Showing papers on "Energy (signal processing) published in 2003"
TL;DR: In this paper, the first nucleon-nucleon potential at the fourth order of chiral perturbation theory was presented, and the accuracy for the reproduction of the nucleon nucleon $(NN)$ data below $290\text{\ensuremath{-}}\text{MeV}$ lab energy is comparable to the one of phenomenological high-precision potentials.
Abstract: We present the first nucleon-nucleon potential at next-to-next-to-next-to-leading order (fourth order) of chiral perturbation theory. Charge dependence is included up to next-to-leading order of the isospin-violation scheme. The accuracy for the reproduction of the nucleon-nucleon $(NN)$ data below $290\text{\ensuremath{-}}\text{MeV}$ lab energy is comparable to the one of phenomenological high-precision potentials. Since $NN$ potentials of order three and less are known to be deficient in quantitative terms, the present work shows that the fourth order is necessary and sufficient for a $NN$ potential reliable up to $290\phantom{\rule{0.3em}{0ex}}\text{MeV}$. The new potential provides a promising starting point for exact few-body calculations and microscopic nuclear structure theory (including chiral many-body forces derived on the same footing).
1,151 citations
Patent•
07 Mar 2003
TL;DR: In this paper, an automatic querying of energy users within a system of buildings for energy curtailment possibilities is provided such immediate, automatic queries may be answered by the energy users through artificial intelligence and/or neural network technology provided to or programmed into the users.
Abstract: Automatic energy management is provided, in even the most complex multi-building system The necessity of a human operator for managing energy in a complex, multi-building system is reduced and even eliminated Computer-based monitoring and computer-based recognition of adverse energy events (such as the approach of a new energy peak) is highly advantageous in energy management Immediate automatic querying of energy users within a system of buildings for energy curtailment possibilities is provided Such immediate, automatic querying may be answered by the energy users through artificial intelligence and/or neural network technology provided to or programmed into the energy users, and the queried energy users may respond in real-time Those real-time computerized responses with energy curtailment possibilities may be received automatically by a data processing facility, and processed in real-time Advantageously, the responses from queried energy users with energy curtailment possibilities may be automatically processed into a round-robin curtailment rotation which may be implemented by a computer-based control system Thus, impact on occupants is minimized, and energy use and energy cost may be beneficially reduced in an intelligent, real-time manner The invention also provides for early-recognition of impending adverse energy events, optimal response to a particular energy situation, real-time analysis of energy-related data, etc
468 citations
TL;DR: The energy of wavelet coefficients of EMG signals in nine scales, and the cepstrum coefficients were found to produce the best features in these views.
Abstract: The purpose of this research is to select the best features to have a high rate of motion classification for controlling an artificial hand. Here, 19 EMG signal features have been taken into account. Some of the features suggested in this study include combining wavelet transform with other signal processing techniques. An assessment is performed with respect to three points of view: (i) classification of motions, (ii) noise tolerance and (iii) calculation complexity. The energy of wavelet coefficients of EMG signals in nine scales, and the cepstrum coefficients were found to produce the best features in these views.
389 citations
TL;DR: In this article, the nuclear liquid-drop model is revisited and an explicit introduction of the surface-curvature terms is presented, and the corresponding parameters of the extended classical energy formula are adjusted to the contemporarily known nuclear binding energies and fission-barrier heights.
Abstract: Nuclear liquid-drop model is revisited and an explicit introduction of the surface-curvature terms is presented. The corresponding parameters of the extended classical energy formula are adjusted to the contemporarily known nuclear binding energies and fission-barrier heights. Using 2766 binding energies of nuclei with $Zg~8$ and $Ng~8$ it is shown that the performance of the new approach is improved by a factor of about 6, compared to the previously published liquid-drop model results, in terms of the masses (new rms deviation $〈\ensuremath{\delta}M〉=0.698\mathrm{MeV})$ and the fission barriers by a factor of about 3.5 (new rms deviation of the fission barriers of isotopes with $Zg70$ is $〈\ensuremath{\delta}{V}_{B}〉=0.88\mathrm{MeV}).$ The role of the nuclear surface-curvature terms and their effects on the description of the experimental quantities are discussed in detail. For comparison, the parameters of the more ``traditional'' classical energy expressions are refitted, taking into account the nuclear masses known today and the performances of several variants of the model are compared. The isospin dependence in the new description of the barriers is in a good agreement with the extended Thomas-Fermi approach. It also demonstrates a good qualitative agreement with the fission lifetime systematics tested on the long chain of Fermium isotopes known experimentally. The new approach offers a very high stability in terms of the extrapolation from the narrower range of nuclides to a more extended one---a property of particular interest for the contemporary exotic beam projects: the corresponding properties are illustrated and discussed. The new description of the fission barriers being significantly improved, in particular, the new calculated barriers being lower, flatter, but stiffer against high-multipolarity deformations. The chances for ``extra'' stabilization of the hyperdeformed minima at high spin increase, thus calling for the new total energy Strutinsky-type calculations.
311 citations
TL;DR: Unless climate sensitivity is low and acceptable amounts of climate change are high, climate stabilization will require a massive transition to CO2 emission–free energy technologies.
Abstract: The UN Framework Convention on Climate Change calls for “stabilization of greenhouse gas concentrations at a level that would prevent dangerous anthropogenic interference with the climate system.”Even if we could determine a “safe” level of interference in the climate system, the sensitivity of global mean temperature to increasing atmospheric CO2 is known perhaps only to a factor of three or less. Here we show how a factor of three uncertainty in climate sensitivity introduces even greater uncertainty in allowable increases in atmospheric CO2 concentration and allowable CO 2 emissions. Nevertheless, unless climate sensitivity is low and acceptable amounts of climate change are high, climate stabilization will require a massive transition to CO 2 emission–free energy technologies.
282 citations
05 May 2003
TL;DR: It is shown that with several typical compression tools, there is a net energy increase when compression is applied before transmission, and hardware-aware programming optimizations are demonstrated, which improve energy efficiency by 51%.
Abstract: Wireless transmission of a bit can require over 1000 times more energy than a single 32-bit computation. It would therefore seem desirable to perform significant computation to reduce the number of bits transmitted. If the energy required to compress data is less than the energy required to send it, there is a net energy savings and consequently, a longer battery life for portable computers. This paper reports on the energy of lossless data compressors as measured on a StrongARM SA-110 system. We show that with several typical compression tools, there is a net energy increase when compression is applied before transmission. Reasons for this increase are explained, and hardware-aware programming optimizations are demonstrated. When applied to Unix compress, these optimizations improve energy efficiency by 51%. We also explore the fact that, for many usage models, compression and decompression need not be performed by the same algorithm. By choosing the lowest-energy compressor and decompressor on the test platform, rather than using default levels of compression, overall energy to send compressible web data can be reduced 31%. Energy to send harder-to-compress English text can be reduced 57%. Compared with a system using a single optimized application for both compression and decompression, the asymmetric scheme saves 11% or 12% of the total energy depending on the dataset.
269 citations
TL;DR: In this paper, the existence of static striped density of electronic states in nearly optimally doped lattice constants in zero-field scanning tunneling spectroscopy has been shown, and the observed modulation is strongest at roughly half the superconducting gap energy.
Abstract: In this paper we show, using scanning tunneling spectroscopy, the existence of static striped density of electronic states in nearly optimally doped ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$ in zero field. The observed modulation is strongest at roughly half the superconducting gap energy and is aligned with the Cu-O bonds, with a periodicity of four lattice constants, exhibiting features characteristic of a two-dimensional system of line objects. These features also exhibit asymmetries between the two orthogonal directions locally, pointing to a possible broken symmetry state (i.e., a stripe phase). We further show that the density of states modulation manifests itself as a shift of states from above to below the superconducting gap. The fact that a single energy scale (i.e., the gap) appears for both superconductivity and stripes suggests that these two effects have the same microscopic origin.
259 citations
TL;DR: In this article, the authors present a complete set of virtual and real corrections to the parton level processes of the CERN Large Hadron Collider with a center-of-mass energy of 14 TeV.
Abstract: We present in detail the calculation of the $O({\ensuremath{\alpha}}_{s}^{3})$ inclusive total cross section for the process $p\stackrel{\ensuremath{\rightarrow}}{p}t\overline{t}h,$ in the standard model, at the CERN Large Hadron Collider with a center-of-mass energy $\sqrt{{s}_{H}}=14\mathrm{TeV}.$ The calculation is based on the complete set of virtual and real $O({\ensuremath{\alpha}}_{s})$ corrections to the parton level processes $q\overline{q}\ensuremath{\rightarrow}t\overline{t}h$ and $g\stackrel{\ensuremath{\rightarrow}}{g}t\overline{t}h,$ as well as the tree level processes $(q,\overline{q})\stackrel{\ensuremath{\rightarrow}}{g}t\overline{t}h+(q,\overline{q}).$ The virtual corrections involve the computation of pentagon diagrams with several internal and external massive particles, first encountered in this process. The real corrections are computed using both the single and the two cutoff phase space slicing method. The next-to-leading order QCD corrections significantly reduce the renormalization and factorization scale dependence of the Born cross section and moderately increase the Born cross section for values of the renormalization and factorization scales above ${m}_{t}.$
256 citations
TL;DR: In this article, a coarse molecular dynamics approach is used to study the kinetics and thermodynamics of a peptide fragment dissolved in water, where short bursts of appropriately initialized simulations are used to infer the deterministic and stochastic components of the peptide motion parametrized by an appropriate set of coarse variables.
Abstract: We present a “coarse molecular dynamics” approach and apply it to studying the kinetics and thermodynamics of a peptide fragment dissolved in water. Short bursts of appropriately initialized simulations are used to infer the deterministic and stochastic components of the peptide motion parametrized by an appropriate set of coarse variables. Techniques from traditional numerical analysis (Newton–Raphson, coarse projective integration) are thus enabled; these techniques help analyze important features of the free-energy landscape (coarse transition states, eigenvalues and eigenvectors, transition rates, etc.). Reverse integration of coarse variables backward in time can assist escape from free energy minima and trace low-dimensional free energy surfaces. To illustrate the coarse molecular dynamics approach, we combine multiple short (0.5 ps) replica simulations to map the free energy surface of the “alanine dipeptide” in water, and to determine the ∼1/(1000 ps) rate of interconversion between the two stable configurational basins corresponding to the α-helical and extended minima.
255 citations
TL;DR: In this article, a numerical simulation system was developed adopting a new one-dimensional urban canopy meteorological model coupled with a simple sub-model for the building energy analysis to simulate the increase in cooling energy demands and evaluate urban warming countermeasures from the viewpoint of buildings' energy savings.
227 citations
TL;DR: In this article, the authors demonstrate a quantum interference switch where a laser pulse with an energy per area of 23$ photons per ${\ensuremath{\sim}23$ photon per ${ \ensuremath{\lambda}}^{2}/(2 \ensureMath{\pi})$ causes a $1/e$ absorption of a second pulse.
Abstract: Electromagnetically induced transparency in an optically thick, cold medium creates a unique system where pulse-propagation velocities may be orders of magnitude less than c and optical nonlinearities become exceedingly large. As a result, nonlinear processes may be efficient at low-light levels. Using an atomic system with three, independent channels, we demonstrate a quantum interference switch where a laser pulse with an energy per area of $\ensuremath{\sim}23$ photons per ${\ensuremath{\lambda}}^{2}/(2\ensuremath{\pi})$ causes a $1/e$ absorption of a second pulse.
TL;DR: In this article, the authors consider a single-molecule system with a single oscillator mode and compare it to a reference model with frequency-independent damping, and find a qualitative agreement between their theory and recent experiments on singlemolecules devices.
Abstract: Transport through molecular devices with strong coupling to a single vibrational mode is considered in the case where the vibration is damped by coupling to the environment. We focus on the weak tunneling limit, for which a rate equation approach is valid. The role of the environment can be characterized by a frictional damping term $\mathcal{S}(\ensuremath{\omega})$ and a corresponding frequency shift. We consider a molecule that is attached to a substrate, leading to a frequency-dependent frictional damping of the single oscillator mode of the molecule, and compare it to a reference model with frequency-independent damping featuring a constant quality factor Q. For large values of Q, the transport is governed by tunneling between displaced oscillator states, giving rise to the well-known series of the Frank-Condon steps, while at small Q, there is a crossover to the classical regime with an energy gap given by the classical displacement energy. Using realistic values for the elastic properties of the substrate and the size of the molecule, we calculate $I\ensuremath{-}V$ curves and find a qualitative agreement between our theory and recent experiments on ${\mathrm{C}}_{60}$ single-molecule devices.
TL;DR: In this paper, computer simulations of the performance of a specific commercial lithium-ion polymer cell (Sony's UP383562) are used to examine the capacity, energy density, and rate capability attainable by these systems.
Abstract: Most commercial lithium-ion polymer cells differ from traditional lithium-ion cells only in their cell construction and packaging. Their use of thinner separators, immobilized gel electrolyte solutions, and metallized plastic laminated packaging potentially allow an improvement in both rate capability and energy density over previous generations of thin prismatic cells. Computer simulations of the performance of a specific commercial lithium-ion polymer cell (Sony's UP383562) are used to examine the capacity, energy density, and rate capability attainable by these systems. The current first-generation commercial cells are studied, and their performance is extrapolated to next-generation designs that are shown to achieve even higher capacities and energy densities. Fundamental limits in the energy density attainable by these systems are described. © 2003 The Electrochemical Society. All rights reserved.
TL;DR: It turns out that escapes from MBs do not happen by single hops between PEL minima, but correspond to complicated multiminima sequences, and the concept of return probabilities to the bottom of the MBs is introduced in order to judge when the attraction range of a MB has been left.
Abstract: We study the relation of the potential energy landscape (PEL) topography to relaxation dynamics of a small model glass former of Lennard-Jones type. The mechanism under investigation is the hopping between superstructures of PEL minima, called metabasins (MBs). Guided by the idea that the mean durations 〈\ensuremath{\tau}〉 of visits to MBs should reflect the local PEL structure, we first derive the effective depths of MBs from dynamics, by the relation ${E}_{\mathrm{app}}=d\mathrm{ln}〈\ensuremath{\tau}〉/d\ensuremath{\beta},$ where $\ensuremath{\beta}{=1/k}_{B}T.$ Second, we establish a connection of ${E}_{\mathrm{app}}$ to the barriers that surround MBs. As the consequence of a rugged PEL, it turns out that escapes from MBs do not happen by single hops between PEL minima, but correspond to complicated multiminima sequences. We introduce the concept of return probabilities to the bottom of the MBs in order to judge when the attraction range of a MB has been left. The energy barriers overcome can then be identified. These turn out to be in good agreement with the effective depths ${E}_{\mathrm{app}},$ calculated from dynamics. We are thus able to relate MB lifetimes to their local structure. Moreover, we can trace back the overall diffusive dynamics to the population of MBs and to their local topology, i.e., to purely thermodynamic and structural quantities. Single energy barriers are identified with the help of a new method, which accurately performs a descent along the ridge between two minima. We analyze the population of transition regions between minima, called basin borders. No indication for the mechanism of diffusion to change around the mode-coupling temperature can be found. We discuss the question whether the one-dimensional reaction paths connecting two minima are relevant for the calculation of reaction rates at the temperatures under study.
TL;DR: The problem of how to understand this phenomenological behavior in terms of functional integrals is solved for the case of an isospin chemical through the study of the spectrum of the operator gamma(0)(/D+m).
Abstract: In a Euclidean space functional integral treatment of the free energy of QCD, a chemical potential enters only through the functional determinant of the Dirac operator which for any flavor is $\mathrm{D\ensuremath{\llap{
ot\;}}}+m\ensuremath{-}{\ensuremath{\mu}}_{f}{\ensuremath{\gamma}}_{0}$ (where ${\ensuremath{\mu}}_{f}$ is the chemical potential for the given flavor). Any nonzero $\ensuremath{\mu}$ alters all of the eigenvalues of the Dirac operator relative to the $\ensuremath{\mu}=0$ value, leading to a naive expectation that the determinant is altered and which thereby alters the free energy. Phenomenologically, this does not occur at $T=0$ for sufficiently small $\ensuremath{\mu}$, in contradiction to this naive expectation. The problem of how to understand this phenomenological behavior in terms of functional integrals is solved for the case of an isospin chemical through the study of the spectrum of the operator ${\ensuremath{\gamma}}_{0}(\mathrm{D\ensuremath{\llap{
ot\;}}}+m)$. The case of the baryon chemical potential is briefly discussed.
TL;DR: Ab initio molecular dynamics is used as a basis for quasichemical theory evaluation of the free energy of water near conventional liquid thermodynamic states and the hydration freeEnergy of water in water at 314 K is calculated to be -5.1 kcal/mole with the rPBE functional, in encouraging agreement with the experimental value.
Abstract: We use ab initio molecular dynamics as a basis for quasichemical theory evaluation of the free energy of water near conventional liquid thermodynamic states. The Perdew-Wang-91 (PW91), Perdew-Burke-Ernzerhof (PBE), and revised PBE (rPBE) functionals are employed. The oxygen radial density distribution using the rPBE functional is in reasonable agreement with current experiments, whereas the PW91 and PBE functionals predict a more structured oxygen radial density distribution. The diffusion coefficient with the rPBE functional is in reasonable accord with experiments. Using a maximum entropy procedure, we obtain ${x}_{0}$ from the coordination number distribution ${x}_{n}$ for oxygen atoms having n neighbors. Likewise, we obtain ${p}_{0}$ from ${p}_{n},$ the probability of observing cavities of specified radius containing n water molecules. The probability ${x}_{0}$ is a measure of the local chemical interactions and is central to the quasichemical theory of solutions. The probability ${p}_{0},$ central to the theory of liquids, is a measure of the free energy required to open cavities of defined sizes in the solvent. Using these values and a reasonable model for electrostatic and dispersion effects, the hydration free energy of water in water at 314 K is calculated to be $\ensuremath{-}5.1\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{e}$ with the rPBE functional, in encouraging agreement with the experimental value of $\ensuremath{-}6.1\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{e}.$
TL;DR: Mapping the complete final state momentum space with high resolution, a distinct local minimum is observed at P( e parallel )=0, where P(e parallel ) is the electron momentum parallel to the laser polarization.
Abstract: Electron emission for single ionization of Ne by 25 fs, $1.0\text{ }\mathrm{P}\mathrm{W}/{\mathrm{c}\mathrm{m}}^{2}$ laser pulses at 800 nm has been investigated in a kinematically complete experiment using a ``reaction microscope.'' Mapping the complete final state momentum space with high resolution, a distinct local minimum is observed at ${P}_{e\ensuremath{\parallel}}=0$, where ${P}_{e\ensuremath{\parallel}}$ is the electron momentum parallel to the laser polarization. Whereas tunneling theory predicts a maximum at zero momentum, our findings are in good agreement with recent semiclassical predictions which were interpreted to be due to ``recollision.''
TL;DR: This work demonstrates that the effective potential of exchange-correlation functionals can be obtained iteratively by solving the partial differential equations for the orbital shifts that exactify the Krieger-Li-Iafrate approximation.
Abstract: For exchange-correlation functionals that depend explicitly on the Kohn-Sham orbitals, the potential ${V}_{\mathrm{x}\mathrm{c}\ensuremath{\sigma}}(\mathbf{r})$ must be obtained as the solution of the optimized effective potential (OEP) integral equation. This is very demanding and has limited the use of orbital functionals. We demonstrate that instead the OEP can be obtained iteratively by solving the partial differential equations for the orbital shifts that exactify the Krieger-Li-Iafrate approximation. Unoccupied orbitals do not need to be calculated. Accuracy and efficiency of the method are shown for atoms and clusters using the exact-exchange energy. Counterintuitive asymptotic limits of the exact OEP are presented.
TL;DR: In the ASDEX Upgrade tokamak, complex power deposition structures on the divertor target plates during type-I edge-localized modes (ELMs) have been discovered by fast (few microseconds), two-dimensional infrared thermography.
Abstract: In the ASDEX Upgrade tokamak, complex power deposition structures on the divertor target plates during type-I edge-localized modes (ELMs) have been discovered by fast (few microseconds), two-dimensional ($40\ifmmode\times\else\texttimes\fi{}40\text{ }{\mathrm{c}\mathrm{m}}^{2}$) infrared thermography. In addition to the usual axisymmetric power deposition line near the separatrix, there appear, statistically distributed, several laterally displaced and inclined stripes, mostly well separated from each other and from the main strike zone. These structures are interpreted as footprints of approximately field aligned, helical perturbations at the low field side of the main plasma edge related to the nonlinear ELM evolution. Based on this picture, the ELM related mode structure can be derived from the target load pattern, yielding on average toroidal mode numbers in a range of 8\char21{}24.
TL;DR: In this paper, the first-principles total energy calculation of BN nanotubes was performed based on a density functional spin-polarized method. And the authors showed that the levels in the gap region present an exchange splitting greater than 0.5 eV for some open shell systems (carbon substitutionals and vacancy defects).
Abstract: Antisites, carbon substitutionals, and vacancy defects in BN nanotubes have been investigated by first-principles total energy calculations, based on a density functional spin-polarized method. All defects introduce localized energy levels inside the band gap. For some open-shell systems (carbon substitutionals and vacancy defects) the levels in the gap region present an exchange splitting greater than 0.5 eV. The ${\mathrm{C}}_{\mathrm{B}}$ and ${\mathrm{N}}_{\mathrm{B}}$ defects, in N-rich growth condition, and ${\mathrm{C}}_{\mathrm{N}}$ in B-rich growth condition, are the ones that present the lower formation energies.
TL;DR: In this paper, a detailed site-selective spectroscopy has been performed as a function of temperature on the transition of the ions at both crystallographic sites, and the authors measured the temperature dependence of the optical dephasing, transition energy, and linewidth of the ion.
Abstract: Detailed site-selective spectroscopy has been performed as a function of temperature on the ${}^{7}{F}_{0}{\ensuremath{\leftrightarrow}}^{5}{D}_{0}$ transition of ${\mathrm{Eu}}^{3+}:{\mathrm{Y}}_{2}{\mathrm{SiO}}_{5}$ for ${\mathrm{Eu}}^{3+}$ concentrations of 002%, 01%, 05%, and 1% Time-domain optical dephasing, spectral hole lifetimes, anisotropic absorption coefficients, inhomogeneous linewidths, and fluorescence lifetimes for ${\mathrm{Eu}}^{3+}$ ions at both crystallographic sites were measured The temperature dependence of the optical dephasing, transition energy, and linewidth of the ${}^{7}{\stackrel{\ensuremath{\rightarrow}}{{F}_{0}}}^{5}{D}_{0}$ absorption was measured and interpreted in terms of Raman scattering of phonons Photon echo measurements of optical dephasing gave ${T}_{2}$ values as long as 26 ms, approaching the limit set by the fluorescence decay time Spectral hole lifetimes were measured for temperatures from 2 K to 18 K, with observed lifetimes varying from 1 s at 18 K to an estimated value of greater than 20 days at 2 K Anisotropic absorption coefficients were measured, and an increase in ${\mathrm{Eu}}^{3+}$ concentration from 002% to 7% produced an increase in the inhomogeneous linewidth ${\ensuremath{\Gamma}}_{\mathrm{inh}}$ from 05 GHz to \ensuremath{\sim}150 GHz, indicating that ${\mathrm{Eu}}^{3+}$ doping induces significant strain in the crystal New determinations of many energy levels of ${}^{7}{F}_{J}$ multiplets have been made for $J=0$ to 6
TL;DR: In this paper, a measurement of the one-neutron removal channel, utilizing a secondary ion beam with an energy of 520 MeV/nucleon impinging on lead and carbon targets, was performed.
Abstract: Electromagnetic and nuclear inelastic scattering of the halo nucleus ${}^{11}\mathrm{Be}$ have been investigated by a measurement of the one-neutron removal channel, utilizing a secondary ${}^{11}\mathrm{Be}$ beam with an energy of 520 MeV/nucleon impinging on lead and carbon targets. All decay products, i.e., ${}^{10}\mathrm{Be}$ fragments, neutrons, and $\ensuremath{\gamma}$ rays have been detected in coincidence. Partial cross sections for the population of ground and excited states in ${}^{10}\mathrm{Be}$ were determined for nuclear diffractive breakup as well as for electromagnetically induced breakup. The partial cross sections for ground-state transitions have been differentiated further with respect to excitation energy, and the dipole-strength function associated solely with transitions of the halo ${2s}_{1/2}$ neutron to the continuum has been derived. The extracted dipole strength integrated from the neutron threshold up to 6.1 MeV excitation energy amounts to ${0.90(6)e}^{2}{\mathrm{fm}}^{2}.$ A spectroscopic factor for the $\ensuremath{
u}{2s}_{1/2}{\ensuremath{\bigotimes}}^{10}\mathrm{Be}{(0}^{+})$ single-particle configuration of 0.61(5) and a root-mean-square radius of the ${2s}_{1/2}$ neutron wave function of 5.7(4) fm have been deduced.
TL;DR: At numerical resolutions around 512(3) and above, three-dimensional energy spectra from turbulence simulations begin to show noticeably shallower spectra than k-5/3 near the dissipation wave number ("bottleneck effect").
Abstract: At numerical resolutions around ${512}^{3}$ and above, three-dimensional energy spectra from turbulence simulations begin to show noticeably shallower spectra than ${k}^{\ensuremath{-}5/3}$ near the dissipation wave number (``bottleneck effect''). This effect is shown to be significantly weaker in one-dimensional spectra such as those obtained in wind tunnel turbulence. The difference can be understood in terms of the transformation between the one-dimensional and three-dimensional energy spectra under the assumption that the turbulent velocity field is isotropic. Transversal and longitudinal energy spectra are similar and can both accurately be computed from the full three-dimensional spectra. Second-order structure functions are less susceptible to the bottleneck effect and may be better suited for inferring the scaling exponent from numerical simulation data.
TL;DR: In this article, the authors observed a mass renormalization or ''kink'' in the E vs.k dispersion relations localized near the nodal direction of the bilayer splitting.
Abstract: Using high-resolution angle-resolved photoemission spectroscopy on ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}},$ we observe a new mass renormalization or ``kink'' in the E vs $\stackrel{\ensuremath{\rightarrow}}{k}$ dispersion relations localized near $(\ensuremath{\pi},0).$ The resolution of bilayer splitting allowed the first direct measurements of this interaction effect. The kink is clearly stronger than the kink observed along the nodal direction, appears at a lower energy (near 40 meV for overdoped samples), and is only apparent in the superconducting state. The kink energy scale defines a cutoff below which well-defined quasiparticle excitations occur. The most likely origin of this effect is coupling to the magnetic-resonance mode observed in inelastic neutron scattering.
TL;DR: In this article, Chandra observations of the x-ray luminosity of galaxy clusters with independent measurements of baryonic matter density and the latest measurements of the Hubble parameter as given by the HST key project are constrained by the equation of state characterizing the dark energy component.
Abstract: The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the x-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest measurements of the Hubble parameter as given by the HST key project. By assuming a spatially flat scenario driven by a ``quintessence'' component with an equation of state ${p}_{x}=\ensuremath{\omega}{\ensuremath{\rho}}_{x},$ we place the following limits on the cosmological parameters $\ensuremath{\omega}$ and ${\ensuremath{\Omega}}_{\mathrm{m}}:$ (i) $\ensuremath{-}1l~\ensuremath{\omega}l~\ensuremath{-}0.55$ and ${\ensuremath{\Omega}}_{\mathrm{m}}{=0.32}_{\ensuremath{-}0.014}^{+0.027}$ $(1\ensuremath{\sigma})$ if the equation of state of the dark energy is restricted to the interval $\ensuremath{-}1l~\ensuremath{\omega}l0$ (the usual quintessence) and (ii) $\ensuremath{\omega}=\ensuremath{-}{1.29}_{\ensuremath{-}0.792}^{+0.686}$ and ${\ensuremath{\Omega}}_{\mathrm{m}}{=0.31}_{\ensuremath{-}0.034}^{+0.037}$ $(1\ensuremath{\sigma})$ if $\ensuremath{\omega}$ violates the null energy condition and assume values below $\ensuremath{-}1$ (extended quintessence or ``phantom'' energy). These results are in good agreement with independent studies based on supernovae observations, large-scale structure, and the anisotropies of the cosmic background radiation.
TL;DR: In this paper, the authors studied the crashworthiness characteristics of thin-walled steel tubes containing annular grooves and found that the buckling mode and energy absorption capacity of the tubes could be controlled by the introduction of circumferential grooves with different distances.
Abstract: In the present study, crashworthiness characteristics of thin-walled steel tubes containing annular grooves are studied. For this purpose, the grooves are introduced in the tube to force the plastic deformation to occur at predetermined intervals along the tube. The aims are controlling the buckling mode and predicting energy absorption capacity of the tubes. To do so, circumferential grooves are cut alternately inside and outside of the tubes at predetermined intervals. Quasi-static axial crushing tests are performed and the load-displacement curves are studied. Theoretical formulations are presented for predicting the energy absorption and mean crushing load. It is found a good agreement between the theoretical results and experimental findings. The results indicate that the load-displacement curve and energy absorbed by the axial crushing of tubes could be controlled by the introduction of grooves with different distances. Also, grooves can stabilize the deformation behavior and thus, the proposed method could be a good candidate as a controllable energy absorption element.
TL;DR: Analysis of the low temperature phase of La0.5Sr1.5MnO4, a compound that displays charge and orbital ordering, reports the first direct resonant soft x-ray scattering observations of orbital ordering.
Abstract: We report the first direct resonant soft x-ray scattering observations of orbital ordering. We have studied the low temperature phase of ${\mathrm{L}\mathrm{a}}_{0.5}{\mathrm{S}\mathrm{r}}_{1.5}{\mathrm{M}\mathrm{n}\mathrm{O}}_{4}$, a compound that displays charge and orbital ordering. Previous claims of orbital ordering in such materials have relied on observations at the manganese $K$ edge. These claims have been questioned in several theoretical studies. Instead we have employed resonant soft x-ray scattering at the manganese ${L}_{\mathrm{I}\mathrm{I}\mathrm{I}}$ and ${L}_{\mathrm{I}\mathrm{I}}$ edges which probes the orbital ordering directly. Energy scans at constant wave vector are compared to theoretical predictions and suggest that at all temperatures there are two separate contributions to the scattering: direct orbital ordering and strong cooperative Jahn-Teller distortions of the ${\mathrm{M}\mathrm{n}}^{3+}$ ions.
TL;DR: In this paper, the geometric and electronic properties of small 2D Au clusters were studied using the density-functional method, and a clear odd-even oscillation was found for the stability and energy gaps of small two-dimensional (2D) Au clusters.
Abstract: The geometric and electronic properties of small two-dimensional (2D) ${\mathrm{Au}}_{N}$ $(N=2\char21{}20)$ clusters are studied using the density-functional method. The lowest-energy geometries of a closed-packed nature are selected for 2D ${\mathrm{Au}}_{2}\ensuremath{-}{\mathrm{}\mathrm{Au}}_{8}$ clusters. A clear odd-even oscillation is found for the stability and energy gaps of ${\mathrm{Au}}_{N}$ clusters with $Nl~15.$ The polarizabilities of the 2D clusters are calculated and found to be strongly anisotropic. In the normal direction of a 2D cluster, the polarizability is smaller than that of bulk Si, indicating a nonmetallic character. A fitting formula is proposed to estimate the polarizability of a 2D Au cluster with arbitrary size and shape in the normal direction. The behavior of a 2D Au cluster in a strong electric field is also discussed.
TL;DR: In this article, the effects of the 13-mixing (sin^2 theta_{13}) and of the type of mass hierarchy/ordering (sign[ Delta m^2{13}]) on neutrino signals from the gravitational collapses of stars have been calculated.
Abstract: We consider in details the effects of the 13-mixing (sin^2 theta_{13}) and of the type of mass hierarchy/ordering (sign[ Delta m^2_{13}]) on neutrino signals from the gravitational collapses of stars. The observables (characteristics of the energy spectra of nu_e and antinu_e events) sensitive to sin^2 theta_{13} and sign[Delta m^2_{13}] have been calculated. They include the ratio of average energies of the spectra, r_E = / , the ratio of widths of the energy distributions, r_Gamma, the ratios of total numbers of nu_e and antinu_e events at low energies, S, and in the high energy tails, R_{tail}. We construct and analyze scatter plots which show the predictions for the observables for different intervals of sin^2 theta_{13} and signs of Delta m^2_{13}, taking into account uncertainties in the original neutrino spectra, the star density profile, etc.. Regions in the space of observables r_E, r_Gamma, S, R_{tail} exist in which certain mass hierarchy and intervals of sin^2 theta_{13} can be identified or discriminated. We elaborate on the method of the high energy tails in the spectra of events. The conditions are formulated for which sin^2 theta_{13} can be (i) measured, (ii) restricted from below, (iii) restricted from above. We comment on the possibility to determine sin^2 theta_{13} using the time dependence of the signals due to the propagation of the shock wave through the resonance layers of the star. We show that the appearance of the delayed Earth matter effect in one of the channels (nu_e or antinu_e) in combination with the undelayed effect in the other channel will allow to identify the shock wave appeareance and determine the mass hierarchy.
TL;DR: In this paper, the authors discuss the physics potential of intermediate baseline neutrino experiments at nuclear power plants and show that such an intermediate baseline experiment can determine both the solar neutrinos oscillation parameters and the mixing angle with high precision with a remarkably high precision.
Abstract: We discuss the physics potential of intermediate $L\ensuremath{\sim}20--30\mathrm{km}$ baseline experiments at reactor facilities. Assuming that the solar neutrino oscillation parameters $\ensuremath{\Delta}{m}_{\ensuremath{\bigodot}}^{2}$ and ${\ensuremath{\theta}}_{\ensuremath{\bigodot}}$ lie in the high LMA solution region, we show that such an intermediate baseline reactor experiment can determine both $\ensuremath{\Delta}{m}_{\ensuremath{\bigodot}}^{2}$ and ${\ensuremath{\theta}}_{\ensuremath{\bigodot}}$ with a remarkably high precision. We perform also a detailed study of the sensitivity of the indicated experiment to $\ensuremath{\Delta}{m}_{\mathrm{atm}}^{2},$ which drives the dominant atmospheric ${\ensuremath{
u}}_{\ensuremath{\mu}}$ $({\overline{\ensuremath{
u}}}_{\ensuremath{\mu}})$ oscillations, and to \ensuremath{\theta}---the neutrino mixing angle limited by the data from the CHOOZ and Palo Verde experiments. Irrespective of the actual values of $\ensuremath{\Delta}{m}_{\ensuremath{\bigodot}}^{2},$ we find that this experiment can improve the bounds on ${\mathrm{sin}}^{2}\ensuremath{\theta},$ and, if the value of ${\mathrm{sin}}^{2}\ensuremath{\theta}$ is large enough, ${\mathrm{sin}}^{2}\ensuremath{\theta}\ensuremath{\gtrsim}0.02,$ the energy resolution of the detector is sufficiently good and if the statistics is relatively high, it can determine with extremely high precision the value of $\ensuremath{\Delta}{m}_{\mathrm{atm}}^{2}.$ We also explore the potential of the intermediate baseline reactor neutrino experiment for determining the type of the neutrino mass spectrum, which can be with normal or inverted hierarchy, assuming $\ensuremath{\Delta}{m}_{\ensuremath{\bigodot}}^{2}$ to lie in the high LMA solution region. We show that the conditions under which the type of neutrino mass hierarchy can be determined are quite challenging, but are within the reach of the experiment under discussion.