Improving the performance of photo-electrically controlled lighting systems
Rubinstein, F.; Ward, G.; Verderber, R.
1988-08-01T23:59:59.000Z
The ability of a photo-electrically controlled lighting system to maintain a constant total light level on a task surface by responding to changing daylight levels is affected by the control algorithm used to relate the photosensor signal to the supplied electric light level and by the placement and geometry of the photosensor. We describe the major components of a typical control system, discuss the operation of three different control algorithms, and derive expressions for each algorithm that express the total illuminance at the task as a function of the control photosensor signal. Using a specially-designed scale model, we measured the relationship between the signal generated by various ceiling-mounted control photosensors and workplane illuminance for two room geometries under real sky conditions. The measured data were used to determine the performance of systems obeying the three control algorithms under varying daylight conditions. Control systems employing the commonly-used integral reset algorithm supplied less electric light than required, failing to satisfy the control objective regardless of the control photosensor used. Systems employing an alternative, closed-loop proportional control algorithm achieved the control objective under virtually all tested conditions when operated by a ceiling-mounted photosensor shielded from direct window light.
An investigation of the applicability of the photo-electric cell to the determination of solubility
Nordsieck, Herbert Henry
1936-01-01T23:59:59.000Z
AN IWESTIGATION OF THE APPLICABILITI OF THE PHOTO ELECTRIC CELL TO THE DETER~PINATIQN 07 30LUBILITI A Thesis h~nF 1EEE Approval ae to aaFle and oontent reoommended; Head nf the Department of cheeistry and chenioa EngineerinE AN INF...-'~STIGATIOS OF TLE APPLICABILITY OF THE PHOTO FLECTBIG CELL TO THE O';TER", II'~ TION OF OOLUBILITF A Th04i4 E4rt&art HearF HorAs foes AH INVESTIGATION CF ~o APPLICABILITT OF Tkig Plh&T?-ELECTRIC CELL TO THE "ET. . R'"&HA IIOJi' OF, !?LOB&~ A ThEsis Subs...
The use of the photo-electric cell in the determination of ammonia
Adams, Leon Milton
1934-01-01T23:59:59.000Z
', 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...
Noisy Independent Factor Analysis Model for Density Estimation and Classification
Amato, U.
2009-06-09T23:59:59.000Z
We consider the problem of multivariate density estimation when the unknown density is assumed to follow a particular form of dimensionality reduction, a noisy independent factor analysis (IFA) model. In this model the ...
Gotie, Robert Francis
1972-01-01T23:59:59.000Z
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...
Gotie, Robert Francis
1972-01-01T23:59:59.000Z
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... in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1972 Major Subject: Wildlife Science NESTING SUCCESS OF THE GREAT-TAILED GRACKLE (CASSIDIX MEXICANUS PROSOPIDICOLA) IN RELATION TO CERTAIN DENSITY DEPENDENT...
Development and evaluation of probability density functions for a set of human exposure factors
Maddalena, R.L.; McKone, T.E.; Bodnar, A.; Jacobson, J.
1999-06-01T23:59:59.000Z
The purpose of this report is to describe efforts carried out during 1998 and 1999 at the Lawrence Berkeley National Laboratory to assist the U.S. EPA in developing and ranking the robustness of a set of default probability distributions for exposure assessment factors. Among the current needs of the exposure-assessment community is the need to provide data for linking exposure, dose, and health information in ways that improve environmental surveillance, improve predictive models, and enhance risk assessment and risk management (NAS, 1994). The U.S. Environmental Protection Agency (EPA) Office of Emergency and Remedial Response (OERR) plays a lead role in developing national guidance and planning future activities that support the EPA Superfund Program. OERR is in the process of updating its 1989 Risk Assessment Guidance for Superfund (RAGS) as part of the EPA Superfund reform activities. Volume III of RAGS, when completed in 1999 will provide guidance for conducting probabilistic risk assessments. This revised document will contain technical information including probability density functions (PDFs) and methods used to develop and evaluate these PDFs. The PDFs provided in this EPA document are limited to those relating to exposure factors.
An investigation of factors affecting intersection control by volume density actuated equipment
Radke, Milton L
1966-01-01T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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 DeliciousPlasmaPLawrence County,1980) | OpenAl., 2001) |New Berlin,Newark,Nick's Utility JumpNighthawkNilarNingbo Qixin
Engineering Density of States of Earth Abundant Semiconductors...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced...
Alpha track density using a semiconductor detector
Hamilton, Ian Scott
1993-01-01T23:59:59.000Z
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...
Vranjes, J
2015-01-01T23:59:59.000Z
Inhomogeneous plasmas and fluids contain energy stored in inhomogeneity and they naturally tend to relax into lower energy states by developing instabilities or by diffusion. But the actual amount of energy in such inhomogeneities has remained unknown. In the present work the amount of energy stored in a density gradient is calculated for several specific density profiles in a cylindric configuration. This is of practical importance for drift wave instability in various plasmas, and in particular in its application in models dealing with the heating of solar corona because the instability is accompanied with stochastic heating, so the energy contained in inhomogeneity is effectively transformed into heat. It is shown that even for a rather moderate increase of the density at the axis in magnetic structures in the corona by a factor 1.5 or 3, the amount of excess energy per unit volume stored in such a density gradient becomes several orders of magnitude greater than the amount of total energy losses per unit ...
TMD theory, factorization and evolution
John Collins
2013-07-10T23:59:59.000Z
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)
2000-08-01T23:59:59.000Z
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].
The determination of vapor composition curves by means of the photo-electric cell
Chaney, Preston Earl
1938-01-01T23:59:59.000Z
. Calibratiea Cares for CHCllg - CC14 Usiag Riyal& Phase kbsosptiea at gg * ~ a ~ ~ ~ t ~ a ~ ~ ~ ~ ~ FIGURES I, Wltfng JNageua of the Asylifier . ~ ~ ~ ~ ~ 4 XX* Ayyasebas Use4 ha Abets bg Vayex Abssxytiaa IXX. Ayyaeabas Use4 ka Asslike by XAqs14..., sable to the ~eoIsriaetrie& ~ nalpeis ef alxtares ef vayers Or 1iqaLSs obese absorytioa saaRe is yartiallg er eaapiotolJ oataL4e tho visible rosieay as is the ease sith aasy erSani? aixtaros obtaiaablo by 4istillatioai (1) A4aae, "Tbe See of tho Phet...
The use of the photo-electric cell in the determination of ammonia
Adams, Leon Milton
1934-01-01T23:59:59.000Z
, especially in the form of' ammonia or ammonium compounds, is, . enerclly 1ndicative of tho degree of polut1on. Of tho various prooodurcs that have been dovolopod for tho determination of the amount sf nitro;. , on pro:;ant as srmonla, the nethod usia...
Laboratory Density Functionals
B. G. Giraud
2007-07-26T23:59:59.000Z
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
2008-10-08T23:59:59.000Z
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.
Neutral depletion and the helicon density limit
Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)
2013-12-15T23:59:59.000Z
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.
Lula, J.W.
1982-01-01T23:59:59.000Z
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.
J. R. Stone
2013-02-11T23:59:59.000Z
The microscopic composition and properties of matter at super-saturation densities have been the subject of intense investigation for decades. The scarcity of experimental and observational data has lead to the necessary reliance on theoretical models. However, there remains great uncertainty in these models, which, of necessity, have to go beyond the over-simple assumption that high density matter consists only of nucleons and leptons. Heavy strange baryons, mesons and quark matter in different forms and phases have to be included to fulfil basic requirements of fundamental laws of physics. In this review the latest developments in construction of the Equation of State (EoS) of high-density matter at zero and finite temperature assuming different composition of the matter are surveyed. Critical comparison of model EoS with available observational data on neutron stars, including gravitational masses, radii and cooling patterns is presented. The effect of changing rotational frequency on the composition of neutron stars during their lifetime is demonstrated. Compatibility of EoS of high-density, low temperature compact objects and low density, high temperature matter created in heavy-ion collisions is discussed.
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
2015-01-01T23:59:59.000Z
The spatial volume occupied by an atom depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent algorithms and packages to calculate it numerically for other materials. Three-dimensional visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. In this paper, we explore several approaches to this, including the extension of an analglyphic stereo visualization application based on the AViz package for hydrogen atoms and simple molecules to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answeringmore »interesting physical questions about nanotube properties.« less
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 ...
Multiple density layered insulator
Alger, T.W.
1994-09-06T23:59:59.000Z
A multiple density layered insulator for use with a laser is disclosed which 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. 4 figs.
Update of axion CDM energy density
Huh, Ji-Haeng [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)
2008-11-23T23:59:59.000Z
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}{sub QCD}, the current quark masses m{sub q}'s and the Peccei-Quinn scale F{sub a}, including firstly introduced 1.85 factor which is from the initial overshoot.
Optimally focused cold atom systems obtained using density-density correlations
Putra, Andika; Campbell, Daniel L.; Price, Ryan M.; Spielman, I. B. [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States)] [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States); De, Subhadeep [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States) [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States); CSIR-National Physical Laboratory, New Delhi 110012 (India)
2014-01-15T23:59:59.000Z
Resonant absorption imaging is a common technique for detecting the two-dimensional column density of ultracold atom systems. In many cases, the system's thickness along the imaging direction greatly exceeds the imaging system's depth of field, making the identification of the optimally focused configuration difficult. Here we describe a systematic technique for bringing Bose-Einstein condensates (BEC) and other cold-atom systems into an optimal focus even when the ratio of the thickness to the depth of field is large: a factor of 8 in this demonstration with a BEC. This technique relies on defocus-induced artifacts in the Fourier-transformed density-density correlation function (the power spectral density, PSD). The spatial frequency at which these artifacts first appear in the PSD is maximized on focus; the focusing process therefore both identifies and maximizes the range of spatial frequencies over which the PSD is uncontaminated by finite-thickness effects.
High Energy Density Capacitors
None
2010-07-01T23:59:59.000Z
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
2014-01-01T23:59:59.000Z
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.
Low density microcellular foams
LeMay, J.D.
1991-11-19T23:59:59.000Z
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.
Oberacker, V E
2015-01-01T23:59:59.000Z
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)
1991-01-01T23:59:59.000Z
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)
1992-01-01T23:59:59.000Z
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.
V. E. Oberacker; A. S. Umar
2015-02-13T23:59:59.000Z
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.
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)
2011-07-10T23:59:59.000Z
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.
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)
1987-01-01T23:59:59.000Z
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.
Low density microcellular foams
Aubert, J.H.; Clough, R.L.; Curro, J.G.; Quintana, C.A.; Russick, E.M.; Shaw, M.T.
1985-10-02T23:59:59.000Z
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.
Minimization of Fractional Power Densities
Minimization of Fractional Power Densities. Robert Hardt, Rice University. Abstract: A k dimensional rectifiable current is given by an oriented k dimensional
Optimal Seismic Network Density for Earthquake Early Warning: A Case
Allen, Richard M.
. Serdar Kuyuk and Richard M. Allen INTRODUCTION Earthquake Early Warning Systems (EEWS) rapidly detect and the public actively use early warning information is a crucial factor in early warning system design (AktasOptimal Seismic Network Density for Earthquake Early Warning: A Case Study from California by H
Low density carbonized composite foams
Kong, Fung-Ming (Pleasanton, CA)
1991-01-01T23:59:59.000Z
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.
High Energy Density Laboratory Plasmas
to IFE #12;5 The PorDolio FY 2012 1. High Energy Density (HED) Hydrodynamics (HYDRO SBIR IFE Technology Small-Business JS-1 JS-2 JS-3 Lab-DS ECA's Facili
Low density metal hydride foams
Maienschein, Jon L. (Oakland, CA); Barry, Patrick E. (Pleasant Hill, CA)
1991-01-01T23:59:59.000Z
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.
Effect of Lithium PFC Coatings on NSTX Density Control
Kugel, H W; Bell, M G; Bush, C; Gates, D; Gray, T; Kaita, R; Leblanc, B; Maingi, R; Majeski, R; Mansfield, D; Mueller, D; Raman, R; Roquemore, A L; Sabbagh, S; Skinner, C H; Soukhanovskii, V; Stevenson, T; Zakharov, L
2006-08-21T23:59:59.000Z
Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null Ohmic Helium Discharges were used to coat graphite surfaces that had been pre-conditioned with Ohmic Helium Discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating.
Pion transverse charge density and the edge of hadrons
Carmignotto, Marco [Catholic University of America; Horn, Tanja [Catholic University of America; Miller, Gerald A. [University of Washington
2014-08-01T23:59:59.000Z
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.
A step towards quantitative lipoprotein density profiling analysis: applied Rayleigh scattering
Nowlin, Michael
2009-05-15T23:59:59.000Z
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.
2007-01-23T23:59:59.000Z
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.
The effects of stocking density on two Tilapia species raised in an intensive culture system
Henderson-Arzapalo, Anne
1979-01-01T23:59:59.000Z
Culture practices Stocking density MATERIAI, S AND METHODS RESULTS AND DISCUSSION 10 14 19 Mortality Water quality Final fish length Final fish weight Condition 19 25 33 33 35 Total biomass Feed conversion 41 41 Summary REFERENCES 45... at various stocking densities. 36 8 Final mean condition factors for T. auras and T. mossambica at various stocking densities. 9 Total mean tank biomass for T. auras and T. mossambica at termination. 44 10 Mean feed conversion ratios (FOR) for 1". sures...
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)
2006-02-01T23:59:59.000Z
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.
About density functional theory interpretation
Kirill Koshelev
2015-05-28T23:59:59.000Z
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.
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
Likelihood-based modification of experimental crystal structure electron density maps
Terwilliger, Thomas C. (Sante Fe, NM)
2005-04-16T23:59:59.000Z
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.
Density functional theory of freezing: Analysis of crystal density
Laird, Brian Bostian; McCoy, John D.; Haymet, A. D. J.
1987-09-01T23:59:59.000Z
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...
Density Log | 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 DeliciousPlasmaP aCentrotherm PhotovoltaicsDOI-BLM-NV-W030-20??-????-CXDawuDelawareEnergyDenmark:Density Log Jump to:
Lower crustal density estimation using the density-slowness relationship: a preliminary study
Jones, Gary Wayne
1996-01-01T23:59:59.000Z
The density of the Earths crust is an important parameter. Carlson and Raskin [1984] and Carlsan and Herrick (1990] used an empirical approach an the relationship between density and seismic slowness to estimate the density ...
Neutral H density at the termination shock: a consolidation of recent results
M. Bzowski; E. Moebius; S. Tarnopolski; V. Izmodenov; G. Gloeckler
2008-12-04T23:59:59.000Z
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
Oxides having high energy densities
Ceder, Gerbrand; Kang, Kisuk
2013-09-10T23:59:59.000Z
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.
Lipoprotein subclass analysis by immunospecific density
Lester, Sandy Marie
2009-05-15T23:59:59.000Z
to obtain a lipoprotein density profile in the absence and presence of apo C-1. Density Lipoprotein Profiling (DLP) gives relevant information of lipoproteins, such as density and subclass characterization, and is a novel approach to purify apo C-1-enriched...
Liquid Walls Innovative High Power Density Concepts
California at Los Angeles, University of
Liquid Walls Innovative High Power Density Concepts (Based on the APEX Study) http better? #12;Primary Goals 1. High Power Density Capability (main driver) Neutron Wall Load > 10 MW/m2\\VLFV UHJLPHV LI OLTXLG PHWDOV DUH XVHG · High Power Density Capability -Eliminate thermal stress and wall
Jacek Dobaczewski Density functional theory and energy
Dobaczewski, Jacek
in Poland per voivodship Energy density functional 245 647 Price voivodship functional 654 763 295 580Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek://www.fuw.edu.pl/~dobaczew/Stellenbosch/dobaczewski_lecture.pdf Home page: http://www.fuw.edu.pl/~dobaczew/ #12;Jacek Dobaczewski Nuclear Structure Energy scales
Ultimate Energy Densities for Electromagnetic Pulses
Mankei Tsang
2008-03-06T23:59:59.000Z
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))
1991-04-01T23:59:59.000Z
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.
Chapter 4: High-Density Regimes in the FTU
Frigione, D.; Pieroni, L.; Buratti, P.; Giovannozzi, E.; Romanelli, M.; Esposito, B.; Leigheb, M.; Gabellieri, L. [Associazione EURATOM-ENEA sulla fusione (Italy)
2004-05-15T23:59:59.000Z
High-density plasmas (n{sub o} {approx} 8 x 10{sup 20} m{sup -3}) achieving steady improved core-confinement have been obtained in the Frascati Tokamak Upgrade (FTU) up to the maximum nominal toroidal field (8 T) by deep multiple pellet injection. These plasmas exhibit also high purity, efficient electron-ion coupling, and peaked density profiles sustained for several energy confinement times. Neutron yields in excess of 1 x 10{sup 13} n/s are measured, consistent with the reduction of the ion transport to neoclassical levels. Improved performance is associated with sawtooth stabilization that occurs when the pellet penetrates close to the q = 1 surface. In this regime, impurity accumulation can be prevented if a slow sawtooth activity is maintained. Experiments aimed at obtaining radiation-improved modes at high field have also been carried out using neon injection. The observed increase of the average density, with respect to the reference discharge, is significantly larger than the contribution of Ne. The neutron yield increases also by a factor of 3 to 6, and the energy confinement time increases by a factor up to 1.4.
The volume densities of GMCs in M81
Jonathan S. Heiner; Ronald J. Allen; Bjorn H. C. Emonts; Pieter C. van der Kruit
2007-10-05T23:59:59.000Z
HI features near young star clusters in M81 are identified as the photodissociated surfaces of Giant Molecular Clouds (GMCs) from which the young stars have recently formed. The HI column densities of these features show a weak trend, from undetectable values inside R = 3.7 kpc and increasing rapidly to values around 3 x 10^21 cm^-2 near R ~ 7.5 kpc. This trend is similar to that of the radially-averaged HI distribution in this galaxy, and implies a constant area covering factor of ~ 0.21 for GMCs throughout M81. The incident UV fluxes G0 of our sample of candidate PDRs decrease radially. A simple equilibrium model of the photodissociation-reformation process connects the observed values of the incident UV flux, the HI column density, and the relative dust content, permitting an independent estimate to be made of the total gas density in the GMC. Within the GMC this gas will be predominantly molecular hydrogen. Volume densities of 1 < n < 200 cm^-3 are derived, with a geometric mean of 17 cm^-3. These values are similar to the densities of GMCs in the Galaxy, but somewhat lower than those found earlier for M101 with similar methods. Low values of molecular density in the GMCs of M81 will result in low levels of collisional excitation of the CO(1-0) transition, and are consistent with the very low surface brightness of CO(1-0) emission observed in the disk of M81.
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)
2003-10-01T23:59:59.000Z
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
2014-02-24T23:59:59.000Z
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.
Viljoen, T. A.
1979-01-01T23:59:59.000Z
Power factor control is a necessary ingredient in any successful Energy Management Program. Many companies are operating with power factors of 70% or less and are being penalized through the electrical utility bill. This paper starts by describing...
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
1994-07-01T23:59:59.000Z
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., E-mail: m.mahdavi@umz.ac.ir [Physics Department, University of Mazandaran, P.O. Box 47415-416, Babolsar (Iran, Islamic Republic of); Khodadadi Azadboni, F., E-mail: f.khodadadi@stu.umz.ac.ir [Physics Department, University of Mazandaran, P.O. Box 47415-416, Babolsar (Iran, Islamic Republic of); Young Researchers Club, Sari Branch, Islamic Azad University, P.O. Box 48161-194, Sari (Iran, Islamic Republic of)
2014-02-15T23:59:59.000Z
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.
Quartz resonator fluid density and viscosity monitor
Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)
1998-01-01T23:59:59.000Z
A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.
Solid angle and surface density as criticality parameters
Thomas, J.T.
1980-10-01T23:59:59.000Z
Two methods often used to establish nuclear criticality safety limits for operations with fissile materials are the surface density and solid angle techniques. The two methods are used as parameters to express experimental and validated calculations of critical configurations. It is demonstrated that each method can represent critical arrangements of subcritical units and that there can be established a one-to-one correspondence between them. The analyses further show that the effect on an array neutron multiplication factor of perturbations to the array can be reliably estimated and that each form of fissile material and unit shape has a specific representation.
Method of synthesizing a low density material
Lorensen, L.E.; Monaco, S.B.
1987-02-27T23:59:59.000Z
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.
Some recent efforts toward high density implosions
McClellan, G.E.
1980-12-04T23:59:59.000Z
Some recent Livermore efforts towards achieving high-density implosions are presented. The implosion dynamics necessary to compress DT fuel to 10 to 100 times liquid density are discussed. Methods of diagnosing the maximum DT density for a specific design are presented along with results to date. The dynamics of the double-shelled target with an exploding outer shell are described, and some preliminary experimental results are presented.
Considering Air Density in Wind Power Production
Farkas, Zénó
2011-01-01T23:59:59.000Z
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.
Considering Air Density in Wind Power Production
Zénó Farkas
2011-03-11T23:59:59.000Z
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.
A High Power Density DC-DC Converter for Distributed PV Architectures
Mohammed S. Agamy; Song Chi; Ahmed Elasser; Maja Harfman-Todorovic; Yan Jiang; Frank Mueller; Fengfeng Tao
2012-06-01T23:59:59.000Z
In order to maximize solar energy harvesting capabilities, power converters have to be designed for high efficiency and good MPPT and voltage/current performance. When many converters are used in distributed systems, power density also becomes an important factor as it allows for simpler system integration. In this paper a high power density string dc-dc converter suitable for distributed medium to large scale PV installation is presented. A simple partial power processing topology, implemented with all silicon carbide devices provides high efficiency as well as high power density. A 3.5kW, 100kHz converter is designed and tested to verify the proposed methods.
3-D capacitance density imaging system
Fasching, G.E.
1988-03-18T23:59:59.000Z
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.
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. [Texas A& M Univ., Commerce, TX (United States)
2014-09-10T23:59:59.000Z
This grant had two components: Density functional theory and pairing and Nuclear reactions. This final report summarizes the activities for this SciDAC-2 project.
On the Extensive Air Shower density spectrum
Aleksander Zawadzki; Tadeusz Wibig; Jerzy Gawin
1998-07-29T23:59:59.000Z
In search for new methods of determining the primary energy spectrum of Cosmic Rays, the attention was paid to the density spectrum measurement. New methods available at present warrant an accurateness of conclusions derived from the density spectrum measurements. The general statement about the change of the spectral index of the charged particle density spectrum is confirmed very clearly. Results concerning the shower size and primary energy spectra are also presented and discussed. Interesting future prospects for applications of the density spectrum method are proposed.
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
Density functional theory for carbon dioxide crystal
Chang, Yiwen; Mi, Jianguo, E-mail: mijg@mail.buct.edu.cn; Zhong, Chongli [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)
2014-05-28T23:59:59.000Z
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.
motor power: 117.7 V x 5.1 A = 600 W? = 0.6 kW? NOT the power measured by meter #12;Page 9 PSERC: displacement power factor: angle between voltage and current = 0 degrees pf = cos(0 degrees) = 1.0 true powerPage 1 PSERC Power Factor and Reactive Power Ward Jewell Wichita State University Power Systems
Density Prediction of Uranium-6 Niobium Ingots
D.F.Teter; P.K. Tubesing; D.J.Thoma; E.J.Peterson
2003-04-15T23:59:59.000Z
The densities of uranium-6 niobium (U-Nb) alloys have been compiled from a variety of literature sources such as Y-12 and Rocky Flats datasheets. We also took advantage of the 42 well-pedigreed, homogeneous baseline U-Nb alloys produced under the Enhanced Surveillance Program for density measurements. Even though U-Nb alloys undergo two-phase transitions as the Nb content varies from 0 wt. % to 8 wt %, the theoretical and measured densities vary linearly with Nb content. Therefore, the effect of Nb content on the density was modeled with a linear regression. From this linear regression, a homogeneous ingot of U-6 wt.% Nb would have a density of 17.382 {+-} 0.040 g/cc (95% CI). However, ingots produced at Y-12 are not homogeneous with respect to the Nb content. Therefore, using the 95% confidence intervals, the density of a Y-12 produced ingot would vary from 17.310 {+-} 0.043 g/cc at the center to 17.432 {+-} 0.039 g/cc at the edge. Ingots with larger Nb inhomogeneities will also have larger variances in the density.
Factors Affecting Option Premium Values
Johnson, Jason; Smith, Jackie; Dhuyvetter, Kevin C.; Waller, Mark L.
1999-06-23T23:59:59.000Z
Many factors affect option premium values. This publication list these factors and gives brief explanations of them.
Low density, resorcinol-formaldehyde aerogels
Pekala, R.W.
1988-05-26T23:59:59.000Z
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)
1991-01-01T23:59:59.000Z
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.
Low density, resorcinol-formaldehyde aerogels
Pekala, Richard W. (Pleasant Hill, CA)
1989-01-01T23:59:59.000Z
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, R.W.
1989-10-10T23:59:59.000Z
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.
Instabilities in the Nuclear Energy Density Functional
M. Kortelainen; T. Lesinski
2010-02-05T23:59:59.000Z
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.
Collective enhancement of nuclear state densities by the shell model Monte Carlo approach
C. Özen; Y. Alhassid; H. Nakada
2015-01-22T23:59:59.000Z
The shell model Monte Carlo (SMMC) approach allows for the microscopic calculation of statistical and collective properties of heavy nuclei using the framework of the configuration-interaction shell model in very large model spaces. We present recent applications of the SMMC method to the calculation of state densities and their collective enhancement factors in rare-earth nuclei.
A Framework to Determine the Probability Density Function for the Output Power of Wind Farms
Liberzon, Daniel
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
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
2015-07-31T23:59:59.000Z
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
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 onsource History View New PagessourceRaven Biofuels Internationalsource History View NewNew
Microstructural factors important for the development of high critical current density Nb3Sn strand
) to fields below $11 T. The huge potential of the round wire multifilament HTS superconduc- tor Bi-2212
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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...
Density controlled carbon nanotube array electrodes
Ren, Zhifeng F. (Newton, MA); Tu, Yi (Belmont, MA)
2008-12-16T23:59:59.000Z
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.
High density load bearing insulation peg
Nowobilski, J.J.; Owens, W.J.
1985-01-29T23:59:59.000Z
A high density peg is disclosed which can support a large load and exhibits excellent thermal resistance produced by a method wherein the peg is made in compliance with specified conditions of time, temperature and pressure. 4 figs.
Primordial Density Fluctuations in Phase Coupling Gravity
C. E. M. Batista; M. Schiffer
1996-01-10T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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...
Magnetic fields and density functional theory
Salsbury Jr., Freddie
1999-02-01T23:59:59.000Z
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.
Tweedie Family Densities: Methods of Evaluation
Smyth, Gordon K.
of Queensland, St Lucia, Q 4072, Australia. 2 University of Southern Queensland, Toowoomba, Q 4350, Australia. Tweedie family densities are characterised by power variance functions of the form V[µ] = µp , where p
Breast Density and Cancer | GE Global Research
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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...
Spacetime Average Density (SAD) cosmological measures
Page, Don N., E-mail: profdonpage@gmail.com [Department of Physics, 4-183 CCIS, University of Alberta, Edmonton, Alberta, T6G 2E1 Canada (Canada)
2014-11-01T23:59:59.000Z
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.
Turbulent density fluctuations in the solar wind
Ingale, Madhusudan
2015-01-01T23:59:59.000Z
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...
Shock compression of low-density foams
Holmes, N.C.
1993-07-01T23:59:59.000Z
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.
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 ...
Alpha track density using a semiconductor detector
Hamilton, Ian Scott
1993-01-01T23:59:59.000Z
Determination of the alpha track density in the cellulose nitrate (CN) dielectric version of solid state nuclear track detectors (SSNTD) has traditionally been tedious work which produced results that relied upon the person counting the film as well...
The Chemistry of Atherogenic High Density Lipoprotein
Moore, D'Vesharronne J.
2012-07-16T23:59:59.000Z
An array of analytical methods including density gradient ultracentrifugation, capillary electrophoresis, and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), were utilized to analyze serum high ...
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
Zamora, Paul O. (Gaithersburg, MD); Pena, Louis A. (Poquott, NY); Lin, Xinhua (Plainview, NY); Takahashi, Kazuyuki (Germantown, MD)
2012-07-24T23:59:59.000Z
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.
Electromagetic proton form factors
M Y Hussein
2006-10-31T23:59:59.000Z
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.
Redshift Evolution of Galaxy Cluster Densities
R. G. Carlberg; S. L. Morris; H. K. C. Yee; E. Ellingson
1997-01-20T23:59:59.000Z
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.
Ligand identification using electron-density mapcorrelations
Terwilliger, Thomas C.; Adams, Paul D.; Moriarty, Nigel W.; Cohn,Judith D.
2006-12-01T23:59:59.000Z
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.
Partial level density of the n-quasiparticle excitations in the nuclei of the 39< A <201 region
A. M. Sukhovoj; V. A. Khitrov
2005-12-16T23:59:59.000Z
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.
Radial evolution of intermittency of density fluctuations in the fast solar wind
Bruno, R; Primavera, L; Pietropaolo, E; D'Amicis, R; Sorriso-Valvo, L; Carbone, V; Malara, F; Veltri, P
2014-01-01T23:59:59.000Z
We study the radial evolution of intermittency of density fluctuations in the fast solar wind. The study is performed 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 time scales 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 fast wind are rather intermittent and their level of intermittency, together with the amplitude of intermittent events, decreases with distance from the Sun, at odds with intermittency of both magnetic field and all the 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....
On-line method of determining utilization factor in Hg-196 photochemical separation process
Grossman, Mark W. (Belmont, MA); Moskowitz, Philip E. (Peabody, MA)
1992-01-01T23:59:59.000Z
The present invention is directed to a method for determining the utilization factor [U] in a photochemical mercury enrichment process (.sup.196 Hg) by measuring relative .sup.196 Hg densities using absorption spectroscopy.
Geothermal Plant Capacity Factors
Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood
2015-01-01T23:59:59.000Z
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.
Hamlet, Jason R; Pierson, Lyndon G
2014-10-21T23:59:59.000Z
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.
Precise and Accurate Density Determination of Explosives Using Hydrostatic Weighing
B. Olinger
2005-07-01T23:59:59.000Z
Precise and accurate density determination requires weight measurements in air and water using sufficiently precise analytical balances, knowledge of the densities of air and water, knowledge of thermal expansions, availability of a density standard, and a method to estimate the time to achieve thermal equilibrium with water. Density distributions in pressed explosives are inferred from the densities of elements from a central slice.
Fabrication of low density ceramic material
Meek, T.T.; Blake, R.D.; Sheinberg, H.
1985-01-01T23:59:59.000Z
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. [Department of Physics, Central Michigan University, Mount Pleasant, MI 48859 (United States); Zelevinsky, V. G. [Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States)
2014-10-15T23:59:59.000Z
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.
2004-10-12T23:59:59.000Z
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.
Density matrix of black hole radiation
Lasma Alberte; Ram Brustein; Andrei Khmelnitsky; A. J. M. Medved
2015-02-09T23:59:59.000Z
Hawking's model of black hole evaporation is not unitary and leads to a mixed density matrix for the emitted radiation, while the Page model describes a unitary evaporation process in which the density matrix evolves from an almost thermal state to a pure state. We compare a recently proposed model of semiclassical black hole evaporation to the two established models. In particular, we study the density matrix of the outgoing radiation and determine how the magnitude of the off-diagonal corrections differs for the three frameworks. For Hawking's model, we find power-law corrections to the two-point functions that induce exponentially suppressed corrections to the off-diagonal elements of the full density matrix. This verifies that the Hawking result is correct to all orders in perturbation theory and also allows one to express the full density matrix in terms of the single-particle density matrix. We then consider the semiclassical theory for which the corrections, being non-perturbative from an effective field-theory perspective, are much less suppressed and grow monotonically in time. In this case, the R\\'enyi entropy for the outgoing radiation is shown to grow linearly at early times; but this growth slows down and the entropy eventually starts to decrease at the Page time. In addition to comparing models, we emphasize the distinction between the state of the radiation emitted from a black hole, which is highly quantum, and that of the radiation emitted from a typical classical black body at the same temperature.
Maximum likelihood density modification by pattern recognition of structural motifs
Terwilliger, Thomas C.
2004-04-13T23:59:59.000Z
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.
Low density, microcellular foams, preparation, and articles
Young, A.T.
1982-03-03T23:59:59.000Z
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.
Density functional theory study of (OCS)2^-
Bilalbegovic, G
2007-01-01T23:59:59.000Z
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)
1984-01-01T23:59:59.000Z
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.
Level densities of transitional Sm nuclei
Capote, R.; Ventura, A.; Cannata, F.; Quesada, J.M. [Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Ente Nuove Tecnologie, Energia e Ambiente, and Istituto Nazionale di Fisica Nucleare, Bologna (Italy); Dipartimento di Fisica dell Universita and Istituto Nazionale di Fisica Nucleare, Bologna (Italy); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla (Spain)
2005-06-01T23:59:59.000Z
Experimentally determined level densities of the transitional isotopes {sup 148,149,150,152}Sm at excitation energies below and around the neutron binding energy are compared with microcanonical calculations based on a Monte Carlo approach to noncollective level densities, folded with a collective enhancement estimated in the frame of the interacting boson model (IBM). The IBM parameters are adjusted so as to reproduce the low-lying discrete levels of both parities, with the exception of the odd-mass nucleus, {sup 149}Sm, where complete decoupling of the unpaired neutron from the core is assumed.
Error Analysis in Nuclear Density Functional Theory
Nicolas Schunck; Jordan D. McDonnell; Jason Sarich; Stefan M. Wild; Dave Higdon
2014-07-11T23:59:59.000Z
Nuclear density functional theory (DFT) is the only microscopic, global approach to the structure of atomic nuclei. It is used in numerous applications, from determining the limits of stability to gaining a deep understanding of the formation of elements in the universe or the mechanisms that power stars and reactors. The predictive power of the theory depends on the amount of physics embedded in the energy density functional as well as on efficient ways to determine a small number of free parameters and solve the DFT equations. In this article, we discuss the various sources of uncertainties and errors encountered in DFT and possible methods to quantify these uncertainties in a rigorous manner.
Gordon Chalmers
2005-09-20T23:59:59.000Z
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.
Qian, Ning
: THE UNITED STATES SPENDS MORE ON HEALTH CARE THAN ANY OTHER COUNTRY. YET WE CONTINUE TO FALL FAR BEHIND States spends an astonishing percent of our gross domestic product on health care--significantly moreColumbia Public Health HOT TOPIC Climate Change FAT FACTORS Obesity Prevention BOOK SMART
High power density supercapacitors using locally aligned carbon nanotube electrodes
Du, C S; Yeh, J; Pan, Ning
2005-01-01T23:59:59.000Z
4484/16/4/003 High power density supercapacitors usingproduced very high speci?c power density of about 30 kW kg ?manufacturing of high power density supercapacitors and
High-power-density spot cooling using bulk thermoelectrics
Zhang, Y; Shakouri, A; Zeng, G H
2004-01-01T23:59:59.000Z
model, the cooling power densities of the devices can alsothe cooling power densities 2–24 times. Experimentally, the14 4 OCTOBER 2004 High-power-density spot cooling using bulk
Power spectrum of electron number density perturbations at cosmological recombination epoch
B. Venhlovska; B. Novosyadlyj
2009-02-19T23:59:59.000Z
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.
Maps of current density using density-functional methods A. Soncini,1,a
Helgaker, Trygve
, University of Durham, South Road, Durham DH1 3LE, United Kingdom Received 22 May 2008; accepted 17 July 2008 are compared and integration of the current densities to yield shielding constants is performed. In general of induced current density in molecules. © 2008 American Institute of Physics. DOI: 10.1063/1.2969104 I
On the Determination of the Mean Cosmic Matter Density and the Amplitude of Density Fluctuations
Thomas H. Reiprich
2002-07-02T23:59:59.000Z
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.
Nanodosimetry-based quality factors for radiation protection in space Reinhard W. Schulte1,2,Ã with radiation of low ionization density. Currently, quality factors of radiation both on the ground and in space. This approach makes the determination of the average quality factor of a given radiation field a rather complex
Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...
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Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...
Effects of Ambient Density and Temperature on Soot Formation...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Density and Temperature on Soot Formation under High-EGR Conditions Effects of Ambient Density and Temperature on Soot Formation under High-EGR Conditions Presentation given at...
Mitigating Breakdown in High Energy Density Perovskite Polymer...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors 2012...
Real-Time Simultaneous Measurements of Size, Density, and Composition...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
of Size, Density, and Composition of Single Ultrafine Diesel Tailpipe Particles Real-Time Simultaneous Measurements of Size, Density, and Composition of Single Ultrafine Diesel...
TEMPO-based Catholyte for High Energy Density Nonaqueous Redox...
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TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. Abstract: We will...
BUILDING A UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL (UNEDF...
Office of Scientific and Technical Information (OSTI)
Technical Report: BUILDING A UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL (UNEDF) Citation Details In-Document Search Title: BUILDING A UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL...
Pauling bond strength, bond length and electron density distribution...
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Pauling bond strength, bond length and electron density distribution. Pauling bond strength, bond length and electron density distribution. Abstract: A power law regression...
Density Functional Theory Study of Oxygen Reduction Activity...
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Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes. Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum...
A Density Functional Theory Study of Formaldehyde Adsorption...
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Density Functional Theory Study of Formaldehyde Adsorption on Ceria. A Density Functional Theory Study of Formaldehyde Adsorption on Ceria. Abstract: Molecular adsorption of...
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...
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...
DIAGNOSTICS FOR ION BEAM DRIVEN HIGH ENERGY DENSITY PHYSICS EXPERIMENTS
Bieniosek, F.M.
2010-01-01T23:59:59.000Z
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.
Estimating density of Florida Key deer
Roberts, Clay Walton
2006-08-16T23:59:59.000Z
for this species since 1968; however, a need to evaluate the precision of existing and alternative survey methods (i.e., road counts, mark-recapture, infrared-triggered cameras [ITC]) was desired by USFWS. I evaluated density estimates from unbaited ITCs and road...
Lipoprotein subclass analysis by immunospecific density
Lester, Sandy Marie
2009-05-15T23:59:59.000Z
Separation of Lipoprotein Particles by Single Spin Ultracentrifugation ......................................................................... 27 Layering Ultracentrifugation Tubes ............................................... 28 Digital..., and HDL. (Fig 4) 14 As one moves down the Ultracentrifugation (UC) tube, the density increases and the particle size decreases from chylomicrons to HDL. The lipoprotein fractions also differ in lipid to protein ratios, apolipoprotein...
Effective Field Theory and Finite Density Systems
R. J. Furnstahl; G. Rupak; T. Schaefer
2008-01-04T23:59:59.000Z
This review gives an overview of effective field theory (EFT) as applied at finite density, with a focus on nuclear many-body systems. Uniform systems with short-range interactions illustrate the ingredients and virtues of many-body EFT and then the varied frontiers of EFT for finite nuclei and nuclear matter are surveyed.
Density-Functional Theory for Complex Fluids
Wu, Jianzhong
. This generic methodology is built upon a mathematical theorem that states, for an equilibrium system at a given modeling of the microscopic struc- tures and phase behavior of soft-condensed matter. The methodol- ogy to the one-body density profile Grand potential: the free energy of an open system at fixed volume
Population density of San Joaquin kit fox
McCue, P.; O'Farrell, T.P.; Kato, T.; Evans, B.G.
1982-01-01T23:59:59.000Z
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
Dynamic Evolution for Risk-Neutral Densities
2008-10-27T23:59:59.000Z
specifications of the data are as follows: the spot asset price is 590, the risk- free interest rate is ... than 10) the recovered risk-neutral densities exhibit less smoothness than in the cases .... Technical report, Purdue University, 1995. [31] A. M. ...
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
Durable high-density data storage
Stutz, R.A.; Lamartine, B.C.
1996-09-01T23:59:59.000Z
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 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
High power density thermophotovoltaic energy conversion
Noreen, D.L. [R& D Technologies, Inc., Hoboken, New Jersey 07030 (United States); Du, H. [Department of Materials Science and Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030 (United States)
1995-01-05T23:59:59.000Z
R&D Technologies is developing thermophotovoltaic (TPV) technology based on the use of porous/fibrous ceramic broadband-type emitter designs that utilize recuperative or regenerative techniques to improve thermal efficiency and power density. This paper describes preliminary estimates of what will be required to accomplish sufficient power density to develop a practical, commercially-viable TPV generator. It addresses the needs for improved, thermal shock-resistant, long-life porous/fibrous ceramic emitters and provides information on the photocell technology required to achieve acceptable power density in broadband-type (with selective filter) TPV systems. TPV combustors/systems operating at a temperature of 1500 {degree}C with a broadband-type emitter is proposed as a viable starting point for cost-effective TPV conversion. Based on current projections for photocell cost, system power densities of 7.5--10 watts per square centimeter of emitter area will be required for TPV to become a commercially viable technology. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
?Linear Gas Jet with Tailored Density Profile"
KRISHNAN, Mahadevan
2012-12-10T23:59:59.000Z
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.
Farrar, G.R.; Huleihel, K.; Zhang, H. (Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States))
1995-01-30T23:59:59.000Z
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.
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
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
Zhang, L.; Ding, B. J.; Li, M. H.; Kong, E. H.; Wei, W.; Liu, F. K.; Shan, J. F.; Wu, Z. G.; Zhu, L.; Ma, W. D.; Tong, Y. Y.; Li, Y. C.; Wang, M.; Zhao, L. M.; Hu, H. C.; Liu, L. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Collaboration: EAST Team
2013-06-15T23:59:59.000Z
A triple Langmuir probe is mounted on the top of the Lower Hybrid (LH) antenna to measure the electron density near the LH grills in Experimental Advanced Superconducting Tokamak. In this work, the LH power density ranges from 2.3 MWm{sup ?2} to 10.3 MWm{sup ?2} and the rate of puffing gas varies from 1.7 × 10{sup 20} el/s to 14 × 10{sup 20} el/s. The relation between the edge density (from 0.3 × n{sub e-cutoff} to 20 × n{sub e-cutoff}, where n{sub e-cutoff} is the cutoff density, n{sub e-cutoff} = 0.74 × 10{sup 17} m{sup ?3} for 2.45 GHz lower hybrid current drive) near the LH grill and the LH power reflection coefficients is investigated. The factors, including the gap between the LH grills and the last closed magnetic flux surface, line-averaged density, LH power, edge safety factor, and gas puffing, are analyzed. The experiments show that injection of LH power is beneficial for increasing edge density. Gas puffing is beneficial for increasing grill density but excess gas puffing is unfavorable for coupling and current drive.
Lower crustal density estimation using the density-slowness relationship: a preliminary study
Jones, Gary Wayne
1996-01-01T23:59:59.000Z
, and seismic velocity models were used to estimate the densities of th lower crustal rocks frcm the Wind River Mountains, the Ivrea Zone in Italy, and the average 1~ continental crustal model developed b/ ~istensen and Mconey [1995] . The. densities... by Carlson and Raskin [1984) yields a precision of about 1 percent. 'Ihe objective of this study is to evaluate this approach to estimate the density of the more complex continental crust, which is more variable in composition and affected hy a wider range...
Density equalizing map projections: A new algorithm
Merrill, D.W.; Selvin, S.; Mohr, M.S.
1992-02-01T23:59:59.000Z
In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst`s task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm.
Density equalizing map projections: A new algorithm
Merrill, D.W.; Selvin, S.; Mohr, M.S.
1992-02-01T23:59:59.000Z
In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst's task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm.
Ultra-high density diffraction grating
Padmore, Howard A.; Voronov, Dmytro L.; Cambie, Rossana; Yashchuk, Valeriy V.; Gullikson, Eric M.
2012-12-11T23:59:59.000Z
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.
Current density fluctuations and ambipolarity of transport
Shen, W.; Dexter, R.N.; Prager, S.C.
1991-10-01T23:59:59.000Z
The fluctuation in the plasma current density is measured in the MIST reversed field pinch experiment. Such fluctuations, and the measured radial profile of the k spectrum of magnetic fluctuations, supports the view and that low frequency fluctuations (f < 30 kHz) are tearing modes and high frequency fluctuations (30 kHz < f < 250 kHz) are localized turbulence in resonance with the local equilibrium magnetic field (i.e., k {center dot} B = 0). Correlation of current density and magnetic fluctuations (< {tilde j}{parallel}{tilde B}{sub r} >) demonstrates that radial particle transport from particle motion parallel to a fluctuating magnetic field is ambipolar over the full frequency range.
Current density fluctuations and ambipolarity of transport
Shen, W.; Dexter, R.N.; Prager, S.C.
1991-10-01T23:59:59.000Z
The fluctuation in the plasma current density is measured in the MIST reversed field pinch experiment. Such fluctuations, and the measured radial profile of the k spectrum of magnetic fluctuations, supports the view and that low frequency fluctuations (f < 30 kHz) are tearing modes and high frequency fluctuations (30 kHz < f < 250 kHz) are localized turbulence in resonance with the local equilibrium magnetic field (i.e., k {center_dot} B = 0). Correlation of current density and magnetic fluctuations (< {tilde j}{parallel}{tilde B}{sub r} >) demonstrates that radial particle transport from particle motion parallel to a fluctuating magnetic field is ambipolar over the full frequency range.
Ion Density Deviations in Semipermeable Ionic Microcapsules
Qiyun Tang; Alan R. Denton
2015-07-07T23:59:59.000Z
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.
Deuterium density profile determination at JET using a neutron camera and a neutron spectrometer
Eriksson, J., E-mail: jacob.eriksson@physics.uu.se; Castegnetti, G.; Conroy, S.; Ericsson, G.; Hellesen, C. [EURATOM-VR, Department of Physics and Astronomy, Uppsala University (Sweden); Giacomelli, L. [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); EURATOM-CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom)
2014-11-15T23:59:59.000Z
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.
Thermodynamics and Structural Properties of the High Density Gaussian Core Model
Atsushi Ikeda; Kunimasa Miyazaki
2011-07-20T23:59:59.000Z
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.
Fiber felts as low density structural materials
Milewski, J.V.; Newfield, S.E.
1981-01-01T23:59:59.000Z
Short fiber felts structures can be made which provide improvements in properties over foams. In applications where resistance to compression set or stress relaxation are important, bonded fiber felts excel due to the flexing of individual fibers within their elastic limit. Felts of stainless steel and polyester fibers were prepared by deposition from liquid slurries. Compressive properties were determined as a function of felt parent material, extent of bonding, felt density, and length-to-diameter (L/D) ratio of starting fibers.
Nuclear fission in covariant density functional theory
A. V. Afanasjev; H. Abusara; P. Ring
2013-09-12T23:59:59.000Z
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 trapping from Hagedorn densities of states
Connor Behan; Klaus Larjo; Nima Lashkari; Brian Swingle; Mark Van Raamsdonk
2013-04-26T23:59:59.000Z
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.
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.
2007-04-29T23:59:59.000Z
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.
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)
2008-01-01T23:59:59.000Z
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.
Tiled QR factorization algorithms
Bouwmeester, Henricus; Langou, Julien; Robert, Yves
2011-01-01T23:59:59.000Z
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.
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)
2012-07-01T23:59:59.000Z
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.
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)
2010-10-15T23:59:59.000Z
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.
2010-03-01T23:59:59.000Z
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.
Generalized Holographic Quantum Criticality at Finite Density
B. Goutéraux; E. Kiritsis
2013-01-23T23:59:59.000Z
We show that the near-extremal solutions of Einstein-Maxwell-Dilaton theories, studied in ArXiv:1005.4690, provide IR quantum critical geometries, by embedding classes of them in higher-dimensional AdS and Lifshitz solutions. This explains the scaling of their thermodynamic functions and their IR transport coefficients, the nature of their spectra, the Gubser bound, and regulates their singularities. We propose that these are the most general quantum critical IR asymptotics at finite density of EMD theories.
Method of high-density foil fabrication
Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.
2003-12-16T23:59:59.000Z
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.
Wigner density of a rigid rotator
Malta, C.P. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil)] [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil); Marshall, T.S. [Department of Mathematics, University of Manchester, Manchester M139PL (United Kingdom)] [Department of Mathematics, University of Manchester, Manchester M139PL (United Kingdom); Santos, E. [Departamento de Fisica Moderna, Universidad de Cantabria, 39005, Santander (Spain)] [Departamento de Fisica Moderna, Universidad de Cantabria, 39005, Santander (Spain)
1997-03-01T23:59:59.000Z
We show that the Wigner density of the rigid rotator, in an appropriate, i.e., four-dimensional, phase space, is positive. This result holds in the ground state (S state), and also in the thermal mixture state at all finite temperatures. We discuss the implications of our result for the description of angular momentum in quantum mechanics; in particular, we reexamine, in the light of this new evidence, the suggestion made by Einstein and Stern [Ann. Phys. {bold 40}, 551 (1913)] that there is a nontrivial distribution of angular momentum in the S state. {copyright} {ital 1997} {ital The American Physical Society}
Symmetry energy in nuclear density functional theory
W. Nazarewicz; P. -G. Reinhard; W. Satula; D. Vretenar
2013-07-22T23:59:59.000Z
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.
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
2014-10-30T23:59:59.000Z
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.
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)
2014-05-15T23:59:59.000Z
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.
Landau's necessary density conditions for LCA groups
Gröchenig, K; Seip, K
2008-01-01T23:59:59.000Z
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.
The density of states approach for the simulation of finite density quantum field theories
K. Langfeld; B. Lucini; A. Rago; R. Pellegrini; L. Bongiovanni
2015-03-02T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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...
Measuring the entanglement of analogue Hawking radiation by the density-density correlation function
Steinhauer, Jeff
2015-01-01T23:59:59.000Z
We theoretically study the entanglement of Hawking radiation emitted by an analogue black hole. We find that this entanglement can be measured by the experimentally accessible density-density correlation function, which only requires standard imaging techniques. It is seen that the high energy tail of the distribution of Hawking radiation should be entangled, whereas the low energy part is not. This confirms a previous numerical study. The full Peres-Horodecki criterion is considered, but a significant simplification is found in the stationary, homogeneous case. Our method applies to systems which are sufficiently cold that the thermal phonons can be neglected.
Attarian Shandiz, M., E-mail: mohammad.attarianshandiz@mail.mcgill.ca; Gauvin, R. [Department of Materials Engineering, McGill University, Montreal, Quebec H3A 0C5 (Canada)
2014-10-28T23:59:59.000Z
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.
Cosmological and astrophysical aspects of finite-density QCD
Dominik J. Schwarz
1998-07-23T23:59:59.000Z
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
2011-09-28T23:59:59.000Z
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.
Innovative fuel designs for high power density pressurized water reactor
Feng, Dandong, Ph. D. Massachusetts Institute of Technology
2006-01-01T23:59:59.000Z
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 ...
Constrained Density-Functional Theory--Configuration Interaction
Kaduk, Benjamin James
2012-01-01T23:59:59.000Z
In this thesis, I implemented a method for performing electronic structure calculations, "Constrained Density Functional Theory-- Configuration Interaction" (CDFT-CI), which builds upon the computational strengths of Density ...
Nonparametric Comparison of Densities Based on Statistical Bootstrap
Nonparametric Comparison of Densities Based on Statistical Bootstrap De Brabanter, K.1 , Sahhaf, S. Keywords: Statistical Bootstrap, Variance Stabilization, Least Squares Support Vector Machines, Hypothesis on statistical bootstrap with variance stabilization and a nonparametric kernel density estimator, assisting
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)
2014-05-15T23:59:59.000Z
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.
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
Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring
Gonsalves, Anthony
2012-01-01T23:59:59.000Z
38 fs. Laser and electron beam diagnostics Laser radiationdiagnostic provided charge density images of the electron beam
Competition between superconductivity and spin density wave
Tian De Cao
2012-08-25T23:59:59.000Z
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.
Band terminations in density functional theory
A. V. Afanasjev
2009-02-01T23:59:59.000Z
The analysis of the terminating bands has been performed in the relativistic mean field framework. It was shown that nuclear magnetism provides an additional binding to the energies of the specific configuration and this additional binding increases with spin and has its {\\it maximum} exactly at the terminating state. This suggests that the terminating states can be an interesting probe of the time-odd mean fields {\\it provided that other effects can be reliably isolated.} Unfortunately, a reliable isolation of these effects is not that simple: many terms of the density functional theories contribute into the energies of the terminating states and the deficiencies in the description of those terms affect the result. The recent suggestion \\cite{ZSW.05} that the relative energies of the terminating states in the $N \
High energy density redox flow device
Chiang, Yet-Ming; Carter, W. Craig; Ho, Bryan Y; Duduta, Mihai; Limthongkul, Pimpa
2014-05-13T23:59:59.000Z
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.
Marking Streets to Improve Parking Density
Xu, Chao
2015-01-01T23:59:59.000Z
Street parking spots for automobiles are a scarce commodity in most urban environments. The heterogeneity of car sizes makes it inefficient to rigidly define fixed-sized spots. Instead, unmarked streets in cities like New York leave placement decisions to individual drivers, who have no direct incentive to maximize street utilization. In this paper, we explore the effectiveness of two different behavioral interventions designed to encourage better parking, namely (1) educational campaigns to encourage parkers to "kiss the bumper" and reduce the distance between themselves and their neighbors, or (2) painting appropriately-spaced markings on the street and urging drivers to "hit the line". Through analysis and simulation, we establish that the greatest densities are achieved when lines are painted to create spots roughly twice the length of average-sized cars. Kiss-the-bumper campaigns are in principle more effective than hit-the-line for equal degrees of compliance, although we believe that the visual cues of...
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
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
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
PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES
PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES Beatrix Schunke JET Mercer St., New York NY 10012-1185 The temperature and density profiles of the Joint European Torus to determine which terms in the log-linear model to include. The density and temperature profiles
PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES
PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES Beatrix Schunke JET Mercer St., New York NY 100121185 Abstract The temperature and density profiles of the Joint European are used to determine which terms in the loglinear model to include. The density and temperature profiles
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)
2008-08-05T23:59:59.000Z
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.
Vaidyanathan, Vidya
2009-05-15T23:59:59.000Z
Predominance of small dense Low Density Lipoprotein (LDL) is associated with a two to threefold increase in risk for Coronary Heart Disease (CVD). Small, dense HDL (High Density Lipoprotein) particles protect small dense LDL from oxidative stress...
Filling factors and Braid group
Wellington Cruz
1998-02-25T23:59:59.000Z
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, $\
State densities and spectrum fluctuations: Information propagation in complex nuclei
French, J.B.; Kota, V.K.B.
1988-01-01T23:59:59.000Z
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.
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)
2002-12-01T23:59:59.000Z
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.
Shumack, A. E.; Schram, D. C.; Biesheuvel, J.; Goedheer, W. J.; Rooij, G. J. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein (Netherlands)
2011-03-15T23:59:59.000Z
Ion and neutral parameters are determined in the high electron density, magnetized, hydrogen plasma beam of an ITER divertor relevant plasma via measurements of the n=2 excited neutrals. Ion rotation velocity (up to 7 km/s) and temperature (2-3 eV{approx}T{sub e}) are obtained from analysis of H{alpha} spectra measured close to the plasma source. The methodology for neutral density determination is explained whereby measurements in the linear plasma beam of Pilot-PSI are compared to modeling. Ground-state atomic densities are obtained via the production rate of n=2 and the optical thickness of the Lyman-{alpha} transition (escape factor {approx}0.6) and yield an ionization degree >85% and dissociation degree in the residual gas of {approx}4%. A 30% proportion of molecules with a rovibrational excitation of more than 2 eV is deduced from the production rate of n=2 atoms. This proportion increases by more than a factor of 4 for a doubling of the electron density in the transition to ITER divertor relevant electron densities, probably because of a large increase in the production and confinement of ground-state neutrals. Measurements are made using laser-induced fluorescence (LIF) and absorption, the suitability of which are evaluated as diagnostics for this plasma regime. Absorption is found to have a much better sensitivity than LIF, mainly owing to competition with background emission.
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
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
Building a Universal Nuclear Energy Density Functional
Carlson, Joe A. [Michigan State University; Furnstahl, Dick; Horoi, Mihai; Lust, Rusty; Nazaewicc, Witek; Ng, Esmond; Thompson, Ian; Vary, James
2012-12-30T23:59:59.000Z
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.
Balanced homodyne detectors and Casimir energy densities
P. Marecki
2008-03-22T23:59:59.000Z
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.
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...
High energy density redox flow device
Chiang, Yet-Ming; Carter, William Craig; Duduta, Mihai; Limthongkul, Pimpa
2014-05-13T23:59:59.000Z
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.
Smooth Light Curves from a Bumpy Ride: Relativistic Blast Wave Encounters a Density Jump
Nakar, Ehud; /Caltech; Granot, Jonathan; /KIPAC, Menlo Park
2006-06-06T23:59:59.000Z
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.
Textured-surface quartz resonator fluid density and viscosity monitor
Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)
1998-08-25T23:59:59.000Z
A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.
The Quantum Energy Density: Improved Efficiency for Quantum Monte Carlo
Krogel, Jaron T; Kim, Jeongnim; Ceperley, David M
2013-01-01T23:59:59.000Z
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.
Electron density and carriers of the diffuse interstellar bands
P. Gnacinski; J. K. Sikorski; G. A. Galazutdinov
2007-02-07T23:59:59.000Z
We have used the ionisation equilibrium equation to derive the electron density in interstellar clouds in the direction to 13 stars. A linear relation was found, that allows the determination of the electron density from the Mg I and Mg II column densities in diffuse clouds. The comparison of normalised equivalent width of 12 DIBs with the electron density shows that the DIBs equivalent width do not change with electron density varying in the range ne=0.01-2.5 cm^-3. Therefore the DIBs carriers (1) can be observed only in one ionisation stage, or (2) the DIBs are arising in cloud regions (eg. cores or cloud coronas) for which we can not determine the electron density.
Model comparison for the density structure across solar coronal waveguides
Arregui, I; Ramos, A Asensio
2015-01-01T23:59:59.000Z
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...
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)
2001-01-01T23:59:59.000Z
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.
Nuclear symmetry energy at subnormal densities from measured nuclear masses
Min Liu; Ning Wang; Zhuxia Li; Fengshou Zhang
2010-11-17T23:59:59.000Z
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.
Crystallization of polyethylene by modified weighted density approximation(MWDA)
Razeghizadeh, Alireza; Lavafpour, Farhad
2015-01-01T23:59:59.000Z
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
2015-02-07T23:59:59.000Z
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.
High-Precision Thermodynamics and Hagedorn Density of States
Harvey B. Meyer
2009-05-26T23:59:59.000Z
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.
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
Effects of Phase Transition induced density fluctuations on pulsar dynamics
Bagchi, Partha; Layek, Biswanath; Srivastava, Ajit M
2015-01-01T23:59:59.000Z
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...
Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search OpenEI Reference LibraryAdd to...
Density-dependent acoustic properties of PBX 9502
Brown, Geoffrey W [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Hartline, Ernest L [Los Alamos National Laboratory; Hagelberg, Stephanie I [Los Alamos National Laboratory
2009-07-31T23:59:59.000Z
We have measured the longitudinal and shear acoustic velocities of PBX 9502 as a function of density for die-pressed samples over the range 1.795 g/cc to 1.888 g/cc. The density dependence of the velocities is linear. Thermal cycling of PBX 9502 is known to induce irreversible volume growth. We have measured this volume growth dependence on density for a subset of the pressed parts and find that the most growth occurs for the samples with lowest initial density. The acoustic velocity changes due to the volume growth are significant and reflect damage in the samples.
Polymer Electrolytes for High Energy Density Lithium Batteries
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Electrolytes for High Energy Density Lithium Batteries Ashoutosh Panday Scott Mullin Nitash Balsara Proposed Battery anode (Li metal) Li Li + + e - e - Li salt in a hard solid...
Density Functional Theory Studies of the Electronic Structure...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Theory Studies of the Electronic Structure of Solid State Actinide Oxides. Density Functional Theory Studies of the Electronic Structure of Solid State Actinide Oxides. Abstract:...
Distributions of Fourier modes of cosmological density fields
Fan, Z.; Bardeen, J.M. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)
1995-06-15T23:59:59.000Z
We discuss the probability distributions of Fourier modes of cosmological density fields using the central limit theorem is it applies to weighted integrals of random fields. It is shown that if the cosmological principle holds in a certain sense, i.e., the Universe approaches homogeneity and isotropy sufficiently rapidly on very large scales, the one-point distribution of each Fourier mode of the density field is Gaussian whether or not the density field itself is Gaussian. Therefore, one-point distributions of the power spectrum obtained from observational data or from simulations are not a good test of whether the density field is Gaussian.
Symmetry Lowering in Extreme-Electron-Density Perovskite Quantum Wells
Zhang, Jack Y.; Hwang, Jinwoo; Raghavan, Santosh; Stemmer, Susanne
2013-01-01T23:59:59.000Z
in Extreme-Electron-Density Perovskite Quantum Wells Jack Y.in the ideal cubic perovskite structure. The insulatingan orthorhombic distorted perovskite (space group Pnma [17])
Inexpensive Production of High Density Thin Ceramic Films on...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Inexpensive Production of High Density Thin Ceramic Films on Rigid or Porous Substrates Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing...
Factors Affecting Option Premium Values
Johnson, Jason; Smith, Jackie; Dhuyvetter, Kevin C.; Waller, Mark L.
1999-06-23T23:59:59.000Z
Factors Affecting Option Premium Values Jason Johnson, Jackie Smith, Kevin Dhuyvetter and Mark Waller* Put Options Hedging in the futures market with options is much like buying an insurance policy to protect commodity sellers against declining...
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
Risk factors for equine laminitis
Polzer, John Patrick
1995-01-01T23:59:59.000Z
logistic regression to assess age, breed, sex, and seasonality as risk factors for equine laminitis. There were 70 acute cases, 183 chronic cases, and 779 controls. No statistical association was found between age, breed, sex, or seasonality...
Electrical and Production Load Factors
Sen, Tapajyoti
2010-07-14T23:59:59.000Z
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...
Automatic Test Factoring for Java
Saff, David
2005-06-08T23:59:59.000Z
Test factoring creates fast, focused unit tests from slow system-widetests; each new unit test exercises only a subset of the functionalityexercised by the system test. Augmenting a test suite with factoredunit tests ...
Radiant-interchange configuration factors
Reddin, Thomas Edward
1965-01-01T23:59:59.000Z
an important role in any situation involving radiant interchange. The engineer desiring to compute the radiant heat transfer in a system is usually discouraged from performing more than a superficial estimation because of the excessive amount of time... Monitor System using the Fortran IV Compiler and the Macro Assembly Program. Listings of the programs appear in the appendices. CHAPTER II THE GEOMETRY OF THE BLACK BODY CONFIGURATION FACTOR 2. 1 Derivation of the Configuration Factor To evaluate...
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.
2010-01-01T23:59:59.000Z
x ORIGINAL ARTICLE Bone mineral density and fractures inwas associated with lower bone mineral density (BMD) at theKeywords Bone loss . Bone mineral density . Elderly .
Palacio Mizrahi, J. H. [Physics Department, Technion, Haifa 32000 (Israel)
2014-06-15T23:59:59.000Z
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.
Symmetry energy systematics and its high density behavior
Lie-Wen Chen
2015-06-30T23:59:59.000Z
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.
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)
2007-01-01T23:59:59.000Z
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.
Power-law tails in probability density functions of molecular cloud column density
Brunt, Chris
2015-01-01T23:59:59.000Z
Power-law tails are often seen in probability density functions (PDFs) of molecular cloud column densities, and have been attributed to the effect of gravity. We show that extinction PDFs of a sample of five molecular clouds obtained at a few tenths of a parsec resolution, probing extinctions up to A$_{{\\mathrm{V}}}$ $\\sim$ 10 magnitudes, are very well described by lognormal functions provided that the field selection is tightly constrained to the cold, molecular zone and that noise and foreground contamination are appropriately accounted for. In general, field selections that incorporate warm, diffuse material in addition to the cold, molecular material will display apparent core+tail PDFs. The apparent tail, however, is best understood as the high extinction part of a lognormal PDF arising from the cold, molecular part of the cloud. We also describe the effects of noise and foreground/background contamination on the PDF structure, and show that these can, if not appropriately accounted for, induce spurious ...
T. Thomas; P. Katgert
2005-10-10T23:59:59.000Z
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.
Junichi Takahashi; Junpei Sugano; Masahiro Ishii; Hiroaki Kouno; Masanobu Yahiro
2014-10-30T23:59:59.000Z
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.
Regulation of Xylella fastidiosa virulence factors by c-di-GMP phosphodiesterases
Ancona-Contreras, Veronica
2012-10-19T23:59:59.000Z
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...
On models of polydisperse sedimentation with particle-size-specific hindered-settling factors
Bürger, Raimund
On models of polydisperse sedimentation with particle-size-specific hindered-settling factors David in size or density that are dispersed in a viscous fluid. During sedimentation, the different particle Numerous engineering applications involve the sedimentation of small solid particles dispersed in a viscous
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
Evolution of particle density in high-energy pp collisions
I. Bautista; C. Pajares; J. Dias de Deus
2012-03-09T23:59:59.000Z
We study the evolution of the particle density, dn/d\\eta at fixed \\eta with the beam rapidity Y in the framework of string percolation model. Our main results are: (i) The width of the "plateau" increases proportionally to Y, (ii) limiting fragmentation is violated, and (iii) the particle density, reduces to a step function.
Kernel Density Based Linear Regression Estimate and Zhibiao Zhao
Zhao, Zhibiao
Kernel Density Based Linear Regression Estimate Weixin Yao and Zhibiao Zhao Abstract For linear regression models with non-normally distributed errors, the least squares estimate (LSE) will lose some words: EM algorithm, Kernel density estimate, Least squares estimate, Linear regression, Maximum
Locating a Recycling Center: The General Density Case Jannett Highfill
Mou, Libin
Locating a Recycling Center: The General Density Case Jannett Highfill Department of Economics) 677-3374. #12;2 Locating a Recycling Center: The General Density Case Abstract: The present paper considers a municipality that has a landfill (fixed in location) and plans to optimally locate a "recycling
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
Turbulence, Transport and the Density Limit in Magnetic Fusion Experiments
Greenwald, Martin
Turbulence, Transport and the Density Limit in Magnetic Fusion Experiments Martin Greenwald - MIT AND MAGNETIC CONFINEMENT· · · · THE DENSITY LIMIT PROBLEM INTERLUDE ON TRANSPORT AND TURBULENCE TOWARDS OF THE FUSION REACTION AND FOR ELASTIC SCATTERING LEAD US DIRECTLY TO THE STUDY OF CONFINED PLASMAS · · imes
Density functional theory for self-bound systems
Nir Barnea
2007-11-06T23:59:59.000Z
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.
Distributional Energy-Momentum Densities of Schwarzschild Space-Time
Toshiharu Kawai; Eisaku Sakane
1997-07-14T23:59:59.000Z
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^{\
Coded modulation with Low Density Parity Check codes
Narayanaswami, Ravi
2001-01-01T23:59:59.000Z
This thesis proposes the design of Low Density Parity Check (LDPC) codes for cases where coded modulation is used. We design these codes by extending the idea of Density Evolution (DE) that has been introduced as a powerful tool to analyze LDPC...
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
Observation of the density minimum in deeply supercooled confined water
Chen, Sow-Hsin
of SANS data allows us to determine the absolute value of the density of D2O as a function of temperature remarkable physical properties of liquid water (1), the density maximum is probably the most well known is considered to be the most accurate model for reproducing experimental data when used with a simple spherical
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 energy for creating defects in the polyethylene lattice as a function of the incident angle. We found
Expansion of X-ray form factor for close shell using uncorrelated wave function
AL-Robayi, Enas M. [Babylon University , College of Science for Women, laser Physics Department, Hilla (Iraq)
2013-12-16T23:59:59.000Z
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.
A Review of Electrochromic Window Performance Factors
Selkowitz Ed, S.E.
2010-01-01T23:59:59.000Z
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
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
Density Power Spectrum of Compressible Hydrodynamic Turbulent Flows
Jongsoo Kim; Dongsu Ryu
2005-07-26T23:59:59.000Z
Turbulent flows are ubiquitous in astrophysical environments, and understanding density structures and their statistics in turbulent media is of great importance in astrophysics. In this paper, we study the density power spectra, $P_{\\rho}$, of transonic and supersonic turbulent flows through one and three-dimensional simulations of driven, isothermal hydrodynamic turbulence with root-mean-square Mach number in the range of $1 \\la M_{\\rm rms} \\la 10$. From one-dimensional experiments we find that the slope of the density power spectra becomes gradually shallower as the rms Mach number increases. It is because the density distribution transforms from the profile with {\\it discontinuities} having $P_{\\rho} \\propto k^{-2}$ for $M_{\\rm rms} \\sim 1$ to the profile with {\\it peaks} having $P_{\\rho} \\propto k^0$ for $M_{\\rm rms} \\gg 1$. We also find that the same trend is carried to three-dimension; that is, the density power spectrum flattens as the Mach number increases. But the density power spectrum of the flow with $M_{\\rm rms} \\sim 1$ has the Kolmogorov slope. The flattening is the consequence of the dominant density structures of {\\it filaments} and {\\it sheets}. Observations have claimed different slopes of density power spectra for electron density and cold H I gas in the interstellar medium. We argue that while the Kolmogorov spectrum for electron density reflects the {\\it transonic} turbulence of $M_{\\rm rms} \\sim 1$ in the warm ionized medium, the shallower spectrum of cold H I gas reflects the {\\it supersonic} turbulence of $M_{\\rm rms} \\sim$ a few in the cold neutral medium.
Lee, Jui-Che; Lin, Shiang-Tai
2015-01-01T23:59:59.000Z
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...
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
2014-05-15T23:59:59.000Z
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.
Microslit Nod-shuffle Spectroscopy - a technique for achieving very high densities of spectra
Glazebrook, K; Glazebrook, Karl; Bland-Hawthorn, Joss
2000-01-01T23:59:59.000Z
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...
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)
2008-01-15T23:59:59.000Z
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.
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
How are mortality rates affected by population density?
Wang, Lei; Di, Zengru; Roehner, Bertrand M
2013-01-01T23:59:59.000Z
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)
2012-10-15T23:59:59.000Z
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.
Precision Cosmology and the Density of Baryons in the Universe
M. Kaplinghat; M. S. Turner
2000-11-14T23:59:59.000Z
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.
Symmetry energy at subnuclear densities deduced from nuclear masses
Kazuhiro Oyamatsu; Kei Iida
2010-04-19T23:59:59.000Z
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.
Nuclear Energy Density Functionals Constrained by Low-Energy QCD
Dario Vretenar
2008-02-06T23:59:59.000Z
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.
Measurements of electron density profiles using an angular filter refractometer
Haberberger, D., E-mail: dhab@lle.rochester.edu; Ivancic, S.; Hu, S. X.; Boni, R.; Barczys, M.; Craxton, R. S.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)
2014-05-15T23:59:59.000Z
A novel diagnostic technique, angular filter refractometry (AFR), has been developed to characterize high-density, long-scale-length plasmas relevant to high-energy-density physics experiments. AFR measures plasma densities up to 10{sup 21}?cm{sup ?3} with a 263-nm probe laser and is used to study the plasma expansion from CH foil and spherical targets that are irradiated with ?9?kJ of ultraviolet (351-nm) laser energy in a 2-ns pulse. The data elucidate the temporal evolution of the plasma profile for the CH planar targets and the dependence of the plasma profile on target radius for CH spheres.
2012-01-01T23:59:59.000Z
density profile of the inner 0.5 pc of the Milky Way nuclearold) stars in the central 0.5 pc of the Milky Way nucleara factor of 3 radially out to 0.5 pc from Sgr A* along the
Optimization Online - Integer Factorization is in P
Yuly Shipilevsky
2012-08-31T23:59:59.000Z
Aug 31, 2012 ... Integer Factorization is in P. Yuly Shipilevsky (yulysh2000 ***at*** yahoo.ca). Abstract: A polynomial-time algorithm for integer factorization, ...
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)
1999-11-01T23:59:59.000Z
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.
ccsd00002198, Asymmetric Silver to Oxide Adhesion in
on glass are widely used for at optical, photo- electric and electrochromic devices. Typical applications
Low density lipoprotein fraction assay for cardiac disease risk
Krauss, R.M.; Blanche, P.J.; Orr, J.
1999-07-20T23:59:59.000Z
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.
Nuclear Level Density: Shell Model vs Mean Field
Sen'kov, Roman
2015-01-01T23:59:59.000Z
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...
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
Magnetic moments of octet baryons at finite density and temperature
C. Y. Ryu; C. H. Hyun; M. -K. Cheoun
2010-08-12T23:59:59.000Z
We investigate the change of magnetic moments of octet baryons in nuclear matter at a finite density and temperature. Quark-meson coupling models are employed in describing properties of octet baryons and their interactions. Magnetic moments of octet baryons are found to increase non-negligibly as density and temperature increase, and we find that temperature dependence can be strongly correlated with the quark-hadron phase transition. Model dependence is also examined by comparing the results from the quark-meson coupling (QMC) model to those by the modified QMC (MQMC) model where the bag constant is assumed to depend on density. Both models predict sizable dependence on density and temperature, but the MQMC model shows a more drastic change of magnetic moments. Feasible changes of the nucleon mass by strong magnetic fields are also reported in the given models.
Paper area density measurement from forward transmitted scattered light
Koo, Jackson C. (San Ramon, CA)
2001-01-01T23:59:59.000Z
A method whereby the average paper fiber area density (weight per unit area) can be directly calculated from the intensity of transmitted, scattered light at two different wavelengths, one being a non-absorpted wavelength. Also, the method makes it possible to derive the water percentage per fiber area density from a two-wavelength measurement. In the optical measuring technique optical transmitted intensity, for example, at 2.1 microns cellulose absorption line is measured and compared with another scattered, optical transmitted intensity reference in the nearby spectrum region, such as 1.68 microns, where there is no absorption. From the ratio of these two intensities, one can calculate the scattering absorption coefficient at 2.1 microns. This absorption coefficient at this wavelength is, then, experimentally correlated to the paper fiber area density. The water percentage per fiber area density can be derived from this two-wavelength measurement approach.
The design of high power density annular fuel for LWRs
Yuan, Yi, 1975-
2004-01-01T23:59:59.000Z
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 ...
Probing Electron Dynamics with the Laplacian of the Momentum Density
Sukumar, N.; MacDougall, Preston J. [Middle Tennessee State University; Levit, M. Creon [Nasa Ames Research Center
2012-09-24T23:59:59.000Z
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.
A microwave interferometer for small and tenuous plasma density measurements
Tudisco, O.; Falcetta, C.; De Angelis, R.; Florean, M.; Neri, C.; Mazzotta, C.; Pollastrone, F.; Rocchi, G.; Tuccillo, A. A. [ENEA CR Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Lucca Fabris, A.; Manente, M.; Ferri, F.; Tasinato, L.; Trezzolani, F. [CISAS 'G.Colombo,' Universita degli studi di Padova, Via Venezia 15, 35131 Padova (Italy); Accatino, L. [ACC Antenna and MW tech, Via Trieste 16/B, 10098 Rivoli (Italy); Pavarin, D. [Dip. di Ingegneria Industriale (DII), Universita degli Studi di Padova, Via Venezia 1, 35131 Padova (Italy); Selmo, A. [RESIA, Studio Progettazione e Realizzazione di Apparati Elettronici, via Roma 17, 37041 Albaredo d'Adige (Italy)
2013-03-15T23:59:59.000Z
The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10{sup 16} m{sup -3} and 10{sup 19} m{sup -3}) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small ({lambda}= 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02 Degree-Sign has been used, corresponding to a density of 0.5 Multiplication-Sign 10{sup 16} m{sup -3}.
Quantum Control of Many-Body Systems by the Density
S. E. B. Nielsen; M. Ruggenthaler; R. van Leeuwen
2014-12-11T23:59:59.000Z
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.
Efficient Real-Time Time-Dependent Density Functional Theory...
Office of Scientific and Technical Information (OSTI)
Efficient Real-Time Time-Dependent Density Functional Theory Method and its Application to a Collision of an Ion with a 2D Material This content will become publicly available on...
Direct experimental determination of spectral densities of molecular complexes
Pachón, Leonardo A. [Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada); Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)
2014-11-07T23:59:59.000Z
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.
Direct Experimental Determination of Spectral Densities of Molecular Complexes
Leonardo A. Pachon; Paul Brumer
2014-10-15T23:59:59.000Z
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.
A novel density of state method for complex action systems
Biagio Lucini; Kurt Langfeld
2014-11-01T23:59:59.000Z
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.
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
2007-04-17T23:59:59.000Z
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.
Anomalous Density Properties and Ion Solvation in Liquid Water...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Anomalous Density Properties and Ion Solvation in Liquid Water: A Path-Integral Ab Initio Study PI Name: Robert A. DiStasio PI Email: distasio@princeton.edu Institution: Princeton...
An evolutionary fuel assembly design for high power density BWRs
Karahan, Aydin
2007-01-01T23:59:59.000Z
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 ...
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.)
2004-01-01T23:59:59.000Z
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.
Low density lipoprotein fraction assay for cardiac disease risk
Krauss, Ronald M. (Berkeley, CA); Blanche, Patricia J. (Berkeley, CA); Orr, Joseph (San Pablo, CA)
1999-01-01T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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...
Magnetic Fields in High-Density Stellar Matter
German Lugones
2005-04-20T23:59:59.000Z
I briefly review some aspects of the effect of magnetic fields in the high density regime relevant to neutron stars, focusing mainly on compact star structure and composition, superconductivity, combustion processes, and gamma ray bursts.
Aspects of the density field in an active nematic
Shradha Mishra; Sanjay Puri; Sriram Ramaswamy
2014-10-21T23:59:59.000Z
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.
Kernel density estimation of a multidimensional efficiency profile
Anton Poluektov
2014-11-20T23:59:59.000Z
Kernel density estimation is a convenient way to estimate the probability density of a distribution given the sample of data points. However, it has certain drawbacks: proper description of the density using narrow kernels needs large data samples, whereas if the kernel width is large, boundaries and narrow structures tend to be smeared. Here, an approach to correct for such effects, is proposed that uses an approximate density to describe narrow structures and boundaries. The approach is shown to be well suited for the description of the efficiency shape over a multidimensional phase space in a typical particle physics analysis. An example is given for the five-dimensional phase space of the $\\Lambda_b^0\\to D^0p\\pi$ decay.
Towards A Resolution Of The Vacuum Energy Density Crisis
R. L. Oldershaw
2010-10-21T23:59:59.000Z
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.
Negative vacuum energy densities and the causal diamond measure
Salem, Michael P. [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)
2009-07-15T23:59:59.000Z
Arguably a major success of the landscape picture is the prediction of a small, nonzero vacuum energy density. The details of this prediction depend in part on how the diverging spacetime volume of the multiverse is regulated, a question that remains unresolved. One proposal, the causal diamond measure, has demonstrated many phenomenological successes, including predicting a distribution of positive vacuum energy densities in good agreement with observation. In the string landscape, however, the vacuum energy density is expected to take positive and negative values. We find the causal diamond measure gives a poor fit to observation in such a landscape - in particular, 99.6% of observers in galaxies seemingly just like ours measure a vacuum energy density smaller than we do, most of them measuring it to be negative.
Does Cosmological Vacuum Energy Density have an Electric Reason ?
Claus W. Turtur
2004-03-11T23:59:59.000Z
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.
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 ...
Simulations of liquid ribidium expanded to the critical density
Ross, M; Yang, L H; Pilgrim, W
2006-05-16T23:59:59.000Z
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.
Non-invasive fluid density and viscosity measurement
Sinha, Dipen N. (Los Alamos, NM)
2012-05-01T23:59:59.000Z
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.
Preface: Special Topic on Advances in Density Functional Theory
Yang, Weitao [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)] [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)
2014-05-14T23:59:59.000Z
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.
Special generalized densities and propagators: a geometric account
Daniel Canarutto
2015-09-03T23:59:59.000Z
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.
Density dependence of symmetry free energy of hot nuclei
S. K. Samaddar; J. N. De; X. Vinas; M. Centelles
2008-09-04T23:59:59.000Z
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.
Energy propagation by transverse waves in multiple flux tube systems using filling factors
Van Doorsselaere, T.; Gijsen, S. E. [Centre for mathematical Plasma Astrophysics, Mathematics Department, KU Leuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Andries, J. [Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels (Belgium); Verth, G., E-mail: tom.vandoorsselaere@wis.kuleuven.be, E-mail: stief.gijsen@wis.kuleuven.be, E-mail: jesse.andries@oma.be, E-mail: g.verth@sheffield.ac.uk [Solar Physics and Space Plasma Research Centre (SP2RC), The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)
2014-11-01T23:59:59.000Z
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.
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)
2013-04-15T23:59:59.000Z
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.
Large-scale tidal fields on primordial density perturbations ?
Alejandro Gonzalez
1997-02-17T23:59:59.000Z
We calculate the strength of the tidal field produced by the large-scale density field acting on primordial density perturbations in power law models. By analysing changes in the orientation of the deformation tensor, resulted from smoothing the density field on different mass scales, we show that the large-scale tidal field can strongly affect the morphology and orientation of density peaks. The measure of the strength of the tidal field is performed as a function of the distance to the peak and of the spectral index. We detected evidence that two populations of perturbations seems to coexist; one, with a misalignment between the main axes of their inertia and deformation tensors. This would lead to the angular momentum acquisition and morphological changes. For the second population, the perturbations are found nearly aligned in the direction of the tidal field, which would imprint them low angular momentum and which would allow an alignment of structures as those reported between clusters of galaxies in filaments, and between galaxies in clusters. Evidence is presented that the correlation between the orientation of perturbations and the large-scale density field could be a common property of Gaussian density fields with spectral indexes $n < 0$. We argue that alignment of structures can be used to probe the flatness of the spectrum on large scales but it cannot determine the exact value of the spectral index.
Density Functional Resonance Theory of Unbound Electronic Systems
Daniel L. Whitenack; Adam Wasserman
2011-06-20T23:59:59.000Z
Density Functional Resonance Theory (DFRT) is a complex-scaled version of ground-state Density Functional Theory (DFT) that allows one to calculate the resonance energies and lifetimes of metastable anions. In this formalism, the exact energy and lifetime of the lowest-energy resonance of unbound systems is encoded into a complex "density" that can be obtained via complex-coordinate scaling. This complex density is used as the primary variable in a DFRT calculation just as the ground-state density would be used as the primary variable in DFT. As in DFT, there exists a mapping of the N-electron interacting system to a Kohn-Sham system of N non-interacting particles in DFRT. This mapping facilitates self consistent calculations with an initial guess for the complex density, as illustrated with an exactly-solvable model system. Whereas DFRT yields in principle the exact resonance energy and lifetime of the interacting system, we find that neglecting the complex-correlation contribution leads to errors of similar magnitude to those of standard scattering close-coupling calculations under the bound-state approximation.
Densities and energies of nuclei in dilute matter
P. Papakonstantinou; J. Margueron; F. Gulminelli; Ad. R. Raduta
2013-05-01T23:59:59.000Z
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.
Testing gravity with halo density profiles observed through gravitational lensing
Narikawa, Tatsuya; Yamamoto, Kazuhiro, E-mail: narikawa@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)
2012-05-01T23:59:59.000Z
We present a new test of the modified gravity endowed with the Vainshtein mechanism with the density profile of a galaxy cluster halo observed through gravitational lensing. A scalar degree of freedom in the galileon modified gravity is screened by the Vainshtein mechanism to recover Newtonian gravity in high-density regions, however it might not be completely hidden on the outer side of a cluster of galaxies. Then the modified gravity might yield an observational signature in a surface mass density of a cluster of galaxies measured through gravitational lensing, since the scalar field could contribute to the lensing potential. We investigate how the transition in the Vainshtein mechanism affects the surface mass density observed through gravitational lensing, assuming that the density profile of a cluster of galaxies follows the original Navarro-Frenk-White (NFW) profile, the generalized NFW profile and the Einasto profile. We compare the theoretical predictions with observational results of the surface mass density reported recently by other researchers. We obtain constraints on the amplitude and the typical scale of the transition in the Vainshtein mechanism in a subclass of the generalized galileon model.
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)
2013-07-01T23:59:59.000Z
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)
On Factorization of Molecular Wavefunctions
Thierry Jecko; Brian T. Sutcliffe; R. Guy Woolley
2015-07-18T23:59:59.000Z
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
2015-09-05T23:59:59.000Z
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.
Hausdorff dimension and filling factor
Wellington Cruz
1998-02-25T23:59:59.000Z
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.
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
Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry
Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Rother, Gernot [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Wallacher, Dirk [Helmholtz-Zentrum Berlin
2012-01-01T23:59:59.000Z
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.
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)
2012-05-21T23:59:59.000Z
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.
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)
2013-10-01T23:59:59.000Z
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.
Rethinking the N(H2)/I(CO) Conversion Factor
W. F. Wall
2007-03-01T23:59:59.000Z
An improved formulation for the X-factor is proposed. The statement that the velocity-integrated radiation temperature of the $\\COone$ line, $I(\\CO)$, ``counts'' optically thick clumps is quantified using the formalism of \\citet{Martin84} for line emission in a clumpy cloud. Adopting the simplifying assumptions of thermalized $\\COone$ line emission and isothermal gas, an effective optical depth, $\\tef$, is defined as the product of the clump filling factor within each velocity interval and the clump effective optical depth as a function of the optical depth on the clump's central sightline, $\\tau_0$. The clump effective optical depth is well approximated as a power law in $\\tau_0$ with power-law index, $\\epsilon$, referred to here as the clump ``fluffiness,'' and has values between zero and unity. While the $\\COone$ line is optically thick within each clump (i.e., high $\\tau_0$), it is optically thin ``to the clumps'' (i.e., low $\\tef$). Thus the dependence of $I(CO)$ on $\\tef$ is linear, resulting in an X-factor that depends only on clump properties and {\\it not} directly on the entire cloud. Assuming virialization of the clumps yields an expression for the X-factor whose dependence on physical parameters like density and temperature is ``softened'' by power-law indices of less than unity that depend on the fluffiness parameter, $\\epsilon$. The X-factor provides estimates of gas column density because each sightline within the beam has optically thin gas within certain narrow velocity ranges. Determining column density from the optically thin gas is straightforward and parameters like $\\epsilon$ then allow extrapolation of the column density of the optically thin gas to that of all the gas.
An analysis of factors contributing to train-involved crashes
Cooner, Scott Allen
1995-01-01T23:59:59.000Z
analyzed for the contributing factors. The contributing factors were classified into four categories: railroad factors, environmental factors, roadway factors, and driver/passenger factors. The accident data was analyzed using one and two-way classification...
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))
1990-11-01T23:59:59.000Z
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
2008-09-08T23:59:59.000Z
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.
Cosmic density and velocity fields in Lagrangian perturbation theory
Mikel Susperregi; Thomas Buchert
1997-08-04T23:59:59.000Z
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.
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)
2010-03-01T23:59:59.000Z
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.
Fayer, Michael D.
(CO2) as a function of density from low density (well below the critical density) to high density ethane, carbon dioxide, and fluoroform as a function of density at two temperatures are presented of input information on the SCF properties obtained from the fluids' equations of state and other tabulated
Kempes, Christopher P; Dooris, William; West, Geoffrey B
2015-01-01T23:59:59.000Z
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...
Qiang Zhao; Jian Min Dong; Jun Ling Song; Wen Hui Long
2014-07-23T23:59:59.000Z
Half-life of proton radioactivity of spherical proton emitters is studied within the scheme of covariant density functional (CDF) theory, and for the first time the potential barrier that prevents the emitted proton is extracted with the similarity renormalization group (SRG) method, in which the spin-orbit potential along with the others that turn out to be non-negligible can be derived automatically. The spectroscopic factor that is significant is also extracted from the CDF calculations. The estimated half-lives are found in good agreement with the experimental values, which not only confirms the validity of the CDF theory in describing the proton-rich nuclei, but also indicates the prediction power of present approach to calculate the half-lives and in turn to extract the structural information of proton emitters.
Nonlinear relationships between individual IEQ factors and overall workspace satisfaction
Kim, Jungsoo; de Dear, Richard
2011-01-01T23:59:59.000Z
in dissatisfaction. So for Bonus Factors, the absolute valuemarketing literature), (2) Bonus Factors (synonyms include “for occupants’ satisfaction. Bonus Factors: Bonus Factors go
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)
2011-12-21T23:59:59.000Z
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.
Density waves in the shearing sheet III. Disc heating
B. Fuchs
2001-04-25T23:59:59.000Z
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.
Addressing spectroscopic quality of covariant density functional theory
A. V. Afanasjev
2014-09-17T23:59:59.000Z
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.
Magnetic confinement of a high-density cylindrical plasma
Ahedo, Eduardo [E. T. S. Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)
2011-10-15T23:59:59.000Z
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.
Ducted kinetic Alfven waves in plasma with steep density gradients
Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)
2011-11-15T23:59:59.000Z
Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.
Background Oriented Schlieren in a Density Stratified Fluid
Verso, Lilly
2015-01-01T23:59:59.000Z
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.
Thermodynamics of the low density excluded volume hadron gas
Zalewski, Kacper
2015-01-01T23:59:59.000Z
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...
Thermodynamics of the low density excluded volume hadron gas
Kacper Zalewski; Krzysztof Redlich
2015-07-20T23:59:59.000Z
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.
Relativistic density functional theory for finite nuclei and neutron stars
J. Piekarewicz
2015-02-05T23:59:59.000Z
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.
The dependence of natural graphite anode performance on electrode density
Shim, Joongpyo; Striebel, Kathryn A.
2003-11-01T23:59:59.000Z
The effect of electrode density for lithium intercalation and irreversible capacity loss on the natural graphite anode in lithium ion batteries was studied by electrochemical methods. Both the first-cycle reversible and irreversible capacities of the natural graphite anode decreased with an increase in the anode density though compression. The reduction in reversible capacity was attributed to a reduction in the chemical diffusion coefficient for lithium though partially agglomerated particles with a larger stress. For the natural graphite in this study the potentials for Li (de)insertion shifted between the first and second formation cycles and the extent of this shift was dependent on electrode density. The relation between this peak shift and the irreversible capacity loss are probably both due to the decrease in graphite surface area with compression.
Pion Superfluidity and Meson Properties at Finite Isospin Density
Lianyi He; Meng Jin; Pengfei Zhuang
2009-09-27T23:59:59.000Z
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.
Stable laser–plasma accelerators at low densities
Li, Song; Hafz, Nasr A. M., E-mail: nasr@sjtu.edu.cn; Mirzaie, Mohammad; Ge, Xulei; Sokollik, Thomas; Chen, Min; Sheng, Zhengming; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)
2014-07-28T23:59:59.000Z
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.
Dissecting Soft Radiation with Factorization
Iain W. Stewart; Frank J. Tackmann; Wouter J. Waalewijn
2015-02-10T23:59:59.000Z
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.
Microslit Nod-shuffle Spectroscopy - a technique for achieving very high densities of spectra
Karl Glazebrook; Joss Bland-Hawthorn
2000-11-04T23:59:59.000Z
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.
Uniform electron gases: III. Low-density gases on three-dimensional spheres
Agboola, Davids; Gill, Peter M W; Loos, Pierre-François
2015-01-01T23:59:59.000Z
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 ...
High density electronic circuit and process for making
Morgan, W.P.
1999-06-29T23:59:59.000Z
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.
High density electronic circuit and process for making
Morgan, William P. (Albuquerque, NM)
1999-01-01T23:59:59.000Z
High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits. 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.
Holographic energy density in the Brans-Dicke teory
Hungsoo Kim; H. W. Lee; Y. S. Myung
2005-01-15T23:59:59.000Z
We study cosmological applications of the holographic energy density. Considering the holographic energy density as a dynamical cosmological constant, we need the Brans-Dicke theory as a dynamical framework instead of general relativity. In this case we use the Bianchi identity as a consistency relation to obtain physical solutions. It is shown that the future event horizon as the IR cutoff provides the dark energy in the Brans-Dicke theory. Furthermore the role of the Brans-Dicke scalar is clarified in the dark energy-dominated universe by calculating its equation of state.
Energy Density of Vortices in the Schroedinger Picture
J. D. Laenge; M. Engelhardt; H. Reinhardt
2003-01-31T23:59:59.000Z
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.
Enhanced residual entropy in high-density nanoconfined bilayer ice
Fabiano Corsetti; Jon Zubeltzu; Emilio Artacho
2015-06-15T23:59:59.000Z
A novel kind of crystal order in high-density nanoconfined bilayer ice is proposed from molecular dynamics and density-functional theory simulations. A first-order transition is observed between a low-temperature proton-ordered solid and a high-temperature proton-disordered solid. The latter is shown to possess crystalline order for the oxygen positions, arranged on a close-packed triangular lattice with AA stacking. Uniquely amongst the ice phases, the triangular bilayer is characterized by two levels of disorder (for the bonding network and for the protons) which results in a residual entropy twice that of bulk ice.
Systematics of nucleon density distributions and neutron skin of nuclei
Seif, W M
2015-01-01T23:59:59.000Z
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 Nuclear Matter in Heavy Ion Collisions
Qin, Lijun
2010-01-14T23:59:59.000Z
the nuclear and astrophysical context [32, 33, 34, 35, 36]. In the latter, knowledge of specific heats and the density de- pendence of the symmetry energy are crucial to understanding collapse of supernovae 8 Fig. 3. Density dependence of the symmetry energy... predicated by various interactions. and the properties of neutron stars resulting from supernova collapse [37, 38, 39, 40]. A great e?ort has been made to explore the symmetry energy in di?erent ways in many di?erent works [41, 42, 43, 44, 45]. The strength...
Density functional theory and optimal transportation with Coulomb cost
Codina Cotar; Gero Friesecke; Claudia Klüppelberg
2011-04-04T23:59:59.000Z
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.
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)
1989-01-01T23:59:59.000Z
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.
Transition density and pressure in hot neutron stars
Xu, Jun; Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An.
2010-01-01T23:59:59.000Z
- ton fraction in a newly formed neutron star immediately after gravitational collapse of a massive star [20?22], neutrinos are abundantly produced from the Urca process in its inner core. Although high-energy neutrinos can be trapped at densities... densities, can be expressed as [8,11] V (?, ?) = Au(x)?n?p ?0 + Al(x) 2?0 ( ?2n + ? 2 p ) + B ? + 1 ??+1 ??0 (1? x?2) + 1 ?0 ? ?,? ? C?,? ? ?? d3pd3p? f? (#3;r, #3;p)f? ?(#3;r ?, #3;p?) 1+ ( #3;p ? #3;p?)2/#6;2 . (1...
Low density microcellular carbon foams and method of preparation
Arnold, C. Jr.; Aubert, J.H.; Clough, R.L.; Rand, P.B.; Sylwester, A.P.
1988-06-20T23:59:59.000Z
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.
Temperature Power Law of Equilibrium Heavy Particle Density
Sh. Matsumoto; M. Yoshimura
1999-10-19T23:59:59.000Z
A standard calculation of the energy density of heavy stable particles that may pair-annihilate into light particles making up thermal medium is performed to second order of coupling, using the technique of thermal field theory. At very low temperatures a power law of temperature is derived for the energy density of the heavy particle. This is in sharp contrast to the exponentially suppressed contribution estimated from the ideal gas distribution function. The result supports a previous dynamical calculation based on the Hartree approximation, and implies that the relic abundance of dark matter particles is enhanced compared to that based on the Boltzmann equation.
Ion Density Deviations in Polyelectrolyte Microcapsules: Influence on Biosensors
Qiyun Tang; Alan R. Denton
2014-10-24T23:59:59.000Z
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
2014-12-12T23:59:59.000Z
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.
Chandan Mondal; Dipankar Chakrabarti
2015-06-17T23:59:59.000Z
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.
Yan, Zhong
2013-01-01T23:59:59.000Z
the development of high-power density semiconductor devices.Management of High-Power Density Electronics A DissertationManagement of High-Power Density Electronics by Zhong Yan
Automatic measurement of propositional idea density from part-of-speech tagging
Brown, Cati; Snodgrass, Tony; Kemper, Susan; Herman, Ruth; Covington, Michael A.
2008-05-01T23:59:59.000Z
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...
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.
2004-01-01T23:59:59.000Z
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-
Factors for Bioenergy Market Development
Roos, A.; Hektor, B.; Graham, R.L.; Rakos, C.
1998-10-04T23:59:59.000Z
Focusing on the development of the whole bioenergy market rather than isolated projects, this paper contributes to the identification of barriers and drivers behind bioenergy technology implementation. It presents a framework for the assessment of the potentials for bioenergy market growth to be used by decision makers in administration and industry. The conclusions are based on case studies of operating bioenergy markets in Austria, US and Sweden. Six important factors for bioenergy market growth have been identified: (1) Integration with other business, e.g. for biomass procurement, (2) Scale effects of bioenergy market, (3) Competition on bioenergy market, (4) Competition with other business, (5) National policy, (6) Local policy and local opinion. Different applications of the framework are discussed.
Industrial Equipment Demand and Duty Factors
Dooley, E. S.; Heffington, W. M.
1998-01-01T23:59:59.000Z
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 compressors were near 100...
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.
2014-03-05T23:59:59.000Z
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.
Guidelines for Power Factor Improvement Projects
Massey, G. W.
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...
Common risk factors in bank stocks
Viale, Ariel Marcelo
2007-09-17T23:59:59.000Z
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...
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)
2011-05-23T23:59:59.000Z
We address the possibility in factorization proofs that low-energy collinear gluons can couple to soft gluons.
Synthetic Nano-Low Density Lipoprotein as Targeted Drug Delivery Vehicle for Glioblastoma Multiforme
Nikanjam, Mina; Blakely, Eleanor A.; Bjornstad, Kathleen A.; Shu, Xiao; Budinger, Thomas F.; Forte, Trudy M.
2006-01-01T23:59:59.000Z
Synthetic Nano-Low Density Lipoprotein as Targeted Drugmicroemulsion; peptide; nano-low density lipoproteintherapeutic agents. A synthetic nano-LDL (nLDL) particle was
The Impact of Residential Density on Vehicle Usage and Energy Consumption
Golob, Thomas F.; Brownstone, David
2005-01-01T23:59:59.000Z
residential transportation energy usage is vital for theDensity on Vehicle Usage and Energy Consumption Table 2Density on Vehicle Usage and Energy Consumption with
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
Model Predictive Control of Variable Density Multiphase Flows Governed by
Hinze, Michael
of model predictive control (MPC) consists in steering or keeping the state of a dynamical systemModel Predictive Control of Variable Density Multiphase Flows Governed by Diffuse Interface Models appearing in the model predictive control strategy. The resulting control concept is known as instantaneous
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
Density inhomogeneity driven electrostatic shock waves in planetary rings
Masood, W.; Siddiq, M. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P. O. Nilore, Islamabad 44000 (Pakistan); National Center for Physics (NCP), Islamabad 44000 (Pakistan); Rizvi, H.; Haque, Q. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P. O. Nilore, Islamabad 44000 (Pakistan); Hasnain, H. [NILOP, P. O. Nilore, Islamabad 44000 (Pakistan); PIEAS, P. O. Nilore, Islamabad 44000 (Pakistan)
2011-05-15T23:59:59.000Z
Dust inertia and background density driven dust drift shock waves are theoretically studied in a rotating planetary environment and are subsequently applied to the planetary rings where the collisional effects are pronounced. It has been found that the system under consideration admits significant shock formation if the collision frequency is of the order of or less than the rotational frequency of the Saturn's rings.
Author's Accepted Manuscript ORBIT-CENTERED ATMOSPHERIC DENSITY
Wohlberg, Brendt
density measurements or estimates on a given orbit and a set of proxies for solar and geomagnetic solar and geomagnetic activities and different prediction windows. Compar- ison with previously (LEO) contain the majority of artificial sa- tellites currently in operation. At LEO below 700 km
Low Density Nuclear Matter in Heavy Ion Collisions
Qin, Lijun
2010-01-14T23:59:59.000Z
this effort and broaden the density range over which the symmetry energies are experimentally determined we have now carried out a series of experiments in which the reactions of 112Sn and 124Sn with projectiles, ranging from 4He,10B, 20Ne, 40Ar to 64Zn, all...
Method to reduce dislocation density in silicon using stress
Buonassisi, Anthony; Bertoni, Mariana; Argon, Ali; Castellanos, Sergio; Fecych, Alexandria; Powell, Douglas; Vogl, Michelle
2013-03-05T23:59:59.000Z
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.
Evaluation of Tweedie exponential dispersion model densities by Fourier inversion
Smyth, Gordon K.
and Computing University of Southern Queensland Toowoomba Queensland 4350 Australia Gordon K. Smyth Bioinformatics Division Walter and Eliza Hall Institute of Medical Research Melbourne, Vic 3050, Australia August with power variance functions V (µ) = µp for p (0, 1). These distri- butions do not generally have density
Calibrating Speed-Density Functions for ff SMesoscopic Traffic Simulation
Bertini, Robert L.
. (1999), Tavana & Mahmassani (2000), Wang & Papageorgiou (2005), Antoniou et al. (2007) #12;Case Studies) supply #12;Case Studies (contd.) · DynaMIT speed-density function form · Performance measures ( )= - S i pointsdataofnumber speed)(count,simulated : : S iy #12;Case Studies (contd.) · Methodology Large
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 influ- enced the compounding quality of woodpolymer blends and finally affected the interfacial bonding strength and flexural modulus of the resultant composites. With 50 wt % wood fiber, the optimum compounding
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
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
Meson phase space density in heavy ion collisions from interferometry
Bertsch, G.F. (Department of Physics and Institute for Nuclear Theory, FM-15, University of Washington, Seattle, Washington 98195 (United States))
1994-04-11T23:59:59.000Z
The interferometric analysis of meson correlations provides a measure of the average phase space density of the mesons in the final state. This quantity is a useful indicator of the statistical properties of the system, and it can be extracted with a minimum of model assumptions. Values obtained from recent measurements are consistent with the thermal value, but do not rule out superradiance effects.
Computing spectral densities in finite temperature field theory
Jeon, S. (Physics Department FM-15, University of Washington, Seattle, Washington 98195 (United States))
1993-05-15T23:59:59.000Z
Convenient Cutkosky-like diagrammatic rules for computing the spectral densities of arbitrary two-point correlation functions in finite temperature field theory are derived. The approach is based on an explicit analytic continuation of imaginary-time Feynman diagrams. The application of this method to the perturbative evaluation of transport coefficients is briefly discussed.
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
Film cooling on a flat plate: investigating density
Grizzle, Joshua Peter Fletcher
2009-05-15T23:59:59.000Z
This study is an investigation of two specific effects on turbine blade film cooling. The effect of coolant to mainstream density ratio and upstream steps was studied. The studies were conducted on two flat plates with 4mm cylindrical film cooling...
Wood-Fiber/High-Density-Polyethylene Composites: Coupling Agent Performance
Wood-Fiber/High-Density-Polyethylene Composites: Coupling Agent Performance John Z. Lu,1 Qinglin Wu structure. As a coupling agent, mal- eated polyethylene (MAPE) had a better performance in WPC than oxidized polyethylene (OPE) and pure polyeth- ylene (PPE) because of its stronger interfacial bonding. A combination
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
Constraints on power spectrum of density fluctuations from PBH evaporations
Edgar Bugaev; Peter Klimai
2006-12-21T23:59:59.000Z
We calculate neutrino and photon energy spectra in extragalactic space from evaporation of primordial black holes, assuming that the power spectrum of primordial density fluctuations has a strong bump in the region of small scales. The constraints on the parameters of this bump based on neutrino and photon cosmic background data are obtained.
Spectral density of generalized Wishart matrices and free multiplicative convolution
Wojciech Mlotkowski; Maciej A. Nowak; Karol A. Penson; Karol Zyczkowski
2015-02-28T23:59:59.000Z
We investigate level density for several ensembles of positive random matrices of a Wishart--like structure, $W=XX^{\\dagger}$, where $X$ stands for a nonhermitian random matrix. In particular, making use of the Cauchy transform we study free multiplicative powers of the Marchenko-Pastur (MP) distribution, ${\\rm MP}^{\\boxtimes s}$, which for an integer $s$ yield Fuss-Catalan distributions corresponding to a product of $s$ independent square random matrices, $X=X_1\\cdots X_s$. Known formulae for the level densities are rederived in the case $s=2$ and $s=1/2$ and explicit distributions are obtained for $s=3$ and $s=1/3$. Moreover, the level density generated by a product of two rectangular random matrices $X=X_1 X_2$ is obtained and the generalized Bures distribution given by the free convolution of arcsine and MP distributions is derived. The technique proposed here allows us to obtain level densities for several related cases.
Terrace housing : providing quality in higher-density housing
Atthakor, Songpol
1992-01-01T23:59:59.000Z
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 ...
High energy density lithium-oxygen secondary battery
Sammells, A.F.
1989-02-07T23:59:59.000Z
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.
Nuclear Level Density: Shell Model vs Mean Field
Roman Sen'kov; Vladimir Zelevinsky
2015-08-15T23:59:59.000Z
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.
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
Improved association in a classical density functional theory for water
Eric J. Krebs; Jeff B. Schulte; David Roundy
2013-09-07T23:59:59.000Z
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.
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
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)
2014-10-15T23:59:59.000Z
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.
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
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
Note on Integer Factoring Algorithms II
N. A. Carella
2007-02-08T23:59:59.000Z
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.
Walls, Joel; Taner, M. Turhan; Dvorkin, Jack
2006-08-08T23:59:59.000Z
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.
Fabrication and evaluation of uniform and gradient density epoxies
Domeier, L.A.; Skala, D.M.; Goods, S.H. [and others
1997-11-01T23:59:59.000Z
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
2002-01-08T23:59:59.000Z
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.
Xiaohu Wang; Abraham Loeb; Eli Waxman
2002-12-22T23:59:59.000Z
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.
The static structure factor of amorphous silicon and vitreous silica
Adam M. R. de Graff; M. F. Thorpe
2009-09-14T23:59:59.000Z
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.
High Efficiency m-plane LEDs on Low Defect Density Bulk GaN Substrates
David, Aurelien
2012-10-15T23:59:59.000Z
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.
QCD Viscosity to Entropy Density Ratio in the Hadronic Phase
Jiunn-Wei Chen; Yen-Han Li; Yen-Fu Liu; Eiji Nakano
2007-04-20T23:59:59.000Z
Shear viscosity (eta) of QCD in the hadronic phase is computed by the coupled Boltzmann equations of pions and nucleons in low temperatures and low baryon number densities. The eta to entropy density ratio eta/s maps out the nuclear gas-liquid phase transition by forming a valley tracing the phase transition line in the temperature-chemical potential plane. When the phase transition turns into a crossover, the eta/s valley gradually disappears. We suspect the general feature for a first-order phase transition is that eta/s has a discontinuity in the bottom of the eta/s valley. The discontinuity coincides with the phase transition line and ends at the critical point. Beyond the critical point, a smooth eta/s valley is seen. However, the valley could disappear further away from the critical point. The eta/s measurements might provide an alternative to identify the critical points.
Subsystem real-time Time Dependent Density Functional Theory
Krishtal, Alisa; Pavanello, Michele
2015-01-01T23:59:59.000Z
We present the extension of Frozen Density Embedding (FDE) theory to real-time Time Dependent Density Functional Theory (rt-TDDFT). FDE a is DFT-in-DFT embedding method that allows to partition a larger Kohn-Sham system into a set of smaller, coupled Kohn-Sham systems. Additional to the computational advantage, FDE provides physical insight into the properties of embedded systems and the coupling interactions between them. The extension to rt-TDDFT is done straightforwardly by evolving the Kohn-Sham subsystems in time simultaneously, while updating the embedding potential between the systems at every time step. Two main applications are presented: the explicit excitation energy transfer in real time between subsystems is demonstrated for the case of the Na$_4$ cluster and the effect of the embedding on optical spectra of coupled chromophores. In particular, the importance of including the full dynamic response in the embedding potential is demonstrated.
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
1998-06-01T23:59:59.000Z
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 [University of Texas at Austin; Fredrickson, Kurt [University of Texas at Austin; Posadas, Agham B. [University of Texas at Austin; Ren, Yuan [University of Texas at Austin; Vasudevan, Rama K [ORNL; Okatan, Mahmut Baris [ORNL; Jesse, Stephen [ORNL; Aoki, Toshihiro [Arizona State University; McCartney, Martha [Arizona State University; Smith, David J [Arizona State University; Kalinin, Sergei V [ORNL; Lai, Keji [University of Texas at Austin; Demkov, Alexander A. [University of Texas at Austin
2015-01-01T23:59:59.000Z
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.
Density waves in the shearing sheet I. Swing amplification
B. Fuchs
2001-03-02T23:59:59.000Z
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.
Role of density dependent symmetry energy in nuclear stopping
Karan Singh Vinayak; Suneel Kumar
2011-07-27T23:59:59.000Z
Information about the nuclear matter under the extreme conditions of temperature and density and the role of symmetry energy under these conditions is still a topic of crucial importance in the present day nuclear physics research. The multifragmentation, collective flow and the nuclear stopping is among the various rare phenomenon which can be observed in heavy-ion collisions at intermediate energies. The nuclear stopping, which is sensitive towards the symmetry energy has gained a lot of interest because it provides the possibility to examine the degree of thermalization or equilibration in the matter. Aim of the present study is to pin down the nuclear stopping for the different forms of density dependent symmetry energy
Relativistic Coulomb excitation within Time Dependent Superfluid Local Density Approximation
I. Stetcu; C. Bertulani; A. Bulgac; P. Magierski; K. J. Roche
2015-01-13T23:59:59.000Z
Within the framework of the unrestricted time-dependent density functional theory, we present for the first time an analysis of the relativistic Coulomb excitation of the heavy deformed open shell nucleus $^{238}$U. The approach is based on Superfluid Local Density Approximation (SLDA) formulated on a spatial lattice that can take into account coupling to the continuum, enabling self-consistent studies of superfluid dynamics of any nuclear shape. We have computed the energy deposited in the target nucleus as a function of the impact parameter, finding it to be significantly larger than the estimate using the Goldhaber-Teller model. The isovector giant dipole resonance, the dipole pygmy resonance and giant quadrupole modes were excited during the process. The one body dissipation of collective dipole modes is shown to lead a damping width $\\Gamma_\\downarrow \\approx 0.4$ MeV and the number of pre-equilibrium neutrons emitted has been quantified.
Method of measuring reactive acoustic power density in a fluid
Wheatley, J.C.; Swift, G.W.; Migliori, A.
1985-09-03T23:59:59.000Z
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. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)
1985-01-01T23:59:59.000Z
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.
Limits to the power density of very large wind farms
Nishino, Takafumi
2013-01-01T23:59:59.000Z
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 $U_{F0}$.
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
2012-12-04T23:59:59.000Z
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.
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 [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein, Uthrecht 3430BE (Netherlands); Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein, Uthrecht 3430BE (NL) and Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)
2007-03-19T23:59:59.000Z
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.
Universal iso-density polarizable continuum model for molecular solvents
Gunceler, Deniz
2014-01-01T23:59:59.000Z
Implicit electron-density solvation models based on joint density-functional theory offer a computationally efficient solution to the problem of calculating thermodynamic quantities of solvated systems from first-principles quantum mechanics. However, despite much recent interest in such models, to date the applicability of such models to non-aqueous solvents has been limited because the determination of the model parameters requires fitting to a large database of experimental solvation energies for each new solvent considered. This work presents an alternate approach which allows development of new solvation models for a large class of protic and aprotic solvents from only simple, single-molecule ab initio calculations and readily available bulk thermodynamic data. We find that this model is accurate to nearly 1.7 kcal/mol even for solvents outside our development set.
A Tale of Two Electrons: Correlation at High Density
Loos, Pierre-François
2010-01-01T23:59:59.000Z
We review our recent progress in the determination of the high-density correlation energy $\\Ec$ in two-electron systems. Several two-electron systems are considered, such as the well known helium-like ions (helium), and the Hooke's law atom (hookium). We also present results regarding two electrons on the surface of a sphere (spherium), and two electrons trapped in a spherical box (ballium). We also show that, in the large-dimension limit, the high-density correlation energy of two opposite-spin electrons interacting {\\em via} a Coulomb potential is given by $\\Ec \\sim -1/(8D^2)$ for any radial external potential $V(r)$, where $D$ is the dimensionality of the space. This result explains the similarity of $\\Ec$ in the previous two-electron systems for $D=3$.
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
2012-03-20T23:59:59.000Z
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.
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
2014-11-28T23:59:59.000Z
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.
1996-03-19T23:59:59.000Z
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.
Ultra-low density microcellular polymer foam and method
Simandl, Ronald F. (Farragut, TN); Brown, John D. (Harriman, TN)
1996-01-01T23:59:59.000Z
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
ALICE collaboration; K. Aamodt; B. Abelev; A. Abrahantes Quintana; D. Adamová; A. M. Adare; M. M. Aggarwal; G. Aglieri Rinella; A. G. Agocs; S. Aguilar Salazar; Z. Ahammed; A. Ahmad Masoodi; N. Ahmad; S. U. Ahn; A. Akindinov; D. Aleksandrov; B. Alessandro; R. Alfaro Molina; A. Alici; A. Alkin; E. Almaráz Aviña; T. Alt; V. Altini; S. Altinpinar; I. Altsybeev; C. Andrei; A. Andronic; V. Anguelov; C. Anson; T. Anti\\vci?; F. Antinori; P. Antonioli; L. Aphecetche; H. Appelshäuser; N. Arbor; S. Arcelli; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Äystö; M. D. Azmi; M. Bach; A. Badalà; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; R. Baldini Ferroli; A. Baldisseri; A. Baldit; F. Baltasar Dos Santos Pedrosa; J. Bán; R. Barbera; F. Barile; G. G. Barnaföldi; L. S. Barnby; V. Barret; J. Bartke; M. Basile; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; H. Beck; I. Belikov; F. Bellini; R. Bellwied; E. Belmont-Moreno; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; C. Bergmann; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Biel\\vcík; J. Biel\\vc\\'\\iková; A. Bilandzic; E. Biolcati; A. Blanc; F. Blanco; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. B\\oggild; M. Bogolyubsky; L. Boldizsár; M. Bombara; C. Bombonati; J. Book; H. Borel; A. Borissov; C. Bortolin; S. Bose; F. Bossú; M. Botje; S. Böttger; B. Boyer; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; M. Broz; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; K. Bugaiev; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. Calvo Villar; P. Camerini; V. Canoa Roman; G. Cara Romeo; F. Carena; W. Carena; F. Carminati; A. Casanova D\\'\\iaz; M. Caselle; J. Castillo Castellanos; V. Catanescu; C. Cavicchioli; J. Cepila; P. Cerello; B. Chang; S. Chapeland; J. L. Charvet; S. Chattopadhyay; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. Chibante Barroso; D. D. Chinellato; P. Chochula; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; F. Coccetti; J. -P. Coffin; S. Coli; G. Conesa Balbastre; Z. Conesa del Valle; P. Constantin; G. Contin; J. G. Contreras; T. M. Cormier; Y. Corrales Morales; I. Cortés Maldonado; P. Cortese; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; G. D Erasmo; A. Dainese; H. H. Dalsgaard; A. Danu; D. Das; I. Das; K. Das; A. Dash; S. Dash; S. De; A. De Azevedo Moregula; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; D. De Gruttola; N. De Marco; S. De Pasquale; R. De Remigis; R. de Rooij; P. R. Debski; E. Del Castillo Sanchez; H. Delagrange; Y. Delgado Mercado; G. Dellacasa; A. Deloff; V. Demanov; E. Dénes; A. Deppman; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; T. Dietel; R. Divià; Ø. Djuvsland; A. Dobrin; T. Dobrowolski; I. Dom\\'\\inguez; B. Dönigus; O. Dordic; O. Driga; A. K. Dubey; J. Dubuisson; L. Ducroux; P. Dupieux; A. K. Dutta Majumdar; M. R. Dutta Majumdar; D. Elia; D. Emschermann; H. Engel; H. A. Erdal; B. Espagnon; M. Estienne; S. Esumi; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; G. Feofilov; A. Fernández Téllez; A. Ferretti; R. Ferretti; J. Figiel; M. A. S. Figueredo; S. Filchagin; R. Fini; D. Finogeev; F. M. Fionda; E. M. Fiore; M. Floris; S. Foertsch; P. Foka; S. Fokin; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; U. Fuchs; F. Furano; C. Furget; M. Fusco Girard; J. J. Gaardh\\oje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; D. R. Gangadharan; P. Ganoti; M. S. Ganti; C. Garabatos; E. Garcia-Solis; I. Garishvili; R. Gemme; J. Gerhard; M. Germain; C. Geuna; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; P. Gianotti; M. R. Girard; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; P. Glässel; R. Gomez; E. G. Ferreiro; H. González Santos; L. H. González-Trueba; P. González-Zamora; S. Gorbunov; S. Gotovac; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; S. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. -Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. Guerra Gutierrez; B. Guerzoni; K. Gulbrandsen; T. Gunji; A. Gupta; R. Gupta; H. Gutbrod; Ø. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. W. Harris; M. Hartig; D. Hasch; D. Hasegan; D. Hatzifotiadou; A. Hayrapetyan; M. Heide; M. Heinz; H. Helstrup; A. Herghelegiu; C. Hernández; G. Herrera Corral; N. Herrmann; K. F. Hetland; B. Hicks; P. T. Hille; B. Hippolyte; T. Horaguchi; Y. Hori; P. Hristov; I. H\\vrivná\\vcová
2011-02-04T23:59:59.000Z
The first measurement of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at a centre-of-mass energy per nucleon pair sqrt(sNN) = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section the pseudo-rapidity density of primary charged particles at mid-rapidity is 1584 +- 4 (stat) +- 76 (sys.), which corresponds to 8.3 +- 0.4 (sys.) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at sqrt(sNN) = 0.2 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.
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
2013-01-01T23:59:59.000Z
index that corresponds to increased vascu- lar density [32]. DOSI scanning is performed without compression
Measuring the Density Fluctuation From the Cluster Gas Mass Function
Kazuhiro Shimasaku
1997-01-27T23:59:59.000Z
We investigate the gas mass function of clusters of galaxies to measure the density fluctuation spectrum on cluster scales. The baryon abundance confined in rich clusters is computed from the gas mass function and compared with the mean baryon density in the universe which is predicted by the Big Bang Nucleosynthesis. This baryon fraction and the slope of the gas mass function put constraints on $\\sigma_8$, the rms linear fluctuation on scales of $8h^{-1}\\Mpc$, and the slope of the fluctuation spectrum, where $h$ is the Hubble constant in units of 100 $\\kms \\oMpc$. We find $\\sigma_8 = 0.80 \\pm 0.15$ and $n \\sim -1.5$ for $0.5 \\le h \\le 0.8$, where we assume that the density spectrum is approximated by a power law on cluster scales: $\\sigma(r) \\propto r^{-{3+n\\over{2}}}$. Our value of $\\sigma_8$ is independent of the density parameter, $\\Omega_0$, and thus we can estimate $\\Omega_0$ by combining $\\sigma_8$ obtained in this study with those from $\\Omega_0$-dependent analyses to date. We find that $\\sigma_8(\\Omega_0)$ derived from the cluster abundance such as the temperature function gives $\\Omega_0 \\sim 0.5$ while $\\sigma_8(\\Omega_0)$ measured from the peculiar velocity field of galaxies gives $\\Omega_0 \\sim 0.2-1$, depending on the technique used to analyze peculiar velocity data. Constraints are also derived for open, spatially flat, and tilted Cold Dark Matter models and for Cold + Hot Dark Matter models.
Method and apparatus for measuring lung density by Compton backscattering
Loo, Billy W. (Oakland, CA); Goulding, Frederick S. (Lafayette, CA)
1991-01-01T23:59:59.000Z
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.
Binding Energies in Benzene Dimers: Nonlocal Density Functional Calculations
Aaron Puzder; Maxime Dion; David C. Langreth
2005-09-15T23:59:59.000Z
The interaction energy and minimum energy structure for different geometries of the benzene dimer has been calculated using the recently developed nonlocal correlation energy functional for calculating dispersion interactions. The comparison of this straightforward and relatively quick density functional based method with recent calculations can elucidate how the former, quicker method might be exploited in larger more complicated biological, organic, aromatic, and even infinite systems such as molecules physisorbed on surfaces, and van der Waals crystals.
Method and apparatus for measuring lung density by Compton backscattering
Loo, B.W.; Goulding, F.S.
1988-03-11T23:59:59.000Z
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 back-scattered 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 minimize systematic errors due to the presence of the chestwall and multiple scattering. 11 figs., 1 tab.
Mining the local Universe: the QSO space density
S. Cristiani; A. Grazian; A. Omizzolo; C. Corbally
2000-10-27T23:59:59.000Z
We present progress results of a new survey for bright QSOs (V30. The surface density of QSOs brighter than B_J=14.8 turns out to be 2.9 +- 0.8 10^{-3} deg^{-2}. The optical Luminosity Function at 0.04 < z < 0.3 shows significant departures from the standard pure luminosity evolution, providing new insights in the modelling of the QSO phenomenon.
Transverse momentum dependent quark densities from Lattice QCD
Bernhard Musch,Philipp Hagler,John Negele,Andreas Schafer
2011-02-01T23:59:59.000Z
We study transverse momentum dependent parton distribution functions (TMDs) with non-local operators in lattice QCD, using MILC/LHPC lattices. Results obtained with a simpli?ed operator geometry show visible dipole de- formations of spin-dependent quark momentum densities. We discuss the basic concepts of the method, including renormalization of the gauge link, and an ex- tension to a more elaborate operator geometry that would allow us to analyze process-dependent TMDs such as the Sivers-function.
Mineral density volume gradients in normal and diseased human tissues
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.; Aikawa, Elena
2015-04-09T23:59:59.000Z
Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore »fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less
The Nuclear Equation of State at high densities
Christian Fuchs
2006-10-10T23:59:59.000Z
Ab inito calculations for the nuclear many-body problem make predictions for the density and isospin dependence of the nuclear equation-of-state (EOS) far away from the saturation point of nuclear matter. I compare predictions from microscopic and phenomenological approaches. Constraints on the EOS derived from heavy ion reactions, in particular from subthreshold kaon production, as well as constraints from neutron stars are discussed.
Conductivity Recovery from One Component of the Current Density
Carlos Montalto
2014-08-02T23:59:59.000Z
We prove global injectivity and H\\"older stability in the reconstruction of an isotopic conductivity in the electrostatic approximation of Maxwell's equations, from the information of one voltage at the boundary and one (well chosen) component of the current density. We study the full and partial data problem. We work under the assumption that the voltage potential has no critical points inside the domain.
Frontiers for Discovery in High Energy Density Physics
Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.
2004-07-20T23:59:59.000Z
The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics
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)
2014-07-21T23:59:59.000Z
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
2008-03-04T23:59:59.000Z
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.
1987-05-26T23:59:59.000Z
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.
Mikheyev-Smirnov-Wolfenstein Effect for Linear Electron Density
Harry Lehmann; Per Osland; Tai Tsun Wu
2000-06-19T23:59:59.000Z
When the electron density is a linear function of distance, it is known that the MSW equations for two neutrino species can be solved in terms of known functions. It is shown here that more generally, for any number of neutrino species, these MSW equations can be solved exactly in terms of single integrals. While these integrals cannot be expressed in terms of known functions, some of their simple properties are obtained. Application to the solar neutrino problem is briefly discussed.
Luminosity Density Evolution in the Universe and Cosmological Parameters
Tomonori Totani
1997-10-28T23:59:59.000Z
Star formation history in galaxies is strongly correlated to their present-day colors and the Hubble sequence can be considered as a sequence of different star formation history. Therefore we can model the cosmic star formation history based on the colors of local galaxies, and comparison to direct observations of luminosity density evolution at high redshift gives a new test for the cosmological parameters which is insensitive to merger history of galaxies. The luminosity density evolution in $0$ 0.53 at 95%CL) is strongly favored. The cosmic star formation rate (SFR) at $z>2$ is also compared to the latest data of the Hubble Deep Field including new data which were not incorporated in the previous work of Totani, Yoshii, & Sato (1997), and our model of the luminosity density of spiral galaxies taking account of gas infall is consistent with the observations. Starbursts in elliptical galaxies, which are expected from the galactic wind model, however overproduce SFRs and hence they should be formed at $z \\gtilde 5$ or their UV emission has to be hidden by dust extinction. The amound of metals in galactic winds and escaping ionizing photons are enough to contaminate the Ly$\\alpha$ forests or to reionize the universe.
Terrestrial Planet Formation in Disks with Varying Surface Density Profiles
Sean N. Raymond; Thomas Quinn; Jonathan I. Lunine
2005-06-30T23:59:59.000Z
The ``minimum-mass solar nebula'' (MMSN) model estimates the surface density distribution of the protoplanetary disk by assuming the planets to have formed in situ. However, significant radial migration of the giant planets likely occurred in the Solar system, implying a distortion in the values derived by the MMSN method. The true density profiles of protoplanetary disks is therefore uncertain. Here we present results of simulations of late-stage terrestrial accretion, each starting from a disk of planetary embryos. We assume a power-law surface density profile that varies with heliocentric distance r as r^-alpha, and vary alpha between 1/2 and 5/2 (alpha = 3/2 for the MMSN model). We find that for steeper profiles (higher values of alpha), the terrestrial planets (i) are more numerous, (ii) form more quickly, (iii) form closer to the star, (iv) are more massive, (v) have higher iron contents, and (vi) have lower water contents. However, the possibility of forming potentially habitable planets does not appear to vary strongly with alpha.
EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT
Flach, G.
2012-02-27T23:59:59.000Z
The concept of an effective porosity is widely used in solute transport modeling to account for the presence of a fraction of the medium that effectively does not influence solute migration, apart from taking up space. This non-participating volume or ineffective porosity plays the same role as the gas phase in single-phase liquid unsaturated transport: it increases pore velocity, which is useful towards reproducing observed solute travel times. The prevalent use of the effective porosity concept is reflected by its prominent inclusion in popular texts, e.g., de Marsily (1986), Fetter (1988, 1993) and Zheng and Bennett (2002). The purpose of this commentary is to point out that proper application of the concept for sorbing solutes requires more than simply reducing porosity while leaving other material properties unchanged. More specifically, effective porosity implies the corresponding need for an effective bulk density in a conventional single-porosity model. The reason is that the designated non-participating volume is composed of both solid and fluid phases, both of which must be neglected for consistency. Said another way, if solute does not enter the ineffective porosity then it also cannot contact the adjoining solid. Conceptually neglecting the fluid portion of the non-participating volume leads to a lower (effective) porosity. Likewise, discarding the solid portion of the non-participating volume inherently leads to a lower or effective bulk density. In the author's experience, practitioners virtually never adjust bulk density when adopting the effective porosity approach.
Constraints on the density perturbation spectrum from primordial black holes
Anne M Green; Andrew R Liddle
1997-04-25T23:59:59.000Z
We re-examine the constraints on the density perturbation spectrum, including its spectral index $n$, from the production of primordial black holes. The standard cosmology, where the Universe is radiation dominated from the end of inflation up until the recent past, was studied by Carr, Gilbert and Lidsey; we correct two errors in their derivation and find a significantly stronger constraint than they did, $n \\lesssim 1.25$ rather than their 1.5. We then consider an alternative cosmology in which a second period of inflation, known as thermal inflation and designed to solve additional relic over-density problems, occurs at a lower energy scale than the main inflationary period. In that case, the constraint weakens to $n \\lesssim 1.3$, and thermal inflation also leads to a `missing mass' range, $10^{18} g \\lesssim M \\lesssim 10^{26} g$, in which primordial black holes cannot form. Finally, we discuss the effect of allowing for the expected non-gaussianity in the density perturbations predicted by Bullock and Primack, which can weaken the constraints further by up to 0.05.
Complex saddle points in QCD at finite temperature and density
Hiromichi Nishimura; Michael C. Ogilvie; Kamal Pangeni
2014-08-12T23:59:59.000Z
The sign problem in QCD at finite temperature and density leads naturally to the consideration of complex saddle points of the action or effective action. The global symmetry $\\mathcal{CK}$ of the finite-density action, where $\\mathcal{C}$ is charge conjugation and $\\mathcal{K}$ is complex conjugation, constrains the eigenvalues of the Polyakov loop operator $P$ at a saddle point in such a way that the action is real at a saddle point, and net color charge is zero. The values of $Tr_{F}P$ and $Tr_{F}P^{\\dagger}$ at the saddle point, are real but not identical, indicating the different free energy cost associated with inserting a heavy quark versus an antiquark into the system. At such complex saddle points, the mass matrix associated with Polyakov loops may have complex eigenvalues, reflecting oscillatory behavior in color-charge densities. We illustrate these properties with a simple model which includes the one-loop contribution of gluons and massless quarks moving in a constant Polyakov loop background. Confinement-deconfinement effects are modeled phenomenologically via an added potential term depending on the Polyakov loop eigenvalues. For sufficiently large $T$ and $\\mu$, the results obtained reduce to those of perturbation theory at the complex saddle point. These results may be experimentally relevant for the CBM experiment at FAIR.
Silylation 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.)
2004-01-01T23:59:59.000Z
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, and cometary dust capture agents. However, aerogels are notoriously weak and brittle making it difficult to handle and machine monoliths into desired forms. This complication prevents the development of many applications that would otherwise benefit from the use of the low-density materials. Here, 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 organic-bridged polysilsesquioxane aerogels were prepared by sol-gel polymerization of the respective methoxysilane monomers followed by supercritical carbon dioxide drying of the gels. Then the gels were reactively modified with silylating agents to demonstrate the viability of CVD modification of aerogels, and to determine the effects of silylation of surface silanols on the morphology, surface area, and mechanical properties of the resulting aerogels.
Penetration and scattering of lower hybrid waves by density fluctuations
Horton, W. [Institute for Fusion Studies, University of Texas at Austin (United States); Goniche, M.; Peysson, Y.; Decker, J.; Ekedahl, A.; Litaudon, X. [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France)
2014-02-12T23:59:59.000Z
Lower Hybrid [LH] ray propagation in toroidal plasma is controlled by a combination of the azimuthal spectrum launched from the antenna, the poloidal variation of the magnetic field, and the scattering of the waves by the density fluctuations. The width of the poloidal and radial RF wave spectrum increases rapidly as the rays penetrate into higher density and scatter from the turbulence. The electron temperature gradient [ETG] spectrum is particularly effective in scattering the LH waves due to its comparable wavelengths and parallel phase velocities. ETG turbulence is also driven by the radial gradient of the electron current density giving rise to an anomalous viscosity spreading the LH-driven plasma currents. The scattered LH spectrum is derived from a Fokker-Planck equation for the distribution of the ray trajectories with a diffusivity proportional to the fluctuations. The LH ray diffusivity is large giving transport in the poloidal and radial wavenumber spectrum in one - or a few passes - of the rays through the core plasma.
Protostellar fragmentation in a power-law density distribution
A. Burkert; M. Bate; P. Bodenheimer
1997-06-10T23:59:59.000Z
Hydrodynamical calculations in three space dimensions of the collapse of an isothermal, rotating 1 M\\sol protostellar cloud are presented. The initial density stratification is a power law with density $\\rho \\propto r^{-p}$, with $p=1$. The case of the singular isothermal sphere ($p=2$) is not considered; however $p=1$ has been shown observationally to be a good representation of the density distribution in molecular cloud cores just before the beginning of collapse. The collapse is studied with two independent numerical methods, an SPH code with 200,000 particles, and a finite-difference code with nested grids which give high spatial resolution in the inner regions. Although previous numerical studies have indicated that such a power-law distribution would not result in fragmentation into a binary system, both codes show, in contrast, that multiple fragmentation does occur in the central regions of the protostar. Thus the process of binary formation by fragmentation is shown to be consistent with the fact that a large fraction of young stars are observed to be in binary or multiple systems.
Rapid model building of ?-helices in electron-density maps
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2010-03-01T23:59:59.000Z
A method for rapid model building of ?-helices at moderate resolution is presented. A method for the identification of ?-helices in electron-density maps at low resolution followed by interpretation at moderate to high resolution is presented. Rapid identification is achieved at low resolution, where ?-helices appear as tubes of density. The positioning and direction of the ?-helices is obtained at moderate to high resolution, where the positions of side chains can be seen. The method was tested on a set of 42 experimental electron-density maps at resolutions ranging from 1.5 to 3.8 Å. An average of 63% of the ?-helical residues in these proteins were built and an average of 76% of the residues built matched helical residues in the refined models of the proteins. The overall average r.m.s.d. between main-chain atoms in the modeled ?-helices and the nearest atom with the same name in the refined models of the proteins was 1.3 Å.
Chapter 7: High-Density H-Mode Operation in ASDEX Upgrade
Stober, Joerg Karl; Lang, Peter Thomas; Mertens, Vitus [Max-Planck-Institut fuer Plasmaphysik (Germany)
2003-11-15T23:59:59.000Z
Recent results are reported on the maximum achievable H-mode density and the behavior of pedestal density and central density peaking as this limit is approached. The maximum achievable H-mode density roughly scales as the Greenwald density, though a dependence on B{sub t} is clearly observed. In contrast to the stiff temperature profiles, the density profiles seem to allow more shape variation and especially with high-field-side pellet-injection, strongly peaked profiles with good confinement have been achieved. Also, spontaneous density peaking at high densities is observed in ASDEX Upgrade, which is related to the generally observed large time constants for the density profile equilibration. The equilibrated density profile shapes depend strongly on the heat-flux profile in the sense that central heating leads to significantly flatter profiles.
Predicting the cosmological constant with the scale-factor cutoff measure
De Simone, Andrea; Guth, Alan H. [Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Salem, Michael P.; Vilenkin, Alexander [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)
2008-09-15T23:59:59.000Z
It is well known that anthropic selection from a landscape with a flat prior distribution of cosmological constant {lambda} gives a reasonable fit to observation. However, a realistic model of the multiverse has a physical volume that diverges with time, and the predicted distribution of {lambda} depends on how the spacetime volume is regulated. A very promising method of regulation uses a scale-factor cutoff, which avoids a number of serious problems that arise in other approaches. In particular, the scale-factor cutoff avoids the 'youngness problem' (high probability of living in a much younger universe) and the 'Q and G catastrophes' (high probability for the primordial density contrast Q and gravitational constant G to have extremely large or small values). We apply the scale-factor cutoff measure to the probability distribution of {lambda}, considering both positive and negative values. The results are in good agreement with observation. In particular, the scale-factor cutoff strongly suppresses the probability for values of {lambda} that are more than about 10 times the observed value. We also discuss qualitatively the prediction for the density parameter {omega}, indicating that with this measure there is a possibility of detectable negative curvature.
The Column Density Distribution of the Lyman-Alpha Forest: A Measure of Small Scale Power
Lam Hui; Nickolay Y. Gnedin; Yu Zhang
1997-02-19T23:59:59.000Z
Absorption lines in the Lyman-alpha forest can be thought of as peaks in neutral hydrogen density along lines of sight. The column density distribution (the number density of absorption lines as a function of column density) is then a statistic of density peaks, which contains information about the underlying power spectrum. In particular, we show that the slope of the distribution provides a measure of power on scales smaller than those probed by studies of present-day large scale structure.
L. B. Bhuiyan; D. Henderson; S. Soko?owski
2012-07-13T23:59:59.000Z
A recently proposed local second contact value theorem [Henderson D., Boda D., J. Electroanal. Chem., 2005, 582, 16] for the charge profile of an electric double layer is used in conjunction with the existing Monte Carlo data from the literature to assess the contact behavior of the electrode-ion distributions predicted by the density functional theory. The results for the contact values of the co- and counterion distributions and their product are obtained for the symmetric valency, restricted primitive model planar double layer for a range of electrolyte concentrations and temperatures. Overall, the theoretical results satisfy the second contact value theorem reasonably well, the agreement with the simulations being semi-quantitative or better. The product of the co- and counterion contact values as a function of the electrode surface charge density is qualitative with the simulations with increasing deviations at higher concentrations.
Synthetic heparin-binding growth factor analogs
Pena, Louis A.; Zamora, Paul; Lin, Xinhua; Glass, John D.
2007-01-23T23:59:59.000Z
The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain that binds a heparin-binding growth factor receptor, covalently bound to a hydrophobic linker, which is in turn covalently bound to a non-signaling peptide that includes a heparin-binding domain. The synthetic heparin-binding growth factor analogs are useful as soluble biologics or as surface coatings for medical devices.
Paris-Sud XI, Université de
.006-1.210 g/ml were separated by density gradient ultracentrifugation into 25 fractions. Their respective apo-I and apo B. Gradient distributions of apo A-I (d 1.046-1.180 g/ml; max at d 1.080 g/ml) and apo B (d 1: Intestinal Lipid and Lipoprotein Metabolism (Windler E, Greten H, eds), W Zuckschwerdt Verlag, Munchen, 50
Emerging alternatives to the impact factor
Banks, Marcus A.; Dellavalle, Robert
2008-01-01T23:59:59.000Z
abs/0709.0896. 12. Public Library of Science Medicineimpact factor game,” Public Library of Science Medicine Voljournals published by the Public Library of Science, follows
Factorization for hadronic heavy quarkonium production
Jian-Wei Qiu
2006-10-31T23:59:59.000Z
We briefly review several models of heavy quarkonium production in hadronic collisions, and discuss the status of QCD factorization for these production models.
Vitiligo: A good prognostic factor in melanoma?
Cunha, Daniela; Pacheco, Fernando Assis; Cardoso, Jorge
2009-01-01T23:59:59.000Z
with intermediate to thick melanomas (>1 mm) with the use ofgood prognostic factor in melanoma? Daniela Cunha, Fernandoimmunologic therapy for melanoma is generally regarded as a
Lower bounds for approximate factorizations via semidefinite ...
ABSTRACT The problem of approximately factoring a real or complex multivariate polynomial f seeks minimal perturbations ? f to the coefficients of the input ...
M. Oettel; S. Goerig; A. Haertel; H. Loewen; M. Radu; T. Schilling
2010-09-03T23:59:59.000Z
We perform a comparative study of the free energies and the density distributions in hard sphere crystals using Monte Carlo simulations and density functional theory (employing Fundamental Measure functionals). Using a recently introduced technique (Schilling and Schmid, J. Chem. Phys 131, 231102 (2009)) we obtain crystal free energies to a high precision. The free energies from Fundamental Measure theory are in good agreement with the simulation results and demonstrate the applicability of these functionals to the treatment of other problems involving crystallization. The agreement between FMT and simulations on the level of the free energies is also reflected in the density distributions around single lattice sites. Overall, the peak widths and anisotropy signs for different lattice directions agree, however, it is found that Fundamental Measure theory gives slightly narrower peaks with more anisotropy than seen in the simulations. Among the three types of Fundamental Measure functionals studied, only the White Bear II functional (Hansen-Goos and Roth, J. Phys.: Condens. Matter 18, 8413 (2006)) exhibits sensible results for the equilibrium vacancy concentration and a physical behavior of the chemical potential in crystals constrained by a fixed vacancy concentration.
Chen, Sheng-Wei
Timed Nuclear Import of a Transcription Factor During Erythropoiesis Erythroid Krüppel-like factor. The regulatory mechanisms of the nuclear transport of EKLF during erythroid differentiation have remained unclear provided essential new insights into this process. They show that nuclear import of EKLF in erythroid cells
Dalitz plot studies of D0 --> K0S pi+ pi- decays in a factorization approach
J. -P. Dedonder; R. Kaminski; L. Lesniak; B. Loiseau
2014-09-23T23:59:59.000Z
The presently available high-statistics data of the D0 --> K0S pi+ pi- processes measured by the Belle and BABAR Collaborations are analyzed within a quasi two-body QCD factorization framework. Starting from the weak effective Hamiltonian, tree and annihilation amplitudes build up the D0 --> K0S pi+ pi- decay amplitude. Two of the three final-state mesons are assumed to form a single scalar, vector or tensor state originating from a quark-antiquark pair so that the factorization hypothesis can be applied. The meson-meson final state interactions are described by K pi and pi pi scalar and vector form factors for the S and P waves and by relativistic Breit-Wigner formulae for the D waves. A combined chi^2 fit to a Belle Dalitz plot density distribution, to the total experimental branching fraction and to the tau^- --> K0S pi- nu_tau decay data is carried out to fix the 33 free parameters. These are mainly related to the strengths of the scalar form factors and to unknown meson to meson transition form factors at a large momentum transfer squared equal to the D0 mass squared. A good overall agreement to the Belle Dalitz plot density distribution is achieved. Another set of parameters fits equally well the BABAR Collaboration Dalitz plot model. The branching fractions of the dominant channels compare well with those of the isobar Belle or BABAR models.The lower-limit values of the branching fractions of the annihilation amplitudes are significant. Built upon experimental data from other processes, the unitary K pi and pi pi scalar form factors, entering our decay amplitude and satisfying analyticity and chiral symmetry constraints, are furthermore constrained by the present Dalitz plot analysis. Our decay amplitude could be a useful input for determinations of D0-D0bar mixing parameters and of the CKM angle gamma (or phi3).
Factors Affecting PMU Installation Costs (October 2014) | Department...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Factors Affecting PMU Installation Costs (October 2014) Factors Affecting PMU Installation Costs (October 2014) The Department of Energy investigated the major cost factors that...
Radio Scintillation due to Discontinuities in the Interstellar Plasma Density
Hendrik Lambert; Barney Rickett
1999-11-18T23:59:59.000Z
We develop the theory of interstellar scintillation as caused by an irregular plasma having a power-law spatial density spectrum with a spectral exponent of 4 corresponding to a medium with abrupt changes in its density. An ``outer scale'' is included in the model representing the typical scale over which the density of the medium remains uniform. Such a spectrum could be used to model plasma shock fronts in supernova remnants or other plasma discontinuities. We investigate and develop equations for the decorrelation bandwidth of diffractive scintillations and the refractive scintillation index and compare our results with pulsar measurements. We consider both a medium concentrated in a thin layer and an extended irregular medium. We conclude that the discontinuity model gives satisfactory agreement for many diffractive measurements, in particular the VLBI meaurements of the structure function exponent between 5/3 and 2. However, it gives less satisfactory agreement for the refractive scintillation index than does the Kolmogorov turbulence spectrum. The comparison suggests that the medium consists of a pervasive background distribution of turbulence embedded with randomly placed discrete plasma structures such as shocks or HII regions. This can be modeled by a composite spectrum following the Kolmogorov form at high wavenumbers and steepening at lower wavenumbers corresponding to the typical (inverse) size of the discrete structures. Such a model can also explain the extreme scattering events. However, lines of sight through the enhanced scattering prevalent at low galactic latitudes are accurately described by the Kolmogorov spectrum in an extended medium and do not appear to have a similar low-wavenumber steepening.
Surface density profiles of collisionless disc merger remnants
Thorsten Naab; Ignacio Trujillo
2006-03-01T23:59:59.000Z
We present a detailed surface density analysis of a large sample of simulated collisionless mergers of disc galaxies with bulges (mass ratios 1:1, 2:1, 3:1, 4:1, and 6:1) and without bulges (mass ratios 1:1 and 3:1). They were classified, according to their bulge--to--total ($B/T$) ratio, either as a one-component system or as a two-component systems. In general projection effects change the classification of a remnant. Only merger remnants of discs with bulges show properties similar to observed early--type galaxies. Their B/T ratios are in the range $0.2densities). No indications for a correlation between the surface density profiles and other global parameters are found. The remnants have properties similar to giant elliptical galaxies in the intermediate mass regime. A binary disc merger origin for all early-type galaxies, especially the most massive ones, is unlikely. Observed nearby merger remnants have properties similar to the simulated remnants. They can have formed from binary disc mergers and might evolve into early--type galaxies within a few Gyrs (abbreviated).
Disk heating by more than one spiral density wave
I. Minchev; A. C. Quillen
2005-11-01T23:59:59.000Z
We consider a differentially rotating, 2D stellar disk perturbed by two steady state spiral density waves moving at different patterns speeds. Our investigation is based on direct numerical integration of initially circular test-particle orbits. We examine a range of spiral strengths and spiral speeds and show that stars in this time dependent gravitational field can be heated (their random motions increased).This is particularly noticeable in the simultaneous propagation of a 2-armed spiral density wave near the corotation resonance (CR), and a weak 4-armed one near the inner and outer 4:1 Lindblad resonances. In simulations with 2 spiral waves moving at different pattern speeds we find: (1) the variance of the radial velocity, sigma_R^2, exceeds the sum of the variances measured from simulations with each individual pattern; (2) sigma_R^2 can grow with time throughout the entire simulation; (3) sigma_R^2 is increased over a wider range of radii compared to that seen with one spiral pattern; (4) particles diffuse radially in real space whereas they don't when only one spiral density wave is present. Near the CR with the stronger, 2-armed pattern, test particles are observed to migrate radially. These effects take place at or near resonances of both spirals so we interpret them as the result of stochastic motions. This provides a possible new mechanism for increasing the stellar velocity dispersion in galactic disks. If multiple spiral patterns are present in the Galaxy we predict that there should be large variations in the stellar velocity dispersion as a function of radius.
STANDING WAVE PROBES FOR DIMENSIONAL METROLOGY OF LOW DENSITY FOAMS
Seugling, R M; Woody, S C; Bauza, M B
2010-03-23T23:59:59.000Z
Typically, parts and geometries of interest to LLNL are made from a combination of complex geometries and a wide array of different materials ranging from metals and ceramics to low density foams and plastic foils. These parts are combined to develop physics experiments for studying material properties, equation of state (EOS) and radiation transport. Understanding the dimensional uncertainty of the parts contained within an experiment is critical to the physical understanding of the phenomena being observed and represents the motivation for developing probe metrology capability that can address LLNL's unique problems. Standing wave probes were developed for measuring high aspect ratio, micrometer scaled features with nanometer resolution. Originally conceived of for the use in the automotive industry for characterizing fuel injector bores and similar geometries, this concept was investigated and improved for use on geometries and materials important to LLNL needs within target fabrication. As part of the original project, detailed understanding of the probe dynamics and interactions with the surface of the sample was investigated. In addition, the upgraded system was utilized for measuring fuel injector bores and micro-lenses as a means of demonstrating capability. This report discusses the use of the standing wave probe for measuring features in low density foams, 55 mg/cc SiO{sub 2} and 982 mg/cc (%6 relative density) copper foam respectively. These two foam materials represent a difficult metrology challenge because of their material properties and surface topography. Traditional non-contact metrology systems such as normal incident interferometry and/or confocal microscopy have difficulty obtaining a signal from the relatively absorptive characteristics of these materials. In addition to the foam samples, a solid copper and plastic (Rexolite{trademark}) sample of similar geometry was measured with the standing wave probe as a reference for both conductive and dielectric materials.
Radial disk heating by more than one spiral density wave
I. Minchev; A. C. Quillen
2005-10-28T23:59:59.000Z
We consider a differentially rotating, 2D stellar disk perturbed by two steady state spiral density waves moving at different patterns speeds. Our investigation is based on direct numerical integration of initially circular test-particle orbits. We examine a range of spiral strengths and spiral speeds and show that stars in this time dependent gravitational field can be heated (their random motions increased). This is particularly noticeable in the simultaneous propagation of a 2-armed spiral density wave near the corotation resonance (CR), and a weak 4-armed one near the inner and outer 4:1 Lindblad resonances. In simulations with 2 spiral waves moving at different pattern speeds we find: (1) the variance of the radial velocity, sigma_R^2, exceeds the sum of the variances measured from simulations with each individual pattern; (2) sigma_R^2 can grow with time throughout the entire simulation; (3) sigma_R^2 is increased over a wider range of radii compared to that seen with one spiral pattern; (4) particles diffuse radially in real space whereas they don't when only one spiral density wave is present. Near the CR with the stronger, 2-armed pattern, test particles are observed to migrate radially. These effects take place at or near resonances of both spirals so we interpret them as the result of stochastic motions. This provides a possible new mechanism for increasing the stellar velocity dispersion in galactic disks. If multiple spiral patterns are present in the Galaxy we predict that there should be large variations in the stellar velocity dispersion as a function of radius.
Spatiotemporal evolution of dielectric driven cogenerated dust density waves
Sarkar, Sanjib; Bose, M. [Department of Physics, Jadavpur University, Kolkata 700032 (India)] [Department of Physics, Jadavpur University, Kolkata 700032 (India); Mukherjee, S. [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India)] [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India); Pramanik, J. [Kharagpur College, Kharagpur 721305, West Bengal (India)] [Kharagpur College, Kharagpur 721305, West Bengal (India)
2013-06-15T23:59:59.000Z
An experimental observation of spatiotemporal evolution of dust density waves (DDWs) in cogenerated dusty plasma in the presence of modified field induced by glass plate is reported. Various DDWs, such as vertical, oblique, and stationary, were detected simultaneously for the first time. Evolution of spatiotemporal complexity like bifurcation in propagating wavefronts is also observed. As dust concentration reaches extremely high value, the DDW collapses. Also, the oblique and nonpropagating mode vanishes when we increase the number of glass plates, while dust particles were trapped above each glass plates showing only vertical DDWs.
Mixing device for materials with large density differences
Gregg, David W. (Moraga, CA)
1994-01-01T23:59:59.000Z
An auger-tube pump mixing device for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided.
Quantification of Uncertainties in Nuclear Density Functional theory
N. Schunck; J. D. McDonnell; D. Higdon; J. Sarich; S. Wild
2014-09-17T23:59:59.000Z
Reliable predictions of nuclear properties are needed as much to answer fundamental science questions as in applications such as reactor physics or data evaluation. Nuclear density functional theory is currently the only microscopic, global approach to nuclear structure that is applicable throughout the nuclear chart. In the past few years, a lot of effort has been devoted to setting up a general methodology to assess theoretical uncertainties in nuclear DFT calculations. In this paper, we summarize some of the recent progress in this direction. Most of the new material discussed here will be be published in separate articles.
Helicon Plasma Source Configuration Analysis by Means of Density Measurements
Angrilli, F.; Barber, G.C.; Carter, M.D.; Goulding, R.H.; Maggiora, R.; Pavarin, D.; Sparks, D.O.
1999-11-13T23:59:59.000Z
Initial results have been obtained from operation of a helicon plasma source built to conduct optimization studies for space propulsion applications. The source features an easily reconfigurable antenna to test different geometries. Operating with He as the source gas, peak densities >= 1.6X10{sup 19} m{sup -3} have been achieved. Radial and axial plasma profiles have been obtained using a microwave interferometer that can be scanned axially and a Langmuir probe. The source will be used to investigate operation at high magnetic field, frequency, and input power.
Transition density and pressure in hot neutron stars
Xu, Jun; Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An.
2010-01-01T23:59:59.000Z
); Astrophys. J. 697, 1549 (2009). [20] A. Burrows and J. M. Lattimer, Astrophys. J. 307, 178 (1986). [21] H. A. Bethe, Rev. Mod. Phys. 62, 801 (1990). [22] R. Buras, M. Rampp, H. T. Janka, and K. Kifonidis, Phys. Rev. Lett. 90, 241101 (2003). [23] H. A.... Rev. C 67, 041602(R) (2003). 055805-6 TRANSITION DENSITY AND PRESSURE IN HOT . . . PHYSICAL REVIEW C 81, 055805 (2010) [30] B. A. Li, A. T. Sustich, M. Tilley, and B. Zhang, Phys. Rev. C 64, 051303(R) (2001); Nucl. Phys. A 699, 493 (2002). [31] B...
High density harp or wire scanner for particle beam diagnostics
Fritsche, Craig T. (Overland Park, KS); Krogh, Michael L. (Lee's Summit, MO)
1996-05-21T23:59:59.000Z
A diagnostic detector head harp (23) used to detect and characterize high energy particle beams using an array of closely spaced detector wires (21), typically carbon wires, spaced less than 0.1 cm (0.040 inch) connected to a hybrid microcircuit (25) formed on a ceramic substrate (26). A method to fabricate harps (23) to obtain carbon wire spacing and density not previously available utilizing hybrid microcircuit technology. The hybrid microcircuit (25) disposed on the ceramic substrate (26) connects electrically between the detector wires (21) and diagnostic equipment (37) which analyzes pulses generated in the detector wires (21) by the high energy particle beams.
High density harp or wire scanner for particle beam diagnostics
Fritsche, C.T.; Krogh, M.L.
1996-05-21T23:59:59.000Z
Disclosed is a diagnostic detector head harp used to detect and characterize high energy particle beams using an array of closely spaced detector wires, typically carbon wires, spaced less than 0.1 cm (0.040 inch) connected to a hybrid microcircuit formed on a ceramic substrate. A method to fabricate harps to obtain carbon wire spacing and density not previously available utilizing hybrid microcircuit technology. The hybrid microcircuit disposed on the ceramic substrate connects electrically between the detector wires and diagnostic equipment which analyzes pulses generated in the detector wires by the high energy particle beams. 6 figs.
Validating the BHR RANS model for variable density turbulence
Israel, Daniel M [Los Alamos National Laboratory; Gore, Robert A [Los Alamos National Laboratory; Stalsberg - Zarling, Krista L [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
The BHR RANS model is a turbulence model for multi-fluid flows in which density variation plays a strong role in the turbulence processes. In this paper they demonstrate the usefulness of BHR over a wide range of flows which include the effects of shear, buoyancy, and shocks. The results are in good agreement with experimental and DNS data across the entire set of validation cases, with no need to retune model coefficients between cases. The model has potential application to a number of aerospace related flow problems.
Broadcasting but not receiving: density dependence considerations for SETI signals
Reginald D. Smith
2010-02-07T23:59:59.000Z
This paper develops a detailed quantitative model which uses the Drake equation and an assumption of an average maximum radio broadcasting distance by an communicative civilization to derive a minimum civilization density for contact between two civilizations to be probable in a given volume of space under certain conditions, the amount of time it would take for a first contact, and whether reciprocal contact is possible. Results show that under certain assumptions, a galaxy can be teeming with civilizations yet not have a guarantee of communication between any of them given either short lifetimes or small maximum distances for communication.
Mixing device for materials with large density differences
Gregg, D.W.
1994-08-16T23:59:59.000Z
An auger-tube pump mixing device is disclosed for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided. 2 figs.