Main-Grid. This paper proposes a novel distributed coordinated controller combined with a multi-agent-based consensus algorithm...... which is applied to distributed generators in the Energy Internet. Then, the decomposed tasks, models, and information flow of the proposed method are analyzed. The proposed coordinated controller installed between the Energy Internet and the Main-Grid keeps voltage angles and amplitudes consensus while...... providing accurate power-sharing and minimizing circulating currents. Finally, the Energy Internet can be integrated into the Main-Grid seamlessly if necessary. Hence the Energy Internet can be operated as a spinning reserve system. Simulation results are provided to show the effectiveness of the proposed...

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...

Mu opioid receptor binding sites in human brain

International Nuclear Information System (INIS)

Pilapil, C.; Welner, S.; Magnan, J.; Zamir, N.; Quirion, R.

1986-01-01

Our experiments focused on the examination of the distribution of mu opioid receptor binding sites in normal human brain using the highly selective ligand [ 3 H]DAGO, in both membrane binding assay and in vitro receptor autoradiography. Mu opioid binding sites are very discretely distributed in human brain with high densities of sites found in the posterior amygdala, caudate, putamen, hypothalamus and certain cortical areas. Moreover the autoradiographic distribution of [ 3 H]DAGO binding sites clearly reveals the discrete lamination (layers I and III-IV) of mu sites in cortical areas

Energy distribution of nanoflares in the quiet solar corona

Science.gov (United States)

Ulyanov, Artyom

2012-07-01

We present a detailed statistical analysis of flare-like events in low layer of solar corona detected with TESIS instrument onboard CORONAS-PHOTON satellite in 171 {Å} during high-cadence (5 sec) time-series. The estimated thermal energies of these small events amount to 10^{23} - 10^{26} erg. According to modern classification flare-like events with such energies are usually referred to as nanoflares. The big number of registered events (above 2000) allowed us to obtain precise distributions of geometric and physical parameters of nanoflares, the most intriguing being energy distribution. Following Aschwanden et al. (2000) and other authors we approximated the calculated energy distribution with a single power law slope: N(E)dE ˜ N^{-α}dE. The power law index was derived to be α = 2.4 ± 0.2, which is very close to the value reported by Krucker & Benz (1998): α ≈ 2.3 - 2.4. The total energy input from registered events constitute about 10^4 erg \\cdot cm^{-2} \\cdot s^{-1}, which is well beyond net losses in quiet corona (3 \\cdot 10^5 erg \\cdot cm^{-2} \\cdot s^{-1}). However, the value of α > 2 indicates that nanoflares with lower energies dominate over nanoflares with bigger energies and could contribute considerably to quiet corona heating.

10 CFR 431.193 - Test procedures for measuring energy consumption of distribution transformers.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Test procedures for measuring energy consumption of distribution transformers. 431.193 Section 431.193 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY... § 431.193 Test procedures for measuring energy consumption of distribution transformers. The test...

Localization-enhanced biexciton binding in semiconductors

DEFF Research Database (Denmark)

Langbein, Wolfgang Werner; Hvam, Jørn Märcher

1999-01-01

The influence of excitonic localization on the binding energy of biexcitons is investigated for quasi-three-dimensional and quasi-two-dimensional AlxGa1-xAs structures. An increase of the biexciton binding energy is observed for localization energies comparable to or larger than the free biexcito...

Mapping of barley alpha-amylases and outer subsite mutants reveals dynamic high-affinity subsites and barriers in the long substrate binding cleft

DEFF Research Database (Denmark)

Kandra, L.; Abou Hachem, Maher; Gyemant, G.

2006-01-01

Subsite affinity maps of long substrate binding clefts in barley alpha-amylases, obtained using a series of maltooligosaccharides of degree of polymerization of 3-12, revealed unfavorable binding energies at the internal subsites -3 and -5 and at subsites -8 and +3/+4 defining these subsites...... as binding barriers. Barley a-amylase I mutants Y105A and T212Y at subsite -6 and +4 resulted in release or anchoring of bound substrate, thus modifying the affinities of other high-affinity subsites (-2 and +2) and barriers. The double mutant Y105A-T212Y displayed a hybrid subsite affinity profile......, converting barriers to binding areas. These findings highlight the dynamic binding energy distribution and the versatility of long maltooligosaccharide derivatives in mapping extended binding clefts in a-amylases....

Free energy calculations offer insights into the influence of receptor flexibility on ligand-receptor binding affinities.

Science.gov (United States)

Dolenc, Jožica; Riniker, Sereina; Gaspari, Roberto; Daura, Xavier; van Gunsteren, Wilfred F

2011-08-01

Docking algorithms for computer-aided drug discovery and design often ignore or restrain the flexibility of the receptor, which may lead to a loss of accuracy of the relative free enthalpies of binding. In order to evaluate the contribution of receptor flexibility to relative binding free enthalpies, two host-guest systems have been examined: inclusion complexes of α-cyclodextrin (αCD) with 1-chlorobenzene (ClBn), 1-bromobenzene (BrBn) and toluene (MeBn), and complexes of DNA with the minor-groove binding ligands netropsin (Net) and distamycin (Dist). Molecular dynamics simulations and free energy calculations reveal that restraining of the flexibility of the receptor can have a significant influence on the estimated relative ligand-receptor binding affinities as well as on the predicted structures of the biomolecular complexes. The influence is particularly pronounced in the case of flexible receptors such as DNA, where a 50% contribution of DNA flexibility towards the relative ligand-DNA binding affinities is observed. The differences in the free enthalpy of binding do not arise only from the changes in ligand-DNA interactions but also from changes in ligand-solvent interactions as well as from the loss of DNA configurational entropy upon restraining.

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.

The Bi{sup 3+} 6s and 6p electron binding energies in relation to the chemical environment of inorganic compounds

Energy Technology Data Exchange (ETDEWEB)

Awater, Roy H.P., E-mail: R.H.P.Awater@tudelft.nl; Dorenbos, Pieter

2017-04-15

This paper provides an overview and interpretation of the spectroscopic data of the Bi{sup 3+} activator ion in 117 different inorganic compounds. The energies of the metal-to-metal charge transfer and the interconfigurational transitions of Bi{sup 3+} were collected from the archival literature. Using these energies, in combination with the electron binding energies in the host conduction and valence band, the binding energies in the 6s ground state and 6p excited state were determined relative to the vacuum level. The locations of the Bi{sup 3+} energy levels within the forbidden gap of the host compound provides valuable insight in the physical properties of the Bi{sup 3+} activator ion in different compounds.

Energy spectrum and angular distribution of prompt cosmic-ray muons

Energy Technology Data Exchange (ETDEWEB)

Castagnoli, C; Picchi, P [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica Generale); Castellina, A; D' Ettorre Piazzoli, B; Mannocchi, G; Vernetto, S [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica

1984-07-01

The energy spectrum and angular distribution of atmospheric prompt muons are calculated by using an integral solution for production of charmed particles, their decay and muon transport in the atmosphere. Current experimental information from accelerator and theoretical ideas about charm cross-section and semi-leptonic decay are used to give a reference prompt muon spectrum to compare with that from conventional sources (..pi.. and K decay). The obtained differential spectrum has an energy dependence which approaches that of the primary cosmic rays. The integral intensity of prompt muons is equal to the conventional one at about 250 TeV. The angular distribution is found to be practically flat in the range (0/80)/sup 0/ irrespective of the muon energy. On the basis of this analysis we estimate that accurate measurements of muon energy spectrum and angular distribution at energies greater than 10 TeV should allow one to obtain useful information regarding charm hadroproduction cross-section in the 100 TeV region.

The effect of including tensor forces in nucleon-nucleon interaction on three-nucleon binding energy

International Nuclear Information System (INIS)

Osman, A.; Ramadan, S.

1986-01-01

Separable two-body interactions are used in considering the three-nucleon problem. The nucleon-nucleon potentials are taken to include attraction and repulsion as well as tensor forces. The separable approximation is used in order to investigate the effect of the tensor forces. The separable expansion is introduced in the three-nucleon problem, by which the Faddeev equations are reduced to a well-behaved set of coupled integral equations. Numerical calculations are carried out for the obtained integral equations using potential functions of the Yamaguchi, Gaussian, Takabin, Mongan and Reid forms. The present calculated values of the binding energies of the 3 H and 3 He nuclei are in good agreement with the experimental values. The effect of including the tensor forces in the nucleon-nucleon interactions is found to improve the three-nucleon binding energy by about 4.490% to 8.324%. 37 refs., 2 tabs. (author)

The effect of higher order different meson exchange nucleon-nucleon interactions on the three-nucleon binding energy coupling problem

International Nuclear Information System (INIS)

Osman, A.; Ramadan, S.

1989-01-01

Faddeev equations of bound three-nucleon system are presented as a set of integral equations. To solve them, a sutable form of the nucleon-nucleon interactions is used: with the exchange of a scalar meson, a pseudoscalar meson and a massless vector meson. Higher orders of these different meson exchanges in the nucleon-nucleon interactions have been taken into account. With these nuclear forces and nucleon-nucleon interactions, the three-nucleon binding energy is calculated by solving the Faddeev integral equations. The obtained value of the three-nucleon binding energy is 8.441 MeV. The inclusion of the higher order terms of the different meson exchange in the nuclear nucleon-nucleon interaction is found to affect the three-nucleon binding by about 3.92%. 3 figs., 16 refs

Estimation of neutron energy distributions from prompt gamma emissions

Science.gov (United States)

Panikkath, Priyada; Udupi, Ashwini; Sarkar, P. K.

2017-11-01

A technique of estimating the incident neutron energy distribution from emitted prompt gamma intensities from a system exposed to neutrons is presented. The emitted prompt gamma intensities or the measured photo peaks in a gamma detector are related to the incident neutron energy distribution through a convolution of the response of the system generating the prompt gammas to mono-energetic neutrons. Presently, the system studied is a cylinder of high density polyethylene (HDPE) placed inside another cylinder of borated HDPE (BHDPE) having an outer Pb-cover and exposed to neutrons. The emitted five prompt gamma peaks from hydrogen, boron, carbon and lead can be utilized to unfold the incident neutron energy distribution as an under-determined deconvolution problem. Such an under-determined set of equations are solved using the genetic algorithm based Monte Carlo de-convolution code GAMCD. Feasibility of the proposed technique is demonstrated theoretically using the Monte Carlo calculated response matrix and intensities of emitted prompt gammas from the Pb-covered BHDPE-HDPE system in the case of several incident neutron spectra spanning different energy ranges.

Strategies for Power/Energy Saving in Distribution Networks

Directory of Open Access Journals (Sweden)

GRIGORAS, G.

2010-05-01

Full Text Available The power/energy losses reduction in distribution systems is an important issue during planning and operation, with important technical and economical implications. Thus, the energy losses minimization implies not only the technical improvement of the network, through its renewal with the introduction of the technological innovations in the equipment and circuit components as well as the optimal planning of the design and development of the network, but also requires the use of the methods and software tools to facilitate the operation process. The paper presents a strategy for power/energy saving which replacement of the 6 kV voltage level with 20 kV voltage level in correlation with the extent of using efficient transformers. In this line, different urban distribution networks were analyzed using fuzzy techniques.

Agent-based reactive power management of power distribution networks with distributed energy generation

International Nuclear Information System (INIS)

Rahman, M.S.; Mahmud, M.A.; Oo, A.M.T.; Pota, H.R.; Hossain, M.J.

2016-01-01

Highlights: • A coordinated multi-agent system is proposed for reactive power management. • A linear quadratic regulator with a proportional integral controller is designed. • Proposed multi-agent scheme provides accurate estimation and control of the system. • Voltage stability is improved with proper power management for different scenarios. • Results obtained from the proposed scheme is compared to the traditional approach. - Abstract: In this paper, a new agent-based distributed reactive power management scheme is proposed to improve the voltage stability of energy distribution systems with distributed generation units. Three types of agents – distribution system agent, estimator agent, and control agent are developed within the multi-agent framework. The agents simultaneously coordinated their activities through the online information and energy flow. The overall achievement of the proposed scheme depends on the coordination between two tasks – (i) estimation of reactive power using voltage variation formula and (ii) necessary control actions to provide the estimated reactive power to the distribution networks through the distributed static synchronous compensators. A linear quadratic regulator with a proportional integrator is designed for the control agent in order to control the reactive component of the current and the DC voltage of the compensators. The performance of the proposed scheme is tested on a 10-bus power distribution network under various scenarios. The effectiveness is validated by comparing the proposed approach to the conventional proportional integral control approach. It is found that, the agent-based scheme provides excellent robust performance under various operating conditions of the power distribution network.

Electron energy-distribution functions in gases

International Nuclear Information System (INIS)

Pitchford, L.C.

1981-01-01

Numerical calculation of the electron energy distribution functions in the regime of drift tube experiments is discussed. The discussion is limited to constant applied fields and values of E/N (ratio of electric field strength to neutral density) low enough that electron growth due to ionization can be neglected

Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network

Science.gov (United States)

Palanisamy, Thirumoorthy; Krishnasamy, Karthikeyan N.

2015-01-01

Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN) presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD) technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow) into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead. PMID:26426701

Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network.

Science.gov (United States)

Palanisamy, Thirumoorthy; Krishnasamy, Karthikeyan N

2015-01-01

Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN) presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD) technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow) into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead.

On the binding energy of double Λ hypernuclei in the relativistic mean field theory

International Nuclear Information System (INIS)

Marcos, S.; Lombard, R.J.

1997-01-01

The binding energy of two Λ hyperons bound to a nuclear core is calculated within the relativistic mean field theory. The starting point is a two body relativistic equation of the Breit type suggested by the RMFT, and corrected for the two-particle interaction. The 2 Λ correlation energy is evaluated and the contribution of the δ and φ mesons, acting solely between hyperons, to the bond energy σB ΛΛ of ( ΛΛ ) 6 He, ( ΛΛ ) 10 Be and ( ΛΛ ) 13 B is calculated. Predictions of the ΔB ΛΛ A dependence are made for heavier Λ-hypernuclei. (K.A.)

The energy distribution of electrons in radio jets

Science.gov (United States)

Tsouros, Alexandros; Kylafis, Nikolaos D.

2017-07-01

Context. Black-hole and neutron-star X-ray binaries exhibit compact radio jets, when they are in the so called quiescent, hard, or hard intermediate states. The radio spectrum in these states is flat to slightly inverted, I.e., the spectral index of the observed flux density is in the range 0 ≲ α ≲ 0.5. It is widely accepted that the energy distribution of the electrons, in the rest frame of the jet, is a power law with index in the range 3 ≲ p ≲ 5. Aims: Contrary to what our thinking was decades ago, now we know that the jets originate in the hot, inner flow around black holes and neutron stars. So it is worth investigating the radio spectrum that is emitted by a thermal jet as a function of direction. Methods: As an example, we consider a parabolic jet and, with the assumption of flux freezing, we compute the emitted spectrum in all directions, from radio to near infrared, using either a thermal distribution of electrons or a power-law one. Results: We have found that parabolic jets with a thermal distribution of electrons give also flat to slightly inverted spectra. In particular, for directions along the jet (θ = 0), both distributions of electron energies give α = 0 ± 0.01. The index α increases as the viewing angle θ increases and for directions perpendicular to the jet (θ = π/ 2), the thermal distribution gives α = 0.40 ± 0.05, while the power-law distribution gives α = 0.20 ± 0.05. The break frequency νb, which marks the transition from partially optically thick to optically thin synchrotron emission, is comparable for the power-law and the thermal distributions. Conclusions: Contrary to common belief, it is not necessary to invoke a power-law energy distribution of the electrons in a jet to explain its flat to slightly inverted radio spectrum. A relativistic Maxwellian produces similar radio spectra. Thus, the jet may be the widely invoked "corona" around black holes in X-ray binaries.

Energy and Pitch Distribution of Spontaneously-generated High-energy Bulk Ions in the RFP

Science.gov (United States)

Kim, Jungha; Anderson, Jay; Reusch, Joshua; Eilerman, Scott; Capecchi, William

2014-10-01

Magnetic reconnection events in the reversed field pinch (RFP) are known to heat bulk and impurity ions. Runaway due to a parallel electric field has recently been confirmed as an important acceleration mechanism for high energy test ions supplied by a neutral beam. This effect does not, however, explain the change in distribution of nearly Maxwellian bulk ions at a reconnection event. By operating MST near maximum current and low electron density, significant fusion neutron flux can be generated without neutral beam injection. The bulk ion distribution created in these plasmas is well-confined, non-Maxwellian, and can be measured by the Advanced Neutral Particle Analyzer (ANPA) placed at a radial or tangential porthole. Data show a high energy tail up to 25 keV with a relatively higher signal in the low energy channels (8-15 keV) at the radial port following a reconnection event. Analysis of the energy dependence of trapped orbits sampled by the ANPA at the radial view implies an abundance of lower energy particles in regions of higher neutral density. This mandates a careful deconvolution of the measured ANPA signal to compute the fast ion distribution. This work is supported by the US DOE and NSF.

Developing electricity distribution networks and their regulation to support sustainable energy

International Nuclear Information System (INIS)

Shaw, Rita; Attree, Mike; Jackson, Tim

2010-01-01

A more sustainable energy system will alter the current patterns of electricity demand and generation. This means technical, commercial and regulatory change for electricity network systems such as distribution networks. This paper traces the links in Great Britain between changes in energy policy since privatisation, changes in the objectives of the electricity regulator and changes in the objectives of the distribution networks and their owners, the distribution network operators (DNOs). The paper identifies tensions in regulatory policy and suggests reforms to the regulatory framework to support a lower-carbon future. DNOs are licensed regional infrastructure providers. In addition to their network services, the network companies can potentially deliver public policy objectives to facilitate heat infrastructure, energy-efficiency and distributed renewables. The paper identifies the potential benefits of a novel approach to facilitating renewable energy feed-in tariffs for electricity and heat, using DNOs.

Choreographing Cyber-Physical Distributed Control Systems for the Energy Sector

DEFF Research Database (Denmark)

López-Acosta, Hugo-Andrés; Heussen, Kai

2017-01-01

Energy Systems are facing a significant change in the way their management and control is conceived. With the introduction of distributed and renewable energy based resources, a shift to a more distributed operation paradigm is emerging, overturning the conventional top-down design and operation...... principles. This shift creates a demand for distributed control systems (DCS) to facilitate a more adaptive and efficient operation of power networks. One key challenge here is to ensure the required reliability of distributed control systems. Whereas proven strategies exist for reliable control...... for coordination of physical actions, with increasing distribution of such control, the reliability and degradation properties in response to communications issues become more important. We build on the notion of Quality Choreographies, a formal model for the development of failure-aware distributed systems...

Estimation of monthly solar radiation distribution for solar energy system analysis

International Nuclear Information System (INIS)

Coskun, C.; Oktay, Z.; Dincer, I.

2011-01-01

The concept of probability density frequency, which is successfully used for analyses of wind speed and outdoor temperature distributions, is now modified and proposed for estimating solar radiation distributions for design and analysis of solar energy systems. In this study, global solar radiation distribution is comprehensively analyzed for photovoltaic (PV) panel and thermal collector systems. In this regard, a case study is conducted with actual global solar irradiation data of the last 15 years recorded by the Turkish State Meteorological Service. It is found that intensity of global solar irradiance greatly affects energy and exergy efficiencies and hence the performance of collectors. -- Research highlights: → The first study to apply global solar radiation distribution in solar system analyzes. → The first study showing global solar radiation distribution as a parameter of the solar irradiance intensity. → Time probability intensity frequency and probability power distribution do not have similar distribution patterns for each month. → There is no relation between the distribution of annual time lapse and solar energy with the intensity of solar irradiance.

Distributed energy store powered railguns for hypervelocity launch

Science.gov (United States)

Maas, Brian L.; Bauer, David P.; Marshall, Richard A.

1993-01-01

Highly distributed power supplies are proposed as a basis for current difficulties with hypervelocity railgun power-supply compactness. This distributed power supply configuration reduces rail-to-rail voltage behind the main armature, thereby reducing the tendency for secondary armature current formation; secondary current elimination is essential for achieving the efficiencies associated with muzzle velocity above 6 km/sec. Attention is given to analytical and experimental results for two distributed energy storage schemes.

Conformational Dynamics of the Receptor Protein Galactose/Glucose Binding Protein

Science.gov (United States)

Messina, Troy; Talaga, David

2006-03-01

We have performed time-correlated single photon counting (TCSPC) anisotropy and Stokes Shift measurements on bulk solutions of galactose/glucose binding protein. Site-directed mutagenesis was used to provide a single cysteine amino acid near the sugar-binding center of the protein (glutamine 26 to cysteine -- Q26C). The cysteine was covalently labeled with the environmentally-sensitive fluorophore acrylodan, and a long-lived ruthenium complex was covalently attached to the N-terminus to provide a fluorescent reference. The TCSPC data were analyzed using global convolute-and-compare fitting routines over the entire glucose titration and temperature range to provide minimal reduced chi-squared values and the highest time resolution possible. Using a standard ligand-binding model, the resulting distributions show that the closed (ligand-bound) conformation exists even at zero glucose concentration. At 20^oC, the relative abundance of this conformation is as high as 40%. The temperature dependence of this conformational study will be discussed and related to the ligand-binding free energy surface.

Coordinated Optimization of Distributed Energy Resources and Smart Loads in Distribution Systems: Preprint

Energy Technology Data Exchange (ETDEWEB)

Yang, Rui; Zhang, Yingchen

2016-08-01

Distributed energy resources (DERs) and smart loads have the potential to provide flexibility to the distribution system operation. A coordinated optimization approach is proposed in this paper to actively manage DERs and smart loads in distribution systems to achieve the optimal operation status. A three-phase unbalanced Optimal Power Flow (OPF) problem is developed to determine the output from DERs and smart loads with respect to the system operator's control objective. This paper focuses on coordinating PV systems and smart loads to improve the overall voltage profile in distribution systems. Simulations have been carried out in a 12-bus distribution feeder and results illustrate the superior control performance of the proposed approach.

Distributed Energy Systems in the Built Environment - European Legal Framework on Distributed Energy Systems in the Built Environment

NARCIS (Netherlands)

Pront-van Bommel, S.; Bregman, A.

2013-01-01

This paper aims to outline the stimuli provided by European law for promoting integrated planning of distributed renewable energy installations on the one hand and its limitations thereof on the other hand, also with regard to the role of local governments.

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

TCP (truncated compound Poisson) process for multiplicity distributions in high energy collisions

International Nuclear Information System (INIS)

Srivastave, P.P.

1990-01-01

On using the Poisson distribution truncated at zero for intermediate cluster decay in a compound Poisson process, the authors obtain TCP distribution which describes quite well the multiplicity distributions in high energy collisions. A detailed comparison is made between TCP and NB for UA5 data. The reduced moments up to the fifth agree very well with the observed ones. The TCP curves are narrower than NB at high multiplicity tail, look narrower at very high energy and develop shoulders and oscillations which become increasingly pronounced as the energy grows. At lower energies the distributions, of the data for fixed intervals of rapidity for UA5 data and for the data (at low energy) for e + e - annihilation and pion-proton, proton-proton and muon-proton scattering. A discussion of compound Poisson distribution, expression of reduced moments and Poisson transforms are also given. The TCP curves and curves of the reduced moments for different values of the parameters are also presented

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.

CaFE: a tool for binding affinity prediction using end-point free energy methods.

Science.gov (United States)

Liu, Hui; Hou, Tingjun

2016-07-15

Accurate prediction of binding free energy is of particular importance to computational biology and structure-based drug design. Among those methods for binding affinity predictions, the end-point approaches, such as MM/PBSA and LIE, have been widely used because they can achieve a good balance between prediction accuracy and computational cost. Here we present an easy-to-use pipeline tool named Calculation of Free Energy (CaFE) to conduct MM/PBSA and LIE calculations. Powered by the VMD and NAMD programs, CaFE is able to handle numerous static coordinate and molecular dynamics trajectory file formats generated by different molecular simulation packages and supports various force field parameters. CaFE source code and documentation are freely available under the GNU General Public License via GitHub at https://github.com/huiliucode/cafe_plugin It is a VMD plugin written in Tcl and the usage is platform-independent. tingjunhou@zju.edu.cn. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Blockchain for Smart Grid Resilience: Exchanging Distributed Energy at Speed, Scale and Security

Energy Technology Data Exchange (ETDEWEB)

Mylrea, Michael E.; Gourisetti, Sri Nikhil Gup

2017-09-18

Blockchain may help solve several complex problems related to integrity and trustworthiness of rapid, distributed, complex energy transactions and data exchanges. In a move towards resilience, blockchain commoditizes trust and enables automated smart contracts to support auditable multiparty transactions based on predefined rules between distributed energy providers and customers. Blockchain based smart contracts also help remove the need to interact with third-parties, facilitating the adoption and monetization of distributed energy transactions and exchanges, both energy flows as well as financial transactions. This may help reduce transactive energy costs and increase the security and sustainability of distributed energy resource (DER) integration, helping to remove barriers to a more decentralized and resilient power grid.

Optimal Planning Method of On-load Capacity Regulating Distribution Transformers in Urban Distribution Networks after Electric Energy Replacement Considering Uncertainties

Directory of Open Access Journals (Sweden)

Yu Su

2018-06-01

Full Text Available Electric energy replacement is the umbrella term for the use of electric energy to replace oil (e.g., electric automobiles, coal (e.g., electric heating, and gas (e.g., electric cooking appliances, which increases the electrical load peak, causing greater valley/peak differences. On-load capacity regulating distribution transformers have been used to deal with loads with great valley/peak differences, so reasonably replacing conventional distribution transformers with on-load capacity regulating distribution transformers can effectively cope with load changes after electric energy replacement and reduce the no-load losses of distribution transformers. Before planning for on-load capacity regulating distribution transformers, the nodal effective load considering uncertainties within the life cycle after electric energy replacement was obtained by a Monte Carlo method. Then, according to the loss relation between on-load capacity regulating distribution transformers and conventional distribution transformers, three characteristic indexes of annual continuous apparent power curve and replacement criteria for on-load capacity regulating distribution transformers were put forward in this paper, and a set of distribution transformer replaceable points was obtained. Next, based on cost benefit analysis, a planning model of on-load capacity regulating distribution transformers which consists of investment profitability index within the life cycle, investment cost recouping index and capacity regulating cost index was put forward. The branch and bound method was used to solve the planning model within replaceable point set to obtain upgrading and reconstruction scheme of distribution transformers under a certain investment. Finally, planning analysis of on-load capacity regulating distribution transformers was carried out for electric energy replacement points in one urban distribution network under three scenes: certain load, uncertain load and nodal

Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network.

Directory of Open Access Journals (Sweden)

Thirumoorthy Palanisamy

Full Text Available Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead.

Developing electricity distribution networks and their regulation to support sustainable energy

Energy Technology Data Exchange (ETDEWEB)

Shaw, Rita; Attree, Mike [Electricity North West Ltd., 304 Bridgewater Place, Birchwood, Warrington, Cheshire WA3 6XG (United Kingdom); Jackson, Tim [RESOLVE, Centre for Environmental Strategy D3, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2010-10-15

A more sustainable energy system will alter the current patterns of electricity demand and generation. This means technical, commercial and regulatory change for electricity network systems such as distribution networks. This paper traces the links in Great Britain between changes in energy policy since privatisation, changes in the objectives of the electricity regulator and changes in the objectives of the distribution networks and their owners, the distribution network operators (DNOs). The paper identifies tensions in regulatory policy and suggests reforms to the regulatory framework to support a lower-carbon future. DNOs are licensed regional infrastructure providers. In addition to their network services, the network companies can potentially deliver public policy objectives to facilitate heat infrastructure, energy-efficiency and distributed renewables. The paper identifies the potential benefits of a novel approach to facilitating renewable energy feed-in tariffs for electricity and heat, using DNOs. (author)

Quantitative analysis on electric dipole energy in Rashba band splitting.

Science.gov (United States)

Hong, Jisook; Rhim, Jun-Won; Kim, Changyoung; Ryong Park, Seung; Hoon Shim, Ji

2015-09-01

We report on quantitative comparison between the electric dipole energy and the Rashba band splitting in model systems of Bi and Sb triangular monolayers under a perpendicular electric field. We used both first-principles and tight binding calculations on p-orbitals with spin-orbit coupling. First-principles calculation shows Rashba band splitting in both systems. It also shows asymmetric charge distributions in the Rashba split bands which are induced by the orbital angular momentum. We calculated the electric dipole energies from coupling of the asymmetric charge distribution and external electric field, and compared it to the Rashba splitting. Remarkably, the total split energy is found to come mostly from the difference in the electric dipole energy for both Bi and Sb systems. A perturbative approach for long wave length limit starting from tight binding calculation also supports that the Rashba band splitting originates mostly from the electric dipole energy difference in the strong atomic spin-orbit coupling regime.

First lattice calculation of the B-meson binding and kinetic energies

CERN Document Server

Crisafulli, M; Martinelli, G; Sachrajda, Christopher T C

1995-01-01

We present the first lattice calculation of the B-meson binding energy \\labar and of the kinetic energy -\\lambda_1/2 m_Q of the heavy-quark inside the pseudoscalar B-meson. This calculation has required the non-perturbative subtraction of the power divergences present in matrix elements of the Lagrangian operator \\bar h D_4 h and of the kinetic energy operator \\bar h \\vec D^2 h. The non-perturbative renormalisation of the relevant operators has been implemented by imposing suitable renormalisation conditions on quark matrix elements, in the Landau gauge. Our numerical results have been obtained from several independent numerical simulations at \\beta=6.0 and 6.2, and using, for the meson correlators, the results obtained by the APE group at the same values of \\beta. Our best estimate, obtained by combining results at different values of \\beta, is \\labar =190 \\err{50}{30} MeV. For the \\overline{MS} running mass, we obtain \\overline {m}_b(\\overline {m}_b) =4.17 \\pm 0.06 GeV, in reasonable agreement with previous...

Distributed technologies in California's energy future: A preliminary report. Volume 2

Energy Technology Data Exchange (ETDEWEB)

Christensen, M.; Craig, P.; McGuire, C.B.; Simmons, M. (eds.)

1977-09-01

The chapters in Volume 2 of Distributed Energy Systems in California's Future are: Environmental Impacts of Alternative Energy Technologies for California; Land Use Configurations and the Utilization of Distributive Energy Technology; Land Use Implications of a Dispersed Energy Path; Belief, Behavior, and Technologies as Driving Forces in Transitional Stages--The People Problem in Dispersed Energy Futures; Development of an Energy Attitude Survey; Interventions to Influence Firms Toward the Adoption of ''Soft'' Energy Technology; The Entry of Small Firms into Distributed Technology Energy Industries; Short-Term Matching of Supply and Demand in Electrical Systems with Renewable Sources; Vulnerability of Renewable Energy Systems; and District Heating for California.

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.)

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.)

The distribution of iron between the metal-binding sites of transferrin human serum.

Science.gov (United States)

Williams, J; Moreton, K

1980-02-01

The Makey & Seal [(1976) Biochim. Biophys. Acta 453, 250--256] method of polyacrylamide-gel electrophoresis in buffer containing 6 M-urea was used to determine the distribution of iron between the N-terminal and C-terminal iron-binding sites of transferrin in human serum. In fresh serum the two sites are unequally occupied; there is preferential occupation of the N-terminal site. On incubation of the serum at 37 degrees C the preference of iron for the N-terminal site becomes more marked. On storage of serum at -15 degrees C the iron distribution changes so that there is a marked preference for the C-terminal site. Dialysis of serum against buffer at pH 7.4 also causes iron to be bound much more strongly by the C-terminal than by the N-terminal site. The original preference for the N-terminal site can be resroted to the dialysed serum by addition of the diffusible fraction.

Operation optimization of a distributed energy system considering energy costs and exergy efficiency

International Nuclear Information System (INIS)

Di Somma, M.; Yan, B.; Bianco, N.; Graditi, G.; Luh, P.B.; Mongibello, L.; Naso, V.

2015-01-01

Highlights: • Operation optimization model of a Distributed Energy System (DES). • Multi-objective strategy to optimize energy cost and exergy efficiency. • Exergy analysis in building energy supply systems. - Abstract: With the growing demand of energy on a worldwide scale, improving the efficiency of energy resource use has become one of the key challenges. Application of exergy principles in the context of building energy supply systems can achieve rational use of energy resources by taking into account the different quality levels of energy resources as well as those of building demands. This paper is on the operation optimization of a Distributed Energy System (DES). The model involves multiple energy devices that convert a set of primary energy carriers with different energy quality levels to meet given time-varying user demands at different energy quality levels. By promoting the usage of low-temperature energy sources to satisfy low-quality thermal energy demands, the waste of high-quality energy resources can be reduced, thereby improving the overall exergy efficiency. To consider the economic factor as well, a multi-objective linear programming problem is formulated. The Pareto frontier, including the best possible trade-offs between the economic and exergetic objectives, is obtained by minimizing a weighted sum of the total energy cost and total primary exergy input using branch-and-cut. The operation strategies of the DES under different weights for the two objectives are discussed. The operators of DESs can choose the operation strategy from the Pareto frontier based on costs, essential in the short run, and sustainability, crucial in the long run. The contribution of each energy device in reducing energy costs and the total exergy input is also analyzed. In addition, results show that the energy cost can be much reduced and the overall exergy efficiency can be significantly improved by the optimized operation of the DES as compared with the

Energy Distributions from Three-Body Decaying Many-Body Resonances

International Nuclear Information System (INIS)

Alvarez-Rodriguez, R.; Jensen, A. S.; Fedorov, D. V.; Fynbo, H. O. U.; Garrido, E.

2007-01-01

We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0 + and 1 + resonances in 12 C populated in β decays. These states are dominated by sequential, through the 8 Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the ''dynamic'' evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wave functions are accurately computed

Modeling of customer adoption of distributed energy resources

Energy Technology Data Exchange (ETDEWEB)

Marnay, Chris; Chard, Joseph S.; Hamachi, Kristina S.; Lipman, Timothy; Moezzi, Mithra M.; Ouaglal, Boubekeur; Siddiqui, Afzal S.

2001-08-01

This report describes work completed for the California Energy Commission (CEC) on the continued development and application of the Distributed Energy Resources Customer Adoption Model (DER-CAM). This work was performed at Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) between July 2000 and June 2001 under the Consortium for Electric Reliability Technology Solutions (CERTS) Distributed Energy Resources Integration (DERI) project. Our research on distributed energy resources (DER) builds on the concept of the microgrid ({mu}Grid), a semiautonomous grouping of electricity-generating sources and end-use sinks that are placed and operated for the benefit of its members. Although a {mu}Grid can operate independent of the macrogrid (the utility power network), the {mu}Grid is usually interconnected, purchasing energy and ancillary services from the macrogrid. Groups of customers can be aggregated into {mu}Grids by pooling their electrical and other loads, and the most cost-effective combination of generation resources for a particular {mu}Grid can be found. In this study, DER-CAM, an economic model of customer DER adoption implemented in the General Algebraic Modeling System (GAMS) optimization software is used, to find the cost-minimizing combination of on-site generation customers (individual businesses and a {mu}Grid) in a specified test year. DER-CAM's objective is to minimize the cost of supplying electricity to a specific customer by optimizing the installation of distributed generation and the self-generation of part or all of its electricity. Currently, the model only considers electrical loads, but combined heat and power (CHP) analysis capability is being developed under the second year of CEC funding. The key accomplishments of this year's work were the acquisition of increasingly accurate data on DER technologies, including the development of methods for forecasting cost reductions for these technologies, and the creation of a

Proton multiplicity distributions in high-energy hadron-nuclei collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1979-01-01

The fast proton emission process is analyzed in high-energy hadron-nuclei collisions. The formula describing the proton multiplicity distributions is derived. It describes well enough the proton multiplicity distribution of pion-nuclei and proton-nuclei collisions at 200 and 400 GeV

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.

Forest Biomass Energy Resources in China: Quantity and Distribution

Directory of Open Access Journals (Sweden)

Caixia Zhang

2015-11-01

Full Text Available As one of the most important renewable and sustainable energy sources, the forest biomass energy resource has always been the focus of attention of scholars and policy makers. However, its potential is still uncertain in China, especially with respect to its spatial distribution. In this paper, the quantity and distribution of Chinese forest biomass energy resources are explored based mainly on forestry statistics data rather than forest resource inventory data used by most previous studies. The results show that the forest biomass energy resource in China was 169 million tons in 2010, of which wood felling and bucking residue (WFBR,wood processing residue (WPR, bamboo processing residue, fuel wood and firewood used by farmers accounted for 38%, 37%, 6%, 4% and 15%, respectively. The highest resource was located in East China, accounting for nearly 39.0% of the national amount, followed by the Southwest and South China regions, which accounted for 17.4% and 16.3%, respectively. At the provincial scale, Shandong has the highest distribution, accounting for 11.9% of total resources, followed by Guangxi and Fujian accounting for 10.3% and 10.2%, respectively. The actual wood-processing residue (AWPR estimated from the actual production of different wood products (considering the wood transferred between regions showed apparent differences from the local wood processing residue (LWPR, which assumes that no wood has been transferredbetween regions. Due to the large contribution of WPR to total forestry bioenergy resources, the estimation of AWPR will provide a more accurate evaluation of the total amount and the spatial distribution of forest biomass energy resources in China.