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1

Physics at the Planck scale  

SciTech Connect

Effective supergravity theories suggested by superstrings can be explored to determine their potential for successfully describing both observed physics at zero temperature and an inflationary cosmology. An important ingredient in this study is the dynamics of gaugino condensation, which has been the subject of recent activity. 33 refs., 2 figs.

Gaillard, M.K. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)

1990-12-06

2

Cosmological texture is incompatible with Planck-scale physics  

NASA Technical Reports Server (NTRS)

Nambu-Goldstone modes are sensitive to the effects of physics at energies comparable to the scale of spontaneous symmetry breaking. We show that as a consequence of this the global texture proposal for structure formation requires rather severe assumptions about the nature of physics at the Planck scale.

Holman, Richard; Hsu, Stephen D. H.; Kolb, Edward W.; Watkins, Richard; Widrow, Lawrence M.

1992-01-01

3

Wonders of Planck Scale Physics with Real Dimensions  

NASA Astrophysics Data System (ADS)

Postulating the probability of an interaction between two particles as inversely proportional to the square of their separation in Planck lengths, recovers Newtonian inverse square law and explains many unknowns. For one Planck length separation, it gives the force of the strong coupling constant between two coupled nucleons. For a million Planck lengths separation between two particles, it gives a probability interaction of a trillionth showing quantum particles do experience gravity detectable once in trillion times. Since Planck length is never zero, it kills the renormalization issue. It gives total probability of interaction with all other particles as greater than one, explaining spooky action at a distance or simultaneous display of one photon's spin to two separated particles. Planck scale when used with Boltzmann law, enables to express the reciprocal of ALPHA as greater than or equal to the natural logarithm of the age of the universe in Planck times (10E60) which is equal to the inverse of the square root of the cosmological constant in Planck units. See later versions of physics/0210040. Planck scale shows more on the horizon. Natural logarithm links to transcendentality per French mathematician C. Hermite (1873).

Goradia, Shantilal

2008-05-01

4

Planck-scale quintessence and the physics of structure formation  

NASA Astrophysics Data System (ADS)

In a recent paper we considered the possibility of a scalar field providing an explanation for the cosmic acceleration. Our model had the interesting properties of attractorlike behavior and having its parameters of O(1) in Planck units. Here we discuss the effect of the field on large scale structure and CMB anisotropies. We show how some versions of our model inspired by ``brane'' physics have novel features due to the fact that the scalar field has a significant role over a wider range of redshifts than for typical ``dark energy'' models. One of these features is the additional suppression of the formation of the large scale structure, as compared with cosmological constant models. In light of the new pressures being placed on cosmological parameters (in particulr H0) by CMB data, this added suppression allows our ``brane'' models to give excellent fits to both CMB and large scale structure data.

Skordis, Constantinos; Albrecht, Andreas

2002-08-01

5

Planck scale physics and topology change through an exactly solvable model  

NASA Astrophysics Data System (ADS)

We consider the collapse of a charged radiation fluid in a Planck-suppressed quadratic extension of General Relativity (GR) formulated à la Palatini. We obtain exact analytical solutions that extend the charged Vaidya-type solution of GR, which allows to explore in detail new physics at the Planck scale. Starting from Minkowski space, we find that the collapsing fluid generates wormholes supported by the electric field. We discuss the relevance of our findings in relation to the quantum foam structure of space-time and the meaning of curvature divergences in this theory.

Lobo, Francisco S. N.; Martinez-Asencio, Jesus; Olmo, Gonzalo J.; Rubiera-Garcia, D.

2014-04-01

6

Physics at the planck scale: Strings and symmetries  

NASA Astrophysics Data System (ADS)

The emergence of symmetries in the earlier proposed model of the Universe (3D network of strings in a thermal bath) is studied. The number is introduced which estimates the relative probability of changing the Gibbs distribution (or its nonequilibrium analogue) under action of stochastic forces. The principle of maximal stability (PMS) stating that only the most stable distributions are realized in the Universe is formulated. The nature of gauge symmetries and supersymmetries is discussed. According to PMS the groups SU(5) and SU(3) are advantageous. It is shown that in this model the Kaluza—Klein-Mandel-Fock unification of gravity and the Yang-Mills fields appears in the natural way. The list of thirty consequences of the model is given. They form the basis of modern physics (classical Hamiltonian mechanics, quantum mechanics, gauge symmetries, internal symmetries and so on).

Prokhorov, L. V.

2012-01-01

7

Effects of Planck scale physics on neutrino mixing parameters in left-right symmetric models  

NASA Astrophysics Data System (ADS)

Left-right symmetric models (LRSM) are extensions of the standard model by an enlarged gauge group SU(2)L×SU(2)R×U(1)B-L, where automatic inclusion of right-handed fermions as SU(2)R doublets guarantees a natural seesaw origin of neutrino masses. Apart from the extended gauge symmetry, LRSM also has a built-in global discrete symmetry, called D-parity, which ensures equal gauge couplings for left and right sectors. Motivated by the fact that global symmetries are expected to be explicitly broken by theories of quantum gravity, here we study the effects of such gravity, or Planck scale physics, on neutrino masses and mixings by introducing explict D-parity breaking, Planck-scale-suppressed, higher-dimensional operators. Although such Planck-scale-suppressd operators have dimensions of at least six in generic LRSM, dimension five operators can also arise in the presence of additional scalar fields, which can be naturally accommodated within SO(10) grand unified theory multiplets. We show that such corrections can give rise to significant changes in the predictions for neutrino mixing parameters compared to the ones predicted by tree-level seesaw formula if the left-right symmetry breaking scale is lower than 1014GeV.

Borah, Debasish

2013-05-01

8

[Probing Planck-scale Physics with a Ne-21/He-3 Zeeman Maser  

NASA Technical Reports Server (NTRS)

The Ne-21/He-3 Zeeman maser is a recently developed device which employs co-located ensembles of Ne-21 and He-3 atoms to provide sensitive differential measurements of the noble gas nuclear Zeeman splittings as a function of time, thereby greatly attenuating common-mode systematic effects such as uniform magnetic field variations. The Ne-21 maser will serve as a precision magnetometer to stabilize the system's static magnetic field, while the He-3 maser is used as a sensitive probe for violations of CPT and Lorentz symmetry by searching for small variations in the 3He maser frequency as the spatial orientation of the apparatus changes due to the rotation of the Earth (or placement on a rotating table). In the context of a general extension of the Standard Model of particle physics, the Ne-21/He-3 maser will provide the most sensitive search to date for CPT and Lorentz violation of the neutron: better than 10(exp -32) GeV, an improvement of more than an order of magnitude over past experiments. This exceptional precision will offer a rare opportunity to probe physics at the Planck scale. A future space-based Ne-21/He-3 maser or related device could provide even greater sensitivity to violations of CPT and Lorentz symmetry, and hence to Planck-scale physics, because of isolation from dominant systematic effects associated with ground-based operation, and because of access to different positions in space-time.

2003-01-01

9

Neutrinos:. Windows to Planck Physics  

NASA Astrophysics Data System (ADS)

After recalling some elegant contributions of the late Freydoon Mansouri, we turn to neutrino physics and use a modicum of grand unification to relate quark and lepton mixing matrices. We advocate an expansion for the MNS matrix, à la Wolfenstein, and argue that in a wide class of models, ?13 is a Cabibbo mixing effect. Also the large neutrino mixing angles reflect the mass patterns of the right-handed neutrinos near the Planck scale, and provide evidence for family structure at that scale.

Ramond, P.

2004-10-01

10

High-energy cosmic rays and tests of basic principles of Physics. Looking at the Planck scale and beyond  

NASA Astrophysics Data System (ADS)

With the present understanding of data, the observed flux suppression for ultra-high energy cosmic rays (UHECR) at energies above 4.1019 eV can be a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or be related to a similar mechanism. But it may also correspond, for instance, to the maximum energies available at the relevant sources. In both cases, violations of special relativity modifying cosmic-ray propagation or acceleration at very high energy can potentially play a role. Other violations of fundamental principles of standard particle physics (quantum mechanics, energy and momentum conservation, vacuum homogeneity and "static" properties, effective space dimensions, quark confinement…) can also be relevant at these energies. In particular, UHECR data would in principle allow to set bounds on Lorentz symmetry violation (LSV) in patterns incorporating a privileged local reference frame (the "vacuum rest frame", VRF). But the precise analysis is far from trivial, and other effects can also be present. The effective parameters can be related to Planckscale physics, or even to physics beyond Planck scale, as well as to the dynamics and effective symmetries of LSV for nucleons, quarks, leptons and the photon. LSV can also be at the origin of GZK-like effects. In the presence of a VRF, and contrary to a "grand unification" view, LSV and other violations of standard principles can modify the internal structure of particles at very high energy and conventional symmetries may cease to be valid at energies close to the Planck scale. We present an updated discussion of these topics, including experimental prospects, new potentialities for high-energy cosmic ray phenomenology and the possible link with unconventional pre-Big Bang scenarios, superbradyon (superluminal preon) patterns… The subject of a possible superluminal propagation of neutrinos at accelerator energies is also dealt with.

Gonzalez-Mestres, L.

2014-04-01

11

Phenomenology of a Realistic Accelerating Universe Using Only Planck-Scale Physics  

NASA Astrophysics Data System (ADS)

Modern data are showing increasing evidence that the Universe is accelerating. So far, all attempts to account for the acceleration have required some fundamental dimensionless quantities to be extremely small. We show how a class of scalar field models (which may emerge naturally from superstring theory) can account for acceleration which starts in the present epoch with all the potential parameters O\\(1\\) in Planck units.

Albrecht, Andreas; Skordis, Constantinos

2000-03-01

12

Phenomenology of a realistic accelerating universe using only planck-scale physics  

PubMed

Modern data are showing increasing evidence that the Universe is accelerating. So far, all attempts to account for the acceleration have required some fundamental dimensionless quantities to be extremely small. We show how a class of scalar field models (which may emerge naturally from superstring theory) can account for acceleration which starts in the present epoch with all the potential parameters O(1) in Planck units. PMID:11017213

Albrecht; Skordis

2000-03-01

13

What Can We Learn from the 126 GeV Higgs Boson for the Planck Scale Physics? - Hierarchy Problem and the Stability of the Vacuum -  

NASA Astrophysics Data System (ADS)

The discovery of the Higgs particle at around 126 GeV has given us a big hint towards the origin of the Higgs potential. The running quartic self-coupling decreases and crosses zero somewhere in the very high energy scale. It is usually considered as a signal of the instability of the standard model (SM) vacuum, but it can also indicate a link between the physics in the electroweak scale and the Planck scale. Furthermore, the LHC experiments as well as the flavor physics experiments give strong constraints on the physics beyond the SM. It urges us to reconsider the widely taken approach to the physics beyond the SM (BSM), namely the approach based on the gauge unification below the Planck scale and the resulting hierarchy problem. Motivated by the recent experiments, we first revisit the hierarchy problem and consider an alternative appoach based on a classical conformality of the SM without the Higgs mass term. In this talk, I review our recent proposal of a B-L extension of the SM with a flat Higgs potential at the Planck scale.1,2 This model can be an alternative solution to the hierarchy problem as well as being phenomenologically viable to explain the neutrino oscillations and the baryon asymmetry of the universe. With an assumption that the Higgs has a flat potential at the Planck scale, we show that the B-L symmetry is radiatively broken at the TeV scale via the Coleman-Weinberg mechanism, and it triggers the electroweak symmetry breaking through a radiatively generated scalar mixing. The ratio of these two breaking scales is dynamically determined by the B-L gauge coupling.

Iso, Satoshi

14

Planck-scale corrections to Friedmann equation  

NASA Astrophysics Data System (ADS)

Recently, Verlinde proposed that gravity is an emergent phenomenon which originates from an entropic force. In this work, we extend Verlinde's proposal to accommodate generalized uncertainty principles (GUP), which are suggested by some approaches to quantum gravity such as string theory, black hole physics and doubly special relativity (DSR). Using Verlinde's proposal and two known models of GUPs, we obtain modifications to Newton's law of gravitation as well as the Friedmann equation. Our modification to the Friedmann equation includes higher powers of the Hubble parameter which is used to obtain a corresponding Raychaudhuri equation. Solving this equation, we obtain a leading Planck-scale correction to Friedmann-Robertson-Walker (FRW) solutions for the p = ?p equation of state.

Awad, Adel; Ali, Ahmed Farag

2014-04-01

15

Scalar-Qed ?-FUNCTIONS Near Planck's Scale  

NASA Astrophysics Data System (ADS)

The Renormalization Group Flow Equations of the Scalar-QED model near Planck's scale are computed within the framework of the average effective action. Exact Flow Equations, corrected by Einstein Gravity, for the running self-interacting scalar coupling parameter and for the running v.e.v. of ?*?, are computed taking into account threshold effects. Analytic solutions are given in the infrared and ultraviolet limits.

Pires, Gentil O.

16

Planck scale boundary conditions and the Higgs mass  

NASA Astrophysics Data System (ADS)

If the LHC does only find a Higgs boson in the low mass region and no other new physics, then one should reconsider scenarios where the Standard Model with three right-handed neutrinos is valid up to Planck scale. We assume in this spirit that the Standard Model couplings are remnants of quantum gravity which implies certain generic boundary conditions for the Higgs quartic coupling at Planck scale. This leads to Higgs mass predictions at the electroweak scale via renormalization group equations. We find that several physically well motivated conditions yield a range of Higgs masses from 127 - 142 GeV. We also argue that a random quartic Higgs coupling at the Planck scale favours M H > 150 GeV, which is clearly excluded. We discuss also the prospects for differentiating different boundary conditions imposed for ?( M pl) at the LHC. A striking example is M H = 127 ± 5 GeV corresponding to ?( M pl) = 0, which would imply that the quartic Higgs coupling at the electroweak scale is entirely radiatively generated.

Holthausen, Martin; Lim, Kher Sham; Lindner, Manfred

2012-02-01

17

Max Planck Institute for Gravitational Physics  

NSDL National Science Digital Library

This expansive Web site features the Max Planck Institute for Gravitational Physics' research dealing primarily with geometric analysis and gravitation, astrophysical relativity, quantum gravity and unified theories, and laser interferometry and gravitational wave astronomy. After learning about the Institute's origins in 1995, researchers can find out about the institute's intense efforts and hardships in developing a consistent theory of quantum gravity as well as its investigation in gravitational radiation and causal structures. The site provides visitors with downloads to many published articles as well as links to two free access electronic review journals: _Living Reviews in Relativity_ and _Living Reviews in Solar Physics_. While some content is not in English, all visitors can find valuable information about research in gravitational physics.

18

Space-Time at the Planck Scale:. the Quantum Computer View  

NASA Astrophysics Data System (ADS)

We assume that space-time at the Planck scale is discrete, quantised in Planck units and "qubitised" (each pixel of Planck area encodes one qubit), that is, quantum space-time can be viewed as a quantum computer. Within this model, one finds that quantum space-time itself is entangled, and can quantum-evaluate Boolean functions which are the laws of Physics in their discrete and fundamental form.

Zizzi, Paola A.

2006-06-01

19

Revisiting neutrino masses from Planck scale operators  

NASA Astrophysics Data System (ADS)

Planck scale lepton number violation is an interesting and natural possibility to explain nonzero neutrino masses. We consider such operators in the context of Randall-Sundrum (RS1) scenarios. Implementation of this scenario with a single Higgs localized on the IR brane (standard RS1) is not phenomenologically viable as they lead to inconsistencies in the charged lepton mass fits. In this paper we propose a setup with two Higgs doublets. We present a detailed numerical analysis of the fits to fermion masses and mixing angles. This model solves the issues regarding the fermion mass fits but solutions with consistent electroweak symmetry breaking are highly fine-tuned. A simple resolution is to consider supersymmetry in the bulk and a detailed discussion of which is provided. Constraints from flavor are found to be strong and minimal flavor violation (MFV) is imposed to alleviate them.

Iyer, Abhishek M.

2014-06-01

20

The Holometer: A Measurement of Planck Scale Quantum Geometry  

NASA Astrophysics Data System (ADS)

Direct experiments show that light and matter obey fundamental quantum principles such as nonlocality, superposition and entanglement. On the other hand, standard, experimentally verified particle theory generally assumes that space-time itself obeys classical determinism and locality — an approximation that cannot be reconciled with quantum matter and general relativity at intervals shorter than the Planck scale, or with the theory of black holes. These suggest that geometry has nonlocal quantum states and finite, holographic information content. The hints of new Planck scale physics open up a new experimental path: in some theories of quantum geometry, new degrees of freedom cause fluctuations in position with detectable, uniquely quantum correlations. We are developing an experiment called the Fermilab Holometer, a correlated pair of high-bandwidth Michelson interferometers. It is the first, and at present unique experiment designed to prepare and measure a coherent quantum state of position over an extended region in space. The sensitivity to transverse position noise, expressed in spectral density units, is smaller than a Planck time. When operating at its design noise limit, it will either detect or rule out some candidate forms of holographic quantum geometry.

Meyer, Stephan

2013-04-01

21

Shadows of the Planck Scale: Scale Dependence of Compactification Geometry  

Microsoft Academic Search

By studying the effects of the shape moduli associated with toroidal compactifications, we demonstrate that Planck-sized extra dimensions can cast significant ``shadows'' over low-energy physics. These shadows distort our perceptions of the compactification geometry associated with large extra dimensions and place a fundamental limit on our ability to probe the geometry of compactification by measuring Kaluza-Klein states. We also find

Keith R. Dienes; Arash Mafi

2002-01-01

22

Flat Higgs potential from Planck scale supersymmetry breaking  

NASA Astrophysics Data System (ADS)

The observed Higgs boson mass poses a new puzzle in addition to the longstanding problem of the origin of the electroweak scale; the shallowness of the Higgs potential. The Higgs quartic coupling even seems to vanish at around the Planck scale within the uncertainties of the top quark mass and the strong gauge coupling. We show that the shallowness of the Higgs potential might be an outcome of supersymmetry breaking at around the Planck scale. There, the electroweak fine-tuning in the Higgs quadratic terms leads to an almost vanishing quartic coupling at around the Planck scale.

Ibe, Masahiro; Matsumoto, Shigeki; Yanagida, Tsutomu T.

2014-05-01

23

Predictive description of Planck-scale-induced spacetime fuzziness  

NASA Astrophysics Data System (ADS)

Several approaches to the quantum-gravity problem predict that spacetime should be “fuzzy,” but so far these approaches have been unable to provide a crisp physical characterization of this notion. An intuitive picture of spacetime fuzziness has been proposed on the basis of semiheuristic arguments and, in particular, involves an irreducible Planck-scale contribution to the uncertainty of the energy of a particle. These arguments also inspired a rather active phenomenological program that looks for the blurring of images of distant astrophysical sources that would result from such energy uncertainties. Here we report the first ever physical characterization of spacetime fuzziness derived constructively within a quantum picture of spacetime, the one provided by spacetime noncommutativity. Our results confirm earlier heuristic arguments suggesting that spacetime fuzziness, while irrelevantly small on terrestrial scales, could be observably large for propagation of particles over cosmological distances. However, we find no Planck-scale-induced lower bound on the uncertainty of the energy of particles; we observe that this changes how we should picture a quantum spacetime, and it also imposes a reanalysis of the associated phenomenology.

Amelino-Camelia, Giovanni; Astuti, Valerio; Rosati, Giacomo

2013-04-01

24

Holographic Noise in Michelson Interferometers: A Direct Experimental Probe of Unification at the Planck Scale  

ScienceCinema

Classical spacetime and quantum mass-energy form the basis of all of physics. They become inconsistent at the Planck scale, 5.4 times 10^{-44} seconds, which may signify a need for reconciliation in a unified theory. Although proposals for unified theories exist, a direct experimental probe of this scale, 16 orders of magnitude above Tevatron energy, has seemed hopelessly out of reach. However in a particular interpretation of holographic unified theories, derived from black hole evaporation physics, a world assembled out of Planck-scale waves displays effects of unification with a new kind of uncertainty in position at the Planck diffraction scale, the geometric mean of the Planck length and the apparatus size. In this case a new phenomenon may measurable, an indeterminacy of spacetime position that appears as noise in interferometers. The colloquium will discuss the theory of the effect, and our plans to build a holographic interferometer at Fermilab to measure it.

Craig Hogan

2010-01-08

25

Holographic Noise in Michelson Interferometers: A Direct Experimental Probe of Unification at the Planck Scale  

SciTech Connect

Classical spacetime and quantum mass-energy form the basis of all of physics. They become inconsistent at the Planck scale, 5.4 times 10^{-44} seconds, which may signify a need for reconciliation in a unified theory. Although proposals for unified theories exist, a direct experimental probe of this scale, 16 orders of magnitude above Tevatron energy, has seemed hopelessly out of reach. However in a particular interpretation of holographic unified theories, derived from black hole evaporation physics, a world assembled out of Planck-scale waves displays effects of unification with a new kind of uncertainty in position at the Planck diffraction scale, the geometric mean of the Planck length and the apparatus size. In this case a new phenomenon may measurable, an indeterminacy of spacetime position that appears as noise in interferometers. The colloquium will discuss the theory of the effect, and our plans to build a holographic interferometer at Fermilab to measure it.

Craig Hogan

2009-07-22

26

Testing Planck-scale gravity with accelerators.  

PubMed

Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 10(-35)??m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement, since the smallest distance accessible in experiment is about 10(-19)??m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 10(-31)??m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data. PMID:23083234

Gharibyan, Vahagn

2012-10-01

27

Testing Planck-Scale Gravity with Accelerators  

NASA Astrophysics Data System (ADS)

Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 10-35m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement, since the smallest distance accessible in experiment is about 10-19m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 10-31m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data.

Gharibyan, Vahagn

2012-10-01

28

The Planck Mission: Recent Results, Cosmological and Fundamental Physics Perspectives  

NASA Astrophysics Data System (ADS)

We provide a description of the latest status and performance of the Planck satellite, focusing on the final predicted sensitivity of Planck. The optimization of the observational strategy for the additional surveys following the nominal 15 months of integration (about two surveys) originally allocated and the limitation represented by astrophysical foreground emissions are presented. An outline of early and intermediate astrophysical results from the Planck Collaboration is provided. A concise view of some fundamental cosmological results that will be achieved by exploiting Planck's full set of temperature and polarization data are presented. Finally, the perspectives opened by Planck in answering some key questions in fundamental physics, with particular attention to parity symmetry analyses, are described.

Mandolesi, Nazzareno; Burigana, Carlo; Gruppuso, Alessandro; Natoli, Paolo

2013-12-01

29

Gravitation and Special Relativity from Compton Wave Interactions at the Planck Scale: An Algorithmic Approach  

NASA Technical Reports Server (NTRS)

In this paper space is modeled as a lattice of Compton wave oscillators (CWOs) of near- Planck size. It is shown that gravitation and special relativity emerge from the interaction between particles Compton waves. To develop this CWO model an algorithmic approach was taken, incorporating simple rules of interaction at the Planck-scale developed using well known physical laws. This technique naturally leads to Newton s law of gravitation and a new form of doubly special relativity. The model is in apparent agreement with the holographic principle, and it predicts a cutoff energy for ultrahigh-energy cosmic rays that is consistent with observational data.

Blackwell, William C., Jr.

2004-01-01

30

Astrophysical Constraints on Planck Scale Dissipative Phenomena  

NASA Astrophysics Data System (ADS)

The emergence of a classical spacetime from any quantum gravity model is still a subtle and only partially understood issue. If indeed spacetime is arising as some sort of large scale condensate of more fundamental objects, then it is natural to expect that matter, being a collective excitation of the spacetime constituents, will present modified kinematics at sufficiently high energies. We consider here the phenomenology of the dissipative effects necessarily arising in such a picture. Adopting dissipative hydrodynamics as a general framework for the description of the energy exchange between collective excitations and the spacetime fundamental degrees of freedom, we discuss how rates of energy loss for elementary particles can be derived from dispersion relations and used to provide strong constraints on the base of current astrophysical observations of high-energy particles.

Liberati, Stefano; Maccione, Luca

2014-04-01

31

Astrophysical constraints on Planck scale dissipative phenomena.  

PubMed

The emergence of a classical spacetime from any quantum gravity model is still a subtle and only partially understood issue. If indeed spacetime is arising as some sort of large scale condensate of more fundamental objects, then it is natural to expect that matter, being a collective excitation of the spacetime constituents, will present modified kinematics at sufficiently high energies. We consider here the phenomenology of the dissipative effects necessarily arising in such a picture. Adopting dissipative hydrodynamics as a general framework for the description of the energy exchange between collective excitations and the spacetime fundamental degrees of freedom, we discuss how rates of energy loss for elementary particles can be derived from dispersion relations and used to provide strong constraints on the base of current astrophysical observations of high-energy particles. PMID:24785026

Liberati, Stefano; Maccione, Luca

2014-04-18

32

Event horizon - Magnifying glass for Planck length physics  

Microsoft Academic Search

An attempt is made to describe the `thermodynamics' of semiclassical\\u000aspacetime without specifying the detailed `molecular structure' of the quantum\\u000aspacetime, using the known properties of blackholes. I give detailed arguments,\\u000aessentially based on the behaviour of quantum systems near the event horizon,\\u000awhich suggest that event horizon acts as a magnifying glass to probe Planck\\u000alength physics even in

T. Padmanabhan

1998-01-01

33

Do we have unitary and (super)renormalizable quantum gravity below the Planck scale?  

NASA Astrophysics Data System (ADS)

We explore how the stability of metric perturbations in higher-derivative theories of gravity depends on the energy scale of the initial seeds of such perturbations and on a typical energy scale of the gravitational vacuum background. It is shown that, at least in the cases of specific cosmological backgrounds, the unphysical massive ghost which is present in the spectrum of such theories is not growing up as a physical excitation and remains in the vacuum state until the initial frequency of the perturbation is close to the Planck order of magnitude. In this situation, the existing versions of renormalizable and super-renormalizable theories can be seen as very satisfactory effective theories of quantum gravity below the Planck scale.

Salles, Filipe de O.; Shapiro, Ilya L.

2014-04-01

34

Quantum Geometry and Quantum Dynamics at the Planck Scale  

SciTech Connect

Canonical quantum gravity provides insights into the quantum dynamics as well as quantum geometry of space-time by its implications for constraints. Loop quantum gravity in particular requires specific corrections due to its quantization procedure, which also results in a discrete picture of space. The corresponding changes compared to the classical behavior can most easily be analyzed in isotropic models, but perturbations around them are more involved. For one type of corrections, consistent equations have been found which shed light on the underlying space-time structure at the Planck scale: not just quantum dynamics but also the concept of space-time manifolds changes in quantum gravity. Effective line elements provide indications for possible relationships to other frameworks, such as non-commutative geometry.

Bojowald, Martin [Institute for Gravitation and the Cosmos, The Pennsylvania State University, 104 Davey Lab, University Park, PA 16802 (United States)

2009-12-15

35

The Fractal Universe: From the Planck to the Hubble Scale  

Microsoft Academic Search

We examine the fractal structure of the physical universe from the large\\u000ascale to the smallest scale, including the phenomenon of fractal scaling. This\\u000ais explained in terms of a stochastic underpinning for the laws of physics. A\\u000apicture in pleasing agreement with experiment and observation at all scales\\u000aemerges, very much in the spirit of Wheeler's \\

B. G. Sidharth; B. M. Birla; Adarsh Nagar

1999-01-01

36

Radiative symmetry breaking at the Fermi scale and flat potential at the Planck scale  

NASA Astrophysics Data System (ADS)

We investigate a possibility of the "flatland scenario," in which the electroweak gauge symmetry is radiatively broken via the Coleman-Weinberg mechanism starting from a completely flat Higgs potential at the Planck scale. We show that the flatland scenario is realizable only when an inequality K<1 among the coefficients of the ? functions is satisfied. We show several models satisfying the condition.

Hashimoto, Michio; Iso, Satoshi; Orikasa, Yuta

2014-01-01

37

Scale problem in wormhole physics  

SciTech Connect

Wormhole physics from the quantum thoery of gravity coupled to the second-rank antisymmetric tensor or Goldstone-boson fields leads to an effective potential for these fields. The cosmological energy-density bound is shown to put an upper bound on the cosmological constant which wormhole physics can make zero. This upper bound, of order 10/sup 11/ GeV, is far smaller than the Planck scale and barely compatible with the possible cosmological constant arising from grand unified theories. In addition, the effect of wormholes on the axion for the strong /ital CP/ problem is discussed.

Kim, J. E.; Lee, K.

1989-07-03

38

Sub-Planck-scale structures in a vibrating molecule in the presence of decoherence  

SciTech Connect

We study the effect of decoherence on the sub-Planck scale structures of the vibrational wave packet of a molecule. The time evolution of these wave packets is investigated under the influence of a photonic or phononic environment. We determine the master equation describing the reduced dynamics of the wave packet and analyze the sensitivity of the sub-Planck structures against decoherence in the case of a hydrogen iodide (HI) molecule.

Ghosh, Suranjana; Roy, Utpal; Vitali, David [Dipartimento di Fisica, Universita di Camerino, I-62032 Camerino (Italy); Genes, Claudiu [Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

2009-05-15

39

Planck early results. XII. Cluster Sunyaev-Zeldovich optical scaling relations  

NASA Astrophysics Data System (ADS)

We present the Sunyaev-Zeldovich (SZ) signal-to-richness scaling relation (Y500 - N200) for the MaxBCG cluster catalogue. Employing a multi-frequency matched filter on the Planck sky maps, we measure the SZ signal for each cluster by adapting the filter according to weak-lensing calibrated mass-richness relations (N200 - M500). We bin our individual measurements and detect the SZ signal down to the lowest richness systems (N200 = 10) with high significance, achieving a detection of the SZ signal in systems with mass as low as M500 ? 5 × 1013 M?. The observed Y500 - N200 relation is well modeled by a power law over the full richness range. It has a lower normalisation at given N200 than predicted based on X-ray models and published mass-richness relations. An X-ray subsample, however, does conform to the predicted scaling, and model predictions do reproduce the relation between our measured bin-average SZ signal and measured bin-average X-ray luminosities. At fixed richness, we find an intrinsic dispersion in the Y500 - N200 relation of 60% rising to of order 100% at low richness. Thanks to its all-sky coverage, Planck provides observations for more than 13000 MaxBCG clusters and an unprecedented SZ/optical data set, extending the list of known cluster scaling laws to include SZ-optical properties. The data set offers essential clues for models of galaxy formation. Moreover, the lower normalisation of the SZ-mass relation implied by the observed SZ-richness scaling has important consequences for cluster physics and cosmological studies with SZ clusters. Corresponding author: J. G. Bartlett, e-mail: bartlett@apc.univ-paris7.fr

Planck Collaboration; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartelmann, M.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Brown, M. L.; Bucher, M.; Burigana, C.; Cabella, P.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Chiang, L.-Y.; Chiang, C.; Chon, G.; Christensen, P. R.; Churazov, E.; Clements, D. L.; Colafrancesco, S.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Cuttaia, F.; da Silva, A.; Dahle, H.; Danese, L.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Diego, J. M.; Dolag, K.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Finelli, F.; Flores-Cacho, I.; Forni, O.; Frailis, M.; Franceschi, E.; Fromenteau, S.; Galeotta, S.; Ganga, K.; Génova-Santos, R. T.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Jaffe, A. H.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leonardi, R.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; MacTavish, C. J.; Maffei, B.; Maino, D.; Mandolesi, N.; Mann, R.; Maris, M.; Marleau, F.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Mei, S.; Melchiorri, A.; Melin, J.-B.; Mendes, L.; Mennella, A.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, A.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Pajot, F.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Piffaretti, R.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Savini, G.; Schaefer, B. M.; Scott, D.; Seiffert, M. D.; Shellard, P.; Smoot, G. F.; Starck, J.-L.; Stivoli, F.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Torre, J.-P.; Tristram, M.; Tuovinen, J.; Valenziano, L.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wandelt, B. D.; White, S. D. M.; White, M.; Yvon, D.; Zacchei, A.; Zonca, A.

2011-12-01

40

Planck 2010  

ScienceCinema

Planck 2010 From the Planck Scale to the ElectroWeak Scale The conference will be the twelfth one in a series of meetings on physics beyond the Standard Model, organized jointly by several European groups: Bonn, CERN, Ecole Polytechnique, ICTP, Madrid, Oxford, Padua, Pisa, SISSA and Warsaw as part of activities in the framework of the European network UNILHC.Topics to be discussed: Supersymmetry Supergravity & string phenomenology Extra dimensions Electroweak symmetry breaking LHC and Tevatron Physics Collider physics Flavor & neutrinos physics Astroparticle & cosmology Gravity & holography Strongly coupled physics & CFT Registration: registration will be open until May 1st. Registration fees amount to 150 CHF and cover the cost of the coffee breaks and the social dinner. Payment has to be made online. The deadline for registration has been postponed to May 7th. However, after May 3th, we shall not accept any talk request any more. The meeting will be partly supported by ° the Marie Curie Initial Training Network "UNILHC" PITN-GA-2009-23792, ° the ERC Advanced Grant "MassTeV" 226371, ° and the CERN-TH unit.

None

2011-10-06

41

Planck 2010  

ScienceCinema

Planck 2010 From the Planck Scale to the ElectroWeak Scale The conference will be the twelfth one in a series of meetings on physics beyond the Standard Model, organized jointly by several European groups: Bonn, CERN, Ecole Polytechnique, ICTP, Madrid, Oxford, Padua, Pisa, SISSA and Warsaw as part of activities in the framework of the European network UNILHC.Topics to be discussed: Supersymmetry Supergravity & string phenomenology Extra dimensions Electroweak symmetry breaking LHC and Tevatron Physics Collider physics Flavor & neutrinos physics Astroparticle & cosmology Gravity & holography Strongly coupled physics & CFT Registration: registration will be open until May 1st. Registration fees amount to 150 CHF and cover the cost of the coffee breaks and the social dinner. Payment has to be made online. The deadline for registration has been postponed to May 7th. However, after May 3th, we shall not accept any talk request any more. The meeting will be partly supported by ° the Marie Curie Initial Training Network "UNILHC" PITN-GA-2009-23792, ° the ERC Advanced Grant "MassTeV" 226371, ° and the CERN-TH unit.

42

Planck 2010  

SciTech Connect

Planck 2010 From the Planck Scale to the ElectroWeak Scale The conference will be the twelfth one in a series of meetings on physics beyond the Standard Model, organized jointly by several European groups: Bonn, CERN, Ecole Polytechnique, ICTP, Madrid, Oxford, Padua, Pisa, SISSA and Warsaw as part of activities in the framework of the European network UNILHC.Topics to be discussed: Supersymmetry Supergravity & string phenomenology Extra dimensions Electroweak symmetry breaking LHC and Tevatron Physics Collider physics Flavor & neutrinos physics Astroparticle & cosmology Gravity & holography Strongly coupled physics & CFT Registration: registration will be open until May 1st. Registration fees amount to 150 CHF and cover the cost of the coffee breaks and the social dinner. Payment has to be made online. The deadline for registration has been postponed to May 7th. However, after May 3th, we shall not accept any talk request any more. The meeting will be partly supported by ° the Marie Curie Initial Training Network "UNILHC" PITN-GA-2009-23792, ° the ERC Advanced Grant "MassTeV" 226371, ° and the CERN-TH unit.

None

2010-06-02

43

TeV astrophysics constraints on Planck scale Lorentz violation  

NASA Astrophysics Data System (ADS)

We analyze observational constraints from TeV astrophysics on Lorentz violating nonlinear dispersion for photons and electrons without assuming any a priori equality between the photon and electron parameters. The constraints arise from thresholds for vacuum ?erenkov radiation, photon decay and photo-production of electron-positron pairs. We show that the parameter plane for cubic momentum terms in the dispersion relations is constrained to an order unity region in Planck units. We find that the threshold configuration can occur with an asymmetric distribution of momentum for pair creation, and with a hard photon for vacuum ?erenkov radiation.

Jacobson, Ted; Liberati, Stefano; Mattingly, David

2002-10-01

44

TeV-scale B - L model with a flat Higgs potential at the Planck scale: In view of the hierarchy problem  

NASA Astrophysics Data System (ADS)

The recent discovery of a Higgs-like particle at around 126 GeV has provided a big hint towards the origin of the Higgs potential. In particular, the running quartic coupling vanishes near the Planck scale, which indicates a possible link between the physics in the electroweak and Planck scales. Motivated by this and the hierarchy problem, we investigate a possibility that the Higgs has a flat potential at the Planck scale. In particular, we study the renormalization group analysis of the B - L (baryon number minus lepton number) extension of the standard model [1,2] with classical conformality. The B - L symmetry is radiatively broken at the TeV scale via the Coleman-Weinberg mechanism. The electroweak symmetry breaking is triggered by a radiatively generated scalar mixing so that its scale, 246 GeV, is dynamically related to the B - L breaking scale at the TeV level. The Higgs boson mass is given at the border of the stability bound, which is lowered by a few GeV from the standard model by the effect of the B - L gauge interaction.

Iso, Satoshi; Orikasa, Yuta

2013-02-01

45

Shadows of the Planck Scale: The Changing Face of Compactification Geometry  

Microsoft Academic Search

By studying the effects of the shape moduli associated with toroidal\\u000acompactifications, we demonstrate that Planck-sized extra dimensions can cast\\u000asignificant ``shadows'' over low-energy physics. These shadows can greatly\\u000adistort our perceptions of the compactification geometry associated with large\\u000aextra dimensions, and place a fundamental limit on our ability to probe the\\u000ageometry of compactification simply by measuring Kaluza-Klein states.

Keith R. Dienes; Arash Mafi

2001-01-01

46

Constraining the Energy-Momentum Dispersion Relation with Planck-Scale Sensitivity Using Cold Atoms  

SciTech Connect

We use the results of ultraprecise cold-atom-recoil experiments to constrain the form of the energy-momentum dispersion relation, a structure that is expected to be modified in several quantum-gravity approaches. Our strategy of analysis applies to the nonrelativistic (small speeds) limit of the dispersion relation, and is therefore complementary to an analogous ongoing effort of investigation of the dispersion relation in the ultrarelativistic regime using observations in astrophysics. For the leading correction in the nonrelativistic limit the exceptional sensitivity of cold-atom-recoil experiments remarkably allows us to set a limit within a single order of magnitude of the desired Planck-scale level, thereby providing the first example of Planck-scale sensitivity in the study of the dispersion relation in controlled laboratory experiments.

Amelino-Camelia, Giovanni; Mercati, Flavio [Dipartimento di Fisica, Universita di Roma 'La Sapienza' and Sezione Roma1 INFN, Piazzale Moro 2, 00185 Roma (Italy); Laemmerzahl, Claus [ZARM, Universitaet Bremen, Am Fallturm, 28359 Bremen (Germany); Tino, Guglielmo M. [Dipartimento di Fisica and LENS, Universita di Firenze, Sezione INFN di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy)

2009-10-23

47

Planck early results. XII. Cluster Sunyaev-Zeldovich optical scaling relations  

Microsoft Academic Search

We present the Sunyaev-Zeldovich (SZ) signal-to-richness scaling relation (Y500 - N200) for the MaxBCG cluster catalogue. Employing a multi-frequency matched filter on the Planck sky maps, we measure the SZ signal for each cluster by adapting the filter according to weak-lensing calibrated mass-richness relations (N200 - M500). We bin our individual measurements and detect the SZ signal down to the

N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; M. Bartelmann; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; M. L. Brown; M. Bucher; C. Burigana; P. Cabella; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; L.-Y. Chiang; C. Chiang; G. Chon; P. R. Christensen; E. Churazov; D. L. Clements; S. Colafrancesco; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; A. da Silva; H. Dahle; L. Danese; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; J. M. Diego; K. Dolag; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; F. Finelli; I. Flores-Cacho; O. Forni; M. Frailis; E. Franceschi; S. Fromenteau; S. Galeotta; K. Ganga; R. T. Génova-Santos; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; D. Harrison; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; F. Marleau; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; S. Mei; A. Melchiorri; J.-B. Melin; L. Mendes; A. Mennella; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; S. Osborne; F. Pajot; F. Pasian; G. Patanchon; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; E. Pierpaoli; R. Piffaretti; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. W. Pratt; G. Prézeau; S. Prunet; J.-L. Puget; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; G. Savini; B. M. Schaefer; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sudiwala; R. Sunyaev; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; L. Valenziano; L. Vibert; P. Vielva; F. Villa; N. Vittorio; B. D. Wandelt; S. D. M. White; M. White; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

48

Conjecture on the physical implications of the scale anomaly  

SciTech Connect

Murray Gell-Mann, after co-inventing QCD, recognized the interplay of the scale anomaly, the renormalization group, and the origin of the strong scale, {Lambda}{sub QCD}. I tell a story, then elaborate this concept, and for the sake of discussion, propose a conjecture that the physical world is scale invariant in the classical, {h_bar}, limit. This principle has implications for the dimensionality of space-time, the cosmological constant, the weak scale, and Planck scale.

Hill, Christopher T.; /Fermilab

2005-10-01

49

A Vlasov-Fokker-Planck code for high energy density physics  

SciTech Connect

OSHUN is a parallel relativistic 2D3P Vlasov-Fokker-Planck code, developed primarily to study electron transport and instabilities pertaining to laser-produced-including laser-fusion-plasmas. It incorporates a spherical harmonic expansion of the electron distribution function, where the number of terms is an input parameter that determines the angular resolution in momentum-space. The algorithm employs the full 3D electromagnetic fields and a rigorous linearized Fokker-Planck collision operator. The numerical scheme conserves energy and number density. This enables simulations for plasmas with temperatures from MeV down to a few eV and densities from less than critical to more than solid. Kinetic phenomena as well as electron transport physics can be recovered accurately and efficiently.

Tzoufras, M., E-mail: m.tzoufras1@physics.ox.ac.uk [Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Bell, A.R. [Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Norreys, P.A. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Tsung, F.S. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

2011-07-20

50

Combining Planck data with large scale structure information gives a strong neutrino mass constraint  

NASA Astrophysics Data System (ADS)

We present the strongest current cosmological upper limit on the neutrino mass of ?m?<0.18 eV (95% confidence). It is obtained by adding observations of the large-scale matter power spectrum from the WiggleZ Dark Energy Survey to observations of the cosmic microwave background data from the Planck surveyor, and measurements of the baryon acoustic oscillation scale. The limit is highly sensitive to the priors and assumptions about the neutrino scenario. We explore scenarios with neutrino masses close to the upper limit (degenerate masses), neutrino masses close to the lower limit where the hierarchy plays a role, and the addition of massive or massless sterile species.

Riemer-Sørensen, Signe; Parkinson, David; Davis, Tamara M.

2014-05-01

51

Notes on Plasma Physics at the Max-Planck-Institute for Physics and Astrophysics (Munich) and the Institute for Plasma Physics (Garching Near Munich).  

National Technical Information Service (NTIS)

This report gives a brief account of a recent visit to selected installations and to chosen scientists in the Max-Planck-Institute for Physics and Astrophysics, in Munich, and in the Institute for Plasma Physics at Garching, near Munich. The report descri...

A. Banos

1968-01-01

52

Application of scaling properties of the Vlasov and the Fokker-Planck equations to improved macroparticle models  

SciTech Connect

Numerical simulations of cooling processes over minutes or hours of real time are usually carried out using direct solution of the Fokker-Planck equation. However, by using scaling rules derived from that equation, it is possible to use macroparticle representations of the beam distribution. Besides having applications for cooling alone, the macroparticle approach allows combining the cooling process with other dynamical processes which are represented by area-preserving maps. A time-scaling rule derived from the Vlasov equation can be used to adjust the time step of a map-based dynamics calculation to one more suitable for combining with a macroparticle Fokker-Planck calculation. The time scaling for the Vlasov equation is also useful for substantially more rapid calculations when a macroparticle model of a conservative multiparticle system requires a large number of macroparticles to faithfully produce the collective potential or when the model must simulate a long time period.

James A. MacLachlan

2001-07-12

53

Planck-scale modifications to electrodynamics characterized by a spacelike symmetry-breaking vector  

SciTech Connect

In the study of Planck-scale ('quantum-gravity-induced') violations of Lorentz symmetry, an important role was played by the deformed-electrodynamics model introduced by Myers and Pospelov. Its reliance on conventional effective quantum field theory, and its description of symmetry-violation effects simply in terms of a four-vector with a nonzero component only in the time direction, rendered it an ideal target for experimentalists and a natural concept-testing ground for many theorists. At this point however the experimental limits on the single Myers-Pospelov parameter, after improving steadily over these past few years, are 'super-Planckian'; i.e. they take the model out of actual interest from a conventional quantum-gravity perspective. In light of this we here argue that it may be appropriate to move on to the next level of complexity, still with vectorial symmetry violation but adopting a generic four-vector. We also offer a preliminary characterization of the phenomenology of this more general framework, sufficient to expose a rather significant increase in complexity with respect to the original Myers-Pospelov setup. Most of these novel features are linked to the presence of spatial anisotropy, which is particularly pronounced when the symmetry-breaking vector is spacelike, and they are such that they reduce the bound-setting power of certain types of observations in astrophysics.

Gubitosi, Giulia; Amelino-Camelia, Giovanni; Melchiorri, Alessandro [Dipartimento di Fisica, Universita di Roma 'La Sapienza' and Sezione Roma1 INFN, Piazzale Aldo Moro 2, 00185 Roma (Italy); Genovese, Giuseppe [Dipartimento di Matematica, Universita di Roma 'La Sapienza' and Sezione Roma1 INFN, Piazzale Aldo Moro 2, 00185 Roma (Italy)

2010-07-15

54

Scaling GDL for Multi-cores to Process Planck HFI Beams Monte Carlo on HPC  

NASA Astrophysics Data System (ADS)

After reviewing the majors progress done in GDL –now in 0.9.4– on performance and plotting capabilities since ADASS XXI paper (Coulais et al. 2012), we detail how a large code for Planck HFI beams Monte Carlo was successfully transposed from IDL to GDL on HPC.

Coulais, A.; Schellens, S. M.; Duvert, S. G.; Park, J.; Arabas, S.; Erard, S.; Roudier, G.; Hivon, D. E.; Mottet, D. S.; Laurent, D. B.; Pinter, M.; Kasradze, N.; Ayad, M.

2014-05-01

55

Planck early results. XI. Calibration of the local galaxy cluster Sunyaev-Zeldovich scaling relations  

Microsoft Academic Search

We present precise Sunyaev-Zeldovich (SZ) effect measurements in the direction of 62 nearby galaxy clusters (z < 0.5) detected at high signal-to-noise in the first Planck all-sky data set. The sample spans approximately a decade in total mass, 2 × 1014 M&sun; < M500 < 2 × 1015 M&sun;, where M500 is the mass corresponding to a total density contrast

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; M. Bartelmann; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; H. Bourdin; M. L. Brown; M. Bucher; C. Burigana; P. Cabella; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; L.-Y. Chiang; C. Chiang; G. Chon; P. R. Christensen; E. Churazov; D. L. Clements; S. Colafrancesco; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; A. da Silva; H. Dahle; L. Danese; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; J. M. Diego; K. Dolag; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; F. Finelli; I. Flores-Cacho; O. Forni; M. Frailis; E. Franceschi; S. Fromenteau; S. Galeotta; K. Ganga; R. T. Génova-Santos; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; D. Harrison; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; J. Lanoux; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; A. Liddle; P. B. Lilje; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; F. Marleau; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; A. Melchiorri; J.-B. Melin; L. Mendes; A. Mennella; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; S. Osborne; F. Pajot; F. Pasian; G. Patanchon; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; E. Pierpaoli; R. Piffaretti; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. W. Pratt; G. Prézeau; S. Prunet; J.-L. Puget; J. P. Rachen; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; G. Savini; B. M. Schaefer; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sudiwala; R. Sunyaev; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; L. Valenziano; L. Vibert; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; S. D. M. White; M. White; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

56

Taming nonlocality in theories with Planck-scale deformed Lorentz symmetry.  

PubMed

We report a general analysis of worldlines for theories with deformed relativistic symmetries and momentum dependence of the speed of photons. Our formalization is faithful to Einstein's program, with spacetime points viewed as an abstraction of physical events. The emerging picture imposes the renunciation of the idealization of absolutely coincident events, but is free from some pathologies which had been previously conjectured. PMID:21405507

Amelino-Camelia, Giovanni; Matassa, Marco; Mercati, Flavio; Rosati, Giacomo

2011-02-18

57

A better presentation of Planck's radiation law  

NASA Astrophysics Data System (ADS)

Introductory physics and astronomy courses commonly use Wien's displacement law to explain the colors of blackbodies, including the Sun and other stars, in terms of their temperatures. We argue here that focusing on the peak of the blackbody spectrum is misleading for three reasons. First, the Planck curve is too broad for an individual spectral color to stand out. Second, the location of the peak of the Planck curve depends on the choice of the independent variable in the plot. And third, Wien's displacement law is seldom used in actual practice to find a temperature and direct fitting to the Planck function is preferable. We discuss these flaws and argue that, at the introductory level, presentation of blackbody radiation in terms of photon statistics would be more effective pedagogically. The average energy of the emitted photons would then be presented in place of Wien's displacement law, and discussion of the Stefan-Boltzmann law would include the total number of photons emitted per second. Finally, we suggest that the Planck spectrum is most appropriately plotted as a ``spectral energy density per fractional bandwidth distribution,'' using a logarithmic scale for the wavelength or frequency.

Marr, Jonathan M.; Wilkin, Francis P.

2012-05-01

58

Planck Surveyor On Its Way to Orbit  

ScienceCinema

An Ariane 5 rocket carried the Planck Surveyor and a companion satellite into space May 14, 2009 from the European Space Agency (ESA) base on the northwest coast of South America. Once in orbit beyond the moon, Planck will produce the most accurate measurements ever made of the relic radiation from the big bang, plus the largest set of CMB data ever recorded. Berkeley Labs long and continuing involvement with Planck began when George Smoot of the Physics Division proposed Plancks progenitor to ESA and continues with preparations for ongoing data analysis for the U.S. Planck team at NERSC, led by Julian Borrill, co-leader of the Computational Cosmology Center.

Borrill, Julian

2013-05-29

59

Planck Surveyor On Its Way to Orbit  

ScienceCinema

An Ariane 5 rocket carried the Planck Surveyor and a companion satellite into space May 14, 2009 from the European Space Agency (ESA) base on the northwest coast of South America. Once in orbit beyond the moon, Planck will produce the most accurate measurements ever made of the relic radiation from the big bang, plus the largest set of CMB data ever recorded. Berkeley Labs long and continuing involvement with Planck began when George Smoot of the Physics Division proposed Plancks progenitor to ESA and continues with preparations for ongoing data analysis for the U.S. Planck team at NERSC, led by Julian Borrill, co-leader of the Computational Cosmology Center

None

2010-01-08

60

Planck Surveyor On Its Way to Orbit  

SciTech Connect

An Ariane 5 rocket carried the Planck Surveyor and a companion satellite into space May 14, 2009 from the European Space Agency (ESA) base on the northwest coast of South America. Once in orbit beyond the moon, Planck will produce the most accurate measurements ever made of the relic radiation from the big bang, plus the largest set of CMB data ever recorded. Berkeley Labs long and continuing involvement with Planck began when George Smoot of the Physics Division proposed Plancks progenitor to ESA and continues with preparations for ongoing data analysis for the U.S. Planck team at NERSC, led by Julian Borrill, co-leader of the Computational Cosmology Center.

Borrill, Julian

2009-01-01

61

Planck Surveyor On Its Way to Orbit  

SciTech Connect

An Ariane 5 rocket carried the Planck Surveyor and a companion satellite into space May 14, 2009 from the European Space Agency (ESA) base on the northwest coast of South America. Once in orbit beyond the moon, Planck will produce the most accurate measurements ever made of the relic radiation from the big bang, plus the largest set of CMB data ever recorded. Berkeley Labs long and continuing involvement with Planck began when George Smoot of the Physics Division proposed Plancks progenitor to ESA and continues with preparations for ongoing data analysis for the U.S. Planck team at NERSC, led by Julian Borrill, co-leader of the Computational Cosmology Center

2009-05-14

62

Characterizing Large-Scale Computational Physics  

NASA Astrophysics Data System (ADS)

Large-scale computational physics calculations typically share some of a number of basic characteristics: *Brute-force approaches: Atomistic molecular dynamics, particle-in-cell plasma physics, particle-mesh cosmological simulations, DNS of turbulence, lattice QCD, Monte Carlo, . *Wide range of relevant scales: Angstroms to millimeters in molecular dynamics, ion/electron cyclotron period to seconds or minutes in plasmas, galaxy to observable universe in cosmology, high Reynolds number turbulence, . *Obvious need for yet larger scale: higher resolution, larger simulation domain, more particles, . *Code is named, parallel, community, long-lived (but evolving). This talk views the computational physics landscape from the perspective a physicist who has worked at three DOE large-scale computing centers: the Argonne Leadership Computing Facility, the (former) Advanced Computing Laboratory, and NERSC. The "usual suspects" at the large-scale end of computational physics are remarkably persistent, even in the face of an ever-increasing definition of large-scale.

Williams, Timothy

2011-03-01

63

Planck early results. X. Statistical analysis of Sunyaev-Zeldovich scaling relations for X-ray galaxy clusters  

Microsoft Academic Search

All-sky data from the Planck survey and the Meta-Catalogue of X-ray detected Clusters of galaxies (MCXC) are combined to investigate the relationship between the thermal Sunyaev-Zeldovich (SZ) signal and X-ray luminosity. The sample comprises ~1600 X-ray clusters with redshifts up to ~1 and spans a wide range in X-ray luminosity. The SZ signal is extracted for each object individually, and

N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; M. Bartelmann; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; M. L. Brown; M. Bucher; C. Burigana; P. Cabella; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; R.-R. Chary; L.-Y. Chiang; C. Chiang; G. Chon; P. R. Christensen; E. Churazov; D. L. Clements; S. Colafrancesco; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; A. da Silva; H. Dahle; L. Danese; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; J. M. Diego; K. Dolag; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; F. Finelli; I. Flores-Cacho; O. Forni; M. Frailis; E. Franceschi; S. Fromenteau; S. Galeotta; K. Ganga; R. T. Génova-Santos; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; D. Harrison; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; F. Marleau; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; A. Melchiorri; J.-B. Melin; L. Mendes; A. Mennella; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; S. Osborne; F. Pajot; F. Pasian; G. Patanchon; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; E. Pierpaoli; R. Piffaretti; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. W. Pratt; G. Prézeau; S. Prunet; J.-L. Puget; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; B. M. Schaefer; D. Scott; M. D. Seiffert; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sunyaev; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; M. Tristram; J. Tuovinen; L. Valenziano; L. Vibert; P. Vielva; F. Villa; N. Vittorio; B. D. Wandelt; S. D. M. White; M. White; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

64

The Planck Aether Hypothesis  

Microsoft Academic Search

The Planck aether hypothesis (F. Winterberg, VRI Verlag, Karlsbad, Germany, 2000) assumes that space is densely filled with positive and negative Planck mass particles, locally interacting over a Planck length with the Planck force. Making this hypothesis, quantum mechanics and Lorentz invariance can be derived as low energy approximations, with Einstein's gravitational and Maxwell's electromagnetic waves explained as the symmetric

Friedwardt Winterberg

2000-01-01

65

Warming up for Planck  

NASA Astrophysics Data System (ADS)

The recent Planck results and future releases on the horizon present a key opportunity to address a fundamental question in inflationary cosmology of whether primordial density perturbations have a quantum or thermal origin, i.e. whether particle production may have significant effects during inflation. Warm inflation provides a natural arena to address this issue, with interactions between the scalar inflaton and other degrees of freedom leading to dissipative entropy production and associated thermal fluctuations. In this context, we present relations between CMB observables that can be directly tested against observational data. In particular, we show that the presence of a thermal bath warmer than the Hubble scale during inflation decreases the tensor-to-scalar ratio with respect to the conventional prediction in supercooled inflation, yielding r < 8|nt|, where nt is the tensor spectral index. Focusing on supersymmetric models at low temperatures, we determine consistency relations between the observables characterizing the spectrum of adiabatic scalar and tensor modes, both for generic potentials and particular canonical examples, and which we compare with the WMAP and Planck results. Finally, we include the possibility of producing the observed baryon asymmetry during inflation through dissipative effects, thereby generating baryon isocurvature modes that can be easily accommodated by the Planck data.

Bartrum, Sam; Berera, Arjun; Rosa, João G.

2013-06-01

66

Planck and the Special Theory of Relativity  

NASA Astrophysics Data System (ADS)

Max Planck was considered to be among the most conservative figures in the history of physical science, because of his reluctance of accepting quantum mechanics (which he himself had helped to create) and his life-long effort to reconcile it with classical mechanics. Thus, it is something of a puzzle to see Planck as among the first physicists to embrace Einstein's special theory of relativity, equally revolutionary as quantum mechanics. The main burden of this paper is to find out why Planck so readily accepted and defended Einstein's theory. I suggest that Einstein's later criticism of certain interpretations of quantum mechanic may have its roots in Planck's skeptical attitude.

Liu, Chuang

2005-11-01

67

Planck early results. I. The Planck mission  

Microsoft Academic Search

The European Space Agency's Planck satellite was launched on 14 May 2009, and has been surveying the sky stably and continuously since 13 August 2009. Its performance is well in line with expectations, and it will continue to gather scientific data until the end of its cryogenic lifetime. We give an overview of the history of Planck in its first

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; M. Baker; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; K. Bennett; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; T. Bradshaw; M. Bremer; M. Bucher; C. Burigana; R. C. Butler; P. Cabella; C. M. Cantalupo; B. Cappellini; J.-F. Cardoso; R. Carr; M. Casale; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; J. Charra; R.-R. Chary; L.-Y. Chiang; C. Chiang; P. R. Christensen; D. L. Clements; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; G. Crone; M. Crook; F. Cuttaia; L. Danese; O. D'Arcangelo; R. D. Davies; R. J. Davis; P. de Bernardis; J. de Bruin; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; J. Dick; C. Dickinson; K. Dolag; H. Dole; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; H. K. Eriksen; F. Finelli; S. Foley; O. Forni; P. Fosalba; M. Frailis; E. Franceschi; M. Freschi; T. C. Gaier; S. Galeotta; J. Gallegos; B. Gandolfo; K. Ganga; M. Giard; G. Giardino; G. Gienger; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; G. Guyot; J. Haissinski; F. K. Hansen; D. Harrison; G. Helou; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; A. Hornstrup; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; T. Jagemann; W. C. Jones; J. J. Juillet; M. Juvela; P. Kangaslahti; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; M. Krassenburg; H. Kurki-Suonio; G. Lagache; A. Lähteenmäki; J.-M. Lamarre; A. E. Lange; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; J. P. Leahy; R. Leonardi; C. Leroy; P. B. Lilje; M. Linden-Vørnle; M. López-Caniego; S. Lowe; P. M. Lubin; J. F. Macías-Pérez; T. Maciaszek; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; E. Martínez-González; S. Masi; M. Massardi; S. Matarrese; F. Matthai; P. Mazzotta; A. McDonald; P. R. Meinhold; A. Melchiorri; J.-B. Melin; L. Mendes; A. Mennella; C. Mevi; R. Miniscalco; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; N. Morisset; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; I. Ortiz; S. Osborne; P. Osuna; C. A. Oxborrow; F. Pajot; R. Paladini; B. Partridge; F. Pasian; T. Passvogel; G. Patanchon; D. Pearson; T. J. Pearson; O. Perdereau; L. Perotto; F. Piacentini; M. Piat; E. Pierpaoli; S. Plaszczynski; P. Platania; E. Pointecouteau; G. Polenta; N. Ponthieu; L. Popa; T. Poutanen; G. Prézeau; S. Prunet; J.-L. Puget; J. P. Rachen; W. T. Reach; R. Rebolo; M. Reinecke; J.-M. Reix; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; E. Salerno; M. Sandri; D. Santos; G. Savini; B. M. Schaefer; D. Scott; M. D. Seiffert; P. Shellard; A. Simonetto; G. F. Smoot; C. Sozzi; J.-L. Starck; J. Sternberg; F. Stivoli; V. Stolyarov; R. Stompor; L. Stringhetti; R. Sudiwala; R. Sunyaev; J.-F. Sygnet; D. Tapiador; J. A. Tauber; D. Tavagnacco; D. Taylor; L. Terenzi; D. Texier; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; M. Türler; M. Tuttlebee; G. Umana; L. Valenziano; J. Valiviita; J. Varis; L. Vibert; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; C. Watson; S. D. M. White; M. White; A. Wilkinson; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

68

Neutrino cosmology and Planck  

NASA Astrophysics Data System (ADS)

Relic neutrinos play an important role in the evolution of the Universe, modifying some of the cosmological observables. We summarize the main aspects of cosmological neutrinos and describe how the precision of present cosmological data can be used to learn about neutrino properties. In particular, we discuss how cosmology provides information on the absolute scale of neutrino masses, complementary to beta decay and neutrinoless double-beta decay experiments. We explain why the combination of Planck temperature data with measurements of the baryon acoustic oscillation angular scale provides a strong bound on the sum of neutrino masses, 0.23 eV at the 95% confidence level, while the lensing potential spectrum and the cluster mass function measured by Planck are compatible with larger values. We also review the constraints from current data on other neutrino properties. Finally, we describe the very good perspectives from future cosmological measurements, which are expected to be sensitive to neutrino masses close to the minimum values guaranteed by flavour oscillations.

Lesgourgues, Julien; Pastor, Sergio

2014-06-01

69

Planck early results. I. The Planck mission  

NASA Astrophysics Data System (ADS)

The European Space Agency's Planck satellite was launched on 14 May 2009, and has been surveying the sky stably and continuously since 13 August 2009. Its performance is well in line with expectations, and it will continue to gather scientific data until the end of its cryogenic lifetime. We give an overview of the history of Planck in its first year of operations, and describe some of the key performance aspects of the satellite. This paper is part of a package submitted in conjunction with Planck's Early Release Compact Source Catalogue, the first data product based on Planck to be released publicly. The package describes the scientific performance of the Planck payload, and presents results on a variety of astrophysical topics related to the sources included in the Catalogue, as well as selected topics on diffuse emission. Corresponding author: J. A. Tauber, e-mail: jtauber@rssd.esa.int

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Baker, M.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Bennett, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bradshaw, T.; Bremer, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cabella, P.; Cantalupo, C. M.; Cappellini, B.; Cardoso, J.-F.; Carr, R.; Casale, M.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Charra, J.; Chary, R.-R.; Chiang, L.-Y.; Chiang, C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Crone, G.; Crook, M.; Cuttaia, F.; Danese, L.; D'Arcangelo, O.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Bruin, J.; de Gasperis, G.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dick, J.; Dickinson, C.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Foley, S.; Forni, O.; Fosalba, P.; Frailis, M.; Franceschi, E.; Freschi, M.; Gaier, T. C.; Galeotta, S.; Gallegos, J.; Gandolfo, B.; Ganga, K.; Giard, M.; Giardino, G.; Gienger, G.; Giraud-Héraud, Y.; González, J.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Guyot, G.; Haissinski, J.; Hansen, F. K.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Jaffe, A. H.; Jagemann, T.; Jones, W. C.; Juillet, J. J.; Juvela, M.; Kangaslahti, P.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Krassenburg, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lange, A. E.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leahy, J. P.; Leonardi, R.; Leroy, C.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lowe, S.; Lubin, P. M.; Macías-Pérez, J. F.; Maciaszek, T.; MacTavish, C. J.; Maffei, B.; Maino, D.; Mandolesi, N.; Mann, R.; Maris, M.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McDonald, A.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Melin, J.-B.; Mendes, L.; Mennella, A.; Mevi, C.; Miniscalco, R.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Morisset, N.; Mortlock, D.; Munshi, D.; Murphy, A.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Ortiz, I.; Osborne, S.; Osuna, P.; Oxborrow, C. A.; Pajot, F.; Paladini, R.; Partridge, B.; Pasian, F.; Passvogel, T.; Patanchon, G.; Pearson, D.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Plaszczynski, S.; Platania, P.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Reix, J.-M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Salerno, E.; Sandri, M.; Santos, D.; Savini, G.; Schaefer, B. M.; Scott, D.; Seiffert, M. D.; Shellard, P.; Simonetto, A.; Smoot, G. F.; Sozzi, C.; Starck, J.-L.; Sternberg, J.; Stivoli, F.; Stolyarov, V.; Stompor, R.; Stringhetti, L.; Sudiwala, R.; Sunyaev, R.; Sygnet, J.-F.; Tapiador, D.; Tauber, J. A.; Tavagnacco, D.; Taylor, D.; Terenzi, L.; Texier, D.; Toffolatti, L.; Tomasi, M.; Torre, J.-P.; Tristram, M.; Tuovinen, J.; Türler, M.; Tuttlebee, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Varis, J.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, C.; White, S. D. M.; White, M.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

2011-12-01

70

Multiple Scales in Solid State Physics  

Microsoft Academic Search

The quest for an accurate simulations of the physical world, most vividly expressed in the vision of Laplace's daemon [1], is almost as old as quantitative science. Naturally, such a simulation requires the knowledge of all the relevant physical\\u000a laws, i.e., a Theory of Everything. For the phenomena involving scales larger than an atomic nucleus and smaller than a star,

Erik Koch; Eva Pavarini

71

Overview of Icing Physics Relevant to Scaling  

NASA Technical Reports Server (NTRS)

An understanding of icing physics is required for the development of both scaling methods and ice-accretion prediction codes. This paper gives an overview of our present understanding of the important physical processes and the associated similarity parameters that determine the shape of Appendix C ice accretions. For many years it has been recognized that ice accretion processes depend on flow effects over the model, on droplet trajectories, on the rate of water collection and time of exposure, and, for glaze ice, on a heat balance. For scaling applications, equations describing these events have been based on analyses at the stagnation line of the model and have resulted in the identification of several non-dimensional similarity parameters. The parameters include the modified inertia parameter of the water drop, the accumulation parameter and the freezing fraction. Other parameters dealing with the leading edge heat balance have also been used for convenience. By equating scale expressions for these parameters to the values to be simulated a set of equations is produced which can be solved for the scale test conditions. Studies in the past few years have shown that at least one parameter in addition to those mentioned above is needed to describe surface-water effects, and some of the traditional parameters may not be as significant as once thought. Insight into the importance of each parameter, and the physical processes it represents, can be made by viewing whether ice shapes change, and the extent of the change, when each parameter is varied. Experimental evidence is presented to establish the importance of each of the traditionally used parameters and to identify the possible form of a new similarity parameter to be used for scaling.

Anderson, David N.; Tsao, Jen-Ching

2005-01-01

72

The Planck mission  

NASA Astrophysics Data System (ADS)

The European Space Agency's Planck satellite was launched on 14 May 2009, and has been surveying the sky stably and continuously since August 2009. Its performance is well in line with expectations, and it will continue to gather scientific data until the end of its cryogenic lifetime. We give an overview of the current status of Planck and describe the first data (the Early Release Compact Source Catalogue) and scientific papers which have been released to date by the Planck Collaboration.

Tauber, J. A.; Planck Collaboration

73

Perspective on TeV-scale physics  

SciTech Connect

These lectures review theoretical motivations and experimental prospects for the study of TeV-scale physics. Three clues to the importance of TeV physics are discussed: implications of quantum corrections for the masses of a fourth generation quark-lepton family, the gauge hierarchy problem and known solutions, and implications of symmetry and unitarity for the symmetry-breaking sector of the electroweak gauge theory. The experimental prospects are reviewed with emphasis on the multi-TeV pp colliders that may be built in the 1990's. The topics include new phenomena that might occur - e.g., a fourth generation, heavy gauge bosons, composite structure, and supersymmetry - as well as the signals of the unknown SU(2)/sub L/ /times/ U(1)/sub Y/ breaking mechanism that must occur within the TeV domain. 96 refs., 21 figs.

Chanowitz, M.S.

1989-02-01

74

THE PHYSICAL BASIS OF ZERO-POINT ENERGY? Planck's Constant from Hubble's Constant: Cosmological Origin of Terrestrial ZPF & Zitterbewegung  

Microsoft Academic Search

In a Newtonian model of e.g. the Bohr atom, it is physically incorrect to omit the aggregate forces from all electrostatic charges (monopole potential (with or without retarded potentials)) in the visible universe. Though the standard hypotheses of cosmic homogeneity\\/isotropy imply such forces have a zero-mean, they also have a non-zero variance! It is known since Fényes (1952) & Nelson

Robert W. Bass; Dean Zes

75

The Planck Mission: Early Results  

ScienceCinema

The ESA Planck space mission, launched on May 14, 2009, is dedicated to high precision measurements of the cosmic microwave background (CMB), the first light of the universe, both in temperature and polarization. The satellite observes the full sky from a far-Earth orbit with two cryogenic instruments in the 30-850 GHz range at the focal plane of a 1.5-meter telescope. The primary objective of Planck is to measure with unprecedented precision the key cosmological parameters and to provide accurate tests of physics in the early universe. Planck has recently completed the fifth full-sky survey. The data analysis is underway. The first cosmology results are expected in early 2013 while a number of astrophysical results have been recently delivered to the community, including galactic and extragalactic astrophysics and a rich catalogue of radio and infrared sources. These results demonstrate the excellent in-orbit performance of the instruments and give excellent prospects for the forthcoming cosmological results.

76

The Planck Mission: Early Results  

SciTech Connect

The ESA Planck space mission, launched on May 14, 2009, is dedicated to high precision measurements of the cosmic microwave background (CMB), the first light of the universe, both in temperature and polarization. The satellite observes the full sky from a far-Earth orbit with two cryogenic instruments in the 30-850 GHz range at the focal plane of a 1.5-meter telescope. The primary objective of Planck is to measure with unprecedented precision the key cosmological parameters and to provide accurate tests of physics in the early universe. Planck has recently completed the fifth full-sky survey. The data analysis is underway. The first cosmology results are expected in early 2013 while a number of astrophysical results have been recently delivered to the community, including galactic and extragalactic astrophysics and a rich catalogue of radio and infrared sources. These results demonstrate the excellent in-orbit performance of the instruments and give excellent prospects for the forthcoming cosmological results.

Marco Bersanelli (University of Milan, Italy) [University of Milan, Italy

2012-03-07

77

Initiation and Detonation Physics on Millimeter Scales  

SciTech Connect

The LLNL Detonation Science Project has a major interest in understanding the physics of detonation on a millimeter scale. This report summarizes the rate stick experiment results of two high explosives. The GO/NO-GO threshold between varying diameters of ultra-fine TATB (ufTATB) and LX-16 were recorded on an electronic streak camera and analyzed. This report summarizes the failure diameters of rate sticks for ufTATB and LX-16. Failure diameter for the ufTATB explosive, with densities at 1.80 g/cc, begin at 2.34 mm (not maintaining detonation velocity over the entire length of the rate stick). ufTATB rate sticks at the larger 3.18 mm diameter maintain a constant detonation velocity over the complete length. The PETN based and LLNL developed explosive, LX-16, with densities at 1.7 g/cc, shows detonation failure between 0.318 mm and 0.365 mm. Additional tests would be required to narrow this failure diameter further. Many of the tested rate sticks were machined using a femtosecond laser focused into a firing tank - in case of accidental detonation.

Philllips, D F; Benterou, J J; May, C A

2012-03-20

78

Planck, the Quantum, and the Historians  

NASA Astrophysics Data System (ADS)

In late 1900, the German theoretical physicist Max Planck derived an expression for the spectrum of black-body radiation. That derivation was the first step in the introduction of quantum concepts into physics. But how did Planck think about his result in the early years of the twentieth century? Did he assume that his derivation was consistent with the continuous energies inherent in Maxwellian electrodynamics and Newtonian mechanics? Or did he see the beginnings, however tentative and uncertain, of the quantum revolution to come? Historians of physics have debated this question for over twenty years. In this article, I review that debate and, at the same time, present Planck's achievement in its historical context.

Gearhart, Clayton A.

2002-05-01

79

Development of a Physical Education Teaching Efficacy Scale  

ERIC Educational Resources Information Center

Relationships have been found between teacher efficacy and many teaching and learning variables, but few researchers have examined teaching efficacy in physical education. The instrument reported here, the Physical Education Teaching Efficacy Scale, was developed based on the teaching efficacy literature, existing scales, and National Association…

Humphries, Charlotte A.; Hebert, Edward; Daigle, Kay; Martin, Jeffrey

2012-01-01

80

PSM: Planck Sky Model  

NASA Astrophysics Data System (ADS)

The Planck Sky Model (PSM) is a global representation of the multi-component sky at frequencies ranging from a few GHz to a few THz. It summarizes in a synthetic way as much of our present knowledge as possible of the GHz sky. PSM is a complete and versatile set of programs and data that can be used for the simulation or the prediction of sky emission in the frequency range of typical CMB experiments, and in particular of the Planck sky mission. It was originally developed as part of the activities of Planck component separation Working Group (or "Working Group 2" - WG2), and of the ADAMIS team at APC. PSM gives users the opportunity to investigate the model in some depth: look at its parameters, visualize its predictions for all individual components in various formats, simulate sky emission compatible with a given parameter set, and observe the modeled sky with a synthetic instrument. In particular, it makes possible the simulation of sky emission maps as could be plausibly observed by Planck or other CMB experiments that can be used as inputs for the development and testing of data processing and analysis techniques.

Ashdown, Mark; Aumont, Jonathan; Baccigalupi, Carlo; Banday, Anthony; Basak, Soumen; Bernard, Jean-Philippe; Betoule, Marc; Bouchet, François; Castex, Guillaume; Clements, Dave; Da Silva, Antonio; De Zotti, Gianfranco; Delabrouille, Jacques; Dickinson, Clive; Dodu, Fabrice; Dolag, Klaus; Elsner, Franz; Fauvet, Lauranne; Fay, Gilles; Giardino, Giovanna; Gonzalez-Nuevo, Joaquin; le Jeune, Maude; Leach, Samuel; Lesgourgues, Julien; Liguori, Michele; Macias, Juan; Massardi, Marcella; Matarrese, Sabino; Mazzotta, Pasquale; Melin, Jean-Baptiste; Miville-Deschènes, Marc-Antoine; Montier, Ludovic; Mottet, Sylvain; Paladini, Roberta; Partridge, Bruce; Piffaretti, Rocco; Prézeau, Gary; Prunet, Simon; Ricciardi, Sara; Roman, Matthieu; Schaefer, Bjorn; Toffolatti, Luigi

2012-08-01

81

Composite inflation confronts BICEP2 and PLANCK  

NASA Astrophysics Data System (ADS)

We examine observational constraints on single-field inflation in which the inflaton is a composite field stemming from a four-dimensional strongly interacting field theory. We confront the predictions with the Planck and very recent BICEP2 data. In the large non-minimal coupling regions, we discover for the minimal composite inflationary model that the predictions lie well inside the joint 68% CL for the Planck data, but is in tension with the recent BICEP2 observations. In the case of the glueball inflationary model, the predictions satisfy the Planck results. However, this model can produce a large tensor-to-scalar ratio consistent with the recent BICEP2 observations if the number of e-foldings is slightly smaller than the range commonly used. For a super Yang-Mills paradigm, we discover that the predictions satisfy the Planck data, and surprisingly a large tensor-to-scalar ratio consistent with the BICEP2 results can also be produced for an acceptable range of the number of e-foldings and of the confining scale. In the small non-minimal coupling regions, all of the models can satisfy the BICEP2 results. However, the predictions of the glueball and superglueball inflationary models cannot satisfy the observational bound on the amplitude of the curvature perturbation launched by Planck, and the techni-inflaton self-coupling in the minimal composite inflationary model is constrained to be extremely small.

Karwan, Khamphee; Channuie, Phongpichit

2014-06-01

82

The Planck Aether model for a unified theory of elementary particles  

Microsoft Academic Search

A dense assembly of an equal number of two kinds of Planck masses, one having positive and the other one negative kinetic energy, described by a nonrelativistic nonlinear Heisenberg equation with pointlike interactions, is proposed as a model for a unified theory of elementary particles. The dense assembly of Planck masses leads to a vortex field below the Planck scale

F. Winterberg

1994-01-01

83

Small-scale physics of the ocean  

NASA Technical Reports Server (NTRS)

Observations and theoretical models of small-scale phenomena in the oceans are reviewed, with a focus on progress during the period 1983-1986. Topics examined include surface layers, equatorial turbulence, off-equator mixed layers, the scaling of mixing, turbulence concepts, laboratory results, internal waves and mixing, rings, the nature of the bottom layer, double diffusion and intrusions, salt fingers, and biological interactions. Also discussed are developments in instrumentation (fast sampling profilers with upward-profiling capability, deep profilers, ship-motion correction, horizontal samplers, small submersibles, submarines, towed packages, conductivity sensors, dissolved-oxygen sensors, and acoustic Doppler current profilers) and goals for future research.

Caldwell, Douglas R.

1987-01-01

84

PLANCK+MUSTANG SZ  

NASA Astrophysics Data System (ADS)

It has been proposed that the over-representation of disturbed and merging systems in SZ-selected cluster samples is due to a bias in the selection function of these samples towards such objects. Characterizing this bias, and the processes responsible for it, is important for cosmological applications using cluster data from low resolution SZ observations, such as that from the Planck satellite. High resolution SZ observations towards objects which have been detected for the first time in the Planck all-sky catalogue will provide detail on high energy non-gravitational processes within these clusters by probing inhomogeneities in the pressure sub-structure of the intra-cluster medium. I will discuss a sample of such clusters which have been observed with the MUSTANG camera on the Green Bank Telescope and their implications for cluster cosmology.

Scaife, Anna

2012-05-01

85

Dominant Physical Controls of Soil Hydrology at Different Spatial Scales  

NASA Astrophysics Data System (ADS)

Soil moisture and soil hydrologic fluxes (infiltration, ET, runoff) are affected at different scales by the spatial variability of influencing factors such as soil, topography, vegetation, and climatic forcings such as precipitation and temperature patterns. Understanding the nature of the linkage between these physical controls and the soil hydraulic parameters is critical in developing efficient scaling schemes for effective hydrologic modeling at large domains. We present results from a multi-location, multi-scale study designed to tease out the dominant physical control of soil hydraulic parameter variability at each scale of interest, and the evolution of the dominance with scale. Mathematical techniques such as Wavelet analysis and Karhunen-Loeve expansion are applied to bring out the extent of influence of the physical controls on the distribution signatures of the hydraulic parameters at the various scales. Data from diverse hydro-climatic locations across the globe, at various scales, derived from multiple platforms/sensors such as in-situ sensors, airborne remote sensors, and various satellite-borne remote sensors are used in this study to improve our understanding of the processes governing the hydraulic variability of soils. The study also considers the correlations among the soil hydraulic parameters, and their progression with change in scale. Further, we test the efficacy of certain existing soil hydraulic parameter scaling algorithms with regard to preserving these relationships (both among the hydraulic parameters, and with the physical controls) and provide guidelines for their usage at specific scales.

Jana, R. B.; Mohanty, B. P.

2011-12-01

86

The thermal Sunyaev-Zel'dovich effect power spectrum in light of Planck  

NASA Astrophysics Data System (ADS)

The amplitude of the thermal Sunyaev-Zel'dovich effect (tSZ) power spectrum is extremely sensitive to the abundance of the most massive dark matter haloes (galaxy clusters) and therefore to fundamental cosmological parameters that control their growth, such as ?8 and ?m. Here we explore the sensitivity of the tSZ power spectrum to important non-gravitational (`subgrid') physics by employing the cosmo-OWLS suite of large-volume cosmological hydrodynamical simulations, run in both the Planck and 7-year Wilkinson Microwave Anisotropy Probe (WMAP7) best-fitting cosmologies. On intermediate and small angular scales (? ? 1000, or ??10 arcmin), accessible with the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT), the predicted tSZ power spectrum is highly model dependent, with gas ejection due to active galactic nuclei (AGN) feedback having a particularly large effect. However, at large scales, observable with the Planck telescope, the effects of subgrid physics are minor. Comparing the simulated tSZ power spectra with observations, we find a significant amplitude offset on all measured angular scales (including large scales), if the Planck best-fitting cosmology is assumed by the simulations. This is shown to be a generic result for all current models of the tSZ power spectrum. By contrast, if the WMAP7 cosmology is adopted, there is full consistency with the Planck tSZ power spectrum measurements on large scales and agreement at the 2? level with the SPT and ACT measurements at intermediate scales for our fiducial AGN model, which Le Brun et al. have shown reproduces the `resolved' properties of the Local Group and cluster population remarkably well. These findings strongly suggest that there are significantly fewer massive galaxy clusters than expected for the Planck best-fitting cosmology, which is consistent with recent measurements of the tSZ number counts. Our findings therefore pose a significant challenge to the cosmological parameter values preferred (and/or the model adopted) by the Planck primary cosmic microwave background analyses.

McCarthy, I. G.; Le Brun, A. M. C.; Schaye, J.; Holder, G. P.

2014-06-01

87

Scaling and Renormalization in Statistical Physics  

Microsoft Academic Search

This text provides a thoroughly modern graduate-level introduction to the theory of critical behavior. Beginning with a brief review of phase transitions in simple systems and of mean field theory, the text then goes on to introduce the core ideas of the renormalization group. Following chapters cover phase diagrams, fixed points, cross-over behavior, finite-size scaling, perturbative renormalization methods, low-dimensional systems,

John Cardy

1996-01-01

88

Mathematical and physical scaling of triggered lightning  

SciTech Connect

As the aircraft industry incorporates current technology in airborne systems, electromagnetic compatibility can decrease. Composite fuselages can be more transparent to EMP, whether nuclear or lightning generated, than metal ones. Solid-state circuitry is sensitive to intense EM fluctuations whereas mechanical controls generally are not. With this increased vulnerability comes increased concern for these dangers. Recently the anxiety over lightning has risen. Answers are sought to such questions as: how do the lightning EM effects couple into the aircraft's interior. Do aircraft trigger lightning, and if so, can the triggering be minimized. An understanding, at least to some extent, of lightning would provide a needed foundation to examine the interaction of aircraft with lightning. A review of the literature on lightning and lightning-aircraft investigations, including triggered lightning, was conducted and is briefly summarized in this paper. In addition to this brief literature review, scaling the lightning event to laboratory size is also discussed. The ability to scale would allow accurate investigation of lightning effects, as well as the triggering phenomena, in scaled experiments.

Ziolkowski, R.W.; Grant, J.B.

1982-12-01

89

Multi-physics multi-scale modeling issues in LED  

Microsoft Academic Search

Multi-physics multi-scale modeling issues in various stages of the LED manufacturing such as MOCVD reactor design, epitaxial growth based on silicon wafer, chip design and manufacturing, module packaging and assembly have been discussed, which are critical to LED fabrication. In order to enhance the LED design and fabrication efficiency, we propose a new concept to integrate multi-physics\\/multi-scale modeling as a

Sheng Liu; Zhiyin Gan; Xiaobing Luo; Kai Wang; Xiaohui Song; Zhaohui Chen; Han Yan; Zongyuan Liu; Pei Wang; Wei Wei

2008-01-01

90

Predicting a prior for Planck  

NASA Astrophysics Data System (ADS)

The quantum state of the universe combined with the structure of the landscape potential implies a prior that specifies predictions for observations. We compute the prior for CMB related observables given by the no-boundary wave function (NBWF) in a landscape model that includes a range of inflationary patches representative of relatively simple single-field models. In this landscape the NBWF predicts our classical cosmological background emerges from a region of eternal inflation associated with a plateau-like potential. The spectra of primordial fluctuations on observable scales are characteristic of concave potentials, in excellent agreement with the Planck data. By contrast, alternative theories of initial conditions that strongly favor inflation at high values of the potential are disfavored by observations in this landscape.

Hertog, Thomas

2014-02-01

91

Psychometric Properties of the Commitment to Physical Activity Scale  

ERIC Educational Resources Information Center

Objective: To assess psychometric properties of the Commitment to Physical Activity Scale (CPAS). Methods: Girls in third to fifth grades (n = 932) completed the CPAS before and after a physical activity intervention. Psychometric measures included internal consistency, factor analysis, and concurrent validity. Results: Three CPAS factors emerged:…

DeBate, Rita DiGioacchino; Huberty, Jennifer; Pettee, Kelley

2009-01-01

92

Development of a Scale Measuring Trait Anxiety in Physical Education  

ERIC Educational Resources Information Center

The aim of the present study was to examine the validity and reliability of a multi-dimensional measure of trait anxiety specifically designed for the physical education lesson. The Physical Education Trait Anxiety Scale was initially completed by 774 high school students during regular school classes. A confirmatory factor analysis supported the…

Barkoukis, Vassilis; Rodafinos, Angelos; Koidou, Eirini; Tsorbatzoudis, Haralambos

2012-01-01

93

Scaling and Renormalization in Statistical Physics  

NASA Astrophysics Data System (ADS)

This text provides a thoroughly modern graduate-level introduction to the theory of critical behavior. Beginning with a brief review of phase transitions in simple systems and of mean field theory, the text then goes on to introduce the core ideas of the renormalization group. Following chapters cover phase diagrams, fixed points, cross-over behavior, finite-size scaling, perturbative renormalization methods, low-dimensional systems, surface critical behavior, random systems, percolation, polymer statistics, critical dynamics and conformal symmetry. The book closes with an appendix on Gaussian integration, a selected bibliography, and a detailed index. Many problems are included. The emphasis throughout is on providing an elementary and intuitive approach. In particular, the perturbative method introduced leads, among applications, to a simple derivation of the epsilon expansion in which all the actual calculations (at least to lowest order) reduce to simple counting, avoiding the need for Feynman diagrams.

Cardy, John

1996-04-01

94

Impact Cratering Physics al Large Planetary Scales  

NASA Astrophysics Data System (ADS)

Present understanding of the physics controlling formation of ˜10^3 km diameter, multi-ringed impact structures on planets were derived from the ideas of Scripps oceanographer, W. Van Dorn, University of London's, W, Murray, and, Caltech's, D. O'Keefe who modeled the vertical oscillations (gravity and elasticity restoring forces) of shock-induced melt and damaged rock within the transient crater immediately after the downward propagating hemispheric shock has processed rock (both lining, and substantially below, the transient cavity crater). The resulting very large surface wave displacements produce the characteristic concentric, multi-ringed basins, as stored energy is radiated away and also dissipated upon inducing further cracking. Initial calculational description, of the above oscillation scenario, has focused upon on properly predicting the resulting density of cracks, and, their orientations. A new numerical version of the Ashby--Sammis crack damage model is coupled to an existing shock hydrodynamics code to predict impact induced damage distributions in a series of 15--70 cm rock targets from high speed impact experiments for a range of impactor type and velocity. These are compared to results of crack damage distributions induced in crustal rocks with small arms impactors and mapped ultrasonically in recent Caltech experiments (Ai and Ahrens, 2006).

Ahrens, Thomas J.

2007-06-01

95

Localizability and the planck mass  

SciTech Connect

The author combines the assumption of environmental decoherence, as the mechanism generating the classical (i.e. no quantum interferences) nature of spacetime, with the limit on its other classical feature, point-like continuity, namely Planck length. As a result, quantum extended objects with masses larger than Planck mass have to derive their quantum behavior from long-range correlations; objects with masses smaller than Planck mass cannot display classical behavior.

Ne`eman, Y. [Tel-Aviv Univ. (Israel). Sackler Faculty of Exact Sciences]|[Univ. of Texas, Austin, TX (United States). Center for Particle Physics

1993-06-01

96

Detection of thermal SZ-CMB lensing cross-correlation in Planck nominal mission data  

NASA Astrophysics Data System (ADS)

The nominal mission maps from the Planck satellite contain a wealth of information about secondary anisotropies in the cosmic microwave background (CMB), including those induced by the thermal Sunyaev-Zel'dovich (tSZ) effect and gravitational lensing. As both the tSZ and CMB lensing signals trace the large-scale matter density field, the anisotropies sourced by these processes are expected to be correlated. We report the first detection of this cross-correlation signal, which we measure at 6.2? significance using the Planck data. We take advantage of Planck's multifrequency coverage to construct a tSZ map using internal linear combination techniques, which we subsequently cross-correlate with the publicly-released Planck CMB lensing potential map. The cross-correlation is subject to contamination from the cosmic infrared background (CIB), which is known to correlate strongly with CMB lensing. We correct for this contamination via cross-correlating our tSZ map with the Planck 857 GHz map and confirm the robustness of our measurement using several null tests. We interpret the signal using halo model calculations, which indicate that the tSZ-CMB lensing cross-correlation is a unique probe of the physics of intracluster gas in high-redshift, low-mass groups and clusters. Our results are consistent with extrapolations of existing gas physics models to this previously unexplored regime and show clear evidence for contributions from both the one- and two-halo terms, but no statistically significant evidence for contributions from diffuse, unbound gas outside of collapsed halos. We also show that the amplitude of the signal depends rather sensitively on the amplitude of fluctuations (?8) and the matter density (?m), scaling as ?86.1?m1.5 at l = 1000. We constrain the degenerate combination ?8(?m/0.282)0.26 = 0.824±0.029, a result that is in less tension with primordial CMB constraints than some recent tSZ analyses. We also combine our measurement with the Planck measurement of the tSZ auto-power spectrum to demonstrate a technique that can in principle constrain both cosmology and the physics of intracluster gas simultaneously. Our detection is a direct confirmation that hot, ionized gas traces the dark matter distribution over a wide range of scales in the universe ( ~ 0.1–50 Mpc/h).

Hill, J. Colin; Spergel, David N.

2014-02-01

97

Planck pre-launch status: The Planck mission  

Microsoft Academic Search

The European Space Agency's Planck satellite, launched on 14 May 2009, is the third-generation space experiment in the field of cosmic microwave background (CMB) research. It will image the anisotropies of the CMB over the whole sky, with unprecedented sensitivity ({{Delta T}over T} 2 × 10-6) and angular resolution ( 5 arcmin). Planck will provide a major source of information

J. A. Tauber; N. Mandolesi; J.-L. Puget; T. Banos; M. Bersanelli; F. R. Bouchet; R. C. Butler; J. Charra; G. Crone; J. Dodsworth; G. Efstathiou; R. Gispert; G. Guyot; A. Gregorio; J. J. Juillet; J.-M. Lamarre; R. J. Laureijs; C. R. Lawrence; H. U. Nørgaard-Nielsen; T. Passvogel; J. M. Reix; D. Texier; L. Vibert; A. Zacchei; P. A. R. Ade; N. Aghanim; B. Aja; E. Alippi; L. Aloy; P. Armand; M. Arnaud; A. Arondel; A. Arreola-Villanueva; E. Artal; E. Artina; A. Arts; M. Ashdown; J. Aumont; M. Azzaro; A. Bacchetta; C. Baccigalupi; M. Baker; M. Balasini; A. Balbi; A. J. Banday; G. Barbier; R. B. Barreiro; M. Bartelmann; P. Battaglia; E. Battaner; K. Benabed; J.-L. Beney; R. Beneyton; K. Bennett; A. Benoit; J.-P. Bernard; P. Bhandari; R. Bhatia; M. Biggi; R. Biggins; G. Billig; Y. Blanc; H. Blavot; J. J. Bock; A. Bonaldi; R. Bond; J. Bonis; J. Borders; J. Borrill; L. Boschini; F. Boulanger; J. Bouvier; M. Bouzit; R. Bowman; E. Bréelle; T. Bradshaw; M. Braghin; M. Bremer; D. Brienza; D. Broszkiewicz; C. Burigana; M. Burkhalter; P. Cabella; T. Cafferty; M. Cairola; S. Caminade; P. Camus; C. M. Cantalupo; B. Cappellini; J.-F. Cardoso; R. Carr; A. Catalano; L. Cayón; M. Cesa; M. Chaigneau; A. Challinor; A. Chamballu; J. P. Chambelland; M. Charra; L.-Y. Chiang; G. Chlewicki; P. R. Christensen; S. Church; E. Ciancietta; M. Cibrario; R. Cizeron; D. Clements; B. Collaudin; J.-M. Colley; S. Colombi; A. Colombo; F. Colombo; O. Corre; F. Couchot; B. Cougrand; A. Coulais; P. Couzin; B. Crane; B. Crill; M. Crook; D. Crumb; F. Cuttaia; U. Dörl; P. da Silva; R. Daddato; C. Damasio; L. Danese; G. D'Aquino; O. D'Arcangelo; K. Dassas; R. D. Davies; W. Davies; R. J. Davis; P. de Bernardis; D. de Chambure; G. de Gasperis; M. L. de La Fuente; P. de Paco; A. de Rosa; G. de Troia; G. de Zotti; M. Dehamme; J. Delabrouille; J.-M. Delouis; F.-X. Désert; G. di Girolamo; C. Dickinson; E. Doelling; K. Dolag; I. Domken; M. Douspis; D. Doyle; S. Du; D. Dubruel; C. Dufour; C. Dumesnil; X. Dupac; P. Duret; C. Eder; A. Elfving; T. A. Enßlin; K. English; H. K. Eriksen; P. Estaria; M. C. Falvella; F. Ferrari; F. Finelli; A. Fishman; S. Fogliani; S. Foley; A. Fonseca; G. Forma; O. Forni; P. Fosalba; J.-J. Fourmond; M. Frailis; C. Franceschet; E. Franceschi; S. François; M. Frerking; M. F. Gómez-Reñasco; K. M. Górski; T. C. Gaier; S. Galeotta; K. Ganga; J. García Lázaro; A. Garnica; M. Gaspard; E. Gavila; M. Giard; G. Giardino; G. Gienger; Y. Giraud-Heraud; J.-M. Glorian; M. Griffin; A. Gruppuso; L. Guglielmi; D. Guichon; B. Guillaume; P. Guillouet; J. Haissinski; F. K. Hansen; J. Hardy; D. Harrison; A. Hazell; M. Hechler; V. Heckenauer; D. Heinzer; R. Hell; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; J. M. Herreros; V. Hervier; A. Heske; A. Heurtel; S. R. Hildebrandt; R. Hills; E. Hivon; M. Hobson; D. Hollert; W. Holmes; A. Hornstrup; W. Hovest; R. J. Hoyland; G. Huey; K. M. Huffenberger; N. Hughes; U. Israelsson; B. Jackson; A. Jaffe; T. R. Jaffe; T. Jagemann; N. C. Jessen; J. Jewell; W. Jones; M. Juvela; J. Kaplan; P. Karlman; F. Keck; E. Keihänen; M. King; T. S. Kisner; P. Kletzkine; R. Kneissl; J. Knoche; L. Knox; T. Koch; M. Krassenburg; H. Kurki-Suonio; A. Lähteenmäki; G. Lagache; E. Lagorio; P. Lami; J. Lande; A. Lange; F. Langlet; R. Lapini; M. Lapolla; A. Lasenby; M. Le Jeune; J. P. Leahy; M. Lefebvre; F. Legrand; G. Le Meur; R. Leonardi; B. Leriche; C. Leroy; P. Leutenegger; S. M. Levin; P. B. Lilje; C. Lindensmith; M. Linden-Vørnle; A. Loc; Y. Longval; P. M. Lubin; T. Luchik; I. Luthold; J. F. Macias-Perez; T. Maciaszek; C. MacTavish; S. Madden; B. Maffei; C. Magneville; D. Maino; A. Mambretti; B. Mansoux; D. Marchioro; M. Maris; F. Marliani; J.-C. Marrucho; J. Martí-Canales; E. Martínez-González; A. Martín-Polegre; P. Martin; C. Marty; W. Marty; S. Masi; M. Massardi; S. Matarrese; F. Matthai; P. Mazzotta; A. McDonald; P. McGrath; A. Mediavilla; P. R. Meinhold; J.-B. Mélin; F. Melot; L. Mendes; A. Mennella; C. Mervier; L. Meslier; M. Miccolis; M.-A. Miville-Deschenes; A. Moneti; D. Montet; L. Montier; J. Mora; G. Morgante; G. Morigi; G. Morinaud; N. Morisset; D. Mortlock; S. Mottet; J. Mulder; D. Munshi; A. Murphy; P. Murphy; P. Musi; J. Narbonne; P. Naselsky; A. Nash; F. Nati; P. Natoli; B. Netterfield; J. Newell; M. Nexon; C. Nicolas; P. H. Nielsen; N. Ninane; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; P. Oldeman; P. Olivier; L. Ouchet; C. A. Oxborrow; L. Pérez-Cuevas; L. Pagan; C. Paine; F. Pajot; R. Paladini; F. Pancher; J. Panh; G. Parks; P. Parnaudeau; B. Partridge; B. Parvin; J. P. Pascual; F. Pasian; D. P. Pearson; T. Pearson; M. Pecora; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; E. Pierpaoli; O. Piersanti; E. Plaige; S. Plaszczynski; P. Platania; E. Pointecouteau; G. Polenta; N. Ponthieu; L. Popa; G. Poulleau; T. Poutanen

2010-01-01

98

Relativistic Fluid Dynamics: Physics for Many Different Scales  

Microsoft Academic Search

The relativistic fluid is a highly successful model used to describe the\\u000adynamics of many-particle, relativistic systems. It takes as input basic\\u000aphysics from microscopic scales and yields as output predictions of bulk,\\u000amacroscopic motion. By inverting the process, an understanding of bulk features\\u000acan lead to insight into physics on the microscopic scale. Relativistic fluids\\u000ahave been used to

N. Andersson; G. L. Comer

2006-01-01

99

Reconstruction of space weather physical parameters on 400-year scale  

Microsoft Academic Search

The main goal of this paper is to get physically informative comprehensive data about dynamics of the solar magnetic field,\\u000a geomagnetic field, and interplanetary magnetic field over large time scales. The total sunspot magnetic flux, aa and IDV indices of geomagnetic activity, the IMF strength, the dipole-octopole index of the large-scale magnetic field of\\u000a the Sun, and the open magnetic

Yu. A. Nagovitsyn; E. V. Miletsky; V. G. Ivanov; S. A. Guseva

2008-01-01

100

Physical controls of soil moisture variability at multiple scales  

NASA Astrophysics Data System (ADS)

Understanding what factors drive soil hydrological processes at different scales and their variability is very critical to further our ability to model the various components of the hydrologic cycle more accurately. Soil moisture, and, by association, soil hydraulic parameters have been known to be a function of location, and the support scale at which they are measured. Recent increase in remote sensing platforms necessitates increased calibration/validation efforts of their soil moisture products with ground-based measurements. Such cal/val operations require some form of up- or down-scaling process. Understanding the factors that drive soil hydrological processes at different scales, and their variability, is very critical to minimize errors due to this step in the cal/val procedure. Existing literature provides a description of the different sources of soil moisture variability across a range of resolutions from point to continental scales, classified under four categories: soil texture and structure, topography, vegetation, and meteorological forcings. While it is accepted that a dynamic relationship exists between these physical controls and the soil hydraulic properties across spatial scales, the nature of the relationship is not very well understood. In order to formulate better scaling algorithms, it is first necessary to determine the form and amount of influence exerted by the controlling factors on the variability of the soil moisture or hydraulic parameters at each scale of interest. One method to understand the effect of the physical controls is to analyze the covariance or coherence of the physical controls with the soil hydraulic properties across multiple scales and different hydro-climates. Such a study, using wavelet analysis, is presented here. A variety of datasets from multiple platforms across the globe were employed in this study. The AMSR-E soil moisture product was used as the remotely sensed, coarse resolution dataset. Fine resolution, ground-based soil moisture data at the study sites were obtained from the International Soil Moisture Network (ISMN) database. Elevation and slope were derived from SRTM Digital Elevation Data. Soil physical properties such as sand, silt, and clay contents, and precipitation information were obtained from the respective ancillary data from the ISMN database. Vegetation information was derived from the LAI product of the MODIS platform. Similarities in behavior of soil moisture dynamics across hydroclimates at corresponding scales were observed. It was also observed that the influence of the physical controls depended not only on the spatial scale of observation but also on the degree of saturation of the soil. We present these and other inferences drawn from the study.

Jana, R. B.; Mohanty, B.

2013-12-01

101

Unveiling the most massive Planck clusters at z>0.5 (XMM LP re-observations).  

NASA Astrophysics Data System (ADS)

We have been awarded a Large Program in AO11 to gather spatially resolved X ray spectroscopy on a sample of 32 massive (M_500 > 5e+14Msun) clusters detected blindly by Planck in the redshift range 0.5scalings between YSZ, YX and M500, and the pressure and entropy profiles. This will provide an important probe of the physics of cluster gravitational collapse and be of large legacy value for the cosmological exploitation of the Planck sample. We propose to re-observe 8 targets, the observations of which are dramatically affected by flares.

Arnaud, Monique

2012-10-01

102

Physical Foundation of a Unified Statistical Theory of Fields and the Scale-Invariant Schrödinger Equation  

Microsoft Academic Search

An invariant statistical theory of fields from cosmic to tachyonic scales is presented. The invariant wavefunction is defined as the first perturbation of action S_beta = rho_betaPhi_beta, the product of density and velocity potential. The invariant Schrödinger equation is derived, and invariant forms of Planck constant, de Broglie matter wave hypothesis, and Heisenberg uncertainty relation are presented. The field of

S. H. Sohrab

1998-01-01

103

2D VARIABLY SATURATED FLOWS: PHYSICAL SCALING AND BAYESIAN ESTIMATION  

EPA Science Inventory

A novel dimensionless formulation for water flow in two-dimensional variably saturated media is presented. It shows that scaling physical systems requires conservation of the ratio between capillary forces and gravity forces. A direct result of this finding is that for two phys...

104

Nonequilibrium Physics at Short Time Scales: Formation of Correlations  

Microsoft Academic Search

It is a happy situation when similar concepts and theoretical techniques can be applied to widely different physical systems because of a deep similarity in the situations being studied. The book illustrates this well; it focuses on the description of correlations in quantum systems out of equilibrium at very short time scales, prompted by experiments with short laser pulses in

L Peliti

2005-01-01

105

Does Planck really rule out monomial inflation?  

NASA Astrophysics Data System (ADS)

We consider the modifications of monomial chaotic inflation models due to radiative corrections induced by inflaton couplings to bosons and/or fermions necessary for reheating. To the lowest order, ignoring gravitational corrections and treating the inflaton as a classical background field, they are of the Coleman-Weinberg type and parametrized by the renormalization scale ?. In cosmology, there are not enough measurements to fix ? so that we end up with a family of models, each having a slightly different slope of the potential. We demonstrate by explicit calculation that within the family of chaotic phi2 models, some may be ruled out by Planck whereas some remain perfectly viable. In contrast, radiative corrections do not seem to help chaotic phi4 models to meet the Planck constraints.

Enqvist, Kari; Kar?iauskas, Mindaugas

2014-02-01

106

Physical naturalness and dynamical breaking of classical scale invariance  

NASA Astrophysics Data System (ADS)

We propose a model of a confining dark sector, dark technicolor, that communicates with the Standard Model (SM) through the Higgs portal. In this model electroweak (EW) symmetry breaking and dark matter (DM) share a common origin, and the EW scale is generated dynamically. Our motivation to suggest this model is the absence of evidence for new physics from recent Large Hadron Collider (LHC) data. Although the conclusion is far from certain at this point, this lack of evidence may suggest that no mechanism exists at the EW scale to stabilize the Higgs mass against radiative corrections from ultraviolet (UV) physics. The usual reaction to this puzzling situation is to conclude that the stabilizing new physics is either hidden from us by accident, or that it appears at energies that are currently inaccessible, such that nature is indeed fine-tuned. In order to re-examine the arguments that have led to this dichotomy, we review the concept of naturalness in effective field theories, discussing in particular the role of quadratic divergences in relation to different energy scales. This leads us to suggest classical scale invariance as a guideline for model building, implying that explicit mass scales are absent in the underlying theory.

Heikinheimo, Matti; Racioppi, Antonio; Spethmann, Christian; Raidal, Martti; Tuominen, Kimmo

2014-05-01

107

Physical scales in the Wigner-Boltzmann equation  

PubMed Central

The Wigner–Boltzmann equation provides the Wigner single particle theory with interactions with bosonic degrees of freedom associated with harmonic oscillators, such as phonons in solids. Quantum evolution is an interplay of two transport modes, corresponding to the common coherent particle-potential processes, or to the decoherence causing scattering due to the oscillators. Which evolution mode will dominate depends on the scales of the involved physical quantities. A dimensionless formulation of the Wigner–Boltzmann equation is obtained, where these scales appear as dimensionless strength parameters. A notion called scaling theorem is derived, linking the strength parameters to the coupling with the oscillators. It is shown that an increase of this coupling is equivalent to a reduction of both the strength of the electric potential, and the coherence length. Secondly, the existence of classes of physically different, but mathematically equivalent setups of the Wigner–Boltzmann evolution is demonstrated.

Nedjalkov, M.; Selberherr, S.; Ferry, D.K.; Vasileska, D.; Dollfus, P.; Querlioz, D.; Dimov, I.; Schwaha, P.

2013-01-01

108

Determining Planck's Constant with LEDs  

NSDL National Science Digital Library

This resource, created by Dean Zollman of Kansas State University, discusses plank's constant and how it can be determined with the use of a light emitting diode (LED). Additionally, it discusses the Planck relation, Planck's constant and threshold voltage, accepted values and provides a complete analysis of these methods. Each section includes a detailed description and contains the mathematical equations to better explain the theories. This resource is a part of the "Visual Quantum Mechanics Project."

Zollman, Dean

2009-03-26

109

Physical scales in the Wigner-Boltzmann equation  

SciTech Connect

The Wigner-Boltzmann equation provides the Wigner single particle theory with interactions with bosonic degrees of freedom associated with harmonic oscillators, such as phonons in solids. Quantum evolution is an interplay of two transport modes, corresponding to the common coherent particle-potential processes, or to the decoherence causing scattering due to the oscillators. Which evolution mode will dominate depends on the scales of the involved physical quantities. A dimensionless formulation of the Wigner-Boltzmann equation is obtained, where these scales appear as dimensionless strength parameters. A notion called scaling theorem is derived, linking the strength parameters to the coupling with the oscillators. It is shown that an increase of this coupling is equivalent to a reduction of both the strength of the electric potential, and the coherence length. Secondly, the existence of classes of physically different, but mathematically equivalent setups of the Wigner-Boltzmann evolution is demonstrated. - Highlights: Black-Right-Pointing-Pointer Dimensionless parameters determine the ratio of quantum or classical WB evolution. Black-Right-Pointing-Pointer The scaling theorem evaluates the decoherence effect due to scattering. Black-Right-Pointing-Pointer Evolution processes are grouped into classes of equivalence.

Nedjalkov, M., E-mail: mixi@iue.tuwien.ac.at [Institute for Microelectronics, Vienna University of Technology, Vienna (Austria); Selberherr, S. [Institute for Microelectronics, Vienna University of Technology, Vienna (Austria)] [Institute for Microelectronics, Vienna University of Technology, Vienna (Austria); Ferry, D.K.; Vasileska, D. [Department of Electrical Engineering, Arizona State University, Tempe, AZ (United States)] [Department of Electrical Engineering, Arizona State University, Tempe, AZ (United States); Dollfus, P.; Querlioz, D. [Institute of Fundamental Electronics, CNRS, University of Paris-sud, Orsay (France)] [Institute of Fundamental Electronics, CNRS, University of Paris-sud, Orsay (France); Dimov, I. [Institute for IC Technology, Bulgarian Academy of Sciences, Sofia (Bulgaria)] [Institute for IC Technology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Schwaha, P. [Shenteq s.r.o., Bratislava (Slovakia)] [Shenteq s.r.o., Bratislava (Slovakia)

2013-01-15

110

Effective cosmological constant from TeV-scale physics  

SciTech Connect

It has been suggested previously that the observed cosmological constant {Lambda} corresponds to the remnant vacuum energy density of dynamical processes taking place at a cosmic age set by the mass scale M{approx}E{sub ew} of ultramassive particles with electroweak interactions. Here, a simple modification of the nondissipative dynamic equations of q-theory is presented, which produces a remnant vacuum energy density (effective cosmological constant) of the correct order of magnitude. Combined with the observed value of {Lambda}, a first estimate of the required value of the energy scale E{sub ew} ranges from 3 to 9 TeV, depending on the number of species of ultramassive particles and assuming a dissipative coupling constant of order unity. If correct, this estimate implies the existence of new TeV-scale physics beyond the standard model.

Klinkhamer, F. R. [Institute for Theoretical Physics, University of Karlsruhe, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany)

2010-10-15

111

On the Einstein-Cartan cosmology vs. Planck data  

NASA Astrophysics Data System (ADS)

The first comprehensive analyses of Planck data reveal that the cosmological model with dark energy and cold dark matter can satisfactorily explain the essential physical features of the expanding Universe. However, the inability to simultaneously fit the large and small scale TT power spectrum, the scalar power index smaller than unity, and the observations of the violation of the isotropy found by few statistical indicators of the CMB urge theorists to search for explanations. We show that the model of the Einstein-Cartan cosmology with clustered dark matter halos and their corresponding clustered angular momenta coupled to torsion can account for small-scale-large-scale discrepancy and larger peculiar velocities (bulk flows) for galaxy clusters. The nonvanishing total angular momentum (torsion) of the Universe enters as a negative effective density term in the Einstein-Cartan equations causing partial cancellation of the mass density. The integrated Sachs-Wolfe contribution of the Einstein-Cartan model is negative, and it can therefore provide partial cancellation of the large-scale power of the TT CMB spectrum. The observed violation of the isotropy appears as a natural ingredient of the Einstein-Cartan model caused by the spin densities of light Majorana neutrinos in the early stage of the evolution of the Universe and bound to the lepton CP violation and matter-antimatter asymmetry.

Palle, D.

2014-04-01

112

Poisson-Boltzmann-Nernst-Planck model  

SciTech Connect

The Poisson-Nernst-Planck (PNP) model is based on a mean-field approximation of ion interactions and continuum descriptions of concentration and electrostatic potential. It provides qualitative explanation and increasingly quantitative predictions of experimental measurements for the ion transport problems in many areas such as semiconductor devices, nanofluidic systems, and biological systems, despite many limitations. While the PNP model gives a good prediction of the ion transport phenomenon for chemical, physical, and biological systems, the number of equations to be solved and the number of diffusion coefficient profiles to be determined for the calculation directly depend on the number of ion species in the system, since each ion species corresponds to one Nernst-Planck equation and one position-dependent diffusion coefficient profile. In a complex system with multiple ion species, the PNP can be computationally expensive and parameter demanding, as experimental measurements of diffusion coefficient profiles are generally quite limited for most confined regions such as ion channels, nanostructures and nanopores. We propose an alternative model to reduce number of Nernst-Planck equations to be solved in complex chemical and biological systems with multiple ion species by substituting Nernst-Planck equations with Boltzmann distributions of ion concentrations. As such, we solve the coupled Poisson-Boltzmann and Nernst-Planck (PBNP) equations, instead of the PNP equations. The proposed PBNP equations are derived from a total energy functional by using the variational principle. We design a number of computational techniques, including the Dirichlet to Neumann mapping, the matched interface and boundary, and relaxation based iterative procedure, to ensure efficient solution of the proposed PBNP equations. Two protein molecules, cytochrome c551 and Gramicidin A, are employed to validate the proposed model under a wide range of bulk ion concentrations and external voltages. Extensive numerical experiments show that there is an excellent consistency between the results predicted from the present PBNP model and those obtained from the PNP model in terms of the electrostatic potentials, ion concentration profiles, and current-voltage (I-V) curves. The present PBNP model is further validated by a comparison with experimental measurements of I-V curves under various ion bulk concentrations. Numerical experiments indicate that the proposed PBNP model is more efficient than the original PNP model in terms of simulation time.

Zheng Qiong [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Wei Guowei [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)

2011-05-21

113

Poisson-Boltzmann-Nernst-Planck model.  

PubMed

The Poisson-Nernst-Planck (PNP) model is based on a mean-field approximation of ion interactions and continuum descriptions of concentration and electrostatic potential. It provides qualitative explanation and increasingly quantitative predictions of experimental measurements for the ion transport problems in many areas such as semiconductor devices, nanofluidic systems, and biological systems, despite many limitations. While the PNP model gives a good prediction of the ion transport phenomenon for chemical, physical, and biological systems, the number of equations to be solved and the number of diffusion coefficient profiles to be determined for the calculation directly depend on the number of ion species in the system, since each ion species corresponds to one Nernst-Planck equation and one position-dependent diffusion coefficient profile. In a complex system with multiple ion species, the PNP can be computationally expensive and parameter demanding, as experimental measurements of diffusion coefficient profiles are generally quite limited for most confined regions such as ion channels, nanostructures and nanopores. We propose an alternative model to reduce number of Nernst-Planck equations to be solved in complex chemical and biological systems with multiple ion species by substituting Nernst-Planck equations with Boltzmann distributions of ion concentrations. As such, we solve the coupled Poisson-Boltzmann and Nernst-Planck (PBNP) equations, instead of the PNP equations. The proposed PBNP equations are derived from a total energy functional by using the variational principle. We design a number of computational techniques, including the Dirichlet to Neumann mapping, the matched interface and boundary, and relaxation based iterative procedure, to ensure efficient solution of the proposed PBNP equations. Two protein molecules, cytochrome c551 and Gramicidin A, are employed to validate the proposed model under a wide range of bulk ion concentrations and external voltages. Extensive numerical experiments show that there is an excellent consistency between the results predicted from the present PBNP model and those obtained from the PNP model in terms of the electrostatic potentials, ion concentration profiles, and current-voltage (I-V) curves. The present PBNP model is further validated by a comparison with experimental measurements of I-V curves under various ion bulk concentrations. Numerical experiments indicate that the proposed PBNP model is more efficient than the original PNP model in terms of simulation time. PMID:21599038

Zheng, Qiong; Wei, Guo-Wei

2011-05-21

114

Testing discrete symmetries with the cosmic microwave background: current constraints and Planck forecasts  

NASA Astrophysics Data System (ADS)

Anisotropy and polarization of the CMB are probing cosmological models with unprecedented precision. The WMAP satellite data are largely consistent with concordance ACDM cosmology. However, intriguing flukes are known to exist that may pinpoint at physics beyond the standard model. Constraining the violations of discrete symmetries in the CMB pattern is a promising mean to investigate these discrepancies. In this paper we constrain the Parity and Script CScript VScript T symmetries through CMB datasets. We describe the basic formalism, the relevant estimators and the overall analysis strategy. We provide marginal evidence for large scale Parity anomaly in the WMAP data that may be soon confirmed or discarded by the Planck satellite. Planck is currently measuring CMB anisotropies and their polarization with a level of precision that will remain unparalleled for many years to come. We also show how the CMB can be used to constrain fundamental symmetry violations in the photon sector through the so-called cosmological birefringence phenomenon. Finally, we provide forecasts for Planck and we discuss how emission from a specific diffuse foreground component arising within the Solar System needs to be kept under strict control to avoid incurring into false positive detections.

Mandolesi, N.; Burigana, C.; Gruppuso, A.; Natoli, P.

2011-12-01

115

Radial Fokker-Planck model for plasmas confined by magnetic mirror fields  

SciTech Connect

A time-dependent computer model has been developed for the spatially dependent distribution function f(r,v,t). An orbit averaged Fokker-Planck equation treats Coulomb collisions and various atomic physics processes. The motivation for the present code is to provide an accurate treatment of gyro-radius effects and realistic beam geometries which have been neglected in previous Fokker-Planck codes. Finite width beams may be offset from the plasma center to determine beam injection for build-up studies. The inclusion of a finite gyro-radius is essential for studying radial transport due to both quasilinear fluctuations and charge exchange collisions. Charge exchange with energetic beam atoms and plasma erosion due to charge-exchange collisions with thermal gas are both included. Quasilinear diffusion terms include the effects of turbulent diffusion in the model. The model has been used to study particle and energy confinement times in the 2XIIB experiment and in the mirror plug of the TMX experiment. Calculated values of T/sub e/ decrease from classical Fokker-Planck values (1000 eV for 2XIIB) to the 50 eV to 200 eV range observed in 2XIIB and TMX experiments. Radial density profiles and n tau scaling with plasma radius and magnetic field agree with experimental data.

Futch, A.H.

1986-05-01

116

Reconstruction of broad features in the primordial spectrum and inflaton potential from Planck  

NASA Astrophysics Data System (ADS)

With the recently published Cosmic Microwave Background data from Planck we address the optimized binning of the primordial power spectrum. As an important modification to the usual binning of the primordial spectrum, along with the spectral amplitude of the bins, we allow the position of the bins also to vary. This technique enables us to address the location of the possible broad physical features in the primordial spectrum with relatively smaller number of bins compared to the analysis performed earlier. This approach is in fact a reconstruction method looking for broad features in the primordial spectrum and avoiding fitting noise in the data. Performing Markov Chain Monte Carlo analysis we present samples of the allowed primordial spectra with broad features consistent with Planck data. To test how realistic it is to have step-like features in primordial spectrum we revisit an inflationary model, proposed by A. A. Starobinsky which can address the similar features obtained from the binning of the spectrum. Using the publicly available code BINGO, we numerically calculate the local fNL for this model in equilateral and arbitrary triangular configurations of wavevectors and show that the obtained non-Gaussianity for this model is consistent with Planck results. In this paper we have also considered different spectral tilts at different bins to identify the cosmological scale that the spectral index needs to have a red tilt and it is interesting to report that spectral index cannot be well constrained up to k ? 0.01Mpc-1.

Hazra, Dhiraj Kumar; Shafieloo, Arman; Smoot, George F.

2013-12-01

117

Planck Visualization Project: Seeing and Hearing the Cosmic Microwave Background  

NASA Astrophysics Data System (ADS)

The Planck Mission, launched May 14, 2009, will measure the sky over nine frequency channels, with temperature sensitivity of a few microKelvin, and angular resolution of up to 5 arc minutes. Planck is expected to provide the data needed to set tight constraints on cosmological parameters, study the ionization history of the Universe, probe the dynamics of the inflationary era, and test fundamental physics. The Planck Education and Public Outreach collaborators at NASA's Jet Propulsion Laboratory, the University of California, Santa Barbara and Purdue University are preparing a variety of materials to present the science goals of the Planck Mission to the public. Two products currently under development are an interactive simulation of the mission which can be run in a virtual reality environment, and an interactive presentation on interpreting the power spectrum of the Cosmic Microwave Background with music. In this paper we present a brief overview of CMB research and the Planck Mission, and discuss how to explain, to non-technical audiences, the theory of how we derive information about the early universe from the power spectrum of the CMB by using the physics of music.

van der Veen, J.

2010-08-01

118

Planck's orders of magnitude and the limits of the quantum gravity conception  

NASA Astrophysics Data System (ADS)

In this paper it is shown how the universal constants h, c and G prevent one from deriving measurable quantum GRT effects for energies near the Planck energy. Planck's units thus screen those GRT regions where difficulties for the quantization procedure occur, from a physically sensible quantum-field (or graviton) interpretation.

Vonborzeszkowski, H. H.

1988-02-01

119

Stable mass hierarchies and dark matter from hidden sectors in the scale-invariant standard model  

NASA Astrophysics Data System (ADS)

Scale invariance may be a classical symmetry which is broken radiatively. This provides a simple way to stabilize the scale of electroweak symmetry breaking against radiative corrections. But for such a theory to be fully realistic, it must actually incorporate a hierarchy of scales, including the Planck and the neutrino mass scales in addition to the electroweak scale. The dark matter sector and the physics responsible for baryogenesis may or may not require new scales, depending on the scenario. We develop a generic way of using hidden sectors to construct a technically-natural hierarchy of scales in the framework of classically scale-invariant theories. We then apply the method to generate the Planck mass and to solve the neutrino mass and dark matter problems through what may be termed the “scale-invariant standard model.” The model is perturbatively renormalizable for energy scales up to the Planck mass.

Foot, Robert; Kobakhidze, Archil; Volkas, Raymond R.

2010-08-01

120

Galactic cold cores. II. Herschel study of the extended dust emission around the first Planck detections  

NASA Astrophysics Data System (ADS)

Context. Within the project Galacticcoldcores we are carrying out Herschel photometric observations of cold interstellar clouds detected with the Planck satellite. The three fields observed as part of the Herschel science demonstration phase (SDP) provided the first glimpse into the nature of these sources. The aim of the project is to derive the physical properties of the full cold core population revealed by Planck. Aims: We examine the properties of the dust emission within the three fields observed during the SDP. We determine the dust sub-millimetre opacity, look for signs of spatial variations in the dust spectral index, and estimate how the apparent variations of the parameters could be affected by different sources of uncertainty. Methods: We use the Herschel observations where the zero point of the surface brightness scale is set with the help of the Planck satellite data. We derive the colour temperature and column density maps of the regions and determine the dust opacity by a comparison with extinction measurements. By simultaneously fitting the colour temperature and the dust spectral index values we look for spatial variations in the apparent dust properties. With a simple radiative transfer model we estimate to what extent these can be explained by line-of-sight temperature variations, without changes in the dust grain properties. Results: The analysis of the dust emission reveals cold and dense clouds that coincide with the Planck sources and confirm those detections. The derived dust opacity varies in the range ?(250 ?m) ~ 0.05-0.2 cm2 g-1, higher values being observed preferentially in regions of high column density. The average dust spectral index ? is ~1.9-2.2. There are indications that ? increases towards the coldest regions. The spectral index decreases strongly near internal heating sources but, according to radiative transfer models, this can be explained by the line-of-sight temperature variations without a change in the dust properties. Planck (http://www.esa.int/Planck) is a project of the European Space Agency - ESA - with instruments provided by two scientific consortia funded by ESA member states (in particular the lead countries: France and Italy) with contributions from NASA (USA), and telescope reflectors provided in a collaboration between ESA and a scientific Consortium led and funded by Denmark.Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are only available in electronic form at http://www.aanda.org

Juvela, M.; Ristorcelli, I.; Pelkonen, V.-M.; Marshall, D. J.; Montier, L. A.; Bernard, J.-P.; Paladini, R.; Lunttila, T.; Abergel, A.; André, Ph.; Dickinson, C.; Dupac, X.; Malinen, J.; Martin, P.; McGehee, P.; Pagani, L.; Ysard, N.; Zavagno, A.

2011-03-01

121

String inflation after Planck 2013  

NASA Astrophysics Data System (ADS)

We briefly summarize the impact of the recent Planck measurements for string inflationary models, and outline what might be expected to be learned in the near future from the expected improvement in sensitivity to the primordial tensor-to-scalar ratio. We comment on whether these models provide sufficient added value to compensate for their complexity, and ask how they fare in the face of the new constraints on non-gaussianity and dark radiation. We argue that as a group the predictions made before Planck agree well with what has been seen, and draw conclusions from this about what is likely to mean as sensitivity to primordial gravitational waves improves.

Burgess, C. P.; Cicoli, M.; Quevedo, F.

2013-11-01

122

Planck early results. II. The thermal performance of Planck  

Microsoft Academic Search

The performance of the Planck instruments in space is enabled by their low operating temperatures, 20 K for LFI and 0.1 K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. The scientific requirement for very broad frequency coverage led to two detector technologies with widely different temperature and cooling needs. Active coolers could

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; M. Baker; A. Balbi; A. J. Banday; R. B. Barreiro; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; P. Bhandari; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borders; J. Borrill; B. Bowman; T. Bradshaw; E. Bréelle; M. Bucher; C. Burigana; R. C. Butler; P. Cabella; C. M. Cantalupo; B. Cappellini; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; J. P. Chambelland; J. Charra; M. Charra; L.-Y. Chiang; C. Chiang; P. R. Christensen; D. L. Clements; B. Collaudin; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; M. Crook; F. Cuttaia; C. Damasio; L. Danese; R. D. Davies; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; J. Delabrouille; J.-M. Delouis; F.-X. Désert; K. Dolag; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; H. K. Eriksen; C. Filliard; F. Finelli; S. Foley; O. Forni; P. Fosalba; J.-J. Fourmond; M. Frailis; E. Franceschi; S. Galeotta; K. Ganga; E. Gavila; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; G. Guyot; D. Harrison; G. Helou; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; A. Hornstrup; W. Hovest; R. J. Hoyland; K. M. Huffenberger; U. Israelsson; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; P. Lami; A. Lasenby; R. J. Laureijs; A. Lavabre; C. R. Lawrence; S. Leach; R. Lee; R. Leonardi; C. Leroy; P. B. Lilje; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; T. Maciaszek; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; P. McGehee; P. R. Meinhold; A. Melchiorri; F. Melot; L. Mendes; A. Mennella; M.-A. Miville-Deschênes; A. Moneti; L. Montier; J. Mora; G. Morgante; N. Morisset; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; A. Nash; P. Natoli; C. B. Netterfield; D. Novikov; I. Novikov; I. J. O'Dwyer; S. Osborne; F. Pajot; F. Pasian; G. Patanchon; D. Pearson; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; S. Plaszczynski; P. Platania; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; M. Prina; S. Prunet; J.-L. Puget; J. P. Rachen; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; G. Savini; B. M. Schaefer; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; P. Stassi; F. Stivoli; V. Stolyarov; R. Stompor; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; L. Valenziano; L. Vibert; P. Vielva; F. Villa; N. Vittorio; A. Wilkinson; B. D. Wandelt; C. Watson; S. D. M. White; P. Wilson; D. Yvon; A. Zacchei; B. Zhang; A. Zonca

2011-01-01

123

Planck Visualization Project: Seeing and Hearing the CMB  

NASA Astrophysics Data System (ADS)

The Planck Education and Public Outreach collaborators at the University of California, Santa Barbara and Purdue University have prepared a variety of materials to present the science goals of the Planck Mission to the public. Here we present our interactive simulation of the Cosmic Microwave Background, in which the user can change the ingredients of the universe and hear the different harmonics. We also present how we derive information about the early universe from the power spectrum of the CMB by using the physics of music for the public.

Van Der Veen, Jatila; Lubin, P. M.; 2; Alper, B.; 3; Smith, W.; 4; McGee, R.; 5; US Planck Collaboration

2011-01-01

124

Entropy production and nonlinear Fokker-Planck equations  

NASA Astrophysics Data System (ADS)

The entropy time rate of systems described by nonlinear Fokker-Planck equations—which are directly related to generalized entropic forms—is analyzed. Both entropy production, associated with irreversible processes, and entropy flux from the system to its surroundings are studied. Some examples of known generalized entropic forms are considered, and particularly, the flux and production of the Boltzmann-Gibbs entropy, obtained from the linear Fokker-Planck equation, are recovered as particular cases. Since nonlinear Fokker-Planck equations are appropriate for the dynamical behavior of several physical phenomena in nature, like many within the realm of complex systems, the present analysis should be applicable to irreversible processes in a large class of nonlinear systems, such as those described by Tsallis and Kaniadakis entropies.

Casas, G. A.; Nobre, F. D.; Curado, E. M. F.

2012-12-01

125

Development of scales to assess children's perceptions of friend and parental influences on physical activity  

Microsoft Academic Search

BACKGROUND: Many children do not meet physical activity guidelines. Parents and friends are likely to influence children's physical activity but there is a shortage of measures that are able to capture these influences. METHODS: A new questionnaire with the following three scales was developed: 1) Parental influence on physical activity; 2) Motives for activity with friends scale; and 3) Physical

Russell Jago; Kenneth R Fox; Angie S Page; Rowan Brockman; Janice L Thompson

2009-01-01

126

Orthogonal non-Gaussianity in DBI galileon: prospect for Planck polarization and post-Planck experiments  

NASA Astrophysics Data System (ADS)

In this paper, we study cosmic microwave background (CMB) constraints on primordial non-Gaussianity in Dirac-Born-Infeld (DBI) galileon models in which an induced gravity term is added to the DBI action. In this model, the non-Gaussianity of orthogonal shape can be generated. We provide a relation between theoretical parameters and orthogonal/equilateral nonlinear parameters using the Fisher matrix approach for the CMB bispectrum. In doing so, we include the effect of the CMB transfer functions and experimental noise properties by employing the recently developed second order non-Gaussianity code. The relation is also shown in the language of effective theory so that it can be applied to general single-field models. Using the bispectrum Fisher matrix and the central values for equilateral and orthogonal non-Gaussianities found by the Planck temperature survey, we provide forecasts on the theoretical parameters of the DBI galileon model. We consider the upcoming Planck polarization data and the proposed post-Planck experiments Cosmic Origins Explore (COrE) and Polarized Radiation Imaging and Spectroscopy Mission (PRISM). We find that Planck polarization measurements may provide a hint for a non-canonical sound speed at the 68% confidence level. COrE and PRISM will not only confirm a non-canonical sound speed but also exclude the conventional DBI inflation model at more than the 95% and 99% confidence level respectively, assuming that the central values will not change. This indicates that improving constraints on non-Gaussianity further by future CMB experiments is invaluable to constrain the physics of the early universe.

Koyama, Kazuya; Pettinari, Guido Walter; Mizuno, Shuntaro; Fidler, Christian

2014-06-01

127

New porous medium Poisson-Nernst-Planck equations for strongly oscillating electric potentials  

NASA Astrophysics Data System (ADS)

We consider the Poisson-Nernst-Planck system which is well-accepted for describing dilute electrolytes as well as transport of charged species in homogeneous environments. Here, we study these equations in porous media whose electric permittivities show a strong contrast compared with the electric permittivity of the electrolyte phase. Our main result is the derivation of convenient low-dimensional equations, that is, of effective macroscopic porous media Poisson-Nernst-Planck equations, which reliably describe ionic transport. The contrast in the electric permittivities between liquid and solid phase and the heterogeneity of the porous medium induce strongly oscillating electric potentials (fields). In order to account for this specific physical scenario, we introduce a modified asymptotic multiple-scale expansion which takes advantage of the nonlinearly coupled structure of the ionic transport equations. This allows for a systematic upscaling resulting in a new effective porous medium formulation which shows a new transport term on the macroscale. Solvability of all arising equations is rigorously verified. The emergence of a new transport term indicates promising physical insights into the influence of the microscale material properties on the macroscale. Hence, systematic upscaling strategies provide a source and a prospective tool to capitalize intrinsic scale effects for scientific, engineering, and industrial applications.

Schmuck, M.

2013-02-01

128

Astrophysical Data Transmission in Planck Units  

NASA Astrophysics Data System (ADS)

``Data Communication and Net Working'' by Forouzan expresses (an informatics equivalent of statistics) that N (data rate or bits/second) divided by r (number of data elements per signal or log2L) is the baud rate. For N = 10^43 Planck times per second, and L = 10^90, the number of photons in the universe, the baud rate is more than 10^40, so high a signal rate for the carriers of the attractive and repulsive pulses that we, the observers, would think that gravity is continuous, and not probabilistic. Any potential slight correction to the above as it may apply to the case, or its application to smaller baryon number (10^79) would not change the above implicit message, considering the order of magnitudes involved. This communicative aspect of gravity, and our postulation, slight modification to the inverse square law, in [1] that the probability of an interaction between two particles is inversely proportional to the square of their separations in integer number of Planck lengths, are mutually supplementary and complimentary, portraying two ducks that, not only walk like ducks, but also talk like ducks. Therefore, they are ducks. Refer to: [1] Goradia, Shantilal http://www.arXiv.org/pdf/physics/0210040v4.

Goradia, Shantilal

2008-10-01

129

Effects of supersymmetric grand unification scale physics on {Gamma}({ital b}{r_arrow}{ital s}{gamma})  

SciTech Connect

Although calculations of the {ital b}{r_arrow}{ital s}{gamma} rate in supersymmetric grand unified models have always either ignored the gluino-mediated contribution or found it to be negligible, we show that taking universal supersymmetry-breaking masses at the Planck scale, rather than at the gauge unification scale, as is customary, leads to the gluino contribution being more significant and in fact sometimes even larger than the chargino-mediated contributions when {mu}{gt}0 and tan{beta} is of order 1. The impact is felt greatest when the gluinos are relatively light. Taking the universal boundary condition at the Planck scale also has an effect on the chargino contribution by increasing the effect of the {ital W}-ino and Higgsino--{ital W}-ino mediated decays. The neutralino-mediated contribution is found to be enhanced, but nevertheless it remains relatively insignificant.

Dutta, B. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)] [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States); Keith, E. [Department of Physics, University of California, Riverside, California 92521 (United States)] [Department of Physics, University of California, Riverside, California 92521 (United States)

1995-12-01

130

Inflationary steps in the Planck data  

NASA Astrophysics Data System (ADS)

We extend and improve the modeling and analysis of large-amplitude, sharp inflationary steps for second order corrections required by the precision of the Planck cosmic microwave background power spectrum and for arbitrary Dirac-Born-Infeld sound speed. With two parameters, the amplitude and frequency of the resulting oscillations, step models improve the fit by ??2=-11.4. Evidence for oscillations damping before the Planck beam scale is weak: damping only improves the fit to ??2=-14.0 for one extra parameter, if step and cosmological parameters are jointly fit, in contrast to analyses which fix the latter. Likewise, further including the sound speed as a parameter only marginally improves the fit to ??2=-15.2 but has interesting implications for the lowest multipole temperature and polarization anisotropy. Since chance features in the noise can mimic these oscillatory features, we discuss tests from polarization power spectra, lensing reconstruction and squeezed and equilateral bispectra that should soon verify or falsify their primordial origin.

Miranda, Vinícius; Hu, Wayne

2014-04-01

131

Evaluation of the MOS SF36 physical functioning scale (PF10): I. Unidimensionality and reproducibility of the Rasch item scale  

Microsoft Academic Search

Indexes developed to measure physical functioning as an essential component of general health status are often based on sets of hierarchically-structured items intended to represent a broad underlying concept. Rasch Item Response Theory (IRT) provides a methodology to examine the hierarchical structure, unidimensionality, and reproducibility of item positions (calibrations) along a scale. Data gathered on the 10-item Physical Functioning Scale

Stephen M. Haley; Colleen A. McHorney; Ware John E. Jr

1994-01-01

132

Are Correct the Planck's Units? Is the Fine-Structure Constant Really Dimensionless?  

NASA Astrophysics Data System (ADS)

The dimensional exhaustive elucidation of matter and the Unified Theory of the Physical and Mathematical Universal Constants allow to understand and to prove the basic mistakes of Planck's Units and dimensionality of the fine-structure constant.

Montero García, José De La Luz; Novoa Blanco, Jesús Francisco

2007-04-01

133

Inflationary paradigm after Planck 2013  

NASA Astrophysics Data System (ADS)

Models of cosmic inflation posit an early phase of accelerated expansion of the universe, driven by the dynamics of one or more scalar fields in curved spacetime. Though detailed assumptions about fields and couplings vary across models, inflation makes specific, quantitative predictions for several observable quantities, such as the flatness parameter (?k=1-?) and the spectral tilt of primordial curvature perturbations (ns-1=dln PR/dln k), among others-predictions that match the latest observations from the Planck satellite to very good precision. In the light of data from Planck as well as recent theoretical developments in the study of eternal inflation and the multiverse, we address recent criticisms of inflation by Ijjas, Steinhardt, and Loeb. We argue that their conclusions rest on several problematic assumptions, and we conclude that cosmic inflation is on a stronger footing than ever before.

Guth, Alan H.; Kaiser, David I.; Nomura, Yasunori

2014-06-01

134

Scale relativity and fractal space-time: Applications to quantum physics, cosmology and chaotic systems  

Microsoft Academic Search

The theory of scale relativity is a new approach to the problem of the origin of fundamental scales and of scaling laws in physics, that consists of generalizing Einstein's principle of relativity (up to now applied to motion laws) to scale transformations. Namely, we redefine space-time resolutions as characterizing the state of scale of the reference system and require that

L. Nottale

1996-01-01

135

Fully Kinetic Fokker-Planck Model of Thermal Smoothing in Nonuniform Laser-Target Interactions  

SciTech Connect

Using a fully kinetic 2D Fokker-Planck model, the generation and evolution of ion density perturbations from nonuniform laser deposition in a plasma slab have been studied. It is found that significant smoothing of the ion density perturbations from nonuniform optically smoothed single beam laser deposition can be achieved on hydrodynamic times scales over a range of scale sizes. In addition, it is observed that the Fokker-Planck model predicts more smoothing than the hydrodynamic Spitzer model.

Keskinen, M. J. [Charged Particle Physics Branch, Plasma Physics Division, Naval Research Laboratory, Washington, D.C. 20375 (United States)

2009-07-31

136

Fully kinetic Fokker-Planck model of thermal smoothing in nonuniform laser-target interactions.  

PubMed

Using a fully kinetic 2D Fokker-Planck model, the generation and evolution of ion density perturbations from nonuniform laser deposition in a plasma slab have been studied. It is found that significant smoothing of the ion density perturbations from nonuniform optically smoothed single beam laser deposition can be achieved on hydrodynamic times scales over a range of scale sizes. In addition, it is observed that the Fokker-Planck model predicts more smoothing than the hydrodynamic Spitzer model. PMID:19792507

Keskinen, M J

2009-07-31

137

Developing a Rasch Measurement Physical Fitness Scale for Hong Kong Primary School-Aged Students  

Microsoft Academic Search

The main purpose of this study was to develop a Rasch Measurement Physical Fitness Scale (RMPFS) based on physical fitness indicators routinely used in Hong Kong primary schools. A total of 9,439 records of students' performances on physical fitness indicators, retrieved from the database of a Hong Kong primary school, were used to develop the Rasch scale. Following a series

Zi Yan; Trevor G. Bond

2011-01-01

138

CONTENT AND CONSTRUCT VALIDITY OF THE EARLY CHILDHOOD PHYSICAL ENVIRONMENT RATING SCALE (ECPERS)1  

Microsoft Academic Search

The Early Childhood Physical Environment Rating Scale (ECPERS) has been designed to assess the quality of the physical environment of early childhood educational facilities. The purpose of the current research was to examine the content and construct validity of the scale. With regard to content validity, the vast majority of items (93%) in the scale were found to be important

Takemi Sugiyama; Gary T Moore

139

Planck pre-launch status: The Planck-LFI programme  

NASA Astrophysics Data System (ADS)

This paper provides an overview of the Low Frequency Instrument (LFI) programme within the ESA Planck mission. The LFI instrument has been developed to produce high precision maps of the microwave sky at frequencies in the range 27-77 GHz, below the peak of the cosmic microwave background (CMB) radiation spectrum. The scientific goals are described, ranging from fundamental cosmology to Galactic and extragalactic astrophysics. The instrument design and development are outlined, together with the model philosophy and testing strategy. The instrument is presented in the context of the Planck mission. The LFI approach to ground and inflight calibration is described. We also describe the LFI ground segment. We present the results of a number of tests demonstrating the capability of the LFI data processing centre (DPC) to properly reduce and analyse LFI flight data, from telemetry information to calibrated and cleaned time ordered data, sky maps at each frequency (in temperature and polarization), component emission maps (CMB and diffuse foregrounds), catalogs for various classes of sources (the Early Release Compact Source Catalogue and the Final Compact Source Catalogue). The organization of the LFI consortium is briefly presented as well as the role of the core team in data analysis and scientific exploitation. All tests carried out on the LFI flight model demonstrate the excellent performance of the instrument and its various subunits. The data analysis pipeline has been tested and its main steps verified. In the first three months after launch, the commissioning, calibration, performance, and verification phases will be completed, after which Planck will begin its operational life, in which LFI will have an integral part.

Mandolesi, N.; Bersanelli, M.; Butler, R. C.; Artal, E.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartelmann, M.; Bennett, K.; Bhandari, P.; Bonaldi, A.; Borrill, J.; Bremer, M.; Burigana, C.; Bowman, R. C.; Cabella, P.; Cantalupo, C.; Cappellini, B.; Courvoisier, T.; Crone, G.; Cuttaia, F.; Danese, L.; D'Arcangelo, O.; Davies, R. D.; Davis, R. J.; de Angelis, L.; de Gasperis, G.; de Rosa, A.; de Troia, G.; de Zotti, G.; Dick, J.; Dickinson, C.; Diego, J. M.; Donzelli, S.; Dörl, U.; Dupac, X.; Enßlin, T. A.; Eriksen, H. K.; Falvella, M. C.; Finelli, F.; Frailis, M.; Franceschi, E.; Gaier, T.; Galeotta, S.; Gasparo, F.; Giardino, G.; Gomez, F.; Gonzalez-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Hansen, F.; Hell, R.; Herranz, D.; Herreros, J. M.; Hildebrandt, S.; Hovest, W.; Hoyland, R.; Huffenberger, K.; Janssen, M.; Jaffe, T.; Keihänen, E.; Keskitalo, R.; Kisner, T.; Kurki-Suonio, H.; Lähteenmäki, A.; Lawrence, C. R.; Leach, S. M.; Leahy, J. P.; Leonardi, R.; Levin, S.; Lilje, P. B.; López-Caniego, M.; Lowe, S. R.; Lubin, P. M.; Maino, D.; Malaspina, M.; Maris, M.; Marti-Canales, J.; Martinez-Gonzalez, E.; Massardi, M.; Matarrese, S.; Matthai, F.; Meinhold, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Morgante, G.; Morigi, G.; Morisset, N.; Moss, A.; Nash, A.; Natoli, P.; Nesti, R.; Paine, C.; Partridge, B.; Pasian, F.; Passvogel, T.; Pearson, D.; Pérez-Cuevas, L.; Perrotta, F.; Polenta, G.; Popa, L. A.; Poutanen, T.; Prezeau, G.; Prina, M.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Ricciardi, S.; Riller, T.; Rocha, G.; Roddis, N.; Rohlfs, R.; Rubiño-Martin, J. A.; Salerno, E.; Sandri, M.; Scott, D.; Seiffert, M.; Silk, J.; Simonetto, A.; Smoot, G. F.; Sozzi, C.; Sternberg, J.; Stivoli, F.; Stringhetti, L.; Tauber, J.; Terenzi, L.; Tomasi, M.; Tuovinen, J.; Türler, M.; Valenziano, L.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.; White, M.; White, S.; Wilkinson, A.; Zacchei, A.; Zonca, A.

2010-09-01

140

Particle physics models at the electroweak scale and beyond  

NASA Astrophysics Data System (ADS)

We consider various particle physics models constructed to address issues in electroweak-scale supersymmetry, grand unification, and inflation. We begin by exploring the phenomenology of a supersymmetric SU(5) theory living in a truncated, warped 5-dimensional spacetime, with the gauge group broken down to the Standard Model at both ends. The low-energy spectrum of this setup is exotic, and in particular includes a particle of O (TeV) mass with the quantum numbers of an off diagonal SU(5) adjoint. Via the AdS/CFT correspondence, this is interpreted as a pseudo-Goldstone boson of a broken global symmetry within the strongly-coupled sector responsible for supersymmetry breaking. We consider the phenomenology of such a particle in some detail, including collider signals and cosmology. We proceed to consider a generic framework for ameliorating fine-tuning in the Minimal Supersymmetric Standard Model, utilizing new contributions to the Higgs boson mass. We demonstrate this idea with two explicit models. Returning to warped spacetime, we then demonstrate the feasibility of applying AdS/CFT ideas to the breaking of grand unified theories. In this context, the warped spacetime description is dual to a strong gauge sector which develops condensates and breaks the unified gauge group into which the Standard Model is embedded. Finally, we consider the generation of primordial density perturbations in the model of chain inflation, utilizing a combination of analytic and numerical techniques.

Tweedie, Brock Adam

141

Parametrized modified gravity constraints after Planck  

NASA Astrophysics Data System (ADS)

We constrain f(R) and chameleon-type modified gravity in the framework of the Berstchinger-Zukin parametrization using the recently released Planck data, including both the cosmic mircowave background radiation (CMB) temperature power spectrum and the lensing potential power spectrum. Some other external data sets are included, such as baryon acoustic oscillation (BAO) measurements from the 6dFGS, SDSS DR7 and BOSS DR9 surveys; Hubble Space Telescope (HST) H0 measurements, and supernovae from the Union2.1 compilation. We also use WMAP9 data for a consistency check and comparison. For f(R) gravity, WMAP9 results can only give a quite loose constraint on the modified gravity parameter B0, which is related to the present value of the Compton wavelength of the extra scalar degree of freedom, B0<3.37 at 95% C.L. We demonstrate that this constraint mainly comes from the late integrated Sachs-Wolfe effect. With only Planck CMB temperature power-spectrum data, we can improve the WMAP9 result by a factor 3.7 (B0<0.91 at 95% C.L.). If the Planck lensing potential power-spectrum data are also taken into account, the constraint can be further strengthened by a factor 5.1 (B0<0.18 at 95% C.L.). This major improvement mainly comes from the small-scale lensing signal. Furthermore, BAO, HST and supernovae data could slightly improve the B0 bound (B0<0.12 at 95% C.L.). For the chameleon-type model, we find that the data set that we used cannot constrain the Compton wavelength B0 or the potential index s of the chameleon field, but it can give a tight constraint on the parameter ?1=1.043-0.104+0.163 at 95% C.L. (?1=1 in general relativity), which accounts for the nonminimal coupling between the chameleon field and the matter component. In addition, we find that both modified gravity models we consider favor a relatively higher Hubble parameter than the concordance ?CDM model in general relativity.

Hu, Bin; Liguori, Michele; Bartolo, Nicola; Matarrese, Sabino

2013-12-01

142

Full-scale physical model of landslide triggering  

NASA Astrophysics Data System (ADS)

Landslide triggering induced by high-intensity rainfall infiltration in hillslopes is a complex phenomenon that involves hydrological processes operating at different spatio-temporal scales. Empirical methods give rough information about landslide-prone areas, without investigating the theoretical framework needed to achieve an in-depth understanding of the involved physical processes. In this study, we tackle this issue through physical experiments developed in an artificial hillslope realized in the Department of Civil, Environmental and Architectural Engineering of the University of Padua. The structure consists of a reinforced concrete box containing a soil prism with the following maximum dimensions: 3.5 m high, 6 m long, and 2 m wide. In order to analyze and examine the triggered failure state, the experiments are carried out with intensive monitoring of pore water pressure and moisture content response. Subsurface monitoring instruments are installed at several locations and depths to measure downward infiltration and/or a rising groundwater table. We measure the unsaturated soil water pressure as well as positive pore pressures preceding failure in each experiments with six tensiometers. The volumetric water content is determined through six Time Domain Reflectometry probes. Two pressure transducers are located in observation wells to determine the position of the water table in time. Two stream gauges are positioned at the toeslope, for measuring both runoff and subsurface outflow. All data are collected and recorded by an acquisition data system from Campbell Scientific. The artificial hillslope is characterized by well-known and controlled conditions, which are designed to reproduce an ideal set-up susceptible to heavy rainfall landslide. The hydrologic forcing is generated by a rainfall simulator realized with nozzles from Sprying System and. specifically designed to produce a spatially uniform rainfall of intensity ranging from 50 to 150 mm/h. The aim of our experiments is to reproduce the instability trigger that occurs in saturated or partially unsaturated conditions depending on the specific characteristics of the soil and its initial conditions; the retention curve of fine sand and the initial porosity are taken into account to highlight the hydrological condition of the surface layer during the trigger occurrence. Through our experimental setup we can investigate the succession of phases and their magnitude that cause the landslide trigger, in order to understand the instability mechanism that heavy rainfall can induce in fine sandy hillslopes. Particular attention is given on the role of water pressure head, not only with respect to the violation of Coulomb failure within a sloping soil, but also with respect to the subsequent deformation that involves the upper hillslope layers. In particular, we report here on the characterization of the sandy terrain used in the experiments and the preliminary results, together with a first discussion of the observed data.

Lora, M.; Camporese, M.; Salandin, P.

2013-12-01

143

Planck early results. XXII. The submillimetre properties of a sample of Galactic cold clumps  

Microsoft Academic Search

We perform a detailed investigation of sources from the Cold Cores Catalogue of Planck Objects (C3PO). Our goal is to probe the reliability of the detections, validate the separation between warm and cold dust emission components, provide the first glimpse at the nature, internal morphology and physical characterictics of the Planck-detected sources. We focus on a sub-sample of ten sources

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; F. Boulanger; M. Bucher; C. Burigana; P. Cabella; C. M. Cantalupo; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; L.-Y. Chiang; P. R. Christensen; D. L. Clements; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; L. Danese; R. D. Davies; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; C. Dickinson; Y. Doi; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; E. Falgarone; F. Finelli; O. Forni; M. Frailis; E. Franceschi; S. Galeotta; K. Ganga; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; F. K. Hansen; D. Harrison; G. Helou; S. Henrot-Versillé; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; N. Ikeda; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; Y. Kitamura; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; C. Leroy; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; J. Malinen; N. Mandolesi; R. Mann; M. Maris; D. J. Marshall; P. Martin; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; P. McGehee; A. Melchiorri; L. Mendes; A. Mennella; C. Meny; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; F. Nati; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; S. Osborne; L. Pagani; F. Piacentini; R. Paladini; F. Pasian; G. Patanchon; V.-M. Pelkonen; O. Perdereau; L. Perotto; F. Perrotta; M. Piat; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; S. Prunet; J.-L. Puget; W. T. Reach; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; G. Savini; D. Scott; M. D. Seiffert; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; V. Toth; M. Tristram; J. Tuovinen; G. Umana; L. Valenziano; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; N. Ysard; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

144

Planck early results. II. The thermal performance of Planck  

NASA Astrophysics Data System (ADS)

The performance of the Planck instruments in space is enabled by their low operating temperatures, 20 K for LFI and 0.1 K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. The scientific requirement for very broad frequency coverage led to two detector technologies with widely different temperature and cooling needs. Active coolers could satisfy these needs; a helium cryostat, as used by previous cryogenic space missions (IRAS, COBE, ISO, Spitzer, AKARI), could not. Radiative cooling is provided by three V-groove radiators and a large telescope baffle. The active coolers are a hydrogen sorption cooler (<20 K), a 4He Joule-Thomson cooler (4.7 K), and a 3He-4He dilution cooler (1.4 K and 0.1 K). The flight system was at ambient temperature at launch and cooled in space to operating conditions. The HFI bolometer plate reached 93 mK on 3 July 2009, 50 days after launch. The solar panel always faces the Sun, shadowing the rest of Planck, andoperates at a mean temperature of 384 K. At the other end of the spacecraft, the telescope baffle operates at 42.3 K and the telescope primary mirror operates at 35.9 K. The temperatures of key parts of the instruments are stabilized by both active and passive methods. Temperature fluctuations are driven by changes in the distance from the Sun, sorption cooler cycling and fluctuations in gas-liquid flow, and fluctuations in cosmic ray flux on the dilution and bolometer plates. These fluctuations do not compromise the science data.

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Baker, M.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhandari, P.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borders, J.; Borrill, J.; Bouchet, F. R.; Bowman, B.; Bradshaw, T.; Bréelle, E.; Bucher, M.; Burigana, C.; Butler, R. C.; Cabella, P.; Camus, P.; Cantalupo, C. M.; Cappellini, B.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Chambelland, J. P.; Charra, J.; Charra, M.; Chiang, L.-Y.; Chiang, C.; Christensen, P. R.; Clements, D. L.; Collaudin, B.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Crook, M.; Cuttaia, F.; Damasio, C.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Rosa, A.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dolag, K.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Filliard, C.; Finelli, F.; Foley, S.; Forni, O.; Fosalba, P.; Fourmond, J.-J.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Gavila, E.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Guyot, G.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Israelsson, U.; Jaffe, A. H.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lami, P.; Lasenby, A.; Laureijs, R. J.; Lavabre, A.; Lawrence, C. R.; Leach, S.; Lee, R.; Leonardi, R.; Leroy, C.; Lilje, P. B.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maciaszek, T.; MacTavish, C. J.; Maffei, B.; Maino, D.; Mandolesi, N.; Mann, R.; Maris, M.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Melot, F.; Mendes, L.; Mennella, A.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Mora, J.; Morgante, G.; Morisset, N.; Mortlock, D.; Munshi, D.; Murphy, A.; Naselsky, P.; Nash, A.; Natoli, P.; Netterfield, C. B.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Pajot, F.; Pasian, F.; Patanchon, G.; Pearson, D.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Platania, P.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Poutanen, T.; Prézeau, G.; Prina, M.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Schaefer, B. M.; Scott, D.; Seiffert, M. D.; Shellard, P.; Smoot, G. F.; Starck, J.-L.; Stassi, P.; Stivoli, F.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Torre, J.-P.; Tristram, M.; Tuovinen, J.; Valenziano, L.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, C.; White, S. D. M.; Wilkinson, A.; Wilson, P.; Yvon, D.; Zacchei, A.; Zhang, B.; Zonca, A.

2011-12-01

145

Testing Dvali-Gabadadze-Porrati gravity with Planck  

NASA Astrophysics Data System (ADS)

Recently, the Planck Collaboration has released the first cosmological papers providing the highest resolution, full sky, maps of the cosmic microwave background (CMB) temperature anisotropies. It is crucial to understand that whether the accelerating expansion of our universe at present is driven by an unknown energy component (Dark Energy) or a modification to general relativity (Modified Gravity). In this Letter we study a phenomenological model which interpolates between the pure ?CDM model and the Dvali-Gabadadze-Porrati (DGP) braneworld model with an additional parameter ?. Firstly, we calculate the “distance information” of Planck data which includes the “shift parameter” R, the “acoustic scale” lA, and the photon decoupling epoch z* in different cosmological models and find that this information is almost independent on the input models we use. Then, we compare the constraints on the free parameter ? of the DGP model from the “distance information” of Planck and WMAP data and find that the Planck data with high precision do not improve the constraint on ?, but give the higher median value and the better limit on the current matter density fraction ?m. Then, combining the “distance information” of Planck measurement, baryon acoustic oscillations (BAO), Type Ia supernovae (SNIa) and the prior on the current Hubble constant (HST), we obtain the tight constraint on the parameter ?<0.20 at 95% confidence level, which implies that the flat DGP model has been ruled out by the current cosmological data. Finally, we allow the additional parameter ?<0 in our calculations and interestingly obtain ?=-0.29±0.20 (68% C.L.), which means the current data slightly favor the effective equation of state weff<-1. More importantly, the tension between constraints on H0 from different observational data has been eased.

Li, Hong; Xia, Jun-Qing

2013-11-01

146

Global scale, physical models of the F region ionosphere  

NASA Technical Reports Server (NTRS)

Consideration is given to the development and verification of global computer models of the F-region which simulate the interactions between physical processes in the ionosphere. The limitations of the physical models are discussed, focusing on the inputs to the ionospheric system such as magnetospheric electric field and auroral precipitation. The possibility of coupling ionospheric models with thermospheric and magnetospheric models is examined.

Sojka, J. J.

1989-01-01

147

Zero Point Energy: Planck Radiation Law  

Microsoft Academic Search

The assumption of discrete radiation energy in Planck's 1901 radiation law, conflicted with Planck's belief in radiation of continuous waves. To reconcile his quantum hypothesis with his conception of wave radiation, he avoided the conclusion that radiation energy must be made of particles, and postulated that radiation is a transition between the energy levels of an oscillator. Furthermore, ignoring the

H. Vic Dannon

148

Physical modeling and analysis of rain and clouds by anisotropic scaling multiplicative processes  

Microsoft Academic Search

We argue that the basic properties of rain and cloud fields (particularly their scaling and intermittency) are best understood in terms of coupled (anisotropic and scaling) cascade processes. We show how such cascades provide a framework not only for theoretically and empirically investigating these fields, but also for constructing physically based stochastic models. This physical basis is provided by cascade

Daniel Schertzer; Shaun Lovejoy

1987-01-01

149

Measuring Physical & Psychological Maltreatment of Children with the Conflict Tactics Scales.  

ERIC Educational Resources Information Center

The Conflict Tactics Scales (CTS) are intended to measure use of nonviolent discipline, psychological aggression, and physical assault in parent-child and other family relationships. The latter two scales provide a basis for identifying psychological and physical maltreatment. Two revisions of the CTS became available in 1996. One, the CTS2 is…

Straus, Murray A.; Hamby, Sherry L.

150

A MULTI-SCALE\\/MULTI-PHYSICS MODELING FRAMEWORK FOR SOLIDIFICATION SYSTEMS  

Microsoft Academic Search

Models of solidification need to account for multiple physical processes that occur at multiple length scales. A general solidification modelling framework is outlined which can be used to systematically handle the multi- scale\\/multi-physics nature of a given process. This framework is illustrated by considering specific models, a model of a alloy casting, and a model of dendrite growth in an

Vaughan R. VOLLER

151

WMAP OBSERVATIONS OF PLANCK ESZ CLUSTERS  

SciTech Connect

We examine the Sunyaev-Zeldovich (SZ) effect in the seven year Wilkinson Microwave Anisotropy Probe (WMAP) data by cross-correlating it with the Planck Early-release Sunyaev-Zeldovich catalog. Our analysis proceeds in two parts. We first perform a stacking analysis in which the filtered WMAP data are averaged at the locations of the 175 Planck clusters. We then perform a regression analysis to compare the mean amplitude of the SZ signal, Y{sub 500}, in the WMAP data to the corresponding amplitude in the Planck data. The aggregate Planck clusters are detected in the seven year WMAP data with a signal-to-noise ratio of 16.3. In the regression analysis, we find that the SZ amplitude measurements agree to better than 25%: a = 1.23 {+-} 0.18 for the fit Y{sup wmap}{sub 500}= aY{sup planck}{sub 500}.

Ma Yinzhe; Hinshaw, Gary; Scott, Douglas [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

2013-07-10

152

Novel Micrometeorological Surface Parameterization Using Physically Based Scaling Variables  

NASA Astrophysics Data System (ADS)

Surface parameterizations based on novel scaling parameters were developed, tested in a field experiment, and compared to the Monin-Obuhov similarity theory. Dimensionless wind shears based on the standard deviation of the turbulent vertical velocity, and a turbulent kinetic energy defined velocity scale, FMsw and FMuTKE respectively, are better at characterizing the stable regime and are far better for the strongly unstable conditions than the conventionally defined dimensionless wind shear based on the friction velocity, FMu* . This establishes that direct turbulent velocity measures, rather than the momentum-flux based friction velocity, are superior scaling variables for surface layer dimensional analyses. The same scaling velocities were applied to the dimensionless temperature profile but due to experimental errors in temperature gradient measurements the relationships between them couldn't be examined. Richardson numbers, whether defined conventionally or on new scaling variables, were also not reliable because of the large experimental errors in the temperature profile measurements.

Stephens, Jilmarie

153

Physical meaning of one-machine and multimachine tokamak scalings  

SciTech Connect

Specific features of energy confinement scalings constructed using different experimental databases for tokamak plasmas are considered. In the multimachine database, some pairs of engineering variables are collinear; e.g., the current I and the input power P both increase with increasing minor radius a. As a result, scalings derived from this database are reliable only for discharges in which such ratios as I/a{sup 2} or P/a{sup 2} are close to their values averaged over the database. The collinearity of variables allows one to exclude the normalized Debye radius d* from the scaling expressed in a nondimensional form. In one-machine databases, the dimensionless variables are functionally dependent, which allow one to cast a scaling without d*. In a database combined from two devices, the collinearity may be absent, so the Debye radius cannot generally be excluded from the scaling. It is shown that the experiments performed in support of the absence of d* in the two-machine scaling are unconvincing. Transformation expressions are given that allow one to compare experiments for the determination of scaling in any set of independent variables.

Dnestrovskij, Yu. N., E-mail: dnyn@nfi.kiae.ru; Danilov, A. V.; Dnestrovskij, A. Yu.; Lysenko, S. E. [National Research Centre Kurchatov Institute, Institute of Tokamak Physics (Russian Federation)] [National Research Centre Kurchatov Institute, Institute of Tokamak Physics (Russian Federation); Ongena, J. [Euratom-Belgium State Association, Laboratory for Plasma Physics (Belgium)] [Euratom-Belgium State Association, Laboratory for Plasma Physics (Belgium)

2013-04-15

154

Scale covariant physics: a 'quantum deformation' of classical electrodynamics  

NASA Astrophysics Data System (ADS)

We present a deformation of classical electrodynamics, continuously depending on a 'quantum parameter', featuring manifest gauge, Poincaré and scale covariance. The theory, dubbed extended charge dynamics (ECD), associates a certain length scale with each charge which, due to scale covariance, is an attribute of a solution, not a parameter of the theory. When the EM field experienced by an ECD charge is slowly varying over that length scale, the dynamics of the charge reduces to classical dynamics, its emitted radiation reduces to the familiar Liénard-Wiechert potential and the above length scale is identified as the charge's Compton length. It is conjectured that quantum mechanics describes statistical aspects of ensembles of ECD solutions, much like classical thermodynamics describes statistical aspects of ensembles of classical solutions. A unique 'remote sensing' feature of ECD, supporting that conjecture, is presented, along with an explanation for the illusion of a photon within a classical treatment of the EM field. Finally, a novel conservation law associated with the scale covariance of ECD is derived, indicating that the scale of a solution may 'drift' with time at a constant rate, much like translation covariance implies a uniform drift of the (average) position.

Knoll, Yehonatan; Yavneh, Irad

2010-02-01

155

Developing a Rasch Measurement Physical Fitness Scale for Hong Kong Primary School-Aged Students  

ERIC Educational Resources Information Center

The main purpose of this study was to develop a Rasch Measurement Physical Fitness Scale (RMPFS) based on physical fitness indicators routinely used in Hong Kong primary schools. A total of 9,439 records of students' performances on physical fitness indicators, retrieved from the database of a Hong Kong primary school, were used to develop the…

Yan, Zi; Bond, Trevor G.

2011-01-01

156

Evolving desiderata for validating engineered-physics systems without full-scale testing  

SciTech Connect

Theory and principles of engineered-physics designs do not change over time, but the actual engineered product does evolve. Engineered components are prescient to the physics and change with time. Parts are never produced exactly as designed, assembled as designed, or remain unperturbed over time. For this reason, validation of performance may be regarded as evolving over time. Desired use of products evolves with time. These pragmatic realities require flexibility, understanding, and robustness-to-ignorance. Validation without full-scale testing involves engineering, small-scale experiments, physics theory and full-scale computer-simulation validation. We have previously published an approach to validation without full-scale testing using information integration, small-scale tests, theory and full-scale simulations [Langenbrunner et al. 2008]. This approach adds value, but also adds complexity and uncertainty due to inference. We illustrate a validation example that manages evolving desiderata without full-scale testing.

Langenbrunner, James R [Los Alamos National Laboratory; Booker, Jane M [Los Alamos National Laboratory; Hemez, Francois M [Los Alamos National Laboratory; Ross, Timothy J [Los Alamos National Laboratory

2010-01-01

157

Measuring sub-Planck structural analogues in chronocyclic phase space  

NASA Astrophysics Data System (ADS)

Phase space quasi-probability distributions of certain quantum states reveal structure on a scale that is small compared to the Planck area. Using an analog between the wavefunction of a single photon and the electric field of a classical ultrashort optical pulse we show that spectral shearing interferometry enables measurement of such structure directly, thereby extending an idea of Krzysztof Wódkiewicz and others. In particular, we use multiple-shear spectral interferometry to fully characterize a pulse consisting of two sub-pulses which are temporally and spectrally disjoint, without a relative-phase ambiguity. This enables us to compute the Wigner distribution of the pulse. This spectrographic representation of the pulse field features fringes that are tilted with respect to both the time- and frequency axes, showing that in general the shortest sub-Planck distances may not be in the directions of the canonical (and easily experimentally accessible) directions. Further, independent of this orientation, evidence of the sub-Planck scale of the structure may be extracted directly from the measured signal.

Austin, Dane R.; Witting, Tobias; Wyatt, Adam S.; Walmsley, Ian A.

2010-03-01

158

Solution of the Fokker-Planck equation in a wind turbine array boundary layer  

NASA Astrophysics Data System (ADS)

Hot-wire velocity signals from a model wind turbine array boundary layer flow wind tunnel experiment are analyzed. In confirming Markovian properties, a description of the evolution of the probability density function of velocity increments via the Fokker-Planck equation is attained. Solution of the Fokker-Planck equation is possible due to the direct computation of the drift and diffusion coefficients from the experimental measurement data which were acquired within the turbine canopy. A good agreement is observed in the probability density functions between the experimental data and numerical solutions resulting from the Fokker-Planck equation, especially in the far-wake region. The results serve as a tool for improved estimation of wind velocity within the array and provide evidence that the evolution of such a complex and turbulent flow is also governed by a Fokker-Planck equation at certain scales.

Melius, Matthew S.; Tutkun, Murat; Cal, Raúl Bayoán

2014-07-01

159

Electrodynamic similitude and physical scale modeling of nondispersive targets  

Microsoft Academic Search

The predictions of electrodynamic similitude, relating scattering from scaled targets to scattering from full-size targets, have been treated completely and rigorously. The usual assumption is made that the targets are those whose conductivity, permittivity, and permeability do not change with frequency. A complete set of solutions is presented to the three general nonlinear modeling equations in six variables. For the

Clifford R. Schumacher; David W. Taylor

1987-01-01

160

Measuring enjoyment of physical activity in older adults: invariance of the physical activity enjoyment scale (paces) across groups and time.  

PubMed

The purpose of this study was to validate the Physical Activity Enjoyment Scale (PACES) in a sample of older adults. Participants within two different exercise groups were assessed at two time points, 6 months apart. Group and longitudinal invariance was established for a novel, 8-item version of the PACES. The shortened, psychometrically sound measure provides researchers and practitioners an expedited and reliable instrument for assessing the enjoyment of physical activity. PMID:21951520

Mullen, Sean P; Olson, Erin A; Phillips, Siobhan M; Szabo, Amanda N; Wójcicki, Thomas R; Mailey, Emily L; Gothe, Neha P; Fanning, Jason T; Kramer, Arthur F; McAuley, Edward

2011-01-01

161

Updated constraints from the Planck experiment on modified gravity  

NASA Astrophysics Data System (ADS)

A modification of the action of the general relativity produces a different pattern for the growth of the cosmic structures below a certain length scale leaving an imprint on the cosmic microwave background anisotropies. We reexamine the upper limits on the length-scale parameter B0 of f(R) models using the recent data from the Planck satellite experiment. We also investigate the combined constraints obtained when including the Hubble Space Telescope H0 measurement and the baryon acoustic oscillations measurements from the SDSS, WiggleZ and BOSS surveys.

Marchini, Andrea; Salvatelli, Valentina

2013-07-01

162

Innovative dimensional metrology of meso-scale physics targets.  

SciTech Connect

For Indirect-drive inertial confinement fusion (ICF) ignition at the National Ignition Facility (NIF): (1) Shock timing measurement and predictive capabilities must be accurate to - 100 ps. (2) Ablator burn through measurement and predictive capabilities must be accurate to -5%. How accurate are our present capabilities? As a first step, we are using planar ablator samples in 'square pulse' Omega halfraum experiments to validate our measurement and predictive capabilities and our understanding of indirect-drive ablator physics issues.

Sebring, R. J. (Robert J.); Reinovsky, R. E. (Robert E.); Edwards, J. M. (John M.); Nobile, A. (Arthur), Jr.; Anderson, W. E. (Wallace E.); Olson, R. E. (Richard E.)

2002-01-01

163

Study for Planck Cold Clumps with molecular lines  

NASA Astrophysics Data System (ADS)

To probe dynamical processes and physical properties of Planck Cold Clumps, we have observed 674 of the most reliable 915 sources with J=1-0 of CO,13CO and C18O using PMO 13.7 m telescope of Purple Mountain Observatory. J=1-0 lines of HCO+ and HCN at CO emission peaks were also observed, of which 24 were mapped with IRAM 30 m telescope. Results show excitation temperatures are from 4 to 17 K, and column densities range from 1020 to 4.5x1023 cm-2. Planck cold clumps have the smallest line width among samples of IRDCs, weak IRAS, EGOs, UC HII candidates and methanol maser chosen cores. However the lines are still wider than those of low-mass cores and have non-thermal supersonic dispersion. Filament is the majority in their morphologies and fragmented structures were found with dense molecular lines. More than 70% of CO cores are starless. Planck cold clumps seem to be ideal samples to search for candidates of massive prestellar cores and pre-clusters.

Wu, Yuefang

2014-07-01

164

Importance of Physical Scaling Factors to Benthic Marine Invertebrate Recolonization of Laboratory Microcosms.  

National Technical Information Service (NTIS)

Five laboratory studies of benthic macroinvertebrate recolonization were conducted for six-wk periods to evaluate the effects of physical scaling factors (i.e., microcosm size, seawater flow rates and sediment depth) on benthic community structure. Design...

D. A. Flemer J. R. Clark R. S. Stanley C. M. Bundrick G. R. Plaia

1993-01-01

165

Compact wire array sources: power scaling and implosion physics.  

SciTech Connect

A series of ten shots were performed on the Saturn generator in short pulse mode in order to study planar and small-diameter cylindrical tungsten wire arrays at {approx}5 MA current levels and 50-60 ns implosion times as candidates for compact z-pinch radiation sources. A new vacuum hohlraum configuration has been proposed in which multiple z pinches are driven in parallel by a pulsed power generator. Each pinch resides in a separate return current cage, serving also as a primary hohlraum. A collection of such radiation sources surround a compact secondary hohlraum, which may potentially provide an attractive Planckian radiation source or house an inertial confinement fusion fuel capsule. Prior to studying this concept experimentally or numerically, advanced compact wire array loads must be developed and their scaling behavior understood. The 2008 Saturn planar array experiments extend the data set presented in Ref. [1], which studied planar arrays at {approx}3 MA, 100 ns in Saturn long pulse mode. Planar wire array power and yield scaling studies now include current levels directly applicable to multi-pinch experiments that could be performed on the 25 MA Z machine. A maximum total x-ray power of 15 TW (250 kJ in the main pulse, 330 kJ total yield) was observed with a 12-mm-wide planar array at 5.3 MA, 52 ns. The full data set indicates power scaling that is sub-quadratic with load current, while total and main pulse yields are closer to quadratic; these trends are similar to observations of compact cylindrical tungsten arrays on Z. We continue the investigation of energy coupling in these short pulse Saturn experiments using zero-dimensional-type implosion modeling and pinhole imaging, indicating 16 cm/?s implosion velocity in a 12-mm-wide array. The same phenomena of significant trailing mass and evidence for resistive heating are observed at 5 MA as at 3 MA. 17 kJ of Al K-shell radiation was obtained in one Al planar array fielded at 5.5 MA, 57 ns and we compare this to cylindrical array results in the context of a K-shell yield scaling model. We have also performed an initial study of compact 3 mm diameter cylindrical wire arrays, which are alternate candidates for a multi-pinch vacuum hohlraum concept. These massive 3.4 and 6 mg/cm loads may have been impacted by opacity, producing a maximum x-ray power of 7 TW at 4.5 MA, 45 ns. Future research directions in compact x-ray sources are discussed.

Serrano, Jason Dimitri; Chuvatin, Alexander S. (Laboratoire du Centre National de la Recherche Scientifique Ecole Polytechnique, Palaiseau, France); Jones, M. C.; Vesey, Roger Alan; Waisman, Eduardo M.; Ivanov, V. V. (University of Nevada - Reno, Reno, NV); Esaulov, Andrey A. (University of Nevada - Reno, Reno, NV); Ampleford, David J.; Cuneo, Michael Edward; Kantsyrev, Victor Leonidovich (University of Nevada - Reno, Reno, NV); Coverdale, Christine Anne; Rudakov, L. I. (Icarus Research, Bethesda, MD); Jones, Brent Manley; Safronova, Alla S. (University of Nevada - Reno, Reno, NV); Vigil, Marcelino Patricio

2008-09-01

166

Seismic-Scale Rock Physics of Methane Hydrate  

SciTech Connect

We quantify natural methane hydrate reservoirs by generating synthetic seismic traces and comparing them to real seismic data: if the synthetic matches the observed data, then the reservoir properties and conditions used in synthetic modeling might be the same as the actual, in-situ reservoir conditions. This approach is model-based: it uses rock physics equations that link the porosity and mineralogy of the host sediment, pressure, and hydrate saturation, and the resulting elastic-wave velocity and density. One result of such seismic forward modeling is a catalogue of seismic reflections of methane hydrate which can serve as a field guide to hydrate identification from real seismic data. We verify this approach using field data from known hydrate deposits.

Amos Nur

2009-01-08

167

Urban Impacts on Physical Stream Condition: Effects of Spatial Scale, Connectivity, and Longitudinal Trends  

Microsoft Academic Search

An assessment of physical conditions in urban streams of the Puget Sound region, coupled with spatially explicit watershed characterizations, demonstrates the importance of spatial scale, drainage network connectivity, and longitudinal downstream trends when considering the effects of urbanization on streams. A rapid stream assessment technique and a multimetric index were used to describe the physical conditions of multiple reaches in

Maeve McBride; Derek B. Booth

2005-01-01

168

Multi physics multi scale modeling of microwave circuits and systems hybridizing circuit, electromagnetic and thermal modeling  

Microsoft Academic Search

Modeling of complex systems requires that a systematic approach be adopted for multi scale and multi physics modeling. The current state of physical modeling tools in the arena of microwave and electromagnetic model is considerably mature enabling discrete problems to be considered. The real need is for hybridization of discrete modeling systems to obtain a seamless simulation environment from atoms

Michael B. Steer

2004-01-01

169

Developing an Attitude Scale for the Profession of Physical Education Teaching (ASPPET)  

ERIC Educational Resources Information Center

In this study, the development of a Likert-type attitude scale for the profession of physical education teaching (ASPPET) was aimed. The group of the study was consisted of totally 556 pre-service physical education teachers. In order to determine the structural validity of ASPPET, an exploratory and confirmative factor analyses were performed. A…

Unlu, Huseyin

2011-01-01

170

Using Rasch modeling to re-evaluate three scales related to physical activity: enjoyment, perceived benefits and perceived barriers  

Microsoft Academic Search

Studies suggest that enjoyment, perceived bene- fits and perceived barriers may be important mediators of physical activity. However, the psychometric properties of these scales have not been assessed using Rasch modeling. The purpose of this study was to use Rasch modeling to evaluate the properties of three scales com- monly used in physical activity studies: the Physical Activity Enjoyment Scale,

K. C. Heesch; L. C. Masse; A. L. Dunn

2006-01-01

171

Crocodile Head Scales Are Not Developmental Units But Emerge from Physical Cracking  

NSDL National Science Digital Library

In most amniotes, keratinized structures like scales, hair, and feathers are formed from primordia, developmental nodes distributed in a predictable pattern. In their Report, Milinkovitch and colleagues show that the scales on the face and jaws of crocodiles do not develop in a predictable pattern but instead are the result of a physical cracking process.

Michel C. Milinkovitch (University of Geneva, Sciences III, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland;Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution); Liana Manukyan (University of Geneva, Sciences III, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland;Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution); Nicolas Di-Poi (University of Geneva, Sciences III, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland;Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution); Adrien Debry (University of Geneva, Sciences III, 30, Quai Ernest-Ansermet, 1211 Geneva, Switzerland;Laboratory of Artificial and Natural Evolution (LANE), Department of Genetics and Evolution); Samuel Martin (La Ferme aux Crocodiles, Pierrelatte, France;); Daljit Singh (University of Bern, Switzerland;Computer Graphics Group)

2012-11-29

172

Planck focal plane instruments: advanced modelization and combined analysis  

NASA Astrophysics Data System (ADS)

This thesis is the result of my work as research fellow at IASF-MI, Milan section of the Istituto di Astrofisica Spaziale e Fisica Cosmica, part of INAF, Istituto Nazionale di Astrofisica. This work started in January 2006 in the context of the PhD school program in Astrophysics held at the Physics Department of Universita' degli Studi di Milano under the supervision of Aniello Mennella. The main topic of my work is the software modelling of the Low Frequency Instrument (LFI) radiometers. The LFI is one of the two instruments on-board the European Space Agency Planck Mission for high precision measurements of the anisotropies of the Cosmic Microwave Background (CMB). I was also selected to participate at the International Doctorate in Antiparticles Physics, IDAPP. IDAPP is funded by the Italian Ministry of University and Research (MIUR) and coordinated by Giovanni Fiorentini (Universita' di Ferrara) with the objective of supporting the growing collaboration between the Astrophysics and Particles Physics communities. It is an international program in collaboration with the Paris PhD school, involving Paris VI, VII and XI Universities, leading to a double French-Italian doctoral degree title. My work was performed with the co-tutoring of Jean-Michel Lamarre, Instrument Scientist of the High Frequency Instrument (HFI), the bolometric instrument on-board Planck. Thanks to this collaboration I had the opportunity to work with the HFI team for four months at the Paris Observatory, so that the focus of my activity was broadened and included the study of cross-correlation between HFI and LFI data. Planck is the first CMB mission to have on-board the same satellite very different detection technologies, which is a key element for controlling systematic effects and improve measurements quality.

Zonca, Andrea; Mennella, Aniello

2012-08-01

173

Expectations test: trauma scales for sexual abuse, physical abuse, exposure to family violence, and posttraumatic stress.  

PubMed

Gully's 2000 Expectations Test was developed as a tool to use with children ages 4 through 17 to measure social information processing. Prior research suggested it could help identify abused and emotionally traumatized children. Results from regression analyses were used to develop four scales that could be calculated simply. Prior research demonstrated excellent interrater reliability for the variables from the Expectations Test used in the regression analyses. The minimum Cronbach's alpha for any scale is .75. The minimum test-retest reliability is .88. Classification results indicated each scale can provide data to help evaluate children: Sexual Abuse Scale (sensitivity = 81% and specificity = 78%), Physical Abuse Scale (84% and 78%), Exposure to Family Violence Scale (65% and 63%), and Posttraumatic Stress Scale (86% and 54%). However, careful attention needs to be given to the potential limitations of these scales to prevent their misuse. PMID:12934639

Gully, Kevin J

2003-08-01

174

Physical Analysis and Scaling of a Jet and Vortex Actuator  

NASA Technical Reports Server (NTRS)

Our previous studies have shown that the Jet and Vortex Actuator generates free-jet, wall-jet, and near- wall vortex flow fields. That is, the actuator can be operated in different modes by simply varying the driving frequency and/or amplitude. For this study, variations are made in the actuator plate and wide-slot widths and sine/asymmetrical actuator plate input forcing (drivers) to further study the actuator induced flow fields. Laser sheet flow visualization, particle- image velocimetry, and laser velocimetry are used to measure and characterize the actuator induced flow fields. Laser velocimetry measurements indicate that the vortex strength increases with the driver repetition rate for a fixed actuator geometry (wide slot and plate width). For a given driver repetition rate, the vortex strength increases as the plate width decreases provided the wide-slot to plate-width ratio is fixed. Using an asymmetric plate driver, a stronger vortex is generated for the same actuator geometry and a given driver repetition rate. The nondimensional scaling provides the approximate ranges for operating the actuator in the free jet, wall jet, or vortex flow regimes. Finally, phase-locked velocity measurements from particle image velocimetry indicate that the vortex structure is stationary, confirming previous computations. Both the computations and the particle image velocimetry measurements (expectantly) show unsteadiness near the wide-slot opening, which is indicative of mass ejection from the actuator.

Lachowicz, Jason T.; Yao, Chung-Sheng; Joslin, Ronald D.

2004-01-01

175

Validation and factorial invariance of children's attraction to physical activity (CAPA) scale in Portugal.  

PubMed

Abstract The Children's Attraction to Physical Activity (CAPA) scale assesses interest in and attraction to the physical activity (PA) of children of elementary school age. The original (25 items) and shorter versions (15 items) of the scale were developed and validated with American children. The purpose of this study was to cross-validate the shorter version of the CAPA scale for use with Portuguese schoolchildren and to examine the invariance of the multidimensional factor structure of the scale in two samples. The sample comprised 683 children (7-10 years) from public primary schools. The sample was divided into calibration and cross-validation samples. The scale was translated into Portuguese and underwent forward translation, synthesis of the translation and backward translation and was then subjected to expert committee review, pretest and reliability assessment. Internal consistency for each of the five subscales within the a priori 5-factor structure of the CAPA scale was evaluated through Cronbach's alpha, followed by a series of confirmatory factor analyses (CFAs) for both the calibration and cross-validation samples. The maximum likelihood robust estimation method was used. The CFA demonstrated that a 5-factor structural model of the Portuguese translation of the CAPA scale was invariant. The construct analysed had the same basic meaning and structural and item differences within the two samples. The results indicated that the CAPA scale is appropriate for use with Portuguese schoolchildren. The availability of a valid and reliable scale should enhance opportunities for further understanding of children's involvement in PA. PMID:23957906

Seabra, Ana C; Malina, Robert M; Parker, Melissa; Seabra, André; Brustad, Robert; Maia, José A; Fonseca, António M

2014-06-01

176

Probing the scale of New Physics at the LHC: The example of Higgs data  

NASA Astrophysics Data System (ADS)

We present a technique to determine the scale of New Physics (NP) compatible with any set of data, relying on well-defined credibility intervals. Our approach relies on the statistical view of the effective field theory capturing New Physics at low energy. We introduce formally the notion of testable NP and show that it ensures integrability of the posterior distribution. We apply our method to the Standard Model Higgs sector in light of recent LHC data, considering two generic scenarios. In the scenario of democratic higher-dimensional operators generated at one-loop, we find the testable NP scale to lie within [10,260] TeV at 95% Bayesian credibility level. In the scenario of loop-suppressed field strength-Higgs operators, the testable NP scale is within [28,1200] TeV at 95% Bayesian credibility level. More specific UV models are necessary to allow lower values of the NP scale.

Fichet, Sylvain

2014-07-01

177

Multi-scale/multi-physical modeling in head/disk interface of magnetic data storage  

NASA Astrophysics Data System (ADS)

The model integration of the head-disk interface (HDI) in the hard disk drive system, which includes the hierarchy of highly interactive layers (magnetic layer, carbon overcoat (COC), lubricant, and air bearing system (ABS)), has recently been focused upon to resolve technical barriers and enhance reliability. Heat-assisted magnetic recording especially demands that the model simultaneously incorporates thermal and mechanical phenomena by considering the enormous combinatorial cases of materials and multi-scale/multi-physical phenomena. In this paper, we explore multi-scale/multi-physical simulation methods for HDI, which will holistically integrate magnetic layers, COC, lubricants, and ABS in non-isothermal conditions.

Chung, Pil Seung; Smith, Robert; Vemuri, Sesha Hari; Jhon, Young In; Tak, Kyungjae; Moon, Il; Biegler, Lorenz T.; Jhon, Myung S.

2012-04-01

178

Physical model of scale-formation reduction under magnetic treatment of water in thermal engineering devices  

Microsoft Academic Search

The calculations of reduction of the rate of scale formation at heat exchanger walls with time are presented. A physical model\\u000a describing a decrease in the scale formation by decreasing the area of the wall surface of the heat exchanger in comparison\\u000a with the surface area of the suspended crystals generated by the magnetic device has been analyzed.

S. I. Koshoridze; Yu. K. Levin

2009-01-01

179

Multi-scale multi-physics approaches for accurate simulations of complex chemical systems  

Microsoft Academic Search

Predicting the behavior of real macroscopic system from its basic chemical constituents has always been one of the ultimate goals of computational chemistry. Multi-scale multi-physics based ap- proaches present a natural evolution of conventional computational chemistry applications. These methods recognize natural decomposition of the chemical system into distinct regions (multi-scale) and the advantages, both computational and conceptual, of the integrated

Marat Valiev; Karol Kowalski; Eric Bylaska; John Weare

180

Relations between scaling-transformed Husimi functions, Wigner functions and symplectic tomograms describing corresponding physical states  

NASA Astrophysics Data System (ADS)

Husimi Q-functions are the only functions from the class of Cohen quasi-distributions on phase space that after scaling transformation (q,p)?(?q, ?p) remain in the same class when the modulus of the scaling parameter is smaller than unity and so, in this case, describe a physical state. We found the Wigner functions and symplectic tomograms of such states. We applied the obtained general results to the Fock states of the harmonic oscillator.

Andreev, V. A.; Davidovi?, D. M.; Davidovi?, L. D.; Davidovi?, M. D.

2011-02-01

181

On the statistical significance of the bulk flow measured by the Planck satellite  

NASA Astrophysics Data System (ADS)

A recent analysis of data collected by the Planck satellite detected a net dipole at the location of X-ray selected galaxy clusters, corresponding to a large-scale bulk flow extending at least to z ~ 0.18, the median redshift of the cluster sample. The amplitude of this flow, as measured with Planck, is consistent with earlier findings based on data from the Wilkinson Microwave Anisotropy Probe (WMAP). However, the uncertainty assigned to the dipole by the Planck team is much larger than that found in the WMAP studies, leading the authors of the Planck study to conclude that the observed bulk flow is not statistically significant. Here, we show that two of the three implementations of random sampling used in the error analysis of the Planck study lead to systematic overestimates in the uncertainty of the measured dipole. Random simulations of the sky do not take into account that the actual realization of the sky leads to filtered data that have a 12% lower root-mean-square dispersion than the average simulation. Using rotations around the Galactic pole (the Z axis), increases the uncertainty of the X and Y components of the dipole and artificially reduces the significance of the dipole detection from 98-99% to less than 90% confidence. When either effect is taken into account, the corrected errors agree with those obtained using random distributions of clusters on Planck data, and the resulting statistical significance of the dipole measured by Planck is consistent with that of the WMAP results.

Atrio-Barandela, F.

2013-09-01

182

Fast algorithms for numerical, conservative, and entropy approximations of the Fokker-Planck-Landau equation  

SciTech Connect

We present fast numerical algorithms to solve the nonlinear Fokker-Planck-Landau equation in 3D velocity space. The discretization of the collision operator preserves the properties required by the physical nature of the Fokker-Planck-Landau equation, such as the conservation of mass, momentum, and energy, the decay of the entropy, and the fact that the steady states are Maxwellians. At the end of this paper, we give numerical results illustrating the efficiency of these fast algorithms in terms of accuracy and CPU time. 20 refs., 7 figs.

Buet, C. [CEA-CEL-V, Villeneuve Saint Georges (France)] [CEA-CEL-V, Villeneuve Saint Georges (France); Cordier [Universite de Paris VI, Paris (France)] [Universite de Paris VI, Paris (France); Degond, P.; Lemou, M. [Universite Paul Sabatier, Toulouse (France)] [Universite Paul Sabatier, Toulouse (France)

1997-05-15

183

Testing the Applicability of Nernst-Planck Theory in Ion Channels: Comparisons with Brownian Dynamics Simulations  

Microsoft Academic Search

The macroscopic Nernst-Planck (NP) theory has often been used for predicting ion channel currents in recent years, but the validity of this theory at the microscopic scale has not been tested. In this study we systematically tested the ability of the NP theory to accurately predict channel currents by combining and comparing the results with those of Brownian dynamics (BD)

Chen Song; Ben Corry; Jörg Langowski

2011-01-01

184

Planck Early Results. XV. Spectral Energy Distributions and Radio Continuum Spectra of Northern Extragalactic Radio Sources  

NASA Technical Reports Server (NTRS)

Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources. based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multi frequency data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data, including the Planck ERCSC data, were calculated. SED modelling methods are discussed, with an emphasis on proper. physical modelling of the synchrotron bump using multiple components. Planck ERCSC data also suggest that the original accelerated electron energy spectrum could be much harder than commonly thought, with power-law index around 1.5 instead of the canonical 2.5. The implications of this are discussed for the acceleration mechanisms effective in blazar shock. Furthermore in many cases the Planck data indicate that gamma-ray emission must originate in the same shocks that produce the radio emission.

Aatrokoski, J.; Ade, P. A. R.; Aghanim, N.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Amaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoit, A.; Berdyugin, A.; Bernard, J. P.; Bersanelli, M.; Bhatia, R.; Bonaldi, A.; Bonavera, L.; Gehrels, N.

2011-01-01

185

Two-component Thermal Dust Emission Model: Application to the Planck HFI Maps  

NASA Astrophysics Data System (ADS)

We present full-sky, 6.1 arcminute resolution maps of dust optical depth and temperature derived by fitting the Finkbeiner et al. (1999) two-component dust emission model to the Planck HFI and IRAS 100 micron maps. This parametrization of the far infrared thermal dust SED as the sum of two modified blackbodies serves as an important alternative to the commonly adopted single modified blackbody dust emission model. We expect our Planck-based maps of dust temperature and optical depth to form the basis for a next-generation, high-resolution extinction map which will additionally incorporate small-scale detail from WISE imaging.

Meisner, Aaron M.; Finkbeiner, Douglas P.

2014-06-01

186

Affective Response to Physical Activity: Testing for Measurement Invariance of the Physical Activity Affect Scale Across Active and Non-Active Individuals  

Microsoft Academic Search

Affective responses to physical activity are assumed to play a role in exercise initiation and maintenance. The Physical Activity Affect Scale measures four dimensions of an individual's affective response to exercise. Group differences in the interpretation of scale items can impact the interpretability of mean differences, underscoring the need to examine whether measurement structure holds across groups (e.g., active vs.

Laura C. Carpenter; Sara Anne Tompkins; Sarah J. Schmiege; Renea Nilsson; Angela Bryan

2010-01-01

187

Relation of Physical Form to Spatial Knowledge in Large-Scale Virtual Environments  

ERIC Educational Resources Information Center

This study used a desktop virtual environmental simulation of 18 large-scale residential environments to test effects of plan layout complexity, physical differentiation, and gender on acquired spatial knowledge. One hundred sixty people (95 males and 65 females) were assigned at random to the different conditions. After a learning phase,…

Cubukcu, Ebru; Nasar, Jack L.

2005-01-01

188

Retrospective Assessment of Childhood Sexual and Physical Abuse: A Comparison of Scaled and Behaviorally Specific Approaches  

ERIC Educational Resources Information Center

This study compared retrospective reports of childhood sexual and physical abuse as assessed by two measures: the Childhood Trauma Questionnaire (CTQ), which uses a Likert-type scaling approach, and the Computer Assisted Maltreatment Inventory (CAMI), which employs a behaviorally specific means of assessment. Participants included 1,195…

DiLillo, David; Fortier, Michelle A.; Hayes, Sarah A.; Trask, Emily; Perry, Andrea R.; Messman-Moore, Terri; Fauchier, Angele; Nash, Cindy

2006-01-01

189

The Psychometric Properties of the Physical Education Lesson Attitude Scale for Preservice Classroom Teachers  

ERIC Educational Resources Information Center

The purpose of this study was to examine the psychometric properties of the Physical Education Attitude Scale for Preservice Classroom Teachers (PEAS-PCT). The study was conducted on 561 Turkish preservice classroom teachers at the end of the 2011-2012 Fall Semester. Exploratory and confirmatory factor analyses were conducted to ascertain the…

Oncu, Erman

2013-01-01

190

Physical Education Teacher Attitudes toward Fitness Tests Scale: Cross-Revalidation and Modification  

ERIC Educational Resources Information Center

This study aimed to provide further evidence of validity and reliability for the Physical Education Teacher Attitudes toward Fitness Tests Scale (PETAFTS), which consisted of affective and cognitive domains. There were two subdomains in the affective domain (i.e., enjoyment of implementing fitness tests and enjoyment of using test results) and one…

Keating, Xiaofen D.; Guan, Jianmin; Ferguson, Robert H.; Chen, Li; Bridges, Dwan M.

2008-01-01

191

Evaluation of Social Cognitive Scaling Response Options in the Physical Activity Domain  

ERIC Educational Resources Information Center

The purpose of this study was to compare the reliability, variability, and predictive validity of two common scaling response formats (semantic differential, Likert-type) and two numbers of response options (5-point, 7-point) in the physical activity domain. Constructs of the theory of planned behavior were chosen in this analysis based on its…

Rhodes, Ryan E.; Matheson, Deborah Hunt; Mark, Rachel

2010-01-01

192

Comparison of Seriation and Multidimensional Scaling: Two Techniques for Validating Constructs in Physical Education  

ERIC Educational Resources Information Center

Research into statistical validations of constructs in physical education obtained by seriation and multidimensional scaling, revealed that (a) larger matrix sizes produced the most accurate results; (b) as data error introduction was increased, solution accuracy decreased; and (c) seriation produced slightly more accurate results than one- and…

Korell, Diane M.; Safrit, Margaret J.

1977-01-01

193

Introduction to SCALE-UP: Student-Centered Activities for Large Enrollment University Physics.  

ERIC Educational Resources Information Center

SCALE-UP is an extension of the highly successful IMPEC (Integrated Math, Physics, Engineering, and Chemistry) project, one of North Carolina State's curricular reform efforts undertaken as part of the SUCCEED coalition. The authors utilize the interactive, collaboratively based instruction that worked well in smaller class settings and find ways…

Beichner, Robert J.; Saul, Jeffery M.; Allain, Rhett J.; Deardorff, Duane L.; Abbott, David S.

194

BOOK REVIEW: Nonequilibrium Physics at Short Time Scales: Formation of Correlations  

Microsoft Academic Search

It is a happy situation when similar concepts and theoretical techniques can be applied to widely different physical systems because of a deep similarity in the situations being studied. The book illustrates this well; it focuses on the description of correlations in quantum systems out of equilibrium at very short time scales, prompted by experiments with short laser pulses in

K. Morawetz

2005-01-01

195

Reliability and Construct Validity of Turkish Version of Physical Education Activities Scale  

ERIC Educational Resources Information Center

This research was conducted to examine the reliability and construct validity of Turkish version of physical education activities scale (PEAS) which was developed by Thomason (2008). Participants in this study included 313 secondary and high school students from 7th to 11th grades. To analyse the data, confirmatory factor analysis, post hoc…

Memis, Ugur Altay

2013-01-01

196

BICEP2, the Higgs mass and the SUSY-breaking scale  

NASA Astrophysics Data System (ADS)

Recent BICEP2 results on CMB polarisation B-modes suggest a high value for the inflation scale V01/4?1016 GeV, giving experimental evidence for a physical scale in between the EW scale and the Planck mass. We propose that this new high scale could be interpreted as evidence for a high SUSY breaking scale with MSSM sparticles with masses of order Mss?1012-1013 GeV. We show that such a large value for Mss is consistent with a Higgs mass around 126 GeV. We briefly discuss some possible particle physics implications of this assumption.

Ibáñez, Luis E.; Valenzuela, Irene

2014-06-01

197

Two hydrogen sorption cryocoolers for the Planck mission  

NASA Astrophysics Data System (ADS)

Two continuous operation 18 K/20 K sorption cryocoolers are being developed by the Jet Propulsion Laboratory (JPL) as a NASA contribution to the European Space Agency (ESA) Planck mission, currently planned for a 2007 launch. Each individual sorption cooler will be capable of providing a total of about 200 mW of cooling power at 18 K and 1.2 W at 20 K, given a passive radiative precooling at 50 K. These coolers work by thermally cycling a metal-hydride to absorb and desorb hydrogen gas, used as the working fluid in a Joule-Thomson (J-T) refrigerator. The major advantage of the sorption coolers is their truly vibration-free operation capability together with the fact that they can be readily scaled to perform over a wide range of cooling powers. The hydrogen sorption coolers will directly cool the Planck Low Frequency Instrument (LFI) HEMT amplifiers to approximately 20 K and will provide precooling at 18 K to the RAL 4 K closed-cycle Helium J-T cooler for the High Frequency Instrument (HFI). The concept design, the cooler operations and the predicted performances of the flight models are here presented. .

Morgante, G.; Barber, D.; Bhandari, P.; Bowman, R. C.; Cowgill, P.; Crumb, D.; Loc, T.; Nash, A.; Pearson, D.; Prina, M.; Sirbi, A.; Schemlzel, M.; Sugimura, R.; Wade, L. A.

2002-05-01

198

The stability of polysiloxanes incorporating nano-scale physical property modifiers  

NASA Astrophysics Data System (ADS)

Reported here is the synthesis and subsequent characterization of the physical and chemical properties of novel polysiloxane elastomers modified with a series of polyhedraloligomericsilsequioxane (POSS) molecular silicas. The physical properties of the formulated nanocomposite systems have been characterized with a combination of dynamic mechanical analysis (DMA), broadband dielectric spectroscopy (BDS) and confocal Raman microscopy. The results of the physical property characterization demonstrate that the incorporation of low levels (1-4% by wt.) of POSS particles into the polysiloxane network leads to significant improvements in the mechanical properties of the elastomer and significantly alters the motional chain dynamics of the system as a whole. The results of studies performed to assess the long-term stability of these novel nanocomposite systems have demonstrated that POSS physical property modifiers can significantly alter the thermal stability of polysiloxane elastomers. Physically dispersed POSS has also been shown in some cases to be both mobile and disruptive within the polysiloxane networks, agglomerating into domains on a micron scale and migrating to the surface of the elastomers. This work demonstrates both the potential of POSS nanoparticles as physical property modifiers and describes the effects of POSS on the physical and chemical stability of polysiloxane systems.

Lewicki, James P.; Patel, Mogon; Morrell, Paul; Liggat, John; Murphy, Julian; Pethrick, Richard

2008-04-01

199

Sub-Planck structures and Quantum Metrology  

SciTech Connect

The significance of sub-Planck structures in relation to quantum metrology is explored, in close contact with experimental setups. It is shown that an entangled cat state can enhance the accuracy of parameter estimations. The possibility of generating this state, in dissipative systems has also been demonstrated. Thereafter, the quantum Cramer-Rao bound for phase estimation through a pair coherent state is calculated, which achieves the maximum possible resolution in an interferometer.

Panigrahi, Prasanta K. [Indian Institute of Science Education and Research-Kolkata (India); Kumar, Abhijeet [Indian Institute of Science Education and Research, Pune (India); Roy, Utpal; Ghosh, Suranjana [Indian Institute of Technology Patna (India)

2011-09-23

200

Astrophysical Data Transmission in Planck Units  

Microsoft Academic Search

``Data Communication and Net Working'' by Forouzan expresses (an informatics equivalent of statistics) that N (data rate or bits\\/second) divided by r (number of data elements per signal or log2L) is the baud rate. For N = 10^43 Planck times per second, and L = 10^90, the number of photons in the universe, the baud rate is more than 10^40,

Shantilal Goradia

2008-01-01

201

The ellipsoidal universe in the Planck satellite era  

NASA Astrophysics Data System (ADS)

Recent Planck data confirm that the cosmic microwave background displays the quadrupole power suppression together with large-scale anomalies. Progressing from previous results, that focused on the quadrupole anomaly, we strengthen the proposal that the slightly anisotropic ellipsoidal universe may account for these anomalies. We solved at large scales the Boltzmann equation for the photon distribution functions by taking into account both the effects of the inflation produced primordial scalar perturbations and the anisotropy of the geometry in the ellipsoidal universe. We showed that the low quadrupole temperature correlations allowed us to fix the eccentricity at decoupling, edec = (0.86 ± 0.14) 10-2, and to constraint the direction of the symmetry axis. We found that the anisotropy of the geometry of the universe contributes only to the large-scale temperature anisotropies without affecting the higher multipoles of the angular power spectrum. Moreover, we showed that the ellipsoidal geometry of the universe induces sizeable polarization signal at large scales without invoking the reionization scenario. We explicitly evaluated the quadrupole TE and EE correlations. We found an average large-scale polarization ?Tpol = (1.20 ± 0.38) ?K. We point out that great care is needed in the experimental determination of the large-scale polarization correlations since the average temperature polarization could be misinterpreted as foreground emission leading, thereby, to a considerable underestimate of the cosmic microwave background polarization signal.

Cea, Paolo

2014-06-01

202

The SF36 scales are not accurately summarised by independent physical and mental component scores  

Microsoft Academic Search

Objectives  The Short Form 36 Health Status Questionnaire (SF-36) has eight scales that can be condensed into two components: physical\\u000a component summary (PCS) and mental component summary (MCS). This paper investigates: (1) the assumption that PCS and MCS are\\u000a orthogonal, (2) the applicability of a single model to different condition-specific subgroups, and (3) a reduced five-scale\\u000a model.\\u000a \\u000a \\u000a \\u000a Study design and setting  We

Mark Hann; David Reeves

2008-01-01

203

Physical aspects of a length scale for the Gulf Stream front  

SciTech Connect

A discussion is presented of the physical interpretation of the length scale, lambda, introduced in a recent paper by Kao and Cheney (1982) to scale the sea surface height anomaly across the Gulf Stream front. Additional results of sea-surface height anomaly profiles computed from the hydrographic data from Fuglister's GULF STREAM 60 are also included. In all cases the width of the anomaly is spanned rather precisely by 2lambda. The relationship between lambda and the internal Rossby radius of deformation lambda, is discussed.

Kao, T.W.

1983-07-20

204

The physical conditions in the core of the quasar 3C 273 on parsec scales  

NASA Astrophysics Data System (ADS)

VLBI observations of the quasar 3C 273 are analyzed. The physical parameters of the components in the parsec-scale jet of the quasar are estimated using amethod based on an inhomogeneous synchrotron sourcemodel. All the jet components (on scales of˜0.1 pc) have magnetic fields that are either uniform or close to uniform, with magnitudes B ˜ 0.1 G. The core component, which is probably associated with the central engine, differs from the remaining components in its unusually high density of relativistic electrons.

Artyukh, V. S.; Tyul'bashev, S. A.; Chernikov, P. A.

2012-07-01

205

Current dependence of spin torque switching rate based on Fokker-Planck approach  

NASA Astrophysics Data System (ADS)

The spin torque switching rate of an in-plane magnetized system in the presence of an applied field is derived by solving the Fokker-Planck equation. It is found that three scaling currents are necessary to describe the current dependence of the switching rate in the low-current limit. The dependences of these scaling currents on the applied field strength are also studied.

Taniguchi, Tomohiro; Imamura, Hiroshi

2014-05-01

206

Can There BE Physics Without Experiments? Challenges and Pitfalls  

NASA Astrophysics Data System (ADS)

Physicists investigating space, time and matter at the Planck scale will probably have to work with much less guidance from experimental input than has ever happened before in the history of Physics. This may imply that we should insist on much higher demands of logical and mathematical rigour than before. Working with long chains of arguments linking theories to experiment, we must be able to rely on logical precision when and where experimental checks cannot be provided.

't Hooft, Gerard

2014-03-01

207

Using Rasch Modeling to Re-Evaluate Three Scales Related to Physical Activity: Enjoyment, Perceived Benefits and Perceived Barriers  

ERIC Educational Resources Information Center

Studies suggest that enjoyment, perceived benefits and perceived barriers may be important mediators of physical activity. However, the psychometric properties of these scales have not been assessed using Rasch modeling. The purpose of this study was to use Rasch modeling to evaluate the properties of three scales commonly used in physical

Heesch, K. C.; Masse, L. C.; Dunn, A. L.

2006-01-01

208

Materials Science and Physics at Micro/Nano-Scales. FINAL REPORT  

SciTech Connect

The scope of this project is to study nanostructures of semiconductors and superconductors, which have been regarded as promising building blocks for nanoelectronic and nanoelectric devices. The emphasis of this project is on developing novel synthesis approaches for fabrication of nanostructures with desired physical properties. The ultimate goal is to achieve a full control of the nanostructure growth at microscopic scales. The major experimental achievements obtained are summarized

Wu, Judy Z

2009-09-07

209

Multi-scale, Multi-physics Heart Simulator as a Tool to Link Bench and Bedside  

Microsoft Academic Search

\\u000a Advances in molecular and cell biology have enabled us to identify the genes responsible for the origin of various heart diseases\\u000a but, in most cases, the detailed mechanisms by which such genetic defects lead to the signs and symptoms observed at the bedside\\u000a remain to be elucidated. In an attempt to investigate such problems, we have developed a multi-scale, multi-physics

S. Sugiura; T. Washio; J. Okada; H. Watanabe; T. Hisada

210

Validity and reliability of Physical Activity Enjoyment Scale questionnaire (PACES) in children with asthma.  

PubMed

Abstract Objective: The aim of this study is to test the psychometric properties of the Physical Activity Enjoyment Scale (PACES) in children with asthma. Method: Participants included 185 children (age?=?11.38?±?1.12 years; body mass index?=?20.66?±?4.13?kg/m(2)): 107 children with asthma and 78 healthy children. To test the enjoyment of physical activity, PACES of Motl et al. was used in its Spanish version. In addition, the Physical Activity Questionnaire for Children (PAQ-C), Paediatric Asthma Quality of Life Questionnaire (PAQLQ) and Physical Self-Concept Questionnaire (CAF) have been used. Results: The results have shown a two-factor structure corresponding to the model whose settings have been good. PACES internal consistency was very high (Cronbach's alpha?=?0.906). The PACES test-retest reliability indicates a good temporal concordance (Spearman rho?=?0.868, p?physical self-concept. Conclusions: The findings confirm that PACES is a valid and reliable measure of physical activity enjoyment in children with asthma. PMID:24580370

Latorre Román, Pedro Ángel; García Pinillos, Felipe; Navarro Martínez, Ana Vanesa; Izquierdo Rus, Tomás

2014-08-01

211

Strong Predictability Of Spatially Distributed Physical Habitat Preferences For O. Mykiss Spawning Across Three Spatial Scales  

NASA Astrophysics Data System (ADS)

Currently accepted perception assumes Oncorhynchus mykiss prefer different ranges of similar physical habitat elements for spawning than Chinook salmon (Oncorhynchus tshawytscha), taking into account their difference in size. While there is increasing research interest regarding O. mykiss habitat use and migratory behavior, research conducted to date distinguishing the physical habitat conditions utilized for O. mykiss spawning has not provided quantified understanding of their spawning habitat preferences. The purpose of this study was to use electivity indices and other measures to assess the physical habitat characteristics preferred for O. mykiss spawning in terms of both 1-m scale microhabitat attributes, and landforms at different spatial scales from 0.1-100 times channel width. The testbed for this study was the 37.5-km regulated gravel-cobble Lower Yuba River (LYR). Using spatially distributed 2D hydrodynamic model results, substrate mapping, and a census of O. mykiss redds from two years of observation, micro- and meso-scale representations of physical habitat were tested for their ability to predict spawning habitat preference and avoidance. Overall there was strong stratification of O. mykiss redd occurrence for all representation types of physical habitat. A strong preference of hydraulic conditions was shown for mean water column velocities of 1.18-2.25 ft/s, and water depths of 1.25-2.76 ft. There was a marked preference for the two most upstream alluvial reaches of the LYR (out of 8 total reaches), accounting for 92% of all redds observed. The preferred morphological units (MUs) for O. mykiss spawning were more variable than for Chinook salmon and changed with increasing discharge, demonstrating that O. mykiss shift spawning to different MUs in order to utilize their preferred hydraulic conditions. The substrate range preferred for O. mykiss spawning was within 32-90 mm. Overall, O. mykiss spawning behavior was highly predictable and required a holistic blend of hydraulic and geomorphic representations to explain.

Kammel, L.; Pasternack, G. B.; Wyrick, J. R.; Massa, D.; Bratovich, P.; Johnson, T.

2012-12-01

212

Development of a physically based runoff routing model and its application at regional scale  

NASA Astrophysics Data System (ADS)

Adequate description of surface water transport is of critical importance for a land surface model to provide spatiotemporal distribution of available water resource, which is a key driver of sustainable management under current and future climate. Most existing runoff transport models are limited to applications over a certain range of scales. For instance, highly distributed runoff routing models require detailed information which is usually not globally available. Most global routing models oversimplify important physical processes limiting their accuracy at small scales. We aim to develop a physically based runoff routing model which is applicable across local, regional and global scales. Within each spatial unit, runoff is first routed as overland flow routing across hillslopes, then through a "tributary sub-network" before discharging into the main channel. The spatial units are then linked via routing through the main channel network. All model parameters are physically-based except two which are obtained through calibration.. We applied this model to the Columbia River Basin, USA at 1/16th, 1/8th, 1/4th, 1/2nd and 1 degree resolutions. The model results were validated against naturalized streamflow at 15 major gauge stations, and compared with two other widely used routing models, the River Transport Model (RTM) contained in the Community Land Model (CLM) and the Variable Infiltration Capability (VIC) routing model. The performance of this routing framework is shown to be superior to the RTM, and comparable with the VIC routing model.

Li, H.; Wigmosta, M. S.; Wu, H.; Huang, M.; Ke, Y.; Coleman, A.; Leung, L.

2011-12-01

213

Physics design and scaling of recirculating induction accelerators: from benchtop prototypes to drivers  

SciTech Connect

Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all of the critical beam dynamics issues that have been raised. We review the design equations for recirculators and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion/extraction, vacuum requirements, and emittance growth, scale from small-prototype to driver-size accelerator.

Barnard, J.J.; Cable, M.D.; Callahan, D.A.

1996-02-06

214

Prospects for colliders and collider physics to the 1 PeV energy scale  

NASA Astrophysics Data System (ADS)

A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing our progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC-one each of e+e- and hadron colliders and three ?+?- colliders - and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R&D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory. .

King, Bruce J.

2000-08-01

215

Characterizing Scale and Location-Dependent Correlation of Water Retention Parameters with Soil Physical Properties Using Wavelet Techniques  

Microsoft Academic Search

Understanding the correlation between soil hydraulic parameters and soil physical properties is a prerequisite for the prediction of soil hydraulic properties from soil physical properties. Th e objective of this study was to examine the scale- and location-dependent correlation between two water retention parameters (? and n) in the van Genuchten (1980) function and soil physical properties (sand content, bulk

Qiaosheng Shu; Zuoxin Liu; Bingcheng Si

2008-01-01

216

DUMUX: A MULTI-SCALE MULTI-PHYSICS TOOLBOX FOR FLOW AND TRANSPORT PROCESSES IN POROUS MEDIA  

Microsoft Academic Search

Flow and transport processes in porous media occur on different spatial and tem- poral scales and may also exhibit different physical behavior in different parts of the model domain. Additionally, the structure of the porous medium itself generally shows a high depen- dence on the spatial scale. Employing a complex fine scale model throughout the whole domain is in general

Bernd Flemisch; Jochen Fritz; Rainer Helmig; Jennifer Niessner

217

MOLECULAR ENVIRONMENTS OF 51 PLANCK COLD CLUMPS IN THE ORION COMPLEX  

SciTech Connect

A mapping survey of 51 Planck cold clumps projected on the Orion complex was performed with J = 1-0 lines of {sup 12}CO and {sup 13}CO with the 13.7 m telescope at the Purple Mountain Observatory. The mean column densities of the Planck gas clumps range from 0.5 to 9.5 Multiplication-Sign 10{sup 21} cm{sup -2}, with an average value of (2.9 {+-} 1.9) Multiplication-Sign 10{sup 21} cm{sup -2}. The mean excitation temperatures of these clumps range from 7.4 to 21.1 K, with an average value of 12.1 {+-} 3.0 K and the average three-dimensional velocity dispersion {sigma}{sub 3D} in these molecular clumps is 0.66 {+-} 0.24 km s{sup -1}. Most of the clumps have {sigma}{sub NT} larger than or comparable to {sigma}{sub Therm}. The H{sub 2} column density of the molecular clumps calculated from molecular lines correlates with the aperture flux at 857 GHz of the dust emission. By analyzing the distributions of the physical parameters, we suggest that turbulent flows can shape the clump structure and dominate their density distribution on large scales, but not function on small scales due to local fluctuations. Eighty-two dense cores are identified in the molecular clumps. The dense cores have an average radius and local thermal equilibrium (LTE) mass of 0.34 {+-} 0.14 pc and 38{sup +5}{sub -30} M{sub Sun }, respectively. The structures of low column density cores are more affected by turbulence, while the structures of high column density cores are more affected by other factors, especially by gravity. The correlation of velocity dispersion versus core size is very weak for the dense cores. The dense cores are found to be most likely gravitationally bounded rather than pressure confined. The relationship between M{sub vir} and M{sub LTE} can be well fitted with a power law. The core mass function here is much flatter than the stellar initial mass function. The lognormal behavior of the core mass distribution is most likely determined by internal turbulence.

Liu Tie; Wu Yuefang; Zhang Huawei, E-mail: liutiepku@gmail.com, E-mail: ywu@pku.edu.cn [Department of Astronomy, Peking University, 100871 Beijing (China)

2012-09-15

218

Fokker-Planck equation in mirror research  

SciTech Connect

Open confinement systems based on the magnetic mirror principle depend on the maintenance of particle distributions that may deviate substantially from Maxwellian distributions. Mirror research has therefore from the beginning relied on theoretical predictions of non-equilibrium rate processes obtained from solutions to the Fokker-Planck equation. The F-P equation plays three roles: Design of experiments, creation of classical standards against which to compare experiment, and predictions concerning mirror based fusion power systems. Analytical and computational approaches to solving the F-P equation for mirror systems will be reviewed, together with results and examples that apply to specific mirror systems, such as the tandem mirror.

Post, R.F.

1983-08-11

219

The physics of energy transfer toward improved subgrid-scale models  

NASA Astrophysics Data System (ADS)

Starting from physical insight on the energy transfer phenomena in wall turbulent flows, it is shown how modeling of subgrid stresses in large-eddy simulations can be improved. Each model should aim at reproducing the double feature of energy sink and source of the small scales of wall flows which become relevant when large filter lengths are considered. Here we propose one possible choice where the main ingredient is the coupling of the classical linear formulation of eddy viscosity with the nonlinear anisotropic features of the velocity increments tensor. This approach, which actually presents most of the features of the mixed models, captures the near-wall dynamics for very large filter lengths reproducing the small scales source physics responsible for backward energy transfer. A posteriori tests show excellent agreement with direct numerical simulation of turbulent channel flows even when very coarse grids are considered. The capability of the balance of the filtered second order structure function as a post-processing tool to evaluate the physics of any model is also shown.

Cimarelli, Andrea; De Angelis, Elisabetta

2014-05-01

220

Pre-Big Bang, fundamental Physics and noncyclic cosmologies. Possible alternatives to standard concepts and laws  

NASA Astrophysics Data System (ADS)

Detailed analyses of WMAP and Planck data can have significant implications for noncyclic pre-Big Bang approaches incorporating a new fundamental scale beyond the Planck scale and, potentially, new ultimate constituents of matter with unconventional basic properties as compared to standard particles. Cosmic-ray experiments at the highest energies can also yield relevant information. Hopefully, future studies will be able to deal with alternatives: i) to standard physics for the structure of the physical vacuum, the nature of space-time, the validity of quantum field theory and conventional symmetries, the interpretation of string-like theories...; ii) to standard cosmology concerning the origin and evolution of our Universe, unconventional solutions to the cosmological constant problem, the validity of inflationary scenarios, the need for dark matter and dark energy... Lorentz-like symmetries for the properties of matter can then be naturally stable space-time configurations resulting from more general primordial scenarios that incorporate physics beyond the Planck scale and describe the formation and evolution of the physical vacuum. A possible answer to the question of the origin of half-integer spins can be provided by a primordial spinorial space-time with two complex coordinates instead of the conventional four real ones, leading to a really new cosmology. We discuss basic questions and phenomenological topics concerning noncyclic pre-Big Bang cosmologies and potentially related physics.

Gonzalez-Mestres, L.

2014-04-01

221

Model-independent forecasts of CMB angular power spectra for the Planck mission  

NASA Astrophysics Data System (ADS)

The Planck mission, designed for making measurements of the cosmic microwave background (CMB) radiation with unprecedented accuracy and angular resolution, is expected to release its entire data in the near future. In this paper, we provide model-independent forecasts for the TT, EE, and TE angular power spectra for the Planck mission using synthetic data based on the best-fit Lambda cold dark matter (?CDM) model. The nonparametric function estimation methodology we use here is based on the agnostic viewpoint of allowing the data to speak for themselves rather than letting the models decide what is inferred from the data. Our analysis indicates that the three Planck angular power spectra will be determined sufficiently well for 2?l ?lmax, where lmax=25001ex" stretchy="true">(TT1ex" stretchy="true">), 1377(EE), and 1727(TE) respectively. A key signature of reionization, namely, a bump at low values of l, is evident in our forecasts for the EE and TE power spectra. Nonparametric confidence bands in the phase shift (?m) versus acoustic scale (lA) plane, corresponding to the first eight peaks in the TT power spectrum, show a confluence region for 300?lA?305 which is in good agreement with the estimate lA=300 based on the best-fit ?CDM model. From our results, we expect that the final Planck data should lead to accurate model-independent estimates of CMB angular power spectra using our nonparametric regression formalism.

Aghamousa, Amir; Arjunwadkar, Mihir; Souradeep, Tarun

2014-01-01

222

Fermion Loops in the Effective Potential of N = 1 Supergravity, with Application to No-Scale Models  

Microsoft Academic Search

Powerful and quite general arguments suggest that N = 1 supergravity, and in particular the superstring-inspired no-scale models, may describe the physics of the four-dimensional vacuum at energy densities below the Planck scale. These models are not renormalizable, since they arise as effective theories after the large masses have been integrated out of the fundamental theory; thus, they have divergences

Joshua Wingate Burton

1990-01-01

223

An Activity-based Curriculum for Large Introductory Physics Classes: The SCALE-UP Project  

NSDL National Science Digital Library

This article offers a description of the activities involved in the Student-Centered Activities for Large Enrollment Undergraduate Programs (SCALE-UP) Project and describes some of the successes the program has seen in classrooms over the last three years. SCALE-UP offers instructors of large introductory science classes an economical and effective alternative to the lecture/laboratory format. This program combines lecture and laboratory in an approach that uses technology and minimal lecturing to create a highly collaborative, technology-rich, hands-on, interactive learning environment. In addition to developing classroom designs and management techniques, the project involves the development, evaluation, and dissemination of curricular materials for introductory physics that support this type of learning.

Saul, Jeffrey; Beichner, Robert J.

2006-12-06

224

A natural hierarchy and a low new physics scale from a bulk Higgs  

NASA Astrophysics Data System (ADS)

We show that a bulk Higgs with a mass saturating the Breitenlohner-Freedman bound can naturally generate and stabilize an exponential hierarchy on an asymptotically AdS background provided appropriate UV boundary conditions are chosen. Such a framework is dual to a strongly coupled, large N CFT deformed by a marginally relevant Higgs mass operator. On the gravity side, the marginally relevant nature of the Higgs mass operator implies that the Higgs VEV is maximally spread in the bulk. This feature significantly decreases the lower bound on the new physics scale in models that address the SM flavor problem. In this framework the radion has a mass strictly lighter than the Kaluza-Klein scale, and the collider phenomenology resembles that of composite Higgs models.

Vecchi, Luca

2011-11-01

225

Extracting physical properties of arbitrarily shaped laser-doped micro-scale areas in semiconductors  

NASA Astrophysics Data System (ADS)

We present a method that allows the extraction of relevant physical properties such as sheet resistance and dopant profile from arbitrarily shaped laser-doped micro-scale areas formed in semiconductors with a focused pulsed laser beam. The key feature of the method is to use large laser-doped areas with an identical average number of laser pulses per area (laser pulse density) as the arbitrarily shaped areas. The method is verified using sheet resistance measurements on laser-doped silicon samples. Furthermore, the method is extended to doping with continuous-wave lasers by using the average number of passes per area or density of passes.

Heinrich, Martin; Kluska, Sven; Hameiri, Ziv; Hoex, Bram; Aberle, Armin G.

2013-12-01

226

The best inflationary models after Planck  

NASA Astrophysics Data System (ADS)

We compute the Bayesian evidence and complexity of 193 slow-roll single-field models of inflation using the Planck 2013 Cosmic Microwave Background data, with the aim of establishing which models are favoured from a Bayesian perspective. Our calculations employ a new numerical pipeline interfacing an inflationary effective likelihood with the slow-roll library ASPIC and the nested sampling algorithm MultiNest. The models considered represent a complete and systematic scan of the entire landscape of inflationary scenarios proposed so far. Our analysis singles out the most probable models (from an Occam's razor point of view) that are compatible with Planck data, while ruling out with very strong evidence 34% of the models considered. We identify 26% of the models that are favoured by the Bayesian evidence, corresponding to 15 different potential shapes. If the Bayesian complexity is included in the analysis, only 9% of the models are preferred, corresponding to only 9 different potential shapes. These shapes are all of the plateau type.

Martin, Jérôme; Ringeval, Christophe; Trotta, Roberto; Vennin, Vincent

2014-03-01

227

Fundamental Scalings of Zonal Flows in a Basic Plasma Physics Experiment  

NASA Astrophysics Data System (ADS)

A basic physics experimental study of zonal flows (ZF) associated with ITG (ion temperature gradient) drift modes has been performed in the Columbia Linear Machine (CLM) and ZF has been definitively identified [1]. However, in contrast to most tokamak experiments, the stabilizing effect of ZF shear to ITG appears to be small in CLM. We now report on the study of important scaling behavior of ZF. First and most importantly, we report on the collisional damping scaling of ZF, which is considered to be its saturation mechanism [2]. By varying the sum of ion-ion and ion-neutral collision frequency over nearly half an order of magnitude, we find no change in the amplitude of ZF. Secondly, we study the scaling of ZF amplitude with ITG amplitude via increasing ITG drive though ?i, as well as feedback (stabilizing / destabilizing). We have observed markedly different scaling near and far above marginal stability. [1] V. Sokolov, X. Wei, A.K. Sen and K. Avinash, Plasma Phys.Controlled Fusion 48, S111 (2006). [2] P.H. Diamond, S.-I. Itoh, K.Itoh and T.S. Hahm, Plasma Phys.Controlled Fusion 47, R35 (2005).

Sokolov, Vladimir; Wei, Xiao; Sen, Amiya K.

2007-11-01

228

Physics of large-scale star formation: The GAS-Dynamic aspect  

NASA Astrophysics Data System (ADS)

The subject of the review is the nature of regions of large-scale starbursts in galaxies. Theoretical investigations are presented and discussed, for the most part. Principal attention is devoted to the gas-dynamic approach to the problem. The review has the following plan. First we give a brief summary of empirical data on superassociations as regions of collective star formation on the largest scale in disk and irregular galaxies (Sec. 2); we then describe one possible gas-dynamic scenario for the origin of these objects (Sec. 3); the key physical mechanism on which the scenario is based — a collision of shock waves — is studied on the basis of general considerations (Sec. 4), as well as using computer simulation (Sec. 5) and laboratory experiments with shock waves (Sec. 6); the possibilities for the occurrence of this process under the specific conditions of the interstellar medium in disk and irregular galaxies are discussed in Sec. 7; in Sec. 8 we then consider features of large-scale collective star formation in barred galaxies; the evolution of spiral shocks that can initiate this process is the subject of Sec. 9; possible means of generation of large-scale regions of star formation like superassociations at the center of a bar (Sec. 10) and near its ends (Sec. 11) are then described; a brief conclusion is given in Sec. 12.

Chernin, A. D.

1996-10-01

229

MAPU: Max-Planck Unified database of organellar, cellular, tissue and body fluid proteomes  

Microsoft Academic Search

Mass spectrometry (MS)-based proteomics has become a powerful technology to map the protein composition of organelles, cell types and tissues. In our department, a large-scale effort to map these proteomes is complemented by the Max-Planck Unified (MAPU) proteome database. MAPU contains several body fluid proteomes; including plasma, urine, and cerebrospinal fluid. Cell lines have been mapped to a depth of

Yanling Zhang; Yong Zhang; Jun Adachi; Jesper V. Olsen; Rong Shi; Gustavo De Souza; Erica Pasini; Leonard J. Foster; Boris Macek; Alexandre Zougman; Chanchal Kumar; Jacek R. Wisniewski; Jan Wang; Matthias Mann

2007-01-01

230

An Analysis of the Purposes for Engaging in Physical Activity Scale (PEPAS) as an Instrument for Curriculum Research.  

ERIC Educational Resources Information Center

This study tested the reliability and factorial validity of the Purposes for Engaging in Physical Activity Scale (PEPAS). The instrument is designed to measure motivational factors for the purpose of curricular decision making and curriculum research. (JD)

Steinhardt, Mary A.; And Others

1988-01-01

231

Multi-physics and multi-scale characterization of shale anisotropy  

NASA Astrophysics Data System (ADS)

Shales are the most abundant sedimentary rock type in the Earth's shallow crust. In the past decade or so, they have attracted increased attention from the petroleum industry as reservoirs, as well as more traditionally for their sealing capacity for hydrocarbon/CO2 traps or underground waste repositories. The effectiveness of both fundamental and applied shale research is currently limited by (i) the extreme variability of physical, mechanical and chemical properties observed for these rocks, and by (ii) the scarce data currently available. The variability in observed properties is poorly understood due to many factors that are often irrelevant for other sedimentary rocks. The relationships between these properties and the petrophysical measurements performed at the field and laboratory scales are not straightforward, translating to a scale dependency typical of shale behaviour. In addition, the complex and often anisotropic micro-/meso-structures of shales give rise to a directional dependency of some of the measured physical properties that are tensorial by nature such as permeability or elastic stiffness. Currently, fundamental understanding of the parameters controlling the directional and scale dependency of shale properties is far from complete. Selected results of a multi-physics laboratory investigation of the directional and scale dependency of some critical shale properties are reported. In particular, anisotropic features of shale micro-/meso-structures are related to the directional-dependency of elastic and fluid transport properties: - Micro-/meso-structure (?m to cm scale) characterization by electron microscopy and X-ray tomography; - Estimation of elastic anisotropy parameters on a single specimen using elastic wave propagation (cm scale); - Estimation of the permeability tensor using the steady-state method on orthogonal specimens (cm scale); - Estimation of the low-frequency diffusivity tensor using NMR method on orthogonal specimens (scale). For each of the above properties, leading-edge experimental techniques have been associated with novel interpretation tools. In this contribution, these experimental and interpretation methods are described. Relationships between the measured properties and the corresponding micro-/meso-structural features are discussed. For example, P-wave velocity was measured along 100 different propagation paths on a single cylindrical shale specimen using miniature ultrasonic transducers. Assuming that (i) the elastic tensor of this shale is transversely isotropic; and (i) the sample has been cored perfectly perpendicular to the bedding plane (symmetry plane is horizontal), Thomsen's anisotropy parameters inverted from the measured velocities are: - P-wave velocity along the symmetry axis (perpendicular to the bedding plane) ?o=3.45km/s; - P-wave anisotropy ?=0.12; - Parameter controlling the wave front geometry ?=0.058. A novel inversion algorithm allows for recovering these parameters without assuming a priori a horizontal bedding (symmetry) plane. The inversion of the same data set using this algorithm yields (i) ?o=3.23km/s, ?=0.25 and ?=0.18, and (ii) the elastic symmetry axis is inclined of ?=30° with respect to the specimen's axis. Such difference can have strong impact on field applications (AVO, ray tracing, tomography).

Sarout, J.; Nadri, D.; Delle Piane, C.; Esteban, L.; Dewhurst, D.; Clennell, M. B.

2012-12-01

232

Planck early results. VII. The Early Release Compact Source Catalogue  

Microsoft Academic Search

A brief description of the methodology of construction, contents and usage of the Planck Early Release Compact Source Catalogue (ERCSC), including the Early Cold Cores (ECC) and the Early Sunyaev-Zeldovich (ESZ) cluster catalogue is provided. The catalogue is based on data that consist of mapping the entire sky once and 60% of the sky a second time by Planck, thereby

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; A. Bonaldi; L. Bonavera; J. R. Bond; J. Borrill; M. Bucher; C. Burigana; R. C. Butler; P. Cabella; C. M. Cantalupo; B. Cappellini; J.-F. Cardoso; P. Carvalho; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; R.-R. Chary; X. Chen; L.-Y. Chiang; C. Chiang; P. R. Christensen; D. L. Clements; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; L. Danese; R. J. Davis; P. de Bernardis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; C. Dickinson; J. M. Diego; K. Dolag; H. Dole; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; H. K. Eriksen; F. Finelli; O. Forni; P. Fosalba; M. Frailis; E. Franceschi; S. Galeotta; K. Ganga; M. Giard; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; J. Haissinski; F. K. Hansen; D. Harrison; G. Helou; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; A. Hornstrup; W. Hovest; R. J. Hoyland; K. M. Huffenberger; M. Huynh; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; A. Lähteenmäki; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; J. P. Leahy; R. Leonardi; J. León-Tavares; C. Leroy; P. B. Lilje; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; G. Maggio; D. Maino; N. Mandolesi; R. Mann; M. Maris; F. Marleau; D. J. Marshall; E. Martínez-González; S. Masi; M. Massardi; S. Matarrese; F. Matthai; P. Mazzotta; P. R. Meinhold; A. Melchiorri; J.-B. Melin; L. Mendes; A. Mennella; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; S. Osborne; F. Pajot; R. Paladini; B. Partridge; F. Pasian; G. Patanchon; T. J. Pearson; O. Perdereau; L. Perotto; F. Piacentini; M. Piat; R. Piffaretti; S. Plaszczynski; P. Platania; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. W. Pratt; G. Prézeau; S. Prunet; J.-L. Puget; J. P. Rachen; W. T. Reach; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; A. Sajina; M. Sandri; D. Santos; G. Savini; B. M. Schaefer; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sudiwala; R. Sunyaev; J.-F. Sygnet; J. A. Tauber; D. Tavagnacco; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; M. Türler; G. Umana; L. Valenziano; J. Valiviita; J. Varis; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; S. D. M. White; A. Wilkinson; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

233

Fokker-Planck/Transport model for neutral beam driven tokamaks  

SciTech Connect

The application of nonlinear Fokker-Planck models to the study of beam-driven plasmas is briefly reviewed. This evolution of models has led to a Fokker-Planck/Transport (FPT) model for neutral-beam-driven Tokamaks, which is described in detail. The FPT code has been applied to the PLT, PDX, and TFTR Tokamaks, and some representative results are presented.

Killeen, J.; Mirin, A.A.; McCoy, M.G.

1980-01-01

234

The presentation of the Planck radiation formula (tutorial)  

Microsoft Academic Search

Errors in the treatment of complex concepts may be due to authors being too selective in their choice of theoretical material to include, to keep complication of the explanation to a minimum. This situation seems to exist in the treatment of Planck's derivation of the Planck radiation formula, the distribution function for the energy density of black-body (or cavity) radiation,

R. C. Dougal

1976-01-01

235

Zero Point Energy: Thermodynamic Equilibrium and Planck Radiation Law  

Microsoft Academic Search

In a recent paper, we proved that Planck's radiation law with zero point energy is equivalent to the combined assumptions of zero point energy hypothesis, the quantum law and the approximated Boson statistics. Here, we apply the principle of maximal entropy to show that Planck's radiation law with zero point energy represents a state of thermodynamic equilibrium.

H. Vic Dannon

236

Design and analysis of the cryoharness for Planck LFI  

Microsoft Academic Search

Planck is the third Medium-Sized Mission (M3) of ESA Horizon 2000 Scientific Programme. It is designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky, with unprecedented sensitivity and angular resolution. Planck carries two main experiments named HFI (High Frequency Instrument) and LFI (Low Frequency Instrument). The first is based on bolometers, the latter is

Paolo H. Leutenegger; Marco Bersanelli; Roberto Ferretti; Mauro Prina

2003-01-01

237

The Nature of Light: I. A Historical Survey Up to the Pre-Planck Era and Implications for Teaching  

ERIC Educational Resources Information Center

The objective of this article is to contribute to the scant literature that exists on historical developments on the nature of light. It traces the nature of light from the times of the ancient Greeks to the classical theories prior to Planck. The development of thought that characterizes the evolution of a concept in physics over time affords…

Oon, Pey Tee; Subramaniam, R.

2009-01-01

238

PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE  

SciTech Connect

A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e{sup +}e{sup {minus}} and hadron colliders and three {mu}{sup +}{mu}{sup {minus}} colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory.

KING,B.J.

2000-05-05

239

Physical descriptions of the bacterial nucleoid at large scales, and their biological implications.  

PubMed

Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organized at various length scales. This has implications for modulating (when not directly enabling) the core biological processes of replication, transcription and segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. In particular, we highlight the role that statistical and soft condensed matter physics play in describing this system of fundamental biological importance, specifically reviewing classic and more modern tools from the theory of polymers. We also discuss some attempts toward unifying interpretations of the current results, pointing to possible directions for future investigation. PMID:22790781

Benza, Vincenzo G; Bassetti, Bruno; Dorfman, Kevin D; Scolari, Vittore F; Bromek, Krystyna; Cicuta, Pietro; Lagomarsino, Marco Cosentino

2012-07-01

240

Physical descriptions of the bacterial nucleoid at large scales, and their biological implications  

NASA Astrophysics Data System (ADS)

Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organized at various length scales. This has implications for modulating (when not directly enabling) the core biological processes of replication, transcription and segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. In particular, we highlight the role that statistical and soft condensed matter physics play in describing this system of fundamental biological importance, specifically reviewing classic and more modern tools from the theory of polymers. We also discuss some attempts toward unifying interpretations of the current results, pointing to possible directions for future investigation.

Benza, Vincenzo G.; Bassetti, Bruno; Dorfman, Kevin D.; Scolari, Vittore F.; Bromek, Krystyna; Cicuta, Pietro; Cosentino Lagomarsino, Marco

2012-07-01

241

Evaluating Introductory Physics Classes in Light of the ABET Criteria: An Example from the SCALE-UP Project.  

ERIC Educational Resources Information Center

The Student-Centered Activities for Large Enrollment University Physics (SCALE-UP) project at North Carolina State University (NCSU) is developing a curriculum to promote learning through in-class group activities in introductory physics classes up to 100 students. The authors are currently in Phase II of the project using a specially designed…

Saul, Jeffery M.; Deardorff, Duane L.; Abbott, David S.; Allain, Rhett J.; Beichner, Robert J.

242

Physics on noncommutative spacetimes  

NASA Astrophysics Data System (ADS)

The structure of spacetime at the Planck scale remains a mystery to this date with a lot of insightful attempts to unravel this puzzle. One such attempt is the proposition of a 'pointless' structure for spacetime at this scale. This is done by studying the geometry of the spacetime through a noncommutative algebra of functions defined on it. We call such spacetimes 'noncommutative spacetimes'. This dissertation probes physics on several such spacetimes. These include compact noncommutative spaces called fuzzy spaces and noncompact spacetimes. The compact examples we look at are the fuzzy sphere and the fuzzy Higg's manifold. The noncompact spacetimes we study are the Groenewold-Moyal plane and the Bcn? plane. A broad range of physical effects are studied on these exotic spacetimes. We study spin systems on the fuzzy sphere. The construction of Dirac and chirality operators for an arbitrary spin j is studied on both S2F and S2 in detail. We compute the spectrums of the spin 1 and spin 32 Dirac operators on S2F . These systems have novel thermodynamical properties which have no higher dimensional analogs, making them interesting models. The fuzzy Higg's manifold is found to exhibit topology change, an important property for any theory attempting to quantize gravity. We study how this change occurs in the classical setting and how quantizing this manifold smoothens the classical conical singularity. We also show the construction of the star product on this manifold using coherent states on the noncommutative algebra describing this noncommutative space. On the Moyal plane we develop the LSZ formulation of scalar quantum field theory. We compute scattering amplitudes and remark on renormalization of this theory. We show that the LSZ formalism is equivalent to the interaction representation formalism for computing scattering amplitudes on the Moyal plane. This result is true for on-shell Green's functions and fails to hold for off-shell Green's functions. With the present technology available, there is a scarcity of experiments which directly involve the Planck scale. However there are interesting low and medium energy experiments which put bounds on the validity of established principles which are thought to be violated at the Planck scale. One such principle is the Pauli principle which is expected to be violated on noncommutative spacetimes. We introduce a noncommutative spacetime called the Bcn? plane to show how transitions, not obeying the Pauli principle, occur in atomic systems. On confronting with the data from experiments, we place bounds on the noncommutative parameter.

Padmanabhan, Pramod

243

Physics-Based Multi-Scale Modeling of Shear Initiated Reactions in Energetic and Reactive Materials.  

National Technical Information Service (NTIS)

We developed a multi-scale approach for simulating shear initiated reactions that spans from the molecular scale to the mesoscale (length scale of material heterogeneities) to the full continuum scale (length scale of the weapon system) and implemented it...

J. K. Brennan L. Tran M. Fermen-Coker

2010-01-01

244

Validity and reliability of the Chinese translation of the Physical Activity Scale for the Elderly (PASE)  

PubMed Central

Purpose To translate and assess the reliability and validity of a Chinese version of the Physical Activity Scale for the Elderly (PASE). Methods Participants included Chinese individuals >65 living in the community or assistive living facilities. At baseline, 73 subjects completed the translated PASE, and Chinese versions of 3 other scales to evaluate validity; the Timed-Up and Go (TUG), the Older American Resources Services Activities of Daily Living (OARS ADL), and the Activities Balance Confidence Scale (ABC). At follow-up, 66 subjects completed the PASE and a questionnaire to determine if there were any changes in health over the retest period. Results The mean baseline PASE-C score was 76.0 (±49.1) at baseline and 78.33 (±50.27) at follow up. Correlations between the PASE-C and other variables were: age r= ?0.51; TUG r= ?0.52; OARS ADL r= 0.56 and ABC score r=0.62. The retest reliability was ICC= 0.79 (95% confidence interval 0.68–0.86). Conclusion Our results indicate that the PASE-C has acceptable reliability and there is support for validity in the older Chinese population.

Vaughn, Kristine; Miller, William C.

2012-01-01

245

A Scale for Home Visiting Nurses to Identify Risks of Physical Abuse and Neglect among Mothers with Newborn Infants  

ERIC Educational Resources Information Center

Objective: The aim was to construct and test the reliability (utility, internal consistency, interrater agreement) and the validity (internal validity, concurrent validity) of a scale for home visiting social nurses to identify risks of physical abuse and neglect in mothers with a newborn child. Method: A 71-item scale was constructed based on a…

Grietens, Hans; Geeraert, Liesl; Hellinckx, Walter

2004-01-01

246

The Assessment of Denial and Physical Complaints: The Validity of the Hy Scale and Associated MMPI Signs.  

ERIC Educational Resources Information Center

Using samples of psychiatric, medical, and chronic pain patients, the effectiveness of the Hysteria scale and of various combinations of Minnesota Multiphasic Personality Inventory scales as predictors of the simultaneous occurrence of two characteristics was evaluated: denial of psychological problems and admission of physical problems. The value…

McGrath, Robert E.; O'Malley, W. Brian

1986-01-01

247

Emergent behaviour in electrodiffusion: Planck's other quanta  

NASA Astrophysics Data System (ADS)

A well-established nonlinear continuum model of time-independent electrodiffusion describes the migrational and diffusional transport of two ionic species, with equal and opposite valences, across a liquid junction. The ionic charge densities provide the source for a static electric field, which in turn feeds back on the charges to contribute the migrational component of the ionic transport. Underpinning the model is a form of the second Painlevé ordinary differential equation (PII). When Bäcklund transformations, extended from those known in the context of PII, are applied to an exact solution of the model first found by Planck, a sequence of exact solutions emerges. These are characterized by corresponding ionic flux and current densities that are found to be quantized in a particularly simple way. It is argued here that this flux quantization reflects the underlying quantization of charge at the ionic level: the nonlinear continuum model ‘remembers' its discrete roots, leading to this emergent phenomenon.

Bass, L.; Bracken, A. J.

2014-02-01

248

Planck & Herschel unveil extreme submillimeter structures  

NASA Astrophysics Data System (ADS)

Planck is the first FIR/sub-mm all sky survey with the sensitivity required to systematically identify the rarest, most luminous high-redshift sub-mm sources on the sky, either strongly gravitationally lensed galaxies, or the joint FIR/sub-mm emission from multiple intense starbursts as expected for the most massive, most rapidly collapsing dark-matter environments in the early Universe. We use a color selection to identify a population of 500 bright, high-fidelity Planck high-z candidates, 180 of which we are now following up with Herschel/SPIRE, including an extraordinary allocation of ``Must Do'' Director's Discretionary Time. All of our sources have typical SPIRE colors of high-z galaxies, and the redshifts of several have already been confirmed spectroscopically. We will use Spitzer/IRAC to identify and analyze the stellar counterparts of 35 of these sources, aided (but not replaced) by existing and scheduled ground-based optical/NIR photometry. This will allow us to measure photometric redshifts, stellar masses, star formation histories and stellar ages of these sources. We will search for candidate member galaxies of nascent galaxy clusters, and prepare detailed spectroscopic follow-up. At what cosmic epoch did massive galaxy clusters form most of their stars? Will we find that star formation is more or less vigorous in these galaxies compared to galaxies in the field? Is the upper end of the ``red sequence'' already in place? These are only some of the questions that IRAC will help us address.

Dole, Herve; Chary, Ranga-Ram; Montier, Ludovic; Lagache, Guilaine; Beelen, Alexandre; Welikala, Niraj; Puget, Jean-Loup; Giard, Martin; Pointecouteau, Etienne; Omont, Alain; Guery, David; Nesvabda, Nicole; Chary, Ranga; Scott, Douglas; Le Floc'h, Emeric; Frye, Brenda; Soucail, Genevieve

2012-12-01

249

History and progress on accurate measurements of the Planck constant  

NASA Astrophysics Data System (ADS)

The measurement of the Planck constant, h, is entering a new phase. The CODATA 2010 recommended value is 6.626?069 57 × 10-34 J s, but it has been a long road, and the trip is not over yet. Since its discovery as a fundamental physical constant to explain various effects in quantum theory, h has become especially important in defining standards for electrical measurements and soon, for mass determination. Measuring h in the International System of Units (SI) started as experimental attempts merely to prove its existence. Many decades passed while newer experiments measured physical effects that were the influence of h combined with other physical constants: elementary charge, e, and the Avogadro constant, NA. As experimental techniques improved, the precision of the value of h expanded. When the Josephson and quantum Hall theories led to new electronic devices, and a hundred year old experiment, the absolute ampere, was altered into a watt balance, h not only became vital in definitions for the volt and ohm units, but suddenly it could be measured directly and even more accurately. Finally, as measurement uncertainties now approach a few parts in 108 from the watt balance experiments and Avogadro determinations, its importance has been linked to a proposed redefinition of a kilogram unit of mass. The path to higher accuracy in measuring the value of h was not always an example of continuous progress. Since new measurements periodically led to changes in its accepted value and the corresponding SI units, it is helpful to see why there were bumps in the road and where the different branch lines of research joined in the effort. Recalling the bumps along this road will hopefully avoid their repetition in the upcoming SI redefinition debates. This paper begins with a brief history of the methods to measure a combination of fundamental constants, thus indirectly obtaining the Planck constant. The historical path is followed in the section describing how the improved techniques and discoveries in quantum mechanics steadily reduced the uncertainty of h. The central part of this review describes the technical details of the watt balance technique, which is a combination of the mechanical and electronic measurements that now determine h as a direct result, i.e. not requiring measured values of additional fundamental constants. The first technical section describes the basics and some of the common details of many watt balance designs. Next is a review of the ongoing advances at the (currently) seven national metrology institutions where these experiments are pursued. A final summary of the recent h determinations of the last two decades shows how history keeps repeating itself; there is again a question of whether there is a shift in the newest results, albeit at uncertainties that are many orders of magnitude less than the original experiments. The conclusion is that there is room for further development to resolve these differences and find new ideas for a watt balance system with a more universal application. Since the next generation of watt balance experiments are expected to become kilogram realization standards, the historical record suggests that there is yet a need for proof that Planck constant results are finally reproducible at an acceptable uncertainty.

Steiner, Richard

2013-01-01

250

Planck early results. IX. XMM-Newton follow-up for validation of Planck cluster candidates  

Microsoft Academic Search

We present the XMM-Newton follow-up for confirmation of Planck cluster candidates. Twenty-five candidates have been observed to date using snapshot (~10ks) exposures, ten as part of a pilot programme to sample a low range of signal-to-noise ratios (4 < S\\/N 5 candidates. The sensitivity and spatial resolution of XMM-Newton allows unambiguous discrimination between clusters and false candidates. The 4 false

N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; M. Bartelmann; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; M. L. Brown; M. Bucher; C. Burigana; P. Cabella; C. M. Cantalupo; J.-F. Cardoso; P. Carvalho; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; L.-Y. Chiang; G. Chon; P. R. Christensen; E. Churazov; D. L. Clements; S. Colafrancesco; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; A. da Silva; H. Dahle; L. Danese; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; J. M. Diego; K. Dolag; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; F. Finelli; I. Flores-Cacho; O. Forni; M. Frailis; E. Franceschi; S. Fromenteau; S. Galeotta; K. Ganga; R. T. Génova-Santos; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; R. González-Riestra; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; D. Harrison; P. Heinämäki; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; G. Hurier; A. H. Jaffe; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; M. Linden-Vornle; S. Leach; R. Leonardi; A. Liddle; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; F. Marleau; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; A. Melchiorri; J.-B. Melin; L. Mendes; A. Mennella; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; S. Osborne; F. Pajot; F. Pasian; G. Patanchon; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; E. Pointecouteau; R. Piffaretti; S. Plaszczynski; G. Polenta; N. Ponthieu; T. Poutanen; G. W. Pratt; G. Prézeau; S. Prunet; J.-L. Puget; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; J. A. Rubiño-Martín; B. Rusholme; E. Saar; M. D. Seiffert; D. Santos; B. M. Schaefer; D. Scott; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sunyaev; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; L. Valenziano; L. Vibert; P. Vielva; F. Villa; N. Vittorio; B. D. Wandelt; S. D. M. White; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

251

Scale Development for Measuring and Predicting Adolescents' Leisure Time Physical Activity Behavior  

PubMed Central

The aim of this study was to develop a scale for assessing and predicting adolescents’ physical activity behavior in Spain and Luxembourg using the Theory of Planned Behavior as a framework. The sample was comprised of 613 Spanish (boys = 309, girls = 304; M age =15.28, SD =1.127) and 752 Luxembourgish adolescents (boys = 343, girls = 409; M age = 14.92, SD = 1.198), selected from students of two secondary schools in both countries, with a similar socio-economic status. The initial 43-items were all scored on a 4-point response format using the structured alternative format and translated into Spanish, French and German. In order to ensure the accuracy of the translation, standardized parallel back-translation techniques were employed. Following two pilot tests and subsequent revisions, a second order exploratory factor analysis with oblimin direct rotation was used for factor extraction. Internal consistency and test-retest reliabilities were also tested. The 4-week test-retest correlations confirmed the items’ time stability. The same five factors were obtained, explaining 63.76% and 63.64% of the total variance in both samples. Internal consistency for the five factors ranged from ? = 0.759 to ? = 0. 949 in the Spanish sample and from ? = 0.735 to ? = 0.952 in the Luxembourgish sample. For both samples, inter-factor correlations were all reported significant and positive, except for Factor 5 where they were significant but negative. The high internal consistency of the subscales, the reported item test-retest reliabilities and the identical factor structure confirm the adequacy of the elaborated questionnaire for assessing the TPB-based constructs when used with a population of adolescents in Spain and Luxembourg. The results give some indication that they may have value in measuring the hypothesized TPB constructs for PA behavior in a cross-cultural context. Key points When using the structured alternative format, weak internal consistency was obtained. Rephrasing the items and scoring items on a Likert-type scale enhanced greatly the subscales reliability. Identical factorial structure was extracted for both culturally different samples. The obtained factors, namely perceived physical competence, parents’ physical activity, perceived resources support, attitude toward physical activity and perceived parental support were hypothesized as for the original TPB constructs.

Ries, Francis; Romero Granados, Santiago; Arribas Galarraga, Silvia

2009-01-01

252

Fractional Fokker-Planck Equation and Black-Scholes Formula in Composite-Diffusive Regime  

NASA Astrophysics Data System (ADS)

In statistical physics, anomalous diffusion plays an important role, whose applications have been found in many areas. In this paper, we introduce a composite-diffusive fractional Brownian motion X ?, H ( t)= X H ( S ? ( t)), 0< ?, H<1, driven by anomalous diffusions as a model of asset prices and discuss the corresponding fractional Fokker-Planck equation and Black-Scholes formula. We obtain the fractional Fokker-Planck equation governing the dynamics of the probability density function of the composite-diffusive fractional Brownian motion and find the Black-Scholes differential equation driven by the stock asset X ?, H ( t) and the corresponding Black-Scholes formula for the fair prices of European option.

Liang, Jin-Rong; Wang, Jun; L?, Long-Jin; Gu, Hui; Qiu, Wei-Yuan; Ren, Fu-Yao

2012-01-01

253

Use and Abuse of a Fractional Fokker-Planck Dynamics for Time-Dependent Driving  

NASA Astrophysics Data System (ADS)

We investigate a subdiffusive, fractional Fokker-Planck dynamics occurring in time-varying potential landscapes and thereby disclose the failure of the fractional Fokker-Planck equation (FFPE) in its commonly used form when generalized in an ad hoc manner to time-dependent forces. A modified FFPE (MFFPE) is rigorously derived, being valid for a family of dichotomously alternating force fields. This MFFPE is numerically validated for a rectangular time-dependent force with zero average bias. For this case, subdiffusion is shown to become enhanced as compared to the force free case. We question, however, the existence of any physically valid FFPE for arbitrary varying time-dependent fields that differ from this dichotomous varying family.

Heinsalu, E.; Patriarca, M.; Goychuk, I.; Hänggi, P.

2007-09-01

254

Some aspects of wind tunnel magnetic suspension systems with special application at large physical scales  

NASA Technical Reports Server (NTRS)

Wind tunnel magnetic suspension and balance systems (MSBSs) have so far failed to find application at the large physical scales necessary for the majority of aerodynamic testing. Three areas of technology relevant to such application are investigated. Two variants of the Spanwise Magnet roll torque generation scheme are studied. Spanwise Permanent Magnets are shown to be practical and are experimentally demonstrated. Extensive computations of the performance of the Spanwise Iron Magnet scheme indicate powerful capability, limited principally be electromagnet technology. Aerodynamic testing at extreme attitudes is shown to be practical in relatively conventional MSBSs. Preliminary operation of the MSBS over a wide range of angles of attack is demonstrated. The impact of a requirement for highly reliable operation on the overall architecture of Large MSBSs is studied and it is concluded that system cost and complexity need not be seriously increased.

Britcher, C. P.

1983-01-01

255

NRAO Astronomer Wins Max-Planck Research Award  

NASA Astrophysics Data System (ADS)

Dr. Christopher Carilli, a National Radio Astronomy Observatory (NRAO) astronomer in Socorro, New Mexico, has been chosen to receive the prestigious Max Planck Research Award from the Alexander von Humboldt Foundation and the Max Planck Society in Germany. Christopher Carilli Dr. Christopher Carilli Click on image for more photos CREDIT: NRAO/AUI/NSF Carilli, a radio astronomer, and German particle physicist Christof Wetterich are the 2005 recipients of the award, conferred on "one researcher working in Germany and one working abroad who have already gained an international reputation and who are expected to produce outstanding achievements in the framework of international collaboration," according to an announcement from the Humboldt Foundation. "This is a great honor for Chris, and we are proud to see him receive such important international recognition for the excellence of his research," said NRAO Director Fred K.Y. Lo. Carilli's research has focused on studying very distant galaxies in the early Universe, and a quest to find the first luminous objects, such as stars or galaxies, to emerge. His most recent interests focus on unveiling the mysteries of what cosmologists call the "Epoch of Reionization," when the first stars and galaxies ionized the neutral hydrogen that pervaded the young Universe. Carilli and his research colleagues have used NRAO's Very Large Array and other radio telescopes to discover that the molecular raw material for star formation already was present in a galaxy seen as it was about 800 million years after the Big Bang, less than 1/16 the current age of the Universe. The Max Planck Research Award provides 750,000 Euros (currently about $900,000), to be used over five years, for research. The funding is provided by the German Ministry of Education and Research. Carilli will use the funding to support young researchers and to build scientific instrumentation, with a focus on fostering radio studies of cosmic reionization and the first galaxies. "The phone call from Prof. Fruehwald, president of the Humboldt Foundation, was quite a shock, and overwhelming, but much appreciated," Carilli said. "Now I just have to make good on their investment. Fortunately, I have a lot of help. I consider this award a recognition of our team's efforts over the last few years." The team includes collaborators in Bonn, Profs. Karl Menten and Frank Bertoldi; Heidelberg, Drs. Fabian Walter and Eva Schinnerer; and in France, Dr. Pierre Cox and Prof. Alain Omont. Carilli added: "In an era of big international telescope projects, I think we have set the standard for successful international research collaborations. These folks are not only my professional colleagues, but good friends." Carilli received a B.A. in Physics and Astronomy from the University of Pennsylvania and, in 1989, a Ph.D. in Physics from the Massachusetts Institute of Technology. After serving in research positions at NRAO in Socorro, the Harvard-Smithsonian Center for Astrophysics, and Leiden Observatory in the Netherlands, Carilli joined NRAO's permanent scientific staff in 1996. He also was a visiting Humboldt fellow in Bonn in 1999. He serves on a number of scientific advisory committees, and recently was chair of the international science advisory committee for the Square Kilometer Array project. He has co-edited five books and authored numerous research papers in a wide variety of scientific journals. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

2005-04-01

256

The International Max Planck Research School (IMPRS) for Astrophysics at Garching-Munich  

NASA Astrophysics Data System (ADS)

The "International Max Planck Research School for Astrophysics at the University of Munich" is an international graduate school which aims at training highly qualified young scientists from all over the world. The Research School is supported by all astrophyscial institutes and research groups in the Garching-Munich area (MPI for Extraterrestrial Physics, MPI for Astrophysics, Institute for Astronomy and Astrophysics of the University Munich, European Southern Obervatory, Astroparticle Groups at the Technical University Munich and at the MPI for Physics). This article summarizes the history, the design and the operation of the school which started teaching in September 2001.

Trümper, Joachim

257

A physics-based stochastic approach to representing unresolved scales in ocean models  

NASA Astrophysics Data System (ADS)

Recently, there has been an enormous development to represent unresolved scales by stochastic processes. But current stochastic techniques remain imperfect because the physical properties of the subgridscale processes are either introduced a posteriori as in data-based approaches, or they are prescribed ad hoc by Gaussian closures as in order reduction techniques. In a unifying approach, we combine elements from deterministic physics-based parameterizations and stochastic techniques to give a self-contained stochastic representation of subgridscale interactions. In a nutshell, the largely fixed spatial patterns of the subgridscale interactions are represented by the interactions of the most-unstable modes, whereas the amplitudes of these interactions are assumed to be stochastic with their statistics given via the amplitude equations of the most-unstable modes. For an efficient implementation, we exploit new, powerful tools such as generalized eigenvalue solvers suited to compute targeted eigenmodes of large dimensional systems, and the Dynamical Orthogonal Field method to solve the stochastic differential equations which yields the entire probability distribution of the flow field. As a first demonstration, we discuss the stochastic representation of baroclinic turbulence in the double gyre circulation.

Viebahn, Jan; Dijkstra, Henk A.

2014-05-01

258

Pore-scale Analysis on Physics Property Changes of CO2 Bleached Sandstone, Entrada Fromation, Utah  

NASA Astrophysics Data System (ADS)

Since carbon dioxide injected into geological formations can cause a variety of physical and chemical reaction with minerals, it is important to evaluate the characteristics and aspects of these effects in CO2 geological sequestration. For the analog of the phenomena, we conducted pore-scale analysis on porosity and permeability changes and their characteristics for CO2-bleached Entrada formation, Utah due to natural leakage of CO2. From thin section analysis, we observed mineralogical and pore-shape changes: precipitation of carbonate minerals. Then, we estimated porosity and permeability from thin section, using a computational rock physics technique. The estimated porosity of unbleached sample is approximately 13% and that of bleached sample is around 10%, which implies the precipitation of carbonate minerals. The estimated permeability showed a little differences between two samples. This observations seems to imply that the precipitation would occur where permeability is not significantly affected: grain contacts. For more systematic analysis, we obtained 3D pore microstructures by X-ray microtomography technique. The preliminary analysis using the 3D pore microstructures showed similar results to what we found in the thin-section analysis. And a set of simulations for porosity and permeability are now being conducted. The final result will help understand how injected CO2 changes pore structures and physical properties such as porosity and permeability, and will also help accurate monitoring of geological storage sites. Acknowledgement: This work was supported by the Energy Resources R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2010201020001A).

Han, J.; Keehm, Y.

2012-12-01

259

Scaling of hollow cathode magnetrons for ionized metal physical vapor deposition  

SciTech Connect

Ionized metal physical vapor deposition is being increasingly used to deposit diffusion barriers and Cu seed layers into high aspect ratio trenches for microelectronics fabrication. Hollow cathode magnetrons (HCMs) represent a technology capable of depositing metal over large areas at pressures of a few millitorrs. The fundamental mechanisms of these devices are not well understood and so their optimization is difficult. In this article, results from a two-dimensional computational investigation of HCMs are discussed to illuminate scaling issues. The hybrid model incorporates algorithms whereby transport coefficients for use in fluid equations are derived using a kinetic simulation. The goal is to enable the fluid algorithms in the model to be able to more accurately represent low pressure operation. The consequences of power, pressure, and magnitude and orientation of applied magnetic fields were investigated. The authors found that the magnetic field configuration significantly affects the magnitude and distribution of fluxes incident on the substrate. A study of the Cu seed layer deposition process, carried out using a feature scale model, correlates changes in plasma properties with conformal deposition into trenches.

Vyas, Vivek; Kushner, Mark J. [Department of Materials Science and Engineering, University of Illinois, 1304 W. Green St., Urbana, Illinois 61801 (United States); Department of Electrical and Computer Engineering, Iowa State University, 104 Marston Hall, Ames, Iowa 50011 (United States)

2006-09-15

260

Construction of the Eight Item PROMIS Pediatric Physical Function Scales: Built Using Item Response Theory  

PubMed Central

Objective To create self-report physical function (PF) measures for children using modern psychometric methods for item analysis as part of Patient Reported Outcomes Measurement Information System (PROMIS). Study Design and Setting PROMIS qualitative methodology was applied to develop two PF item pools comprised of 32 mobility and 38 upper extremity items. Items were computer administered to subjects aged 8–17 years. Scale dimensionality and sources of local dependence (LD) were evaluated with factor analysis. Items were analyzed for differential item functioning (DIF) between genders. Items with LD, DIF, or low discrimination were considered for removal. Computerized adaptive testing performance was simulated, and short forms were constructed. Results 3,048 children (51.8% female, 40% non-white, 22.7% chronically ill) participated. At least 754 respondents answered each item. Factor analytic results confirmed two dimensions of PF. Fifty-two of 70 items tested were retained. A 23 item mobility bank and a 29 item upper extremity bank resulted, and 8 item short forms were created. The item banks have high information from the population mean to 3 standard deviations below. Conclusions PROMIS pediatric PF item banks and 8-item short forms assess two dimensions, mobility and upper extremity function, and show good psychometric characteristics after large scale testing.

DeWitt, Esi Morgan; Stucky, Brian D.; Thissen, David; Irwin, Debra E.; Langer, Michelle; Varni, James W.; Lai, Jin-Shei; Yeatts, Karin B.; DeWalt, Darren A.

2010-01-01

261

Investigation of the physical scaling of sea spray spume droplet production  

NASA Astrophysics Data System (ADS)

In this paper we report on a laboratory study, the Spray Production and Dynamics Experiment (SPANDEX), conducted at the University of New South Wales Water Research Laboratory in Australia. The goals of SPANDEX were to illuminate physical aspects of spume droplet production and dispersion; verify theoretical simplifications used to estimate the source function from ambient droplet concentration measurements; and examine the relationship between the implied source strength and forcing parameters such as wind speed, surface turbulent stress, and wave properties. Observations of droplet profiles give reasonable confirmation of the basic power law profile relationship that is commonly used to relate droplet concentrations to the surface source strength. This essentially confirms that, even in a wind tunnel, there is a near balance between droplet production and removal by gravitational settling. The observations also indicate considerable droplet mass may be present for sizes larger than 1.5 mm diameter. Phase Doppler Anemometry observations revealed significant mean horizontal and vertical slip velocities that were larger closer to the surface. The magnitude seems too large to be an acceleration time scale effect. Scaling of the droplet production surface source strength proved to be difficult. The wind speed forcing varied only 23% and the stress increased a factor of 2.2. Yet, the source strength increased by about a factor of 7. We related this to an estimate of surface wave energy flux through calculations of the standard deviation of small-scale water surface disturbance, a wave-stress parameterization, and numerical wave model simulations. This energy index only increased by a factor of 2.3 with the wind forcing. Nonetheless, a graph of spray mass surface flux versus surface disturbance energy is quasi-linear with a substantial threshold.

Fairall, C. W.; Banner, M. L.; Peirson, W. L.; Asher, W.; Morison, R. P.

2009-10-01

262

Scaling properties of rainfall induced landslides predicted by a physically based model  

NASA Astrophysics Data System (ADS)

Natural landslides exhibit scaling properties revealed by power law relationships. These relationships include the frequency of the size (e.g., area, volume) of the landslides, and the rainfall conditions responsible for slope failures in a region. Reasons for the scaling behavior of landslides are poorly known. We investigate the possibility of using the Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability analysis code (TRIGRS), a consolidated, physically-based, numerical model that describes the stability/instability conditions of natural slopes forced by rainfall, to determine the frequency statistics of the area of the unstable slopes and the rainfall intensity (I)–duration (D) conditions that result in landslides in a region. We apply TRIGRS in a portion of the Upper Tiber River Basin, Central Italy. The spatially distributed model predicts the stability/instability conditions of individual grid cells, given the local terrain and rainfall conditions. We run TRIGRS using multiple, synthetic rainfall histories, and we compare the modeling results with empirical evidences of the area of landslides and of the rainfall conditions that have caused landslides in the study area. Our findings revealed that TRIGRS is capable of reproducing the frequency of the size of the patches of terrain predicted as unstable by the model, which match the frequency size statistics of landslides in the study area, and the mean rainfall D, I conditions that result in unstable slopes in the study area, which match rainfall I ? D thresholds for possible landslide occurrence. Our results are a step towards understanding the mechanisms that give rise to landslide scaling properties.

Alvioli, Massimiliano; Guzzetti, Fausto; Rossi, Mauro

2014-05-01

263

Nicholas Metropolis Award for Outstanding Doctoral Thesis Work in Computational Physics Talk: Understanding Nano-scale Electronic Systems via Large-scale Computation  

NASA Astrophysics Data System (ADS)

Nano-scale physical phenomena and processes, especially those in electronics, have drawn great attention in the past decade. Experiments have shown that electronic and transport properties of functionalized carbon nanotubes are sensitive to adsorption of gas molecules such as H2, NO2, and NH3. Similar measurements have also been performed to study adsorption of proteins on other semiconductor nano-wires. These experiments suggest that nano-scale systems can be useful for making future chemical and biological sensors. Aiming to understand the physical mechanisms underlying and governing property changes at nano-scale, we start off by investigating, via first-principles method, the electronic structure of Pd-CNT before and after hydrogen adsorption, and continue with coherent electronic transport using non-equilibrium Green’s function techniques combined with density functional theory. Once our results are fully analyzed they can be used to interpret and understand experimental data, with a few difficult issues to be addressed. Finally, we discuss a newly developed multi-scale computing architecture, OPAL, that coordinates simultaneous execution of multiple codes. Inspired by the capabilities of this computing framework, we present a scenario of future modeling and simulation of multi-scale, multi-physical processes.

Cao, Chao

2009-03-01

264

A Vlasov-Fokker-Planck Code for Shock Ignition  

NASA Astrophysics Data System (ADS)

A 2D3P parallel object-oriented Vlasov-Fokker-Planck code that relies on the expansion of the electron distribution function to spherical harmonics [1] has been developed and it is used to study non-local electron transport for Shock Ignition [2]. The code makes use of a rigorous formalism for the collisions between electrons, which derives from the Rosenbluth potentials and conserves energy and number. This code makes it possible to accurately model the kinetic as well as the hydrodynamic behavior of the plasma and is particularly efficient for collisional plasmas. The features of the code are showcased using standard plasma physics problems. For Shock Ignition the electron temperatures can reach up to 100keV while densities range from less than critical to greater than solid. Shock Ignition is therefore an excellent candidate for this VFP code, because the target is sufficiently collisional to allow for extremely efficient modeling.[4pt] [1] A. R. Bell et al, Plasma Phys. Control. Fusion 48, R37-R57 (2006).[0pt] [2] R. Betti et al, Phys. Rev. Lett. 98, 155001 (2007).

Tzoufras, Michail; Bell, Tony; Trines, Raoul; Norreys, Peter; Tsung, Frank

2010-11-01

265

A novel scale including strabismus and 'cuspidal ear' for distinguishing schizophrenia patients from controls using minor physical anomalies.  

PubMed

The present study explored minor physical anomaly items relevant to schizophrenia in order to establish a scale that can distinguish schizophrenia from controls using newly identified items along with items from the refined Waldrop scale. Seven items were significantly more frequent among schizophrenia patients (N=218) than controls (N=226). Among these seven items, two novel features, strabismus and 'cuspidal ear' showed markedly different prevalence rates between schizophrenia and control groups. A six-item scale, including the newly identified strabismus and cuspidal ear, was selected for most accurately discriminating patients with schizophrenia from controls. This scale correctly classified 59.6% of patients and 78.9% of control subjects. This new scale is procedurally more exacting and quantitative, and more relevant to schizophrenia than the original Waldrop scale. The validity of this scale should be sound since it was tested on a larger number of cohorts than used in previous research. Our scale can be used as a biomarker for predicting risk for future development of schizophrenia. The scale may also facilitate the identification of schizophrenia susceptibility genetic/environmental factors by stratifying etiologically heterogeneous patients according to physical abnormalities. PMID:17070930

Yoshitsugu, Kiyoshi; Yamada, Kazuo; Toyota, Tomoko; Aoki-Suzuki, Mika; Minabe, Yoshio; Nakamura, Kazuhiko; Sekine, Yoshimoto; Suzuki, Katsuaki; Takei, Noriyoshi; Itokawa, Masanari; Mori, Norio; Yoshikawa, Takeo

2006-12-01

266

Max Planck Institute for Plant Breeding Research  

NSDL National Science Digital Library

The Max Planck Institute for Plant Breeding Research is committed to a number of research goals, one of which is "to determine whether and how a detailed understanding of molecular mechanisms defined in model plant species can be used to rationally manipulate selected traits in crop plants." The Institute was founded in 1928 as part of the Kaiser-Willhelm-Gesellschaft and the first director, Edwin Baur, was interested in creating breeding programs with fruits and berries, though the Institute's scope has expanded since then. Visitors to the homepage should start by clicking on the News section. Here they can peruse recent releases from the Institute on how plants use mobile proteins to defend themselves against bacteria and the evolutionary "dead end" of powdery mildew. Scholars and others will want to click on the Reports and Publications area to look at some recent scholarly works and annual reports from 2009, 2006, and 2003. Moving on, the Public Outreach area contains a nice photo gallery and additional publications.

2012-04-06

267

Gauge-flation confronted with Planck  

NASA Astrophysics Data System (ADS)

Gauge-flation is a recently proposed model in which inflation is driven solely by a non-Abelian gauge field thanks to a specific higher order derivative operator. The nature of the operator is such that it does not introduce ghosts. We compute the cosmological scalar and tensor perturbations for this model, improving over an existing computation. We then confront these results with the Planck data. The model is characterized by the quantity ? ? g2Q2/H2 (where g is the gauge coupling constant, Q the vector vev, and H the Hubble rate). For ? < 2, the scalar perturbations show a strong tachyonic instability. In the stable region, the scalar power spectrum ns is too low at small ?, while the tensor-to-scalar ratio r is too high at large ?. No value of ? leads to acceptable values for ns and r, and so the model is ruled out by the CMB data. The same behavior with ? was obtained in Chromo-natural inflation, a model in which inflation is driven by a pseudo-scalar coupled to a non-Abelian gauge field. When the pseudo-scalar can be integrated out, one recovers the model of Gauge-flation plus corrections. It was shown that this identification is very accurate at the background level, but differences emerged in the literature concerning the perturbations of the two models. On the contrary, our results show that the analogy between the two models continues to be accurate also at the perturbative level.

Namba, Ryo; Dimastrogiovanni, Emanuela; Peloso, Marco

2013-11-01

268

Evaluation of hydride compressor elements for the Planck sorption cryocooler  

NASA Technical Reports Server (NTRS)

Hydrogen sorption crycoolers are being developed for the European Space Agency Planck mission to provide nominal 19 K cooling to instruments for measuring the temperature anisotropy of the cosmic microwave background with extreme sensitivity and resolution.

Bowman, R. C.; Prina, M.; Barber, D. S.; Bhandari, P.; Crumb, D.; Loc, A. S.; Morgante, G.; Reiter, J. W.; Schmelzel, M. E.

2002-01-01

269

ICS: An Implicit Compton-Fokker-Planck Solver.  

National Technical Information Service (NTIS)

A computer software package for solving the time evolution equations for the electron temperature, ion temperature, and multigroup radiation densities resulting from Compton-Fokker-Planck scattering is described. (ERA citation 12:046973)

J. E. Morel

1987-01-01

270

The Atacama Cosmology Telescope: cross correlation with Planck maps  

NASA Astrophysics Data System (ADS)

We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACT × Planck cross-spectra. We use these cross-correlations to measure the calibration of the ACT data at 148 and 218 GHz relative to Planck, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments.

Louis, Thibaut; Addison, Graeme E.; Hasselfield, Matthew; Bond, J. Richard; Calabrese, Erminia; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dünner, Rolando; Gralla, Megan; Hajian, Amir; Hincks, Adam D.; Hlozek, Renée; Huffenberger, Kevin; Infante, Leopoldo; Kosowsky, Arthur; Marriage, Tobias A.; Moodley, Kavilan; Næss, Sigurd; Niemack, Michael D.; Nolta, Michael R.; Page, Lyman A.; Partridge, Bruce; Sehgal, Neelima; Sievers, Jonathan L.; Spergel, David N.; Staggs, Suzanne T.; Walter, Benjamin Z.; Wollack, Edward J.

2014-07-01

271

Determining Planck's Constant Using a Light-emitting Diode.  

ERIC Educational Resources Information Center

Describes a method for making a simple, inexpensive apparatus which can be used to determine Planck's constant. Provides illustrations of a circuit diagram using one or more light-emitting diodes and a BASIC computer program for simplifying calculations. (RT)

Sievers, Dennis; Wilson, Alan

1989-01-01

272

Planck early results. IX. XMM-Newton follow-up for validation of Planck cluster candidates  

NASA Astrophysics Data System (ADS)

We present the XMM-Newton follow-up for confirmation of Planck cluster candidates. Twenty-five candidates have been observed to date using snapshot (~10ks) exposures, ten as part of a pilot programme to sample a low range of signal-to-noise ratios (4 < S/N < 6), and a further 15 in a programme to observe a sample of S/N > 5 candidates. The sensitivity and spatial resolution of XMM-Newton allows unambiguous discrimination between clusters and false candidates. The 4 false candidates have S/N ? 4.1. A total of 21 candidates are confirmed as extended X-ray sources. Seventeen are single clusters, the majority of which are found to have highly irregular and disturbed morphologies (about ~70%). The remaining four sources are multiple systems, including the unexpected discovery of a supercluster at z = 0.45. For 20 sources we are able to derive a redshift estimate from the X-ray Fe K line (albeit of variable quality). The new clusters span the redshift range 0.09 ? z ? 0.54, with a median redshift of z ~ 0.37. A first determination is made of their X-ray properties including the characteristic size, which is used to improve the estimate of the SZ Compton parameter, Y500. The follow-up validation programme has helped to optimise the Planck candidate selection process. It has also provided a preview of the X-ray properties of these newly-discovered clusters, allowing comparison with their SZ properties, and to the X-ray and SZ properties of known clusters observed in the Planck survey. Our results suggest that Planck may have started to reveal a non-negligible population of massive dynamically perturbed objects that is under-represented in X-ray surveys. However, despite their particular properties, these new clusters appear to follow the Y500-YX relation established for X-ray selected objects, where YX is the product of the gas mass and temperature. Corresponding author: E. Pointecouteau, e-mail: etienne.pointecouteau@irap.omp.eu

Planck Collaboration; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartelmann, M.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Brown, M. L.; Bucher, M.; Burigana, C.; Cabella, P.; Cantalupo, C. M.; Cardoso, J.-F.; Carvalho, P.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Chiang, L.-Y.; Chon, G.; Christensen, P. R.; Churazov, E.; Clements, D. L.; Colafrancesco, S.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Cuttaia, F.; da Silva, A.; Dahle, H.; Danese, L.; de Bernardis, P.; de Gasperis, G.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Diego, J. M.; Dolag, K.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Finelli, F.; Flores-Cacho, I.; Forni, O.; Frailis, M.; Franceschi, E.; Fromenteau, S.; Galeotta, S.; Ganga, K.; Génova-Santos, R. T.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; González-Riestra, R.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Harrison, D.; Heinämäki, P.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Le Jeune, M.; Leach, S.; Leonardi, R.; Liddle, A.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mann, R.; Maris, M.; Marleau, F.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Melchiorri, A.; Melin, J.-B.; Mendes, L.; Mennella, A.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, A.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Pajot, F.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Piffaretti, R.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rubiño-Martín, J. A.; Rusholme, B.; Saar, E.; Sandri, M.; Santos, D.; Schaefer, B. M.; Scott, D.; Seiffert, M. D.; Smoot, G. F.; Starck, J.-L.; Stivoli, F.; Stolyarov, V.; Sunyaev, R.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Torre, J.-P.; Tristram, M.; Tuovinen, J.; Valenziano, L.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wandelt, B. D.; White, S. D. M.; Yvon, D.; Zacchei, A.; Zonca, A.

2011-12-01

273

New multigroup Monte Carlo scattering algorithm suitable for neutral- and charged-particle Boltzmann and Fokker-Planck calculations  

SciTech Connect

Morel (1981) has developed multigroup Legendre cross sections suitable for input to standard discrete ordinates transport codes for performing charged-particle Fokker-Planck calculations in one-dimensional slab and spherical geometries. Since the Monte Carlo neutron transport code, MORSE, uses the same multigroup cross section data that discrete ordinates codes use, it was natural to consider whether Fokker-Planck calculations could be performed with MORSE. In order to extend the unique three-dimensional forward or adjoint capability of MORSE to Fokker-Planck calculations, the MORSE code was modified to correctly treat the delta-function scattering of the energy operator, and a new set of physically acceptable cross sections was derived to model the angular operator. Morel (1979) has also developed multigroup Legendre cross sections suitable for input to standard discrete ordinates codes for performing electron Boltzmann calculations. These electron cross sections may be treated in MORSE with the same methods developed to treat the Fokker-Planck cross sections. The large magnitude of the elastic scattering cross section, however, severely increases the computation or run time. It is well-known that approximate elastic cross sections are easily obtained by applying the extended transport (or delta function) correction to the Legendre coefficients of the exact cross section. An exact method for performing the extended transport cross section correction produces cross sections which are physically acceptable. Sample calculations using electron cross sections have demonstrated this new technique to be very effective in decreasing the large magnitude of the cross sections.

Sloan, D.P.

1983-05-01

274

Improved alumina scale adhesion of electron beam physical vapor deposited Dy/Hf-doped ?-NiAl coatings  

NASA Astrophysics Data System (ADS)

The cyclic oxidation behavior of Dy/Hf-doped ?-NiAl coatings produced by electron beam physical vapor deposition (EB-PVD) was investigated. For the undoped NiAl coating, numerous voids were formed at the alumina scale/coating interface and large rumpling developed in the scale, leading to premature oxide spallation. The addition of Dy and Hf both improved scale adhesion and the alumina scale grown on the NiAl-Hf coating showed better adhesion than that on the NiAl-Dy coating, although the suppressing effect on interfacial void formation and the scale rumpling resistance were stronger in the NiAl-Dy coating. It is proposed that the segregation of Dy and Hf ions at the scale/coating interfaces not only prevent interfacial sulfur segregation but also may directly enhance interfacial adhesion by participating in bonding across the interfaces, and this strengthening effect is relatively stronger for Hf ionic segregation.

Li, Dongqing; Guo, Hongbo; Peng, Hui; Gong, Shengkai; Xu, Huibin

2013-10-01

275

Does the Physical Self-Effi cacy Scale Assess Self-Effi cacy or Self-Esteem?  

Microsoft Academic Search

This study was designed to address whether the Perceived Physical Ability (PPA) subscale of the Physical Self-Effi cacy Scale (PSES; Ryckman, Robbins, Thornton, & Cantrell, 1982) measures self-effi cacy or self-esteem. Secondary analyses of four previously reported data sets were conducted to examine the extent to which the PPA overlaps with multidimensional self-esteem measures. Once the factor structure of the

Liang Hu; Edward McAuley; Steriani Elavsky

2005-01-01

276

Breakdown of the Planck blackbody radiation law at nanoscale gaps  

Microsoft Academic Search

The Planck theory of blackbody radiation imposes a limit on the maximum radiative transfer between two objects at given temperatures.\\u000a When the two objects are close enough, near-field effects due to tunneling of evanescent waves lead to enhancement of radiative\\u000a transfer above the Planck limit. When the objects can support electromagnetic surface polaritons, the enhancement can be a\\u000a few orders-of-magnitude

Arvind Narayanaswamy; Sheng Shen; Lu Hu; Xiaoyuan Chen; Gang Chen

2009-01-01

277

Pore-scaling Modeling of Physical Property Changes During CO2 Injection into Sandstone  

NASA Astrophysics Data System (ADS)

Carbon dioxide is a green-house gas and is believed to be an important factor in global warming and climate change. Many countries around the world are working on reducing and sequestrating CO2 to follow international regulations. One of promising area for CO2 sequestration is the storage in geological formation. To accurately determine the performance of geological injection and storage, quantification and monitoring of the physical property changes are essential. In this paper, we are presenting a new approach for the monitoring of CO2 sequestration in sandstone using pore-scale simulation techniques. The method consists of three steps: 1) acquisition of high-resolution pore microstructures by X-ray micro-tomography; 2) CO2 injection simulation using lattice-Boltzmann (LB) two-phase flow simulation; and 3) FEM property simulations (electrical and elastic) at different CO2 saturations during the injection. We use three different sandstone samples: sand-pack, Berea sandstone, and B2 sandstone from offshore of Korea. The porosity of the sand-pack is 42% and that of two sandstone samples is around 17%. The digital pore structures were obtained by X-ray micro-tomography with a spatial resolution of 2 micron. The LB two-phase flow simulation is then conducted by injecting CO2 into fully water-saturated samples and gives a realistic movement of CO2 in the pore structure. At each CO2 saturation, electrical and elastic properties are determined by pore-scale FEM simulation techniques. The electrical conductivity decreases almost linearly as CO2 saturations increases; however, the P-wave velocity decrease more rapidly at the low CO2 saturation (up to 30%), than at higher saturation. S-wave velocity does not show any significant changes. The higher porosity rock shows more sensitivity to saturation changes. The modeling shows that we can have quantitative relations between physical properties and CO2 saturation, which can be used to determine injection performance and migration of CO2. However, the change in P-wave velocity is not very significant during CO2 injection, which indicates that the monitoring of CO2 sequestration by acoustic survey would be difficult. Our modeling technique can be a very effective tool for the characterizing of prospecting geological sequestration formation and determining an effective monitoring technique for specific sites. Acknowledgement: This research was funded by CO2 Storage in Marine Geological Structure Program of Ministry of Land, Transport, and Maritime Affairs of South Korea, Grant No. E10500109A060000121.

Keehm, Y.; Yoo, G.

2009-12-01

278

Poisson-Nernst-Planck Equations for Simulating Biomolecular Diffusion-Reaction Processes I: Finite Element Solutions.  

PubMed

In this paper we developed accurate finite element methods for solving 3-D Poisson-Nernst-Planck (PNP) equations with singular permanent charges for electrodiffusion in solvated biomolecular systems. The electrostatic Poisson equation was defined in the biomolecules and in the solvent, while the Nernst-Planck equation was defined only in the solvent. We applied a stable regularization scheme to remove the singular component of the electrostatic potential induced by the permanent charges inside biomolecules, and formulated regular, well-posed PNP equations. An inexact-Newton method was used to solve the coupled nonlinear elliptic equations for the steady problems; while an Adams-Bashforth-Crank-Nicolson method was devised for time integration for the unsteady electrodiffusion. We numerically investigated the conditioning of the stiffness matrices for the finite element approximations of the two formulations of the Nernst-Planck equation, and theoretically proved that the transformed formulation is always associated with an ill-conditioned stiffness matrix. We also studied the electroneutrality of the solution and its relation with the boundary conditions on the molecular surface, and concluded that a large net charge concentration is always present near the molecular surface due to the presence of multiple species of charged particles in the solution. The numerical methods are shown to be accurate and stable by various test problems, and are applicable to real large-scale biophysical electrodiffusion problems. PMID:21709855

Lu, Benzhuo; Holst, Michael J; McCammon, J Andrew; Zhou, Y C

2010-09-20

279

The Simultaneous Medicina-Planck Experiment: data acquisition, reduction and first results  

NASA Astrophysics Data System (ADS)

The Simultaneous Medicina-Planck Experiment (SiMPlE) is aimed at observing a selected sample of 263 extragalactic and Galactic sources with the Medicina 32-m single-dish radio telescope in the same epoch as the Planck satellite observations. The data, acquired with a frequency coverage down to 5 GHz and combined with Planck at frequencies above 30 GHz, will constitute a useful reference catalogue of bright sources over the whole Northern hemisphere. Furthermore, source observations performed in different epochs and comparisons with other catalogues will allow the investigation of source variabilities on different time-scales. In this work, we describe the sample selection, the ongoing data acquisition campaign, the data reduction procedures, the developed tools and the comparison with other data sets. We present 5 and 8.3 GHz data for the SiMPlE Northern sample, consisting of 79 sources with ?? 45° selected from our catalogue and observed during the first 6 months of the project. A first analysis of their spectral behaviour and long-term variability is also presented.

Procopio, P.; Massardi, M.; Righini, S.; Zanichelli, A.; Ricciardi, S.; Libardi, P.; Burigana, C.; Cuttaia, F.; Mack, K.-H.; Terenzi, L.; Villa, F.; Bonavera, L.; Morgante, G.; Trigilio, C.; Trombetti, T.; Umana, G.

2011-10-01

280

Poisson-Nernst-Planck Equations for Simulating Biomolecular Diffusion-Reaction Processes I: Finite Element Solutions  

PubMed Central

In this paper we developed accurate finite element methods for solving 3-D Poisson-Nernst-Planck (PNP) equations with singular permanent charges for electrodiffusion in solvated biomolecular systems. The electrostatic Poisson equation was defined in the biomolecules and in the solvent, while the Nernst-Planck equation was defined only in the solvent. We applied a stable regularization scheme to remove the singular component of the electrostatic potential induced by the permanent charges inside biomolecules, and formulated regular, well-posed PNP equations. An inexact-Newton method was used to solve the coupled nonlinear elliptic equations for the steady problems; while an Adams-Bashforth-Crank-Nicolson method was devised for time integration for the unsteady electrodiffusion. We numerically investigated the conditioning of the stiffness matrices for the finite element approximations of the two formulations of the Nernst-Planck equation, and theoretically proved that the transformed formulation is always associated with an ill-conditioned stiffness matrix. We also studied the electroneutrality of the solution and its relation with the boundary conditions on the molecular surface, and concluded that a large net charge concentration is always present near the molecular surface due to the presence of multiple species of charged particles in the solution. The numerical methods are shown to be accurate and stable by various test problems, and are applicable to real large-scale biophysical electrodiffusion problems.

Lu, Benzhuo; Holst, Michael J.; McCammon, J. Andrew; Zhou, Y. C.

2010-01-01

281

Universal Scaling Laws in Quantum Theory and Cosmology  

NASA Astrophysics Data System (ADS)

We have developed a hyperdimensional geometry, Dn or Descartes space of dimensionality of n > 4, for our consideration n = 10. This model introduces a formation in terms of the conditions of constants as the space that allows us to calculate a unique set of scaling laws from the lower end scale of the quantum vacuum foam to the current universe. A group theoretical matrix formalism is made for the ten and eleven dimensional model of this space. For the eleven dimensional expressions of this geometry, a fundamental frequency is introduced and utilized as an additional condition on the topology. The constraints on the Dn space are imposed by the relationship of the universal constraints of nature expressed in terms of physical variables. The quantum foam picture can be related to the Fermi-Dirac vacuum model. Consideration is made for the lower limit of a universal size scaling from the Planck length, l = 10-33 cm, temporal component, t = 10-44 sec, density, 1093 gm/cm3 and additional Planck units of quantized variables. The upper limit of rotational frequency in the Dn space is given as 1043 Hz, as conditions or constraints that apply to the early universe which are expressed uniquely in terms of the universal constants, h, Planck's constant, the G, the gravitational constant and c, the velocity of light. We have developed a scaling law for cosmogenesis from the early universe to our present day universe. We plot the physical variables of the ten and eleven dimensional space versus a temporal evolution of these parameters. From this formalism, in order to maintain the compatibility of Einstein's General Relativity with the current model of cosmology, we replace Guth's inflationary model with a matter creation term. Also we have developed a fundamental scaling relationship between the "size scale" of organized matter with their associated fundamental frequency.

Rauscher, Elizabeth A.; Hurtak, James J.; Hurtak, D. E.

2013-09-01

282

Steamflooding Cold Lake oil reservoirs through a bottomwater zone: A scaled physical model study  

SciTech Connect

A series of experiments was conducted in one-eighth of a five-spot-pattern, high-pressure, scaled physical model to evaluate the potential of steamflooding oil-sand reservoirs through a bottomwater zone in Cold Lake, Alberta. During the experiments, steam was injected into the bottomwater zone at a constant rate until steam breakthrough occurred at the production well. The steam injection rate then was reduced to limit steam production. Results demonstrate that the process is influenced by the steam injection flow rate because of the important role played by gravity override. Increasing the steam injection rate beyond an optimum value results in decreased oil/steam ratios (OSR's) and reduced final oil recovery because steam channels to the production well. A delay in oil production was noticed in all experiments. A moving-heat-source, gravity-override, analytical model was used to investigate the mechanisms of reservoir heating in the presence of steam-gravity override. In addition, the thermal efficiency of the process, determined from the experiments and extrapolated to field conditions, was compared with prediction from Prats' thermal efficiency model. Prats' model predicted the measured thermal efficiency reasonably well at lower injection rates. As the injection rate increased, however, larger differences between Prats' model and the experiments were noticed.

Nasr, T.N.; Pierce, G.E. (Alberta Research Council, Edmonton (Canada))

1993-05-01

283

Physical controls of near-surface soil moisture across varying spatial scales in an agricultural landscape during SMEX02  

NASA Astrophysics Data System (ADS)

Understanding of near-surface soil moisture variability at different spatial scales and associated dominant physical controls is limited. In the past, soil moisture dynamics studies have been conducted extensively at different spatial scales using both in situ and remote sensing (RS) data in the subhumid Southern Great Plains region, which has mostly pasture and range land cover with rolling topography. Compared to the past efforts, we investigated the space-time characterization of near-surface soil moisture and associated physical controls at multiple scales (field, watershed, and region) in a humid hydroclimatic region with different topography and agricultural land cover. Soil moisture data from two different measurement support scales (theta probe based (point scale) and airborne RS derived; footprint scale, 800 m × 800 m), obtained during the Soil Moisture Experiment 2002 (SMEX02) in Iowa were used. Geostatistical analysis showed the spatial soil moisture correlation lengths varied between 78 m and 307 m (at the field scale), 2044 m and 11,882 m (at the watershed scale), and 19,500 m and 118,500 m (at the regional scale). The correlation length values were usually smaller on wet days than the relatively dry days at the field and watershed scales. The trend was opposite at the regional scale with correlation lengths being larger on wet days. Furthermore, the soil moisture data sets were decomposed into spatial Empirical Orthogonal Function (EOF) patterns, and their relationship with various geophysical parameters (rainfall, topography, soil texture, and vegetation) was examined to determine the dominant control on the near-surface soil moisture variability. At the field scale, the first four EOFs together explained about 81% of the total variability. At the watershed scale, the first two EOFs were dominant explaining about 93% of the total variance, whereas at the regional scale, the primary EOF itself explained more than 70% of the variance. In other words, the complicated dynamics of near-surface soil moisture fields can be described by a few underlying orthogonal spatial structures related to the geophysical attributes of the region. Correlation analysis of the RS soil moisture data showed that rainfall, topography, and soil texture have mixed effects on the variability explained by the dominant EOFs, at both watershed and regional scales, with limited influence of vegetation parameters. The effect of rainfall on the soil moisture variability is higher at the watershed scale compared to the regional scale in Iowa.

Joshi, Champa; Mohanty, Binayak P.

2010-12-01

284

Planck constraints on single-field inflation  

NASA Astrophysics Data System (ADS)

We place observational constraints on slow-variation single-field inflationary models by carrying out the cosmological Monte Carlo simulation with the recent data of Planck combined with the WMAP large-angle polarization, baryon acoustic oscillations, and Atacama Cosmology Telescope/South Pole Telescope temperature data. Our analysis covers a wide variety of models with second-order equations of motion, including potential-driven slow-roll inflation, nonminimally coupled models, running kinetic couplings, Brans-Dicke theories, potential-driven Galileon inflation, field-derivative couplings to the Einstein tensor, and k-inflation. In the presence of running kinetic exponential couplings, covariant Galileon terms, and field-derivative couplings, the tensor-to-scalar ratio of the self-coupling potential V(?)=??4/4 gets smaller relative to that in standard slow-roll inflation, but the models lie outside the 1? observational contour. We also show that k-inflation models can be tightly constrained by adding the bounds from the scalar non-Gaussianities. The small-field inflationary models with asymptotic flat Einstein-frame potentials in the regime ??Mpl generally fit the data very well. These include the models such as Kähler-moduli inflation, nonminimally coupled Higgs inflation, and inflation in Brans-Dicke theories in the presence of the potential V(?)=3M2(?-Mpl)2/4 with the Brans-Dicke parameter ?BD?O(1) (which covers the Starobinsky’s model f(R)=R+R2/(6M2) as a special case).

Tsujikawa, Shinji; Ohashi, Junko; Kuroyanagi, Sachiko; De Felice, Antonio

2013-07-01

285

Post16 physics and chemistry uptake: combining large-scale secondary analysis with in-depth qualitative methods  

Microsoft Academic Search

Quantitative secondary analysis of large-scale data can be combined with in-depth qualitative methods. In this paper, we discuss the role of this combined methods approach in examining the uptake of physics and chemistry in post compulsory schooling for students in England. The secondary data analysis of the National Pupil Database (NPD) served three distinct purposes in the design of this

Gillian Hampden-Thompson; Fred Lubben; Judith Bennett

2011-01-01

286

Promoting Leisure Physical Activity Participation among Adults with Intellectual Disabilities: Validation of Self-Efficacy and Social Support Scales  

ERIC Educational Resources Information Center

Background: Many individuals with intellectual disabilities are not sufficiently active for availing health benefits. Little is known about correlates of physical activity among this population on which to build health promotion interventions. Materials and Methods: We developed scales for measurement of self-efficacy and social support for…

Peterson, Jana J.; Peterson, N. Andrew; Lowe, John B.; Nothwehr, Faryle K.

2009-01-01

287

Large-Scale Digitizer System (Lsd) for Charge and Time Digitization in High-Energy Physics Experiments.  

National Technical Information Service (NTIS)

A large-scale digitizer (LSD) system for acquiring charge and time-of-arrival particle data from high-energy-physics experiments has been developed at the Lawrence Berkeley Laboratory. The objective in this development was to significantly reduce the cost...

R. F. Althaus F. A. Kirsten K. L. Lee S. R. Olson L. J. Wagner

1976-01-01

288

Scaling up of physical activity interventions in Brazil: how partnerships and research evidence contributed to policy action  

PubMed Central

The global health burden due to physical inactivity is enormous and growing. There is a need to consider new ways of generating evidence and to identify the role of government in promoting physical activity at the population level. In this paper, we summarize key findings from a large-scale cross-national collaboration to understand physical activity promotion in Brazil. We describe the main aspects of the partnership of Project GUIA (Guide for Useful Interventions for Activity in Brazil and Latin America) that sustained the collaborative effort for eight years and describe how the evidence gathered from the collaboration triggered political action in Brazil to scale up a physical activity intervention at the national level. Project GUIA is a cross-national multidisciplinary research partnership designed to understand and evaluate current efforts for physical activity promotion at the community level in Latin America. This example of scaling up is unprecedented for promoting health in the region and is an example that must be followed and evaluated.

Hoehner, Christine M.; Hallal, Pedro C.; Reis, Rodrigo S.; Simoes, Eduardo J.; Malta, Deborah C.; Pratt, Michael; Brownson, Ross C.

2013-01-01

289

Post-Planck constraints on interacting vacuum energy  

NASA Astrophysics Data System (ADS)

We present improved constraints on an interacting vacuum model using updated astronomical observations including the first data release from Planck. We consider a model with one dimensionless parameter, ?, describing the interaction between dark matter and vacuum energy (with fixed equation of state w=-1). The background dynamics correspond to a generalized Chaplygin gas cosmology, but the perturbations have a zero sound speed. The tension between the value of the Hubble constant, H0, determined by Planck data plus WMAP polarization (Planck +WP) and that determined by the Hubble Space Telescope (HST) can be alleviated by energy transfer from dark matter to vacuum (?>0). A positive ? increases the allowed values of H0 due to parameter degeneracy within the model using only cosmic microwave background data. Combining with additional data sets of including supernova type Ia (SN Ia) and baryon acoustic oscillation (BAO), we can significantly tighten the bounds on ?. Redshift-space distortions (RSD), which constrain the linear growth of structure, provide the tightest constraints on vacuum interaction when combined with Planck+WP, and prefer energy transfer from vacuum to dark matter (?<0) which suppresses the growth of structure. Using the combined data sets of Planck +WP+Union2.1+BAO+RSD, we obtain the constraint on ? to be -0.083Planck +WP in the ?CDM model for ? <0, or between HST measurements of H0 and Planck+WP for ?>0, but not both at the same time.

Wang, Yuting; Wands, David; Zhao, Gong-Bo; Xu, Lixin

2014-07-01

290

A statistical physics approach to scale-free networks and their behaviors  

NASA Astrophysics Data System (ADS)

This thesis studies five problems of network properties from a unified local-to-global viewpoint of statistical physics: (1) We propose an algorithm that allows the discovery of communities within graphs of arbitrary size, based on Kirchhoff theory of electric networks. Its time complexity scales linearly with the network size. We additionally show how this algorithm allows for the swift discovery of the community surrounding a given node without having to extract all the communities out of a graph. (2) We present a dynamical theory of opinion formation that takes explicitly into account the structure of the social network in which individuals are embedded. We show that the weighted fraction of the population that holds a certain opinion is a martingale. We show that the importance of a given node is proportional to its degree. We verify our predictions by simulations. (3) We show that, when the information transmissibility decays with distance, the epidemic spread on a scale-free network has a finite threshold. We test our predictions by measuring the spread of messages in an organization and by numerical experiments. (4) Suppose users can switch between two behaviors when entering a queueing system: one that never restarts an initial request and one that restarts infinitely often. We show the existence of two thresholds. When the system load is below the lower threshold, it is always better off to be impatient. When above, it is always better off to be patient. Between the two thresholds there exists a homogeneous Nash equilibrium with non-trivial properties. We obtain exact solutions for the two thresholds. (5) We study the endogenous dynamics of reputations in a system consisting of firms with long horizons that provide services with varying levels of quality, and customers who assign to them reputations on the basis of the quality levels that they experience when interacting with them. We show that the dynamics can lead to either well defined equilibria or persistent nonlinear oscillations in the number of customers visiting a firm, implying unstable reputations. We establish the stable criteria.

Wu, Fang

291

The Development and Validation of the Physical Self-Concept Scale for Older Adults  

ERIC Educational Resources Information Center

Physical self-concept plays a central role in older adults' physical health, mental health and psychological well-being; however, little attention has been paid to the underlying dimensions of physical self-concept in the elderly. The purpose of this study was to develop and validate a new measurement for older adults. First, a qualitative…

Hsu, Ya-Wen; Lu, Frank Jing-Horng

2013-01-01

292

Geothermal alteration of Kamchatka rock physical properties: experimental and pore-scale modeling study  

NASA Astrophysics Data System (ADS)

Alternative renewable energy sources research is getting more and more attention due to its importance for future exploitation and low ecological impacts. Geothermal energy is quite abundant and represents a cheap and easily extractable power source for electricity generation or central heating. For these purposes naturally heated geothermal fluids are extracted via drilled wells; after cooling water is usually pumped back to the reservoir to create a circle, or dumped into local streams. In addition to fundamental interest in understanding natural geothermal processes inside the reservoir, in both cases fluids can significantly alter rock properties around the well or stream bed, which is of great practical and ecological importance for the geothermal industry. Detailed knowledge of these transformations is necessary for power plant construction and well design, geophysical modeling and the prediction of geological properties. Under natural conditions such processes occur within geological time frames and are hard to capture. To accelerate geothermal alteration and model deep reservoir high temperature and pressure conditions we use autoclave laboratory experiments. To represent different geothermal conditions, rock samples are autoclaved using a wide range of parameters: temperature (100-450°C), pressure (16-1000 Bars), solution chemistry (from acidic to alkali artificial solutions and natural geothermal fluids sampled in Kamchatka), duration (from weeks to 1 year). Rock samples represent unaltered andesite-dacite tuffs, basalts and andesite collected at the Kamchatka peninsula. Numerous rock properties, e.g., density (bulk and specific), porosity (total and effective), hygroscopicity, P/S wave velocities, geomechanical characteristics (compressive and tensile strength, elastic modulus), etc., were thoroughly analyzed before and after alteration in laboratory autoclave or natural conditions (in situ). To reveal structural changes, some samples were scanned using X-ray microtomography prior to any alteration and after the experiments. 3D images were used to quantify structural changes and to determine permeability values using a pore-scale modeling approach, as laboratory measurements with through flow are known to have a potential to modify the pore structure. Chemical composition and local mineral formations were investigated using a «Spectroscan Max GV» spectrometer and scanning electron microscope imaging. Our study revealed significant relationships between structure modifications, physical properties and alteration conditions. Main results and conclusions include: 1) initial porosity and its connectivity have substantial effect on alteration dynamics, rocks with higher porosity values and connected pore space exhibit more pronounced alterations; 2) under similar experimental conditions (pressure, temperature, duration) pH plays an important role, acidic conditions result in significant new mineral formation; 3) almost all physical properties, including porosity, permeability, and elastic properties, were seriously modified in the modeled geothermal processes within short (from geological point of view) time frames; 4) X-ray microtomography was found useful for mineral phases distribution and the pore-scale modeling approach was found to be a promising technique to numerically obtain rock properties based on 3D scans; 5) we conclude that alteration and change of reservoir rocks should be taken into account for re-injecting well and geothermal power-plant design.

Shanina, Violetta; Gerke, Kirill; Bichkov, Andrey; Korost, Dmitry

2013-04-01

293

Atomic-Scale Investigation of Latent Fission Tracks in Fluorapatite: Physical Characteristics and Annealing Behavior.  

NASA Astrophysics Data System (ADS)

A JEOL JEM-2000FX analytical transmission electron microscope, equipped with a cold stage and anticontamination device, has been used to study the physical characteristics and annealing behavior of artificially induced fission tracks in fluorapatite. Near the atomic level, unetched fission tracks are not continuous, but are comprised of segments of extended damage that are separated by gaps of undamaged microstructure. From dark-field transmission electron microscopy (TEM) images, it appears that the crystalline damage around tracks, although intensive, is not extensive. As such, the defect density may be represented by a Gaussian-type distribution function. The disordered nature of the track core and defect distribution geometry supports the Ion-Explosion Theory that has been proposed for track formation. TEM analysis reveals that track width is crystallographically controlled. Parallel to the c-axis, tracks display widths of 5 to 13 nm and hexagonal faceting on the (0001) plane. Tracks perpendicular to the c-axis display widths of 3 to 9 nm and prismatic faceting on the (1000) plane. The track cross-section facets mimic etch-pit morphologies and provide a relative measure of the crystal's surface free energy. A consequence of differential bond strengths and elastic properties in the fluorapatite structure, track-width anisotropy resolves etching- and annealing-rate anisotropy that has been reported for fission tracks in fluorapatite. TEM observation of the behavior of fission tracks in response to electron beam exposure (i.e., radiolytic annealing), and temperature increase (i.e., thermal annealing), yields a physical and a kinetic description of the annealing process. Annealing commences with bulging at the track's tapered ends, followed by detachment of a single sphere. This process is replicated until a critical track radius is encountered at which the track geometry approaches an ideal right cylinder. A sinusoidal boundary develops at the track-matrix interface and increases in amplitude until the track spontaneously collapses into a row of spheres and small rods. The rods continue to evolve into spheres until the track remnant is comprised solely of a row of spheres. Although the spheres possess a stable surface energy geometry, ultimately they are restored to the original microstructure and the track disappears. Documentation of annealing suggests that the process is analogous to that of drop detachment, ovulation, and spheroidization. From these better known processes, it is possible to formulate a kinetic equation that describes fission-track annealing. Unlike the empirically-derived or physically-based kinetic equations that are presently employed in the reconstruction of thermo -tectonic histories from apatite fission-track data, the equation proposed in this study accurately predicts fission -track behavior over all of the scales of interest (i.e., microscopic to macroscopic dimensions, high to low temperatures, laboratory to geologic timescales). Furthermore, the equation reveals that surface interface diffusion is the primary mass transport mechanism that controls fission-track annealing.

Paul, Tracy Anne

1993-01-01

294

Scaled physical model studies of the steam drive process. First annual report, September 1977-September 1978  

SciTech Connect

Scaling laws of the heat transport mechanism in steam displacement processes are developed based upon an integral energy balance equation. Unlike the differential approach adopted by previous workers, the above scaling laws do not necessitate the use of any empirical correction factor as has been done in previous scaling calculations. The results provide a complete and consistent scale-down of the energy transport behavior, which is the critical mechanism for the success of a steam injection process. In the course of the study, the scaling problems associated with relative permeability and capillary pressure are also discussed. A method which has often been used in scaling nonthermal displacement processes is applied to reduce errors due to scaling in relative permeability. Both dimensional and inspectional analyses are applied to illustrate their use in steam processes. Scale-up laws appeared in the literature and those used in this study are compared and numerical examples are given.

Doscher, T M

1980-12-01

295

Minimal Fokker-Planck theory for the thermalization of mesoscopic subsystems.  

PubMed

We explore a minimal paradigm for thermalization, consisting of two weakly coupled, low dimensional, nonintegrable subsystems. As demonstrated for Bose-Hubbard trimers, chaotic ergodicity results in a diffusive response of each subsystem, insensitive to the details of the drive exerted on it by the other. This supports the hypothesis that thermalization can be described by a Fokker-Planck equation. We also observe, however, that Levy-flight type anomalies may arise in mesoscopic systems, due to the wide range of time scales that characterize 'sticky' dynamics. PMID:23414006

Tikhonenkov, Igor; Vardi, Amichay; Anglin, James R; Cohen, Doron

2013-02-01

296

Mesoscopic superposition of states with sub-Planck structures in phase space  

SciTech Connect

We propose the cavity quantum electrodynamics method, using dispersive interaction between atoms and a high-quality cavity to realize the mesoscopic superposition of coherent states that would exhibit sub-Planck structures in phase space, i.e., the structures at a scale smaller than the Plank's constant (({Dirac_h}/2{pi})). These structures are direct signatures of quantum coherence and are formed as a result of interference between the two superposed cat states. In particular we focus on a superposition involving four coherent states. We show interferences in the conditional measurements involving two atoms.

Agarwal, G.S.; Pathak, P.K. [Physical Research Laboratory, Navrangpura, Ahmedabad-380 009 (India)

2004-11-01

297

Transport in the spatially tempered, fractional Fokker-Planck equation  

NASA Astrophysics Data System (ADS)

A study of truncated Lévy flights in super-diffusive transport in the presence of an external potential is presented. The study is based on the spatially tempered, fractional Fokker-Planck (TFFP) equation in which the fractional diffusion operator is replaced by a tempered fractional diffusion (TFD) operator. We focus on harmonic (quadratic) potentials and periodic potentials with broken spatial symmetry. The main objective is to study the dependence of the steady-state probability density function (PDF), and the current (in the case of periodic potentials) on the level of tempering, ?, and on the order of the fractional derivative in space, ?. An expansion of the TFD operator for large ? is presented, and the corresponding equation for the coarse grained PDF is obtained. The steady-state PDF solution of the TFFP equation for a harmonic potential is computed numerically. In the limit ? ? ?, the PDF approaches the expected Boltzmann distribution. However, nontrivial departures from this distribution are observed for finite (? > 0) truncations, and ? ? 2. In the study of periodic potentials, we use two complementary numerical methods: a finite-difference scheme based on the Grunwald-Letnikov discretization of the truncated fractional derivatives and a Fourier-based spectral method. In the limit ? ? ?, the PDFs converges to the Boltzmann distribution and the current vanishes. However, for ? ? 2, the PDF deviates from the Boltzmann distribution and a finite non-equilibrium ratchet current appears for any ? > 0. The current is observed to converge exponentially in time to the steady-state value. The steady-state current exhibits algebraical decay with ?, as J ˜ ?-?, for ? ? 1.75. However, for ? ? 1.5, the steady-state current decays exponentially with ?, as J ˜ e-??. In the presence of an asymmetry in the TFD operator, the tempering can lead to a current reversal. A detailed numerical study is presented on the dependence of the current on ? and the physical parameters of the system.

Kullberg, A.; del-Castillo-Negrete, D.

2012-06-01

298

Searching for primordial non-Gaussianity in Planck CMB maps using a combined estimator  

NASA Astrophysics Data System (ADS)

The extensive search for deviations from Gaussianity in cosmic microwave background radiation (CMB) data is very important due to the information about the very early moments of the universe encoded there. Recent analyses from Planck CMB data do not exclude the presence of non-Gaussianity of small amplitude, although they are consistent with the Gaussian hypothesis. The use of different techniques is essential to provide information about types and amplitudes of non-Gaussianities in the CMB data. In particular, we find interesting to construct an estimator based upon the combination of two powerful statistical tools that appears to be sensitive enough to detect tiny deviations from Gaussianity in CMB maps. This estimator combines the Minkowski functionals with a Neural Network, maximizing a tool widely used to study non-Gaussian signals with a reinforcement of another tool designed to identify patterns in a data set. We test our estimator by analyzing simulated CMB maps contaminated with different amounts of local primordial non-Gaussianity quantified by the dimensionless parameter f NL. We apply it to these sets of CMB maps and find gtrsim 98% of chance of positive detection, even for small intensity local non-Gaussianity like f NL = 38±18, the current limit from Planck data for large angular scales. Additionally, we test the suitability to distinguish between primary and secondary non-Gaussianities: first we train the Neural Network with two sets, one of nearly Gaussian CMB maps (|f NL| <= 10) but contaminated with realistic inhomogeneous Planck noise (i.e., secondary non-Gaussianity) and the other of non-Gaussian CMB maps, that is, maps endowed with weak primordial non-Gaussianity (28 <= f NL <= 48); after that we test an ensemble composed of CMB maps either with one of these non-Gaussian contaminations, and find out that our method successfully classifies ~ 95% of the tested maps as being CMB maps containing primordial or secondary non-Gaussianity. Furthermore, we analyze the foreground-cleaned Planck maps obtaining constraints for non-Gaussianity at large-angles that are in good agreement with recent constraints. Finally, we also test the robustness of our estimator including cut-sky masks and realistic noise maps measured by Planck, obtaining successful results as well.

Novaes, C. P.; Bernui, A.; Ferreira, I. S.; Wuensche, C. A.

2014-01-01

299

Improving the Rapid Refresh and High Resolution Rapid Refresh physics to better perform across a wide range of spatial scales  

NASA Astrophysics Data System (ADS)

Model development at NOAA/GSD spans a wide range of spatial scales: global scale (Flow-following finite-volume Icosohedral Model, FIM; 10-250 km grid spacing), continental scale (RAP; 13 km grid spacing), CONUS scale (HRRR; 3 km grid spacing), and regional modeling (experimental nesting at 1 km grid spacing over complex terrain). As the model resolution changes, the proportion of resolved vs unresolved physical processes changes; therefore, physical parameterizations need to adapt to different model resolutions to more accurately handle the unresolved processes. The Limited Area Model (LAM) component of the Grey Zone Experiment was designed to assess the change in behavior of numerical weather prediction models between 16 and 1 km by simulating a cold-air outbreak over the North Atlantic and North Sea. The RAP and HRRR model physics were tested in this case study in order to examine the change in behavior of the model physics at 16, 8, 4, 2, and 1 km grid spacings with and without the use a convective parameterization. The primary purpose of these tests is to better understand the change in behavior of the boundary layer and convective schemes across the grey zone, such that further targeted modifications can then help improve general performance at various scales. The RAP currently employs a modified form of the Mellor-Yamada-Nakanishi-Niino (MYNN) PBL scheme, which is an improved TKE-based scheme tuned to match large-eddy simulations. Modifications have been performed to better match observations at 13 km (RAP) grid spacing but more multi-scale testing is required before modifications are introduced to make it scale-aware. A scale-aware convective parameterization, the Grell-Freitas scheme (both deep- and shallow-cumulus scheme), has been developed to better handle the transition in behavior of the sub-grid scale convective processes through the grey zone. This study examines the change in behavior of both schemes across the grey zone. Their transitional behavior is characterized and strategies to improve each scheme are explored. Further tests are performed to elucidate the impacts of specific model configurations and parameters that may improve weather prediction across the grey zone.

Olson, Joseph; Grell, Georg

2014-05-01

300

Multi-level multi-domain simulations: a new approach to multi-scale multi-physics descriptions  

NASA Astrophysics Data System (ADS)

There are a number of modeling challenges posed by space weather numerical simulations. Most of them arise from the multi-scale and multi-physics aspects of the problem. The multiple scales dramatically increase the requirements, in terms of computational resources, because of the need to carry large scale simulations with the proper small-scales resolution. Lately, many suggestions have been made to overcome this difficulty by using various refinement methods which consist in splitting the domain into regions of different resolutions. The multiple physics are generally treated in a similar way: interfaces separate the regions where different equations are solved. We present here an innovative approach based on the coexistence of several levels of description, which differ either by their resolutions or by their physics. Instead of interacting through interfaces, these levels are all entirely simulated and are interlocked over the complete extension of their overlapping area. This scheme has been applied to a two-dimensional implicit Particle in Cell code. Some results of magnetic reconnection simulations are presented and we also discuss the optimal implementation of this scheme on very large clusters.

Beck, Arnaud; Innocenti, M. E.; Lapenta, Giovanni; Markidis, Stefano

2012-10-01

301

Generalized Fokker-Planck equation with generalized interval probability  

NASA Astrophysics Data System (ADS)

The Fokker-Planck equation is widely used to describe the time evolution of stochastic systems in drift-diffusion processes. Yet, it does not differentiate two types of uncertainties: aleatory uncertainty that is inherent randomness and epistemic uncertainty due to lack of perfect knowledge. In this paper, a generalized differential Chapman-Kolmogorov equation based on a new generalized interval probability theory is derived, where epistemic uncertainty is modeled by the generalized interval while the aleatory one is by the probability measure. A generalized Fokker-Planck equation is proposed to describe drift-diffusion processes under both uncertainties. A path integral approach is developed to numerically solve the generalized Fokker-Planck equation. The resulted interval-valued probability density functions rigorously bound the real-valued ones computed from the classical path integral method. The method is demonstrated by numerical examples.

Wang, Yan

2013-05-01

302

Neutrino mass, dark matter, and Baryon asymmetry via TeV-scale physics without fine-tuning.  

PubMed

We propose an extended version of the standard model, in which neutrino oscillation, dark matter, and the baryon asymmetry of the Universe can be simultaneously explained by the TeV-scale physics without assuming a large hierarchy among the mass scales. Tiny neutrino masses are generated at the three-loop level due to the exact Z2 symmetry, by which the stability of the dark matter candidate is guaranteed. The extra Higgs doublet is required not only for the tiny neutrino masses but also for successful electroweak baryogenesis. The model provides discriminative predictions especially in Higgs phenomenology, so that it is testable at current and future collider experiments. PMID:19257506

Aoki, Mayumi; Kanemura, Shinya; Seto, Osamu

2009-02-01

303

Performance predictions of scaled BiCMOS gates using physical simulation  

Microsoft Academic Search

The necessary reduction in supply voltage for future scaled-down BiCMOS technologies will cause a degradation in speed because the base-emitter forward voltage drop is not scaled. The analysis of how the performance difference between BiCMOS and CMOS changes with scaling has been ambiguous in previous work because of insufficient model accuracy. In this work, mixed-level device-circuit simulation with accurate numerical

T. Arnborg

1992-01-01

304

WMAP five-year constraints on lepton asymmetry and radiation energy density: implications for Planck  

SciTech Connect

In this paper we set bounds on the radiation content of the Universe and neutrino properties by using the WMAP (Wilkinson microwave anisotropy probe) five-year CMB (cosmic microwave background) measurements complemented with most of the existing CMB and LSS (large scale structure) data (WMAP5+All), imposing also self-consistent BBN (big bang nucleosynthesis) constraints on the primordial helium abundance. We consider lepton asymmetric cosmological models parametrized by the neutrino degeneracy parameter {xi}{sub {nu}} and the variation of the relativistic degrees of freedom, {Delta}N{sub eff}{sup oth}, due to possible other physical processes occurring between BBN and structure formation epochs. We get a mean value of the effective number of relativistic neutrino species of N{sub eff} = 2.98 {sub 2.27}{sup 3.60} {sub 1.65}{sup 4.37}, providing an important improvement over the similar result obtained from WMAP5+BAO+SN+HST (BAO: baryonic acoustic oscillations; SN: supernovae; HST: Hubble Space Telescope) data (Komatsu et al (WMAP Collaboration), 2008 Astrophys. J. Suppl. submitted [0803.0547]). We also find a strong correlation between {Omega}{sub m}h{sup 2} and z{sub eq}, showing that we observe N{sub eff} mainly via the effect of z{sub eq}, rather than via neutrino anisotropic stress as claimed by the WMAP team (Komatsu et al (WMAP Collaboration), 2008 Astrophys. J. Suppl. submitted [0803.0547]). WMAP5+All data provide a strong bound on the helium mass fraction of Y{sub p} = 0.2486 {+-} 0.0085 (68% CL), that rivals the bound on Y{sub p} obtained from the conservative analysis of the present data on helium abundance. For the neutrino degeneracy parameter we find a bound of -0.216{<=}{xi}{sub {nu}}{<=}0.226 (68% CL), which represents an important improvement over the similar result obtained by using the WMAP three-year data. The inclusion in the analysis of LSS data reduces the upper limit of the neutrino mass to m{sub {nu}}<0.46 eV (95% CL) with respect to the values obtained from the analysis from WMAP5-only data (Dunkley et al (WMAP Collaboration), 2008 Astrophys. J. Suppl. submitted [0803.0586]) and WMAP5+BAO+SN+HST data (Komatsu et al (WMAP Collaboration), 2008 Astrophys. J. Suppl. submitted [0803.0547]). We forecast that the CMB temperature and polarization measurements observed with high angular resolutions and sensitivities by the future Planck satellite will reduce the errors on {xi}{sub {nu}} and Y{sub p} down to {sigma}({xi}{sub {nu}}){approx_equal}0.089 (68% CL) and {sigma}(Y{sub p}) = 0.013 (68% CL) respectively, values fully consistent with the BBN bounds on these parameters. This work has been done on behalf of Planck-LFI (low frequency instrument) activities.

Popa, L A; Vasile, A, E-mail: lpopa@venus.nipne.ro, E-mail: avasile@venus.nipne.ro [ISS Institute for Space Sciences Bucharest-Magurele, Ro-077125 (Romania)] [ISS Institute for Space Sciences Bucharest-Magurele, Ro-077125 (Romania)

2008-06-15

305

Mathematics and Epistemology in Planck's Theoretical Work (1898-1915)  

NASA Astrophysics Data System (ADS)

It is quite easy to verify that, in the continuous theoretical evolution of Planck's quantum construction from 1898 till 1915, mathematics plays an evident basic role. There are, firstly the formal analogy with Boltzmann's mechanical theory of gas, and secondly the formal analogy with Boltzmann's probabilistic theory of gas, giving to mathematical algorithms a particular investigative and ideative power. But, in this context of discovering some aspects of the quantum world, Planck's epistemology and natural philosophy also plays an equally creative powerful role. So one finds the real key of this theoretical progress, only in a strong dialectic relation between these elements inextricably bound by reciprocal influence.

Campogalliani, Paolo

2006-06-01

306

Flux-limited diffusion and Fokker-Planck equations  

SciTech Connect

A recently reported description of radiative transfer is generalized to the case of a linear transport equation containing a Fokker-Planck treatment of very peaked scattering. The resulting diffusion theory is naturally flux (current) limited; i.e., the magnitude of the current cannot exceed the scalar flux. It is shown that the effect of the Fokker-Planck terms is, within this theory, identical to treating the very peaked scattering via the classical transport correction to the scattering cross section. This description of linear transport has potential application in charged-particle and high-energy neutron transport calculations.

Pomraning, G.C.

1983-10-01

307

Bounce-averaged Fokker-Planck code for stellarator transport  

SciTech Connect

A computer code for solving the bounce-averaged Fokker-Planck equation appropriate to stellarator transport has been developed, and its first applications made. The code is much faster than the bounce-averaged Monte-Carlo codes, which up to now have provided the most efficient numerical means for studying stellarator transport. Moreover, because the connection to analytic kinetic theory of the Fokker-Planck approach is more direct than for the Monte-Carlo approach, a comparison of theory and numerical experiment is now possible at a considerably more detailed level than previously.

Mynick, H.E.; Hitchon, W.N.G.

1985-07-01

308

Physics on the Smallest Scales: An Introduction to Minimal Length Phenomenology  

ERIC Educational Resources Information Center

Many modern theories which try to unify gravity with the Standard Model of particle physics, such as e.g. string theory, propose two key modifications to the commonly known physical theories: the existence of additional space dimensions; the existence of a minimal length distance or maximal resolution. While extra dimensions have received a wide…

Sprenger, Martin; Nicolini, Piero; Bleicher, Marcus

2012-01-01

309

Scaling of the Multilevel Physical Optics parallel algorithm on a large grid  

Microsoft Academic Search

The MultiLevel fast Physical Optics (MLPO) algorithm allows to perform Physical Optics integrals with a computational complexity comparable to that of the Fast Fourier Transform (FFT). The multilevel scheme is based on hierarchical domain decomposition and phase compensated interpolation approach. An optimized distributed memory parallelized MLPO algorithm has been designed by partitioning not only the radiating aperture but also the

Christian Parrot; Daniel Millont; Christine Letrou; Amir Boag

2010-01-01

310

Adolescents' Self-Efficacy to Overcome Barriers to Physical Activity Scale  

ERIC Educational Resources Information Center

This paper describes a revised measure of self-efficacy to overcome barriers to moderate and vigorous physical activity in a sample of 484 high school students in Toronto, Ontario. The students had a mean age of 15.3 years. Principal axis factoring with oblique rotation yielded five factors: self-efficacy to overcome internal, harassment, physical

Dwyer, John J. M.; Chulak, Tala; Maitland, Scott; Allison, Kenneth R.; Lysy, Daria C.; Faulkner, Guy E. J.; Sheeshka, Judy

2012-01-01

311

Prospects for colliders and collider physics to the 1 pev energy scale.  

National Technical Information Service (NTIS)

A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron a...

King

2000-01-01

312

Multiple scales in Pati-Salam unification models  

NASA Astrophysics Data System (ADS)

We investigate models where gauge unification (GUT) proceeds in steps that include Pati-Salam symmetry. Beyond the Standard Model, we allow for a well-defined set of small representations of the GUT gauge group. We show that all possible chains of PatiSalam symmetry breaking can be realized in accordance with gauge-coupling unification. We identify, in particular, models with unification near the Planck scale, with intermediate left-right or SU(4) quark-lepton symmetries that are relevant for flavor physics, with new colored particles at accessible energies, and with an enlarged electroweak Higgs sector. We look both at supersymmetric and non-supersymmetric scenarios.

Hartmann, Florian; Kilian, Wolfgang; Schnitter, Karsten

2014-05-01

313

Children of War: The Long-Run Effects of Large-Scale Physical Destruction and Warfare on Children  

Microsoft Academic Search

During World War II, more than one-half million tons of bombs were dropped in aerial raids on German cities, destroying about one-third of the total housing stock nationwide. This paper provides causal evidence on long-term consequences of large-scale physical destruction on the educational attainment, health status and labor market outcomes of German children. I combine a unique dataset on city-level

Mevlude Akbulut-Yuksel

2009-01-01

314

Children of War: The Long-Run Effects of Large-Scale Physical Destruction and Warfare on Children  

Microsoft Academic Search

During World War II, more than half a million tons of bombs were dropped in aerial raids on German cities, destroying about one-third of the total housing stock. This paper provides causal evidence on long-term consequences of large-scale physical destruction on the educational attainment, health status and labor market outcomes of German children. I combine a unique dataset on city-level

Mevlude Akbulut-Yuksel

2009-01-01

315

Advances in understanding and parameterization of small-scale physical processes in the marine Arctic climate system: a review  

NASA Astrophysics Data System (ADS)

The Arctic climate system includes numerous highly interactive small-scale physical processes in the atmosphere, sea ice, and ocean. During and since the International Polar Year 2007-2008, significant advances have been made in understanding these processes. Here these advances are reviewed, synthesized and discussed. In atmospheric physics, the primary advances have been in cloud physics, radiative transfer, mesoscale cyclones, coastal and fjordic processes, as well as in boundary-layer processes and surface fluxes. In sea ice and its snow cover, advances have been made in understanding of the surface albedo and its relationships with snow properties, the internal structure of sea ice, the heat and salt transfer in ice, the formation of super-imposed ice and snow ice, and the small-scale dynamics of sea ice. In the ocean, significant advances have been related to exchange processes at the ice-ocean interface, diapycnal mixing, tidal currents and diurnal resonance. Despite this recent progress, some of these small-scale physical processes are still not sufficiently understood: these include wave-turbulence interactions in the atmosphere and ocean, the exchange of heat and salt at the ice-ocean interface, and the mechanical weakening of sea ice. Many other processes are reasonably well understood as stand-alone processes but challenge is to understand their interactions with, and impacts and feedbacks on, other processes. Uncertainty in the parameterization of small-scale processes continues to be among the largest challenges facing climate modeling, and nowhere is this more true than in the Arctic. Further improvements in parameterization require new year-round field campaigns on the Arctic sea ice, closely combined with satellite remote sensing studies and numerical model experiments.

Vihma, T.; Pirazzini, R.; Renfrew, I. A.; Sedlar, J.; Tjernström, M.; Nygård, T.; Fer, I.; Lüpkes, C.; Notz, D.; Weiss, J.; Marsan, D.; Cheng, B.; Birnbaum, G.; Gerland, S.; Chechin, D.; Gascard, J. C.

2013-12-01

316

A Multi-physics Multi-scale Modeling Platform for Research and Development in Solid State Lighting  

Microsoft Academic Search

A multi-physics multi-scale modeling platform has been developed and it has been applied to various stages of the LED manufacturing such as MOCVD reactor design, epitaxial growth based on silicon wafer, chip design and manufacturing, module packaging and assembly, and specific lamps. Discussions are also given to the ultra-scalable reactor design, material constitutive modeling, and curvature evolution prediction during a

Sheng Liu; Kai Wang; Zhiyin Gan; Zongyuan Liu; Zhaohui Chen; Han Yan; Xiaobing Luo; Wei Wei; Pei Wang

2008-01-01

317

Grid-Scale Comparison of Climate Versus Mesoscale Model Microphysics Using the Separate Physics and Dynamics Setup  

NASA Astrophysics Data System (ADS)

The Separate Physics and Dynamics Setup (SPADS) can be used to isolate the grid-scale dependence of specific physics types to better understand how they behave when applied at various model scales. The SPADS technique permits selected physics to be run on an alternate grid with different grid spacing than used for the rest of the model. This allows one to construct scenarios to determine how various assumptions within parameterizations affect their behavior at various grid spacings, and thus their ability to be scale aware. The behavior of the remainder of the model is held constant since the grid spacing does not change, except for the targeted physics. A comparison using SPADS for the Morrison-Gettelman scheme, which originates from the CAM5 model, versus the Morrison scheme, from the WRF model, has been performed for grid spacings spanning the so-called "gray zone" of cloud parameterization. The two schemes differ in their handling of low-density cloudy cells when compared at a grid spacing of 32 km versus 4 km. The Morrison-Gettelman scheme produces less clear-sky grid cells at the coarser resolution than the fine resolution when given the same meteorological conditions, while the Morrison scheme does the opposite. A primary difference between the two schemes is the possibility for a continuum of cloud fractions in Morrison-Gettelman but only a binary cloud fraction of 0 or 100% cloud in Morrison. It is hypothesized that this difference leads to the different scaling behavior. Results from testing this hypothesis will be presented.

Gustafson, W. I.; Ma, P.; Singh, B.; Xiao, H.

2012-12-01

318

Assessment of physical strain in younger and older subjects using heart rate and scalings of perceived exertion.  

PubMed

Physical strain is usually evaluated physiologically by using the heart rate (HR) or psychologically using scaled perceived exertion (PE). In order to explore the relationship between these approaches, we compared the series of both measurements taken simultaneously during work on a bicycle ergometer. A total of 29 participants aged between 27 and 41, 42 and 56, and 57 and 71 years took part in 28 minutes of cycling with systematically increased and decreased load as well as in 7 hours of continuous cycling with low to medium exertion, interrupted by brief peak loads at high to very high exertion levels. Results revealed that, while both measurements are suitable to capture physical strain, HR is not as specific as PE. The older participants further perceived comparable physical loads as more demanding as the younger participants. With an aging workforce, results have potential implications for the organisation of work places. PMID:24761802

Kakarot, Nadine; Müller, Friedrich

2014-07-01

319

High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems.  

PubMed

An integrated multi-physics simulation capability for the design and analysis of current and future nuclear reactor models is being investigated, to tightly couple neutron transport and thermal-hydraulics physics under the SHARP framework. Over several years, high-fidelity, validated mono-physics solvers with proven scalability on petascale architectures have been developed independently. Based on a unified component-based architecture, these existing codes can be coupled with a mesh-data backplane and a flexible coupling-strategy-based driver suite to produce a viable tool for analysts. The goal of the SHARP framework is to perform fully resolved coupled physics analysis of a reactor on heterogeneous geometry, in order to reduce the overall numerical uncertainty while leveraging available computational resources. The coupling methodology and software interfaces of the framework are presented, along with verification studies on two representative fast sodium-cooled reactor demonstration problems to prove the usability of the SHARP framework. PMID:24982250

Mahadevan, Vijay S; Merzari, Elia; Tautges, Timothy; Jain, Rajeev; Obabko, Aleksandr; Smith, Michael; Fischer, Paul

2014-08-01

320

Physics  

NSDL National Science Digital Library

Physics is the scientific study of the basic principles of the universe, including matter, energy, motion and force, and their interactions. Major topics include classical mechanics, thermodynamics, light and optics, electromagnetism and relativity.

K-12 Outreach,

321

NEW APPROACHES: A closer look at Planck's blackbody equation  

NASA Astrophysics Data System (ADS)

The spectral distribution of blackbody radiation is given by Planck's blackbody equation. This can be integrated across the complete spectrum to obtain the total blackbody emissive power (the Stefan - Boltzmann law). In some circumstances we shall want to investigate behaviour only in a band of the spectrum. For example, rare earth oxides which are commonly used in thermophotovoltaic devices typically emit significantly only in a single narrow band. The complexity of Planck's blackbody equation is such that it appears to require significant computing prowess to be able to obtain useful results. In a recent paper in this journal, Jain (1996) calculated the emissive power of the visible region using the high-powered mathematical software package Mathematica. The requirement of advanced numerical techniques and/or a powerful piece of software limit the range of students who can study spectral blackbody effects. However, by taking a closer look at Planck's equation we find that it is possible to learn much about spectral blackbody effects (including all of Jain's results) by careful use of mathematical techniques covered in A-level and a spreadsheet (or other simple computational tool). This opens a study of Planck's equation to all undergraduates.

Lawson, Duncan

1997-09-01

322

Stability and size of galaxies from Planck's constant  

Microsoft Academic Search

Stability and characterisitic geometrical and kinematical sizes of galaxies\\u000aare strictly related to a minimal characteristic action whose value is of order\\u000a$h$, the Planck constant. We infer that quantum mechanics, in some sense,\\u000adetermines the structure and the size of galaxies.

Salvatore Capozziello; Silvio De Siena; Fabrizio Illuminati; E. R. Caianiello

1999-01-01

323

A nodal integral method for the Fokker-Planck equation  

SciTech Connect

The Fokker-Planck equation is important in the kinetic theory of plasmas for the description of long-range coulomb collisions of charged particles. Hence, it is used extensively in modeling fusion devices, such as magnetic mirrors and certain aspects of tokamaks. The authors have developed a nodal integral method (NIM) for the accurate numerical solution of the Fokker-Planck equation, applied it to test problems, and compared the results obtained with those obtained using a finite difference method (FDM). These comparisons show that the NIM is more accurate and more computationally efficient than the FDM, especially in the calculation of particle and energy leakages and when applied to more difficult test problems. The new method significantly extends ideas developed previously to more complicated partial differential equations (PDEs) in two important ways. Since the nonlinearities in the Fokker-Planck equation are considerably more complicated than those that arise in the Navier-Stokes equations and the Boussinesq equations, the NIM developed here extends the general technique farther into the nonlinear regime. Further, since the Fokker-Planck equation is singular at the origin in spherical velocity coordinates, the geometry relevant to most practical problems, special origin equations had to be developed for the computational elements adjacent to the v = 0 boundary.

McArdle, K.R.; Dorning, J.J. (Univ. of Virginia, Charlottesville (USA))

1989-01-01

324

Thermal stability in precision cosmology experiments: the Planck LFI case  

NASA Astrophysics Data System (ADS)

After the great success of NASA's satellite missions COBE and WMAP, the Planck mission represents the third generation of mm-wave instruments designed for space observations of CMB anisotropies. Two instruments, the Low-Frequency Instrument (LFI) and the High-Frequency Instrument (HFI) will produce CMB maps with unprecedented angular resolution, sensitivity and frequency coverage. This ambitious task will be achieved by using low noise HEMT detectors cryogenically cooled at ~20K for the LFI and bolometric detectors cooled at 0.1K for the HFI; in particular, the LFI is based on pseudo-correlation receivers in which the sky signal is continuously compared to a cryogenic reference load in thermal contact with the HFI 4K stage. Such high sensitivity in Planck detectors calls for a strict control of systematic effects, which must be kept at ?K level in the final maps; this in turn imposes tight requirements on the thermal and electrical stability of the different stages in the instrument. In this paper we discuss a study of the impact of thermal fluctuations at the level of the 20K cooler cold-end on the Planck-LFI measurements and present some viable solutions that have been adopted to keep the residual systematic error within the required values for Planck-LFI.

Terenzi, Luca; Mennella, Aniello; Bersanelli, Marco; Mandolesi, Nazzareno; Morgante, Gianluca; Prina, Mauro; Tomasi, Maurizio; Valenziano, Luca

2004-03-01

325

Planck intermediate results. XVI. Profile likelihoods for cosmological parameters  

NASA Astrophysics Data System (ADS)

We explore the 2013 Planck likelihood function with a high-precision multi-dimensional minimizer (Minuit). This allows a refinement of the ?CDM best-fit solution with respect to previously-released results, and the construction of frequentist confidence intervals using profile likelihoods. The agreement with the cosmological results from the Bayesian framework is excellent, demonstrating the robustness of the Planck results to the statistical methodology. We investigate the inclusion of neutrino masses, where more significant differences may appear due to the non-Gaussian nature of the posterior mass distribution. By applying the Feldman-Cousins prescription, we again obtain results very similar to those of the Bayesian methodology. However, the profile-likelihood analysis of the cosmic microwave background (CMB) combination (Planck+WP+highL) reveals a minimum well within the unphysical negative-mass region. We show that inclusion of the Planck CMB-lensing information regularizes this issue, and provide a robust frequentist upper limit ? m? ? 0.26 eV (95% confidence) from the CMB+lensing+BAO data combination.

2014-06-01

326

Effect of Finite Computational Domain on Turbulence Scaling Law in Both Physical and Spectral Spaces  

NASA Technical Reports Server (NTRS)

The well-known translation between the power law of energy spectrum and that of the correlation function or the second order structure function has been widely used in analyzing random data. Here, we show that the translation is valid only in proper scaling regimes. The regimes of valid translation are different for the correlation function and the structure function. Indeed, they do not overlap. Furthermore, in practice, the power laws exist only for a finite range of scales. We show that this finite range makes the translation inexact even in the proper scaling regime. The error depends on the scaling exponent. The current findings are applicable to data analysis in fluid turbulence and other stochastic systems.

Hou, Thomas Y.; Wu, Xiao-Hui; Chen, Shiyi; Zhou, Ye

1998-01-01

327

Scalings between Physical and their Observationally Related Quantities of Merger Remnants  

Microsoft Academic Search

We present scaling relations between the virial velocity (V) and the one-dimensional central velocity dispersion (sigma0); the gravitational radius (Rv) and the effective radius (Re); and the total mass (M) and the luminous mass (ML) found in N-body simulations of binary mergers of spiral galaxies. These scalings are of the form V2 ? sigma0alpha, Rv ? Rebeta and M? MLgamma.

Hector Aceves; H. Velázquez

2005-01-01

328

Evaluation of the MOS SF36 physical functioning scale (PF40): II. Comparison of relative precision using Likert and Rasch scoring methods  

Microsoft Academic Search

This study examined the relative precision (RP) of two methods of scoring the 10-item Physical Functioning Scale (PF-10) from a large sample of patients (n = 3445) of the Medical Outcomes Study. Based on a Likert scaling model, the PF-10 summated scoring method was compared with a Rasch Item Response Theory (IRT) scaling model in which raw scores were transformed

Colleen A. McHorney; Stephen M. Haley; John E. Ware

1997-01-01

329

Eliminating the Gravitational Constant, G, and Improving SI Units, Using Two New Planck-Unit Frameworks With All Parameters as Ratios of Only H, C, and a  

NASA Astrophysics Data System (ADS)

This paper presents a tool kit of new ways of understanding fundamental physics and the relationships between parameters. The novel insights and predictions include: A self-contained consistent new Planck unit set of maximal-sized parameters from which all observed values can be compared and easily combined in equations. A self-contained consistent new Planck unit set of electroncharge-based parameters, some of which are directly observable in experiments. The interpretation of the gravitational constant, G as a dimensionless ratio eliminates the need to test the equivalence of gravitational and inertial mass. That all parameters can be displayed in terms of only h and c for the Planck maximal-parameter set and additionally in a for the electron-charge-based set, previously considered impossible. A new dimensional analysis employed to describe parameter dimensionality and to uncover any law of nature or universal constant. That all electron-charge-based Planck parameters can be described solely in terms of ratios of Rk and Kj and so will benefit from the precision of measurement of these two parameters. That most electromagnetic parameters can be reinterpreted in terms of mechanical parameters. By adjusting currently misaligned SI units to be self-consistent and consistent with these Double-adjusted-Planck units, greater clarity will ensue.

Lawrence, Michael

2013-09-01

330

A Novel Multi-Dimensional Vlasov-Fokker-Planck Code for Modeling Electron Transport in High Energy Density Plasmas  

NASA Astrophysics Data System (ADS)

The unexpected macroscopic behaviour of laser-irradiated plasmas is often attributable to complex kinetic phenomena that depend on the detailed structure of the electron distribution function. For example, the non-local transport of electrons can have a dramatic effect on the temperature and pressure profile of inertial confinement fusion targets. To explore the kinetic physics of high energy density plasmas we have developed the parallel relativistic 2D3P Vlasov-Fokker-Planck code OSHUN [1] that incorporates a spherical harmonic expansion of the electron distribution function. The expansion is truncated such that the necessary resolution in momentum space is retained for a given problem. Finite collisionality results in rapid decay of the high-order harmonics, thereby providing a natural truncation mechanism for the expansion. The code has both implicit and fully explicit electromagnetic field-solvers and employs a rigorous ``linearized'' Fokker-Planck collision operator. OSHUN has been benchmarked against well-known problems, in the highly kinetic limit to model collisionless relativistic instabilities, and in the hydrodynamic limit to recover transport coefficients. We will demonstrate the applicability and limitations of the code by discussing a number of studies we have recently undertaken with relevance to shock ignition and the national ignition facility. [4pt] [1] M. Tzoufras, A. R. Bell, P. A. Norreys, F. S. Tsung, ``A Vlasov-Fokker-Planck code for high energy density physics,'' J. Comp. Phys. 230, 17, 6475-6494 (2011)

Tzoufras, Michail

2012-10-01

331

Testing WMAP data via Planck radio and SZ catalogues  

NASA Astrophysics Data System (ADS)

The prime evidence underpinning the standard ? cold dark matter cosmological model is the cosmic microwave background (CMB) power spectrum as observed by Wilkinson Microwave Anisotropy Probe (WMAP) and other microwave experiments. But Sawangwit and Shanks have recently shown that the WMAP CMB power spectrum is highly sensitive to the beam profile of the WMAP telescope. Here, we use the source catalogue from the Planck early data release to test further the WMAP beam profiles. We confirm that stacked beam profiles at Q, V and particularly at W, appear wider than expected when compared to the Jupiter beam, normalized either directly to the radio source profiles or using Planck fluxes. The same result is also found based on WMAP-CMB-free source catalogues and NRAO VLA Sky Survey (NVSS) sources. The accuracy of our beam profile measurements is supported by analysis of CMB sky simulations. However, the beam profiles from WMAP7 at the W band are narrower than previously found in WMAP5 data and the rejection of the WMAP beam is now only at the ?3? level. We also find that the WMAP source fluxes demonstrate possible non-linearity with Planck fluxes. But including ground-based and Planck data for the bright Weiland et al. sources may suggest that the discrepancy is a linear offset rather than a non-linearity. Additionally, we find that the stacked Sunyaev-Zel'dovich (SZ) decrements of ?151 galaxy clusters observed by Planck are in agreement with the WMAP data. We find that there is no evidence for a WMAP SZ deficit as has previously been reported. In the particular case of Coma, we find evidence for the presence of an {O}(0.1 mK) downwards CMB fluctuation. We conclude that beam profile systematics can have significant effects on both the amplitude and position of the acoustic peaks, with potentially important implications for cosmology parameter fitting.

Whitbourn, J. R.; Shanks, T.; Sawangwit, U.

2014-01-01

332

Large and local-scale influences on physical and chemical characteristics of coastal waters of Western Europe during winter  

NASA Astrophysics Data System (ADS)

There is now a strong scientific consensus that coastal marine systems of Western Europe are highly sensitive to the combined effects of natural climate variability and anthropogenic climate change. However, it still remains challenging to assess the spatial and temporal scales at which climate influence operates. While large-scale hydro-climatic indices, such as the North Atlantic Oscillation (NAO) or the East Atlantic Pattern (EAP) and the weather regimes such as the Atlantic Ridge (AR), are known to be relevant predictors of physical processes, changes in coastal waters can also be related to local hydro-meteorological and geochemical forcing. Here, we study the temporal variability of physical and chemical characteristics of coastal waters located at about 48°N over the period 1998-2013 using (1) sea surface temperature, (2) sea surface salinity and (3) nutrient concentration observations for two coastal sites located at the outlet of the Bay of Brest and off Roscoff, (4) river discharges of the major tributaries close to these two sites and (5) regional and local precipitation data over the region of interest. Focusing on the winter months, we characterize the physical and chemical variability of these coastal waters and document changes in both precipitation and river runoffs. Our study reveals that variability in coastal waters is connected to the large-scale North Atlantic atmospheric circulation but is also partly explained by local river influences. Indeed, while the NAO is strongly related to changes in sea surface temperature at the Brest and Roscoff sites, the EAP and the AR have a major influence on precipitations, which in turn modulate river discharges that impact sea surface salinity at the scale of the two coastal stations.

Tréguer, Paul; Goberville, Eric; Barrier, Nicolas; L'Helguen, Stéphane; Morin, Pascal; Bozec, Yann; Rimmelin-Maury, Peggy; Czamanski, Marie; Grossteffan, Emilie; Cariou, Thierry; Répécaud, Michel; Quéméner, Loic

2014-11-01

333

The Higgs mass and the emergence of new physics  

NASA Astrophysics Data System (ADS)

We investigate the physical implications of formulating the electroweak (EW) part of the Standard Model (SM) in terms of a superconnection involving the supergroup SU(2/1). In particular, we relate the observed Higgs mass to new physics at around 4 TeV. The ultraviolet incompleteness of the superconnection approach points to its emergent nature. The new physics beyond the SM is associated with the emergent supergroup SU(2/2), which is natural from the point of view of the Pati-Salam model. Given that the Pati-Salam group is robust in certain constructions of string vacua, these results suggest a deeper connection between low energy (4 TeV) and high energy (Planck scale) physics via the violation of decoupling in the Higgs sector.

Aydemir, Ufuk; Minic, Djordje; Takeuchi, Tatsu

2013-07-01

334

Derivation of quantum mechanics from the Boltzmann equation for the Planck aether  

Microsoft Academic Search

The Planck aether hypothesis assumes that space is densely filled with an equal number of locally interacting positive and negative Planck masses obeying an exactly nonrelativistic law of motion. The Planck masses can be described by a quantum mechanical two-component nonrelativistic operator field equation having the form of a two-component nonlinear Schrödinger equation, with a spectrum of quasiparticles obeying Lorentz

F. Winterberg

1995-01-01

335

Physics Research in the SciDAC Center for Wave-Plasma Interactions  

SciTech Connect

This paper describes physics research on wave-plasma interactions in the ion cyclotron range of frequencies (ICRF) and the lower hybrid range of frequencies (LHRF) that takes advantage of advances in large scale computation as well as applied mathematics expertise. A combined Fokker-Planck and full-wave solver is used to simulate the interaction of ICRF waves with nonthermal ions generated by the wave itself, with fast ions from neutral beam injection (NBI), and with alpha particles from fusion processes. Finite ion drift orbit effects are included in this analysis through the use of a Monte Carlo approach. Models for simulating the linear and nonlinear interaction of an ICRF antenna with the tenuous edge plasma are also described. Finally we describe advances that have been made to perform a combined full-wave and Fokker Planck analysis of nonthermal electrons during LH current drive.

Bonoli, P. T. [PSFC-MIT (United States); Batchelor, D. B.; Berry, L. A.; Jaeger, E. F.; Wright, J. C. [ORNL (United States)](and others)

2007-09-28

336

Construction of large-scale simulation codes using ALPAL (A Livermore Physics Applications Language)  

SciTech Connect

A Livermore Physics Applications Language (ALPAL) is a new computer tool that is designed to leverage the abilities and creativity of computational scientist. Some of the ways that ALPAL provides this leverage are: first, it eliminates many sources of errors; second, it permits building code modules with far greater speed than is otherwise possible; third, it provides a means of specifying almost any numerical algorithm; and fourth, it is a language that is close to a journal-style presentation of physics models and numerical methods for solving them. 13 refs., 9 figs.

Cook, G.

1990-10-01

337

Transport in the spatially tempered, fractional Fokker-Planck equation  

SciTech Connect

A study of truncated Levy flights in super-diffusive transport in the presence of an external potential is presented. The study is based on the spatially tempered, fractional Fokker-Planck (TFFP) equation in which the fractional diffusion operator is replaced by a tempered fractional diffusion (TFD) operator. We focus on harmonic (quadratic) potentials and periodic potentials with broken spatial symmetry. The main objective is to study the dependence of the steady-state probability density function (PDF), and the current (in the case of periodic potentials) on the level of tempering, lambda, and on the order of the fractional derivative in space, alpha. An expansion of the TFD operator for large lambda is presented, and the corresponding equation for the coarse grained PDF is obtained. The steady-state PDF solution of the TFFP equation for a harmonic potential is computed numerically. In the limit lambda -> infinity, the PDF approaches the expected Boltzmann distribution. However, nontrivial departures from this distribution are observed for finite (lambda > 0) truncations, and alpha not equal 2. In the study of periodic potentials, we use two complementary numerical methods: a finite-difference scheme based on the Grunwald-Letnikov discretization of the truncated fractional derivatives and a Fourier-based spectral method. In the limit lambda -> infinity, the PDFs converges to the Boltzmann distribution and the current vanishes. However, for alpha not equal 2, the PDF deviates from the Boltzmann distribution and a finite non-equilibrium ratchet current appears for any lambda > 0. The current is observed to converge exponentially in time to the steady-state value. The steady-state current exhibits algebraical decay with lambda, as J similar to lambda(-zeta), for alpha >= 1.75. However, for alpha <= 1.5, the steady-state current decays exponentially with lambda, as J similar to e(-xi lambda). In the presence of an asymmetry in the TFD operator, the tempering can lead to a current reversal. A detailed numerical study is presented on the dependence of the current on lambda and the physical parameters of the system.

Kullberg, A. [University of California, Los Angeles; Del-Castillo-Negrete, Diego B [ORNL

2012-01-01

338

Detailed Computational Study of Translocation Dynamics: Revealing the Physical Mechanisms of Viscosity Dependent Scaling Laws  

NASA Astrophysics Data System (ADS)

Noting the limitations of current methods of characterizing the unbiased translocation of a polymer through a nanopore, we demonstrate a measurement which more completely maps out the process in time. Applying this approach to Langevin Dynamics simulations of translocation at different viscosities for a relatively tight nanopore yields interesting results for the scaling of the translocation time with polymer length: ?˜N^?. At low viscosities, super-diffusive results are obtained. At high viscosities, while translocation is found to obey simple scaling with ?=2.2 near the beginning of the process, length dependent deviations from simple scaling near the end result in an overall ? exponent which is viscosity dependent. The memory and entropic effects giving rise to this behaviour will be discussed.

de Haan, Hendrick W.; Slater, Gary W.

2010-03-01

339

Dynamical properties of fractal networks: Scaling, numerical simulations, and physical realizations  

SciTech Connect

This article describes the advances that have been made over the past ten years on the problem of fracton excitations in fractal structures. The relevant systems to this subject are so numerous that focus is limited to a specific structure, the percolating network. Recent progress has followed three directions: scaling, numerical simulations, and experiment. In a happy coincidence, large-scale computations, especially those involving array processors, have become possible in recent years. Experimental techniques such as light- and neutron-scattering experiments have also been developed. Together, they form the basis for a review article useful as a guide to understanding these developments and for charting future research directions. In addition, new numerical simulation results for the dynamical properties of diluted antiferromagnets are presented and interpreted in terms of scaling arguments. The authors hope this article will bring the major advances and future issues facing this field into clearer focus, and will stimulate further research on the dynamical properties of random systems.

Nakayama, T.; Yakubo, K. (Department of Applied Physics, Hokkaido University, Sapporo 060 (Japan)); Orbach, R.L. (Department of Physics, University of California, Riverside, California 92521 (United States))

1994-04-01

340

IMPORTANCE OF PHYSICAL SCALING FACTORS TO BENTHIC MARINE INVERTEBRATE RECOLONIZATION OF LABORATORY MICROCOSMS  

EPA Science Inventory

Five laboratory studies of benthic macroinvertebrate recolonization were conducted for 6-wk periods to evaluate the effects of physical factors (i.e., microcosm size, seawater flow rates and sediment depth) on benthic community structure. esign variables included4 open-faced acry...

341

Using the RPE-Talk Scale to Individualize Physical Activity for Students  

ERIC Educational Resources Information Center

For some students, self-selecting a pace during exercise may not provide enough of a physical challenge. Others push themselves so hard that they tire out before they can experience the benefits of exercise. In order to improve self-monitoring of exercise intensity, a variety of tools using the perception of effort and the ability to talk while…

Nye, Susan B.; Todd, M. Kent

2013-01-01

342

Investigation of the physical scaling of sea spray spume droplet production  

Microsoft Academic Search

In this paper we report on a laboratory study, the Spray Production and Dynamics Experiment (SPANDEX), conducted at the University of New South Wales Water Research Laboratory in Australia. The goals of SPANDEX were to illuminate physical aspects of spume droplet production and dispersion; verify theoretical simplifications used to estimate the source function from ambient droplet concentration measurements; and examine

C. W. Fairall; M. L. Banner; W. L. Peirson; W. Asher; R. P. Morison

2009-01-01

343

Planck pre-launch status: Expected LFI polarisation capability  

NASA Astrophysics Data System (ADS)

We present a system-level description of the Low Frequency Instrument (LFI) considered as a differencing polarimeter, and evaluate its expected performance. The LFI is one of the two instruments on board the ESA Planck mission to study the cosmic microwave background. It consists of a set of 22 radiometers sensitive to linear polarisation, arranged in orthogonally-oriented pairs connected to 11 feed horns operating at 30, 44 and 70 GHz. In our analysis, the generic Jones and Mueller-matrix formulations for polarimetry are adapted to the special case of the LFI. Laboratory measurements of flight components are combined with optical simulations of the telescope to investigate the values and uncertainties in the system parameters affecting polarisation response. Methods of correcting residual systematic errors are also briefly discussed. The LFI has beam-integrated polarisation efficiency >99% for all detectors, with uncertainties below 0.1%. Indirect assessment of polarisation position angles suggests that uncertainties are generally less than 0.5°, and this will be checked in flight using observations of the Crab nebula. Leakage of total intensity into the polarisation signal is generally well below the thermal noise level except for bright Galactic emission, where the dominant effect is likely to be spectral-dependent terms due to bandpass mismatch between the two detectors behind each feed, contributing typically 1-3% leakage of foreground total intensity. Comparable leakage from compact features occurs due to beam mismatch, but this averages to < 5 × 10-4 for large-scale emission. An inevitable feature of the LFI design is that the two components of the linear polarisation are recovered from elliptical beams which differ substantially in orientation. This distorts the recovered polarisation and its angular power spectrum, and several methods are being developed to correct the effect, both in the power spectrum and in the sky maps. The LFI will return a high-quality measurement of the CMB polarisation, limited mainly by thermal noise. To meet our aspiration of measuring polarisation at the 1% level, further analysis of flight and ground data is required. We are still researching the most effective techniques for correcting subtle artefacts in polarisation; in particular the correction of bandpass mismatch effects is a formidable challenge, as it requires multi-band analysis to estimate the spectral indices that control the leakage.

Leahy, J. P.; Bersanelli, M.; D'Arcangelo, O.; Ganga, K.; Leach, S. M.; Moss, A.; Keihänen, E.; Keskitalo, R.; Kurki-Suonio, H.; Poutanen, T.; Sandri, M.; Scott, D.; Tauber, J.; Valenziano, L.; Villa, F.; Wilkinson, A.; Zonca, A.; Baccigalupi, C.; Borrill, J.; Butler, R. C.; Cuttaia, F.; Davis, R. J.; Frailis, M.; Francheschi, E.; Galeotta, S.; Gregorio, A.; Leonardi, R.; Mandolesi, N.; Maris, M.; Meinhold, P.; Mendes, L.; Mennella, A.; Morgante, G.; Prezeau, G.; Rocha, G.; Stringhetti, L.; Terenzi, L.; Tomasi, M.

2010-09-01

344

Fokker-Planck modeling of current penetration during electron cyclotron current drive  

SciTech Connect

The current penetration during electron cyclotron current drive (ECCD) on the resistive time scale is studied with a Fokker-Planck simulation, which includes a model for the magnetic diffusion that determines the parallel electric field evolution. The existence of the synergy between the inductive electric field and EC driven current complicates the process of the current penetration and invalidates the standard method of calculation in which Ohm's law is simply approximated by j-j{sub cd}={sigma}E. Here it is proposed to obtain at every time step a self-consistent approximation to the plasma resistivity from the Fokker-Planck code, which is then used in a concurrent calculation of the magnetic diffusion equation in order to obtain the inductive electric field at the next time step. A series of Fokker-Planck calculations including a self-consistent evolution of the inductive electric field has been performed. Both the ECCD power and the electron density have been varied, thus varying the well known nonlinearity parameter for ECCD P{sub rf}[MW/m{sup -3}]/n{sub e}{sup 2}[10{sup 19} m{sup -3}] [R. W. Harvey et al., Phys. Rev. Lett 62, 426 (1989)]. This parameter turns out also to be a good predictor of the synergetic effects. The results are then compared with the standard method of calculations of the current penetration using a transport code. At low values of the Harvey parameter, the standard method is in quantitative agreement with Fokker-Planck calculations. However, at high values of the Harvey parameter, synergy between ECCD and E{sub parallel} is found. In the case of cocurrent drive, this synergy leads to the generation of large amounts of nonthermal electrons and a concomitant increase of the electrical conductivity and current penetration time. In the case of countercurrent drive, the ECCD efficiency is suppressed by the synergy with E{sub parallel} while only a small amount of nonthermal electrons is produced.

Merkulov, A.; Westerhof, E.; Schueller, F. C. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster (Netherlands)

2007-05-15

345

A Cross-Cultural Validation of Perceived Locus of Causality Scale in Physical Education Context  

ERIC Educational Resources Information Center

We examined the validity of the factor structure and invariance of the Perceived Locus of Causality (PLOC) scale instrument scores across two nations endorsing collectivist (Singapore) and individualist (Great Britain) cultural values. Results indicated that confirmatory factor analytic models of the PLOC exhibited adequate ft according to…

Wang, C. K. John; Hagger, Martin; Liu, Woon Chia

2009-01-01

346

The evolutionary model of physics large-scale simulation on parallel dataflow architecture  

Microsoft Academic Search

The problem of effective mapping of computational algorithms to parallel architecture is very important in the large-scale simulation. The developed model allows us to explore and utilize fine-grain parallelism, as well as coarse-grain parallelism. The model was tested by the nonlinear 3D magnetohydrodynamic (MHD) code.

A. V. Nikitin; L. I. Nikitina

2003-01-01

347

Physics of large-scale star formation: The GAS-Dynamic aspect  

Microsoft Academic Search

The subject of the review is the nature of regions of large-scale starbursts in galaxies. Theoretical investigations are presented and discussed, for the most part. Principal attention is devoted to the gas-dynamic approach to the problem. The review has the following plan. First we give a brief summary of empirical data on superassociations as regions of collective star formation on

A. D. Chernin

1996-01-01

348

Oscillating bispectra and galaxy clustering: A novel probe of inflationary physics with large-scale structure  

SciTech Connect

Many models of inflation predict oscillatory features in the bispectrum of primordial fluctuations. Since it has been shown that primordial non-Gaussianity can lead to a scale-dependent halo bias, we investigate the effect of oscillations in the three-point function on the clustering of dark-matter halos. Interestingly, we find that features in the inflaton potential such as oscillations or sharp steps get imprinted in the mass dependence of the non-Gaussian halo bias. In this paper, we focus on models displaying a sharp feature in the inflaton potential as well as resonant non-Gaussianity. In both cases, we find a strong scale dependence for the non-Gaussian halo bias with a slope similar to that of the local model. In the resonant case, we find that the non-Gaussian bias oscillates with halo mass, a novel feature that is unique to this type of models. In the case of a sharp feature in the inflaton potential, we find that the clustering of halos is enhanced at the mass scale corresponding to the Fourier mode that exited the horizon when the inflaton was crossing the feature in the potential. Both of these are new effects that open the possibility of characterizing the inflationary potential with large-scale-structure surveys. We briefly discuss the prospects for detecting these non-Gaussian effects.

Cyr-Racine, Francis-Yan [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada); California Institute of Technology, Pasadena, California 91125 (United States); Schmidt, Fabian [California Institute of Technology, Pasadena, California 91125 (United States)

2011-10-15

349

Computationally efficient numerical methods for time- and space-fractional Fokker-Planck equations  

NASA Astrophysics Data System (ADS)

Fractional Fokker-Planck equations have been used to model several physical situations that present anomalous diffusion. In this paper, a class of time- and space-fractional Fokker-Planck equations (TSFFPE), which involve the Riemann-Liouville time-fractional derivative of order 1-? (?in(0, 1)) and the Riesz space-fractional derivative (RSFD) of order ?in(1, 2), are considered. The solution of TSFFPE is important for describing the competition between subdiffusion and Lévy flights. However, effective numerical methods for solving TSFFPE are still in their infancy. We present three computationally efficient numerical methods to deal with the RSFD, and approximate the Riemann-Liouville time-fractional derivative using the Grünwald method. The TSFFPE is then transformed into a system of ordinary differential equations (ODE), which is solved by the fractional implicit trapezoidal method (FITM). Finally, numerical results are given to demonstrate the effectiveness of these methods. These techniques can also be applied to solve other types of fractional partial differential equations.

Yang, Qianqian; Liu, Fawang; Turner, Ian

2009-10-01

350

Spatial-Scale Effects on Relative Importance of Physical Habitat Predictors of Stream Health  

NASA Astrophysics Data System (ADS)

A common theme in recent landscape studies is the comparison of riparian and watershed land use as predictors of stream health. The objective of this study was to compare the performance of reach-scale habitat and remotely assessed watershed-scale habitat as predictors of stream health over varying spatial extents. Stream health was measured with scores on a fish index of biotic integrity (IBI) using data from 95 stream reaches in the Eastern Corn Belt Plain (ECBP) ecoregion of Indiana. Watersheds hierarchically nested within the ecoregion were used to regroup sampling locations to represent varying spatial extents. Reach habitat was represented by metrics of a qualitative habitat evaluation index, whereas watershed variables were represented by riparian forest, geomorphology, and hydrologic indices. The importance of reach- versus watershed-scale variables was measured by multiple regression model adjusted-R2 and best subset comparisons in the general linear statistical framework. Watershed models had adjusted-R2 ranging from 0.25 to 0.93 and reach models had adjusted-R2 ranging from 0.09 to 0.86. Better-fitting models were associated with smaller spatial extents. Watershed models explained about 15% more variation in IBI scores than reach models on average. Variety of surficial geology contributed to decline in model predictive power. Results should be interpreted bearing in mind that reach habitat was qualitatively measured and only fish assemblages were used to measure stream health. Riparian forest and length-slope (LS) factor were the most important watershed-scale variables and mostly positively correlated with IBI scores, whereas substrate and riffle-pool quality were the important reach-scale variables in the ECBP.

Frimpong, Emmanuel A.; Sutton, Trent M.; Engel, Bernard A.; Simon, Thomas P.

2005-12-01

351

Exploring spatiotemporal patterns and physical controls of soil moisture at various spatial scales  

NASA Astrophysics Data System (ADS)

Soil moisture variability of various spatial scales is analyzed based on empirical orthogonal function (EOF) method using soil moisture datasets with various spatial resolutions: 1 km eco-hydrological model simulation, 0.25° passive microwave (Advanced Microwave Scanning Radiometer for the Earth Observing System, AMSR-E) dataset, and 0.5° land surface model simulation from Climate Predictor Center (CPC). All three datasets generate EOFs that explain similar variances with those generated from in situ observations from agro-meteorological network. Using AMSR-E product and eco-hydrological model simulation, it is found that the primary spatial pattern of soil moisture obtained from watershed scale has a strong connection to topographic attributes, followed by soil texture and rainfall variability, as suggested by the correlation between the primary EOF mode (EOF1) of soil moisture and landscape attributes. However, the EOF analysis of both AMSR-E and CPC datasets at regional scale reaches the conclusion that soil texture indices, such as sand and clay content, is of higher importance to soil moisture EOF1 spatial pattern (explaining 61 % variance) than topography is. Furthermore, correlation between soil moisture EOF1 and soil property is higher in spring than in autumn, which indicates that soil water-holding and drainage capabilities are more important under dry conditions. At national scale, the combined effects of topographic feature and soil property are clearly exhibited in EOF1. The study results reveal that different emphases should be placed on accurate acquisition of landscape attributes for soil moisture estimation according to various spatial scales.

Qiu, Jianxiu; Mo, Xingguo; Liu, Suxia; Lin, Zhonghui

2013-12-01

352

Conceptual and methodological frameworks for large scale and high resolution analysis of the physical flood susceptibility of buildings  

NASA Astrophysics Data System (ADS)

There are some approaches available for assessing flood damage to buildings and critical infrastructure. However, these methods up to now can hardly be adapted to a large scale because of lacking high resolution classification and characterisation approaches for the built structures. To overcome this obstacle, the paper presents, first, a conceptual framework for understanding physical flood susceptibility of buildings; and second, a methodological framework for its analysis. The latter ranges from automatic extraction of buildings mainly from remote sensing with their subsequent classification and characterisation to a systematic physical flood susceptibility assessment. The work shows the results of implementation and testing a respective methodology in a district of the city of Magangué, Magdalena River Colombia.

Blanco-Vogt, A.; Schanze, J.

2013-10-01

353

On the physical and logical topology design of large-scale optical networks  

Microsoft Academic Search

We consider the problem of designing a network of optical cross-connects (OXCs) to provide end-to-end lightpath services to large numbers of label switched routers (LSRs). We present a set of heuristic algorithms to address the combined problem of physical topology design (i.e., determine the number of OXCs required and the fiber links among them) and logical topology design (i.e., determine

Yufeng Xin; George N. Rouskas; Harry G. Perros

2003-01-01

354

Physical parameters of the Small Magellanic Cloud RR Lyrae stars and the distance scale  

NASA Astrophysics Data System (ADS)

We present a careful and detailed light curve analysis of RR Lyrae stars in the Small Magellanic Cloud (SMC) discovered by the Optical Gravitational Lensing Experiment (OGLE) project. Out of 536 single-mode RR Lyrae stars selected from the data base, we have investigated the physical properties of 335 `normal-looking' RRab stars and 17 RRc stars that have good quality photometric light curves. We have also been able to estimate the distance modulus of the cloud which is in good agreement with those determined from other independent methods. The Fourier decomposition method has been used to study the basic properties of these variables. Accurate Fourier decomposition parameters of 536 RR Lyrae stars in the OGLE-II data base are computed. Empirical relations between the Fourier parameters and some physical parameters of these variables have been used to estimate the physical parameters for the stars from the Fourier analysis. Further, the Fourier decomposition of the light curves of the SMC RR Lyrae stars yields their mean physical parameters as and MV = 0.78 +/- 0.02 for 335 RRab variables and and MV = 0.76 +/- 0.05 for 17 RRc stars. Using the absolute magnitude together with the mean magnitude, intensity-weighted mean magnitude and the phase-weighted mean magnitude of the RR Lyrae stars, the mean distance modulus to the SMC is estimated to be 18.86 +/- 0.01, 18.83 +/- 0.01 and 18.84 +/- 0.01 mag, respectively, from the RRab stars. From the RRc stars, the corresponding distance modulus values are found to be 18.92 +/- 0.04, 18.89 +/- 0.04 and 18.89 +/- 0.04 mag, respectively. Since the Fourier analysis is a very powerful tool for the study of the physical properties of the RR Lyrae stars, we emphasize the importance of exploring the reliability of the calculation of Fourier parameters together with the uncertainty estimates keeping in view the large collections of photometric light curves that will become available from variable star projects of the future.

Deb, Sukanta; Singh, Harinder P.

2010-02-01

355

A Physical-Experimental Model for Small-Scale Basaltic Vulcanian Eruptions  

Microsoft Academic Search

In the last period of its summer 2001 flank activity Mt. Etna produced ash explosions not common at this basaltic volcano. The explosions took place at a new vent at 2550 m.a.s.l. and followed Strombolian and effusive activity. At first the ash erupted as a continuous, pulsing plume a few km high, occasionally undergoing small-scale, partial collapses. Afterward the frequency

P. Scarlato; J. Taddeucci; O. Spieler; B. Kennedy; D. B. Dingwell; M. Pompilio

2003-01-01

356

Quantum scale of inflation and particle physics of the early universe  

Microsoft Academic Search

The quantum gravitational scale of inflation is calculated by finding a sharp\\u000aprobability peak in the distribution function of chaotic inflationary\\u000acosmologies driven by a scalar field with large negative constant $\\\\xi$ of\\u000anonminimal interaction. In the case of the no-boundary state of the universe\\u000athis peak corresponds to the eternal inflation, while for the tunnelling\\u000aquantum state it generates

A. O. Barvinsky; A. Yu. Kamenshchik

1994-01-01

357

Integrating Delta Building Physics & Economics: Optimizing the Scale of Engineered Avulsions in the Mississippi River Delta  

NASA Astrophysics Data System (ADS)

Land loss in the Mississippi River Delta caused by subsidence and erosion has resulted in habitat loss, interference with human activities, and increased exposure of New Orleans and other settled areas to storm surge risks. Prior to dam and levee building and oil and gas production in the 20th century, the long term rates of land building roughly balanced land loss through subsidence. Now, however, sediment is being deposited at dramatically lower rates in shallow areas in and adjacent to the Delta, with much of the remaining sediment borne by the Mississippi being lost to the deep areas of the Gulf of Mexico. A few projects have been built in order to divert sediment from the river to areas where land can be built, and many more are under consideration as part of State of Louisiana and Federal planning processes. Most are small scale, although there have been some proposals for large engineered avulsions that would divert a significant fraction of the remaining available sediment (W. Kim, et al. 2009, EOS). However, there is debate over whether small or large diversions are the economically optimally and socially most acceptable size of such land building projects. From an economic point of view, the optimal size involves tradeoffs between scale economies in civil work construction, the relationship between depth of diversion and sediment concentration in river water, effects on navigation, and possible diminishing returns to land building at a single location as the edge of built land progresses into deeper waters. Because land building efforts could potentially involve billions of dollars of investment, it is important to gain as much benefit as possible from those expenditures. We present the result of a general analysis of scale economies in land building from engineered avulsions. The analysis addresses the question: how many projects of what size should be built at what time in order to maximize the amount of land built by a particular time? The analysis integrates three models: 1. coarse sediment diversion as a function of the width, depth, and timing of water diversions (using our field measurements of sediment concentration as a function of depth), 2. land building as a function of the location, water, and amount of sediment diverted, accounting for bathymetry, subsidence, and other factors, and 3. cost of building and operating the necessary civil works. Our statistical analysis of past diversions indicates existence of scale economies in width and scale of diseconomies in depth. The analysis explores general relationships between size, cost, and land building, and does not consider specific actual project proposals or locations. Sensitivity to assumptions about fine sediment capture, accumulation rates for organic material, and other inputs will be discussed.

Kenney, M. A.; Mohrig, D.; Hobbs, B. F.; Parker, G.

2011-12-01

358

Resurrecting power law inflation in the light of Planck results  

NASA Astrophysics Data System (ADS)

It is well known that a canonical scalar field with an exponential potential can drive power law inflation (PLI). However, the tensor-to-scalar ratio in such models turns out to be larger than the stringent limit set by recent Planck results. We propose a new model of power law inflation for which the scalar spectra index, the tensor-to-scalar ratio and the non-gaussianity parameter fNLequil are in excellent agreement with Planck results. Inflation, in this model, is driven by a non-canonical scalar field with an inverse power law potential. The Lagrangian for our model is structurally similar to that of a canonical scalar field and has a power law form for the kinetic term. A simple extension of our model resolves the graceful exit problem which usually afflicts models of power law inflation.

Unnikrishnan, Sanil; Sahni, Varun

2013-10-01

359

Estimating the uncorrelated dark energy evolution in the Planck era  

NASA Astrophysics Data System (ADS)

The equation of state (EOS), w(z), is the most important parameter of dark energy. We reconstruct the evolution of this EOS in a model-independent way using the latest cosmic microwave background (CMB) data from Planck and other observations, such as type Ia supernovae, the baryonic acoustic oscillation measurements (SDSS, 6dF, BOSS, and WiggleZ), and the Hubble parameter value H(z). The results show that the EOS is consistent with the cosmological constant at the 2? confidence level, not preferring a dynamical dark energy. The uncorrelated EOS of dark energy constraints from Planck CMB data are much tighter than those from the WMAP 9-year CMB data.

Wang, F. Y.; Dai, Z. G.

2014-01-01

360

Multi-Level iterative methods in computational plasma physics  

SciTech Connect

Plasma physics phenomena occur on a wide range of spatial scales and on a wide range of time scales. When attempting to model plasma physics problems numerically the authors are inevitably faced with the need for both fine spatial resolution (fine grids) and implicit time integration methods. Fine grids can tax the efficiency of iterative methods and large time steps can challenge the robustness of iterative methods. To meet these challenges they are developing a hybrid approach where multigrid methods are used as preconditioners to Krylov subspace based iterative methods such as conjugate gradients or GMRES. For nonlinear problems they apply multigrid preconditioning to a matrix-few Newton-GMRES method. Results are presented for application of these multilevel iterative methods to the field solves in implicit moment method PIC, multidimensional nonlinear Fokker-Planck problems, and their initial efforts in particle MHD.

Knoll, D.A.; Barnes, D.C.; Brackbill, J.U.; Chacon, L.; Lapenta, G.

1999-03-01

361

Fokker-Planck Equation for a Metastable Time Dependent Potential  

NASA Astrophysics Data System (ADS)

We use the Fokker-Planck equation to study the diffusion process driven for a metastable potential within a temporal dependence. This potential is characterized by the existence of a barrier that increases with time and reduces the particle diffusion. Escape rate across the barrier for different values of diffusion coefficient is analyzed. The results are also associated with the diffusion process through ion channels in biological system.

Araujo, M. T.; Drigo Filho, E.

2014-06-01

362

Cosmology from Gravitational Lens Time Delays and Planck Data  

NASA Astrophysics Data System (ADS)

Under the assumption of a flat ?CDM cosmology, recent data from the Planck satellite point toward a Hubble constant that is in tension with that measured by gravitational lens time delays and by the local distance ladder. Prosaically, this difference could arise from unknown systematic uncertainties in some of the measurements. More interestingly—if systematics were ruled out—resolving the tension would require a departure from the flat ?CDM cosmology, introducing, for example, a modest amount of spatial curvature, or a non-trivial dark energy equation of state. To begin to address these issues, we present an analysis of the gravitational lens RXJ1131-1231 that is improved in one particular regard: we examine the issue of systematic error introduced by an assumed lens model density profile. We use more flexible gravitational lens models with baryonic and dark matter components, and find that the exquisite Hubble Space Telescope image with thousands of intensity pixels in the Einstein ring and the stellar velocity dispersion of the lens contain sufficient information to constrain these more flexible models. The total uncertainty on the time-delay distance is 6.6% for a single system. We proceed to combine our improved time-delay distance measurement with the WMAP9 and Planck posteriors. In an open ?CDM model, the data for RXJ1131-1231 in combination with Planck favor a flat universe with \\Omega _k=0.00^{+0.01}_{-0.02} (68% credible interval (CI)). In a flat wCDM model, the combination of RXJ1131-1231 and Planck yields w=-1.52^{+0.19}_{-0.20} (68% CI).

Suyu, S. H.; Treu, T.; Hilbert, S.; Sonnenfeld, A.; Auger, M. W.; Blandford, R. D.; Collett, T.; Courbin, F.; Fassnacht, C. D.; Koopmans, L. V. E.; Marshall, P. J.; Meylan, G.; Spiniello, C.; Tewes, M.

2014-06-01

363

Classification of Compact Submillimeter Sources in the Planck Archive  

NASA Astrophysics Data System (ADS)

The Planck satellite is a third-generation space-based cosmic microwave background (CMB) experiment with greater resolution and broader frequency range than its predecessors, COBE and WMAP. The completion of the first high-sensitivity submillimeter all-sky survey in April 2010 allows a unique opportunity to study the classes of astronomical sources that are foregrounds to the CMB. This project uses the Planck Early Release Compact Source Catalog (ERCSC) to classify compact objects, which have not previously been seen by IRAS. In an effort to avoid the effects of confusion from the high density of sources in the Galactic plane, we confine our study to |b|>20°. Due to the ~5 arcmin resolution of Planck data and resultant uncertainty in the positions of sources, we used WISE 12-µm and 24-µm data to determine accurate positions and an estimate of the far-infrared color temperature of the sources. Other catalogs, including Akari, IRAS, Sloan and 2MASS, were then searched to pinpoint the counterpart of the source and obtain their spectral energy distribution (SED). The SED was used to constrain the origin of the far-infrared emission and provide further clues as to the nature of the sources. Preliminary results show Planck ERCSC sources include planetary nebulae, star-forming galaxies, stars with surrounding dust, and cold stellar cores. Teachers and students from four schools are active participants in the data analysis process to bring authentic research into the classroom. This research was made possible through the NASA/IPAC Teacher Archive Research Project (NITARP) and was funded by NASA Astrophysics Data Program and Archive Outreach funds.

Johnson, Chelen H.; Border, C.; O'Connor, K.; Rothrock, D.; Chary, R.; Bingham, M.; Clark, M.; Ernst, M.; Gilbert, S.; Koop, S.; Maddaus, M.; Miller, I.; O'Bryan, A.; Ravelomanantsoa, T.; SanMiguel, D.; Schmidt, L.; Searls, E.; Tong, W.; Torres, O.; Zeidner, A.; NITARP

2013-01-01

364

Planck Early Results: The High Frequency Instrument data processing  

Microsoft Academic Search

We describe the processing of the 334 billion raw data samples from the High Frequency Instrument (hereafter HFI) which we performed to produce six temperature maps from the first 295 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545 and 857GHz with an angular resolution ranging from 9.9

P. A. R. Ade; N. Aghanim; R. Ansari; M. Arnaud; M. Ashdown; J. Aumont; A. J. Banday; M. Bartelmann; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; J. J. Bock; J. R. Bond; J. Borrill; F. Boulanger; T. Bradshaw; M. Bucher; J.-F. Cardoso; G. Castex; A. Catalano; A. Challinor; A. Chamballu; R.-R. Chary; X. Chen; C. Chiang; S. Church; D. L. Clements; J.-M. Colley; S. Colombi; F. Couchot; A. Coulais; C. Cressiot; B. P. Crill; M. Crook; P. de Bernardis; J. Delabrouille; J.-M. Delouis; F.-X. Désert; K. Dolag; H. Dole; O. Doré; M. Douspis; J. Dunkley; G. Efstathiou; C. Filliard; O. Forni; P. Fosalba; K. Ganga; M. Giard; D. Girard; Y. Giraud-Héraud; R. Gispert; K. M. Górski; S. Gratton; M. Griffin; G. Guyot; J. Haissinski; D. Harrison; G. Helou; S. Henrot-Versillé; C. Hernández-Monteagudo; S. R. Hildebrandt; R. Hills; E. Hivon; M. Hobson; W. A. Holmes; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; J. Kaplan; R. Kneissl; L. Knox; M. Kunz; G. Lagache; J.-M. Lamarre; A. E. Lange; A. Lasenby; A. Lavabre; C. R. Lawrence; M. Le Jeune; C. Leroy; J. Lesgourgues; A. Lewis; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; N. Mandolesi; R. Mann; F. Marleau; D. J. Marshall; S. Masi; T. Matsumura; I. McAuley; P. McGehee; J.-B. Melin; C. Mercier; S. Mitra; M.-A. Miville-Deschênes; A. Moneti; L. Montier; D. Mortlock; A. Murphy; F. Nati; C. B. Netterfield; H. U. Norgaard-Nielsen; C. North; F. Noviello; D. Novikov; S. Osborne; F. Pajot; G. Patanchon; T. Peacocke; T. J. Pearson; O. Perdereau; L. Perotto; F. Piacentini; M. Piat; S. Plaszczynski; E. Pointecouteau; N. Ponthieu; G. Prézeau; S. Prunet; J.-L. Puget; W. T. Reach; M. Remazeilles; C. Renault; A. Riazuelo; I. Ristorcelli; G. Rocha; C. Rosset; G. Roudier; M. Rowan-Robinson; B. Rusholme; R. Saha; D. Santos; G. Savini; B. M. Schaefer; P. Shellard; L. Spencer; J.-L. Starck; V. Stolyarov; R. Stompor; R. Sudiwala; R. Sunyaev; D. Sutton; J.-F. Sygnet; J. A. Tauber; C. Thum; J.-P. Torre; F. Touze; M. Tristram; F. Van Leeuwen; L. Vibert; D. Vibert; B. D. Wandelt; S. D. M. White; H. Wiesemeyer; A. Woodcraft; V. Yurchenko; D. Yvon; A. Zacchei

2011-01-01

365

Chaotic universe dynamics using a Fokker-Planck equation  

SciTech Connect

A Fokker-Planck equation that accounts for fluctuations in field and its conjugate momentum is solved numerically for the case of a lambda phi/sup 4/ potential. Although the amount of inflation agrees closely with that expected classically, in certain cases (large initial fields or large dispersions),the ''slow rolling'' approximation appears invalid. In such cases inflation would stop prematurely before possibly restarting. 18 refs., 2 figs.

Coule, D.H.; Olynyk, K.O.

1987-07-01

366

Critical Design Decisions of The Planck LFI Level 1 Software  

NASA Astrophysics Data System (ADS)

The PLANCK satellite with two on-board instruments, a Low Frequency Instrument (LFI) and a High Frequency Instrument (HFI) has been launched on May 14th with Ariane 5. The ISDC Data Centre for Astrophysics in Versoix, Switzerland has developed and maintains the Planck LFI Level 1 software for the Data Processing Centre (DPC) in Trieste, Italy. The main tasks of the Level 1 processing are to retrieve the daily available scientific and housekeeping (HK) data of the LFI instrument, the Sorption Cooler and the 4k Cooler data from Mission Operation Centre (MOC) in Darmstadt; to sort them by time and by type (detector, observing mode, etc...); to extract the spacecraft attitude information from auxiliary files; to flag the data according to several criteria; and to archive the resulting Time Ordered Information (TOI), which will then be used to produce maps of the sky in different spectral bands. The output of the Level 1 software are the TOI files in FITS format, later ingested into the Data Management Component (DMC) database. This software has been used during different phases of the LFI instrument development. We started to reuse some ISDC components for the LFI Qualification Model (QM) and we completely rework the software for the Flight Model (FM). This was motivated by critical design decisions taken jointly with the DPC. The main questions were: a) the choice of the data format: FITS or DMC? b) the design of the pipelines: use of the Planck Process Coordinator (ProC) or a simple Perl script? c) do we adapt the existing QM software or do we restart from scratch? The timeline and available manpower are also important issues to be taken into account. We present here the orientation of our choices and discuss their pertinence based on the experience of the final pre-launch tests and the start of real Planck LFI operations.

Morisset, N.; Rohlfs, R.; Türler, M.; Meharga, M.; Binko, P.; Beck, M.; Frailis, M.; Zacchei, A.

2010-12-01

367

Determination of Planck Mean Absorption Coefficients for Hydrocarbon Fuels  

Microsoft Academic Search

Infrared transmission of propane, n-heptane and propylene samples was measured using Fourier transform infrared spectroscopy (FTIR) for temperatures ?1000 K to facilitate calculation of absorption coefficients of fuel molecules at temperatures representative of non-premixed flame interiors. Spectrally resolved fits of the absorption coefficient data using a semi-empirical quantum-based expression provide a basis for calculating infrared spectra at any temperature. Experimentally-derived Planck

Kaoru Wakatsuki; Gregory S. Jackson; Jungho Kim; Anthony Hamins; Marc R. Nyden; Stephen P. Fuss

2008-01-01

368

Fokker-Planck Calculation of the ICF Implosion  

Microsoft Academic Search

A 1-D electron-thermal-conduction calculation code based on the Fokker-Planck equation has been developed. Our code includes the electron-ion and electron-electron collisions. The electron distribution function is expanded into the zeroth-, first-, and second-order terms of Legendre polynomials, which are solved simultaneously. Furthermore, our code includes the time derivative term for the first- and second-order parts of the Legrendre polynomials. We

A. Sunahara; J. A. Delettrez; R. W. Short; S. Skupsky

2001-01-01

369

Thermal stability in precision cosmology experiments: the Planck LFI case  

Microsoft Academic Search

After the great success of NASA's satellite missions COBE and WMAP, the Planck mission represents the third generation of mm-wave instruments designed for space observations of CMB anisotropies. Two instruments, the Low-Frequency Instrument (LFI) and the High-Frequency Instrument (HFI) will produce CMB maps with unprecedented angular resolution, sensitivity and frequency coverage. This ambitious task will be achieved by using low

Luca Terenzi; Aniello Mennella; Marco Bersanelli; Nazzareno Mandolesi; Gianluca Morgante; Mauro Prina; Maurizio Tomasi; Luca Valenziano

2004-01-01

370

Scales  

ScienceCinema

Musical scales involve notes that, sounded simultaneously (chords), sound good together. The result is the left brain meeting the right brain — a Pythagorean interval of overlapping notes. This synergy would suggest less difference between the working of the right brain and the left brain than common wisdom would dictate. The pleasing sound of harmony comes when two notes share a common harmonic, meaning that their frequencies are in simple integer ratios, such as 3/2 (G/C) or 5/4 (E/C).

371

Scales  

SciTech Connect

Musical scales involve notes that, sounded simultaneously (chords), sound good together. The result is the left brain meeting the right brain — a Pythagorean interval of overlapping notes. This synergy would suggest less difference between the working of the right brain and the left brain than common wisdom would dictate. The pleasing sound of harmony comes when two notes share a common harmonic, meaning that their frequencies are in simple integer ratios, such as 3/2 (G/C) or 5/4 (E/C).

Murray Gibson

2007-04-27

372

Scales  

ScienceCinema

Musical scales involve notes that, sounded simultaneously (chords), sound good together. The result is the left brain meeting the right brain ? a Pythagorean interval of overlapping notes. This synergy would suggest less difference between the working of the right brain and the left brain than common wisdom would dictate. The pleasing sound of harmony comes when two notes share a common harmonic, meaning that their frequencies are in simple integer ratios, such as 3/2 (G/C) or 5/4 (E/C).

Murray Gibson

2010-01-08

373

A Small-scale Physical Model of the Lower Mississippi River for Studying the Potential of Medium- and Large-scale Diversions  

NASA Astrophysics Data System (ADS)

Over the past several thousand years the Mississippi River has formed one of the world's largest deltas and much of the Louisiana coast. However, in the last 100 years or so, anthropogenic controls have been placed on the system to maintain important navigation routes and for flood control resulting in the loss of the natural channel shifting necessary for replenishment of the deltaic coast with fresh sediment and resources. In addition, the high relative sea level rise in the lowermost portion of the river is causing a change in the distributary flow patterns of the river and deposition center. River and sediment diversions are being proposed as way to re-create some of the historical distribution of river water and sediments into the delta region. In response to a need for improving the understanding of the potential for medium- and large-scale river and sediment diversions, the state of Louisiana funded the construction of a small-scale physical model (SSPM) of the lower ~76 river miles (RM). The SSPM is a 1:12,000 horizontal, 1:500 vertical, highly-distorted, movable bed physical model designed to provide qualitative and semi-quantitative results regarding bulk noncohesive sediment transport characteristics in the river and through medium- and large-scale diversion structures. The SSPM was designed based on Froude similarity for the hydraulics and Shields similarity for sand transport and has a sediment time scale of 1 year prototype to 30 minutes model allowing for decadal length studies of the land building potential of diversions. Annual flow and sediment hydrographs were developed from historical records and a uniform relative sea level rise of 3 feet in 100 years is used to account for the combined effects of eustatic sea level rise and subsidence. Data collected during the experiments include river stages, dredging amounts and high-resolution video of transport patterns within the main channel and photographs of the sand deposition patterns in the diversion receiving areas. First, the similarity analysis that went into the model design along with a discussion of the resulting limitations will be presented. Next, calibration and validation results will be shown demonstrating the ability of the SSPM to capture the general lower Mississippi River sediment transport trends and deposition patterns. Third, results from a series of diversion experiments will be presented to semi-quantitatively show the effectiveness of diversion locations, sizes, and operating strategies on the quantities of sand diverted from the main river and the changes in main channel dredging volumes. These results will are then correlated with recent field and numerical studies of the study area. This talk will then close with a brief discussion of a new and improved physical model that will cover a larger domain and be designed to provide more quantitative results.

Willson, C. S.

2011-12-01

374

Physics on the smallest scales: an introduction to minimal length phenomenology  

NASA Astrophysics Data System (ADS)

Many modern theories which try to unify gravity with the Standard Model of particle physics, such as e.g. string theory, propose two key modifications to the commonly known physical theories: the existence of additional space dimensions; the existence of a minimal length distance or maximal resolution. While extra dimensions have received a wide coverage in publications over the last ten years (especially due to the prediction of micro black hole production at the Large Hadron Collider), the phenomenology of models with a minimal length is still less investigated. In a summer study project for bachelor students in 2010, we have explored some phenomenological implications of the potential existence of a minimal length. In this paper, we review the idea and formalism of a quantum gravity-induced minimal length in the generalized uncertainty principle framework as well as in the coherent state approach to non-commutative geometry. These approaches are effective models which can make model-independent predictions for experiments and are ideally suited for phenomenological studies. Pedagogical examples are provided to grasp the effects of a quantum gravity-induced minimal length. This paper is intended for graduate students and non-specialists interested in quantum gravity.

Sprenger, Martin; Nicolini, Piero; Bleicher, Marcus

2012-07-01

375

Confronting the concordance model of cosmology with Planck data  

NASA Astrophysics Data System (ADS)

We confront the concordance (standard) model of cosmology, the spatially flat ?CDM Universe with power-law form of the primordial spectrum with Planck CMB angular power spectrum data searching for possible smooth deviations beyond the flexibility of the standard model. The departure from the concordance cosmology is modeled in the context of Crossing statistic and statistical significance of this deviation is used as a measure to test the consistency of the standard model to the Planck data. Derived Crossing functions suggest the presence of some broad features in angular spectrum beyond the expectations of the concordance model. Our results indicate that the concordance model of cosmology is consistent to the Planck data only at 2 to 3? confidence level if we allow smooth deviations from the angular power spectrum given by the concordance model. This might be due to random fluctuations or may hint towards smooth features in the primordial spectrum or departure from another aspect of the standard model. Best fit Crossing functions indicate that there are lack of power in the data at both low-l and high-l with respect to the concordance model. This hints that we may need some modifications in the foreground modeling to resolve the significant inconsistency at high-l. However, presence of some systematics at high-l might be another reason for the deviation we found in our analysis.

Hazra, Dhiraj Kumar; Shafieloo, Arman

2014-01-01

376

Black Body Detector Temperature from Gall and Planck Perspectives  

NASA Astrophysics Data System (ADS)

The laws of Gall (http://sites.google.com/site/purefieldphysics) and Planck are generally defined with zero intensity at 0 K. However actual measurements involve detectors above absolute zero. These detectors must also be treated as approximate black body radiators. The zero intensity reference point is thus defined by the radiated intensity at the detector temperature. Planck's law thus becomes ( IP=c1?^51e^c2?T;-1-c1?^51e^c2?Td;-1) where Td is the detector temperature. Provided that T>Td;;;IP;is;always>0. Thus from a Planck perspective, wavelength increase should not be a factor in defining detector temperature. The corresponding expression for Gall's law is ( IG=?T^6b^2?e^-?Tb-?Td^6b^2?e^-?Tdb) . Above the crossover wavelength (http://absimage.aps.org/image/MWSMAR09-2008-000004.pdf), even though T>Td;;;IG<0. From a Gall perspective, this sets a limit on the long wavelength range for a given detector temperature. Longer wavelength measurements require lower detector temperatures. For a 6000 K black body radiator, the long wavelength crossover limits for detectors at 300 K, 100 K and 4 K are 9.138, 12.066 and 21.206 microns respectively.

Gall, Clarence A.

2009-05-01

377

Planck pre-launch status: HFI ground calibration  

NASA Astrophysics Data System (ADS)

Context. The Planck satellite was successfully launched on May 14th 2009. We have completed the pre-launch calibration measurements of the High Frequency Instrument (HFI) on board Planck and their processing. Aims: We present the results ot the pre-launch calibration of HFI in which we have multiple objectives. First, we determine instrumental parameters that cannot be measured in-flight and predict parameters that can. Second, we take the opportunity to operate and understand the instrument under a wide range of anticipated operating conditions. Finally, we estimate the performance of the instrument built. Methods: We obtained our pre-launch calibration results by characterising the component and subsystems, then by calibrating the focal plane at IAS (Orsay) in the Saturne simulator, and later from the tests at the satellite level carried out in the CSL (Liège) cryogenic vacuum chamber. We developed models to estimate the instrument pre-launch parameters when no measurement could be performed. Results: We reliably measure the Planck-HFI instrument characteristics and behaviour, and determine the flight nominal setting of all parameters. The expected in-flight performance exceeds the requirements and is close or superior to the goal specifications.

Pajot, F.; Ade, P. A. R.; Beney, J.-L.; Bréelle, E.; Broszkiewicz, D.; Camus, P.; Carabétian, C.; Catalano, A.; Chardin, A.; Charra, M.; Charra, J.; Cizeron, R.; Couchot, F.; Coulais, A.; Crill, B. P.; Dassas, K.; Daubin, J.; de Bernardis, P.; de Marcillac, P.; Delouis, J.-M.; Désert, F.-X.; Duret, P.; Eng, P.; Evesque, C.; Fourmond, J.-J.; François, S.; Giard, M.; Giraud-Héraud, Y.; Guglielmi, L.; Guyot, G.; Haissinski, J.; Henrot-Versillé, S.; Hervier, V.; Holmes, W.; Jones, W. C.; Lamarre, J.-M.; Lami, P.; Lange, A. E.; Lefebvre, M.; Leriche, B.; Leroy, C.; Macias-Perez, J.; Maciaszek, T.; Maffei, B.; Mahendran, A.; Mansoux, B.; Marty, C.; Masi, S.; Mercier, C.; Miville-Deschenes, M.-A.; Montier, L.; Nicolas, C.; Noviello, F.; Perdereau, O.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Pointecouteau, E.; Pons, R.; Ponthieu, N.; Puget, J.-L.; Rambaud, D.; Renault, C.; Renault, J.-C.; Rioux, C.; Ristorcelli, I.; Rosset, C.; Savini, G.; Sudiwala, R.; Torre, J.-P.; Tristram, M.; Vallée, D.; Veneziani, M.; Yvon, D.

2010-09-01

378

1/12-scale physical modeling experiments in support of tank 241-SY- 101 hydrogen mitigation  

SciTech Connect

Hanford tank 241-SY-101 is a 75-ft-dia double-shell tank that contains approximately 1.1 M gal of radioactive fuel reprocessing waste. Core samples have shown that the tank contents are separated into two main layers, a article laden supernatant liquid at the top of the tank and a more dense slurry on the bottom. Two additional layers may be present, one being a potentially thick sludge lying beneath the slurry at the bottom of the tank and the other being the crust that has formed on the surface of the supernatant liquid. The supernatant is more commonly referred to as the convective layer and the slurry as the non-convective layer. Accumulation of gas (partly hydrogen) in the non-convective layer is suspected to be the key mechanism behind the gas burp phenomena, and several mitigation schemes are being developed to encourage a more uniform gas release rate (Benegas 1992). To support the full-scale hydraulic mitigation test, scaled experiments were performed to satisfy two objectives: 1. provide an experimental database for numerical- model validation; 2. establish operating parameter values required to mobilize the settled solids and maintain the solids in suspension.

Fort, J.A.; Bamberger, J.A.; Bates, J.M.; Enderlin, C.W.; Elmore, M.R.

1993-01-01

379

Scale-invariant resonance tagging in multijet events and new physics in Higgs pair production  

NASA Astrophysics Data System (ADS)

We study resonant pair production of heavy particles in fully hadronic final states by means of jet substructure techniques. We propose a new resonance tagging strategy that smoothly interpolates between the highly boosted and fully resolved regimes, leading to uniform signal efficiencies and background rejection rates across a broad range of masses. Our method makes it possible to efficiently replace independent experimental searches, based on different final state topologies, with a single common analysis. As a case study, we apply our technique to pair production of Higgs bosons decaying into pairs in generic New Physics scenarios. We adopt as benchmark models radion and massive KK graviton production in warped extra dimensions. We find that despite the overwhelming QCD background, the 4 b final state has enough sensitivity to provide a complementary handle in searches for enhanced Higgs pair production at the LHC.

Gouzevitch, Maxime; Oliveira, Alexandra; Rojo, Juan; Rosenfeld, Rogerio; Salam, Gavin P.; Sanz, Veronica

2013-07-01

380

Investigation of the Physical Processes Governing Large-scale Tracer Transport in the Stratosphere and Troposphere  

NASA Technical Reports Server (NTRS)

This report reviews the second year of a three-year research program to investigate the physical mechanisms which underlie the transport of trace constituents in the stratosphere- troposphere system. The primary scientific goal of the research is to identify the processes which transport air masses within the lower stratosphere, particularly between the tropics and middle latitudes. The SASS program seeks to understand the impact of the present and future fleets of conventional jet traffic on the upper troposphere and lower stratosphere, while complementary airborne observations under UARP seek to understand the complex interactions of dynamical and chemical processes that affect the ozone layer. The present investigation contributes to the goals of each of these by diagnosing the history of air parcels intercepted by NASA research aircraft in UARP and AEAP campaigns.

Selkirk, Henry B.

1996-01-01

381

A Statistical Physics View of Pitch Fluctuations in the Classical Music from Bach to Chopin: Evidence for Scaling  

PubMed Central

Because classical music has greatly affected our life and culture in its long history, it has attracted extensive attention from researchers to understand laws behind it. Based on statistical physics, here we use a different method to investigate classical music, namely, by analyzing cumulative distribution functions (CDFs) and autocorrelation functions of pitch fluctuations in compositions. We analyze 1,876 compositions of five representative classical music composers across 164 years from Bach, to Mozart, to Beethoven, to Mendelsohn, and to Chopin. We report that the biggest pitch fluctuations of a composer gradually increase as time evolves from Bach time to Mendelsohn/Chopin time. In particular, for the compositions of a composer, the positive and negative tails of a CDF of pitch fluctuations are distributed not only in power laws (with the scale-free property), but also in symmetry (namely, the probability of a treble following a bass and that of a bass following a treble are basically the same for each composer). The power-law exponent decreases as time elapses. Further, we also calculate the autocorrelation function of the pitch fluctuation. The autocorrelation function shows a power-law distribution for each composer. Especially, the power-law exponents vary with the composers, indicating their different levels of long-range correlation of notes. This work not only suggests a way to understand and develop music from a viewpoint of statistical physics, but also enriches the realm of traditional statistical physics by analyzing music.

Liu, Lu; Wei, Jianrong; Zhang, Huishu; Xin, Jianhong; Huang, Jiping

2013-01-01

382

A statistical physics view of pitch fluctuations in the classical music from Bach to Chopin: evidence for scaling.  

PubMed

Because classical music has greatly affected our life and culture in its long history, it has attracted extensive attention from researchers to understand laws behind it. Based on statistical physics, here we use a different method to investigate classical music, namely, by analyzing cumulative distribution functions (CDFs) and autocorrelation functions of pitch fluctuations in compositions. We analyze 1,876 compositions of five representative classical music composers across 164 years from Bach, to Mozart, to Beethoven, to Mendelsohn, and to Chopin. We report that the biggest pitch fluctuations of a composer gradually increase as time evolves from Bach time to Mendelsohn/Chopin time. In particular, for the compositions of a composer, the positive and negative tails of a CDF of pitch fluctuations are distributed not only in power laws (with the scale-free property), but also in symmetry (namely, the probability of a treble following a bass and that of a bass following a treble are basically the same for each composer). The power-law exponent decreases as time elapses. Further, we also calculate the autocorrelation function of the pitch fluctuation. The autocorrelation function shows a power-law distribution for each composer. Especially, the power-law exponents vary with the composers, indicating their different levels of long-range correlation of notes. This work not only suggests a way to understand and develop music from a viewpoint of statistical physics, but also enriches the realm of traditional statistical physics by analyzing music. PMID:23544047

Liu, Lu; Wei, Jianrong; Zhang, Huishu; Xin, Jianhong; Huang, Jiping

2013-01-01

383

Scaling of Physical Constraints at the Root-Soil Interface to Macroscopic Patterns of Nitrogen Retention in Ecosystems  

NASA Astrophysics Data System (ADS)

Nutrient limitation in terrestrial ecosystems is often accompanied with maintaining a nearly closed vegetation-soil nutrient cycle. The ability to retain nutrients in an ecosystem requires the capacity of the plant-soil system to draw down nutrient levels in soils effectually such that export concentrations in soil solutions remain low. Here we address the physical constraints of plant nutrient uptake which may be limited by the diffusive movement of nutrients in soils, the uptake at the root/mycorrhizal surface, and from interactions with soil water flow. We derive an analytical framework of soil nutrient transport and uptake and predict levels of plant available nutrient concentration and residence time. Our results, which we evaluate for nitrogen, show that the physical environment permits plants to lower soil solute concentration substantially. Our analysis confirms that plant uptake capacities in soils are considerable such that water movement in soils is generally too small to significantly erode dissolved plant available nitrogen. Inorganic nitrogen concentrations in headwater streams are congruent with the prediction of our theoretical framework. Our framework offers a physical-based parameterization of nutrient uptake in ecosystem models and has the potential to serve as an important tool towards scaling biogeochemical cycles from individual roots to landscapes.

Gerber, S.; Brookshire, J.

2013-12-01

384

Physical Scales of Runoff Production in the Upper Colorado River Basin: Implications for Response to Climate Change (Invited)  

NASA Astrophysics Data System (ADS)

Roughly 15 million acre feet (maf) discharges annually from the Upper Colorado River Basin (UCRB). Yet, this is a mere drop in the bucket compared to the moisture dousing the basin--- weather systems deliver annual precipitation that is five-fold greater than the basin’s runoff. A fundamental question is the cause for the UCRB’s low runoff production efficiency (~20%), and whether knowledge of the region’s climatological surface water balance can offer clues on how the river will respond to global warming. Our study particularly explores the physics essential for runoff production in the Upper Colorado River Basin. We inquire how runoff production varies with elevation and spatial scale across the basin. To address these issues quantitatively, we use a simple two-layer water balance model to simulate annual runoff within the UCRB. Calculations are performed at 4km spatial resolution using monthly temperature and precipitation data derived from PRISM for 1895-2006. Our analysis reveals that the physical processes of UCRB runoff production and its climate sensitivity depends critically on representing the fine spatial scales of the water balance. In this regard, the empirical studies of how Colorado River flow would respond to climate change based on gross area-averaged water balance considerations should be interpreted with great caution. Likewise, the scales resolved in existing global climate models are likely too coarse to resolve critical land surface processes within the UCRB, and the sensitivity of the such IPCC projected runoff to climate change need to be viewed with great caution. Downscaling procedures are clearly crucial in modeling the basin’s runoff and its potential sensitivity to climate change realistically. Downscaling modeling approaches are not without their own limitations, and there is currently a wide spread among projections of UCRB runoff response to climate change among high resolution land surface models that requires explanation.

Hoerling, M.; Eischeid, J.

2009-12-01

385

Planck early results. XIII. Statistical properties of extragalactic radio sources in the Planck Early Release Compact Source Catalogue  

Microsoft Academic Search

The data reported in Planck's Early Release Compact Source Catalogue (ERCSC) are exploited to measure the number counts (dN\\/dS) of extragalactic radio sources at 30, 44, 70, 100, 143 and 217 GHz. Due to the full-sky nature of the catalogue, this measurement extends to the rarest and brightest sources in the sky. At lower frequencies (30, 44, and 70 GHz)

P. A. R. Ade; N. Aghanim; F. Argüeso; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; J.-P. Bernard; M. Bersanelli; R. Bhatia; A. Bonaldi; L. Bonavera; J. R. Bond; J. Borrill; M. Bucher; C. Burigana; P. Cabella; B. Cappellini; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; R.-R. Chary; X. Chen; L.-Y. Chiang; P. R. Christensen; D. L. Clements; S. Colafrancesco; S. Colombi; F. Couchot; B. P. Crill; F. Cuttaia; L. Danese; R. D. Davies; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; C. Dickinson; H. Dole; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; H. K. Eriksen; F. Finelli; O. Forni; M. Frailis; E. Franceschi; S. Galeotta; K. Ganga; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; F. K. Hansen; D. Harrison; S. Henrot-Versillé; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; A. Lähteenmäki; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; J. P. Leahy; R. Leonardi; P. B. Lilje; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; B. Maffei; M. Magliocchetti; D. Maino; N. Mandolesi; R. Mann; M. Maris; E. Martínez-González; S. Masi; M. Massardi; S. Matarrese; F. Matthai; P. Mazzotta; P. R. Meinhold; A. Melchiorri; L. Mendes; A. Mennella; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; S. Osborne; F. Pajot; R. Paladini; B. Partridge; F. Pasian; G. Patanchon; T. J. Pearson; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; E. Pierpaoli; S. Plaszczynski; P. Platania; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; S. Prunet; J.-L. Puget; J. P. Rachen; R. Rebolo; M. Reinecke; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; A. Sajina; M. Sandri; D. Scott; M. D. Seiffert; S. Serjeant; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Stompor; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; M. Türler; G. Umana; L. Valenziano; J. Varis; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; A. Wilkinson; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

386

Planck Early Results: All sky temperature and dust optical depth from Planck and IRAS: Constraints on the \\  

Microsoft Academic Search

We construct an all-sky map of the apparent temperature and optical depth of\\u000athermal dust emission using the Planck-HFI and IRAS data. The optical depth\\u000amaps are correlated to tracers of the atomic and molecular gas. The correlation\\u000ais linear in the lowest column density regions at high galactic latitudes. At\\u000ahigh NH, the correlation is consistent with that of

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. Borrill; F. Boulanger; M. Bucher; C. Burigana; P. Cabella; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; L.-Y Chiang; C. Chiang; P. R. Christensen; D. L. Clements; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; T. Dame; L. Danese; R. D. Davies; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; C. Dickinson; K. Dobashi; U. Doerl; S. Donzelli; O. Doré; M. Douspis; X. Dupac; G. Efstathiou; T. A. Ensslin; H. K. Eriksen; F. Finelli; O. Forni; P. Fosalba; M. Frailis; E. Franceschi; Y. Fukui; S. Galeotta; K. Ganga; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; I. A. Grenier; A. Gruppuso; F. K. Hansen; D. Harrison; G. Helou; S. Henrot-Versillé; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; M. Juvela; A. Kawamura; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; C. Leroy; P. B. Lilje; M. Linden-Vornle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; D. Mortlock; N. Mandolesi; R. Mann; M. Maris; P. Martin; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; P. McGehee; P. R. Meinhold; A. Melchiorri; L. Mendes; A. Mennella; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Norgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; T. Onishi; S. Osborne; F. Pajot; R. Paladini; D. Paradis; F. Pasian; G. Patanchon; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; S. Prunet; J.-L. Puget; W. T. Reach; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; G. Savini; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Stompor; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; G. Umana; L. Valenziano; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; A. Wilkinson; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

387

Planck early results. XIX. All-sky temperature and dust optical depth from Planck and IRAS. Constraints on the  

Microsoft Academic Search

An all sky map of the apparent temperature and optical depth of thermal dust emission is constructed using the Planck-HFI (350mum to 2 mm) andIRAS(100mum) data. The optical depth maps are correlated with tracers of the atomic (Hi) and molecular gas traced by CO. The correlation with the column density of observed gas is linear in the lowest column density

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; F. Boulanger; M. Bucher; C. Burigana; P. Cabella; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; L.-Y. Chiang; C. Chiang; P. R. Christensen; D. L. Clements; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; T. M. Dame; L. Danese; R. D. Davies; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; C. Dickinson; K. Dobashi; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; H. K. Eriksen; E. Falgarone; F. Finelli; O. Forni; P. Fosalba; M. Frailis; E. Franceschi; Y. Fukui; S. Galeotta; K. Ganga; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; I. A. Grenier; A. Gruppuso; F. K. Hansen; D. Harrison; G. Helou; S. Henrot-Versillé; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; M. Juvela; A. Kawamura; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; C. Leroy; P. B. Lilje; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; P. Martin; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; P. McGehee; P. R. Meinhold; A. Melchiorri; L. Mendes; A. Mennella; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; I. J. O'Dwyer; T. Onishi; S. Osborne; F. Pajot; R. Paladini; D. Paradis; F. Pasian; G. Patanchon; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; S. Prunet; J.-L. Puget; W. T. Reach; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; G. Savini; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Stompor; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; G. Umana; L. Valenziano; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; A. Wilkinson; D. Yvon; A. Zacchei; A. Zonca

2011-01-01

388

Scale-free flow of life: on the biology, economics, and physics of the cell  

PubMed Central

The present work is intended to demonstrate that most of the paradoxes, controversies, and contradictions accumulated in molecular and cell biology over many years of research can be readily resolved if the cell and living systems in general are re-interpreted within an alternative paradigm of biological organization that is based on the concepts and empirical laws of nonequilibrium thermodynamics. In addition to resolving paradoxes and controversies, the proposed re-conceptualization of the cell and biological organization reveals hitherto unappreciated connections among many seemingly disparate phenomena and observations, and provides new and powerful insights into the universal principles governing the emergence and organizational dynamics of living systems on each and every scale of biological organizational hierarchy, from proteins and cells to economies and ecologies.

Kurakin, Alexei

2009-01-01

389

Point defect dynamics in MOSFETs -- From atomic-scale physics to engineering models  

NASA Astrophysics Data System (ADS)

Dopant impurities are the key ingredient that makes semiconductors so useful in microelectronics. Other point defects, e.g., vacancies and self-interstitial, play major roles in mediating diffusion, which can be both good and bad. Hydrogen is another element that is very useful in passivating point defects at the Si-SiO2 interface of metal-oxide-semiconductor field-effect transistors (MOSFETs), but it also lurks dormant in all kinds of places. Oxygen vacancies also abound dormant and benign in the SiO2 gate layer, but both hydrogen and oxygen vacancies reveal sinister personas when radiation strikes (as in space electronics). This talk will give a brief account of how, over the last few decades, atomic-scale quantum mechanical calculations have impacted the process of constructing engineering models that are used in technology development and then focus on recent results on point defect dynamics in MOSFETs, some of which have been fed into engineering models.

Pantelides, Sokrates T.

2003-03-01

390

Detection of hidden structures for arbitrary scales in complex physical systems  

PubMed Central

Recent decades have experienced the discovery of numerous complex materials. At the root of the complexity underlying many of these materials lies a large number of contending atomic- and largerscale configurations. In order to obtain a more detailed understanding of such systems, we need tools that enable the detection of pertinent structures on all spatial and temporal scales. Towards this end, we suggest a new method that applies to both static and dynamic systems which invokes ideas from network analysis and information theory. Our approach efficiently identifies basic unit cells, topological defects, and candidate natural structures. The method is particularly useful where a clear definition of order is lacking, and the identified features may constitute a natural point of departure for further analysis.

Ronhovde, P.; Chakrabarty, S.; Hu, D.; Sahu, M.; Sahu, K. K.; Kelton, K. F.; Mauro, N. A.; Nussinov, Z.

2012-01-01

391

Planck constraints on Higgs modulated reheating of renormalization group improved inflation  

NASA Astrophysics Data System (ADS)

Within the framework of renormalization group improved inflationary cosmology motivated by asymptotically safe gravity, we study the dynamics of a scalar field which can be interpreted as the Higgs field. The background trajectories of this model can provide sufficient inflationary e-folds and a graceful exit to a radiation dominated phase. We study the possibility of generating primordial curvature perturbations through the Standard Model Higgs boson. This can be achieved under finely tuned parameter choices by making use of the modulated reheating mechanism. The primordial non-Gaussianity is expected to be sizable in this model. Though tightly constrained by the newly released Planck cosmic microwave background data, this model provides a potentially interesting connection between collider and early Universe physics.

Cai, Yi-Fu; Chang, Yu-Chiao; Chen, Pisin; Easson, Damien A.; Qiu, Taotao

2013-10-01

392

Conceptual foundation of the Fokker-Planck approach to space-charge effects  

SciTech Connect

An rms-mismatched beam can evolve rapidly to a configuration of quasiequilibrium under the influence of space-charge forces. As sit evolves, its emittance grows and a diffuse halo forms. The beam`s distribution function accounts for all the complicated dynamics. Unfortunately, the distribution function is difficult to calculate inasmuch as the physics lies at the interface between classical mechanics and thermodynamics. This paper presents the foundation for a statistical theory of the dynamics of nonequilibrium space-charge-dominated beams. Within certain approximations, the theory takes on a Fokker-Planck form. Key questions arise concerning the nature of the dynamical friction and diffusion in the beam`s phase space and of the quasiequilibrium configuration that ensues.

Bohn, C.L.

1996-07-01

393

Modeling for cardiac excitation propagation based on the Nernst-Planck equation and homogenization  

NASA Astrophysics Data System (ADS)

The bidomain model is a commonly used mathematical model of the electrical properties of the cardiac muscle that takes into account the anisotropy of both the intracellular and extracellular spaces. However, the equations contain self-contradiction such that the update of ion concentrations does not consider intracellular or extracellular ion movements due to the gradient of electric potential and the membrane charge as capacitive currents in spite of the fact that those currents are taken into account in forming Kirchhoff's first law. To overcome this problem, we start with the Nernst-Planck equation, the ionic conservation law, and the electroneutrality condition at the cellular level, and by introducing a homogenization method and assuming uniformity of variables at the microscopic scale, we derive rational bidomain equations at the macroscopic level.

Okada, Jun-ichi; Sugiura, Seiryo; Hisada, Toshiaki

2013-06-01

394

Simulations of cosmic rays in large-scale structures: numerical and physical effects  

NASA Astrophysics Data System (ADS)

Non-thermal (relativistic) particles are injected into the cosmos by structure formation shock waves, active galactic nuclei and stellar explosions. We present a suite of unigrid cosmological simulations (up to 20483) using a two-fluid model in the grid code ENZO. The simulations include the dynamical effects of cosmic ray (CR) protons and cover a range of theoretically motivated acceleration efficiencies. For the bulk of the cosmic volume the modelling of CR processes is rather stable with respect to resolution, provided that a minimum (cell) resolution of ?100 kpc h-1 is employed. However, the results for the innermost cluster regions depend on the assumptions for the baryonic physics. Inside clusters, non-radiative runs at high resolution tend to produce an energy density of CRs that are below available upper limits from the Fermi satellite, while the radiative runs are found to produce a higher budget of CRs. We show that weak (M ? 3-5) shocks and shock-re-acceleration are crucial to set the level of CRs in the innermost region of clusters, while in the outer regions the level of CR energy is mainly set via direct injection by stronger shocks, and is less sensitive to cooling and feedback from active galactic nuclei and supernovae.

Vazza, F.; Gheller, C.; Brüggen, M.

2014-04-01

395

Perturbed physics ensemble simulations of cirrus on the cloud system-resolving scale  

NASA Astrophysics Data System (ADS)

In this study, the effect of uncertainties in the parameterization of ice microphysical processes and initial conditions on the variability of cirrus microphysical and radiative properties are investigated in a series of cloud system-resolving perturbed physics ensemble (PPE) and initial condition ensemble (ICE) simulations. Three cirrus cases representative of midlatitude, subtropical, and tropical anvil cirrus are examined. The variability in cirrus properties induced by perturbing uncertain parameters in ice microphysics parameterizations outweighs the variability induced by perturbing the initial conditions in midlatitude and subtropical cirrus. However, in tropical anvil cirrus the variability spanned by the PPE and ICE simulations is on the same order of magnitude. Uncertainties in the parameterization of ice microphysical processes affect the vertical distribution of cloud fraction, ice water content, and cloud thickness, whereas cirrus cloud cover is only marginally affected. The top three uncertainties controlling the microphysical variability and radiative impact of cirrus clouds are the mode of ice nucleation, the number concentrations of ice nuclei available for heterogeneous freezing, and the threshold size of the parameterized ice autoconversion process. Uncertainties in ice fall speeds are of minor importance. Changes in the ice deposition coefficient induce only transient effects on the microphysical properties and radiative impacts of cirrus except in cases of very low ice deposition coefficients of about 0.05. Changes in the sulfate aerosol number concentration available for homogeneous freezing have virtually no effect on the microphysical properties and radiative impact of midlatitude and subtropical cirrus but a minor effect on tropical anvil cirrus.

Muhlbauer, Andreas; Berry, Elizabeth; Comstock, Jennifer M.; Mace, Gerald G.

2014-04-01

396

Investigation of the Physical Processes Governing Large-Scale Tracer Transport in the Stratosphere and Troposphere  

NASA Technical Reports Server (NTRS)

This report summarizes work conducted from January 1996 through April 1999 on a program of research to investigate the physical mechanisms that underlie the transport of trace constituents in the stratosphere-troposphere system. The primary scientific goal of the research has been to identify the processes which transport air masses within the lower stratosphere, particularly between the tropics and middle latitudes. This research was conducted in collaboration with the Subsonic Assessment (SASS) of the NASA Atmospheric Effects of Radiation Program (AEAP) and the Upper Atmospheric Research Program (UARP). The SASS program sought to understand the impact of the present and future fleets of conventional jet traffic on the upper troposphere and lower stratosphere, while complementary airborne observations under UARP seek to understand the complex interactions of dynamical and chemical processes that affect the ozone layer. The present investigation contributed to the goals of each of these by diagnosing the history of air parcels intercepted by NASA research aircraft in UARP and AEAP campaigns. This was done by means of a blend of trajectory analyses and tracer correlation techniques.

Selkirk, Henry B.

2001-01-01

397

Three-dimensional flow patterns in a scaled, physical vocal fold model with a unilateral polyp  

NASA Astrophysics Data System (ADS)

Trauma to the vocal folds often causes the formation of polyps; affecting the efficiency of speech and making voice rough and breathy. The change in flow characteristics due to a unilateral polyp positioned on the medial surface of a 7.5 times life-size physical vocal fold model was investigated. Previously reported phase-averaged intraglottal particle image velocimetry (PIV) investigations in a coronal plane indicated significant variations in the flow behavior on different anterior offset planes relative to the polyp. Flow three-dimensionality was investigated by resolving the temporal evolution of the flow with laser Doppler velocimetry (LDV). Data were acquired superior to the glottal exit. Physiological values of Reynolds, Strouhal, and Euler numbers were matched. Results were compared to velocity fields generated by healthy vocal fold motion. The glottal jet trajectory, flow separation points, and the velocity distribution along the vocal fold walls were influenced. Thus, a polyp significantly disturbs and modifies the airflow through the vocal folds, which has implications on both the fluid-structure energy exchange and the sound production.

Seawright, Angela; Erath, Byron; Plesniak, Michael

2009-11-01

398

Physical training programs for mass scale use: effects on cardiovascular disease--facts and theories.  

PubMed

A significant increase in the numbers of Americans exercising during the 1970's has occurred, stimulated by an increased desire to improve the quality and, hopefully, the quantity of life. Fitness improvement is associated with an increase in HDL-cholesterol and a reduction in blood pressure, serum total cholesterol, LDL- and VLDL-cholesterol, triglycerides, glucose, uric acid and with weight loss and decrease in percent body fat. Correlations of risk factor changes with weight loss are greater than correlations with fitness improvement. After controlling for weight loss correlation of triglycerides and uric acid and percent body fat fitness improvement remains significant. Risk factor reduction has been shown to occur with fitness improvement without weight loss and with weight loss unaccompanied by fitness change, but the largest risk factor changes occur in the presence of both weight loss and fitness improvement. The aerobics exercise program concentrates on developing cardiorespiratory fitness first and musculoskeletal strength secondarily. Various physical activities can be quantified by means of a point system based on the intensity and duration of the activity. A fitness goal of 30 points per week for men and 24 points per week for women is reasonable and achievable by nearly all, regardless of age or sex. The most beneficial effect of exercise may be a biochemical mediated feeling of well-being. PMID:7149628

Cooper, K H

1982-01-01

399

Microphysics in Multi-scale Modeling System with Unified Physics (Invited)  

NASA Astrophysics Data System (ADS)

Recently, several major improvements of ice microphysical processes (or schemes) have been developed for cloud-resolving models (Goddard Cumulus Ensemble, GCE, model), regional scale (Weather Research and Forecast, WRF) model and MMF. These improvements include an improved 3-ICE (cloud ice, snow and graupel) scheme (Lang et al. 2011); a 4-ICE (cloud ice, snow, graupel and hail; Lang et al. 2013) scheme and a spectral bin microphysics scheme and two different two-moment microphysics schemes. These models have improved the radiative processes and their interactions with cloud and aerosol. The performance of these schemes has been evaluated by using observational data from TRMM and major field campaigns. In this talk, we will present high-resolution GCE, WRF and MMF model simulations and compare the model results with observations [i.e., Typhoon (Morakot 2009 - an updated simulations), Anvil and Aerosol (AMMA 2006); MCSs (MC3E; 2010; diurnal variation) and CloudSat/TRMM]. In addition, the main issues of the microphysics schemes in high-resolution (1-6 km grid spacing) numerical models will be discussed.

Tao, W.; Lang, S. E.; Wu, D.; Chern, J.

2013-12-01

400

A Physically-based Model For Rainfall-triggered Landslides At A Regional Scale  

NASA Astrophysics Data System (ADS)

Rainfall has long been recognized as a major cause of landslides. Historical records have shown that large rainfall can generate hundreds of landslides over hundreds of square kilometers. Although a great body of work has documented the morphology and mechanics of individual slope failure, few studies have considered the process at basin and regional scale. A landslide model is integrated in the landscape evolution model CHILD and simulates rainfall-triggered events based on a geotechnical index, the factor of safety, which takes into account the slope, the soil effective cohesion and weight, the friction angle, the regolith thickness and the saturated thickness. The stat- urated thickness is represented by the wetness index developed in the TOPMODEL. The topography is represented by a Triangulated Irregular Network (TIN). The factor of safety is computed at each node of the TIN. If the factor of safety is lower than 1, a landslide is intiated at this node. The regolith is then moved downstream. We applied the model to the Fortore basin whose valley cuts the flysch terrain that constitute the framework of the so called "sub-Apennines" chain that is the most eastern part of the Southern Apennines (Italy). We will discuss its value according to its sensitivity to the used parameters and compare it to the actual data available for this basin.

Teles, V.; Capolongo, D.; Bras, R. L.

401

Towards a virtual lung: multi-scale, multi-physics modelling of the pulmonary system  

PubMed Central

The essential function of the lung, gas exchange, is dependent on adequate matching of ventilation and perfusion, where air and blood are delivered through complex branching systems exposed to regionally varying transpulmonary and transmural pressures. Structure and function in the lung are intimately related, yet computational models in pulmonary physiology usually simplify or neglect structure. The geometries of the airway and vascular systems and their interaction with parenchymal tissue have an important bearing on regional distributions of air and blood, and therefore on whole lung gas exchange, but this has not yet been addressed by modelling studies. Models for gas exchange have typically incorporated considerable detail at the level of chemical reactions, with little thought for the influence of structure. To date, relatively little attention has been paid to modelling at the cellular or subcellular level in the lung, or to linking information from the protein structure/interaction and cellular levels to the operation of the whole lung. We review previous work in developing anatomically based models of the lung, airways, parenchyma and pulmonary vasculature, and some functional studies in which these models have been used. Models for gas exchange at several spatial scales are briefly reviewed, and the challenges and benefits from modelling cellular function in the lung are discussed.

Burrowes, K.S; Swan, A.J; Warren, N.J; Tawhai, M.H

2008-01-01

402

Understanding the physical properties controlling protein crystallization based on analysis of large-scale experimental data  

PubMed Central

Crystallization has proven to be the most significant bottleneck to high-throughput protein structure determination using diffraction methods. We have used the large-scale, systematically generated experimental results of the Northeast Structural Genomics Consortium to characterize the biophysical properties that control protein crystallization. Datamining of crystallization results combined with explicit folding studies lead to the conclusion that crystallization propensity is controlled primarily by the prevalence of well-ordered surface epitopes capable of mediating interprotein interactions and is not strongly influenced by overall thermodynamic stability. These analyses identify specific sequence features correlating with crystallization propensity that can be used to estimate the crystallization probability of a given construct. Analyses of entire predicted proteomes demonstrate substantial differences in the bulk amino acid sequence properties of human versus eubacterial proteins that reflect likely differences in their biophysical properties including crystallization propensity. Finally, our thermodynamic measurements enable critical evaluation of previous claims regarding correlations between protein stability and bulk sequence properties, which generally are not supported by our dataset.

Price, W. Nicholson; Chen, Yang; Handelman, Samuel K.; Neely, Helen; Manor, Philip; Karlin, Richard; Nair, Rajesh; Liu, Jinfeng; Baran, Michael; Everett, John; Tong, Saichiu N.; Forouhar, Farhad; Swaminathan, Swarup S.; Acton, Thomas; Xiao, Rong; Luft, Joseph R.; Lauricella, Angela; DeTitta, George T.; Rost, Burkhard; Montelione, Gaetano T.; Hunt, John F.

2009-01-01

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TeV scale horizontal gauge symmetry and its implications in B physics  

NASA Astrophysics Data System (ADS)

We propose a gauged U(1)H horizontal symmetry around a TeV scale that is a subgroup of a SU(3)H horizontal gauge symmetry broken at O(1014)GeV. The breaking generates right-handed Majorana neutrino masses through a SU(3)H sextet scalar. A particular M