Type Ia Supernovae and the Hubble Constant
D. Branch
1998-01-08T23:59:59.000Z
The focus of this review is the work that has been done during the 1990s on using Type Ia supernovae (SNe Ia) to measure the Hubble constant ($H_0$). SNe Ia are well suited for measuring $H_0$. A straightforward maximum-light color criterion can weed out the minority of observed events that are either intrinsically subluminous or substantially extinguished by dust, leaving a majority subsample that has observational absolute-magnitude dispersions of less than $\\sigma_{obs}(M_B) \\simeq \\sigma_{obs}(M_V) \\simeq 0.3$ mag. Correlations between absolute magnitude and one or more distance-independent SN Ia or parent-galaxy observables can be used to further standardize the absolute magnitudes to better than 0.2 mag. The absolute magnitudes can be calibrated in two independent ways --- empirically, using Cepheid-based distances to parent galaxies of SNe Ia, and physically, by light curve and spectrum fitting. At present the empirical and physical calibrations are in agreement at $M_B \\simeq M_V \\simeq -19.4$ or -19.5. Various ways that have been used to match Cepheid-calibrated SNe Ia or physical models to SNe Ia that have been observed out in the Hubble flow have given values of $H_0$ distributed throughout the range 54 to 67 km/s Mpc$^{-1}$. Astronomers who want a consensus value of $H_0$ from SNe Ia with conservative errors could, for now, use $60 \\pm 10$ km/s Mpc^{-1}$.
Equilibrium surface distributions for constant energy ensembles B. I. Henry
Henry, Bruce Ian
Equilibrium surface distributions for constant energy ensembles B. I. Henry Department of Applied distributions are seen [11,12]. In this paper we shall discuss how one calculates the constant energy energy en semble are discussed. An equilibrium surface density is introduced and used to calculate
Seismic pulse propagation with constant Q and stable probability distributions
Francesco Mainardi; Massimo Tomirotti
2010-08-07T23:59:59.000Z
The one-dimensional propagation of seismic waves with constant Q is shown to be governed by an evolution equation of fractional order in time, which interpolates the heat equation and the wave equation. The fundamental solutions for the Cauchy and Signalling problems are expressed in terms of entire functions (of Wright type) in the similarity variable and their behaviours turn out to be intermediate between those for the limiting cases of a perfectly viscous fluid and a perfectly elastic solid. In view of the small dissipation exhibited by the seismic pulses, the nearly elastic limit is considered. Furthermore, the fundamental solutions for the Cauchy and Signalling problems are shown to be related to stable probability distributions with index of stability determined by the order of the fractional time derivative in the evolution equation.
Estimation of the effective distribution coefficient from the solubility constant
Wang, Yug-Yea; Yu, C.
1994-07-01T23:59:59.000Z
An updated version of RESRAD has been developed by Argonne National Laboratory for the US Department of Energy to derive site-specific soil guidelines for residual radioactive material. In this updated version, many new features have been added to the, RESRAD code. One of the options is that a user can input a solubility constant to limit the leaching of contaminants. The leaching model used in the code requires the input of an empirical distribution coefficient, K{sub d}, which represents the ratio of the solute concentration in soil to that in solution under equilibrium conditions. This paper describes the methodology developed to estimate an effective distribution coefficient, Kd, from the user-input solubility constant and the use of the effective K{sub d} for predicting the leaching of contaminants.
The Hubble Constant from Type Ia Supernovae in Early-Type Galaxies
Tom Richtler; Georg Drenkhahn
1999-09-07T23:59:59.000Z
Type Ia supernovae (SNe) are the best standard candles available today in spite of an appreciable intrinsic variation of their luminosities at maximum phase, and of probably non-uniform progenitors. For an unbiased use of type Ia SNe as distance indicators it is important to know accurately how the decline rate and colour at maximum phase correlate with the peak brightness. In order to calibrate the Hubble diagram of type Ia SNe, i.e. to derive the Hubble constant, one needs to determine the absolute brightness of nearby type Ia SNe. Globular cluster systems of early type Ia host galaxies provide suitable distance indicators. We discuss how Ia SNe can be calibrated and explain the method of Globular Cluster Luminosity Functions (GCLFs). At present, the distance to the Fornax galaxy cluster is most important for deriving the Hubble constant. Our present data indicate a Hubble constant of H_0=72+-4 km/s/Mpc. As an appendix, we summarise what is known about absolute magnitudes of Ia's in late-type galaxies.
Distribution Function of Dark Matter with Constant Anisotropy
Ding Ma; Ping He
2008-08-01T23:59:59.000Z
N-body simulations of dark matter halos show that the density is cusped near the center of the halo. The density profile behaves as $r^{-\\gamma}$ in the inner parts, where $\\gamma \\simeq 1$ for the NFW model and $\\gamma \\simeq 1.5$ for the Moore's model, but in the outer parts, both models agree with each other in the asymptotic behavior of the density profile. The simulations also show the information about anisotropy parameter $\\beta(r)$ of velocity distribution. $\\beta\\approx 0$ in the inner part and $\\beta\\approx 0.5$ (radially anisotropic) in the outer part of the halo. We provide some distribution functions $F(E,L)$ with the constant anisotropy parameter $\\beta$ for the two spherical models of dark matter halos: a new generalized NFW model and a generalized Moore model. There are two parameters $\\alpha$ and $\\epsilon$ for those two generalized models to determine the asymptotic behavior of the density profile. In this paper, we concentrate on the situation of $\\beta(r)=1/2$ from the viewpoint of the simulation.
Hardy–Sobolev Type Inequalities with Sharp Constants in Carnot ...
2010-06-22T23:59:59.000Z
nonlinear case p = 2. We also obtain a sharp inequality of Hardy–Sobolev type. Keywords Hardy type inequalities·Carnot groups·Carnot–Carathéodory spaces·.
Fine-structure constant constraints on Bekenstein-type models
P. M. M. Leal; C. J. A. P. Martins; L. B. Ventura
2014-07-15T23:59:59.000Z
Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\\alpha$, are an area of much increased recent activity, following some indications of possible spacetime variations at the few parts per million level. Here we obtain updated constraints on the Bekenstein-Sandvik-Barrow-Magueijo model, which is arguably the simplest model allowing for $\\alpha$ variations. Recent accurate spectroscopic measurements allow us to improve previous constraints by about an order of magnitude. We briefly comment on the dependence of the results on the data sample, as well as on the improvements expected from future facilities.
Analysis of error in using fractured gas well type curves for constant pressure production
Schkade, David Wayne
1987-01-01T23:59:59.000Z
ANALYSIS DF ERROR IN USING FRACTURED GAS WELL TYPE CURVES FOR CONSTANT PRESSURE PRODUCTION A Thesis by DAVID WAYNE SCHKADE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1987 Major Subject: Petroleum Engineering ANALYSIS OF ERROR IN USING FRACTURED GAS WELL TYPE CURVES FOR CONSTANT PRESSURE PRDDUCTION A Thesis by DAVID WAYNE SCHKADE Approved as to style and content by: S. A. Ho lditch...
On the distribution of estimators of diffusion constants for Brownian motion
Denis Boyer; David S. Dean
2011-07-26T23:59:59.000Z
We discuss the distribution of various estimators for extracting the diffusion constant of single Brownian trajectories obtained by fitting the squared displacement of the trajectory. The analysis of the problem can be framed in terms of quadratic functionals of Brownian motion that correspond to the Euclidean path integral for simple Harmonic oscillators with time dependent frequencies. Explicit analytical results are given for the distribution of the diffusion constant estimator in a number of cases and our results are confirmed by numerical simulations.
Distribution and Abstract Types in Emerald N. Hutchinson
Black, Andrew P.
Distribution and Abstract Types in Emerald A. Black N. Hutchinson E. Jul H. Levy L. CarterEEE TRANSACTIONS ON SOFTWARE ENGINEERING, VOL. SE-13. NO. 1, JANUARY 1987 65 Distribution and Abstract Types-Emerald is an object-based language for programming distributed subsystems and applications. Its novel features include
Goobar, A.
2008-01-01T23:59:59.000Z
at z = 1. uncertainty for supernovae at z = 1. mR Adding theMass Density .Q Using Type Ia Supernovae A. Goobar and S.Density Q Using Type Ia Supernovae Ariel Goobar l and Saul
Energy Distribution of a Gödel-Type Space-Time
Ragab M. Gad
2004-01-29T23:59:59.000Z
We calculate the energy and momentum distributions associated with a G\\"{o}del-type space-time, using the well-known energy-momentum complexes of Landau and Lifshitz and M{\\o}ller. We show that the definitions of Landau and Lifshitz and M{\\o}ller do not furnish a consistent result.
Elastic constants determined by nanoindentation for p-type thermoelectric half-Heusler
Gahlawat, S.; Wheeler, L.; White, K. W., E-mail: zren@uh.edu, E-mail: kwwhite@uh.edu [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); He, R.; Chen, S.; Ren, Z. F., E-mail: zren@uh.edu, E-mail: kwwhite@uh.edu [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States)
2014-08-28T23:59:59.000Z
This paper presents a study of the elastic properties of the p-type thermoelectric half-Heusler material, Hf{sub 0.44}Zr{sub 0.44}Ti{sub 0.12}CoSb{sub 0.8}Sn{sub 0.2}, using nanoindentation. Large grain-sized polycrystalline specimens were fabricated for these measurements, providing sufficient indentation targets within single grains. Electron Backscatter Diffraction methods indexed the target grains for the correlation needed for our elastic analysis of individual single crystals for this cubic thermoelectric material. Elastic properties, including the Zener ratio and the Poisson ratio, obtained from the elasticity tensor are also reported.
Dobigeon, Nicolas
truncated on a simplex Nicolas Dobigeon and Jean-Yves Tourneret E-mail: dobigeon@umich.edu TECHNICAL REPORT simplex: S = r 0, r = 1, . . . , R - 1, R-1 r=1 r 1 , (1) Let NS(A, B) denote the truncated multivariate normal distribution defined on the simplex S with mean vector A and covariance matrix B
On P_T-distribution of gluon production rate in constant chromoelectric field
D. G. Pak
2007-02-22T23:59:59.000Z
A complete expression for the p_T-distribution of the gluon production rate in the homogeneous chromoelectric field has been obtained. Our result contains a new additional term proportional to the singular function \\delta(p_T^2). We demonstrate that the presence of this term is consistent with the dual symmetry of QCD effective action and allows to reproduce the known result for the total imaginary part of the effective action after integration over transverse momentum.
Dai, Mi
2015-01-01T23:59:59.000Z
In order to obtain robust cosmological constraints from Type Ia supernova (SN Ia) data, we have applied Markov Chain Monte Carlo (MCMC) to SN Ia lightcurve fitting. We develop a method for sampling the resultant probability density distributions (pdf) of the SN Ia lightcuve parameters in the MCMC likelihood analysis to constrain cosmological parameters. Applying this method to the Joint Lightcurve Analysis (JLA) data set of SNe Ia, we find that sampling the SN Ia lightcurve parameter pdf's leads to cosmological parameters closer to that of a flat Universe with a cosmological constant, compared to the usual practice of using only the best fit values of the SN Ia lightcurve parameters. Our method will be useful in the use of SN Ia data for precision cosmology.
Childers, L.; Liming, L.; Foster, I.; Mathematics and Computer Science; Univ. of Chicago
2008-10-15T23:59:59.000Z
This report summarizes the methodology and results of a user perspectives study conducted by the Community Driven Improvement of Globus Software (CDIGS) project. The purpose of the study was to document the work-related goals and challenges facing today's scientific technology users, to record their perspectives on Globus software and the distributed-computing ecosystem, and to provide recommendations to the Globus community based on the observations. Globus is a set of open source software components intended to provide a framework for collaborative computational science activities. Rather than attempting to characterize all users or potential users of Globus software, our strategy has been to speak in detail with a small group of individuals in the scientific community whose work appears to be the kind that could benefit from Globus software, learn as much as possible about their work goals and the challenges they face, and describe what we found. The result is a set of statements about specific individuals experiences. We do not claim that these are representative of a potential user community, but we do claim to have found commonalities and differences among the interviewees that may be reflected in the user community as a whole. We present these as a series of hypotheses that can be tested by subsequent studies, and we offer recommendations to Globus developers based on the assumption that these hypotheses are representative. Specifically, we conducted interviews with thirty technology users in the scientific community. We included both people who have used Globus software and those who have not. We made a point of including individuals who represent a variety of roles in scientific projects, for example, scientists, software developers, engineers, and infrastructure providers. The following material is included in this report: (1) A summary of the reported work-related goals, significant issues, and points of satisfaction with the use of Globus software; (2) A method for characterizing users according to their technology interactions, and identification of four user types among the interviewees using the method; (3) Four profiles that highlight points of commonality and diversity in each user type; (4) Recommendations for technology developers and future studies; (5) A description of the interview protocol and overall study methodology; (6) An anonymized list of the interviewees; and (7) Interview writeups and summary data. The interview summaries in Section 3 and transcripts in Appendix D illustrate the value of distributed computing software--and Globus in particular--to scientific enterprises. They also document opportunities to make these tools still more useful both to current users and to new communities. We aim our recommendations at developers who intend their software to be used and reused in many applications. (This kind of software is often referred to as 'middleware.') Our two core recommendations are as follows. First, it is essential for middleware developers to understand and explicitly manage the multiple user products in which their software components are used. We must avoid making assumptions about the commonality of these products and, instead, study and account for their diversity. Second, middleware developers should engage in different ways with different kinds of users. Having identified four general user types in Section 4, we provide specific ideas for how to engage them in Section 5.
Richard G. Forbes
2015-02-25T23:59:59.000Z
In the 1940s/50s, Landau and Lifschitz (LL) published in their Quantum Mechanics textbook what is now a well known formula for the rate-constant for the electrostatic field ionization (ESFI) of a hydrogen atom in its ground electronic state. This formula is widely regarded as correct in the low field limit, and has played a significant role in development of ESFI theory. The formula was originally derived and presented in the atomic units system, with the hydrogen ionization energy I_H set equal to (1/2), making it impossible to determine by inspection to what power I_H is raised in its pre-exponential. Knowledge of this power would be useful in the context of near-surface ESFI, where significant image-force-induced shifts in effective ionization energy can occur. Also, large numbers of applied scientists and engineers work with ESFI as a process of technological importance, but cannot nowadays be expected to have familiarity with the Gaussian or atomic units equation systems. In the 1970s, what is now called the International System of Quantities (ISQ), which includes the equation system behind SI units, was internationally adopted as the primary system for university teaching and for communication of scientific equations between theoreticians and applied scientists and engineers. However, 40 years on, no transparent derivation of an ISQ equivalent of the LL formula is easily found in the literature. This tutorial paper presents a detailed ISQ derivation, finds that ionization energy appears in the pre-exponential as I_H to the power (7/2) (not 5/2, as sometimes stated) and defines a universal "tunnelling ionization constant" that appears in the ISQ formula pre-exponential. It is shown how this formula relates to the "attempt frequency" form often used to describe rate-constants for tunnelling processes, and an ISQ expression is given for the motive energy in the related JWKB integral.
Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX
Purwaningsih, Anik [Center for development of nuclear informatics, National Nuclear Energy Agency, PUSPIPTEK, Serpong, Banten 15310 (Indonesia)
2014-09-30T23:59:59.000Z
Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.
MESURE DE LA DISTRIBUTION RADIALE DU COURANT DANS UN PLASMA DU TYPE TOKAMAK,
Boyer, Edmond
85 MESURE DE LA DISTRIBUTION RADIALE DU COURANT DANS UN PLASMA DU TYPE TOKAMAK, A L'AIDE D plasma du type Tokamak à l'aide d'un faisceau de lithium neutre. On décrit les différentes parties du analyse. Finalement les résultats expérimentaux obtenus sur un Tokamak sont décrits. Les profils sont
FROM CONSTANT TO NON-DEGENERATELY VANISHING MAGNETIC FIELDS IN SUPERCONDUCTIVITY
the distribution of superconductivity in a type II superconductor submitted to a vari- able magnetic fieldFROM CONSTANT TO NON-DEGENERATELY VANISHING MAGNETIC FIELDS IN SUPERCONDUCTIVITY BERNARD HELFFER- tivity in a type II superconductor subjected to a constant magnetic field. The second function describes
ExSample -- A Library for Sampling Sudakov-Type Distributions
Simon Platzer
2012-03-19T23:59:59.000Z
Sudakov-type distributions are at the heart of generating radiation in parton showers as well as contemporary NLO matching algorithms along the lines of the POWHEG algorithm. In this paper, the C++ library ExSample is introduced, which implements adaptive sampling of Sudakov-type distributions for splitting kernels which are in general only known numerically. Besides the evolution variable, the splitting kernels can depend on an arbitrary number of other degrees of freedom to be sampled, and any number of further parameters which are fixed on an event-by-event basis.
Frank Znidarsic
2000-11-12T23:59:59.000Z
A Bose condensate of electrons may exist in nickel hydrogen and palladium hydrogen systems. The motion constants associated with the gravitational and nuclear forces motion tend toward the electromagnetic in these systems. The change in the motion constants produces unexpected gravitomagnetic and nuclear affects.
Brad K. Gibson; Peter B. Stetson; Wendy L. Freedman; Jeremy R. Mould; Robert C. Kennicutt, Jr.; John P. Huchra; Shoko Sakai; John A. Graham; Caleb I. Fassett; Daniel D. Kelson; Laura Ferrarese; Shaun M. G. Hughes; Garth D. Illingworth; Lucas M. Macri; Barry F. Madore; Kim M. Sebo; Nancy A. Silbermann
1999-08-13T23:59:59.000Z
Cepheid-based distances to seven Type Ia supernovae (SNe)-host galaxies have been derived using the standard HST Key Project on the Extragalactic Distance Scale pipeline. For the first time, this allows for a transparent comparison of data accumulated as part of three different HST projects, the Key Project, the Sandage et al. Type Ia SNe program, and the Tanvir et al. Leo I Group study. Re-analyzing the Tanvir et al. galaxy and six Sandage et al. galaxies we find a mean (weighted) offset in true distance moduli of 0.12+/-0.07 mag -- i.e., 6% in linear distance -- in the sense of reducing the distance scale, or increasing H0. Adopting the reddening-corrected Hubble relations of Suntzeff et al. (1999), tied to a zero point based upon SNe~1990N, 1981B, 1998bu, 1989B, 1972E and 1960F and the photometric calibration of Hill et al. (1998), leads to a Hubble constant of H0=68+/-2(random)+/-5(systematic) km/s/Mpc. Adopting the Kennicutt et al. (1998) Cepheid period-luminosity-metallicity dependency decreases the inferred H0 by 4%. The H0 result from Type Ia SNe is now in good agreement, to within their respective uncertainties, with that from the Tully-Fisher and surface brightness fluctuation relations.
Kumar, Jitendra; Hoffman, Forrest M.
2014-03-18T23:59:59.000Z
Arctic ecosystems have been observed to be warming faster than the global average and are predicted to experience accelerated changes in climate due to global warming. Arctic vegetation is particularly sensitive to warming conditions and likely to exhibit shifts in species composition, phenology and productivity under changing climate. Mapping and monitoring of changes in vegetation is essential to understand the effect of climate change on the ecosystem functions. Vegetation exhibits unique spectral characteristics which can be harnessed to discriminate plant types and develop quantitative vegetation indices. We have combined high resolution multi-spectral remote sensing from the WorldView 2 satellite with LIDAR-derived digital elevation models to characterize the tundra landscape on the North Slope of Alaska. Classification of landscape using spectral and topographic characteristics yields spatial regions with expectedly similar vegetation characteristics. A field campaign was conducted during peak growing season to collect vegetation harvests from a number of 1m x 1m plots in the study region, which were then analyzed for distribution of vegetation types in the plots. Statistical relationships were developed between spectral and topographic characteristics and vegetation type distributions at the vegetation plots. These derived relationships were employed to statistically upscale the vegetation distributions for the landscape based on spectral characteristics. Vegetation distributions developed are being used to provide Plant Functional Type (PFT) maps for use in the Community Land Model (CLM).
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Kumar, Jitendra; Hoffman, Forrest M.
Arctic ecosystems have been observed to be warming faster than the global average and are predicted to experience accelerated changes in climate due to global warming. Arctic vegetation is particularly sensitive to warming conditions and likely to exhibit shifts in species composition, phenology and productivity under changing climate. Mapping and monitoring of changes in vegetation is essential to understand the effect of climate change on the ecosystem functions. Vegetation exhibits unique spectral characteristics which can be harnessed to discriminate plant types and develop quantitative vegetation indices. We have combined high resolution multi-spectral remote sensing from the WorldView 2 satellite with LIDAR-derived digital elevation models to characterize the tundra landscape on the North Slope of Alaska. Classification of landscape using spectral and topographic characteristics yields spatial regions with expectedly similar vegetation characteristics. A field campaign was conducted during peak growing season to collect vegetation harvests from a number of 1m x 1m plots in the study region, which were then analyzed for distribution of vegetation types in the plots. Statistical relationships were developed between spectral and topographic characteristics and vegetation type distributions at the vegetation plots. These derived relationships were employed to statistically upscale the vegetation distributions for the landscape based on spectral characteristics. Vegetation distributions developed are being used to provide Plant Functional Type (PFT) maps for use in the Community Land Model (CLM).
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Zachary Langford; Forrest Hoffman; Jitendra Kumar
Arctic ecosystems have been observed to be warming faster than the global average and are predicted to experience accelerated changes in climate due to global warming. Arctic vegetation is particularly sensitive to warming conditions and likely to exhibit shifts in species composition, phenology and productivity under changing climate. Mapping and monitoring of changes in vegetation is essential to understand the effect of climate change on the ecosystem functions. Vegetation exhibits unique spectral characteristics which can be harnessed to discriminate plant types and develop quantitative vegetation indices. We have combined high resolution multi-spectral remote sensing from the WorldView 2 satellite with LIDAR-derived digital elevation models to characterize the tundra landscape on the North Slope of Alaska. Classification of landscape using spectral and topographic characteristics yields spatial regions with expectedly similar vegetation characteristics. A field campaign was conducted during peak growing season to collect vegetation harvests from a number of 1m x 1m plots in the study region, which were then analyzed for distribution of vegetation types in the plots. Statistical relationships were developed between spectral and topographic characteristics and vegetation type distributions at the vegetation plots. These derived relationships were employed to statistically upscale the vegetation distributions for the landscape based on spectral characteristics. Vegetation distributions developed are being used to provide Plant Functional Type (PFT) maps for use in the Community Land Model (CLM).
The lengths distribution of laminar phases for type-I intermittency in the presence of noise
A. E. Hramov; A. A. Koronovskii; M. K. Kurovskaja; A. A. Ovchinnikov; S. Boccaletti
2008-01-26T23:59:59.000Z
We consider a type of intermittent behavior that occurs as the result of the interplay between dynamical mechanisms giving rise to type-I intermittency and random dynamics. We analytically deduce the laws for the distribution of the laminar phases, with the law for the mean length of the laminar phases versus the critical parameter deduced earlier [PRE 62 (2000) 6304] being the corollary fact of the developed theory. We find a very good agreement between the theoretical predictions and the data obtained by means of both the experimental study and numerical calculations. We discuss also how this mechanism is expected to take place in other relevant physical circumstances.
Mandel, Kaisey S.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Foley, Ryan J., E-mail: kmandel@cfa.harvard.edu [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)
2014-12-20T23:59:59.000Z
We investigate the statistical dependence of the peak intrinsic colors of Type Ia supernovae (SNe Ia) on their expansion velocities at maximum light, measured from the Si II ?6355 spectral feature. We construct a new hierarchical Bayesian regression model, accounting for the random effects of intrinsic scatter, measurement error, and reddening by host galaxy dust, and implement a Gibbs sampler and deviance information criteria to estimate the correlation. The method is applied to the apparent colors from BVRI light curves and Si II velocity data for 79 nearby SNe Ia. The apparent color distributions of high-velocity (HV) and normal velocity (NV) supernovae exhibit significant discrepancies for B – V and B – R, but not other colors. Hence, they are likely due to intrinsic color differences originating in the B band, rather than dust reddening. The mean intrinsic B – V and B – R color differences between HV and NV groups are 0.06 ± 0.02 and 0.09 ± 0.02 mag, respectively. A linear model finds significant slopes of –0.021 ± 0.006 and –0.030 ± 0.009 mag (10{sup 3} km s{sup –1}){sup –1} for intrinsic B – V and B – R colors versus velocity, respectively. Because the ejecta velocity distribution is skewed toward high velocities, these effects imply non-Gaussian intrinsic color distributions with skewness up to +0.3. Accounting for the intrinsic-color-velocity correlation results in corrections to A{sub V} extinction estimates as large as –0.12 mag for HV SNe Ia and +0.06 mag for NV events. Velocity measurements from SN Ia spectra have the potential to diminish systematic errors from the confounding of intrinsic colors and dust reddening affecting supernova distances.
Pota, Himanshu Roy
will affect the flow of power and the voltage profiles [6]. The steady state voltage rise resulting from types of load. The importance of load modeling in power system simulation studies is highlighted by IEEE with respect to voltage are. On the other hand, a dynamic load model expresses this active/reactive power
From constant to non-degenerately vanishing magnetic fields in superconductivity
Bernard Helffer; Ayman Kachmar
2015-03-30T23:59:59.000Z
We explore the relationship between two reference functions arising in the analysis of the Ginzburg-Landau functional. The first function describes the distribution of superconductivity in a type II superconductor subjected to a constant magnetic field. The second function describes the distribution of superconductivity in a type II superconductor submitted to a variable magnetic field that vanishes non-degenerately along a smooth curve.
A Type-Based Locality Analysis for a Functional Distributed Language
Moreira, Alvaro F
's viewpoint, the same reference on different machines refers to the same data object in a single logical store, but data is in fact distributed among the machines. A coherent protocol is then responsible for determining for each operation with references...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan
2014-10-27T23:59:59.000Z
The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7$~\\mathrm{TeV}$ was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0$~\\mathrm{fb}^{-1}$. The measurement covers a phase space up to 2$~\\mathrm{TeV}$ in jet transverse momentum and 2.5 in absolute jet rapidity. The statistical precision of these data leads to stringent constraints on the parton distribution functions of the proton. The data provide important input for the gluon density at high fractions of the proton momentum and for the strong coupling constant at large energy scales. Using predictions from perturbative quantummore »chromodynamics at next-to-leading order, complemented with electroweak corrections, the constraining power of these data is investigated and the strong coupling constant at the Z boson mass $M_{\\mathrm{Z}}$ is determined to be $\\alpha_S(M_{\\mathrm{Z}}) = 0.1185 \\pm 0.0019\\,(\\mathrm{exp})\\,^{+0.0060}_{-0.0037}\\,(\\mathrm{theo})$, which is in agreement with the world average.« less
Khachatryan, Vardan [Yerevan Physics Institute (Armenia); et al.,
2014-10-27T23:59:59.000Z
The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7$~\\mathrm{TeV}$ was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0$~\\mathrm{fb}^{-1}$. The measurement covers a phase space up to 2$~\\mathrm{TeV}$ in jet transverse momentum and 2.5 in absolute jet rapidity. The statistical precision of these data leads to stringent constraints on the parton distribution functions of the proton. The data provide important input for the gluon density at high fractions of the proton momentum and for the strong coupling constant at large energy scales. Using predictions from perturbative quantum chromodynamics at next-to-leading order, complemented with electroweak corrections, the constraining power of these data is investigated and the strong coupling constant at the Z boson mass $M_{\\mathrm{Z}}$ is determined to be $\\alpha_S(M_{\\mathrm{Z}}) = 0.1185 \\pm 0.0019\\,(\\mathrm{exp})\\,^{+0.0060}_{-0.0037}\\,(\\mathrm{theo})$, which is in agreement with the world average.
CMS Collaboration
2015-07-02T23:59:59.000Z
The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7 TeV was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0 inverse femtobarns. The measurement covers a phase space up to 2 TeV in jet transverse momentum and 2.5 in absolute jet rapidity. The statistical precision of these data leads to stringent constraints on the parton distribution functions of the proton. The data provide important input for the gluon density at high fractions of the proton momentum and for the strong coupling constant at large energy scales. Using predictions from perturbative quantum chromodynamics at next-to-leading order, complemented with electroweak corrections, the constraining power of these data is investigated and the strong coupling constant at the Z boson mass M[Z] is determined to be alpha[S(M[Z])} = 0.1185 +/- 0.0019 (exp) +0.0060 -0.0037 (theo), which is in agreement with the world average.
CMS Collaboration
2014-10-24T23:59:59.000Z
The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7 TeV was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0 inverse femtobarns. The measurement covers a phase space up to 2 TeV in jet transverse momentum and 2.5 in absolute jet rapidity. The statistical precision of these data leads to stringent constraints on the parton distribution functions of the proton. The data provide important input for the gluon density at high fractions of the proton momentum and for the strong coupling constant at large energy scales. Using predictions from perturbative quantum chromodynamics at next-to-leading order, complemented with electroweak corrections, the constraining power of these data is investigated and the strong coupling constant at the Z boson mass M[Z] is determined to be alpha[S(M[Z])} = 0.1185 +/- 0.0019 (exp) +0.0060 -0.0037 (theo), which is in agreement with the world average.
Davies, D.K.; Vessell, R.K. [David K. Davies & Associates, Kingwood, TX (United States); Doublet, L.E. [Texas A& M Univ., College Station, TX (United States)] [and others
1997-08-01T23:59:59.000Z
An integrated geological/petrophysical and reservoir engineering study was performed for a large, mature waterflood project (>250 wells, {approximately}80% water cut) at the North Robertson (Clear Fork) Unit, Gaines County, Texas. The primary goal of the study was to develop an integrated reservoir description for {open_quotes}targeted{close_quotes} (economic) 10-acre (4-hectare) infill drilling and future recovery operations in a low permeability, carbonate (dolomite) reservoir. Integration of the results from geological/petrophysical studies and reservoir performance analyses provide a rapid and effective method for developing a comprehensive reservoir description. This reservoir description can be used for reservoir flow simulation, performance prediction, infill targeting, waterflood management, and for optimizing well developments (patterns, completions, and stimulations). The following analyses were performed as part of this study: (1) Geological/petrophysical analyses: (core and well log data) - {open_quotes}Rock typing{close_quotes} based on qualitative and quantitative visualization of pore-scale features. Reservoir layering based on {open_quotes}rock typing {close_quotes} and hydraulic flow units. Development of a {open_quotes}core-log{close_quotes} model to estimate permeability using porosity and other properties derived from well logs. The core-log model is based on {open_quotes}rock types.{close_quotes} (2) Engineering analyses: (production and injection history, well tests) Material balance decline type curve analyses to estimate total reservoir volume, formation flow characteristics (flow capacity, skin factor, and fracture half-length), and indications of well/boundary interference. Estimated ultimate recovery analyses to yield movable oil (or injectable water) volumes, as well as indications of well and boundary interference.
deLaski, A.; Suozzo, M.
Nearly 90% of the electricity that powers the industrial sector flows through dry-type distribution transformers. These transformers are very efficient- most convert in excess of 95% of input power to output power. However, because transformers...
Ortiz, Guillermo P; Boggio, Norberto G; Vorobioff, Juan; Ortiz, Juan J; Gómez, Sergio; Aucar, Gustavo A; Lamagna, Alberto; Boselli, Alfredo
2009-01-01T23:59:59.000Z
Ion Mobility Spectrometry (IMS) is a well-known, sensitive and rapid technique to detect dangerous organic compounds. We propose a system in which a crown type discharge generates a ionic flow that is swept towards an array of collectors by a transverse electric field. The ions are separated as they enter the cell according to their mobility. Thus, the distribution of the charge deposited at the detector assembly constitutes a {\\em fingerprint} for each organic compound. Simulations of our cell and experiments were performed for small amounts of acetone, ethanol and toluene. The dependence on the cell parameters of the current and charge versus time of flight was analyzed. Our simulation reproduces only qualitatively the experimental results. However, a PCA statistical analysis of the results obtained by simulation of the proposed design shows that the fingerprint is useful for a clear identification of such compounds.
Cosmology with Varying Constants
C. J. A. P. Martins
2000-08-18T23:59:59.000Z
I motivate and discuss some recent work on theories with varying constants, and consider some possible observational consequences and tests. Particular emphasis is given to models which can (almost) exactly mimic the predictions of standard inflationary models.
Ghosh, Indranil
2011-01-01T23:59:59.000Z
for a hidden truncated bivariate P (IV ) distributionfor a hidden truncated bivariate P (II) distributionof ? and the large sample distribution of the likelihood ra-
R. L. Collins
2006-01-10T23:59:59.000Z
Hubble plots of the distance of stellar objects vs. recession velocity normally assume the red shift is wholly Doppler and ignore any gravitational contribution. This is unwarranted: gravity and Doppler velocity red shifts are found to be separable and contribute about equally. A recent data set, to Z=1.2, by Riess (1), was analyzed. Upon plotting distance vs. Doppler velocity, the slope of the Hubble plot increases. The Hubble plot is also curved, upwards, and this can be understood in terms of the relativistic metric changes of the space through which the light travels. On fitting the data to a simple model of a big bang of constant density, this finds the total mass of the big bang is M=21.1x10^52 kg. When present actual distance is plotted vs. Doppler velocity, the plot is linear and agrees with Hubble's concept, without acceleration. Time since the big bang is longer than the 14 billion years that had been thought, 23.5 billion years. The Hubble constant hence shrinks from Ho=71 to Ho=41.6. This is an independent affirmation of a recent CMB finding of a low Ho=35.
A 13-Moment Two-Fluid Plasma Physics Model Based on a Pearson Type-IV Distribution Function
Shumlak, Uri
in Aeronautics and Astronautics University of Washington 2011 Program Authorized to Oer Degree: Aeronautics-IV Distribution Function Shaun Gilliam Chair of the Supervisory Committee: Professor Dr. Uri Shumlak Aeronautics
Unitaxial constant velocity microactuator
McIntyre, T.J.
1994-06-07T23:59:59.000Z
A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment is disclosed. The mechanism includes a flexible coupling having a bore therethrough, and two clamp/pusher assemblies mounted in axial ends of the coupling. The clamp/pusher assemblies are energized by voltage-operated piezoelectrics therewithin to operatively engage the shaft and coupling causing the shaft to move along its rotational axis through the bore. The microactuator is capable of repeatably positioning to sub-nanometer accuracy while affording a scan range in excess of 5 centimeters. Moreover, the microactuator generates smooth, constant velocity motion profiles while producing a drive thrust of greater than 10 pounds. The system is remotely controlled and piezoelectrically driven, hence minimal thermal loading, vibrational excitation, or outgassing is introduced to the operating environment. 10 figs.
Unitaxial constant velocity microactuator
McIntyre, Timothy J. (Knoxville, TN)
1994-01-01T23:59:59.000Z
A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment. The mechanism includes a flexible coupling having a bore therethrough, and two clamp/pusher assemblies mounted in axial ends of the coupling. The clamp/pusher assemblies are energized by voltage-operated piezoelectrics therewithin to operatively engage the shaft and coupling causing the shaft to move along its rotational axis through the bore. The microactuator is capable of repeatably positioning to sub-manometer accuracy while affording a scan range in excess of 5 centimeters. Moreover, the microactuator generates smooth, constant velocity motion profiles while producing a drive thrust of greater than 10 pounds. The system is remotely controlled and piezoelectrically driven, hence minimal thermal loading, vibrational excitation, or outgassing is introduced to the operating environment.
Optimization Online - Optimality gap of constant-order policies ...
Linwei Xin
2014-09-07T23:59:59.000Z
Sep 7, 2014 ... Optimality gap of constant-order policies decays exponentially in the lead time for ... For the special case of exponentially distributed demand, we further ... Category 1: Applications -- OR and Management Sciences (Supply ...
The Cosmological Constant in the Quantum Multiverse
Grant Larsen; Yasunori Nomura; H. L. L. Roberts
2011-12-14T23:59:59.000Z
Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and outcomes of particular experiments, according to a single probability formula. This provides complete unification of the eternally inflating multiverse and many worlds in quantum mechanics. In this paper we elucidate how cosmological parameters can be calculated in this framework, and study the probability distribution for the value of the cosmological constant. We consider both positive and negative values, and find that the observed value is consistent with the calculated distribution at an order of magnitude level. In particular, in contrast to the case of earlier measure proposals, our framework prefers a positive cosmological constant over a negative one. These results depend only moderately on how we model galaxy formation and life evolution therein.
Time-Varying Fine-Structure Constant Requires Cosmological Constant
R. W. Kuhne
1999-08-31T23:59:59.000Z
Webb et al. presented preliminary evidence for a time-varying fine-structure constant. We show Teller's formula for this variation to be ruled out within the Einstein-de Sitter universe, however, it is compatible with cosmologies which require a large cosmological constant.
Dimensionality and the Cosmological Constant
Z. C. Wu
2006-05-01T23:59:59.000Z
In the Kaluza-Klein model with a cosmological constant and a flux, the external spacetime and its dimension of the created universe from a $S^s \\times S^{n-s}$ seed instanton can be identified in quantum cosmology. One can also show that in the internal space the effective cosmological constant is most probably zero.
QCD coupling constants and VDM
Erkol, G.; Ozpineci, A.; Zamiralov, V. S. [Laboratory for Fundamental Research, Ozyegin University, Istanbul (Turkey); Physics Department, Middle East Technical University, 06531, Ankara (Turkey); Skobeltsyn Institute of Nuclear Physics, Lomonosov MSU, Moscow (Russian Federation)
2012-10-23T23:59:59.000Z
QCD sum rules for coupling constants of vector mesons with baryons are constructed. The corresponding QCD sum rules for electric charges and magnetic moments are also derived and with the use of vector-meson-dominance model related to the coupling constants. The VDM role as the criterium of reciprocal validity of the sum rules is considered.
La Mura, G; Ciroi, S; Rafanelli, P; Salvetti, D; Berton, M; Cracco, V
2015-01-01T23:59:59.000Z
During its first four years of scientific observations, the Fermi Large Area Telescope (Fermi-LAT) detected 3033 $\\gamma$-ray sources above a 4$\\sigma$ significance level. Although most of the extra-Galactic sources are active galactic nuclei (AGN) of the blazar class, other families of AGNs are observed too, while a still high fraction of detections ($\\sim 30\\%$) remains with uncertain association or classification. According to the currently accepted interpretation, the AGN $\\gamma$-ray emission arises from inverse Compton (IC) scattering of low energy photons by relativistic particles confined in a jet that, in the case of blazars, is oriented very close to our line of sight. Taking advantage of data from radio and X-ray wavelengths, which we expect to be produced together with $\\gamma$-rays, providing a much better source localization potential, we focused our attention on a sample of $\\gamma$-ray Blazar Candidates of Undetermined Type (BCUs), starting a campaign of optical spectroscopic observations. The...
Varying constants, Gravitation and Cosmology
Jean-Philippe Uzan
2010-09-28T23:59:59.000Z
Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. It is thus of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We thus detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, Solar system observations, meteorites dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.
Dimensionless constants, cosmology and other dark matters
Max Tegmark; Anthony Aguirre; Martin J Rees; Frank Wilczek
2006-01-11T23:59:59.000Z
We identify 31 dimensionless physical constants required by particle physics and cosmology, and emphasize that both microphysical constraints and selection effects might help elucidate their origin. Axion cosmology provides an instructive example, in which these two kinds of arguments must both be taken into account, and work well together. If a Peccei-Quinn phase transition occurred before or during inflation, then the axion dark matter density will vary from place to place with a probability distribution. By calculating the net dark matter halo formation rate as a function of all four relevant cosmological parameters and assessing other constraints, we find that this probability distribution, computed at stable solar systems, is arguably peaked near the observed dark matter density. If cosmologically relevant WIMP dark matter is discovered, then one naturally expects comparable densities of WIMPs and axions, making it important to follow up with precision measurements to determine whether WIMPs account for all of the dark matter or merely part of it.
How fundamental are fundamental constants?
M. J. Duff
2014-12-17T23:59:59.000Z
I argue that the laws of physics should be independent of one's choice of units or measuring apparatus. This is the case if they are framed in terms of dimensionless numbers such as the fine structure constant, alpha. For example, the Standard Model of particle physics has 19 such dimensionless parameters whose values all observers can agree on, irrespective of what clock, rulers, scales... they use to measure them. Dimensional constants, on the other hand, such as h, c, G, e, k..., are merely human constructs whose number and values differ from one choice of units to the next. In this sense only dimensionless constants are "fundamental". Similarly, the possible time variation of dimensionless fundamental "constants" of nature is operationally well-defined and a legitimate subject of physical enquiry. By contrast, the time variation of dimensional constants such as c or G on which a good many (in my opinion, confusing) papers have been written, is a unit-dependent phenomenon on which different observers might disagree depending on their apparatus. All these confusions disappear if one asks only unit-independent questions. We provide a selection of opposing opinions in the literature and respond accordingly.
How fundamental are fundamental constants?
Duff, M J
2014-01-01T23:59:59.000Z
I argue that the laws of physics should be independent of one's choice of units or measuring apparatus. This is the case if they are framed in terms of dimensionless numbers such as the fine structure constant, alpha. For example, the Standard Model of particle physics has 19 such dimensionless parameters whose values all observers can agree on, irrespective of what clock, rulers, scales... they use to measure them. Dimensional constants, on the other hand, such as h, c, G, e, k..., are merely human constructs whose number and values differ from one choice of units to the next. In this sense only dimensionless constants are "fundamental". Similarly, the possible time variation of dimensionless fundamental "constants" of nature is operationally well-defined and a legitimate subject of physical enquiry. By contrast, the time variation of dimensional constants such as c or G on which a good many (in my opinion, confusing) papers have been written, is a unit-dependent phenomenon on which different observers might...
Hardy–Sobolev Type Inequalities with Sharp Constants in Carnot ...
2011-03-02T23:59:59.000Z
Jun 24, 2010 ... To introduce our main result consider a system X = {X1, ..., Xm} of C ... (personal communication), where a similar construction was carried in ...
The Effects of Quantum Entropy on the Bag Constant
Miller, D E; Miller, David E.; Tawfik, Abdel-Nasser
2003-01-01T23:59:59.000Z
The effects of quantum entropy on the bag constant are studied at low temperatures and small chemical potentials. The inclusion of the quantum entropy of the quarks in the equation of state provides the hadronic bag with an additional heat which causes a decrease in the effective latent heat inside the bag. We have considered two types of baryonic bags, $\\Delta$ and $\\Omega^-$. In both cases we have found that the bag constant without the quantum entropy almost does not change with the temperature and the quark chemical potential. The contribution from the quantum entropy to the equation of state clearly decreases the value of the bag constant.
Makhkamov, K.K.; Ingham, D.B.
1999-11-01T23:59:59.000Z
A theoretical study on the air flow and temperature in the heat receiver, affected by free convection, of a Stirling Engine for a Dish/Stirling Engine Power System is presented. The standard {kappa}-{epsilon} turbulence model for the fluid flow has been used and the boundary conditions employed were obtained using a second level mathematical model of the Stirling Engine working cycle. Physical models for the distribution of the solar insolation from the Concentrator on the bottom and side walls of the cavity-type heat receiver have been taken into account. The numerical results show that most of the heat losses in the receiver are due to re-radiation from the cavity and conduction through the walls of the cavity. It is in the region of the boundary of the input window of the heat receiver where there is a sensible reduction in the temperature in the shell of the heat exchangers and this is due to the free convection of the air. Further, the numerical results show that convective heat losses increase with decreasing tilt angle.
Distinct Cyclin D Genes Show Mitotic Accumulation or Constant Levels of Transcripts in Tobacco
Murray, J.A.H.
Distinct Cyclin D Genes Show Mitotic Accumulation or Constant Levels of Transcripts in Tobacco-type cyclins accumulate peri- odically during the S, G2, and early M phases (A types) or G2 and early M phases
Constant-Time Distributed Dominating Set Approximation Fabian Kuhn
- less devices have much lower bandwidth than their wired counterparts and 2) wireless devices are mobile part) by the National Competence Center in Research on Mobile Information and Communication Systems. A particular application can be found in the fast growing field of mobile ad-hoc networks. In mobile ad
Renormalization of Newton's constant and Particle Physics
X. Calmet
2010-02-02T23:59:59.000Z
We report on particle physics applications of the renormalization group equation of Newton's constant.
Low-energy constants from ALEPH hadronic tau decay data
Boito, Diogo; Golterman, Maarten; Hudspith, Renwick; Lewis, Randy; Maltman, Kim; Peris, Santiago
2015-01-01T23:59:59.000Z
We determined the NLO chiral low-energy constant $L_{10}$, and various combinations of NNLO chiral low-energy constants employing recently revised ALEPH results for the non-strange vector (V) and axial-vector (A) hadronic tau decay distributions and recently updated RBC/UKQCD lattice data for the non-strange V-A two-point function. In this talk, we explain the ingredients of this determination. Our errors are at or below the level expected for contributions of yet higher order in the chiral expansion, suggesting that our results exhaust the possibilities of what can be meaningfully achieved in an NNLO analysis.
Towards the cosmological constant problem
Eun Kyung Park; Pyung Seong Kwon
2014-12-15T23:59:59.000Z
We apply a new self-tuning mechanism to the well-known Kachru-Kallosh-Linde-Trivedi (KKLT) model to address the cosmological constant problem. In this mechanism the cosmological constant $\\lambda$ contains a supersymmetry breaking term ${\\mathcal E}_{\\rm SB}$ besides the usual scalar potential ${\\mathcal V}_{\\rm scalar}$ of the $N=1$ supergravity, which is distinguished from the usual theories where $\\lambda$ is directly identified with ${\\mathcal V}_{\\rm scalar}$ alone. Also in this mechanism, whether $\\lambda$ vanishes or not is basically determined by the tensor structure of the scalar potential density, not by the zero or nonzero values of the scalar potential itself. As a result of this application we find that the natural scenario for the vanishing $\\lambda$ of the present universe is to take one of the AdS (rather than dS) vacua of KKLT as the background vacuum of our present universe. This AdS vacuum scenario does not suffer from the problematics of the dS vacua of KKLT. The background vacuum is stable both classically and quantum mechanically (no tunneling instabilities), and the value $\\lambda =0$ is also stable against quantum corrections because in this scenario the perturbative corrections of ${\\mathcal V}_{\\rm scalar}$ and quantum fluctuations $\\delta_Q {\\hat I}_{\\rm brane}^{(NS)} + \\delta_Q {\\hat I}_{\\rm brane}^{(R)}$ on the branes are all gauged away by an automatic cancelation between ${\\mathcal V}_{\\rm scalar} + \\delta_Q {\\hat I}_{\\rm brane}^{(NS)} + \\delta_Q {\\hat I}_{\\rm brane}^{(R)}$ and ${\\mathcal E}_{\\rm SB}$.
Statistical theory of elastic constants of cholesteric liquid crystals
A. Kapanowski
2009-10-20T23:59:59.000Z
A statistical theory of cholesteric liquid crystals composed of short rigid biaxial molecules is presented. It is derived in the thermodynamic limit at a small density and a small twist. The uniaxial (biaxial) cholesteric phase is regarded as a distorted form of the uniaxial (biaxial) nematic phase. The chirality of the interactions and the implementation of the inversion to the rotation matrix elements are discussed in detail. General microscopic expressions for the elastic constants are derived. The expressions involve the one-particle distribution function and the potential energy of two-body short-range interactions. It is shown that the elastic constants determine the twist of the phase. The stability condition for the cholesteric and nematic phases is presented. The theory is used to study unary and binary systems. The temperature and concentration dependence of the order parameters, the elastic constants and the twist of the phase are obtained. The possibility of phase separation is not investigated.
An Issue to the Cosmological Constant Problem
R. Triay
2005-04-07T23:59:59.000Z
According to general relativity, the present analysis shows on geometrical grounds that the cosmological constant problem is an artifact due to the unfounded link of this fundamental constant to vacuum energy density of quantum fluctuations.
MINIMAL SURFACES, SURFACES OF CONSTANT MEAN ...
2003-09-25T23:59:59.000Z
constant Ciso(G) > 0 of Theorem 12.1, for any go ? G, R > 0, one has for every ... constant Ciso = Ciso(G) > 0 as in Theorem 12.4, for every X-Caccioppoli set E ...
PHYSICS & ASTRONOMY DATA CARD Physical Constants
Greenaway, Alan
's constant h 6.626 x 10-34 J s Ñ= h/2 1.055 x 10-34 J s Avogadro's constant NA 6.022 x 1023 mol-1 Boltzmann
Constant time algorithms in sparse graph model
Nguyen, Huy Ngoc, Ph. D. Massachusetts Institute of Technology
2010-01-01T23:59:59.000Z
We focus on constant-time algorithms for graph problems in bounded degree model. We introduce several techniques to design constant-time approximation algorithms for problems such as Vertex Cover, Maximum Matching, Maximum ...
CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS...
Office of Scientific and Technical Information (OSTI)
CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE HUBBLE CONSTANT Citation Details In-Document Search Title: CEPHEID CALIBRATIONS OF MODERN TYPE Ia...
Paris-Sud XI, Université de
converts the optical signal into an electrical one. After, the signal is sent into a low noise amplifier a new generation of optoelec- tronic components designed for 60 GHz applications. I. RADIO OVER FIBRE and distribution of a 3 Gb/s OFDM signal. The first one uses low cost well known components and the second one
Ferraro, R. J.; Osborne, R.; Stephens, R.
) an increase in loads that use power electronics in some type of power conversion configuration [1][2]. This paper presents applications of the constant-voltage transformer (CVT) for mitigating the effects of electric service voltage sags on industrial...
Emergent cosmological constant from colliding electromagnetic waves
Halilsoy, M.; Mazharimousavi, S. Habib; Gurtug, O., E-mail: mustafa.halilsoy@emu.edu.tr, E-mail: habib.mazhari@emu.edu.tr, E-mail: ozay.gurtug@emu.edu.tr [Department of Physics, Eastern Mediterranean University, Gazimavgusa, north Cyprus, Mersin 10 (Turkey)
2014-11-01T23:59:59.000Z
In this study we advocate the view that the cosmological constant is of electromagnetic (em) origin, which can be generated from the collision of em shock waves coupled with gravitational shock waves. The wave profiles that participate in the collision have different amplitudes. It is shown that, circular polarization with equal amplitude waves does not generate cosmological constant. We also prove that the generation of the cosmological constant is related to the linear polarization. The addition of cross polarization generates no cosmological constant. Depending on the value of the wave amplitudes, the generated cosmological constant can be positive or negative. We show additionally that, the collision of nonlinear em waves in a particular class of Born-Infeld theory also yields a cosmological constant.
Constant voltage electro-slag remelting control
Schlienger, Max E. (Albuquerque, NM)
1996-01-01T23:59:59.000Z
A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an eletrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable.
Cosmological Constant and Axions in String Theory
Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC
2006-08-18T23:59:59.000Z
String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.
Constant voltage electro-slag remelting control
Schlienger, M.E.
1996-10-22T23:59:59.000Z
A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an electrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable. 1 fig.
Berryman, J.G.; Nakagawa, S.
2009-11-20T23:59:59.000Z
Poroelastic analysis has traditionally focused on the relationship between dry or drained constants which are assumed known and the saturated or undrained constants which are assumed unknown. However, there are many applications in this field of study for which the main measurements can only be made on the saturated/undrained system, and then it is uncertain what the eects of the uids were on the system, since the drained constants remain a mystery. The work presented here shows how to deduce drained constants from undrained constants for anisotropic systems having symmetries ranging from isotropic to orthotropic. Laboratory ultrasound data are then inverted for the drained constants in three granular packings: one of glass beads, and two others for distinct types of more or less angular sand grain packings. Experiments were performed under uniaxial stress, which resulted in hexagonal (transversely isotropic) symmetry of the poroelastic response. One important conclusion from the general analysis is that the drained constants are uniquely related to the undrained constants, assuming that porosity, grain bulk modulus, and pore uid bulk modulus are already known. Since the resulting system of equations for all the drained constants is linear, measurement error in undrained constants also propagates linearly into the computed drained constants.
Turner, Ken
) (ISO/IEC 1995a, ISO/IEC 1995b, ISO/IEC 1995c, ISO/IEC 1995d, ISO/IEC 1995e). We argue that the types be found elsewhere. We present a formalisation of these new considerations in the language Z (ISO/IEC 1995f
A natural cosmological constant from chameleons
Horatiu Nastase; Amanda Weltman
2015-04-06T23:59:59.000Z
We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru-Kallosh-Linde-Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the local density, patches of approximately constant scalar field potential cluster around regions of matter with density above a certain value, generating the effect of a cosmological constant on large scales. This construction addresses both the cosmological constant problem (why $\\Lambda$ is so small, yet nonzero) and the coincidence problem (why $\\Lambda$ is comparable to the matter density now).
Vacuum Energy and the Cosmological Constant
A. C. Melissinos
2001-12-19T23:59:59.000Z
We discuss a numerical relation between the cosmological constant and the vacuum energy arising from the Casimir effect in extra dimensions
Fisher, Aaron Jay
2007-04-25T23:59:59.000Z
is a result of selective grain and pore-wall dissolution related to burial diagenesis. Additionally, saddle dolomite is irregularly distributed throughout the reservoir, indicating that late burial diagenesis contributed to the complexity... is a hybrid of depositional and diagenetic processes and no fracture porosity was found to be evident. It is evident that at least two early stages of cementation and dissolution have taken place. Dissolution of reservoir rock is a diagenetic...
Sequential Constant Size Compressors for Reinforcement Learning
Schmidhuber, Juergen
Sequential Constant Size Compressors for Reinforcement Learning Linus GisslÂ´en, Matt Luciw, Vincent with this problem: standard RL techniques using as input the hidden layer output of a Sequential Constant-Size Compressor (SCSC). The SCSC takes the form of a sequential Recurrent Auto-Associative Mem- ory, trained
Newtonian Constant of Gravitation International Consortium
Newtonian Constant of Gravitation International Consortium I. BACKGROUND Recent measurements of the Newtonian constant of gravitation G are in disagreement, with discrepancies that are roughly ten times forces on a laboratory scale. It also raises the question of whether the Newtonian force law
Vacuum Fluctuations and the Cosmological Constant
Shi Qi
2006-04-29T23:59:59.000Z
The hypothesis is proposed that under the approximation that the quantum equations of motion reduce to the classical ones, the quantum vacuum also reduces to the classical vacuum--the empty space. The vacuum energy of QED is studied under this hypothesis. A possible solution to the cosmological constant problem is provided and a kind of parameterization of the cosmological "constant" is derived.
Bubble Universes With Different Gravitational Constants
Yu-ichi Takamizu; Kei-ichi Maeda
2015-04-21T23:59:59.000Z
We argue a scenario motivated by the context of string landscape, where our universe is produced by a new vacuum bubble embedded in an old bubble and these bubble universes have not only different cosmological constants, but also their own different gravitational constants. We study these effects on the primordial curvature perturbations. In order to construct a model of varying gravitational constants, we use the Jordan-Brans-Dicke (JBD) theory where different expectation values of scalar fields produce difference of constants. In this system, we investigate the nucleation of bubble universe and dynamics of the wall separating two spacetimes. In particular, the primordial curvature perturbation on superhorizon scales can be affected by the wall trajectory as the boundary effect. We show the effect of gravitational constant in the exterior bubble universe can provide a peak like a bump feature at a large scale in a modulation of power spectrum.
Bubble Universes With Different Gravitational Constants
Takamizu, Yu-ichi
2015-01-01T23:59:59.000Z
We argue a scenario motivated by the context of string landscape, where our universe is produced by a new vacuum bubble embedded in an old bubble and these bubble universes have not only different cosmological constants, but also their own different gravitational constants. We study these effects on the primordial curvature perturbations. In order to construct a model of varying gravitational constants, we use the Jordan-Brans-Dicke (JBD) theory where different expectation values of scalar fields produce difference of constants. In this system, we investigate the nucleation of bubble universe and dynamics of the wall separating two spacetimes. In particular, the primordial curvature perturbation on superhorizon scales can be affected by the wall trajectory as the boundary effect. We show the effect of gravitational constant in the exterior bubble universe can provide a peak like a bump feature at a large scale in a modulation of power spectrum.
Ji, Haojie; Dhomkar, Siddharth; Roy, Bidisha; Kuskovsky, Igor L. [Department of Physics, Queens College of CUNY, Queens, New York 11367 (United States); The Graduate Center of CUNY, New York, New York 10016 (United States); Shuvayev, Vladimir [Department of Physics, Queens College of CUNY, Queens, New York 11367 (United States); Deligiannakis, Vasilios; Tamargo, Maria C. [The Graduate Center of CUNY, New York, New York 10016 (United States); Department of Chemistry, City College of CUNY, New York, New York 10031 (United States); Ludwig, Jonathan [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States); Smirnov, Dmitry [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Wang, Alice [Evans Analytical Group, Sunnyvale, California 94086 (United States)
2014-10-28T23:59:59.000Z
For submonolayer quantum dot (QD) based photonic devices, size and density of QDs are critical parameters, the probing of which requires indirect methods. We report the determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer QDs, based on spectral analysis of the optical signature of Aharanov-Bohm (AB) excitons, complemented by photoluminescence studies, secondary-ion mass spectroscopy, and numerical calculations. Numerical calculations are employed to determine the AB transition magnetic field as a function of the type-II QD radius. The study of four samples grown with different tellurium fluxes shows that the lateral size of QDs increases by just 50%, even though tellurium concentration increases 25-fold. Detailed spectral analysis of the emission of the AB exciton shows that the QD radii take on only certain values due to vertical correlation and the stacked nature of the QDs.
Spectral Properties and Dynamical Tunneling in Constant-Width Billiards
B. Dietz; T. Guhr; B. Gutkin; M. Miski-Oglu; A. Richter
2014-07-24T23:59:59.000Z
We determine with unprecedented accuracy the lowest 900 eigenvalues of two quantum constant-width billiards from resonance spectra measured with flat, superconducting microwave resonators. While the classical dynamics of the constant-width billiards is unidirectional, a change of the direction of motion is possible in the corresponding quantum system via dynamical tunneling. This becomes manifest in a splitting of the vast majority of resonances into doublets of nearly degenerate ones. The fluctuation properties of the two respective spectra are demonstrated to coincide with those of a random-matrix model for systems with violated time-reversal invariance and a mixed dynamics. Furthermore, we investigate tunneling in terms of the splittings of the doublet partners. On the basis of the random-matrix model we derive an analytical expression for the splitting distribution which is generally applicable to systems exhibiting dynamical tunneling between two regions with (predominantly) chaotic dynamics.
Constants and Pseudo-Constants of Coupled Beam Motion in the PEP-II Rings
Decker, F.J.; Colocho, W.S.; Wang, M.H.; Yan, Y.T.; Yocky, G.; /SLAC
2011-11-01T23:59:59.000Z
Constants of beam motion help as cross checks to analyze beam diagnostics and the modeling procedure. Pseudo-constants, like the betatron mismatch parameter or the coupling parameter det C, are constant till certain elements in the beam line change them. This can be used to visually find the non-desired changes, pinpointing errors compared with the model.
The Meaning Of The Fine Structure Constant
R. L. Oldershaw
2009-02-21T23:59:59.000Z
A possible explanation is offered for the longstanding mystery surrounding the meaning of the fine structure constant. The reasoning is based on a discrete self-similar cosmological paradigm that has shown promise in explaining the general scaling properties of nature's global hierarchy. The discrete scale invariance of the paradigm implies that "strong gravity" governs gravitational interactions within atomic scale systems. Given the revised gravitational coupling constant and Planck mass, one can demonstrate that the fine structure constant is the ratio of the strengths of the unit electromagnetic interaction and the unit gravitational interaction within atomic scale systems. [Abridged
A Nuclear Data Approach for the Hubble Constant Measurements
Pritychenko, B
2015-01-01T23:59:59.000Z
An extraordinary number of Hubble constant measurements challenges physicists with selection of the best numerical value. The standard U.S. Nuclear Data Program (USNDP) codes and procedures have been applied to resolve this issue. The nuclear data approach has produced the most probable or recommended Hubble constant value of 67.00(770) (km/sec)/Mpc. This recommended value is based on the last 25 years of experimental research and includes contributions from different types of measurements. The present result implies (14.6$\\pm$1.7)$\\times$10$^{9}$ years as a rough estimate for the age of the Universe. The complete list of recommended results is given and possible implications are discussed.
Asymptotically Vanishing Cosmological Constant in the Multiverse
Hikaru Kawai; Takashi Okada
2011-04-21T23:59:59.000Z
We study the problem of the cosmological constant in the context of the multiverse in Lorentzian spacetime, and show that the cosmological constant will vanish in the future. This sort of argument was started from Coleman in 1989, and he argued that the Euclidean wormholes make the multiverse partition a superposition of various values of the cosmological constant $\\Lambda$, which has a sharp peak at $\\Lambda=0$. However, the implication of the Euclidean analysis to our Lorentzian spacetime is unclear. With this motivation, we analyze the quantum state of the multiverse in Lorentzian spacetime by the WKB method, and calculate the density matrix of our universe by tracing out the other universes. Our result predicts vanishing cosmological constant. While Coleman obtained the enhancement at $\\Lambda=0$ through the action itself, in our Lorentzian analysis the similar enhancement arises from the front factor of $e^{iS}$ in the universe wave function, which is in the next leading order in the WKB approximation.
DISTRIBUTED SHORTESTPATH PROTOCOLS TIMEDEPENDENT NETWORKS
Orda, Ariel
DISTRIBUTED SHORTESTPATH PROTOCOLS for TIMEDEPENDENT NETWORKS Ariel Orda Raphael Rom+ Department and the dynamic behavior of networks, since a distributed solution enables constant tracking of changes 32000 October 1992 Revised May 1994, October 1995 ABSTRACT This paper addresses algorithms for networks
FRIB cryogenic distribution system
Ganni, V.; Dixon, K.; Laverdure, N.; Knudsen, P.; Arenius, D. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States); Barrios, M.; Jones, S.; Johnson, M.; Casagrande, F. [Facility for Rare Isotope Beams (FRIB), Michigan State University, East Lansing, MI 48824 (United States)
2014-01-29T23:59:59.000Z
The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.
FRIB cryogenic distribution system
Ganni, Venkatarao [JLAB; Dixon, Kelly D. [JLAB; Laverdure, Nathaniel A. [JLAB; Knudsen, Peter N. [JLAB; Arenius, Dana M. [JLAB; Barrios, Matthew N. [Michigan State; Jones, S. [Michigan State; Johnson, M. [Michigan State; Casagrande, Fabio [Michigan State
2014-01-01T23:59:59.000Z
The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.
Cosmological constant in scale-invariant theories
Foot, Robert; Kobakhidze, Archil; Volkas, Raymond R. [School of Physics, University of Melbourne, Victoria 3010 (Australia)
2011-10-01T23:59:59.000Z
The incorporation of a small cosmological constant within radiatively broken scale-invariant models is discussed. We show that phenomenologically consistent scale-invariant models can be constructed which allow a small positive cosmological constant, providing certain relation between the particle masses is satisfied. As a result, the mass of the dilaton is generated at two-loop level. Another interesting consequence is that the electroweak symmetry-breaking vacuum in such models is necessarily a metastable ''false'' vacuum which, fortunately, is not expected to decay on cosmological time scales.
Electromagnetic corrections to pseudoscalar decay constants
Benjamin Glaessle; Gunnar S. Bali
2011-11-16T23:59:59.000Z
The effects of electromagnetic interactions on pseudoscalar decay constants are investigated. Using a compact QED and QCD action we are able to resolve differences of about 0.1 MeV. We obtain the preliminary results f_pi^0-f_pi^+/- =0.09(3) MeV and f_D^0-f_D^+/- =0.79(11) MeV for light and charmed pseudoscalar decay constants on a N_f=2 nonperturbatively improved Sheikholeslami-Wohlert ensemble.
The Vacuum and the Cosmological Constant Problem
Gerald E. Marsh
2008-06-20T23:59:59.000Z
It will be argued here that the cosmological constant problem exists because of the way the vacuum is defined in quantum field theory. It has been known for some time that for QFT to be gauge invariant certain terms--such as part of the vacuum polarization tensor--must be eliminated either explicitly or by some form of regularization followed by renormalization. It has recently been shown that lack of gauge invariance is a result of the way the vacuum is defined, and redefining the vacuum so that the theory is gauge invariant may also offer a solution to the cosmological constant problem.
Environmental Dependence of Masses and Coupling Constants
Keith A. Olive; Maxim Pospelov
2008-01-04T23:59:59.000Z
We construct a class of scalar field models coupled to matter that lead to the dependence of masses and coupling constants on the ambient matter density. Such models predict a deviation of couplings measured on the Earth from values determined in low-density astrophysical environments, but do not necessarily require the evolution of coupling constants with the redshift in the recent cosmological past. Additional laboratory and astrophysical tests of \\Delta \\alpha and \\Delta(m_p/m_e) as functions of the ambient matter density are warranted.
Matyushov, Dmitry
Thermodynamics and dynamics of a monoatomic glass former. Constant pressure and constant volume-pressure simulations of the thermodynamic and dynamic properties of the low-temperature liquid and crystalline phases the thermodynamics of the configurational manifold as an ensemble of excitations, each carrying an excitation entropy
Constant-Pressure Measurement of Steam-
Stanford University
SGP-TR-169 Constant-Pressure Measurement of Steam- Water Relative Permeability Peter A. O by measuring in-situ steam saturation more directly. Mobile steam mass fraction was established by separate steam and water inlets or by correlating with previous results. The measured steam-water relative
Vacuum Fluctuations Cannot Mimic a Cosmological Constant
Robert D. Klauber
2007-11-05T23:59:59.000Z
When the vacuum fluctuation pressure is calculated directly from fundamental principles of quantum field theory, in the same manner as vacuum fluctuation energy density is commonly calculated, one finds it is not equal to the negative of the vacuum fluctuation energy density. Thus, vacuum fluctuations cannot manifest as a cosmological constant of any order.
High Dielectric Constant Capacitors for Power Electronic Systems...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Dielectric Constant Capacitors for Power Electronic Systems High Dielectric Constant Capacitors for Power Electronic Systems 2009 DOE Hydrogen Program and Vehicle Technologies...
High Dialectric Constant Capacitors for Power Electronic Systems...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
High Dialectric Constant Capacitors for Power Electronic Systems High Dialectric Constant Capacitors for Power Electronic Systems 2012 DOE Hydrogen and Fuel Cells Program and...
High-Dialectric-Constant Capacitors for Power Electronic Systems...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
High-Dialectric-Constant Capacitors for Power Electronic Systems High-Dialectric-Constant Capacitors for Power Electronic Systems 2011 DOE Hydrogen and Fuel Cells Program, and...
High Dialectric Constant Capacitors for Power Electronic Systems...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Dialectric Constant Capacitors for Power Electronic Systems High Dialectric Constant Capacitors for Power Electronic Systems 2010 DOE Vehicle Technologies and Hydrogen Programs...
Cosmological constant and quantum gravitational corrections to the running fine structure constant
David J. Toms
2008-09-23T23:59:59.000Z
The quantum gravitational contribution to the renormalization group behavior of the electric charge in Einstein-Maxwell theory with a cosmological constant is considered. Quantum gravity is shown to lead to a contribution to the running charge not present when the cosmological constant vanishes. This re-opens the possibility, suggested by Robinson and Wilczek, of altering the scaling behaviour of gauge theories at high energies although our result differs. We show the possibility of an ultraviolet fixed point that is linked directly to the cosmological constant.
Variable energy constant current accelerator structure
Anderson, O.A.
1988-07-13T23:59:59.000Z
A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90/degree/ intervals with opposing electrodes maintained at the same potential. 12 figs., 3 tabs.
Light Dragging, the Origin of Hubble's Constant
Walter J. Christensen Jr
2008-10-07T23:59:59.000Z
Recently E. Harrison has argued the Red Shift distance law proposed by Hubble and velocity-distance law developed later on theoretical grounds has no general proof demonstrating the two laws are actually equivalent. It is the purpose of this paper to account for the nebular redshift law of Hubble based on two principles: 1) Spacetime motion and light dragging. 2) An overall spacetime index of refraction based on Hubble's Constant.
Comment on "Black holes constrain varying constants"
V. V. Flambaum
2002-08-20T23:59:59.000Z
A recent paper [DDL] claims that the increase of the proton electric charge e leads to a (forbidden) decrease of black hole entropy, therefore, possible evidence for variation of $\\alpha=e^2/\\hbar c$ [alpha] must be interpreted as a decrease of the speed of light. We argue that purely theoretical consideration of black holes possibly cannot give any model-independent limitations on variation of fundamental constants.
Which Fundamental Constants for CMB and BAO?
Rich, James
2015-01-01T23:59:59.000Z
We study the Cosmic Microwave Background using the three-scale framework of Hu et al. to derive the dependence of the CMB temperature anisotropy spectrum on the fundamental constants. We show that, as expected, the observed spectrum depends only on \\emph{dimensionless} combinations of the constants, and we emphasize the points that make this generally true for cosmological observations. Our analysis suggests that the CMB spectrum shape is mostly determined by $\\alpha^2m_e/m_p$ and the proton-CDM-particle mass ratio, $m_p/\\mchi$, with a sub-dominant dependence on $(G\\mchi m_e/\\hbar c)\\alpha^\\beta$ with $\\beta\\sim -7$. The distance to the last-scattering surface depends on $Gm_p\\mchi/\\hbar c$, so published CMB observational limits on time variations of the constants, besides making assumptions about the form of the dark-energy, implicitly assume the time-independence of this quantity. On the other hand, low-redshift $H_0$, BAO and large-scale structure data can be combined with the \\emph{shape} of the CMB spect...
Can Compactifications Solve the Cosmological Constant Problem?
Hertzberg, Mark P
2015-01-01T23:59:59.000Z
Recently, there have been claims in the literature that the cosmological constant problem can be dynamically solved by specific compactifications of gravity from higher-dimensional toy models. These models have the novel feature that in the four-dimensional theory, the cosmological constant $\\Lambda$ is much smaller than the Planck density and in fact accumulates at $\\Lambda=0$. Here we show that while these are very interesting models, they do not properly address the real cosmological constant problem. As we explain, the real problem is not simply to obtain $\\Lambda$ that is small in Planck units in a toy model, but to explain why $\\Lambda$ is much smaller than other mass scales (and combinations of scales) in the theory. Instead, in these toy models, all other particle mass scales have been either removed or sent to zero, thus ignoring the real problem. To this end, we provide a general argument that the included moduli masses are generically of order Hubble, so sending them to zero trivially sends the cos...
Predicting the Cosmological Constant from the Causal Entropic Principle
Bousso, Raphael; Bousso, Raphael; Harnik, Roni; Kribs, Graham D.; Perez, Gilad
2007-05-01T23:59:59.000Z
We compute the expected value of the cosmological constant in our universe from the Causal Entropic Principle. Since observers must obey the laws of thermodynamics and causality, the principle asserts that physical parameters are most likely to be found in the range of values for which the total entropy production within a causally connected region is maximized. Despite the absence of more explicit anthropic criteria, the resulting probability distribution turns out to be in excellent agreement with observation. In particular, we find that dust heated by stars dominates the entropy production, demonstrating the remarkable power of this thermodynamic selection criterion. The alternative approach-weighting by the number of"observers per baryon" -- is less well-defined, requires problematic assumptions about the nature of observers, and yet prefers values larger than present experimental bounds.
Predicting the Cosmological Constant from the CausalEntropic Principle
Bousso, Raphael; Harnik, Roni; Kribs, Graham D.; Perez, Gilad
2007-02-20T23:59:59.000Z
We compute the expected value of the cosmological constant in our universe from the Causal Entropic Principle. Since observers must obey the laws of thermodynamics and causality, it asserts that physical parameters are most likely to be found in the range of values for which the total entropy production within a causally connected region is maximized. Despite the absence of more explicit anthropic criteria, the resulting probability distribution turns out to be in excellent agreement with observation. In particular, we find that dust heated by stars dominates the entropy production, demonstrating the remarkable power of this thermodynamic selection criterion. The alternative approach--weighting by the number of ''observers per baryon''--is less well-defined, requires problematic assumptions about the nature of observers, and yet prefers values larger than present experimental bounds.
Computing the dielectric constant of liquid water at constant dielectric displacement
Zhang, Chao
2015-01-01T23:59:59.000Z
The static dielectric constant of liquid water is computed using classical force field based molecular dynamics simulation at fixed electric displacement D. The method to constrain the electric displacement is the finite temperature classical variant of the constant-D method developed by Stengel, Spaldin and Vanderbilt (Nat. Phys. 2009, 5: 304). There is also a modification of this scheme imposing fixed values of the macroscopic field E. The method is applied to the popular SPC/E model of liquid water. We compare four different estimates of the dielectric constant, two obtained from fluctuations of the polarization at D = 0 and E = 0 and two from the variation of polarization with finite D and E. It is found that all four estimates agree when properly converged. The computational effort to achieve convergence varies however, with constant D calculations being substantially more efficient. We attribute this difference to the much shorter relaxation time of longitudinal polarization compared to transverse polar...
Osborne, David; Lawson, Patrick; Adams, Nigel, E-mail: ngadams@uga.edu [University of Georgia, Department of Chemistry, 101 Cedar St., Athens, Georgia 30602 (United States)] [University of Georgia, Department of Chemistry, 101 Cedar St., Athens, Georgia 30602 (United States)
2014-01-21T23:59:59.000Z
Following the arrival of Cassini at Titan in 2004, the Titan atmosphere has been shown to contain large complex polycyclic-aromatic hydrocarbons. Since Cassini has provided a great deal of data, there exists a need for kinetic rate data to help with modeling this atmosphere. One type of kinetic data needed is electron-ion dissociative recombination (e-IDR) rate constants. These data are not readily available for larger compounds, such as naphthalene, or oxygen containing compounds, such as 1,4 dioxane or furan. Here, the rate constants for naphthalene, 1,4 dioxane, and furan have been measured and their temperature dependencies are determined when possible, using the University of Georgia's Variable Temperature Flowing Afterglow. The rate constants are compared with those previously published for other compounds; these show trends which illustrate the effects which multi-rings and oxygen heteroatoms substitutions have upon e-IDR rate constants.
Schenato, Luca
Networked Control Systems Clock Sync Channel identification in WSN Distributed control of Smart. Sandro Zampieri #12;Networked Control Systems Clock Sync Channel identification in WSN Distributed Systems Clock Sync Channel identification in WSN Distributed control of Smart Grids Conclusions Issues
Self-gravitating scalar breathers with negative cosmological constant
Gyula Fodor; Péter Forgács; Philippe Grandclément
2015-07-10T23:59:59.000Z
Breather-type (time-periodic and spatially localized) solutions with spherical symmetry are investigated in a massless scalar field theory coupled to Einstein's gravity with cosmological constant in $d$ spatial dimensions imposing anti de Sitter (AdS) asymptotics on space-time. Using a code constructed with the Kadath library that enables the use of spectral methods, the phase space of breather solutions is explored in detail for $d=3$ and $d=4$. It is found that there are discrete families of solutions indexed by an integer and by their frequency. Using a time evolution code these AdS breathers are found to be stable for up to a critical central density, in analogy to boson stars. Using an analytical perturbative expansion small amplitude breathers are worked out for arbitrary dimensions $d$.
On the local variation of the Hubble constant
Odderskov, Io; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Haugbølle, Troels, E-mail: isho07@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: troels.haugboelle@snm.ku.dk [Centre for Star and Planet Formation, Natural History Museum of Denmark and Niels Bohr Institute University of Copenhagen, DK-1350 Copenhagen (Denmark)
2014-10-01T23:59:59.000Z
We have carefully studied how local measurements of the Hubble constant, H{sub 0}, can be influenced by a variety of different parameters related to survey depth, size, and fraction of the sky observed, as well as observer position in space. Our study is based on N-body simulations of structure in the standard ?CDM model and our conclusion is that the expected variance in measurements of H{sub 0} is far too small to explain the current discrepancy between the low value of H{sub 0} inferred from measurements of the cosmic microwave background (CMB) by the Planck collaboration and the value measured directly in the local universe by use of Type Ia supernovae. This conclusion is very robust and does not change with different assumptions about effective sky coverage and depth of the survey or observer position in space.
Fine-structure constant constraints on dark energy
Martins, C J A P
2015-01-01T23:59:59.000Z
We use astrophysical and atomic clock tests of the stability of the fine-structure constant $\\alpha$, together with Type Ia supernova and Hubble parameter data, to constrain the simplest class of dynamical dark energy models where the same degree of freedom is assumed to provide both the dark energy and (through a dimensionless coupling, $\\zeta$, to the electromagnetic sector) the $\\alpha$ variation. We show how current data tightly constrains a combination of $\\zeta$ and the dark energy equation of state $w_0$. At the $95\\%$ confidence level and marginalizing over $w_0$ we find $|\\zeta|<5\\times10^{-6}$, with the atomic clock tests dominating the constraints. The forthcoming generation of high-resolution ultra-stable spectrographs will enable significantly tighter constraints.
Low Energy Constants from the zero mode contribution to the pseudo-scalar correlator
S. Shcheredin; W. Bietenholz
2005-08-31T23:59:59.000Z
We apply different types of overlap operators in quenched QCD simulations to compute the zero mode contribution to the pseudo-scalar correlator. In particular we use the conventional Neuberger Dirac operator and the overlap hypercube Dirac operator. Confronting our data with the analytical predictions by Chiral Perturbation Theory we evaluate the pion decay constant and the parameter \\alpha of the quenched chiral Lagrangian.
randomly and equally likely a point in that interval), the uniform distribution ... Roughly speaking, this means that from any distribution we can create the uniform.
Stability of adhesion clusters under constant force
T. Erdmann; U. S. Schwarz
2004-01-27T23:59:59.000Z
We solve the stochastic equations for a cluster of parallel bonds with shared constant loading, rebinding and the completely dissociated state as an absorbing boundary. In the small force regime, cluster lifetime grows only logarithmically with bond number for weak rebinding, but exponentially for strong rebinding. Therefore rebinding is essential to ensure physiological lifetimes. The number of bonds decays exponentially with time for most cases, but in the intermediate force regime, a small increase in loading can lead to much faster decay. This effect might be used by cell-matrix adhesions to induce signaling events through cytoskeletal loading.
A Measurement of Newton's Gravitational Constant
St. Schlamminger; E. Holzschuh; W. Kündig; F. Nolting; R. E. Pixley; J. Schurr; U. Straumann
2006-09-07T23:59:59.000Z
A precision measurement of the gravitational constant $G$ has been made using a beam balance. Special attention has been given to determining the calibration, the effect of a possible nonlinearity of the balance and the zero-point variation of the balance. The equipment, the measurements and the analysis are described in detail. The value obtained for G is 6.674252(109)(54) 10^{-11} m3 kg-1 s-2. The relative statistical and systematic uncertainties of this result are 16.3 10^{-6} and 8.1 10^{-6}, respectively.
Constant Volume During Combustion | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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 Delicious RankShale_Gas.pdfService on theFossilAction No.Complete StreetsEngines |Ms. M. P. DelozierConstant Volume
TASI Lectures on the cosmological constant
Bousso, Raphael; Bousso, Raphael
2007-08-30T23:59:59.000Z
The energy density of the vacuum, Lambda, is at least 60 orders of magnitude smaller than several known contributions to it. Approaches to this problem are tightly constrained by data ranging from elementary observations to precision experiments. Absent overwhelming evidence to the contrary, dark energy can only be interpreted as vacuum energy, so the venerable assumption that Lambda=0 conflicts with observation. The possibility remains that Lambda is fundamentally variable, though constant over large spacetime regions. This can explain the observed value, but only in a theory satisfying a number of restrictive kinematic and dynamical conditions. String theory offers a concrete realization through its landscape of metastable vacua.
Variable energy constant current accelerator structure
Anderson, Oscar A. (Berkeley, CA)
1990-01-01T23:59:59.000Z
A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90.degree. intervals with opposing electrodes maintained at the same potential. Adjacent cylinder electrodes of the quadrupole structure are maintained at different potentials to thereby reshape the cross section of the charged particle beam to an ellipse in cross section at the mid point along each quadrupole electrode unit in the accelerator modules. The beam is maintained in focus by alternating the major axis of the ellipse along the x and y axis respectively at adjacent quadrupoles. In another embodiment, electrostatic ring electrodes may be utilized instead of the quadrupole electrodes.
Constant-mesh, multiple-shaft transmission
Rea, J.E.; Mills, D.D.; Sewell, J.S.
1992-04-21T23:59:59.000Z
This patent describes a multiple-shaft, constant-mesh transmission adapted to establish selectively a reverse torque delivery path and a forward drive torque delivery path and having a torque input means including a torque input shaft, a mainshaft aligned with the input shaft, a countershaft geared to the input shaft in spaced, parallel relationship with respect to the mainshaft, a torque output shaft joined to the mainshaft; multiple mainshaft gear elements journalled on the main airshaft, multiple cluster gear elements carried by the countershaft in meshing engagement with the mainshaft gear elements, one of the cluster gear elements being rotatably journalled on the countershaft; a reverse idle gear, a reverse gear journalled on the countershaft, the reverse idler gear being in constant mesh with the reverse gear and one of the mainshaft gear elements; first clutch means for connecting selectively the reverse gear and the countershaft; second synchronizer clutch means for connecting selectively the one of the mainshaft gear elements to the mainshaft; and third synchronizer clutch means for selectively connecting another of the mainshaft gear elements to the mainshaft; the first clutch means being a double-acting clutch with a first common axially movable clutch element adapted upon movement in one axial direction to drivably connected the reverse gear to the countershaft and adapted upon movement in the opposite axial direction to connect the one cluster gear element to the countershaft.
CMB constraints on the fine structure constant
Kazuhide Ichikawa; Toru Kanzaki; Masahiro Kawasaki
2006-05-25T23:59:59.000Z
We study constraints on time variation of the fine structure constant alpha from cosmic microwave background (CMB) taking into account simultaneous change in alpha and the electron mass m_e which might be implied in unification theories. We obtain the constraints -0.097 < Delta alpha/alpha < 0.034 at 95% C.L. using WMAP data only, and -0.042 < Delta alpha/alpha < 0.026 combining with the constraint on the Hubble parameter by the HST Hubble Key Project. These are improved by 15% compared with constraints assuming only alpha varies. We discuss other relations between variations in alpha and m_e but we do not find evidence for varying alpha.
Progress in the dynamical parton distributions
Jimenez-Delgado, Pedro [JLAB
2012-06-01T23:59:59.000Z
The present status of the (JR) dynamical parton distribution functions is reported. Different theoretical improvements, including the determination of the strange sea input distribution, the treatment of correlated errors and the inclusion of alternative data sets, are discussed. Highlights in the ongoing developments as well as (very) preliminary results in the determination of the strong coupling constant are presented.
Alberto A. Garcia Diaz
2014-12-17T23:59:59.000Z
Under the hydrodynamic equilibrium Buchdahl's conditions on the behavior of the density and the pressure, for regular fluid static circularly symmetric star in (2 + 1) dimensions in the presence of a cosmological constant, is established that there are no bounds from below on the pressure and also on the mass, except for their positiveness. The metric for a constant density distribution is derived and its matching with the external static solution with a negative cosmological constant is accomplished. Some mistakes of previous works on the topic are pointed out.
A closedform solution for mapping general distributions to minimal PH distributions
A closedform solution for mapping general distributions to minimal PH distributions Takayuki Pittsburgh Digital Greenhouse Grant 011. #12; Abstract Approximating general distributions by phasetype (PH) distributions is a popular technique in queueing analysis, since the Markovian property of PH distributions
A closed-form solution for mapping general distributions to minimal PH distributions
A closed-form solution for mapping general distributions to minimal PH distributions Takayuki Pittsburgh Digital Greenhouse Grant 01-1. #12;Abstract Approximating general distributions by phase-type (PH) distributions is a popular technique in queueing analysis, since the Markovian property of PH distributions
The variation of the fine structure constant: testing the dipole model with thermonuclear supernovae
Kraiselburd, Lucila; Negrelli, Carolina; Berro, Enrique García
2014-01-01T23:59:59.000Z
The large-number hypothesis conjectures that fundamental constants may vary. Accordingly, the spacetime variation of fundamental constants has been an active subject of research for decades. Recently, using data obtained with large telescopes a phenomenological model in which the fine structure constant might vary spatially has been proposed. We test whether this hypothetical spatial variation of {\\alpha}, which follows a dipole law, is compatible with the data of distant thermonuclear supernovae. Unlike previous works, in our calculations we consider not only the variation of the luminosity distance when a varying {\\alpha} is adopted, but we also take into account the variation of the peak luminosity of Type Ia supernovae resulting from a variation of {\\alpha}. This is done using an empirical relation for the peak bolometric magnitude of thermonuclear supernovae that correctly reproduces the results of detailed numerical simulations. We find that there is no significant difference between the several phenome...
Curvature invariants in type-III spacetimes
V. Pravda
1999-08-17T23:59:59.000Z
The results of paper [1] are generalized for vacuum type-III solutions with, in general, a non-vanishing cosmological constant Lambda. It is shown that all curvature invariants containing derivatives of the Weyl tensor vanish if a type-III spacetime admits a non-expanding and non-twisting null geodesic congruence. A non-vanishing curvature invariant containing first derivatives of the Weyl tensor is found in the case of type-III spacetime with expansion or twist.
Cosmic explosions, life in the Universe and the Cosmological Constant
Piran, Tsvi; Cuesta, Antonio J; Simpson, Fergus; Verde, Licia
2015-01-01T23:59:59.000Z
Galactic Gamma-Ray Bursts (GRBs) are copious sources of gamma-rays that can pose a threat to complex life. Using recent determinations of their rate and the probability of GRBs causing massive extinction, we explore what type of universes are most likely to harbour advanced forms of life. For this purpose we use cosmological N-body simulations to determine at what time and for what value of the cosmological constant ($\\Lambda$) the chances of life being unaffected by cosmic explosions are maximised. We find that $\\Lambda-$dominated universes favour the survival of life against GRBs. Within a $\\Lambda$CDM cosmology, the parameters that govern the likelihood of life survival to GRBs are dictated by the value of $\\Lambda$ and the age of the Universe. We find that we seem to live in a favorable point in this parameter phase space which minimises the exposure to cosmic explosions, yet maximises the number of main sequence (hydrogen-burning) stars around which advanced life forms can exist.
Ness, E.
1999-09-02T23:59:59.000Z
Distributed generation, locating electricity generators close to the point of consumption, provides some unique benefits to power companies and customers that are not available from centralized electricity generation. Photovoltaic (PV) technology is well suited to distributed applications and can, especially in concert with other distributed resources, provide a very close match to the customer demand for electricity, at a significantly lower cost than the alternatives. In addition to augmenting power from central-station generating plants, incorporating PV systems enables electric utilities to optimize the utilization of existing transmission and distribution.
Hacker, Randi; Tsutsui, William
2007-03-14T23:59:59.000Z
Sox spent a hundred mil to acquire pitcher Daisuke Matsuzaka; they probably weren't even aware that he is a Type O and that they make the best bankers, politicians and... you guessed it... professional baseball players. #ceas #hacker #japan #tsutsuien...
Initial data sets with ends of cylindrical type: I. The Lichnerowicz equation
Piotr T. Chru?ciel; Rafe Mazzeo
2014-10-07T23:59:59.000Z
We construct large classes of vacuum general relativistic initial data sets, possibly with a cosmological constant Lambda, containing ends of cylindrical type.
Experimental determination of the effective strong coupling constant
Alexandre Deur; Volker Burkert; Jian-Ping Chen; Wolfgang Korsch
2005-09-15T23:59:59.000Z
We extract an effective strong coupling constant from low Q2 data on the Bjorken sum. Using sum rules, we establish its Q2-behavior over the complete Q2-range. The result is compared to effective coupling constants extracted from different processes and to calculations based on Schwinger-Dyson equations, hadron spectroscopy or lattice QCD. Although the connection between the experimentally extracted effective coupling constant and the calculations is not clear, the results agree surprisingly well.
The runaway instability of thick discs around black holes. II. Non constant angular momentum discs
Frederic Daigne; Jose A. Font
2003-11-28T23:59:59.000Z
We present results from a comprehensive number of relativistic, time-dependent, axisymmetric simulations of the runaway instability of non-constant angular momentum thick discs around black holes. This second paper extends earlier results where only constant angular momentum discs were considered. All relevant aspects of the theory of stationary thick discs around rotating black holes, necessary to build the initial state in our simulations, are presented in great detail. The angular momentum of the discs is assumed to increase outwards with the radial distance according to a power law. The main simplifying assumptions of our approach are not to include magnetic fields and self-gravity in the discs. Furthermore, the dynamics of the spacetime is accounted for by computing the transfer of mass and angular momentum from the disc to the black hole through the event horizon : the evolution of the central black hole is assumed to follow a sequence of Kerr black holes of increasing mass and spin. In agreement with previous results based on stationary models we find that by allowing the mass and the spin of the black hole to grow, constant angular momentum discs rapidly become unstable on a dynamical timescale. The comparison with the results of paper I shows that the effect of the angular momentum transfer from the torus to the black hole is to make constant angular momentum discs less unstable, increasing the timescale of the instability. However, we find that non-constant angular momentum discs are dramatically stabilized for very small values of the angular momentum slope. Our time-dependent simulations confirm, thus, the predictions of stationary studies concerning the stabilizing effect of non-constant angular momentum distributions.
ITP Industrial Distributed Energy: Distributed Energy Program...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
ITP Industrial Distributed Energy: Distributed Energy Program Project Profile: Verizon Central Office Building ITP Industrial Distributed Energy: Distributed Energy Program Project...
Flavor dependence of normalization constant for an infrared renormalon
Taekoon Lee
2015-02-09T23:59:59.000Z
An ansatz is proposed for the flavor dependence of the normalization constant for the first IR renormalon in heavy quark pole mass.
Evaluation of data and request distribution policies in clustered servers
Khaleel, Adnan
1999-01-01T23:59:59.000Z
. However, the choice of request distribution and data distribution can play an important role in determining overall system performance. Round Robin type distribution schemes achieve ideal load balancing while ignoring server loading whereas locality based...
Evolving Lorentzian wormholes supported by phantom matter with constant state parameters
Mauricio Cataldo; Pedro Labrana; Sergio del Campo; Juan Crisostomo; Patricio Salgado
2008-10-15T23:59:59.000Z
In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made out of phantom energy. We show that this exotic source can support the existence of evolving wormhole spacetimes. Explicitly, a family of evolving Lorentzian wormholes conformally related to another family of zero-tidal force static wormhole geometries is found in Einstein gravity. Contrary to the standard wormhole approach, where first a convenient geometry is fixed and then the matter distribution is derived, we follow the conventional approach for finding solutions in theoretical cosmology. We derive an analytical evolving wormhole geometry by supposing that the radial tension (which is negative to the radial pressure) and the pressure measured in the tangential directions have barotropic equations of state with constant state parameters. At spatial infinity this evolving wormhole, supported by this anisotropic matter, is asymptotically flat, and its slices $t=$ constant are spaces of constant curvature. During its evolution the shape of the wormhole expands with constant velocity, i.e without acceleration or deceleration, since the scale factor has strictly a linear evolution.
A Closed-Form Solution for Mapping General Distributions to Minimal PH Distributions
Harchol-Balter, Mor
A Closed-Form Solution for Mapping General Distributions to Minimal PH Distributions Takayuki distributions by phase-type (PH) dis- tributions is a popular technique in queueing analysis, since the Marko- vian property of PH distributions often allows analytical tractability. This paper proposes
Preston, Scott
the longest, with a mean of about 2:40. Wax Logs and Duraflame have a mean about 10 minutes lower. Hot Logs:15. For all but Wax Logs, the distributions have similar variability each has a standard deviation around 9 minutes. Wax Logs burn more consistently near the mean time the standard deviation is just over 5
TIME CONSTANTS AND ELECTROTONIC LENGTH OF MEMBRANE CYLINDERS
Zucker, Robert S.
TIME CONSTANTS AND ELECTROTONIC LENGTH OF MEMBRANE CYLINDERS AND NEURONS WILFRID RALL From electrophysiological experiments. It depends upon the several time con- stants present in passive decay of membrane membrane time constant, Tm = RmCm, observed in the decay of a uniform membrane potential, there exist many
Applications of nonlocal constants of motion in Lagrangian Dynamics
Gianluca Gorni; Gaetano Zampieri
2015-01-29T23:59:59.000Z
We give a recipe to generate "nonlocal" constants of motion for ODE Lagrangian systems and we apply the method to find useful constants of motion for dissipative system, for the Lane-Emden equation, and for the Maxwell-Bloch system with RWA.
The Duffing Oscillator And Linearization Techniques For Its Motion Constants
Rashdan, Mouath
2014-01-16T23:59:59.000Z
constant is known, solving the system is no longer needed to analyze the characteristics of the system. Motion constants are time independent integrals that are hard to find for nonlinear dynamic systems. We chose the Duffing Oscillator as a higher order...
Cosmological model with $?_M$-dependent cosmological constant
V. Majernik
2003-10-21T23:59:59.000Z
The idea here is to set the cosmical constant $\\lambda$ proportional to the scalar of the stress-energy tensor of the ordinary matter. We investigate the evolution of the scale factor in a cosmological model in which the cosmological constant is proportional to the scalar of the stress-energy tensor.
The Duffing Oscillator And Linearization Techniques For Its Motion Constants
Rashdan, Mouath
2014-01-16T23:59:59.000Z
constant is known, solving the system is no longer needed to analyze the characteristics of the system. Motion constants are time independent integrals that are hard to find for nonlinear dynamic systems. We chose the Duffing Oscillator as a higher order...
Evolving Lorentzian wormholes supported by phantom matter and cosmological constant
Mauricio Cataldo; Sergio del Campo; Paul Minning; Patricio Salgado
2008-12-23T23:59:59.000Z
In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made of phantom energy in the presence of a cosmological constant. We derive analytical evolving wormhole geometries by supposing that the radial tension of the phantom matter, which is negative to the radial pressure, and the pressure measured in the tangential directions have barotropic equations of state with constant state parameters. In this case the presence of a cosmological constant ensures accelerated expansion of the wormhole configurations. More specifically, for positive cosmological constant we have wormholes which expand forever and, for negative cosmological constant we have wormholes which expand to a maximum value and then recolapse. At spatial infinity the energy density and the pressures of the anisotropic phantom matter threading the wormholes vanish; thus these evolving wormholes are asymptotically vacuum $\\Lambda$-Friedmann models with either open or closed or flat topologies.
Chen, Yangjun
Distributed DBMS Outline Introduction What is a distributed DBMS Problems Current state-of-affairs Background Distributed DBMS Architecture Distributed Database Design Semantic Data Control Distributed Query Processing Distributed Transaction Management Parallel Database Systems Distributed Object DBMS
User
NORMAL DlSTRlBUTION TABLE. Entries represent the area under the standardized normal distribution from -w to z, Pr(Z
Production of natural gas from methane hydrate by a constant downhole pressure well
Ahmadi, G. (Clarkson Univ., Potsdam, NY); Ji, C. (Clarkson Univ., Potsdam, NY); Smith, D.H.
2007-07-01T23:59:59.000Z
Natural gas production from the dissociation of methane hydrate in a confined reservoir by a depressurizing downhole well was studied. The case that the well pressure was kept constant was treated, and two different linearization schemes in an axisymmetric configuration were used in the analysis. For different fixed well pressures and reservoir temperatures, approximate self similar solutions were obtained. Distributions of temperature, pressure and gas velocity field across the reservoir were evaluated. The distance of the decomposition front from the well and the natural gas production rate as functions of time were also computed. Time evolutions of the resulting profiles were presented in graphical forms, and their differences with the constant well output results were studied. It was shown that the gas production rate was a sensitive function of well pressure and reservoir temperature. The sensitivity of the results to the linearization scheme used was also studied.
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 rate constant for radiative association of HF: Comparing quantum and classical dynamics
Gustafsson, Magnus, E-mail: magngu@chem.gu.se; Monge-Palacios, M.; Nyman, Gunnar [Department of Chemistry and Molecular Biology, University of Gothenburg, 41296 Gothenburg (Sweden)] [Department of Chemistry and Molecular Biology, University of Gothenburg, 41296 Gothenburg (Sweden)
2014-05-14T23:59:59.000Z
Radiative association for the formation of hydrogen fluoride through the A{sup 1}? ? X{sup 1}?{sup +} and X{sup 1}?{sup +} ? X{sup 1}?{sup +} transitions is studied using quantum and classical dynamics. The total thermal rate constant is obtained for temperatures from 10 K to 20 000 K. Agreement between semiclassical and quantum approaches is observed for the A{sup 1}? ? X{sup 1}?{sup +} rate constant above 2000 K. The agreement is explained by the fact that the corresponding cross section is free of resonances for this system. At temperatures below 2000 K we improve the agreement by implementing a simplified semiclassical expression for the rate constant, which includes a quantum corrected pair distribution. The rate coefficient for the X{sup 1}?{sup +} ? X{sup 1}?{sup +} transition is calculated using Breit–Wigner theory and a classical formula for the resonance and direct contributions, respectively. In comparison with quantum calculations the classical formula appears to overestimate the direct contribution to the rate constant by about 12% for this transition. Below about 450 K the resonance contribution is larger than the direct, and above that temperature the opposite holds. The biggest contribution from resonances is at the lowest temperature in the study, 10 K, where it is more than four times larger than the direct. Below 1800 K the radiative association rate constant due to X{sup 1}?{sup +} ? X{sup 1}?{sup +} transitions dominates over A{sup 1}? ? X{sup 1}?{sup +}, while above that temperature the situation is the opposite.
Methodology for extracting local constants from petroleum cracking flows
Chang, Shen-Lin (Woodridge, IL); Lottes, Steven A. (Naperville, IL); Zhou, Chenn Q. (Munster, IN)
2000-01-01T23:59:59.000Z
A methodology provides for the extraction of local chemical kinetic model constants for use in a reacting flow computational fluid dynamics (CFD) computer code with chemical kinetic computations to optimize the operating conditions or design of the system, including retrofit design improvements to existing systems. The coupled CFD and kinetic computer code are used in combination with data obtained from a matrix of experimental tests to extract the kinetic constants. Local fluid dynamic effects are implicitly included in the extracted local kinetic constants for each particular application system to which the methodology is applied. The extracted local kinetic model constants work well over a fairly broad range of operating conditions for specific and complex reaction sets in specific and complex reactor systems. While disclosed in terms of use in a Fluid Catalytic Cracking (FCC) riser, the inventive methodology has application in virtually any reaction set to extract constants for any particular application and reaction set formulation. The methodology includes the step of: (1) selecting the test data sets for various conditions; (2) establishing the general trend of the parametric effect on the measured product yields; (3) calculating product yields for the selected test conditions using coupled computational fluid dynamics and chemical kinetics; (4) adjusting the local kinetic constants to match calculated product yields with experimental data; and (5) validating the determined set of local kinetic constants by comparing the calculated results with experimental data from additional test runs at different operating conditions.
Experimental determination of the effective strong coupling constant
Alexandre Deur; Volker Burkert; Jian-Ping Chen; Wolfgang Korsch
2007-07-01T23:59:59.000Z
We extract an effective strong coupling constant from low Q{sup 2} data on the Bjorken sum. Using sum rules, we establish its Q{sup 2}-behavior over the complete Q{sup 2}-range. The result is compared to effective coupling constants extracted from different processes and to calculations based on Schwinger-Dyson equations, hadron spectroscopy or lattice QCD. Although the connection between the experimentally extracted effective coupling constant and the calculations is not clear, the results agree surprisingly well.
EVALUATION OF CONSTANT CURRENT WELD CONTROL FOR PINCH WELDING
Korinko, P; STANLEY, S; HOWARD, H
2005-10-11T23:59:59.000Z
Modern weld controllers typically use current to control the weld process. SRS uses a legacy voltage control method. This task was undertaken to determine if the improvements in the weld control equipment could be implemented to provide improvements to the process control. The constant current mode of operation will reduce weld variability by about a factor of 4. The constant voltage welds were slightly hotter than the constant current welds of the same nominal current. The control mode did not appear to adversely affect the weld quality, but appropriate current ranges need to be established and a qualification methodology for both welding and shunt calibrations needs to be developed and documented.
Compactifications of F-Theory on Calabi-Yau Threefolds at Constant Coupli ng
Changhyun Ahn; Soonkeon Nam
1997-03-03T23:59:59.000Z
Generalizing the work of Sen, we analyze special points in the moduli space of the compactification of the F-theory on elliptically fibered Calabi-Yau threefolds where the coupling remains constant. These contain points where they can be realized as orbifolds of six torus $T^6$ by $Z_m \\times Z_n (m, n=2, 3, 4, 6)$. At various types of intersection points of singularities, we find that the enhancement of gauge symmetries arises from the intersection of two kinds of singularities. We also argue that when we take the Hirzebruch surface as a base for the Calabi- Yau threefold, the condition for constant coupling corresponds to the case where the point like instantons coalesce, giving rise to enhanced gauge group of $Sp(k)$.
V. B. Bezerra; G. L. Klimchitskaya; V. M. Mostepanenko; C. Romero
2014-08-31T23:59:59.000Z
We obtain stronger laboratory constraints on the coupling constants of axion-like particles to nucleons from measurements of the normal and lateral Casimir forces between sinusoidally corrugated surfaces of a sphere and a plate. For this purpose, the normal and lateral additional force arising in the experimental configurations due to two-axion exchange between protons and neutrons are calculated. Our constraints following from measurements of the normal and lateral Casimir forces are stronger than the laboratory constraints reported so far for masses of axion-like particles larger than 11eV and 8eV, respectively. A comparison between various laboratory constraints on the coupling constants of axion-like particles to nucleons obtained from the magnetometer measurements, Eotvos- and Cavendish-type experiments, and from the Casimir effect is performed over the wide range of masses of axion-like particles from 10^{-10}eV to 20eV.
Van't Hoff law for temperature dependent Langmuir constants in clathrate hydrate nanocavities
Lakhlifi, Azzedine
2015-01-01T23:59:59.000Z
This work gives a van't Hoff law expression of Langmuir constants of different species for determining their occupancy in the nanocavities of clathrate hydrates. The van't Hoff law's parameters are derived from a fit with Langmuir constants calculated using a pairwise site-site interaction potential to model the anisotropic potential environment in the cavities, as a function of temperature. The parameters can be used for calculating clathrates compositions. Results are given for nineteen gas species trapped in the small and large cavities of structure types I and II [1]. The accuracy of this approach is based on a comparison with available experimental data for ethane and cyclo- propane clathrate hydrates. The numerical method applied in this work, was recently validated from a comparison with the spherical cell method based on analytical considerations [1
Calculation of the Dimer Equilibrium Constant of Heavy Water Saturated Vapor
L. A. Bulavin; S. V. Khrapatiy; V. N. Makhlaichuk
2015-03-13T23:59:59.000Z
Water is the most common substance on Earth.The discovery of heavy water and its further study have shown that the change of hydrogen for deuterium leads to the significant differences in their properties.The triple point temperature of heavy water is higher,at the same time the critical temperature is lower.Experimental values of the second virial coefficient of the EOS for the vapor of normal and heavy water differ at all temperatures.This fact can influence the values of the dimerization constant for the heavy water vapor.The equilibrium properties of the dimerization process are described with the methods of chemical thermodynamics.The chemical potentials for monomers (m) and dimers (d)are the functions of their concentrations.The interactions of monomer-dimer and dimer-dimer types are taken into account within the solution of equation for chemical potentials.The obtained expression for the dimerization constant contains the contributions of these types.The averaged potentials are modeled by the Sutherland potential.Theoretical values of the dimerization constant for the heavy water vapor at different temperatures are compared to those for normal water.We see the exceeding of the values for the heavy water at all temperatures.This fact is in good agreement with all experimental data that is available.The excess is related to the differences in the character of the heat excitations of the dimers of normal and heavy water,their rotational constants and energy of their vibrational excitations.Significant role is also played by the monomer-dimer and dimer-dimer interactions.
CODATA Recommended Values of the Fundamental Physical Constants: 1998*
of recommended values is available on the World Wide Web at physics.nist.gov/ constants. © 1999 American Institute of Physics and American Chemical Society. S0047-2689 00 00301-9 Key words: CODATA, conversion
High Temperature, Large Sample Volume, Constant Flow Magic Angle...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
High Temperature, Large Sample Volume, Constant Flow Magic Angle Spinning NMR Probe for a 11.7 T Magnetic Field for In Situ Catalytic Reaction Characterization Project start date:...
Specific heat at constant volume in the thermodynamic model
C. B. Das; S. Das Gupta; A. Z. Mekjian
2003-07-04T23:59:59.000Z
A thermodynamic model for multifragmentation which is frequently used appears to give very different values for specific heat at constant volume depending upon whether canonical or grand canonical ensemble is used. The cause for this discrepancy is analysed.
Cosmology models with ?_M-dependent cosmological constant
V. Majernik
2002-01-07T23:59:59.000Z
We investigate the evolution of the scale factor in a cosmological model in which the cosmological constant is given by the scalar arisen by the contraction of the stress-energy tensor.
Statistical Inference for Models with Intractable Normalizing Constants
Jin, Ick Hoon
2011-06-27T23:59:59.000Z
In this dissertation, we have proposed two new algorithms for statistical inference for models with intractable normalizing constants: the Monte Carlo Metropolis-Hastings algorithm and the Bayesian Stochastic Approximation Monte Carlo algorithm...
Constant displacement rate experiments and constitutive modeling of asphalt mixtures
Hariharakumar, Pradeep
2006-04-12T23:59:59.000Z
The focus of this dissertation is on constant displacment rate experiments on asphalt concrete and on developing continuum models in a general thermo-mechanical setting which will corroborate with the experimental results. Modeling asphalt concrete...
CODATA Recommended Values of the Fundamental Physical Constants: 2014
Mohr, Peter J; Taylor, Barry N
2015-01-01T23:59:59.000Z
This report gives the 2014 self-consistent set of values of the constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA). These values are based on a least-squares adjustment that takes into account all data available up to 31 December 2014. The recommended values may also be found on the World Wide Web at physics.nist.gov/constants.
Precision measurements of the Planck and Avogadro constants
Bettin, Horst; Man, John; Mana, Giovanni; Massa, Enrico; Picard, Alain
2013-01-01T23:59:59.000Z
Precision measurements of the fundamental constants are tour de force of basic metrology, where the useful information is usually beyond the last digit of the measured value. They challenge theoretical models and measurement technologies and set a network of measurement equations on which a universal system of units can be built, which stems from the most basic concepts of physics. Because of their connection with the mass unit, the Avogadro and Planck constants are on the spotlight.
DISTRIBUTED DATABASES INTRODUCTION
Liu, Chengfei
D DISTRIBUTED DATABASES INTRODUCTION The development of network and data communication tech- nology distributed database management. Naturally, the decen- tralized approach reflects the distributed aspects in the definition of a distributed database exist. First, a distributed database is distributed
STUDY TYPES What is a "Study Type"?
Dorf, Martin E.
#12;STUDY TYPES What is a "Study Type"? A Study Type is a defined business process. Study Types work together to streamline workflow, track data & keep users informed. There are 2 Study Types in eCOMS: COMS and IACUC. The COMS Study: The COMS Study is an online form that a Principal Investigator fills
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville Power Administration wouldDecemberReportsEnergy Analysis Energy Analysis ElectricityDistributed
Heller, Barbara
probabilities in the standard normal table What is the area to the left of Z=1.51 in a standard normal curve? Z=1.51 Z=1.51 Area is 93.45% #12;Exercises Â· If scores are normally distributed with a mean of 30 beauty of the normal curve: No matter what and are, the area between - and + is about 68%; the area
Key distributionKey distribution Key distribution, symmetric encryption
Fisher, Michael
COMP 522 Key distributionKey distribution COMP 522 Key distribution, symmetric encryption From in a secure way and must keep the key secure" · Important issue: how to distribute secret keys? COMP 522 Key distribution, manual delivery For two parties A and B: · A key could be created by A and delivered physically
Distributed Control of Networked Dynamical Systems: Static Feedback,
Dimarogonas, Dimos
1 Distributed Control of Networked Dynamical Systems: Static Feedback, Integral Action--This paper analyzes distributed control protocols for first- and second-order networked dynamical systems. We systems. The PI controllers successfully attenuate constant disturbances in the network. We prove
CODATA recommended values of the fundamental physical constants: 2002
Mohr, Peter J.; Taylor, Barry N. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8401 (United States)
2005-01-01T23:59:59.000Z
This paper gives the 2002 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. Further, it describes in detail the adjustment of the values of the subset of constants on which the complete 2002 set of recommended values is based. Two noteworthy additions in the 2002 adjustment are recommended values for the bound-state rms charge radii of the proton and deuteron and tests of the exactness of the Josephson and quantum-Hall-effect relations K{sub J}=2e/h and R{sub K}=h/e{sup 2}, where K{sub J} and R{sub K} are the Josephson and von Klitzing constants, respectively, e is the elementary charge, and h is the Planck constant. The 2002 set replaces the previously recommended 1998 CODATA set. The 2002 adjustment takes into account the data considered in the 1998 adjustment as well as the data that became available between 31 December 1998, the closing date of that adjustment, and 31 December 2002, the closing date of the new adjustment. The differences between the 2002 and 1998 recommended values compared to the uncertainties of the latter are generally not unreasonable. The new CODATA set of recommended values may also be found on the World Wide Web at physics.nist.gov/constants.
Reaction Rate Constant for Radiative Association of CF$^+$
Öström, Jonatan; Nyman, Gunnar; Gustafsson, Magnus
2015-01-01T23:59:59.000Z
Reaction rate constants and cross sections are computed for the radiative association of carbon cations ($\\text{C}^+$) and fluorine atoms ($\\text{F}$) in their ground states. We consider reactions through the electronic transition $1^1\\Pi \\rightarrow X^1\\Sigma^+$ and rovibrational transitions on the $X^1\\Sigma^+$ and $a^3\\Pi$ potentials. Semiclassical and classical methods are used for the direct contribution and Breit--Wigner theory for the resonance contribution. Quantum mechanical perturbation theory is used for comparison. A modified formulation of the classical method applicable to permanent dipoles of unequally charged reactants is implemented. The total rate constant is fitted to the Arrhenius--Kooij formula in five temperature intervals with a relative difference of $10$ to $250\\:\\text{K}$, the rate constant is about $10^{-21}\\:\\text{cm}^3\\text{s}^{-1}$, rising toward $10^{-16}\\:\\text{cm}^3\\text{s}^{-1}$ fo...
Study of constant mode in charmonium correlators at finite temperature
Takashi Umeda
2007-10-01T23:59:59.000Z
Recent studies on the spectral function of charmonium in lattice QCD suggest survival of $J/\\psi$ state in the deconfinement phase till relatively high temperature. Based on the studies, different scenarios of $J/\\psi$ suppression are discussed to understand experimental results in the Heavy Ion Collision experiments. The scenarios require the information on the dissociation temperatures of $\\chi_c$ and $\\psi'$ as well as that of $J/\\psi$. In order to investigate these states in finite temperature lattice QCD, we have to consider an effect of a characteristic constant mode in the correlators. As a result of the study on the constant mode, we find that most drastic change in charmonium correlators for $\\chi_c$ states just above the deconfinement transition are caused by the constant mode. It may indicate the survival of $\\chi_c$ states after the deconfinement transition until, at least, $1.4T_c$.
Office of Scientific and Technical Information (OSTI)
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Introduction to Dynamic Distributed
Roma "La Sapienza", Università di
Introduction to Dynamic Distributed SystemsSystems #12;Outline Introduction Churn Building Applications in Dynamic Distributed Systems RegistersRegisters Eventual Leader election Connectivity in Dynamic Distributed Systems #12;Dynamic Distributed Systems: Context & Motivations Advent of Complex Distributed
Electromagnetic low-energy constants in ChPT
Christoph Haefeli; Mikhail A. Ivanov; Martin Schmid
2007-10-29T23:59:59.000Z
We investigate three-flavour chiral perturbation theory including virtual photons in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the external fields are those of two-flavour chiral perturbation theory. In particular we work out the strange quark mass dependence of the electromagnetic two-flavour low-energy constants C and k_i. We expect that these relations will be useful for a more precise determination of the electromagnetic low-energy constants.
Discrete canonical analysis of three dimensional gravity with cosmological constant
J. Berra-Montiel; J. E. Rosales-Quintero
2014-06-03T23:59:59.000Z
We discuss the interplay between standard canonical analysis and canonical discretization in three-dimensional gravity with cosmological constant. By using the Hamiltonian analysis, we find that the continuum local symmetries of the theory are given by the on-shell space-time diffeomorphisms, which at the action level, corresponds to the Kalb-Ramond transformations. At the time of discretization, although this symmetry is explicitly broken, we prove that the theory still preserves certain gauge freedom generated by a constant curvature relation in terms of holonomies and the Gauss's law in the lattice approach.
Period doubling, information entropy, and estimates for Feigenbaum's constants
Reginald D. Smith
2013-08-03T23:59:59.000Z
The relationship between period doubling bifurcations and Feigenbaum's constants has been studied for nearly 40 years and this relationship has helped uncover many fundamental aspects of universal scaling across multiple nonlinear dynamical systems. This paper will combine information entropy with symbolic dynamics to demonstrate how period doubling can be defined using these tools alone. In addition, the technique allows us to uncover some unexpected, simple estimates for Feigenbaum's constants which relate them to log 2 and the golden ratio, phi, as well as to each other.
Low-Energy Constants from Resonance Chiral Theory
Antonio Pich
2008-12-14T23:59:59.000Z
I discuss the recent attempts to build an effective chiral Lagrangian incorporating massive resonance states. A useful approximation scheme to organize the resonance Lagrangian is provided by the large-Nc limit of QCD. Integrating out the resonance fields, one recovers the usual chiral perturbation theory Lagrangian with explicit values for the low-energy constants, parameterized in terms of resonance masses and couplings. The resonance chiral theory generates Green functions that interpolate between QCD and chiral perturbation theory. Analyzing these Green functions, both for large and small momenta, one gets QCD constraints on the resonance couplings and, therefore, information on the low-energy constants governing the Goldstone interactions.
Proposal for new experimental schemes to realize the Avogadro constant
Biraben, F; Clad, P; Genevs, G; Gournay, P; Guellati-Khlifa, S; Julien, L; Juncar, P; De Mirandes, E; Nez, F
2006-01-01T23:59:59.000Z
We propose two experimental schemes to determine and so to realize the Avogadro constant $N\\_{A}$ at the level of 10$^{-7}$ or better with a watt balance experiment and a cold atom experiment measuring $h/m(X)$ (where $h$ is the Planck constant and $m(X)$ the mass of the atom $X$). We give some prospects about achievable uncertainties and we discuss the opportunity to test the existence of possible unknown correction factors for the Josephson effect and quantum Hall effect.
The Equivalence Principle and the Constants of Nature
Thibault Damour
2009-06-17T23:59:59.000Z
We briefly review the various contexts within which one might address the issue of ``why'' the dimensionless constants of Nature have the particular values that they are observed to have. Both the general historical trend, in physics, of replacing a-priori-given, absolute structures by dynamical entities, and anthropic considerations, suggest that coupling ``constants'' have a dynamical nature. This hints at the existence of observable violations of the Equivalence Principle at some level, and motivates the need for improved tests of the Equivalence Principle.
Calculation of the Dimer Equilibrium Constant of Heavy Water Saturated Vapor
Bulavin, L A; Makhlaichuk, V N
2015-01-01T23:59:59.000Z
Water is the most common substance on Earth.The discovery of heavy water and its further study have shown that the change of hydrogen for deuterium leads to the significant differences in their properties.The triple point temperature of heavy water is higher,at the same time the critical temperature is lower.Experimental values of the second virial coefficient of the EOS for the vapor of normal and heavy water differ at all temperatures.This fact can influence the values of the dimerization constant for the heavy water vapor.The equilibrium properties of the dimerization process are described with the methods of chemical thermodynamics.The chemical potentials for monomers (m) and dimers (d)are the functions of their concentrations.The interactions of monomer-dimer and dimer-dimer types are taken into account within the solution of equation for chemical potentials.The obtained expression for the dimerization constant contains the contributions of these types.The averaged potentials are modeled by the Sutherlan...
Low Computation and Low Latency Algorithms for Distributed Sensor Network
Cevher, Volkan
Low Computation and Low Latency Algorithms for Distributed Sensor Network Initialization M. Borkar distribution can be determined in a distributed heterogeneous sensor network with reduced subspace distribution for networks with a variety of sensor types as long as the collective set of measurements from all
University of Technology, Sydney
Assignment Types UTS LIBRARY February 2013 Academic Writing Guide Part 2 Assignment Types: This section outlines the basic types of written assignments, providing structural elements and examples. #12;2 II. Assignment Types 1. Essay Writing
A Constant Gain Kalman Filter Approach to track Maneuvering Targets
Naik, Naren
1 A Constant Gain Kalman Filter Approach to track Maneuvering Targets Ashwin Yadav1 , Peeyush domains. One of the most fundamental and widely used approaches to target tracking is the Kalman filter. In presence of unknown noise statistics there are difficulties in the Kalman filter yielding acceptable
Lower Bounds on Interactive Compressibility by Constant-Depth Circuits
Edinburgh, University of
Lower Bounds on Interactive Compressibility by Constant-Depth Circuits Arkadev Chattopadhyay to prove the first lower bounds on general probabilistic multi-round instance compression. We show, and strengthens results of Dubrov and Ishai [DI06]. We also show that a similar lower bound holds for Majority. We
Temperature and moisture dependence of dielectric constant for silica aerogels
Hrubesh, L.H., LLNL
1997-03-01T23:59:59.000Z
The dielectric constants of silica aerogels are among the lowest measured for any solid material. The silica aerogels also exhibit low thermal expansion and are thermally stable to temperatures exceeding 500{degrees}C. However, due to the open porosity and large surface areas for aerogels, their dielectric constants are strongly affected by moisture and temperature. This paper presents data for the dielectric constants of silica aerogels as a function of moisture content at 25{degrees}C, and as a function of temperature, for temperatures in the range from 25{degrees}C to 450{degrees}C. Dielectric constant data are also given for silica aerogels that are heat treated in dry nitrogen at 500{degrees}C, then cooled to 25{degrees}C for measurements in dry air. All measurements are made on bulk aerogel spheres at 22GHz microwave frequency, using a cavity perturbation method. The results of the dependence found here for bulk materials can be inferred to apply also to thin films of silica aerogels having similar nano-structures and densities.
Quartz resonators thermal modelization using located constants networks
Boyer, Edmond
of quartz resonator. The designed model is tested by comparison of the experimental frequency versus235 Quartz resonators thermal modelization using located constants networks S. Galliou and J. P modelization of quartz resonators is first presented ; next, the method consisting on establishing a located
Optical constants of carbon dioxide ice Stephen G. Warren
Warren, Stephen
Optical constants of carbon dioxide ice Stephen G. Warren Laboratory measurements of the absorption. At pressures belowthe triple point (5.2atm), carbon dioxide exists only as a gas or solid. The sublimation in the ultraviolet (50-130-nm wavelength) due to elec- tronic transitions. It is relatively transparent
Codes of constant Lee or Euclidean weight Jay A. Wood
Wood, Jay
Codes of constant Lee or Euclidean weight Jay A. Wood Department of Mathematics, Computer Science & Statistics Purdue University Calumet Hammond, Indiana 46323--2094 USA wood@calumet.purdue.edu http://www.calumet.purdue.edu/public/math/wood Scholarly Research Awards. #12; JAY A. WOOD 1. Linear codes as modules Throughout this extended abstract
DATA SUMMARIES The measured values of fundamental constants become more
Boal, David
that a mole contains 6.022 x 1023 atoms, a number referred to as Avogadro's number. The usefulness of the mole mass] 1.6750 x 10-27 kg kB [Boltzmann's constant] 1.38 x 10-23 J/Ko No [Avogadro's number] 6.022 x 1023
Two-component equations modelling water waves with constant vorticity
Joachim Escher; David Henry; Boris Kolev; Tony Lyons
2014-09-30T23:59:59.000Z
In this paper we derive a two-component system of nonlinear equations which model two-dimensional shallow water waves with constant vorticity. Then we prove well-posedness of this equation using a geometrical framework which allows us to recast this equation as a geodesic flow on an infinite dimensional manifold. Finally, we provide a criteria for global existence.
CODATA recommended values of the fundamental physical constants: 2010*
constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science. Theory of hydrogen and deuterium energy levels 1534 a. Dirac eigenvalue 1534 b. Relativistic recoil 1534 c. Nuclear polarizability 1535 d. Self energy 1535 e. Vacuum polarization 1536 f. Two
Constant Sustainable Consumption Rate in Optimal Growth with Exhaustible Resources*
Wan, Frederic Yui-Ming
's criterion of maximum sustainable consumption rate, previously formulated as a minimum-resource-extraction or not the constant unit resource extraction cost vanishes. The related problem of maximizing the terminal capital appetite for the earth's finite stock of nonrenew- able resources, such as fossil fuel and minerals, have
Language design for distributed stream processing
Newton, Ryan Rhodes, 1980-
2009-01-01T23:59:59.000Z
Applications that combine live data streams with embedded, parallel, and distributed processing are becoming more commonplace. WaveScript is a domain-specific language that brings high-level, type-safe, garbage-collected ...
Distributed Generation Study/Patterson Farms CHP System Using...
Biogas < Distributed Generation Study Jump to: navigation, search Study Location Auburn, New York Site Description Agricultural Study Type Field Test Technology Internal Combustion...
Tom Broadhurst; Rychard J. Bouwens
1999-03-08T23:59:59.000Z
The optical-IR images of the Northern and Southern Hubble Deep Fields are used to measure the spectral and density evolution of early-type galaxies. The mean optical SED is found to evolve passively towards a mid F-star dominated spectrum by z ~ 2. We demonstrate with realistic simulations that hotter ellipticals would be readily visible if evolution progressed blueward and brightward at z > 2, following a standard IMF. The colour distributions are best fitted by a `red' IMF, deficient above ~2 M_solar and with a spread of formation in the range 1.5 3 Gyrs independent of its formation redshift. Regarding density evolution, we demonstrate that the sharp decline in numbers claimed at z > 1 results from a selection bias against distant red galaxies in the optical, where the flux is too weak for morphological classification, but is remedied with relatively modest IR exposures revealing a roughly constant space density to z ~ 2. We point out that the lack of high mass star-formation inferred here and the requirement of metals implicates cooling-flows of pre-enriched gas in the creation of the stellar content of spheroidal galaxies. Deep-field X-ray images will be very helpful to examine this possibility.
The Ds and D+ Leptonic Decay Constants from Lattice QCD
A. Bazavov; C. Bernard; C. DeTar; E. D. Freeland; E. Gamiz; Steven Gottlieb; U. M. Heller; J. E. Hetrick; A. X. El-Khadra; A. S. Kronfeld; J. Laiho; L. Levkova; P. B. Mackenzie; M. B. Oktay; M. Di Pierro; J. N. Simone; R. Sugar; D. Toussaint; R. S. Van de Water
2009-12-28T23:59:59.000Z
We present the leptonic decay constants fDs and fD+ computed on the MILC collaboration's 2+1 flavor asqtad gauge ensembles. We use clover heavy quarks with the Fermilab interpretation and improved staggered light quarks. The simultaneous chiral and continuum extrapolation, which determines both decay constants, includes partially-quenched lattice results at lattice spacings a ~ 0:09, 0:12 and 0:15 fm. We have made several recent improvements in our analysis: a) we include terms in the fit describing leading order heavy-quark discretization effects, b) we have adopted a more precise input r1 value consistent with our other D and B meson studies, c) we have retuned the input bare charm masses based upon the new r1. Our preliminary results are fDs = 260 +/-10 MeV and fD+ = 217 +/-10 MeV.
Constant-Optimized Quantum Circuits for Modular Multiplication and Exponentiation
Igor L. Markov; Mehdi Saeedi
2015-04-02T23:59:59.000Z
Reversible circuits for modular multiplication $Cx$%$M$ with $x
Sidestepping the Cosmological Constant with Football-Shaped Extra Dimensions
Sean M. Carroll; Monica M. Guica
2003-02-11T23:59:59.000Z
We present an exact solution for a factorizable brane-world spacetime with two extra dimensions and explicit brane sources. The compactification manifold has the topology of a two-sphere, and is stabilized by a bulk cosmological constant and magnetic flux. The geometry of the sphere is locally round except for conical singularities at the locations of two antipodal branes, deforming the sphere into an American-style football. The bulk magnetic flux needs to be fine-tuned to obtain flat geometry on the branes. Once this is done, the brane geometry is insensitive to the brane vacuum energy, which only affects the conical deficit angle of the extra dimensions. Solutions of this form provide a new arena in which to explore brane-world phenomenology and the effects of extra dimensions on the cosmological constant problem.
Confined Dirac Particles in Constant and Tilted Magnetic Field
Abdulaziz D. Alhaidari; Hocine Bahlouli; Ahmed Jellal
2012-02-23T23:59:59.000Z
We study the confinement of charged Dirac particles in 3+1 space-time due to the presence of a constant and tilted magnetic field. We focus on the nature of the solutions of the Dirac equation and on how they depend on the choice of vector potential that gives rise to the magnetic field. In particular, we select a "Landau gauge" such that the momentum is conserved along the direction of the vector potential yielding spinor wavefunctions, which are localized in the plane containing the magnetic field and normal to the vector potential. These wave functions are expressed in terms of the Hermite polynomials. We point out the relevance of these findings to the relativistic quantum Hall effect and compare with the results obtained for a constant magnetic field normal to the plane in 2+1 dimensions.
Mega-masers, Dark Energy and the Hubble Constant
Lo, Fred K. Y.
2007-10-15T23:59:59.000Z
Powerful water maser emission (water mega-masers) can be found in accretion disks in the nuclei of some galaxies. Besides providing a measure of the mass at the nucleus, such mega-masers can be used to determine the distance to the host galaxy, based on a kinematic model. We will explain the importance of determining the Hubble Constant to high accuracy for constraining the equation of state of Dark Energy and describe the Mega-maser Cosmology Project that has the goal of determining the Hubble Constant to better than 3%. Time permitting, we will also present the scientific capabilities of the current and future NRAO facilities: ALMA, EVLA, VLBA and GBT, for addressing key astrophysical problems
Asymptotically Flat Wormhole Solutions in a Generic Cosmological Constant Background
Y. Heydarzade; N. Riazi; H. Moradpour
2015-01-09T23:59:59.000Z
There are a number of reasons to study wormholes with generic cosmological constant $\\Lambda$. Recent observations indicate that present accelerating expansion of the universe demands $\\Lambda>0$. On the other hand, some extended theories of gravitation such as supergravity and superstring theories posses vacuum states with $\\Lambdaenergy density and pressure profiles which support such a geometry are obtained. It is shown that for having such a geometry, the wormhole throat $r_0$, the cosmological constant $\\Lambda$ and the equation of state parameter $\\omega$ should satisfy two specific conditions. The possibility of setting different values for the parameters of the model helps us to find exact solutions for the metric functions, mass functions and energy-momentum profiles. At last, the volume integral quantifier, which provides useful information about the total amount of energy condition violating matter is discussed briefly.
$\\hbar$ as a Physical Constant of Classical Optics and Electrodynamics
Tremblay, Real; Allen, Claudine Ni
2015-01-01T23:59:59.000Z
The Planck constant ($\\hbar$) plays a pivotal role in quantum physics. Historically, it has been proposed as postulate, part of a genius empirical relationship $E=\\hbar \\omega$ in order to explain the intensity spectrum of the blackbody radiation for which classical electrodynamic theory led to an unacceptable prediction: The ultraviolet catastrophe. While the usefulness of the Planck constant in various fields of physics is undisputed, its derivation (or lack of) remains unsatisfactory from a fundamental point of view. In this paper, the analysis of the blackbody problem is performed with a series expansion of the electromagnetic field in terms of TE, TM modes in a metallic cavity with small losses, that leads to developing the electromagnetic fields in a \\textit{complete set of orthonormal functions}. This expansion, based on coupled power theory, maintains both space and time together enabling modeling of the blackbody's evolution toward equilibrium. Reaching equilibrium with a multimodal waveguide analysi...
Photon-Axion-Like Particle Coupling Constant and Cosmological Observations
M. Yu. Piotrovich; Yu. N. Gnedin; T. M. Natsvlishvili
2008-05-23T23:59:59.000Z
We estimated the photon-pseudoscalar particle mixing constant from the effect of cosmological alignment and cosmological rotation of polarization plane of distant QSOs. This effect is explained in terms of birefringent phenomenon due to photon-pseudoscalar (axion-like) particle mixing in a cosmic magnetic field. On the contrary, one can estimate the strength of the cosmic magnetic field using the constraints on the photon-axion-like particle coupling constant from the CAST experiment and from SNe Ia dimming effect. In a result, the lower limit on the intergalactic ($z\\approx 1\\div 2$) magnetic field appears at the level of about $4\\times 10^{-10}\\div 10^{-11}$ G.
Thermodynamics of de Sitter Black Holes: Thermal Cosmological Constant
Yuichi Sekiwa
2006-04-10T23:59:59.000Z
We study the thermodynamic properties associated with the black hole event horizon and the cosmological horizon for black hole solutions in asymptotically de Sitter spacetimes. We examine thermodynamics of these horizons on the basis of the conserved charges according to Teitelboim's method. In particular, we have succeeded in deriving the generalized Smarr formula among thermodynamical quantities in a simple and natural way. We then show that cosmological constant must decrease when one takes into account the quantum effect. These observations have been obtained if and only if cosmological constant plays the role of a thermodynamical state variable. We also touch upon the relation between inflation of our universe and a phase transition of black holes.
New process to avoid emissions: Constant pressure in coke ovens
Giertz, J.; Huhn, F. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany). Inst. for Cokemaking and Fuel Technology; Hofherr, K. [Thyssen Stahl AG, Duisburg (Germany)
1995-12-01T23:59:59.000Z
A chamber pressure regulation (PROven), especially effective in regard to emission control problems of coke ovens is introduced for the first time. Because of the partial vacuum in the collecting main system, it is possible to keep the oven`s raw gas pressure constant on a low level over the full coking time. The individual pressure control for each chamber is assured directly as a function of the oven pressure by an immersion system controlling the flow resistance of the collecting main valve. The latter is a fixed-position design (system name ``FixCup``). By doing away with the interdependence of collecting main pressure and chamber pressure, a parameter seen as a coking constant could not be made variable. This opens a new way to reduce coke oven emissions and simultaneously to prevent the ovens from damage caused by air ingress into the oven.
The Stückelberg Holographic Superconductors in Constant External Magnetic Field
Jian-Pin Wu
2010-07-08T23:59:59.000Z
We investigate the St\\"{u}ckelberg holographic superconductor in present of the constant external magnetic field. We observe that a critical value of magnetic field exists as the cases in usual holographic superconductor. Furthermore, we find that the applied magnetic field strongly influence the phase transition of this model and have a jump in the condensate at the critical temperature even for $c_{4}=1$.
The strong coupling constant at low Q^2
Alexandre Deur
2005-06-06T23:59:59.000Z
We extract an effective strong coupling constant using low-Q{sup 2} data and sum rules. Its behavior is established over the full Q{sup 2}-range and is compared to calculations based on lattice QCD, Schwinger-Dyson equations and a quark model. Although the connection between all these quantities is not known yet, the results are surprisingly alike. Such a similitude may be related to quark-hadron duality.
Scaling behavior of discretization errors in renormalization and improvement constants
Bhattacharya, T; Lee, W; Sharpe, S R; Bhattacharya, Tanmoy; Gupta, Rajan; Lee, Weonjong; Sharpe, Stephen R.
2006-01-01T23:59:59.000Z
Non-perturbative results for improvement and renormalization constants needed for on-shell and off-shell O(a) improvement of bilinear operators composed of Wilson fermions are presented. The calculations have been done in the quenched approximation at beta=6.0, 6.2 and 6.4. To quantify residual discretization errors we compare our data with results from other non-perturbative calculations and with one-loop perturbation theory.
Turbine blade having a constant thickness airfoil skin
Marra, John J
2012-10-23T23:59:59.000Z
A turbine blade is provided for a gas turbine comprising: a support structure comprising a base defining a root of the blade and a framework extending radially outwardly from the base, and an outer skin coupled to the support structure framework. The skin has a generally constant thickness along substantially the entire radial extent thereof. The framework and the skin define an airfoil of the blade.
Noncommutative field with constant background fields and neutral fermion
Cui-bai Luo; Feng-yao Hou; Zhu-fang Cui; Xiao-jun Liu; Hong-shi Zong
2015-03-02T23:59:59.000Z
Introducing constant background fields into the noncommutative gauge theory, we first obtain a Hermitian fermion Lagrangian which involves a Lorentz violation term, then we generalize it to a new deformed canonical noncommutation relations for fermion field. Massless neutrino oscillation in the deformed canonical noncommutation relations is analyzed. The restriction of the noncommutative coefficients is also discussed. By comparing with the existing experimental data of conventional neutrino oscillations, the order of noncommutative deformed coefficients is given from different ways.
Numerical computation of constant mean curvature surfaces using finite elements
Jan Metzger
2004-08-18T23:59:59.000Z
This paper presents a method for computing two-dimensional constant mean curvature surfaces. The method in question uses the variational aspect of the problem to implement an efficient algorithm. In principle it is a flow like method in that it is linked to the gradient flow for the area functional, which gives reliable convergence properties. In the background a preconditioned conjugate gradient method works, that gives the speed of a direct elliptic multigrid method.
Apparatus producing constant cable tension for intermittent demand
Lauritzen, T.
1984-05-23T23:59:59.000Z
This invention relates to apparatus for producing constant tension in cable or the like when it is unreeled and reeled from a drum or spool under conditions of intermittent demand. The invention is particularly applicable to the handling of superconductive cable, but the invention is also applicable to the unreeling and reeling of other strands, such as electrical cable, wire, cord, other cables, fish line, wrapping paper and numerous other materials.
Distributed Theorem Proving for Distributed Hybrid Systems
Platzer, André
system with a varying number of arbitrarily many cars. 1 Introduction Hybrid systems with joint discrete a multi-agent system, e.g., distributed car control systems. Such systems form distributed hybrid systemsDistributed Theorem Proving for Distributed Hybrid Systems David W. Renshaw, Sarah M. Loos
Adams, Amy Lynn
2011-01-01T23:59:59.000Z
This thesis evaluates the constant rate of strain and constant head techniques for measurement of the hydraulic conductivity of fine grained soils. A laboratory program compares hydraulic conductivity measurements made ...
Hydrogen Atom and Time Variation of Fine-Structure Constant
Mu-Lin Yan
2009-11-21T23:59:59.000Z
In this paper, we have solved the de Sitter special relativistic ($\\mathcal{SR}_{cR}$-) Dirac equation of hydrogen in the earth-QSO(quasar) framework reference by means of the adiabatic approach. The aspects of geometry effects of de Sitter space-time described by Beltrami metric are explored and taken into account. It is found that the $\\mathcal{SR}_{cR}$-Dirac equation of hydrogen is a time dependent quantum Hamiltonian system. We provide an explicit calculation to justify the adiabatic approach in dealing with this time-dependent system. Since the radius of de Sitter sphere $R$ is cosmologically large, the evolution of the system is very slow so that the adiabatic approximation legitimately works with high accuracy. We conclude that the electromagnetic fine-structure constant, the electron mass and the Planck constant are time variations. This prediction of fine-structure constant is consistent with the presently available observation data. For confirming it further, experiments/observations are required.
The Effective Fine Structure Constant at TESLA Energies
F. Jegerlehner
2001-05-27T23:59:59.000Z
We present a new estimate of the hadronic contribution to the shift in the fine structure constant at LEP and TESLA energies and calculate the effective fine structure constant. Substantial progress in a precise determination of this important parameter is a consequence of substantially improved total cross section measurements by the BES II collaboration and an improved theoretical understanding. In the standard approach which relies to a large extend on experimental data we find $\\Delta \\al_{\\rm hadrons}^{(5)}(\\mz) = 0.027896 \\pm 0.000395$ which yields $\\alpha^{-1}(\\mz) = 128.907 \\pm 0.054$. Another approach, using the Adler function as a tool to compare theory and experiment, allows us to to extend the applicability of perturbative QCD in a controlled manner. The result in this case reads $\\Delta\\alpha^{(5)}_{\\rm had}(M_Z^2) = 0.027730 \\pm 0.000209$ and hence $\\alpha^{-1}(\\mz) = 128.930 \\pm 0.029$. At TESLA energies a new problem shows up with the definition of an effective charge. A possible solution of the problem is presented. Prospects for further progress in a precise determination of the effective fine structure constant are discussed.
Stars In Other Universes: Stellar structure with different fundamental constants
Fred C. Adams
2008-07-23T23:59:59.000Z
Motivated by the possible existence of other universes, with possible variations in the laws of physics, this paper explores the parameter space of fundamental constants that allows for the existence of stars. To make this problem tractable, we develop a semi-analytical stellar structure model that allows for physical understanding of these stars with unconventional parameters, as well as a means to survey the relevant parameter space. In this work, the most important quantities that determine stellar properties -- and are allowed to vary -- are the gravitational constant $G$, the fine structure constant $\\alpha$, and a composite parameter $C$ that determines nuclear reaction rates. Working within this model, we delineate the portion of parameter space that allows for the existence of stars. Our main finding is that a sizable fraction of the parameter space (roughly one fourth) provides the values necessary for stellar objects to operate through sustained nuclear fusion. As a result, the set of parameters necessary to support stars are not particularly rare. In addition, we briefly consider the possibility that unconventional stars (e.g., black holes, dark matter stars) play the role filled by stars in our universe and constrain the allowed parameter space.
Electronic transport in two-dimensional high dielectric constant nanosystems
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ortuño, M.; Somoza, A. M.; Vinokur, V. M.; Baturina, T. I.
2015-04-10T23:59:59.000Z
There has been remarkable recent progress in engineering high-dielectric constant two dimensional (2D) materials, which are being actively pursued for applications in nanoelectronics in capacitor and memory devices, energy storage, and high-frequency modulation in communication devices. Yet many of the unique properties of these systems are poorly understood and remain unexplored. Here we report a numerical study of hopping conductivity of the lateral network of capacitors, which models two-dimensional insulators, and demonstrate that 2D long-range Coulomb interactions lead to peculiar size effects. We find that the characteristic energy governing electronic transport scales logarithmically with either system size or electrostatic screeningmore »length depending on which one is shorter. Our results are relevant well beyond their immediate context, explaining, for example, recent experimental observations of logarithmic size dependence of electric conductivity of thin superconducting films in the critical vicinity of superconductor-insulator transition where a giant dielectric constant develops. Our findings mark a radical departure from the orthodox view of conductivity in 2D systems as a local characteristic of materials and establish its macroscopic global character as a generic property of high-dielectric constant 2D nanomaterials.« less
K. M. Pitman; A. M. Hofmeister; A. B. Corman; A. K. Speck
2008-03-10T23:59:59.000Z
Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous data to constrain abundances of these dust grains.
Discrete multivariate distributions
Oleg Yu. Vorobyev; Lavrentiy S. Golovkov
2011-02-22T23:59:59.000Z
This article brings in two new discrete distributions: multidimensional Binomial distribution and multidimensional Poisson distribution. Those distributions were created in eventology as more correct generalizations of Binomial and Poisson distributions. Accordingly to eventology new laws take into account full distribution of events. Also, in article its characteristics and properties are described
Energy Distribution of Black Plane Solutions
Paul Halpern
2006-03-27T23:59:59.000Z
We use the Einstein energy-momentum complex to calculate the energy distribution of static plane-symmetric solutions of the Einstein-Maxwell equations in 3+1 dimensions with asymptotic anti-de Sitter behavior. This solution is expressed in terms of three parameters: the mass, electric charge and cosmological constant. We compare the energy distribution to that of the Reissner-Nordstrom-anti-de Sitter solution, pointing to qualitative differences between the models. Finally, we examine these results within the context of the Cooperstock hypothesis.
On the Definitions of Entanglement Spacing and Time Constants in the Tube R.G. Larson*
quantities, including the temperature T, Boltzmann's constant kB, and Avogadro's number NA, from which
Paris-Sud XI, Université de
'application est faite aux molécules SF6 et UF6. 4 constantes cubiques de SF6 ont été déterminées à partir des for the centrifugal distortion constants as a function of harmonic frequencies ; application is made to SF6 and UF6. 4 cubic constants of SF6 have been calculated from the rotational constants. Tome 42 N" 3 1«· FEVRIER 1981
On the possibility of variation of the fundamental constants of physics in the static universe
V. Jonauskas
1999-08-09T23:59:59.000Z
A variation of fundamental constants of physics is proposed in a frame of static universe. It is shown when the velocity of light increases (decreases) the Planck's constant increases (decreases) and mass of bodies decreases (increases). This variation of constants leads to the variation of dimensions of bodies and the energy levels of atoms, but a fine structure constant remains unaltered.
The variation of the fine-structure constant from disformal couplings
van de Bruck, Carsten; Nunes, Nelson J
2015-01-01T23:59:59.000Z
We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure constant, alpha. As a result, the theory we consider can explain the non-zero reported variation in the evolution of alpha by purely considering disformal couplings. We also find that if matter and photons are coupled in the same way to the scalar field, disformal couplings itself do not lead to a variation of the fine-structure constant. A number of scenarios are discussed consistent with the current astrophysical, geochemical, laboratory and the cosmic microwave background radiation constraints on the cosmological evolution of alpha. The models presented are also consistent with the current type Ia supernovae constraints on the effective dark energy equation of state. We find that the Oklo bound in particular puts strong constraints on the model parameters. From our numerical r...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Appointment Types Postdoc Appointment Types Most postdocs will be offered a postdoctoral research associate appointment. Each year, approximately 30 Postdoctoral Fellow...
Broader source: Energy.gov [DOE]
Several commissioning types exist to address the specific needs of equipment and systems across both new and existing buildings. The following commissioning types provide a good overview.
GLOBAL STABILITY IN CHEMOSTAT-TYPE EQUATIONS WITH DISTRIBUTED DELAYS
Ruan, Shigui
recycled after the death of the biomass by bacterial decomposition, and the second delay indicates process, thus neglecting the time required to regenerate the nutrient from the dead biomass by bacterial chemostat ex- periments with microalgae Chlamidomonas Reinhardii even when the limiting nutrient
Modular Session Types for Distributed Object-Oriented Programming
Gay, S.J.
Gay,S.J. Vasconcelos,V.T. Ravara,A. Gesbert,N. Caldeira,A.Z. POPL'10, 37th ACM symposium on Principles of programming languages, Madrid pp 299-312 ACM
Modular Session Types for Distributed Object-Oriented Programming
Gay, S.J.
Gay,S.J. Vasconcelos,V.T. Ravara,A. Gesbert,N. Caldeira,A.Z. DCS Technical Report Series Dept of Computing Science, University of Glasgow
Distributed Newton-type algorithms for network resource allocation
Wei, Ermin
2010-01-01T23:59:59.000Z
Most of today's communication networks are large-scale and comprise of agents with local information and heterogeneous preferences, making centralized control and coordination impractical. This motivated much interest in ...
Changing Pollen Types/Concentrations/ Distribution in the United States
Levetin, Estelle
, University of Tulsa, 800 Tucker Drive, Tulsa, OK 74104, USA. E-mail: estelle-levetin@utulsa.edu Current
d Original Contribution MICROBUBBLE TYPE AND DISTRIBUTION DEPENDENCE OF FOCUSED
Konofagou, Elisa E.
microbubbles were measured, and the microbub- bles were diluted to 6 3 108 /mL before injection. Immediately parameters: frequency 5 1.5 MHz, pulse repetition frequency 5 10 Hz, 1000 cycles, in situ peak rarefactional from entering the brain parenchyma, it also impedes the delivery of therapeutic agents $400 Da
Evaluation of the cosmological constant in inflation with a massive non-minimal scalar field
Huang, Jung-Jeng
2015-01-01T23:59:59.000Z
In Schroedinger picture we study the possible effects of trans-Planckian physics on the quantum evolution of massive non-minimally coupled scalar field in de Sitter space. For the nonlinear Corley-Jacobson type dispersion relations with quartic or sextic correction, we obtain the time evolution of the vacuum state wave functional during slow-roll inflation, and calculate explicitly the corresponding expectation value of vacuum energy density. We find that the vacuum energy density is finite. For the usual dispersion parameter choice, the vacuum energy density for quartic correction to the dispersion relation is larger than for sextic correction, while for some other parameter choices, the vacuum energy density for quartic correction is smaller than for sextic correction. We also use the backreaction to constrain the magnitude of parameters in nonlinear dispersion relation, and show how the cosmological constant depends on the parameters and the energy scale during the inflation at the grand unification phase ...
Pressure difference-based sensing of leaks in water distribution networks
Kornmayer, Páll Magnús
2011-01-01T23:59:59.000Z
Human society and civilization rely on the constant availability of fresh water. In regions where a local source of potable water is not available, a transportation and distribution pipe system is employed. When these pipes ...
Physical Effects of Distributed PV Generation on California's Distribution System
Cohen, Michael A
2015-01-01T23:59:59.000Z
Deployment of high-penetration photovoltaic (PV) power is expected to have a range of effects -- both positive and negative -- on the distribution grid. The magnitude of these effects may vary greatly depending upon feeder topology, climate, PV penetration level, and other factors. In this paper we present a simulation study of eight representative distribution feeders in three California climates at PV penetration levels up to 100\\%, supported by a unique database of distributed PV generation data that enables us to capture the impact of PV variability on feeder voltage and voltage regulating equipment. When comparing the influence of feeder location (i.e. climate) versus feeder type on outcomes, we find that location more strongly influences the incidence of reverse power flow, reductions in peak loading and the presence of voltage excursions. On the other hand, we find that feeder characteristics more strongly influence the magnitude of loss reduction and changes in voltage regulator operations. We find th...
Degravitation, inflation and the cosmological constant as an afterglow
Patil, Subodh P., E-mail: subodh@physik.hu-berlin.de [Humboldt Universitaet zu Berlin, Institut fuer Physik, Newtonstrasse 15, D-12489 Berlin (Germany)
2009-01-15T23:59:59.000Z
In this report, we adopt the phenomenological approach of taking the degravitation paradigm seriously as a consistent modification of gravity in the IR, and investigate its consequences for various cosmological situations. We motivate degravitation - where Netwon's constant is promoted to a scale dependent filter function - as arising from either a small (resonant) mass for the graviton, or as an effect in semi-classical gravity. After addressing how the Bianchi identities are to be satisfied in such a set up, we turn our attention towards the cosmological consequences of degravitation. By considering the example filter function corresponding to a resonantly massive graviton (with a filter scale larger than the present horizon scale), we show that slow roll inflation, hybrid inflation and old inflation remain quantitatively unchanged. We also find that the degravitation mechanism inherits a memory of past energy densities in the present epoch in such a way that is likely significant for present cosmological evolution. For example, if the universe underwent inflation in the past due to it having tunneled out of some false vacuum, we find that degravitation implies a remnant 'afterglow' cosmological constant, whose scale immediately afterwards is parametrically suppressed by the filter scale (L) in Planck units {Lambda} {approx} l{sup 2}{sub pl}/L{sup 2}. We discuss circumstances through which this scenario reasonably yields the presently observed value for {Lambda} {approx} O(10{sup -120}). We also find that in a universe still currently trapped in some false vacuum state, resonance graviton models of degravitation only degravitate initially Planck or GUT scale energy densities down to the presently observed value over timescales comparable to the filter scale. We argue that different functional forms for the filter function will yield similar conclusions. In this way, we argue that although the degravitation models we study have the potential to explain why the cosmological constant is not large in addition to why it is not zero, it does not satisfactorily address the co-incidence problem without additional tuning.
Maximum Tension: with and without a cosmological constant
Barrow, John D.; Gibbons, G. W.
2014-12-04T23:59:59.000Z
(and the ?uid pressure, p) diverges even though a; _a and the ?uid density ? remain ?nite, even though ? + 3p > 0 always. 2 The e¤ect of the cosmological constant Recently, David Thornton (private communication) has raised the question of how... of a mass-radius diagram (Carr and Rees, 1979, Barrow and Tipler, 1986). All bodies, at rest, may be assigned a mass M and a radius or size R. Since inertial mass, passive gravitational mass, and active gravitational mass 7 are equal to a high degree...
Determining coal permeabilities through constant pressure production interference testing
Schubarth, Stephen Kurt
1983-01-01T23:59:59.000Z
Kurt Schubarth, B. S. , Texas A&M Un1versity Chairman of Advisory Committee: Dr. Stephen A. Holditch The determination of format1on propert1es 1s important to the success of any underground coal gasification (UCG) project. There are many ways... method of analysis for a mult1ple well test w1th a constant pressure source. The method is then verified by analyzing data generated from a numer1cal reservoir simulator. An analys1s of a hydrology test performed during the 1980 Texas ASM UCG project...
Photon propagation in noncommutative QED with constant external field
R. Fresneda; D. M. Gitman; A. E. Shabad
2015-01-20T23:59:59.000Z
We find dispersion laws for the photon propagating in the presence of mutually orthogonal constant external electric and magnetic fields in the context of the $\\theta $-expanded noncommutative QED. We show that there is no birefringence to the first order in the noncommutativity parameter $% \\theta .$ By analyzing the group velocities of the photon eigenmodes we show that there occurs superluminal propagation for any direction. This phenomenon depends on the mutual orientation of the external electromagnetic fields and the noncommutativity vector. We argue that the propagation of signals with superluminal group velocity violates causality in spite of the fact that the noncommutative theory is not Lorentz-invariant and speculate about possible workarounds.
Photon propagation in noncommutative QED with constant external field
Fresneda, R; Shabad, A E
2015-01-01T23:59:59.000Z
We find dispersion laws for the photon propagating in the presence of mutually orthogonal constant external electric and magnetic fields in the context of the $\\theta $-expanded noncommutative QED. We show that there is no birefringence to the first order in the noncommutativity parameter $% \\theta .$ By analyzing the group velocities of the photon eigenmodes we show that there occurs superluminal propagation for any direction. This phenomenon depends on the mutual orientation of the external electromagnetic fields and the noncommutativity vector. We argue that the propagation of signals with superluminal group velocity violates causality in spite of the fact that the noncommutative theory is not Lorentz-invariant and speculate about possible workarounds.
Big bang nucleosynthesis as a probe of fundamental "constants"
Thomas Dent; Steffen Stern
2007-10-25T23:59:59.000Z
Big Bang nucleosynthesis (BBN) is the earliest sensitive probe of the values of many fundamental particle physics parameters. We have found the leading linear dependences of primordial abundances on all relevant parameters of the standard BBN code, including binding energies and nuclear reaction rates. This enables us to set limits on possible variations of fundamental parameters. We find that 7Li is expected to be significantly more sensitive than other species to many fundamental parameters, a result which also holds for variations of coupling strengths in grand unified (GUT) models. Our work also indicates which areas of nuclear theory need further development if the values of ``constants'' are to be more accurately probed.
Confined System with Rashba Coupling in Constant Magnetic Field
Mohammed El Bouziani; Rachid Houca; Ahmed Jellal
2012-04-30T23:59:59.000Z
We study a two dimensional system of electrons with Rashba coupling in the constant magnetic field $B$ and confining potential. We algebraically diagonalize the corresponding Hamiltonian to end up with the solutions of the energy spectrum. In terms of two kinds of operator we construct two symmetries and discuss the filling of the shells with electrons for strong and weak $B$. Subsequently, we show that our system is sharing some common features with quantum optics where the exact operator solutions for the basics Jaynes-Cummings variables are derived from our results. An interesting limit is studied and the corresponding quantum dynamics is recovered.
Types of Lights Types of Lights
1 Types of Lights Types of Lights q So far we have studied point lights Radiate in all direc7ons q Other lights Direc7onal lights (posi7on-independent) Spotlights #12;2 Direc1onal Lights q Shine in a single, uniform direc7on q All rays
Charmed and light pseudoscalar meson decay constants from HISQ simulations
A. Bazavov; C. Bernard; C. Bouchard; C. DeTar; D. Du; A. X. El-Khadra; J. Foley; E. D. Freeland; E. Gámiz; Steven Gottlieb; U. M. Heller; J. Kim; J. Komijani; A. S. Kronfeld; J. Laiho; L. Levkova; P. B. Mackenzie; E. T. Neil; J. N. Simone; R. L. Sugar; D. Toussaint; R. S. Van de Water; R. Zhou
2014-11-10T23:59:59.000Z
We compute the leptonic decay constants $f_{D^+}$, $f_{D_s}$, and $f_{K^+}$, and the quark-mass ratios $m_c/m_s$ and $m_s/m_l$ in unquenched lattice QCD. We use the MILC highly improved staggered quark (HISQ) ensembles with four dynamical quark flavors. Our primary results are $f_{D^+} = 212.6(0.4)({}^{+1.0}_{-1.2})\\ \\mathrm{MeV}$, $f_{D_s} = 249.0(0.3)({}^{+1.1}_{-1.5})\\ \\mathrm{MeV}$, and $f_{D_s}/f_{D^+} = 1.1712(10)({}^{+29}_{-32})$, where the errors are statistical and total systematic, respectively. We also obtain $f_{K^+}/f_{\\pi^+} = 1.1956(10)({}^{+26}_{-18})$, updating our previous result, and determine the quark-mass ratios $m_s/m_l = 27.35(5)({}^{+10}_{-7})$ and $m_c/m_s = 11.747(19)({}^{+59}_{-43})$. When combined with experimental measurements of the decay rates, our results lead to precise determinations of the CKM matrix elements $|V_{us}| = 0.22487(51) (29)(20)(5)$, $|V_{cd}|=0.217(1) (5)(1)$ and $|V_{cs}|= 1.010(5)(18)(6)$, where the errors are from this calculation of the decay constants, the uncertainty in the experimental decay rates, structure-dependent electromagnetic corrections, and, in the case of $|V_{us}|$, the uncertainty in $|V_{ud}|$, respectively.
Determining the Hubble constant using HII regions and HII galaxies
Chavez, Ricardo; Terlevich, Roberto; Plionis, Manolis; Bresolin, Fabio; Basilakos, Spyros; Melnick, Jorge
2012-01-01T23:59:59.000Z
We report the first results of a long term program aiming to provide accurate independent estimates of the Hubble constant (H0) and the Dark Energy equation of state parameter (w) using the L(Hbeta)-velocity dispersion (sigma) distance estimator for Giant HII regions and HII galaxies. We have used VLT and Subaru high dispersion spectroscopic observations of a local sample of HII galaxies, identified in the SDSS DR7 catalogue in order to re-define and improve the L(Hbeta) - sigma distance indicator and to determine the Hubble constant. To this end we used as local calibration or 'anchor' of this correlation, giant HII regions in nearby galaxies which have accurate distance measurements determined via primary indicators. Using our best sample of 89 nearby HII galaxies and 23 Giant HII regions in 9 galaxies we obtain H0 = 73.9+- 2.7 (statistical)+- 2.9 (systematic) km s-1 Mpc-1, in excellent agreement with, and independently confirming, the most recent SNe Ia based results.
Axial-vector coupling constants and chiral-symmetry restoration
Henley, E.M. (Department of Physics FM-15 and Institute for Nuclear Theory HN-12, University of Washington, Seattle, Washington 98195 (United States)); Hwang, W.P. (Department of Physics, National Taiwan University, Taipei, Taiwan 10764 (Taiwan, Province of China)); Kisslinger, L.S. (Department of Physics, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 (United States))
1992-07-01T23:59:59.000Z
The isovector axial-vector coupling constant {ital g}{sub {ital A}} is determined by using the method of QCD sum rules. A sum rule for ({ital g}{sub {ital A}}{minus}1) is obtained, and it is shown that, with standard values of the quark condensates, {ital g}{sub {ital A}}=1.26{plus minus}0.08. It is also shown that the isovector axial-vector coupling ({ital g}{sub {ital A}}{minus}1)=0 in the limit in which chiral symmetry is restored, and the quark condensate vanishes. A sum rule is also obtained for the isoscalar'' axial-vector coupling constant {ital g}{sub {ital A}}{sup {ital S}}, which is found to be 0.13 if the isovector values of susceptibilities are used. On the other hand, {ital g}{sub {ital A}}{sup {ital S}}={minus}0.68 if the quark condensate is set to zero while {ital g}{sub {ital A}}{sup {ital S}}={minus}1.00 if both the quark and gluon condensates vanish in the event of chiral-symmetry restoration. The values of {ital g}{sub {ital A}} and {ital g}{sub {ital A}}{sup {ital S}} allow us to deduce {Delta}{ital u} and {Delta}{ital d} in the proton.
Silica aerogel: An intrinsically low dielectric constant material
Hrubesh, L.W.
1995-04-01T23:59:59.000Z
Silica aerogels are highly porous solids having unique morphologies in wavelength of visible which both the pores and particles have sizes less than the wavelength of visible light. This fine nanostructure modifies the normal transport mechanisms within aerogels and endows them with a variety of exceptional physical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. The intrinsically low dielectric properties of silica aerogels are the direct result of the extremely high achievable porosities, which are controllable over a range from 75% to more than 99.8 %, and which result in measured dielectric constants from 2.0 to less than 1.01. This paper discusses the synthesis of silica aerogels, processing them as thin films, and characterizing their dielectric properties. Existing data and other physical characteristics of bulk aerogels (e.g., thermal stablity, thermal expansion, moisture adsorption, modulus, dielectric strength, etc.), which are useful for evaluating them as potential dielectrics for microelectronics, are also given.
Zero-Branes, Quantum Mechanics and the Cosmological Constant
Andrew Chamblin; Neil D. Lambert
2001-07-25T23:59:59.000Z
We analyse some dynamical issues in a modified type IIA supergravity, recently proposed as an extension of M-theory that admits de Sitter space. In particular we find that this theory has multiple zero-brane solutions. This suggests a microscopic quantum mechanical matrix description which yields a massive deformation of the usual M(atrix) formulation of M-theory and type IIA string theory.
Learning poisson binomial distributions
Daskalakis, Constantinos
We consider a basic problem in unsupervised learning: learning an unknown Poisson Binomial Distribution. A Poisson Binomial Distribution (PBD) over {0,1,...,n} is the distribution of a sum of n independent Bernoulli random ...
Pretzelosity distribution function
H. Avakian; A. V. Efremov; P. Schweitzer; F. Yuan
2008-08-28T23:59:59.000Z
The 'pretzelosity' distribution is discussed. Theoretical properties, model results, and perspectives to access experimental information on this leading twist, transverse momentum dependent parton distribution function are reviewed. Its relation to helicity and transversity distributions is highlighted.
Key Distribution Mechanisms for Wireless Sensor Networks: a Survey
Bystroff, Chris
Key Distribution Mechanisms for Wireless Sensor Networks: a Survey SEYIT A. CÂ¸AMTEPE and B distributed and hier- archical wireless sensor networks where unicast, multicast and broadcast type and dynamic key generation algorithms for distributing pair-wise, group-wise and network-wise keys. General
An investigation of the rainfall distribution for selected stations in North and Central America
Martin, Lester Alton
1964-01-01T23:59:59.000Z
Status of Knowledge Need for the Study II DATA LIMITATIONS Sampling Errors Observational Errors III ANALYSIS PROCEDURES Monthly Distribution Curves Annual Distribution Curves Mean Rainfall Distribution Curves Curve Fitting IV PRESENTATION..., Queensland Suva, Fiji Islands Cherrapunj i, India 66. 5 117. 1 4. 25. 1 24. 7 26. 5 36. 4 116 108 158 0. 04 in. or more in a day. the mean rainfall distribution curve for a geographical region is so nearly constant. , especially above the 90...
Zhang, WJ "Chris"
) motor and servo-motor. If a system contains two drivers or more, among which some are of the CV motor while the other are the servo-motor, the system has the so-called hybrid driver architecture is stable. A simulation is performed to show verify the proposed controller. The CV motor has the velocity
About Industrial Distributed Energy
Broader source: Energy.gov [DOE]
The Advanced Manufacturing Office's (AMO's) Industrial Distributed Energy activities build on the success of predecessor DOE programs on distributed energy and combined heat and power (CHP) while...
Broader source: Energy.gov [DOE]
The DOE Systems Integration team funds distribution grid integration research and development (R&D) activities to address the technical issues that surround distribution grid planning,...
When did vacuum energy of the Universe become cosmological constant?
V. Burdyuzha
2007-12-29T23:59:59.000Z
A quark-gluon phase transition in the Universe is researched after which vacuum (dark) energy has hardened and become cosmological constant. Before this a vacuum component of the Universe was changing by jumps during phase transitions since vacuum condensates of quantum fields carried a negative contribution in its positive density energy. This quintessence period of the Universe life took place during the first parts of a second when our Universe was losing high symmetry. Using Zel'dovich's formula the modern value of vacuum energy is also calculated. It is shown that a quantum chromodynamical vacuum which is characterized by pseudogoldstone bosons existed definitely when temperature of the Universe was T~150 MeV. Therefore there is a large probability that dark energy is vacuum energy.
Testing the cosmological constant as a candidate for dark energy
Kratochvil, Jan; Linde, Andrei; Linder, Eric V.; Shmakova, Marina
2003-12-03T23:59:59.000Z
It may be difficult to single out the best model of dark energy on the basis of the existing and planned cosmological observations, because many different models can lead to similar observational consequences. However, each particular model can be studied and either found consistent with observations or ruled out. In this paper, we concentrate on the possibility to test and rule out the simplest and by far the most popular of the models of dark energy, the theory described by general relativity with positive vacuum energy (the cosmological constant). We evaluate the conditions under which this model could be ruled out by the future observations made by the Supernova/Acceleration Probe SNAP (both for supernovae and weak lensing) and by the Planck Surveyor cosmic microwave background satellite.
Second Law Analysis of Constant Temperature Diesel Combustion
Druecke, Dr. Ben [University of Wisconsin; Foster, Prof. Dave [University of Wisconsin; Klein, Prof. Sandy [University of Wisconsin; Daw, C Stuart [ORNL; Chakravarthy, Veerathu K [ORNL; Graves, Ronald L [ORNL
2006-01-01T23:59:59.000Z
The results from a second law analysis of a constant temperature diesel combustion process are presented and show that this process is not significantly more reversible than conventional combustion. In addition to quantifying the total availability destruction in combustion, the magnitudes of the combustion irreversibilities attributable to each irreversible subprocess (mixing, oxidation and internal heat transfer) were determined. The primary contributor to combustion irreversibilities is the thermal interaction of reacting and non-reacting species during the oxidation and internal thermal energy transfer subprocesses. Increasing combustion temperature significantly decreases availability destruction by making the oxidation and internal thermal energy transfer processes more reversible. While increasing combustion temperature decreases combustion irreversibility, it also results in an increase in exhaust temperature. A tradeoff exists between large availability destruction at low combustion temperatures and large amounts of availability discarded in the exhaust at high combustion temperatures. The optimum amount of work was found to occur for a combustion temperature of approximately 1600 K.
Does Quantum Cosmology Predict a Constant Dilatonic Field?
F. G. Alvarenga; A. B. Batista; J. C. Fabris
2004-04-07T23:59:59.000Z
Quantum cosmology may permit to determine the initial conditions of the Universe. In particular, it may select a specific model between many possible classical models. In this work, we study a quantum cosmological model based on the string effective action coupled to matter. The Schutz's formalism is employed in the description of the fluid. A radiation fluid is considered. In this way, a time coordinate may be identified and the Wheeler-DeWitt equation reduces in the minisuperspace to a Schr\\"odinger-like equation. It is shown that, under some quite natural assumptions, the expectation values indicate a null axionic field and a constant dilatonic field. At the same time the scale factor exhibits a bounce revealing a singularity-free cosmological model. In some cases, the mininum value of the scale factor can be related to the value of gravitational coupling.
Statistical Inference for Models with Intractable Normalizing Constants
Jin, Ick Hoon
2011-06-27T23:59:59.000Z
be calculated by S1(y) = X 1?i
Path Integral Confined Dirac Fermions in a Constant Magnetic Field
Abdeldjalil Merdaci; Ahmed Jellal; Lyazid Chetouani
2014-04-17T23:59:59.000Z
We consider Dirac fermion confined in harmonic potential and submitted to a constant magnetic field. The corresponding solutions of the energy spectrum are obtained by using the path integral techniques. For this, we begin by establishing a symmetric global projection, which provides a symmetric form for the Green function. Based on this, we show that it is possible to end up with the propagator of the harmonic oscillator for one charged particle. After some transformations, we derive the normalized wave functions and the eigenvalues in terms of different physical parameters and quantum numbers. By interchanging quantum numbers, we show that our solutions possed interesting properties. The density of current and the non-relativistic limit are analyzed where different conclusions are obtained.
Confined Dirac Fermions in a Constant Magnetic Field
Ahmed Jellal; Abdulaziz D. Alhaidari; Hocine Bahlouli
2009-04-03T23:59:59.000Z
We obtain an exact solution of the Dirac equation in (2+1)-dimensions in the presence of a constant magnetic field normal to the plane together with a two-dimensional Dirac-oscillator potential coupling. The solution space consists of a positive and negative energy solution, each of which splits into two disconnected subspaces depending on the sign of an azimuthal quantum number, k = 0, \\pm 1, \\pm 2,... and whether the cyclotron frequency is larger or smaller than the oscillator frequency. The spinor wavefunction is written in terms of the associated Laguerre polynomials. For negative k, the relativistic energy spectrum is infinitely degenerate due to the fact that it is independent of k. We compare our results with already published work and point out the relevance of these findings to a systematic formulation of the relativistic quantum Hall effect in a confining potential.
The Arrow of Time Forbids a Positive Cosmological Constant $?$
Laura Mersini-Houghton
2007-04-20T23:59:59.000Z
Motivated by the mounting evidence for dark energy, here we explore the consequences of a fundamental cosmological constant $\\Lambda$ for our universe. We show that when the gravitational entropy of a pure DeSitter state ultimately wins over matter, then the thermodynamic arrow of time in our universe must reverse in scales of order a Hubble time. We find that due to the dynamics of gravity and nonlocal entanglement, a finite size system such as a DeSitter patch with horizon size $H_0^{-1}$ has a finite lifetime $\\Delta t$. This phenomenon arises from the dynamic gravitational instabilities that develop during a DeSitter epoch and turn catastrophic. A reversed arrow of time is clearly in disagreement with observations. Thus we are led to conclude: Nature forbids a fundamental $\\Lambda$. Or else general relativity must be modified in the IR regime when $\\Lambda$ dominates the expansion of the Universe.
Vacuum Energy and Cosmological Constant Problem in Krein Quantization Approach
Pejhan, H
2014-01-01T23:59:59.000Z
In this paper, we consider a new version of indefinite metric field quantization called "Krein" quantization approach, where the field operators are constructed by both positive and negative energy/frequency modes, or simply physical and un-physical states. Centering on the zero-point energy, fundamental subjects revolve around this concept will be discussed. In fact the presence of un-physical states in the theory performing as natural renormalizing tools, automatically removes the infinite terms in zero-point energy and expectation value of the energy-momentum tensor, so we are capable of defining absolute meaning for energy. Thus, the method presents an interesting property linked to the cosmological constant problem. Meanwhile, in order to ensure consistency of the theory, we have studied and made comparison essential issues such as unitarity of the theory, physical achievements of renormalizing process and the trace anomaly subject.
Molecular Dynamics Simulations of Solutions at Constant Chemical Potential
Perego, Claudio; Parrinello, Michele
2015-01-01T23:59:59.000Z
Molecular Dynamics studies of chemical processes in solution are of great value in a wide spectrum of applications, that range from nano-technology to pharmaceutical chemistry. However, these calculations are affected by severe finite-size effects, such as the solution being depleted as the chemical process proceeds, that influence the outcome of the simulations. To overcome these limitations, one must allow the system to exchange molecules with a macroscopic reservoir, thus sampling a Grand-Canonical ensemble. Despite the fact that different remedies have been proposed, this still represents a key challenge in molecular simulations. In the present work we propose the C$\\mu$MD method, which introduces an external force that controls the environment of the chemical process of interest. This external force, drawing molecules from a finite reservoir, maintains the chemical potential constant in the region where the process takes place. We have applied the C$\\mu$MD method to the paradigmatic case of urea crystall...
Constant power speed range extension of surface mounted PM motors
Lawler, Jack Steward (Knoxville, TN); Bailey, John Milton (Knoxville, TN)
2001-01-01T23:59:59.000Z
A circuit and method for controlling a rotating machine (11) in the constant horsepower range above base speed uses an inverter (15) having SCR's (T1-T6) connected in series with the primary commutation switches (Q1-Q6) to control turn off of the primary commutation switches and to protect the primary commutation switches from faults. The primary commutation switches (Q1-Q6) are controlled by a controller (14), to fire in advance or after a time when the back emf equals the applied voltage, and then to turn off after a precise dwell time, such that suitable power is developed at speeds up to at least six times base speed.
Comment on "Mixing and Decay Constants of Pseudoscalar Mesons"
Kirchbach, M
1999-01-01T23:59:59.000Z
The key assumption used recently by Feldmann, Kroll and Stich [Phys.Rev. D58, 114006 (1998)] that the decay constants f_\\eta, and f_\\eta ' of the respective eta and eta ' mesons in the quark flavor basis follow the pattern of strange and non--strange quarkonia mixing in their wave functions, is reproduced in identifying the non-isotriplet part of the strong neutral axial current with the genuine axial hypercharge current J_{\\mu, 5}^Y =\\bar q \\gamma_\\mu\\gamma_5 Y/2 q, where Y=C+S+B is defined by the Gell-Mann-Nakano-Nishijima relation as the sum of charm (C), strangeness (S), and baryon (B) quark quantum numbers. The inequivalence between octet and hypercharge axial currents is pointed out.
Scale of gravity and the cosmological constant within a landscape
Graesser, Michael L. [California Institute of Technology, Pasadena, California 91125 (United States); Department of Physics, Rutgers University, Piscataway, New Jersey 08540 (United States); Salem, Michael P. [California Institute of Technology, Pasadena, California 91125 (United States)
2007-08-15T23:59:59.000Z
It is possible that the scale of gravity, parametrized by the apparent Planck mass, may obtain different values within different universes in an encompassing multiverse. We investigate the range over which the Planck mass may scan while still satisfying anthropic constraints. The window for anthropically allowed values of the Planck mass may have important consequences for landscape predictions. For example, if the likelihood to observe some value of the Planck mass is weighted by the inflationary expansion factors of the universes that contain that value, then it appears extremely unlikely to observe the value of the Planck mass that is measured within our universe. This is another example of the runaway inflation problem discussed in recent literature. We also show that the window for the Planck mass significantly weakens the anthropic constraint on the cosmological constant when both are allowed to vary over a landscape.
Precision Measurement of the Newtonian Gravitational Constant Using Cold Atoms
G. Rosi; F. Sorrentino; L. Cacciapuoti; M. Prevedelli; G. M. Tino
2014-12-26T23:59:59.000Z
About 300 experiments have tried to determine the value of the Newtonian gravitational constant, G, so far, but large discrepancies in the results have made it impossible to know its value precisely. The weakness of the gravitational interaction and the impossibility of shielding the effects of gravity make it very difficult to measure G while keeping systematic effects under control. Most previous experiments performed were based on the torsion pendulum or torsion balance scheme as in the experiment by Cavendish in 1798, and in all cases macroscopic masses were used. Here we report the precise determination of G using laser-cooled atoms and quantum interferometry. We obtain the value G=6.67191(99) x 10^(-11) m^3 kg^(-1) s^(-2) with a relative uncertainty of 150 parts per million (the combined standard uncertainty is given in parentheses). Our value differs by 1.5 combined standard deviations from the current recommended value of the Committee on Data for Science and Technology. A conceptually different experiment such as ours helps to identify the systematic errors that have proved elusive in previous experiments, thus improving the confidence in the value of G. There is no definitive relationship between G and the other fundamental constants, and there is no theoretical prediction for its value, against which to test experimental results. Improving the precision with which we know G has not only a pure metrological interest, but is also important because of the key role that G has in theories of gravitation, cosmology, particle physics and astrophysics and in geophysical models.
Simulations Data Simulation Type
Wang, Xiaorui "Ray"
to request different simulations data. The flow chart above demonstrates the different steps and options@ornl.gov) Autotune Drupal 7 CMS Current building energy models (BEMs), using EnergyPlus or other simulations, are unreliable because they have to constantly be calibrated to match actual energy usage data. Currently
Broader source: Energy.gov [DOE]
The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.
Marcus Hutter -1 -Bayesian Regression of Piecewise Constant Functions Bayesian Regression of
Hutter, Marcus
Marcus Hutter - 1 - Bayesian Regression of Piecewise Constant Functions Bayesian Regression6 June 2006 #12;Marcus Hutter - 2 - Bayesian Regression of Piecewise Constant Functions Table of Contents · Bayesian Regression · Quantities of Interest · Efficient Solutions by Dynamic Programming · Determination
G. L. Klimchitskaya; V. M. Mostepanenko
2015-04-09T23:59:59.000Z
We obtain improved constraints on the coupling constants of axion-like particles to nucleons from a recently performed Casimir-less experiment. For this purpose, the differential force between a Au-coated sphere and either Au or Si sectors of a rotating disc, arising due to two-axion exchange, is calculated. Over a wide region of axion masses from 1.7 meV to 0.9 eV the obtained constraints are stronger up to a factor of 60 than the previously known ones following from the Cavendish-type experiment and measurements of the effective Casimir pressure.
Klimchitskaya, G L
2015-01-01T23:59:59.000Z
We obtain stronger constraints on the coupling constants of axion-like particles to nucleons from a recently performed Casimir-less experiment. For this purpose, the differential force between a Au-coated sphe\\-re and either Au or Si sectors of a rotating disc, arising due to two-axion exchange, is calculated. Over a wide region of axion masses from 1.7 meV to 0.9 eV the obtained constraints are stronger up to a factor of 60 than the previously known ones following from the Cavendish-type experiment and measurements of the effective Casimir pressure.
Distributed Paging Yair Bartal
Bartal, Yair
. We survey distributed data management problems including distributed paging, file allocation fantastically on an annual basis. This survey deals with distributed data management problems. Such probÂ lems in distributed data management is the deÂ sign of a dynamic allocation of file copies in a network in order
Introduction to Distributed Systems
Pous, Damien
1 Introduction to Distributed Systems Fabienne Boyer, LIG, fabienne.boyer@inria.fr Sources: Cours d'Olivier Gruber, Sacha Krakowiak, Sara Bouchenak, UJF Fabienne Boyer, Distributed Programming 2 Objectives Study conceptual and practical aspects of distributed systems l Client-server model l Distributed protocols l
Stability constants of HBED with various metal ions
Long, Gregory Neal
1990-01-01T23:59:59.000Z
Page ABSTRACT ACKNOWLEDGEMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES INTRODUCTION vr v111 Radiopharmaceuticals and NMR Contrast Agents Design of Chelate Ligands Reasons for Equilibrium Measurements of HBED EXPERIMENTAL 18... 16. Plot of Fe (III) -HBED spectrophotometric titration. 53 17. Species distribution for Fe(III) and HBED. 18. Proposed structure for HFeL species. 56 64 INTRODUCTION Radiopharmaceuticals and NMR Contrast Agents The importance...
Stability constants of HBED with various metal ions
Long, Gregory Neal
1990-01-01T23:59:59.000Z
Foundation. vi TABLE OF CONTENTS Page ABSTRACT ACKNOWLEDGEMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES INTRODUCTION vr v111 Radiopharmaceuticals and NMR Contrast Agents Design of Chelate Ligands Reasons for Equilibrium Measurements... -log [H]'s. 50 52 16. Plot of Fe (III) -HBED spectrophotometric titration. 53 17. Species distribution for Fe(III) and HBED. 18. Proposed structure for HFeL species. 56 64 INTRODUCTION Radiopharmaceuticals and NMR Contrast Agents...
FOURTH-ORDER ELASTIC CONSTANTS: GENERAL METHOD FOR DETERMINATION AND APPLICATIONS X. Markenscoff
Paris-Sud XI, Université de
FOURTH-ORDER ELASTIC CONSTANTS: GENERAL METHOD FOR DETERMINATION AND APPLICATIONS X. Markenscoff.- A list of the independent fourth-order elastic constants (FOEC's) and the interpenden- cies among the non. The fourth-order elastic constants are related to the second-derivatives of the wave velocity with respect
Paris-Sud XI, Université de
New Variation of Constants Formula for Some Partial Functional Differential Equations with Infinite, Morocco ezzinbi@ucam.ac.ma Abstract In this work, we give a new variation of constants formula for some words and phrases: Hille-Yosida operator, integral solutions, variation of constants formula, uniform
Estimation of the optical constants and the thickness of thin lms using unconstrained
Martínez, José Mario
Estimation of the optical constants and the thickness of thin #12;lms using unconstrained, spectral gradient method, optical constants, thin #12;lms. 1 #12; Proposed running head: Estimation of optical constants of thin #12;lms using SGM Corresponding author: Jos#19;e Mario Mart#19;#16;nez
Constant centrifugal potential approximation for atom-diatom chemical reaction dynamics
Takada, Shoji
Constant centrifugal potential approximation for atom-diatom chemical reaction dynamics Kengo,Myodaiji, Okazaki 444. Japan (Received 28 September 1993; accepted 8 December 1993) The constant centrifugal of such practically useful approxima- tions the constant centrifugal potential approximation (CCPA) (or the energy
Physics 250 -Measurements of the Fine Structure Constant Derek Kimball January 2000 1
Budker, Dmitry
Physics 250 - Measurements of the Fine Structure Constant Derek Kimball January 2000 1 #12;Physics 250 - Measurements of the Fine Structure Constant Derek Kimball January 2000 2 #12;Physics 250 - Measurements of the Fine Structure Constant Derek Kimball January 2000 3 #12;Physics 250 - Measurements
The Photometric Properties of Nearby Type Ia Supernovae
Ganeshalingam, Mohan
2012-01-01T23:59:59.000Z
The Rise-Time Distribution of Nearby Type Ia Supernovae 3.1Highlight: The Physics of Supernovae, ed. W. Hillebrandt &1.1 Supernovae . . . . . . . . . . . . . . 1.1.1
NIHAO III: The constant disc gas mass conspiracy
Stinson, G S; Wang, L; Macciò, A V; Herpich, J; Bradford, J D; Quinn, T R; Wadsley, J; Keller, B
2015-01-01T23:59:59.000Z
We show that the cool gas masses of galactic discs reach a steady state that lasts many Gyr after their last major merger in cosmological hydrodynamic simulations. The mass of disc gas, M$_{\\rm gas}$, depends upon a galaxy halo's spin and virial mass, but not upon stellar feedback. Halos with low spin have high star formation efficiency and lower disc gas mass. Similarly, lower stellar feedback leads to more star formation so the gas mass ends up nearly the same irregardless of stellar feedback strength. Even considering spin, the M$_{\\rm gas}$ relation with halo mass, M$_{200}$ only shows a factor of 3 scatter. The M$_{\\rm gas}$--M$_{200}$ relation show a break at M$_{200}$=$2\\times10^{11}$ M$_\\odot$ that corresponds to an observed break in the M$_{\\rm gas}$--M$_\\star$ relation. The constant disc mass stems from a shared halo gas density profile in all the simulated galaxies. In their outer regions, the profiles are isothermal. Where the profile rises above $n=10^{-3}$ cm$^{-3}$, the gas readily cools and th...
Spectroscopic constants and potential energy curves of tungsten carbide
Balasubramanian, K. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)
2000-05-01T23:59:59.000Z
Spectroscopic constants (R{sub e},{omega}{sub e},T{sub e},{mu}{sub e}) and potential energy curves for 40 low-lying electronic states of the diatomic tungsten carbide (WC) were obtained using the complete active space multiconfiguration self-consistent field followed by the multireference singles+doubles configuration interaction and full first- and second-order configuration interaction calculations that included up to 6.4 mil configurations. Spin-orbit effects were included through the enhanced relativistic configuration interaction method described here for 28 electronic states of WC lying below {approx}20 000 cm-1. The spin-orbit splitting of the ground state of WC was found to be very large (4394 cm-1). The ground and excited electronic states of the W atom were also computed and were found to be in good agreement with the experimental data. The nature of bonding was analyzed through the composition of orbitals, leading configurations, Mulliken populations, and dipole moments. The dissociation energy of WC was computed including spin-orbit and electron correlation effects. The recent photoelectron spectra of WC{sup -} were assigned on the basis of our computed results. (c) 2000 American Institute of Physics.
Toward a sub-ppm measurement of the Fermi constant
David M. Webber
2010-06-21T23:59:59.000Z
The Fermi constant, G_F, describes the strength of the weak force and is determined most precisely from the mean life of the positive muon, tau_mu. Advances in theory have reduced the theoretical uncertainty on G_F as calculated from tau_mu to a few tenths of a part per million (ppm). The remaining uncertainty on G_F is entirely experimental, and is dominated by the uncertainty on tau_mu. The MuLan experiment is designed to measure the muon lifetime to part-per-million precision, a better-than twenty-fold improvement over the previous generation of experiments. In 2007, we reported an intermediate result, tau_mu=2.197013(24) microseconds (11 ppm), which is in excellent agreement with the previous world average. This mean life was measured using a pulsed surface muon beam stopped in a ferromagnetic target, surrounded by a symmetric scintillator detector array. Since this intermediate measurement, the detector was instrumented with waveform digitizers, the muon beam rate and beam extinction were increased, and two data sets were acquired on different targets, each containing over 10^12 muon decays. These data will lead to a new determination of G_F to better than a part per million.
TYPES OF NONIMMIGRANT VISAS Type Description
for pleasure and cannot receive any type of payments. C-1*, Aliens in travel status while travelling directly through the C-2*, United States. C-3* D-1 Alien crewman on shore leave or transferring to another vessel is grounds for deportation. E-1 Aliens who conduct trade or inventories between the United States
Superthermal electron distribution measurements from polarized electron cyclotron emission
Luce, T.C.; Efthimion, P.C.; Fisch, N.J.
1988-06-01T23:59:59.000Z
Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs.
Low Latency Messages on Distributed Memory Multiprocessors
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Rosing, Matt; Saltz, Joel
1995-01-01T23:59:59.000Z
This article describes many of the issues in developing an efficient interface for communication on distributed memory machines. Although the hardware component of message latency is less than 1 ws on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 ?s. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. This article describes several tests performed and many of the issues involvedmore »in supporting low latency messages on distributed memory machines.« less
Chantal Valeriani; Rosalind J. Allen; Marco J. Morelli; Daan Frenkel; Pieter Rein ten Wolde
2009-07-03T23:59:59.000Z
We present a method for computing stationary distributions for activated processes in equilibrium and non-equilibrium systems using Forward Flux Sampling (FFS). In this method, the stationary distributions are obtained directly from the rate constant calculations for the forward and backward reactions; there is no need to perform separate calculations for the stationary distribution and the rate constant. We apply the method to the non-equilibrium rare event problem proposed by Maier and Stein, to nucleation in a 2-dimensional Ising system, and to the flipping of a genetic switch.
A New Look At Gravitational Coupling Constant And The Dark Energy Problem
Akinto, O F
2015-01-01T23:59:59.000Z
In this paper, we establish that the solution to the dark energy problem is connected to the cutoff Ultraviolet scale manifesting itself as linearly independent infrared sectors of the effective theory of gravity interacting with QCD fields. We work in the combined frameworks of finite temperature-density corrections and effective quantum field theory (as low energy quantum gravity). We strongly suggest that the failure to reproduce the exact observed value of dark energy from the framework of Veneziano ghost theory of QCD is intimately linked to the unverifiable ad hoc assumption that conditions the gravitational coupling constant to be unity C Gravity is equal to 0ne. A close perusal of the Minkowski vacuum structure reveals that C Gravity is not equal to one. We compute the value of C Gravity from the Bose-Einstein distribution function. With this value of C Gravity coupled with the value of vacuum energy estimated from the Veneziano ghost theory of QCD, we reproduce the observed value of row lambda to be ...
Testable solution of the cosmological constant and coincidence problems
Shaw, Douglas J.; Barrow, John D. [DAMTP, Centre for Mathematical Sciences, Cambridge CB3 0WA (United Kingdom)
2011-02-15T23:59:59.000Z
We present a new solution to the cosmological constant (CC) and coincidence problems in which the observed value of the CC, {Lambda}, is linked to other observable properties of the Universe. This is achieved by promoting the CC from a parameter that must be specified, to a field that can take many possible values. The observed value of {Lambda}{approx_equal}(9.3 Gyrs){sup -2}[{approx_equal}10{sup -120} in Planck units] is determined by a new constraint equation which follows from the application of a causally restricted variation principle. When applied to our visible Universe, the model makes a testable prediction for the dimensionless spatial curvature of {Omega}{sub k0}=-0.0056({zeta}{sub b}/0.5), where {zeta}{sub b}{approx}1/2 is a QCD parameter. Requiring that a classical history exist, our model determines the probability of observing a given {Lambda}. The observed CC value, which we successfully predict, is typical within our model even before the effects of anthropic selection are included. When anthropic selection effects are accounted for, we find that the observed coincidence between t{sub {Lambda}={Lambda}}{sup -1/2} and the age of the Universe, t{sub U}, is a typical occurrence in our model. In contrast to multiverse explanations of the CC problems, our solution is independent of the choice of a prior weighting of different {Lambda} values and does not rely on anthropic selection effects. Our model includes no unnatural small parameters and does not require the introduction of new dynamical scalar fields or modifications to general relativity, and it can be tested by astronomical observations in the near future.
Energy-Momentum Distribution in Weyl Metrics
M. Sharif; Tasnim Fatima
2005-07-16T23:59:59.000Z
In this paper, we evaluate energy and momentum density distributions for the Weyl metric by using the well-known prescriptions of Einstein, Landau-Lifshitz, Papaterou and M$\\ddot{o}$ller. The metric under consideration is the static axisymmetric vacuum solution to the Einstein field equations and one of the field equations represents the Laplace equation. Curzon metric is the special case of this spacetime. We find that the energy density is different for each prescription. However, momentum turns out to be constant in each case.
Energy Distribution in f(R) Gravity
M. Sharif; M. Farasat Shamir
2009-12-18T23:59:59.000Z
The well-known energy problem is discussed in f(R) theory of gravity. We use the generalized Landau-Lifshitz energy-momentum complex in the framework of metric f(R) gravity to evaluate the energy density of plane symmetric solutions for some general f(R) models. In particular, this quantity is found for some popular choices of f(R) models. The constant scalar curvature condition and the stability condition for these models are also discussed. Further, we investigate the energy distribution of cosmic string spacetime.
Broader source: Energy.gov [DOE]
Distributed Wind 2015 is committed to the advancement of both distributed and community wind energy. This two day event includes a Business Conference with sessions focused on advancing the...
2012-03-14T23:59:59.000Z
Index Terms—Basis pursuit, distributed optimization, sensor networks, augmented ... and image denoising and restoration [1], [2], compression, fitting and ...
Transversity Parton Distribution
Alexei Prokudin
2013-04-01T23:59:59.000Z
Transversity distribution is one of the three fundamental parton distributions that completely describe polarized spin 1/2 nucleon. Its chiral odd nature prevented for many years its experimental exploration, however presently we have obtained great deal of information about this distribution. This includes experimental data from Semi Inclusive Deep Inelastic Scattering, knowledge of scale dependence and phenomenological extractions. I will discuss main features of this distribution and indicate the future improvements of our knowledge.
Distributed Power Allocation in Prosumer Thiagarajan Ramachandran,
Egerstedt, Magnus
. In the near future, any agent on the power grid will be able to have generation capacity, storage capacity blackout. Each type of power system, such electric utilities, microgrids and buildings need to addressDistributed Power Allocation in Prosumer Networks Thiagarajan Ramachandran, Zak Costello, Peter
A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
S. D. Hornstein; K. Matthews; A. M. Ghez; J. R. Lu; M. Morris; E. E. Becklin; M. Rafelski; F. K. Baganoff
2007-06-12T23:59:59.000Z
We report the first time-series of broadband infrared (IR) color measurements of Sgr A*, the variable emission source associated with the supermassive black hole at the Galactic Center. Using the laser and natural guide star AO systems on the Keck II telescope, we imaged Sgr A* in multiple near-infrared broadband filters with a typical cycle time of ~3 min during 4 observing runs (2005-2006), two of which were simultaneous with Chandra X-ray measurements. In spite of the large range of dereddened flux densities for Sgr A* (2-30 mJy), all of our near-IR measurements are consistent with a constant spectral index of alpha = -0.6+-0.2. Furthermore, this value is consistent with the spectral indices observed at X-ray wavelengths during nearly all outbursts; which is consistent with the synchrotron self-Compton model for the production of the X-ray emission. During the coordinated observations, one IR outburst occurs 1 GeV is generated, and it is this high-energy tail that gives rise to the X-ray outbursts. One possible explanation for this type of variation is from the turbulence induced by a magnetorotational instability, in which the outer scale length of the turbulence varies and changes the high-energy cutoff.
Wightman function and the Casimir effect for a Robin sphere in a constant curvature space
S. Bellucci; A. A. Saharian; N. A. Saharyan
2014-07-03T23:59:59.000Z
We evaluate the Wightman function, the mean field squared and the vacuum expectation value (VEV) of the energy-momentum tensor for a scalar field with Robin boundary condition on a spherical shell in the background of a constant negative curvature space. For the coefficient in the boundary condition there is a critical value above which the scalar vacuum becomes unstable. In both interior and exterior regions, the VEVs are decomposed into the boundary-free and sphere-induced contributions. For the latter, rapidly convergent integral representations are provided. In the region inside the sphere, the eigenvalues are expressed in terms of the zeros of the combination of the associated Legendre function and its derivative and the decomposition is achieved by making use of the Abel-Plana type summation formula for the series over these zeros. The sphere-induced contribution to the VEV of the field squared is negative for Dirichlet boundary condition and positive for Neumann one. At distances from the sphere larger than the curvature scale of the background space the suppression of the vacuum fluctuations in the gravitational field corresponding to the negative curvature space is stronger compared with the case of the Minkowskian bulk. In particular, the decay of the VEVs with the distance is exponential for both massive and massless fields. The corresponding results are generalized for spaces with spherical bubbles and for cosmological models with negative curvature spaces.
Integrated Transmission and Distribution Control
Kalsi, Karanjit; Fuller, Jason C.; Tuffner, Francis K.; Lian, Jianming; Zhang, Wei; Marinovici, Laurentiu D.; Fisher, Andrew R.; Chassin, Forrest S.; Hauer, Matthew L.
2013-01-16T23:59:59.000Z
Distributed, generation, demand response, distributed storage, smart appliances, electric vehicles and renewable energy resources are expected to play a key part in the transformation of the American power system. Control, coordination and compensation of these smart grid assets are inherently interlinked. Advanced control strategies to warrant large-scale penetration of distributed smart grid assets do not currently exist. While many of the smart grid technologies proposed involve assets being deployed at the distribution level, most of the significant benefits accrue at the transmission level. The development of advanced smart grid simulation tools, such as GridLAB-D, has led to a dramatic improvement in the models of smart grid assets available for design and evaluation of smart grid technology. However, one of the main challenges to quantifying the benefits of smart grid assets at the transmission level is the lack of tools and framework for integrating transmission and distribution technologies into a single simulation environment. Furthermore, given the size and complexity of the distribution system, it is crucial to be able to represent the behavior of distributed smart grid assets using reduced-order controllable models and to analyze their impacts on the bulk power system in terms of stability and reliability. The objectives of the project were to: • Develop a simulation environment for integrating transmission and distribution control, • Construct reduced-order controllable models for smart grid assets at the distribution level, • Design and validate closed-loop control strategies for distributed smart grid assets, and • Demonstrate impact of integrating thousands of smart grid assets under closed-loop control demand response strategies on the transmission system. More specifically, GridLAB-D, a distribution system tool, and PowerWorld, a transmission planning tool, are integrated into a single simulation environment. The integrated environment allows the load flow interactions between the bulk power system and end-use loads to be explicitly modeled. Power system interactions are modeled down to time intervals as short as 1-second. Another practical issue is that the size and complexity of typical distribution systems makes direct integration with transmission models computationally intractable. Hence, the focus of the next main task is to develop reduced-order controllable models for some of the smart grid assets. In particular, HVAC units, which are a type of Thermostatically Controlled Loads (TCLs), are considered. The reduced-order modeling approach can be extended to other smart grid assets, like water heaters, PVs and PHEVs. Closed-loop control strategies are designed for a population of HVAC units under realistic conditions. The proposed load controller is fully responsive and achieves the control objective without sacrificing the end-use performance. Finally, using the T&D simulation platform, the benefits to the bulk power system are demonstrated by controlling smart grid assets under different demand response closed-loop control strategies.
Uniqueness theorems for equations of Keldysh Type
Thomas H. Otway
2010-05-25T23:59:59.000Z
A fundamental result that characterizes elliptic-hyperbolic equations of Tricomi type, the uniqueness of classical solutions to the open Dirichlet problem, is extended to a large class of elliptic-hyperbolic equations of Keldysh type. The result implies the non-existence of classical solutions to the closed Dirichlet problem for this class of equations. A uniqueness theorem is also proven for a mixed Dirichlet-Neumann problem. A generalized uniqueness theorem for the adjoint operator leads to the existence of distribution solutions to the closed Dirichlet problem in a special case.
Your Guide to Diabetes: Type 1 and Type 2
Rau, Don C.
Your Guide to Diabetes: Type 1 and Type 2 National Diabetes Information Clearinghouse #12;#12;Your Guide to Diabetes: Type 1 and Type 2 #12;#12;Contents Learn about Diabetes ............................................................ 1 What is diabetes? .............................................................. 2 What
Innovation flow through social networks: Productivity distribution
T. Di Matteo; T. Aste; M. Gallegati
2004-06-19T23:59:59.000Z
A detailed empirical analysis of the productivity of non financial firms across several countries and years shows that productivity follows a non-Gaussian distribution with power law tails. We demonstrate that these empirical findings can be interpreted as consequence of a mechanism of exchanges in a social network where firms improve their productivity by direct innovation or/and by imitation of other firm's technological and organizational solutions. The type of network-connectivity determines how fast and how efficiently information can diffuse and how quickly innovation will permeate or behaviors will be imitated. From a model for innovation flow through a complex network we obtain that the expectation values of the productivity level are proportional to the connectivity of the network of links between firms. The comparison with the empirical distributions reveals that such a network must be of a scale-free type with a power-law degree distribution in the large connectivity range.
HI in Low-Luminosity Early-Type Galaxies
Tom Oosterloo; Raffaella Morganti; Elaine Sadler
1998-09-07T23:59:59.000Z
We discuss the properties of the HI in low-luminosity early-type galaxies. The morphology of the HI is more regular than that of the HI in many more-luminous early-type galaxies. The HI is always distributed in a disk and is more centrally concentrated. The central HI surface densities are higher than in luminous early-type galaxies and are high enough for star formation to occur.
book review: Species distribution models for species distribution modellers
Dormann, Carsten F
2012-01-01T23:59:59.000Z
Mapping species distributions: spa? tial inference and news and update book review Species distribution models for species distribution modellers Ecological niches and
DTERMINATION DES CONSTANTES SCALAIRES DE L'TAT DE BASE DE SF6
Paris-Sud XI, Université de
L-373 DÉTERMINATION DES CONSTANTES SCALAIRES DE L'ÉTAT DE BASE DE SF6 H. BERGER, A. ABOUMAJD et R'analyse de la bande Raman 03BD2 de SF6, les constantes scalaires de l'état de base ont pu être déterminéesBD2 Raman band the molecular constants of the ground state of SF6 have been determined : B0 = 0
On the Running of the Cosmological Constant in Quantum General Relativity
B. F. L. Ward
2009-08-12T23:59:59.000Z
We present arguments that show what the running of the cosmological constant means when quantum general relativity is formulated following the prescription developed by Feynman.
Layered Copper-Based Electrode for High-Dielectric Constant Oxide...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Copper-Based Electrode for High-Dielectric Constant Oxide Thin-Film-Based Devices Technology available for licenisng: A multilayer thin-film device containing copper layers...
Cosmological Constant as Vacuum Energy Density of Quantum Field Theories on Noncommutative Spacetime
Xiao-Jun Wang
2004-12-15T23:59:59.000Z
We propose a new approach to understand hierarchy problem for cosmological constant in terms of considering noncommutative nature of space-time. We calculate that vacuum energy density of the noncommutative quantum field theories in nontrivial background, which admits a smaller cosmological constant by introducing an higher noncommutative scale $\\mu_{NC}\\sim M_p$. The result $\\rho_\\Lambda\\sim 10^{-6}\\Lambda_{SUSY}^8M_p^4/\\mu_{NC}^8$ yields cosmological constant at the order of current observed value for supersymmetry breaking scale at 10TeV. It is the same as Banks' phenomenological formula for cosmological constant.
Elastic Constants of Ni-Mn-Ga Magnetic Shape Memory Alloys
Stipcich, M. [Universitat de Barcelona; Manosa, L. [Universitat de Barcelona; Planes, A. [Universitat de Barcelona; Morin, M. [INSA de Lyon; Zarestky, Jerel L [ORNL; Lograsso, Tom [Ames Laboratory; Stassis, C. [Ames Laboratory
2004-01-01T23:59:59.000Z
We have measured the adiabatic second order elastic constants of two Ni-Mn-Ga magnetic shape memory crystals with different martensitic transition temperatures, using ultrasonic methods. The temperature dependence of the elastic constants has been followed across the ferromagnetic transition and down to the martensitic transition temperature. Within experimental errors no noticeable change in any of the elastic constants has been observed at the Curie point. The temperature dependence of the shear elastic constant C' has been found to be very different for the two alloys. Such a different behavior is in agreement with recent theoretical predictions for systems undergoing multi-stage structural transitions.
A solvable model of fracture with power-law distribution of fragment sizes
Ken Yamamoto; Yoshihiro Yamazaki
2011-06-08T23:59:59.000Z
The present paper describes a stochastic model of fracture, whose fragment size distribution can be calculated analytically as a power-law-like distribution. The model is basically cascade fracture, but incorporates the effect that each fragment in each stage of cascade ceases fracture with a certain probability. When the probability is constant, the exponent of the power-law cumulative distribution lies between -1 and 0, depending not only on the probability but the distribution of fracture points. Whereas, when the probability depends on the size of a fragment, the exponent is less than -1, irrespective of the distribution of fracture points.
Entanglement Distribution in Optical Networks
Alex Ciurana; Vicente Martin; Jesus Martinez-Mateo; Bernhard Schrenk; Momtchil Peev; Andreas Poppe
2014-09-21T23:59:59.000Z
The ability to generate entangled photon-pairs over a broad wavelength range opens the door to the simultaneous distribution of entanglement to multiple users in a network by using centralized sources and flexible wavelength-division multiplexing schemes. Here we show the design of a metropolitan optical network consisting of tree-type access networks whereby entangled photon-pairs are distributed to any pair of users, independent of their location. The network is constructed employing commercial off-the-shelf components and uses the existing infrastructure, which allows for moderate deployment costs. We further develop a channel plan and a network-architecture design to provide a direct optical path between any pair of users, thus allowing classical and one-way quantum communication as well as entanglement distribution. This allows the simultaneous operation of multiple quantum information technologies. Finally, we present a more flexible backbone architecture that pushes away the load limitations of the original network design by extending its reach, number of users and capabilities.
Mitroi, F C
2011-01-01T23:59:59.000Z
The aim of this paper is to present some new Fejer-type results for convex functions. Improvements of Young's inequality (the arithmetic-geometric mean inequality) and other applications to special means are pointed as well.
Froissart Bound on Inelastic Cross Section Without Unknown Constants
Martin, André
2015-01-01T23:59:59.000Z
Assuming that axiomatic local field theory results hold for hadron scattering, Andr\\'e Martin and S. M. Roy recently obtained absolute bounds on the D-wave below threshold for pion-pion scattering and thereby determined the scale of the logarithm in the Froissart bound on total cross sections in terms of pion mass only. Previously, Martin proved a rigorous upper bound on the inelastic cross-section $\\sigma_{inel}$ which is one-fourth of the corresponding upper bound on $\\sigma_{tot}$, and Wu, Martin,Roy and Singh improved the bound by adding the constraint of a given $\\sigma_{tot}$. Here we use unitarity and analyticity to determine, without any high energy approximation, upper bounds on energy averaged inelastic cross sections in terms of low energy data in the crossed channel. These are Froissart-type bounds without any unknown coefficient or unknown scale factors and can be tested experimentally. Alternatively, their asymptotic forms,together with the Martin-Roy absolute bounds on pion-pion D-waves below t...
Resilient Core Networks for Energy Distribution
Kuntze, Nicolai; Rudolph, Carsten; Leivesley, Sally; Manz, David O.; Endicott-Popovsky, Barbara E.
2014-07-28T23:59:59.000Z
Abstract—Substations and their control are crucial for the availability of electricity in today’s energy distribution. Ad- vanced energy grids with Distributed Energy Resources require higher complexity in substations, distributed functionality and communication between devices inside substations and between substations. Also, substations include more and more intelligent devices and ICT based systems. All these devices are connected to other systems by different types of communication links or are situated in uncontrolled environments. Therefore, the risk of ICT based attacks on energy grids is growing. Consequently, security measures to counter these risks need to be an intrinsic part of energy grids. This paper introduces the concept of a Resilient Core Network to interconnected substations. This core network provides essen- tial security features, enables fast detection of attacks and allows for a distributed and autonomous mitigation of ICT based risks.
Alvina Burgazli; Maxim Eingorn; Alexander Zhuk
2015-03-14T23:59:59.000Z
In this paper, we consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At these scales, the Universe is filled with inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies). Supposing that the Universe contains also the cosmological constant and a perfect fluid with a negative constant equation of state (EoS) parameter $\\omega$ (e.g., quintessence, phantom or frustrated network of topological defects), we investigate scalar perturbations of the FRW metrics due to inhomogeneities. Our analysis shows that, to be compatible with the theory of scalar perturbations, this perfect fluid, first, should be clustered and, second, should have the equation of state parameter $\\omega=-1/3$. In particular, this value corresponds to the frustrated network of cosmic strings. Therefore, the frustrated network of domain walls with $\\omega =-2/3$ is ruled out. A perfect fluid with $\\omega =-1/3$ neither accelerates nor decelerates the Universe. We also obtain the equation for the nonrelativistic gravitational potential created by a system of inhomogeneities. Due to the perfect fluid with $\\omega = -1/3$, the physically reasonable solutions take place for flat, open and closed Universes. This perfect fluid is concentrated around the inhomogeneities and results in screening of the gravitational potential.
Energy-momentum distribution of a general plane symmetric spacetime in metric f(R) gravity
Morteza Yavari
2014-06-13T23:59:59.000Z
In this paper, the exact vacuum solution of a general plane symmetric spacetime is investigated in metric f(R) gravity with the assumption of constant Ricci scalar. For this solution, we have studied the generalized Landau-Lifshitz energy-momentum complex in this theory to determine the energy distribution expressions for some specific f(R) models. Also, we show that these models satisfy the constant curvature condition.
The Parallel BGL: A Generic Library for Distributed Graph Computations
Lumsdaine, Andrew
] and written in a style similar to the C++ Standard Template Library (STL) [38, 46], 1 #12;data types providedThe Parallel BGL: A Generic Library for Distributed Graph Computations Douglas Gregor and Andrew,lums}@osl.iu.edu Abstract This paper presents the Parallel BGL, a generic C++ library for distributed graph computation
A Distributed Problem Solving Approach to Cooperative Information Gathering
Massachusetts at Amherst, University of
A Distributed Problem Solving Approach to Cooperative Information Gathering Tim Oates, M. V in Distributed Problem Solving (DPS) to present a model of this type of cooperative information ac quisition and no official endorsement should be inferred. Problem Solving: The task of information gathering
A New Look At Gravitational Coupling Constant And The Dark Energy Problem
O. F. Akinto; Farida Tahir
2015-03-20T23:59:59.000Z
In this paper, we establish that the solution to the dark energy problem is connected to the cutoff Ultraviolet scale manifesting itself as linearly independent infrared sectors of the effective theory of gravity interacting with QCD fields. We work in the combined frameworks of finite temperature-density corrections and effective quantum field theory (as low energy quantum gravity). We strongly suggest that the failure to reproduce the exact observed value of dark energy from the framework of Veneziano ghost theory of QCD is intimately linked to the unverifiable ad hoc assumption that conditions the gravitational coupling constant to be unity C Gravity is equal to 0ne. A close perusal of the Minkowski vacuum structure reveals that C Gravity is not equal to one. We compute the value of C Gravity from the Bose-Einstein distribution function. With this value of C Gravity coupled with the value of vacuum energy estimated from the Veneziano ghost theory of QCD, we reproduce the observed value of row lambda to be row lambda congruent to C Gravity. An important prediction of these combined frameworks (made manifest by the application of standard box-quantization procedure to the UV scale Max Planck states that there are to ten raise to power one hundred and twenty two linearly independent "subuniverses" representing the linearly independent infrared sectors of the effective theory of gravity interacting with QCD fields. A direct consequence of this is that our subuniverse is embedded on a non-trivial manifold M such as a torus group T raise to power ten raise to power one hundred and twenty two with different linear sizes.
Fake state attack on practically decoy state quantum key distribution
Yong-gang Tan
2012-02-15T23:59:59.000Z
In this paper, security of practically decoy state quantum key distribution under fake state attack is considered. If quantum key distribution is insecure under this type of attack, decoy sources can not also provide it with enough security. Strictly analysis shows that Eve should eavesdrop with the aid of photon-number-resolving instruments. In practical implementation of decoy state quantum key distribution where statistical fluctuation is considered, however, Eve can attack it successfully with threshold detectors.
Self-Organizing Maps and Parton Distribution Functions
K. Holcomb, Simonetta Liuti, D. Z. Perry
2011-05-01T23:59:59.000Z
We present a new method to extract parton distribution functions from high energy experimental data based on a specific type of neural networks, the Self-Organizing Maps. We illustrate the features of our new procedure that are particularly useful for an anaysis directed at extracting generalized parton distributions from data. We show quantitative results of our initial analysis of the parton distribution functions from inclusive deep inelastic scattering.
Cooling water distribution system
Orr, Richard (Pittsburgh, PA)
1994-01-01T23:59:59.000Z
A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.
* Department of Energy Washington, DC 20585 December 20, 2007 MEMORANDUM FOR DISTRIBUTION FROM: MICHAEL W. OWEN
DIGITAL VISION & PHOTODISC Distributed
Simeone, Osvaldo
of scalability and energy efficiency and offers new opportunities through the interplay with specific distributed, to the advances in telegraphy and, later, wireless transmission. Railroad transportation, geodesy (measurement
Distribution of Correspondence
Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]
1996-08-30T23:59:59.000Z
Defines correct procedures for distribution of correspondence to the Naval Reactors laboratories. Does not cancel another directive. Expired 8-30-97.
Distributionally Robust Convex Optimization
2013-09-22T23:59:59.000Z
Distributionally Robust Convex Optimization. Wolfram Wiesemann1, Daniel Kuhn2, and Melvyn Sim3. 1Imperial College Business School, Imperial College ...
Constant communication complexity protocols for multiparty accumulative boolean functions
Sudebkumar Prasant Pal; Sima Das; Somesh Kumar
2006-06-13T23:59:59.000Z
Generalizing a boolean function from Cleve and Buhrman \\cite{cb:sqec}, we consider the class of {\\it accumulative boolean functions} of the form $f_B(X_1,X_2,..., X_m)=\\bigoplus_{i=1}^n t_B(x_i^1x_i^2... x_i^m)$, where $X_j=(x^j_1,x^j_2,..., x^j_n), 1\\leq j\\leq m$ and $t_B(x_i^1x_i^2... x_i^m)=1$ for input $m$-tuples $x_i^1x_i^2...x_i^m\\in B\\subseteq A\\subseteq \\{0,1\\}^n$, and 0, if $x_i^1x_i^2...x_i^m\\in A\\setminus B$. Here the set $A$ is the input {\\it promise} set for function $f_B$. The input vectors $X_j, 1\\leq j\\leq m$ are given to the $m\\geq 3$ parties respectively, who communicate cbits in a distributed environment so that one of them (say Alice) comes up with the value of the function. We algebraically characterize entanglement assisted LOCC protocols requiring only $m-1$ cbits of communication for such multipartite boolean functions $f_B$, for certain sets $B\\subseteq \\{0,1\\}^n$, for $m\\geq 3$ parties under appropriate uniform parity promise restrictions on input $m$-tuples $x_i^1x_i^2...x_i^m, 1\\leq i\\leq n$. We also show that these functions can be computed using $2m-3$ cbits in a purely classical deterministic setup. In contrast, for certain $m$-party accumulative boolean functions ($m\\geq 2$), we characterize promise sets of mixed parity for input $m$-tuples so that $m-1$ cbits of communication suffice in computing the functions in the absence of any a priori quantum entanglement. We compactly represent all these protocols and the corresponding input promise restrictions using uniform group theoretic and hamming distance characterizations.
Analysis of Voltage Rise Effect on Distribution Network with Distributed
Pota, Himanshu Roy
Analysis of Voltage Rise Effect on Distribution Network with Distributed Generation M. A. Mahmud.hossain@adfa.edu.au, and H.Pota@adfa.edu.au). Abstract: Connections of distributed generation (DG) in distribution networks are increasing. These connections of distributed generation cause voltage rise in the distribution network
THE LIND-LEHMER CONSTANT FOR Zn DILUM DESILVA AND CHRISTOPHER PINNER
Pinner, Christopher
THE LIND-LEHMER CONSTANT FOR Zn p DILUM DESILVA AND CHRISTOPHER PINNER Abstract. We determine the Lind Lehmer constant for groups of the form Zn p . 1. Introduction Let G be a compact abelian group of integral combinations of characters, Lind [6] defines a logarithmic Mahler measure of f over G m(f) = m
Truong, Thanh N.
of a focusing technique to minimize the number of electronic structure calculations, while still preservingA direct ab inifio dynamics approach for calculating thermal rate constants using variational dynamics, " for calculations of thermal rate constants and related properties from first principles
DETERMINING OPTICAL CONSTANTS OF URANIUM NITRIDE THIN FILMS IN THE EXTREME
Hart, Gus
deposition and characterization of reactively-sputtered uranium nitride thin films. I also report opticalDETERMINING OPTICAL CONSTANTS OF URANIUM NITRIDE THIN FILMS IN THE EXTREME ULTRAVIOLET (1.6-35 NM.1 Application 1 1.2 Optical Constants 2 1.3 Project Focus 7 2 Uranium Nitride Thin Films 8 2.1 Sputtering 8 2
Dynamics of kinematically constrained bimolecular reactions having constant product recoil energy
Dynamics of kinematically constrained bimolecular reactions having constant product recoil energy reactions in which the product recoil energy is assumed constant (CPR approximation). It is further assumed that the reaction probability is independent ofboth the impact parameter and the collision energy for all collisions
Universal Gravitational Constant EX-9908 Page 1 of 13 Re-Written by Geoffrey R. Clarion
Dai, Pengcheng
Newton was able to deduce his law of universal gravitation. Newton's law of universal gravitation: 2 21 rUniversal Gravitational Constant EX-9908 Page 1 of 13 Re-Written by Geoffrey R. Clarion Universal Gravitational Constant EQUIPMENT 1 Gravitational Torsion Balance AP-8215 1 X-Y Adjustable Diode Laser OS-8526A 1
Liu, Yijun
A fast multipole boundary element method for modeling 2-D multiple crack problems with constant 3 April 2014 Accepted 20 May 2014 Keywords: Fast multipole BEM 2-D multi-crack problems Constant elements Crack opening displacements Stress intensity factors a b s t r a c t A fast multipole boundary
THE PURIFICATION OF SF6 IN A CONSTANT TEMPERATURE ADSORPTION PROCESS
Boyer, Edmond
1423 THE PURIFICATION OF SF6 IN A CONSTANT TEMPERATURE ADSORPTION PROCESS C. BRASSARD Laboratoire propagation du SF6 dû à son adsorption dans une colonne de charbon actif à une tempéra- ture constante de 2014 20 °C. Abstract. 2014 The Dynamitron and the Tandem SF6 gas, initially contained 11 % and 35 % non
Evolution of the coupling constant in SU(2) lattice gauge theory with two adjoint fermions
Ari J. Hietanen; Kari Rummukainen; Kimmo Tuominen
2009-11-24T23:59:59.000Z
We measure the evolution of the coupling constant using the Schroedinger functional method in the lattice formulation of SU(2) gauge theory with two massless Dirac fermions in the adjoint representation. We observe strong evidence for an infrared fixed point, where the theory becomes conformal. We measure the continuum beta-function and the coupling constant as a function of the energy scale.
Sezgin, Metin
2006-01-01T23:59:59.000Z
in the binary expansions of Feigenbaum constants a and d for the logistic map. The analysis is carried out constants; Normal numbers; Random number generation; Statistical analysis In a recent article Karamanos their conclusions. For example in the first table the calculated w2 value is 1.421 as stated. But this value fails
Direct Test of the Time-Independence of Fundamental Nuclear Constants Using the Oklo
Shlyakhter, Ilya
Direct Test of the Time-Independence of Fundamental Nuclear Constants Using the Oklo Natural Reactor #3; Alexander I. Shlyakhter November 18, 1982 1 Introduction The following eight quantities enter the important natural constants of cosmology and atomic theory are connected by simple mathematical relations
Performance of W4 theory for spectroscopic constants and electrical properties of small molecules
Martin, Jan M.L.
Performance of W4 theory for spectroscopic constants and electrical properties of small molecules Accurate spectroscopic constants and electrical properties of small molecules are determined by means of W4 and post-W4 theories. For a set of 28 first- and second-row diatomic molecules for which very accurate
Statistics of Landscapes Based on Free Energies, Replication and Degradation Rate Constants of
Stadler, Peter F.
Statistics of Landscapes Based on Free Energies, Replication and Degradation Rate Constants of RNA are computed from primary sequences by means of a folding algorithm which uses a minimum free energy criterion. Free energies as well as replication and degradation rate constants are derived from secondary
The Asymptotic Minimax Constant for Sup-Norm Loss in Nonparametric Density Estimation
Nussbaum, Michael
The Asymptotic Minimax Constant for Sup-Norm Loss in Nonparametric Density Estimation ALEXANDER, uniform nor- m risk, white noise RUNNING TITLE: Asymptotic minimax density estimation To whom) an asymptotically minimax exact constant has been found for loss in the uniform norm, for Gaussian nonparametric
Avoiding Distribution System Upgrade Costs Using Distributed Generation
Schienbein, Lawrence A.; Balducci, Patrick J.; Nguyen, Tony B.; Brown, Daryl R.; DeSteese, John G.; Speer, Gregory A.
2004-01-20T23:59:59.000Z
PNNL, in cooperation with three utilities, developed a database and methodology to analyze and characterize the avoided costs of Distributed Generation (DG) deployment as an alternative to traditional distribution system investment. After applying a number of screening criteria to the initial set of 307 cases, eighteen were selected for detailed analysis. Alternative DG investment scenarios were developed for these cases to permit capital, operation, maintenance, and fuel costs to be identified and incorporated into the analysis. The “customer-owned” backup power generator option was also investigated. The results of the analysis of the 18 cases show that none yielded cost savings under the alternative DG scenarios. However, the DG alternative systems were configured using very restrictive assumptions concerning reliability, peak rating, engine types and acceptable fuel. In particular it was assumed that the DG alternative in each case must meet the reliability required of conventional distribution systems (99.91% reliability). The analysis was further constrained by a requirement that each substation meet the demands placed upon it by a one in three weather occurrence. To determine if, by relaxing these requirements, the DG alternative might be more viable, one project was re-examined. The 99.91% reliability factor was still assumed for normal operating conditions but redundancy required to maintain reliability was relaxed for the relatively few hours every three years where extreme weather caused load to exceed present substation capacity. This resulted in the deferment of capital investment until later years and reduced the number of engines required for the project. The cost of both the conventional and DG alternative also dropped because the centralized power generation, variable O&M, and DG fuels costs were calculated based on present load requirements in combination with long-term forecasts of load growth, as opposed to load requirements plus a buffer based on predictions of extraordinary weather conditions. Application of the relaxed set of assumptions reduced the total cost of the DG alternative by roughly 57 percent from $7.0 million to $3.0 million. The reduction, however, did not change the overall result of the analysis, as the cost of the conventional distribution system upgrade alternative remained lower at $1.7 million. This paper also explores the feasibility of using a system of backup generators to defer investment in distribution system infrastructure. Rather than expanding substation capacity at substations experiencing slow load growth rates, PNNL considered a scenario where diesel generators were installed on location at customers participating in a program designed to offer additional power security and reliability to the customer and connection to the grid. The backup generators, in turn, could be used to meet peak demand for a limited number of hours each year, thus deferring distribution system investment. Data from an existing program at one of the three participating utilities was used to quantify the costs associated with the backup generator scenario. The results of the “customer owned” backup power generator analysis showed that in all cases the nominal cost of the DG scenario is more than the nominal cost of the base-case conventional distribution system upgrade scenario. However, in two of the cases the total present value costs of the alternative backup generator scenarios were between 15 and 22% less than those for the conventional scenarios. Overall, the results of the study offer considerable encouragement that the use of DG systems can defer conventional distribution system upgrades under the right conditions and when the DG configurations are intelligently designed. Using existing customer-owned DG to defer distribution system upgrades appears to be an immediate commercially-viable opportunity.
Teleparallel Energy-Momentum Distribution of Static Axially Symmetric Spacetimes
M. Sharif; M. Jamil Amir
2007-04-17T23:59:59.000Z
This paper is devoted to discuss the energy-momentum for static axially symmetric spacetimes in the framework of teleparallel theory of gravity. For this purpose, we use the teleparallel versions of Einstein, Landau-Lifshitz, Bergmann and M$\\ddot{o}$ller prescriptions. A comparison of the results shows that the energy density is different but the momentum turns out to be constant in each prescription. This is exactly similar to the results available in literature using the framework of General Relativity. It is mentioned here that M$\\ddot{o}$ller energy-momentum distribution is independent of the coupling constant $\\lambda$. Finally, we calculate energy-momentum distribution for the Curzon metric, a special case of the above mentioned spacetime.
Controllable giant dielectric constant in AlO{sub x}/TiO{sub y} nanolaminates.
Li, W.; Chen, Z.; Premnath, R. N.; Kabius, B.; Auciello, O. (Center for Nanoscale Materials); ( MSD); (Univ. of Puerto Rico)
2011-01-01T23:59:59.000Z
Dielectric materials exhibiting high dielectric constants play critical roles in a wide range of applications from microchip energy storage embedded capacitors for implantable biomedical devices to energy storage capacitors for a new generation of renewable energy generation/storage systems. Instead of searching for new materials, we demonstrate that giant dielectric constants can be achieved by integrating two simple oxides with low dielectric constants into nanolaminate structures. In addition, the obtained dielectric constant values are highly tunable by manipulating the sub-layer thicknesses of the component oxides to control the number of interfaces and oxygen redistribution. The work reported here opens a new pathway for the design and development of high dielectric constant materials based on the nanolaminate concept.
An accurate determination of the Avogadro constant by counting the atoms in a 28Si crystal
Andreas, B; Bartl, G; Becker, P; Bettin, H; Borys, M; Busch, I; Gray, M; Fuchs, P; Fujii, K; Fujimoto, H; Kessler, E; Krumrey, M; Kuetgens, U; Kuramoto, N; Mana, G; Manson, P; Massa, E; Mizushima, S; Nicolaus, A; Picard, A; Pramann, A; Rienitz, O; Schiel, D; Valkiers, S; Waseda, A
2010-01-01T23:59:59.000Z
The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by "counting" the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, 6.02214084(18) x 10^23 mol^-1, is the most accurate input datum for a new definition of the kilogram.
Jiang, Xikai [ORNL] [ORNL; Huang, Jingsong [ORNL] [ORNL; Zhao, Hui [University of Nevada, Las Vegas] [University of Nevada, Las Vegas; Sumpter, Bobby G [ORNL] [ORNL; Qiao, Rui [Clemson University] [Clemson University
2014-01-01T23:59:59.000Z
We report detailed simulation results on the formation dynamics of an electrical double layer (EDL) inside an electrochemical cell featuring room-temperature ionic liquids (RTILs) enclosed between two planar electrodes. Under relatively small charging currents, the evolution of cell potential during charging can be suitably predicted by the Landau-Ginzburg-type continuum model proposed recently (M. Z. Bazant, B. D. Storey, and A. A. Kornyshev, Phys. Rev. Lett., 106, 046102, 2011). Under very large charging currents, the cell potential shows pronounced oscillation during the initial stage of charging, a feature not captured by the continuum model. Such oscillation originates from the sequential growth of the ionic space charge layers near the electrode surface, allowing the evolution of EDLs in RTILs with time, an atomistic process difficult to visualize experimentally, to be studied by analyzing the cell potential under constant current charging conditions. While the continuum model cannot predict the potential oscillation under such far-from-equilibrium charging conditions, it can nevertheless qualitatively capture the growth of cell potential during the later stage of charging. Improving the continuum model by introducing frequency-dependent dielectric constant and density-dependent ion diffusion coefficients may help to further extend the applicability of the model. Keywords: ionic
Distribution, Morphology, and Synaptic Targets of Corticothalamic Terminals in
Casanova, Christian
Distribution, Morphology, and Synaptic Targets of Corticothalamic Terminals in the Cat Lateral terminals have been identified in higher order nuclei, large (type II) and smaller (type I), which have been into area 17 or PMLS. Results indicate that area 17 injections preferentially labelled large terminals
Vlach & Sandhofer, In Press, Child Development Distributing Learning Over Time
Rose, Michael R.
of the spacing effect have focused on memory processes rather than for other types of learning simple and complex concepts. Spaced learning schedules promote several types of learning, strengtheningVlach & Sandhofer, In Press, Child Development Distributing Learning Over Time: The Spacing Effect
Terrestrial-type planet formation: Comparing different types of initial conditions
Ronco, M P; Guilera, O M
2015-01-01T23:59:59.000Z
To study the terrestrial-type planet formation during the post oligarchic growth, the initial distributions of planetary embryos and planetesimals used in N-body simulations play an important role. Most of these studies typically use ad hoc initial distributions based on theoretical and numerical studies. We analyze the formation of planetary systems without gas giants around solar-type stars focusing on the sensitivity of the results to the particular initial distributions of planetesimals and embryos. The formation of terrestrial planets in the habitable zone (HZ) and their final water contents are topics of interest. We developed two different sets of N-body simulations from the same protoplanetary disk. The first set assumes ad hoc initial distributions for embryos and planetesimals and the second set obtains these distributions from the results of a semi-analytical model which simulates the evolution of the gaseous phase of the disk. Both sets form planets in the HZ. Ad hoc initial conditions form planet...
Distributed Road Grade Estimation
Johansson, Karl Henrik
Distributed Road Grade Estimation for Heavy Duty Vehicles PER SAH LHOLM Doctoral Thesis in Automatic Control Stockholm, Sweden 2011 #12;Distributed Road Grade Estimation for Heavy Duty Vehicles PER state-of-charge control decrease the energy consumption of vehicles and increase the safety
DISTRIBUTION John R. Jones Qualung aspen is the most widely distributed native North American tree aspen (Populus tremula), has a wider range (Weigle and Frothingham 1911). In the humid East, aspen plateaus. Aspen is one of the most common trees in the interior West, where its range (fig.1)coincides
Dynamics and length distribution of microtubules under force and confinement
Björn Zelinski; Nina Müller; Jan Kierfeld
2012-12-14T23:59:59.000Z
We investigate the microtubule polymerization dynamics with catastrophe and rescue events for three different confinement scenarios, which mimic typical cellular environments: (i) The microtubule is confined by rigid and fixed walls, (ii) it grows under constant force, and (iii) it grows against an elastic obstacle with a linearly increasing force. We use realistic catastrophe models and analyze the microtubule dynamics, the resulting microtubule length distributions, and force generation by stochastic and mean field calculations; in addition, we perform stochastic simulations. We also investigate the force dynamics if growth parameters are perturbed in dilution experiments. Finally, we show the robustness of our results against changes of catastrophe models and load distribution factors.
Vickers, James
The lifetime T (years) of an electronic component is a continuous random variable with a probability density (see the Section on Reliability in Workbook 46) by f(t) = 1 µ e-t/µ t 0 µ a constant The advantage function given by f(t) = e-t t 0 (i.e. = 1 or µ = 1) Find the lifetime L which a typical component is 60
IntrAst2 (Petrovay) The distribution of stars THE SPATIAL DISTRIBUTION OF STARS
Petrovay, Kristóf
generic method: spectral type + lumin. class place on HRD absolute magnitude: Applying it individually) The distribution of stars SURFACE BRIGHTNESS Astronomical unit: 1µ = 1m / " Night sky: 22µ Night sky in city: 18µ Daytime sky: -8µ Solar disk: -13µ Physical unit: I intensity energy/time/area/solid angle [W/m2 /sr
ARM - Measurement - Hydrometeor types
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt Documentation ARM DatagovInstrumentsuhsasSize Distribution ARM Data Discovery Browsetypes ARM Data
Structure–performance relationships for cantilever-type piezoelectric energy harvesters
Cho, Kyung-Hoon, E-mail: kh97.cho@samsung.com, E-mail: spriya@vt.edu; Park, Hwi-Yeol; Heo, Jin S. [Samsung Advanced Institute of Technology, Samsung Electronics, Yongin 446-712 (Korea, Republic of); Priya, Shashank, E-mail: kh97.cho@samsung.com, E-mail: spriya@vt.edu [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Virginia 24061 (United States)
2014-05-28T23:59:59.000Z
This study provides comprehensive analysis of the structure–performance relationships in cantilever-type piezoelectric energy harvesters. It provides full understanding of the effect of all the practical global control variables on the harvester performance. The control variables considered for the analysis were material parameters, areal and volumetric dimensions, and configuration of the inactive and active layers. Experimentally, the output power density of the harvester was maximum when the shape of the beam was close to a square for a constant bending stiffness and a fixed beam area. Through analytical modeling of the effective stiffness for the piezoelectric bimorph, the conditions for enhancing the bending stiffness within the same beam volume as that of a conventional bimorph were identified. The harvester configuration with beam aspect ratio of 0.86 utilizing distributed inactive layers exhibited an giant output power of 52.5?mW and power density of 28.5?mW?cm{sup ?3} at 30?Hz under 6.9?m?s{sup ?2} excitation. The analysis further indicates that the trend in the output power with varying damping ratio is dissimilar to that of the efficiency. In order to realize best performance, the harvester should be designed with respect to maximizing the magnitude of output power.
Window Types | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
aluminum or vinyl cladding reduces maintenance requirements. Types of Window Glazing or Glass In addition to choosing a frame type, you will need to consider what type of glazing...
Practical pluggable types for Java
Papi, Matthew M
2008-01-01T23:59:59.000Z
This paper introduces the Checker Framework, which supports adding pluggable type systems to the Java language in a backward-compatible way. A type system designer defines type qualifiers and their semantics, and a compiler ...
Leptonic B- and D-meson decay constants with 2+1 flavors of asqtad fermions
Andreas S. Kronfeld; Ethan T. Neil; James N. Simone; Ruth S. Van de Water; for the Fermilab Lattice Collaboration; for the MILC Collaboration
2015-01-08T23:59:59.000Z
We present the status of our updated D- and B-meson decay-constant analysis, based on the MILC $N_f = 2+1$ asqtad gauge ensembles. Heavy quarks are incorporated using the Wilson clover action with the Fermilab interpretation. This analysis includes ensembles at five lattice spacings from a $\\approx$ 0.045 to 0.15 fm, and light sea-quark masses down to 1/20th of the strange-quark mass. Projected error budgets for ratios of decay constants, in particular between bottom- and charm-meson decay constants, are presented.
B and D meson decay constants from 2+1 flavor improved staggered simulations
E. T. Neil; Jon A. Bailey; A. Bazavov; C. Bernard; C. M. Bouchard; C. DeTar; M. Di Pierro; A. X. El-Khadra; R. T. Evans; E. Freeland; E. Gamiz; Steven Gottlieb; U. M. Heller; J. E. Hetrick; R. Jain; A. S. Kronfeld; J. Laiho; L. Levkova; P. B. Mackenzie; M. B. Oktay; J. N. Simone; R. Sugar; D. Toussaint; R. S. Van de Water; for the Fermilab Lattice Collaboration; for the MILC Collaboration
2011-12-16T23:59:59.000Z
We give an update on simulation results for the decay constants f_B, f_{B_s}, f_D and f_{D_s}. These decay constants are important for precision tests of the standard model, in particular entering as inputs to the global CKM unitarity triangle fit. The results presented here make use of the MILC (2+1)-flavor asqtad ensembles, with heavy quarks incorporated using the clover action with the Fermilab method. Partially quenched, staggered chiral perturbation theory is used to extract the decay constants at the physical point. In addition, we give error projections for a new analysis in progress, based on an extended data set.
Decay constants of the pion and its excitations on the lattice.
Mastropas, Ekaterina V. [William and Mary College, JLAB; Richards, David G. [JLAB
2014-07-01T23:59:59.000Z
We present a calculation using lattice QCD of the ratios of decay constants of the excited states of the pion, to that of the pion ground state, at three values of the pion mass between 400 and 700 MeV, using an anisotropic clover fermion action with three flavors of quarks. We find that the decay constant of the first excitation, and more notably of the second, is suppressed with respect to that of the ground-state pion, but that the suppression shows little dependence on the quark mass. The strong suppression of the decay constant of the second excited state is consistent with its interpretation as a predominantly hybrid state.
Towards a consistent estimate of the chiral low-energy constants
V. Cirigliano; G. Ecker; M. Eidemuller; R. Kaiser; A. Pich; J. Portoles
2006-07-17T23:59:59.000Z
Guided by the large-Nc limit of QCD, we construct the most general chiral resonance Lagrangian that can generate chiral low-energy constants up to O(p^6). By integrating out the resonance fields, the low-energy constants are parametrized in terms of resonance masses and couplings. Information on those couplings and on the low-energy constants can be extracted by analysing QCD Green functions of currents both for large and small momenta. The chiral resonance theory generates Green functions that interpolate between QCD and chiral perturbation theory. As specific examples we consider the VAP and SPP Green functions.
R. F. O'Connell
2010-09-22T23:59:59.000Z
In contrast to classical physics, the language of quantum mechanics involves operators and wave functions (or, more generally, density operators). However, in 1932, Wigner formulated quantum mechanics in terms of a distribution function $W(q,p)$, the marginals of which yield the correct quantum probabilities for $q$ and $p$ separately \\cite{wigner}. Its usefulness stems from the fact that it provides a re-expression of quantum mechanics in terms of classical concepts so that quantum mechanical expectation values are now expressed as averages over phase-space distribution functions. In other words, statistical information is transferred from the density operator to a quasi-classical (distribution) function.
Dust around Type Ia supernovae
Wang, Lifan
2005-01-01T23:59:59.000Z
Dust around Type Ia supernovae Lifan Wang 1,2 LawrenceIa. Subject headings: Supernovae: General, Dust, Extinctionline) bands for Type Ia supernovae. (a), upper panel, shows
Dabek, Frank (Frank Edward), 1977-
2006-01-01T23:59:59.000Z
DHash is a new system that harnesses the storage and network resources of computers distributed across the Internet by providing a wide-area storage service, DHash. DHash frees applications from re-implementing mechanisms ...
Edelstein, Elspeth Claire
2012-11-28T23:59:59.000Z
The distribution of adverbs is particularly difficult to account for, given the amount of variation it encompasses. Not only are adverbs typically optional, but any adverb may also appear in several different positions ...
Rappels: 4) Piles Types abstraits de donnes (Abstract Data Type)
Hamel, Sylvie
Rappels: 4) Piles #12;Types abstraits de données (Abstract Data Type) IFT2015, A2009, Sylvie Hamel Université de Montréal 1Piles Type de données Un ensemble de valeurs Un ensemble d'opérations Structure de Université de Montréal 2Piles #12;Type abstrait de données PILE (§4.2) Garde en mémoire des objets
Equilibrium Distributions and Superconductivity
Ashot Vagharshakyan
2011-06-07T23:59:59.000Z
In this article two models for charges distributions are discussed. On the basis of our consideration we put different points of view for stationary state. We prove that only finite energy model for charges' distribution and well-known variation principle explain some well-known experimental results. A new model for superconductivity was suggested, too. In frame of that model some characteristic experimental results for superconductors is possible to explain.
SUPERTHERMAL ELECTRON DISTRIBUTION
Kauffman, R
2007-12-20T23:59:59.000Z
This memo discusses the analysis of the high-energy x-ray distribution from a laser-induced plasma to determine the superthermal electron distribution. The methods of deconvolution outlined in I are similar to formulae derived in the literature not including and including effects due to electron stopping. In II the methods are applied to an x-ray spectrum from an Au disc irradiated by ARGUS.
Polygamy of distributed entanglement
Buscemi, Francesco [Statistical Laboratory, DPMMS, University of Cambridge, Cambridge CB3 0WB (United Kingdom); Gour, Gilad [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada); Department of Mathematics and Statistics, University of Calgary, Alberta, T2N 1N4 (Canada); Kim, Jeong San [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada)
2009-07-15T23:59:59.000Z
While quantum entanglement is known to be monogamous (i.e., shared entanglement is restricted in multipartite settings), here we show that distributed entanglement (or the potential for entanglement) is by nature polygamous. By establishing the concept of one-way unlocalizable entanglement (UE) and investigating its properties, we provide a polygamy inequality of distributed entanglement in tripartite quantum systems of arbitrary dimension. We also provide a polygamy inequality in multiqubit systems and several trade-offs between UE and other correlation measures.
Quantum dense key distribution
Degiovanni, I.P.; Ruo Berchera, I.; Castelletto, S.; Rastello, M.L.; Bovino, F.A.; Colla, A.M.; Castagnoli, G. [Istituto Elettrotecnico Nazionale G. Ferraris, Strada delle Cacce 91, 10135 Torino (Italy); ELSAG SpA, Via Puccini 2, 16154, Genova (Italy)
2004-03-01T23:59:59.000Z
This paper proposes a protocol for quantum dense key distribution. This protocol embeds the benefits of a quantum dense coding and a quantum key distribution and is able to generate shared secret keys four times more efficiently than the Bennet-Brassard 1984 protocol. We hereinafter prove the security of this scheme against individual eavesdropping attacks, and we present preliminary experimental results, showing its feasibility.
Absolute-magnitude distributions of supernovae
Richardson, Dean; Wright, John [Department of Physics, Xavier University of Louisiana, New Orleans, LA 70125 (United States); Jenkins III, Robert L. [Applied Physics Department, Richard Stockton College, Galloway, NJ 08205 (United States); Maddox, Larry, E-mail: drichar7@xula.edu [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States)
2014-05-01T23:59:59.000Z
The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.
New ideas about multiplication of tensorial distributions
Skakala, Jozef
2009-01-01T23:59:59.000Z
There is a huge need in general relativity for a consistent and useful mathematical theory defining the multiplication of tensor distributions in a geometric (diffeomorphism invariant) way. Significant progress has been made through the concept of Colombeau algebras, and the construction of full Colombeau algebras on differential manifolds for arbitrary tensors. Despite the fact that this goal was achieved, it does not incorporate clearly enough the concept of covariant derivative and hence has a limited meaning. We take a different approach: we consider any type of preference for smooth distributions (on a smooth manifold) as nonintuitive, which means all our approach must be based fully on the Colombeau equivalence relation as the fundamental feature of the theory. After taking this approach we very naturally obtain a canonical and geometric theory defining tensorial operations with tensorial distributions, including covariant derivative. This also happens because we no longer need any explicit canonical ge...
The Gravitational Instability of the Vacuum: Insight into the Cosmological Constant Problem
Alexander, S
2004-07-06T23:59:59.000Z
A mechanism for suppressing the cosmological constant is developed, based on an analogy with a superconducting phaseshift in which free fermions coupled perturbatively to a weak gravitational field are in an unstable false vacuum state. The coupling of the fermions to the gravitational field generates fermion condensates with zero momentum and a phase transition induces a nonperturbative transition to a true vacuum state by producing a positive energy gap {Delta} in the vacuum energy, identified with {radical}{Lambda}, where {Lambda} is the cosmological constant. In the strong coupling limit a large cosmological constant induces a period of inflation in the early universe, followed by a weak coupling limit in which {radical}{Lambda} vanishes exponentially fast as the universe expands due to the dependence of the energy gap on the density of Fermi surface fermions, D({epsilon}), predicting a small cosmological constant in the present universe.
Research on Fuzzy Regulation Strategies in the Constant Air Volume Air Conditioning System
Bai, T.; Zhang, J.; Ning, N.; Tong, K.; Wu, Y.; Wang, H.
2006-01-01T23:59:59.000Z
The energy consumption of the constant air volume (CAV) system largely depends on the regulation strategies. Although some air conditioning systems are equipped with automatic regulation devices, others lack effective regulation strategies. To avoid...
Al-Asaad, Hussain
1 ABSTRACT Microprocessors are becoming increasingly complex and difficult to debug. Researchers are constantly looking for new methods to increase the observability and control- lability of microprocessors to important internal signals without inter- rupting the microprocessor execution. The output
A new scheme for the running coupling constant in gauge theories using Wilson loops
Erek Bilgici; Antonino Flachi; Etsuko Itou; Masafumi Kurachi; C. -J David Lin; Hideo Matsufuru; Hiroshi Ohki; Tetsuya Onogi; Takeshi Yamazaki
2010-01-21T23:59:59.000Z
We propose a new renormalization scheme of the running coupling constant in general gauge theories using the Wilson loops. The renormalized coupling constant is obtained from the Creutz ratio in lattice simulations and the corresponding perturbative coefficient at the leading order. The latter can be calculated by adopting the zeta-function resummation techniques. We perform a benchmark test of our scheme in quenched QCD with the plaquette gauge action. The running of the coupling constant is determined by applying the step-scaling procedure. Using several methods to improve the statistical accuracy, we show that the running coupling constant can be determined in a wide range of energy scales with relatively small number of gauge configurations.
A constant-mass fuel delivery system for use in underwater autonomous vehicles
Saxton-Fox, Theresa Ann
2012-01-01T23:59:59.000Z
This thesis describes the design and assembly of two constant-mass fuel tanks to be used in autonomous underwater vehicles (AUVs). The fuel tanks are part of a power supply designed to increase AUV endurance without limiting ...
Sack, Jean H. (Jean Hope)
2013-01-01T23:59:59.000Z
The purpose of this thesis was to construct and seal air and containment tanks and other parts for a constant buoyancy power supply for an Autonomous Underwater Vehicle, or AUV. While multiple materials and techniques were ...
Universe Decay, Inflation and the Large Eigenvalue of the Cosmological Constant Seesaw
Michael McGuigan
2007-02-22T23:59:59.000Z
We discuss implications of the large eigenvalue of the cosmological constant seesaw mechanism extending hep-th/0602112 and hep-th/0604108. While the previous papers focused on the small eigenvalue as a cosmological constant associated with the accelerating Universe, here we draw attention to the physical implications of the large eigenvalue. In particular we find that the large eigenvalue can give rise to a period of inflation terminated by Universe decay. The mechanism involves quantum tunneling and mixing and introduces parameters $\\Gamma$, the decay constant, and $\\theta$, the mixing angle. We discuss the cosmological constant seesaw mechanism in the context of various models of current interest including chain inflation, inflatonless inflation, string theory, Universe entanglement and different approaches to the hierarchy problem.
Study of Thermal Properties of Graphene-Based Structures Using the Force Constant Method
Study of Thermal Properties of Graphene-Based Structures Using the Force Constant Method Hossein, 2012) Abstract The thermal properties of graphene-based materials are theoretically investigated transport is investigated for different structures including graphene, graphene antidot lat- tices
CODATA recommended values of the fundamental physical constants: Peter J. Mohr
, People's Republic of China Electronic address: mohr@nist.gov Electronic address: barry.taylor@nist.gov be found on the World Wide Web at physics.nist.gov/constants. CONTENTS Glossary 3 I. Introduction 5 A
AbstractStock-rebuilding time iso pleths relate constant levels of fishing
519 AbstractStock-rebuilding time iso pleths relate constant levels of fishing mortality (F. Iso pleths calculated in previous studies by deterministic models approximate median, rather than mean
On Possible Causes of Divergencies in Experimental Values of Gravitational Constant
A. L. Dmitriev
2006-10-31T23:59:59.000Z
It is shown that discrepancies in the experimental values of the gravitational constant might be caused by the temperature dependence of the gravitational force and inequality of the absolute temperatures of sample masses used in various gravitational experiments.
Optimality gap of constant-order policies decays exponentially in the ...
2014-09-07T23:59:59.000Z
demand, we further compute all expressions appearing in our bound in closed .... positive lead times, sometimes the best constant-order policy outperforms the ..... bounds tight enough to be useful in practice. ...... and consumer responses.
An alternative to constant rate link padding for the prevention of traffic analysis
Graham, Bryan Wayne
2002-01-01T23:59:59.000Z
approach to prevent traffic analysis has always been constant rate link padding. However, the effectiveness of this method when an adversary has access to advanced monitoring equipment and knowledge of statistical analysis has not been addressed...
Localitysensitive hashing using stable distributions
Localitysensitive hashing using stable distributions 4.1 LSH scheme based sstable distributions. of work appeared earlier in [DIIM04]. 4.1.1 sstable distributions Stable distributions [Zol86] defined limits of normalized sums independent identically distributed variables alternate definition follows
THE LIND-LEHMER CONSTANT FOR CYCLIC GROUPS OF ORDER LESS THAN 892, 371, 480.
Pinner, Christopher
THE LIND-LEHMER CONSTANT FOR CYCLIC GROUPS OF ORDER LESS THAN 892, 371, 480. VINCENT PIGNO AND CHRISTOPHER PINNER Abstract. We determine the Lind Lehmer constant for the cyclic group Zn when n is not a multiple of 892, 371, 480 = 23 Â· 3 Â· 5 Â· 7 Â· 11 Â· 13 Â· 17 Â· 19 Â· 23. 1. Introduction In [4] Lind introduced
Limits on the integration constant of the dark radiation term in Brane Cosmology
A. S. Al-Rawaf
2005-05-25T23:59:59.000Z
We consider the constraints from primordial Helium abundances on the constant of integration of the dark radiation term of the brane-world generalized Friedmann equation derived from the Randall-Sundrum Single brane model. We found that -- using simple, approximate and semianalytical Method -- that the constant of integration is limited to be between -8.9 and 2.2 which limits the possible contribution from dark radiation term to be approximately between -27% to 7% of the background photon energy density.
Variation of jet quenching from RHIC to LHC and thermal suppression of QCD coupling constant
B. G. Zakharov
2011-05-10T23:59:59.000Z
We perform a joint jet tomographic analysis of the data on the nuclear modification factor $R_{AA}$ from PHENIX at RHIC and ALICE at LHC. The computations are performed accounting for radiative and collisional parton energy loss with running coupling constant. Our results show that the observed slow variation of $R_{AA}$ from RHIC to LHC indicates that the QCD coupling constant is suppressed in the quark-gluon plasma produced at LHC.
Millimet, Scott Alan
1982-01-01T23:59:59.000Z
THE EXPORT RESPONSIVENESS OF THE ARGENTINE GRAIN EXPORT MARKET NG SYSTEM: A CONSTANT MARKET SHARE ANALYSIS A Thesis by SCOTT ALAN MILLIMET Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1982 Ma) or Subject: Agricultural Economics THE EXPORT RESPONSIVENESS OF THE ARGENTINE GRAIN EXPORT MARKETING SYSTEM: A CONSTANT MARKET SHARE ANALYSIS A Thesis by SCOTT ALAN MILLIMET Approved as to style...
Constants of geodesic motion in higher-dimensional black-hole spacetimes
Krtous, Pavel [Institute of Theoretical Physics, Charles University, V Holesovickach 2, Prague (Czech Republic); Kubiznak, David [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); Institute of Theoretical Physics, Charles University, V Holesovickach 2, Prague (Czech Republic); Page, Don N. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); Vasudevan, Muraari [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); JLR Engineering, 111 SE Everett Mall Way, E-201, Everett, Washington 98208-3236 (United States)
2007-10-15T23:59:59.000Z
In [Phys. Rev. Lett. 98, 061102 (2007)], we announced the complete integrability of geodesic motion in the general higher-dimensional rotating black-hole spacetimes. In the present paper we prove all the necessary steps leading to this conclusion. In particular, we demonstrate the independence of the constants of motion and the fact that they Poisson commute. The relation to a different set of constants of motion constructed in [J. High Energy Phys. 02 (2007) 004] is also briefly discussed.
Variation of calibration constant of alpha track detectors with respect to altitude
Vasudevan, Latha
1991-01-01T23:59:59.000Z
and earthquake prediction (Fleischer et al. 1980). A number of methods for monitoring radon gas concentrations in air have been developed in recent years. They encompass a variety of experimental techniques with a wide range of sensitivities and time... of the calibration constant is essential for the reliable determination of indoor air concentration and other applications of the Alpha Track Detector (ATD) measurements. The calibration constant was derived from the observed track densities (tracks/cm') for each...
Millimet, Scott Alan
1982-01-01T23:59:59.000Z
THE EXPORT RESPONSIVENESS OF THE ARGENTINE GRAIN EXPORT MARKET NG SYSTEM: A CONSTANT MARKET SHARE ANALYSIS A Thesis by SCOTT ALAN MILLIMET Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1982 Ma) or Subject: Agricultural Economics THE EXPORT RESPONSIVENESS OF THE ARGENTINE GRAIN EXPORT MARKETING SYSTEM: A CONSTANT MARKET SHARE ANALYSIS A Thesis by SCOTT ALAN MILLIMET Approved as to style...
Null-plane phenomenology for the pion decay constant and radius
Frederico, T.; Miller, G.A. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))
1992-06-01T23:59:59.000Z
The pion decay constant and the electromagnetic form factor are computed by using quark diagrams and projecting the bound-state wave function on the null plane. We show that the resulting formulas are the same as those of the Hamiltonian front-form scheme. The connection between the radius ({ital r}{sub {pi}}) and the pion decay constant ({ital f}{sub {pi}}) is studied using different models of confinement.
Optimal transport of two ions under slow spring-constant drifts
Xiao-Jing Lu; Mikel Palmero; Andreas Ruschhaupt; Xi Chen; Juan Gonzalo Muga
2015-02-05T23:59:59.000Z
We investigate the effect of slow spring-constant drifts of the trap used to shuttle two ions of different mass. We design transport protocols to suppress or mitigate the final excitation energy by applying invariant-based inverse engineering, perturbation theory, and a harmonic dynamical normal-mode approximation. A simple, explicit trigonometric protocol for the trap trajectory is found to be robust with respect to the spring-constant drifts.
The generalized Mackenzie distribution: disorientation angle distributions for arbitrary textures
Mason, J. K.
A general formulation for the disorientation angle distribution function is derived. The derivation employs the hyperspherical harmonic expansion for orientation distributions, and an explicit solution is presented for ...
Spinor Field with Polynomial Nonlinearity in LRS Bianchi type-I spacetime
Bijan Saha
2015-07-22T23:59:59.000Z
Within the scope of Bianchi type-I cosmological model the role of spinor field on the evolution of the Universe is investigated. In doing so we have considered a polynomial type of nonlinearity. It is found that depending on the sign of self-coupling constant the model allows either accelerated mode of expansion or oscillatory mode of evolution. Unlike general Bianchi type-I and Bianchi type $VI_0$ models in this case neither mass term nor the nonlinear term in the Lagrangian of spinor field vanish.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (MillionStructural Basis of WntSupportBRAP-focused topicsTwodimensional timeFuel Cells Â» Types
Sampling properties of random graphs: The degree distribution Michael P. H. Stumpf*
Fienberg, Stephen E.
the degree distribution of a node in the network is affected by the two types of sampling. Here we derive analysis we will concentrate on the sam- pling properties of the degree distribution of a network distribution, which for scale-free networks takes on a power-law form, Pr k k- 2,911 . Frequently a model
Inductive Characteristics of Power Distribution Grids in High Speed Integrated Circuits
Friedman, Eby G.
Inductive Characteristics of Power Distribution Grids in High Speed Integrated Circuits Andrey V characteristics of several types of gridded power distribution networks are described in this paper interconnect. In power distribution grids with alternating power and ground lines, the inductance is shown
On the Comparison of Fisher Information of the Weibull and GE Distributions
Kundu, Debasis
On the Comparison of Fisher Information of the Weibull and GE Distributions Rameshwar D. Gupta exponen- tial (GE) and Weibull distributions for complete and Type-I censored observations. Fisher is much more than the GE distribution. We compute the total information of the Weibull and GE
Distributed Radio Interferometric Calibration
Yatawatta, Sarod
2015-01-01T23:59:59.000Z
Increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. In this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. We exploit the data parallelism across frequency that is inherent in radio astronomical observations that are recorded as multiple channels at different frequencies. Moreover, we also exploit the smoothness of the variation of calibration parameters across frequency. Data parallelism enables us to distribute the computing load across a network of compute agents. Smoothness in frequency enables us reformulate calibration as a consensus optimization problem. With this formulation, we enable flow of information between compute agents calibrating data at different frequencies, without actually passing the data, and thereby improving robustness. We present simulation results to show the feasibility as well as the advantages of distribute...
Brown, Kenneth Dewayne (Grain Valley, MO); Dunson, David (Kansas City, MO)
2006-08-08T23:59:59.000Z
A distributed data transmitter (DTXR) which is an adaptive data communication microwave transmitter having a distributable architecture of modular components, and which incorporates both digital and microwave technology to provide substantial improvements in physical and operational flexibility. The DTXR has application in, for example, remote data acquisition involving the transmission of telemetry data across a wireless link, wherein the DTXR is integrated into and utilizes available space within a system (e.g., a flight vehicle). In a preferred embodiment, the DTXR broadly comprises a plurality of input interfaces; a data modulator; a power amplifier; and a power converter, all of which are modularly separate and distinct so as to be substantially independently physically distributable and positionable throughout the system wherever sufficient space is available.
Brown, Kenneth Dewayne (Grain Valley, MO); Dunson, David (Kansas City, MO)
2008-06-03T23:59:59.000Z
A distributed data transmitter (DTXR) which is an adaptive data communication microwave transmitter having a distributable architecture of modular components, and which incorporates both digital and microwave technology to provide substantial improvements in physical and operational flexibility. The DTXR has application in, for example, remote data acquisition involving the transmission of telemetry data across a wireless link, wherein the DTXR is integrated into and utilizes available space within a system (e.g., a flight vehicle). In a preferred embodiment, the DTXR broadly comprises a plurality of input interfaces; a data modulator; a power amplifier; and a power converter, all of which are modularly separate and distinct so as to be substantially independently physically distributable and positionable throughout the system wherever sufficient space is available.
Hasinoff, M D; Azuelos, Georges; Bertl, W; Blecher, M; Chen, C Q; Depommier, P; Doyle, B; Von Egidy, T; Gorringe, T P; Gumplinger, P; Henderson, R; Jonkmans, G; Larabee, A J; MacDonald, J A; McDonald, S C; Munro, M H; Poutissou, J M; Poutissou, R; Robertson, B C; Sample, D G; Schott, W; Taylor, G N; Veillette, S; Wright, D H
1992-01-01T23:59:59.000Z
Determination of the semi-leptonic weak interaction pseudoscalar coupling constant , g$_{P}$, using the reaction $\\mu^{-}$p --> $\
A New Linearization Method of Unbalanced Electrical Distribution Networks
Liu, Guodong [ORNL; Xu, Yan [ORNL; Ceylan, Oguzhan [ORNL; Tomsovic, Kevin [University of Tennessee, Knoxville (UTK)
2014-01-01T23:59:59.000Z
Abstract--- With increasing penetration of distributed generation in the distribution networks (DN), the secure and optimal operation of DN has become an important concern. As DN control and operation strategies are mostly based on the linearized sensitivity coefficients between controlled variables (e.g., node voltages, line currents, power loss) and control variables (e.g., power injections, transformer tap positions), efficient and precise calculation of these sensitivity coefficients, i.e. linearization of DN, is of fundamental importance. In this paper, the derivation of the node voltages and power loss as functions of the nodal power injections and transformers' tap-changers positions is presented, and then solved by a Gauss-Seidel method. Compared to other approaches presented in the literature, the proposed method takes into account different load characteristics (e.g., constant PQ, constant impedance, constant current and any combination of above) of a generic multi-phase unbalanced DN and improves the accuracy of linearization. Numerical simulations on both IEEE 13 and 34 nodes test feeders show the efficiency and accuracy of the proposed method.
Worst Case Scenario for Large Distribution Networks with Distributed Generation
Pota, Himanshu Roy
Worst Case Scenario for Large Distribution Networks with Distributed Generation M. A. Mahmud) in distri- bution network has significant effects on voltage profile for both customers and distribution on variation of the voltage and the amount of DG that can be connected to the distribution networks. This paper
History and Analysis of Distributed Acoustic Sensing (DAS) for Oilfield Applications
Kimbell, Jeremiah
2013-05-15T23:59:59.000Z
The inherent nature of distributed acoustic sensing technology is a direct result of two key components: optical fiber and the speed of light. Because the speed of light is constant and optical fiber is an isolated medium, combining the two creates...
NOAA Technical Memorandum OAR PMEL-122 Tidal Datum Distributions in Puget Sound,
NOAA Technical Memorandum OAR PMEL-122 Tidal Datum Distributions in Puget Sound, Washington, Based . . . . . . . . . . . . . . 5 3. Puget Sound Channel Tide Model . . . . . . . . . . . . . . . 6 3.1 Description of the channel . . . . . . . . . . . . . . . . . . . . . . . . . 30 9. Appendix: Tidal harmonic constants in Puget Sound . . . 30 10. References
Web-scale distributed AI search across disconnected and heterogeneous infrastructures
St Andrews, University of
structures [3], [4], and obtaining qualitative models of dynamics systems arising in a wide range, and allowing easy verification of every step of the distribution process. The unique challenges our framework of the constant increase of computing power available to computing users of all levels, the processing of so
Pluggable type-checking for custom type qualifiers in Java
Papi, Matthew M.
2007-09-17T23:59:59.000Z
We have created a framework for adding custom type qualifiers to the Javalanguage in a backward-compatible way. The type system designer definesthe qualifiers and creates a compiler plug-in that enforces theirsemantics. ...
Rappels: 4) Piles Types abstraits de donnes (Abstract Data Type)
Hamel, Sylvie
Rappels: 4) Piles Types abstraits de donnÃ©es (Abstract Data Type) IFT2015, A2009, Sylvie Hamel UniversitÃ© de MontrÃ©al 1Piles Type de donnÃ©es Un ensemble de valeurs Un ensemble d'opÃ©rations Structure de UniversitÃ© de MontrÃ©al 2Piles Type abstrait de donnÃ©es PILE (Â§4.2) Garde en mÃ©moire des objets arbitraires
Abstract Data Types 5 Algebraic Theory of Abstract Data Types
Berger, Ulrich
stack top: stack elts The following is an algebra for the signature STACK. Algebra SeqN Carriers N, N43 Part II Abstract Data Types #12;44 5 Algebraic Theory of Abstract Data Types An Abstract Data Type (ADT) is a collection of objects and functions, that is, an algebra, where one ignores how
Vail, III, William Banning (Bothell, WA)
2000-01-01T23:59:59.000Z
Methods of operation of different types of multiple electrode apparatus vertically disposed in a cased well to measure information related to the resistivity of adjacent geological formations from within the cased well are described. The multiple electrode apparatus has a minimum of two spaced apart voltage measurement electrodes that electrically engage a first portion of the interior of the cased well and that provide at least first voltage information. Current control means are used to control the magnitude of any selected current that flows along a second portion of the interior of the casing to be equal to a predetermined selected constant. The first portion of the interior of the cased well is spaced apart from the second portion of the interior of the cased well. The first voltage information and the predetermined selected constant value of any selected current flowing along the casing are used in part to determine a magnitude related to the formation resistivity adjacent to the first portion of the interior of the cased well. Methods and apparatus having a plurality of voltage measurement electrodes are disclosed that provide voltage related information in the presence of constant currents flowing along the casing which is used to provide formation resistivity.
Cook, William R.
1 Web Services versus Distributed Objects William R. Cook, Janel Barfield University of Texas at Austin 2 How many times have you heard... 3 "Web Services suck..." ? 4 "WS are a bad version Objects 10 to 100 times faster than Web Services 7 Test Case Call a remote service that returns an integer
Distributed Quantum Programming
Ellie D'Hondt; Yves Vandriessche
2010-01-11T23:59:59.000Z
In this paper we explore the structure and applicability of the Distributed Measurement Calculus (DMC), an assembly language for distributed measurement-based quantum computations. We describe the formal language's syntax and semantics, both operational and denotational, and state several properties that are crucial to the practical usability of our language, such as equivalence of our semantics, as well as compositionality and context-freeness of DMC programs. We show how to put these properties to use by constructing a composite program that implements distributed controlled operations, in the knowledge that the semantics of this program does not change under the various composition operations. Our formal model is the basis of a quantum virtual machine construction for distributed quantum computations, which we elaborate upon in the latter part of this work. This virtual machine embodies the formal semantics of DMC such that programming execution no longer needs to be analysed by hand. Far from a literal translation, it requires a substantial concretisation of the formal model at the level of data structures, naming conventions and abstraction mechanisms. At the same time we provide automatisation techniques for program specification where possible to obtain an expressive and user-friendly programming environment.
Figure 1. Approximate distribution of beluga whales in Alaska waters. The dark shading displays (DeMaster 1995: pp. 16). CURRENT AND MAXIMUM NET PRODUCTIVITY RATES A reliable estimate of the maximum net productivity rate is currently unavailable for the Beaufort Sea stock of beluga whales. Hence
MAIL DISTRIBUTION MAIL PRODUCTION
MAIL DISTRIBUTION AND MAIL PRODUCTION OPERATIONS GUIDE November 07 Revised November 07 #12;2 Mail/billing......................................................................................1-5346 Mail Production of the University non-profit permit. 3. All bulk mailings must be coordinated with Mail Production at the earliest
CCured: Type-Safe Retrofitting of Legacy Software
Weimer, Westley
Engineering]: Testing and Debugging; D.2.7 [Software Engineering]: Distribution, Maintenance, and Enhancement, Reliability, Security, Verification Additional Key Words and Phrases: Memory safety, pointer qualifier, a program transformation system that adds type safety guarantees to existing C programs. CCured attempts
Method of preparing mercury with an arbitrary isotopic distribution
Grossman, M.W.; George, W.A.
1986-12-16T23:59:59.000Z
This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg[sub 2]Cl[sub 2], corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H[sub 2]O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H[sub 2]O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered. 1 fig.
Distributed Energy Resources for Carbon Emissions Mitigation
Firestone, Ryan; Marnay, Chris
2008-01-01T23:59:59.000Z
Distributed Energy Resource Technology Characterizations. ”ABORATORY Distributed Energy Resources for Carbon Emissions5128 Distributed Energy Resources for Carbon Emissions
Distributed Energy Alternatives to Electrical
Pennycook, Steve
Distributed Energy Alternatives to Electrical Distribution Grid Expansion in Consolidated Edison.www.gastechnology.org 2 #12;Distributed Energy Alternatives to Electrical Distribution Grid Expansion in Consolidated-Battelle for the Department of Energy Subcontract Number: 4000052360 GTI Project Number: 20441 New York State Energy Research
Bonnen, C. A.
1960-01-01T23:59:59.000Z
.......... .......-.----------------------. 8 Labor -..-.....-----...------------------------------------------------. 9 Land Tenure .--.----....---....--------------------------------- 9 Number and Size of Farms ....----...----.-._--------- 10 Capital... -------------...-------.---------------------------- 21 Hogs -......-....--------------------------------------------------- 22 Poultry .-.---.-.....--.-..------.---------------------------------- 22 Horses and Mules ---..-....---..--..------------------------ 23 Types of Farming and Type-of-farming...
Predicting the Reactivity of Hydride Donors in Water: Thermodynamic Constants for Hydrogen
Connelly, Samantha J.; Wiedner, Eric S.; Appel, Aaron M.
2015-01-01T23:59:59.000Z
Chemical reactivity of hydride complexes can be predicted by comparing bond strengths for homolytic and heterolytic cleavage of bonds to hydrogen. To determine these bond strengths, thermodynamic constants for H+, H•, H–, and H2 are essential and need to be used uniformly to enable the prediction of reactivity and equilibria. One of the largest challenges is quantifying the stability of solvated H– in water, which is discussed. Due to discrepancies in the literature for the constants used in water, we propose the use of a set of self-consistent constants with convenient standard states. The work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences.
Dynamical friction in constant density cores: a failure of the Chandrasekhar formula
J. I. Read; Tobias Goerdt; Ben Moore; A. P. Pontzen; Joachim Stadel; George Lake
2006-10-04T23:59:59.000Z
Using analytic calculations and N-body simulations we show that in constant density (harmonic) cores, sinking satellites undergo an initial phase of very rapid (super-Chandrasekhar) dynamical friction, after which they experience no dynamical friction at all. For density profiles with a central power law profile of log-slope, $-\\alpha$, the infalling satellite heats the background and causes $\\alpha$ to decrease. For $\\alpha < 0.5$ initially, the satellite generates a small central constant density core and stalls as in the $\\alpha = 0$ case. We discuss some astrophysical applications of our results to decaying satellite orbits, galactic bars and mergers of supermassive black hole binaries. In a companion paper we show that a central constant density core can provide a natural solution to the timing problem for Fornax's globular clusters.
Constant-intensity waves and their modulation instability in non-Hermitian potentials
Konstantinos G. Makris; Ziad H. Musslimani; Demetrios N. Christodoulides; Stefan Rotter
2015-03-31T23:59:59.000Z
In all of the diverse areas of science where waves play an important role, one of the most fundamental solutions of the corresponding wave equation is a stationary wave with constant intensity. The most familiar example is that of a plane wave propagating in free space. In the presence of any Hermitian potential, a wave's constant intensity is, however, immediately destroyed due to scattering. Here we show that this fundamental restriction is conveniently lifted when working with non-Hermitian potentials. In particular, we present a whole new class of waves that have constant intensity in the presence of linear as well as of nonlinear inhomogeneous media with gain and loss. These solutions allow us to study, for the first time, the fundamental phenomenon of modulation instability in an inhomogeneous environment. Our results pose a new challenge for the experiments on non-Hermitian scattering that have recently been put forward.
Degree-distribution stability of scale-free networks
Zhenting Hou; Xiangxing Kong; Dinghua Shi; Guanrong Chen
2008-05-09T23:59:59.000Z
Based on the concept and techniques of first-passage probability in Markov chain theory, this letter provides a rigorous proof for the existence of the steady-state degree distribution of the scale-free network generated by the Barabasi-Albert (BA) model, and mathematically re-derives the exact analytic formulas of the distribution. The approach developed here is quite general, applicable to many other scale-free types of complex networks.
Optimal steering of a linear stochastic system to a final probability distribution, part II
Yongxin Chen; Tryphon Georgiou; Michele Pavon
2014-10-13T23:59:59.000Z
We consider the problem of minimum energy steering of a linear stochastic system to a final prescribed distribution over a finite horizon and to maintain a stationary distribution over an infinite horizon. We present sufficient conditions for optimality in terms of a system of dynamically coupled Riccati equations in the finite horizon case and algebraic in the stationary case. We then address the question of feasibility for both problems. For the finite-horizon case, provided the system is controllable, we prove that without any restriction on the directionality of the stochastic disturbance it is always possible to steer the state to any arbitrary Gaussian distribution over any specified finite time-interval. For the stationary infinite horizon case, it is not always possible to maintain the state at an arbitrary Gaussian distribution through constant state-feedback. It is shown that covariances of admissible stationary Gaussian distributions are characterized by a certain Lyapunov-like equation. We finally present an alternative to solving the system of coupled Riccati equations, by expressing the optimal controls in the form of solutions to (convex) semi-definite programs for both cases. We conclude with an example to steer the state covariance of the distribution of inertial particles to an admissible stationary Gaussian distribution over a finite interval, to be maintained at that stationary distribution thereafter by constant-gain state-feedback control.
Type Ia Supernova Progenitors, Environmental Effects, and Cosmic Supernova Rates
Ken'ichi Nomoto; Hideyuki Umeda; Izumi Hachisu; Mariko Kato; Chiaki Kobayashi; Takuji Tsujimoto
1999-07-27T23:59:59.000Z
Relatively uniform light curves and spectral evolution of Type Ia supernovae (SNe Ia) have led to the use of SNe Ia as a ``standard candle'' to determine cosmological parameters, such as the Hubble constant, the density parameter, and the cosmological constant. Whether a statistically significant value of the cosmological constant can be obtained depends on whether the peak luminosities of SNe Ia are sufficiently free from the effects of cosmic and galactic evolutions. Here we first review the single degenerate scenario for the Chandrasekhar mass white dwarf (WD) models of SNe Ia. We identify the progenitor's evolution and population with two channels: (1) the WD+RG (red-giant) and (2) the WD+MS (near main-sequence He-rich star) channels. In these channels, the strong wind from accreting white dwarfs plays a key role, which yields important age and metallicity effects on the evolution. We then address the questions whether the nature of SNe Ia depends systematically on environmental properties such as metallicity and age of the progenitor system and whether significant evolutionary effects exist. We suggest that the variation of the carbon mass fraction $X$(C) in the C+O WD (or the variation of the initial WD mass) causes the diversity of the brightness of SNe Ia. This model can explain the observed dependence of SNe Ia brighness on the galaxy types. Finally, applying the metallicity effect on the evolution of SN Ia progenitors, we make a prediction of the cosmic supernova rate history as a composite of the supernova rates in different types of galaxies.
Distributed decision fusion using empirical estimation
Rao, N.S.V. [Oak Ridge National Lab., TN (United States). Center for Engineering Systems Advanced Research
1996-09-01T23:59:59.000Z
The problem of optimal data fusion in multiple detection systems is studied in the case where training examples are available, but no a priori information is available about the probability distributions of errors committed by the individual detectors. Earlier solutions to this problem require some knowledge of the error distributions of the detectors, for example, either in a parametric form or in a closed analytical form. Here the authors show that, given a sufficiently large training sample, an optimal fusion rule can be implemented with an arbitrary level of confidence. They first consider the classical cases of Bayesian rule and Neyman-Pearson test for a system of independent detectors. Then they show a general result that any test function with a suitable Lipschitz property can be implemented with arbitrary precision, based on a training sample whose size is a function of the Lipschitz constant, number of parameters, and empirical measures. The general case subsumes the cases of non-independent and correlated detectors.
PROGRAMMING WITH TYPES A Dissertation
Weirich, Stephanie
WITH TYPES Stephanie Claudene Weirich, Ph.D. Cornell University 2002 Run-time type analysis, facilities to support type analysis often require complicated language semantics that allow little freedom to list. Steve's parents Arthur and Deborah Zdancewic have encouraged me as long as I have known them. I
Annotated Type Systems Program Analysis
Palsberg, Jens
Danish Summary xi 1 Introduction 1 1.1 The Standard Type System . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . . . . . . . 36 2.1.3 The Conjunction Type System . . . . . . . . . . . . 37 2.2 The Power of tAnnotated Type Systems for Program Analysis Kirsten Lackner Solberg Computer Science Department
SU(2) chiral fits to light pseudoscalar masses and decay constants
A. Bazavov; C. Bernard; C. DeTar; X. Du; W. Freeman; Steven Gottlieb; Urs M. Heller; J. E. Hetrick; J. Laiho; L. Levkova; M. B. Oktay; J. Osborn; R. Sugar; D. Toussaint; R. S. Van de Water
2009-11-03T23:59:59.000Z
We present the results of fits to recent asqtad data in the light pseudoscalar sector using SU(2) partially-quenched staggered chiral perturbation theory. Superfine (a~0.06 fm) and ultrafine (a~0.045 fm) ensembles are used, where light sea quark masses and taste splittings are small compared to the strange quark mass. Our fits include continuum NNLO chiral logarithms and analytic terms. We give preliminary results for the pion decay constant, SU(2) low-energy constants and the chiral condensate in the two-flavor chiral limit.
Is the zero-point energy a source of the cosmological constant?
Yasunori Fujii
2014-03-15T23:59:59.000Z
We discuss how we remove a huge discrepancy between the theory of a cosmological constant, due to the zero-point energies of matter fields, and the observation. The technique of dimensional regularization plays a decisive role. We eventually reach the desired behavior of the vacuum densities falling off like t^{-2}, allowing us to understand how an extremely small result comes about naturally. As a price, however, the zero-point energy vacuum fails to act as a true cosmological constant. Its expected role responsible for the observed accelerating universe is then to be inherited by the gravitational scalar field, dark energy, as we suggest in the scalar-tensor theory.
Singlet axial-vector coupling constant of the nucleon in QCD without instantons
Janardan P. Singh
2015-07-19T23:59:59.000Z
We have analyzed axial-vector current-current correlation functions between one-nucleon states to calculate the singlet axial-vector coupling constant of the nucleon. The octet-octet and the octet-singlet current correlators, investigated in this work, do not require any use of instanton effects. The QCD and hadronic parameters used for the evaluation of correlators have been varied by (10 - 20)%. The value of the singlet axial-vector coupling constant of the nucleon obtained from this analysis is consistent with its current determination from experiments and QCD theory.
Lattice study of the leptonic decay constant of the pion and its excitations
Mastropas, Ekaterina; Richard, David
2014-11-01T23:59:59.000Z
We present a calculation of the decay constant of the pion, and its lowest-lying three excitations, at three values of the pion mass between around 400 and 700 MeV, using anisotropic clover lattices. We use the variational method to determine an optimal interpolating operator for each of the states. We find that the decay constant of the first excitation, and more notably of the second, is suppressed with respect to that of the ground-state pion, but that the suppression shows little dependence on the quark mass.
Information content in $F(R)$ brane models with non-constant curvature
Correa, R A C; Dutra, A de Souza; da Rocha, Roldao; Menezes, R
2015-01-01T23:59:59.000Z
In this work we investigate the entropic information-measure in the context of braneworlds with non-constant curvature. The braneworld entropic information is studied for gravity modified by the squared of the Ricci scalar, besides the usual Einstein-Hilbert term. We showed that the minimum value of the brane configurational entropy provides a stricter bound on the parameter that is responsible for the $F(R)$ model to differ from the Einstein-Hilbert standard one. Our results are moreover consistent to a negative bulk cosmological constant.
Electronic constant current and current pulse signal generator for nuclear instrumentation testing
Brown, Roger A. (Amsterdam, NY)
1994-01-01T23:59:59.000Z
Circuitry for testing the ability of an intermediate range nuclear instrut to detect and measure a constant current and a periodic current pulse. The invention simulates the resistance and capacitance of the signal connection of a nuclear instrument ion chamber detector and interconnecting cable. An LED flasher/oscillator illuminates an LED at a periodic rate established by a timing capacitor and circuitry internal to the flasher/oscillator. When the LED is on, a periodic current pulse is applied to the instrument. When the LED is off, a constant current is applied. An inductor opposes battery current flow when the LED is on.
New Phantom and non-Phantom Wormhole Solutions with Generic Cosmological Constant
Heydarzade, Y; Moradpour, H
2014-01-01T23:59:59.000Z
There are a number of reasons to study wormholes with generic cosmological constant $\\Lambda$. Recent observations indicate that present accelerating expansion of the universe demands $\\Lambda>0$. On the other hand, some extended theories of gravitation such as supergravity and superstring theories posses vacuum states with $\\Lambdaenergy density and pressure profiles which support such a geometry are obtained. It is shown that for having such a geometry, the wormhole throat $r_0$, the cosmological constant $\\Lambda$ and the equation of state parameter $\\omega$ sh...
Electronic constant current and current pulse signal generator for nuclear instrumentation testing
Brown, R.A.
1994-04-19T23:59:59.000Z
Circuitry is described for testing the ability of an intermediate range nuclear instrument to detect and measure a constant current and a periodic current pulse. The invention simulates the resistance and capacitance of the signal connection of a nuclear instrument ion chamber detector and interconnecting cable. An LED flasher/oscillator illuminates an LED at a periodic rate established by a timing capacitor and circuitry internal to the flasher/oscillator. When the LED is on, a periodic current pulse is applied to the instrument. When the LED is off, a constant current is applied. An inductor opposes battery current flow when the LED is on. 1 figures.
On the Verdet constant and Faraday rotation for graphene-like materials
Mikkel H. Brynildsen; Horia D. Cornean
2013-02-21T23:59:59.000Z
We present a rigorous and rather self-contained analysis of the Verdet constant in graphene- like materials. We apply the gauge-invariant magnetic perturbation theory to a nearest- neighbour tight-binding model and obtain a relatively simple and exactly computable formula for the Verdet constant, at all temperatures and all frequencies of sufficiently large absolute value. Moreover, for the standard nearest neighbour tight-binding model of graphene we show that the transverse component of the conductivity tensor has an asymptotic Taylor expansion in the external magnetic field where all the coefficients of even powers are zero.
Lomboy, Gilson [Department of Civil, Construction, and Environmental Engineering, Iowa State University, Ames, Iowa 50011 (United States); Sundararajan, Sriram, E-mail: srirams@iastate.edu [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States); Wang Kejin [Department of Civil, Construction, and Environmental Engineering, Iowa State University, Ames, Iowa 50011 (United States); Subramaniam, Shankar [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)
2011-11-15T23:59:59.000Z
A method for determining Hamaker constant of cementitious materials is presented. The method involved sample preparation, measurement of adhesion force between the tested material and a silicon nitride probe using atomic force microscopy in dry air and in water, and calculating the Hamaker constant using appropriate contact mechanics models. The work of adhesion and Hamaker constant were computed from the pull-off forces using the Johnson-Kendall-Roberts and Derjagin-Muller-Toropov models. Reference materials with known Hamaker constants (mica, silica, calcite) and commercially available cementitious materials (Portland cement (PC), ground granulated blast furnace slag (GGBFS)) were studied. The Hamaker constants of the reference materials obtained are consistent with those published by previous researchers. The results indicate that PC has a higher Hamaker constant than GGBFS. The Hamaker constant of PC in water is close to the previously predicted value C{sub 3}S, which is attributed to short hydration time ({<=} 45 min) used in this study.
Hsu, Cheng-Ting (Ames, IA)
1984-01-01T23:59:59.000Z
A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.
Marginal evidence for cosmic acceleration from Type Ia supernovae
Nielsen, Jeppe Trøst; Sarkar, Subir
2015-01-01T23:59:59.000Z
The `standard' model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present --- as was inferred originally from the Hubble diagram of Type Ia supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these `standardisable candles' indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find, rather surprisingly, that the data are still quite consistent with a constant rate of expansion.
Marginal evidence for cosmic acceleration from Type Ia supernovae
Jeppe Trøst Nielsen; Alberto Guffanti; Subir Sarkar
2015-06-09T23:59:59.000Z
The "standard" model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present --- as was inferred originally from the Hubble diagram of Type Ia supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these "standardisable candles" indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find, rather surprisingly, that the data are still quite consistent with a constant rate of expansion.
Multipartite secure state distribution
Duer, W.; Briegel, H.-J. [Institut fuer Theoretische Physik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria); Institut fuer Quantenoptik und Quanteninformation der Oesterreichischen, Akademie der Wissenschaften, Innsbruck (Austria); Calsamiglia, J. [Institut fuer Theoretische Physik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria)
2005-04-01T23:59:59.000Z
We introduce the distribution of a secret multipartite entangled state in a real-world scenario as a quantum primitive. We show that in the presence of noisy quantum channels (and noisy control operations), any state chosen from the set of two-colorable graph states (Calderbank-Shor-Steane codewords) can be created with high fidelity while it remains unknown to all parties. This is accomplished by either blind multipartite entanglement purification, which we introduce in this paper, or by multipartite entanglement purification of enlarged states, which offers advantages over an alternative scheme based on standard channel purification and teleportation. The parties are thus provided with a secret resource of their choice for distributed secure applications.
Light Meson Distribution Amplitudes
R. Arthur; P. A. Boyle; D. Brömmel; M. A. Donnellan; J. M. Flynn; A. Jüttner; H. Pedroso de Lima; T. D. Rae; C. T. Sachrajda; B. Samways
2010-11-12T23:59:59.000Z
We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.
A dependent nominal type theory
Cheney, James
2012-01-01T23:59:59.000Z
Nominal abstract syntax is an approach to representing names and binding pioneered by Gabbay and Pitts. So far nominal techniques have mostly been studied using classical logic or model theory, not type theory. Nominal extensions to simple, dependent and ML-like polymorphic languages have been studied, but decidability and normalization results have only been established for simple nominal type theories. We present a LF-style dependent type theory extended with name-abstraction types, prove soundness and decidability of beta-eta-equivalence checking, discuss adequacy and canonical forms via an example, and discuss extensions such as dependently-typed recursion and induction principles.
Mapping Biomass Distribution Potential
Schaetzel, Michael
2010-11-18T23:59:59.000Z
Mapping Biomass Distribution Potential Michael Schaetzel Undergraduate ? Environmental Studies ? University of Kansas L O C A T S I O N BIOMASS ENERGY POTENTIAL o According to DOE, Biomass has the potential to provide 14% of... the nation’s power o Currently 1% of national power supply o Carbon neutral? combustion of biomass is part of the natural carbon cycle o Improved crop residue management has potential to benefit environment, producers, and economy Biomass Btu...
Symmetric generalized binomial distributions
Bergeron, H. [Univ Paris-Sud, ISMO, UMR 8214, 91405 Orsay (France)] [Univ Paris-Sud, ISMO, UMR 8214, 91405 Orsay (France); Curado, E. M. F. [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150 22290-180 - Rio de Janeiro (Brazil) [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150 22290-180 - Rio de Janeiro (Brazil); Instituto Nacional de Ciência e Tecnologia - Sistemas Complexos, Rua Xavier Sigaud 150, 22290-180 - Rio de Janeiro, RJ (Brazil); Gazeau, J. P. [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150 22290-180 - Rio de Janeiro (Brazil) [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150 22290-180 - Rio de Janeiro (Brazil); APC, UMR 7164, Univ Paris Diderot, Sorbonne Paris Cité, 75205 Paris (France); Rodrigues, Ligia M. C. S., E-mail: herve.bergeron@u-psud.fr, E-mail: evaldo@cbpf.br, E-mail: gazeau@apc.univ-paris7.fr, E-mail: ligia@cbpf.br [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150 22290-180 - Rio de Janeiro (Brazil)
2013-12-15T23:59:59.000Z
In two recent articles, we have examined a generalization of the binomial distribution associated with a sequence of positive numbers, involving asymmetric expressions of probabilities that break the symmetry win-loss. We present in this article another generalization (always associated with a sequence of positive numbers) that preserves the symmetry win-loss. This approach is also based on generating functions and presents constraints of non-negativeness, similar to those encountered in our previous articles.
University of Alberta SafeType: Detecting Type Violations for Type-Based Alias
Amaral, José Nelson
University of Alberta SafeType: Detecting Type Violations for Type-Based Alias Analysis of C Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries to reproduce single, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other
Sivaramakrishnan, R.; Michael, J. V.; Chemical Sciences and Engineering Division
2009-04-30T23:59:59.000Z
High-temperature rate constant experiments on OH with the five large (C{sub 5}-C{sub 8}) saturated hydrocarbons n-heptane, 2,2,3,3-tetramethylbutane (2,2,3,3-TMB), n-pentane, n-hexane, and 2,3-dimethylbutane (2,3-DMB) were performed with the reflected-shock-tube technique using multipass absorption spectrometric detection of OH radicals at 308 nm. Single-point determinations at {approx}1200 K on n-heptane, 2,2,3,3-TMB, n-hexane, and 2,3-DMB were previously reported by Cohen and co-workers; however, the present work substantially extends the database to both lower and higher temperature. The present experiments span a wide temperature range, 789-1308 K, and represent the first direct measurements of rate constants at T > 800 K for n-pentane. The present work utilized 48 optical passes corresponding to a total path length of {approx}4.2 m. As a result of this increased path length, the high OH concentration detection sensitivity permitted pseudo-first-order analyses for unambiguously measuring rate constants. The experimental results can be expressed in Arrhenius form in units of cm{sup 3} molecule{sup -1} s{sup -1} as follows: K{sub OH+n-heptane} = (2.48 {+-} 0.17) x 10{sup -10} exp[(-1927 {+-} 69 K)/T] (838-1287 K); k{sub OH+2,2,3,3-TMB} = (8.26 {+-} 0.89) x 10{sup -11} exp[(-1337 {+-} 94 K)/T] (789-1061 K); K{sub OH+n-pentane} = (1.60 {+-} 0.25) x 10{sup -10} exp[(-1903 {+-} 146 K)/T] (823-1308 K); K{sub OH+n-hexane} = (2.79 {+-} 0.39) x 10{sup -10} exp[(-2301 {+-} 134 K)/T] (798-1299 K); and k{sub OH+2,3-DMB} = (1.27 {+-} 0.16) x 10{sup -10} exp[(-1617 {+-} 118 K)/T] (843-1292 K). The available experimental data, along with lower-T determinations, were used to obtain evaluations of the experimental rate constants over the temperature range from {approx}230 to 1300 K for most of the title reactions. These extended-temperature-range evaluations, given as three-parameter fits, are as follows: k{sub OH+n-heptane} = 2.059 x 10{sup -5}T{sup 1.401} exp(33 K/T) cm{sup 3} molecule{sup -1} s{sup -1} (241-1287 K); k{sub OH+2,2,3,3-TMB} = 6.835 x 10{sup -17}T{sup 1.886} exp(-365 K/T) cm{sup 3} molecule{sup -1} s{sup -1} (290-1180 K); k{sub OH+n-pentane} = 2.495 x 10{sup -16}T{sup 1.649} exp(80 K/T) cm{sup 3} molecule{sup -1} s{sup -1} (224-1308 K); k{sub OH+n-hexane} = 3.959 x 10{sup -18}T{sup 2.218} exp(443 K/T) cm{sup 3} molecule{sup -1} s{sup -1} (292-1299 K); and k{sub OH+2,3-DMB} = 2.287 x 10{sup -17}T{sup 1.958} exp(365 K/T) cm{sup 3} molecule{sup -1} s{sup -1} (220-1292 K). The experimental data and the evaluations obtained for these five larger alkanes in the present work were used along with prior data/evaluations obtained in this laboratory for H abstractions by OH from a series of smaller alkanes (C{sub 3}?C{sub 5}) to devise rate rules for abstractions from various types of primary, secondary, and tertiary H atoms. Specifically, the current scheme was applied with good success to H abstractions by OH from a series of n-alkanes (n-octane through n-hexadecane). The total rate constants using this group scheme for reactions of OH with selected large alkanes are given as three-parameter fits in this article. The rate constants for the various abstraction channels in any large n-alkane can also be obtained using the groups listed in this article. The present group scheme serves to reduce the uncertainties in rate constants for OH + alkane reactions.
Orchestrating Distributed Resource Ensembles for Petascale Science
Baldin, Ilya; Mandal, Anirban; Ruth, Paul; Yufeng, Xin
2014-04-24T23:59:59.000Z
Distributed, data-intensive computational science applications of interest to DOE scientific com- munities move large amounts of data for experiment data management, distributed analysis steps, remote visualization, and accessing scientific instruments. These applications need to orchestrate ensembles of resources from multiple resource pools and interconnect them with high-capacity multi- layered networks across multiple domains. It is highly desirable that mechanisms are designed that provide this type of resource provisioning capability to a broad class of applications. It is also important to have coherent monitoring capabilities for such complex distributed environments. In this project, we addressed these problems by designing an abstract API, enabled by novel semantic resource descriptions, for provisioning complex and heterogeneous resources from multiple providers using their native provisioning mechanisms and control planes: computational, storage, and multi-layered high-speed network domains. We used an extensible resource representation based on semantic web technologies to afford maximum flexibility to applications in specifying their needs. We evaluated the effectiveness of provisioning using representative data-intensive ap- plications. We also developed mechanisms for providing feedback about resource performance to the application, to enable closed-loop feedback control and dynamic adjustments to resource allo- cations (elasticity). This was enabled through development of a novel persistent query framework that consumes disparate sources of monitoring data, including perfSONAR, and provides scalable distribution of asynchronous notifications.
Non-trivial, static, geodesically complete, vacuum space-times with a negative cosmological constant
Anderson, Michael
Non-trivial, static, geodesically complete, vacuum space-times with a negative solutions of the vacuum Einstein equations with a negative cosmological constant. The new families of this paper is to show that such rigidity is false in this last situation. More precisely, for
Letters to Analytical Chemistry Effects of Constant Voltage on Time Evolution of
Santiago, Juan G.
Letters to Analytical Chemistry Effects of Constant Voltage on Time Evolution of Propagating, California 94305 We extend the analytical theory of propagating concentra- tion polarization (CP) to describe which has a significant influence on analyte concentrations and electric fields in these devices.10
A Constant Gain Kalman Filter Approach to target tracking in Wireless Sensor Networks
Naik, Naren
A Constant Gain Kalman Filter Approach to target tracking in Wireless Sensor Networks Ashwin Yadav1 domains. One of the most fundamen- tal and widely used approaches to target tracking is the Kalman filter. In presence of unknown noise statistics there are difficulties in the Kalman filter yielding good results
Schlegel, H. Bernhard
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States *S Supporting Information ABSTRACT, and cellular death.1-9 Among the canonical nucleobases, guanine is well-known to be the most susceptible at a constant pH of 7 (E7). Redox potentials were obtained by chemical oxidation and kinetic rate measurements
Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment
Unger, L.M.; Trubey, D.K.
1981-09-01T23:59:59.000Z
Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed.
Allouche, Jean-Paul
Algebraic irrational binary numbers cannot be fixed points of nonÂtrivial constant length irrational number in a given base? A common conjectured answer to this vague question is that these digits . A widely believed conjecture is that an algebraic irrational number is a normal number in each base k â?? 2
Spring Constants for Hockey Dan Russell and Linda Hunt, Kettering University, Flint, MI
Russell, Daniel A.
of Static Bending Hockey sticks are rated according to weight, shaft flex, and the amount of curvature- ing the effective spring constant of a hockey stick. The butt end of the shaft is clamped to a rigid bench and masses are hung from a hook at the other end of the shaft where the blade and shaft meet. We
Viscosity and elastic constants of amorphous Si and Ge Ann Witwow@ and Frans Spaepen
Spaepen, Frans A.
Viscosity and elastic constants of amorphous Si and Ge Ann Witwow@ and Frans Spaepen Division expansion. Viscous flow was measured by stress relaxation and was found to be Newtonian. The viscosity of the viscosity of sputter-deposited samples as a function of stress (to establish the Newtonian charac- ter
Nonholonomic Ricci Flows and Running Cosmological Constant: 3D Taub-NUT Metrics
Sergiu I. Vacaru; Mihai Visinescu
2007-10-11T23:59:59.000Z
The common assertion that the Ricci flows of Einstein spaces with cosmological constant can be modelled by certain classes of nonholonomic frame, metric and linear connection deformations resulting in nonhomogeneous Einstein spaces is examined in the light of the role played by topological three dimensional (3D) Taub-NUT-AdS/dS spacetimes.
Scaling of classical rate constants on scaled potential-energy surfaces Myung Soo Kim,a)
Kim, Myung Soo
or dynamical calculation of a rate constant is to use data from electronic structure calculation. Structure at moderately high levels of electronic structure calculation. © 2001 American Institute of Physics. DOI: 10 state theories and the methods based on classical or quantal dynamics calculation.47 When
Bell, Alexis T.
As ab initio electronic structure calculations become more accurate, inherent sources of error, facilitate reactive flux calculations. As an example we compute the dynamically corrected rate constant on which the reaction occurs. A large number of electronic structure theo- ries are available
Constant Proportion Debt Obligations, Zeno's Paradox, and the Spectacular Financial Crisis of 2008
Richards, Donald St. P.
Constant Proportion Debt Obligations, Zeno's Paradox, and the Spectacular Financial Crisis of 2008-going worldwide financial crisis are heightened by the existence of other financial derivatives more arcane than, to the beat of his dying heart, The Devil drum on the darkened pane: "You did it, but was it Art?" Rudyard
Reid, Scott A.
: Application to ozone formation Mikhail V. Ivanov and Dmitri Babikov Citation: J. Chem. Phys. 136, 184304 (2012 for computing thermal rate constant of recombination: Application to ozone formation Mikhail V. Ivanov of ozone. Comparison of the predicted rate vs. experimental result is presented. © 2012 American Institute
Molenaar, P.; Malta, E.
1986-04-01T23:59:59.000Z
In electrically driven guinea pig left atria, positive inotropic responses to (-)-isoprenaline and the selective beta 1-adrenoceptor agonist RO363 were obtained in the absence and in the presence of the functional antagonists adenosine, carbachol, gallopamil, nifedipine, and Ro 03-7894. Each of the functional antagonists reduced the maximum response to both agonists and produced nonparallel rightward shifts in the cumulative concentration effect curves. For both agonists, dissociation constants (KA) were calculated using the equation described by Furchgott (1966) for irreversible antagonism. For RO363, which is a partial agonist with high agonist activity, the equations outlined for functional interaction by Mackay (1981) were also employed to calculate KA values. The KA values obtained by each method were compared with the dissociation constants (KD) for the two agonists determined from their ability to displace the radioligand (-)-(/sup 125/I)iodocyanopindolol from beta 1-adrenoceptors in guinea pig left atrial membrane preparations. The estimates of KA varied substantially from KD values. The KD values were taken as more accurate estimates of the true values for the dissociation constants because a high degree of correlation exists between pKD and pD2 values for a number of other beta-adrenoceptor agonists that behave as partial agonists and between pKD and pKB values for a number of beta-adrenoceptor antagonists. Thus, it appears that there are serious limitations in the current theory for using functional antagonism as a means of obtaining agonist dissociation constants.
THE GEOMETRY OF EMBEDDED CONSTANT MEAN CURVATURE TORI IN THE 3-SPHERE VIA INTEGRABLE SYSTEMS
Hauswirth, Laurent
THE GEOMETRY OF EMBEDDED CONSTANT MEAN CURVATURE TORI IN THE 3-SPHERE VIA INTEGRABLE SYSTEMS L Alexandrov embedded cylinders is explicitly determined. We prove that all embedded cmc tori in the 3-sphere are surfaces of revolution using a combination of integrable systems methods and geometric analysis techniques
Logistic Growth: Quadratic, No Time Delay, K Constant b = [K -N(0)]/N(0)
Caraco, Thomas
Logistic Growth: Quadratic, No Time Delay, K Constant #12;b = [K - N(0)]/N(0) Logistic Population-Cummings Protozoan, small metazoan & large mammal: Logistic growth (app.), Increasing time to max dN/dt #12;Gause, sociology, technology How might logistic growth's assumptions fail biologically? #12;Density
Constant Propagation with Conditional MARK N. WEGMAN and F. KENNETH ZADECK
Cytron, Ron K.
Constant Propagation with Conditional Branches MARK N. WEGMAN and F. KENNETH ZADECK IBM T. J Symposium on Principles of Programming Languages, 1985. Authors' current addresses: Mark N. Wegman, IBM T. J on Programming Languages and Systems, Vol. 13, No. 2, April 1991, Pages 181-210. #12;182 . M. N. Wegman and F. K
Rezwanur Rahman; Douglas K. McCarty; Manika Prasad; John A. Scales
2015-02-13T23:59:59.000Z
We implement a technique to characterize electromagnetic properties at frequencies 100 to 165 GHz (3 cm$^{-1}$ to 4.95 cm$^{-1}$) of oriented montmorillionite samples using an open cavity resonator connected to a sub-millimeter wave VNA (Vector Network Analyzer). We measured dielectric constants perpendicular to the bedding plane on oriented Na$^{+}$ and Ca$^{++}$-ion stabilized montmorillionite samples deposited on a glass slide at ambient laboratory conditions (room temperature and room light). The clay layer is much thinner ($\\sim$ 30 $\\mu$m) than the glass substrate ($\\sim$ 2.18 mm). The real part of dielectric constant,$\\epsilon_{re}$, is essentially constant over this frequency range but is larger in Na$^{+}$- than in Ca$^{++}$-ioned clay. The total electrical conductivity (associated with the imaginary part of dielectric constant, $\\epsilon_{im}$) of both samples increases monotonically at lower frequencies ($$ 110 GHz. The dispersion of the samples display a dependence on the ionic strength in the clay interlayers, i.e., $\\zeta$-potential in the Stern layers.
Time Domain Reflectometry Surface Reflections for Dielectric Constant in Highly Conductive Soils
Nowack, Robert L.
Time Domain Reflectometry Surface Reflections for Dielectric Constant in Highly Conductive Soils reflectometry TDR mea- surement in highly conductive soils. It makes use of information contained in the TDR signal from the reflection at the surface of the soil rather than the reflection from the end
Evaluating the von Kármán Constant in Sediment-laden Air Flow
Li, Bailiang
2012-02-14T23:59:59.000Z
Shear velocity is a critical variable used in many hydrodynamic and aeolian applications. The Law of the Wall is commonly used to derive shear velocity as the product of the slope of a measured velocity profile and the von Kármán constant, ? = 0...
Rubloff, Gary W.
Dependence of exchange coupling interaction on micromagnetic constants in hard/soft magnetic bilayer systems A. J. Zambano,1, * H. Oguchi,1 I. Takeuchi,1 Y. Choi,2,3 J. S. Jiang,2 J. P. Liu,3 S. E December 2006; published 30 April 2007 To elucidate the dependence of exchange coupling behavior of hard/soft
Proofs of Retrievability with Public Verifiability and Constant Communication Cost in Cloud
International Association for Cryptologic Research (IACR)
Proofs of Retrievability with Public Verifiability and Constant Communication Cost in Cloud Jiawei, requires prior specific permission and/or a fee. CloudComputing'13, May 8, 2013, Hangzhou, China. Copyright 2013 ACM 978-1-4503-2067-2/13/05 ...$15.00. Keywords Proofs of Retrievability, Cloud Storage, Public
Overall Rate Constant Measurements of the Reaction of Chloroalkylperoxy Radicals with Nitric Oxide
Elrod, Matthew J.
abundant alkenessethene, propene, 1-butene, 2-butene, 2-methylpropene, 1,3-butadiene, and isoprene (2-methyl-1,3-butadiene)swere determined for the first time via the turbulent flow technique and pseudo, whereas the corresponding rate constants for 1,3-butadiene and isoprene were both 20% higher than
Application of SiO2 aerogel film with low dielectric constant to intermetal dielectrics
Jo, Moon-Ho
Application of SiO2 aerogel film with low dielectric constant to intermetal dielectrics Moon-Ho Jo aerogel film was characterized from its structural and chemical viewpoints. High porosity of material infrared spectroscopy (FT-IR) for their chemical states. The improved electrical properties of SiO2 aerogel
Determination of Binding Constants of Cyclodextrins in Room-Temperature Ionic Liquids
Reid, Scott A.
unique chemical and physical properties, including being air and moisture stable, a high solubility power with supercritical fluid CO2;9-11 (4) electrochemical reactions;12,13 and (5) as a medium for enzymatic reactions.14Determination of Binding Constants of Cyclodextrins in Room-Temperature Ionic Liquids by Near
Table A1 Molar mass, gas constant, and critical-point properties
Kostic, Milivoje M.
of carbon dioxide, CO2 Table A21 Ideal-gas properties of carbon monoxide, CO Table A22 Ideal Properties of the atmosphere at high altitude Table A17 Ideal-gas properties of air Table A18 Ideal-point properties Molar mass, constant, Temperature, Pressure, Volume, Substance Formula M kg/kmol R kJ/kg·K* K MPa
Miller, William H.
Path integral evaluation of the quantum instanton rate constant for proton transfer in a polar developed by Azzouz and Borgis. Monte Carlo path integral methods are used to carry out the calculations evaluated for comparison using the present path integral approach. A technique is then introduced
Attard, Phil
Calibration of the torsional spring constant and the lateral photodiode response of frictional simultaneously calibrates the photodiode response to the angular deflection of the cantilever. It does not rely and with an independent measurement of the angle calibration. This nondestructive calibration may be performed with any
Relaxation Time Constants and Apparent Diffusion Coefficients of Rat Retina at 7 Tesla
Duong, Timothy Q.
Relaxation Time Constants and Apparent Diffusion Coefficients of Rat Retina at 7 Tesla Govind Nair* and ADC of the rat eyes were measured at 50 3 50 3 800 lm at 7 Tesla. Profiles of T1, T2, T2* and ADC
Relating the Newman-Penrose constants to the Geroch-Hansen multipole moments
Thomas Bäckdahl
2009-08-25T23:59:59.000Z
In this paper, we express the Newman--Penrose constants in terms of the Geroch--Hansen multipole moments for stationary spacetimes. These expressions are translation-invariant combinations of the multipole moments up to quadrupole order, which do not normally vanish.
V. P. Neznamov
2015-02-02T23:59:59.000Z
The paper presents the representation of quantum field theory without introduction of infinity bare masses and coupling constants of fermions. Counter-terms, compensating for divergent quantities in self-energy diagrams of fermions and vacuum polarization diagrams at all orders of the perturbation theory, appear in the appropriate Hamiltonians under the special time-dependent unitary transformation.