Dynamic time expansion and compression using nonlinear waveguides
Findikoglu, Alp T. (Los Alamos, NM); Hahn, Sangkoo F. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)
2004-06-22T23:59:59.000Z
Dynamic time expansion or compression of a small-amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small-amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.
Dynamic Time Expansion and Compression Using Nonlinear Waveguides
Findikoglu, Alp T.; Hahn, Sangkoo F.; Jia, Quanxi
2004-06-22T23:59:59.000Z
Dynamic time expansion or compression of a small amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.
Expansion dynamics of laser produced plasma
Doggett, B.; Lunney, J. G. [School of Physics, Trinity College Dublin, Dublin 2 (Ireland)
2011-05-01T23:59:59.000Z
We consider the applicability of the isentropic, adiabatic gas dynamical model of plume expansion for laser ablation in vacuum. We show that the model can be applied to ionized plumes and estimate the upper electron temperature limit on the applicability of the isentropic approximation. The model predictions are compared with Langmuir ion probe measurements and deposition profiles obtained for excimer laser ablation of silver.
Internal structure and expansion dynamics of laser ablation plumes into ambient gases
Harilal, S. S.
Internal structure and expansion dynamics of laser ablation plumes into ambient gases S. S. Harilal 13 December 2002 The effect of ambient gas on the expansion dynamics of the plasma generated by laser together with time resolved emission diagnostics, a triple structure of the plume was observed
Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon
Camara, Gilberto
Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon Douglas C ranching or new deforestation has not been quantified and has major implications for future deforestation dynamics, carbon fluxes, forest fragmentation, and other ecosystem services. We combine deforestation maps
Chaos expansion of local time of fractional Brownian motions
Hu, Yaozhong; Oksendal, B.
2002-07-01T23:59:59.000Z
We find the chaos expansion of local time l(T)((H))(x, (.)) of fractional Brownian motion with Hurst coefficient H is an element of (0, 1) at a point x is an element of R-d. As an application we show that when H(0)d < 1 then l...
Dynamical effects in the Coulomb expansion following nuclear fragmentation
Chung, K.C.; Donangelo, R.; Schechter, H.
1987-09-01T23:59:59.000Z
The effects of the Coulomb expansion on the fragment kinetic energy spectrum for a fragmentating hot nuclear system is investigated. In particular, /sup 12/C-fragment spectra are calculated and compared with those predicted by the uniform expansion approximation. The results indicate that the energy spectra of fragments are quite sensitive to the details of the Coulomb expansion treatment.
Exact Stochastic Unraveling of an Optical Coherence Dynamics by Cumulant Expansion
Jan Olsina; Tobias Kramer; Christoph Kreisbeck; Tomas Mancal
2014-08-25T23:59:59.000Z
A numerically exact Monte Carlo scheme for calculation of open quantum system dynamics is proposed and implemented. The method consists of a Monte-Carlo summation of a perturbation expansion in terms of trajectories in Liouville phase-space with respect to the coupling between the excited states of the molecule. The trajectories are weighted by a complex decoherence factor based on the second-order cumulant expansion of the environmental evolution. The method can be used with an arbitrary environment characterized by a general correlation function and arbitrary coupling strength. It is formally exact for harmonic environments, and it can be used with arbitrary temperature. Time evolution of an optically excited Frenkel exciton dimer representing a molecular exciton interacting with a charge transfer state is calculated by the proposed method. We calculate the evolution of the optical coherence elements of the density matrix and linear absorption spectrum, and compare them with the predictions of standard simulation methods.
A Short-Time Quantum Mechanical Expansion Approach to Vibrational Relaxation Eran Rabani*,
Rabani, Eran
A Short-Time Quantum Mechanical Expansion Approach to Vibrational Relaxation Eran Rabani*, School" molecule embedded in a "quantum" host is approached from the perspective of a short-time expansion that depend on both position and momentum. A simple ansatz is used to connect the short-time and long
Jordan, Rhonda LeNai
2013-01-01T23:59:59.000Z
This research develops a novel approach to long-term power system capacity expansion planning for developing countries by incorporating endogenous demand dynamics resulting from social processes of technology adoption. ...
Dabir, Aditi Sandeep
2010-07-14T23:59:59.000Z
AUTOMATION OF THE LAGUERRE EXPANSION TECHNIQUE FOR ANALYSIS OF TIME-RESOLVED FLUORESCENCE SPECTROSCOPY DATA A Thesis by ADITI SANDEEP DABIR Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2009 Major Subject: Biomedical Engineering AUTOMATION OF THE LAGUERRE EXPANSION TECHNIQUE FOR ANALYSIS OF TIME-RESOLVED FLUORESCENCE SPECTROSCOPY DATA A Thesis...
Ambient gas effects on the dynamics of laser-produced tin plume expansion
Tillack, Mark
Ambient gas effects on the dynamics of laser-produced tin plume expansion S. S. Harilal,a Beau O online 28 April 2006 Controlling the debris from a laser-generated tin plume is one of the prime issues radiation can be used for controlling highly energetic particles from the tin plume. We employed a partial
Dynamics of gravitational clustering I. Building perturbative expansions
P. Valageas
2001-10-09T23:59:59.000Z
We develop a systematic method to obtain the solution of the collisionless Boltzmann equation which describes the growth of large-scale structures as a perturbative series over the initial density perturbations. We give an explicit calculation of the second-order terms which are shown to agree with the results obtained from the hydrodynamical description of the system. Then, we explain that this identity extends to all orders of perturbation theory and that the perturbative series actually diverge for hierarchical scenarios. However, since the collisionless Boltzmann equation provides the exact description of the dynamics (including the non-linear regime) these results may serve as a basis for a study of the non-linear regime. In particular, we derive a non-perturbative quadratic integral equation which explicitly relates the actual non-linear distribution function to the initial conditions (more precisely, to the linear growing mode). This allows us to write an explicit path-integral expression for the probability distribution of the exact non-linear density field.
Ju, J.-C., E-mail: jujinchuan@126.com [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Laboratoire de Physique des Gaz et des Plasmas, CNRS-Université Paris-Sud, Orsay 91405 (France); Liu, L.; Cai, D. [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)
2014-06-09T23:59:59.000Z
Thermal plasma expansion is characterised during the operation of a high power diode with an explosive emission carbon-fiber-aluminum cathode driven by a 250?kV, 150?ns accelerating pulse. It is found that a quasi-stationary state of plasma expansion is obtained during the main part of the accelerating pulse and the whole plasma expansion exhibits an “U”-shape velocity evolution. A theoretical model describing the dynamics of plasma expansion is developed, which indicates that the plasma expansion velocity is determined by equilibrium between the diode current density and plasma thermal electron current density.
Dynamical 3-Space: Supernovae and the Hubble Expansion - Older Universe and End of Dark Energy
Reginald T Cahill
2007-06-05T23:59:59.000Z
We apply the new dynamics of 3-space to cosmology by deriving a Hubble expansion solution. This dynamics involves two constants; G and alpha - the fine structure constant. This solution gives an excellent parameter-free fit to the recent supernova and gamma-ray burst data without the need for `dark energy' or `dark matter'. The data and theory together imply an older age for the universe of some 14.7Gyrs. Various problems such as fine tuning, the event horizon problem etc are now resolved. A brief review discusses the origin of the 3-space dynamics and how that dynamics explained the bore hole anomaly, spiral galaxy flat rotation speeds, the masses of black holes in spherical galaxies, gravitational light bending and lensing, all without invoking `dark matter' or `dark energy'. These developments imply that a new understanding of the universe is now available.
Dynamic Vehicle Routing with Stochastic Time Constraints
Pavone, Marco
In this paper we study a dynamic vehicle routing problem where demands have stochastic deadlines on their waiting times. Specifically, a network of robotic vehicles must service demands whose time of arrival, location and ...
Takashi Hosokawa; Shu-ichiro Inutsuka
2005-01-08T23:59:59.000Z
We analyze the dynamical expansion of the HII region and outer photodissociation region (PDR) around a massive star by solving the UV and FUV radiation transfer and the thermal and chemical processes in a time-dependent hydrodynamics code. We focus on the physical structure of the shell swept up by the shock front (SF) preceding the ionization front (IF). After the IF reaches the initial Stromgren radius, the SF emerges in front of the IF and the geometrically thin shell bounded with the IF and the SF is formed. The gas density inside the shell is about 10-100 times as high as the ambient gas density. Initially the dissociation fronts expands faster than IF and the PDR is formed outside the HII region. Thereafter the IF and SF gradually overtakes the proceeding dissociation fronts (DFs), and eventually DFs are taken in the shell. The chemical composition within the shell is initially atomic, but hydrogen and carbon monoxide molecules are gradually formed. This is partly because the IF and SF overtake DFs and SF enters the molecular region, and partly because the reformation timescales of the molecules become shorter than the dynamical timescale. The gas shell becomes dominated by the molecular gas by the time of gravitational fragmentation, which agrees with some recent observations. A simple estimation of star formation rate in the shell can provide a significant star formation rate in our galaxy.
Time Centrality in Dynamic Complex Networks
Costa, Eduardo Chinelate; Wehmuth, Klaus; Ziviani, Artur; da Silva, Ana Paula Couto
2015-01-01T23:59:59.000Z
There is an ever-increasing interest in investigating dynamics in time-varying graphs (TVGs). So far, however, the notion of centrality in TVG scenarios usually refers to metrics that assess the relative importance of nodes along the temporal evolution of the network. Nevertheless, for some TVG scenarios, more important than identifying the central nodes under a given definition is identifying the \\emph{key time instants} for taking certain actions. In this paper, we introduce the notion of \\emph{time centrality} in TVGs. Analogously to node centrality, time centrality evaluates the relative importance of time instants in dynamic complex networks. We present two time centrality metrics related to diffusion processes. We evaluate the two defined metrics using a real-world dataset representing a in-person contact dynamic network. We validate the concept of time centrality showing that diffusion starting at the best classified time instants (i.e. the most central ones), according to our metrics, can perform a fa...
Continuous Time Group Discovery in Dynamic Graphs
Miller, K; Eliassi-Rad, T
2010-11-04T23:59:59.000Z
With the rise in availability and importance of graphs and networks, it has become increasingly important to have good models to describe their behavior. While much work has focused on modeling static graphs, we focus on group discovery in dynamic graphs. We adapt a dynamic extension of Latent Dirichlet Allocation to this task and demonstrate good performance on two datasets. Modeling relational data has become increasingly important in recent years. Much work has focused on static graphs - that is fixed graphs at a single point in time. Here we focus on the problem of modeling dynamic (i.e. time-evolving) graphs. We propose a scalable Bayesian approach for community discovery in dynamic graphs. Our approach is based on extensions of Latent Dirichlet Allocation (LDA). LDA is a latent variable model for topic modeling in text corpora. It was extended to deal with topic changes in discrete time and later in continuous time. These models were referred to as the discrete Dynamic Topic Model (dDTM) and the continuous Dynamic Topic Model (cDTM), respectively. When adapting these models to graphs, we take our inspiration from LDA-G and SSN-LDA, applications of LDA to static graphs that have been shown to effectively factor out community structure to explain link patterns in graphs. In this paper, we demonstrate how to adapt and apply the cDTM to the task of finding communities in dynamic networks. We use link prediction to measure the quality of the discovered community structure and apply it to two different relational datasets - DBLP author-keyword and CAIDA autonomous systems relationships. We also discuss a parallel implementation of this approach using Hadoop. In Section 2, we review LDA and LDA-G. In Section 3, we review the cDTM and introduce cDTMG, its adaptation to modeling dynamic graphs. We discuss inference for the cDTM-G and details of our parallel implementation in Section 4 and present its performance on two datasets in Section 5 before concluding in Section 6.
Bo Yang; Xihua Xu; John Z. F. Pang; Christopher Monterola
2015-04-06T23:59:59.000Z
We propose a framework for constructing microscopic traffic models from microscopic acceleration patterns that can in principle be experimental measured and proper averaged. The exact model thus obtained can be used to justify the consistency of various popular models in the literature. Assuming analyticity of the exact model, we suggest that a controlled expansion around the constant velocity, uniform headway "ground state" is the proper way of constructing various different effective models. Assuming a unique ground state for any fixed average density, we discuss the universal properties of the resulting effective model, focusing on the emergent quantities of the coupled non-linear ODEs. These include the maximum and minimum headway that give the coexistence curve in the phase diagram, as well as an emergent intrinsic scale that characterizes the strength of interaction between clusters, leading to non-trivial cluster statistics when the unstable ground state is randomly perturbed. Utilizing the universal properties of the emergent quantities, a simple algorithm for constructing an effective traffic model is also presented. The algorithm tunes the model with statistically well-defined quantities extracted from the flow-density plot, and the resulting effective model naturally captures and predicts many quantitative and qualitative empirical features of the highway traffic, especially in the presence of an on-ramp bottleneck. The simplicity of the effective model provides strong evidence that stochasticity, diversity of vehicle types and modeling of complicated individual driving behaviors are \\emph{not} fundamental to many observations of the complex spatiotemporal patterns in the real traffic dynamics. We also propose the nature of the congested phase can be well characterized by the long lasting transient states of the effective model, from which the wide moving jams evolve.
Construction of dynamics and time-ordered exponential for unbounded non-symmetric Hamiltonians
Futakuchi, Shinichiro; Usui, Kouta [Department of Mathematics, Hokkaido University, 060-0810 Sapporo (Japan)
2014-06-15T23:59:59.000Z
We prove under certain assumptions that there exists a solution of the Schrödinger or the Heisenberg equation of motion generated by a linear operator H acting in some complex Hilbert space H, which may be unbounded, not symmetric, or not normal. We also prove that, under the same assumptions, there exists a time evolution operator in the interaction picture and that the evolution operator enjoys a useful series expansion formula. This expansion is considered to be one of the mathematically rigorous realizations of so-called “time-ordered exponential,” which is familiar in the physics literature. We apply the general theory to prove the existence of dynamics for the mathematical model of Quantum Electrodynamics quantized in the Lorenz gauge, the interaction Hamiltonian of which is not even symmetric or normal.
Roy A. Lacey
2014-08-06T23:59:59.000Z
The flow harmonic $v_{n}$ and the emission source radii $R_{\\text{out}}$, $R_{\\text{side}}$ and $R_{\\text{long}}$ are studied for a broad range of centrality selections and beam collision energies in Au+Au ($\\sqrt{s_{NN}}= 7.7 - 200$ GeV) and Pb+Pb ($\\sqrt{s_{NN}}= 2.76$ TeV) collisions at RHIC and the LHC respectively. They validate the acoustic scaling patterns expected for hydrodynamic-like expansion over the entire range of beam energies studied. The combined data sets allow estimates for the \\sqsn\\ dependence of the mean expansion speed $\\left$, emission duration $\\left$ and the viscous coefficients $\\left$ that encode the magnitude of the specific shear viscosity $\\left$. The estimates indicate initial-state model independent values of $\\left$ which are larger for the plasma produced at 2.76 TeV (LHC) compared to that produced at 200 GeV (RHIC) ($\\left_{\\text{LHC}}=2.2\\pm 0.2$ and $\\left_{\\text{RHIC}}=1.3\\pm 0.2$). They also show a non-monotonic \\sqsn\\ dependence for $\\left$, $\\left$ and $\\left$, with minima for $\\left$ and $\\left$, and a complimentary maximum for $\\left$. These dependencies signal a significant change in reaction dynamics in a narrow span of $\\sqrt{s_{NN}}$, which may be linked to reaction trajectories close to the critical end point (CEP) in the phase diagram for nuclear matter.
Li, Xingwen; Wei, Wenfu; Wu, Jian; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)
2013-06-28T23:59:59.000Z
Laser produced copper plasmas of different spot sizes in air were investigated using fast photography and optical emission spectroscopy (OES). The laser energy was 33 mJ. There were dramatic changes in the plasma plume expansion into the ambient air when spot sizes changed from {approx}0.1 mm to {approx}0.6 mm. A stream-like structure and a hemispherical structure were, respectively, observed. It appeared that the same spot size resulted in similar expansion dynamics no matter whether the target was located in the front of or behind the focal point, although laser-induced air breakdown sometimes occurred in the latter case. Plasma plume front positions agree well with the classic blast wave model for the large spot-size cases, while an unexpected stagnation of {approx}80 ns occurred after the laser pulse ends for the small spot size cases. This stagnation can be understood in terms of the evolution of enhanced plasma shielding effects near the plasma front. Axial distributions of plasma components by OES revealed a good confinement effect. Electron number densities were estimated and interpreted using the recorded Intensified Charge Coupled Device (ICCD) images.
Energy Levels of "Hydrogen Atom" in Discrete Time Dynamics
Andrei Khrennikov; Yaroslav Volovich
2006-04-27T23:59:59.000Z
We analyze dynamical consequences of a conjecture that there exists a fundamental (indivisible) quant of time. In particular we study the problem of discrete energy levels of hydrogen atom. We are able to reconstruct potential which in discrete time formalism leads to energy levels of unperturbed hydrogen atom. We also consider linear energy levels of quantum harmonic oscillator and show how they are produced in the discrete time formalism. More generally, we show that in discrete time formalism finite motion in central potential leads to discrete energy spectrum, the property which is common for quantum mechanical theory. Thus deterministic (but discrete time!) dynamics is compatible with discrete energy levels.
A wide-dynamic-range time-based CMOS imager
O'Halloran, Micah G. (Micah Galletta), 1978-
2008-01-01T23:59:59.000Z
This thesis describes a novel dual-threshold time-based current sensing algorithm suitable for use in wide-dynamic-range CMOS imagers. A prototype 150 x 256 pixel imager employing this algorithm experimentally achieves ...
Maintaining dynamic sequences under equalitytests in polylogarithmic time
Maintaining dynamic sequences under equalitytests in polylogarithmic time K. Mehlhorn R. Sundar C. Uhrig January 16, 1996 Abstract We present a randomized and a deterministic data structure
Multilinear Dynamical Systems for Tensor Time Series
Russell, Stuart
of the stock prices of n multiple companies comprise a time series of 6 × n tensors. A grayscale video sequence ocean temperatures will increase. Prediction of stock prices may not only inform investors but also help to stabilize the economy and prevent market collapse. The relationships between particular subsets of tensor
Alexander B. Balakin; Vladimir V. Bochkarev
2011-02-04T23:59:59.000Z
We establish a new self-consistent model in order to explain from a unified viewpoint two key features of the cosmological evolution: the inflation in the early Universe and the late-time accelerated expansion. The key element of this new model is the Archimedean-type coupling of the dark matter with dark energy, which form the so-called cosmic dark fluid. We suppose that dark matter particles immersed into the dark energy reservoir are affected by the force proportional to the four-gradient of the dark energy pressure. The Archimedean-type coupling is shown to play a role of effective energy-momentum redistributor between the dark matter and the dark energy components of the dark fluid, thus providing the Universe's evolution to be a quasiperiodic and/or multistage process. In the first part of the work we discuss a theoretical base and new exact solutions of the model master equations. Special attention is focused on the exact solutions for which the scale factor is presented by the anti-Gaussian function: these solutions describe the late-time acceleration and are characterized by a nonsingular behavior in the early Universe. The second part contains qualitative and numerical analysis of the master equations; we focus there on the solutions describing a multi-inflationary Universe.
Dynamic Rebinding for Marshalling and Update, with Destruct-time
Hicks, Michael
Dynamic Rebinding for Marshalling and Update, with Destruct-time Gavin Bierman Michael Hicks Peter is required in various guises, for exam- ple when a marshalled value is received from the network, contain-time strategies. The latter forms the basis for a marsh calculus that supports dy- namic rebinding of marshalled
The flashing ratchet: long time behavior and dynamical systems interpretation
Dolbeault, Jean
The flashing ratchet: long time behavior and dynamical systems interpretation Jean Dolbeault@mcs.kent.edu December 11, 2002 Abstract. The flashing ratchet is a model for certain types of molecular motors as well then study the long time behavior of the flashing ratchet model. By entropy methods, we prove the existence
Chemical dynamics in time and energy space
Myers, J.D.
1993-04-01T23:59:59.000Z
The development of a versatile picosecond ultraviolet/vacuum ultraviolet temporal spectrometer and its potential use for measuring internal energy redistribution in isolated molecules are described in detail. A detailed description of the double-pass Nd:YAG amplifier and the dye amplifiers is given with the pulse energies achieved in the visible, ultraviolet, and vacuum ultraviolet. The amplified visible pulses are shown to be of sub-picosecond duration and near transform limited. The instrument`s temporal response ({le}10 ps) is derived from an instrument limited measurement of the dissociation lifetime of methyl iodide at 266 nm. The methyl iodide experiment is used to discuss the various sources of noise and background signals that are intrinsic to this type of experiment. Non-time-resolved experiments measuring the branching ratio and kinetic energy distributions of products from the 193 nm photodissociation of cyclopentadiene and thiophene are presented. These studies were done using the molecular beam Photofragment Translational Spectroscopy (PTS) technique. The results from the cyclopentadiene experiment confirm that H atom elimination to yield the cyclopentadienyl radical is the dominant dissociation channel. A barrier of {ge}5 kcal/mol can be understood in terms of the delocalization of the radical electron of the cyclopentadienyl fragment. A concerted elimination yielding cyclopropene and acetylene was also observed and is proposed to occur via a bicyclo-[2.1.0]pent-2-ene intermediate. Two other channels, yielding acetylene plus the CH{sub 2}CHCH triplet carbene, and CH{sub 2} plus 1-buten-3-yne, are postulated to occur via ring opening. The implications of the experimental results for bulk thermal oxidation and pyrolysis models are discussed. The thiophene experiment shows six competing dissociation channels. The postulated intermediates for the various thiophene dissociation channels include bicyclo, ring opened, and possibly ring contracted forms.
Time-dependent HF approach to SHE dynamics
A. S. Umar; V. E. Oberacker
2014-12-04T23:59:59.000Z
We employ the time-dependent Hartree-Fock (TDHF) method to study various aspects of the reactions utilized in searches for superheavy elements. These include capture cross-sections, quasifission, prediction of $P_{\\mathrm{CN}}$, and other interesting dynamical quantities. We show that the microscopic TDHF approach provides an important tool to shed some light on the nuclear dynamics leading to the formation of superheavy elements.
Can the ring polymer molecular dynamics method be interpreted as real time quantum dynamics?
Jang, Seogjoo, E-mail: sjang@qc.cuny.edu [Department of Chemistry and Biochemistry, Queens College and the Graduate Center, City University of New York, 65-30 Kissena Boulevard, Flushing, New York 11367 (United States)] [Department of Chemistry and Biochemistry, Queens College and the Graduate Center, City University of New York, 65-30 Kissena Boulevard, Flushing, New York 11367 (United States); Sinitskiy, Anton V.; Voth, Gregory A., E-mail: gavoth@uchicago.edu [Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics and Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, Illinois 60637 (United States)
2014-04-21T23:59:59.000Z
The ring polymer molecular dynamics (RPMD) method has gained popularity in recent years as a simple approximation for calculating real time quantum correlation functions in condensed media. However, the extent to which RPMD captures real dynamical quantum effects and why it fails under certain situations have not been clearly understood. Addressing this issue has been difficult in the absence of a genuine justification for the RPMD algorithm starting from the quantum Liouville equation. To this end, a new and exact path integral formalism for the calculation of real time quantum correlation functions is presented in this work, which can serve as a rigorous foundation for the analysis of the RPMD method as well as providing an alternative derivation of the well established centroid molecular dynamics method. The new formalism utilizes the cyclic symmetry of the imaginary time path integral in the most general sense and enables the expression of Kubo-transformed quantum time correlation functions as that of physical observables pre-averaged over the imaginary time path. Upon filtering with a centroid constraint function, the formulation results in the centroid dynamics formalism. Upon filtering with the position representation of the imaginary time path integral, we obtain an exact quantum dynamics formalism involving the same variables as the RPMD method. The analysis of the RPMD approximation based on this approach clarifies that an explicit quantum dynamical justification does not exist for the use of the ring polymer harmonic potential term (imaginary time kinetic energy) as implemented in the RPMD method. It is analyzed why this can cause substantial errors in nonlinear correlation functions of harmonic oscillators. Such errors can be significant for general correlation functions of anharmonic systems. We also demonstrate that the short time accuracy of the exact path integral limit of RPMD is of lower order than those for finite discretization of path. The present quantum dynamics formulation also serves as the basis for developing new quantum dynamical methods that utilize the cyclic nature of the imaginary time path integral.
Modeling exchange rate dependence dynamics at different time horizons
Embrechts, Paul
, Copula-GARCH, Conditional dependence, Dynamic copula Corresponding author. Tel.: +44(0) 247 657 4297. Financial time-series are often modeled with GARCH type models. In the multivariate GARCH literature there exist several models, like CCC- GARCH, DVEC, matrix-diagonal GARCH, BEKK and principal components GARCH
On the Dynamics of Small Continuous-Time Recurrent
Beer, Randall D.
On the Dynamics of Small Continuous-Time Recurrent Neural Networks Randall D. Beer* Case Western of Biology, Case Western Reserve University, Cleveland, Ohio; E-mail: beer@alpha.ces.cwru.edu , unauthorized for controlling the behavior of agents (Beer, 1990) and in the evolution of such networks (Collins & Jefferson
Haxton, D. J.; Lawler, K. V. [Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); McCurdy, C. W. [Chemical Sciences and Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); Departments of Applied Science and Chemistry, Davis, California, 95616 (United States)
2011-06-15T23:59:59.000Z
The multiconfiguration time-dependent Hartree-Fock (MCTDHF) method is formulated for treating the coupled electronic and nuclear dynamics of diatomic molecules without the Born-Oppenheimer approximation. The method treats the full dimensionality of the electronic motion, uses no model interactions, and is in principle capable of an exact nonrelativistic description of diatomics in electromagnetic fields. An expansion of the wave function in terms of configurations of orbitals whose dependence on internuclear distance is only that provided by the underlying prolate spheroidal coordinate system is demonstrated to provide the key simplifications of the working equations that allow their practical solution. Photoionization cross sections are also computed from the MCTDHF wave function in calculations using short pulses.
Morzan, Uriel N.; Ramírez, Francisco F.; Scherlis, Damián A., E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires (C1428EHA) (Argentina); Oviedo, M. Belén; Sánchez, Cristián G. [Departamento de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba (Argentina)] [Departamento de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba (Argentina); Lebrero, Mariano C. González, E-mail: damian@qi.fcen.uba.ar, E-mail: mcgl@qb.ffyb.uba.ar [Instituto de Química y Fisicoquímica Biológicas, IQUIFIB, CONICET (Argentina)] [Instituto de Química y Fisicoquímica Biológicas, IQUIFIB, CONICET (Argentina)
2014-04-28T23:59:59.000Z
This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrix—required to propagate the electron dynamics—, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.
Long-time protein folding dynamics from short-time molecular dynamics simulations
Chodera, J D; Swope, W C; Pitera, J W; Dill, Ken A
2006-01-01T23:59:59.000Z
On the simulation of protein folding by short time scaleand W. A. Eaton, The protein folding “speed limit,” Curr.and T. Head-Gordon, Protein folding by distributed computing
Dynamical "breaking" of time reversal symmetry and converse quantum ergodicity
Boris Gutkin
2007-04-25T23:59:59.000Z
It is a common assumption that quantum systems with time reversal invariance and classically chaotic dynamics have energy spectra distributed according to GOE-type of statistics. Here we present a class of systems which fail to follow this rule. We show that for convex billiards of constant width with time reversal symmetry and "almost" chaotic dynamics the energy level distribution is of GUE-type. The effect is due to the lack of ergodicity in the "momentum" part of the phase space and, as we argue, is generic in two dimensions. Besides, we show that certain billiards of constant width in multiply connected domains are of interest in relation to the quantum ergodicity problem. These billiards are quantum ergodic, but not classically ergodic.
Nonlinear-damped Duffing oscillators having finite time dynamics
Ronald E. Mickens; Ray Bullock; Warren E. Collins; Kale Oyedeji
2014-04-22T23:59:59.000Z
A class of modified Duffing oscillator differential equations, having nonlinear damping forces, are shown to have finite time dynamics, i.e., the solutions oscillate with only a finite number of cycles, and, thereafter, the motion is zero. The relevance of this feature is briefly discussed in relationship to the mathematical modeling, analysis, and estimation of parameters for the vibrations of carbon nano-tubes and graphene sheets, and macroscopic beams and plates.
Constant pressure and temperature discrete-time Langevin molecular dynamics
Niels Grønbech-Jensen; Oded Farago
2014-11-13T23:59:59.000Z
We present a new and improved method for simultaneous control of temperature and pressure in molecular dynamics simulations with periodic boundary conditions. The thermostat-barostat equations are build on our previously developed stochastic thermostat, which has been shown to provide correct statistical configurational sampling for any time step that yields stable trajectories. Here, we extend the method and develop a set of discrete-time equations of motion for both particle dynamics and system volume in order to seek pressure control that is insensitive to the choice of the numerical time step. The resulting method is simple, practical, and efficient. The method is demonstrated through direct numerical simulations of two characteristic model systems - a one dimensional particle chain for which exact statistical results can be obtained and used as benchmarks, and a three dimensional system of Lennard-Jones interacting particles simulated in both solid and liquid phases. The results, which are compared against the method of Kolb & Dunweg, show that the new method behaves according to the objective, namely that acquired statistical averages and fluctuations of configurational measures are accurate and robust against the chosen time step applied to the simulation.
David A. Sivak; John D. Chodera; Gavin E. Crooks
2014-04-09T23:59:59.000Z
When simulating molecular systems using deterministic equations of motion (e.g., Newtonian dynamics), such equations are generally numerically integrated according to a well-developed set of algorithms that share commonly agreed-upon desirable properties. However, for stochastic equations of motion (e.g., Langevin dynamics), there is still broad disagreement over which integration algorithms are most appropriate. While multiple desiderata have been proposed throughout the literature, consensus on which criteria are important is absent, and no published integration scheme satisfies all desiderata simultaneously. Additional nontrivial complications stem from simulating systems driven out of equilibrium using existing stochastic integration schemes in conjunction with recently-developed nonequilibrium fluctuation theorems. Here, we examine a family of discrete time integration schemes for Langevin dynamics, assessing how each member satisfies a variety of desiderata that have been enumerated in prior efforts to construct suitable Langevin integrators. We show that the incorporation of a novel time step rescaling in the deterministic updates of position and velocity can correct a number of dynamical defects in these integrators. Finally, we identify a particular splitting that has essentially universally appropriate properties for the simulation of Langevin dynamics for molecular systems in equilibrium, nonequilibrium, and path sampling contexts.
Thermoacoustic instability - a dynamical system and time domain analysis
Sayadi, Taraneh; Schmid, Peter; Richecoeur, Franck; Massot, Marc
2013-01-01T23:59:59.000Z
This study focuses on the Rijke tube problem, which includes features relevant to the modeling of thermoacoustic coupling in reactive flows: a compact acoustic source, an empirical model for the heat source, and nonlinearities. This system features both linear and nonlinear flow regimes with complex dynamical behavior. In order to synthesize accurate time-series, we tackle this problem from a numerical point-of-view, and start by proposing a dedicated solver designed for dealing with the underlying stiffness, in particular, the retarded time and the discontinuity at the location of the heat source. Stability analysis is performed on the limit of the low amplitude perturbations by means of the projection method proposed by Jarlebring (2008), which alleviates the linearization of the retarded term. The results are then compared to the analytical solution of the undamped system, in addition to the analysis based on Galerkin projection. The method provides insight into the consequence of the simplification due to...
A Tutorial on Time-Evolving Dynamical Bayesian Inference
Tomislav Stankovski; Andrea Duggento; Peter V. E. McClintock; Aneta Stefanovska
2014-05-21T23:59:59.000Z
In view of the current availability and variety of measured data, there is an increasing demand for powerful signal processing tools that can cope successfully with the associated problems that often arise when data are being analysed. In practice many of the data-generating systems are not only time-variable, but also influenced by neighbouring systems and subject to random fluctuations (noise) from their environments. To encompass problems of this kind, we present a tutorial about the dynamical Bayesian inference of time-evolving coupled systems in the presence of noise. It includes the necessary theoretical description and the algorithms for its implementation. For general programming purposes, a pseudocode description is also given. Examples based on coupled phase and limit-cycle oscillators illustrate the salient features of phase dynamics inference. State domain inference is illustrated with an example of coupled chaotic oscillators. The applicability of the latter example to secure communications based on the modulation of coupling functions is outlined. MatLab codes for implementation of the method, as well as for the explicit examples, accompany the tutorial.
Dynamic Scheduling of Real-Time Tasks on Multicore Architectures
Paris-Sud XI, Université de
, for industrial purposes such as avionics, automotive or nuclear industry or domotics. We present a dynamic
Multiagent Bayesian Forecasting of Structural Time-Invariant Dynamic Systems with
Xiang, Yang
. Alternatively, time series are represented by state-space models, also referred to as multivariate dynamic and science. We study forecasting of stochastic, dynamic systems based on observations from multivariate time to a discrete time, multivariate time series [1, 2]. The primary inference that we address is one- step
Time lapse HDR: time lapse photography with high dynamic range images
Clark, Brian Sean
2005-08-29T23:59:59.000Z
?Malley saved me countless hours with AHDRIA. Felice House lent me her Canon G3, which proved to be an excellent image capture device, and Glen Vigus somehow always found time to provide imaging hardware support. Don Lake provided inspiration for this and other... (or literal ones, either). One way HDR images can be created is synthetically, by rendering a scene from some imaging software. Radiance is one such package, and is one of the first ones to make use of the High Dynamic Range format. In fact, the native...
Validating Dynamic Message Sign Freeway Travel Time Messages Using Ground Truth Geospatial Data
Bertini, Robert L.
Validating Dynamic Message Sign Freeway Travel Time Messages Using Ground Truth Geospatial Data agencies have invested more than $300 million in dynamic message sign (DMS) systems for communicating important messages to travelers, including weather conditions, incidents, construction, homeland security
Quasi-real-time analysis of dynamic near field scattering data using a graphics processing unit
Giovanni Cerchiari; Fabrizio Croccolo; Frédéric Cardinaux; Frank Scheffold
2012-09-15T23:59:59.000Z
We present an implementation of the analysis of dynamic near field scattering (NFS) data using a graphics processing unit (GPU). We introduce an optimized data management scheme thereby limiting the number of operations required. Overall, we reduce the processing time from hours to minutes, for typical experimental conditions. Previously the limiting step in such experiments, the processing time is now comparable to the data acquisition time. Our approach is applicable to various dynamic NFS methods, including shadowgraph, Schlieren and differential dynamic microscopy.
Nassif, Claudio
2007-01-01T23:59:59.000Z
We attempt to find new symmetries in the space-time structure,leading to a modified gravitation at large length scales,which provides the foundations of a quantum gravity at very low energies. This search begins by considering a unified model for electrodynamics and gravitation,so that the influence of the gravitational field on the electrodynamics at very large distances leads to a reformulation of our understanding about space-time through the elimination of the classical idea of rest at quantum level. This leads us to a modification of the relativistic theory by introducing the idea of a universal minimum speed related to Planck minimum length. Such a speed,unattainable by the particles,represents a privileged inertial reference frame associated with a cosmic background field (a kind vacuum energy). The structure of space-time becomes extended due to such a vacuum energy density,which leads to a negative pressure at the cosmological length scales as being an anti-gravity,playing the role of the cosmologica...
Zhigilei, Leonid V.
Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural Short pico- and femtosecond pulse laser irradiation has the ability to bring material into a highly dynamics simulations of a 20 nm Au film irradiated with 200 fs laser pulses of different intensity
Dynamics on the Way to Forming Glass: Bubbles in Space-time David Chandler1
Chandler, David
Dynamics on the Way to Forming Glass: Bubbles in Space-time David Chandler1 and Juan P. Garrahan2 1 a theoretical perspective of the dynamics of glass forming liquids and the glass tran- sition of trajectory space. This structure emerges from spatial correlations of dynamics that appear in disordered
Stopping and time reversing a light pulse using dynamic loss tuning of coupled-resonator
Fan, Shanhui
Stopping and time reversing a light pulse using dynamic loss tuning of coupled-resonator delay. ID 85496); published November 12, 2007 We introduce a light-stopping process that uses dynamic loss processing [1,2]. For this pur- pose, dynamically tuned delay lines based on cas- caded optical resonators
Dynamics and real-time optimal control of satellite attitude and satellite formation systems
Yan, Hui
2006-10-30T23:59:59.000Z
In this dissertation the solutions of the dynamics and real-time optimal control of magnetic attitude control and formation flying systems are presented. In magnetic attitude control, magnetic actuators for the time-optimal rest-to-rest maneuver...
Time, dynamics and chaos. Integrating Poincare's "non-integrable systems"
Prigogine, I.
1990-01-01T23:59:59.000Z
This report discusses the nature of time. The author attempts to resolve the conflict between the concept of time reversibility in classical and quantum mechanics with the macroscopic world's irreversibility of time. (LSP)
Real Time Dynamic Wind Calculation for a Pressure Driven Wind System Criss Martin
Parberry, Ian
for controllable real time dynamic wind cal- culation for a pressure driven wind system. Our method allows re to specify the positions and pressure val- ues of a high and a low pressure system to drive the wind. SetupReal Time Dynamic Wind Calculation for a Pressure Driven Wind System Criss Martin Dept. of Computer
Task Merging for Dynamic Power Management of Cyclic Applications in Real-Time Multiprocessor Systems
Qiu, Qinru
Task Merging for Dynamic Power Management of Cyclic Applications in Real-Time Multiprocessor--In this paper we propose the method of task merging and idle period clustering for dynamic power management (DPM management, low power, multiprocessor, real-time I. INTRODUCTION Multiprocessor systems, which were used only
Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed)
Sadoulet, Elisabeth
Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed) Maurice, continuous-time modeling allows application of a powerful mathematical tool, the theory of optimal dynamic control. The basic idea of optimal control theory is easy to grasp-- indeed it follows from elementary
Quintessence Scalar Field: A Dynamical Systems Study
Nandan Roy; Narayan Banerjee
2014-02-27T23:59:59.000Z
The present work deals with a dynamical systems study of quintessence potentials leading to the present accelerated expansion of the universe. The principal interest is to check for late time attractors which give an accelerated expansion for the universe. Two examples are worked out, namely the exponential and the power-law potentials.
Symbolic Dynamic Analysis of Transient Time Series for Fault
Ray, Asok
. A recently developed data-driven technique, called the symbolic dynamic filtering (SDF) [8], has been shown), and Bayesian techniques [9]. Recently, in a two-part paper [10,11], an SDF-based algorithm for detection- stationarity made in SDF. Due to this assumption, SDF may not be able to adequately handle transient data
Dynamic RealTime Task Scheduling on Hypercubes 1
Mohapatra, Prasant
Available Time Window (ATW). By using ATW, the system utilization can be improved and thereby the deadlines
Finite-time rotation number: a fast indicator for chaotic dynamical structures
J. D. Szezech Jr.; A. B. Schelin; I. L. Caldas; S. R. Lopes; P. J. Morrison; R. L. Viana
2011-02-10T23:59:59.000Z
Lagrangian coherent structures are effective barriers, sticky regions, that separate phase space regions of different dynamical behavior. The usual way to detect such structures is via finite-time Lyapunov exponents. We show that similar results can be obtained for single-frequency systems from finite-time rotation numbers, which are much faster to compute. We illustrate our claim by considering examples of continuous and discrete-time dynamical systems of physical interest.
university-logo Graph Expansions
St Andrews, University of
university-logo Graph Expansions Green's Relations Closing Remarks Semigroup Graph Expansions January 2009 Rebecca Noonan Heale Semigroup Graph Expansions: #12;university-logo Graph Expansions Green;university-logo Graph Expansions Green's Relations Closing Remarks History Definitions Graph Expansions
Perturbation Theory for Population Dynamics
Francisco M. Fernandez
2007-12-20T23:59:59.000Z
We prove that a recently proposed homotopy perturbation method for the treatment of population dynamics is just the Taylor expansion of the population variables about initial time. Our results show that this perturbation method fails to provide the global features of the ecosystem dynamics.
Dynamic Pricing Strategies under a Finite Time Horizon Joan Morris DiMicco
to scalpers. Cost has been perhaps the greatest factor precluding the widespread use of dynamic pricing goods, but in digital markets, the costs associated with making frequent, instantaneous price changesDynamic Pricing Strategies under a Finite Time Horizon Joan Morris DiMicco MIT Media Laboratory 20
RICE UNIVERSITY Early Time Ion Dynamics and Progress Towards Laser Cooling in an
Killian, Thomas C.
RICE UNIVERSITY Early Time Ion Dynamics and Progress Towards Laser Cooling in an Ultracold Neutral Dynamics and Progress Towards Laser Cooling in an Ultracold Neutral Plasma by Clayton Earl Simien The progress toward laser cooling an ultracold plasma is presented in this thesis. Ultracold neutral plasmas
Dynamic Programming Approximations for Stochastic, Time-Staged Integer Multicommodity Flow Problems
Topaloglu, Huseyin
. We propose an iterative, adaptive dynamic programming-based methodology that makes use of linear andDynamic Programming Approximations for Stochastic, Time-Staged Integer Multicommodity Flow Problems by a set of indivisible and reusable resources of different types. The assignment of a resource to a task
Time-resolved dynamics in acetonitrile cluster anions CH3CN Ryan M. Young a
Neumark, Daniel M.
Time-resolved dynamics in acetonitrile cluster anions Ã°CH3CNÃ?Ã? n Ryan M. Young a , Graham B December 2009 a b s t r a c t Excited state dynamics of acetonitrile cluster anions, Ã°CH3CNÃ?Ã? n , were, antiparallel solvent molecules [19,20]. Evidence for two electron solvation motifs in acetonitrile also comes
Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model Output
Shi, Tao
Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model of aerosol optical depth across mainland Southeast Asia. We include a cross validation study to assess
CPS : Small : Dynamically Managing the Real-time Fabric of a Wireless Sensor-Actuator Network
Lemmon, Michael
CPS : Small : Dynamically Managing the Real-time Fabric of a Wireless Sensor-Actuator Network 1 as a multi-player game between applications (users) that is essentially a network utility maximization (NUM
Dr. Shih-Lung Shaw's Research on Space-Time GIS, Human Dynamics and Big Data
Grissino-Mayer, Henri D.
1 Dr. Shih-Lung Shaw's Research on Space-Time GIS, Human Dynamics and Big Data for Geography Department's Faculty Research Highlight October 12, 2014 Shih-Lung Shaw, Ph.D. Alvin and Sally Beaman
Moorcroft, Paul R.
Mechanistic scaling of ecosystem function and dynamics in space and time: Ecosystem Demography] Insights into how terrestrial ecosystems affect the Earth's response to changes in climate and rising contain detailed mechanistic representations of biological processes affecting terrestrial ecosystems
A dynamic slack management technique for real-time distributed embedded systems
Acharya, Subrata
2006-04-12T23:59:59.000Z
This work presents a novel slack management technique, the Service Rate Based Slack Distribution Technique, for dynamic real-time distributed embedded systems targeting the reduction and management of energy consumption. Energy minimization...
A Nonlinear Continuous Time Optimal Control Model of Dynamic Pricing and Inventory Control with no
Adida, Elodie
time optimal control model for studying a dynamic pricing and inventory control problem for a make-to-stock of not introducing any approximation to the real setting: it provides the exact solution of the system. When taking
Quantum Mechanics and Discrete Time from "Timeless" Classical Dynamics
H. -T. Elze
2003-07-03T23:59:59.000Z
We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless'' reparametrization invariant model of a relativistic particle with two compactified extradimensions. In this example, discrete physical time is constructed based on quasi-local observables. - Generally, employing the path-integral formulation of classical mechanics developed by Gozzi et al., we show that these deterministic classical systems can be naturally described as unitary quantum mechanical models. The emergent quantum Hamiltonian is derived from the underlying classical one. It is closely related to the Liouville operator. We demonstrate in several examples the necessity of regularization, in order to arrive at quantum models with bounded spectrum and stable groundstate.
Precomputed Wave Simulation for Real-Time Sound Propagation of Dynamic Sources in Complex Scenes
North Carolina at Chapel Hill, University of
Precomputed Wave Simulation for Real-Time Sound Propagation of Dynamic Sources in Complex Scenes of North Carolina at Chapel Hill Abstract We present a method for real-time sound propagation that captures all wave effects, including diffraction and reverberation, for multi- ple moving sources and a moving
FLUORESCENCE AND FIBER-OPTICS BASED REAL-TIME THICKNESS SENSOR FOR DYNAMIC LIQUID FILMS
Narain, Amitabh
/analyzed the incident reflected waves to identify and measure the total transit time of the sound wave (of known wave-speed1 FLUORESCENCE AND FIBER-OPTICS BASED REAL-TIME THICKNESS SENSOR FOR DYNAMIC LIQUID FILMS T. W. Ng/disadvantages of many known liquid film thickness sensing devices (viz. conductivity probes, reflectance based fiber
Analysis of Cardio-respiratory Dynamics during Mental Stress using (Partial) Time-Frequency Spectra
important to determine the mechanisms un- derlying stress. In this paper, we aim at studying the cardio-respiratory to conduct a combined analysis of the cardio-respiratory system. In this study, we will perform cross timeAnalysis of Cardio-respiratory Dynamics during Mental Stress using (Partial) Time-Frequency Spectra
O'Brien, James F.
Precomputed Radiance Transfer for Real-Time Rendering in Dynamic, Low-Frequency Lighting a new, real-time method for rendering diffuse and glossy objects in low-frequency lighting environments-frequency incident lighting into transferred radiance which includes global effects like shadows and interreflections
Dynamic Voltage Scaling for the Schedulability of Jitter-Constrained Real-Time Embedded Systems*
Hu, Xiaobo Sharon
Dynamic Voltage Scaling for the Schedulability of Jitter-Constrained Real-Time Embedded Systems}@ida.ing.tu-bs.de Abstract-- Jitter is a critical problem for the design of both distributed embedded systems and real-time control systems. This work considers meeting the completion jitter constraints of a set of independent
Space- and Time-Resolved Mapping of Ionic Dynamic and Electroresistive Phenomena in Lateral Devices
Strelcov, Evgheni [ORNL; Jesse, Stephen [ORNL; Yen-Lin, Huang [National Chiao Tung University, Hsinchu, Taiwan; Yung-Chun, Teng [National Chiao Tung University, Hsinchu, Taiwan; Kravchenko, Ivan I [ORNL; Ying-Hao, Chu [National Chiao Tung University, Hsinchu, Taiwan; Kalinin, Sergei V [ORNL
2013-01-01T23:59:59.000Z
A novel scanning probe microscopy (SPM) based technique for probing local ionic and electronic transport and their dynamic behavior on the 10 ms 10 s scale is presented. The time-resolved Kelvin Probe Force Microscopy (tr-KPFM) allows mapping surface potential in both space and time domains, visualizing electronic and ionic charge dynamics and separating underlying processes based on their time responses. Here, tr-KPFM is employed to explore the interplay of the adsorbed surface ions and bulk oxygen vacancies and their role in the resistive switching in the Ca-substituted bismuth ferrite thin film.
Wide dynamic range neutron flux monitor having fast time response for the Large Helical Device
Isobe, M., E-mail: isobe@nifs.ac.jp; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan); Department of Fusion Science, The Graduate University for Advanced Studies, Toki 509-5292 (Japan); Ogawa, K.; Miyake, H.; Hayashi, H.; Kobuchi, T. [National Institute for Fusion Science, Toki 509-5292 (Japan); Nakano, Y.; Watanabe, K.; Uritani, A. [Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan); Misawa, T. [Kyoto University Research Reactor Institute, Kumatori 590-0494 (Japan); Nishitani, T. [Japan Atomic Energy Agency, Rokkasho 039-3212 (Japan); Tomitaka, M.; Kumagai, T.; Mashiyama, Y.; Ito, D.; Kono, S. [Toshiba Corporation, Fuchu 183-8511 (Japan); Yamauchi, M. [Toshiba Nuclear Engineering Services Corporation, Yokohama 235-8523 (Japan)
2014-11-15T23:59:59.000Z
A fast time response, wide dynamic range neutron flux monitor has been developed toward the LHD deuterium operation by using leading-edge signal processing technologies providing maximum counting rate up to ?5 × 10{sup 9} counts/s. Because a maximum total neutron emission rate over 1 × 10{sup 16} n/s is predicted in neutral beam-heated LHD plasmas, fast response and wide dynamic range capabilities of the system are essential. Preliminary tests have demonstrated successful performance as a wide dynamic range monitor along the design.
Aeschlimann, Martin
relaxation dynamics is played by the electronic structure of the system close to the Fermi level. For exampleExcited electron dynamics in bulk ytterbium: Time-resolved two-photon photoemission and GW+T ab November 2007 The excited electron dynamics in ytterbium is investigated by means of the time-resolved two
Ihee, Hyotcherl
Sub-100-ps structural dynamics of horse heart myoglobin probed by time-resolved X-ray solution-slicing Structural dynamics Myoglobin a b s t r a c t Here we report sub-100-ps structural dynamics of horse heart rearrangement [27]. In this work, we extend the time-slicing scheme to a protein, horse heart myoglobin (Mb
Integrating Random Matrix Theory Predictions with Short-Time Dynamical Effects in Chaotic Systems
A. Matthew Smith; Lev Kaplan
2010-06-29T23:59:59.000Z
We discuss a modification to Random Matrix Theory eigenstate statistics, that systematically takes into account the non-universal short-time behavior of chaotic systems. The method avoids diagonalization of the Hamiltonian, instead requiring only a knowledge of short-time dynamics for a chaotic system or ensemble of similar systems. Standard Random Matrix Theory and semiclassical predictions are recovered in the limits of zero Ehrenfest time and infinite Heisenberg time, respectively. As examples, we discuss wave function autocorrelations and cross-correlations, and show that significant improvement in accuracy is obtained for simple chaotic systems where comparison can be made with brute-force diagonalization. The accuracy of the method persists even when the short-time dynamics of the system or ensemble is known only in a classical approximation. Further improvement in the rate of convergence is obtained when the method is combined with the correlation function bootstrapping approach introduced previously.
Real-time dynamics of open quantum spin systems driven by dissipative processes
Hebenstreit, Florian; Hornung, Manes; Jiang, Fu-Jiun; Schranz, Franziska; Wiese, Uwe-Jens
2015-01-01T23:59:59.000Z
We study the real-time evolution of large open quantum spin systems in two spatial dimensions, whose dynamics is entirely driven by a dissipative coupling to the environment. We consider different dissipative processes and investigate the real-time evolution from an ordered phase of the Heisenberg or XY-model towards a disordered phase at late times. The corresponding Kossakowski-Lindblad equation is solved via an efficient cluster algorithm. We find that the symmetry of the dissipative process determines the time scales which govern the approach towards a new equilibrium phase at late times. Most notably, we find a slow equilibration if the dissipative process conserves any of the magnetization Fourier modes. In these cases, the dynamics can be interpreted as a diffusion process of the conserved quantity.
Real-time dynamics of open quantum spin systems driven by dissipative processes
Florian Hebenstreit; Debasish Banerjee; Manes Hornung; Fu-Jiun Jiang; Franziska Schranz; Uwe-Jens Wiese
2015-02-10T23:59:59.000Z
We study the real-time evolution of large open quantum spin systems in two spatial dimensions, whose dynamics is entirely driven by a dissipative coupling to the environment. We consider different dissipative processes and investigate the real-time evolution from an ordered phase of the Heisenberg or XY-model towards a disordered phase at late times. The corresponding Kossakowski-Lindblad equation is solved via an efficient cluster algorithm. We find that the symmetry of the dissipative process determines the time scales which govern the approach towards a new equilibrium phase at late times. Most notably, we find a slow equilibration if the dissipative process conserves any of the magnetization Fourier modes. In these cases, the dynamics can be interpreted as a diffusion process of the conserved quantity.
Fission dynamics within time-dependent Hartree-Fock: deformation-induced fission
Goddard, P M; Rios, A
2015-01-01T23:59:59.000Z
Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations ignoring dynamical excitations of the fissioning nucleus, and the daughter products. Purpose: To explore the ability of dynamic mean-field methods to describe fast fission processes beyond the fission barrier, using the nuclide $^{240}$Pu as an example. Methods: Time-dependent Hartree-Fock calculations based on the Skyrme interaction are used to calculate non-adiabatic fission paths, beginning from static constrained Hartree-Fock calculations. The properties of the dynamic states are interpreted in terms of the nature of their collective motion. Fission product properties are compared to data. Results: Parent nuclei constrained to begin dynamic evolution with a deformation less than the fission barrier exhibit giant-resonance-type behaviour. Those beginning just beyond the ...
Roston, Gerald Paul
1985-01-01T23:59:59.000Z
A COMPARISON OF LAGRANGIAN INERTIA COEFFICIENTS FOR ROBOT MANIPULATOR DYNAMICS TO EXAMINE REAL-TIME APPLICABILITY A Thesis by GERALD PAUL ROSTON Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1985 Major Subject: Mechanical Engineering A COMPARISON OF LAGRANGIAN INERTIA COEFFICIENTS FOR ROBOT MANIPULATOR DYiNAMICS TO EXAMINE REAL-TIME APPLICABILITY A Thesis by GERALD PAUL ROSTON...
An efficient algorithm for real-time estimation and prediction of dynamic OD tables
Bierlaire, Michel
An efficient algorithm for real-time estimation and prediction of dynamic OD tables M. Bierlaire and F. Crittin February, 2002 Abstract The problem of estimating and predicting Origin-Destination (OD more intricate. We consider here a least-square modeling approach for solving the OD estimation
Title of dissertation: DYNAMICS AND SYNCHRONIZATION OF NONLINEAR OSCILLATORS WITH TIME
Anlage, Steven
ABSTRACT Title of dissertation: DYNAMICS AND SYNCHRONIZATION OF NONLINEAR OSCILLATORS WITH TIME DELAYS: A STUDY WITH FIBER LASERS Anthony Lawrence Franz Doctor of Philosophy, 2007 Dissertation directed Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park
A Dynamic Inventory Control Policy Under Demand, Yield and Lead Time Uncertainties
Boyer, Edmond
A Dynamic Inventory Control Policy Under Demand, Yield and Lead Time Uncertainties Mohamed Zied@lgi.ecp.fr, dallery@lgi.ecp.fr) ABSTRACT In this paper, we analyze a single-stage and single-item inventory control it. Keywords: inventory control, forecasts, cycle service level, fill rate, safety stock, policy
Convergence Time of Power-Control Dynamics Johannes Dams Martin Hoefer Thomas Kesselheim
Convergence Time of Power-Control Dynamics Johannes Dams Martin Hoefer Thomas Kesselheim April 20, 2011 Abstract We study two (classes of) distributed algorithms for power control in a general model for power control using regret learning algorithms and iterative discretization. While the exact convergence
Sutton, Richard S.
Dynamic Switching and Real-time Machine Learning for Improved Human Control of Assistive Biomedical Abstract-- A general problem for human-machine interaction occurs when a machine's controllable dimensions outnumber the control channels available to its human user. In this work, we examine one prominent example
Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting
Qiu, Qinru
University, State University of New York Binghamton, New York 13902, USA {sliu5, qqiu, qwu problem and prolong the system operating duration, a new technology called energy harvesting, also knownEnergy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting
Influence of Dynamic Wrinkles on the Perceived Realism of Real-Time Character Animation
Paris-Sud XI, Université de
. It is thus necessary to study the impact of secondary animations on realism by including human perceptionInfluence of Dynamic Wrinkles on the Perceived Realism of Real-Time Character Animation Javier Alcon Universidad Rey Juan Carlos Modeling and Virtual Reality Group c/ Tulipàn, s/n 28933, Mòstoles
Sibener, Steven
Oxygen driven reconstruction dynamics of Ni,,977... measured by time-lapse scanning tunneling-lapse scanning tunneling microscopy STM has been used to observe the oxygen induced reconstruction behavior of Ni for the merging of steps in the presence of small amounts of adsorbed oxygen, less than 2% of a monolayer. Point
Dynamic reliability using entry-time approach for maintenance of nuclear power plants
Wang, Shuwen
2009-05-15T23:59:59.000Z
V APPLICATION OF ENTRY-TIME MODEL TO NPP APPLICATIONS .......................................................................................116 5.1 Introduction to the Main Generator System...................................... 117 vii... of methods such as Probabilistic Risk Assessment (PRA), Markov models (cf. [1]), simulation [13] and other methods for risk assessment of dynamic systems [14] have been used to evaluate SSC (System, Structure and Component) reliability in NPP (Nuclear...
ATM678, Mesoscale Dynamics, Spring 2014 Class time: TR 11:30am to 1pm
Moelders, Nicole
ATM678, Mesoscale Dynamics, Spring 2014 Class time: TR 11:30am to 1pm Classroom: Elvy auditorium, Akasofu 319 Course Description: The class provides a comprehensive explanation of mesoscale air motions their phenology, basic physics and mechanisms, why they build and how mesoscale motions interact with the micro
Short communication Real-time estimation of lead-acid battery parameters: A dynamic
Ray, Asok
-charged and over-discharged; similarly, reliable SOH estimates enhance preventive maintenance and life cycle cost situations. Â© 2014 Elsevier B.V. All rights reserved. 1. Introduction Lead-acid batteries provide low-costShort communication Real-time estimation of lead-acid battery parameters: A dynamic data
Ultrafast time dynamics studies of periodic lattices with free electron laser radiation
Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)
2012-11-01T23:59:59.000Z
It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.
Efficient and accurate surface hopping for long time nonadiabatic quantum dynamics
Kelly, Aaron; Markland, Thomas E. [Department of Chemistry, Stanford University, Stanford, California 94305 (United States)
2013-07-07T23:59:59.000Z
The quantum-classical Liouville equation offers a rigorous approach to nonadiabatic quantum dynamics based on surface hopping type trajectories. However, in practice the applicability of this approach has been limited to short times owing to unfavorable numerical scaling. In this paper we show that this problem can be alleviated by combining it with a formally exact generalized quantum master equation treatment. This allows dramatic improvements in the efficiency of the approach in nonadiabatic regimes, making it computationally tractable to treat the quantum dynamics of complex systems for long times. We demonstrate our approach by applying it to a model of condensed phase charge transfer where our method is shown to be numerically exact in regimes where fewest-switches surface hopping and mean field approaches fail to obtain either the correct rates or long-time populations.
Chemical dynamics in the gas phase: Time-dependent quantum mechanics of chemical reactions
Gray, S.K. [Argonne National Laboratory, IL (United States)
1993-12-01T23:59:59.000Z
A major goal of this research is to obtain an understanding of the molecular reaction dynamics of three and four atom chemical reactions using numerically accurate quantum dynamics. This work involves: (i) the development and/or improvement of accurate quantum mechanical methods for the calculation and analysis of the properties of chemical reactions (e.g., rate constants and product distributions), and (ii) the determination of accurate dynamical results for selected chemical systems, which allow one to compare directly with experiment, determine the reliability of the underlying potential energy surfaces, and test the validity of approximate theories. This research emphasizes the use of recently developed time-dependent quantum mechanical methods, i.e. wave packet methods.
Short-time Dynamics of Frictional Strength in Dry Friction O. Ben-David, G. Cohen and J. Fineberg
Fineberg, Jay
Short-time Dynamics of Frictional Strength in Dry Friction O. Ben-David, G. Cohen and J. Fineberg interface that separates two PMMA blocks in dry frictional contact. At applied shear forces significantly weakening 1. Introduction The short-time dynamics of dry friction are of fundamental interest in fields
Short-time Dynamics of Frictional Strength in Dry Friction O. Ben-David and J. Fineberg
Fineberg, Jay
Short-time Dynamics of Frictional Strength in Dry Friction O. Ben-David and J. Fineberg The Racah that separates two PMMA blocks in dry frictional contact. At applied shear forces significantly below the static The short-time dynamics of dry friction are of fundamental interest in fields ranging from hard drive disk
Skrynnikov, Nikolai
be made that 180° pulses refocus the chemical shift evolution and thus prevent the build-up of randomlyMicrosecond time-scale dynamics from relaxation in the rotating frame: experiments using spin lockÞðÀxÞðxÞðÀxÞ . . ., is proposed as a new technique to probe microsecond time-scale dynamics. A series of R1q measurements using
Real-time dynamic simulator for the Topaz II reactor power system
Kwok, K.S.
1994-10-01T23:59:59.000Z
A dynamic simulator of the TOPAZ II reactor system has been developed for the Nuclear Electric Propulsion Space Test Program. The simulator is a self-contained IBM-PC compatible based system that executes at a speed faster than real-time. The simulator combines first-principle modeling and empirical correlations in its algorithm to attain the modeling accuracy and computational through-put that are required for real-time execution. The overall execution time of the simulator for each time step is 15 ms when no data is written to the disk, and 18 ms when nine double precision data points are written to the disk once in every time step. The simulation program has been tested and it is able to handle a step decrease of $8 worth of reactivity. It also provides simulation of fuel, emitter, collector, stainless steel, and ZrH moderator failures. Presented in this paper are the models used in the calculations, a sample simulation session, and a discussion of the performance and limitations of the simulator. The simulator has been found to provide realistic real-time dynamic response of the TOPAZ II reactor system under both normal and causality conditions.
Fission dynamics within time-dependent Hartree-Fock: deformation-induced fission
P. M. Goddard; P. D. Stevenson; A. Rios
2015-04-03T23:59:59.000Z
Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations ignoring dynamical excitations of the fissioning nucleus, and the daughter products. Purpose: To explore the ability of dynamic mean-field methods to describe fast fission processes beyond the fission barrier, using the nuclide $^{240}$Pu as an example. Methods: Time-dependent Hartree-Fock calculations based on the Skyrme interaction are used to calculate non-adiabatic fission paths, beginning from static constrained Hartree-Fock calculations. The properties of the dynamic states are interpreted in terms of the nature of their collective motion. Fission product properties are compared to data. Results: Parent nuclei constrained to begin dynamic evolution with a deformation less than the fission barrier exhibit giant-resonance-type behaviour. Those beginning just beyond the barrier explore large amplitude motion but do not fission, whereas those beginning beyond the two-fragment pathway crossing fission to final states which differ according to the exact initial deformation. Conclusions: Time-dependent Hartree-Fock is able to give a good qualitative and quantitative description of fast fission, provided one begins from a sufficiently deformed state.
Titas Chanda; Utkarsh Mishra; Aditi Sen De; Ujjwal Sen
2015-02-10T23:59:59.000Z
The time-evolution of multiparty quantum correlations as quantified by monogamy scores and bipartition collections of quantum correlations is investigated for light-harvesting complexes modeled by the fully connected and the Fenna-Mathews-Olson (FMO) networks. The dynamics consists of a coherent term as well as dissipative, dephasing, and sink operator terms. The multiparty quantum correlation reveals important information regarding the sharability of quantum correlations in the networks, which allow us to categorize the network sites into three distinct groups in the FMO complex and to predict the structural geometry of the complex. In particular, we show that the relative values of the ingredients of multiparty quantum correlation measures in the time dynamics clearly indicate the primary route of energy transfer from the antenna to the bacterial reaction center in the FMO complex.
Anisotropic model of dark energy dominated universe with hybrid expansion law
Suresh Kumar
2013-08-22T23:59:59.000Z
The paper deals with the study of the dynamics of Universe within the framework of a spatially homogeneous Bianchi-V space-time filled with a perfect fluid composed of non-interacting matter and dynamical dark energy components. We determine the Bianchi-V space-time by considering hybrid expansion law (HEL) for the average scale factor that yields power-law and exponential-law cosmologies in its special cases. In the HEL cosmology, the Universe exhibits transition from deceleration to acceleration. We find that the HEL Universe within the framework of Bianchi-V space-time is anisotropic at the early stages of evolution and becomes isotropic at late times. The dynamical dark energy in the HEL Bianchi-V Universe does not show departure from the usual cosmological constant at later times.
Characteristics and control response of the TOPAZ II Reactor System Real-time Dynamic Simulator
Kwok, K.S.
1993-11-12T23:59:59.000Z
A dynamic simulator of the TOPAZ II reactor system has been developed for the Nuclear Electric Propulsion Space Test Program. The simulator combines first-principle modeling and empirical correlations in its algorithm to attain the modeling accuracy and computational through-put that are required for real-time execution. The overall execution time of the simulator for each time step is 15 ms when no data is written to the disk, and 18 ms when nine double precision data points are written to the disk once in every time step. The simulation program has been tested and it is able to handle a step decrease of $8 worth of reactivity. It also provides simulations of fuel, emitter, collector, stainless steel, and ZrH moderator failures. Presented in this paper are the models used in the calculations, a sample simulation session, and a discussion of the performance and limitations of the simulator. The simulator has been found to provide realistic real-time dynamic response of the TOPAZ II reactor system under both normal and casualty conditions.
Late-Time Dynamics of Scalar Fields on Rotating Black Hole Backgrounds
William Krivan
1999-07-08T23:59:59.000Z
Motivated by results of recent analytic studies, we present a numerical investigation of the late-time dynamics of scalar test fields on Kerr backgrounds. We pay particular attention to the issue of mixing of different multipoles and their fall-off behavior at late times. Confining ourselves to the special case of axisymmetric modes with equatorial symmetry, we show that, in agreement with the results of previous work, the late-time behavior is dominated by the lowest allowed l-multipole. However the numerical results imply that, in general, the late-time fall-off of the dominating multipole is different from that in the Schwarzschild case, and seems to be incompatible with a result of a recently published analytic study.
Sudden Expansion of a One-Dimensional Bose Gas from Power-Law Traps
A. S. Campbell; D. M. Gangardt; K. V. Kheruntsyan
2015-03-27T23:59:59.000Z
We analyze free expansion of a trapped one-dimensional Bose gas after a sudden release from the confining trap potential. By using the stationary phase and local density approximations, we show that the long-time asymptotic density profile and the momentum distribution of the gas are determined by the initial distribution of Bethe rapidities (quasimomenta) and hence can be obtained from the solutions to the Lieb-Liniger equations in the thermodynamic limit. For expansion from a harmonic trap, and in the limits of very weak and very strong interactions, we recover the self-similar scaling solutions known from the hydrodynamic approach. For all other power-law traps and arbitrary interaction strengths, the expansion is not self-similar and shows strong dependence of the density profile evolution on the trap anharmonicity. We also characterize dynamical fermionization of the expanding cloud in terms of correlation functions describing phase and density fluctuations.
Noda, Masashi; Ishimura, Kazuya; Nobusada, Katsuyuki [Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585 (Japan); Yabana, Kazuhiro; Boku, Taisuke [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan)
2014-05-15T23:59:59.000Z
A highly efficient program of massively parallel calculations for electron dynamics has been developed in an effort to apply the method to optical response of nanostructures of more than ten-nanometers in size. The approach is based on time-dependent density functional theory calculations in real-time and real-space. The computational code is implemented by using simple algorithms with a finite-difference method in space derivative and Taylor expansion in time-propagation. Since the computational program is free from the algorithms of eigenvalue problems and fast-Fourier-transformation, which are usually implemented in conventional quantum chemistry or band structure calculations, it is highly suitable for massively parallel calculations. Benchmark calculations using the K computer at RIKEN demonstrate that the parallel efficiency of the program is very high on more than 60?000 CPU cores. The method is applied to optical response of arrays of C{sub 60} orderly nanostructures of more than 10 nm in size. The computed absorption spectrum is in good agreement with the experimental observation.
Prior, Javier; Castro, Enrique [Departamento de Física Aplicada, Universidad Politécnica de Cartagena, Cartagena 30202 (Spain)] [Departamento de Física Aplicada, Universidad Politécnica de Cartagena, Cartagena 30202 (Spain); Chin, Alex W. [Theory of Condensed Matter Group, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom)] [Theory of Condensed Matter Group, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Almeida, Javier; Huelga, Susana F.; Plenio, Martin B. [Institut für Theoretische Physik, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm (Germany)] [Institut für Theoretische Physik, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm (Germany)
2013-12-14T23:59:59.000Z
New experimental techniques based on nonlinear ultrafast spectroscopies have been developed over the last few years, and have been demonstrated to provide powerful probes of quantum dynamics in different types of molecular aggregates, including both natural and artificial light harvesting complexes. Fourier transform-based spectroscopies have been particularly successful, yet “complete” spectral information normally necessitates the loss of all information on the temporal sequence of events in a signal. This information though is particularly important in transient or multi-stage processes, in which the spectral decomposition of the data evolves in time. By going through several examples of ultrafast quantum dynamics, we demonstrate that the use of wavelets provide an efficient and accurate way to simultaneously acquire both temporal and frequency information about a signal, and argue that this greatly aids the elucidation and interpretation of physical process responsible for non-stationary spectroscopic features, such as those encountered in coherent excitonic energy transport.
Viscosity, relaxation time, and dynamics within a model asphalt of larger molecules
Li, Derek D.; Greenfield, Michael L., E-mail: greenfield@egr.uri.edu [Department of Chemical Engineering, University of Rhode Island, Kingston, Rhode Island 02881 (United States)
2014-01-21T23:59:59.000Z
The dynamics properties of a new “next generation” model asphalt system that represents SHRP AAA-1 asphalt using larger molecules than past models is studied using molecular simulation. The system contains 72 molecules distributed over 12 molecule types that range from nonpolar branched alkanes to polar resins and asphaltenes. Molecular weights range from 290 to 890 g/mol. All-atom molecular dynamics simulations conducted at six temperatures from 298.15 to 533.15 K provide a wealth of correlation data. The modified Kohlrausch-Williams-Watts equation was regressed to reorientation time correlation functions and extrapolated to calculate average rotational relaxation times for individual molecules. The rotational relaxation rate of molecules decreased significantly with increasing size and decreasing temperature. Translational self-diffusion coefficients followed an Arrhenius dependence. Similar activation energies of ?42 kJ/mol were found for all 12 molecules in the model system, while diffusion prefactors spanned an order of magnitude. Viscosities calculated directly at 533.15 K and estimated at lower temperatures using the Debye-Stokes-Einstein relationship were consistent with experimental data for asphalts. The product of diffusion coefficient and rotational relaxation time showed only small changes with temperature above 358.15 K, indicating rotation and translation that couple self-consistently with viscosity. At lower temperatures, rotation slowed more than diffusion.
Dissipation dynamics and spin-orbit force in time-dependent Hartree-Fock theory
Gao-Feng Dai; Lu Guo; En-Guang Zhao; Shan-Gui Zhou
2014-10-21T23:59:59.000Z
We investigate the one-body dissipation dynamics in heavy-ion collisions of $^{16}{\\rm O}$+$^{16}{\\rm O}$ using a fully three-dimensional time-dependent Hartree-Fock (TDHF) theory with the modern Skyrme energy functional and without any symmetry restrictions. The energy dissipation is revealed to decrease in deep-inelastic collisions of the light systems as the bombarding energy increases owing to the competition between collective motion and single-particle degrees of freedom. The role of spin-orbit force is given particular emphasis in deep-inelastic collisions. The spin-orbit force causes a significant enhancement of the dissipation. The time-even coupling of spin-orbit force plays a dominant role at low energies, while the influence of time-odd terms is notable at high energies. About 40-65\\% of the total dissipation depending on the different parameter sets is predicted to arise from the spin-orbit force. The theoretical fusion cross section has a reasonably good agreement with the experimental data, considering that no free parameters are adjusted to reaction dynamics in the TDHF approach.
Multiple Time-Scale Behaviour and Network Dynamics in Liquid Methanol
Ruchi Sharma; Charusita Chakravarty
2008-11-11T23:59:59.000Z
Canonical ensemble molecular dynamics simulations of liquid methanol, modeled using a rigid-body, pair-additive potential, are used to compute static distributions and temporal correlations of tagged molecule potential energies as a means of characterising the liquid state dynamics. The static distribution of tagged molecule potential energies shows a clear multimodal structure with three distinct peaks, similar to those observed previously in water and liquid silica. The multimodality is shown to originate from electrostatic effects, but not from local, hydrogen-bond interactions. An interesting outcome of this study is the remarkable similarity in the tagged potential energy power spectra of methanol, water and silica, despite the differences in the underlying interactions and the dimensionality of the network. All three liquids show a distinct multiple time scale (MTS) regime with a 1/f dependence with a clear positive correlation between the scaling exponent alpha and the diffusivity. The low-frequency limit of the MTS regime is determined by the frequency of crossover to white noise behaviour which occurs at approximately 0.1 cm{-1} in the case of methanol under standard temperature and pressure conditions. The power spectral regime above 200 cm{-1} in all three systems is dominated by resonances due to localised vibrations, such as librations. The correlation between $\\alpha$ and the diffusivity in all three liquids appears to be related to the strength of the coupling between the localised motions and the larger length/time-scale network reorganizations. Thus the time scales associated with network reorganization dynamics appear to be qualitatively similar in these systems, despite the fact that water and silica both display diffusional anomalies but methanol does not.
Spectral fluctuations of billiards with mixed dynamics: from time series to superstatistics
A. Y. Abul-Magd; B. Dietz; T. Friedrich; A. Richter
2008-03-22T23:59:59.000Z
A statistical analysis of the eigenfrequencies of two sets of superconducting microwave billiards, one with mushroom-like shape and the other from the familiy of the Limacon billiards, is presented. These billiards have mixed regular-chaotic dynamics but different structures in their classical phase spaces. The spectrum of each billiard is represented as a time series where the level order plays the role of time. Two most important findings follow from the time-series analysis. First, the spectra can be characterized by two distinct relaxation lengths. This is a prerequisite for the validity of the superstatistical approach which is based on the folding of two distribution functions. Second, the shape of the resulting probability density function of the so-called superstatistical parameter is reasonably approximated by an inverse chi-square distribution. This distribution is used to compute nearest-neighbor spacing distributions and compare them with those of the resonance frequencies of billiards with mixed dynamics within the framework of superstatistics. The obtained spacing distribution is found to present a good description of the experimental ones and is of the same or even better quality as a number of other spacing distributions, including the one from Berry and Robnik. However, in contrast to other approaches towards a theoretical description of spectral properties of systems with mixed dynamics, superstatistics also provides a description of properties of the eigenfunctions. Indeed, the inverse chi-square parameter distribution is found suitable for the analysis of experimental resonance strengths in the Limacon billiards within the framework of superstatistics.
High thermal expansion, sealing glass
Brow, Richard K. (Albuquerque, NM); Kovacic, Larry (Albuquerque, NM)
1993-01-01T23:59:59.000Z
A glass composition for hermetically sealing to high thermal expansion materials such as aluminum alloys, stainless steels, copper, and copper/beryllium alloys, which includes between about 10 and about 25 mole percent Na.sub.2 O, between about 10 and about 25 mole percent K.sub.2 O, between about 5 and about 15 mole percent Al.sub.2 O.sub.3, between about 35 and about 50 mole percent P.sub.2 O.sub.5 and between about 5 and about 15 mole percent of one of PbO, BaO, and mixtures thereof. The composition, which may also include between 0 and about 5 mole percent Fe.sub.2 O.sub.3 and between 0 and about 10 mole percent B.sub.2 O.sub.3, has a thermal expansion coefficient in a range of between about 160 and 210.times.10-7/.degree.C. and a dissolution rate in a range of between about 2.times.10.sup.- 7 and 2.times.10.sup.-9 g/cm.sup.2 -min. This composition is suitable to hermetically seal to metallic electrical components which will be subjected to humid environments over an extended period of time.
High thermal expansion, sealing glass
Brow, R.K.; Kovacic, L.
1993-11-16T23:59:59.000Z
A glass composition is described for hermetically sealing to high thermal expansion materials such as aluminum alloys, stainless steels, copper, and copper/beryllium alloys, which includes between about 10 and about 25 mole percent Na[sub 2]O, between about 10 and about 25 mole percent K[sub 2]O, between about 5 and about 15 mole percent Al[sub 2]O[sub 3], between about 35 and about 50 mole percent P[sub 2]O[sub 5] and between about 5 and about 15 mole percent of one of PbO, BaO, and mixtures thereof. The composition, which may also include between 0 and about 5 mole percent Fe[sub 2]O[sub 3] and between 0 and about 10 mole percent B[sub 2]O[sub 3], has a thermal expansion coefficient in a range of between about 160 and 210[times]10[sup [minus]7]/C and a dissolution rate in a range of between about 2[times]10[sup [minus]7] and 2[times]10[sup [minus]9]g/cm[sup 2]-min. This composition is suitable to hermetically seal to metallic electrical components which will be subjected to humid environments over an extended period of time.
Lee, Chaehwa
2012-02-14T23:59:59.000Z
AND COMPETITIVENESS TO STRATEGIC PLANNING ....................... 46 6.1 Shift of trade partner over time ............................................... 47 6.2 Location selection in the automotive industry ........................ 48... 6.3 Logistics systems ...................................................................... 50 6.4 Clustering in the automotive industry ...................................... 51 VII INCORPORATING COMPETITIVENESS INDICATORS...
Geometry of quantum dynamics and a time-energy uncertainty relation for mixed states
Ole Andersson; Hoshang Heydari
2013-02-07T23:59:59.000Z
In this paper we establish important relations between Hamiltonian dynamics and Riemannian structures on phase spaces for unitarily evolving finite level quantum systems in mixed states. We show that the energy dispersion (i.e. $1/\\hbar$ times the path integral of the energy uncertainty) of a unitary evolution is bounded from below by the length of the evolution curve. Also, we show that for each curve of mixed states there is a Hamiltonian for which the curve is a solution to the corresponding von Neumann equation, and the energy dispersion equals the curve's length. This allows us to express the distance between two mixed states in terms of a measurable quantity, and derive a time-energy uncertainty relation for mixed states. In a final section we compare our results with an energy dispersion estimate by Uhlmann.
Fukumoto, Keiki, E-mail: fukumoto.k.ab@m.titech.ac.jp; Yamada, Yuki; Matsuki, Takashi; Koshihara, Shin-ya [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan); Japan Science and Technology Agency JST-CREST, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Onda, Ken [Interactive Research Center of Science, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Japan Science and Technology Agency JST-PRESTO, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Mukuta, Tatsuhiko; Tanaka, Sei-ichi [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan)
2014-08-15T23:59:59.000Z
We constructed an instrument for time-resolved photoemission electron microscopy (TR-PEEM) utilizing femtosecond (fs) laser pulses to visualize the dynamics of photogenerated electrons in semiconductors on ultrasmall and ultrafast scales. The spatial distribution of the excited electrons and their relaxation and/or recombination processes were imaged by the proposed TR-PEEM method with a spatial resolution about 100 nm and an ultrafast temporal resolution defined by the cross-correlation of the fs laser pulses (240 fs). A direct observation of the dynamical behavior of electrons on higher resistivity samples, such as semiconductors, by TR-PEEM has still been facing difficulties because of space and/or sample charging effects originating from the high photon flux of the ultrashort pulsed laser utilized for the photoemission process. Here, a regenerative amplified fs laser with a widely tunable repetition rate has been utilized, and with careful optimization of laser parameters, such as fluence and repetition rate, and consideration for carrier lifetimes, the electron dynamics in semiconductors were visualized. For demonstrating our newly developed TR-PEEM method, the photogenerated carrier lifetimes around a nanoscale defect on a GaAs surface were observed. The obtained lifetimes were on a sub-picosecond time scale, which is much shorter than the lifetimes of carriers observed in the non-defective surrounding regions. Our findings are consistent with the fact that structural defects induce mid-gap states in the forbidden band, and that the electrons captured in these states promptly relax into the ground state.
Dynamic environment coupling induce synchronized states in coupled time-delayed electronic circuits
R. Suresh; K. Srinivasan; D. V. Senthilkumar; K. Murali; M. Lakshmanan; J. Kurths
2014-01-27T23:59:59.000Z
We experimentally demonstrate the occurrence of various synchronized states in coupled piece-wise linear time-delayed electronic circuits using dynamic environment coupling where the environment has its own intrinsic dynamics via feedback from the circuits. We carry out these experiments in two different coupling configurations, namely mutual and subsystem coupling configurations. Depending upon the coupling strength and the nature of feedback, we observe a transition from nonsynchronization to complete synchronization via phase synchronization and from nonsynchronization to inverse synchronization via inverse-phase synchronization between the circuits in hyperchaotic regime. Snapshots of the time evolution, phase projection plots and localized sets of the circuits as observed experimentally from the oscilloscope, along with supporting numerical simulations confirm the existence of different synchronized states. Further, the transition to different synchronized states can be verified from the changes in the largest Lyapunov exponents, Correlation of Probability of Recurrence and Correlation Coefficient as a function of the coupling strength. We present a detailed linear stability analysis and obtain conditions for different synchronized states.
Long-Time Relaxation on Spin Lattice as Manifestation of Chaotic Dynamics
Boris V. Fine
2004-08-10T23:59:59.000Z
The long-time behavior of the infinite temperature spin correlation functions describing the free induction decay in nuclear magnetic resonance and intermediate structure factors in inelastic neutron scattering is considered. These correlation functions are defined for one-, two- and three-dimensional infinite lattices of interacting spins both classical and quantum. It is shown that, even though the characteristic timescale of the long-time decay of the correlation functions considered is non-Markovian, the generic functional form of this decay is either simple exponential or exponential multiplied by cosine. This work contains (i) summary of the existing experimental and numerical evidence of the above asymptotic behavior; (ii) theoretical explanation of this behavior; and (iii) semi-empirical analysis of various factors discriminating between the monotonic and the oscillatory long-time decays. The theory is based on a fairly strong conjecture that, as a result of chaos generated by the spin dynamics, a Brownian-like Markovian description can be applied to the long-time properties of ensemble average quantities on a non-Markovian timescale. The formalism resulting from that conjecture can be described as ``correlated diffusion in finite volumes.''
Accelerated expansion from cosmological holography
van Putten, Maurice H P M
2015-01-01T23:59:59.000Z
It is shown that holographic cosmology implies an evolving Hubble radius $c^{-1}\\dot{R}_H = -1 + 3\\Omega_m$ in the presence of a dimensionless matter density $\\Omega_m$ scaled to the closure density $3H^2/8\\pi G$, where $c$ denotes the velocity of light and $H$ and $G$ denote the Hubble parameter and Newton's constant. It reveals a dynamical dark energy and a sixfold increase in gravitational attraction to matter on the scale of the Hubble acceleration. It reproduces the transition redshift $z_t\\simeq 0.4$ to the present epoch of accelerated expansion and is consistent with $(q_0,(dq/dz)_0)$ of the deceleration parameter $q(z)=q_0+(dq/dz)_0z$ observed in Type Ia supernovae.
Guzek, J.C.; Lujan, R.A.
1984-01-01T23:59:59.000Z
Disclosed is a cooler for television cameras and other temperature sensitive equipment. The cooler uses compressed gas ehich is accelerated to a high velocity by passing it through flow passageways having nozzle portions which expand the gas. This acceleration and expansion causes the gas to undergo a decrease in temperature thereby cooling the cooler body and adjacent temperature sensitive equipment.
Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading
Lambert, P. K.; Hustedt, C. J.; Zhao, M.; Ananiadis, A. G.; Hufnagel, T. C. [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Vecchio, K. S. [Department of NanoEngineering, University of California San Diego, La Jolla, California 92093 (United States); Huskins, E. L. [Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830 (United States); US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005 (United States); Casem, D. T. [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005 (United States); Gruner, S. M. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853 (United States); Tate, M. W.; Philipp, H. T.; Purohit, P.; Weiss, J. T. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Woll, A. R. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Kannan, V.; Ramesh, K. T. [Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Kenesei, P.; Okasinski, J. S.; Almer, J. [X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2014-09-15T23:59:59.000Z
We have developed two techniques for time-resolved x-ray diffraction from bulk polycrystalline materials during dynamic loading. In the first technique, we synchronize a fast detector with loading of samples at strain rates of ?10{sup 3}–10{sup 4} s{sup ?1} in a compression Kolsky bar (split Hopkinson pressure bar) apparatus to obtain in situ diffraction patterns with exposures as short as 70 ns. This approach employs moderate x-ray energies (10–20 keV) and is well suited to weakly absorbing materials such as magnesium alloys. The second technique is useful for more strongly absorbing materials, and uses high-energy x-rays (86 keV) and a fast shutter synchronized with the Kolsky bar to produce short (?40??s) pulses timed with the arrival of the strain pulse at the specimen, recording the diffraction pattern on a large-format amorphous silicon detector. For both techniques we present sample data demonstrating the ability of these techniques to characterize elastic strains and polycrystalline texture as a function of time during high-rate deformation.
Dynamical diffraction peak splitting in time-of-flight neutron diffraction
Uestuendag, E.; Karnesky, R. A.; Daymond, M. R.; Noyan, I. C. [Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario K7L3N6 (Canada); Department of Applied Physics and Applied Mathematics, Materials Science Program, Columbia University, New York, New York 10027 (United States)
2006-12-04T23:59:59.000Z
Time-of-flight neutron diffraction data from 20 and 0.7 mm thick perfect Si single crystal samples, which exhibit dynamical diffraction effects associated with finite crystal size, are presented. This effect is caused by constructive interference occurring solely from thin layers bounded by the front (entry) and back (exit) surfaces of the sample with no scattering originating from the layers in between, resulting in two distinct peaks observed for each reflection. If the sample is thin and/or the instrument resolution is insufficient, these two peaks can convolve and cause peak shape aberrations which can lead to significant errors in the strain and peak-broadening parameters obtained from a kinematical diffraction analysis.
Characterization of beam dynamics in the APS injector rings using time-resolved imaging techniques
Yang, B.X.; Lumpkin, A.H.; Borland, M. [and others
1997-06-01T23:59:59.000Z
Images taken with streak cameras and gated intensified cameras with both time (longitudinal) and spatial (transverse) resolution reveal a wealth of information about circular accelerators. The authors illustrate a novel technique by a sequence of dual-sweep streak camera images taken at a high dispersion location in the booster synchrotron, where the horizontal coordinate is strongly correlated with the particle energy and the {open_quotes}top-view{close_quotes} of the beam gives a good approximation to the particle density distribution in the longitudinal phase space. A sequence of top-view images taken fight after injection clearly shows the beam dynamics in the phase space. We report another example from the positron accumulator ring for the characterization of its beam compression bunching with the 12th harmonic rf.
Solid waste bin detection and classification using Dynamic Time Warping and MLP classifier
Islam, Md. Shafiqul, E-mail: shafique@eng.ukm.my [Dept. of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia); Hannan, M.A., E-mail: hannan@eng.ukm.my [Dept. of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia); Basri, Hassan [Dept. of Civil and Structural Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia); Hussain, Aini; Arebey, Maher [Dept. of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangore (Malaysia)
2014-02-15T23:59:59.000Z
Highlights: • Solid waste bin level detection using Dynamic Time Warping (DTW). • Gabor wavelet filter is used to extract the solid waste image features. • Multi-Layer Perceptron classifier network is used for bin image classification. • The classification performance evaluated by ROC curve analysis. - Abstract: The increasing requirement for Solid Waste Management (SWM) has become a significant challenge for municipal authorities. A number of integrated systems and methods have introduced to overcome this challenge. Many researchers have aimed to develop an ideal SWM system, including approaches involving software-based routing, Geographic Information Systems (GIS), Radio-frequency Identification (RFID), or sensor intelligent bins. Image processing solutions for the Solid Waste (SW) collection have also been developed; however, during capturing the bin image, it is challenging to position the camera for getting a bin area centralized image. As yet, there is no ideal system which can correctly estimate the amount of SW. This paper briefly discusses an efficient image processing solution to overcome these problems. Dynamic Time Warping (DTW) was used for detecting and cropping the bin area and Gabor wavelet (GW) was introduced for feature extraction of the waste bin image. Image features were used to train the classifier. A Multi-Layer Perceptron (MLP) classifier was used to classify the waste bin level and estimate the amount of waste inside the bin. The area under the Receiver Operating Characteristic (ROC) curves was used to statistically evaluate classifier performance. The results of this developed system are comparable to previous image processing based system. The system demonstration using DTW with GW for feature extraction and an MLP classifier led to promising results with respect to the accuracy of waste level estimation (98.50%). The application can be used to optimize the routing of waste collection based on the estimated bin level.
Constraints on Cardassian Expansion
W. J. Frith
2003-11-10T23:59:59.000Z
High redshift supernovae and Cosmic Microwave Background data are used to constrain the Cardassian expansion model (Freese & Lewis 2002), a cosmology in which a modification to the Friedmann equation gives rise to a flat, matter-dominated Universe which is currently undergoing a phase of accelerated expansion. In particular, the precision of the positions of the Doppler peaks in the CMB angular power spectrum provided by WMAP tightly constrains the cosmology. The available parameter space is further constrained by various high redshift supernova datasets taken from Tonry et al. (2003), a sample of 230 supernovae collated from the literature, in which fits to the distance and extinction have been recomputed where possible and a consistent zero-point has been applied. In addition, the Cardassian model can also be loosely constrained by inferred upper limits on the epoch at which the Cardassian term in the modified Friedmann equation begins to dominate the expansion (z_eq). Using these methods, a Cardassian cosmology is constrained at the 2 sigma level to 0.191, as opposed to the supernova data which supports a high-Omega_m, low-n cosmology.
Time-dependent and outflow boundary conditions for Dissipative Particle Dynamics
Lei Huan [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Fedosov, Dmitry A. [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Institut fuer Festkoerperforschung, Forschungszentrum Juelich, 52425 Juelich (Germany); Karniadakis, George Em, E-mail: George_Karniadakis@brown.ed [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States)
2011-05-10T23:59:59.000Z
We propose a simple method to impose both no-slip boundary conditions at fluid-wall interfaces and at outflow boundaries in fully developed regions for Dissipative Particle Dynamics (DPD) fluid systems. The procedure to enforce the no-slip condition is based on a velocity-dependent shear force, which is a generalized force to represent the presence of the solid-wall particles and to maintain locally thermodynamic consistency. We show that this method can be implemented in both steady and time-dependent fluid systems and compare the DPD results with the continuum limit (Navier-Stokes) results. We also develop a force-adaptive method to impose the outflow boundary conditions for fully developed flow with unspecified outflow velocity profile or pressure value. We study flows over the backward-facing step and in idealized arterial bifurcations using a combination of the two new boundary methods with different flow rates. Finally, we explore the applicability of the outflow method in time-dependent flow systems. The outflow boundary method works well for systems with Womersley number of O(1), i.e. when the pressure and flowrate at the outflow are approximately in-phase.
Mehdi Farzanehpour; I. V. Tokatly
2015-06-29T23:59:59.000Z
We use analytic (current) density-potential maps of time-dependent (current) density functional theory (TD(C)DFT) to inverse engineer analytically solvable time-dependent quantum problems. In this approach the driving potential (the control signal) and the corresponding solution of the Schr\\"odinger equation are parametrized analytically in terms of the basic TD(C)DFT observables. We describe the general reconstruction strategy and illustrate it with a number of explicit examples. First we consider the real space one-particle dynamics driven by a time-dependent electromagnetic field and recover, from the general TDDFT reconstruction formulas, the known exact solution for a driven oscillator with a time-dependent frequency. Then we use analytic maps of the lattice TD(C)DFT to control quantum dynamics in a discrete space. As a first example we construct a time-dependent potential which generates prescribed dynamics on a tight-binding chain. Then our method is applied to the dynamics of spin-1/2 driven by a time dependent magnetic field. We design an analytic control pulse that transfers the system from the ground to excited state and vice versa. This pulse generates the spin flip thus operating as a quantum NOT gate.
AIAA 20030185 Aerodynamically Controlled Expansion
Texas at Arlington, University of
undesirable over-expansion in generalized supersonic nozzle flows. Nomenclature A cross-sectional area fgAIAA 20030185 Aerodynamically Controlled Expansion Nozzle for STOVL Aircraft D.A. Terrier Lockheed Controlled Expansion Nozzle for STOVL Aircraft Douglas A. Terrier* Lockheed Martin Aeronautics Company, Fort
Gyrification from constrained cortical expansion
Tuomas Tallinen; Jun Young Chung; John S. Biggins; L. Mahadevan
2015-03-12T23:59:59.000Z
The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated as a soft solid lead to the formation of cusped sulci and smooth gyri similar to those in the brain. The resulting gyrification patterns are a function of relative cortical expansion and relative thickness (compared with brain size), and are consistent with observations of a wide range of brains, ranging from smooth to highly convoluted. Furthermore, this dependence on two simple geometric parameters that characterize the brain also allows us to qualitatively explain how variations in these parameters lead to anatomical anomalies in such situations as polymicrogyria, pachygyria, and lissencephalia.
Loop expansion in Yang-Mills thermodynamics
Ralf Hofmann
2009-11-05T23:59:59.000Z
We argue that a selfconsistent spatial coarse-graining, which involves interacting (anti)calorons of unit topological charge modulus, implies that real-time loop expansions of thermodynamical quantities in the deconfining phase of SU(2) and SU(3) Yang-Mills thermodynamics are, modulo 1PI resummations, determined by a finite number of connected bubble diagrams.
Reinforcement Learning Control with Approximation of Time-Dependent Agent Dynamics
Kirkpatrick, Kenton
2013-04-30T23:59:59.000Z
.4.2 Rotating Robot . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4. DYNAMICS APPROXIMATION LEARNING . . . . . . . . . . . . . . . 56 4.1 First-Order Dynamics Learning . . . . . . . . . . . . . . . . . . . . . 58 4.2 Second-Order Dynamics Learning... . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 B.4 Overdamped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 viii LIST OF FIGURES FIGURE Page 2.1 Perceptron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Q-learning Simulation of Robot - Goal...
Time-dependent self-consistent-field dynamics based on a reaction path Hamiltonian. I. Theory
Hammes-Schiffer, Sharon
the coupling between the normal modes and the curvature are zero, the dynamics of an F-dimensional system is zero and the coupling between the normal modes is non-zero, the dynamics is shown to still reduce as a dynamical process of nu- clei moving on a multidimensional adiabatic potential energy surface. Modern ab
Ohmura, Shu; Kono, Hirohiko, E-mail: hirohiko-kono@m.tohoku.ac.jp [Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Oyamada, Takayuki [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Kato, Tsuyoshi; Nakai, Katsunori [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Koseki, Shiro [Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Osaka 599-8531 (Japan)
2014-09-21T23:59:59.000Z
Using the framework of multiconfiguration theory, where the wavefunction ?(t) of a many-electron system at time t is expanded as ?(t)=?{sub I}C{sub I}(t)?{sub I}(t) in terms of electron configurations (?{sub I}(t)), we divided the total electronic energy E(t) as E(t)=?{sub I}|C{sub I}(t)|{sup 2}E{sub I}(t) . Here E{sub I}(t) is the instantaneous phase changes of C{sub I}(t) regarded as a configurational energy associated with ?{sub I}(t). We then newly defined two types of time-dependent states: (i) a state at which the rates of population transfer among configurations are all zero; (ii) a state at which (E{sub I}(t)) associated with the quantum phases of C{sub I}(t) are all the same. We call the former time-dependent state a classical stationary state by analogy with the stationary (steady) states of classical reaction rate equations and the latter one a quantum stationary state. The conditions (i) and (ii) are satisfied simultaneously for the conventional stationary state in quantum mechanics. We numerically found for a LiH molecule interacting with a near-infrared (IR) field ?(t) that the condition (i) is satisfied whenever the average velocity of electrons is zero and the condition (ii) is satisfied whenever the average acceleration is zero. We also derived the chemical potentials ?{sub j}(t) for time-dependent natural orbitals ?{sub j}(t) of a many-electron system. The analysis of the electron dynamics of LiH indicated that the temporal change in ??{sub j}(t) ? ?{sub j}(t) + ?(t) · d{sub j}(t) ? ?{sub j}(0) correlates with the motion of the dipole moment of ?{sub j}(t), d{sub j}(t). The values ??{sub j}(t) are much larger than the energy ?{sub j}(t) directly supplied to ?{sub j}(t) by the field, suggesting that valence electrons exchange energy with inner shell electrons. For H{sub 2} in an intense near-IR field, the ionization efficiency of ?{sub j}(t) is correlated with ??{sub j}(t). Comparing ??{sub j}(t) to ?{sub j}(t), we found that energy accepting orbitals of ??{sub j}(t) > ?{sub j}(t) indicate high ionization efficiency. The difference between ??{sub j}(t) and ?{sub j}(t) is significantly affected by electron-electron interactions in real time.
Load regulating expansion fixture
Wagner, Lawrence M. (San Jose, CA); Strum, Michael J. (San Jose, CA)
1998-01-01T23:59:59.000Z
A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components.
Johnson, Walter R.
Multipole Expansion (r) = 1 4 0 q r + p · r r3 + 1 2 ij rirj r5 Qij + · · · q = (r) d3 r p = (r) r of multipole r0: E = - = 1 4 0 qn |r - r0|2 + 3 n(p · n) - p |r - r0|3 + · · · where n is unit vector in direction r - r0. Energy of multipole in external field: W = q(r0) - p · E(r0) - 1 6 ij Qij Ei rj r0
Load regulating expansion fixture
Wagner, L.M.; Strum, M.J.
1998-12-15T23:59:59.000Z
A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig.
Wopperer, P; Reinhard, P -G; Suraud, E
2014-01-01T23:59:59.000Z
Various ways to analyze the dynamical response of clusters and molecules to electromagnetic perturbations exist. Particularly rich information can be obtained from measuring the properties of electrons emitted in the course of the excitation dynamics. Such an analysis of electron signals covers total ionization, Photo-Electron Spectra, Photoelectron Angular Distributions, and ideally combined PES/PAD, with a long history in molecular physics, also increasingly used in cluster physics. Recent progress in the design of new light sources (high intensity and/or frequency, ultra short pulses) opens new possibilities for measurements and thus has renewed the interest on the analysis of dynamical scenarios through these observables, well beyond a simple access to a density of states. This, in turn, has motivated many theoretical investigations of the dynamics of electronic emission for molecules and clusters. A theoretical tool of choice is here Time-Dependent Density Functional Theory (TDDFT) propagated in real tim...
Gutierrez, Rafael M.; Useche, Gina M.; Buitrago, Elias [Centro de Investigaciones, Universidad Antonio Narino, Carrera 3 Este No. 47A--15 Bogota (Colombia)
2007-11-13T23:59:59.000Z
We present a procedure developed to detect stochastic and deterministic information contained in empirical time series, useful to characterize and make models of different aspects of complex phenomena represented by such data. This procedure is applied to a seismological time series to obtain new information to study and understand geological phenomena. We use concepts and methods from nonlinear dynamics and maximum entropy. The mentioned method allows an optimal analysis of the available information.
Huse, Nils; Kim, Tae Kyu; Khalil, Munira; Jamula, Lindsey; McCusker, James K.; Schoenlein, Robert W.
2010-05-02T23:59:59.000Z
We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding.
Ramaswamy, Ram
Long time fluctuation of liquid water: l/f spectrum of energy fluctuation in hydrogen bond network of the potential energy fluctuation of liquid water is examined and found to yield so-called l/f frequency of hydrogen bond network relaxations in liquid water. A simple model of cellular dynamics is proposed
Apkarian, V. Ara
contribution to laser plasmas generated in air,26 ionized oxygen O2 + plays an important role in the upperNonresonant ionization of oxygen molecules by femtosecond pulses: Plasma dynamics studied by time for exploring laser-induced ionization and plasma formation in gases. Plasma was produced in gaseous oxygen
Henn, T.; Kiessling, T., E-mail: tobias.kiessling@physik.uni-wuerzburg.de; Ossau, W.; Molenkamp, L. W. [Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg (Germany)] [Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg (Germany); Biermann, K.; Santos, P. V. [Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin (Germany)] [Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin (Germany)
2013-12-15T23:59:59.000Z
We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast “white light” supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.
Iyengar, Srinivasan S.
Dynamics and Electronic Structure David Hocker, Xiaohu Li, and Srinivasan S. Iyengar* Department) approximates the electronic structure alongside the nuclei to simulate molecular dynamics. When AIMD techniques in electronic structure calculation. The approach is quantum-classical40,57-63 and involves the synergy between
Schwerdtfeger, Christine A.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon, E-mail: shs3@illinois.edu [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)] [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)
2014-01-21T23:59:59.000Z
The development of efficient theoretical methods for describing electron transfer (ET) reactions in condensed phases is important for a variety of chemical and biological applications. Previously, dynamical dielectric continuum theory was used to derive Langevin equations for a single collective solvent coordinate describing ET in a polar solvent. In this theory, the parameters are directly related to the physical properties of the system and can be determined from experimental data or explicit molecular dynamics simulations. Herein, we combine these Langevin equations with surface hopping nonadiabatic dynamics methods to calculate the rate constants for thermal ET reactions in polar solvents for a wide range of electronic couplings and reaction free energies. Comparison of explicit and implicit solvent calculations illustrates that the mapping from explicit to implicit solvent models is valid even for solvents exhibiting complex relaxation behavior with multiple relaxation time scales and a short-time inertial response. The rate constants calculated for implicit solvent models with a single solvent relaxation time scale corresponding to water, acetonitrile, and methanol agree well with analytical theories in the Golden rule and solvent-controlled regimes, as well as in the intermediate regime. The implicit solvent models with two relaxation time scales are in qualitative agreement with the analytical theories but quantitatively overestimate the rate constants compared to these theories. Analysis of these simulations elucidates the importance of multiple relaxation time scales and the inertial component of the solvent response, as well as potential shortcomings of the analytical theories based on single time scale solvent relaxation models. This implicit solvent approach will enable the simulation of a wide range of ET reactions via the stochastic dynamics of a single collective solvent coordinate with parameters that are relevant to experimentally accessible systems.
Burial Ground Expansion Hydrogeologic Characterization
Gaughan , T.F.
1999-02-26T23:59:59.000Z
Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.
Tong, Xiao-Min; Chu, Shih-I
2000-02-01T23:59:59.000Z
We present a general time-dependent approach for efficient and accurate treatment of high-resolution spectrocopy and quantum dynamics. The procedure is applied to an ab initio time-dependent study of three-dimensional ...
Field-Failure Predictions Based on Failure-time Data with Dynamic Covariate Information
; Dynamic data; Lifetime data; Usage history, Warranty returns. 1 #12;1 Introduction 1.1 Background Modern products, such as automobiles, high-end copying machines, and smart phones. For products contain- ing ADCDs
K. Grzybowska; A. Grzybowski; S. Pawlus; J. Pionteck; M. Paluch
2014-10-23T23:59:59.000Z
In this Letter, we investigate how changes in the system entropy influence the characteristic time scale of the system molecular dynamics near the glass transition. Independently of any model of thermodynamic evolution of the time scale, against some previous suppositions, we show that the system entropy $S$ is not sufficient to govern the time scale defined by structural relaxation time $\\tau $. In the density scaling regime, we argue that the decoupling between $\\tau $ and $S$ is a consequence of different values of the scaling exponents $\\gamma $ and $\\gamma_S $ in the density scaling laws, $\\tau = f(\\rho ^\\gamma /T)$ and $S = h(\\rho ^{\\gamma_S}/T)$, where $\\rho $ and $T$ denote density and temperature, respectively. It implies that the proper relation between $\\tau $ and $S$ requires supplementing with a density factor, $u(\\rho)$, i.e.,$\\tau = g(u(\\rho)w(S))$. This meaningful finding additionally demonstrates that the density scaling idea can be successfully used to separate physically relevant contributions to the time scale of molecular dynamics near the glass transition. As an example, we revise the Avramov entropic model of the dependence $\\tau (T,\\rho)$, giving evidence that its entropic basis has to be extended by the density dependence of the maximal energy barrier for structural relaxation. We also discuss the excess entropy $S_{ex}$, the density scaling of which is found to mimic the density scaling of the total system entropy $S$.
Beta-conjugates of real algebraic numbers as Puiseux expansions
Paris-Sud XI, UniversitÃ© de
Beta-conjugates of real algebraic numbers as Puiseux expansions Jean-Louis Verger-Gaugry Abstract. The beta-conjugates of a base of numeration > 1, being a Parry number, were introduced by Boyd, in the context of the RÂ´enyi-Parry dynamics of numeration system and the beta-transformation. These beta
Fujisawa, Tetsuro; Takahashi, Satoshi [RIKEN Harima Institute, SPring-8 Center, Laboratory for Biometal Science, Hyogo 679-5148 (Japan); Institute for Protein Research, Osaka University Suita Osaka 565-0871/CREST, JST (Japan)
2007-03-30T23:59:59.000Z
The polypeptide collapse is an essential dynamics in protein folding. To understand the mechanism of the collapse, in situ observation of folding by various probes is necessary. The changes in secondary and tertiary structures in the folding process of globular proteins, whose chain lengths are less than 300 polypeptides, were observed by circular dichrosim and intrinsic fluorescence spectroscopies, respectively. On the other hand, those in protein compactness could be only detected by using time-resolved synchrotron x-ray small-angle scattering technique. The observed dynamics for several proteins with different topologies suggested a common folding mechanism termed 'collapse and search' dynamics, in which the polypeptide collapse precedes the formation of the native contact formation. In 'collapse and search' dynamics, the most outstanding feature lied in the compactness of the initial intermediates. The collapsed intermediates demonstrated the scaling relationship between radius of gyration (Rg) and chain length with a scaling exponent of 0.35 {+-} 0.11, which is close to the value (1/3) predicted by mechano-statistical theory for the collapsed globules of polymers in poor solvent. Thus, it was suggested that the initial collapse is caused by the coil-globule transition of polymers. Since the collapse is essential to the folding of larger proteins, further investigations on the collapse likely lead to an important insight into the protein folding phenomena.
Tests for the Expansion of the Universe
Martin Lopez-Corredoira
2015-01-07T23:59:59.000Z
Almost all cosmologists accept nowadays that the redshift of the galaxies is due to the expansion of the Universe (cosmological redshift), plus some Doppler effect of peculiar motions, but can we be sure of this fact by means of some other independent cosmological test? Here I will review some recent tests: CMBR temperature versus redshift, time dilation, the Hubble diagram, the Tolman or surface brightness test, the angular size test, the UV surface brightness limit and the Alcock--Paczy\\'nski test. Some tests favour expansion and others favour a static Universe. Almost all the cosmological tests are susceptible to the evolution of galaxies and/or other effects. Tolman or angular size tests need to assume very strong evolution of galaxy sizes to fit the data with the standard cosmology, whereas the Alcock--Paczynski test, an evaluation of the ratio of observed angular size to radial/redshift size, is independent of it.
Tests for the Expansion of the Universe
Lopez-Corredoira, Martin
2015-01-01T23:59:59.000Z
Almost all cosmologists accept nowadays that the redshift of the galaxies is due to the expansion of the Universe (cosmological redshift), plus some Doppler effect of peculiar motions, but can we be sure of this fact by means of some other independent cosmological test? Here I will review some recent tests: CMBR temperature versus redshift, time dilation, the Hubble diagram, the Tolman or surface brightness test, the angular size test, the UV surface brightness limit and the Alcock--Paczy\\'nski test. Some tests favour expansion and others favour a static Universe. Almost all the cosmological tests are susceptible to the evolution of galaxies and/or other effects. Tolman or angular size tests need to assume very strong evolution of galaxy sizes to fit the data with the standard cosmology, whereas the Alcock--Paczynski test, an evaluation of the ratio of observed angular size to radial/redshift size, is independent of it.
Dynamical behaviours in time-delay systems with delayed feedback and digitized coupling
Chiranjit Mitra; G. Ambika; Soumitro Banerjee
2014-11-05T23:59:59.000Z
We consider a network of delay dynamical systems connected in a ring via unidirectional positive feedback with constant delay in coupling. For the specific case of Mackey-Glass systems on the ring topology, we capture the phenomena of amplitude death, isochronous synchronization and phase-flip bifurcation as the relevant parameters are tuned. Using linear stability analysis and master stability function approach, we predict the region of amplitude death and synchronized states respectively in the parameter space and study the nature of transitions between the different states. For a large number of systems in the same dynamical configuration, we observe splay states, mixed splay states and phase locked clusters. We extend the study to the case of digitized coupling and observe that these emergent states still persist. However, the sampling and quantization reduce the regions of amplitude death and induce phase-flip bifurcation.
SAGEWASP. Optimal Electric Utility Expansion
Clark, P.D.II; Ullrich, C.J. [Lakeland Electric and Water, FL (United States)
1989-10-10T23:59:59.000Z
SAGE-WASP is designed to find the optimal generation expansion policy for an electrical utility system. New units can be automatically selected from a user-supplied list of expansion candidates which can include hydroelectric and pumped storage projects. The existing system is modeled. The calculational procedure takes into account user restrictions to limit generation configurations to an area of economic interest. The optimization program reports whether the restrictions acted as a constraint on the solution. All expansion configurations considered are required to pass a user supplied reliability criterion. The discount rate and escalation rate are treated separately for each expansion candidate and for each fuel type. All expenditures are separated into local and foreign accounts, and a weighting factor can be applied to foreign expenditures.
Liu, Ping; Zhao, Jing; Liu, Jinxiang; Zhang, Meng; Bu, Yuxiang, E-mail: byx@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)] [School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100 (China)
2014-01-28T23:59:59.000Z
In view of the important implications of excess electrons (EEs) interacting with CO{sub 2}–H{sub 2}O clusters in many fields, using ab initio molecular dynamics simulation technique, we reveal the structures and dynamics of an EE associated with its localization and subsequent time evolution in heterogeneous CO{sub 2}–H{sub 2}O mixed media. Our results indicate that although hydration can increase the electron-binding ability of a CO{sub 2} molecule, it only plays an assisting role. Instead, it is the bending vibrations that play the major role in localizing the EE. Due to enhanced attraction of CO{sub 2}, an EE can stably reside in the empty, low-lying ?{sup *} orbital of a CO{sub 2} molecule via a localization process arising from its initial binding state. The localization is completed within a few tens of femtoseconds. After EE trapping, the ?OCO angle of the core CO{sub 2}{sup ?} oscillates in the range of 127°?142°, with an oscillation period of about 48 fs. The corresponding vertical detachment energy of the EE is about 4.0 eV, which indicates extreme stability of such a CO{sub 2}-bound solvated EE in [CO{sub 2}(H{sub 2}O){sub n}]{sup ?} systems. Interestingly, hydration occurs not only on the O atoms of the core CO{sub 2}{sup ?} through formation of O?H–O H–bond(s), but also on the C atom, through formation of a C?H–O H–bond. In the latter binding mode, the EE cloud exhibits considerable penetration to the solvent water molecules, and its IR characteristic peak is relatively red-shifted compared with the former. Hydration on the C site can increase the EE distribution at the C atom and thus reduce the C?H distance in the C?H–O H–bonds, and vice versa. The number of water molecules associated with the CO{sub 2}{sup ?} anion in the first hydration shell is about 4?7. No dimer-core (C{sub 2}O{sub 4}{sup ?}) and core-switching were observed in the double CO{sub 2} aqueous media. This work provides molecular dynamics insights into the localization and time evolution dynamics of an EE in heterogeneous CO{sub 2}–H{sub 2}O media.
Expansion Methods Habib Ammari
Ammari, Habib
. . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 Asymptotic Formulas in the Frequency-Domain . . . . . . . . . . 11 3.3 Asymptotic Formulas 3.4.4 Time-Reversal Imaging . . . . . . . . . . . . . . . . . . . 18 3.5 Bibliography and Open With Magnetic Induction . . . . . . . 34 6.2.1 Physical Principles
Anterior-to-posterior wave of buccal expansion in suction feeding fishes is critical
Wainwright, Peter C.
fluid dynamic model to demonstrate that the inclusion of an anterior-to-posterior wave of buccal constrained conditions, whereas models that do not allow this wave of expansion inevitably predict peakAnterior-to-posterior wave of buccal expansion in suction feeding fishes is critical for optimizing
Beta-expansions for cubic Pisot numbers Fr ed erique Bassino
Bassino, FrÃ©dÃ©rique
Beta-expansions for cubic Pisot numbers Fr#19;ed#19;erique Bassino I.G.M., Universit#19;e de Marne of fa 2 N j a beta-shift. This dynamical system is characterized by the beta a simple beta-number. We #12;rst compute the beta-expansion of 1 for any cubic Pisot number. Next we show
Time-Dynamic Density and Mode Estimation with Application to Fast Mode Tracking
Müller, Hans-Georg
studied in the recursive density estimation framework (see, for example, Wegman and Davies 1995; Hall; Wegman and Marchette 2003). Real-time density estimation has been treated in Hall and Patil (1994), using
Schmidt, Douglas C.
as response-time, latency, and scalability) based on system structure/composi- tion. As enterprise DRE systems (e.g., urban traffic management systems, air traffic control systems, powergrid SCADA sys
Siracusa, Michael Richard, 1980-
2009-01-01T23:59:59.000Z
In this dissertation we investigate the problem of reasoning over evolving structures which describe the dependence among multiple, possibly vector-valued, time-series. Such problems arise naturally in variety of settings. ...
Computational image analysis of subcellular dynamics in time-lapse fluorescence microscopy
Huang, Austin V., 1980-
2005-01-01T23:59:59.000Z
The use of image segmentation and motion tracking algorithms was adapted for analyzing time-lapse data of cells with fluorescently labeled protein. Performance metrics were devised and algorithm parameters were matched to ...
Time finite element methods for large rotational dynamics of multibody systems
Mello, F.J.; Borri, M.; Atluri, S.N. (Georgia Inst. of Tech., Atlanta, GA (USA). Center for Computational Mechanics)
1990-01-01T23:59:59.000Z
Weak formulations in Analytical Dynamics are developed, paralleling the variational methods in elastostatics, and including a fundamental yet novel approach for treating constraints (both holonomic and nonholonomic). A general three field approach is presented, in which the momentum balance conditions, the compatibility conditions between displacement and velocity, the constitutive relations and the displacement and momentum boundary conditions are all enforced in weak form. A primal, or kinematic formulation is developed from the general form by enforcing the compatibility conditions and displacement boundary conditions a priori. The conditional stability of the kinematic formulation is the counterpart of the locking phenomenon in elastostatics and may be avoided, either by reduced order integration, or by utilizing a mixed formulation. Toward this end, a two field mixed formulation is presented, which follows from the general form, when the constitutive relations are satisfied a priori. A general set of the constraint equations are introduced into the kinematic and mixed formulations, using a specific choice of multipliers, which results in modified variational principles. Several simple examples concerning rigid body dynamics are presented. 15 refs., 18 figs.
Expansion and Collapse in the Cosmic Web
Michael Rauch; George D. Becker; Matteo Viel; Wallace L. W. Sargent; Alain Smette; Robert A. Simcoe; Thomas A. Barlow; Martin G. Haehnelt
2005-09-09T23:59:59.000Z
We study the kinematics of the gaseous cosmic web at high redshift with Lyman alpha forest absorption in multiple QSO sightlines. Using a simple analytic model and a cosmological hydrodynamic simulation we constrain the underlying three-dimensional distribution of velocities from the observed line-of-sight distribution of velocity shear across the plane of the sky. The distribution is found to be in good agreement with the intergalactic medium (IGM) undergoing large scale motions dominated by the Hubble flow. Modeling the Lyman alpha clouds analytically and with a hydrodynamics simulation, the average expansion velocity of the gaseous structures causing the Lyman alpha forest in the lower redshift (z = 2) sample appears about 20 percent lower than the local Hubble expansion velocity. We interpret this as tentative evidence for some clouds undergoing gravitational collapse. However, the distribution of velocities is highly skewed, and the majority of clouds at redshifts from 2 to 3.8 expand typically about 5 - 20 percent faster than the Hubble flow. This behavior is explained if most absorbers in the column density range typically detectable are expanding filaments that stretch and drain into more massive nodes. We find no evidence for the observed distribution of velocity shear being significantly influenced by processes other than Hubble expansion and gravitational instability, like galactic winds. To avoid overly disturbing the IGM, winds may be old and/or limp by the time we observe them in the Lyman alpha forest, or they may occupy only an insignificant volume fraction of the IGM. (abridged)
Contrasting real-time dynamics with screening phenomena at finite temperature
Huang, S.; Lissia, M. [Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 0219] [Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 0219; [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States); [Istituto Nazionale di Fisica Nucleare, via Ada Negri 18, I-09127 Cagliari (Italy); [Dipartimento di Fisica dell`Universita di Cagliari, I-09124 Cagliari (Italy)
1996-06-01T23:59:59.000Z
We discuss the interpretation of Euclidean correlation functions at finite temperature ({ital T}) and their relationship with the corresponding real-time Green{close_quote}s functions. The soluble (2+1)-dimensional Gross-Neveu model in the large-{ital N} limit is used throughout as a working example. First, the real-time bound state, identified as an elementary excitation at finite {ital T}, is solved. The bound state mass, the dispersion relation at low momenta, the coupling constant, and decay constant are calculated. To characterize the structure of the bound state the on-shell form factor is carefully introduced and calculated. Then we examine the corresponding screening state and contrast the screening mass, coupling constant, decay constant, and the screening Bethe-Salpeter amplitude with the real-time quantities. We find that, although they can be used as qualitative indicators in the low-{ital T} regime, the screening states at finite {ital T} in general do not reflect the properties of the corresponding real-time bound states. In addition, other relevant issues, such as the subtlety of the real-time manifestation of conservation laws due to some internal symmetries at {ital T}{ne}0, the temperature dependence of the pseudoscalar spectral function and its sum rule, and the high-{ital T} limit of the screening state and its implications to the dimensional reduction, are also discussed in detail. {copyright} {ital 1996 The American Physical Society.}
Duplij, Steven
2013-01-01T23:59:59.000Z
A formulation of singular classical theories (determined by degenerate Lagrangians) without constraints is presented. A partial Hamiltonian formalism in the phase space having an initially arbitrary number of momenta (which can be smaller than the number of velocities) is proposed. The equations of motion become first-order differential equations, and they coincide with those of multi-time dynamics, if a certain condition is imposed. In a singular theory, this condition is fulfilled in the case of the coincidence of the number of generalized momenta with the rank of the Hessian matrix. The noncanonical generalized velocities satisfy a system of linear algebraic equations, which allows an appropriate classification of singular theories (gauge and nongauge). A new antisymmetric bracket (similar to the Poisson bracket) is introduced, which describes the time evolution of physical quantities in a singular theory. The origin of constraints is shown to be a consequence of the (unneeded in our formulation) extension...
Time-resolved dynamics of granular matter by random laser emission
Folli, Viola; Puglisi, Andrea; Leuzzi, Luca; Conti, Claudio
2013-01-01T23:59:59.000Z
Because of the huge commercial importance of granular systems, the second-most used material in industry after water, intersecting the industry in multiple trades, like pharmacy and agriculture, fundamental research on grain-like materials has received an increasing amount of attention in the last decades. In photonics, the applications of granular materials have been only marginally investigated. We report the first phase-diagram of a granular as obtained by laser emission. The dynamics of vertically-oscillated granular in a liquid solution in a three-dimensional container is investigated by employing its random laser emission. The granular motion is function of the frequency and amplitude of the mechanical solicitation, we show how the laser emission allows to distinguish two phases in the granular and analyze its spectral distribution. This constitutes a fundamental step in the field of granulars and gives a clear evidence of the possible control on light-matter interaction achievable in grain-like system.
Time-resolved dynamics of granular matter by random laser emission
Viola Folli; Neda Ghofraniha; Andrea Puglisi; Luca Leuzzi; Claudio Conti
2013-10-22T23:59:59.000Z
Because of the huge commercial importance of granular systems, the second-most used material in industry after water, intersecting the industry in multiple trades, like pharmacy and agriculture, fundamental research on grain-like materials has received an increasing amount of attention in the last decades. In photonics, the applications of granular materials have been only marginally investigated. We report the first phase-diagram of a granular as obtained by laser emission. The dynamics of vertically-oscillated granular in a liquid solution in a three-dimensional container is investigated by employing its random laser emission. The granular motion is function of the frequency and amplitude of the mechanical solicitation, we show how the laser emission allows to distinguish two phases in the granular and analyze its spectral distribution. This constitutes a fundamental step in the field of granulars and gives a clear evidence of the possible control on light-matter interaction achievable in grain-like system.
Non-Markovian spin transfer dynamics in magnetic semiconductors despite short memory times
Christoph Thurn; Moritz Cygorek; Vollrath Martin Axt; Tilmann Kuhn
2013-03-18T23:59:59.000Z
A quantum kinetic theory of the spin transfer between carriers and Mn atoms in a Mn doped diluted magnetic semiconductor is presented. It turns out that the typical memory time associated with these processes is orders of magnitude shorter than the time scale of the spin transfer. Nevertheless, Markovian rate equations, which are obtained by neglecting the memory, work well only for bulk systems. For quantum wells and wires the quantum kinetic results qualitatively deviate from the Markovian limit under certain conditions. Instead of a monotonic decay of an initially prepared excess electron spin, an overshoot or even coherent oscillations are found. It is demonstrated that these features are caused by energetic redistributions of the carriers due to the energy-time uncertainty.
Bolinger, Joshua C.; Bixby, Teresa J.; Reid, Philip J. [Box 351700, Department of Chemistry, University of Washington, Seattle, Washington 98195 (United States)
2005-08-22T23:59:59.000Z
We report a series of time-resolved infrared absorption studies on chlorine dioxide (OClO) dissolved in H{sub 2}O, D{sub 2}O, and acetonitrile. Following the photoexcitation at 401 nm, the evolution in optical density for frequencies corresponding to asymmetric stretch of OClO is measured with a time resolution of 120{+-}50 fs. The experimentally determined optical-density evolution is compared with theoretical models of OClO vibrational relaxation derived from collisional models as well as classical molecular-dynamics (MD) studies. The vibrational relaxation rates in D{sub 2}O are reduced by a factor of 3 relative to H{sub 2}O consistent with the predictions of MD. This difference reflects modification of the frequency-dependent solvent-solute coupling accompanying isotopic substitution of the solvent. Also, the geminate-recombination quantum yield for the primary photofragments resulting in the reformation of ground-state OClO is reduced in D{sub 2}O relative to H{sub 2}O. It is proposed that this reduction reflects enhancement of the dissociation rate accompanying vibrational excitation along the asymmetric-stretch coordinate. In contrast to H{sub 2}O and D{sub 2}O, the vibrational-relaxation dynamics in acetonitrile are not well described by the theoretical models. Reproduction of the optical-density evolution in acetonitrile requires significant modification of the frequency-dependent solvent-solute coupling derived from MD. It is proposed that this modification reflects vibrational-energy transfer from the asymmetric stretch of OClO to the methyl rock of acetonitrile. In total, the results presented here provide a detailed description of the solvent-dependent geminate-recombination and vibrational-relaxation dynamics of OClO in solution.
Huse, N.; Kim, T.-K.; Khalil, M.; Jamula, L.; McCusker, J.K.; Schoenlein, R.W.
2008-08-01T23:59:59.000Z
We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding. We report the first time-resolved soft x-ray spectroscopy of solution-phase molecular dynamics. Changes in ligand-field splitting and spin-state populations in 3d orbitals of the Fe{sup II} complex are directly probed via transient absorption changes of the Fe L{sub 2} and L{sub 3} edges following photo-induced metal-to-ligand charge transfer. With the emergence of high-flux ultrafast soft x-ray sources, details on interplay between atomic structure, electronic states, and spin contributions will be revealed. Our experimental approach opens the door to femtosecond soft x-ray investigations of liquid phase chemistry that have previously been inaccessible.
Real-time Non-contact Millimeter Wave Characterization of Water-Freezing and Ice-Melting Dynamics
Sundaram, S. K.; Woskov, Paul P.
2008-11-12T23:59:59.000Z
We applied millimeter wave radiometry for the first time to monitor water-freezing and ice-melting dynamics in real-time non-contact. The measurements were completed at a frequency of 137 GHz. Small amounts (about 2 mL) of freshwater or saltwater were frozen over a Peltier cooler and the freezing and melting sequence was recorded. Saltwater was prepared in the laboratory that contained 3.5% of table salt to simulate the ocean water. The dynamics of freezing-melting was observed by measuring the millimeter wave temperature as well as the changes in the ice or water surface reflectivity and position. This was repeated using large amounts of freshwater and saltwater (800 mL) mimicking glaciers. Millimeter wave surface level fluctuations indicated as the top surface melted, the light ice below floated up indicating lower surface temperature until the ice completely melted. Our results are useful for remote sensing and tracking temperature for potentially large-scale environmental applications, e.g., global warming.
Private and Dynamic Time-Series Data Aggregation with Trust Relaxation
of users along a specific time period. These statistics can then help the energy provider perform various operations such as load balancing and forecasting for potential acquirement. Despite its merits, statistical analyzer to compute global statistics over the set of individual inputs that are protected by some
Formation Of The Rare Earth Peak: Gaining Insight Into Late-Time r-Process Dynamics
Matthew Mumpower; Gail McLaughlin; Rebecca Surman
2011-09-16T23:59:59.000Z
We study the formation and final structure of the rare earth peak ($A\\sim160$) of the $r$-process nucleosynthesis. The rare earth peak forms at late times in the $r$-process after neutron exhaustion (neutron-to-seed ratio unity or R=1) as matter decays back to stability. Since rare earth peak formation does not occur during \
Zeng, Xiaosi
2011-02-22T23:59:59.000Z
into the ANN model development, despite that incident might be a major source of prediction degradations. Additionally, directly deriving corridor travel times in a one-step manner raises some intractable problems, such as pairing input-target data, which have...
Production, Manufacturing and Logistics Using real time information for effective dynamic scheduling
Grossmann, Ignacio E.
In many production processes real time information may be obtained from process control computers of the revised schedule against the production disturbance which results from changing the planned schedule. We into scheduling the complex production processes of steel continuous caster planning. Ó 2002 Elsevier Science B
Relativistic effects on plasma expansion
Benkhelifa, El-Amine; Djebli, Mourad, E-mail: mdjebli@usthb.dz [USTHB, Faculty of Physics, Theoretical Physics Laboratory, B.P. 32 Bab-Ezzouar, 16079 Algiers (Algeria)
2014-07-15T23:59:59.000Z
The expansion of electron-ion plasma is studied through a fully relativistic multi-fluids plasma model which includes thermal pressure, ambipolar electrostatic potential, and internal energy conversion. Numerical investigation, based on quasi-neutral assumption, is performed for three different regimes: nonrelativistic, weakly relativistic, and relativistic. Ions' front in weakly relativistic regime exhibits spiky structure associated with a break-down of quasi-neutrality at the expanding front. In the relativistic regime, ion velocity is found to reach a saturation limit which occurs at earlier stages of the expansion. This limit is enhanced by higher electron velocity.
Office of Legacy Management (LM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7111AWell: Gas productionDynamic , and Static ,
Knowledge-based intelligent controller architecture for a real-time dynamic system
Glass, Emily Ann
1990-01-01T23:59:59.000Z
Painter (Chair ol' Committee) c L C c Sallie Sheppard (iVIember) Shiping Li (3''Iernber) Karen Watson (itlember) Jo Howze (flea d of Department) ivlay 1990 ABSTRACT Ifnov, ledge-Base&i Intelligent Controller Architecturr. for a Real... of the Power System 'vlodel 1. The Circuit Itlodel 2. Continuous-Time State Analysis 3. Discretization 4. Feedback o. Simulation Peculis, rities . . 9 . . . 9 . . . 19 . . . 30 . 33 III. IIvIPLEUIEVTATIOrV OF THE ItVTELLIGEXT CONTROLLER . . . . . 39...
Horizon dynamics of distorted rotating black holes
Tony Chu; Harald P. Pfeiffer; Michael I. Cohen
2011-04-28T23:59:59.000Z
We present numerical simulations of a Kerr black hole perturbed by a pulse of ingoing gravitational radiation. For strong perturbations we find up to five concentric marginally outer trapped surfaces. These trapped surfaces appear and disappear in pairs, so that the total number of such surfaces at any given time is odd. The world tubes traced out by the marginally outer trapped surfaces are found to be spacelike during the highly dynamical regime, approaching a null hypersurface at early and late times. We analyze the structure of these marginally trapped tubes in the context of the dynamical horizon formalism, computing the expansion of outgoing and incoming null geodesics, as well as evaluating the dynamical horizon flux law and the angular momentum flux law. Finally, we compute the event horizon. The event horizon is well-behaved and approaches the apparent horizon before and after the highly dynamical regime. No new generators enter the event horizon during the simulation.
Learning Dynamic Systems From Time-Series Data - An Application to Gene Regulatory Networks
Timoteo, Ivo J. P. M.; Holden, Sean B.
2015-01-01T23:59:59.000Z
the second half of the time-series data provided; that is, from the point when the pertur- bation is lifted, as we do not know the exact nature of the perturbation. The DREAM4 Challenge evaluated performance using the p-values for the area under the ROC curve... ., and Druzdzel, M. (2010). Learn- ing why things change: The difference-based causal- ity learner. In Proceedings of the Twenty-Sixth An- nual Conference on Uncertainty in Artificial Intelli- gence (UAI). Yip, K., Alexander, R., Yan, K., and Gerstein, M. (2010...
Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions
Chen, G; Kapusta, J I; Li, Y
2015-01-01T23:59:59.000Z
Nuclei colliding at very high energy create a strong, quasi-classical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromo-electric and chromo-magnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for energy density and energy flow as well as for longitudinal and transverse pressure of this system. For example, we find that the ratio of longitudinal to transverse pressure very early in the system behaves as $p_L/p_T = -[1-\\frac{3}{2a}(Q\\tau)^2]/[1-\\frac{1}{a}(Q\\tau)^2]+\\mathcal{O}(Q\\tau)^4$ where $\\tau$ is the longitudinal proper time, $Q$ is related to the saturation scales $Q_s$ of the two nuclei, and $a = \\ln (Q^2/\\hat{m}^2)$ with $\\hat m$ a scale to be defined later. Our results are generally applicable if $\\tau \\less...
Kilpatrick, Peter K.
Dynamic Asphaltene-Resin Exchange at the Oil/Water Interface: Time-Dependent W/O Emulsion Stability for Asphaltene/Resin Model Oils Xiaoli Yang, Vincent J. Verruto, and Peter K. Kilpatrick* Department of Chemical was used to determine the time-dependent stability of water-in- oil emulsions in which asphaltenes
Miyagi, Haruhide; Bojer Madsen, Lars [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)] [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)
2014-04-28T23:59:59.000Z
The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell N{sub e}-electron systems, the TD-RASSCF-S wave function can be fully converged using only N{sub e}/2 + 1 ? M ? N{sub e} spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with M = N{sub e} is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.
Test Cases for Wind Power Plant Dynamic Models on Real-Time Digital Simulator: Preprint
Singh, M.; Muljadi, E.; Gevorgian, V.
2012-06-01T23:59:59.000Z
The objective of this paper is to present test cases for wind turbine generator and wind power plant models commonly used during commissioning of wind power plants to ensure grid integration compatibility. In this paper, different types of wind power plant models based on the Western Electricity Coordinating Council Wind Generator Modeling Group's standardization efforts are implemented on a real-time digital simulator, and different test cases are used to gauge their grid integration capability. The low-voltage ride through and reactive power support capability and limitations of wind turbine generators under different grid conditions are explored. Several types of transient events (e.g., symmetrical and unsymmetrical faults, frequency dips) are included in the test cases. The differences in responses from different types of wind turbine are discussed in detail.
Timans, P.J.; McMahon, R.A.; Ahmed, H.
1988-11-07T23:59:59.000Z
A time-resolved reflectivity (TRR) technique has been developed for dynamic studies of swept beam heating of silicon-on-insulator (SOI) materials. The method exploits the temperature dependence of the reflectivity of SOI films to allow noncontact temperature measurement with high spatial and temporal resolution. This technique is of considerable practical importance for beam processing, since it allows the temperature distribution induced by a beam being scanned across a specimen to be determined. The temperature distribution produced by a line electron beam swept across a SOI specimen was experimentally measured and found to be consistent with a theoretical prediction. The TRR technique can also be used to study melting and will prove useful for characterizing zone melting recrystallization, where thermal modeling is often inadequate for the complex structures involved.
ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE
Zaheer, S. [Permanent address: Department of Physics, Forman Christian College, Lahore, Punjab 54000, Pakistan. (Pakistan); Yoon, P. H. [Also at SSR, KHU, Yongin, Korea. (Korea, Republic of)
2013-10-01T23:59:59.000Z
A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup –?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.
Calculate thermal-expansion coefficients
Yaws, C.L. [Lamar Univ., Beaumont, TX (United States)
1995-08-01T23:59:59.000Z
To properly design and use process equipment, an engineer needs a sound knowledge of physical and thermodynamic property data. A lack of such knowledge can lead to design or operating mistakes that can be dangerous, costly or even fatal. One useful type of property data is the thermal-expansion coefficient. This article presents equations and tables to find the thermal-expansion coefficients of many liquids that contain carbon. These data are useful in process-engineering applications, including the design of relief systems which are crucial to safeguarding process equipment. Data are provided for approximately 350 compounds. A computer software program, which contains the thermophysical property data for all of the compounds discussed in this article, is available for $43 prepaid from the author (Carl L. Yaws, Box 10053, Lamar University, beaumont, TX 77710; Tel. 409-880-8787; fax 409-880-8404). The program is in ASCII format, which can be accessed by most other types of computer software.
Production expansion continues to accelerate
Not Available
1992-08-01T23:59:59.000Z
This paper reports that Saudi Arabian Oil Co. (Saudi Aramco) is continuing its accelerated Crude Oil Expansion Program initiated in 1989 that aims at achieving a 10 million bpd productive capacity by 1995. In addition to major engineering, construction and renovation work related to production expansion, Saudi Aramco drilling and workover operations have been markedly expanded. Since January 1991, rig activity has doubled. As an indication of aging of Saudi production, projects include modernizing current injection water treatment facilities, installing a new seawater injection plant on the Persian Gulf, installing dewatering facilities in a number of locations and installing a pilot gas lift project. In addition, equipment orders indicate the new discoveries south of Riyadh may also need the assistance of water injection from inception of production.
Capacity expansion in contemporary telecommunication networks
Sivaraman, Raghavendran
2007-01-01T23:59:59.000Z
We study three capacity expansion problems in contemporary long distance telecommunication networks. The first two problems, motivated by a major long distance provider, address capacity expansion in national hybrid long ...
Modified Fourier expansions: theory, construction and applications
Adcock, Ben
2010-10-12T23:59:59.000Z
Modified Fourier expansions present an alternative to more standard algorithms for the approximation of nonperiodic functions in bounded domains. This thesis addresses the theory of such expansions, their effective construction and computation...
Nonabelian plasma instabilities in Bjorken expansion
Anton Rebhan
2008-10-17T23:59:59.000Z
Plasma instabilities are parametrically the dominant nonequilibrium dynamics of a weakly coupled quark-gluon plasma. In recent years the time evolution of the corresponding collective colour fields has been studied in stationary anisotropic situations. Here I report on recent numerical results on the time evolution of the most unstable modes in a longitudinally expanding plasma as they grow from small rapidity fluctuations to amplitudes where non-Abelian self-interactions become important.
Local gravitational physics of the Hubble expansion
Sergei Kopeikin
2015-01-21T23:59:59.000Z
We study physical consequences of the Hubble expansion of FLRW manifold on measurement of space, time and light propagation in the local inertial frame. We analyse the solar system radar ranging and Doppler tracking experiments, and time synchronization. FLRW manifold is covered by global coordinates (t,y^i), where t is the cosmic time coinciding with the proper time of the Hubble observers. We introduce local inertial coordinates x^a=(x^0,x^i) in the vicinity of a world line of a Hubble observer with the help of a special conformal transformation. The local inertial metric is Minkowski flat and is materialized by the congruence of time-like geodesics of static observers being at rest with respect to the local spatial coordinates x^i. We consider geodesic motion of test particles and notice that the local coordinate time x^0=x^0(t) taken as a parameter along the world line of particle, is a function of the Hubble's observer time t. This function changes smoothly from x^0=t for a particle at rest (observer's clock), to x^0=t+1/2 Ht^2 for photons, where H is the Hubble constant. Thus, motion of a test particle is non-uniform when its world line is parametrized by time t. NASA JPL Orbit Determination Program presumes that motion of light (after the Shapiro delay is excluded) is uniform with respect to the time t but it does not comply with the non-uniform motion of light on cosmological manifold. For this reason, the motion of light in the solar system analysed with the Orbit Determination Program appears as having a systematic blue shift of frequency, of radio waves circulating in the Earth-spacecraft radio link. The magnitude of the anomalous blue shift of frequency is proportional to the Hubble constant H that may open an access to the measurement of this fundamental cosmological parameter in the solar system radiowave experiments.
Extended space expectation values in quantum dynamical system evolutions
Demiralp, Metin [Istanbul Technical University, Informatics Institute, Maslak, 34469, Istanbul (Turkey)
2014-10-06T23:59:59.000Z
The time variant power series expansion for the expectation value of a given quantum dynamical operator is well-known and well-investigated issue in quantum dynamics. However, depending on the operator and Hamiltonian singularities this expansion either may not exist or may not converge for all time instances except the beginning of the evolution. This work focuses on this issue and seeks certain cures for the negativities. We work in the extended space obtained by adding all images of the initial wave function under the system Hamiltonian’s positive integer powers. This requires the introduction of certain appropriately defined weight operators. The resulting better convergence in the temporal power series urges us to call the new defined entities “extended space expectation values” even though they are constructed over certain weight operators and are somehow pseudo expectation values.
Coarse Grained Quantum Dynamics
Cesar Agon; Vijay Balasubramanian; Skyler Kasko; Albion Lawrence
2014-12-09T23:59:59.000Z
We consider coarse graining a quantum system divided between short distance and long distance degrees of freedom, which are coupled by the Hamiltonian. Observations using purely long distance observables can be described by the reduced density matrix that arises from tracing out the short-distance observables. The dynamics of this density matrix is that of an open quantum system, and is nonlocal in time, on the order of some short time scale. We describe these dynamics in a model system with a simple hierarchy of energy gaps $\\Delta E_{UV} > \\Delta E_{IR}$, in which the coupling between high-and low-energy degrees of freedom is treated to second order in perturbation theory. We then describe the equations of motion under suitable time averaging, reflecting the limited time resolution of actual experiments, and find an expansion of the master equation in powers of $\\Delta E_{IR}/\\Delta E_{UV}$, in which the failure of the system to be Hamiltonian or even Markovian appears at higher orders in this ratio. We compute the evolution of the density matrix in two specific examples -- coupled spins, and linearly coupled simple harmonic oscillators. Finally, we discuss the evolution of the density matrix using the path integral approach, computing the Feynman-Vernon influence functional for the IR degrees of freedom in perturbation theory, and argue that this influence functional is the correct analog of the Wilsonian effective action for this problem.
Indian Policy and Westward Expansion
Malin, James Claude
1921-11-01T23:59:59.000Z
and the in vestigation of his activity on that committee led to a study of Indian policy in the Trans-Mississippi Valley and its relation to the westward movement. This latter problem, begun as a phase of Atchison's career in the Senate, de veloped into one... policy and its relation to westward expansion now furnish a frame-work upon which the history of the Trans-Mississippi Valley before the Civil War may be written. The period is given a unity otherwise impossible and a foundation is laid upon which...
Melamed, Timor
Progress In Electromagnetics Research, Vol. 114, 317332, 2011 PULSED BEAM EXPANSION-based pulsed-beams expansion of planar aperture time- dependent electromagnetic fields. The propagating field-beam waveobjects over the frame spectral lattice. Explicit asymptotic expressions for the electromagnetic pulsed
Eugene V. Stefanovich
2015-02-16T23:59:59.000Z
This book is an attempt to build a consistent relativistic quantum theory of interacting particles. In the first part of the book "Quantum electrodynamics" we follow rather traditional approach to particle physics. Our discussion proceeds systematically from the principle of relativity and postulates of quantum measurements to the renormalization in quantum electrodynamics. In the second part of the book "Quantum theory of particles" this traditional approach is reexamined. We find that formulas of special relativity should be modified to take into account particle interactions. We also suggest reinterpreting quantum field theory in the language of physical "dressed" particles. This formulation eliminates the need for renormalization and opens up a new way for studying dynamical and bound state properties of quantum interacting systems. The developed theory is applied to realistic physical objects and processes including the energy spectrum of the hydrogen atom, the decay law of moving unstable particles, and the electric field of relativistic electron beams. These results force us to take a fresh look at some core issues of modern particle theories, in particular, the Minkowski space-time unification, the role of quantum fields and renormalization as well as the alleged impossibility of action-at-a-distance. A new perspective on these issues is suggested. It can help to solve the old problem of theoretical physics -- a consistent unification of relativity and quantum mechanics.
Ravindran, Binoy
. An important technique used for optimizing the energy consumption of real-time embedded systems is dynamic in the physical world). Further, they are energy-critical, as they must operate on battery, with finite energy and minimizing the system's energy consumption, and not just the CPU's energy consumption. Moreover, such systems
Abductive Reasoning, Belief Expansion and Nonmonotonic Consequence \\Lambda
Pagnucco, Maurice
Abductive Reasoning, Belief Expansion and Nonmonotonic Consequence \\Lambda Maurice Pagnucco Abhaya operator known as abductive expansion which adds abductive inference to the belief expansion process. They develop rationality postulates for abductive belief expansion and provide a construction in terms
Chu, Shih-I
for electron transport dynamics in molecular devices Zhongyuan Zhou(a) and Shih-I Chu Department of Chemistry and structures PACS 85.65.+h Â Molecular electronic devices PACS 71.15.Pd Â Molecular dynamics calculations (Carr) approach in momentum (P) space for the study of electron transport in molecular devices under arbitrary
DOE/EA-0845 Environmental Assessment Expansion
Broader source: Energy.gov (indexed) [DOE]
45 Environmental Assessment Expansion of the Idaho National Engineering Laboratory Research Center March 1994 U.S. Department of Energy MASTER DOE Idaho Operations Office Idaho...
Energy Infrastructure Events and Expansions Infrastructure Security...
Office of Environmental Management (EM)
Year-in-Review: 2010 Energy Infrastructure Events and Expansions Infrastructure Security and Energy Restoration Office of Electricity Delivery and Energy Reliability U.S....
Ablation Plume Dynamics in a Background Gas
Amoruso, Salvatore [CNR-SPIN and Dipartimento di Scienze Fisiche, Universita degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Schou, Joergen [Deparment of Photonics Engineering, Risoe Campus, Technical University of Denmark, DK-4000 Roskilde (Denmark); Lunney, James G. [School of Physics, Trinity College Dublin, Dublin 2 (Ireland)
2010-10-08T23:59:59.000Z
The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during the expansion. The model also leads to an insightful treatment of the stopping behavior in dimensionless units for plumes and background gases of different atomic/molecular masses. The energetics of the plume dynamics can also be treated with this model. Experimental time-of-flight data of silver ions in a neon background gas show a fair agreement with predictions from the PM-model. Finally we discuss the validity of the model, if the work done by the pressure of the background gas is neglected.
Dynamic reactor modeling with applications to SPR and ZEDNA.
Suo-Anttila, Ahti Jorma
2011-12-01T23:59:59.000Z
A dynamic reactor model has been developed for pulse-type reactor applications. The model predicts reactor power, axial and radial fuel expansion, prompt and delayed neutron population, and prompt and delayed gamma population. All model predictions are made as a function of time. The model includes the reactivity effect of fuel expansion on a dynamic timescale as a feedback mechanism for reactor power. All inputs to the model are calculated from first principles, either directly by solving systems of equations, or indirectly from Monte Carlo N-Particle Transport Code (MCNP) derived results. The model does not include any empirical parameters that can be adjusted to match experimental data. Comparisons of model predictions to actual Sandia Pulse Reactor SPR-III pulses show very good agreement for a full range of pulse magnitudes. The model is also applied to Z-pinch externally driven neutron assembly (ZEDNA) type reactor designs to model both normal and off-normal ZEDNA operations.
Delayed Linear Expansion of Two Ultra-low Expansion Dental Stones
Oppedisano, Michael
2013-12-20T23:59:59.000Z
The purpose of this study was to measure the linear setting expansion of two ultra-low expansion dental stones used in definitive cast/ prosthesis fabrication which claim to have very low to no setting expansion. Five specimens of each material...
Delayed Linear Expansion of Two Ultra-low Expansion Dental Stones
Oppedisano, Michael
2013-12-20T23:59:59.000Z
The purpose of this study was to measure the linear setting expansion of two ultra-low expansion dental stones used in definitive cast/ prosthesis fabrication which claim to have very low to no setting expansion. Five specimens of each material...
Critical Dynamics in the Early Universe
B. L. Hu
1993-02-22T23:59:59.000Z
Methods and concepts for the study of phase transitions mediated by a time-dependent order-parameter field in curved spacetimes are discussed. A practical example is the derivation of an effective (quasi-)potential for the description of `slow-roll' inflation in the early universe. We first summarize our early results on viewing the symmetry behavior of constant background fields in curved but static spacetimes as finite size effect, and the use of derivative expansions for constructing effective actions for slowly-varying background fields. We then introduce the notion of dynamical finite size effect to explain how an exponential expansion of the scale factor imparts a finite size to the system and how the symmetry behavior in de Sitter space can be understood qualitatively in this light. We reason why the exponential inflation can be described equivalently by a scale transformation, thus rendering this special class of dynamics as effectively static. Finally we show how, in this view, one can treat the class of `slow-roll' inflation as a dynamic perturbation off the effectively static class of exponential inflation and understand it as a dynamical critical phenomenon in cosmology.
Matched asymptotic expansions in financial engineering
Howison, Sam
Matched asymptotic expansions in financial engineering Sam Howison OCIAM and Nomura Centre of the approach in `plain vanilla' option valuation, in valuation using a fast mean-reverting-stochastic expansions applied directly to stochastic processes of diffusion type is also proposed. Keywords: option
Multipole expansion method for supernova neutrino oscillations
Duan, Huaiyu
2014-01-01T23:59:59.000Z
We demonstrate a multipole expansion method to calculate collective neutrino oscillations in supernovae using the neutrino bulb model. We show that it is much more efficient to solve multi-angle neutrino oscillations in multipole basis than in angle basis. The multipole expansion method also provides interesting insights into multi-angle calculations that were accomplished previously in angle basis.
Multipole expansion method for supernova neutrino oscillations
Huaiyu Duan; Shashank Shalgar
2014-12-24T23:59:59.000Z
We demonstrate a multipole expansion method to calculate collective neutrino oscillations in supernovae using the neutrino bulb model. We show that it is much more efficient to solve multi-angle neutrino oscillations in multipole basis than in angle basis. The multipole expansion method also provides interesting insights into multi-angle calculations that were accomplished previously in angle basis.
Multipole Expansion Model in Gravitational Lensing
T. Fukuyama; Y. Kakigi; T. Okamura
1997-01-31T23:59:59.000Z
Non-transparent models of multipole expansion model and two point-mass model are analyzed from the catastrophe theory. Singularity behaviours of $2^n$-pole moments are discussed. We apply these models to triple quasar PG1115+080 and compare with the typical transparent model, softened power law spheroids. Multipole expansion model gives the best fit among them.
Tirthankar Dutta; S. Ramasesha
2011-12-29T23:59:59.000Z
We investigate the effect of static electron-phonon coupling, on real-time dynamics of spin and charge transport in $\\pi$-conjugated polyene chains. The polyene chain is modeled by the Pariser-Parr-Pople Hamiltonian with dimerized nearest-neighbor parameter $t_{0}(1+\\delta)$ for short bonds and $t_{0}(1-\\delta)$ for long bonds, and long-range electron-electron interactions. We follow the time evolution of the spin and charge using time-dependent density matrix renormalization group technique, when a hole is injected at one end of the chain in its ground state. We find that spin and charge dynamics followed through spin and charge velocities, depend both on chain length and extent of dimerization, $\\delta$. Analysis of the results requires focusing on physical quantities such as average spin and charge polarizations, particularly in the large dimerization limit. In the dimerization range 0.0 $\\le$ $\\delta$ $\\le$ 0.15, spin-charge dynamics is found to have a well defined behavior, with spin-charge separation (measured as the ratio of charge velocity to spin velocity) as well as, the total amount of charge and spin transported in a given time, along the chain, decreasing as dimerization increases. However, in the range 0.3 $\\le$ $\\delta$ $\\le$ 0.5, it is observed that the dynamics of spin and charge transport becomes complicated. It is observed that for large $\\delta$ values, spin-charge separation is suppressed and the injected hole fails to travel the entire length of the chain.
Dutta, Tirthankar
2011-01-01T23:59:59.000Z
We investigate the effect of static electron-phonon coupling, on real-time dynamics of spin and charge transport in $\\pi$-conjugated polyene chains. The polyene chain is modeled by the Pariser-Parr-Pople Hamiltonian with dimerized nearest-neighbor parameter $t_{0}(1+\\delta)$ for short bonds and $t_{0}(1-\\delta)$ for long bonds, and long-range electron-electron interactions. We follow the time evolution of the spin and charge using time-dependent DMRG technique, when a hole is injected at one end of the chain in its ground state. We find that spin and charge dynamics followed through spin and charge velocities, depend both on chain length and extent of dimerization, $\\delta$. Analysis of the results requires focusing on physical quantities such as average spin and charge polarizations, particularly in the large dimerization limit. In the dimerization range 0.0 $\\le$ $\\delta$ $\\le$ 0.15, spin-charge dynamics is found to have a well defined behavior, with spin-charge separation (measured as the ratio of charge v...
Influence of structure formation on the cosmic expansion
Clarkson, Chris; Ananda, Kishore; Larena, Julien [Cosmology and Gravity Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)
2009-10-15T23:59:59.000Z
We investigate the effect that the average backreaction of structure formation has on the dynamics of the cosmological expansion, within the concordance model. Our approach in the Poisson gauge is fully consistent up to second order in a perturbative expansion about a flat Friedmann background, including a cosmological constant. We discuss the key length scales which are inherent in any averaging procedure of this kind. We identify an intrinsic homogeneity scale that arises from the averaging procedure, beyond which a residual offset remains in the expansion rate and deceleration parameter. In the case of the deceleration parameter, this can lead to a quite large increase in the value, and may therefore have important ramifications for dark energy measurements, even if the underlying nature of dark energy is a cosmological constant. We give the intrinsic variance that affects the value of the effective Hubble rate and deceleration parameter. These considerations serve to add extra intrinsic errors to our determination of the cosmological parameters, and, in particular, may render attempts to measure the Hubble constant to percent precision overly optimistic.
Chu, Shih-I; Zhou, Zhongyuan
2009-10-27T23:59:59.000Z
We propose a time-dependent density functional theoretical (TDDFT) approach in momentum (\\mathcal{P} ) space for the study of electron transport in molecular devices under arbitrary biases. The basic equation of motion, which is a time...
Reid, Philip J.
dioxide OClO dissolved in H2O, D2O, and acetonitrile. Following the photoexcitation at 401 nm and D2O, the vibrational-relaxation dynamics in acetonitrile are not well described by the theoretical models. Reproduction of the optical-density evolution in acetonitrile requires significant modification
THE EXPANSION OF ACTIVE REGIONS INTO THE EXTENDED SOLAR CORONA
Morgan, Huw; Jeska, Lauren; Leonard, Drew, E-mail: hmorgan@aber.ac.uk [Sefydliad Mathemateg a Ffiseg, Prifysgol Aberystwyth, Ceredigion SY23 3BZ (United Kingdom)
2013-06-01T23:59:59.000Z
Advanced image processing of Large Angle and Spectrometric Coronagraph Experiment (LASCO) C2 observations reveals the expansion of the active region closed field into the extended corona. The nested closed-loop systems are large, with an apparent latitudinal extent of 50 Degree-Sign , and expanding to heights of at least 12 R{sub Sun }. The expansion speeds are {approx}10 km s{sup -1} in the AIA/SDO field of view, below {approx}20 km s{sup -1} at 2.3 R{sub Sun }, and accelerate linearly to {approx}60 km s{sup -1} at 5 R{sub Sun }. They appear with a frequency of one every {approx}3 hr over a time period of around three days. They are not coronal mass ejections (CMEs) since their gradual expansion is continuous and steady. They are also faint, with an upper limit of 3% of the brightness of background streamers. Extreme ultraviolet images reveal continuous birth and expansion of hot, bright loops from a new active region at the base of the system. The LASCO images show that the loops span a radial fan-like system of streamers, suggesting that they are not propagating within the main coronal streamer structure. The expanding loops brighten at low heights a few hours prior to a CME eruption, and the expansion process is temporarily halted as the closed field system is swept away. Closed magnetic structures from some active regions are not isolated from the extended corona and solar wind, but can expand to large heights in the form of quiescent expanding loops.
Toru Miyazawa
2011-12-26T23:59:59.000Z
A new formalism is presented for high-energy analysis of the Green function for Fokker-Planck and Schr\\"odinger equations in one dimension. Formulas for the asymptotic expansion in powers of the inverse wave number are derived, and conditions for the validity of the expansion are studied through the analysis of the remainder term. The short-time expansion of the Green function is also discussed.
Landi, S.; Matteini, L. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Firenze Largo E. Fermi 2, I-50125 Firenze (Italy); Pantellini, F. [LESIA, Observatoire de Paris 5, Place J. Janssen, F-92195 Meudon Cedex (France)
2012-12-01T23:59:59.000Z
We present numerical simulations of the solar wind using a fully kinetic model which takes into account the effects of particle's binary collisions in a quasi-neutral plasma in spherical expansion. Starting from an isotropic Maxwellian velocity distribution function for the electrons, we show that the combined effect of expansion and Coulomb collisions leads to the formation of two populations: a collision-dominated cold and dense population almost isotropic in velocity space and a weakly collisional, tenuous field-aligned and antisunward drifting population generated by mirror force focusing in the radially decreasing magnetic field. The relative weights and drift velocities for the two populations observed in our simulations are in excellent agreement with the relative weights and drift velocities for both core and strahl populations observed in the real solar wind. The radial evolution of the main moments of the electron velocity distribution function is in the range observed in the solar wind. The electron temperature anisotropy with respect to the magnetic field direction is found to be related to the ratio between the collisional time and the solar wind expansion time. Even though collisions are found to shape the electron velocity distributions and regulate the properties of the strahl, it is found that the heat flux is conveniently described by a collisionless model where a fraction of the electron thermal energy is advected at the solar wind speed. This reinforces the currently largely admitted fact that collisions in the solar wind are clearly insufficient to force the electron heat flux obey the classical Spitzer-Haerm expression where heat flux and temperature gradient are proportional to each other. The presented results show that the electron dynamics in the solar wind cannot be understood without considering the role of collisions.
Concentric ring flywheel without expansion separators
Kuklo, Thomas C. (Oakdale, CA)
1999-01-01T23:59:59.000Z
A concentric ring flywheel wherein the adjacent rings are configured to eliminate the need for differential expansion separators between the adjacent rings. This is accomplished by forming a circumferential step on an outer surface of an inner concentric ring and forming a matching circumferential step on the inner surface of an adjacent outer concentric ring. During operation the circumferential steps allow the rings to differentially expand due to the difference in the radius of the rings without the formation of gaps therebetween, thereby eliminating the need for expansion separators to take up the gaps formed by differential expansion.
Concentric ring flywheel without expansion separators
Kuklo, T.C.
1999-08-24T23:59:59.000Z
A concentric ring flywheel wherein the adjacent rings are configured to eliminate the need for differential expansion separators between the adjacent rings. This is accomplished by forming a circumferential step on an outer surface of an inner concentric ring and forming a matching circumferential step on the inner surface of an adjacent outer concentric ring. During operation the circumferential steps allow the rings to differentially expand due to the difference in the radius of the rings without the formation of gaps therebetween, thereby eliminating the need for expansion separators to take up the gaps formed by differential expansion. 3 figs.
Narku-Tetteh, Noble Nii Nortey
2014-01-06T23:59:59.000Z
Photomultiplier Tube PV Process Voltage PVT Process Voltage and Temperature RADAR Radio Detection and Ranging RES Resolution SADFF Sense-Amplifier based D Flip Flop SSE Single-Shot Experiment SSP Single-Shot Precision TCSPC Time...] ................................................................ 3 Figure 1.2 Idealized waveforms on nodes VSPAD, VINV and VOUT illustrating the circuit operation when a photon is detected [26] ....................................... 3 Figure 1.3 Lidar system depiction diagram (fiber point type) [29...
Underwater Gas Expansion and Deflagration
Jones, Van; Gilbert, John; McCue-Weil, Leigh
2013-01-01T23:59:59.000Z
The underwater combustion of a propane-air mixture in an acrylic cylinder is captured on video from multiple angles. This experiment is designed to provide visual data and pressure time-histories for future CFD validation studies.
SF2I.7.pdf CLEO:2014 2014 OSA Emission and expansion features of ns and fs laser ablation
Harilal, S. S.
of an ambient leading to further excitation of plume species as well as enhancing excited molecular species and hydrodynamic expansion dynamics of ns and fs laser ablated metal plasmas in the presence of an ambient were studied. The structure and dynamics of both ns and fs plumes obtained from optical diagnostic
Transmission System Expansion Plans in View Point of Deterministic, Probabilistic and Security control system as well as reasonable strength of grid originally. Because investment for power system the stability, and dynamic characteristics of the new system. A main reason of the separated work process
Exact asymptotic expansions for thermodynamics of the hydrogen gas in the Saha regime
Boyer, Edmond
Exact asymptotic expansions for thermodynamics of the hydrogen gas in the Saha regime A. Alastuey and V. Ballenegger Abstract We consider the hydrogen quantum plasma in the Saha regime, where it almost of thermo- dynamical functions beyond Saha theory, which describes an ideal mixture of ionized protons
Puliafito, Vito, E-mail: vpuliafito@unime.it; Azzerboni, Bruno; Finocchio, Giovanni [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, 98166 Messina (Italy); Torres, Luis [Department of Applied Physics, University of Salamanca, 37008 Salamanca (Spain); Ozatay, Ozhan [Department of Physics, Bogazici University, 34342 Bebek/Istanbul (Turkey); Hauet, Thomas [Institut Jean Lamour, Université de Lorraine-CNRS UMR 7198, 54506 Nancy (France)
2014-05-07T23:59:59.000Z
Dynamical bubble-like solitons have been recently investigated in nanocontact-based spin-torque oscillators with a perpendicular free layer. Those magnetic configurations can be excited also in different geometries as long as they consist of perpendicular materials. Thus, in this paper, a systematic study of the influence of both external field and high current on that kind of dynamics is performed for a spin-valve point-contact geometry where both free and fixed layers present strong perpendicular anisotropy. The usage of the topological density tool highlights the excitation of complex bubble/antibubble configurations. In particular, at high currents, a deformation of the soliton and its simultaneous shift from the contact area are observed and can be ascribable to the Oersted field. Results provide further detailed information on the excitation of solitons in perpendicular materials for application in spintronics, magnonics, and domain wall logic.
Jung, Kwangyun
2014-01-01T23:59:59.000Z
We demonstrate a method that enables accurate timing jitter spectral density characterization of free-running mode-locked laser oscillators over more than 10-decade of Fourier frequency from mHz to tens MHz range. The method is based on analyzing both the input voltage noise to the slave laser and the output voltage noise from the balanced optical cross- correlator (BOC), when two mode-locked lasers are synchronized in repetition rate by the BOC. As a demonstration experiment, timing jitter spectrum of a free-running mode-locked Er-fiber laser with a dynamic range of >340 dB is measured over Fourier frequency ranging from 1 mHz to 38.5 MHz (Nyquist frequency). The demonstrated method can resolve different noise mechanisms that cause specific jitter characteristics in free-running mode-locked laser oscillators for a vast range of time scales from 1000-s.
Major Business Expansion Bond Program (Maine)
Broader source: Energy.gov [DOE]
The Major Business Expansion Bond Program provides long-term, credit-enhanced financing up to $25,000,000 at taxable bond rates for businesses creating or retaining at least 50 jobs; up to $10,000...
Cumulant expansions for atmospheric flows
Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B
2015-01-01T23:59:59.000Z
The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...
Expansion of Bubbles in Inflationary Universe
M. Mohazzab; M. M. Sheikh Jabbari; H. Salehi
1995-10-14T23:59:59.000Z
We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and expansion of the bubbles (including extended inflation) may not be viable.
Heat Flow Database Expansion for NGDS Data Development, Collection...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU) Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU)...
Energy Infrastructure Events and Expansions Year-in-Review 2011...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Infrastructure Events and Expansions Year-in-Review 2011 Available (April 2012) Energy Infrastructure Events and Expansions Year-in-Review 2011 Available (April 2012) May 1, 2012 -...
Year-in-Review: 2014 Energy Infrastructure Events and Expansions...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Year-in-Review: 2014 Energy Infrastructure Events and Expansions Report Now Available (May 2015) Year-in-Review: 2014 Energy Infrastructure Events and Expansions Report Now...
Year-in-Review: 2013 Energy Infrastructure Events and Expansions...
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3 Energy Infrastructure Events and Expansions Now Available (May 2014) Year-in-Review: 2013 Energy Infrastructure Events and Expansions Now Available (May 2014) May 12, 2014 -...
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2 Energy Infrastructure Events and Expansions Now Available (July 2013) Year-in-Review: 2012 Energy Infrastructure Events and Expansions Now Available (July 2013) July 26, 2013 -...
Expansion of Novolyte Capacity for Lithium Ion Electrolyte Production...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
15eswise2012p.pdf More Documents & Publications Expansion of Novolyte Capacity for Lithium Ion Electrolyte Production Expansion of Novolyte Capacity for Lithium Ion Electrolyte...
Expansion of Novolyte Capacity for Lithium Ion Electrolyte Production...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
15eswise2011p.pdf More Documents & Publications Expansion of Novolyte Capacity for Lithium Ion Electrolyte Production Expansion of Novolyte Capacity for Lithium Ion Electrolyte...
High Efficiency Full Expansion (FEx) Engine for Automotive Application...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Full Expansion (FEx) Engine for Automotive Applications High Efficiency Full Expansion (FEx) Engine for Automotive Applications Large increases in engine thermal efficiency result...
Present accelerated expansion of the universe from new Weyl-Integrable gravity approach
Ricardo Aguila; José Edgar Madriz Aguilar; Claudia Moreno; Mauricio Bellini
2014-11-07T23:59:59.000Z
We investigate if a recently introduced formulation of general relativity on a Weyl-integrable geometry, contains cosmological solutions exhibiting acceleration in the present cosmic expansion. We derive the general conditions to have acceleration in the expansion of the universe and obtain a particular solution for the Weyl scalar field describing a cosmological model for the present time in concordance with the data combination Planck + WP + BAO + SN.
Boyer, Edmond
1 Time-resolved spectroscopy on epitaxial graphene in the infrared spectral range: relaxation graphene samples performed in a wide spectral range, namely from the near signatures of the highly doped graphene layers at the interface to Si
Effects of restraint on expansion due to delayed ettringite formation
Bouzabata, Hassina [Universite de Toulouse, UPS, INSA, LMDC (Laboratoire Materiaux et Durabilite des Constructions), 135, avenue de Rangueil, F-31 077 Toulouse Cedex 04 (France); Laboratoire Materiaux et Durabilite des Constructions, Department of Civil Engineering, University of Constantine (Algeria); Multon, Stephane, E-mail: multon@insa-toulouse.fr [Universite de Toulouse, UPS, INSA, LMDC (Laboratoire Materiaux et Durabilite des Constructions), 135, avenue de Rangueil, F-31 077 Toulouse Cedex 04 (France); Sellier, Alain [Universite de Toulouse, UPS, INSA, LMDC (Laboratoire Materiaux et Durabilite des Constructions), 135, avenue de Rangueil, F-31 077 Toulouse Cedex 04 (France); Houari, Hacene [Laboratoire Materiaux et Durabilite des Constructions, Department of Civil Engineering, University of Constantine (Algeria)
2012-07-15T23:59:59.000Z
Delayed ettringite formation (DEF) is a chemical reaction that causes expansion in civil engineering structures. The safety level of such damaged structures has to be reassessed. To do this, the mechanical conditions acting on DEF expansions have to be analysed and, in particular, the variation of strength with expansion and the effect of restraint on the DEF expansion. This paper highlights several points: DEF expansion is isotropic in stress-free conditions, compressive stresses decrease DEF expansion in the direction subjected to restraint and lead to cracks parallel to the restraint, and expansion measured in the stress-free direction of restrained specimens is not modified. Thus restraint causes a decrease of the volumetric expansion and DEF expansion under restraint is anisotropic. Moreover, the paper examines the correlation between DEF expansion and concrete damage, providing data that can be used for the quantification of the effect of stresses on DEF induced expansion.
Expansion analyses of strategic petroleum reserve in Bayou Choctaw : revised locations.
Ehgartner, Brian L.; Park, Byoung Yoon
2010-11-01T23:59:59.000Z
This report summarizes a series of three-dimensional simulations for the Bayou Choctaw Strategic Petroleum Reserve. The U.S. Department of Energy plans to leach two new caverns and convert one of the existing caverns within the Bayou Choctaw salt dome to expand its petroleum reserve storage capacity. An existing finite element mesh from previous analyses is modified by changing the locations of two caverns. The structural integrity of the three expansion caverns and the interaction between all the caverns in the dome are investigated. The impacts of the expansion on underground creep closure, surface subsidence, infrastructure, and well integrity are quantified. Two scenarios were used for the duration and timing of workover conditions where wellhead pressures are temporarily reduced to atmospheric pressure. The three expansion caverns are predicted to be structurally stable against tensile failure for both scenarios. Dilatant failure is not expected within the vicinity of the expansion caverns. Damage to surface structures is not predicted and there is not a marked increase in surface strains due to the presence of the three expansion caverns. The wells into the caverns should not undergo yield. The results show that from a structural viewpoint, the locations of the two newly proposed expansion caverns are acceptable, and all three expansion caverns can be safely constructed and operated.
Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)
2011-03-14T23:59:59.000Z
The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.
Prezhdo, Oleg V.
2012-03-22T23:59:59.000Z
Funded by the DOE grant (i) we continued to study and analyze the atomistic detail of the electron transfer (ET) across the chromophore-TiO2 interface in Gratzel cell systems for solar hydrogen production. (ii) We extensively investigated the nature of photoexcited states and excited state dynamics in semiconductor quantum dots (QD) designed for photovoltaic applications. (iii) We continued a newly initiated research direction focusing on excited state properties and electron-phonon interactions in nanoscale carbon materials. Over the past year, the results of the DOE funded research were summarized in 3 review articles. 12 original manuscripts were written. The research results were reported in 28 invited talks at conferences and university seminars. 20 invitations were accepted for talks in the near future. 2 symposia at national and international meetings have being organized this year on topics closely related to the DOE funded project, and 2 more symposia have been planned for the near future. We summarized the insights into photoinduced dynamics of semiconductor QDs, obtained from our time-domain ab initio studies. QDs exhibit both molecular and bulk properties. Unlike either bulk or molecular materials, QD properties can be modified continuously by changing QD shape and size. However, the chemical and physical properties of molecular and bulk materials often contradict each other, which can lead to differing viewpoints about the behavior of QDs. For example, the molecular view suggests strong electron-hole and charge-phonon interactions, as well as slow energy relaxation due to mismatch between electronic energy gaps and phonon frequencies. In contrast, the bulk view advocates that the kinetic energy of quantum confinement is greater than electron-hole interactions, that charge-phonon coupling is weak, and that the relaxation through quasi-continuous bands is rapid. By synthesizing the bulk and molecular viewpoints, we clarified the controversies and provided a unified atomistic picture of the nature and dynamics of photoexcited states in semiconductor QDs. We also summarized our recent findings about the photoinduced electron dynamics at the chromophore-semiconductor interfaces from a time-domain ab initio perspective. The interface provides the foundation for a new, promising type of solar cell and presents a fundamentally important case study for several fields, including photo-, electro- and analytical chemistries, molecular electronics, and photography. Further, the interface offers a classic example of an interaction between an organic molecular species and an inorganic bulk material. Scientists employ different concepts and terminologies to describe molecular and solid states of matter, and these differences make it difficult to describe the interface with a single model. At the basic atomistic level of description, however, this challenge can be largely overcome. Recent advances in non-adiabatic molecular dynamics and time-domain density functional theory have created a unique opportunity for simulating the ultrafast, photoinduced processes on a computer very similar to the way that they occur in nature. These state-of-the-art theoretical tools offered a comprehensive picture of a variety of electron transfer processes that occur at the interface, including electron injection from the chromophore to the semiconductor, electron relaxation and delocalization inside the semiconductor, back-transfer of the electron to the chromophore and to the electrolyte, and regeneration of the neutral chromophore by the electrolyte. The ab initio time-domain modeling is particularly valuable for understanding these dynamic features of the ultrafast electron transfer processes, which cannot be represented by a simple rate description. We demonstrated using symmetry adapted cluster theory with configuration interaction (SAC-CI) that charging of small PbSe nanocrystals (NCs) greatly modifies their electronic states and optical excitations. Conduction and valence band transitions that are not available in neutral NCs dominate
Hanyk, Ladislav
by modeling the linear response of a self-gravitating viscoelastic planet, the gravity field anoma- lies haveEarth Planets Space, 57, 895Â902, 2005 Short time-scale heating of the Earth's mantle by ice-scale energy transfer from the ice sheet loading and unloading processes to the Earth's interior via viscous
T-ABAC: An Attribute-Based Access Control Model for Real-Time Availability in Highly Dynamic Systems
Burmester, Mike
of network technologies and standard communication pro- tocols. For example in cyber-physical systems (CPS) such as smart grids [1] and power plants [2] a bridge between the physical and cyber world is established making etc). In particular CPS deal with real-time events, either system-based or Nature-based, which cannot
Supercritical flow in rectangular expansions
Walsh, Peter.
1968-01-01T23:59:59.000Z
is the differential element of length along C. Equations [7] and [8] may be rearranged in the following manner: du = ? dx + ? dy du Qu gx ay dv = ? dx + ? dy 3v av 'bx Py [10] where du = (3u/Bs)ds, dv = (pv/3s)ds, dx = (3x/as)ds, and dy = (s y/p s) ds. The four... common tangent A P . Since a disturbance travels from A to P in n 1 the same time that a particle moves from A to A it follows that n A P = sin S =? A A v 1 n where I9 is the angle between the shock wave and the direction of flow. When the flow...
The shortest time and/or the shortest path strategies in a CA FF pedestrian dynamics model
Ekaterina Kirik; Tat'yana Yurgel'yan; Dmitriy Krouglov
2009-06-23T23:59:59.000Z
This paper deals with a mathematical model of a pedestrian movement. A stochastic cellular automata (CA) approach is used here. The Floor Field (FF) model is a basis model. FF models imply that virtual people follow the shortest path strategy. But people are followed by a strategy of the shortest time as well. This paper is focused on how to mathematically formalize and implement to a model these features of the pedestrian movement. Some results of a simulation are presented.
Bongers, W. A.; Beveren, V. van; Westerhof, E.; Goede, A. P. H.; Krijger, B.; Berg, M. A. van den; Graswinckel, M. F.; Schueller, F. C. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Thoen, D. J. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Nuij, P. J. W. M. [Eindhoven University of Technology, Control Systems Technology Group, and Applied Physics Department, PO Box 513, NL-5600 MB Eindhoven (Netherlands); Baar, M. R. de; Donne, A. J. H.; Hennen, B. A. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, Control Systems Technology Group, and Applied Physics Department, PO Box 513, NL-5600 MB Eindhoven (Netherlands); Kantor, M. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Forschungszentrum Juelich GMBH, Institute of Energy and Climate research, Plasma Physics, Association EURATOM-FZJ, Trilateral Euregio Cluster, 52425 Juelich (Germany); Ioffe Institute, RAS, Saint-Petersburg, 195256 (Russian Federation)
2011-06-15T23:59:59.000Z
An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototype system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.
Expansion in a contracting industry
Prichard, S.L.
1995-08-01T23:59:59.000Z
Many organizations have faced the distasteful task of downsizing, but it was probably dressed up in the euphemistic term {open_quotes}rightsizing{close_quotes}. Most of us would agree that our companies are not the correct size, but why is the {open_quotes}right{close_quotes} size always smaller and not larger? Mergers and acquisitions have also had their effects on many of our colleagues, if not us ourselves. Both of these circumstances have led to fundamental changes in organizational structures and power centers. As a business group flattens the hierarchy, there are fewer steps between those who do and those who manage. Work groups may now be constructed into teams based upon products or customers rather than in their functional areas, such as accounting or sales. Employee empowerment may not be the magic pill that many had hoped for, but it has altered how our businesses operate at practically every level. And as our individual businesses change, the very structure of the energy industry is changing as well. I know many people wish for the dust to settle, see who is left to compete with, and put all this uncomfortable change behind us. This is not about to happen any time soon. Utilities will be the next to feel the intense pressure to change.
Phantom Friedmann Cosmologies and Higher-Order Characteristics of Expansion
Mariusz P. Dabrowski; Tomasz Stachowiak
2005-11-25T23:59:59.000Z
We discuss a more general class of phantom ($p -1$) matter. We show that many types of evolution which include both Big-Bang and Big-Rip singularities are admitted and give explicit examples. Among some interesting models, there exist non-singular oscillating (or "bounce") cosmologies, which appear due to a competition between positive and negative pressure of variety of matter content. From the point of view of the current observations the most interesting cosmologies are the ones which start with a Big-Bang and terminate at a Big-Rip. A related consequence of having a possibility of two types of singularities is that there exists an unstable static universe approached by the two asymptotic models - one of them reaches Big-Bang, and another reaches Big-Rip. We also give explicit relations between density parameters $\\Omega$ and the dynamical characteristics for these generalized phantom models, including higher-order observational characteristics such as jerk and "kerk". Finally, we discuss the observational quantities such as luminosity distance, angular diameter, and source counts, both in series expansion and explicitly, for phantom models. Our series expansion formulas for the luminosity distance and the apparent magnitude go as far as to the fourth-order in redshift $z$ term, which includes explicitly not only the jerk, but also the "kerk" (or "snap") which may serve as an indicator of the curvature of the universe.
Wu, Yue-Liang
2015-01-01T23:59:59.000Z
Treating the gravitational force on the same footing as the electroweak and strong forces, we present a quantum field theory (QFT) of gravity based on spinnic and scaling gauge symmetries. The so-called Gravifield sided on both locally flat non-coordinate space-time and globally flat Minkowski space-time is an essential ingredient for gauging global spinnic and scaling symmetries. The locally flat Gravifield space-time spanned by the Gravifield is associated with a non-commutative geometry characterized by a gauge-type field strength of Gravifield. A gauge invariant and coordinate independent action for the quantum gravity is built in the Gravifield basis, we derive equations of motion for all quantum fields with including the gravitational effect and obtain basic conservation laws for all symmetries. The equation of motion for Gravifield tensor is deduced in connection directly with the energy-momentum tensor. When the spinnic and scaling gauge symmetries are broken down to a background structure that posses...
Expansion of a Fermi gas interacting with a Bose-Einstein condensate
F. Ferlaino; E. de Mirandes; G. Roati; G. Modugno; M. Inguscio
2003-12-10T23:59:59.000Z
We study the expansion of an atomic Fermi gas interacting attractively with a Bose-Einstein condensate. We find that the interspecies interaction affects dramatically both the expansion of the Fermi gas and the spatial distribution of the cloud in trap. We observe indeed a slower evolution of the radial-to-axial aspect ratio which reveals the importance of the mutual attraction between the two samples during the first phase of the expansion. For large atom numbers, we also observe a bimodal momentum distribution of the Fermi gas, which reflects directly the distribution of the mixture in trap. This effect allows us to extract information on the dynamics of the system at the collapse.
Doppler-like effect and doubtful expansion of universe
Edward Szaraniec
2003-10-01T23:59:59.000Z
The distance contraction, as observed in electrical soundings over horizontally stratified earth (static system), is identified as a counterpart of Doppler shift in dynamical systems. Identification of Doppler-like effect in a stock-still systems makes it possible to give an al-ternative answer to the question about an effective cause of the Doppler shift, which sounds: the inhomogeneities. This answer opens different static as well as kinematic possibilities, which challenge established theories of expanding universe and energizing big bang.The energy propagating in stratified universe of layers exhibits a shift which could be at-tributed not only to the expansion (Hubble's theory) but alternatively to fluctuations in material properties (inhomogeneities).
Polytope expansion of Lie characters and applications
Walton, Mark A., E-mail: walton@uleth.ca [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada)
2013-12-15T23:59:59.000Z
The weight systems of finite-dimensional representations of complex, simple Lie algebras exhibit patterns beyond Weyl-group symmetry. These patterns occur because weight systems can be decomposed into lattice polytopes in a natural way. Since lattice polytopes are relatively simple, this decomposition is useful, in addition to being more economical than the decomposition into single weights. An expansion of characters into polytope sums follows from the polytope decomposition of weight systems. We study this polytope expansion here. A new, general formula is given for the polytope sums involved. The combinatorics of the polytope expansion are analyzed; we point out that they are reduced from those of the Weyl character formula (described by the Kostant partition function) in an optimal way. We also show that the weight multiplicities can be found easily from the polytope multiplicities, indicating explicitly the equivalence of the two descriptions. Finally, we demonstrate the utility of the polytope expansion by showing how polytope multiplicities can be used in the calculation of tensor product decompositions, and subalgebra branching rules.
Polymer Expansions for Cycle LDPC Codes
Nicolas Macris; Marc Vuffray
2012-02-13T23:59:59.000Z
We prove that the Bethe expression for the conditional input-output entropy of cycle LDPC codes on binary symmetric channels above the MAP threshold is exact in the large block length limit. The analysis relies on methods from statistical physics. The finite size corrections to the Bethe expression are expressed through a polymer expansion which is controlled thanks to expander and counting arguments.
Climate Science: Tropical Expansion by Ocean Swing
Lu, Jian
2014-04-01T23:59:59.000Z
The tropical belt has become wider over the past decades, but climate models fall short of capturing the full rate of the expansion. The latest analysis of the climate simulations suggests that a long-term swing of the Pacific Decadal Oscillation is the main missing cause.
Taylor Expansion Diagrams: A Canonical Representation for
Kalla, Priyank
Taylor series expansion that allows one to model word-level signals as algebraic symbols. This power systems has made it essential to address verification issues at early stages of the design cycle representations. TEDs are applicable to modeling, symbolic simulation, and equivalence verification of dataflow
Application of Gradient Expansion to Inflationary Universe
Yasusada Nambu; Atsushi Taruya
1994-11-03T23:59:59.000Z
Using the long wave perturbation scheme(gradient expansion), the effect of inhomogeneity on the inflationary phase is investigated. We solved the perturbation equation of which source term comes from inhomogeneity of a scalar field and a seed metric. The result indicates that sub-horizon scale inhomogeneity strongly affects the onset of inflation.
LANGUAGE INFORMED BANDWIDTH EXPANSION EECS department
Pardo, Bryan
. INTRODUCTION Audio Bandwidth Expansion (BWE) refers to methods that increase the frequency bandwidth. A typical application of BWE is telephone speech en- hancement [1]. The degradation of speech quality loudspeakers and high-quality reproduction of historical recordings. Most BWE methods are based on the source
Scott G. Bauer; Matthew O. Anderson; James R. Hanneman
2005-10-01T23:59:59.000Z
The proven value of DOD Unmanned Aerial Vehicles (UAVs) will ultimately transition to National and Homeland Security missions that require real-time aerial surveillance, situation awareness, force protection, and sensor placement. Public services first responders who routinely risk personal safety to assess and report a situation for emergency actions will likely be the first to benefit from these new unmanned technologies. ‘Packable’ or ‘Portable’ small class UAVs will be particularly useful to the first responder. They require the least amount of training, no fixed infrastructure, and are capable of being launched and recovered from the point of emergency. All UAVs require wireless communication technologies for real- time applications. Typically on a small UAV, a low bandwidth telemetry link is required for command and control (C2), and systems health monitoring. If the UAV is equipped with a real-time Electro-Optical or Infrared (EO/Ir) video camera payload, a dedicated high bandwidth analog/digital link is usually required for reliable high-resolution imagery. In most cases, both the wireless telemetry and real-time video links will be integrated into the UAV with unity gain omni-directional antennas. With limited on-board power and payload capacity, a small UAV will be limited with the amount of radio-frequency (RF) energy it transmits to the users. Therefore, ‘packable’ and ‘portable’ UAVs will have limited useful operational ranges for first responders. This paper will discuss the limitations of small UAV wireless communications. The discussion will present an approach of utilizing a dynamic ground based real-time tracking high gain directional antenna to provide extend range stand-off operation, potential RF channel reuse, and assured telemetry and data communications from low-powered UAV deployed wireless assets.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Nowak-Lovato, Kristy L.; Rector, Kirk D.
2012-01-01T23:59:59.000Z
This review captures the use of live cells as dynamic microlaboratories through implementation of labeled nanoparticles (nanosensors) that have both sensing and targeting functions. The addition of 2,4-?-dinitrophenol-L-lysine (DNP) as a Fc?RI targeting ligand and 4-mercaptopyridine (4-MPy) as a pH-sensing ligand enables spatial and temporal monitoring of Fc?RI receptors and their pH environment within the endocytic pathway. To ensure reliability, the sensor is calibratedin vivousing the ionophore nigericin and standard buffer solutions to equilibrate the external[H+]concentration with that of the cell compartments. This review highlights the nanosensors, ability to traffic and respond to pH of receptor-bound nanosensors (1) at physiologicalmore »temperature(37°C)versus room temperature(25°C), (2) after pharmacological treatment with bafilomycin, anH+ATPase pump inhibitor, or amiloride, an inhibitor ofNa+/H+exchange, and (3) in response to both temperature and pharmacological treatment. Whole-cell, time lapse images are demonstrated to show the ability to transform live cells into dynamic laboratories to monitor temporal and spatial endosomal pH. The versatility of these probes shows promise for future applications relevant to intracellular trafficking and intelligent drug design.« less
Computational approaches to many-body dynamics of unstable nuclear systems
Alexander Volya
2014-12-19T23:59:59.000Z
The goal of this presentation is to highlight various computational techniques used to study dynamics of quantum many-body systems. We examine the projection and variable phase methods being applied to multi-channel problems of scattering and tunneling; here the virtual, energy-forbidden channels and their treatment are of particular importance. The direct time-dependent solutions using Trotter-Suzuki propagator expansion provide yet another approach to exploring the complex dynamics of unstable systems. While presenting computational tools, we briefly revisit the general theory of the quantum decay of unstable states. The list of questions here includes those of the internal dynamics in decaying systems, formation and evolution of the radiating state, and low-energy background that dominates at remote times. Mathematical formulations and numerical approaches to time-dependent problems are discussed using the quasi-stationary methods involving effective Non-Hermitian Hamiltonian formulation.
216-B-3 expansion ponds closure plan
Not Available
1994-10-01T23:59:59.000Z
This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.
General relativity limit of Ho?ava-Lifshitz gravity with a scalar field in gradient expansion
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gümrükçüo?lu, A. Emir; Mukohyama, Shinji; Wang, Anzhong
2012-03-01T23:59:59.000Z
We present a fully nonlinear study of long-wavelength cosmological perturbations within the framework of the projectable Horava-Lifshitz gravity, coupled to a single scalar field. Adopting the gradient expansion technique, we explicitly integrate the dynamical equations up to any order of the expansion, then restrict the integration constants by imposing the momentum constraint. While the gradient expansion relies on the long-wavelength approximation, amplitudes of perturbations do not have to be small. When the ??1 limit is taken, the obtained nonlinear solutions exhibit a continuous behavior at any order of the gradient expansion, recovering general relativity in the presence of a scalar field and the “dark matter as an integration constant.” This is in sharp contrast to the results in the literature based on the “standard” (and naive) perturbative approach where in the same limit, the perturbative expansion of the action breaks down and the scalar graviton mode appears to be strongly coupled. We carry out a detailed analysis on the source of these apparent pathologies and determine that they originate from an improper application of the perturbative approximation in the momentum constraint. We also show that there is a new branch of solutions, valid in the regime where |?-1| is smaller than the order of perturbations. In the limit ??1, this new branch allows the theory to be continuously connected to general relativity, with an effective component which acts like pressureless fluid.
Kalyanasundaram, K.
1988-04-21T23:59:59.000Z
The dynamics of photoinduced formation of M(CO)/sub 4/(LL) (M = Mo(O), Cr(O), and W(O) and LL = various polypyridyl ligands such as 5-chloro-1, 10-phen, 1,10-phen, 2,2'-bpy, and 4,4'-Me/sub 2/-2,2'-bpy) from M(CO)/sub 6/ and LL in benzene has been examined via pulsed laser photolysis techniques. The formation of the polypyridyl tetracarbonyl complex occurs in several steps, extending over a wide range of time scales (from a few nanoseconds to several milliseconds). Spectral evidence is presented for the formation of a pentacarbonyl monodentate polypyridine intermediate. The rate of formation of the complexes follows the order Mo(O) > Cr(O) > W(O). For a given metal carbonyl, the reactivity of various ligands follows the order 5-Clphen greater than or equal to phen > bpy greater than or equal to Me/sub 2/bpy.
D. A. Simakov
2015-04-28T23:59:59.000Z
In this article we study a particular method of detection of chirp signals from coalescing compact binary stars -- the so-called dynamical tuning, i.e. amplification of the signal via tracking of its instantaneous frequency by the tuning of the signal-recycled detector. A time-domain consideration developed for signal-recycled interferometers, in particular GEO 600, describes the signal and noise evolution in the non-stationary detector. Its non-stationarity is caused by motion of the signal recycling mirror, whose position defines the tuning of the detector. We prove that the shot noise from the dark port and optical losses remains white. The analysis of the transient effects shows that during the perfect tracking of the chirp frequency only transients from amplitude changes arise. The signal-to-noise-ratio gain, calculated in this paper, is ~ 16 for a shot-noise limited detector and ~ 4 for a detector with thermal noise.
Zhang, Yan; Sahinidis, Nikolaos V.
2013-04-06T23:59:59.000Z
In this paper, surrogate models are iteratively built using polynomial chaos expansion (PCE) and detailed numerical simulations of a carbon sequestration system. Output variables from a numerical simulator are approximated as polynomial functions of uncertain parameters. Once generated, PCE representations can be used in place of the numerical simulator and often decrease simulation times by several orders of magnitude. However, PCE models are expensive to derive unless the number of terms in the expansion is moderate, which requires a relatively small number of uncertain variables and a low degree of expansion. To cope with this limitation, instead of using a classical full expansion at each step of an iterative PCE construction method, we introduce a mixed-integer programming (MIP) formulation to identify the best subset of basis terms in the expansion. This approach makes it possible to keep the number of terms small in the expansion. Monte Carlo (MC) simulation is then performed by substituting the values of the uncertain parameters into the closed-form polynomial functions. Based on the results of MC simulation, the uncertainties of injecting CO{sub 2} underground are quantified for a saline aquifer. Moreover, based on the PCE model, we formulate an optimization problem to determine the optimal CO{sub 2} injection rate so as to maximize the gas saturation (residual trapping) during injection, and thereby minimize the chance of leakage.
Wu, Jian; Wei, Wenfu; Li, Xingwen; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi 710049 (China)
2013-04-22T23:59:59.000Z
We have investigated the dynamics of the nanosecond laser ablated plasma within and after the laser pulse irradiation using fast photography. A 1064 nm, 15 ns laser beam was focused onto a target made from various materials with an energy density in the order of J/mm{sup 2} in atmosphere. The plasma dynamics during the nanosecond laser pulse were observed, which could be divided into three stages: fast expansion, division into the primary plasma and the front plasma, and stagnation. After the laser terminated, a critical moment when the primary plasma expansion transited from the shock model to the drag model was resolved, and this phenomenon could be understood in terms of interactions between the primary and the front plasmas.
The curious case of large-N expansions on a (pseudo)sphere
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Polyakov, Alexander M. [Princeton Univ., NJ (United States); Saleem, Zain H. [Univ. of Pennsylvania, Philadelphia, PA (United States)] (ORCID:0000000281822764); Stokes, James [Univ. of Pennsylvania, Philadelphia, PA (United States)
2015-04-01T23:59:59.000Z
We elucidate the large-N dynamics of one-dimensional sigma models with spherical and hyperbolic target spaces and find a duality between the Lagrange multiplier and the angular momentum. In the hyperbolic model we propose a new class of operators based on the irreducible representations of hyperbolic space. We also uncover unexpected zero modes which lead to the double scaling of the 1/N expansion and explore these modes using Gelfand-Dikiy equations.
Expansion schemes for gravitational clustering: computing two-point and three-point functions
P. Valageas
2008-10-24T23:59:59.000Z
We describe various expansion schemes that can be used to study gravitational clustering. Obtained from the equations of motion or their path-integral formulation, they provide several perturbative expansions that are organized in different fashion or involve different partial resummations. We focus on the two-point and three-point correlation functions, but these methods also apply to all higher-order correlation and response functions. We present the general formalism, which holds for the gravitational dynamics as well as for similar models, such as the Zeldovich dynamics, that obey similar hydrodynamical equations of motion with a quadratic nonlinearity. We give our explicit analytical results up to one-loop order for the simpler Zeldovich dynamics. For the gravitational dynamics, we compare our one-loop numerical results with numerical simulations. We check that the standard perturbation theory is recovered from the path integral by expanding over Feynman's diagrams. However, the latter expansion is organized in a different fashion and it contains some UV divergences that cancel out as we sum all diagrams of a given order. Resummation schemes modify the scaling of tree and one-loop diagrams, which exhibit the same scaling over the linear power spectrum (contrary to the standard expansion). However, they do not significantly improve over standard perturbation theory for the bispectrum, unless one uses accurate two-point functions (e.g. a fit to the nonlinear power spectrum from simulations). Extending the range of validity to smaller scales, to reach the range described by phenomenological models, seems to require at least two-loop diagrams.
Frostless heat pump having thermal expansion valves
Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN)
2002-10-22T23:59:59.000Z
A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.
Low thermal expansion seal ring support
Dewis, David W. (San Diego, CA); Glezer, Boris (Del Mar, CA)
2000-01-01T23:59:59.000Z
Today, the trend is to increase the temperature of operation of gas turbine engines. To cool the components with compressor discharge air, robs air which could otherwise be used for combustion and creates a less efficient gas turbine engine. The present low thermal expansion sealing ring support system reduces the quantity of cooling air required while maintaining life and longevity of the components. Additionally, the low thermal expansion sealing ring reduces the clearance "C","C'" demanded between the interface between the sealing surface and the tip of the plurality of turbine blades. The sealing ring is supported by a plurality of support members in a manner in which the sealing ring and the plurality of support members independently expand and contract relative to each other and to other gas turbine engine components.
Locally-smeared operator product expansions
Monahan, Christopher; Orginos, Kostantinos
2014-12-01T23:59:59.000Z
We propose a "locally-smeared Operator Product Expansion" (sOPE) to decompose non-local operators in terms of a basis of locally-smeared operators. The sOPE formally connects nonperturbative matrix elements of smeared degrees of freedom, determined numerically using the gradient flow, to non-local operators in the continuum. The nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale prevents a simple connection to the standard operator product expansion and therefore requires the construction of a two-scale formalism. We demonstrate the feasibility of our approach using the example of real scalar field theory.
Center-symmetric 1/N expansion
Schaden, Martin [Department of Physics, Rutgers University in Newark, 365 Smith Hall, 101 Warren Street, Newark, New Jersey 07102 (United States)
2005-05-15T23:59:59.000Z
The free energy of U(N) gauge theory is expanded about a center-symmetric topological background configuration with vanishing action and vanishing Polyakov loops. We construct this background for SU(N) lattice gauge theory and show that it uniquely describes center-symmetric minimal action orbits in the limit of infinite lattice volume. The leading contribution to the free energy in the 1/N expansion about this background is of O(N{sup 0}) rather than O(N{sup 2}) as one finds when the center symmetry is spontaneously broken. The contribution of planar 't Hooft diagrams to the free energy is O(1/N{sup 2}) and subleading in this case. The change in behavior of the diagrammatic expansion is traced to Linde's observation that the usual perturbation series of non-Abelian gauge theories suffers from severe infrared divergences [A. Linde, Phys. Lett. B 96, 289 (1980).]. This infrared problem does not arise in a center-symmetric expansion. The 't Hooft coupling {lambda}=g{sup 2}N is found to decrease {proportional_to}1/ln(N) for large N. There is evidence of a vector-ghost in the planar truncation of the model.
Small distance expansion for radiative heat transfer between curved objects
Golyk, Vladyslav A.
We develop a small distance expansion for the radiative heat transfer between gently curved objects, in terms of the ratio of distance to radius of curvature. A gradient expansion allows us to go beyond the lowest-order ...
Year-in-Review: 2011 Energy Infrastructure Events and Expansions...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
1 Energy Infrastructure Events and Expansions (April 2012) Year-in-Review: 2011 Energy Infrastructure Events and Expansions (April 2012) The 2011 Year-in-Review (YIR) provides a...
Procedures to predict vertical differential soil movement for expansive soils
Naiser, Donald David
1997-01-01T23:59:59.000Z
Damage to lightly loaded structures, paving and service piping in areas of expansive clay soils has occurred throughout the world. The cause of this damage has been the inability to accurately model expansive soil movement so that foundations...
Earth pressures and deformations in civil infrastructure in expansive soils
Hong, Gyeong Taek
2008-10-10T23:59:59.000Z
This dissertation includes the three major parts of the study: volume change, and lateral earth pressure due to suction change in expansive clay soils, and design of civil infrastructure drilled pier, retaining wall and pavement in expansive soils...
An Expansion in the Exponent for Compound Binomial Approximations
Roos, Bero
distributions. One paper in this direction was published by Bikelis [5], who proposed an expansion, which identic
Matching of asymptotic expansions for the wave propagation in media
Paris-Sud XI, UniversitÃ© de
Matching of asymptotic expansions for the wave propagation in media with thin slot S-SAM Matching of asymptotic expansions for the wave propagation in media with thin slot Â p.1/38 inria-00528070 of asymptotic expansions for the wave propagation in media with thin slot Â p.2/38 inria-00528070,version1-21Oct
Matching of asymptotic expansions for the wave propagation in media
Paris-Sud XI, UniversitÃ© de
Matching of asymptotic expansions for the wave propagation in media with thin slot S-SAM Matching of asymptotic expansions for the wave propagation in media with thin slot Â p.1/29 inria-00528072 The wavelength The width of the slot Â¡ Matching of asymptotic expansions for the wave propagation in media
A test of Taylor- and modified Taylor-expansion
Max Wilfling; Christof Gattringer
2014-04-08T23:59:59.000Z
We compare Taylor expansion and a modified variant of Taylor expansion, which incorporates features of the fugacity series, for expansions in the chemical potential around a zero-density lattice field theory. As a first test we apply both series to the cases of free fermions and free bosons. Convergence and other properties are analyzed.
Grid cell firing patterns signal environmental novelty by expansion
Burgess, Neil
Grid cell firing patterns signal environmental novelty by expansion Caswell Barrya,b,c,1 , Lin Lin novelty causes the spatial firing patterns of grid cells to expand in scale and reduce in regularity firing fields remapped and showed a smaller, temporary expansion. Grid expansion provides a potential
Global dynamics and asymptotics for monomial scalar field potentials and perfect fluids
Alho, Artur; Uggla, Claes
2015-01-01T23:59:59.000Z
We consider a minimally coupled scalar field with a monomial potential and a perfect fluid in flat FLRW cosmology. We apply local and global dynamical systems techniques to a new three-dimensional dynamical systems reformulation of the field equations on a compact state space. This leads to a visual global description of the solution space and asymptotic behavior. At late times we employ averaging techniques to prove statements about how the relationship between the equation of state of the fluid and the monomial exponent of the scalar field affects asymptotic source dominance and asymptotic manifest self-similarity breaking. We also situate the `attractor' solution in the three-dimensional state space and show that it corresponds to the one-dimensional unstable center manifold of a de Sitter fixed point, located on an unphysical boundary associated with the dynamics at early times. By deriving a center manifold expansion we obtain approximate expressions for the attractor solution. We subsequently improve th...
Sevostianov, Igor
expansion and thermal conductivity Igor Sevostianov Department of Mechanical and Aerospace Engineering, NewOn the thermal expansion of composite materials and cross-property connection between thermal: Composite material Thermal expansion Cross-property Microstructure Thermal conductivity a b s t r a c
Lattice-structures and constructs with designed thermal expansion coefficients
Spadaccini, Christopher; Hopkins, Jonathan
2014-10-28T23:59:59.000Z
A thermal expansion-managed lattice structure having a plurality of unit cells each having flexure bearing-mounted tabs supported on a base and actuated by thermal expansion of an actuator having a thermal expansion coefficient greater than the base and arranged so that the tab is inwardly displaced into a base cavity. The flexure bearing-mounted tabs are connected to other flexure-bearing-mounted tabs of adjacent unit cells so that the adjacent unit cells are spaced from each other to accommodate thermal expansion of individual unit cells while maintaining a desired bulk thermal expansion coefficient of the lattice structure as a whole.
Suzuki, Yasumitsu; Maitra, Neepa T; Gross, E K U
2015-01-01T23:59:59.000Z
We study the exact nuclear time-dependent potential energy surface (TDPES) for laser-induced electron localization with a view to eventually developing a mixed quantum-classical dynamics method for strong-field processes. The TDPES is defined within the framework of the exact factorization [A. Abedi, N. T. Maitra, and E. K. U. Gross, Phys. Rev. Lett. 105, 123002 (2010)] and contains the exact effect of the couplings to the electronic subsystem and to any external fields within a scalar potential. We compare its features with those of the quasistatic potential energy surfaces (QSPES) often used to analyse strong-field processes. We show that the gauge-independent component of the TDPES has a mean-field-like character very close to the density-weighted average of the QSPESs. Oscillations in this component are smoothened out by the gauge-dependent component, and both components are needed to yield the correct force on the nuclei. Once the localization begins to set in, the gradient of the exact TDPES tracks one ...
Viscous fluid dynamics in Au+Au collisions at RHIC
A. K. Chaudhuri
2008-06-18T23:59:59.000Z
We have studied the space-time evolution of minimally viscous ($\\frac{\\eta}{s}$=0.08) QGP fluid, undergoing boost-invariant longitudinal motion and arbitrary transverse expansion. Relaxation equations for the shear stress tensor components, derived from the phenomenological Israel-Stewart's theory of dissipative relativistic fluid, are solved simultaneously with the energy-momentum conservation equations. Comparison of evolution of ideal and viscous fluid, both initialized under the similar conditions, e.g. same equilibration time, energy density and velocity profile, indicate that in viscous fluid, energy density or temperature of the fluid evolve slowly than in an ideal fluid. Transverse expansion is also more in viscous evolution. We have also studied particle production in viscous dynamics. Compared to ideal dynamics, in viscous dynamics, particle yield at high $p_T$ is increased. Elliptic flow on the other hand decreases. Minimally viscous QGP fluid, initialized at entropy density $s_{ini}$=110 $fm^{-3}$ at the initial time $\\tau_i$=0.6 fm, if freeze-out at temperature $T_F$=130 MeV, explains the centrality dependence of $p_T$ spectra of identified particles. Experimental $p_T$ spectra of $\\pi^-$, $K^+$ and protons in 0-5%, 5-10%, 10-20%, 20-30%, 30-40% and 40-50% Au+Au collisions are well reproduced through out the experimental $p_T$ range. This is in contrast to ideal dynamics, where, the spectra are reproduced only up to $p_T\\approx$1.5 GeV. Minimally viscous QGP fluid, also explain the elliptic flow in mid-central (10-20%, 16-23%, 20-30%) collisions. The minimum bias elliptic flow is also explained. However, the model under-predict/over-predict the elliptic flow in very central/peripheral collisions.
Transient particle energies in shortcuts to adiabatic expansions of harmonic traps
Yang-Yang Cui; Xi Chen; J. G. Muga
2015-05-12T23:59:59.000Z
The expansion of a harmonic potential that holds a quantum particle may be realized without any final particle excitation but much faster than adiabatically via "shortcuts to adiabaticity" (STA). While ideally the process time can be reduced to zero, practical limitations and constraints impose minimal finite times for the externally controlled time-dependent frequency protocols. We examine the role of different time-averaged energies (total, kinetic, potential, non-adiabatic) and of the instantaneous power in characterizing or selecting different protocols.Specifically, we prove a virial theorem for STA processes, set minimal energies for specific times or viceversa, and discuss their realizability by means of Dirac impulses or otherwise.
Reversible expansion of gallium-stabilized (delta)-plutonium
Wolfer, W G; Oudot, B; Baclet, N
2006-02-27T23:59:59.000Z
It is shown that the transient expansion of plutonium-gallium alloys observed both in the lattice parameter as well as in the dimension of a sample held at ambient temperature can be explained by assuming incipient precipitation of Pu{sub 3}Ga. However, this ordered {zeta}-phase is also subject to radiation-induced disordering. As a result, the gallium-stabilized {delta}-phase, being metastable at ambient temperature, is driven towards thermodynamic equilibrium by radiation-enhanced diffusion of gallium and at the same time reverted back to its metastable state by radiation-induced disordering. A steady state is reached in which only a modest fraction of the gallium present is arranged in ordered {zeta}-phase regions.
Growth of Cosmic Structure: Probing Dark Energy Beyond Expansion
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huterer, Dragan [University of Michigan, Department of Physics Ann Harbor, MI (United States); Kirkby, David [UC Irvine, Department of Physics and Astronomy, CA (United States); Bean, Rachel [Cornell University, Department of Astronomy, Ithaca, NY (United States); Connolly, Andrew [University of Washington, Department of Astronomy, Seattle, WA (United States); Dawson, Kyle [University of Utah, Department of Physics & Astronomy, Salt Lake City, UT (United States); Dodelson, Scott [Fermi National Accelerator Laboratory, Fermilab Center for Particle Astrophysics, Batavia, IL (United States); University of Chicago, Department of Physics & Astrophysics, Chicago, IL (United States); Evrard, August [University of Michigan, Department of Physics Ann Harbor, MI (United States); Jain, Bhuvnesh [University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, PA (United States); Jarvis, Michael [University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, PA (United States); Linder, Eric [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Mandelbaum, Rachel [Carnegie Mellon University, Department of Physics, Pittsburgh, PA (United States); May, Morgan [Brookhaven National Laboratory (BNL), Upton, NY (United States); Raccanelli, Alvise [California Institute of Technology, NASA Jet Propulsion Laboratory, Pasadena, CA (United States); Reid, Beth [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Rozo, Eduardo [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Schmidt, Fabian [Princeton University, Department of Astrophysical Sciences, Princeton, NJ (United States); Max-Planck-Insitute for Astrophysics, Garching (Germany); Sehgal, Neelima [Stony Brook University, NY (United States); Slosar, Anze [Brookhaven National Laboratory (BNL), Upton, NY (United States); Van Engelen, Alex [Stony Brook University, NY (United States); Wu, Hao-Yi [University of Michigan, Department of Physics, Ann Harbor, MI (United States); Zhao, Gongbo [Chinese Academy of Science, National Astronomy Observatories, Beijing (China)
2015-03-01T23:59:59.000Z
The quantity and quality of cosmic structure observations have greatly accelerated in recent years, and further leaps forward will be facilitated by imminent projects. These will enable us to map the evolution of dark and baryonic matter density fluctuations over cosmic history. The way that these fluctuations vary over space and time is sensitive to several pieces of fundamental physics: the primordial perturbations generated by GUT-scale physics; neutrino masses and interactions; the nature of dark matter and dark energy. We focus on the last of these here: the ways that combining probes of growth with those of the cosmic expansion such as distance-redshift relations will pin down the mechanism driving the acceleration of the Universe.
Alistar Ottochian; Dino Leporini
2011-01-14T23:59:59.000Z
The scaling of the slow structural relaxation with the fast caged dynamics is evidenced in the molten salt Ca_{0.4}K_{0.6}(NO_{3}$)_{1.4} (CKN) over about thirteen decades of the structural relaxation time. Glycerol caling was analyzed in detail. In glycerol, the short-time mean-square displacement , a measure of the caged dynamics, is contributed by free-volume. It is seen that, in order to evidence the scaling, the observation time of the fast dynamics must be shorter than the time scales of the relaxation processes. Systems with both negligible (like CKN, glycerol and network glassformers) and high (like van der Waals liquids and polymers) pressure-energy correlations exhibit the scaling between the slow relaxation and the fast caged dynamics. According to the available experiments, an isomorph-invariant expression of the master curve of the scaled data is not distinguishable from a simpler not-invariant expression. Instead, the latter grees better with the simulations on a wide class of model polymers.
First passage times in integrate-and-fire neurons with stochastic thresholds
Braun, Wilhelm; Thul, Rüdiger
2015-01-01T23:59:59.000Z
We consider a leaky integrate--and--fire neuron with deterministic subthreshold dynamics and a firing threshold that evolves as an Ornstein-Uhlenbeck process. The formulation of this minimal model is motivated by the experimentally observed widespread variation of neural firing thresholds. We show numerically that the mean first passage time can depend non-monotonically on the noise amplitude. For sufficiently large values of the correlation time of the stochastic threshold the mean first passage time is maximal for non-vanishing noise. We provide an explanation for this effect by analytically transforming the original model into a first passage time problem for Brownian motion. This transformation also allows for a perturbative calculation of the first passage time histograms. In turn this provides quantitative insights into the mechanisms that lead to the non-monotonic behaviour of the mean first passage time. The perturbation expansion is in excellent agreement with direct numerical simulations. The approa...
Is Hubble's Expansion due to Dark Energy
R. C. Gupta; Anirudh Pradhan
2010-10-19T23:59:59.000Z
{\\it The universe is expanding} is known (through Galaxy observations) since 1929 through Hubble's discovery ($V = H D$). Recently in 1999, it is found (through Supernovae observations) that the universe is not simply expanding but is accelerating too. We, however, hardly know only $4\\%$ of the universe. The Wilkinson Microwave Anisotropy Probe (WMAP) satellite observational data suggest $73\\%$ content of the universe in the form of dark-energy, $23\\%$ in the form of non-baryonic dark-matter and the rest $4\\%$ in the form of the usual baryonic matter. The acceleration of the universe is ascribed to this dark-energy with bizarre properties (repulsive-gravity). The question is that whether Hubble's expansion is just due to the shock of big-bang & inflation or it is due to the repulsive-gravity of dark-energy? Now, it is believed to be due to dark-energy, say, by re-introducing the once-discarded cosmological-constant $\\Lambda$. In the present paper, it is shown that `the formula for acceleration due to dark-energy' is (almost) exactly of same-form as `the acceleration formula from the Hubble's law'. Hence, it is concluded that: yes, `indeed it is the dark-energy responsible for the Hubble's expansion too, in-addition to the current on-going acceleration of the universe'.
Xifeng Su; Lei Zhang; Rafael de la Llave
2015-03-11T23:59:59.000Z
We consider 1-D quasi-periodic Frenkel-Kontorova models (describing, for example, deposition of materials in a quasi-periodic substratum). We study the existence of equilibria whose frequency (i.e. the inverse of the density of deposited material) is resonant with the frequencies of the substratum. We study perturbation theory for small potential. We show that there are perturbative expansions to all orders for the quasi-periodic equilibria with resonant frequencies. Under very general conditions, we show that there are at least two such perturbative expansions for equilibria for small values of the parameter. We also develop a dynamical interpretation of the equilibria in these quasi-periodic media. We show that the dynamical system has very unusual properties. Using these, we obtain results on the Lyapunov exponents of the resonant quasi-periodic solutions. In a companion paper, we develop a rather unusual KAM theory (requiring new considerations) which establishes that the perturbative expansions converge when the perturbing potentials satisfy a one-dimensional constraint.
Phase dynamics and particle production in preheating
Charters, T. [Departamento de Mecanica/Seccao de Matematica, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1, P-1949-014 Lisbon (Portugal) and Centro de Fisica Teorica e Computacional da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal); Nunes, A.; Mimoso, J.P. [Departamento de Fisica, Faculdade de Ciencias da Universidade de Lisboa and Centro de Fisica Teorica e Computacional da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal)
2005-04-15T23:59:59.000Z
We study a simple model of a massive inflaton field {phi} coupled to another scalar field {chi} with interaction term g{sup 2}{phi}{sup 2}{chi}{sup 2}. We use the theory developed by Kofman et al. [L. Kofman, A. D. Linde, and A. A. Starobinsky, Phys. Rev. D 56, 3258 (1997).] for the first stage of preheating to give a full description of the dynamics of the {chi} field modes, including the behavior of the phase, in terms of the iteration of a simple family of circle maps. The parameters of this family of maps are a function of time when expansion of the Universe is taken into account. With this more detailed description, we obtain a systematic study of the efficiency of particle production as a function of the inflaton field and coupling parameters, and we find that for g < or approx. 3x10{sup -4} the broad resonance ceases during the first stage of preheating.
Weston, Ken
Abstract Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics correlation. Additionally, ultrafast electron shadow imaging (UESI) can explore the dynamics of laser induced System The femtosecond "camera" mentioned above is comprised of an amplified femtosecond pulsed laser
Dynamics of a magnetized Bianchi I universe with vacuum energy
Emma J. King; Peter Coles
2007-03-27T23:59:59.000Z
We make use of a flat, axisymmetric Bianchi I metric to investigate the effects of a magnetic field upon the dynamics of the universe for the case in which the accompanying fluid is a cosmological constant and derive two exact solutions to the dynamical equations for this situation. We examine the behaviour of the scale factor perpendicular and parallel to the field lines, A(t) and W(t) respectively, and find the expected behaviour. The field has the strongest effect when A(t) is small, decelerating collapse perpendicular to the field lines, due to magnetic pressure, and accelerating collapse along the field lines, due to magnetic tension, while the vacuum energy dominates at late time, driving accelerated expansion.
Quantum Operation Time Reversal
Crooks, Gavin E.
2008-03-25T23:59:59.000Z
The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.
Pokorna, Sarka; Jurkiewicz, Piotr; Hof, Martin, E-mail: martin.hof@jh-inst.cas.cz [J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8 (Czech Republic); Vazdar, Mario [Division of Organic Chemistry and Biochemistry, Rudjer Boškovi? Institute, P.O.B. 180, HR-10002 Zagreb (Croatia); Cwiklik, Lukasz [J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8 (Czech Republic); Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic); Jungwirth, Pavel [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic); Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland)
2014-12-14T23:59:59.000Z
Time-dependent fluorescence shift (TDFS) of Laurdan embedded in phospholipid bilayers reports on hydration and mobility of the phospholipid acylgroups. Exchange of H{sub 2}O with D{sub 2}O prolongs the lifetime of lipid-water and lipid-water-lipid interactions, which is reflected in a significantly slower TDFS kinetics. Combining TDFS measurements in H{sub 2}O and D{sub 2}O hydrated bilayers with atomistic molecular dynamics (MD) simulations provides a unique tool for characterization of the hydrogen bonding at the acylgroup level of lipid bilayers. In this work, we use this approach to study the influence of fluoride anions on the properties of cationic bilayers composed of trimethylammonium-propane (DOTAP). The results obtained for DOTAP are confronted with those for neutral phosphatidylcholine (DOPC) bilayers. Both in DOTAP and DOPC H{sub 2}O/D{sub 2}O exchange prolongs hydrogen-bonding lifetime and does not disturb bilayer structure. These results are confirmed by MD simulations. TDFS experiments show, however, that for DOTAP this effect is cancelled in the presence of fluoride ions. We interpret these results as evidence that strongly hydrated fluoride is able to steal water molecules that bridge lipid carbonyls. Consequently, when attracted to DOTAP bilayer, fluoride disrupts the local hydrogen-bonding network, and the differences in TDFS kinetics between H{sub 2}O and D{sub 2}O hydrated bilayers are no longer observed. A distinct behavior of fluoride is also evidenced by MD simulations, which show different lipid-ion binding for Cl{sup ?} and F{sup ?}.
Nuclear dynamical diffraction using synchrotron radiation
Brown, D.E.
1993-05-01T23:59:59.000Z
The scattering of synchrotron radiation by nuclei is extensively explored in this thesis. From the multipole electric field expansion resulting from time-dependent nonrelativistic perturbation theory, a dynamical scattering theory is constructed. This theory is shown, in the many particle limit, to be equivalent to the semi-classical approach where a quantum mechanical scattering amplitude is used in the Maxwell inhomogeneous wave equation. The Moessbauer specimen whose low-lying energy levels were probed is a ferromagnetic lattice of {sup 57}Fe embedded in a yttrium iron garnet (YIG) crystal matrix. The hyperfine fields in YIG thin films were studied at low and room temperature using time-resolved quantum beat spectroscopy. Nuclear hyperfine structure quantum beats were measured using a fast plastic scintillator coincidence photodetector and associated electronics having a time resolution of 2.5 nsec. The variation of the quantum beat patterns near the Bragg [0 0 2] diffraction peak gave a Lamb-Moessbauer factor of 8.2{plus_minus}0.4. Exploring characteristic dynamical features in the higher order YIG [0 0 10] reflection revealed that one of the YIG crystals had bifurcated into two different layers. The dynamics of nuclear superradiance was explored. This phenomenon includes the radiative speedup exhibited by a collective state of particles, and, in striking concurrence, resonance frequency shifts. A speedup of a factor of 4 in the total decay rate and a beat frequency shift of 1{1/2} natural resonance linewidths were observed. Nuclear resonance scattering was also found to be a useful way of performing angular interferometry experiments, and it was used to observe the phase shift of a rotated quantum state. On the whole, nuclear dynamical diffraction theory has superbly explained many of the fascinating features of resonant magnetic dipole radiation scattered by a lattice of nuclei.
PHOTOSPHERIC RADIUS EXPANSION IN SUPERBURST PRECURSORS FROM NEUTRON STARS
Keek, L., E-mail: keek@nscl.msu.edu [National Superconducting Cyclotron Laboratory, Department of Physics and Astronomy, and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)
2012-09-10T23:59:59.000Z
Thermonuclear runaway burning of carbon is in rare cases observed from accreting neutron stars as day-long X-ray flares called superbursts. In the few cases where the onset is observed, superbursts exhibit a short precursor burst at the start. In each instance, however, the data are of insufficient quality for spectral analysis of the precursor. Using data from the propane anti-coincidence detector of the Proportional Counter Array instrument on the Rossi X-ray Timing Explorer, we perform the first detailed time-resolved spectroscopy of precursors. For a superburst from 4U 1820-30 we demonstrate the presence of photospheric radius expansion. We find the precursor to be 1.4-2 times more energetic than other short bursts from this source, indicating that the burning of accreted helium is insufficient to explain the full precursor. Shock heating would be able to account for the shortfall in energy. We argue that this precursor is a strong indication that the superburst starts as a detonation, and that a shock induces the precursor. Furthermore, we employ our technique to study the superexpansion phase of the same superburst in greater detail.
EMPIRE ULTIMATE EXPANSION: RESONANCES AND COVARIANCES.
HERMAN,M.; MUGHABGHAB, S.F.; OBLOZINSKY, P.; ROCHMAN, D.; PIGNI, M.T.; KAWANO, T.; CAPOTE, R.; ZERKIN, V.; TRKOV, A.; SIN, M.; CARSON, B.V.; WIENKE, H. CHO, Y.-S.
2007-04-22T23:59:59.000Z
The EMPIRE code system is being extended to cover the resolved and unresolved resonance region employing proven methodology used for the production of new evaluations in the recent Atlas of Neutron Resonances. Another directions of Empire expansion are uncertainties and correlations among them. These include covariances for cross sections as well as for model parameters. In this presentation we concentrate on the KALMAN method that has been applied in EMPIRE to the fast neutron range as well as to the resonance region. We also summarize role of the EMPIRE code in the ENDF/B-VII.0 development. Finally, large scale calculations and their impact on nuclear model parameters are discussed along with the exciting perspectives offered by the parallel supercomputing.
Systematic expansion for infrared oscillator basis extrapolations
R. J. Furnstahl; S. N. More; T. Papenbrock
2014-03-20T23:59:59.000Z
Recent work has demonstrated that the infrared effects of harmonic oscillator basis truncations are well approximated by imposing a partial-wave Dirichlet boundary condition at a properly identified radius L. This led to formulas for extrapolating the corresponding energy E_L and other observables to infinite L and thus infinite basis size. Here we reconsider the energy for a two-body system with a Dirichlet boundary condition at L to identify and test a consistent and systematic expansion for E_L that depends only on observables. We also generalize the energy extrapolation formula to nonzero angular momentum, and apply it to the deuteron. Formulas given previously for extrapolating the radius are derived in detail.
Prolate spheroidal harmonic expansion of gravitational field
Fukushima, Toshio, E-mail: Toshio.Fukushima@nao.ac.jp [National Astronomical Observatory, Ohsawa, Mitaka, Tokyo 181-8588 (Japan)
2014-06-01T23:59:59.000Z
As a modification of the oblate spheroidal case, a recursive method is developed to compute the point value and a few low-order derivatives of the prolate spheroidal harmonics of the second kind, Q{sub nm} (y), namely the unnormalized associated Legendre function (ALF) of the second kind with its argument in the domain, 1 < y < ?. They are required in evaluating the prolate spheroidal harmonic expansion of the gravitational field in addition to the point value and the low-order derivatives of P-bar {sub nm}(t), the 4? fully normalized ALF of the first kind with its argument in the domain, |t| ? 1. The new method will be useful in the gravitational field computation of elongated celestial objects.
Oleg Kupervasser
2013-05-23T23:59:59.000Z
The paper consists of the two independent papers:(Part V) We see that exact equations of quantum and classical mechanics describe ideal dynamics which is reversible and leads to Poincare's returns. Real equations of physics describing observable dynamics, for example, hydrodynamic equations of viscous fluid, are irreversible and exclude Poincare's returns to the initial state. Besides, these equations describe systems in terms of macroparameters or phase distribution functions of microparameters. For many systems introduction of macroparameters that allow exhaustive describing of dynamics of the system is impossible. Their dynamics becomes unpredictable in principle, sometimes even unpredictable by the probabilistic way. We will refer to dynamics describing such system as unpredictable dynamics. Dynamics of unpredictable systems is not described and not predicted by scientific methods. Thus, the science itself puts boundaries for its applicability. But such systems can intuitively "understand itself" and "predict" the behavior "of its own" or even "communicate with each other" at intuitive level. (Part VI) Perspective of the future of artificial intellect (AI) is considered. It is shown that AI development in the future will be closer rather to art than to science. Complex dissipative systems whose behavior cannot be understood completely in principle will be the basis of AI. Nevertheless, it will not be a barrier for their practical use.
Year-in-Review: 2012 Energy Infrastructure Events and Expansions...
Broader source: Energy.gov (indexed) [DOE]
in the face of both manmade and natural disasters, visit the Energy Assurance page. Year-in-Review: 2012 Energy Infrastructure Events and Expansions More Documents &...
Load Expansion with Diesel/Gasoline RCCI for Improved Engine...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
with DieselGasoline RCCI for Improved Engine Efficiency and Emissions Load Expansion with DieselGasoline RCCI for Improved Engine Efficiency and Emissions This poster will...
Load Expansion of Stoichiometric HCCI Using Spark Assist and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation Load Expansion of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation Presentation given at...
FOA aimed at growing expansive database of Renewable Energy and...
FOA aimed at growing expansive database of Renewable Energy and Energy Efficiency Incentives and Policies Home > Groups > Utility Rate Graham7781's picture Submitted by...
accelerated cosmic expansion: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
an accelerated expansion (cosmological constant, quintessence) introduce a component of dark energy besides standard'' cold dark matter (CDM) we resort to a phenomenological...
adiabatic expansion cooling: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
As illustrative examples we consider the ultrafast expansion of a Tonks-Girardeau gas and of Bose-Einstein condensates in different dimensions, where the method exhibits an...
Singh, Nirvikar; Mora, Jesse; Carolan, Terrie
2012-01-01T23:59:59.000Z
in the current analysis. Trade Dynamics in the East AsianProduct fragmentation and trade integration: East Asia in aand William H. Branson, ed. , Trade and Structural Change in
Gherib, Rami; Izmaylov, Artur F
2015-01-01T23:59:59.000Z
Adequate simulation of non-adiabatic dynamics through conical intersection requires account for a non-trivial geometric phase (GP) emerging in electronic and nuclear wave-functions in the adiabatic representation. Popular mixed quantum-classical (MQC) methods, surface hopping and Ehrenfest, do not carry a nuclear wave-function to be able to incorporate the GP into nuclear dynamics. Surprisingly, the MQC methods reproduce ultra-fast interstate crossing dynamics generated with the exact quantum propagation so well as if they contained information about the GP. Using two-dimensional linear vibronic coupling models we unravel how the MQC methods can effectively mimic the most significant dynamical GP effects: 1) compensation for repulsive diagonal second order non-adiabatic couplings and 2) transfer enhancement for a fully cylindrically symmetric component of a nuclear distribution.
Kim, Chansoo, S.M. Massachusetts Institute of Technology
2008-01-01T23:59:59.000Z
A series of Molecular Dynamics (MD) simulations using the GROMACS® package has been performed in this thesis. It is used to mimic and simulate the hydration water in Lysozyme with three different hydration levels (h = 0.3, ...
Cuellar, Tamara Melissa
2008-10-10T23:59:59.000Z
A WEB-BASED APPROACH TO IMAGE-BASED LIGHTING USING HIGH DYNAMIC RANGE IMAGES AND QUICKTIME ™ OBJECT VIRTUAL REALITY A Thesis by TAMARA CUELLAR Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE May 2008 Major Subject: Visualization Sciences A WEB-BASED APPROACH TO IMAGE-BASED LIGHTING USING HIGH DYNAMIC RANGE IMAGES AND QUICKTIME ™ OBJECT VIRTUAL REALITY A...
Nonlinear bulk viscosity and the stability of accelerated expansion in FRW spacetime
G. Acquaviva; A. Beesham
2014-05-14T23:59:59.000Z
In the context of dark energy solutions, we consider a Friedmann-Robertson-Walker spacetime filled with a non-interacting mixture of dust and a viscous fluid, whose bulk viscosity is governed by the nonlinear model proposed in [15]. Through a phase space analysis of the equivalent dynamical system, existence and stability of critical solutions are established and the respective scale factors are computed. The results point towards the possibility of describing the current accelerated expansion of the Universe by means of the abovementioned nonlinear model for viscosity.
Effects of Electromagnetic Field on The Collapse and Expansion of Anisotropic Gravitating Source
G. Abbas
2014-05-27T23:59:59.000Z
This paper is devoted to study the effects of electromagnetic on the collapse and expansion of anisotropic gravitating source. For this purpose, we have evaluated the generating solutions of Einstein-Maxwell field equations with spherically symmetric anisotropic gravitating source. We found that a single function generates the various anisotropic solutions. In this case every generating function involves an arbitrary function of time which can be chosen to fit several astrophysical time profiles. Two physical phenomenon occur, one is gravitational collapse and other is the cosmological expanding solution. In both cases electromagnetic field effects the anisotropy of the model. For collapse the anisotropy is increased while for expansion it deceases from maximum value to finite positive value. In case of collaps there exits two horizons like in case of Reissner-Nordstr$\\ddot{o}$m metric.
Climate impacts of a large-scale biofuels expansion*
Climate impacts of a large-scale biofuels expansion* Willow Hallgren, C. Adam Schlosser, Erwan impacts of a large-scale biofuels expansion Willow Hallgren,1 C. Adam Schlosser,1 Erwan Monier,1 David March 2013. [1] A global biofuels program will potentially lead to intense pressures on land supply
Multipole expansion for relativistic Coulomb excitation H. Esbensen
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Multipole expansion for relativistic Coulomb excitation H. Esbensen Physics Division, Argonne a general expression for the multipole expansion of the electromagnetic interaction in relativistic heavy. The interaction has diagonal as well as off-diagonal multipole components, associated with the intrinsic
BUCKLING OF DOUBLE BELLOWS EXPANSION JOINTS UNDER INTERNAL PRESSURE
Newland, David E.
of the bellows and the bellows supporting structure. To reduce the susceptibility to buckling, lateral supports270 BUCKLING OF DOUBLE BELLOWS EXPANSION JOINTS UNDER INTERNAL PRESSURE By D. E. Newland* Corrugated bellows expansion joints may buckle under internal pressure in the same way as an elasticstrut may
Gauge-invariant Green function dynamics: A unified approach
Swiecicki, Sylvia D., E-mail: sswiecic@physics.utoronto.ca; Sipe, J.E., E-mail: sipe@physics.utoronto.ca
2013-11-15T23:59:59.000Z
We present a gauge-invariant description of Green function dynamics introduced by means of a generalized Peirels phase involving an arbitrary differentiable path in space–time. Two other approaches to formulating a gauge-invariant description of systems, the Green function treatment of Levanda and Fleurov [M. Levanda, V. Fleurov, J. Phys.: Condens. Matter 6 (1994) 7889] and the usual multipolar expansion for an atom, are shown to arise as special cases of our formalism. We argue that the consideration of paths in the generalized Peirels phase that do not lead to introduction of an effective gauge-invariant Hamiltonian with polarization and magnetization fields may prove useful for the treatment of the response of materials with short electron correlation lengths. -- Highlights: •Peirels phase for an arbitrary path in space–time established. •Gauge-invariant Green functions and the Power–Zienau–Wooley transformation connected. •Limitations on possible polarization and magnetization fields established.
A model for accelerated expansion of the universe from $\\mathcal{N}=1$ Supergravity
Landim, Ricardo C G
2015-01-01T23:59:59.000Z
In this paper we present a model for accelerated expansion of the universe, both during inflation and the present stage of the expansion, from four dimensional $\\mathcal{N}=1$ supergravity. We evaluate the tensor-to-scalar ratio ($r\\approx 0.00034$), the scalar spectral index ($n_s\\approx 0.970$) and the running spetral index ($dn_s/dk\\approx -6\\times10^{-5}$), and we notice that these parameters are in agreement with Planck+WP+lensing data and with BICEP2/Keck and Planck joint analysis, at $95\\%$ CL. The number of e-folds is $50$ or higher. The reheating period has an associated temperature $T_R\\sim10^{12}$ Gev, which agrees with the one required by thermal leptogenesis. Regarding the scalar field as dark energy, the autonomous system for the scalar field in the presence of a barotropic fluid provides a stable fixed point that leads to a late-time accelerated expansion of the universe, with an equation of state that mimics the cosmological constant ($w_\\Phi\\approx -0.997$).
Dynamics of Matter in a Compactified Kaluza-Klein Model
Valentino Lacquaniti; Giovanni Montani
2009-02-10T23:59:59.000Z
A longstanding problem in Kaluza-Klein models is the description of matter dynamics. Within the 5D model, the dimensional reduction of the geodesic motion for a 5D free test particle formally restores electrodynamics, but the reduced 4D particle shows a charge-mass ratio that is upper bounded, such that it cannot fit to any kind of elementary particle. At the same time, from the quantum dynamics viewpoint, there is the problem of the huge massive modes generation. We present a criticism against the 5D geodesic approach and face the hypothesis that in Kaluza-Klein space the geodesic motion does not deal with the real dynamics of test particle. We propose a new approach: starting from the conservation equation for the 5D matter tensor, within the Papapetrou multipole expansion, we prove that the 5D dynamical equation differs from the 5D geodesic one. Our new equation provides right coupling terms without bounding and in such a scheme the tower of massive modes is removed.
Crystal structure and thermal expansion of (Mg,Fe)SiO sub 3 perovskite
Parise, J.B.; Wang, Y.; Yenganeh-Haeri, A. (State Univ. of New York, Stony Brook (USA)); Cox, D.E. (Brookhaven National Lab., Upton, NY (USA)); Fei, Y. (Carnegie Institution of Washington, DC (USA))
1990-11-01T23:59:59.000Z
High-resolution x-ray diffraction data were collected from 10 to 433K on a homogeneous polycrystalline specimen of Mg{sub 0.9}Fe{sub 0.1}SiO{sub 3}-perovskite. Rietveld structural refinement and x-ray absorption fluorescence measurements demonstrate that Fe substitutes for Mg and not Si. The thermal expansion behavior is anisotropic, with the orthorhombic distortion becoming less with increasing temperature. The volumetric thermal expansion, which is dominated by the decrease in octahedral tilts, is 1.9 {times} 10{sup {minus}5} K{sup {minus}1} between 150 and 373K. No evidence of conversion to enstatite could be found up to 873 K.
Sai Venkata Ramana, A., E-mail: asaivenk@barc.gov.in [Theoretical Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)
2014-04-21T23:59:59.000Z
The coupling parameter series expansion and the high temperature series expansion in the thermodynamic perturbation theory of fluids are shown to be equivalent if the interaction potential is pairwise additive. As a consequence, for the class of fluids with the potential having a hardcore repulsion, if the hard-sphere fluid is chosen as reference system, the terms of coupling parameter series expansion for radial distribution function, direct correlation function, and Helmholtz free energy follow a scaling law with temperature. The scaling law is confirmed by application to square-well fluids.
Generation and transmission expansion planning for renewable energy integration
Bent, Russell W [Los Alamos National Laboratory; Berscheid, Alan [Los Alamos National Laboratory; Toole, G. Loren [Los Alamos National Laboratory
2010-11-30T23:59:59.000Z
In recent years the expansion planning problem has become increasingly complex. As expansion planning (sometimes called composite or integrated resource planning) is a non-linear and non-convex optimization problem, researchers have traditionally focused on approximate models of power flows to solve the problem. The problem has also been split into generation expansion planning (GEP) and transmission network expansion planning (TNEP) to improve computational tractability. Until recently these approximations have produced results that are straight-forward to combine and adapt to the more complex and complete problem. However, the power grid is evolving towards a state where the adaptations are no longer easy (e.g. large amounts of limited control, renewable generation, comparable generation and transmission construction costs) and necessitates new approaches. Recent work on deterministic Discrepancy Bounded Local Search (DBLS) has shown it to be quite effective in addressing the TNEP. In this paper, we propose a generalization of DBLS to handle simultaneous generation and transmission planning.
QCD Multipole Expansion and Hadronic Transitions in Heavy Quarkonium Systems
Yu-Ping Kuang
2006-01-18T23:59:59.000Z
We review the developments of QCD multipole expansion and its applications to hadronic transitions and some radiative decays of heavy quarkonia. Theoretical predictions are compsred with updated experimental results.
Expansion Joint Concepts for High Temperature Insulation Systems
Harrison, M. R.
1980-01-01T23:59:59.000Z
As high temperature steam and process piping expands with heat, joints begin to open between the insulation sections, resulting in increased energy loss and possible unsafe surface temperatures. Many different expansion joint designs are presently...
Value of Options in Airport Expansion - Example of AICM
Morgado, Frederico
Investments decisions for airport capacity expansion are usually taken, either when demand exceeds the current capacity and the airport is working under congestion, or when current demand is expected to overcome current ...
Ion emission and expansion in laser-produced tin plasma
Burdt, Russell Allen
2011-01-01T23:59:59.000Z
scale length laser-produced tin plasmas, PhD dissertation,and Expansion in Laser-Produced Tin Plasma A dissertationof a CO 2 laser pulse with tin-based plasma for an extreme
Biochemical and photochemical control of leaf disk expansion
Scott, Ralph A.
1957-01-01T23:59:59.000Z
promotive effect with kin ins .............. ................ k9 f. Relation of kinetin added to its analogs... .. 51 (1) Effect of kinin-KEN combinations on the relative amount of leaf expansion with red light versus darkness....... .. 53 (2) Effect...-naphthalene acetic acid,..... ,,??? 87 (4) Effect of X-irradiation on leaf disk expansion with kin ins, IAA, and low intensity light.................... 9^ b. Response of X-irradiated intact plants to kinins, IAA, and low intensity light... ?????? 101 LIST...
Elastic capsules in shear flow: Analytical solutions for constant and time-dependent shear rates
Steffen Kessler; Reimar Finken; Udo Seifert
2009-02-26T23:59:59.000Z
We investigate the dynamics of microcapsules in linear shear flow within a reduced model with two degrees of freedom. In previous work for steady shear flow, the dynamic phases of this model, i.e. swinging, tumbling and intermittent behaviour, have been identified using numerical methods. In this paper, we integrate the equations of motion in the quasi-spherical limit analytically for time-constant and time-dependent shear flow using matched asymptotic expansions. Using this method, we find analytical expressions for the mean tumbling rate in general time-dependent shear flow. The capsule dynamics is studied in more detail when the inverse shear rate is harmonically modulated around a constant mean value for which a dynamic phase diagram is constructed. By a judicious choice of both modulation frequency and phase, tumbling motion can be induced even if the mean shear rate corresponds to the swinging regime. We derive expressions for the amplitude and width of the resonance peaks as a function of the modulation frequency.
Multipole expansion at the level of the action
Andreas Ross
2013-04-05T23:59:59.000Z
Sources of long wavelength radiation are naturally described by an effective field theory (EFT) which takes the form of a multipole expansion. Its action is given by a derivative expansion where higher order terms are suppressed by powers of the ratio of the size of the source over the wavelength. In order to determine the Wilson coefficients of the EFT, i.e. the multipole moments, one needs the mapping between a linear source term action and the multipole expansion form of the action of the EFT. In this paper we perform the multipole expansion to all orders by Taylor expanding the field in the source term and then decomposing the action into symmetric trace free tensors which form irreducible representations of the rotation group. We work at the level of the action, and we obtain the action to all orders in the multipole expansion and the exact expressions for the multipole moments for a scalar field, electromagnetism and linearized gravity. Our results for the latter two cases are manifestly gauge invariant. We also give expressions for the energy flux and the (gauge dependent) radiation field to all orders in the multipole expansion. The results for linearized gravity are a component of the EFT framework NRGR and will greatly simplify future calculations of gravitational wave observables in the radiation sector of NRGR.
Dynamical dark matter. I. Theoretical overview
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Dienes, Keith R.; Thomas, Brooks
2012-04-01T23:59:59.000Z
In this paper, we propose a new framework for dark-matter physics. Rather than focus on one or more stable dark-matter particles, we instead consider a multicomponent framework in which the dark matter of the universe comprises a vast ensemble of interacting fields with a variety of different masses, mixings, and abundances. Moreover, rather than impose stability for each field individually, we ensure the phenomenological viability of such a scenario by requiring that those states with larger masses and standard-model decay widths have correspondingly smaller relic abundances, and vice versa. In other words, dark-matter stability is not an absolute requirement in such a framework, but is balanced against abundance. This leads to a highly dynamical scenario in which cosmological quantities such as ?CDM experience nontrivial time-dependences beyond those associated with the expansion of the universe. Although it may seem difficult to arrange an ensemble of states which have the required decay widths and relic abundances, we present one particular example in which this balancing act occurs naturally: an infinite tower of Kaluza-Klein (KK) states living in the bulk of large extra spacetime dimensions. Remarkably, this remains true even if the stability of the KK tower itself is entirely unprotected. Thus theories with large extra dimensions—and by extension, certain limits of string theory—naturally give rise to dynamical dark matter. Such scenarios also generically give rise to a rich set of collider and astrophysical phenomena which transcend those usually associated with dark matter.
The Dynamics of Quintessence, The Quintessence of Dynamics
Eric V. Linder
2007-06-13T23:59:59.000Z
Quintessence theories for cosmic acceleration imbue dark energy with a non-trivial dynamics that offers hope in distinguishing the physical origin of the component. We review quintessence models with an emphasis on this dynamics and discuss classifications of the different physical behaviors. The pros and cons of various parameterizations are examined as well as the extension from scalar fields to other modifications of the Friedmann expansion equation. New results on the ability of cosmological data to distinguish among and between thawing and freezing fields are presented.
The Political History of Hydraulic Fracturing’s Expansion Across the West
Forbis, Robert E.
2014-01-01T23:59:59.000Z
Political History of Hydraulic Fracturing’s Expansion AcrossPolitical History of Hydraulic Fracturing’s Expansion Acrosss use of the hydraulic fracturing development process.
Lind, Douglas A.
EXPANSIVE SUBDYNAMICS FOR ALGEBRAIC Zd-ACTIONS MANFRED EINSIEDLER, DOUGLAS LIND of Zd * *on compact metric spaces was proposed by Boyle and Lind in terms of expansive
Tennessee, University of
materials. In this paper, we study the real-time dynamics of holon-doublon pairs in an MI connected. Moreover, the propagation of holon- doublon excitations within the MI dynamically changes the spin either doubly occupied doublons or empty holons electronic sites. A doublon-holon pair is thus a charge
Michael Murray; for the BRAHMS Collaboration
2007-10-24T23:59:59.000Z
The purpose of BRAHMS is to survey the dynamics of relativistic heavy ion (as well as pp and d-A) collisions over a very wide range of rapidity and transverse momentum. The sum of these data may give us a glimpse of the initial state of the system, its transverse and longitudinal evolution and how the nature of the system changes with time. Here I will concentrate on the origin and dynamics of the light flavors, i.e. the creation and transport of the up, down and strange quarks. The results presented here are certainly not the end of the story. It is my hope that in a few years new detectors will reveal the rapidity dependence of the charm and bottom quarks.
Tunneling and propagation of vacuum bubbles on dynamical backgrounds
Dennis Simon; Julian Adamek; Aleksandar Rakic; Jens C. Niemeyer
2009-11-19T23:59:59.000Z
In the context of bubble universes produced by a first-order phase transition with large nucleation rates compared to the inverse dynamical time scale of the parent bubble, we extend the usual analysis to non-vacuum backgrounds. In particular, we provide semi-analytic and numerical results for the modified nucleation rate in FLRW backgrounds, as well as a parameter study of bubble walls propagating into inhomogeneous (LTB) or FLRW spacetimes, both in the thin-wall approximation. We show that in our model, matter in the background often prevents bubbles from successful expansion and forces them to collapse. For cases where they do expand, we give arguments why the effects on the interior spacetime are small for a wide range of reasonable parameters and discuss the limitations of the employed approximations.
Tunneling and propagation of vacuum bubbles on dynamical backgrounds
Simon, Dennis; Rakic, Aleksandar; Niemeyer, Jens C
2009-01-01T23:59:59.000Z
In the context of bubble universes produced by a first-order phase transition with large nucleation rates compared to the inverse dynamical time scale of the parent bubble, we extend the usual analysis to non-vacuum backgrounds. In particular, we provide semi-analytic and numerical results for the modified nucleation rate in FLRW backgrounds, as well as a parameter study of bubble walls propagating into inhomogeneous (LTB) or FLRW spacetimes, both in the thin-wall approximation. We show that in our model, matter in the background often prevents bubbles from succesful expansion and forces them to collapse. For cases where they do expand, we give arguments why the effects on the interior spacetime are small for a wide range of reasonable parameters and discuss the limitations of the employed approximations.
Dynamics of excess electrons in atomic and molecular clusters
Young, Ryan Michael
2011-01-01T23:59:59.000Z
Time-Resolved Dynamics in Acetonitrile Cluster Anions (CH 3Time-resolved dynamics in acetonitrile clusters anions (CH 3resolved dynamics in acetonitrile clusters anions (CH 3 CN)
Pedram, Massoud
of batteries in conventional battery-powered embedded systems. In particular, the question of how one can achieve full energy autonomy (i.e., perpetual, battery-free operation) of a real-time embedded system harvesting module is comprised of a Photovoltaic (PV) panel for harvesting energy and a supercapacitor
Gerwert, Klaus
bilayers can be investigated in near physiological con- ditions with the attenuated total reflection (ATR online 22 August 2011 Keywords: Infrared Time-resolved Difference spectroscopy Rapid scan Step scan GTPases GTP Caged-substances Ras Isotopic labeling Band assignment Global fit Attenuated total reflection
Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Kontar, Eduard P. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)
2013-05-10T23:59:59.000Z
Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial location, and, thus, (4) physical parameters from those of the separately identified trapped or precipitating electron components. To derive evolution of physical parameters of the radio sources we apply forward fitting of the radio spectrum time sequence with the gyrosynchrotron source function with five to six free parameters. At the stage when the contribution from the acceleration region dominates the radio spectrum, the X-ray- and radio-derived electron energy spectral indices agree well with each other. During this time the maximum energy of the accelerated electron spectrum displays a monotonic increase with time from {approx}300 keV to {approx}2 MeV over roughly one minute duration indicative of an acceleration process in the form of growth of the power-law tail; the fast electron residence time in the acceleration region is about 2-4 s, which is much longer than the time of flight and so requires a strong diffusion mode there to inhibit free-streaming propagation. The acceleration region has a relatively strong magnetic field, B {approx} 120 G, and a low thermal density, n{sub e} {approx}< 2 Multiplication-Sign 10{sup 9} cm{sup -3}. These acceleration region properties are consistent with a stochastic acceleration mechanism.
TEMPERATURE DEPENDENT CREEP EXPANSION OF Ti-6Al-4V LOW DENSITY CORE SANDWICH STRUCTURES
Wadley, Haydn
by their high manufacturing costs. Interest has therefore developed in an entrapped gas expansion process entrapped gas expansion processing the driving force governing the re-expansion step is the internal pore of the expansion itself (an increase in void volume lowers the gas pressure) or because of gas lost through
Locally smeared operator product expansions in scalar field theory
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Monahan, Christopher J. [College of William & Mary; Orginos, Kostas [William and Mary College, JLAB
2015-04-01T23:59:59.000Z
We propose a new locally smeared operator product expansion to decompose non-local operators in terms of a basis of smeared operators. The smeared operator product expansion formally connects nonperturbative matrix elements determined numerically using lattice field theory to matrix elements of non-local operators in the continuum. These nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, which significantly complicates calculations of quantities such as the moments of parton distribution functions, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale complicates the connection to the Wilson coefficients of the standard operator product expansion and requires the construction of a suitable formalism. We demonstrate the feasibility of our approach with examples in real scalar field theory.
Generating expansion model incorporating compact DC power flow equations
Nderitu, D.G.; Sparrow, F.T.; Yu, Z. [Purdue Inst. for Interdisciplinary Engineering Studies, West Lafayette, IN (United States)
1998-12-31T23:59:59.000Z
This paper presents a compact method of incorporating the spatial dimension into the generation expansion problem. Compact DC power flow equations are used to provide real-power flow coordination equations. Using these equations the marginal contribution of a generator to th total system loss is formulated as a function of that generator`s output. Incorporating these flow equations directly into the MIP formulation of the generator expansion problem results in a model that captures a generator`s true net marginal cost, one that includes both the cost of generation and the cost of transport. This method contrasts with other methods that iterate between a generator expansion model and an optimal power flow model. The proposed model is very compact and has very good convergence performance. A case study with data from Kenya is used to provide a practical application to the model.
Perturbation Expansion for Option Pricing with Stochastic Volatility
Petr Jizba; Hagen Kleinert; Patrick Haener
2007-08-22T23:59:59.000Z
We fit the volatility fluctuations of the S&P 500 index well by a Chi distribution, and the distribution of log-returns by a corresponding superposition of Gaussian distributions. The Fourier transform of this is, remarkably, of the Tsallis type. An option pricing formula is derived from the same superposition of Black-Scholes expressions. An explicit analytic formula is deduced from a perturbation expansion around a Black-Scholes formula with the mean volatility. The expansion has two parts. The first takes into account the non-Gaussian character of the stock-fluctuations and is organized by powers of the excess kurtosis, the second is contract based, and is organized by the moments of moneyness of the option. With this expansion we show that for the Dow Jones Euro Stoxx 50 option data, a Delta-hedging strategy is close to being optimal.
Self-similar expansion of a warm dense plasma
Djebli, Mourad [USTHB, Faculty of Physics, Theoretical Physics Laboratory, B.P. 32 Bab-Ezzouar, 16079 Algiers (Algeria)] [USTHB, Faculty of Physics, Theoretical Physics Laboratory, B.P. 32 Bab-Ezzouar, 16079 Algiers (Algeria); Moslem, Waleed M. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt)] [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt)
2013-07-15T23:59:59.000Z
The properties of an expanding plasma composed of degenerate electron fluid and non-degenerate ions are studied. For our purposes, we use fluid equations for ions together with the electron momentum equation that include quantum forces (e.g., the quantum statistical pressure, forces due to the electron-exchange and electron correlations effects) and the quasi-neutrality condition. The governing equation is written in a tractable form by using a self-similar transformation. Numerical results for typical beryllium plasma parameters revealed that, during the expansion, the ion acoustic speed decreases for both isothermal and adiabatic ion pressure. When compared with classical hydrodynamic plasma expansion model, the electrons and ions are found to initially escape faster in vacuum creating thus an intense electric field that accelerates most of the particles into the vacuum ahead of the plasma expansion. The relevancy of the present model to beryllium plasma produced by a femto-second laser is highlighted.
Locally smeared operator product expansions in scalar field theory
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Monahan, Christopher J.; Orginos, Kostas
2015-04-01T23:59:59.000Z
We propose a new locally smeared operator product expansion to decompose non-local operators in terms of a basis of smeared operators. The smeared operator product expansion formally connects nonperturbative matrix elements determined numerically using lattice field theory to matrix elements of non-local operators in the continuum. These nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, which significantly complicates calculations of quantities such as the moments of parton distribution functions, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale complicates the connection to the Wilson coefficients of the standardmore »operator product expansion and requires the construction of a suitable formalism. We demonstrate the feasibility of our approach with examples in real scalar field theory.« less
Overlapping Community Detection Using Neighborhood-Inflated Seed Expansion
Whang, Joyce Jiyoung; Dhillon, Inderjit S
2015-01-01T23:59:59.000Z
Community detection is an important task in network analysis. A community (also referred to as a cluster) is a set of cohesive vertices that have more connections inside the set than outside. In many social and information networks, these communities naturally overlap. For instance, in a social network, each vertex in a graph corresponds to an individual who usually participates in multiple communities. In this paper, we propose an efficient overlapping community detection algorithm using a seed expansion approach. The key idea of our algorithm is to find good seeds, and then greedily expand these seeds based on a community metric. Within this seed expansion method, we investigate the problem of how to determine good seed nodes in a graph. In particular, we develop new seeding strategies for a personalized PageRank clustering scheme that optimizes the conductance community score. Experimental results show that our seed expansion algorithm outperforms other state-of-the-art overlapping community detection meth...
Schilling, O; Latini, M
2010-01-12T23:59:59.000Z
The dynamics of the reshocked multi-mode Richtmyer-Meshkov instability is investigated using 513 x 257{sup 2} three-dimensional ninth-order weighted essentially nonoscillatory shock-capturing simulations. A two-mode initial perturbation with superposed random noise is used to model the Mach 1.5 air/SF{sub 6} Vetter-Sturtevant shock tube experiment. The mass fraction and enstrophy isosurfaces, and density cross-sections are utilized to show the detailed flow structure before, during, and after reshock. It is shown that the mixing layer growth agrees well with the experimentally measured growth rate before and after reshock. The post-reshock growth rate is also in good agreement with the prediction of the Mikaelian model. A parametric study of the sensitivity of the layer growth to the choice of amplitudes of the short and long wavelength initial interfacial perturbation is also presented. Finally, the amplification effects of reshock are quantified using the evolution of the turbulent kinetic energy and turbulent enstrophy spectra, as well as the evolution of the baroclinic enstrophy production, buoyancy production, and shear production terms in the enstrophy and turbulent kinetic transport equations.
Glass ceramics for sealing to high-thermal-expansion metals
Wilder, Jr., J. A.
1980-10-01T23:59:59.000Z
Glass ceramics were studied, formulated in the Na/sub 2/O CaO.P/sub 2/O/sub 5/, Na/sub 2/O.BaOP/sub 2/O/sub 5/, Na/sub 2/O.Al/sub 2/O/sub 3/.P/sub 2/O/sub 5/, and Li/sub 2/O.BaO.P/sub 2/O/sub 5/ systems to establish their suitability for sealing to high thermal expansion metals, e.g. aluminum, copper, and 300 series stainless steels. Glass ceramics in Na/sub 2/O.CaO.P/sub 2/O/sub 5/ and Na/sub 2/O.BaO.P/sub 2/O/sub 5/ systems have coefficients of thermal expansion in the range 140 x 10/sup -1/ per /sup 0/C less than or equal to ..cap alpha.. less than or equal to 225 x 10/sup -7/ per /sup 0/C and fracture toughness values generally greater than those of phosphate glasses; they are suitable for fabricating seals to high thermal expansion metals. Crystal phases include NaPo/sub 3/, (NaPO/sub 3/)/sub 3/, NaBa(PO/sub 3/)/sub 3/, and NaCa(PO/sub 3/)/sub 3/. Glass ceramics formed in the Na/sub 2/O.Al/sub 2/O/sub 3/.P/sub 2/O/sub 5/ systems have coefficients of thermal expansion greater than 240 x 10/sup -7/ per /sup 0/C, but they have extensive microcracking. Due to their low thermal expansion values (..cap alpha.. less than or equal to 120 x 10/sup -7/ per /sup 0/C), glass ceramics in the Li/sub 2/O.BaO.P/sub 2/O/sub 5/ system are unsuitable for sealing to high thermal expansion metals.
Proton polarizabilities from polarized Compton scattering: low-energy expansion
Nadiia Krupina
2014-05-06T23:59:59.000Z
We reexamine the low-energy expansion of polarized Compton scattering off the proton and show that the leading non-Born contribution to the beam asymmetry of low-energy Compton scattering is given by the magnetic polarizability alone, the electric polarizability cancels out. Based on this fact we propose to determine the magnetic dipole polarizability of the proton from the beam asymmetry. We also present the low-energy expansion of doubly-polarized observables, from which the spin polarizabilities can be extracted.
Perturbative exponential expansion and matter neutrino oscillations
A. D. Supanitsky; J. C. D'Olivo; G. Medina-Tanco
2008-10-13T23:59:59.000Z
We derive an analytical description of neutrino oscillations in matter based on the Magnus exponential representation of the time evolution operator. Our approach is valid in a wide range of the neutrino energies and properly accounts for the modifications that the respective probability transitions suffer when neutrinos originated in different sources traverse the Earth. The present approximation considerably improves over other perturbative treatments existing in the current literature. Furthermore, the analytical expressions derived inside the Magnus framework are remarkably simple, which facilitates their practical use. When applied to the calculation of the day-night asymmetry in the solar neutrino flux our result reproduces the numerical calculation with an accuracy better than 1% for the first order approximation. When the approximation is extended to the second order, the accuracy of the method is further improved by almost one order of magnitude, and it is still better than 5% even for neutrino energies as large as 100 MeV. In the GeV regime characteristic of atmospheric and accelerator neutrinos this accuracy is complemented by a good reproduction of the position of the maxima in the flavor transition probabilities.
A new approach to gravitational clustering: a path-integral formalism and large-N expansions
P. Valageas
2004-07-01T23:59:59.000Z
We show that the formation of large-scale structures through gravitational instability in the expanding universe can be fully described through a path-integral formalism. We derive the action S[f] which gives the statistical weight associated with any phase-space distribution function f(x,p,t). This action S describes both the average over the Gaussian initial conditions and the Vlasov-Poisson dynamics. Next, applying a standard method borrowed from field theory we generalize our problem to an N-field system and we look for an expansion over powers of 1/N. We describe three such methods and we derive the corresponding equations of motion at the lowest non-trivial order for the case of gravitational clustering. This yields a set of non-linear equations for the mean $\\fb$ and the two-point correlation G of the phase-space distribution f, as well as for the response function R. These systematic schemes match the usual perturbative expansion on quasi-linear scales but should also be able to handle the non-linear regime. Our approach can also be extended to non-Gaussian initial conditions and may serve as a basis for other tools borrowed from field theory.
Expansion and Growth of Structure Observables in a Macroscopic Gravity Averaged Universe
Wijenayake, Tharake
2015-01-01T23:59:59.000Z
We investigate the effect of averaging inhomogeneities on expansion and large-scale structure growth observables using the exact and covariant framework of Macroscopic Gravity (MG). It is well-known that applying the Einstein's equations and spatial averaging do not commute and lead to the averaging problem. For the MG formalism applied to the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, this gives an extra dynamical term encapsulated as an averaging density parameter denoted $\\Omega_A$. An exact isotropic cosmological solution of MG for the flat FLRW metric is already known in the literature, we derive here an anisotropic exact solution. Using the isotropic solution, we compare the expansion history to current data of distances to supernovae, Baryon Acoustic Oscillations, CMB last scattering surface, and Hubble constant measurements, and find $-0.05 \\le \\Omega_A \\le 0.07$ (at the 95% CL). For the flat metric case this reduces to $-0.03 \\le \\Omega_A \\le 0.05$. We also find that the inclusion of this ter...
Comoving to expansion Newtonian potential of galaxies and clusters instead of dark matter
Zahid Zakir
2014-08-04T23:59:59.000Z
Stretching of the Newtonian potential (NP) at early epochs is investigated and it is shown that observed effects, usually ascribed to a dark matter, can by explained by such stretching only. Increasing by time radius of the gravitationally-bound region (GBR) and conservation of gravitational energy lead to a new scenario in which values of NP in expanding volume are maintained, while in physical volume are stretched. Really, the energy conservation in expanding volume requires for NP values to be comoving to the expanding shells. In addition, the radius of gravitationally-bound region increases by time due to decreasing of expansion velocity and different shells around galaxy cease expansion at different times. Thus, as far a shell placed from galaxy, as longer it was expanded and thickened, while potential difference on its boundaries remained unchanged. This shifts the values of NP around galaxy proportional to the distance r and, as the result, the gravitational acceleration, from NP's $1/r^2$ dependence, turned to 1/r dependence, as for centrifugal acceleration. This fact naturally explains the known empirical facts, such as flatness of rotation curves and velocity-mass relationships for galaxies and velocity dispersion in clusters.
Wang, Deli
Clean Energy Alliance Expansion Continues http://www.mmdnewswire.com/pdf-86054/clean-energy-alliance-expansion-continues.pdf[2/3/2012 12:13:14 PM] Clean Energy Alliance Expansion Continues UCSD and Chicago Members Expand CEA's Geographic Reach Golden, CO (MMD Newswire) February 1, 2012 -- Clean Energy Alliance, Inc. (CEA
Waslylenko, Walter; Frei, Heinz
2007-01-31T23:59:59.000Z
Propylene hydrogenation over Pt nanoparticles supported onmesoporous silica type SBA-15 was monitored by time-resolved FT-IRspectroscopy at 23 ms resolution using short propylene gas pulses thatjoined a continuous flow of hydrogen in N2 (1 atm total pressure).Experiments were conducted in the temperature range 323-413 K. Propanewas formed within 100 milliseconds or faster. The CH stretching regionrevealed distinct bands for propane molecules emerging inside thenanoscale channels of the silica support. Spectral analysis gave thedistribution of the propane product between support and surrounding gasphase as function of time. Kinetic analysis showed that the escape ofpropane molecules from the channels occurred within hundreds ofmilliseconds (3.1 + 0.4 s-1 at 383 K). A steady state distribution ofpropane between gas phase and mesoporous support is established as theproduct is swept from the catalyst zone by the continuous flow ofhydrogen co-reactant. This is the first direct spectroscopic observationof emerging products of heterogeneous catalysis on nanoporous supportsunder reaction conditions.
Single-enzyme kinetics with branched pathways: exact theory and series expansion
Ashok Garai; Debashish Chowdhury
2014-12-10T23:59:59.000Z
The progress of the successive rounds of catalytic conversion of substrates into product(s) by a single enzyme is characterized by the distribution of turnover times. Establishing the most general form of dependence of this distribution on the substrate concentration [S] is one of the fundamental challenges in single molecule enzymology. The distribution of the times of dwell of a molecular motor at the successive positions on its track is an analogous quantity. We derive approximate series expansions for the [ATP]-dependence of the first two moments of the dwell time distributions of motors that catalyze hydrolysis of ATP to draw input energy. Comparison between our results for motors with branched pathways and the corresponding expressions reported earlier for linear enzymatic pathways provides deep insight into the effects of the branches. Such insight is likely to help in discovering the most general form of [S]-dependence of these fundamental distributions.
Right tail expansion of Tracy-Widom beta laws
Gaëtan Borot; Céline Nadal
2011-11-11T23:59:59.000Z
Using loop equations, we compute the large deviation function of the maximum eigenvalue to the right of the spectrum in the Gaussian beta matrix ensembles, to all orders in 1/N. We then give a physical derivation of the all order asymptotic expansion of the right tail Tracy-Widom beta laws, for all positive beta, by studying the double scaling limit.
Gradient expansion of superhorizon perturbations in G-inflation
Frusciante, Noemi; Zhou, Shuang-Yong; Sotiriou, Thomas P., E-mail: nfruscia@sissa.it, E-mail: szhou@sissa.it, E-mail: sotiriou@sissa.it [SISSA and INFN Sezione di Trieste, Via Bonomea 265, 34136, Trieste (Italy)
2013-07-01T23:59:59.000Z
We develop the gradient expansion formalism for shift-symmetric Galileon-type actions. We focus on backgrounds that undergo inflation, work in the synchronous gauge, and obtain a general solution up to second order without imposing extra conditions at first order. The solution simplifies during the late stages of inflation. We also define a curvature perturbation conserved up to first order.
Testing of Expansive Clays in a Centrifuge Permeameter
Zornberg, Jorge G.
Testing of Expansive Clays in a Centrifuge Permeameter M. D. Plaisted & J. G. Zornberg with the objective of characterizing the swelling of highly plastic clays using a centrifuge permeameter. The new. This study, conducted using a comparatively simple, non- instrumented centrifuge device complements ongo- ing
ORIGINAL PAPER Range expansion and prey use of American mink
Boyer, Edmond
ORIGINAL PAPER Range expansion and prey use of American mink in Argentinean Patagonia: dilemmas of American mink as an introduced species in Patagonia and elsewhere, together with our own survey, we discuss the implications of this invasion for biodiversity conservation in Argentinean Patagonia and the associated
YOKAYO BIOFUELS, INC. GRANT FOR IMPROVEMENTS AND EXPANSION OF
YOKAYO BIOFUELS, INC. GRANT FOR IMPROVEMENTS AND EXPANSION OF AN EXISTING FACILITY INITIAL STUDY-11-601) to expand an existing biofuels production facility (Yokayo Biofuels, Inc.) located at 350 Orr: THE PROPOSED PROJECT: Yokayo Biofuels, Inc. is an existing biofuels facility located at 350 Orr Springs Road
Sequence space and the ongoing expansion of the protein universe
Nachman, Michael
LETTERS Sequence space and the ongoing expansion of the protein universe Inna S. Povolotskaya1 whether these restrictions impose a global limit on how far homologous protein sequences can diverge from each other. Here we explore the limits of protein evolution using sequence divergence data. We
A Novel Visual Secret Sharing Scheme without Image Size Expansion
Heys, Howard
A Novel Visual Secret Sharing Scheme without Image Size Expansion Nazanin Askari, Cecilia Moloney. Visual cryptography is a secure secret sharing scheme that divides secret images into shares which on their own reveal no information of the original secret image. Recovery of the secret image can be performed
Ron Moon
2011-06-30T23:59:59.000Z
This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically, power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. The goal of the 'Recovery Act: Decreasing Data Center Energy Use through Network and Infrastructure Control' is to develop a state of the art approach for autonomously and intelligently reducing and managing data center power through real-time optimal control. Advances in microelectronics and software are enabling the opportunity to realize significant data center power savings through the implementation of autonomous power management control algorithms. The first step to realizing these savings was addressed in this study through the successful creation of a flexible and scalable mathematical model (equation) for data center behavior and the formulation of an acceptable low technical risk market introduction strategy leveraging commercial hardware and software familiar to the data center market. Follow-on Stage 3 Concept Development efforts include predictive modeling and simulation of algorithm performance, prototype demonstrations with representative data center equipment to verify requisite performance and continued commercial partnering agreement formation to ensure uninterrupted development, and deployment of the real-time optimal control algorithm. As a software implementable technique for reducing power consumption, the RTOC has two very desirable traits supporting rapid prototyping and ultimately widespread dissemination. First, very little capital is required for implementation. No major infrastructure modifications are required and there is no need to purchase expensive capital equipment. Second, the RTOC can be rolled out incrementally. Therefore, the effectiveness can be proven without a large scale initial roll out. Through the use of the Impact Projections Model provided by the DOE, monetary savings in excess of $100M in 2020 and billions by 2040 are predicted. In terms of energy savings, the model predicts a primary energy displacement of 260 trillion BTUs (33 trillion kWh), or a 50% reduction in server power consumption. The model also predicts a corresponding reduction of pollutants such as SO2 and NOx in excess of 100,000 metric tonnes assuming the RTOC is fully deployed. While additional development and prototyping is required to validate these predictions, the relative low cost and ease of implementation compared to large capital projects makes it an ideal candidate for further investigation.
hal-00123470,version1-9Jan2007 Expansion of a lithium gas in the BEC-BCS crossover
Paris-Sud XI, Université de
hal-00123470,version1-9Jan2007 Expansion of a lithium gas in the BEC-BCS crossover L. Tarruell1 , M an experimental study of the time of flight properties of a gas of ultra-cold fermions in the BEC-BCS crossover. Since interactions can be tuned by changing the value of the magnetic field, we are able to probe both
Expansion of Facilities on the North Slope of Alaska in Time for the
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist. Category UC-l 1,Energy Consumers | Department ofa
N-body Lyapunov expansion rates in one component strongly coupled plasmas
Ueshima, Y.; Nishihara, K.; Barnett, D.M.; Tajima, T.; Furukawa, H. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565 (Japan)
1996-05-01T23:59:59.000Z
Phase space Lyapunov expansion rates are measured for the first time for Coulomb many body systems with the use of a 3-{ital d} particle code. The time averaged Lyapunov exponents, {lambda}/{omega}{sub {ital p}}, are found to be proportional to {Gamma}{sup {minus}2/5} and the cubic root of the diffusion coefficient in the range of 1{lt}{Gamma}{lt}160, where {omega}{sub {ital p}} and {Gamma} are plasma frequency and ion coupling constant, respectively. A large jump of the averaged Lyapunov exponent is observed near {Gamma}{approximately}170, corresponding to the phase transition from liquid to solid. Instantaneous Lyapunov exponent has chaotic behavior and consists of three different spectra, flat, {ital f}{sup {minus}2} and {ital f}{sup {minus}1}. {copyright} {ital 1996 American Institute of Physics.}
Generalized $f(R,?,X)$ gravity and the late-time cosmic acceleration
Sebastian Bahamonde Beltran; Christian G. Boehmer; Francisco S. N. Lobo; Diego Saez-Gomez
2015-06-25T23:59:59.000Z
High-precision observational data have confirmed with startling evidence that the Universe is currently undergoing a phase of accelerated expansion. This phase, one of the most important and challenging current problems in cosmology, represents a new imbalance in the governing gravitational equations. Historically, physics has addressed such imbalances by either identifying sources that were previously unaccounted for, or by altering the gravitational theory. Several candidates, responsible for this expansion, have been proposed in the literature, in particular, dark energy models and modified gravity models, amongst others. Outstanding questions are related to the nature of this so-called "dark energy" that is driving this acceleration, and whether it is due to the vacuum energy or a dynamical field. On the other hand, the late-time cosmic acceleration may be due to modifications of General Relativity. In this work we explore a generalised modified gravity theory, namely $f(R,\\phi,X)$ gravity, where $R$ is the Ricci scalar, $\\phi$ is a scalar field, and $X$ is a kinetic term. This theory contains a wide range of dark energy and modified gravity models. We considered specific models and applications to the late-time cosmic acceleration.
The Elusive Coefficients of Thermal Expansion in PBX 9502
C.B. Skidmore; T.A. Butler; C.W. Sandoval
2003-05-01T23:59:59.000Z
PBX 9502 has been in war reserve service for over two decades. Ninety-five percent of the solid phase of this insensitive high explosive is composed of energetic crystallites designated as TATB (1,3,5-triamino-2,4,6-trinitrobenzene), held together by the remaining solid fraction--an inert, polymeric binder named Kel-F 800. The unusual combination of extreme insensitivity and adequate performance characteristics is not the only enigmatic feature of such TATB-based materials. In this report, we describe the difficulty and progress to date in reliably determining the coefficients of thermal expansion for consolidated components of PBX 9502. We provide bulk linear coefficient of thermal expansion (CTE) values for PBX 9502 consolidated to a density of approximately 1.890 g/cm{sup 3} and offer a simple set of equations for calculating dimensional changes for temperatures from 218 to 347 K (-55 C to 74 C).
Multipole expansions in four-dimensional hyperspherical harmonics
A. V. Meremianin
2006-06-27T23:59:59.000Z
The technique of vector differentiation is applied to the problem of the derivation of multipole expansions in four-dimensional space. Explicit expressions for the multipole expansion of the function $r^n C_j (\\hr)$ with $\\vvr=\\vvr_1+\\vvr_2$ are given in terms of tensor products of two hyperspherical harmonics depending on the unit vectors $\\hr_1$ and $\\hr_2$. The multipole decomposition of the function $(\\vvr_1 \\cdot \\vvr_2)^n$ is also derived. The proposed method can be easily generalised to the case of the space with dimensionality larger than four. Several explicit expressions for the four-dimensional Clebsch-Gordan coefficients with particular values of parameters are presented in the closed form.
Unitary Fermi gas, epsilon expansion, and nonrelativistic conformal field theories
Yusuke Nishida; Dam Thanh Son
2010-04-20T23:59:59.000Z
We review theoretical aspects of unitary Fermi gas (UFG), which has been realized in ultracold atom experiments. We first introduce the epsilon expansion technique based on a systematic expansion in terms of the dimensionality of space. We apply this technique to compute the thermodynamic quantities, the quasiparticle spectrum, and the critical temperature of UFG. We then discuss consequences of the scale and conformal invariance of UFG. We prove a correspondence between primary operators in nonrelativistic conformal field theories and energy eigenstates in a harmonic potential. We use this correspondence to compute energies of fermions at unitarity in a harmonic potential. The scale and conformal invariance together with the general coordinate invariance constrains the properties of UFG. We show the vanishing bulk viscosities of UFG and derive the low-energy effective Lagrangian for the superfluid UFG. Finally we propose other systems exhibiting the nonrelativistic scaling and conformal symmetries that can be in principle realized in ultracold atom experiments.
Experiences using DAKOTA stochastic expansion methods in computational simulations.
Templeton, Jeremy Alan; Ruthruff, Joseph R.
2012-01-01T23:59:59.000Z
Uncertainty quantification (UQ) methods bring rigorous statistical connections to the analysis of computational and experiment data, and provide a basis for probabilistically assessing margins associated with safety and reliability. The DAKOTA toolkit developed at Sandia National Laboratories implements a number of UQ methods, which are being increasingly adopted by modeling and simulation teams to facilitate these analyses. This report disseminates results as to the performance of DAKOTA's stochastic expansion methods for UQ on a representative application. Our results provide a number of insights that may be of interest to future users of these methods, including the behavior of the methods in estimating responses at varying probability levels, and the expansion levels for the methodologies that may be needed to achieve convergence.
Theoretical model for plasma expansion generated by hypervelocity impact
Ju, Yuanyuan; Zhang, Qingming, E-mail: qmzhang@bit.edu.cn; Zhang, Dongjiang; Long, Renrong; Chen, Li; Huang, Fenglei [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Gong, Zizheng [National Key Laboratory of Science and Technology on Reliability and Environment Engineering, Beijing Institute of Spacecraft Environment Engineering, Beijing 100094 (China)
2014-09-15T23:59:59.000Z
The hypervelocity impact experiments of spherical LY12 aluminum projectile diameter of 6.4?mm on LY12 aluminum target thickness of 23?mm have been conducted using a two-stage light gas gun. The impact velocity of the projectile is 5.2, 5.7, and 6.3?km/s, respectively. The experimental results show that the plasma phase transition appears under the current experiment conditions, and the plasma expansion consists of accumulation, equilibrium, and attenuation. The plasma characteristic parameters decrease as the plasma expands outward and are proportional with the third power of the impact velocity, i.e., (T{sub e}, n{sub e})???v{sub p}{sup 3}. Based on the experimental results, a theoretical model on the plasma expansion is developed and the theoretical results are consistent with the experimental data.
Relational Dynamic Bayesian Networks
Domingos, P; Weld, D; 10.1613/jair.1625
2011-01-01T23:59:59.000Z
Stochastic processes that involve the creation of objects and relations over time are widespread, but relatively poorly studied. For example, accurate fault diagnosis in factory assembly processes requires inferring the probabilities of erroneous assembly operations, but doing this efficiently and accurately is difficult. Modeled as dynamic Bayesian networks, these processes have discrete variables with very large domains and extremely high dimensionality. In this paper, we introduce relational dynamic Bayesian networks (RDBNs), which are an extension of dynamic Bayesian networks (DBNs) to first-order logic. RDBNs are a generalization of dynamic probabilistic relational models (DPRMs), which we had proposed in our previous work to model dynamic uncertain domains. We first extend the Rao-Blackwellised particle filtering described in our earlier work to RDBNs. Next, we lift the assumptions associated with Rao-Blackwellization in RDBNs and propose two new forms of particle filtering. The first one uses abstracti...
ForPeerReview Cavity expansion in cross anisotropic rock
Wagner, Peter
for Numerical and Analytical Methods in Geomechanics Manuscript ID: NAG-10-0026.R1 Wiley - Manuscript type in Geomechanics #12;ForPeerReview Only Cavity expansion in cross-anisotropic rock Dimitrios Kolymbas Peter Wagner://mc.manuscriptcentral.com/nag International Journal for Numerical and Analytical Methods in Geomechanics 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Intermediate Vapor Expansion Distillation and Nested Enrichment Cascade Distillation
Erickson, D. C.
INTERMEDIATE VAPOR EXPANSION DISTILLATION AND NESTED ENRICHMENT CASCADE DISTILLATION D.. C. Erickson Energy Concepts Company Annapolis, Maryland ABSTRACT Although it is known that incorporating an intermediate reboiler or reflux... condenser in a distillation ~olumn will improve column efficiency by 15 to 100%, there has been little use of this technique to date." Intermediate vapor compression heat pumping was recently introduced as one practical means of achieving this benefit...
Adiabatic expansion and magnetic fields in AGN jets
A. B. Pushkarev; Y. Y. Kovalev; A. P. Lobanov
2008-12-25T23:59:59.000Z
Results of high-resolution simultaneous multi-frequency 8.1-15.4 GHz VLBA polarimetric observations of relativistic jets in active galactic nuclei (the MOJAVE-2 project) are analyzed. We compare characteristics of VLBI features with jet model predictions and test if adiabatic expansion is a dominating mechanism for the evolution of relativistic shocks in parsec-scale AGN jets. We also discuss magnetic field configuration, both predicted by the model and deduced from electric vector position angle measurements.
Single eta production in heavy quarkonia: breakdown of multipole expansion
Yu. A. Simonov; A. I. Veselov
2008-12-26T23:59:59.000Z
The $\\eta$ production in the $(n,n')$ bottomonium transitions $\\Upsilon (n) \\to \\Upsilon (n') \\eta, $ is studied in the method used before for dipion heavy quarkonia transitions. The widths $\\Gamma_\\eta(n,n')$ are calculated without fitting parameters for $n=2,3,4,5, n'=1$. Resulting $\\Gamma_\\eta(4,1)$ is found to be large in agreement with recent data. Multipole expansion method is shown to be inadequate for large size systems considered.
Comment on "Accelerating cosmological expansion from shear and bulk viscosity"
Giovannini, Massimo
2015-01-01T23:59:59.000Z
In a recent Letter [Phys. Rev. Lett. 114 091301 (2105)] the cause of the acceleration of the present Universe has been identified with the shear viscosity of an imperfect relativistic fluid even in the absence of any bulk viscous contribution. The gist of this comment is that the shear viscosity, if anything, can only lead to an accelerated expansion over sufficiently small scales well inside the Hubble radius.
An engineering geology analysis of home foundations on expansive clays
Castleberry, Joe Patterson
1974-01-01T23:59:59.000Z
Center Lift Model 70 14 Regression Analysis With Interactions End Lift Model 71 APPENDIX C C-1 Studies in Which Swelling Potential and Pressure Were Compared Against Several Soil Index Properties . . . . . . . . . 126 iX Table APPENDIX D Page.... environmental parameters. Studies directed toward light foundations on expansive soil have been limited to case histories of damaged structures, and, for most purposes, do little more than restate the problem. The Carter's &rove Addition, located...
Adaptive sparse polynomial chaos expansion based on least angle regression
Blatman, Geraud, E-mail: geraud.blatman@edf.f [Clermont Universite, IFMA, EA 3867, Laboratoire de Mecanique et Ingenieries, BP 10448, F-63000 Clermont-Ferrand (France); EDF R and D, Departement Materiaux et Mecanique des Composants, Site des Renardieres, 77250 Moret-sur-Loing cedex (France); Sudret, Bruno [Clermont Universite, IFMA, EA 3867, Laboratoire de Mecanique et Ingenieries, BP 10448, F-63000 Clermont-Ferrand (France); Phimeca Engineering, Centre d'Affaires du Zenith, 34 rue de Sarlieve, F-63800 Cournon d'Auvergne (France)
2011-03-20T23:59:59.000Z
Polynomial chaos (PC) expansions are used in stochastic finite element analysis to represent the random model response by a set of coefficients in a suitable (so-called polynomial chaos) basis. The number of terms to be computed grows dramatically with the size of the input random vector, which makes the computational cost of classical solution schemes (may it be intrusive (i.e. of Galerkin type) or non intrusive) unaffordable when the deterministic finite element model is expensive to evaluate. To address such problems, the paper describes a non intrusive method that builds a sparse PC expansion. First, an original strategy for truncating the PC expansions, based on hyperbolic index sets, is proposed. Then an adaptive algorithm based on least angle regression (LAR) is devised for automatically detecting the significant coefficients of the PC expansion. Beside the sparsity of the basis, the experimental design used at each step of the algorithm is systematically complemented in order to avoid the overfitting phenomenon. The accuracy of the PC metamodel is checked using an estimate inspired by statistical learning theory, namely the corrected leave-one-out error. As a consequence, a rather small number of PC terms are eventually retained (sparse representation), which may be obtained at a reduced computational cost compared to the classical 'full' PC approximation. The convergence of the algorithm is shown on an analytical function. Then the method is illustrated on three stochastic finite element problems. The first model features 10 input random variables, whereas the two others involve an input random field, which is discretized into 38 and 30 - 500 random variables, respectively.
Tennessee, University of
Quantum distillation: Dynamical generation of low-entropy states of strongly correlated fermions of double occupancies. We promote the notion of quantum distillation: during the expansion and in the case
Mastering Uncertainty and Risk at Multiple Time Scales in the Future Electrical Grid
Chertkov, Michael [Los Alamos National Laboratory; Bent, Russell W. [Los Alamos National Laboratory; Backhaus, Scott N. [Los Alamos National Laboratory
2012-07-10T23:59:59.000Z
Today's electrical grids enjoy a relatively clean separation of spatio-temporal scales yielding a compartmentalization of grid design, optimization, control and risk assessment allowing for the use of conventional mathematical tools within each area. In contrast, the future grid will incorporate time-intermittent renewable generation, operate via faster electrical markets, and tap the latent control capability at finer grid modeling scales; creating a fundamentally new set of couplings across spatiotemporal scales and requiring revolutionary advances in mathematics techniques to bridge these scales. One example is found in decade-scale grid expansion planning in which today's algorithms assume accurate load forecasts and well-controlled generation. Incorporating intermittent renewable generation creates fluctuating network flows at the hourly time scale, inherently linking the ability of a transmission line to deliver electrical power to hourly operational decisions. New operations-based planning algorithms are required, creating new mathematical challenges. Spatio-temporal scales are also crossed when the future grid's minute-scale fluctuations in network flows (due to intermittent generation) create a disordered state upon which second-scale transient grid dynamics propagate effectively invalidating today's on-line dynamic stability analyses. Addressing this challenge requires new on-line algorithms that use large data streams from new grid sensing technologies to physically aggregate across many spatial scales to create responsive, data-driven dynamic models. Here, we sketch the mathematical foundations of these problems and potential solutions.
On Perturbation theory improved by Strong coupling expansion
Masazumi Honda
2014-10-13T23:59:59.000Z
In theoretical physics, we sometimes have two perturbative expansions of physical quantity around different two points in parameter space. In terms of the two perturbative expansions, we introduce a new type of smooth interpolating function consistent with the both expansions, which includes the standard Pad\\'e approximant and fractional power of polynomial method constructed by Sen as special cases. We point out that we can construct enormous number of such interpolating functions in principle while the "best" approximation for the exact answer of the physical quantity should be unique among the interpolating functions. We propose a criterion to determine the "best" interpolating function, which is applicable except some situations even if we do not know the exact answer. It turns out that our criterion works for various examples including specific heat in two-dimensional Ising model, average plaquette in four-dimensional SU(3) pure Yang-Mills theory on lattice and free energy in c=1 string theory at self-dual radius. We also mention possible applications of the interpolating functions to system with phase transition.
SEMI-ANNUAL REPORTS FOR FREEPORT LNG EXPANSION, L.P. & FLNG LIQUEFACTI...
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Dodds, Walter
The expansion of woody riparian vegetation, and subsequent stream restoration, influences, the restoration allowed recovery of some features of open-canopy prairie streams. Woody expansion apparently. Keywords: macroalgae, microalgae, primary production, restoration, streams Introduction North American
Freeport LNG Expansion, L.P. and FLNG Liquefaction, LLC - FE...
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Freeport LNG Expansion, L.P. and FLNG Liquefaction, LLC - FE Dkt. No. 11-161-LNG Freeport LNG Expansion, L.P. and FLNG Liquefaction, LLC - FE Dkt. No. 11-161-LNG On November 15,...
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Lind, Douglas A.
EXPANSIVE SUBDYNAMICS FOR ALGEBRAIC Z d ÂACTIONS MANFRED EINSIEDLER, DOUGLAS LIND, RICHARD MILES spaces was proposed by Boyle and Lind in terms of expansive behavior along lowerÂdimensional subspaces
Lind, Douglas A.
EXPANSIVE SUBDYNAMICS FOR ALGEBRAIC Zd-ACTIONS MANFRED EINSIEDLER, DOUGLAS LIND, RICHARD MILES spaces was proposed by Boyle and Lind in terms of expansive behavior along lower-dimensional subspaces
Luscher, Darby J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-05-08T23:59:59.000Z
We detail a modeling approach to simulate the anisotropic thermal expansion of polycrystalline (1,3,5-triamino-2,4,6-trinitrobenzene) TATB-based explosives that utilizes microstructural information including porosity, crystal aspect ratio, and processing-induced texture. This report, the first in a series, focuses on nonlinear thermal expansion of “neat-pressed” polycrystalline TATB specimens which do not contain any binder; additional complexities related to polymeric binder and irreversible ratcheting behavior are briefly discussed, however detailed investigation of these aspects are deferred to subsequent reports. In this work we have, for the first time, developed a mesoscale continuum model relating the thermal expansion of polycrystal TATB specimens to their microstructural characteristics. A self-consistent homogenization procedure is used to relate macroscopic thermoelastic response to the constitutive behavior of single-crystal TATB. The model includes a representation of grain aspect ratio, porosity, and crystallographic texture attributed to the consolidation process. A quantitative model is proposed to describe the evolution of preferred orientation of graphitic planes in TATB during consolidation and an algorithm constructed to develop a discrete representation of the associated orientation distribution function. Analytical and numerical solutions using this model are shown to produce textures consistent with previous measurements and characterization for isostatic and uniaxial “die-pressed” specimens. Predicted thermal strain versus temperature for textured specimens are shown to be in agreement with corresponding experimental measurements. Using the developed modeling approach, several simulations have been run to investigate the influence of microstructure on macroscopic thermal expansion behavior. Results from these simulations are used to identify qualitative trends. Implications of the identified trends are discussed in the context of thermal deformation of engineered components whose consolidation process is generally more complex than isostatic or die-pressed specimens. Finally, an envisioned application of the modeling approach to simulating thermal expansion of weapon systems and components is outlined along with necessary future work to introduce the effects of binder and ratcheting behavior. Key conclusions from this work include the following. Both porosity and grain aspect ratio have an influence on the thermal expansion of polycrystal TATB considering realistic material variability. Thepreferred orientation of the single crystal TATB [001] poles within a polycrystal gives rise to pronounced anisotropy of the macroscopic thermal expansion. The extent of this preferred orientation depends on the magnitude of deformation, and consequently, is expected to vary spatially throughout manufactured components much like porosity. The modeling approach presented here has utility toward bringing spatially variable microstructural features into macroscale system engineering modelsAbstract Not Provided
Energy recovery during expansion of compressed gas using power plant low-quality heat sources
Ochs, Thomas L. (Albany, OR); O'Connor, William K. (Lebanon, OR)
2006-03-07T23:59:59.000Z
A method of recovering energy from a cool compressed gas, compressed liquid, vapor, or supercritical fluid is disclosed which includes incrementally expanding the compressed gas, compressed liquid, vapor, or supercritical fluid through a plurality of expansion engines and heating the gas, vapor, compressed liquid, or supercritical fluid entering at least one of the expansion engines with a low quality heat source. Expansion engines such as turbines and multiple expansions with heating are disclosed.
Incomplete beta-function expansions of the solutions to the confluent Heun equation
Artur Ishkhanyan
2009-09-09T23:59:59.000Z
Several expansions of the solutions to the confluent Heun equation in terms of incomplete Beta functions are constructed. A new type of expansion involving certain combinations of the incomplete Beta functions as expansion functions is introduced. The necessary and sufficient conditions when the derived expansions are terminated, thus generating closed-form solutions, are discussed. It is shown that termination of a Beta-function series solution always leads to a solution that is necessarily an elementary function.
Ambient gas effects on the dynamics of laser-produced tin plume expansion
Harilal, S S; O'Shay, B; Tillac, M S; Tao, Y
2006-01-01T23:59:59.000Z
mitigation in a laser-produced tin plasma is one of the mostambient pressure, the tin species with kinetic Downloaded 19Sn + species ejected by the tin plume exhibits a Downloaded
Zheng, M.; Kong, F.; Han, Z.; Liu, W.
2006-01-01T23:59:59.000Z
better heat exchanger ability caused by the larger surface of sheet ice, steady and low chilled water temperature was directly extracted from an ice storage tank. The longitudinal and axial fin-added coils improved the COP of the refrigerating unit...
Dynamics of laser-blow-off induced Li plume in confined geometry
Kumar, Bhupesh; Singh, R K; Kumar, Ajai [Institute for Plasma Research, Bhat, Gandhinagar-382 428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar-382 428 (India)
2013-08-15T23:59:59.000Z
Dynamics of Li plasma plume created by laser-blow-off technique in air ambient is reported. Plasma plume dynamics and its optical emission are investigated in planar and confined geometries using time resolved shadowgraph imaging and optical emission spectroscopy. Significant differences in the plasma characteristics in confined geometry are quantitatively investigated by comparing the plasma parameters (temperature and density) in free expansion and confined geometry configurations. Dynamics and physical parameters of the primary as well as the reflected shock waves (in confined geometry) and their interactions with expanding plasma are briefly addressed. A large enhancement in the emission intensities of Li I 610.3 nm (2p {sup 2}P{sub 1/2,3/2}? 3d {sup 2}P{sub 3/2,5/2}) and 670.8 nm (2s {sup 2}S{sub 1/2}? 2p {sup 2}P{sub 1/2,3/2}) is correlated with the shock wave dynamics in the two geometries. Strong self reversal in the neutral emission infers an increase in the population density of neutrals within the confined plasma plume.
Asymptotic expansions in n-1 percolation critical values on the n-cube and Zn
Slade, Gordon
Hofstad Gordon Slade October 19, 2004 Abstract We use the lace expansion to prove that the critical values.4) was reported in [12], but with no rigorous bound on the remainder. We expect that the full asymptotic expansion is based on the lace expansion and follows the same general approach as that used for the connective
Multipole expansion for inclusions in a lamellar phase M. S. Turner1,2
Sens, Pierre
Multipole expansion for inclusions in a lamellar phase M. S. Turner1,2 and P. Sens3 1 Department the ordering of nearby layers. We argue that a multipole expansion for this distortion represents a powerful a multipole expansion. We argue that this represents a powerful technique as it allows us to extract the far
TRANSMISSION EXPANSION PLANNING WITH RE-DESIGN A Greedy Randomized Adaptive Search Procedure
Paris-Sud XI, Université de
for the managing entity to change the electrical power system, adding new transmission lines and power generatorsTRANSMISSION EXPANSION PLANNING WITH RE-DESIGN A Greedy Randomized Adaptive Search Procedure Rosa: TRANSMISSION EXPANSION PLANNING: NETWORK DESIGN: GRASP. Abstract: Transmission expansion planning with re
On the modular structure of the genus-one Type II superstring low energy expansion
Eric D'Hoker; Michael B. Green; Pierre Vanhove
2015-02-24T23:59:59.000Z
The analytic contribution to the low energy expansion of Type II string amplitudes at genus-one is a power series in space-time derivatives with coefficients that are determined by integrals of modular functions over the complex structure modulus of the world-sheet torus. These modular functions are associated with world-sheet vacuum Feynman diagrams and given by multiple sums over the discrete momenta on the torus. In this paper we exhibit exact differential and algebraic relations for a certain infinite class of such modular functions by showing that they satisfy Laplace eigenvalue equations with inhomogeneous terms that are polynomial in non-holomorphic Eisenstein series. Furthermore, we argue that the set of modular functions that contribute to the coefficients of interactions up to order D**10 R*4 are linear sums of functions in this class and quadratic polynomials in Eisenstein series and odd Riemann zeta values. Integration over the complex structure results in coefficients of the low energy expansion that are rational numbers multiplying monomials in odd Riemann zeta values.
Expansion-contraction cycles for cement optimized as a function of additives
Talabani, S.; Hareland, G. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)
1995-12-31T23:59:59.000Z
An experimental study was carried out to investigate the addition of specific additives to cement in order to eliminate the micro-fractures and micro-annuli that cause gas migration. The experiments performed monitored the change in the cement slurry pressure during the setting of the cement. During the setting period of the cement, two time cycles of cement expansion and contraction were observed. This is due to the individual contributions of each part of the cement mixture. To obtain the optimum tightness of the cement, final optimum concentrations of the additives were obtained experimentally, where the cyclic pressure behavior of the cement was optimized for the best final cement results. By utilizing the correct amount of Anchorage Clay, XC-Polymer, Ironite Scavenger, Ultrafine cement and Synthetic Rubber powder in a class G mixture at a given temperature and confining pressure, an impermeable cement mixture can be obtained. The correct amount of Synthetic Rubber used for cyclic pressure reduction is a function of cement setting temperature and pressure as well as the elastic properties of the rubber. By using laboratory testing at different pressure and temperature with different rubber concentrations and elastic properties, it is estimated that the entire annulus can have an impermeable cement from surface to total depth. The difference in temperature and pressure with depth dictates the concentration and elastic properties of the rubber as the required expansion and contraction changes with depth.
On the modular structure of the genus-one Type II superstring low energy expansion
Eric D'Hoker; Michael B. Green; Pierre Vanhove
2015-06-03T23:59:59.000Z
The analytic contribution to the low energy expansion of Type II string amplitudes at genus-one is a power series in space-time derivatives with coefficients that are determined by integrals of modular functions over the complex structure modulus of the world-sheet torus. These modular functions are associated with world-sheet vacuum Feynman diagrams and given by multiple sums over the discrete momenta on the torus. In this paper we exhibit exact differential and algebraic relations for a certain infinite class of such modular functions by showing that they satisfy Laplace eigenvalue equations with inhomogeneous terms that are polynomial in non-holomorphic Eisenstein series. Furthermore, we argue that the set of modular functions that contribute to the coefficients of interactions up to order D**10 R*4 are linear sums of functions in this class and quadratic polynomials in Eisenstein series and odd Riemann zeta values. Integration over the complex structure results in coefficients of the low energy expansion that are rational numbers multiplying monomials in odd Riemann zeta values.
Lateral Expansion of the Bridges of Cygnus A and other Powerful Radio Sources
Greg F. Wellman; Ruth A. Daly
1995-07-25T23:59:59.000Z
Measurements of the width of the radio bridge at several locations along the bridge for each of four powerful extended radio sources are presented. Adopting a few simple assumptions, these measurements may be used to predict the radio surface brightness as a function of position across the radio bridge. The predicted and observed surface brightnesses across the bridges are compared and found to agree fairly well. The results are consistent with a simple picture in which the radio power and size of the radio lobe at the forward edge of the radio bridge are roughly time-independent for a given source, and the expansion of the bridge in the lateral direction is adiabatic. There is no indication that reacceleration or energy transport is important in the bridges of these sources. The rate of lateral expansion of the bridge just behind the radio lobe and hotspot in terms of the rate of forward propagation is compared with that predicted, and found to be in good agreement with the predicted value.
Evaluating transport coefficients in real time thermal field theory
S. Mallik; Sourav Sarkar
2012-11-12T23:59:59.000Z
Transport coefficients in a hadronic gas have been calculated earlier in the imaginary time formulation of thermal field theory. The steps involved are to relate the defining retarded correlation function to the corresponding time-ordered one and to evaluate the latter in the conventional perturbation expansion. Here we carry out both the steps in the real time formulation.
A Note on Tubular Brane Dynamics
Jose J. Blanco-Pillado
2005-04-19T23:59:59.000Z
We present new time dependent solutions for the dynamics of tubular D2-branes. We comment on the connection to cosmic string dynamics and explicitly give a few simple examples of oscillating and rotating brane configurations.
Real-time dynamics for interactive environments
Timchenko, Alexander Nikolai
2009-05-15T23:59:59.000Z
. Additionally, we will consider the joint torque Qi as an actuator torque acting internally. The state for a single articulated structure can be determined by 20 the collection of these angles, their velocities, accelerations, and torques. These are designated..., for his help and guidance with this thesis; Dr. Frederic Parke for the Immersive Visualization Project at Texas A&M University and his help with the immersive engine; and Dr. John Keyser for introducing me to physically based simulation. I would also like...
Real-time dynamics for interactive environments
Timchenko, Alexander Nikolai
2008-10-10T23:59:59.000Z
. Additionally, we will consider the joint torque Qi as an actuator torque acting internally. The state for a single articulated structure can be determined by 20 the collection of these angles, their velocities, accelerations, and torques. These are designated..., for his help and guidance with this thesis; Dr. Frederic Parke for the Immersive Visualization Project at Texas A&M University and his help with the immersive engine; and Dr. John Keyser for introducing me to physically based simulation. I would also like...
Long Time Dynamic Simulations: Exploring the
Straub, John E.
, Boston University, Boston, Massachusetts 02215, Escuela de Ciencia y Tecnologia, Universidad de San
Fast Valuation and Calibration of Credit Default Swaps Under Levy Dynamics
Oosterlee, Cornelis W. "Kees"
Fast Valuation and Calibration of Credit Default Swaps Under L´evy Dynamics Fang Fang , Henrik J. The method presented is based on the Fourier-cosine series expansion of the underlying model's density. Having a method to generate dynamic CDS spreads available, it is also possible to value so called
2013-01-01T23:59:59.000Z
#12;THE JOURNAL OF CHEMICAL PHYSICS 139, 175101 (2013) Dynamic neutron scattering from, a conformational dynamics theory of dynamical neutron and X-ray scattering is developed, follow- ing our previous spectroscopy (dynamic neutron scattering) probes time correlations on the sub pico- to microsec- ond timescales
Life originated during accelerating expansion in the multiverse
Pedro F. Gonzalez-Diaz
2009-08-22T23:59:59.000Z
It is argued that all notions associated with the origin of life should be related with the participatory anthropic principle of Wheeler and must be extended into the realm of the multiverse. Also discussed is the notion that life can only be possible in a given universe during a finite period along which such a universe expands in an accelerated fashion. We advance finally the idea that life, cosmic accelerated expansion and quantum theory are nothing but three distinct faces from a single, unique coin which describes the physical reality.
EIA - Natural Gas Pipeline Network - Expansion Process Flow Diagram
Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40Coal Stocks at1,066,688 760,877 951,322Development & Expansion >
ARM - Lesson Plans: Expansion of Population and Environment
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Tanzania Energy Development and Access Expansion Project | Open Energy
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X-ray radiographic expansion measurements of isochorically heated thin wire targets
Hochhaus, D. C. [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany) [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany); Goethe-Universität, 60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main (Germany); Aurand, B. [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany) [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany); Johannes Gutenberg-Universität, 55099 Mainz (Germany); Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main (Germany); Basko, M. [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany) [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany); Alikhanov Institute for Theoretical and Experimental Physics, 117218 Moscow (Russian Federation); Ecker, B. [Johannes Gutenberg-Universität, 55099 Mainz (Germany) [Johannes Gutenberg-Universität, 55099 Mainz (Germany); Helmholtz-Institut Jena, 07743 Jena (Germany); Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main (Germany); Kühl, T. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Johannes Gutenberg-Universität, 55099 Mainz (Germany); Helmholtz-Institut Jena, 07743 Jena (Germany); ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany); Ma, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Rosmej, F. [UPMC, UMR7605, LULI, case 128, 4 Place Jussieu, 75252 Paris Cedex 05 (France) [UPMC, UMR7605, LULI, case 128, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Ecole Polytechnique, LULI, PAPD, Route de Saclay, 91128 Palaiseau Cedex (France); Zielbauer, B. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Jena, 07743 Jena (Germany); Neumayer, P. [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany) [ExtreMe Matter Institute EMMI, GSI, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main (Germany)
2013-06-15T23:59:59.000Z
Solid density matter at temperatures ranging from 150 eV to <5 eV has been created by irradiating thin wire targets with high-energy laser pulses at intensities ?10{sup 18}W/cm{sup 2}. Energy deposition and transport of the laser-produced fast electrons are inferred from spatially resolved K{sub ?}-spectroscopy. Time resolved x-ray radiography is employed to image the target mass density up to solid density and proves isochoric heating. The subsequent hydrodynamic evolution of the target is observed for up to 3 ns and is compared to radiation-hydrodynamic simulations. At distances of several hundred micrometers from the laser interaction region, where temperatures of 5–20 eV and small temperature gradients are found, the hydrodynamic evolution of the wire is a near axially symmetric isentropic expansion, and good agreement between simulations and radiography data confirms heating of the wire over hundreds of micrometers.
The expansion of a collisionless plasma into a plasma of lower density
Perego, M.; Gunzburger, M. D. [Department of Scientific Computing, Florida State University, Tallahassee, Florida 32306 (United States)] [Department of Scientific Computing, Florida State University, Tallahassee, Florida 32306 (United States); Howell, P. D.; Ockendon, J. R.; Allen, J. E. [OCIAM, Mathematical Institute, Oxford University, 24-29 St Giles, OX1 3LB Oxford (United Kingdom)] [OCIAM, Mathematical Institute, Oxford University, 24-29 St Giles, OX1 3LB Oxford (United Kingdom)
2013-05-15T23:59:59.000Z
This paper considers the asymptotic and numerical solution of a simple model for the expansion of a collisionless plasma into a plasma of lower density. The dependence on the density ratio of qualitative and quantitative features of solutions of the well-known cold-ion model is explored. In the cold-ion limit, we find that a singularity develops in the ion density in finite time unless the density ratio is zero or close to unity. The classical cold-ion model may cease to be valid when such a singularity occurs and we then regularize the model by the finite ion-temperature Vlasov-Poisson system. Numerical evidence suggests the emergence of a multi-modal velocity distribution.
Shape Dynamics in 2+1 Dimensions
Timothy Budd; Tim Koslowski
2011-07-07T23:59:59.000Z
Shape Dynamics is a formulation of General Relativity where refoliation invariance is traded for local spatial conformal invariance. In this paper we explicitly construct Shape Dynamics for a torus universe in 2+1 dimensions through a linking gauge theory that ensures dynamical equivalence with General Relativity. The Hamiltonian we obtain is formally a reduced phase space Hamiltonian. The construction of the Shape Dynamics Hamiltonian on higher genus surfaces is not explicitly possible, but we give an explicit expansion of the Shape Dynamics Hamiltonian for large CMC volume. The fact that all local constraints are linear in momenta allows us to quantize these explicitly, and the quantization problem for Shape Dynamics turns out to be equivalent to reduced phase space quantization. We consider the large CMC-volume asymptotics of conformal transformations of the wave function. We then use the similarity of Shape Dynamics on the 2-torus with the explicitly constructible strong gravity (BKL) Shape Dynamics Hamiltonian in higher dimensions to suggest a quantization strategy for Shape Dynamics.
Boyer, Edmond
pore fluid is anomalously higher than the one of pure bulk water. The micromechanics model water-to-cement ratios. It permits also to calculate the pore volume thermal expansion coefficient expansion and thermal pressurization of a hardened cement paste, Cement and Concrete Research, DOI 10.1016/j
Hamiltonian Dynamics of Preferential Attachment
Zuev, Konstantin; Krioukov, Dmitri
2015-01-01T23:59:59.000Z
Prediction and control of network dynamics are grand-challenge problems in network science. The lack of understanding of fundamental laws driving the dynamics of networks is among the reasons why many practical problems of great significance remain unsolved for decades. Here we study the dynamics of networks evolving according to preferential attachment, known to approximate well the large-scale growth dynamics of a variety of real networks. We show that this dynamics is Hamiltonian, thus casting the study of complex networks dynamics to the powerful canonical formalism, in which the time evolution of a dynamical system is described by Hamilton's equations. We derive the explicit form of the Hamiltonian that governs network growth in preferential attachment. This Hamiltonian turns out to be nearly identical to graph energy in the configuration model, which shows that the ensemble of random graphs generated by preferential attachment is nearly identical to the ensemble of random graphs with scale-free degree d...
THE INTER-ERUPTION TIMESCALE OF CLASSICAL NOVAE FROM EXPANSION OF THE Z CAMELOPARDALIS SHELL
Shara, Michael M.; Mizusawa, Trisha; Zurek, David [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192 (United States); Martin, Christopher D.; Neill, James D. [Department of Physics, Math and Astronomy, California Institute of Technology, 1200 East California Boulevard, Mail Code 405-47, Pasadena, CA 91125 (United States); Seibert, Mark [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
2012-09-10T23:59:59.000Z
The dwarf nova Z Camelopardalis is surrounded by the largest known classical nova shell. This shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts. The current size of the shell, its known distance, and the largest observed nova ejection velocity set a lower limit to the time since Z Cam's last outburst of 220 years. The radius of the brightest part of Z Cam's shell is currently {approx}880 arcsec. No expansion of the radius of the brightest part of the ejecta was detected, with an upper limit of {<=}0.17 arcsec yr{sup -1}. This suggests that the last Z Cam eruption occurred {>=}5000 years ago. However, including the important effect of deceleration as the ejecta sweeps up interstellar matter in its snowplow phase reduces the lower limit to 1300 years. This is the first strong test of the prediction of nova thermonuclear runaway theory that the interoutburst times of classical novae are longer than 1000 years. The intriguing suggestion that Z Cam was a bright nova, recorded by Chinese imperial astrologers in October-November 77 B.C.E., is consistent with our measurements. If Z Cam was indeed the nova of 77 B.C.E. we predict that its ejecta are currently expanding at 85 km s{sup -1}, or 0.11 arcsec yr{sup -1}. Detection and measurement of this rate of expansion should be possible in just a few years.
Glass-ceramic hermetic seals to high thermal expansion metals
Kramer, D.P.; Massey, R.T.
1987-04-28T23:59:59.000Z
A process for forming glass-ceramic materials from an alkaline silica-lithia glass composition comprising 60-72 mole-% SiO/sub 2/, 18-27 mole-% Li/sub 2/O, 0-5 mole-% Al/sub 2/O/sub 3/, 0-6 mole-% K/sub 2/O, 0-3 mole-% B/sub 2/O/sub 3/, and 0.5-2.5 mole-% P/sub 2/O/sub 5/, which comprises heating said glass composition at a first temperature within the 950-1050/degree/C range for 5-60 minutes, and then at a devitrification temperature within the 700-900/degree/C range for about 5-300 minutes to obtain a glass-ceramic having a thermal expansion coefficient of up to 210 x 10/sup /minus/7///degree/C. These ceramics form strong, hermetic seals with high expansion metals such as stainless steel alloys. An intermediate nucleation heating step conducted at a temperature within the range of 675-750/degree/C for 10-120 minutes may be employed between the first stage and the devitrification stage. 1 fig., 2 tabs.
Multipole expansions and Fock symmetry of the Hydrogen atom
A. V. Meremianin; J-M. Rost
2006-06-27T23:59:59.000Z
The main difficulty in utilizing the O(4) symmetry of the Hydrogen atom in practical calculations is the dependence of the Fock stereographic projection on energy. This is due to the fact that the wave functions of the states with different energies are proportional to the hyperspherical harmonics (HSH) corresponding to different points on the hypersphere. Thus, the calculation of the matrix elements reduces to the problem of re-expanding HSH in terms of HSH depending on different points on the hypersphere. We solve this problem by applying the technique of multipole expansions for four-dimensional HSH. As a result, we obtain the multipole expansions whose coefficients are the matrix elements of the boost operator taken between hydrogen wave functions (i.e. hydrogen form-factors). The explicit expressions for those coefficients are derived. It is shown that the hydrogen matrix elements can be presented as derivatives of an elementary function. Such an operator representation is convenient for the derivation of recurrency relations connecting matrix elements between states corresponding to different values of the quantum numbers $n$ and $l$.
Feasibility of wavelet expansion methods to treat the energy variable
Van Rooijen, W. F. G. [Research Inst. of Nuclear Engineering, Univ. of Fukui, Kanawa-cho 1-2-4, 914-0055, Fukui-ken, Tsuruga-shi (Japan)
2012-07-01T23:59:59.000Z
This paper discusses the use of the Discrete Wavelet Transform (DWT) to implement a functional expansion of the energy variable in neutron transport. The motivation of the work is to investigate the possibility of adapting the expansion level of the neutron flux in a material region to the complexity of the cross section in that region. If such an adaptive treatment is possible, 'simple' material regions (e.g., moderator regions) require little effort, while a detailed treatment is used for 'complex' regions (e.g., fuel regions). Our investigations show that in fact adaptivity cannot be achieved. The most fundamental reason is that in a multi-region system, the energy dependence of the cross section in a material region does not imply that the neutron flux in that region has a similar energy dependence. If it is chosen to sacrifice adaptivity, then the DWT method can be very accurate, but the complexity of such a method is higher than that of an equivalent hyper-fine group calculation. The conclusion is thus that, unfortunately, the DWT approach is not very practical. (authors)
Expansion joint for guideway for magnetic levitation transportation system
Rossing, T.D.
1993-02-09T23:59:59.000Z
An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The side walls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging side walls so that the cuts have a substantially dove-tail shape.
Expansion joint for guideway for magnetic levitation transportation system
Rossing, Thomas D. (DeKalb, IL)
1993-01-01T23:59:59.000Z
An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The sidewalls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging sidewalls so that the cuts have a substantially dove-tail shape.
Aussie LNG players target NE Asia in expansion bid
Not Available
1994-02-28T23:59:59.000Z
Australia's natural gas players, keen to increase their presence in world liquefied natural gas trade, see Asia as their major LNG market in the decades to come. That's despite the fact that two spot cargoes of Australian Northwest Shelf LNG were shipped to Europe during the last 12 months and more are likely in 1994. Opportunities for growth are foreseen within the confines of the existing Northwest Shelf gas project for the rest of the 1990s. But the main focus for potential new grassroots project developers and expansions of the existing LNG plant in Australia is the expected shortfall in contract volumes of LNG to Japan, South Korea, and Taiwan during 2000--2010. Traditionally the price of crude oil has been used as a basis for calculating LNG prices. This means the economics of any new 21st century supply arrangements are delicately poised because of the current low world oil prices, a trend the market believes is likely to continue. In a bid to lessen the effect of high initial capital outlays and still meet projected demand using LNG from new projects and expansion of the existing plant, Australia's gas producers are working toward greater cooperation with prospective Asian buyers.
Conversion of batch to molten glass, I: Volume expansion
Henager, Samuel H.; Hrma, Pavel R.; Swearingen, Kevin J.; Schweiger, Michael J.; Marcial, Jose; Tegrotenhuis, Nathan E.
2011-02-01T23:59:59.000Z
Batches designed to simulate nuclear high-level waste glass were compressed into pellets that were heated at a rate of 5°C/min and photographed to obtain the profile area as a function of temperature. Three types of batches were prepared with different nitrate-carbonate ratios. To determine the impact of the heat supply by an exothermic reaction and the batch expansion, the nitrated batches were prepared with varying addition of sucrose. To obtain the impact of the grain size of the quartz component, the mixed nitrate-carbonate batches were prepared with silica particles ranging in size from 5 µm to 195 µm. One batch containing only carbonates was also tested. Sucrose addition had little effect on the batch expansion, while the size of silica was very influential. The 5-?m grains had a strongest effect, causing the generation of both primary and secondary foam, whereas only secondary foam was produced in batches with grains of 45 µm and larger. The retention of gases evolved as the batch melts creates primary foam. Gases evolved from oxidation-reduction reactions once the batch has melted produce secondary foam. We suggest that the viscosity of the melt and the amount of gas evolved are the main influences on foam production. As more gas is produced in the melt and as the glass becomes less viscous, the bubbles of gas coalesce into larger and larger cavities, until the glass can no longer contain the bubbles and they burst, causing the foam to collapse.
Plasma expansion in the presence of a dipole magnetic field
Winske, D.; Omidi, N. [Applied Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); SciberNet, Inc., Solana Beach, California 92075 (United States)
2005-07-15T23:59:59.000Z
Simulations of the initial expansion of a plasma injected into a stationary magnetized background plasma in the presence of a dipole magnetic field are carried out in two dimensions with a kinetic ion, massless fluid electron (hybrid) electromagnetic code. For small values of the magnetic dipole, the injected ions have large gyroradii compared to the scale length of the dipole field and are essentially unmagnetized. As a result, these ions expand, excluding the ambient magnetic field and plasma to form a diamagnetic cavity. However, for stronger magnetic dipoles, the ratio of the gyroradii of the injected ions to the dipole field scale length is small so that they remain magnetized, and hence trapped in the dipole field, as they expand. The trapping and expansion then lead to additional plasma currents and resulting magnetic fields that not only exclude the background field but also interact with the dipole field in a more complex manner that stretches the closed dipole field lines. A criterion to distinguish between the two regimes is derived and is then briefly discussed in the context of applying the results to the plasma sail scheme for the propulsion of small spacecraft in the solar wind.
Lattice thermal expansion for normal tetrahedral compound semiconductors
Omar, M.S. [Department of Physics, College of Science, University of Salahaddin, Arbil, Iraqi Kurdistan (Iraq)]. E-mail: dr_m_s_omar@yahoo.com
2007-02-15T23:59:59.000Z
The cubic root of the deviation of the lattice thermal expansion from that of the expected value of diamond for group IV semiconductors, binary compounds of III-V and II-VI, as well as several ternary compounds from groups I-III-VI{sub 2}, II-IV-V{sub 2} and I-IV{sub 2}V{sub 3} semiconductors versus their bonding length are given straight lines. Their slopes were found to be 0.0256, 0.0210, 0.0170, 0.0259, 0.0196, and 0.02840 for the groups above, respectively. Depending on the valence electrons of the elements forming these groups, a formula was found to correlate all the values of the slopes mentioned above to that of group IV. This new formula which depends on the melting point and the bonding length as well as the number of valence electrons for the elements forming the compounds, will gives best calculated values for lattice thermal expansion for all compounds forming the groups mentioned above. An empirical relation is also found between the mean ionicity of the compounds forming the groups and their slopes mentioned above and that gave the mean ionicity for the compound CuGe{sub 2}P{sub 3} in the range of 0.442.
Wire core and coronal plasma expansion in wire-array Z pinches with small numbers of wires
Shelkovenko, T. A.; Pikuz, S. A.; Douglass, J. D.; Blesener, I. C.; Greenly, J. B.; McBride, R. D.; Hammer, D. A.; Kusse, B. R. [Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)
2007-10-15T23:59:59.000Z
Wire core and coronal plasma formation and expansion in wire-array Z pinches with small numbers of wires have been studied on a 1 MA, 100 ns rise time pulsed power generator and a 500 kA, 50 ns generator. Two-frame point-projection x-ray imaging and three-frame laser optical imaging and interferometry were the principal diagnostic methods used for these studies. The x-ray images show that dense coronal plasma forms and is maintained close to each dense wire core in the array. A less dense, rapidly expanding ({approx}10 {mu}m/ns) coronal plasma, best seen in the laser images, surrounds the {approx}100 {mu}m radius dense corona. These results are in agreement with computer simulations and modeling carried out by Yu et al. [Phys. Plasmas 14, 022705 (2007)]. Results are also presented for the dependence of the wire core and coronal plasma expansion rates on the wire diameter, number of wires and current through individual wires and the overall configuration for Al, Cu, and W wire arrays. For example, the W wire dense core expansion rate increases with increasing initial wire diameter from 5.1 {mu}m (0.1 {mu}m/ns) to 12.7 {mu}m diameter (0.3 {mu}m/ns)
Rezaei, F.; Tavassoli, S. H. [Laser and Plasma Research Institute, ShahidBeheshti University, 19396 4716, G. C., Evin, Tehran (Iran, Islamic Republic of)
2013-01-15T23:59:59.000Z
In the present study, the ablation behavior of aluminum target and its plasma radiation in noble ambient gases by a laser pulse with wavelength of 266 nm and pulse duration of 10 ns are numerically studied. A thermal model of laser ablation considering heat conduction, Euler equations, Saha-Eggert equations, Knudsen layer, mass and energy balance relations and optical shielding effects are used for calculation of plasma parameters. Effects of excitation energy on plasma expansion and its emissivity are investigated. Time and spatial-resolved plasma emission including bremsstrahlung, recombination and spectral emission at early delay times after laser irradiation is obtained. Effects of two ambient gases (He and Ar) as well as different gas pressures of 100, 300, 500, and 760 Torr on plasma expansion and its spectrum are studied. Results illustrate that at initial delay times, especially at high noble gas pressures, ionic lines have the maximum intensities, while at later times neutral lines dominate. When the pressure of ambient gas increases, a confinement of the plasma plume is predicted and the intensity of neutral lines decreases. Continuous emission increases with wavelength in both ambient gases. Spatially resolved analysis shows that an intense continuous emission is predicted next to the sample surface decreasing with distance from the latter.
Dynamic coupling drives conformational evolution of branched...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Materials Characterization Dynamic coupling drives conformational evolution of branched polymers in solutions March 06, 2015 Inter-particle collision time (filled circles) and...
A Dynamic Near-Optimal Algorithm for Online Linear Programming
Ye, Yinyu
-time forward dynamic pricing for PEVs charging/discharging on smart-grid; Yinyu Ye Online Linear Program 2009
Complex Dynamics Bernardo Da Costa, Koushik Ramachandran, Jingjing Qu, and I had a two semester learning seminar in complex analysis and potential ...
Dynamics and self-similarity in min-driven Govind Menon1
by Gallay and Mielke, extended using a careful choice of time scale. Keywords: dynamic scaling, coalescence
M. Heller; W. Sasin
1997-11-17T23:59:59.000Z
In the groupoid approach to noncommutative quantization of gravity, gravitational field is quantized in terms of a C*-algebra A of complex valued funcions on a groupoid G (with convolution as multiplication). In the noncommutative quantum gravitational regime the concepts of space and time are meaningless. We study the "emergence of time" in the transition process from the noncommutative regime to the standard space-time geometry. Precise conditions are specified under which modular groups of the von Neumann algebra generated by A can be defined. These groups are interpreted as a state depending time flow. If the above conditions are further refined one obtains a state independent time flow. We show that quantum gravitational dynamics can be expressed in terms of modular groups.
L. R. G. Fontes; C. M. Newman; K. Ravishankar; E. Schertzer
2007-04-20T23:59:59.000Z
The dynamical discrete web (DDW), introduced in recent work of Howitt and Warren, is a system of coalescing simple symmetric one-dimensional random walks which evolve in an extra continuous dynamical parameter s. The evolution is by independent updating of the underlying Bernoulli variables indexed by discrete space-time that define the discrete web at any fixed s. In this paper, we study the existence of exceptional (random) values of s where the paths of the web do not behave like usual random walks and the Hausdorff dimension of the set of such exceptional s. Our results are motivated by those about exceptional times for dynamical percolation in high dimension by H\\"aggstrom, Peres and Steif, and in dimension two by Schramm and Steif. The exceptional behavior of the walks in DDW is rather different from the situation for dynamical random walks of Benjamini, H\\"aggstrom, Peres and Steif. In particular, we prove that there are exceptional values of s for which the walk from the origin S^s(n) has limsup S^s(n)/\\sqrt n \\leq K with a nontrivial dependence of the Hausdorff dimension on K. We also discuss how these and other results extend to the dynamical Brownian web, a natural scaling limit of DDW. The scaling limit is the focus of a paper in preparation; it was studied by Howitt and Warren and is related to the Brownian net of Sun and Swart.
Construction of operator product expansion coefficients via consistency conditions
Jan Holland
2009-06-30T23:59:59.000Z
In this thesis an iterative scheme for the construction of operator product expansion (OPE) coefficients is applied to determine low order coefficients in perturbation theory for a specific toy model. We use the approach to quantum field theory proposed by S. Hollands [arXiv:0802.2198], which is centered around the OPE and a number of axioms on the corresponding OPE coefficients. This framework is reviewed in the first part of the thesis. In the second part we apply an algorithm for the perturbative construction of OPE coefficients to a toy model: Euclidean $\\varphi^6$-theory in 3-dimensions. Using a recently found formulation in terms of vertex operators and a diagrammatic notation in terms of trees [arXiv:0906.5313v1], coefficients up to second order are constructed, some general features of coefficients at arbitrary order are presented and an exemplary comparison to the corresponding customary method of computation is given.
HAZARDS OF THERMAL EXPANSION FOR RADIOLOGICAL CONTAINER ENGULFED IN FIRE
Donna Post Guillen
2013-05-01T23:59:59.000Z
Fire accidents pose a serious threat to nuclear facilities. It is imperative that transport casks or shielded containers designed to transport/contain radiological materials have the ability to withstand a hypothetical fire. A numerical simulation was performed for a shielded container constructed of stainless steel and lead engulfed in a hypothetical fire as outlined by 10 CFR §71.73. The purpose of this analysis was to determine the thermal response of the container during and after the fire. The thermal model shows that after 30 minutes of fire, the stainless steel will maintain its integrity and not melt. However, the lead shielding will melt since its temperature exceeds the melting point. Due to the method of construction of the container under consideration, ample void space must be provided to allow for thermal expansion of the lead upon heating and melting, so as to not overstress the weldment.
Ultra low thermal expansion, highly thermal shock resistant ceramic
Limaye, S.Y.
1996-01-30T23:59:59.000Z
Three families of ceramic compositions having the given formula: {phi}{sub 1+X}Zr{sub 4}P{sub 6{minus}2X}Si{sub 2X}O{sub 24}, {phi}{sub 1+X}Zr{sub 4{minus}2X}Y{sub 2X}P{sub 6}O{sub 24} and {phi}{sub 1+X}Zr{sub 4{minus}X}Y{sub X}P{sub 6{minus}2X}Si{sub X}O{sub 24} wherein {phi} is either strontium or barium and X has a value from about 0.2 to about 0.8 have been disclosed. Ceramics formed from these compositions exhibit very low, generally near neutral, thermal expansion over a wide range of elevated temperatures. 7 figs.
Ultra low thermal expansion, highly thermal shock resistant ceramic
Limaye, Santosh Y. (1440 Sandpiper Cir. #38, Salt Lake City, UT 84117)
1996-01-01T23:59:59.000Z
Three families of ceramic compositions having the given formula: .phi..sub.1+X Zr.sub.4 P.sub.6-2X Si.sub.2X O.sub.24, .phi..sub.1+X Zr.sub.4-2X Y.sub.2X P.sub.6 O.sub.24 and .phi..sub.1+X Zr.sub.4-X Y.sub.X P.sub.6-2X Si.sub.X O.sub.24 wherein .phi. is either Strontium or Barium and X has a value from about 0.2 to about 0.8 have been disclosed. Ceramics formed from these compositions exhibit very low, generally near neutral, thermal expansion over a wide range of elevated temperatures.
Renormalization and asymptotic expansion of Dirac's polarized vacuum
Philippe Gravejat; Mathieu Lewin; Eric Séré
2010-04-10T23:59:59.000Z
We perform rigorously the charge renormalization of the so-called reduced Bogoliubov-Dirac-Fock (rBDF) model. This nonlinear theory, based on the Dirac operator, describes atoms and molecules while taking into account vacuum polarization effects. We consider the total physical density including both the external density of a nucleus and the self-consistent polarization of the Dirac sea, but no `real' electron. We show that it admits an asymptotic expansion to any order in powers of the physical coupling constant $\\alphaph$, provided that the ultraviolet cut-off behaves as $\\Lambda\\sim e^{3\\pi(1-Z_3)/2\\alphaph}\\gg1$. The renormalization parameter $0
Winding expansion techniques for lattice QCD with chemical potential
Julia Danzer; Christof Gattringer
2008-09-16T23:59:59.000Z
We analytically derive a decomposition of the lattice fermion determinant for Wilson's Dirac operator with chemical potential into winding sectors, i.e., factors with a fixed number of quarks. Dividing the lattice into four domains, the determinant is factorized into terms which can be classified with respect to the winding number of the closed loops they consist of. The individual factors are expressed in terms of subdeterminants and propagators on the domains of the lattice. We numerically analyze properties of the factorization formula and discuss two applications for the determination of canonical partition functions with a fixed quark number: A speedup for the Fourier transformation technique through a dimensional reduction, and a power series expansion.
Chen, Z. F.; Reading, John F.
1993-01-01T23:59:59.000Z
by Wilets and Gallaher. The discrepancy may be attributed to the inaccuracy in numerical calcula- tion. These two-centered expansions (TCE) consume much computing time. Reading, Ford, and Becker [23?25] have invented a set of one... ranges have been extended from 100 keV in previous work to 250 keV. The charge-transfer cross sections to the 2p state fit the experimental data at 30 keV and are almost the same as those calculated using TCE method by Cheshire and Shakeshaft...
Dynamics of Clouds Fall Semester 2012
ATS712 Dynamics of Clouds Fall Semester 2012 Meeting Times: T/Th: 9-10:15am Room: ATS 101-2pm Course Description: This class focuses on the general dynamics of cloud systems. Models of fog and other Tools / Skills Cotton, W.R., G.H. Bryan, and S.C. van den Heever, 2010: Storm and Cloud Dynamics
Microsoft Word - CX-SnoKingSubstationExpansionFY12_WEB.doc
Broader source: Energy.gov (indexed) [DOE]
REPLY TO ATTN OF: KEPR-4 SUBJECT: Environmental Clearance Memorandum Michael Marleau Project Manager - TEP-TPP-1 Proposed Action: Sno-King Substation Expansion Categorical...
Arbanas, Goran [ORNL] [ORNL; Dunn, Michael E [ORNL] [ORNL; Larson, Nancy M [ORNL] [ORNL; Leal, Luiz C [ORNL] [ORNL; Williams, Mark L [ORNL] [ORNL
2012-01-01T23:59:59.000Z
Convergence properties of Legendre expansion of a Doppler-broadened double-differential elastic neutron scattering cross section of {sup 238}U near the 6.67 eV resonance at temperature 10{sup 3} K are studied. A variance of Legendre expansion from a reference Monte Carlo computation is used as a measure of convergence and is computed for as many as 15 terms in the Legendre expansion. When the outgoing energy equals the incoming energy, it is found that the Legendre expansion converges very slowly. Therefore, a supplementary method of computing many higher-order terms is suggested and employed for this special case.
Dynamics of femtosecond laser produced tungsten nanoparticle plumes
Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Farid, N. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States) [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); School of Physics and Optical Engineering, Dalian University of Technology, Dalian 116024 (China); Kozhevin, V. M. [Ioffe Physics Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)] [Ioffe Physics Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)
2013-11-28T23:59:59.000Z
We investigated the expansion features of femtosecond laser generated tungsten nanoparticle plumes in vacuum. Fast gated images showed distinct two components expansion features, viz., plasma and nanoparticle plumes, separated by time of appearance. The persistence of plasma and nanoparticle plumes are ?500 ns and ?100 ?s, respectively, and propagating with velocities differed by 25 times. The estimated temperature of the nanoparticles showed a decreasing trend with increasing time and space. Compared to low-Z materials (e.g., Si), ultrafast laser ablation of high-Z materials like W provides significantly higher nanoparticle yield. A comparison between the nanoparticle plumes generated by W and Si is also discussed along with other metals.
Dynamical Transition and Heterogeneous Hydration Dynamics in RNA
Jeseong Yoon; Jong-Chin Lin; Changbong Hyeon; D. Thirumalai
2014-04-24T23:59:59.000Z
Enhanced dynamical fluctuations of RNAs, facilitated by a network of water molecules with strong interactions with RNA, are suspected to be critical in their ability to respond to a variety of cellular signals. Using atomically detailed molecular dynamics simulations at various temperatures of purine (adenine)- and preQ$_1$ sensing riboswitch aptamers, we show that water molecules in the vicinity of RNAs undergo complex dynamics depending on the local structures of the RNAs. The overall lifetimes of hydrogen bonds (HBs) of surface bound waters are more than at least 1-2 orders of magnitude longer than bulk water. Slow hydration dynamics, revealed in non-Arrhenius behavior of the relaxation time, arises from high activation barriers to break water hydrogen bonds with a nucleotide and by reduced diffusion of water. The relaxation kinetics at specific locations in the two RNAs show a broad spectrum of time scales reminiscent of glass-like behavior, suggesting that the hydration dynamics is highly heterogeneous. Both RNAs undergo dynamic transition at $T = T_D \\gtrsim 200$ K as assessed by the mean square fluctuation of hydrogen atoms $\\langle x^2\\rangle$, which undergoes an abrupt harmonic-to-anharmonic transition at $T_D$. The near universal value of $T_D$ found for these RNAs and previously for tRNA is strongly correlated with changes in hydration dynamics as $T$ is altered. Hierarchical dynamics of waters associated with the RNA surface, revealed in the motions of distinct classes of water with well-separated time scales, reflects the heterogeneous local environment on the molecular surface of RNA. At low temperatures slow water dynamics predominates over structural transitions. Our study demonstrates that the complex interplay of dynamics between water and local environment in the RNA structures could be a key determinant of the functional activities of RNA.
Synchronous Machine Parameter Estimation Using Orthogonal Series Expansion
, such as analysis of linear time invariant and time varying systems, model reduction; optimal control and system an alternative to estimate armature circuit parameters of large utility generators using real time operating data and currents measurements) and/or synthetic input-output data. This allows writing a set of linear algebraic
Carbon and Nitrogen Dynamics in Agricultural Soils
Carbon and Nitrogen Dynamics in Agricultural Soils Model Applications at Different Scales in Time Print: SLU Service/Repro, Uppsala 2012 #12;Carbon and Nitrogen Dynamics in Agricultural Soils. Model Applications at Different Scales in Time and Space Abstract An understanding of soil organic carbon (C
Representation of Solar Capacity Value in the ReEDS Capacity Expansion Model
Sigrin, B.; Sullivan, P.; Ibanez, E.; Margolis, R.
2014-03-01T23:59:59.000Z
An important issue for electricity system operators is the estimation of renewables' capacity contributions to reliably meeting system demand, or their capacity value. While the capacity value of thermal generation can be estimated easily, assessment of wind and solar requires a more nuanced approach due to the resource variability. Reliability-based methods, particularly assessment of the Effective Load-Carrying Capacity, are considered to be the most robust and widely-accepted techniques for addressing this resource variability. This report compares estimates of solar PV capacity value by the Regional Energy Deployment System (ReEDS) capacity expansion model against two sources. The first comparison is against values published by utilities or other entities for known electrical systems at existing solar penetration levels. The second comparison is against a time-series ELCC simulation tool for high renewable penetration scenarios in the Western Interconnection. Results from the ReEDS model are found to compare well with both comparisons, despite being resolved at a super-hourly temporal resolution. Two results are relevant for other capacity-based models that use a super-hourly resolution to model solar capacity value. First, solar capacity value should not be parameterized as a static value, but must decay with increasing penetration. This is because -- for an afternoon-peaking system -- as solar penetration increases, the system's peak net load shifts to later in the day -- when solar output is lower. Second, long-term planning models should determine system adequacy requirements in each time period in order to approximate LOLP calculations. Within the ReEDS model we resolve these issues by using a capacity value estimate that varies by time-slice. Within each time period the net load and shadow price on ReEDS's planning reserve constraint signals the relative importance of additional firm capacity.
Modelling the thermo-mechanical volume change behaviour of compacted expansive clays
Paris-Sud XI, Université de
Modelling the thermo-mechanical volume change behaviour of compacted expansive clays Anh-Minh Tang expansive clays are often considered as a possible buffer material in high-level deep radioactive waste disposals. After the installation of waste canisters, the engineered clay barriers are subjected to thermo
Nuclear Electric Propulsion and Power Systems By Bryan K. Smith Submitted to the System Design, expansion and screening of Nuclear Electric Propulsion and Power concepts capable of achieving planetaryDefinition, Expansion and Screening of Architectures for Planetary Exploration Class Nuclear
Queensland, University of
Multipole expansion of strongly focussed laser beams T. A. Nieminen , H. Rubinsztein-Dunlop, N. R, Brisbane QLD 4072, Australia Abstract Multipole expansion of an incident radiation field that is an efficient method for determining the multipole representation of an arbitrary focussed beam. Key words
Iterative-Expansion A* Colin M. Potts and Kurt D. Krebsbach
Krebsbach, Kurt D.
Iterative-Expansion A* (IEA*), fo- cuses on reducing redundant node expansions within indi- vidual depth IEA* with several other competing approaches. We also sketch proofs of optimality and com- pleteness for IEA*, and note that IEA* is particularly ef- ficient for solving implicitly-defined general graph
DETERMINATION OF THE SWELL-STRESS CURVE OF AN EXPANSIVE SOIL USING CENTRIFUGE TECHNOLOGY
Zornberg, Jorge G.
DETERMINATION OF THE SWELL-STRESS CURVE OF AN EXPANSIVE SOIL USING CENTRIFUGE TECHNOLOGY project was conducted on the use of centrifuge technology to characterize the expansive properties of a soil sample in the centrifuge. This paper focuses on the analysis of testing results, specifically how
SOLVING GENERATION EXPANSION PLANNING PROBLEMS WITH ENVIRONMENTAL CONSTRAINTS BY A BUNDLE METHOD
Solodov, Mikhail V.
for the construction of new power plants, while ensuring economic and reliable supply to the future electricity demandSOLVING GENERATION EXPANSION PLANNING PROBLEMS WITH ENVIRONMENTAL CONSTRAINTS BY A BUNDLE METHOD discuss the energy generation expansion planning with environmental constraints, formulated as a nonsmooth
Fourier Series Expansion in a Non-Orthogonal System of Coordinates for the Simulation of
Torres-Verdín, Carlos
Fourier Series Expansion in a Non-Orthogonal System of Coordinates for the Simulation of 3D DC of a Fourier series expansion in a non-orthogonal system of coordinates with an existing 2D goal 3D simulators, since the number of Fourier modes (basis functions) needed to solve practical
Relation between thermal expansion and interstitial formation energy in pure Fe and Cr
Relation between thermal expansion and interstitial formation energy in pure Fe and Cr Janne potentials give lower interstitial formation energy, but predict too small thermal expansion. We also show University, Uppsala, Sweden Abstract By fitting a potential of modified FinnisÂSinclair type to the thermal
Project Fever - Fostering Electric Vehicle Expansion in the Rockies
Swalnick, Natalia
2013-06-30T23:59:59.000Z
Project FEVER (Fostering Electric Vehicle Expansion in the Rockies) is a part of the Clean Cities Community Readiness and Planning for Plug-in Electric Vehicles and Charging Infrastructure Funding Opportunity funded by the U.S. Department of Energy (DOE) for the state of Colorado. Tasks undertaken in this project include: Electric Vehicle Grid Impact Assessment; Assessment of Electrical Permitting and Inspection for EV/EVSE (electric vehicle/electric vehicle supply equipment); Assessment of Local Ordinances Pertaining to Installation of Publicly Available EVSE;Assessment of Building Codes for EVSE; EV Demand and Energy/Air Quality Impacts Assessment; State and Local Policy Assessment; EV Grid Impact Minimization Efforts; Unification and Streamlining of Electrical Permitting and Inspection for EV/EVSE; Development of BMP for Local EVSE Ordinances; Development of BMP for Building Codes Pertaining to EVSE; Development of Colorado-Specific Assessment for EV/EVSE Energy/Air Quality Impacts; Development of State and Local Policy Best Practices; Create Final EV/EVSE Readiness Plan; Develop Project Marketing and Communications Elements; Plan and Schedule In-person Education and Outreach Opportunities.
West Foster Creek Expansion Project 2007 HEP Report.
Ashley, Paul R.
2008-02-01T23:59:59.000Z
During April and May 2007, the Columbia Basin Fish and Wildlife Authority's (CBFWA) Regional HEP Team (RHT) conducted baseline Habitat Evaluation Procedures (HEP) (USFWS 1980, 1980a) analyses on five parcels collectively designated the West Foster Creek Expansion Project (3,756.48 acres). The purpose of the HEP analyses was to document extant habitat conditions and to determine how many baseline/protection habitat units (HUs) to credit Bonneville Power Administration (BPA) for funding maintenance and enhancement activities on project lands as partial mitigation for habitat losses associated with construction of Grand Coulee and Chief Joseph Dams. HEP evaluation models included mule deer (Odocoileus hemionus), western meadowlark (Sturnella neglecta), sharp-tailed grouse, (Tympanuchus phasianellus), Bobcat (Lynx rufus), mink (Neovison vison), mallard (Anas platyrhynchos), and black-capped chickadee (Parus atricapillus). Combined 2007 baseline HEP results show that 4,946.44 habitat units were generated on 3,756.48 acres (1.32 HUs per acre). HEP results/habitat conditions were generally similar for like cover types at all sites. Unlike crediting of habitat units (HUs) on other WDFW owned lands, Bonneville Power Administration received full credit for HUs generated on these sites.
Patruno, Alessandro; Bult, Peter; Wijnands, Rudy; Van der Klis, Michiel [Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Gopakumar, Achamveedu [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Colaba, Mumbai 400005 (India); Hartman, Jacob M. [Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Chakrabarty, Deepto [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
2012-02-20T23:59:59.000Z
The accreting millisecond pulsar SAX J1808.4-3658 has shown a peculiar orbital evolution in the past with an orbital expansion much faster than expected from standard binary evolutionary scenarios. Previous limits on the pulsar spin frequency derivative during transient accretion outbursts were smaller than predicted by standard magnetic accretion torque theory, while the spin evolution between outbursts was consistent with magnetic dipole spin-down. In this Letter, we present the results of a coherent timing analysis of the 2011 outburst observed by the Rossi X-Ray Timing Explorer and extend our previous long-term measurements of the orbital and spin evolution over a baseline of 13 years. We find that the expansion of the 2 hr orbit is accelerating at a rate of P-double dot{sub b} approx. = 1.6 x 10{sup -20} s s{sup -2} and we interpret this as the effect of short-term angular momentum exchange between the mass donor and the orbit. The gravitational quadrupole coupling due to variations in the oblateness of the companion can be a viable mechanism for explaining the observations. No significant spin frequency derivatives are detected during the 2011 outburst (|{nu}-dot| < or approx. 4 x 10{sup -13} Hz s{sup -1}) and the long-term spin-down remains stable over 13 years with {nu}-dot approx. = -10{sup -15} Hz s{sup -1}.
Zeghib, Abdelghani
Introduction Results Linear Dynamics Lorentz Dynamics Actions of discrete groups on stationary Piccione) Geodeycos Meeting, Lyon, 28-30 April 2010 Abdelghani Zeghib Dynamics on Lorentz manifolds #12;Introduction Results Linear Dynamics Lorentz Dynamics Motivations and questions Examples 1 Introduction
Konstantin E. Dorfman; Benjamin P. Fingerhut; Shaul Mukamel
2013-05-23T23:59:59.000Z
Vibrational motions in electronically excited states can be observed by either time and frequency resolved infrared absorption or by off resonant stimulated Raman techniques. Multipoint correlation function expressions are derived for both signals. Three representations for the signal which suggest different simulation protocols are developed. These are based on the forward and the backward propagation of the wavefunction, sum over state expansion using an effective vibration Hamiltonian and a semiclassical treatment of a bath. We show that the effective temporal ($\\Delta t$) and spectral ($\\Delta\\omega$) resolution of the techniques is not controlled solely by experimental knobs but also depends on the system dynamics being probed. The Fourier uncertainty $\\Delta\\omega\\Delta t>1$ is never violated.
Halanay type inequalities on time scales
Ad\\ivar, Murat
2011-01-01T23:59:59.000Z
This paper aims to introduce Halanay type inequalities on time scales. By means of these inequalities we derive new global stability conditions for nonlinear dynamic equations on time scales. Giving several examples we show that beside generalization and extension to q-difference case, our results also provide improvements for the existing theory regarding differential and difference inequalites, which are the most important particular cases of dynamic inequalities on time scales.
Tappert, Charles
Series Using a Focused Time Lagged FeedForward Neural Network N. Moseley ABSTRACT, - Artificial neural other series expansion.[2]. The motivation for analysis of time series using neural netwoProceedings of Student Research Day, CSIS, Pace University, May 9th, 2003 Modeling Economic Time
Dynamic radioactive particle source
Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence
2012-06-26T23:59:59.000Z
A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.
Infrared Gupta-Bleuler Quantum Electrodynamics: Solvable Models And Perturbative Expansion
Simone Zerella
2014-11-10T23:59:59.000Z
We study two Hamiltonian models, based on infrared approximations which render them solvable, in order to obtain an operator formulation of the soft-photon corrections to the scattering of a single electron, as given in Quantum Electrodynamics by the method of Feynman's diagrams. The first model is based on the same approximations of the Pauli-Fierz Hamiltonian, the second one stems from an expansion in powers of the four-momentum transfer, along the lines of Bloch and Nordsieck. For both models, the dynamics of the charge is accounted for by suitably chosen classical currents, interacting with the quantum e.m. potential. M\\"oller operators, preserving respectively the Hilbert scalar product, for the Coulomb-gauge formulation of the models, and an indefinite metric, for the formulation of the models in the Feynman-Gupta-Bleuler gauge, are obtained in the presence of an infrared cutoff, with the help of suitable renormalization counterterms. We show that the soft-photon corrections to the electron scattering under consideration are reproduced by suitable matrix elements of the M\\"oller operators pertaining to the model "of the Bloch-Nordsieck type", both in the FGB gauge and in the Coulomb gauge. Further, we prove that if one assumes that the charged particle is non relativistic and employs a dipole approximation, the resulting low-energy radiative corrections admit an operator formulation as well, in terms of the M\\"oller operators of the model "of Pauli-Fierz type", but lack the invariance property with respect to the gauge employed in their calculation. The reason why such a discrepancy occurs is finally traced back in full generality, also in connection with the Gupta-Bleuler formulation of non-relativistic models.
Predictive Dynamic Security Assessment through Advanced Computing
Huang, Zhenyu; Diao, Ruisheng; Jin, Shuangshuang; Chen, Yousu
2014-11-30T23:59:59.000Z
Abstract— Traditional dynamic security assessment is limited by several factors and thus falls short in providing real-time information to be predictive for power system operation. These factors include the steady-state assumption of current operating points, static transfer limits, and low computational speed. This addresses these factors and frames predictive dynamic security assessment. The primary objective of predictive dynamic security assessment is to enhance the functionality and computational process of dynamic security assessment through the use of high-speed phasor measurements and the application of advanced computing technologies for faster-than-real-time simulation. This paper presents algorithms, computing platforms, and simulation frameworks that constitute the predictive dynamic security assessment capability. Examples of phasor application and fast computation for dynamic security assessment are included to demonstrate the feasibility and speed enhancement for real-time applications.
Influence of Crystal Expansion/Contraction on Zeolite Membrane Permeation
Sorenson, Stephanie G [University of Colorado, Boulder; Payzant, E Andrew [ORNL; Noble, Richard D [University of Colorado, Boulder; Falconer, John L. [University of Colorado, Boulder
2010-01-01T23:59:59.000Z
X-ray diffraction was used to measure the unit cell parameters of B-ZSM-5, SAPO-34, and NaA zeolite powders as a function of adsorbate loading at 303 K, and in one case, at elevated temperatures. Most adsorbates expanded the zeolite crystals below saturation loading at 303 K: n-hexane and SF6 in B-ZSM-5, methanol and CO2 in SAPO-34, and methanol in NaA zeolite. As the loadings increased, the crystals expanded more. Changes in the unit cell volumes of B-ZSM-5 and SAPO-34 zeolite powders correlated with changes in permeation through zeolite membranes defects. When the zeolite crystals expanded or contracted upon adsorption, the defect sizes decreased or increased. In B-ZSM-5 membranes, the fluxes through defects decreased dramatically when n-hexane or SF6 adsorbed. In contrast, i-butane adsorption at 303 K contracted B-ZSM-5 crystals at low loadings and expanded them at higher loadings. Correspondingly, the flux through B-ZSM-5 membrane defects increased at low i-butane loadings and decreased at high loading because the defects increased in size at low loading and decreased at high loadings. At 398 K and 473 K, n-hexane expanded the B-ZSM-5 unit cell more as the temperature increased from 303 to 473 K. The silicalite-1 and B-ZSM-5 unit cell volumes expanded similarly upon n-hexane adsorption at 303 K; boron substitution had little effect on volume expansion.
Nonlinear Dynamics of Dry Friction
Franz-Josef Elmer
1997-07-01T23:59:59.000Z
The dynamical behavior caused by dry friction is studied for a spring-block system pulled with constant velocity over a surface. The dynamical consequences of a general type of phenomenological friction law (stick-time dependent static friction, velocity dependent kinetic friction) are investigated. Three types of motion are possible: Stick-slip motion, continuous sliding, and oscillations without sticking events. A rather complete discussion of local and global bifurcation scenarios of these attractors and their unstable counterparts is present.
Dynamic simulation of voltage collapses
Deuse, J.; Stubbe, M. (Tractebel, Brussels (Belgium))
1993-08-01T23:59:59.000Z
Most of the time the voltage collapse phenomena are studied by means of computer programs designed for the calculation of steady state conditions. But in the real world, the simultaneous occurrences of losses of synchronism, of AVR dynamics or of transformer tap changes call for a full dynamic simulation of voltage phenomena. The present paper shows some examples of dynamic simulations of voltage phenomena using a new general purpose stability program (EUROSTAG), covering in a continuous way the classical fields of transient, mid-term and long-term stability, and also the quasi steady state conditions of a power system.
Taghizadeh, Rouzbeh R
2006-01-01T23:59:59.000Z
Ex vivo expansion of hematopoietic stem cells (HSCs) is a long-standing challenge faced by both researchers and clinicians. To date, no robust, efficient method for the pure, ex vivo expansion of human HSCs has been ...
Lin, Lin; Yang, Chao; He, Lixin
2012-01-01T23:59:59.000Z
We describe how to apply the recently developed pole expansion plus selected inversion (PEpSI) technique to Kohn-Sham density function theory (DFT) electronic structure calculations that are based on atomic orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and eigenvectors of the Kohn-Sham Hamiltonian. We also show how to update the chemical potential without using Kohn-Sham eigenvalues. The advantage of using PEpSI is that it has a much lower computational complexity than that associated with the matrix diagonalization procedure. We demonstrate the performance gain by comparing the timing of PEpSI with that of diagonalization on insulating and metallic nanotubes. For these quasi-1D systems, the complexity of PEpSI is linear with respect to the number of atoms. This linear scaling can be observed in our computational experiments when the number of atoms in a nanotube is larger than a few hundr...
Edgeworth Expansion of the Largest Eigenvalue Distribution Function of GUE and LUE
Leonard N. Choup
2006-05-31T23:59:59.000Z
We derive expansions of the Hermite and Laguerre kernels at the edge of the spectrum of the finite n Gaussian Unitary Ensemble (GUEn) and the finite n Laguerre Unitary Ensem- ble (LUEn), respectively. Using these large n kernel expansions, we prove an Edgeworth type theorem for the largest eigenvalue distribution function of GUEn and LUEn. In our Edgeworth expansion, the correction terms are expressed in terms of the same Painleve II function appearing in the leading term, i.e. in the Tracy-Widom distribution. We conclude with a brief discussion of the universality of these results.
On the ambiguity of field correlators represented by asymptotic perturbation expansions
Irinel Caprini; Jan Fischer; Ivo Vrko?
2009-09-01T23:59:59.000Z
Starting from the divergence pattern of perturbation expansions in Quantum Field Theory and the (assumed) asymptotic character of the series, we address the problem of ambiguity of a function determined by the perturbation expansion. We consider functions represented by an integral of the Laplace-Borel type along a general contour in the Borel complex plane. Proving a modified form of the Watson lemma, we obtain a large class of functions having the same asymptotic perturbation expansion. Some remarks on perturbative QCD are made, using the particular case of the Adler function.
Quantum field theory in the presence of a medium: Green's function expansions
Kheirandish, Fardin [Department of Physics, Islamic Azad University, Shahreza-Branch, Shahreza (Iran, Islamic Republic of); Salimi, Shahriar [Department of Physics, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)
2011-12-15T23:59:59.000Z
Starting from a Lagrangian and using functional-integration techniques, series expansions of Green's function of a real scalar field and electromagnetic field, in the presence of a medium, are obtained. The parameter of expansion in these series is the susceptibility function of the medium. Relativistic and nonrelativistic Langevin-type equations are derived. Series expansions for Lifshitz energy in finite temperature and for an arbitrary matter distribution are derived. Covariant formulations for both scalar and electromagnetic fields are introduced. Two illustrative examples are given.
Metric perturbation theory of quantum dynamics
Antony L Tambyrajah
2006-10-06T23:59:59.000Z
A theory of quantum dynamics based on a discrete structure underlying the space time manifold is developed for single particles. It is shown that at the micro domain the interaction of particles with the underlying discrete structure results in the quantum space time manifold. Regarding the resulting quantum space-time as perturbation from the Lorentz metric it is shown it is possible to discuss the dynamics of particles in the quantum domain.
Inferring Gene Family Histories in Yeast Identifies Lineage Specific Expansions
Ames, Ryan M.; Money, Daniel; Lovell, Simon C.
2014-06-12T23:59:59.000Z
The complement of genes found in the genome is a balance between gene gain and gene loss. Knowledge of the specific genes that are gained and lost over evolutionary time allows an understanding of the evolution of biological ...
A flexible expansion algorithm for user-chosen abbreviations
Willis, Timothy Alan
People with some types of motor disabilities who wish to generate text using a computer can find the process both fatiguing and time-consuming. These problems can be alleviated by reducing the quantity of keystrokes they ...