Quantum, Photo-Electric Single Capacitor Paradox
Darko Kapor; Vladan Pankovic
2009-12-10
In this work single capacitor paradox (a variation of the remarkable two capacitor paradox) is considered in a new, quantum discrete form. Simply speaking we consider well-known usual, photoelectric effect experimental device, i.e. photo electric cell, where cathode and anode are equivalently charged but non-connected. It, obviously, represents a capacitor that initially, i.e. before action of the photons with individual energy equivalent to work function, holds corresponding energy of the electrical fields between cathode and anode. Further, we direct quantum discretely photons, one by one, toward cathode where according to photo-electrical effect electrons discretely, one by one, will be emitted and directed toward anode. It causes discrete discharge of the cell, i.e. capacitor and discrete decrease of the electrical field. Finally, total discharge of the cell, i.e. capacitor, and total disappearance of the electrical field and its energy will occur. Given, seemingly paradoxical, capacitor total energy loss can be simply explained without any dissipative effects (Joule heating or electromagnetic waves emission can be neglected as high order small corrections) by work done by the electrical field by movement of the electrons from cathode to anode. (Remarkable two capacitors paradox can be, obviously, formulated and explained in the completely analogous way.)
The use of the photo-electric cell in the determination of ammonia
Adams, Leon Milton
1934-01-01
', hc li;ht c &cree . , &nsistcd ~f a six imlt flashj. ippt bulb . . mmtcd in a s:v ll ro looter in such v runner as to focus o naxisLu:i aiount of li', ht Un tt?: en4 of thc oolcu tubs~ hc color "ubcs used ' ore l0 ofhce y M QB ~ ~, '0 etio y... and 40 c . ~ in length hoss tubas acro, )noketed polari soopc tub~e havir; a bo c of: ! am. The tubs was a fixe4 distsnoe fro. . ~ the sell sod ias supportod in such a manner sc to bc in tho ssme position t all ti. ws . he photo electric soll used uas...
Unequal density effect on static structure factor of coupled electron layers
Saini, L. K. Nayak, Mukesh G.
2014-04-24
In order to understand the ordered phase, if any, in a real coupled electron layers (CEL), there is a need to take into account the effect of unequal layer density. Such phase is confirmed by a strong peak in a static structure factor. With the aid of quantum/dynamical version of Singwi, Tosi, Land and Sjölander (so-called qSTLS) approximation, we have calculated the intra- and interlayer static structure factors, S{sub ll}(q) and S{sub 12}(q), over a wide range of density parameter r{sub sl} and interlayer spacing d. In our present study, the sharp peak in S{sub 22}(q) has been found at critical density with sufficiently lower interlayer spacing. Further, to find the resultant effect of unequal density on intra- and interlayer static structure factors, we have compared our results with that of the recent CEL system with equal layer density and isolated single electron layer.
Evaluation of Cold Temperatures and Density as Mortality Factors of the Eucalyptus Longhorned Borer
Hanks, Lawrence M.
Evaluation of Cold Temperatures and Density as Mortality Factors of the Eucalyptus Longhorned Borer) ABSTRACT It was hypothesized that the northward spread of the eucalyptus longhorned borer, Phoracantha into most zones occupied by its eucalyptus host plants. In addition, increasing densities of prepupae
Some Consequences of Dark Energy Density varying Exponentially with Scale Factor
Sanil Unnikrishnan; T. R. Seshadri
2005-11-10
In this paper we have explored the consequences of a model of dark energy with its energy density varying exponentially with the scale factor. We first consider the model with $ \\rho_{\\phi} \\propto e^{\\kappa a} $, where $\\kappa $ is a constant. This is a kind of generalisation of the cosmological constant model with $\\kappa = 0$. We show that such an exponentially varying dark energy density with the scale factor naturally leads to an equivalent phantom field. We also consider a model with $ \\rho_{\\phi} \\propto e^{\\kappa /a} $ and we show that this also naturally leads to an equivalent phantom field.
Gotie, Robert Francis
1972-01-01
NESTING SUCCESS OF THE GREAT-TAILED GRACKLE (CASSIDIX MEXICANUS PROSOPIDICOLA) IN RELATION TO CERTAIN DENSITY DEPENDENT AND DENSITY INDEPENDENT FACTORS A Thesis by ROBERT FRANCIS GOTIE Submitted to the Graduate College of Texas A&M University... AND DENSITY INDEPENDENT FACTORS A Thesis by ROBERT FRANCIS GOTIE Approved as to style and content by: (Chairman of Committee) (Head of Department) (Member) (Member) December 1972 ABSTRACT Nesting Success of the Great-tailed Grackle (Cassidix...
Jung, Ju-Hyun; Kim, Hyun-Chul
2015-01-01
We investigate the medium modification of the generalized vector form factors of the nucleon, which include the electromagnetic and energy-momentum tensor form factors, based on an in-medium modified $\\pi$-$\\rho$-$\\omega$ soliton model. We find that the vector form factors of the nucleon in nuclear matter fall off faster than those in free space, which implies that the charge radii of the nucleon become larger in nuclear medium than in free space. We also compute the corresponding transverse charge densities of the nucleon in nuclear matter, which clearly reveal the increasing of the nucleon size in nuclear medium.
Ju-Hyun Jung; Ulugbek Yakhshiev; Hyun-Chul Kim
2015-12-23
We investigate the medium modification of the generalized vector form factors of the nucleon, which include the electromagnetic and energy-momentum tensor form factors, based on an in-medium modified $\\pi$-$\\rho$-$\\omega$ soliton model. We find that the vector form factors of the nucleon in nuclear matter fall off faster than those in free space, which implies that the charge radii of the nucleon become larger in nuclear medium than in free space. We also compute the corresponding transverse charge densities of the nucleon in nuclear matter, which clearly reveal the increasing of the nucleon size in nuclear medium.
Selecting The Optimal Logging Suite For Geothermal Reservoir...
tensile wall fractures, and were adequate to detect stratigraphic features. Density, photo-electric factor (PEF), neutron, and gamma ray (GR) logs provided sufficient...
An investigation of factors affecting intersection control by volume density actuated equipment
Radke, Milton L
1966-01-01
to the extendible portion when there are cars waiting on the opposite phase. The maximum green timing is initiated by a single vehicle call on the opposing phase. The maximum circuit also operates as a safety circuit to prevent the controller from hanging up... Actuation Passage Time Maximum Green Extension. Clearance Interval Time Waiting Against the Red Number of Cars Waiting Against the Red Platoon Carryover Density 7 8 8 9 9 9 10 11 STUDY PROCEDURE A. Non-Gap Associated Features Minimum Green...
Hascoët, Romain; Beloborodov, Andrei M
2015-01-01
Fermi satellite discovered that cosmological gamma-ray bursts (GRBs) are accompanied by long GeV flashes. In two GRBs, an optical counterpart of the GeV flash has been detected. Recent work suggests that the GeV+optical flash is emitted by the external blast wave from the explosion in a medium loaded with copious $e^\\pm$ pairs. The full light curve of the flash is predicted by a first-principle radiative transfer simulation and can be tested against observations. Here we examine a sample of 7 bursts with best GeV+optical data and test the model. We find that the observed light curves are in agreement with the theoretical predictions and allow us to measure three parameters for each burst: the Lorentz factor of the explosion, its isotropic kinetic energy, and the external density. With one possible exception of GRB 090510 (which is the only short burst in the sample) the ambient medium is consistent with a wind from a Wolf-Rayet progenitor. The wind density parameter $A=\\rho r^2$ varies in the sample around $1...
Ningbo Qixin Photo electricity Co Ltd | Open Energy Information
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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPI VenturesNew Hampshire: Energy ResourcesNiigata GeothermalQixin Photo
Gedanken densities and exact constraints in density functional theory
Perdew, John P.; Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 ; Ruzsinszky, Adrienn; Sun, Jianwei; Burke, Kieron
2014-05-14
Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGA’s. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.
Alpha track density using a semiconductor detector
Hamilton, Ian Scott
1993-01-01
of factors including variation in the initial dielectric thickness, and other undefined parameters. In addition, the resultant radon concentration reading is dependent upon the calibration factor used to interpret the track density reading. Obtaining...
Density variations and anomalies in palladium compacts
Back, D.; Jones, T.; Ransick, M.; Walburg, T.; Werkmeister, D.
1992-05-14
Low-density compacts of palladium powder have relative densities of about 30{plus minus}10% TD. The variations in density are of concern for operations such as chemical/hydrogen pump systems because heat, mass, and momentum transport properties can be affected. Variations in density result from the inherent nature and interacting forces of UASA compaction of powder in cylinders. In addition to these expected variations, discontinuous density anomalies, such as cracks or high density ridges, are also found. An anomaly of particular concern was found to resemble a steer's head.'' it is a symmetrical region of low density located at or near the center of a compact. Typically, this region is surrounded by a band of high density, compacted palladium that sometimes exceeds the density of the surrounding compact matrix by a factor of three. This report examines these density variations and anomalies both theoretically and empirically.
Density variations and anomalies in palladium compacts
Back, D.; Jones, T.; Ransick, M.; Walburg, T.; Werkmeister, D.
1992-05-14
Low-density compacts of palladium powder have relative densities of about 30{plus_minus}10% TD. The variations in density are of concern for operations such as chemical/hydrogen pump systems because heat, mass, and momentum transport properties can be affected. Variations in density result from the inherent nature and interacting forces of UASA compaction of powder in cylinders. In addition to these expected variations, discontinuous density anomalies, such as cracks or high density ridges, are also found. An anomaly of particular concern was found to resemble a ``steer`s head.`` it is a symmetrical region of low density located at or near the center of a compact. Typically, this region is surrounded by a band of high density, compacted palladium that sometimes exceeds the density of the surrounding compact matrix by a factor of three. This report examines these density variations and anomalies both theoretically and empirically.
TMD theory, factorization and evolution
John Collins
2013-07-10
The concepts and methods of factorization using transverse-momentum-dependent (TMD) parton densities and/or fragmentation functions are summarized.
Maximum-likelihood density modification
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2000-08-01
A likelihood-based density modification approach is developed that can incorporate expected electron-density information from a wide variety of sources. A likelihood-based approach to density modification is developed that can be applied to a wide variety of cases where some information about the electron density at various points in the unit cell is available. The key to the approach consists of developing likelihood functions that represent the probability that a particular value of electron density is consistent with prior expectations for the electron density at that point in the unit cell. These likelihood functions are then combined with likelihood functions based on experimental observations and with others containing any prior knowledge about structure factors to form a combined likelihood function for each structure factor. A simple and general approach to maximizing the combined likelihood function is developed. It is found that this likelihood-based approach yields greater phase improvement in model and real test cases than either conventional solvent flattening and histogram matching or a recent reciprocal-space solvent-flattening procedure [Terwilliger (1999 ?), Acta Cryst. D55, 1863–1871].
Laboratory Density Functionals
B. G. Giraud
2007-07-26
We compare several definitions of the density of a self-bound system, such as a nucleus, in relation with its center-of-mass zero-point motion. A trivial deconvolution relates the internal density to the density defined in the laboratory frame. This result is useful for the practical definition of density functionals.
Updated Axion CDM energy density
Ji-Haeng Huh
2008-10-08
We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale Lambda_{QCD}, the current quark masses m_q's and the Peccei-Quinn scale F_a, including firstly introduced 1.85 factor which is from the initial overshoot.
Engineering Density of States of Earth Abundant Semiconductors...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric...
The photo-electric effect in the bi-layer graphite
Miroslav Pardy
2008-08-08
We derive the differential probability of the photoelectric effect realized at the very low temperature of double graphene in the very strong magnetic field. The relation of this effect to the elementary particle physics, nuclear physics and Einstein gravity is mentioned. Our approach is the analogue of the Landau discovery of the diamagnetism, where Landau supposed the parabolic dispersion relations for the model of diamagnetism.
Chiral dynamics and peripheral transverse densities
Granados, Carlos G.; Weiss, Christian
2014-01-01
In the partonic (or light-front) description of relativistic systems the electromagnetic form factors are expressed in terms of frame-independent charge and magnetization densities in transverse space. This formulation allows one to identify the chiral components of nucleon structure as the peripheral densities at transverse distances b = O(M{sub {pi}}{sup -1}) and compute them in a parametrically controlled manner. A dispersion relation connects the large-distance behavior of the transverse charge and magnetization densities to the spectral functions of the Dirac and Pauli form factors near the two--pion threshold at timelike t = 4 M{ sub {pi}}{sup 2}, which can be computed in relativistic chiral effective field theory. Using the leading-order approximation we (a) derive the asymptotic behavior (Yukawa tail) of the isovector transverse densities in the "chiral" region b = O(M{sub {pi}}{sup -1}) and the "molecular" region b = O(M{sub N}{sup 2}/M{sub {pi}}{sup 3}); (b) perform the heavy-baryon expansion of the transverse densities; (c) explain the relative magnitude of the peripheral charge and magnetization densities in a simple mechanical picture; (d) include Delta isobar intermediate states and study the peripheral transverse densities in the large-N{ sub c} limit of QCD; (e) quantify the region of transverse distances where the chiral components of the densities are numerically dominant; (f) calculate the chiral divergences of the b{sup 2}-weighted moments of the isovector transverse densities (charge and anomalous magnetic radii) in the limit M{sub {pi}} -> 0 and determine their spatial support. Our approach provides a concise formulation of the spatial structure of the nucleon's chiral component and offers new insights into basic properties of the chiral expansion. It relates the information extracted from low-t elastic form factors to the generalized parton distributions probed in peripheral high-energy scattering processes.
Neutral depletion and the helicon density limit
Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E.
2013-12-15
It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.
Visualization of electronic density
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Grosso, Bastien; Cooper, Valentino R.; Pine, Polina; Hashibon, Adham; Yaish, Yuval; Adler, Joan
2015-04-22
An atom’s volume depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent numerical algorithms and packages to calculate it for other materials. 3D visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. We explore several approaches to 3D charge density visualization, including the extension of an anaglyphic stereo visualization application based on the AViz package to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answering interesting questions about nanotube properties.
Density-dependent covariant energy density functionals
Lalazissis, G. A.
2012-10-20
Relativistic nuclear energy density functionals are applied to the description of a variety of nuclear structure phenomena at and away fromstability line. Isoscalar monopole, isovector dipole and isoscalar quadrupole giant resonances are calculated using fully self-consistent relativistic quasiparticle randomphase approximation, based on the relativistic Hartree-Bogoliubovmodel. The impact of pairing correlations on the fission barriers in heavy and superheavy nuclei is examined. The role of pion in constructing desnity functionals is also investigated.
Lula, J.W.
1982-01-01
A formulation for low density syntactic foam desiccant, using a polyimide resin binder, glass microbubble filler, and molecular sieve desiccant powder has been developed. The formulation may be modified easily to meet specific part requirements such as density and desired moisture pickup. Some parts can be molded to size.
Liquid Walls Innovative High Power Density Concepts
California at Los Angeles, University of
erosion as limiting factors -Results in smaller and lower cost components (chambLiquid Walls Innovative High Power Density Concepts (Based on the APEX Study) http for the Chamber Technology that can: 1. Improve the vision for an attractive fusion energy system 2. Lower
Accurate neutralino relic density
Paolo Gondolo; Joakim Edsjo
1998-04-30
We enlarge our set of supersymmetric models and update accelerator constraints in our precise calculation of the relic density of the lightest neutralino, which includes relativistic Boltzmann averaging, subthreshold and resonant annihilations, and coannihilation processes among charginos and neutralinos.
Grover, William H.
We have used a microfluidic mass sensor to measure the density of single living cells. By weighing each cell in two fluids of different densities, our technique measures the single-cell mass, volume, and density of ...
High Energy Density Laboratory Plasmas
High Energy Density Laboratory Plasmas General Plasma Science Developing founda/ons and advancing fundamental understanding #12;The High Energy Density developing innovative techniques to study the properties of instabilities in magnetized-high-energy-density
Multiple density layered insulator
Alger, Terry W. (Tracy, CA)
1994-01-01
A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.
Energy Density Fluctuations in Inflationary Cosmology
Harald F. Muller; Christoph Schmid
1994-12-07
We analyze the energy density fluctuations contributed by scalar fields $\\Phi$ with vanishing expectation values, $\\langle\\Phi\\rangle=0$, which are present in addition to the inflaton field. For simplicity we take $\\Phi$ to be non--interacting and minimally coupled to gravity. We use normal ordering to define the renormalized energy density operator $\\rho$, and we show that any normal ordering gives the same result for correlation functions of $\\rho$. We first consider massless fields and derive the energy fluctuations in a single mode $\\vk$, the two--point correlation function of the energy density, the power spectrum, and the variance of the smeared energy density, $\\ddR$. Mass effects are investigated for energy fluctuations in single modes. All quantities considered are scale invariant at the second horizon crossing (Harrison--Zel'dovich type) for massless and for unstable massive fields. The magnitude of the relative fluctuations $\\de\\rho/\\rt$ is of order $(\\Hi/\\Mp)^2$ in the massless case, where $\\Hi$ is the Hubble constant during inflation. For an unstable field of mass $m_\\Phi\\ll\\Hi$ with a decay rate $\\Gamma_\\Phi$ the magnitude is enhanced by a factor $\\sqrt{m_\\Phi/\\Gamma_\\Phi}$. Finally, the prediction for the cosmic variance of the average energy density in a sample is given in the massless case.
High Energy Density Capacitors
2010-07-01
BEEST Project: Recapping is developing a capacitor that could rival the energy storage potential and price of today’s best EV batteries. When power is needed, the capacitor rapidly releases its stored energy, similar to lightning being discharged from a cloud. Capacitors are an ideal substitute for batteries if their energy storage capacity can be improved. Recapping is addressing storage capacity by experimenting with the material that separates the positive and negative electrodes of its capacitors. These separators could significantly improve the energy density of electrochemical devices.
Transverse charge and magnetization densities in holographic QCD
Chakrabarti, Dipankar
2014-01-01
We present a study of flavor structures of nucleons transverse charge and anomalous magnetization densities for both unpolarized and transversely polarized nucleons. We consider two different models for the electromagnetic form factors in holographic QCD. The flavor form factors are obtained by decomposing the Dirac and Pauli form factors for nucleons using the charge and isospin symmetry. The results are compared with two standard phenomenological parametrizations.
V. E. Oberacker; A. S. Umar
2015-02-13
In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach, dynamic microscopic calculations are carried out on a three-dimensional lattice and there are no adjustable parameters, the only input is the Skyrme effective NN interaction. After a review of the DC-TDHF theory and the numerical methods, we present results for heavy-ion potentials $V(R)$, coordinate-dependent mass parameters $M(R)$, and precompound excitation energies $E^{*}(R)$ for a variety of heavy-ion reactions. Using fusion barrier penetrabilities, we calculate total fusion cross sections $\\sigma(E_\\mathrm{c.m.})$ for reactions between both stable and neutron-rich nuclei. We also determine capture cross sections for hot fusion reactions leading to the formation of superheavy elements.
Nuclear Energy Density Optimization
M. Kortelainen; T. Lesinski; J. Moré; W. Nazarewicz; J. Sarich; N. Schunck; M. V. Stoitsov; S. Wild
2010-05-27
We carry out state-of-the-art optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, derivative-free optimization algorithm used in this work has been found to be significantly better than standard optimization methods in terms of reliability, speed, accuracy, and precision. The resulting parameter set UNEDFpre results in good agreement with experimental masses, radii, and deformations and seems to be free of finite-size instabilities. An estimate of the reliability of the obtained parameterization is given, based on standard statistical methods. We discuss new physics insights offered by the advanced covariance analysis.
Oberacker, V E
2015-01-01
In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach, dynamic microscopic calculations are carried out on a three-dimensional lattice and there are no adjustable parameters, the only input is the Skyrme effective NN interaction. After a review of the DC-TDHF theory and the numerical methods, we present results for heavy-ion potentials $V(R)$, coordinate-dependent mass parameters $M(R)$, and precompound excitation energies $E^{*}(R)$ for a variety of heavy-ion reactions. Using fusion barrier penetrabilities, we calculate total fusion cross sections $\\sigma(E_\\mathrm{c.m.})$ for reactions between both stable and neutron-rich nuclei. We also determine capture cross sections for hot fusion reactions leading to the formation of superheavy elements.
Low density microcellular foams
LeMay, James D. (Castro Valley, CA)
1991-01-01
Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.
Low density microcellular foams
LeMay, James D. (Castro Valley, CA)
1992-01-01
Disclosed is a process of producing microcellular from which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.
Low density microcellular foams
LeMay, J.D.
1991-11-19
Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 [mu]m is produced. Also disclosed are the foams produced by the process. 8 figures.
Low density microcellular foams
Aubert, J.H.; Clough, R.L.; Curro, J.G.; Quintana, C.A.; Russick, E.M.; Shaw, M.T.
1985-10-02
Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the reusltant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 ..mu..m and a volume such that the foams have a length greater than 1 cm are provided.
Low density microcellular foams
Aubert, James H. (Albuquerque, NM); Clough, Roger L. (Albuquerque, NM); Curro, John G. (Placitas, NM); Quintana, Carlos A. (Albuquerque, NM); Russick, Edward M. (Albuquerque, NM); Shaw, Montgomery T. (Mansfield Center, CT)
1987-01-01
Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the resultant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Means for subjecting such a solvent to one-dimensional cooling are also provided. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 .mu.m and a volume such that the foams have a length greater than 1 cm are provided.
A NEW RECIPE FOR OBTAINING CENTRAL VOLUME DENSITIES OF PRESTELLAR CORES FROM SIZE MEASUREMENTS
Tassis, Konstantinos; Yorke, Harold W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
2011-07-10
We propose a simple analytical method for estimating the central volume density of prestellar molecular cloud cores from their column density profiles. Prestellar cores feature a flat central part of the column density and volume density profiles of the same size indicating the existence of a uniform-density inner region. The size of this region is set by the thermal pressure force which depends only on the central volume density and temperature of the core, and can provide a direct measurement of the central volume density. Thus, a simple length measurement can immediately yield a central density estimate independent of any dynamical model for the core and without the need for fitting. Using the radius at which the column density is 90% of the central value as an estimate of the size of the flat inner part of the column density profile yields an estimate of the central volume density within a factor of two for well-resolved cores.
Constraining snowmelt in a temperature-index model using simulated snow densities
Evans, Jason
Constraining snowmelt in a temperature-index model using simulated snow densities Kathryn J. Georgakakos, Editor-in-Chief Keywords: Snow density Snow modelling Melt factor Degree-day factor Warm maritime snowpack dynamics Snow depth s u m m a r y Current snowmelt parameterisation schemes are largely untested
High Energy Density Microwaves
Phillips, R.M. [Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)
1999-04-01
These proceedings represent papers presented at the RF98 Workshop entitled `High Energy Density Microwaves` held in California in October, 1998. The topics discussed were predominantly accelerator{minus}related. The Workshop dealt, for the most part, with the generation and control of electron beams, the amplification of RF signals, the design of mode converters, and the effect of very high RF field gradients. This Workshop was designed to address the concerns of the microwave tube industry worldwide, the plasma physicists who deal with very high beam currents and gigawatts of RF power, and researchers in accelerator centers around the world. Papers were presented on multibeam klystrons, gyrotron development, plasmas in microwave tubes, RF breakdown, and alternatives to conventional linear coliders at 1 TeV and above. The Workshop was partially sponsored by the US Department of Energy. There were 46 papers presented at the conference,out of which 19 have been abstracted for the Energy,Science and Technology database.(AIP)
Energy Density Inhomogeneities with Polynomial $f(R)$ Cosmology
M. Sharif; Z. Yousaf
2014-08-15
In this paper, we study the effects of polynomial $f(R)$ model on the stability of homogeneous energy density in self-gravitating spherical stellar object. For this purpose, we construct couple of evolution equations which relate the Weyl tensor with matter parameters. We explore different factors responsible for density inhomogeneities with non-dissipative dust, isotropic as well as anisotropic fluids and dissipative dust cloud. We find that shear, pressure, dissipative parameters and $f(R)$ terms affect the existence of inhomogeneous energy density.
Broader source: Energy.gov [DOE]
This scenario provides the planning instructions, guidance, and evaluation forms necessary to conduct an exercise involving a highway shipment of a soil moisture/density gauge (Class 7 -...
Phenomenological Relativistic Energy Density Functionals
Lalazissis, G. A.; Kartzikos, S.; Niksic, T.; Paar, N.; Vretenar, D.; Ring, P.
2009-08-26
The framework of relativistic nuclear energy density functionals is applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of beta-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure is explored using the fully consistent quasiparticle random-phase approximation based on the relativistic Hartree-Bogoliubov model. Recent applications of energy density functionals with explicit density dependence of the meson-nucleon couplings are presented.
Optimal Seismic Network Density for Earthquake Early Warning: A Case
Allen, Richard M.
Optimal Seismic Network Density for Earthquake Early Warning: A Case Study from California by H and the public actively use early warning information is a crucial factor in early warning system design (Aktas detection and alert-filtering algorithms; and (d) well-developed seismic networks with improved station
Low density carbonized composite foams
Kong, Fung-Ming (Pleasanton, CA)
1991-01-01
A carbonized composite foam having a density less than about 50 mg/cm.sup.3 and individual cell sizes no greater than about 1 .mu.m in diameter is described, and the process of making it.
Neutralino relic density including coannihilations
Paolo Gondolo; Joakim Edsjo
1997-11-25
We give an overview of our precise calculation of the relic density of the lightest neutralino, in which we included relativistic Boltzmann averaging, subthreshold and resonant annihilations, and coannihilation processes with charginos and neutralinos.
Low density metal hydride foams
Maienschein, Jon L. (Oakland, CA); Barry, Patrick E. (Pleasant Hill, CA)
1991-01-01
Disclosed is a low density foam having a porosity of from 0 to 98% and a density less than about 0.67 gm/cc, prepared by heating a mixture of powered lithium hydride and beryllium hydride in an inert atmosphere at a temperature ranging from about 455 to about 490 K for a period of time sufficient to cause foaming of said mixture, and cooling the foam thus produced. Also disclosed is the process of making the foam.
Jacek Dobaczewski Density functional theory and energy
Dobaczewski, Jacek
Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek UNEDFCollaboration,http://unedf.org/ Universal Nuclear Energy Density FunctionalUniversal Nuclear Energy Density in Poland per voivodship Energy density functional 245 647 Price voivodship functional 654 763 295 580
Pion transverse charge density and the edge of hadrons
Carmignotto, Marco; Horn, Tanja; Miller, Gerald A.
2014-08-01
We use the world data on the pion form factor for space-like kinematics and a technique used to extract the proton transverse densities, to extract the transverse pion charge density and its uncertainty due to experimental uncertainties and incomplete knowledge of the pion form factor at large values of Q2. The pion charge density at small values of b<0.1 fm is dominated by this incompleteness error while the range between 0.1-0.3 fm is relatively well constrained. A comparison of pion and proton charge densities shows that the pion is denser than the proton for values of b<0.2 fm. The pion and proton distributions seem to be the same for values of b=0.2-0.6 fm. Future data from Jlab 12 GeV and the EIC will increase the dynamic extent of the data to higher values of Q2 and thus reduce the uncertainties in the extracted pion charge density.
High-density fluid compositions
Sanders, D.C.
1981-09-29
Clear, high-density fluids suitable for use as well completion, packing, and perforation media comprise aqueous solutions of zinc bromide and calcium bromide having densities lying in the range of about 14.5 up to about 18.0 pounds per gallon and measured PH's lying in the range of about 3.5 up to about 6.0. Optionally, such fluids may also comprise calcium chloride and/or a soluble film-forming amine-based corrosion inhibitor. Such fluids under conditions of ordinary use exhibit low corrosion rates and have crystallization points lying well below the range of temperatures under which they are used.
A step towards quantitative lipoprotein density profiling analysis: applied Rayleigh scattering
Nowlin, Michael
2009-05-15
is imperative in assessing risk factors accurately. Light scattering techniques, primarily Rayleigh scattering, are applied to density separated serum samples in resulting in improved qualitative data with progress in quantitative measurements through imaging...
Time Dependent Density Functional Theory An introduction
Botti, Silvana
Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique (ETSF) Time Dependent Density Functional Theory Palaiseau, 7 February 2012 1 / 32 #12;Outline 1 Frontiers 4 Perspectives and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory
Statistical density modification using local pattern matching
Terwilliger, Thomas C.
2007-01-23
A computer implemented method modifies an experimental electron density map. A set of selected known experimental and model electron density maps is provided and standard templates of electron density are created from the selected experimental and model electron density maps by clustering and averaging values of electron density in a spherical region about each point in a grid that defines each selected known experimental and model electron density maps. Histograms are also created from the selected experimental and model electron density maps that relate the value of electron density at the center of each of the spherical regions to a correlation coefficient of a density surrounding each corresponding grid point in each one of the standard templates. The standard templates and the histograms are applied to grid points on the experimental electron density map to form new estimates of electron density at each grid point in the experimental electron density map.
About density functional theory interpretation
Kirill Koshelev
2015-05-28
Two forms of relativistic density functional are derived from Dirac equation. Based on their structure analysis model of split electron is proposed. In this model electric charge and mass of electron behave like two point-like particles. It is shown that two electrons obeying this model cannot occupy the same quantum state. Empirical verification of the model is discussed.
Longitudinal polarized parton densities updated
Leader, Elliot; Sidorov, Aleksander V.; Stamenov, Dimiter B. [Imperial College, Prince Consort Road, London SW7 2BW (United Kingdom); Bogoliubov Theoretical Laboratory Joint Institute for Nuclear Research 141980 Dubna (Russian Federation); Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences Blvd. Tsarigradsko Chaussee 72, Sofia 1784 (Bulgaria)
2006-02-01
We have reanalyzed the world data on inclusive polarized DIS, in both NLO and LO QCD, including the new HERMES and COMPASS data. The updated NLO polarized densities are given in both the MS and JET schemes. The impact of the new data on the results is discussed.
Likelihood-based modification of experimental crystal structure electron density maps
Terwilliger, Thomas C. (Sante Fe, NM)
2005-04-16
A maximum-likelihood method for improves an electron density map of an experimental crystal structure. A likelihood of a set of structure factors {F.sub.h } is formed for the experimental crystal structure as (1) the likelihood of having obtained an observed set of structure factors {F.sub.h.sup.OBS } if structure factor set {F.sub.h } was correct, and (2) the likelihood that an electron density map resulting from {F.sub.h } is consistent with selected prior knowledge about the experimental crystal structure. The set of structure factors {F.sub.h } is then adjusted to maximize the likelihood of {F.sub.h } for the experimental crystal structure. An improved electron density map is constructed with the maximized structure factors.
Deep Mixtures of Factor Analysers Introduction
Toronto, University of
Deep Mixtures of Factor Analysers Introduction Experiments - High dimensional data (avg. log An efficient way to learn deep density models is to greedily learn one layer at a time using one layer latent Graphical Model of Deep MFA Illustration with 2D data Each ellipse is a Gaussian Component Aggregated
Human Factors @ UB Fall 2010 Human Factors
Krovi, Venkat
. Outsourcing aviation maintenance: Hu- man factors implications, specifically for communications. C. Drury, K. Guy, C. Wenner. International Journal of Aviation Psychology, 2010, 20, 124 143. #12;2 Human Factors
Chiral solitons in nuclei: Electromagnetic form factors
Jason R. Smith; Gerald A. Miller
2004-09-08
We calculate the electromagnetic form factors of a bound proton. The Chiral Quark-Soliton model provides the quark and antiquark substructure of the proton, which is embedded in nuclear matter. This procedure yields significant modifications of the form factors in the nuclear environment. The sea quarks are almost completely unaffected, and serve to mitigate the valence quark effect. In particular, the ratio of the isoscalar electric to the isovector magnetic form factor decreases by 20% at Q^2=1 GeV^2 at nuclear density, and we do not see a strong enhancement of the magnetic moment.
Density Functional Theory (DFT) Rob Parrish
Sherrill, David
· References 2 #12;Wavefunction Approach 3 Hydrogen 421 Wavefunction at Density Isosurface. Really hard to find Easy to do this Why? Because of Hermitian Operators: Kinetic Energy Density: #12;Density Functional Approach 4 Hydrogen 421 Density (Why is it grayscale?) A bit less obvious Probably easier to find
Probability distribution of the vacuum energy density
Duplancic, Goran; Stefancic, Hrvoje; Glavan, Drazen
2010-12-15
As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are broad and the vacuum expectation value of the Hamiltonian density is not fully representative of the vacuum energy density.
Density functional theory of freezing: Analysis of crystal density
Laird, Brian Bostian; McCoy, John D.; Haymet, A. D. J.
1987-09-01
the natural variables are temperature, chemical potential, and volume. The pressures are set equal by varying the liquid density until the grand thermodynamic potential, flO = - pV /kT, of the solid phase equals that of the liquid phase. It should... with temperature T, volume V, and chemical potential J.L. The particles interact via a potential energy U(rl, ... ,rn ) and feel an external single particle potential ifJ (r). Defining a dimen sionless single particle effective potential by u (r) = pJ.L - pif...
The Transcription Factor Encyclopedia
2012-01-01
Transcription Factor Encyclopedia. Genome Biology 2012 13:Factor Encyclopedia. Gen- ome Biology 2012, 13:000. where ‘Biology 2012, 13:R24 http://genomebiology.com/2012/13/3/R24 SOFTWARE Open Access The Transcription Factor Encyclopedia
Rock Density | Open Energy Information
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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS Report UrlNM-bRenewable Energy|Gas and Electric JumpDensity Jump to:
Neutral H density at the termination shock: a consolidation of recent results
M. Bzowski; E. Moebius; S. Tarnopolski; V. Izmodenov; G. Gloeckler
2008-12-04
We discuss a consolidation of determinations of the density of neutral interstellar H at the nose of the termination shock carried out with the use of various data sets, techniques, and modeling approaches. In particular, we focus on the determination of this density based on observations of H pickup ions on Ulysses during its aphelion passage through the ecliptic plane. We discuss in greater detail a novel method of determination of the density from these measurements and review the results from its application to actual data. The H density at TS derived from this analysis is equal to 0.087 \\pm 0.022 cm-3, and when all relevant determinations are taken into account, the consolidated density is obtained at 0.09 \\pm 0.022 cm-3. The density of H in CHISM based on literature values of filtration factor is then calculated at 0.16 \\pm 0.04 cm-3.
DENSITY OF STATES CALCULATIONS FOR CARBON
Adler, Joan
DENSITY OF STATES CALCULATIONS FOR CARBON ALLOTROPES AND MIXTURES EDUARDO WARSZAWSKI #12;#12;DENSITY OF STATES CALCULATIONS FOR CARBON ALLOTROPES AND MIXTURES Research Thesis Submitted in Partial;#12;Contents Abstract xiii 1 Introduction 1 1.1 Carbon allotropes
Low density expansion for Lyapunov exponents
Hermann Schulz-Baldes
2006-07-12
In some quasi-one-dimensional weakly disordered media, impurities are large and rare rather than small and dense. For an Anderson model with a low density of strong impurities, a perturbation theory in the impurity density is developed for the Lyapunov exponent and the density of states. The Lyapunov exponent grows linearly with the density. Anomalies of the Kappus-Wegner type appear for all rational quasi-momenta even in lowest order perturbation theory.
Oxides having high energy densities
Ceder, Gerbrand; Kang, Kisuk
2013-09-10
Certain disclosed embodiments generally relate to oxide materials having relatively high energy and/or power densities. Various aspects of the embodiments are directed to oxide materials having a structure B.sub.i(M.sub.jY.sub.k)O.sub.2, for example, a structure Li.sub.j(Ni.sub.jY.sub.k)O.sub.2 such as Li(Ni.sub.0.5Mn.sub.0.5)O.sub.2. In this structure, Y represents one or more atoms, each independently selected from the group consisting of alkaline earth metals, transition metals, Group 14 elements, Group 15, or Group 16 elements. In some embodiments, such an oxide material may have an O3 crystal structure, and/or a layered structure such that the oxide comprises a plurality of first, repeating atomic planes comprising Li, and a plurality of second, repeating atomic planes comprising Ni and/or Y.
Low-Density Attack Revisited Tetsuya Izu
International Association for Cryptologic Research (IACR)
Low-Density Attack Revisited Tetsuya Izu Jun Kogure Takeshi Koshiba Takeshi Shimoyama Secure The low-density attack proposed by Lagarias and Odlyzko is a powerful algorithm against the subset sum, densities of the subset sum problems should be higher than 0.9408... in order to avoid the low
Ultimate Energy Densities for Electromagnetic Pulses
Mankei Tsang
2008-03-06
The ultimate electric and magnetic energy densities that can be attained by bandlimited electromagnetic pulses in free space are calculated using an ab initio quantized treatment, and the quantum states of electromagnetic fields that achieve the ultimate energy densities are derived. The ultimate energy densities also provide an experimentally accessible metric for the degree of localization of polychromatic photons.
Dependence of polar hole density on magnetic and solar conditions
Hoegy, W.R.; Grebowsky, J.M. (NASA Goddard Space Flight Center, Greenbelt, MD (USA))
1991-04-01
The dependence of electron density in the polar F region ionization hole on solar activity, universal time (UT), magnetic activity, season, and hemisphere is studied using data from the Langmuir probes on Atmosphere Explorer C and Dynamics Explorer 2. The AE-C data were obtained during solar minimum when the 3-month average 10.7-cm solar flux index varied from 70 to 140; the DE 2 data were obtained near solar maximum when 10.7-cm solar flux index varied from 120 to 220. The polar hole is a region on the nightside of the polar cap where reduced ionization exists because of the long transport time of ionization from the dayside across the polar cap. The behavior of this region as a function of 10.7-cm solar flux (F10.7), UT, and Kp is statistically modeled for equinox, summer, and winter conditions for each hemisphere separately. The strongest dependencies are observed in F10.7 and UT; the Kp dependence is weak because it poorly represents the complexities of convection across the polar cap. A strong hemispherical difference due to the offset of the magnetic poles from the Earth's rotation axis is observed in the UT dependence of the ionization hole: there is a density minimum at about 20.3 hours UT in the south and at about 4.8 hours UT in the north; the minimum to maximum UT density variation is about a factor of 8.9 in the south and about a factor of 2.1 in the north. There is a seasonal variation in the dependence of ion density (N{sub i}) on solar flux (F10.7). Use of the relationship (N{sub i}{approximately}F10.7{sup D}) yields values of D of approximately unity (1.) in the summer polar hole and about 2.1 during equinox. There is an overall asymmetry in the density level between hemispheres; it was found that the winter hole density is about a factor of 10 greater in the north than in the south. The Utah State University time dependent ionosphere model gives similar UT behavior to that found in the AE-C and DE 2 data.
Branch xylem density variations across the Amazon Basin
2009-01-01
increase wood density in Eucalyptus grandis seedlings? ,Changes in wood density of Eucalyptus camaldulensis due to
Investigation of physical processes limiting plasma density in H-mode on DIII-D
Maingi, R.; Mahdavi, M.A.; Jernigan, T.C.
1996-12-01
A series of experiments was conducted on the DIII-D tokamak to investigate the physical processes which limit density in high confinement mode (H-mode) discharges. The typical H-mode to low confinement mode (L-mode) transition limit at high density near the empirical Greenwald density limit was avoided by divertor pumping, which reduced divertor neutral pressure and prevented formation of a high density, intense radiation zone (MARFE) near the X-point. It was determined that the density decay time after pellet injection was independent of density relative to the Greenwald limit and increased non-linearly with the plasma current. Magnetohydrodynamic (MHD) activity in pellet-fueled plasmas was observed at all power levels, and often caused unacceptable confinement degradation, except when the neutral beam injected (NBI) power was {le} 3 MW. Formation of MARFEs on closed field lines was avoided with low safety factor (q) operation but was observed at high q, qualitatively consistent with theory. By using pellet fueling and optimizing discharge parameters to avoid each of these limits, an operational space was accessed in which density {approximately} 1.5 {times} Greenwald limit was achieved for 600 ms, and good H-mode confinement was maintained for 300 ms of the density flattop. More significantly, the density was successfully increased to the limit where a central radiative collapse was observed, the most fundamental density limit in tokamaks.
Statistical density modification using local pattern matching
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2003-10-01
Statistical density modification can make use of local patterns of density found in protein structures to improve crystallographic phases. A method for improving crystallographic phases is presented that is based on the preferential occurrence of certain local patterns of electron density in macromolecular electron-density maps. The method focuses on the relationship between the value of electron density at a point in the map and the pattern of density surrounding this point. Patterns of density that can be superimposed by rotation about the central point are considered equivalent. Standard templates are created from experimental or model electron-density maps by clustering and averaging local patterns of electron density. The clustering is based on correlation coefficients after rotation to maximize the correlation. Experimental or model maps are also used to create histograms relating the value of electron density at the central point to the correlation coefficient of the density surrounding this point with each member of the set of standard patterns. These histograms are then used to estimate the electron density at each point in a new experimental electron-density map using the pattern of electron density at points surrounding that point and the correlation coefficient of this density to each of the set of standard templates, again after rotation to maximize the correlation. The method is strengthened by excluding any information from the point in question from both the templates and the local pattern of density in the calculation. A function based on the origin of the Patterson function is used to remove information about the electron density at the point in question from nearby electron density. This allows an estimation of the electron density at each point in a map, using only information from other points in the process. The resulting estimates of electron density are shown to have errors that are nearly independent of the errors in the original map using model data and templates calculated at a resolution of 2.6 Å. Owing to this independence of errors, information from the new map can be combined in a simple fashion with information from the original map to create an improved map. An iterative phase-improvement process using this approach and other applications of the image-reconstruction method are described and applied to experimental data at resolutions ranging from 2.4 to 2.8 Å.
Aerodynamic Focusing Of High-Density Aerosols
Ruiz, D. E.; Fisch, Nathaniel
2014-02-24
High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.
Energy density bounds for black strings
Shinya Tomizawa
2005-06-07
The conserved charge called Y-ADM mass density associated with asymptotically translational Killing-Yano tensor gives us an appropriate physical meaning about the energy density of $p$ brane spacetimes or black strings. We investigated the positivity of energy density in black string spacetimes, using the spinorial technique introduced by Witten. Recently, the positivity of Y-ADM mass density in p brane spacetimes was discussed. In this paper, we will extend this discussion to the transversely asymptotically flat black string spacetimes containing an apparent horizon. We will give the sufficient conditions for the Y-ADM mass density to become positive in such spacetimes.
Krzysztof Kutak
2012-11-16
Motivated by forthcoming p-Pb experiments at Large Hadron Collider which require both knowledge of gluon densities accounting for saturation and for processes at a wide range of $p_t$ we study basic momentum space evolution equations of high energy QCD factorization. Solutions of those equations might be used to form a set of gluon densities to calculate observables in generalized high energy factorization. Moreover in order to provide a framework for predictions for exclusive final states in p-Pb scattering with high $p_t$ we rewrite the equation for the high energy factorizable gluon density in a resummed form, similarly to what has been done in \\cite{Kutak:2011fu} for the BK equation. The resummed equation is then extended to account for colour coherence. This introduces an external scale to the evolution of the gluon density, and therefore makes it applicable in studies of final states.
Effect of low density H-mode operation on edge and divertor plasma parameters
Maingi, R. [Oak Ridge Associated Universities, Inc., TN (United States); Mioduszewski, P.K. [Oak Ridge National Lab., TN (United States); Cuthbertson, J.W. [Sandia National Labs., Albuquerque, NM (United States)] [and others
1994-07-01
We present a study of the impact of H-mode operation at low density on divertor plasma parameters on the DIII-D tokamak. The line-average density in H-mode was scanned by variation of the particle exhaust rate, using the recently installed divertor cryo-condensation pump. The maximum decrease (50%) in line-average electron density was accompanied by a factor of 2 increase in the edge electron temperature, and 10% and 20% reductions in the measured core and divertor radiated power, respectively. The measured total power to the inboard divertor target increased by a factor of 3, with the major contribution coming from a factor of 5 increase in the peak heat flux very close to the inner strike point. The measured increase in power at the inboard divertor target was approximately equal to the measured decrease in core and divertor radiation.
The effect of density gradient on the growth rate of relativistic Weibel instability
Mahdavi, M.; Khodadadi Azadboni, F.
2014-02-15
In this paper, the effect of density gradient on the Weibel instability growth rate is investigated. The density perturbations in the near corona fuel, where temperature anisotropy, ?, is larger than the critical temperature anisotropy, ?{sub c}, (??>??{sub c}), enhances the growth rate of Weibel instability due to the sidebands coupled with the electron oscillatory velocity. But for ??factor) is sufficiently large, ??>?2. The analysis shows that relativistic effects and density gradient tend to stabilize the Weibel instability. The growth rate can be reduced by 88% by reducing ? by a factor of 100 and increasing relativistic parameter by a factor of 3.
The Quantum Energy Density: Improved E
Krogel, Jaron; Yu, Min; Kim, Jeongnim; Ceperley, David M.
2013-01-01
We establish a physically meaningful representation of a quantum energy density for use in Quantum Monte Carlo calculations. The energy density operator, dened in terms of Hamiltonian components and density operators, returns the correct Hamiltonian when integrated over a volume containing a cluster of particles. This property is demonstrated for a helium-neon \\gas," showing that atomic energies obtained from the energy density correspond to eigenvalues of isolated systems. The formation energies of defects or interfaces are typically calculated as total energy dierences. Using a model of delta-doped silicon (where dopant atoms form a thin plane) we show how interfacial energies can be calculated more eciently with the energy density, since the region of interest is small. We also demonstrate how the energy density correctly transitions to the bulk limit away from the interface where the correct energy is obtainable from a separate total energy calculation.
Considering Air Density in Wind Power Production
Zénó Farkas
2011-03-11
In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.
Method of synthesizing a low density material
Lorensen, L.E.; Monaco, S.B.
1987-02-27
A novel method of synthesizing a polymeric material of low density of the order of 50mg/cc or less. Such a low density material has applications in many areas including laser target fabrication. The method comprises preparing a polymer blend of two incompatible polymers as a major and a minor phase by mixing them and extruding the mixture, and then selectively extracting the major component, to yield a fine, low density structure.
Considering Air Density in Wind Power Production
Farkas, Zénó
2011-01-01
In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.
Effects of Electromagnetic Field on Energy Density Inhomogeneity in Self-Gravitating Fluids
M. Sharif; Neelum Bashir
2012-09-25
This paper is devoted to study the effects of electromagnetic field on the energy density inhomogeneity in the relativistic self-gravitating fluids for spherically symmetric spacetime. Two important equations of the Weyl tensor are formulated which help to analyze the energy density inhomogeneity in this scenario. We investigate two types of fluids, i.e., non-dissipative and dissipative. The non-dissipative fluid further includes dust, locally isotropic, and locally anisotropic charged fluids. We explore the effects of different factors on energy density inhomogeneity in all these cases, in particular, the effect of charge.
3-D capacitance density imaging system
Fasching, G.E.
1988-03-18
A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.
Mini-review of Electron Density Visualization
Adler, Joan; Adler, Omri; Kreif, Meytal; Cohen, Or; Grosso, Bastien; Hashibon, Adham; Cooper, Valentino R
2015-01-01
We describe both educational and research oriented examples of electronic density visualization with AViz. Several detailed cases are presented and the procedures for their preparation are described.
Chiral dynamics and peripheral transverse densities Granados...
Office of Scientific and Technical Information (OSTI)
dynamics and peripheral transverse densities Granados, Carlos G. Uppsala University (Sweden); Weiss, Christian JLAB, Newport News, VA (United States) 72 PHYSICS OF ELEMENTARY...
Uncertainty Quantification for Nuclear Density Functional Theory...
Office of Scientific and Technical Information (OSTI)
Uncertainty Quantification for Nuclear Density Functional Theory and Information Content of New Measurements Citation Details In-Document Search Title: Uncertainty Quantification...
Uncertainty Quantification for Nuclear Density Functional Theory...
Office of Scientific and Technical Information (OSTI)
Uncertainty Quantification for Nuclear Density Functional Theory and Information Content of New Measurements Citation Details In-Document Search This content will become publicly...
Building a Universal Nuclear Energy Density Functional
Bertulani, Carlos A.
2014-09-10
This grant had two components: Density functional theory and pairing and Nuclear reactions. This final report summarizes the activities for this SciDAC-2 project.
Time Dependent Density Functional Theory An Introduction
Botti, Silvana
Time Dependent Density Functional Theory An Introduction Francesco Sottile Laboratoire des Solides) Belfast, 29 Jun 2007 Time Dependent Density Functional Theory Francesco Sottile #12;Intro Formalism Linear Response Formalism 3 TDDFT in practice: The ALDA: Achievements and Shortcomings 4 Resources Time
Enhancing critical current density of cuprate superconductors
Chaudhari, Praveen
2015-06-16
The present invention concerns the enhancement of critical current densities in cuprate superconductors. Such enhancement of critical current densities include using wave function symmetry and restricting movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices by using the half integer vortices associated with d-wave symmetry present in the grain boundary.
Density functional theory for carbon dioxide crystal
Chang, Yiwen; Mi, Jianguo Zhong, Chongli
2014-05-28
We present a density functional approach to describe the solid?liquid phase transition, interfacial and crystal structure, and properties of polyatomic CO{sub 2}. Unlike previous phase field crystal model or density functional theory, which are derived from the second order direct correlation function, the present density functional approach is based on the fundamental measure theory for hard-sphere repulsion in solid. More importantly, the contributions of enthalpic interactions due to the dispersive attractions and of entropic interactions arising from the molecular architecture are integrated in the density functional model. Using the theoretical model, the predicted liquid and solid densities of CO{sub 2} at equilibrium triple point are in good agreement with the experimental values. Based on the structure of crystal-liquid interfaces in different planes, the corresponding interfacial tensions are predicted. Their respective accuracies need to be tested.
Ions in solution: Density corrected density functional theory (DC-DFT)
Kim, Min-Cheol; Sim, Eunji; Burke, Kieron
2014-05-14
Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO·Cl{sup ?} and HO·H{sub 2}O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent.
Periodic subsystem density-functional theory
Genova, Alessandro; Pavanello, Michele; Ceresoli, Davide
2014-11-07
By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.
Low density, resorcinol-formaldehyde aerogels
Pekala, R.W.
1989-10-10
The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer clusters. The covalent crosslinking of these clusters produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density [<=]100 mg/cc; cell size [<=]0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 [angstrom]. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.
Low density, resorcinol-formaldehyde aerogels
Pekala, R.W.
1988-05-26
The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer ''clusters''. The covalent crosslinking of these ''clusters'' produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density less than or equal to100 mg/cc; cell size less than or equal to0.1 microns). The aerogels are transparent,dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 A/degree/. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron. 1 fig., 1 tab.
Low density, resorcinol-formaldehyde aerogels
Pekala, Richard W. (Pleasant Hill, CA)
1989-01-01
The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density .ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 .ANG.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.
Low density, resorcinol-formaldehyde aerogels
Pekala, Richard W. (Pleasant Hill, CA)
1991-01-01
The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "Clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density.ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100.circle.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.
Instabilities in the Nuclear Energy Density Functional
M. Kortelainen; T. Lesinski
2010-02-05
In the field of Energy Density Functionals (EDF) used in nuclear structure and dynamics, one of the unsolved issues is the stability of the functional. Numerical issues aside, some EDFs are unstable with respect to particular perturbations of the nuclear ground-state density. The aim of this contribution is to raise questions about the origin and nature of these instabilities, the techniques used to diagnose and prevent them, and the domain of density functions in which one should expect a nuclear EDF to be stable.
Light-front representation of chiral dynamics in peripheral transverse densities
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Granados, Carlos G.; Weiss, Christian
2015-07-31
The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances b = O(M_pi^{-1}) the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independentmore »and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantized, quantum-mechanical view of chiral dynamics that is fully relativistic and exactly equivalent to the second-quantized, field-theoretical formulation. It relates the charge and magnetization densities measured in low-energy elastic scattering to the generalized parton distributions probed in peripheral high-energy scattering processes. The method can be applied to nucleon form factors of other operators, e.g. the energy-momentum tensor.« less
Light-front representation of chiral dynamics in peripheral transverse densities
C. Granados; C. Weiss
2015-03-16
The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances $b = O(M_\\pi^{-1})$ the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independent and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantized, quantum-mechanical view of chiral dynamics that is fully relativistic and exactly equivalent to the second-quantized, field-theoretical formulation. It relates the charge and magnetization densities measured in low-energy elastic scattering to the generalized parton distributions probed in peripheral high-energy scattering processes. The method can be applied to nucleon form factors of other operators, e.g. the energy-momentum tensor.
A Framework to Determine the Probability Density Function for the Output Power of Wind Farms
Dominguez-Garcia, Alejandro
A Framework to Determine the Probability Density Function for the Output Power of Wind Farms Sairaj to the power output of a wind farm while factoring in the availability of the wind turbines in the farm availability model for the wind turbines, we propose a method to determine the wind-farm power output pdf
Gui Lu Long; Yi-Fan Zhou; Jia-Qi Jin; Yang Sun; Hai-Woong Lee
2006-04-20
We clarify different definitions of the density matrix by proposing the use of different names, the full density matrix for a single-closed quantum system, the compressed density matrix for the averaged single molecule state from an ensemble of molecules, and the reduced density matrix for a part of an entangled quantum system, respectively. We show that ensembles with the same compressed density matrix can be physically distinguished by observing fluctuations of various observables. This is in contrast to a general belief that ensembles with the same compressed density matrix are identical. Explicit expression for the fluctuation of an observable in a specified ensemble is given. We have discussed the nature of nuclear magnetic resonance quantum computing. We show that the conclusion that there is no quantum entanglement in the current nuclear magnetic resonance quantum computing experiment is based on the unjustified belief that ensembles having the same compressed density matrix are identical physically. Related issues in quantum communication are also discussed.
Research on Factors Relating to Density and Climate Change | Open Energy
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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onRAPID/Geothermal/Exploration/ColoradoRemsenburg-Speonk, New York: EnergyOpen Energy InformationInformation on
Turbulent density fluctuations in the solar wind
Ingale, Madhusudan
2015-01-01
Treatments of the radio scattering due to density turbulence in the solar wind typically employ asymptotic approximations to the phase structure function. We use a general structure function (GSF) that straddles the asymptotic limits and quantify the relative error introduced by the approximations. We show that the regimes where GSF predictions are accurate than those of its asymptotic approximations is not only of practical relevance, but are where inner scale effects influence the estimate of the scatter-broadening. Thus we propose that GSF should henceforth be used for scatter broadening calculations and estimates of quantities characterizing density turbulence in the solar corona and solar wind. In the next part of this thesis we use measurements of density turbulence in the solar wind from previously publish observations of radio wave scattering and interplanetary scintillations. Density fluctuations are inferred using the GSF for radio scattering data and existing analysis methods for IPS. Assuming that...
Spin- and Pair-Density-Wave Glasses
Mross, David F.
Spontaneous breaking of translational symmetry, known as density-wave order, is common in nature. However, such states are strongly sensitive to impurities or other forms of frozen disorder leading to fascinating glassy ...
LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS
Kutyniok, Gitta
LANDAU'S NECESSARY DENSITY CONDITIONS FOR LCA GROUPS KARLHEINZ GRÂ¨OCHENIG, GITTA KUTYNIOK's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics
Density controlled carbon nanotube array electrodes
Ren, Zhifeng F. (Newton, MA); Tu, Yi (Belmont, MA)
2008-12-16
CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.
Shock compression of low-density foams
Holmes, N.C.
1993-07-01
Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and experimental measurement of shock velocities. We present data for several materials over a range of initial densities. This paper will explore the applications of these methods for investigations of equations of state and phase diagrams, spectroscopy, and plasma physics. Finally, we discus the need for future work on these and related low-density materials.
Magnetic fields and density functional theory
Salsbury Jr., Freddie
1999-02-01
A major focus of this dissertation is the development of functionals for the magnetic susceptibility and the chemical shielding within the context of magnetic field density functional theory (BDFT). These functionals depend on the electron density in the absence of the field, which is unlike any other treatment of these responses. There have been several advances made within this theory. The first of which is the development of local density functionals for chemical shieldings and magnetic susceptibilities. There are the first such functionals ever proposed. These parameters have been studied by constructing functionals for the current density and then using the Biot-Savart equations to obtain the responses. In order to examine the advantages and disadvantages of the local functionals, they were tested numerically on some small molecules.
Breast Density and Cancer | GE Global Research
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Breast Cancer Awareness Series: Understanding Breast Density Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in...
Primordial Density Fluctuations in Phase Coupling Gravity
C. E. M. Batista; M. Schiffer
1996-01-10
In this paper we study the evolution of density perturbations in the framework of Phase Coupling Gravity theory at the very early universe. We show that these perturbation display an exponential-like behaviour.
Density shock waves in confined microswimmers
Tsang, Alan Cheng Hou
2015-01-01
Motile and driven particles confined in microfluidic channels exhibit interesting emergent behavior from propagating density bands to density shock waves. A deeper understanding of the physical mechanisms responsible for these emergent structures is relevant to a number of physical and biomedical applications. Here, we study the formation of density shock waves in the context of an idealized model of microswimmers confined in a narrow channel and subject to a uniform external flow. Interestingly, these density shock waves exhibit a transition from `subsonic' with compression at the back to `supersonic' with compression at the front of the population as the intensity of the external flow increases. This behavior is the result of a non-trivial interplay between hydrodynamic interactions and geometric confinement, and is confirmed by a novel quasilinear wave model that properly captures the dependence of the shock formation on the external flow. These findings can be used to guide the development of novel mechan...
Density of states of disordered systems
van Rossum, Mark; Nieuwenhuizen, Th.M; Hofstetter, E; Schreiber, M
1994-05-15
Density of states calculations for the tight-binding model with diagonal disorder are presented. An instanton approach is used to calculate the tails of the spectrum, including all prefactors. It is shown that a Hartree ...
Densities of Minor-Closed Graph Families
Eppstein, David
2010-01-01
N. Robertson and P. D. Seymour. Graph Minors. XX. Wagner’sChudnovsky, B. Reed, and P. Seymour. The edge-density for KReferences [1] N. Alon, P. Seymour, and R. Thomas. A
Spacetime Average Density (SAD) cosmological measures
Page, Don N.
2014-11-01
The measure problem of cosmology is how to obtain normalized probabilities of observations from the quantum state of the universe. This is particularly a problem when eternal inflation leads to a universe of unbounded size so that there are apparently infinitely many realizations or occurrences of observations of each of many different kinds or types, making the ratios ambiguous. There is also the danger of domination by Boltzmann Brains. Here two new Spacetime Average Density (SAD) measures are proposed, Maximal Average Density (MAD) and Biased Average Density (BAD), for getting a finite number of observation occurrences by using properties of the Spacetime Average Density (SAD) of observation occurrences to restrict to finite regions of spacetimes that have a preferred beginning or bounce hypersurface. These measures avoid Boltzmann brain domination and appear to give results consistent with other observations that are problematic for other widely used measures, such as the observation of a positive cosmological constant.
Ligand identification using electron-density mapcorrelations
Terwilliger, Thomas C.; Adams, Paul D.; Moriarty, Nigel W.; Cohn,Judith D.
2006-12-01
A procedure for the identification of ligands bound incrystal structuresof macromolecules is described. Two characteristics ofthe density corresponding to a ligand are used in the identificationprocedure. One is the correlation of the ligand density with each of aset of test ligands after optimization of the fit of that ligand to thedensity. The other is the correlation of a fingerprint of the densitywith the fingerprint of model density for each possible ligand. Thefingerprints consist of an ordered list of correlations of each the testligands with the density. The two characteristics are scored using aZ-score approach in which the correlations are normalized to the mean andstandard deviation of correlations found for a variety of mismatchedligand-density pairs, so that the Z scores are related to the probabilityof observing a particular value of the correlation by chance. Theprocedure was tested with a set of 200 of the most commonly found ligandsin the Protein Data Bank, collectively representing 57 percent of allligands in the Protein Data Bank. Using a combination of these twocharacteristics of ligand density, ranked lists of ligand identificationswere made for representative (F-o-F-c) exp(i phi(c)) difference densityfrom entries in the Protein Data Bank. In 48 percent of the 200 cases,the correct ligand was at the top of the ranked list of ligands. Thisapproach may be useful in identification of unknown ligands in newmacromolecular structures as well as in the identification of whichligands in a mixture have bound to a macromolecule.
Redshift Evolution of Galaxy Cluster Densities
R. G. Carlberg; S. L. Morris; H. K. C. Yee; E. Ellingson
1997-01-20
The number of rich galaxy clusters per unit volume is a strong function of Omega, the cosmological density parameter, and sigma_8, the linear extrapolation to z=0 of the density contrast in 8/h Mpc spheres. The CNOC cluster redshift survey provides a sample of clusters whose average mass profiles are accurately known, which enables a secure association between cluster numbers and the filtered density perturbation spectrum. We select from the CNOC cluster survey those EMSS clusters with bolometric L_x>=10^45 erg/s and a velocity dispersion exceeding 800 km/s in the redshift ranges 0.18-0.35 and 0.35-0.55. We compare the number density of these subsamples with similar samples at both high and low redshift. Using the Press-Schechter formalism and CDM style structure models, the density data are described with sigma_8=0.75+/-0.1 and Omega=0.4+/-0.2 (90% confidence). The cluster dynamical analysis gives Omega=0.2+/-0.1$ for which sigma_8=0.95+/-0.1 (90% confidence). The predicted cluster density evolution in an \\Omega=1 CDM model exceeds that observed by more than an order of magnitude.
Force Density Balance inside the Hydrogen Atom
Himpsel, F J
2015-01-01
Motivated by the long-debated question about the internal stability of the electron, the force densities acting on the charge density of the 1s electron in the H atom are investigated. The problem is mapped onto the canonical formalism for a classical Dirac field coupled to the electric field of an external point charge. An explicit calculation shows that the attractive Coulomb force density is balanced exactly at every point in space by the repulsive confinement force density. The latter requires evaluating the divergence of the stress tensor for the 1s solution of the Dirac equation. Such a local force balance goes beyond the global stability criteria that are usually given for the H atom. This concept is extended to the internal stability of any charged particle by investigating the force densities acting on its surrounding vacuum polarization. At large distances one has to consider only the charge density of virtual electrons and positrons, induced by a point charge in the vacuum of quantum electrodynamic...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
MX Factor Test films played a strategic-planning role in the debates of the late 1970s and early 1980s about where and how to deploy the MX intercontinental ballistic missile...
Viljoen, T. A.
1979-01-01
and disadvantages of various locations in the electrical network are described including the cost of installation and network capacity improvement. Sizing of capacitors is also covered. Finally, some case studies involving power factor improvement are presented...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Before PF 100142 0.70 or 70% After PF 100105 0.95 or 95% PB References: B.C. Hydro. Power Factor. The GEM Series. October 1989. Commonwealth Sprague Capacitor, Inc....
Electromagetic proton form factors
M Y Hussein
2006-10-31
The electromagnetic form factors are crucial to our understanding of the proton internal structure, and thus provide a strong constraint of the distributions of the charge and magnetization current within the proton. We adopted the quark-parton model for calculating and understanding the charge structure of the proton interms of the electromagnetic form factors. A remarkable agreement with the available experimental evidence is found.
Optimizing Power Factor Correction
Phillips, R. K.; Burmeister, L. C.
1986-01-01
FACTOR CORRECTION Robert K. Phillips and Louis C. Burmeister, Mechanical Engineering, University of Kansas, Lawrence, KS The optimal investment for power factor correcting capacitors for Kansas Power and Light Company large power contract customers... consumer of electricity were made for demands of 200, 400, 800, 1,600, 3,200, and 6,400 k\\~ and monthly energy consumption periods of 100, 150, 200, 300, 400, and 500 hours for several capacitor purchase and installation costs. The results...
Zamora, Paul O. (Gaithersburg, MD); Pena, Louis A. (Poquott, NY); Lin, Xinhua (Plainview, NY); Takahashi, Kazuyuki (Germantown, MD)
2012-07-24
The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.
Partial level density of the n-quasiparticle excitations in the nuclei of the 39< A <201 region
A. M. Sukhovoj; V. A. Khitrov
2005-12-16
Level density and radiative strength functions are obtained from the analysis of two-step cascades intensities following the thermal neutrons capture. The data on level density are approximated by the sum of the partial level densities corresponding to n quasiparticles excitation. The most probable values of the collective enhancement factor of the level density are found together with the thresholds of the next Cooper nucleons pair breaking. These data allow one to calculate the level density of practically any nucleus in given spin window in the framework of model concepts, taking into account all known nuclear excitation types. The presence of an approximation results discrepancy with theoretical statements specifies the necessity of rather essentially developing the level density models. It also indicates the possibilities to obtain the essentially new information on nucleon correlation functions of the excited nucleus from the experiment.
Orbital-optimized density cumulant functional theory
Sokolov, Alexander Yu. Schaefer, Henry F.
2013-11-28
In density cumulant functional theory (DCFT) the electronic energy is evaluated from the one-particle density matrix and two-particle density cumulant, circumventing the computation of the wavefunction. To achieve this, the one-particle density matrix is decomposed exactly into the mean-field (idempotent) and correlation components. While the latter can be entirely derived from the density cumulant, the former must be obtained by choosing a specific set of orbitals. In the original DCFT formulation [W. Kutzelnigg, J. Chem. Phys. 125, 171101 (2006)] the orbitals were determined by diagonalizing the effective Fock operator, which introduces partial orbital relaxation. Here we present a new orbital-optimized formulation of DCFT where the energy is variationally minimized with respect to orbital rotations. This introduces important energy contributions and significantly improves the description of the dynamic correlation. In addition, it greatly simplifies the computation of analytic gradients, for which expressions are also presented. We offer a perturbative analysis of the new orbital stationarity conditions and benchmark their performance for a variety of chemical systems.
Hamlet, Jason R; Pierson, Lyndon G
2014-10-21
Detection and deterrence of spoofing of user authentication may be achieved by including a cryptographic fingerprint unit within a hardware device for authenticating a user of the hardware device. The cryptographic fingerprint unit includes an internal physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a PUF value. Combining logic is coupled to receive the PUF value, combines the PUF value with one or more other authentication factors to generate a multi-factor authentication value. A key generator is coupled to generate a private key and a public key based on the multi-factor authentication value while a decryptor is coupled to receive an authentication challenge posed to the hardware device and encrypted with the public key and coupled to output a response to the authentication challenge decrypted with the private key.
Geothermal Plant Capacity Factors
Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood
2015-01-01
The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.
Fabrication of low density ceramic material
Meek, T.T.; Blake, R.D.; Sheinberg, H.
1985-01-01
A precursor mixture and a method of making a low-density ceramic structural material are disclosed. The precursor mixture includes hollow microballoons, typically made of glass, together with a cementing agent capable of being cured by microwave irradiation. A preferred cementing agent is liquid hydrated potassium silicate, which is mixed with the glass microballoons to form a slurry. Upon irradiation the potassium silicate is dehydrated to form a solid porous matrix in which the microballoons are evenly distributed. Ground glass or other filling agents may be included in the slurry to enhance the properties of the final product. Low-density structural ceramics having densities on the order of 0.1 to 0.3 are obtained.
Statistical approach to nuclear level density
Sen'kov, R. A.; Horoi, M.; Zelevinsky, V. G.
2014-10-15
We discuss the level density in a finite many-body system with strong interaction between the constituents. Our primary object of applications is the atomic nucleus but the same techniques can be applied to other mesoscopic systems. We calculate and compare nuclear level densities for given quantum numbers obtained by different methods, such as nuclear shell model (the most successful microscopic approach), our main instrument - moments method (statistical approach), and Fermi-gas model; the calculation with the moments method can use any shell-model Hamiltonian excluding the spurious states of the center-of-mass motion. Our goal is to investigate statistical properties of nuclear level density, define its phenomenological parameters, and offer an affordable and reliable way of calculation.
High power density solid oxide fuel cells
Pham, Ai Quoc; Glass, Robert S.
2004-10-12
A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O (LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.
Strongly Interacting Matter at High Energy Density
Larry McLerran
2008-12-08
This lecture concerns the properties of strongly interacting matter (which is described by Quantum Chromodynamics) at very high energy density. I review the properties of matter at high temperature, discussing the deconfinement phase transition . At high baryon density and low temperature, large $N_c$ arguments are developed which suggest that high baryonic density matter is a third form of matter, Quarkyonic Matter, that is distinct from confined hadronic matter and deconfined matter. I finally discuss the Color Glass Condensate which controls the high energy limit of QCD, and forms the low x part of a hadron wavefunction. The Glasma is introduced as matter formed by the Color Glass Condensate which eventually thermalizes into a Quark Gluon Plasma.
Density functional theory study of (OCS)2^-
Bilalbegovic, G
2007-01-01
The structural and electronic properties of the carbonyl sulfide dimer anion are calculated using density functional theory within a pseudopotential method. Three geometries are optimized and investigated: C2v and C2 symmetric, as well as one asymmetric structure. A distribution of an excess charge in three isomers are studied by the Hirshfeld method. In an asymmetric (OCS)2^- isomer the charge is not equally divided between the two moieties, but it is distributed as OCS^{-0.6} OCS^{-0.4}. Low-lying excitation levels of three isomers are compared using the time-dependent density functional theory in the Casida approach.
Low density, microcellular foams, preparation, and articles
Young, Ainslie T. (Los Alamos, NM); Marsters, Robert G. (Jemez Springs, NM); Moreno, Dawn K. (Espanola, NM)
1984-01-01
A microcellular low density foam of poly(4-methyl-1-pentene) which is particularly useful for forming targets for inertial confinement fusion has been developed. Articles made from the foam have been machined to tolerances of 0.0001 inch, although the densities of the fragile foam are low (about 10 to about 100 mg/cc) and the cell sizes are small (about 10 to about 30 .mu.m). Methods for forming the foam and articles are given; and the yield strength of the foam of the invention is higher than was obtained in other structures of this same material.
Low density, microcellular foams, preparation, and articles
Young, A.T.
1982-03-03
A microcellular low-density foam of poly(4-methyl-1-pentene) particularly useful for forming targets for inertial confinement fusion has been developed. Articles made from the foam have been machined to tolerances of 0.0001 inch, although the densities of the fragile foam are low (about 10 to about 100 mg/cc) and the cell sizes are small (about 10 to about 30 ..mu..m). Methods for forming the foam and articles are given. The yield strength of the foam of the invention is higher than was obtained in other structures of this same material.
Dark Energy Density in Brane World
Hai-Bao Wen; Xin-Bing Huang
2005-02-08
We present a possible explanation to the tiny positive cosmological constant under the frame of AdS$_5$ spacetime embedded by a dS$_4$ brane. We calculate the dark energy density by summing the zero point energy of massive scalar fields in AdS$_5$ spacetime. Under the assumption that the radius of AdS$_5$ spacetime is of the same magnitude as the radius of observable universe, the dark energy density in dS$_4$ brane is obtained, which is smaller than the observational value. The reasons are also discussed.
Configuration Interactions Constrained by Energy Density Functionals
B. Alex Brown; Angelo Signoracci; Morten Hjorth-Jensen
2010-09-24
A new method for constructing a Hamiltonian for configuration interaction calculations with constraints to energies of spherical configurations obtained with energy-density-functional (EDF) methods is presented. This results in a unified model that reproduced the EDF binding-energy in the limit of single-Slater determinants, but can also be used for obtaining energy spectra and correlation energies with renormalized nucleon-nucleon interactions. The three-body and/or density-dependent terms that are necessary for good nuclear saturation properties are contained in the EDF. Applications to binding energies and spectra of nuclei in the region above 208Pb are given.
Maximum likelihood density modification by pattern recognition of structural motifs
Terwilliger, Thomas C.
2004-04-13
An electron density for a crystallographic structure having protein regions and solvent regions is improved by maximizing the log likelihood of a set of structures factors {F.sub.h } using a local log-likelihood function: (x)+p(.rho.(x).vertline.SOLV)p.sub.SOLV (x)+p(.rho.(x).vertline.H)p.sub.H (x)], where p.sub.PROT (x) is the probability that x is in the protein region, p(.rho.(x).vertline.PROT) is the conditional probability for .rho.(x) given that x is in the protein region, and p.sub.SOLV (x) and p(.rho.(x).vertline.SOLV) are the corresponding quantities for the solvent region, p.sub.H (x) refers to the probability that there is a structural motif at a known location, with a known orientation, in the vicinity of the point x; and p(.rho.(x).vertline.H) is the probability distribution for electron density at this point given that the structural motif actually is present. One appropriate structural motif is a helical structure within the crystallographic structure.
Behavior of the particle transport coefficients near the density limit in MTX
Marinak, M.M.
1993-04-01
The perturbed particle transport coefficients were determined for a range of plasma conditions in the Alcator C tokamak, a component of the Microwave Tokamak Experiment (MTX), from analysis of density perturbations created in gas modulation experiments. Density measurements from a 15 chord far-infrared interferometer were sufficiently detailed to allow radial profiles of the transport coefficients to be resolved. Gas modulation experiments were carried out on plasmas over a range of relatively low currents and a wide variety of line-averaged densities, including values near the Greenwald density limit. With this technique the perturbed diffusion coefficient D and the perturbed convection velocity V can be determined simultaneously. Measured profiles of D rise toward the outside of the plasma column in a manner generally similar to those determined previously for {chi}{sub e,HP} from sawtooth heat pulse propagation. Values of D are typically smaller than those of {chi}{sub e,HP} given for the same line-averaged densities by a factor of 2-5. Diffusion coefficients from a series of discharges at constant current showed little variation with density through most of the saturated ohmic confinement regime. At the Greenwald density limit threshold a dramatic increase occurred in both the perturbed convective and diffusive transport coefficients in the outer region of the plasma. The increases were most pronounced at the outermost range of the radii where coefficients were determined (r/a = 0.8), but were apparent over a region which extended well into the plasma interior. Density profiles maintained a similar shape near the density limit, congruous with the similar behavior of the transport coefficients. No dramatic deterioration was evident in the global energy confinement.
Gordon Chalmers
2005-09-20
An algorithm is given to factor an integer with $N$ digits in $\\ln^m N$ steps, with $m$ approximately 4 or 5. Textbook quadratic sieve methods are exponentially slower. An improvement with the aid of an a particular function would provide a further exponential speedup.
On the Determination of the Mean Cosmic Matter Density and the Amplitude of Density Fluctuations
Thomas H. Reiprich
2002-07-02
The cosmological implications from a new estimate of the local X-ray galaxy cluster abundance are summarized. The results are then compared to independent observations. It is suggested that `low' values for the mean cosmic matter density and the amplitude of mass density fluctuations currently do not appear unreasonable observationally.
neutron density. The neutron density (nn) of the source was modeled by solving the simul-
West, Stuart
neutron density. The neutron density (nn) of the source was modeled by solving the simul- taneousT is the thermal neutron velocity, l is the decay constant, Ns is the s-process abun- dance, bsÀ is the maxwellian-averaged neutron capture cross-section, and t0 is the average neutron exposure (21). The branching decay of 186Re
Power spectrum of electron number density perturbations at cosmological recombination epoch
B. Venhlovska; B. Novosyadlyj
2009-02-19
The power spectrum of number density perturbations of free electrons is obtained for the epoch of cosmological recombination of hydrogen. It is shown that amplitude of the electron perturbations power spectrum of scales larger than acoustic horizon exceeds by factor of 17 the amplitude of baryon matter density ones (atoms and ions of hydrogen and helium). In the range of the first and second acoustic peaks such relation is 18, in the range of the third one 16. The dependence of such relations on cosmological parameters is analysed too.
Matrix Factorization and Matrix Concentration
Mackey, Lester
2012-01-01
PCA 3 Mixed Membership Matrix Factorization 3.15.2 Matrix concentration3.3 Mixed Membership Matrix Factorization . . . 3.4
Energy density fluctuations in inflationary cosmology
Müller, H F; Muller, Harald F; Schmid, Christoph
1994-01-01
We analyze the energy density fluctuations contributed by scalar fields \\Phi with vanishing expectation values, \\langle\\Phi\\rangle=0, which are present in addition to the inflaton field. For simplicity we take \\Phi to be non--interacting and minimally coupled to gravity. We use normal ordering to define the renormalized energy density operator \\rho, and we show that any normal ordering gives the same result for correlation functions of \\rho. We first consider massless fields and derive the energy fluctuations in a single mode \\vk, the two--point correlation function of the energy density, the power spectrum, and the variance of the smeared energy density, \\ddR. Mass effects are investigated for energy fluctuations in single modes. All quantities considered are scale invariant at the second horizon crossing (Harrison--Zel'dovich type) for massless and for unstable massive fields. The magnitude of the relative fluctuations \\de\\rho/\\rt is of order (\\Hi/\\Mp)^2 in the massless case, where \\Hi is the Hubble constan...
Photovoltaic retinal prosthesis with high pixel density
Palanker, Daniel
Photovoltaic retinal prosthesis with high pixel density Keith Mathieson1,4 , James Loudin1 to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high
Density Functional Theory Models for Radiation Damage
Density Functional Theory Models for Radiation Damage S.L. Dudarev EURATOM/CCFE Fusion Association and informative as the most advanced experimental techniques developed for the observation of radiation damage investigation and assessment of radiation damage effects, offering new insight into the origin of temperature
IMPROVED DENSITY ESTIMATORS FOR INVERTIBLE LINEAR PROCESSES
Wefelmeyer, Wolfgang
IMPROVED DENSITY ESTIMATORS FOR INVERTIBLE LINEAR PROCESSES Anton Schick Department of Mathematical-statistic with kernel of the form K(x) = k(x - ay)k(y) dy. Schick and Wefelmeyer (2004b, 2007a) prove functional central and Schick (2007) obtain similar results for derivatives of convolutions. Schick and Wefelmeyer (2008b
Population density of San Joaquin kit fox
McCue, P.; O'Farrell, T.P.; Kato, T.; Evans, B.G.
1982-01-01
Populations of the endangered San Joaquin kit fox, vulpes macrotis mutica, are known to occur on the Elk Hills Naval Petroleum Reserve No. 1. This study assess the impact of intensified petroleum exploration and production and associated human activities on kit fox population density. (ACR)
ADAPTIVE DENSITY ESTIMATION WITH MASSIVE DATA SETS
Scott, David W.
recognition, density estima tion, and data visualization. However, one already hears stories of logistic the data, and some require the data to be in core. 1.1 Reversing Efficiency Roles What general solution can we propose? It is our po sition that massive data sets reverse our usual focus This research
Nuclear spin-density wave theory
Yao Cheng
2009-09-15
Recently [arXiv:0906.5417], we reported a quantum phase transition of 103mRh excited by bremsstrahlung pumping. The long-lived Moessbauer excitation is delocalized as a neutral quasiparticle carrying a spin current. This letter gives a general theory for a nuclear spin-density wave propagating on crystals consisting of identical nuclei with a multipolar transition.
Durable high-density data storage
Stutz, R.A.; Lamartine, B.C.
1996-09-01
This paper will discuss the Focus Ion Beam (FIB) milling process, media life considerations, and methods of reading the micromilled data. The FIB process for data storage provides a new non-magnetic storage method for archiving large amounts of data. The process stores data on robust materials such as steel, silicon, and gold coated silicon. The storage process was developed to provide a method to insure the long term storage life of data. We estimate the useful life of data written on silicon or gold coated silicon to be a few thousand years. The process uses an ion beam to carve material from the surface much like stone cutting. The deeper information is carved into the media the longer the expected life of the information. The process can read information in three formats: (1) binary at densities of 3.5 Gbits/cm{sup 2}, (2) alphanumeric at optical or non-optical density, and (3) graphical at optical and non-optical density. The formats can be mixed on the same media; and thus it is possible to record, in a human readable format, instructions that can be read using an optical microscope. These instructions provide guidance on reading the higher density information.
Density waves in the Calogero model - revisited
Bardek, V. Feinberg, J. Meljanac, S.
2010-03-15
The Calogero model bears, in the continuum limit, collective excitations in the form of density waves and solitary modulations of the density of particles. This sector of the spectrum of the model was investigated, mostly within the framework of collective-field theory, by several authors, over the past 15 years or so. In this work we shall concentrate on periodic solutions of the collective BPS-equation (also known as 'finite amplitude density waves'), as well as on periodic solutions of the full static variational equations which vanish periodically (also known as 'large amplitude density waves'). While these solutions are not new, we feel that our analysis and presentation add to the existing literature, as we explain in the text. In addition, we show that these solutions also occur in a certain two-family generalization of the Calogero model, at special points in parameter space. A compendium of useful identities associated with Hilbert transforms, including our own proofs of these identities, appears in Appendix A. In Appendix B we also elucidate in the present paper some fine points having to do with manipulating Hilbert-transforms, which appear ubiquitously in the collective field formalism. Finally, in order to make this paper self-contained, we briefly summarize in Appendix C basic facts about the collective field formulation of the Calogero model.
High Energy Density Laboratory Plasmas Program | National Nuclear...
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Photo Gallery Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home High Energy Density Laboratory Plasmas Program High Energy Density Laboratory Plasmas Program...
Controlling the Actuation Rate of Low Density Shape Memory Polymer...
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Controlling the Actuation Rate of Low Density Shape Memory Polymer Foams in Water Citation Details In-Document Search Title: Controlling the Actuation Rate of Low Density Shape...
Using Radio Waves to Control Fusion Plasma Density
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Using Radio Waves to Control Fusion Plasma Density Using Radio Waves to Control Fusion Plasma Density Simulations Run at NERSC Support Fusion Experiments at MIT, General Atomics...
Real-Time Simultaneous Measurements of Size, Density, and Composition...
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Simultaneous Measurements of Size, Density, and Composition of Single Ultrafine Diesel Tailpipe Particles Real-Time Simultaneous Measurements of Size, Density, and Composition of...
Density Log At Valles Caldera - Redondo Geothermal Area (Wilt...
Density Log At Valles Caldera - Redondo Geothermal Area (Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Density Log At Valles...
DIAGNOSTICS FOR ION BEAM DRIVEN HIGH ENERGY DENSITY PHYSICS EXPERIMENTS
Bieniosek, F.M.
2010-01-01
for high energy density physics and fusion applications,IFSA 2007, Journal of Physics, Conference Series 112 (2008)high energy density physics experiments F. M. Bieniosek, E.
Error Analysis in Nuclear Density Functional Theory (Journal...
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Error Analysis in Nuclear Density Functional Theory Citation Details In-Document Search Title: Error Analysis in Nuclear Density Functional Theory Authors: Schunck, N ; McDonnell,...
Error Analysis in Nuclear Density Functional Theory (Journal...
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Error Analysis in Nuclear Density Functional Theory Citation Details In-Document Search Title: Error Analysis in Nuclear Density Functional Theory You are accessing a document...
Mitigating Breakdown in High Energy Density Perovskite Polymer...
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Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors 2012...
Inhomogeneity smoothing using density valley formed by ion beam...
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Inhomogeneity smoothing using density valley formed by ion beam deposition in ICF fuel pellet Citation Details In-Document Search Title: Inhomogeneity smoothing using density...
WAVE-ENERGY DENSITY AND WAVE-MOMENTUM DENSITY OF EACH SPECIES OF A COLLISION-LESS PLASMA
Cary, John R.
2012-01-01
A LiBRARY ANL WAVE-ENERGY DENSITY AND WAVE-MOMENTUM DENSITYof Califomia. To be in WAVE-ENERGY DENSITY AND WAVE~HOMENTUMExpress1ons for the wave-energy density and wave-momentum
?Linear Gas Jet with Tailored Density Profile"
KRISHNAN, Mahadevan
2012-12-10
Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.
Radial evolution of the intermittency of density fluctuations in the fast solar wind
Bruno, R.; D'Amicis, R.; Telloni, D.; Primavera, L.; Sorriso-Valvo, L.; Carbone, V.; Malara, F.; Veltri, P.
2014-05-01
We study the radial evolution of the intermittency of density fluctuations in the fast solar wind. The study is performed by analyzing the plasma density measurements provided by Helios 2 in the inner heliosphere between 0.3 and 0.9 AU. The analysis is carried out by means of a complete set of diagnostic tools, including the flatness factor at different timescales to estimate intermittency, the Kolmogorov-Smirnov test to estimate the degree of intermittency, and the Fourier transform to estimate the power spectral densities of these fluctuations. Density fluctuations within the fast wind are rather intermittent and their level of intermittency, together with the amplitude of intermittent events, decreases with the distance from the Sun, at odds with the intermittency of both magnetic field and all other plasma parameters. Furthermore, the intermittent events are strongly correlated, exhibiting temporal clustering. This indicates that the mechanism underlying their generation departs from a time-varying Poisson process. A remarkable, qualitative similarity with the behavior of plasma density fluctuations obtained from a numerical study of the nonlinear evolution of parametric instability in the solar wind supports the idea that this mechanism has an important role in governing density fluctuations in the inner heliosphere.
Farrar, G.R.; Huleihel, K.; Zhang, H. (Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States))
1995-01-30
We obtain the perturbative QCD (PQCD) prediction for the leading twist deuteron form factor, treated as a pair of nucleons in nonrelativistic bound state. It is [lt]10[sup [minus]3] times experiment at [ital Q][sup 2]=4 GeV[sup 2], suggesting that PQCD is not relevant to the deuteron form factor at present values of [ital Q][sup 2], or that non-nucleon (e.g., hidden color'') degrees of freedom must be included for a correct description of the deuteron. The tree-level amplitude [similar to][ital eg][sup 10] and is the sum of several 10[sup 6] Feynman diagrams, making it an interesting case study in the behavior of perturbation theory.
The problem of the universal density functional and the density matrix functional theory
Bobrov, V. B. Trigger, S. A.
2013-04-15
The analysis in this paper shows that the Hohenberg-Kohn theorem is the constellation of two statements: (i) the mathematically rigorous Hohenberg-Kohn lemma, which demonstrates that the same ground-state density cannot correspond to two different potentials of an external field, and (ii) the hypothesis of the existence of the universal density functional. Based on the obtained explicit expression for the nonrel-ativistic particle energy in a local external field, we prove that the energy of the system of more than two non-interacting electrons cannot be a functional of the inhomogeneous density. This result is generalized to the system of interacting electrons. It means that the Hohenberg-Kohn lemma cannot provide justification of the universal density functional for fermions. At the same time, statements of the density functional theory remain valid when considering any number of noninteracting ground-state bosons due to the Bose condensation effect. In the framework of the density matrix functional theory, the hypothesis of the existence of the universal density matrix functional corresponds to the cases of noninteracting particles and to interaction in the Hartree-Fock approximation.
Journal Information Journal Impact Factor
Krejcí, Pavel
Journal Information Journal Impact Factor 5-Year Journal Impact Factor Journal Self Cites Journal Immediacy Index Journal Cited Half-Life 2014 JCR Science Edition Journal: CZECHOSLOVAK MATHEMATICAL JOURNAL Mark Journal Title ISSN Total Cites Impact Factor 5-Year Impact Factor Immediacy Index Citable Items
Journal Information Journal Impact Factor
Krejcí, Pavel
Journal Information Journal Impact Factor 5-Year Journal Impact Factor Journal Self Cites Journal Immediacy Index Journal Cited Half-Life 2012 JCR Science Edition Journal: CZECHOSLOVAK MATHEMATICAL JOURNAL Mark Journal Title ISSN Total Cites Impact Factor 5-Year Impact Factor Immediacy Index Citable Items
Ion Density Deviations in Semipermeable Ionic Microcapsules
Qiyun Tang; Alan R. Denton
2015-07-07
By implementing the nonlinear Poisson-Boltzmann theory in a cell model, we theoretically investigate the influence of polyelectrolye gel permeability on ion densities and pH deviations inside the cavities of ionic microcapsules. Our calculations show that variations in permeability of a charged capsule shell cause a redistribution of ion densities within the capsule, which ultimately affects the pH deviation and Donnan potential induced by the electric field of the shell. We find that semipermeable capsules can induce larger pH deviations inside their cavities that can permeable capsules. Furthermore, with increasing capsule charge, the influence of permeability on pH deviations progressively increases. Our theory, while providing a self-consistent method for modeling the influence of permeability on fundamental properties of ionic microgels, makes predictions of practical significance for the design of microcapsules loaded with fluorescent dyes, which can serve as biosensors for diagnostic purposes.
Ultra-high density diffraction grating
Padmore, Howard A.; Voronov, Dmytro L.; Cambie, Rossana; Yashchuk, Valeriy V.; Gullikson, Eric M.
2012-12-11
A diffraction grating structure having ultra-high density of grooves comprises an echellette substrate having periodically repeating recessed features, and a multi-layer stack of materials disposed on the echellette substrate. The surface of the diffraction grating is planarized, such that layers of the multi-layer stack form a plurality of lines disposed on the planarized surface of the structure in a periodical fashion, wherein lines having a first property alternate with lines having a dissimilar property on the surface of the substrate. For example, in one embodiment, lines comprising high-Z and low-Z materials alternate on the planarized surface providing a structure that is suitable as a diffraction grating for EUV and soft X-rays. In some embodiments, line density of between about 10,000 lines/mm to about 100,000 lines/mm is provided.
Density of States for HP Lattice Proteins
Michael Bachmann; Wolfhard Janke
2007-10-22
The density of states contains all informations on energetic quantities of a statistical system, such as the mean energy, free energy, entropy, and specific heat. As a specific application, we consider in this work a simple lattice model for heteropolymers that is widely used for studying statistical properties of proteins. For short chains, we have derived exact results from conformational enumeration, while for longer ones we developed a multicanonical Monte Carlo variant of the nPERM-based chain growth method in order to directly simulate the density of states. For simplification, only two types of monomers with respective hydrophobic (H) and polar (P) residues are regarded and only the next-neighbour interaction between hydrophobic monomers, being nonadjacent along the chain, is taken into account. This is known as the HP model for the folding of lattice proteins.
Global coherence of dust density waves
Killer, Carsten; Melzer, André
2014-06-15
The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.
Inductor Geometry With Improved Energy Density
Cui, H; Ngo, KDT; Moss, J; Lim, MHF; Rey, E
2014-10-01
The "constant-flux" concept is leveraged to achieve high magnetic-energy density, leading to inductor geometries with height significantly lower than that of conventional products. Techniques to shape the core and to distribute the winding turns to shape a desirable field profile are described for the two basic classes of magnetic geometries: those with the winding enclosed by the core and those with the core enclosed by the winding. A relatively constant flux distribution is advantageous not only from the density standpoint, but also from the thermal standpoint via the reduction of hot spots, and from the reliability standpoint via the suppression of flux crowding. In this journal paper on a constant-flux inductor (CFI) with enclosed winding, the foci are operating principle, dc analysis, and basic design procedure. Prototype cores and windings were routed from powder-iron disks and copper sheets, respectively. The design of CFI was validated by the assembled inductor prototype.
Alekseev, A E; Potapov, V T
2013-10-31
Spectral characteristics of the noise intensity fluctuations at the output of a scattered-light interferometer, caused by phase fluctuations of semiconductor laser radiation are considered. This kind of noise is one of the main factors limiting sensitivity of interferometric sensors. For the first time, to our knowledge, the expression is obtained for the average noise power spectral density at the interferometer output versus the degree of a light source coherence and length of the scattering segment. Also, the approximate expressions are considered which determine the power spectral density in the low-frequency range (up to 200 kHz) and in the limiting case of extended scattering segments. The expression obtained for the noise power spectral density agrees with experimental normalised power spectra with a high accuracy. (interferometry of radiation)
Deuterium density profile determination at JET using a neutron camera and a neutron spectrometer
Eriksson, J. Castegnetti, G.; Conroy, S.; Ericsson, G.; Hellesen, C.; Giacomelli, L.
2014-11-15
In this work we estimate the fuel ion density profile in deuterium plasmas at JET, using the JET neutron camera, the neutron time-of-flight spectrometer TOFOR, and fusion reactivities modeled by the transport code TRANSP. The framework has been tested using synthetic data, which showed that the density profile could be reconstructed with an average accuracy of the order of 10 %. The method has also been applied to neutron measurements from a neutral beam heated JET discharge, which gave n{sub d}/n{sub e} ? 0.6 ± 0.3 in the plasma core and n{sub d}/n{sub e} ? 0.4 ± 0.3 towards the edge. Correction factors for detector efficiencies, neutron attenuation, and back-scattering are not yet included in the analysis; future work will aim at refining the estimated density.
Energy flux density in a thermoacoustic couple
Cao, N.; Chen, S. |; Olson, R.; Swift, G.W.
1996-06-01
The hydro- and thermodynamical processes near and within a thermoacoustic couple are simulated and analyzed by numerical solution of the compressible Navier-Stokes, continuity, and energy equations for an ideal gas, concentrating on the time-averaged energy flux density in the gas. The numerical results show details of the heat sink at one end of the plates in the thermoacoustic couple. 15 refs., 10 figs., 1 tab.
Fluctuations at finite temperature and density
Borsanyi, Szabolcs
2015-01-01
Fluctuations of conserved charges in a grand canonical ensemble can be calculated as derivatives of the free energy with respect to the respective chemical potential. They are directly related to experimentally available observables that describe the hadronization in heavy ion collisions. The same derivatives can be used to extrapolate zero density results to finite chemical potential. We review the recent lattice calculations in the staggered formalism and discuss its implications to phenomenology and resummed perturbation theory.
Nuclear fission in covariant density functional theory
A. V. Afanasjev; H. Abusara; P. Ring
2013-09-12
The current status of the application of covariant density functional theory to microscopic description of nuclear fission with main emphasis on superheavy nuclei (SHN) is reviewed. The softness of SHN in the triaxial plane leads to an emergence of several competing fission pathes in the region of the inner fission barrier in some of these nuclei. The outer fission barriers of SHN are considerably affected both by triaxiality and octupole deformation.
Energy-momentum Density of Gravitational Waves
Amir M. Abbassi; Saeed Mirshekari
2014-11-29
In this paper, we elaborate the problem of energy-momentum in general relativity by energy-momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to same results that have been obtained by Einstein and Papapetrou prescriptions.
Thermodynamics and Structural Properties of the High Density Gaussian Core Model
Atsushi Ikeda; Kunimasa Miyazaki
2011-07-20
We numerically study thermodynamic and structural properties of the one-component Gaussian core model (GCM) at very high densities. The solid-fluid phase boundary is carefully determined. We find that the density dependence of both the freezing and melting temperatures obey the asymptotic relation, $\\log T_f$, $\\log T_m \\propto -\\rho^{2/3}$, where $\\rho$ is the number density, which is consistent with Stillinger's conjecture. Thermodynamic quantities such as the energy and pressure and the structural functions such as the static structure factor are also investigated in the fluid phase for a wide range of temperature above the phase boundary. We compare the numerical results with the prediction of the liquid theory with the random phase approximation (RPA). At high temperatures, the results are in almost perfect agreement with RPA for a wide range of density, as it has been already shown in the previous studies. In the low temperature regime close to the phase boundary line, although RPA fails to describe the structure factors and the radial distribution functions at the length scales of the interparticle distance, it successfully predicts their behaviors at shorter length scales. RPA also predicts thermodynamic quantities such as the energy, pressure, and the temperature at which the thermal expansion coefficient becomes negative, almost perfectly. Striking ability of RPA to predict thermodynamic quantities even at high densities and low temperatures is understood in terms of the decoupling of the length scales which dictate thermodynamic quantities from the interparticle distance which dominates the peak structures of the static structure factor due to the softness of the Gaussian core potential.
Energy trapping from Hagedorn densities of states
Connor Behan; Klaus Larjo; Nima Lashkari; Brian Swingle; Mark Van Raamsdonk
2013-04-26
In this note, we construct simple stochastic toy models for holographic gauge theories in which distributions of energy on a collection of sites evolve by a master equation with some specified transition rates. We build in only energy conservation, locality, and the standard thermodynamic requirement that all states with a given energy are equally likely in equilibrium. In these models, we investigate the qualitative behavior of the dynamics of the energy distributions for different choices of the density of states for the individual sites. For typical field theory densities of states (\\log(\\rho(E)) ~ E^{\\alphaenergy spread out relatively quickly. For large N gauge theories with gravitational duals, the density of states for a finite volume of field theory degrees of freedom typically includes a Hagedorn regime (\\log(\\rho(E)) ~ E). We find that this gives rise to a trapping of energy in subsets of degrees of freedom for parametrically long time scales before the energy leaks away. We speculate that this Hagedorn trapping may be part of a holographic explanation for long-lived gravitational bound states (black holes) in gravitational theories.
2010-04-01
Broad Funding Opportunity Announcement Project: FastCAP is improving the performance of an ultracapacitor—a battery-like electronic device that can complement, and possibly even replace, an HEV or EV battery pack. Ultracapacitors have many advantages over conventional batteries, including long lifespans (over 1 million cycles, as compared to 10,000 for conventional batteries) and better durability. Ultracapacitors also charge more quickly than conventional batteries, and they release energy more quickly. However, ultracapacitors have fallen short of batteries in one key metric: energy density—high energy density means more energy storage. FastCAP is redesigning the ultracapacitor’s internal structure to increase its energy density. Ultracapacitors traditionally use electrodes made of irregularly shaped, porous carbon. FastCAP’s ultracapacitors are made of tiny, aligned carbon nanotubes. The nanotubes provide a regular path for ions moving in and out of the ultracapacitor’s electrode, increasing the overall efficiency and energy density of the device.
Lee, Hyoung Il
2008-10-10
filter. See, e.g., Tanizaki (1996) for a general introduction to the density-based Kalman fil- ter. The second approach applies the standard Bayesian procedure and estimates the unknown parameters and latent factor by their posterior means, which... transition and persistent la- tent factors. We argue that this model has advantages over theconventional stochastic model for the persistent volatility factor. Though the linear filtering is widely used in the state space model, the simulation result, as well...
Radiography to measure the longitudinal density gradients of Pd compacts
Back, D.D.
1992-05-14
This study used radiography to detect and quantify density gradients in green compacts of Palladium powder. Ultrasonic velocity measurements had been tried previously, but they were affected by material properties, in addition to the density, so that an alternative was sought. The alternative technique used radiographic exposures of a series of standard compacts whose density is known and correlated with the radiographic film density. These correlations are used to predict the density in subsequent compacts.
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States); Grosse-Kunstleve, Ralf W.; Afonine, Pavel V.; Moriarty, Nigel W.; Zwart, Peter H. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States); Read, Randy J. [Department of Haematology, University of Cambridge, Cambridge CB2 0XY (United Kingdom); Adams, Paul D., E-mail: terwilliger@lanl.gov [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States)
2008-01-01
The highly automated PHENIX AutoBuild wizard is described. The procedure can be applied equally well to phases derived from isomorphous/anomalous and molecular-replacement methods. The PHENIX AutoBuild wizard is a highly automated tool for iterative model building, structure refinement and density modification using RESOLVE model building, RESOLVE statistical density modification and phenix.refine structure refinement. Recent advances in the AutoBuild wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model-completion algorithms and automated solvent-molecule picking. Model-completion algorithms in the AutoBuild wizard include loop building, crossovers between chains in different models of a structure and side-chain optimization. The AutoBuild wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 to 3.2 Å, resulting in a mean R factor of 0.24 and a mean free R factor of 0.29. The R factor of the final model is dependent on the quality of the starting electron density and is relatively independent of resolution.
Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545, USA; Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720, USA; Department of Haematology, University of Cambridge, Cambridge CB2 0XY, England; Terwilliger, Thomas; Terwilliger, T.C.; Grosse-Kunstleve, Ralf Wilhelm; Afonine, P.V.; Moriarty, N.W.; Zwart, P.H.; Hung, L.-W.; Read, R.J.; Adams, P.D.
2007-04-29
The PHENIX AutoBuild Wizard is a highly automated tool for iterative model-building, structure refinement and density modification using RESOLVE or TEXTAL model-building, RESOLVE statistical density modification, and phenix.refine structure refinement. Recent advances in the AutoBuild Wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model completion algorithms, and automated solvent molecule picking. Model completion algorithms in the AutoBuild Wizard include loop-building, crossovers between chains in different models of a structure, and side-chain optimization. The AutoBuild Wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 {angstrom} to 3.2 {angstrom}, resulting in a mean R-factor of 0.24 and a mean free R factor of 0.29. The R-factor of the final model is dependent on the quality of the starting electron density, and relatively independent of resolution.
Design of dynamic Hohlraum opacity samples to increase measured sample density on Z
Nash, T. J.; Rochau, G. A.; Bailey, J. E. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
2010-10-15
We are attempting to measure the transmission of iron on Z at plasma temperatures and densities relevant to the solar radiation and convection zone boundary. The opacity data published by us to date has been taken at an electron density about a factor of 10 below the 9x10{sup 22}/cm{sup 3} electron density of this boundary. We present results of two-dimensional (2D) simulations of the heating and expansion of an opacity sample driven by the dynamic Hohlraum radiation source on Z. The aim of the simulations is to design foil samples that provide opacity data at increased density. The inputs or source terms for the simulations are spatially and temporally varying radiation temperatures with a Lambertian angular distribution. These temperature profiles were inferred on Z with on-axis time-resolved pinhole cameras, x-ray diodes, and bolometers. A typical sample is 0.3 {mu}m of magnesium and 0.078 {mu}m of iron sandwiched between 10 {mu}m layers of plastic. The 2D LASNEX simulations indicate that to increase the density of the sample one should increase the thickness of the plastic backing.
Design of dynamic hohlraum opacity samples to increase measured sample density on Z.
Rochau, Gregory Alan; Nash, Thomas J.; Bailey, James E.
2010-03-01
We are attempting to measure the transmission of iron on Z at plasma temperatures and densities relevant to the solar radiation and convection zone boundary. The opacity data published by us to date has been taken at an electron density about a factor of 10 below the 9 x 10{sup 22}/cm{sup 3} electron density of this boundary. We present results of two-dimensional (2D) simulations of the heating and expansion of an opacity sample driven by the dynamic Hohlraum radiation source on Z. The aim of the simulations is to design foil samples that provide opacity data at increased density. The inputs or source terms for the simulations are spatially and temporally varying radiation temperatures with a Lambertian angular distribution. These temperature profiles were inferred on Z with on-axis time-resolved pinhole cameras, x-ray diodes, and bolometers. A typical sample is 0.3{micro}m of magnesium and 0.078{micro}m of iron sandwiched between 10{micro}m layers of plastic. The 2D LASNEX simulations indicate that to increase the density of the sample one should increase the thickness of the plastic backing.
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Read, Randy J. [University of Cambridge, Cambridge CB2 0XY (United Kingdom); Adams, Paul D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Brunger, Axel T. [Stanford University, 318 Campus Drive West, Stanford, CA 94305-5432 (United States); Afonine, Pavel V.; Grosse-Kunstleve, Ralf W. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2012-07-01
A density-based procedure is described for improving a homology model that is locally accurate but differs globally. The model is deformed to match the map and refined, yielding an improved starting point for density modification and further model-building. An approach is presented for addressing the challenge of model rebuilding after molecular replacement in cases where the placed template is very different from the structure to be determined. The approach takes advantage of the observation that a template and target structure may have local structures that can be superimposed much more closely than can their complete structures. A density-guided procedure for deformation of a properly placed template is introduced. A shift in the coordinates of each residue in the structure is calculated based on optimizing the match of model density within a 6 Å radius of the center of that residue with a prime-and-switch electron-density map. The shifts are smoothed and applied to the atoms in each residue, leading to local deformation of the template that improves the match of map and model. The model is then refined to improve the geometry and the fit of model to the structure-factor data. A new map is then calculated and the process is repeated until convergence. The procedure can extend the routine applicability of automated molecular replacement, model building and refinement to search models with over 2 Å r.m.s.d. representing 65–100% of the structure.
Nuclear Energy Density Optimization: UNEDF2
M. Kortelainen; J. McDonnell; W. Nazarewicz; E. Olsen; P. -G. Reinhard; J. Sarich; N. Schunck; S. M. Wild; D. Davesne; J. Erler; A. Pastore
2014-10-30
The parameters of the UNEDF2 nuclear energy density functional (EDF) model were obtained in an optimization to experimental data consisting of nuclear binding energies, proton radii, odd-even mass staggering data, fission-isomer excitation energies, and single particle energies. In addition to parameter optimization, sensitivity analysis was done to obtain parameter uncertainties and correlations. The resulting UNEDF2 is an all-around EDF. However, the sensitivity analysis also demonstrated that the limits of current Skyrme-like EDFs have been reached and that novel approaches are called for.
Landau's necessary density conditions for LCA groups
Gröchenig, K; Seip, K
2008-01-01
H. Landau's necessary density conditions for sampling and interpolation may be viewed as a general principle resting on a basic fact of Fourier analysis: The complex exponentials $e^{i kx}$ ($k$ in $\\mathbb{Z}$) constitute an orthogonal basis for $L^2([-\\pi,\\pi])$. The present paper extends Landau's conditions to the setting of locally compact abelian (LCA) groups, relying in an analogous way on the basics of Fourier analysis. The technicalities--in either case of an operator theoretic nature--are however quite different. We will base our proofs on the comparison principle of J. Ramanathan and T. Steger.
Particle transport inferences from density sawteeth
Chen, J.; Li, Q.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Liao, K.; Gentle, K. W., E-mail: k.gentle@mail.utexas.edu [Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)
2014-05-15
Sawtooth oscillations in tokamaks are defined by their effect on electron temperature: a rapid flattening of the core profile followed by an outward heat pulse and a slow core recovery caused by central heating. Recent high-resolution, multi-chord interferometer measurements on JTEXT extend these studies to particle transport. Sawteeth only partially flatten the core density profile, but enhanced particle diffusion on the time scale of the thermal crash occurs over much of the profile, relevant for impurities. Recovery between crashes implies an inward pinch velocity extending to the center.
Method of high-density foil fabrication
Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.
2003-12-16
A method for preparing flat foils having a high density includes the steps of mixing a powdered material with a binder to form a green sheet. The green sheet is exposed to a high intensity radiative source adapted to emit radiation of wavelengths corresponding to an absorption spectrum of the powdered material. The surface of the green sheet is heated while a lower sub-surface temperature is maintained. An apparatus for preparing a foil from a green sheet using a radiation source is also disclosed.
Symmetry energy in nuclear density functional theory
W. Nazarewicz; P. -G. Reinhard; W. Satula; D. Vretenar
2013-07-22
The nuclear symmetry energy represents a response to the neutron-proton asymmetry. In this survey we discuss various aspects of symmetry energy in the framework of nuclear density functional theory, considering both non-relativistic and relativistic self-consistent mean-field realizations side-by-side. Key observables pertaining to bulk nucleonic matter and finite nuclei are reviewed. Constraints on the symmetry energy and correlations between observables and symmetry-energy parameters, using statistical covariance analysis, are investigated. Perspectives for future work are outlined in the context of ongoing experimental efforts.
Identification of cell density signal molecule
Schwarz, R.I.
1998-04-21
Disclosed herein is a novel proteinaceous cell density signal molecule (CDS) between 25 and 35 kD, which is secreted by fibroblastic primary avian tendon cells in culture, and causes the cells to self-regulate their proliferation and the expression of differentiated function. It effects an increase of procollagen production in avian tendon cell cultures of ten fold while proliferation rates are decreased. CDS, and the antibodies which recognize them, are important for the development of diagnostics and treatments for injuries and diseases involving connective tissues, particularly tendon. Also disclosed are methods of production and use. 2 figs.
Identification of cell density signal molecule
Schwarz, Richard I. (Oakland, CA)
1998-01-01
Disclosed herein is a novel proteinaceous cell density signal molecule (CDS) between 25 and 35 kD, which is secreted by fibroblastic primary avian tendon cells in culture, and causes the cells to self-regulate their proliferation and the expression of differentiated function. It effects an increase of procollagen production in avian tendon cell cultures of ten fold while proliferation rates are decreased. CDS, and the antibodies which recognize them, are important for the development of diagnostics and treatments for injuries and diseases involving connective tissues, particularly tendon. Also disclosed are methods of production and use.
Category:Rock Density | Open Energy Information
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Tiled QR factorization algorithms
Bouwmeester, Henricus; Langou, Julien; Robert, Yves
2011-01-01
This work revisits existing algorithms for the QR factorization of rectangular matrices composed of p-by-q tiles, where p >= q. Within this framework, we study the critical paths and performance of algorithms such as Sameh and Kuck, Modi and Clarke, Greedy, and those found within PLASMA. Although neither Modi and Clarke nor Greedy is optimal, both are shown to be asymptotically optimal for all matrices of size p = q^2 f(q), where f is any function such that \\lim_{+\\infty} f= 0. This novel and important complexity result applies to all matrices where p and q are proportional, p = \\lambda q, with \\lambda >= 1, thereby encompassing many important situations in practice (least squares). We provide an extensive set of experiments that show the superiority of the new algorithms for tall matrices.
The density of states approach for the simulation of finite density quantum field theories
K. Langfeld; B. Lucini; A. Rago; R. Pellegrini; L. Bongiovanni
2015-03-02
Finite density quantum field theories have evaded first principle Monte-Carlo simulations due to the notorious sign-problem. The partition function of such theories appears as the Fourier transform of the generalised density-of-states, which is the probability distribution of the imaginary part of the action. With the advent of Wang-Landau type simulation techniques and recent advances, the density-of-states can be calculated over many hundreds of orders of magnitude. Current research addresses the question whether the achieved precision is high enough to reliably extract the finite density partition function, which is exponentially suppressed with the volume. In my talk, I review the state-of-play for the high precision calculations of the density-of-states as well as the recent progress for obtaining reliable results from highly oscillating integrals. I will review recent progress for the $Z_3$ quantum field theory for which results can be obtained from the simulation of the dual theory, which appears to free of a sign problem.
The density of states approach for the simulation of finite density quantum field theories
Langfeld, K; Rago, A; Pellegrini, R; Bongiovanni, L
2015-01-01
Finite density quantum field theories have evaded first principle Monte-Carlo simulations due to the notorious sign-problem. The partition function of such theories appears as the Fourier transform of the generalised density-of-states, which is the probability distribution of the imaginary part of the action. With the advent of Wang-Landau type simulation techniques and recent advances, the density-of-states can be calculated over many hundreds of orders of magnitude. Current research addresses the question whether the achieved precision is high enough to reliably extract the finite density partition function, which is exponentially suppressed with the volume. In my talk, I review the state-of-play for the high precision calculations of the density-of-states as well as the recent progress for obtaining reliable results from highly oscillating integrals. I will review recent progress for the $Z_3$ quantum field theory for which results can be obtained from the simulation of the dual theory, which appears to fr...
Electrical and Production Load Factors
Sen, T.; Heffington, W. M.
2009-01-01
factors and operating hours of small and medium-sized industrial plants are analyzed to classify shift-work patterns and develop energy conservation diagnostic tools. This paper discusses two types of electric load factors for each shift... The purpose of this paper is to analyze operating hours of small and medium-sized manufacturing plants in the United States and develop ranges of load factors for use as diagnostic tools for effective energy management. Load factor is defined...
Attarian Shandiz, M. Gauvin, R.
2014-10-28
The temperature and pressure dependency of the volume plasmon energy of solids was investigated by density functional theory calculations. The volume change of crystal is the major factor responsible for the variation of valence electron density and plasmon energy in the free electron model. Hence, to introduce the effect of temperature and pressure for the density functional theory calculations of plasmon energy, the temperature and pressure dependency of lattice parameter was used. Also, by combination of the free electron model and the equation of state based on the pseudo-spinodal approach, the temperature and pressure dependency of the plasmon energy was modeled. The suggested model is in good agreement with the results of density functional theory calculations and available experimental data for elements with the free electron behavior.
Author's Accepted Manuscript ORBIT-CENTERED ATMOSPHERIC DENSITY
Wohlberg, Brendt
solar and geomagnetic activities and different prediction windows. Compar- ison with previouslyAuthor's Accepted Manuscript ORBIT-CENTERED ATMOSPHERIC DENSITY PREDICTION USING ARTIFICIAL NEURAL Shoemaker, Riccardo Bevilacqua, ORBIT-CENTERED ATMOSPHERIC DENSITY PREDICTION USING ARTIFICIAL NEURAL
Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process
Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process J. Z. Lu,1 Q. Wu,1 I. I parameters for the wood-fiber/high-density-polyethylene blends at 60 rpm were a temperature of 180°C
Innovative fuel designs for high power density pressurized water reactor
Feng, Dandong, Ph. D. Massachusetts Institute of Technology
2006-01-01
One of the ways to lower the cost of nuclear energy is to increase the power density of the reactor core. Features of fuel design that enhance the potential for high power density are derived based on characteristics of ...
Design of annular fuel for high power density BWRs
Morra, Paolo
2005-01-01
Enabling high power density in the core of Boiling Water Reactors (BWRs) is economically profitable for existing or new reactors. In this work, we examine the potential for increasing the power density in BWR plants by ...
Lanai high-density irradiance sensor network for characterizing...
Office of Scientific and Technical Information (OSTI)
Lanai high-density irradiance sensor network for characterizing solar resource variability of MW-scale PV system. Citation Details In-Document Search Title: Lanai high-density...
Cosmological and astrophysical aspects of finite-density QCD
Dominik J. Schwarz
1998-07-23
The different phases of QCD at finite temperature and density lead to interesting effects in cosmology and astrophysics. In this work I review some aspects of the cosmological QCD transition and of astrophysics at high baryon density.
Observable to explore high density behaviour of symmetry energy
Aman D. Sood
2011-09-28
We aim to see the sensitivity of collective transverse in-plane flow to symmetry energy at low as well as high densities and also to see the effect of different density dependencies of symmetry energy on the same.
Magnetohydrodynamically stable plasma with supercritical current density at the axis
Burdakov, A. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marks Avenue, 630092 Novosibirsk (Russian Federation); Postupaev, V. V., E-mail: V.V.Postupaev@inp.nsk.su; Sudnikov, A. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk (Russian Federation)
2014-05-15
In this work, an analysis of magnetic perturbations in the GOL-3 experiment is given. In GOL-3, plasma is collectively heated in a multiple-mirror trap by a high-power electron beam. During the beam injection, the beam-plasma interaction maintains a high-level microturbulence. This provides an unusual radial profile of the net current (that consists of the beam current, current of the preliminary discharge, and the return current). The plasma core carries supercritical current density with the safety factor well below unity, but as a whole, the plasma is stable with q(a)???4. The net plasma current is counter-directed to the beam current; helicities of the magnetic field in the core and at the edge are of different signs. This forms a system with a strong magnetic shear that stabilizes the plasma core in good confinement regimes. We have found that the most pronounced magnetic perturbation is the well-known n?=?1, m?=?1 mode for both stable and disruptive regimes.
Density driven structural transformations in amorphous semiconductor clathrates
Tulk, Christopher A; dos Santos, Antonio M.; Neuefeind, Joerg C; Molaison, Jamie J; Sales, Brian C; Honkimaeki, Veijo
2015-01-01
The pressure induced crystalline collapse at 14.7 GPa and polyamorphic structures of the semiconductor clathrate Sr8Ga16Ge30 are reported up to 35 GPa. In-situ total scattering measurements under pressure allow the direct microscopic inspection of the mechanisms associated with pressure induced amorphization in these systems, as well as the structure of the recovered phase. It is observed that, between 14.7 and 35 GPa the second peak in the structure factor function gradually disappears. Analysis of the radial distribution function extracted from those data indicate that this feature is associated with gradual cage collapse and breakdown of the tetrahedral structure with the consequent systematic lengthening of the nearest-neighbor framework bonds. This suggests an overall local coordination change to an even higher density amorphous form. Upon recovery from high pressure, the sample remains amorphous, and while there is some indication of the guest-host cage reforming, it doesn't seem that the tetrahedral coordination is recovered. As such, the compresion-decompression process in this systems gives rise to three distict amorphous forms.
Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring
Gonsalves, Anthony
2012-01-01
38 fs. Laser and electron beam diagnostics Laser radiationdiagnostic provided charge density images of the electron beam
Gray squirrel density, habitat suitability, and behavior in urban parks
Gompper, Matthew E.
densities. We used linear regression (SAS Institute, SAS/STAT user's guide. SAS Institute, Cary, NC, 2005
High current density cathode for electrorefining in molten electrolyte
Li, Shelly X.
2010-06-29
A high current density cathode for electrorefining in a molten electrolyte for the continuous production and collection of loose dendritic or powdery deposits. The high current density cathode eliminates the requirement for mechanical scraping and electrochemical stripping of the deposits from the cathode in an anode/cathode module. The high current density cathode comprises a perforated electrical insulated material coating such that the current density is up to 3 A/cm.sup.2.
Competition between superconductivity and spin density wave
Tian De Cao
2012-08-25
The Hubbard model has been investigated widely by many authors, while this work may be new in two aspects. One, we focus on the possible effects of the positions of the gaps associated with the pairing and the spin density wave. Two, we suggest that the models with different parameters are appropriate for different materials (or a material in different doped regions). This will lead to some new insights into the high temperature superconductors. It is shown that the SDW can appear at some temperature region when the on-site Coulomb interaction is larger, while the SC requires a decreased U at a lower temperature. This can qualitatively explain the relationship between superconducting and pseudogap states of Cu-based superconductors in underdoped and optimally doped regions. The superinsulator is also discussed.
Observation of Density Segregation inside Migrating Dunes
Christopher Groh; Ingo Rehberg; Christof A. Kruelle
2011-09-18
Spatiotemporal patterns in nature, such as ripples or dunes, formed by a fluid streaming over a sandy surface show complex behavior despite their simple forms. Below the surface, the granular structure of the sand particles is subject to self-organization processes, exhibiting such phenomena as reverse grading when larger particles are found on top of smaller ones. Here we report results of an experimental investigation with downscaled model dunes revealing that, if the particles differ not in size but in density, the heavier particles, surprisingly, accumulate in the central core close to the top of the dune. This finding contributes to the understanding of sedimentary structures found in nature and might be helpful to improve existing dating methods for desert dunes.
Level Density in the Complex Scaling Method
Ryusuke Suzuki; Takayuki Myo; Kiyoshi Kato
2005-05-18
It is shown that the continuum level density (CLD) at unbound energies can be calculated with the complex scaling method (CSM), in which the energy spectra of bound states, resonances and continuum states are obtained in terms of $L^2$ basis functions. In this method, the extended completeness relation is applied to the calculation of the Green functions, and the continuum-state part is approximately expressed in terms of discretized complex scaled continuum solutions. The obtained result is compared with the CLD calculated exactly from the scattering phase shift. The discretization in the CSM is shown to give a very good description of continuum states. We discuss how the scattering phase shifts can inversely be calculated from the discretized CLD using a basis function technique in the CSM.
High energy density redox flow device
Chiang, Yet-Ming; Carter, W. Craig; Ho, Bryan Y; Duduta, Mihai; Limthongkul, Pimpa
2014-05-13
Redox flow devices are described in which at least one of the positive electrode or negative electrode-active materials is a semi-solid or is a condensed ion-storing electroactive material, and in which at least one of the electrode-active materials is transported to and from an assembly at which the electrochemical reaction occurs, producing electrical energy. The electronic conductivity of the semi-solid is increased by the addition of conductive particles to suspensions and/or via the surface modification of the solid in semi-solids (e.g., by coating the solid with a more electron conductive coating material to increase the power of the device). High energy density and high power redox flow devices are disclosed. The redox flow devices described herein can also include one or more inventive design features. In addition, inventive chemistries for use in redox flow devices are also described.
Density regulation in annual plant communities under variable resource levels
Novoplansky, Ariel
Density regulation in annual plant communities under variable resource levels Hagit Shilo. E. and Turkington, R. 2005. Density regulation in annual plant communities under variable resource levels. Á/ Oikos 108: 241Á/252. Density regulation is assumed to be common, but is very rarely tested
Contributed Paper Wood Density as a Conservation Tool: Quantification
Contributed Paper Wood Density as a Conservation Tool: Quantification of Disturbance to easily identify areas of old-growth forest. The average density of the wood of a tree species is closely wood density can be used to quantify forest disturbance and conservation importance. The average
Microwave Interferometer Density Diagnostic for the Levitated Dipole Experiment
Microwave Interferometer Density Diagnostic for the Levitated Dipole Experiment A. Boxer, J. Kesner the density profile of the plasma in LDX, we are constructing a multi-channel microwave interferometer be inverted to reconstruct a radially symmetric density profile. The microwave interferometer of LDX
Density-Enthalpy Phase Diagram 0D Boiler Simulation
Vuik, Kees
Density-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research Finite Transitions #12;Density-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research;Density-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research Goal
Fusion using time-dependent density-constrained DFT
R. Keser; A. S. Umar; V. E. Oberacker; J. A. Maruhn; P. -G. Reinhard
2014-02-06
We present results for calculating fusion cross-sections using a new microscopic approach based on a time-dependent density-constrained DFT calculations. The theory is implemented by using densities and other information obtained from TDDFT time-evolution of the nuclear system as constraint on the density for DFT calculations.
Gyrokinetic simulations of electron density fluctuations and comparisons with measurements
Budny, Robert
density fluctuations, APS, Orlando, FL, Nov, 2007PRINCETON PLASMA PHYSICS LABORATORY PPPL 1 #12, Gyrokinetic simulations of electron density fluctuations, APS, Orlando, FL, Nov, 2007PRINCETON PLASMA PHYSICS simulations of electron density fluctuations, APS, Orlando, FL, Nov, 2007PRINCETON PLASMA PHYSICS LABORATORY
Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities
Harrison; Neil (Santa Fe, NM), Singleton; John (Los Alamos, NM), Migliori; Albert (Santa Fe, NM)
2008-08-05
A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.
Relativistic plasma nanophotonics for ultrahigh energy density physics
Rocca, Jorge J.
Relativistic plasma nanophotonics for ultrahigh energy density physics Michael A. Purvis1 of the laser energy into a thin surface layer at typically only 0.1% of solid density. Here, we demonstrate density Nec using multi-kilojoule laser pulses14 . Such high- energy laser pulses have ionized mid
Optimal Node Density for Detection in Energy Constrained Random Networks
Anandkumar, Animashree
1 Optimal Node Density for Detection in Energy Constrained Random Networks Animashree Anandkumar node density tends to infinity under any feasible average energy constraint. On the other hand, when of optimal node density maximizing the Neyman-Pearson detection error exponent subject to a constraint
Stellar Wind Accretion in GX301-2: Evidence for a High-density Stream
D. A. Leahy; M. Kostka
2007-09-04
The X-ray binary system GX301-2 consists of a neutron star in an eccentric orbit accreting from the massive early-type star WRAY 977. It has previously been shown that the X-ray orbital light curve is consistent with existence of a gas stream flowing out from Wray 977 in addition to its strong stellar wind. Here, X-ray monitoring observations by the Rossi X-ray Timing Explorer (RXTE)/ All-Sky-Monitor (ASM) and pointed observations by the RXTE/ Proportional Counter Array (PCA) over the past decade are analyzed. We analyze both the flux and column density dependence on orbital phase. The wind and stream dynamics are calculated for various system inclinations, companion rotation rates and wind velocities, as well as parametrized by the stream width and density. These calculations are used as inputs to determine both the expected accretion luminosity and the column density along the line-of-sight to the neutron star. The model luminosity and column density are compared to observed flux and column density vs. orbital phase, to constrain the properties of the stellar wind and the gas stream. We find that the change between bright and medium intensity levels is primarily due to decreased mass loss in the stellar wind, but the change between medium and dim intensity levels is primarily due to decreased stream density. The mass-loss rate in the stream exceeds that in the stellar wind by a factor of 2.5. The quality of the model fits is significantly better for lower inclinations, favoring a mass for WRAY 977 of 53 to 62 Msun.
Scaling Evolution of Universal Dark-Matter Halo Density Profiles
A. Raig; G. Gonzalez-Casado; E. Salvador-Sole
1998-10-10
Dark-matter halos show a universal density profile with a scaling such that less massive systems are typically denser. This mass-density relation is well described by a proportionality between the characteristic density of halos and the mean cosmic density at halo formation time. It has recently been shown that this proportionality could be the result of the following simple evolutionary picture. Halos form in major mergers with essentially the same, cosmogony-dependent, dimensionless profile, and then grow inside-outside, as a consequence of accretion. Here we verify the consistency of this picture and show that it predicts the correct zero point of the mass-density relation.
Statistical density modification with non-crystallographic symmetry
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2002-12-01
Statistical density modification can make use of NCS in a crystal and can include estimates of the deviations from perfect NCS. Statistical density modification is a technique for phase improvement through a calculation of the posterior probability of the phases, given experimental phase information and expectations about features of the electron-density map. The technique can take advantage of both estimates of electron density in the map and uncertainties or probability distributions for those estimates. For crystals with non-crystallographic symmetry (NCS), this allows the use of the expected similarity of electron density at NCS-related points without requiring an implicit assumption that these regions are identical.
State densities and spectrum fluctuations: Information propagation in complex nuclei
French, J.B.; Kota, V.K.B.
1988-01-01
At excitation energies in nuclei where the state density is unambiguously defined there is a sharp separation between the smoothed spectrum (which defines the density) and fluctuations about it which have recently been studied with a view to understanding some aspects of quantum chaos. We briefly review these two complementary subjects, paying special attention to: the role of the effective interaction in determining the density; the calculation of interacting-particle state and level densities, and of expectation values of interesting operators; the information about the effective nucleon-nucleon interaction which is carried both by the density and the fluctuations. 28 refs., 1 fig.
Filling factors and Braid group
Wellington Cruz
1998-02-25
We extract the Braid group structure of a recently derived hierarchy scheme for the filling factors proposed by us which related the Hausdorff dimension, $h$, to statistics, $\
Building a Universal Nuclear Energy Density Functional
Carlson, Joe A.; Furnstahl, Dick; Horoi, Mihai; Lust, Rusty; Nazaewicc, Witek; Ng, Esmond; Thompson, Ian; Vary, James
2012-12-30
During the period of Dec. 1 2006 – Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: ? First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties; ? Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data; ? Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.
A Longitudinal Density Monitor for the LHC
Jeff, Adam; Boccardi, Andrea
At the Large Hadron Collider (LHC), the world’s largest and highest energy particle accelerator, ion bunches circulate in two counter-rotating beams and are brought into collision. Each bunch is confined within a bucket by the longitudinal focusing effect of the radio frequency (RF) cavities. The RF period is 2.5 ns, while the minimum bunch spacing is 25 ns. Thus, 9 out of every 10 buckets should be empty, as well as additional gaps to allow for the rise-time of injection and dump kickers. In practice, however, small numbers of particles can occupy these supposedly empty buckets, causing problems for machine protection and for the absolute calibration of the LHC’s luminosity. The Longitudinal Density Monitor (LDM) is a new monitor, designed to measure the longitudinal distribution of particles in the LHC with a sufficiently high dynamic range to quantify the relative particle population in the supposedly empty buckets. A non-interceptive measurement is made possible by the use of synchrotron radiation (SR...
Balanced homodyne detectors and Casimir energy densities
P. Marecki
2008-03-22
We recall and generalize the analysis of the output of the so-called balanced homodyne detectors. The most important feature of these detectors is their ability to quantify the vacuum fluctuations of the electric field, that is expectation values of products of (quantum-) electric-field operators. More precisely, the output of BHDs provides information on the one- and two-point functions of arbitrary states of quantum fields. We generalize the analysis of the response of BHDs to the case of quantum fields under influence of static external conditions such as cavities or polarizable media. By recalling the expressions for two-point functions of quantum fields in Casimir geometries we show, that a rich, position- and frequency-dependent pattern of BHD responses is predicted for ground states. This points to a potentially new characterization of quantum fields in Casimir setups which would not only complement the current global methods (Casimir forces), but also improve understanding of sub-vacuum energy densities present in some regions in these geometries.
P. R. Young; T. Watanabe; H. Hara; J. T. Mariska
2008-10-28
The EUV Imaging Spectrometer (EIS) instrument on board the Hinode satellite has access to some of the best coronal density diagnostics and the high sensitivity of the instrument now allows electron number density, N_e, measurements to an unprecedented precision of up to +/-5 % in active regions. This paper gives a thorough overview of data analysis issues for the best diagnostics of Fe XII and Fe XIII and assesses the accuracy of the measurements. Two density diagnostics each from Fe XII (186.88/195.12 and 196.64/195.12) and Fe XIII (196.54/202.04 and 203.82/202.04) are analysed in two active region data-sets from 2007 May 3 and 6 that yield densities in the range 8.5 < log N_e < 11.0. The densities are derived using v5.2 of the CHIANTI atomic database. The Fe XII and Fe XIII diagnostics show broadly the same trend in density across the active region, consistent with their similar temperatures of formation. However the high precision of the EIS measurements demonstrates significant discrepancies of up to 0.5 dex in derived log N_e values, with Fe XII always giving higher densities than Fe XIII. The discrepancies may partly be due to real physical differences between the emitting regions of the two plasmas, but the dominant factor lies in the atomic models of the two ions. Two specific problems are identified for Fe XII 196.64 and Fe XIII 203.82: the former is found to be under-estimated in strength by the CHIANTI atomic model, while the high density limit of the 203.82/202.04 is suggested to be inaccurate in the CHIANTI atomic model. The small grating tilt of the EIS instrument is found to be very significant when deriving densities from emission lines separated by more than a few angstroms.
High energy density redox flow device
Chiang, Yet-Ming; Carter, William Craig; Duduta, Mihai; Limthongkul, Pimpa
2014-05-13
Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.
Journal Information Journal Impact Factor
Krejcí, Pavel
Journal Information Journal Impact Factor 5-Year Journal Impact Factor Journal Self Cites Journal Immediacy Index 2014 JCR Science Edition Journal: Applications of Mathematics Mark Journal Title ISSN Total- life APPL MATH-CZECH 0862-7940 241 0.400 0.430 0.024 42 8.9 >10.0 Cited Journal Citing Journal Source
Journal Information Journal Impact Factor
Krejcí, Pavel
Journal Information Journal Impact Factor 5-Year Journal Impact Factor Journal Self Cites Journal Immediacy Index 2012 JCR Science Edition Journal: Applications of Mathematics Mark Journal Title ISSN Total- life APPL MATH-CZECH 0862-7940 240 0.222 0.549 0.054 37 7.3 >10.0 Cited Journal Citing Journal Source
A DENSITY-INDEPENDENT FORMULATION OF SMOOTHED PARTICLE HYDRODYNAMICS
Saitoh, Takayuki R.; Makino, Junichiro
2013-05-01
The standard formulation of the smoothed particle hydrodynamics (SPH) assumes that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives of other quantities. However, this assumption breaks down at the contact discontinuity. At the contact discontinuity, the density of the low-density side is overestimated while that of the high-density side is underestimated. As a result, the pressure of the low-density (high-density) side is overestimated (underestimated). Thus, unphysical repulsive force appears at the contact discontinuity, resulting in the effective surface tension. This tension suppresses fluid instabilities. In this paper, we present a new formulation of SPH, which does not require the differentiability of density. Instead of the mass density, we adopt the internal energy density (pressure) and its arbitrary function, which are smoothed quantities at the contact discontinuity, as the volume element used for the kernel integration. We call this new formulation density-independent SPH (DISPH). It handles the contact discontinuity without numerical problems. The results of standard tests such as the shock tube, Kelvin-Helmholtz and Rayleigh-Taylor instabilities, point-like explosion, and blob tests are all very favorable to DISPH. We conclude that DISPH solved most of the known difficulties of the standard SPH, without introducing additional numerical diffusion or breaking the exact force symmetry or energy conservation. Our new SPH includes the formulation proposed by Ritchie and Thomas as a special case. Our formulation can be extended to handle a non-ideal gas easily.
Smooth Light Curves from a Bumpy Ride: Relativistic Blast Wave Encounters a Density Jump
Nakar, Ehud; /Caltech; Granot, Jonathan; /KIPAC, Menlo Park
2006-06-06
Some gamma-ray burst (GRB) afterglow light curves show significant variability, which often includes episodes of rebrightening. Such temporal variability had been attributed in several cases to large fluctuations in the external density, or density ''bumps''. Here we carefully examine the effect of a sharp increase in the external density on the afterglow light curve by considering, for the first time, a full treatment of both the hydrodynamic evolution and the radiation in this scenario. To this end we develop a semi-analytic model for the light curve and carry out several elaborate numerical simulations using a one dimensional hydrodynamic code together with a synchrotron radiation code. Two spherically symmetric cases are explored in detail--a density jump in a uniform external medium, and a wind termination shock. The effect of density clumps is also constrained. Contrary to previous works, we find that even a very sharp (modeled as a step function) and large (by a factor of a >> 1) increase in the external density does not produce sharp features in the light curve, and cannot account for significant temporal variability in GRB afterglows. For a wind termination shock, the light curve smoothly transitions between the asymptotic power laws over about one decade in time, and there is no rebrightening in the optical or X-rays that could serve as a clear observational signature. For a sharp jump in a uniform density profile we find that the maximal deviation {Delta}{alpha}{sub max} of the temporal decay index {alpha} from its asymptotic value (at early and late times), is bounded (e.g, {Delta}{alpha}{sub max} < 0.4 for {alpha} = 10); {Delta}{alpha}{sub max} slowly increases with {alpha}, converging to {Delta}{alpha}{sub max} {approx} 1 at very large {alpha} values. Therefore, no optical rebrightening is expected in this case as well. In the X-rays, while the asymptotic flux is unaffected by the density jump, the fluctuations in {alpha} are found to be comparable to those in the optical. Finally, we discuss the implications of our results for the origin of the observed fluctuations in several GRB afterglows.
The Quantum Energy Density: Improved Efficiency for Quantum Monte Carlo
Krogel, Jaron T; Kim, Jeongnim; Ceperley, David M
2013-01-01
We establish a physically meaningful representation of a quantum energy density for use in Quantum Monte Carlo calculations. The energy density operator, defined in terms of Hamiltonian components and density operators, returns the correct Hamiltonian when integrated over a volume containing a cluster of particles. This property is demonstrated for a helium-neon "gas," showing that atomic energies obtained from the energy density correspond to eigenvalues of isolated systems. The formation energies of defects or interfaces are typically calculated as total energy differences. Using a model of delta-doped silicon (where dopant atoms form a thin plane) we show how interfacial energies can be calculated more efficiently with the energy density, since the region of interest is small. We also demonstrate how the energy density correctly transitions to the bulk limit away from the interface where the correct energy is obtainable from a separate total energy calculation.
Model comparison for the density structure across solar coronal waveguides
Arregui, I; Ramos, A Asensio
2015-01-01
The spatial variation of physical quantities, such as the mass density, across solar atmospheric waveguides governs the timescales and spatial scales for wave damping and energy dissipation. The direct measurement of the spatial distribution of density, however, is difficult and indirect seismology inversion methods have been suggested as an alternative. We applied Bayesian inference, model comparison, and model-averaging techniques to the inference of the cross-field density structuring in solar magnetic waveguides using information on periods and damping times for resonantly damped magnetohydrodynamic (MHD) transverse kink oscillations. Three commonly employed alternative profiles were used to model the variation of the mass density across the waveguide boundary. Parameter inference enabled us to obtain information on physical quantities such as the Alfv\\'en travel time, the density contrast, and the transverse inhomogeneity length scale. The inference results from alternative density models were compared a...
Luis F. Rojas-Ochoa; Ramon Castaneda-Priego; Vladimir Lobaskin; Anna Stradner; Frank Scheffold; Peter Schurtenberger
2008-04-10
We determine the structure of charge-stabilized colloidal suspensions at low ionic strength over an extended range of particle volume fractions using a combination of light and small angle neutron scattering experiments. The variation of the structure factor with concentration is analyzed within a one-component model of a colloidal suspension. We show that the observed structural behavior corresponds to a non-monotonic density dependence of the colloid effective charge and the mean interparticle interaction energy. Our findings are corroborated by similar observations from primitive model computer simulations of salt-free colloidal suspensions.
Particle number density fluctuations and pressure effects on structure formation
D. R. Matravers; J. Triginer
2001-09-21
We provide a covariant and gauge-invariant approach to the question of how a first order pressure can be incorporated self-consistently in a cosmological scenario. The approximation is relevant, in the linear regime, to weakly self-interacting or warm dark matter models. We also derive number density fluctuations in which new modes appear because the number density fluctuations are no longer simply proportional to the density fluctuations.
Method for measuring the density of lightweight materials
Snow, Samuel G. (Oak Ridge, TN); Giacomelli, Edward J. (Knoxville, TN)
1980-01-01
This invention relates to a nondestructive method for measuring the density of articles composed of elements having a low atomic number such as plastic and carbon composites. The measurement is accomplished by striking the article with a collimated beam of X radiation, simultaneously monitoring the radiation scattered and the radiation transmitted by the article, then relating the ratio of the radiation scattered to the radiation transmitted with the density of the article. The above method is insensitive to all variables except density.
Crystallization of polyethylene by modified weighted density approximation(MWDA)
Razeghizadeh, Alireza; Lavafpour, Farhad
2015-01-01
In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.
Crystallization of polyethylene by modified weighted density approximation(MWDA)
Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour
2015-02-07
In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.
Nuclear symmetry energy at subnormal densities from measured nuclear masses
Min Liu; Ning Wang; Zhuxia Li; Fengshou Zhang
2010-11-17
The symmetry energy coefficients for nuclei with mass number A=20~250 are extracted from more than 2000 measured nuclear masses. With the semi-empirical connection between the symmetry energy coefficients of finite nuclei and the nuclear symmetry energy at reference densities, we investigate the density dependence of symmetry energy of nuclear matter at subnormal densities. The obtained results are compared with those extracted from other methods.
High-Precision Thermodynamics and Hagedorn Density of States
Harvey B. Meyer
2009-05-26
We compute the entropy density of the confined phase of QCD without quarks on the lattice to very high accuracy. The results are compared to the entropy density of free glueballs, where we include all the known glueball states below the two-particle threshold. We find that an excellent, parameter-free description of the entropy density between 0.7Tc and Tc is obtained by extending the spectrum with the exponential spectrum of the closed bosonic string.
Method for solvent extraction with near-equal density solutions
Birdwell, Joseph F. (Knoxville, TN); Randolph, John D. (Maryville, TN); Singh, S. Paul (Oak Ridge, TN)
2001-01-01
Disclosed is a modified centrifugal contactor for separating solutions of near equal density. The modified contactor has a pressure differential establishing means that allows the application of a pressure differential across fluid in the rotor of the contactor. The pressure differential is such that it causes the boundary between solutions of near-equal density to shift, thereby facilitating separation of the phases. Also disclosed is a method of separating solutions of near-equal density.
The Effects of Highly Structured Low Density Carbon Nanotube...
Office of Scientific and Technical Information (OSTI)
Effects of Highly Structured Low Density Carbon Nanotube Networks on the Thermal Degradation Behaviour of Polysiloxanes Citation Details In-Document Search Title: The Effects of...
Fact #661: February 7, 2011 Population Density | Department of...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
states, the population is generally less dense, with the exceptions being California, Hawaii, and Washington. Every state except Michigan experienced increased population density...
Effects of Phase Transition induced density fluctuations on pulsar dynamics
Bagchi, Partha; Layek, Biswanath; Srivastava, Ajit M
2015-01-01
We show that density fluctuations during phase transitions in pulsar cores may have non-trivial effects on pulsar timings, and may also possibly account for glitches and anti-glitches. These density fluctuations invariably lead to non-zero off-diagonal components of the moment of inertia, leading to transient wobbling of star. Thus, accurate measurements of pulsar timing and intensity modulations (from wobbling) may be used to identify the specific pattern of density fluctuations, hence the particular phase transition, occurring inside the pulsar core. Changes in quadrupole moment from rapidly evolving density fluctuations during the transition, with very short time scales, may provide a new source for gravitational waves.
A Comprehensive Study Of Fracture Patterns And Densities In The...
Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search OpenEI Reference LibraryAdd to...
Symmetry Lowering in Extreme-Electron-Density Perovskite Quantum Wells
Zhang, Jack Y.; Hwang, Jinwoo; Raghavan, Santosh; Stemmer, Susanne
2013-01-01
in Extreme-Electron-Density Perovskite Quantum Wells Jack Y.in the ideal cubic perovskite structure. The insulatingan orthorhombic distorted perovskite (space group Pnma [17])
CORRELATION BETWEEN GROUP LOCAL DENSITY AND GROUP LUMINOSITY
Deng Xinfa; Yu Guisheng
2012-11-10
In this study, we investigate the correlation between group local number density and total luminosity of groups. In four volume-limited group catalogs, we can conclude that groups with high luminosity exist preferentially in high-density regions, while groups with low luminosity are located preferentially in low-density regions, and that in a volume-limited group sample with absolute magnitude limit M{sub r} = -18, the correlation between group local number density and total luminosity of groups is the weakest. These results basically are consistent with the environmental dependence of galaxy luminosity.
COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS
Howard, John
COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS J. HOWARD, M. PERSSON* Plasma Research Laboratory, Research School of Physical Sciences, Australian National University, Canberra
High power density supercapacitors using locally aligned carbon nanotube electrodes
Du, C S; Yeh, J; Pan, Ning
2005-01-01
carbon nanotubes in 1 ml of DMF) on two 12 mm × 12 mm nickelnanotubes as electrodes. An [7, 15] obtained high power density with polished nickel
3-D capacitance density imaging of fluidized bed
Fasching, George E. (653 Vista Pl., Morgantown, WV 26505)
1990-01-01
A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved.
Bone mineral density and fractures in older men with chronic obstructive pulmonary disease or asthma
Dam, T.-T.; Harrison, S.; Fink, H. A.; Ramsdell, J.; Barrett-Connor, E.
2010-01-01
x ORIGINAL ARTICLE Bone mineral density and fractures inwas associated with lower bone mineral density (BMD) at theKeywords Bone loss . Bone mineral density . Elderly .
Electrical and Production Load Factors
Sen, Tapajyoti
2010-07-14
Load factors are an important simplification of electrical energy use data and depend on the ratio of average demand to peak demand. Based on operating hours of a facility they serve as an important benchmarking tool for the industrial sector...
Efficient Networks for Quantum Factoring
David Beckman; Amalavoyal N. Chari; Srikrishna Devabhaktuni; John Preskill
1996-02-21
We consider how to optimize memory use and computation time in operating a quantum computer. In particular, we estimate the number of memory qubits and the number of operations required to perform factorization, using the algorithm suggested by Shor. A $K$-bit number can be factored in time of order $K^3$ using a machine capable of storing $5K+1$ qubits. Evaluation of the modular exponential function (the bottleneck of Shor's algorithm) could be achieved with about $72 K^3$ elementary quantum gates; implementation using a linear ion trap would require about $396 K^3$ laser pulses. A proof-of-principle demonstration of quantum factoring (factorization of 15) could be performed with only 6 trapped ions and 38 laser pulses. Though the ion trap may never be a useful computer, it will be a powerful device for exploring experimentally the properties of entangled quantum states.
Human Factors of Reporting Systems
Johnson, C.W.
Johnson,C.W. P. Carayon (ed.), A Handbook of Human Factors and Ergonomics in Healthcare and Patient Safety, Lawrence Erlbaum, London, UK. pp 715-750 Lawrence Erlbaum Associates
Palacio Mizrahi, J. H.
2014-06-15
A rigorous derivation of expressions, starting from the governing equations, for the ionization frequency, edge-to-axis ratio of plasma density, plasma density at the axis, and radially averaged plasma density in a cylindrical gas discharge has been obtained. The derived expressions are simple and involve the relevant parameters of the discharge: Cylinder radius, axial current, and neutral gas pressure. The found expressions account for ion inertia, ion temperature, and changes in plasma ion collisionality.
Ligand identification using electron-density map correlations
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States); Adams, Paul D.; Moriarty, Nigel W. [Lawrence Berkeley National Laboratory, One Cyclotron Road, BLDG 64R0121, Berkeley, CA 94720 (United States); Cohn, Judith D. [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States)
2007-01-01
An automated ligand-fitting procedure is applied to (F{sub o} ? F{sub c})exp(i?{sub c}) difference density for 200 commonly found ligands from macromolecular structures in the Protein Data Bank to identify ligands from density maps. A procedure for the identification of ligands bound in crystal structures of macromolecules is described. Two characteristics of the density corresponding to a ligand are used in the identification procedure. One is the correlation of the ligand density with each of a set of test ligands after optimization of the fit of that ligand to the density. The other is the correlation of a fingerprint of the density with the fingerprint of model density for each possible ligand. The fingerprints consist of an ordered list of correlations of each the test ligands with the density. The two characteristics are scored using a Z-score approach in which the correlations are normalized to the mean and standard deviation of correlations found for a variety of mismatched ligand-density pairs, so that the Z scores are related to the probability of observing a particular value of the correlation by chance. The procedure was tested with a set of 200 of the most commonly found ligands in the Protein Data Bank, collectively representing 57% of all ligands in the Protein Data Bank. Using a combination of these two characteristics of ligand density, ranked lists of ligand identifications were made for representative (F{sub o} ? F{sub c})exp(i?{sub c}) difference density from entries in the Protein Data Bank. In 48% of the 200 cases, the correct ligand was at the top of the ranked list of ligands. This approach may be useful in identification of unknown ligands in new macromolecular structures as well as in the identification of which ligands in a mixture have bound to a macromolecule.
Symmetry energy systematics and its high density behavior
Lie-Wen Chen
2015-06-30
We explore the systematics of the density dependence of nuclear matter symmetry energy in the ambit of microscopic calculations with various energy density functionals, and find that the symmetry energy from subsaturation density to supra-saturation density can be well determined by three characteristic parameters of the symmetry energy at saturation density $\\rho_0 $, i.e., the magnitude $E_{\\text{sym}}({\\rho_0 })$, the density slope $L$ and the density curvature $K_{\\text{sym}}$. This finding opens a new window to constrain the supra-saturation density behavior of the symmetry energy from its (sub-)saturation density behavior. In particular, we obtain $L=46.7 \\pm 12.8$ MeV and $K_{\\text{sym}}=-166.9 \\pm 168.3$ MeV as well as $E_{\\text{sym}}({2\\rho _{0}}) \\approx 40.2 \\pm 12.8$ MeV and $L({2\\rho _{0}}) \\approx 8.9 \\pm 108.7$ MeV based on the present knowledge of $E_{\\text{sym}}({\\rho_{0}}) = 32.5 \\pm 0.5$ MeV, $E_{\\text{sym}}({\\rho_c}) = 26.65 \\pm 0.2$ MeV and $L({\\rho_c}) = 46.0 \\pm 4.5$ MeV at $\\rho_{\\rm{c}}= 0.11$ fm$^{-3}$ extracted from nuclear mass and the neutron skin thickness of Sn isotopes. Our results indicate that the symmetry energy cannot be stiffer than a linear density dependence.In addition, we also discuss the quark matter symmetry energy since the deconfined quarks could be the right degree of freedom in dense matter at high baryon densities.
Junichi Takahashi; Junpei Sugano; Masahiro Ishii; Hiroaki Kouno; Masanobu Yahiro
2014-10-30
We evaluate quark number densities at imaginary chemical potential by lattice QCD with clover-improved two-flavor Wilson fermion. The quark number densities are extrapolated to the small real chemical potential region by assuming some function forms. The extrapolated quark number densities are consistent with those calculated at real chemical potential with the Taylor expansion method for the reweighting factors. In order to study the large real chemical potential region, we use the two-phase model consisting of the quantum hadrodynamics model for the hadron phase and the entanglement-PNJL model for the quark phase. The quantum hadrodynamics model is constructed to reproduce nuclear saturation properties, while the entanglement-PNJL model reproduces well lattice QCD data for the order parameters such as the Polyakov loop, the thermodynamic quantities and the screening masses. Then, we calculate the mass-radius relation of neutron stars and explore the hadron-quark phase transition with the two-phase model.
T. Thomas; P. Katgert
2005-10-10
We study the morphology-radius (MR-) and morphology-density (MD-) relations for a sample of about 850 galaxies (with M = -22), the S0 galaxies and the early spirals have different Sigma1-distributions. The reason for this is that Sigma1 is much less correlated with R than is Sigma10, and thus has much less cross-talk from the (MR-) relation. On average, the 'normal' ellipticals populate environments with higher projected density than do the S0 galaxies while the early spirals populate even less dense environments. The segregation of the brightest ellipticals and the late spirals is driven mostly by global factors, while the segregation between 'normal' ellipticals, S0 galaxies and early spirals is driven primarily by local factors.
Regulation of Xylella fastidiosa virulence factors by c-di-GMP phosphodiesterases
Ancona-Contreras, Veronica
2012-10-19
polysaccharides and the formation of a biofilm. These traits are mediated in a cell-density manner by a cell-to-cell signaling system that transduces a diffusible signaling factor (DSF). This dissertation demonstrates that PD1994, PD1617 and RpfG regulate...
Low Density Nuclear Matter in Heavy Ion Collisions
Qin, Lijun
2010-01-14
The symmetry energy is the energy difference between symmetric nuclear matter and pure neutron matter at a given density. Around normal nuclear density, i.e. p/p0 =1, and temperature, i.e. T = 0, the symmetry energy is ...
Fine density/design variable Computational Science and Engineering
Paulino, Glaucio H.
1400 1600 FE Analysis Optimization Initialization Buildings designed to minimize seismic or wind·Fine density/design variable mesh Computational Science and Engineering 2013 Annual Meeting.01 Fine design variable mesh Fine density variable mesh Comparison of forced vibration results 1
HOW TO IMPROVE DENDROGEOMORPHIC SAMPLING: VARIOGRAM ANALYSES OF WOOD DENSITY
Butler, David R. - Department of Geography, Texas State University
HOW TO IMPROVE DENDROGEOMORPHIC SAMPLING: VARIOGRAM ANALYSES OF WOOD DENSITY USING X-RAY COMPUTED de Drize, CH-1227 Carouge-Geneva, Switzerland ABSTRACT Knowledge of the spatial heterogeneity of wood understanding of 3-D wood density structure in tree stems damaged by geomorphic processes. X-ray computed
Irradiation effects in high-density polyethylene Jussi Polvia
Nordlund, Kai
Irradiation effects in high-density polyethylene Jussi Polvia , Kai Nordlunda a simulations, we have studied the irradiation effects in high density polyethylene. We determined the threshold for the hydrogen atoms in the polyethylene chain. Keywords: molecular dynamics, irradiation, damage threshold
Optimal Base Station Density for Power Efficiency in Cellular Networks
Haenggi, Martin
Optimal Base Station Density for Power Efficiency in Cellular Networks Sanglap Sarkar, Radha, power consumption, power efficiency, optimal base station density. I. INTRODUCTION Cell size reduction by increasing the number of macro base stations or adding tiers of low powered base stations. There are two
Recent declines in benthic macroinvertebrate densities in Lake Ontario1
Recent declines in benthic macroinvertebrate densities in Lake Ontario1 Stephen J. Lozano, Jill V. Scharold, and Thomas F. Nalepa Abstract: Surveys of benthic macroinvertebrates conducted in Lake Ontario in macroinvertebrate densities, especially populations of an important food item such as Diporeia, in Lake Ontario
Neutral hydrogen density profiles derived from geocoronal N. stgaard,1
Mende, Stephen B.
Neutral hydrogen density profiles derived from geocoronal imaging N. Østgaard,1 S. B. Mende,1 H. U an empirical model of the neutral hydrogen density distribution at high altitudes (>3.5 RE geocentric distance from interplanetary hydrogen are obtained from a model. Assuming that the exosphere at high altitudes
HIGHLY COMPRESSED ION BEAMS FOR HIGH ENERGY DENSITY SCIENCE
Wurtele, Jonathan
HIGHLY COMPRESSED ION BEAMS FOR HIGH ENERGY DENSITY SCIENCE A. Friedman1,2 , J.J.Barnard1,2 , R Energy Density regimes required for Inertial Fu- sion Energy and other applications. An interim goal we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto
Simulation of salt migrations in density dependent groundwater flow
Vuik, Kees
Simulation of salt migrations in density dependent groundwater flow E.S. van Baaren Master's Thesis for the salt migration in the groundwater underneath the polders near the coast. The problem description of this thesis is to investigate the possibilities of modelling salt migrations in density dependent groundwater
TESTS FOR NORMALITY BASED ON DENSITY ESTIMATORS OF CONVOLUTIONS
Wefelmeyer, Wolfgang
TESTS FOR NORMALITY BASED ON DENSITY ESTIMATORS OF CONVOLUTIONS ANTON SCHICK, YISHI WANG-type kernel density estimator, goodness-of-fit test. Anton Schick was supported by NSF Grant DMS0906551. 1 #12;2 ANTON SCHICK, YISHI WANG AND WOLFGANG WEFELMEYER Instead of comparing distribution functions, we can
Density profile of strongly correlated spherical Yukawa plasmas
Bonitz, Michael
by means of local density approximation (LDA) similar to 2D system [6] Usage of the energy density und Astrophysik,Christian-Albrechts-UniversitÂ¨at Kiel, D-24118 Kiel, Germany 2 Institut fÂ¨ur Physik, UniversitÂ¨at Rostock, D-18051 Rostock, Germany 3 Institut fÂ¨ur Experimentelle und Angewandte Physik
Distributional Energy-Momentum Densities of Schwarzschild Space-Time
Toshiharu Kawai; Eisaku Sakane
1997-07-14
For Schwarzschild space-time, distributional expressions of energy-momentum densities and of scalar concomitants of the curvature tensors are examined for a class of coordinate systems which includes those of the Schwarzschild and of Kerr-Schild types as special cases. The energy-momentum density $\\tilde T_\\mu^{\
Testing Uniformity versus a Monotone Density Michael Woodroofe 1
Sun, Jiayang
Testing Uniformity versus a Monotone Density Michael Woodroofe 1 The University of Michigan Jiayang Sun 2 Case Western Reserve University Abstract The paper is concerned with testing uniformity versus a monotone density. This problem arises at least in two important contexts, after transformations, testing
Density functional theory for self-bound systems
Nir Barnea
2007-11-06
The density functional theory is extended to account for self-bound systems. To this end the Hohenberg-Kohn theorem is formulated for the intrinsic density and a Kohn-Sham like procedure for an $N$--body system is derived using the adiabatic approximation to account for the center of mass motion.
Scaling Dynamical Correlation Energy from Density Functional Theory Correlation Functionals
Ramachandran, Bala (Ramu)
Scaling Dynamical Correlation Energy from Density Functional Theory Correlation Functionals B for molecules by scaling the electron correlation energy calculated by density functional theory (DFT)1 ReceiVed: February 2, 2005; In Final Form: April 18, 2005 The scaling of dynamical correlation energy
Symmetry Energy as a Function of Density and Mass
Pawel Danielewicz; Jenny Lee
2007-08-21
Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a_a^V=(31.5-33.5) MeV for the volume coefficient and a_a^S=(9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L~95 MeV and K_{sym}~25 MeV.
Glyde, Henry R.
Density and spin-density excitations in normal-liquid 3 He B. Fa°k Commissariat a` l'Energie , the density response is dominated by a single collective zero- sound mode. The mode energy is well described incorporate this central physical feature into the density and spin-density dynamics of normal-liquid 3 He
Paris-Sud XI, Université de
et Tropicales, Hôpital Pellegrin, Centre Hospitalier Universitaire (CHU), Bordeaux, France, b INSERM. Pharmacovigilance: G. Miremont-Salamé. Data collection and Data management: E. Balestre, MJ. Blaizeau, M. Decoin, S
Expansion of X-ray form factor for close shell using uncorrelated wave function
AL-Robayi, Enas M.
2013-12-16
The atomic scattering factor has been studied for Be+ve, and B+2ve ions using the uncorrelated wave function (Hartree-Fock (HF)) for inter particle electronic shells. The physical importance of this factor appears in its relation to several important atomic properties as, the coherent scattering intensity, the total scattering intensity, the incoherent scattering function, the coherent scattering cross section, the total incoherent cross section, the nuclear magnetic shielding constant, the geometrical structure factor. Also there is one atomic properties the one particle radial density distribution function D(r)has been studied using the partitioning technique.
Microslit Nod-shuffle Spectroscopy - a technique for achieving very high densities of spectra
Glazebrook, K; Glazebrook, Karl; Bland-Hawthorn, Joss
2000-01-01
We describe a new approach to obtaining very high surface densities of optical spectra in astronomical observations with extremely accurate subtraction of night sky emission. The observing technique requires that the telescope is nodded rapidly between targets and adjacent sky positions; object and sky spectra are recorded on adjacent regions of a low-noise CCD through charge shuffling. This permits the use of extremely high densities of small slit apertures (`microslits') since an extended slit is not required for sky interpolation. The overall multi-object advantage of this technique is as large as 2.9x that of conventional multi-slit observing for an instrument configuration which has an underfilled CCD detector and is always >1.5 for high target densities. The `nod-shuffle' technique has been practically implemented at the Anglo-Australian Telescope as the `LDSS++ project' and achieves sky-subtraction accuracies as good as 0.04%, with even better performance possible. This is a factor of ten better than i...
High-density carbon ablator experiments on the National Ignition Facilitya)
MacKinnon, A. J.; Meezan, N. B.; Ross, J. S.; Le Pape, S.; Berzak Hopkins, L.; Divol, L.; Ho, D.; Milovich, J.; Pak, A.; Ralph, J.; Döppner, T.; Patel, P. K.; Thomas, C.; Tommasini, R.; Haan, S.; MacPhee, A. G.; McNaney, J.; Caggiano, J.; Hatarik, R.; Bionta, R.; Ma, T.; Spears, B.; Rygg, J. R.; Benedetti, L. R.; Town, R. P. J.; Bradley, D. K.; Dewald, E. L.; Fittinghoff, D.; Jones, O. S.; Robey, H. R.; Moody, J. D.; Khan, S.; Callahan, D. A.; Hamza, A.; Biener, J.; Celliers, P. M.; Braun, D. G.; Erskine, D. J.; Prisbrey, S. T.; Wallace, R. J.; Kozioziemski, B.; Dylla-Spears, R.; Sater, J.; Collins, G.; Storm, E.; Hsing, W.; Landen, O.; Atherton, J. L.; Lindl, J. D.; Edwards, M. J.; Frenje, J. A.; Gatu-Johnson, M.; Li, C. K.; Petrasso, R.; Rinderknecht, H.; Rosenberg, M.; Séguin, F. H.; Zylstra, A.; Knauer, J. P.; Grim, G.; Guler, N.; Merrill, F.; Olson, R.; Kyrala, G. A.; Kilkenny, J. D.; Nikroo, A.; Moreno, K.; Hoover, D. E.; Wild, C.; Werner, E.
2014-05-01
High Density Carbon (HDC) is a leading candidate as an ablator material for Inertial Confinement Fusion (ICF) capsules in x-ray (indirect) drive implosions. HDC has a higher density (3.5?g/cc) than plastic (CH, 1?g/cc), which results in a thinner ablator with a larger inner radius for a given capsule scale. This leads to higher x-ray absorption and shorter laser pulses compared to equivalent CH designs. This paper will describe a series of experiments carried out to examine the feasibility of using HDC as an ablator using both gas filled hohlraums and lower density, near vacuum hohlraums. These experiments have shown that deuterium (DD) and deuterium-tritium gas filled HDC capsules driven by a hohlraum filled with 1.2?mg/cc He gas, produce neutron yields a factor of 2× higher than equivalent CH implosions, representing better than 50% Yield-over-Clean (YoC). In a near vacuum hohlraum (He?=?0.03?mg/cc) with 98% laser-to-hohlraum coupling, such a DD gas-filled capsule performed near 1D expectations. A cryogenic layered implosion version was consistent with a fuel velocity?=?410?±?20?km/s with no observed ablator mixing into the hot spot.
Lee, Jui-Che; Lin, Shiang-Tai
2015-01-01
The exciton binding energy, the energy required to dissociate an excited electron-hole pair into free charge carriers, is one of the key factors to the optoelectronic performance of organic materials. However, it remains unclear whether modern quantum-mechanical calculations, mostly based on Kohn-Sham density functional theory (KS-DFT) and time-dependent density functional theory (TDDFT), are reliably accurate for exciton binding energies. In this study, the exciton binding energies and related optoelectronic properties (e.g., the ionization potentials, electron affinities, fundamental gaps, and optical gaps) of 121 small- to medium-sized molecules are calculated using KS-DFT and TDDFT with various density functionals. Our KS-DFT and TDDFT results are compared with those calculated using highly accurate CCSD and EOM-CCSD methods, respectively. The omegaB97, omegaB97X, and omegaB97X-D functionals are shown to generally outperform (with a mean absolute error of 0.36 eV) other functionals for the properties inve...
Jui-Che Lee; Jeng-Da Chai; Shiang-Tai Lin
2015-08-29
The exciton binding energy, the energy required to dissociate an excited electron-hole pair into free charge carriers, is one of the key factors to the optoelectronic performance of organic materials. However, it remains unclear whether modern quantum-mechanical calculations, mostly based on Kohn-Sham density functional theory (KS-DFT) and time-dependent density functional theory (TDDFT), are reliably accurate for exciton binding energies. In this study, the exciton binding energies and related optoelectronic properties (e.g., the ionization potentials, electron affinities, fundamental gaps, and optical gaps) of 121 small- to medium-sized molecules are calculated using KS-DFT and TDDFT with various density functionals. Our KS-DFT and TDDFT results are compared with those calculated using highly accurate CCSD and EOM-CCSD methods, respectively. The omegaB97, omegaB97X, and omegaB97X-D functionals are shown to generally outperform (with a mean absolute error of 0.36 eV) other functionals for the properties investigated.
High-density carbon ablator experiments on the National Ignition Facility
MacKinnon, A. J., E-mail: mackinnon2@llnl.gov; Meezan, N. B.; Ross, J. S.; Le Pape, S.; Berzak Hopkins, L.; Divol, L.; Ho, D.; Milovich, J.; Pak, A.; Ralph, J.; Döppner, T.; Patel, P. K.; Thomas, C.; Tommasini, R.; Haan, S.; MacPhee, A. G.; McNaney, J.; Caggiano, J.; Hatarik, R.; Bionta, R. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others
2014-05-15
High Density Carbon (HDC) is a leading candidate as an ablator material for Inertial Confinement Fusion (ICF) capsules in x-ray (indirect) drive implosions. HDC has a higher density (3.5?g/cc) than plastic (CH, 1?g/cc), which results in a thinner ablator with a larger inner radius for a given capsule scale. This leads to higher x-ray absorption and shorter laser pulses compared to equivalent CH designs. This paper will describe a series of experiments carried out to examine the feasibility of using HDC as an ablator using both gas filled hohlraums and lower density, near vacuum hohlraums. These experiments have shown that deuterium (DD) and deuterium-tritium gas filled HDC capsules driven by a hohlraum filled with 1.2?mg/cc He gas, produce neutron yields a factor of 2× higher than equivalent CH implosions, representing better than 50% Yield-over-Clean (YoC). In a near vacuum hohlraum (He?=?0.03?mg/cc) with 98% laser-to-hohlraum coupling, such a DD gas-filled capsule performed near 1D expectations. A cryogenic layered implosion version was consistent with a fuel velocity?=?410?±?20?km/s with no observed ablator mixing into the hot spot.
A Review of Electrochromic Window Performance Factors
Selkowitz Ed, S.E.
2010-01-01
controls and a lighting power density of 16.1 W/m2 (1.5controls and a lighting power density of 16.1 W/m2 (1.5ft) office spaces. Lighting power density was 16.1 W/m2 (1.5
Meagher, Mary
Density Measurement Worksheet. Use this sheet to determine if your formula is consistent with the known densities of various compounds. Formula : Formula weight : _______________ (FW) Unit Cell Volume :______________ (V) Probable Z value for your Laue symmetry (based on the unit cell: table 1) : ______ (Z) Formula V
Factors Limiting Complete Tumor Ablation by Radiofrequency Ablation
Paulet, Erwan, E-mail: erwanpaulet@yahoo.fr; Aube, Christophe [University Hospital Angers, Department of Radiology (France); Pessaux, Patrick [University Hospital Angers, Department of Visceral Surgery (France); Lebigot, Jerome [University Hospital Angers, Department of Radiology (France); Lhermitte, Emilie [University Hospital Angers, Department of Visceral Surgery (France); Oberti, Frederic [University Hospital Angers, Department of Hepato-Gastroenterology (France); Ponthieux, Anne [University Hospital Angers, Clinical Research Center (France); Cales, Paul [University Hospital Angers, Department of Hepato-Gastroenterology (France); Ridereau-Zins, Catherine [University Hospital Angers, Department of Radiology (France); Pereira, Philippe L. [Eberhard-Karls University, Department of Diagnostic Radiology (Germany)
2008-01-15
The purpose of this study was to determine radiological or physical factors to predict the risk of residual mass or local recurrence of primary and secondary hepatic tumors treated by radiofrequency ablation (RFA). Eighty-two patients, with 146 lesions (80 hepatocellular carcinomas, 66 metastases), were treated by RFA. Morphological parameters of the lesions included size, location, number, ultrasound echogenicity, computed tomography density, and magnetic resonance signal intensity were obtained before and after treatment. Parameters of the generator were recorded during radiofrequency application. The recurrence-free group was statistically compared to the recurrence and residual mass groups on all these parameters. Twenty residual masses were detected. Twenty-nine lesions recurred after a mean follow-up of 18 months. Size was a predictive parameter. Patients' sex and age and the echogenicity and density of lesions were significantly different for the recurrence and residual mass groups compared to the recurrence-free group (p < 0.05). The presence of an enhanced ring on the magnetic resonance control was more frequent in the recurrence and residual mass groups. In the group of patients with residual lesions, analysis of physical parameters showed a significant increase (p < 0.05) in the time necessary for the temperature to rise. In conclusion, this study confirms risk factors of recurrence such as the size of the tumor and emphasizes other factors such as a posttreatment enhanced ring and an increase in the time necessary for the rise in temperature. These factors should be taken into consideration when performing RFA and during follow-up.
How are mortality rates affected by population density?
Wang, Lei; Di, Zengru; Roehner, Bertrand M
2013-01-01
Biologists have found that the death rate of cells in culture depends upon their spatial density. Permanent "Stay alive" signals from their neighbours seem to prevent them from dying. In a previous paper (Wang et al. 2013) we gave evidence for a density effect for ants. In this paper we examine whether there is a similar effect in human demography. We find that although there is no observable relationship between population density and overall death rates, there is a clear relationship between density and the death rates of young age-groups. Basically their death rates decrease with increasing density. However, this relationship breaks down around 300 inhabitants per square kilometre. Above this threshold the death rates remains fairly constant. The same density effect is observed in Canada, France, Japan and the United States. We also observe a striking parallel between the density effect and the so-called marital status effect in the sense that they both lead to higher suicide rates and are both enhanced fo...
Stoschus, H.; Hudson, B.; Munoz Burgos, J. M. [Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831-0117 (United States); Thomas, D. M. [General Atomics, San Diego, California 92186-5608 (United States); Schweinzer, J. [Max-Planck-Institut fuer Plasmaphysik, Euratom Association, 85748 Garching (Germany)
2012-10-15
Four collisional radiative models (CRMs) for reconstruction of the edge electron density profile from the measured Li I (2s-2p) emission profile of an accelerated lithium beam are compared using experimental data from DIII-D. It is shown for both L- and H-mode plasmas that edge density profiles reconstructed with the CRMs DDD2, ABSOLUT, [Sasaki et al. Rev. Sci. Instrum. 64, 1699 (1993)] and a new model developed at DIII-D agree in a density scan from n{sub e}{sup ped}= (2.0-6.5) Multiplication-Sign 10{sup 19} m{sup -3} within 20%, 20%, <5%, and 40%, respectively, of the pedestal density measured with Thomson scattering. Profile shape and absolute density vary in a scan of the effective ion charge Z{sub eff}= 1-6 up to a factor of two but agree with Thomson data for Z{sub eff}= 1-2 within the error bars.
The Thermal Conductivity of Low Density Concretes Containing Perlite
Yarbrough, D. W.
1985-01-01
CONDUCTIVITY OF LOW DENSITY CONCRETES CONTAINING PERLITE David W. Yarbrough Department of Chemical Engineering Tennessee Technological University Cookeville, Tennessee ABSTRACT The thermal conductivity, k, of low density concretes made from Portland... cement and perlite has been measured near room temperature using an unguarded linear heat flow apparatus. Perlite based concretes having densities from 44.3 1b/ft 3 to 66.6 1b/ft 3 were found to have thermal conductivities from 1.55 Btu?in/ft 2 ?h...
Density Matrix Expansion for Low-Momentum Interactions
S. K. Bogner; R. J. Furnstahl; L. Platter
2008-11-26
A first step toward a universal nuclear energy density functional based on low-momentum interactions is taken using the density matrix expansion (DME) of Negele and Vautherin. The DME is adapted for non-local momentum-space potentials and generalized to include local three-body interactions. Different prescriptions for the three-body DME are compared. Exploratory results are given at the Hartree-Fock level, along with a roadmap for systematic improvements within an effective action framework for Kohn-Sham density functional theory.
Precision Cosmology and the Density of Baryons in the Universe
M. Kaplinghat; M. S. Turner
2000-11-14
Big-bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) anisotropy measurements give independent, accurate measurements of the baryon density and can test the framework of the standard cosmology. Early CMB data are consistent with the longstanding conclusion from BBN that baryons constitute a small fraction of matter in the Universe, but may indicate a slightly higher value for the baryon density. We clarify precisely what the two methods determine, and point out that differing values for the baryon density can indicate either an inconsistency or physics beyond the standard models of cosmology and particle physics. We discuss other signatures of the new physics in CMB anisotropy.
Negative energy density for a Dirac-Maxwell field
Dan Solomon
1999-07-19
It is well known that there can be negative energy densities in quantum field theory. Most of the work done in this area has involved free non-interacting systems. In this paper we show how a quantum state with negative energy density can be formulated for a Dirac field interacting with an Electromagnetic field. It will be shown that, for this case, there exist quantum states whose average energy density over an arbitrary volume is a negative number with an arbitrarily large magnitude.
Nuclear Energy Density Functionals Constrained by Low-Energy QCD
Dario Vretenar
2008-02-06
A microscopic framework of nuclear energy density functionals is reviewed, which establishes a direct relation between low-energy QCD and nuclear structure, synthesizing effective field theory methods and principles of density functional theory. Guided by two closely related features of QCD in the low-energy limit: a) in-medium changes of vacuum condensates, and b) spontaneous breaking of chiral symmetry; a relativistic energy density functional is developed and applied in studies of ground-state properties of spherical and deformed nuclei.
Symmetry energy at subnuclear densities deduced from nuclear masses
Kazuhiro Oyamatsu; Kei Iida
2010-04-19
We examine how nuclear masses are related to the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate nuclear masses in a way dependent on the equation of state of asymmetric nuclear matter. We find by comparison with empirical two-proton separation energies that a smaller symmetry energy at subnuclear densities, corresponding to a larger density symmetry coefficient L, is favored. This tendency, which is clearly seen for nuclei that are neutron-rich, nondeformed, and light, can be understood from the property of the surface symmetry energy in a compressible liquid-drop picture.
A short remark on negative energy densities and quantum inequalities
Dan Solomon
2009-01-20
In quantum field theory it is generally known that the energy density may be negative at a given point in spacetime. A number of papers have shown that there is a restriction on this energy density which is called a quantum inequality (QI). A QI is the lower bound to the "weighted average" of the energy density at a given point integrated over a time dependent sampling function. In this paper we give an example of a sampling function for which there is no QI.
Human factors in software development
Curtis, B.
1986-01-01
This book presents an overview of ergonomics/human factors in software development, recent research, and classic papers. Articles are drawn from the following areas of psychological research on programming: cognitive ergonomics, cognitive psychology, and psycholinguistics. Topics examined include: theoretical models of how programmers solve technical problems, the characteristics of programming languages, specification formats in behavioral research and psychological aspects of fault diagnosis.
Nonnegative matrix factorization with -divergence
Cichocki, Andrzej
Nonnegative matrix factorization with -divergence Andrzej Cichocki a , Hyekyoung Lee b , Yong of Science and Technology San 31 Hyoja-dong, Nam-gu, Pohang 790-784, Korea Abstract Nonnegative matrix reduction, the goal of which is to decompose nonnegative data matrix X into a product of basis matrix
Transfer Factors for Contaminant Uptake
of supply, upon written request as follows: Address: U.S. Nuclear Regulatory Commission OfficeTransfer Factors for Contaminant Uptake by Fruit and Nut Trees Office of Nuclear Regulatory; licensee event reports; and Commission papers and their attachments. NRC publications in the NUREG series
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berendzen, Joel [Biophysics Group, Mail Stop D454, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
1999-11-01
The correlation of local r.m.s. density is shown to be a good measure of the presence of distinct solvent and macromolecule regions in macromolecular electron-density maps. It has recently been shown that the standard deviation of local r.m.s. electron density is a good indicator of the presence of distinct regions of solvent and protein in macromolecular electron-density maps [Terwilliger & Berendzen (1999 ?). Acta Cryst. D55, 501–505]. Here, it is demonstrated that a complementary measure, the correlation of local r.m.s. density in adjacent regions on the unit cell, is also a good measure of the presence of distinct solvent and protein regions. The correlation of local r.m.s. density is essentially a measure of how contiguous the solvent (and protein) regions are in the electron-density map. This statistic can be calculated in real space or in reciprocal space and has potential uses in evaluation of heavy-atom solutions in the MIR and MAD methods as well as for evaluation of trial phase sets in ab initio phasing procedures.
Wu, Yongfeng; Xiao, Weike
2014-02-01
We introduced a new two-dimensional (2D) hexagon technique for probing the topological structure of the universe in which we mapped regions of the sky with high and low galaxy densities onto a 2D lattice of hexagonal unit cells. We defined filled cells as corresponding to high-density regions and empty cells as corresponding to low-density regions. The numbers of filled cells and empty cells were kept the same by controlling the size of the cells. By analyzing the six sides of each hexagon, we could obtain and compare the statistical topological properties of high-density and low-density regions of the universe in order to have a better understanding of the evolution of the universe. We applied this hexagonal method to Two Micron All Sky Survey data and discovered significant topological differences between the high-density and low-density regions. Both regions had significant (>5?) topological shifts from both the binomial distribution and the random distribution.
Optimization Online - Integer Factorization is in P
Yuly Shipilevsky
2012-08-31
Aug 31, 2012 ... Integer Factorization is in P. Yuly Shipilevsky (yulysh2000 ***at*** yahoo.ca). Abstract: A polynomial-time algorithm for integer factorization, ...
Why are Halo Density Profiles Stable at Formation?
G. Gonzalez-Casado; A. Raig; E. Salvador-Sole
1998-10-28
We analyze the physical justification of the picture proposed by Salvador-Sole et al. in these proceedings for the time evolution of the universal density profile of dark-matter halos. According to this picture, halos have at formation a stable (i.e. independent of mass and time) dimensionless density profile, the characteristic length and density scales of the profile depending on the underlying cosmogony. Subsequent evolution is driven by mass accretion onto the outskirts of halos and can be characterized simply by the increment of halo radius with time and the corresponding decrease of the critical density of the universe. We find this picture to be a reasonable good description of the expected evolution of halos in hierarchical models of structure formation.
Urban characteristics attributable to density-driven tie formation
Pan, Wei
Motivated by empirical evidence on the interplay between geography, population density and societal interaction, we propose a generative process for the evolution of social structure in cities. Our analytical and simulation ...
Direct Experimental Determination of Spectral Densities of Molecular Complexes
Leonardo A. Pachon; Paul Brumer
2014-10-15
Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.
Nuclear Level Density: Shell Model vs Mean Field
Sen'kov, Roman
2015-01-01
The knowledge of the nuclear level density is necessary for understanding various reactions including those in the stellar environment. Usually the combinatorics of Fermi-gas plus pairing is used for finding the level density. Recently a practical algorithm avoiding diagonalization of huge matrices was developed for calculating the density of many-body nuclear energy levels with certain quantum numbers for a full shell-model Hamiltonian. The underlying physics is that of quantum chaos and intrinsic thermalization in a closed system of interacting particles. We briefly explain this algorithm and, when possible, demonstrate the agreement of the results with those derived from exact diagonalization. The resulting level density is much smoother than that coming from the conventional mean-field combinatorics. We study the role of various components of residual interactions in the process of thermalization, stressing the influence of incoherent collision-like processes. The shell-model results for the traditionally...
Does Cosmological Vacuum Energy Density have an Electric Reason ?
Claus W. Turtur
2004-03-11
Rather uncomplicated calculations by hand display a surprising connection between the energy density of the vacuum and the diameter and age of the universe. Among other things, the result explains the observation of the accelerated expansion of the universe.
SOLAR CELLS Low trap-state density and long
Sargent, Edward H. "Ted"
REPORTS SOLAR CELLS Low trap-state density and long carrier diffusion in organolead trihalide) perovskite solar cells (PSCs) have now achieved 20.1% certified power con- version efficiencies (1
Aspects of the density field in an active nematic
Shradha Mishra; Sanjay Puri; Sriram Ramaswamy
2014-10-21
Active nematics are conceptually the simplest orientationally ordered phase of self-driven particles, but have proved to be a perennial source of surprises. We show here through numerical solution of coarse-grained equations for order parameter and density that the growth of the active nematic phase from the isotropic phase is necessarily accompanied by a clumping of the density. The growth kinetics of the density domains is shown to be faster than the 1/3-law expected for variables governed by a conservation law. Other results presented include the suppression of density fluctuations in the stationary ordered nematic by the imposition of an orienting field. We close by posing some open questions.
Low density lipoprotein fraction assay for cardiac disease risk
Krauss, Ronald M. (Berkeley, CA); Blanche, Patricia J. (Berkeley, CA); Orr, Joseph (San Pablo, CA)
1999-01-01
A variable rate density gradient electrophoric gel is described which separate LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described.
Nuclear Energy Density Functionals: What do we really know?
Bulgac, Aurel; Jin, Shi
2015-01-01
We present the simplest nuclear energy density functional (NEDF) to date, determined by only 4 significant phenomenological parameters, yet capable of fitting measured nuclear masses with better accuracy than the Bethe-Weizs\\"acker mass formula, while also describing density structures (charge radii, neutron skins etc.) and time-dependent phenomena (induced fission, giant resonances, low energy nuclear collisions, etc.). The 4 significant parameters are necessary to describe bulk nuclear properties (binding energies and charge radii); an additional 2 to 3 parameters have little influence on the bulk nuclear properties, but allow independent control of the density dependence of the symmetry energy and isovector excitations, in particular the Thomas-Reiche-Kuhn sum rule. This Hohenberg-Kohn-style of density functional theory successfully realizes Weizs\\"acker's ideas and provides a computationally tractable model for a variety of static nuclear properties and dynamics, from finite nuclei to neutron stars, where...
Observation of the Density Minimum in Deeply Supercooled Confined Water
Dazhi Liu; Yang Zhang; Chia-Cheng Chen; Chung-Yuan Mou; Peter H Poole; Sow-Hsin Chen
2007-04-17
Small angle neutron scattering (SANS) is used to measure the density of heavy water contained in 1-D cylindrical pores of mesoporous silica material MCM-41-S-15, with pores of diameter of 15+-1 A. In these pores the homogenous nucleation process of bulk water at 235 K does not occur and the liquid can be supercooled down to at least 160 K. The analysis of SANS data allows us to determine the absolute value of the density of D2O as a function of temperature. We observe a density minimum at 210+-5 K with a value of 1.041+-0.003 g/cm3. We show that the results are consistent with the predictions of molecular dynamics simulations of supercooled bulk water. This is the first experimental report of the existence of the density minimum in supercooled water.
Direct experimental determination of spectral densities of molecular complexes
Pachón, Leonardo A.; Brumer, Paul
2014-11-07
Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need to be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.
Quantum Control of Many-Body Systems by the Density
S. E. B. Nielsen; M. Ruggenthaler; R. van Leeuwen
2014-12-11
In this work we focus on a recently introduced method [1] to construct the external potential $v$ that, for a given initial state, produces a prescribed time-dependent density in an interacting quantum many-body system. We show how this method can also be used to perform flexible and efficient quantum control. The simple interpretation of the density (the amount of electrons per volume) allows us to use our physical intuition to consider interesting control problems and to easily restrict the search space in optimization problems. The method's origin in time-dependent density-functional theory makes studies of large systems possible. We further discuss the generalization of the method to higher dimensions and its numerical implementation in great detail. We also present several examples to illustrate the flexibility, and to confirm that the scheme is efficient and stable even for large and rapid density variations irrespective of the initial state and interactions.
An evolutionary fuel assembly design for high power density BWRs
Karahan, Aydin
2007-01-01
An evolutionary BWR fuel assembly design was studied as a means to increase the power density of current and future BWR cores. The new assembly concept is based on replacing four traditional assemblies and large water gap ...
Probing Electron Dynamics with the Laplacian of the Momentum Density
Sukumar, N.; MacDougall, Preston J.; Levit, M. Creon
2012-09-24
This chapter in the above-titled monograph presents topological analysis of the Laplacian of the electron momentum density in organic molecules. It relates topological features in this distribution to chemical and physical properties, particularly aromaticity and electron transport.
Towards A Resolution Of The Vacuum Energy Density Crisis
Oldershaw, R L
2009-01-01
The theoretical vacuum energy density estimated on the basis of the Standard Model of particle physics and very general quantum assumptions is 59 to 123 orders of magnitude larger than the measured vacuum energy density for the observable universe which is determined on the basis of the Standard Model of cosmology and empirical data. This enormous disparity between the expectations of two of our most widely accepted theoretical frameworks demands a credible and self-consistent explanation, and yet even after decades of sporadic effort a generally accepted resolution of this crisis has not surfaced. Very recently, however, a discrete self-similar cosmological paradigm based on the fundamental principle of discrete scale invariance has been found to offer a rationale for reducing the vacuum energy density disparity by at least 115 orders of magnitude, and possibly this new paradigm offers a means of eliminating the vacuum energy density crisis entirely.
Perturbative thermodynamics at nonzero isospin density for cold QCD
Graf, Thorben; Fraga, Eduardo S
2015-01-01
We use next-to-leading-order in perturbation theory to investigate the effects of a finite isospin density on the thermodynamics of cold strongly interacting matter. Our results include nonzero quark masses and are compared to lattice data.
Perturbative thermodynamics at nonzero isospin density for cold QCD
Thorben Graf; Juergen Schaffner-Bielich; Eduardo S. Fraga
2015-11-30
We use next-to-leading-order in perturbation theory to investigate the effects of a finite isospin density on the thermodynamics of cold strongly interacting matter. Our results include nonzero quark masses and are compared to lattice data.
Density and spin response functions in ultracold fermionic atom gases
Bogdan Mihaila; Sergio Gaudio; Krastan B. Blagoev; Alexander V. Balatsky; Peter B. Littlewood; Darryl L. Smith
2005-02-03
We propose a new method of detecting the onset of superfluidity in a two-component ultracold fermionic gas of atoms governed by an attractive short-range interaction. By studying the two-body correlation functions we find that a measurement of the momentum distribution of the density and spin response functions allows one to access separately the normal and anomalous densities. The change in sign at low momentum transfer of the density response function signals the transition between a BEC and a BCS regimes, characterized by small and large pairs, respectively. This change in sign of the density response function represents an unambiguous signature of the BEC to BCS crossover. Also, we predict spin rotational symmetry-breaking in this system.
Surface modification of low density silica and bridged polysilsesquioxane aerogels
DeFriend, K. A. (Kimberly A.); Loy, D. A. (Douglas A.); Salazar, K. V. (Kenneth V.); Wilson, K. V. (Kennard V.)
2004-01-01
Silica and bridged polysilsesquioxane aerogels are low density materials that are attractive for applications such as, thermal insulation, porous separation media or catalyst supports, adsorbents. However, aerogels are notoriously weak and brittle making it difficult to handle and machine monoliths into desired forms. This prevents the development of many applications that would otherwise benefit from the use of the low density materials. We will describe our efforts to chemically modify and mechanically enhance silica-based aerogels using chemical vapor techniques without sacrificing their characteristic low densities. Monolithic silica and organically bridged polysilsesquioxane aerogels were prepared by sol-gel polymerization of the respective methoxysilane monomers followed by supercritical carbon dioxide drying of the gels. Reactive modification of the gels with volatile silylating compounds during and after the drying process and these effects on the mechanical properties and density of the aerogels will be described.
Optical Properties of the Charge-Density-Wave Polychalcogenide...
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Optical Properties of the Charge-Density-Wave Polychalcogenide Compounds R2Te5 (RNd, Sm and Gd) Citation Details In-Document Search Title: Optical Properties of the...
Selection on Gamete Recognition Proteins Depends on Sex, Density,
McQuade, D. Tyler
Selection on Gamete Recognition Proteins Depends on Sex, Density, and Genotype Frequency Don R but high binding rates in males. Polyspermy is costly to both sexes, but it never pays to be the second
TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...
DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...
Optical Properties of the Charge-Density-Wave Polychalcogenide...
Office of Scientific and Technical Information (OSTI)
the rare-earth polychalcogenide Rsub 2Tesub 5 (R Nd, Sm and Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption spectrum we extract the...
Low density lipoprotein fraction assay for cardiac disease risk
Krauss, R.M.; Blanche, P.J.; Orr, J.
1999-07-20
A variable rate density gradient electrophoric gel is described which separates LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described. 8 figs.
Transition density and pressure in hot neutron stars
Xu, Jun; Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An.
2010-01-01
Using the momentum-dependent effective interaction (MDI) for nucleons, we have studied the transition density and pressure at the boundary between the inner crust and the liquid core of hot neutron stars. We find that their values are larger...
The design of high power density annular fuel for LWRs
Yuan, Yi, 1975-
2004-01-01
Fuel performance models have been developed to assess the performance of internally and externally cooled LWR annular fuel. Such fuel may be operated at 30-50% higher core power density than the current operating LWRs, and ...
A novel density of state method for complex action systems
Biagio Lucini; Kurt Langfeld
2014-11-01
Recently, a new and efficient algorithm (the LLR method) has been proposed for computing densities of states in statistical systems and gauge theories. In this talk, we explore whether this novel density of states method can be applied to numerical computations of observables in systems for which the action is complex. To this purpose, we introduce a generalised density of states, in terms of which integrals of oscillating observables can be determined semi-analytically, and we define a strategy to compute it with the LLR method. As a case study, we apply these ideas to the Z(3) spin model at finite density, finding a remarkable agreement of our results for the phase twist with those obtained with the worm algorithm for all explored chemical potentials, including values for which there are cancellations over sixteen orders of magnitude. These findings open new perspectives for dealing with the sign problem on physically more relevant systems.
Towards A Resolution Of The Vacuum Energy Density Crisis
R. L. Oldershaw
2010-10-21
The theoretical vacuum energy density estimated on the basis of the Standard Model of particle physics and very general quantum assumptions is 59 to 123 orders of magnitude larger than the measured vacuum energy density for the observable universe which is determined on the basis of the Standard Model of cosmology and empirical data. This enormous disparity between the expectations of two of our most widely accepted theoretical frameworks demands a credible and self-consistent explanation, and yet even after decades of sporadic effort a generally accepted resolution of this crisis has not surfaced. Very recently, however, a discrete self-similar cosmological paradigm based on the fundamental principle of discrete scale invariance has been found to offer a rationale for reducing the vacuum energy density disparity by at least 115 orders of magnitude, and possibly this new paradigm offers a means of eliminating the vacuum energy density crisis entirely.
Effect of Chemical Pressure on the Charge Density Wave Transition...
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Effect of Chemical Pressure on the Charge Density Wave Transition in Rare-Earth Tritellurides RTe3 Citation Details In-Document Search Title: Effect of Chemical Pressure on the...
Preface: Special Topic on Advances in Density Functional Theory
Yang, Weitao
2014-05-14
This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering.
Non-invasive fluid density and viscosity measurement
Sinha, Dipen N. (Los Alamos, NM)
2012-05-01
The noninvasively measurement of the density and viscosity of static or flowing fluids in a section of pipe such that the pipe performs as the sensing apparatus, is described. Measurement of a suitable structural vibration resonance frequency of the pipe and the width of this resonance permits the density and viscosity to be determined, respectively. The viscosity may also be measured by monitoring the decay in time of a vibration resonance in the pipe.
Density Functional Theory with Dissipation: Transport through Single Molecules
Kieron Burke
2012-04-30
A huge amount of fundamental research was performed on this grant. Most of it focussed on fundamental issues of electronic structure calculations of transport through single molecules, using density functional theory. Achievements were: (1) First density functional theory with dissipation; (2) Pseudopotential plane wave calculations with master equation; (3) Weak bias limit; (4) Long-chain conductance; and (5) Self-interaction effects in tunneling.
Special generalized densities and propagators: a geometric account
Daniel Canarutto
2015-09-03
Starting from a short review of spaces of generalized sections of vector bundles, we give a concise systematic description, in precise geometric terms, of Leray densities, principal value densities, propagators and elementary solutions of field equations in flat spacetime. We then sketch a partly original geometric presentation of free quantum fields and show how propagators arise from their graded commutators in the boson and fermion cases.
Simulations of liquid ribidium expanded to the critical density
Ross, M; Yang, L H; Pilgrim, W
2006-05-16
Quantum molecular dynamic simulations were used to examine the change in atomic and electronic structure in liquid rubidium along its liquid-vapor coexistence curve. Starting from the liquid at the triple point, with increasing expansion we observe a continuous increase in the electron localization leading to ion clustering near the metal-nonmetal transition at about twice the critical density, in agreement with electrical measurements, and to the presence of dimers near and below the critical density.
Density dependence of symmetry free energy of hot nuclei
S. K. Samaddar; J. N. De; X. Vinas; M. Centelles
2008-09-04
The density and excitation energy dependence of symmetry energy and symmetry free energy for finite nuclei are calculated microscopically in a microcanonical framework taking into account thermal and expansion effects. A finite-range momentum and density dependent two-body effective interaction is employed for this purpose. The role of mass, isospin and equation of state (EoS) on these quantities is also investigated; our calculated results are in consonance with the available experimental data.
Effect of density dependent symmetry energy on Elliptical flow
Suneel Kumar; Karan Singh Vinayak
2011-08-30
The effect of the density dependent symmetry energy on elliptical flow is studied using isospin-dependent quantum molecular dynamics model(IQMD). We have used the reduced isospin-dependent cross-section with soft equation of state to study the sensitivity of elliptical flow towards symmetry energy. Aim of the present study is to pin down the Elliptical flow for the various forms of the density dependent symmetry energy.
Observation of low magnetic field density peaks in helicon plasma
Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2013-04-15
Single density peak has been commonly observed in low magnetic field (<100 G) helicon discharges. In this paper, we report the observations of multiple density peaks in low magnetic field (<100 G) helicon discharges produced in the linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. Experiments are carried out using argon gas with m = +1 right helical antenna operating at 13.56 MHz by varying the magnetic field from 0 G to 100 G. The plasma density varies with varying the magnetic field at constant input power and gas pressure and reaches to its peak value at a magnetic field value of {approx}25 G. Another peak of smaller magnitude in density has been observed near 50 G. Measurement of amplitude and phase of the axial component of the wave using magnetic probes for two magnetic field values corresponding to the observed density peaks indicated the existence of radial modes. Measured parallel wave number together with the estimated perpendicular wave number suggests oblique mode propagation of helicon waves along the resonance cone boundary for these magnetic field values. Further, the observations of larger floating potential fluctuations measured with Langmuir probes at those magnetic field values indicate that near resonance cone boundary; these electrostatic fluctuations take energy from helicon wave and dump power to the plasma causing density peaks.
Densities and energies of nuclei in dilute matter
P. Papakonstantinou; J. Margueron; F. Gulminelli; Ad. R. Raduta
2013-05-01
We explore the ground-state properties of nuclear clusters embedded in a gas of nucleons with the help of Skyrme-Hartree-Fock microscopic calculations. Two alternative representations of clusters are introduced, namely coordinate-space and energy-space clusters. We parameterize their density profiles in spherical symmetry in terms of basic properties of the energy density functionals used and propose an analytical, Woods-Saxon density profile whose parameters depend, not only on the composition of the cluster, but also of the nucleon gas. We study the clusters' energies with the help of the local-density approximation, validated through our microscopic results. We find that the volume energies of coordinate-space clusters are determined by the saturation properties of matter, while the surface energies are strongly affected by the presence of the gas. We conclude that both the density profiles and the cluster energies are strongly affected by the gas and discuss implications for the nuclear EoS and related perspectives. Our study provides a simple, but microscopically motivated modeling of the energetics of clusterized matter at subsaturation densities, for direct use in consequential applications of astrophysical interest.
Density-shear instability in electron magneto-hydrodynamics
Wood, T. S. Hollerbach, R.; Lyutikov, M.
2014-05-15
We discuss a novel instability in inertia-less electron magneto-hydrodynamics (EMHD), which arises from a combination of electron velocity shear and electron density gradients. The unstable modes have a lengthscale longer than the transverse density scale, and a growth-rate of the order of the inverse Hall timescale. We suggest that this density-shear instability may be of importance in magnetic reconnection regions on scales smaller than the ion skin depth, and in neutron star crusts. We demonstrate that the so-called Hall drift instability, previously argued to be relevant in neutron star crusts, is a resistive tearing instability rather than an instability of the Hall term itself. We argue that the density-shear instability is of greater significance in neutron stars than the tearing instability, because it generally has a faster growth-rate and is less sensitive to geometry and boundary conditions. We prove that, for uniform electron density, EMHD is “at least as stable” as regular, incompressible MHD, in the sense that any field configuration that is stable in MHD is also stable in EMHD. We present a connection between the density-shear instability in EMHD and the magneto-buoyancy instability in anelastic MHD.
Neutron skin uncertainties of Skyrme energy density functionals
M. Kortelainen; J. Erler; W. Nazarewicz; N. Birge; Y. Gao; E. Olsen
2013-07-16
Background: Neutron-skin thickness is an excellent indicator of isovector properties of atomic nuclei. As such, it correlates strongly with observables in finite nuclei that depend on neutron-to-proton imbalance and the nuclear symmetry energy that characterizes the equation of state of neutron-rich matter. A rich worldwide experimental program involving studies with rare isotopes, parity violating electron scattering, and astronomical observations is devoted to pinning down the isovector sector of nuclear models. Purpose: We assess the theoretical systematic and statistical uncertainties of neutron-skin thickness and relate them to the equation of state of nuclear matter, and in particular to nuclear symmetry energy parameters. Methods: We use the nuclear superfluid Density Functional Theory with several Skyrme energy density functionals and density dependent pairing. To evaluate statistical errors and their budget, we employ the statistical covariance technique. Results: We find that the errors on neutron skin increase with neutron excess. Statistical errors due to uncertain coupling constants of the density functional are found to be larger than systematic errors, the latter not exceeding 0.06 fm in most neutron-rich nuclei across the nuclear landscape. The single major source of uncertainty is the poorly determined slope L of the symmetry energy that parametrizes its density dependence. Conclusions: To provide essential constraints on the symmetry energy of the nuclear energy density functional, next-generation measurements of neutron skins are required to deliver precision better than 0.06 fm.
Energy propagation by transverse waves in multiple flux tube systems using filling factors
Van Doorsselaere, T.; Gijsen, S. E.; Andries, J.; Verth, G. E-mail: stief.gijsen@wis.kuleuven.be E-mail: g.verth@sheffield.ac.uk
2014-11-01
In the last few years, it has been found that transverse waves are present at all times in coronal loops or spicules. Their energy has been estimated with an expression derived for bulk Alfvén waves in homogeneous media, with correspondingly uniform wave energy density and flux. The kink mode, however, is localized in space with the energy density and flux dependent on the position in the cross-sectional plane. The more relevant quantities for the kink mode are the integrals of the energy density and flux over the cross-sectional plane. The present paper provides an approximation to the energy propagated by kink modes in an ensemble of flux tubes by means of combining the analysis of single flux tube kink oscillations with a filling factor for the tube cross-sectional area. This finally allows one to compare the expressions for energy flux of Alfvén waves with an ensemble of kink waves. We find that the correction factor for the energy in kink waves, compared to the bulk Alfvén waves, is between f and 2f, where f is the density filling factor of the ensemble of flux tubes.
The density of injective endomorphisms of a free group 1 The density of injective endomorphisms of a
Ventura, Enric
author was partially supported by Spanish government grant SAP2003-0253. The third author was partially supported by Spanish government grant DGI2003-06613. 2 #12;The density of injective endomorphisms of a free
On Factorization of Molecular Wavefunctions
Thierry Jecko; Brian T. Sutcliffe; R. Guy Woolley
2015-07-18
Recently there has been a renewed interest in the chemical physics literature of factorization of the position representation eigenfunctions \\{$\\Phi$\\} of the molecular Schr\\"odinger equation as originally proposed by Hunter in the 1970s. The idea is to represent $\\Phi$ in the form $\\varphi\\chi$ where $\\chi$ is \\textit{purely} a function of the nuclear coordinates, while $\\varphi$ must depend on both electron and nuclear position variables in the problem. This is a generalization of the approximate factorization originally proposed by Born and Oppenheimer, the hope being that an `exact' representation of $\\Phi$ can be achieved in this form with $\\varphi$ and $\\chi$ interpretable as `electronic' and `nuclear' wavefunctions respectively. We offer a mathematical analysis of these proposals that identifies ambiguities stemming mainly from the singularities in the Coulomb potential energy.
On Factorization of Molecular Wavefunctions
Thierry Jecko; Brian T. Sutcliffe; R. Guy Woolley
2015-09-05
Recently there has been a renewed interest in the chemical physics literature of factorization of the position representation eigenfunctions \\{$\\Phi$\\} of the molecular Schr\\"odinger equation as originally proposed by Hunter in the 1970s. The idea is to represent $\\Phi$ in the form $\\varphi\\chi$ where $\\chi$ is \\textit{purely} a function of the nuclear coordinates, while $\\varphi$ must depend on both electron and nuclear position variables in the problem. This is a generalization of the approximate factorization originally proposed by Born and Oppenheimer, the hope being that an `exact' representation of $\\Phi$ can be achieved in this form with $\\varphi$ and $\\chi$ interpretable as `electronic' and `nuclear' wavefunctions respectively. We offer a mathematical analysis of these proposals that identifies ambiguities stemming mainly from the singularities in the Coulomb potential energy.
On Factorization of Molecular Wavefunctions
Thierry Jecko; Brian T. Sutcliffe; R. Guy Woolley
2015-10-13
Recently there has been a renewed interest in the chemical physics literature of factorization of the position representation eigenfunctions \\{$\\Phi$\\} of the molecular Schr\\"odinger equation as originally proposed by Hunter in the 1970s. The idea is to represent $\\Phi$ in the form $\\varphi\\chi$ where $\\chi$ is \\textit{purely} a function of the nuclear coordinates, while $\\varphi$ must depend on both electron and nuclear position variables in the problem. This is a generalization of the approximate factorization originally proposed by Born and Oppenheimer, the hope being that an `exact' representation of $\\Phi$ can be achieved in this form with $\\varphi$ and $\\chi$ interpretable as `electronic' and `nuclear' wavefunctions respectively. We offer a mathematical analysis of these proposals that identifies ambiguities stemming mainly from the singularities in the Coulomb potential energy.
Factors Impacting Decommissioning Costs - 13576
Kim, Karen; McGrath, Richard [Electric Power Research Institute, 3420 Hillview Ave., Palo Alto, California (United States)] [Electric Power Research Institute, 3420 Hillview Ave., Palo Alto, California (United States)
2013-07-01
The Electric Power Research Institute (EPRI) studied United States experience with decommissioning cost estimates and the factors that impact the actual cost of decommissioning projects. This study gathered available estimated and actual decommissioning costs from eight nuclear power plants in the United States to understand the major components of decommissioning costs. Major costs categories for decommissioning a nuclear power plant are removal costs, radioactive waste costs, staffing costs, and other costs. The technical factors that impact the costs were analyzed based on the plants' decommissioning experiences. Detailed cost breakdowns by major projects and other cost categories from actual power plant decommissioning experiences will be presented. Such information will be useful in planning future decommissioning and designing new plants. (authors)
Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry
Gruszkiewicz, Miroslaw {Mirek} S; Rother, Gernot; Wesolowski, David J; Cole, David R; Wallacher, Dirk
2012-01-01
The densities of pore-confined fluids were measured for the first time by means of a vibrating tube method. Isotherms of total adsorption capacity were measured directly making the method complementary to the conventional gravimetric or volumetric/piezometric adsorption techniques, which yield the excess adsorption (the Gibbsian surface excess). A custom-made high-pressure, high-temperature vibrating tube densimeter (VTD) was used to measure the densities of subcritical and supercritical propane (between 35 C and 97 C) and supercritical carbon dioxide (between 32 C and 50 C) saturating hydrophobic silica aerogel (0.2 g/cm3, 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, excess adsorption isotherms for supercritical CO2 and the same porous solid were measured gravimetrically using a precise magnetically-coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum at a subcritical density of the bulk fluid, and then decreased towards zero or negative values at supercritical densities. Compression of the confined fluid significantly beyond the density of the bulk liquid at the same temperature was observed at subcritical temperatures. The features of the isotherms of confined fluid density are interpreted to elucidate the observed behavior of excess adsorption. The maxima of excess adsorption were found to occur below the critical density of the bulk fluid at the conditions corresponding to the beginning of the plateau of total adsorption, marking the end of the transition of pore fluid to a denser, liquid-like pore phase. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. No measurable effect of pore confinement on the liquid-vapor critical point was found. Quantitative agreement was obtained between excess adsorption isotherms determined from VTD total adsorption results and those measured gravimetrically at the same temperature, confirming the validity of the vibrating tube measurements. Vibrating tube densimetry was demonstrated as a novel experimental approach capable of providing the average density of pore-confined fluids.
Human factors in waste management
Moray, N.
1994-10-01
This article examines the role of human factors in radioactive waste management. Although few problems and ergonomics are special to radioactive waste management, some problems are unique especially with long term storage. The entire sociotechnical system must be looked at in order to see where improvement can take place because operator errors, as seen in Chernobyl and Bhopal, are ultimately the result of management errors.
Hausdorff dimension and filling factor
Wellington Cruz
1998-02-25
We propose a new hierarchy scheme for the filling factor, a parameter which characterizes the occurrence of the Fractional Quantum Hall Effect (FQHE). We consider the Hausdorff dimension, $h$, as a parameter for classifying fractional spin particles, such that, it is written in terms of the statistics of the collective excitations. The number $h$ classifies these excitations with different statistics in terms of its homotopy class.
Solovyeva, Alisa [Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Technical University Braunschweig, Institute for Physical and Theoretical Chemistry, Hans-Sommer-Str. 10, 38106 Braunschweig (Germany); Pavanello, Michele [Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Neugebauer, Johannes [Technical University Braunschweig, Institute for Physical and Theoretical Chemistry, Hans-Sommer-Str. 10, 38106 Braunschweig (Germany)
2012-05-21
Subsystem density-functional theory (DFT) is a powerful and efficient alternative to Kohn-Sham DFT for large systems composed of several weakly interacting subunits. Here, we provide a systematic investigation of the spin-density distributions obtained in subsystem DFT calculations for radicals in explicit environments. This includes a small radical in a solvent shell, a {pi}-stacked guanine-thymine radical cation, and a benchmark application to a model for the special pair radical cation, which is a dimer of bacteriochlorophyll pigments, from the photosynthetic reaction center of purple bacteria. We investigate the differences in the spin densities resulting from subsystem DFT and Kohn-Sham DFT calculations. In these comparisons, we focus on the problem of overdelocalization of spin densities due to the self-interaction error in DFT. It is demonstrated that subsystem DFT can reduce this problem, while it still allows to describe spin-polarization effects crossing the boundaries of the subsystems. In practical calculations of spin densities for radicals in a given environment, it may thus be a pragmatic alternative to Kohn-Sham DFT calculations. In our calculation on the special pair radical cation, we show that the coordinating histidine residues reduce the spin-density asymmetry between the two halves of this system, while inclusion of a larger binding pocket model increases this asymmetry. The unidirectional energy transfer in photosynthetic reaction centers is related to the asymmetry introduced by the protein environment.
Zhen Zhang; Lie-Wen Chen
2014-12-11
Nuclear structure observables usually most effectively probe the properties of nuclear matter at subsaturation densities rather than at saturation density. We demonstrate that the electric dipole polarizibility $\\alpha _ {\\text{D}}$ in $^{208}$Pb is sensitive to both the magnitude $E_{\\text{sym}}(\\rho_{\\text{c}})$ and density slope $L(\\rho_{\\text{c}})$ of the symmetry energy at a subsaturation cross density $\\rho_{\\text{c}} = 0.11$ fm$^{-3}$. Using the experimental data of $\\alpha _ {\\text{D}}$ in $^{208}$Pb from RCNP and the recent accurate constraint of $E_{\\text{sym}}(\\rho_{\\text{c}})$ from the binding energy difference of heavy isotope pairs, we extract a value of $L(\\rho_{\\text{c}}) = 47.3 \\pm 7.8$ MeV. The implication of the present constraint of $L(\\rho_{\\text{c}})$ to the symmetry energy at saturation density, the neutron skin thickness of $^{208}$Pb and the core-crust transition density in neutron stars is discussed.
Improving experimental phases for strong reflections prior to density modification
Uervirojnangkoorn, Monarin [University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Hilgenfeld, Rolf, E-mail: hilgenfeld@biochem.uni-luebeck.de [University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, People’s Republic of (China); Terwilliger, Thomas C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Read, Randy J. [University of Cambridge, Cambridge CB2 0XY (United Kingdom); University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany)
2013-10-01
A genetic algorithm has been developed to optimize the phases of the strongest reflections in SIR/SAD data. This is shown to facilitate density modification and model building in several test cases. Experimental phasing of diffraction data from macromolecular crystals involves deriving phase probability distributions. These distributions are often bimodal, making their weighted average, the centroid phase, improbable, so that electron-density maps computed using centroid phases are often non-interpretable. Density modification brings in information about the characteristics of electron density in protein crystals. In successful cases, this allows a choice between the modes in the phase probability distributions, and the maps can cross the borderline between non-interpretable and interpretable. Based on the suggestions by Vekhter [Vekhter (2005 ?), Acta Cryst. D61, 899–902], the impact of identifying optimized phases for a small number of strong reflections prior to the density-modification process was investigated while using the centroid phase as a starting point for the remaining reflections. A genetic algorithm was developed that optimizes the quality of such phases using the skewness of the density map as a target function. Phases optimized in this way are then used in density modification. In most of the tests, the resulting maps were of higher quality than maps generated from the original centroid phases. In one of the test cases, the new method sufficiently improved a marginal set of experimental SAD phases to enable successful map interpretation. A computer program, SISA, has been developed to apply this method for phase improvement in macromolecular crystallography.
Vacuum Casimir energy densities and field divergences at boundaries
Nicola Bartolo; Salvatore Butera; Margherita Lattuca; Roberto Passante; Lucia Rizzuto; Salvatore Spagnolo
2015-05-14
We consider and review the emergence of singular energy densities and field fluctuations at sharp boundaries or point-like field sources in the vacuum. The presence of singular energy densities of a field may be relevant from a conceptual point of view, because they contribute to the self-energy of the system. They should also generate significant gravitational effects. We first consider the case of the interface between a metallic boundary and the vacuum, and obtain the structure of the singular electric and magnetic energy densities at the interface through an appropriate limit from a dielectric to an ideal conductor. Then, we consider the case of a point-like source of the electromagnetic field, and show that also in this case the electric and magnetic energy densities show a singular structure at the source position. We discuss how, in both cases, these singularities give an essential contribution to the electromagnetic self-energy of the system; moreover, they solve an apparent inconsistency between the space integral of the field energy density and the average value of the field Hamiltonian. The singular behavior we find is softened, or even eliminated, for boundaries fluctuating in space and for extended field sources. We discuss in detail the case in which a reflecting boundary is not fixed in space but is allowed to move around an equilibrium position, under the effect of quantum fluctuations of its position. Specifically, we consider the simple case of a one-dimensional massless scalar field in a cavity with one fixed and one mobile wall described quantum-mechanically. We investigate how the possible motion of the wall changes the vacuum fluctuations and the energy density of the field, compared with the fixed-wall case. Also, we explicitly show how the fluctuating motion of the wall smears out the singular behaviour of the field energy density at the boundary.
Talking About Breast Density and Cancer Risk | GE Global Research
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
by a complicated relationship between ethnic, hereditary, environmental (diet, geography), reproductive (age at first pregnancy, number of children) and hormonal factors....
Rapid model building of ?-sheets in electron-density maps
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2010-03-01
A method for rapid model building of ?-sheets at moderate resolution is presented. A method for rapidly building ?-sheets into electron-density maps is presented. ?-Strands are identified as tubes of high density adjacent to and nearly parallel to other tubes of density. The alignment and direction of each strand are identified from the pattern of high density corresponding to carbonyl and C{sup ?} atoms along the strand averaged over all repeats present in the strand. The ?-strands obtained are then assembled into a single atomic model of the ?-sheet regions. The method was tested on a set of 42 experimental electron-density maps at resolutions ranging from 1.5 to 3.8 Å. The ?-sheet regions were nearly completely built in all but two cases, the exceptions being one structure at 2.5 Å resolution in which a third of the residues in ?-sheets were built and a structure at 3.8 Å in which under 10% were built. The overall average r.m.s.d. of main-chain atoms in the residues built using this method compared with refined models of the structures was 1.5 Å.
Cosmic density and velocity fields in Lagrangian perturbation theory
Mikel Susperregi; Thomas Buchert
1997-08-04
A first- and second-order relation between cosmic density and peculiar-velocity fields is presented. The calculation is purely Lagrangian and it is derived using the second-order solutions of the Lagrange-Newton system obtained by Buchert & Ehlers. The procedure is applied to two particular solutions given generic initial conditions. In this approach, the continuity equation yields a relation between the over-density and peculiar-velocity fields that automatically satisfies Euler's equation because the orbits are derived from the Lagrange-Newton system. This scheme generalizes some results obtained by Nusser et al. (1991) in the context of the Zel'dovich approximation. As opposed to several other reconstruction schemes, in this approach it is not necessary to truncate the expansion of the Jacobian given by the continuity equation in order to calculate a first- or second-order expression for the density field. In these previous schemes, the density contrast given by (a) the continuity equation and (b) Euler's equation are mutually incompatible. This inconsistency arises as a consequence of an improper handling of Lagrangian and Eulerian coordinates in the analysis. Here, we take into account the fact that an exact calculation of the density is feasible in the Lagrangian picture and therefore an accurate and consistent description is obtained.
The latitudinal gradient of the NO peak density
Fesen, C.G.; Rusch, D.W. (Univ. of Colorado, Boulder (United States)); Gerard, J.C. (Univ. de Liege (Belgium))
1990-11-01
The latitudinal gradients of the maximum nitric oxide densities near 110 km are presented for solstice and equinox periods from 1982 through 1985 as observed by the Solar Mesosphere Explorer satellite. The data indicate that the response of the maximum NO densities to the declining level of solar activity is latitudinally and seasonally dependent: the polar regions exhibit little sensitivity to solar activity, while the low latitude NO responds strongly. The data also reveal marked asymmetries in the latitudinal structure of the two hemispheres for each season. During June solstice periods, the latitudinal distribution is fairly flat, unlike December solstice periods which tend to show a definite minimum near 30{degree}N. Similarly, March data show very little latitudinal variation in the NO peak density between about {plus minus} 40{degree}, while the September data show marked gradients for the later years. The SME data further indicate that the nitric oxide densities vary considerably from day to day, even during very quiet geomagnetic periods, suggesting that the concept of an average distribution is of limited usefulness in understanding nitric oxide. A two-dimensional model is used to simualte the June solar cycle minimum data. The latitudinally averaged magnitudes of the observed NO peak densities are reproduced reasonably well by the model, but the shape of the latitudinal variation is not.
Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
T. Niksic; D. Vretenar; P. Ring
2008-09-08
We study a particular class of relativistic nuclear energy density functionals in which only nucleon degrees of freedom are explicitly used in the construction of effective interaction terms. Short-distance (high-momentum) correlations, as well as intermediate and long-range dynamics, are encoded in the medium (nucleon density) dependence of the strength functionals of an effective interaction Lagrangian. Guided by the density dependence of microscopic nucleon self-energies in nuclear matter, a phenomenological ansatz for the density-dependent coupling functionals is accurately determined in self-consistent mean-field calculations of binding energies of a large set of axially deformed nuclei. The relationship between the nuclear matter volume, surface and symmetry energies, and the corresponding predictions for nuclear masses is analyzed in detail. The resulting best-fit parametrization of the nuclear energy density functional is further tested in calculations of properties of spherical and deformed medium-heavy and heavy nuclei, including binding energies, charge radii, deformation parameters, neutron skin thickness, and excitation energies of giant multipole resonances.
Fayer, Michael D.
(CO2) as a function of density from low density (well below the critical density) to high densityVibrational Lifetimes and Spectral Shifts in Supercritical Fluids as a Function of Density Vibrational lifetime and spectral shift data for the asymmetric CO stretching mode of W(CO)6 in supercritical
Kempes, Christopher P; Dooris, William; West, Geoffrey B
2015-01-01
In the face of uncertain biological response to climate change and the many critiques concerning model complexity it is increasingly important to develop predictive mechanistic frameworks that capture the dominant features of ecological communities and their dependencies on environmental factors. This is particularly important for critical global processes such as biomass changes, carbon export, and biogenic climate feedback. Past efforts have successfully understood a broad spectrum of plant and community traits across a range of biological diversity and body size, including tree size distributions and maximum tree height, from mechanical, hydrodynamic, and resource constraints. Recently it was shown that global scaling relationships for net primary productivity are correlated with local meteorology and the overall biomass density within a forest. Along with previous efforts, this highlights the connection between widely observed allometric relationships and predictive ecology. An emerging goal of ecological...
Thermodynamics of the low density excluded volume hadron gas
Zalewski, Kacper
2015-01-01
We discuss the influence of the excluded volume of hadrons on macroscopic variables and thermal parameters of the hadron gas at finite temperature and chemical potential in the low density approximation. Based solely on elementary thermodynamics we show that when the excluded volume grows at constant temperature, pressure, and number of particles, the overall volume increases just as much as the excluded volume, while the entropy and energy remain unchanged. The growth of the chemical potentials is equal to the work needed to create the respective excluded volumes. Consequently, the bulk density functions of a gas with excluded volume are expressed by the corresponding variables in a system of point particles with the shifted chemical potentials. Our results are fully consistent with the previous findings obtained upon applications of more advanced methods of statistical physics. A validity limit for the low density approximation is derived and discussed in the context of the hadron gas created in heavy ion c...
Pion Superfluidity and Meson Properties at Finite Isospin Density
Lianyi He; Meng Jin; Pengfei Zhuang
2009-09-27
We investigate pion superfluidity and its effect on meson properties and equation of state at finite temperature and isospin and baryon densities in the frame of standard flavor SU(2) NJL model. In mean field approximation to quarks and random phase approximation to mesons, the critical isospin chemical potential for pion superfluidity is exactly the pion mass in the vacuum, and corresponding to the isospin symmetry spontaneous breaking, there is in the pion superfluidity phase a Goldstone mode which is the linear combination of the normal sigma and charged pion modes. We calculate numerically the gap equations for the chiral and pion condensates, the phase diagrams, the meson spectra, and the equation of state, and compare them with that obtained in other effective models. The competitions between pion superfluidity and color superconductivity at finite baryon density and between pion and kaon superfluidity at finite strangeness density in flavor SU(3) NJL model are briefly discussed.
Linear response of homogeneous nuclear matter with energy density functionals
A. Pastore; D. Davesne; J. Navarro
2014-12-07
Response functions of infinite nuclear matter with arbitrary isospin asymmetry are studied in the framework of the random phase approximation. The residual interaction is derived from a general nuclear Skyrme energy density functional. Besides the usual central, spin-orbit and tensor terms it could also include other components as new density-dependent terms or three-body terms. Algebraic expressions for the response functions are obtained from the Bethe-Salpeter equation for the particle-hole propagator. Applications to symmetric nuclear matter, pure neutron matter and asymmetric nuclear matter are presented and discussed. Spin-isospin strength functions are analyzed for varying conditions of density, momentum transfer, isospin asymmetry, and temperature for some representative Skyrme functionals. Particular attention is paid to the discussion of instabilities, either real or unphysical, which could manifest in finite nuclei.
Stable laser–plasma accelerators at low densities
Li, Song; Hafz, Nasr A. M. Mirzaie, Mohammad; Ge, Xulei; Sokollik, Thomas; Chen, Min; Sheng, Zhengming; Zhang, Jie
2014-07-28
We report stable laser wakefield acceleration using 17–50 TW laser pulses interacting with 4?mm-long helium gas jet. The initial laser spot size was relatively large (28??m) and the plasma densities were 0.48–2.0?×?10{sup 19?}cm{sup ?3}. High-quality 100–MeV electron beams were generated at the plasma density of 7.5?×?10{sup 18?}cm{sup ?3}, at which the beam parameters (pointing angle, energy spectrum, charge, and divergence angle) were measured and stabilized. At higher densities, filamentation instability of the laser-plasma interaction was observed and it has led to multiple wakefield accelerated electron beams. The experimental results are supported by 2D particle-in-cell simulations. The achievement presented here is an important step toward the use of laser-driven accelerators in real applications.
Density waves in the shearing sheet III. Disc heating
B. Fuchs
2001-04-25
The problem of dynamical heating of galactic discs by spiral density waves is discussed using the shearing sheet model. The secular evolution of the disc is described quantitatively by a diffusion equation for the distribution function of stars in the space spanned by integrals of motion of the stars, in particular the radial action integral and an integral related to the angular momentum. Specifically, disc heating by a succession of transient, `swing amplified' density waves is studied. It is shown that such density waves lead predominantly to diffusion of stars in radial action space. The stochastical changes of angular momenta of the stars and the corresponding stochastic changes of the guiding centre radii of the stellar orbits induced by this process are much smaller.
Spiral density wave generation by vortices in Keplerian flows
G. Bodo; G. Chagelishvili; G. Murante; A. Tevzadze; P. Rossi; A. Ferrari
2005-03-22
We perform a detailed analytical and numerical study of the dynamics of perturbations (vortex/aperiodic mode, Rossby and spiral-density waves) in 2D compressible disks with a Keplerian law of rotation. We draw attention to the process of spiral-density wave generation from vortices, discussing, in particular, the initial, most peculiar stages of wave emission. We show that the linear phenomenon of wave generation by vortices in smooth (without inflection points) shear flows found by using the so-called non-modal approach, is directly applicable to the present case. After an analytical non-modal description of the physics and characteristics of the spiral-density wave generation/propagation in the local shearing-sheet model, we follow the process of wave generation by small amplitude coherent circular vortex structures, by direct global numerical simulation, describing the main features of the generated waves.
Thermodynamics of the low density excluded volume hadron gas
Kacper Zalewski; Krzysztof Redlich
2015-07-20
We discuss the influence of the excluded volume of hadrons on macroscopic variables and thermal parameters of the hadron gas at finite temperature and chemical potential in the low density approximation. Based solely on elementary thermodynamics we show that when the excluded volume grows at constant temperature, pressure, and number of particles, the overall volume increases just as much as the excluded volume, while the entropy and energy remain unchanged. The growth of the chemical potentials is equal to the work needed to create the respective excluded volumes. Consequently, the bulk density functions of a gas with excluded volume are expressed by the corresponding variables in a system of point particles with the shifted chemical potentials. Our results are fully consistent with the previous findings obtained upon applications of more advanced methods of statistical physics. A validity limit for the low density approximation is derived and discussed in the context of the hadron gas created in heavy ion collisions.
New density-independent interactions for nuclear structure calculations
K. Bennaceur; J. Dobaczewski; F. Raimondi
2013-11-06
We present a new two-body finite-range and momentum-dependent but density-independent effective interaction, which can be interpreted as a regularized zero-range force. We show that no three-body or density-dependent terms are needed for a correct description of saturation properties in infinite matter, that is, on the level of low-energy density functional, the physical three-body effects can be efficiently absorbed in effective two-body terms. The new interaction gives a very satisfying equation of state of nuclear matter and opens up extremely interesting perspectives for the mean-field and beyond-mean-field descriptions of atomic nuclei.
Modelling charge transfer reactions with the frozen density embedding formalism
Pavanello, Michele [Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Neugebauer, Johannes [Institute for Physical and Theoretical Chemistry, Technische Universitaet Braunschweig, Hans-Sommer-Strasse 10, 38106 Braunschweig (Germany)
2011-12-21
The frozen density embedding (FDE) subsystem formulation of density-functional theory is a useful tool for studying charge transfer reactions. In this work charge-localized, diabatic states are generated directly with FDE and used to calculate electronic couplings of hole transfer reactions in two {pi}-stacked nucleobase dimers of B-DNA: 5{sup '}-GG-3{sup '} and 5{sup '}-GT-3{sup '}. The calculations rely on two assumptions: the two-state model, and a small differential overlap between donor and acceptor subsystem densities. The resulting electronic couplings agree well with benchmark values for those exchange-correlation functionals that contain a high percentage of exact exchange. Instead, when semilocal GGA functionals are used the electronic couplings are grossly overestimated.
Relativistic density functional theory for finite nuclei and neutron stars
J. Piekarewicz
2015-02-05
The main goal of the present contribution is a pedagogical introduction to the fascinating world of neutron stars by relying on relativistic density functional theory. Density functional theory provides a powerful--and perhaps unique--framework for the calculation of both the properties of finite nuclei and neutron stars. Given the enormous densities that may be reached in the core of neutron stars, it is essential that such theoretical framework incorporates from the outset the basic principles of Lorentz covariance and special relativity. After a brief historical perspective, we present the necessary details required to compute the equation of state of dense, neutron-rich matter. As the equation of state is all that is needed to compute the structure of neutron stars, we discuss how nuclear physics--particularly certain kind of laboratory experiments--can provide significant constrains on the behavior of neutron-rich matter.
On the density limit in the helicon plasma sources
Kotelnikov, Igor A.
2014-12-15
Existence of the density limit in the helicon plasma sources is revisited. The low- and high-frequency regimes of a helicon plasma source operation are distinguished. In the low-frequency regime with ?density limit is deduced from the Golant-Stix criterion of the accessibility of the lower hybrid resonance. In the high-frequency case, ?>?(?{sub ci}?{sub ce}), an appropriate limit is given by the Shamrai-Taranov criterion. Both these criteria are closely related to the phenomenon of the coalescence of the helicon wave with the Trivelpiece-Gould mode. We draw a conclusion that the derived density limits are not currently achieved in existing devices, perhaps, because of high energy cost of gas ionization.
Addressing spectroscopic quality of covariant density functional theory
A. V. Afanasjev
2014-09-17
The spectroscopic quality of covariant density functional theory has been accessed by analyzing the accuracy and theoretical uncertainties in the description of spectroscopic observables. Such analysis is first presented for the energies of the single-particle states in spherical and deformed nuclei. It is also shown that the inclusion of particle-vibration coupling improves the description of the energies of predominantly single-particle states in medium and heavy-mass spherical nuclei. However, the remaining differences between theory and experiment clearly indicate missing physics and missing terms in covariant energy density functionals. The uncertainties in the predictions of the position of two-neutron drip line sensitively depend on the uncertainties in the prediction of the energies of the single-particle states. On the other hand, many spectroscopic observables in well deformed nuclei at ground state and finite spin only weakly depend on the choice of covariant energy density functional.
Background Oriented Schlieren in a Density Stratified Fluid
Verso, Lilly
2015-01-01
Non-intrusive quantitative fluid density measurements methods are essential in stratified flow experiments. Digital imaging leads to synthetic Schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an important extension to one of these methods, called Background Oriented Schlieren (BOS), is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides of a transparent vessel. The multi-media imaging through air-glass-water-glass-air leads to an additional aberration that destroys the reconstruction. A two-step calibration and image remapping transform are the key components that correct the images through the stratified media and provide non-intrusive full-field density measurements of transparent liquids.
Magnetic confinement of a high-density cylindrical plasma
Ahedo, Eduardo [E. T. S. Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)
2011-10-15
The stationary structure of a weakly collisional plasma column, confined by an axial magnetic field and a cylindrical vessel, is studied for the high-density case, when the diamagnetic azimuthal current is large enough to demagnetize partially the plasma. The plasma response is characterized mainly by two dimensionless parameters: the ratios of the electron gyroradius and the electron skin-depth to the plasma radius, and each of them measures the independent influence of the applied magnetic field and the plasma density on the plasma response. The strong magnetic confinement regime, characterized by very small wall losses, is limited to the small gyroradius and large skin-depth ranges. In the high-density case, when the electron skin-depth is smaller than the electron gyroradius, the skin-depth turns out to be the magnetic screening length, so that the bulk of the plasma behaves as unmagnetized.
J. U. Ness; R. Mewe; J. H. M. M. Schmitt; A. J. J. Raassen; D. Porquet; J. S. Kaastra; R. L. J. van der Meer; V. Burwitz; P. Predehl
2000-12-11
Electron density diagnostics based on the triplets of Helium-like CV, NVI, and OVII are applied to the X-ray spectra of Capella and Procyon measured with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra X-ray Observatory. New theoretical models for the calculation of the line ratios between the forbidden (f), intercombination (i), and the resonance (r) lines of the helium-like triplets are used. The derived densities are quite typical of densities found in the solar active regions, and also pressures and temperatures in Procyon's and Capella's corona at a level of T=10^6K are quite similar. We find no evidence for densities as high as measured in solar flares. Comparison of our Capella and Procyon measurements with the Sun shows little difference in the physical properties of the layers producing the CV, NVI, and OVII emission. Assuming the X-ray emitting plasma to be confined in magnetic loops, we obtain typical loop length scales of L_Capella > 8 L_Procyon from the loop scaling laws, implying that the magnetic structures in Procyon and Capella are quite different. The total mean surface fluxes emitted in the helium- and hydrogen-like ions are quite similar for Capella and Procyon, but exceed typical solar values by one order of magnitude. We thus conclude that Procyon's and Capella's coronal filling factors are larger than corresponding solar values.
Radiating Gravitational Collapse with an Initial Inhomogeneous Energy Density Distribution
G. Pinheiro; R. Chan
2014-06-01
A new model is proposed to a collapsing star consisting of an initial inhomogeneous energy density and anisotropic pressure fluid with shear, radial heat flow and outgoing radiation. In previous papers one of us has always assumed an initial star with homogeneous energy density. The aim of this work is to generalize the previous models by introducing an initial inhomogeneous energy density and compare it to the initial homogeneous energy density collapse model. We will show the differences between these models in the evolution of all physical quantities that characterizes the gravitational collapse. The behavior of the energy density, pressure, mass, luminosity and the effective adiabatic index is analyzed. The pressure of the star, at the beginning of the collapse, is isotropic but due to the presence of the shear the pressure becomes more and more anisotropic. The black hole is never formed because the apparent horizon formation condition is never satisfied, in contrast of the previous model where a black hole is formed. An observer at infinity sees a radial point source radiating exponentially until reaches the time of maximum luminosity and suddenly the star turns off. In contrast of the former model where the luminosity also increases exponentially, reaching a maximum and after it decreases until the formation of the black hole. The effective adiabatic index is always positive without any discontinuity in contrast of the former model where there is a discontinuity around the time of maximum luminosity. The collapse is about three thousand times slower than in the case where the energy density is initially homogeneous.
Microslit Nod-shuffle Spectroscopy - a technique for achieving very high densities of spectra
Karl Glazebrook; Joss Bland-Hawthorn
2000-11-04
We describe a new approach to obtaining very high surface densities of optical spectra in astronomical observations with extremely accurate subtraction of night sky emission. The observing technique requires that the telescope is nodded rapidly between targets and adjacent sky positions; object and sky spectra are recorded on adjacent regions of a low-noise CCD through charge shuffling. This permits the use of extremely high densities of small slit apertures (`microslits') since an extended slit is not required for sky interpolation. The overall multi-object advantage of this technique is as large as 2.9x that of conventional multi-slit observing for an instrument configuration which has an underfilled CCD detector and is always >1.5 for high target densities. The `nod-shuffle' technique has been practically implemented at the Anglo-Australian Telescope as the `LDSS++ project' and achieves sky-subtraction accuracies as good as 0.04%, with even better performance possible. This is a factor of ten better than is routinely achieved with long-slits. LDSS++ has been used in various observational modes, which we describe, and for a wide variety of astronomical projects. The nod-shuffle approach should be of great benefit to most spectroscopic (e.g. long-slit, fiber, integral field) methods and would allow much deeper spectroscopy on very large telescopes (10m or greater) than is currently possible. Finally we discuss the prospects of using nod-shuffle to pursue extremely long spectroscopic exposures (many days) and of mimicking nod-shuffle observations with infrared arrays.
Hollman, David S.; Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 ; Schaefer, Henry F.; Valeev, Edward F.
2014-02-14
A local density fitting scheme is considered in which atomic orbital (AO) products are approximated using only auxiliary AOs located on one of the nuclei in that product. The possibility of variational collapse to an unphysical “attractive electron” state that can affect such density fitting [P. Merlot, T. Kjærgaard, T. Helgaker, R. Lindh, F. Aquilante, S. Reine, and T. B. Pedersen, J. Comput. Chem. 34, 1486 (2013)] is alleviated by including atom-wise semidiagonal integrals exactly. Our approach leads to a significant decrease in the computational cost of density fitting for Hartree–Fock theory while still producing results with errors 2–5 times smaller than standard, nonlocal density fitting. Our method allows for large Hartree–Fock and density functional theory computations with exact exchange to be carried out efficiently on large molecules, which we demonstrate by benchmarking our method on 200 of the most widely used prescription drug molecules. Our new fitting scheme leads to smooth and artifact-free potential energy surfaces and the possibility of relatively simple analytic gradients.
Ion Density Deviations in Polyelectrolyte Microcapsules: Influence on Biosensors
Qiyun Tang; Alan R. Denton
2014-10-24
Polyelectrolyte microcapsules loaded with fluorescent dyes have been proposed as biosensors to monitor local pH and ionic strength for diagnostic purposes. In the case of charged microcapsules, however, the local electric field can cause deviations of ion densities inside the cavities, potentially resulting in misdiagnosis of some diseases. Using nonlinear Poisson-Boltzmann theory, we systematically investigate these deviations induced by charged microcapsules. Our results show that the microcapsule charge density, as well as the capsule and salt concentrations, contribute to deviations of local ion concentrations and pH. Our findings are relevant for applications of polyelectrolyte microcapsules with encapsulated ion-sensitive dyes as biosensors.
Monte Carlo tests of Orbital-Free Density Functional Theory
D. I. Palade
2014-12-12
The relationship between the exact kinetic energy density in a quantum system in the frame of Density Functional Theory and the semiclassical functional expression for the same quantity is investigated. The analysis is performed with Monte Carlo simulations of the Kohn-Sham potentials. We find that the semiclassical form represents the statistical expectation value of the quantum nature. Based on the numerical results, we propose an empirical correction to the existing functional and an associated method to improve the Orbital-Free results.
High density electronic circuit and process for making
Morgan, W.P.
1999-06-29
High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits are disclosed. The posts also provide stress relief to accommodate differential thermal expansion. The process allows high interconnect density with fewer alignment restrictions and less wasted circuit area than previous processes. The resulting substrates can be test platforms for die testing and for multi-chip module substrate testing. The test platform can contain active components and emulate realistic operational conditions, replacing shorts/opens net testing. 8 figs.
Density functional theory and optimal transportation with Coulomb cost
Codina Cotar; Gero Friesecke; Claudia Klüppelberg
2011-04-04
We present here novel insight into exchange-correlation functionals in density functional theory, based on the viewpoint of optimal transport. We show that in the case of two electrons and in the semiclassical limit, the exact exchange-correlation functional reduces to a very interesting functional of novel form, which depends on an optimal transport map $T$ associated with a given density $\\rho$. Since the above limit is strongly correlated, the limit functional yields insight into electron correlations. We prove the existence and uniqueness of such an optimal map for any number of electrons and each $\\rho$, and determine the map explicitly in the case when $\\rho$ is radially symmetric.
Systematics of nucleon density distributions and neutron skin of nuclei
Seif, W M
2015-01-01
Proton and neutron density profiles of 760 nuclei in the mass region of A=16-304are analyzed using the Skyrme energy density for the parameter set SLy4. Simple formulae are obtained to fit the resulting radii and diffuseness data. These formulae may be useful to estimate the values of the unmeasured radii, and especially in extrapolating charge radius values for nuclei which are far from the valley of stability or to perform analytic calculations for bound and/or scattering problems. The obtained neutron and proton root-mean-square radii and the neutron skin thicknesses are in agreement with the available experimental data.
Low density microcellular carbon foams and method of preparation
Arnold, C. Jr.; Aubert, J.H.; Clough, R.L.; Rand, P.B.; Sylwester, A.P.
1988-06-20
A low density, open-celled microcellular carbon foam is disclosed which is prepared by dissolving a carbonizable polymer or copolymer in a solvent, pouring the solution into a mold, cooling the solution, removing the solvent, and then carbonizing the polymer or copolymer in a high temperature oven to produce the foam. If desired, an additive can be introduced in order to produce a doped carbon foam, and the foams can be made isotropic by selection of a suitable solvent. The low density, microcellular foams produced by this process are particularly useful in the fabrication of inertial confinement fusion targets, but can also be used as catalysts, absorbents, and electrodes.
Neutron Drops and Skyrme Energy-Density Functionals
B. S. Pudliner; A. Smerzi; J. Carlson; V. R. Pandharipande; Steven C. Pieper; D. G. Ravenhall
1995-10-12
The J$^{\\pi}$=0$^+$ ground state of a drop of 8 neutrons and the lowest 1/2$^-$ and 3/2$^-$ states of 7-neutron drops, all in an external well, are computed accurately with variational and Green's function Monte Carlo methods for a Hamiltonian containing the Argonne $v_{18}$ two-nucleon and Urbana IX three-nucleon potentials. These states are also calculated using Skyrme-type energy-density functionals. Commonly used functionals overestimate the central density of these drops and the spin-orbit splitting of 7-neutron drops. Improvements in the functionals are suggested.
Low density microcellular carbon foams and method of preparation
Arnold, Jr., Charles (Albuquerque, NM); Aubert, James H. (Albuquerque, NM); Clough, Roger L. (Albuquerque, NM); Rand, Peter B. (Albuquerque, NM); Sylwester, Alan P. (Albuquerque, NM)
1989-01-01
A low density, open-celled microcellular carbon foam is disclosed which is prepared by dissolving a carbonizable polymer or copolymer in a solvent, pouring the solution into a mold, cooling the solution, removing the solvent, and then carbonizing the polymer or copolymer in a high temperature oven to produce the foam. If desired, an additive can be introduced in order to produce a doped carbon foam, and the foams can be made isotropic by selection of a suitable solvent. The low density, microcellular foams produced by this process are particularly useful in the fabrication of inertial confinement fusion targets, but can also be used as catalysts, absorbents, and electrodes.
Self-interaction errors in nuclear energy density functionals
N. Chamel
2010-12-21
When applied to a single nucleon, nuclear energy density functionals may yield a non-vanishing internal energy thus implying that the nucleon is interacting with itself. It is shown how to avoid this unphysical feature for semi-local phenomenological functionals containing all possible bilinear combinations of local densities and currents up to second order in the derivatives. The method outlined in this Rapid Communication could be easily extended to functionals containing higher order terms, and could serve as a guide for constraining the time-odd part of the functional.
Energy Density of Vortices in the Schroedinger Picture
J. D. Laenge; M. Engelhardt; H. Reinhardt
2003-01-31
The one-loop energy density of an infinitely thin static magnetic vortex in SU(2) Yang-Mills theory is evaluated using the Schroedinger picture. Both the gluonic fluctuations as well as the quarks in the vortex background are included. The energy density of the magnetic vortex is discussed as a function of the magnetic flux. The center vortices correspond to local minima in the effective potential. These minima are degenerated with the perturbative vacuum if the fermions are ignored. Inclusion of fermions lifts this degeneracy, raising the vortex energy above the energy of the perturbative vacuum.
Influence of density dependent symmetry energy on Elliptical flow
Karan Singh Vinayak; Suneel Kumar
2011-09-18
The effect of density dependent symmetry energy on elliptical flow is studied using isospin-dependent quantum molecular dynamics model(IQMD). We have used the reduced isospin- dependent cross-section with hard(H) equation of state to study the sensitivity of elliptical flow towards symmetry energy in the energy range of 50 - 1000 MeV/nucleon. The elliptical flow becomes zero at a particular energy termed as transition energy. A systematic effort has been made to pin down the transition energy for the density dependent symmetry energy.
The gravitational field energy density for symmetrical and asymmetrical systems
Roald Sosnovskiy
2007-06-22
The relativistic theory of gravitation has the considerable difficulties by description of the gravitational field energy. Pseudotensor t00 in the some cases cannot be interpreted as energy density of the gravitational field. In [1] the approach was proposed, which allow to express the energy density of such a field through the components of a metric tensor. This approach based on the consideration of the isothermal compression of the layer consisted of the incoherent matter. It was employ to the cylindrically and spherically symmetrical static gravitational field. In presented paper the approach is developed.
Uniform electron gases: III. Low-density gases on three-dimensional spheres
Agboola, Davids; Gill, Peter M W; Loos, Pierre-François
2015-01-01
By combining variational Monte Carlo (VMC) and complete-basis-set limit Hartree-Fock (HF) calculations, we have obtained near-exact correlation energies for low-density same-spin electrons on a three-dimensional sphere (3-sphere), i.e.~the surface of a four-dimensional ball. In the VMC calculations, we compare the efficacies of two types of one-electron basis functions for these strongly correlated systems, and analyze the energy convergence with respect to the quality of the Jastrow factor. The HF calculations employ spherical Gaussian functions (SGFs) which are the curved-space analogs of cartesian Gaussian functions. At low densities, the electrons become relatively localized into Wigner crystals, and the natural SGF centers are found by solving the Thomson problem (i.e. the minimum-energy arrangement of $n$ point charges) on the 3-sphere for various values of $n$. We have found 11 special values of $n$ whose Thomson sites are equivalent. Three of these are the vertices of four-dimensional Platonic solids ...
Dissecting Soft Radiation with Factorization
Iain W. Stewart; Frank J. Tackmann; Wouter J. Waalewijn
2015-02-10
An essential part of high-energy hadronic collisions is the soft hadronic activity that underlies the primary hard interaction. It includes soft radiation from the primary hard partons, secondary multiple parton interactions (MPI), and factorization-violating effects. The invariant mass spectrum of the leading jet in $Z$+jet and $H$+jet events is directly sensitive to these effects, and we use a QCD factorization theorem to predict its dependence on the jet radius $R$, jet $p_T$, jet rapidity, and partonic process for both the perturbative and nonperturbative components of primary soft radiation. We prove that the nonperturbative contributions involve only odd powers of $R$, and the linear $R$ term is universal for quark and gluon jets. The hadronization model in PYTHIA8 agrees well with these properties. The perturbative soft initial state radiation (ISR) has a contribution that depends on the jet area in the same way as the underlying event, but this degeneracy is broken by dependence on the jet $p_T$. The size of this soft ISR contribution is proportional to the color state of the initial partons, yielding the same positive contribution for $gg\\to Hg$ and $gq\\to Zq$, but a negative interference contribution for $q\\bar q\\to Z g$. Hence, measuring these dependencies allows one to separate hadronization, soft ISR, and MPI contributions in the data.
EFFICIENT NONPARAMETRIC DENSITY ESTIMATION ON THE SPHERE WITH APPLICATIONS IN FLUID MECHANICS
Egecioglu, Ömer
EFFICIENT NONPARAMETRIC DENSITY ESTIMATION ON THE SPHERE WITH APPLICATIONS IN FLUID MECHANICS ¨OMER density, nonparametric estimation, fluid mechanics, convergence, kernel method, efficient algorithm AMS, an important application of nonparametric density estimation is in computational fluid mechanics. When the flow
One-dimensional ordering of ultra-low density ion beams in a storage ring
Okamoto, H.; Okabe, K.; Yuri, Y.; Mohl, D.; Sessler, A.M.
2004-01-01
One-dimensional ordering of ultra-low density ion beams in ais applicable to an ultra-low density beam where collectiveabout 10 cm. In such an ultra-low density regime, no collec-
Automatic measurement of propositional idea density from part-of-speech tagging
Brown, Cati; Snodgrass, Tony; Kemper, Susan; Herman, Ruth; Covington, Michael A.
2008-05-01
The Computerized Propositional Idea Density Rater (CPIDR, pronounced “spider”) is a computer program that determines the propositional idea density (P-density) of an English text automatically on the basis of partof-speech tags. The key idea...
Effects of Vegetation Structure and Elevation on Lower Keys Marsh Rabbit Density
Dedrickson, Angela
2012-02-14
LKMR density on lands managed by the United States Navy, Naval Air Station Key West and evaluate how vegetation structure and patch elevation effect LKMR population density. I conducted fecal pellet counts to determine LKMR density, collected...
Noland, Jonathan David
2011-01-01
of x-ray power and plasma energy density with microwaveof diamagnetic loop used for plasma energy density mea-the average electron energy and density. During the slowly
Investigation of the formation and energy density of high-current pulsed electron beams
Daichi, Yoshiaki; WANG, ZHIGANG; Yamazaki, Kazuo; Sano, Sadao
2007-01-01
of the formation and energy density of high-current pulsednot clear about the energy density of HCPEB under differentof HCPEB and its energy density. Then, effects of argon gas
Chandan Mondal; Dipankar Chakrabarti
2015-06-17
We present a study of the generalized parton distributions for the quarks in a proton in both momentum and position spaces using the light-front wave functions of a quark-diquark model for the nucleon predicted by the soft-wall model of AdS/QCD. The results are compared with the soft-wall AdS/QCD model of proton GPDs for zero skewness. We also calculate the GPDs for nonzero skewness. We observe that the GPDs have a diffraction pattern in longitudinal position space, as seen before in other models. Then we present a comparitive study of the nucleon charge and anomalous magnetization densities in the transverse plane. Flavor decompositions of the form factors and transverse densities are also discussed.
Terrace housing : providing quality in higher-density housing
Atthakor, Songpol
1992-01-01
The higher demand of higher-density housing in Bangkok due to the rapid growth of the economy and the use of high-performance materials and modern construction methods has changed the forms of housing from low-rise buildings ...
Improved association in a classical density functional theory for water
Eric J. Krebs; Jeff B. Schulte; David Roundy
2013-09-07
We present a modification to our recently published SAFT-based classical density functional theory for water. We have recently developed and tested a functional for the averaged radial distribution function at contact of the hard-sphere fluid that is dramatically more accurate at interfaces than earlier approximations. We now incorporate this improved functional into the association term of our free energy functional for water, improving its description of hydrogen bonding. We examine the effect of this improvement by studying two hard solutes: a hard hydrophobic rod and a hard sphere. The improved functional leads to a moderate change in the density profile and a large decrease in the number of hydrogen bonds broken in the vicinity of the solutes.We present a modification to our recently published SAFT-based classical density functional theory for water. We have recently developed and tested a functional for the averaged radial distribution function at contact of the hard-sphere fluid that is dramatically more accurate at interfaces than earlier approximations. We now incorporate this improved functional into the association term of our free energy functional for water, improving its description of hydrogen bonding. We examine the effect of this improvement by studying two hard solutes: a hard hydrophobic rod and a hard sphere. The improved functional leads to a moderate change in the density profile and a large decrease in the number of hydrogen bonds broken in the vicinity of the solutes.
Wavelet Based Density Estimators for Modeling Multidimensional Data Sets
Shahabi, Cyrus
the distribution of this random variable. We exhibit an estimator for the wavelet coeÃ?cients of this density and ionospheric data. After three levels of o#11;-line pre-processing, observations of temperature, water vapor agreement nr. F30602-99-1-0524, and unrestricted cash/equipment gifts from NCR, IBM, Intel and SUN. #12; 1
Probability Density Function Estimation Using Orthogonal Forward Regression
Chen, Sheng
Probability Density Function Estimation Using Orthogonal Forward Regression S. Chen, X. Hong and C estimation is formulated as a regression problem and the orthogonal forward regression tech- nique is adopted procedure. Two examples are used to demonstrate the ability of this regression- based approach
Nuclear Level Density: Shell Model vs Mean Field
Roman Sen'kov; Vladimir Zelevinsky
2015-08-15
The knowledge of the nuclear level density is necessary for understanding various reactions including those in the stellar environment. Usually the combinatorics of Fermi-gas plus pairing is used for finding the level density. Recently a practical algorithm avoiding diagonalization of huge matrices was developed for calculating the density of many-body nuclear energy levels with certain quantum numbers for a full shell-model Hamiltonian. The underlying physics is that of quantum chaos and intrinsic thermalization in a closed system of interacting particles. We briefly explain this algorithm and, when possible, demonstrate the agreement of the results with those derived from exact diagonalization. The resulting level density is much smoother than that coming from the conventional mean-field combinatorics. We study the role of various components of residual interactions in the process of thermalization, stressing the influence of incoherent collision-like processes. The shell-model results for the traditionally used parameters are also compared with standard phenomenological approaches.
High energy density lithium-oxygen secondary battery
Sammells, A.F.
1989-02-07
A high energy density lithium-oxygen secondary cell is described comprising a lithium-containing negative electrode; a lithium ion conducting molten salt electrolyte contacting the negative electrode; an oxygen ion conducting solid electrolyte contacting and containing the molten salt electrolyte; and an oxygen redox positive electrode contacting the oxygen ion conducting solid electrolyte.
Density-dependent diversification in North American wood warblers
Rabosky, Daniel L.
Density-dependent diversification in North American wood warblers Daniel L. Rabosky1,2,* and Irby J Cornell Laboratory of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA Evidence from both diversification, and we demonstrate this approach using a new phylogeny of North American Dendroica wood warblers
Annealed high-density amorphous ice under pressure
Loss, Daniel
: 28 May 2006; doi:10.1038/nphys313 The well-known expansion of water on cooling below 277 K is one below 277 K responsible for lakes and seas freezing from the top down. This curious behaviour has been- order transition line between low- and high-density water below 220 K, but that cannot be tested
Microwave Interferometer Density Diagnostic for the Levitated Dipole Experiment
Microwave Interferometer Density Diagnostic for the Levitated Dipole Experiment A. Boxer, J. Kesner a multi-channel microwave interferometer. Such a device makes use the relationship between a plasma;Basic Design · An RF of 60 GHz puts our interferometer in the microwave spectrum. · The primary design
Microwave Interferometer Density Diagnostic for the Levitated Dipole Experiment
Microwave Interferometer Density Diagnostic for the Levitated Dipole Experiment A. Boxer, J. Kesner design follows other microwave interferometers in the literature, in particular C.W. Domier et. al. Rev.Sci.Instrum. 59 [1988], 1588 · An RF beam of 60 GHz puts our interferometer in the microwave spectrum. · Our
Numerical Approximation of Vortex Density Evolution in a Superconductor.
Styles, Vanessa
Numerical Approximation of Vortex Density Evolution in a Superconductor. C.M. Elliott & V. Styles Abstract A #12;nite volume/element approximation of a mean #12;eld model of superconducting vortices in one approximations of a two-dimensional version of the mean #12;eld model of superconducting vortices considered
Visualization of Density Variation in Lung Aristofanes C. Silva
Endler, Markus
Visualization of Density Variation in Lung Nodules Arist´ofanes C. Silva e-mail: ari-Rio Inf.MCC09/02 June, 2002 Abstract We propose a method for visualize lung nodule, in order to emphasize, limiar. #12;1 Introduction Lung cancer is known to be the form of cancer with the smallest survival rate
SOIL MICROBIOLOGY Resource Amendments Influence Density and Competitive
Thomas, David D.
SOIL MICROBIOLOGY Resource Amendments Influence Density and Competitive Phenotypes of Streptomyces in Soil Daniel Schlatter & Alfred Fubuh & Kun Xiao & Dan Hernandez & Sarah Hobbie & Linda Kinkel Received Media, LLC 2008 Abstract Carbon from plant rhizospheres is a source of energy for soil microbial
FLAME SURFACE DENSITIES IN PREMIXED COMBUSTION AT MEDIUM TO HIGH
Gülder, Ömer L.
FLAME SURFACE DENSITIES IN PREMIXED COMBUSTION AT MEDIUM TO HIGH TURBULENCE INTENSITIES O¨ MER L in turbulent premixed propane= air flames were determined experimentally. The instantaneous flame fronts were combustion regime as defined by the most recent turbulent premixed combustion dia- grams. From 100 to 800
High-Power Density Target Design and Analyses for Accelerator
McDonald, Kirk
capacity limits applicability Water · Low boiling point must account for twophase flow · CorrosionHigh-Power Density Target Design and Analyses for Accelerator Production of Isotopes W. David Intensity Proton Accelerators Fermi National Accelerator Laboratory October 20, 2009 #12;Outline Purpose
Hydrogen Bonding Increases Packing Density in the Protein Interior
Hydrogen Bonding Increases Packing Density in the Protein Interior David Schell,1,2 Jerry Tsai,1 J System Health Science Center, College Station, Texas 77843-1114 ABSTRACT The contribution of hydrogen to the stability, but experimental studies show that bury- ing polar groups, especially those that are hydrogen
Effects of Neighborhood Density and Noise on Children's Word Learning
Han, Min Kyung
2014-12-31
assigned to one of three listening conditions: 0dB, +6dB, and +15dB signal-to-noise ratio (SNR). Sixteen consonant-vowel-consonant nonword-novel object referent pairs were embedded in two stories for training; neighborhood density for the nonwords varied...
ORIGINAL PAPER BambooFiber Filled High Density Polyethylene Composites
strength, bending modulus and strength were improved with the use of MAPE. The use of the clayORIGINAL PAPER BambooFiber Filled High Density Polyethylene Composites: Effect of Coupling to achieve clay exfoliation. For pure HDPE system, both dynamic and static bending moduli increased, while
Method to reduce dislocation density in silicon using stress
Buonassisi, Anthony; Bertoni, Mariana; Argon, Ali; Castellanos, Sergio; Fecych, Alexandria; Powell, Douglas; Vogl, Michelle
2013-03-05
A crystalline material structure with reduced dislocation density and method of producing same is provided. The crystalline material structure is annealed at temperatures above the brittle-to-ductile transition temperature of the crystalline material structure. One or more stress elements are formed on the crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.
Finding Density Functionals with Machine Learning John C. Snyder,1
Burke, Kieron
) energy as a functional of the electronic spin densities. The quality of the results cru- cially depends) of Kohn and Sham [2] is uniquely defined by the properties of the uniform gas and has been argued attraction to the nuclei. ML is a natural tool
On efficient estimation of densities for sums of squared observations
Schick, Anton
On efficient estimation of densities for sums of squared observations Anton Schick and Wolfgang for each i = 1, . . . , m. Under appropriate functional versions of these conditions, Schick and Wefelmeyer function spaces. The research of Anton Schick was partially supported by NSF Grant DMS 0906551. 1 #12
PUBLISHED VERSION Constrained density functional for noncollinear magnetism
Â© 2015 UNITED KINGDOM ATOMIC ENERGY AUTHORITY This article may be downloaded for personal use only. AnyÂ19]. Although ab initio calculations often assume collinear mag- netic configurations, spin-polarized density] and are widely adopted in ab initio programs [29Â31]. Magnetic DFT calculations are often performed in the atomic
Electron shielding of vortons in high-density quark matter
Paulo F. Bedaque; Evan Berkowitz; Geoffrey Ji; Nathan Ng
2011-12-06
We consider the the effect of the electron cloud about a vorton in the CFL-$K^0$ high-density phase by numerically solving the ultrarelativistic Thomas-Fermi equation about a toroidal charge. Including electrons removes the electric monopole contribution to the energy, and noticeably decreases the equilibrium radius of these stable vortex loops.
Enhanced surfaces lead to increased heat transfer and power density.
be used by electric motors. Aggressive ther- mal management is essential in boosting power density. The National Renewable Energy Laboratory's (NREL's) Advanced Power Electronics Task in the Center components. It is estimated that improved thermal performance can reduce the number or area of the insulated
Turbulence, Transport and the Density Limit in Magnetic Fusion Experiments
Greenwald, Martin
Program) 3 Magnetic Confinement Takes advantage of the motion of charged particles in a magnetic field) · In toroidal devices, plasma is confined by Poloidal magnetic fields #12;DESPITE THE CHALLENGES, PROGRESS HAS AND MAGNETIC CONFINEMENT· · · · THE DENSITY LIMIT PROBLEM INTERLUDE ON TRANSPORT AND TURBULENCE TOWARDS
Turbulence transition and internal wave generation in density stratified jets
Sutherland, Bruce
Turbulence transition and internal wave generation in density stratified jets B. FL Sutherland (Received 3 June 1993; accepted 18 November 1993) The nonlinear evolution of an unstable symmetric jet torques. In this case, the mean flow of the fully evolved jet is stable to subharmonic disturbances
PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES
PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES Beatrix Schunke JET temperature profile shapes have been parameterised in terms of the engineering variablesMRK,RI,IRS . In this article, we report the results of the parame- terisation of the Joint European TorusRebut (JET) electron
The Impact of Residential Density on Vehicle Usage and Energy Consumption
Golob, Thomas F.; Brownstone, David
2005-01-01
residential transportation energy usage is vital for theDensity on Vehicle Usage and Energy Consumption Table 2Density on Vehicle Usage and Energy Consumption with
Capacity Factor Risk At Nuclear Power Plants
Du, Yangbo
We develop a model of the dynamic structure of capacity factor risk. It incorporates the risk that the capacity factor may vary widely from year-to-year, and also the risk that the reactor may be permanently shutdown prior ...
Cone Penetrometer N Factor Determination Testing Results
Follett, Jordan R.
2014-03-05
This document contains the results of testing activities to determine the empirical 'N Factor' for the cone penetrometer in kaolin clay simulant. The N Factor is used to releate resistance measurements taken with the cone penetrometer to shear strength.
Common risk factors in bank stocks
Viale, Ariel Marcelo
2007-09-17
This dissertation provides evidence on the risk factors that are priced in bank equities. Alternative empirical models with precedent in the nonfinancial asset pricing literature are tested, including the single-factor Capital Asset Pricing Model...
Industrial Equipment Demand and Duty Factors
Dooley, E. S.; Heffington, W. M.
1998-01-01
Demand and duty factors have been measured for selected equipment (air compressors, electric furnaces, injection molding machines, centrifugal loads, and others) in industrial plants. Demand factors for heavily loaded air ...
Guidelines for Power Factor Improvement Projects
Massey, G. W.
1999-01-01
Power factor is an indication of electrical system efficiency. Low power factor, or low system efficiency, may be due to one or more causes, including lightly loaded transformers, oversized electric motors, and harmonic-generating non-linear loads...
SURFACE COAL MINE LAKES by David Steven Knuth B.S., Southern Illinois University 2002 A Thesis Submitted OF ABIOTIC AND BIOTIC FACTORS ON BLUEGILL REPRODUCTION AND GROWTH IN SEVEN UNEXPLOITED SURFACE COAL MINE UNEXPLOITED SURFACE COAL MINE LAKES MAJOR PROFESSOR: Jim Garvey Understanding the density
Closing a Loophole in Factorization Proofs
Bodwin, Geoffrey T. [HEP Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois, 60439 (United States); Garcia i Tormo, Xavier [HEP Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois, 60439 (United States); Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); Lee, Jungil [Department of Physics, Korea University, Seoul 136-701 (Korea, Republic of)
2011-05-23
We address the possibility in factorization proofs that low-energy collinear gluons can couple to soft gluons.
Fabrication and evaluation of uniform and gradient density epoxies
Domeier, L.A.; Skala, D.M.; Goods, S.H. [and others
1997-11-01
Filled epoxy materials which vary in density in a designed manner have been fabricated and their mechanical properties evaluated. Density variations were produced by incorporating different volume fractions of either glass microballoons (GMB) or alumina. Several different sample types were evaluated including uniform density (0.8 g/cm{sup 3} < {rho} < 2.0 g/cm{sup 3}) samples and gradient density samples (GMB only, 0.8 g/cm{sup 3} < {rho} < 1.2 g/cm{sup 3}). The uniform density specimens were evaluated for the effects of filler type and concentration on modulus and toughness. Results indicated that addition of alumina filler significantly increased the resulting modulus while addition of GMB had little measurable effect. These differences could be understood in terms of the differing moduli of the additives relative to that of the epoxy matrix. In the former case the alumina particulates had a modulus much greater than that of the epoxy while in the latter case, the modulus of the GMB additive was only slightly greater than that of the matrix. Addition of either filler significantly degraded the toughness of the composite specimens and precluded the use of gradients to enhance toughness performance. Discontinuous {open_quotes}block{close_quotes} gradients used for testing were fabricated by simple sequential pours of formulations with different GMB loadings and were evaluated for modulus, strength and ductility. Continuous gradients were fabricated in process studies by programmed shifts in the peristaltic pumping/mixing ratio of epoxies filled with either alumina or GMB. None of the continuous gradient materials were mechanically tested. These results suggest that applications utilizing gradient materials containing alumina and similar high modulus fillers to provide designed stiffness rather than improved toughness are the most appropriate targets for future investigation.
Parity Violating Measurements of Neutron Densities: Implications for Neutron Stars
C. J. Horowitz; J. Piekarewicz
2002-01-08
Parity violating electron scattering can measure the neutron density of a heavy nucleus accurately and model independently. This is because the weak charge of the neutron is much larger then that of the proton. The Parity Radius Experiment (PREX) at Jefferson Laboratory aims to measure the root mean square neutron radius of $^{208}$Pb with an absolute accuracy of 1% ($\\pm 0.05$ Fm). This is more accurate then past measurements with hadronic probes, which all suffer from controversial strong interaction uncertainties. PREX should clearly resolve the neutron-rich skin. Furthermore, this benchmark value for $^{208}$Pb will provide a calibration for hadronic probes, such as proton scattering, which can then be used to measure neutron densities of many exotic nuclei. The PREX result will also have many implications for neutron stars. The neutron radius of Pb depends on the pressure of neutron-rich matter: the greater the pressure, the larger the radius as neutrons are pushed out against surface tension. The same pressure supports a neutron star against gravity. The Pb radius is sensitive to the equation of state at normal densities while the radius of a 1.4 solar mass neutron star also depends on the equation of state at higher densities. Measurements of the radii of a number of isolated neutron stars such as Geminga and RX J185635-3754 should soon improve significantly. By comparing the equation of state information from the radii of both Pb and neutron stars one can search for a softening of the high density equation of state from a phase transition to an exotic state. Possibilities include kaon condensates, strange quark matter or color superconductors.
On spectroscopic factors of magic and semimagic nuclei
Saperstein, E. E. [Kurchatov Institute, 123182 Moscow (Russian Federation); Gnezdilov, N. V. [Kurchatov Institute, 123182 Moscow, Russia and National Research Nuclear University MEPhI, 115409 Moscow (Russian Federation); Tolokonnikov, S. V. [Kurchatov Institute, 123182 Moscow, Russia and Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation)
2014-10-15
Single-particle spectroscopic factors (SF) of magic and semimagic nuclei are analyzed within the self-consistent theory of finite Fermi systems. The the in-volume energy dependence of the mass operator ? is taken into account in addition to the energy dependence induced by the surface-phonon coupling effects which is commonly considered. It appears due to the effect of high-lying collective and non-collective particle-hole excitations and persists in nuclear matter. The self-consistent basis of the energy density functional method by Fayans et al. is used. Both the surface and in-volume contributions to the SFs turned out to be of comparable magnitude. Results for magic {sup 208}Pb nucleus and semimagic lead isotopes are presented.
Walls, Joel; Taner, M. Turhan; Dvorkin, Jack
2006-08-08
A method for seismic characterization of subsurface Earth formations includes determining at least one of compressional velocity and shear velocity, and determining reservoir parameters of subsurface Earth formations, at least including density, from data obtained from a wellbore penetrating the formations. A quality factor for the subsurface formations is calculated from the velocity, the density and the water saturation. A synthetic seismogram is calculated from the calculated quality factor and from the velocity and density. The synthetic seismogram is compared to a seismic survey made in the vicinity of the wellbore. At least one parameter is adjusted. The synthetic seismogram is recalculated using the adjusted parameter, and the adjusting, recalculating and comparing are repeated until a difference between the synthetic seismogram and the seismic survey falls below a selected threshold.
http://erg.sagepub.com/ Factors Applications
Kaber, David B.
http://erg.sagepub.com/ Factors Applications Ergonomics in Design: The Quarterly of Human httpErgonomics in Design: The Quarterly of Human Factors Applications Peter A. Hancock, Richard J. Jagacinski: Human Factors and Ergonomics Society can be found at:Ergonomics in Design: The Quarterly of Human
Human factors: a necessary tool for industry
Starcher, K.O.
1984-03-09
The need for human factors (ergonomics) input in the layout of a ferroelectric ceramics laboratory is presented as an example of the overall need for human factors professionals in industry. However, even in the absence of one trained in human factors, knowledge of a few principles in ergonomics will provide many possibilities for improving performance in the industrial environment.
Note on Integer Factoring Algorithms II
N. A. Carella
2007-02-08
This note introduces a new class of integer factoring algorithms. Two versions of this method will be described, deterministic and probabilistic. These algorithms are practical, and can factor large classes of balanced integers N = pq, p < q < 2p in superpolynomial time. Further, an extension of the Fermat factoring method is proposed.
Journal influence factors6 Massimo Franceschet
Franceschet, Massimo
Journal influence factors6 Massimo Franceschet Department of Mathematics and Computer Science of journal influence, namely 2- year impact factor, 5-year impact factor, eigenfactor and article influence. These indicators have been recently added by Thomson Reuters to the Journal Citation Reports, in both science
Antenna factorization in strongly ordered limits
Kosower, David A.
2005-02-15
When energies or angles of gluons emitted in a gauge-theory process are small and strongly ordered, the emission factorizes in a simple way to all orders in perturbation theory. I show how to unify the various strongly ordered soft, mixed soft-collinear, and collinear limits using antenna factorization amplitudes, which are generalizations of the Catani-Seymour dipole factorization function.
Xiaohu Wang; Abraham Loeb; Eli Waxman
2002-12-22
We examine the stability of self-similar solutions for an accelerating relativistic blast wave which is generated by a point explosion in an external medium with a steep radial density profile of a power-law index > 4.134. These accelerating solutions apply, for example, to the breakout of a gamma-ray burst outflow from the boundary of a massive star, as assumed in the popular collapsar model. We show that short wavelength perturbations may grow but only by a modest factor <~ 10.
C. Giammanco; J. E. Beckman; A. Zurita; M. Relaño
2004-05-24
The accepted explanation of the observed dichotomy of two orders of magnitude between in situ measurements of electron density in HII regions, derived from emission line ratios, and average measurements based on integrated emission measure, is the inhomogeneity of the ionized medium. This is expressed as a "filling factor", the volume ratio of dense to tenuous gas, measured with values of order 10^-3. Implicit in the filling factor model as normally used, is the assumption that the clumps of dense gas are optically thin to ionizing radiation. Here we explore implications of assuming the contrary: that the clumps are optically thick. A first consequence is the presence within HII regions of a major fraction of neutral hydrogen. We estimate the mean H^o/H^+ ratio for a population of HII regions in the spiral galaxy NGC 1530 to be the order of 10, and support this inference using dynamical arguments. The optically thick clumpy models allow a significant fraction of the photons generated by the ionizing stars to escape from their HII region. We show, by comparing model predictions with observations, that these models give an account at least as good as, and probably better than that of conventional models, of the radial surface brightness distribution and of selected spectral line diagnostics for physical conditions within HII regions. These models explain how an HII region can appear, from its line ratios, to be ionization bounded, yet permit a major fraction of its ionizing photons to escape.
High Efficiency m-plane LEDs on Low Defect Density Bulk GaN Substrates
David, Aurelien
2012-10-15
Solid-state lighting is a key technology for reduction of energy consumption in the US and worldwide. In principle, by replacing standard incandescent bulbs and other light sources with sources based on light-emitting diodes (LEDs), ultimate energy efficiency can be achieved. The efficiency of LEDs has improved tremendously over the past two decades, however further progress is required for solid- state lighting to reach its full potential. The ability of an LED at converting electricity to light is quantified by its internal quantum efficiency (IQE). The material of choice for visible LEDs is Gallium Nitride (GaN), which is at the basis of blue-emitting LEDs. A key factor limiting the performance of GaN LEDs is the so-called efficiency droop, whereby the IQE of the LED decreases significantly at high current density. Despite decades of research, efficiency droop remains a major issue. Since high-current operation is necessary for practical lighting applications, reducing droop is a major challenge for the scientific community and the LED industry. Our approach to solving the droop issue is the use of newly available low-defect-density bulk GaN non-polar substrates. In contrast to the standard foreign substrates (sapphire, silicon carbide, silicon) used in the industry, we have employed native bulk GaN substrates with very low defect density, thus ensuring exquisite material quality and high IQE. Whereas all commercial LEDs are grown along the c-plane crystal direction of GaN, we have used m-plane non-polar substrates; these drastically modify the physical properties of the LED and enable a reduction of droop. With this approach, we have demonstrated very high IQE performance and low droop. Our results focused on violet and blue LEDs. For these, we have demonstrated very high peak IQEs and current droops of 6% and 10% respectively (up to a high current density of 200A.cm-2). All these results were obtained under electrical operation. These high IQE and low droop values are in line with the program’s milestones. They demonstrate that bulk non-polar GaN substrates represent a disruptive technology for LED performance. Application of this technology to real-world products is feasible, provided that the cost of GaN substrates is compatible with the market’s requirement.
Low-Density Low-Mass Planets Forma4on and Structure of Low-Density Exo-Neptunes
Johnson, Robert E.
VE M U N Low-Density Low-Mass Planets #12;Forma4on and Structure of Low: Neptune-size Kepler planet candidates could have low mass (a few Earth masses at Teq=500K). Core Nucleated Accre8on Calcula8ons: Low mass (3-8 M) Planets
The static structure factor of amorphous silicon and vitreous silica
Adam M. R. de Graff; M. F. Thorpe
2009-09-14
Liquids are in thermal equilibrium and have a non-zero static structure factor S(Q->0) = [-^2]/ = rho*k_B*T*Chi_T where rho is the number density, T is the temperature, Q is the scattering vector and Chi_T is the isothermal compressibility. The first part of this result involving the number N (or density) fluctuations is a purely geometrical result and does not involve any assumptions about thermal equilibrium or ergodicity and so is obeyed by all materials. From a large computer model of amorphous silicon, local number fluctuations extrapolate to give S(0) = 0.035+/-0.001. The same computation on a large model of vitreous silica using only the silicon atoms and rescaling the distances gives S(0) = 0.039+/-0.001, which suggests that this numerical result is robust and similar for all amorphous tetrahedral networks. For vitreous silica, we find that S(0) = 0.116+/-0.003, close to the experimental value of S(0) = 0.0900+/-0.0048 obtained recently by small angle neutron scattering. More detailed experimental and modelling studies are needed to determine the relationship between the fictive temperature and structure.
Yang, Guangtao Swaaij, R. A. C. M. M. van; Dobrovolskiy, S.; Zeman, M.
2014-01-21
In this contribution, we demonstrate the application temperature dependent capacitance-frequency measurements (C-f) to n-i-p hydrogenated amorphous silicon (a-Si:H) solar cells that are forward-biased. By using a forward bias, the C-f measurement can detect the density of defect states in a particular energy range of the interface region. For this contribution, we have carried out this measurement method on n-i-p a-Si:H solar cells of which the intrinsic layer has been exposed to a H{sub 2}-plasma before p-type layer deposition. After this treatment, the open-circuit voltage and fill factor increased significantly, as well as the blue response of the solar cells as is concluded from external quantum efficiency. For single junction, n-i-p a-Si:H solar cells initial efficiency increased from 6.34% to 8.41%. This performance enhancement is believed to be mainly due to a reduction of the defect density in the i-p interface region after the H{sub 2}-plasma treatment. These results are confirmed by the C-f measurements. After H{sub 2}-plasma treatment, the defect density in the intrinsic layer near the i-p interface region is lower and peaks at an energy level deeper in the band gap. These C-f measurements therefore enable us to monitor changes in the defect density in the interface region as a result of a hydrogen plasma. The lower defect density at the i-p interface as detected by the C-f measurements is supported by dark current-voltage measurements, which indicate a lower carrier recombination rate.
M. Stoitsov; M. Kortelainen; S. K. Bogner; T. Duguet; R. J. Furnstahl; B. Gebremariam; N. Schunck
2010-09-17
In a recent series of papers, Gebremariam, Bogner, and Duguet derived a microscopically based nuclear energy density functional by applying the Density Matrix Expansion (DME) to the Hartree-Fock energy obtained from chiral effective field theory (EFT) two- and three-nucleon interactions. Due to the structure of the chiral interactions, each coupling in the DME functional is given as the sum of a coupling constant arising from zero-range contact interactions and a coupling function of the density arising from the finite-range pion exchanges. Since the contact contributions have essentially the same structure as those entering empirical Skyrme functionals, a microscopically guided Skyrme phenomenology has been suggested in which the contact terms in the DME functional are released for optimization to finite-density observables to capture short-range correlation energy contributions from beyond Hartree-Fock. The present paper is the first attempt to assess the ability of the newly suggested DME functional, which has a much richer set of density dependencies than traditional Skyrme functionals, to generate sensible and stable results for nuclear applications. The results of the first proof-of-principle calculations are given, and numerous practical issues related to the implementation of the new functional in existing Skyrme codes are discussed. Using a restricted singular value decomposition (SVD) optimization procedure, it is found that the new DME functional gives numerically stable results and exhibits a small but systematic reduction of our test $\\chi^2$ function compared to standard Skyrme functionals, thus justifying its suitability for future global optimizations and large-scale calculations.
High energy density Z-pinch plasmas using flow stabilization
Shumlak, U. Golingo, R. P. Nelson, B. A. Bowers, C. A. Doty, S. A. Forbes, E. G. Hughes, M. C. Kim, B. Knecht, S. D. Lambert, K. K. Lowrie, W. Ross, M. P. Weed, J. R.
2014-12-15
The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and scaling analyses will be presented. In addition to studying fundamental plasma science and high energy density physics, the ZaP and ZaP-HD experiments can be applied to laboratory astrophysics.
Factors fragmenting the Russian Federation
Brown, E.
1993-10-06
This paper examines the factors that threaten the future of the Russian Federation (RF). The observations are based on a study that focused on eight republics: Mordova, Udmurtia, Tatarstan, Mari El, Bashkortostan, Kabardino-Balkaria, Buryatia, and Altay Republic. These republics were selected for their geographic and economic significance to the RF. Tatarstan, Bashkortostan, Udmurtia, and Mari El are located on important supply routes, such as the Volga River and the trans-Siberian railroad. Some of these republics are relatively wealthy, with natural resources such as oil (e.g., Tatarstan and Bashkortostan), and all eight republics play significant roles in the military-industrial complex. The importance of these republics to the RF contrasts to the relative insignificance of the independence-minded Northern Caucasus area. The author chose not to examine the Northern Caucasus region (except Kabardino-Balkaria) because these republics may have only a minor impact on the rest of the RF if they secede. Their impact would be minimized because they lie on the frontiers of the RF. Many Russians believe that {open_quotes}it might be best to let such a troublesome area secede.{close_quotes}
Laboratory Tests of Low Density Astrophysical Equations of State
L. Qin; K. Hagel; R. Wada; J. B. Natowitz; S. Shlomo; A. Bonasera; G. Roepke; S. Typel; Z. Chen; M. Huang; J. Wang; H. Zheng; S. Kowalski; M. Barbui; M. R. D. Rodrigues; K. Schmidt; D. Fabris; M. Lunardon; S. Moretto; G. Nebbia; S. Pesente; V. Rizzi; G. Viesti; M. Cinausero; G. Prete; T. Keutgen; Y. El Masri; Z. Majka
2012-03-20
Clustering in low density nuclear matter has been investigated using the NIMROD multi-detector at Texas A&M University. Thermal coalescence modes were employed to extract densities, $\\rho$, and temperatures, $T$, for evolving systems formed in collisions of 47 $A$ MeV $^{40}$Ar + $^{112}$Sn,$^{124}$Sn and $^{64}$Zn + $^{112}$Sn, $^{124}$Sn. The yields of $d$, $t$, $^{3}$He, and $^{4}$He have been determined at $\\rho$ = 0.002 to 0.032 nucleons/fm$^{3}$ and $T$= 5 to 10 MeV. The experimentally derived equilibrium constants for $\\alpha$ particle production are compared with those predicted by a number of astrophysical equations of state. The data provide important new constraints on the model calculations.
Probability distribution functions in the finite density lattice QCD
S. Ejiri; Y. Nakagawa; S. Aoki; K. Kanaya; H. Saito; T. Hatsuda; H. Ohno; T. Umeda
2012-12-04
We study the phase structure of QCD at high temperature and density by lattice QCD simulations adopting a histogram method. We try to solve the problems which arise in the numerical study of the finite density QCD, focusing on the probability distribution function (histogram). As a first step, we investigate the quark mass dependence and the chemical potential dependence of the probability distribution function as a function of the Polyakov loop when all quark masses are sufficiently large, and study the properties of the distribution function. The effect from the complex phase of the quark determinant is estimated explicitly. The shape of the distribution function changes with the quark mass and the chemical potential. Through the shape of the distribution, the critical surface which separates the first order transition and crossover regions in the heavy quark region is determined for the 2+1-flavor case.
Method of measuring reactive acoustic power density in a fluid
Wheatley, J.C.; Swift, G.W.; Migliori, A.
1985-09-03
A method for determining reactive acoustic power density level and its direction in a fluid using a single sensor is disclosed. In the preferred embodiment, an apparatus for conducting the method, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas. 5 figs.
Method of measuring reactive acoustic power density in a fluid
Wheatley, John C.; Swift, Gregory W.; Migliori, Albert
1985-01-01
A method for determining reactive acoustic power density level and its direction in a fluid using a single sensor is disclosed. In the preferred embodiment, an apparatus for conducting the method, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.
Spin projection with double hybrid density functional theory
Thompson, Lee M.; Hratchian, Hrant P.
2014-07-21
A spin projected double-hybrid density functional theory is presented that accounts for different scaling of opposite and same spin terms in the second order correction. This method is applied to three dissociation reactions which in the unprojected formalism exhibit significant spin contamination with higher spin states. This gives rise to a distorted potential surface and can lead to poor geometries and energies. The projected method presented is shown to improve the description of the potential over unprojected double hybrid density functional theory. Comparison is made with the reference states of the two double hybrid functionals considered here (B2PLYP and mPW2PLYP) in which the projected potential surface is degraded by an imbalance in the description of dynamic and static correlation.
Limits to the power density of very large wind farms
Nishino, Takafumi
2013-01-01
A simple analysis is presented concerning an upper limit of the power density (power per unit land area) of a very large wind farm located at the bottom of a fully developed boundary layer. The analysis suggests that the limit of the power density is about 0.38 times $\\tau_{w0}U_{F0}$, where $\\tau_{w0}$ is the natural shear stress on the ground (that is observed before constructing the wind farm) and $U_{F0}$ is the natural or undisturbed wind speed averaged across the height of the farm to be constructed. Importantly, this implies that the maximum extractable power from such a very large wind farm will not be proportional to the cubic of the wind speed at the farm height, or even the farm height itself, but be proportional to $U_{F0}$.
Level densities and thermodynamical properties of Pt and Au isotopes
F. Giacoppo; F. L. Bello Garrote; L. A. Bernstein; D. L. Bleuel; T. K. Eriksen; R. B. Firestone; A. Görgen; M. Guttormsen; T. W. Hagen; B. V. Kheswa; M. Klintefjord; P. E. Koehler; A. C. Larsen; H. T. Nyhus; T. Renstrøm; E. Sahin; S. Siem; T. Tornyi
2014-11-28
The nuclear level densities of $^{194-196}$Pt and $^{197,198}$Au below the neutron separation energy have been measured using transfer and scattering reactions. All the level density distributions follow the constant-temperature description. Each group of isotopes is characterized by the same temperature above the energy threshold corresponding to the breaking of the first Cooper pair. A constant entropy excess $\\Delta S=1.9$ and $1.1$ $k_B$ is observed in $^{195}$Pt and $^{198}$Au with respect to $^{196}$Pt and $^{197}$Au, respectively, giving information on the available single-particle level space for the last unpaired valence neutron. The breaking of nucleon Cooper pairs is revealed by sequential peaks in the microcanonical caloric curve.
Ultra-low density microcellular polymer foam and method
Simandl, R.F.; Brown, J.D.
1996-03-19
An ultra-low density, microcellular open-celled polymer foam and a method for making such foam are disclosed. A polymer is dissolved in a heated solution consisting essentially of at least one solvent for the dissolution of the polymer in the heated solution and the phase inversion of the dissolved polymer to a liquid gel upon sufficient cooling of the heated solution. The heated solution is contained in a containment means provided with a nucleating promoting means having a relatively rough surface formed of fixed nucleating sites. The heated solution is cooled for a period of time sufficient to form a liquid gel of the polymer by phase inversion. From the gel, a porous foam having a density of less than about 12.0 mg/cm{sup 3} and open porosity provided by well interconnected strut morphology is formed.
Extreme hydrogen plasma densities achieved in a linear plasma generator
Rooij, G. J. van; Veremiyenko, V. P.; Goedheer, W. J.; de Groot, B.; Kleyn, A. W.; Smeets, P. H. M.; Versloot, T. W.; Whyte, D. G.; Engeln, R.; Schram, D. C.; Cardozo, N. J. Lopes
2007-03-19
A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5x10{sup 20} m{sup -3} electron density, {approx}2 eV electron and ion temperatures, and 3.5 km/s axial plasma velocity. This gives a 2.6x10{sup 24} H{sup +} m{sup -2} s{sup -1} peak ion flux density, which is unprecedented in linear plasma generators. The high efficiency of the source is obtained by the combined action of the magnetic field and an optimized nozzle geometry. This is interpreted as a cross-field return current that leads to power dissipation in the beam just outside the source.
Defect density and dielectric constant in perovskite solar cells
Samiee, Mehran; Konduri, Siva; Abbas, Hisham A.; Joshi, Pranav; Zhang, Liang; Dalal, Vikram; Ganapathy, Balaji; Kottokkaran, Ranjith; Noack, Max; Kitahara, Andrew
2014-10-13
We report on measurement of dielectric constant, mid-gap defect density, Urbach energy of tail states in CH{sub 3}NH{sub 3}PbI{sub x}Cl{sub 1?x} perovskite solar cells. Midgap defect densities were estimated by measuring capacitance vs. frequency at different temperatures and show two peaks, one at 0.66?eV below the conduction band and one at 0.24?eV below the conduction band. The attempt to escape frequency is in the range of 2?×?10{sup 11}/s. Quantum efficiency data indicate a bandgap of 1.58?eV. Urbach energies of valence and conduction band are estimated to be ?16 and ?18?meV. Measurement of saturation capacitance indicates that the relative dielectric constant is ?18.
Density waves in the shearing sheet I. Swing amplification
B. Fuchs
2001-03-02
The shearing sheet model of a galactic disk is studied anew. The theoretical description of its dynamics is based on three building blocks: Stellar orbits, which are described here in epicyclic approximation, the collisionless Boltzmann equation determining the distribution function of stars in phase space, and the Poisson equation in order to take account of the self-gravity of the disk. Using these tools I develop a new formalism to describe perturbations of the shearing sheet. Applying this to the unbounded shearing sheet model I demonstrate again how the disturbances of the disk evolve always into `swing amplified' density waves, i.e. spiral-arm like, shearing density enhancements, which grow and decay while the wave crests swing by from leading to trailing orientation. Several examples are given how such `swing amplification' events are incited in the shearing sheet.
Effects of system densities on distillation column performance
Fasesan, S.O.; Sanni, S.A.; Taiwo, E.A. [Obafemi Awolowo Univ., Ile-Ife (Nigeria). Dept. of Chemical Engineering
1998-06-01
Distillation experiments were carried out on three binary systems (ethanol-butanol, ethanol-propan-2-ol, and propan-2-ol-butanol) in a 0.1-m internal diameter glass column packed with 8 mm diameter Raschig rings. The experiments were performed under total reflux conditions and at atmospheric pressure. The data collected on column performance showed that performance declined with increasing average bulk liquid density. The results also lend credence to earlier reports on the behavior of column performance with respect to component concentration in the feed mixtures. The system densities of the three binary systems were measured at four different temperatures, 30, 40, 50, and 60 C. The data were compared with the predicted data of Yen-Woods and Multifluid models. The accuracy of the predictions of the Yen-Woods model was rather poor while that of the Multifluid model was very encouraging.
Carrier Density Modulation in Ge Heterostructure by Ferroelectric Switching
Ponath, Patrick; Fredrickson, Kurt; Posadas, Agham B.; Ren, Yuan; Vasudevan, Rama K; Okatan, Mahmut Baris; Jesse, Stephen; Aoki, Toshihiro; McCartney, Martha; Smith, David J; Kalinin, Sergei V; Lai, Keji; Demkov, Alexander A.
2015-01-01
The development of nonvolatile logic through direct coupling of spontaneous ferroelectric polarization with semiconductor charge carriers is nontrivial, with many issues, including epitaxial ferroelectric growth, demonstration of ferroelectric switching, and measurable semiconductor modulation. Here we report a true ferroelectric field effect carrier density modulation in an underlying Ge(001) substrate by switching of the ferroelectric polarization in the epitaxial c-axis-oriented BaTiO3 (BTO) grown by molecular beam epitaxy (MBE) on Ge. Using density functional theory, we demonstrate that switching of BTO polarization results in a large electric potential change in Ge. Aberration-corrected electron microscopy confirms the interface sharpness, and BTO tetragonality. Electron-energy-loss spectroscopy (EELS) indicates the absence of any low permittivity interlayer at the interface with Ge. Using piezoelectric force microscopy (PFM), we confirm the presence of fully switchable, stable ferroelectric polarization in BTO that appears to be single domain. Using microwave impedance microscopy (MIM), we clearly demonstrate a ferroelectric field effect.
Ultra-low density microcellular polymer foam and method
Simandl, Ronald F. (Farragut, TN); Brown, John D. (Harriman, TN)
1996-01-01
An ultra-low density, microcellular open-celled polymer foam and a method for making such foam. A polymer is dissolved in a heated solution consisting essentially of at least one solvent for the dissolution of the polymer in the heated solution and the phase inversion of the dissolved polymer to a liquid gel upon sufficient cooling of the heated solution. The heated solution is contained in a containment means provided with a nucleating promoting means having a relatively rough surface formed of fixed nucleating sites. The heated solution is cooled for a period of time sufficient to form a liquid gel of the polymer by phase inversion. From the gel, a porous foam having a density of less than about 12.0 mg/cm.sup.3 and open porosity provided by well interconnected strut morphology is formed.
density quantum magnetic storage Stephen Y Chou, Mark S. Wei, Peter R. Krauss, and Paul 6. FischerSingle-domain magnetic pillar array of 35 nm diameter and 65 Gbits/ik2 density for ultrahigh is 65 Gbits/in.2-over two orders of magnitude greater than the state-of-the-art magnetic storage density
Downs, Robert T.
between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions G. V; In Final Form: December 6, 2006 Bond critical point and local energy density properties together with netTheoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection
Estimating low-density snowshoe hare populations using fecal pellet counts
Estimating low-density snowshoe hare populations using fecal pellet counts Dennis L. Murray, James americanus) populations found at high densities can be estimated using fecal pellet densities on rectangular of fecal pellet plots for estimating hare populations by correlating pellet densities with estimated hare
High energy density, thin-lm, rechargeable lithium batteries for marine eld operations
Sadoway, Donald Robert
High energy density, thin-®lm, rechargeable lithium batteries for marine ®eld operations Biying for marines in ®eld operations. With projected practical energy densities exceeding 300 Wh/kg, low safety dimensions are projected to have energy densities exceeding 350 Wh/kg and power densities exceeding 560 W
Energy Density of Introduced Round Goby Compared with Four Native Fishes in a Lake Michigan Ambloplites rupestris. We found positive linear relationships between energy density and the percent dry energy density. Energy density was lower in spring and summer than in fall. The spatial variation
THE ENERGY DENSITY IN THE PLANAR ISING MODEL CLMENT HONGLER AND STANISLAV SMIRNOV
Hongler, ClÃ©ment
THE ENERGY DENSITY IN THE PLANAR ISING MODEL CLÃ?MENT HONGLER AND STANISLAV SMIRNOV Abstract. We boundary conditions. We relate the energy density of the model to a discrete fermionic spinor and compute. Introduction 1 1.1. The model 1 1.2. The energy density 2 1.3. Graph notation 3 1.4. The energy density 5 1
New approaches to measuring biochar density and Catherine E. Brewer a,b,
Gonnermann, Helge
: Brewer CE, et al., New approaches to measuring biochar density and porosity, Biomass and Bioenergy (2014New approaches to measuring biochar density and porosity Catherine E. Brewer a,b, *, Victoria J Accepted 26 March 2014 Available online xxx Keywords: Biochar Skeletal density Envelope density Pore volume
Plasma actuator electron density measurement using microwave perturbation method
Mirhosseini, Farid; Colpitts, Bruce [Electrical and Computer Engineering, University of New Brunswick, Fredericton, New Brunswick E3B 5A3 (Canada)
2014-07-21
A cylindrical dielectric barrier discharge plasma under five different pressures is generated in an evacuated glass tube. This plasma volume is located at the center of a rectangular copper waveguide cavity, where the electric field is maximum for the first mode and the magnetic field is very close to zero. The microwave perturbation method is used to measure electron density and plasma frequency for these five pressures. Simulations by a commercial microwave simulator are comparable to the experimental results.
A Conjecture about the Density of Prime Numbers
L. A. Amarante Ribeiro
2008-03-04
We present in this work a heuristic expression for the density of prime numbers. Our expression leads to results which possesses approximately the same precision of the Riemann's function in the domain that goes from 2 to 1010 at least. Instead of using a constant as was done by Legendre and others in the formula of Gauss, we try to adjust the data through a function. This function has the remarkable property: its points of discontinuity are the prime numbers.
Solvated electron lithium electrode for high energy density battery
Sammells, A.F.
1987-05-26
A rechargeable high energy density lithium-based cell is described comprising: a solvated electron lithium negative electrode comprising a solution of lithium dissolved in liquid ammonia; a lithium ion conducting solid electrolyte contacting the negative electrode; a liquid non-aqueous lithium ion conducting electrolyte comprising a lithium ion conducting supporting electrolyte dissolved in a non-aqueous solvent. The liquid electrolyte contacting the lithium ion conducting solid electrolyte; and a solid lithium intercalation positive electrode contacting the liquid electrolyte.
Noncanonical Hamiltonian density formulation of hydrodynamics and ideal MHD
Morrison, P.J.; Greene, J.M.
1980-04-01
A new Hamiltonian density formulation of a perfect fluid with or without a magnetic field is presented. Contrary to previous work the dynamical variables are the physical variables, rho, v, B, and s, which form a noncanonical set. A Poisson bracket which satisfies the Jacobi identity is defined. This formulation is transformed to a Hamiltonian system where the dynamical variables are the spatial Fourier coefficients of the fluid variables.
Method and apparatus for measuring lung density by Compton backscattering
Loo, Billy W. (Oakland, CA); Goulding, Frederick S. (Lafayette, CA)
1991-01-01
The density of the lung of a patient suffering from pulmonary edema is monitored by irradiating the lung by a single collimated beam of monochromatic photons and measuring the energies of photons Compton backscattered from the lung by a single high-resolution, high-purity germanium detector. A compact system geometry and a unique data extraction scheme are utilized to monimize systematic errors due to the presence of the chestwall and multiple scattering.