Particle creation, inflation, and cosmic isotropy
Energy Technology Data Exchange (ETDEWEB)
Within the framework of homogeneous models of the Universe, inflation provides the simplest explanation for the present cosmic isotropy, and a Bianchi type-IX (mixmaster) model is the least prejudiced guess we can make about the state of the Universe before the inflationary phase. However, a mixmaster model would not inflate unless either shear or the radiation energy density are large enough. Particle creation enhances the radiation energy density and therefore enlarges the set of inflating initial conditions for the Universe.
1991-11-15
Inflation and reheating in Bianchi type-IX cosmology
Energy Technology Data Exchange (ETDEWEB)
Within the framework of the Bianchi type-IX homogeneous space, we set up a system of coupled equations for the cosmic scale factors, scalar field, and radiative energy density. At the tree level, the equations are written in a self-consistent, Hartree-Fock form. For phi/sup 4/ theory, the system of nine first-order differential equations is solved numerically for a varying ratio of the energy of anisotropy to the vacuum energy. As the vacuum energy increases, there appears to be less reheating, since the energy of anisotropy is more efficiently converted into isotropic expansion. If the energy of anisotropy is large enough, the inflationary phase is prevented. In this case, a series of cosmological phase transitions will take place each time the square of the effective mass changes its sign.
1985-02-15
Inflation and reheating in Bianchi type-IX cosmology
International Nuclear Information System (INIS)
Within the framework of the Bianchi type-IX homogeneous space, we set up a system of coupled equations for the cosmic scale factors, scalar field, and radiative energy density. At the tree level, the equations are written in a self-consistent, Hartree-Fock form. For phi"4 theory, the system of nine first-order differential equations is solved numerically for a varying ratio of the energy of anisotropy to the vacuum energy. As the vacuum energy increases, there appears to be less reheating, since the energy of anisotropy is more efficiently converted into isotropic expansion. If the energy of anisotropy is large enough, the inflationary phase is prevented. In this case, a series of cosmological phase transitions will take place each time the square of the effective mass changes its sign.
Generation of the scalar field and anisotropy at quantum creation of the closed universe
Energy Technology Data Exchange (ETDEWEB)
The behaviour of the wave function of the universe under the barrier for the anisotropic cosmological Bianchi type-IX model taking account of the scalar field is explored. In view of the known difficulties with the interpretation of multidimensional ones is offered. For this purpose in the frameworks of the semiclassical approach the system of characteristics equations relative to one variable is written out. This system describes a bundle of the characteristics along which the multidimensional problem is reduced to a one-dimensional one that allows to utilize the standard interpretation of the wave function as well as the usual Schroedinger equation. The obtained results for the Bianchi type-IX model are reduced to the following statement: the universe tunnels through the barrier from an isotropic state with small anisotropy that is necessary for providing a ling-lived inflation to derive the universe.
2000-09-01
Quantum geometrodynamics of the Bianchi IX cosmological model
Energy Technology Data Exchange (ETDEWEB)
The canonical quantum theory of gravity-quantum geometrodynamics (QG)-is applied to the homogeneous Bianchi type IX cosmological model. As a result, a framework for the quantum theory of homogeneous cosmologies is developed. We show that the theory is internally consistent and prove that it possesses the correct classical limit (the theory of general relativity). To emphasize the special role that the constraints play in this new theory, we compare it to the traditional ADM square-root and Wheeler-DeWitt quantization schemes. We show that, unlike traditional approaches, QG leads to a well-defined Schroedinger equation for the wavefunction of the universe that is inherently coupled to the expectation value of the constraint equations. This coupling to the constraints is responsible for the appearance of a coherent spacetime picture. Thus, the physical meaning of the constraints of the theory is quite different from Dirac's ...
2006-07-01
Quantum geometrodynamics of the Bianchi IX cosmological model
International Nuclear Information System (INIS)
The canonical quantum theory of gravity-quantum geometrodynamics (QG)-is applied to the homogeneous Bianchi type IX cosmological model. As a result, a framework for the quantum theory of homogeneous cosmologies is developed. We show that the theory is internally consistent and prove that it possesses the correct classical limit (the theory of general relativity). To emphasize the special role that the constraints play in this new theory, we compare it to the traditional ADM square-root and Wheeler-DeWitt quantization schemes. We show that, unlike traditional approaches, QG leads to a well-defined Schroedinger equation for the wavefunction of the universe that is inherently coupled to the expectation value of the constraint equations. This coupling to the constraints is responsible for the appearance of a coherent spacetime picture. Thus, the physical meaning of the constraints of the theory is quite different from Dirac's interpretation. In ...
2006-07-01
A new proof of the Bianchi type IX attractor theorem
Energy Technology Data Exchange (ETDEWEB)
We consider the dynamics toward the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The 'Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.
2009-04-07
A new proof of the Bianchi type IX attractor theorem
International Nuclear Information System (INIS)
We consider the dynamics toward the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The 'Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.
2009-04-07
A new proof of the Bianchi type IX attractor theorem
We consider the dynamics towards the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The `Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.
2009-01-01
Bianchi type IX brane-world cosmologies
International Nuclear Information System (INIS)
We investigate the asymptotic properties of the Bianchi type IX cosmological model in the brane-world scenario. The matter content is assumed to be a combination of a perfect fluid and a minimimally coupled scalar field that is restricted to the brane. A detailed qualitative analysis of the Bianchi type IX brane-world containing a scalar field having an exponential potential is undertaken. It is found that the brane-Robertson-Walker solution is a local source for the expanding Bianchi type IX models, and if k"2<2 the ever-expanding Bianchi IX models asymptote to the power-law inflationary solution. The only other local sink is the contracting brane-Robertson Walker solution. An analysis of the Bianchi type IX models with a scalar field with a general potential is discussed, and it is shown that in the case of expanding models, for physical scalar field potentials close to the ...
2003-07-15
Proof of the closed-universe-recollapse conjecture for diagonal Bianchi type-IX cosmologies
Energy Technology Data Exchange (ETDEWEB)
It is proven that there do not exist any diagonal Bianchi type-IX universes which expand for an infinite time, provided only that the matter satisfies the dominant energy condition and has non-negative average principal pressures.
1989-11-15
Proof of the closed-universe-recollapse conjecture for diagonal Bianchi type-IX cosmologies
International Nuclear Information System (INIS)
It is proven that there do not exist any diagonal Bianchi type-IX universes which expand for an infinite time, provided only that the matter satisfies the dominant energy condition and has non-negative average principal pressures.
Numerical simulations of quantized Bianchi type IX cosmological models
International Nuclear Information System (INIS)
This paper reports on Monte Carlo path integral simulations of a Bianchi Type IX cosmology which yield a wave function which reflects the known chaotic dynamics of the classical system and predicts a significant probability for a correlation between large universe volume and large anisotropy.
1988-08-08
Wave function of an anisotropic universe
Energy Technology Data Exchange (ETDEWEB)
The wave function of the Bianchi type-IX universe with small anisotropy is calculated using the Hartle-Hawking prescription.
1985-06-15
Wave function of an anisotropic universe
International Nuclear Information System (INIS)
The wave function of the Bianchi type-IX universe with small anisotropy is calculated using the Hartle-Hawking prescription.
Numerical solutions for symmetric Bianchi type IX universes
International Nuclear Information System (INIS)
(Aug 1973). United States Moser, AR Matzner, RA Ryan, MP Jr. Center
Neutrino viscosity in Bianchi type IX universes
International Nuclear Information System (INIS)
The authors investigate the isotropization of anisotropic closed spaces and the entropy production due to neutrino viscosity. (Auth.).
Proof of the closed-universe recollapse conjecture for general Bianchi type-IX cosmologies
Energy Technology Data Exchange (ETDEWEB)
It is proven that there do not exist any Bianchi type-IX universes which expand for an infinite time, provided only that the matter satisfies the dominant energy condition and has non-negative average pressure (i.e., a non-negative trace of the spatial projection of the stress-energy tensor). This generalizes a proof recently given by us for the case of diagonal Bianchi type-IX solutions.
1990-04-15
Proof of the closed-universe recollapse conjecture for general Bianchi type-IX cosmologies
International Nuclear Information System (INIS)
It is proven that there do not exist any Bianchi type-IX universes which expand for an infinite time, provided only that the matter satisfies the dominant energy condition and has non-negative average pressure (i.e., a non-negative trace of the spatial projection of the stress-energy tensor). This generalizes a proof recently given by us for the case of diagonal Bianchi type-IX solutions.
Gravitational fields with space-times of Binachi type IX
International Nuclear Information System (INIS)
Spatially homogeneous space-times of Bianchi type IX are considered. A general scheme for the derivation of exact solutions of Einstein's equations corresponding to perfect fluid plus pure radiation fields is outlined. Some simple rotating Bianchi type IX cosmological models are presented. The details of these solutions are also discussed. 9 refs. (author).
Chaotic behaviour in higher-order gravity theories
Energy Technology Data Exchange (ETDEWEB)
We show that the chaotic dynamical behaviour displayed by diagonal Bianchi type IX metrics in general relativity does not occur on approach to the singularity in higher-order lagrangian theories of gravity. However, chaotic behaviour does occur in the more general non-diagonal type IX models in these theories. An interpretation of these results in terms of the hamiltonian potential picture of the type IX evolution is given. (orig.).
1989-11-30
Chaotic behaviour in higher-order gravity theories
International Nuclear Information System (INIS)
We show that the chaotic dynamical behaviour displayed by diagonal Bianchi type IX metrics in general relativity does not occur on approach to the singularity in higher-order lagrangian theories of gravity. However, chaotic behaviour does occur in the more general non-diagonal type IX models in these theories. An interpretation of these results in terms of the hamiltonian potential picture of the type IX evolution is given. (orig.).
Supersymmetric homogeneous quantum cosmologies coupled to a scalar field
Energy Technology Data Exchange (ETDEWEB)
Recent work on [ital N]=2 supersymmetric Bianchi type IX cosmologies coupled to a scalar field is extended to a general treatment of homogeneous quantum cosmologies with explicitly solvable momentum constraints, i.e., Bianchi types I, II, VII, VIII in addition to the Bianchi type IX, and special cases, namely, the Freidmann universes, the Kantowski-Sachs space, and Taub-NUT space. In addition to the earlier explicit solution of the Wheeler-DeWitt equation for Bianchi type IX, describing a virtual wormhole fluctuation, an additional explicit solution is given and identified with the no-boundary state.''
1994-01-15
Supersymmetric homogeneous quantum cosmologies coupled to a scalar field
International Nuclear Information System (INIS)
Recent work on N=2 supersymmetric Bianchi type IX cosmologies coupled to a scalar field is extended to a general treatment of homogeneous quantum cosmologies with explicitly solvable momentum constraints, i.e., Bianchi types I, II, VII, VIII in addition to the Bianchi type IX, and special cases, namely, the Freidmann universes, the Kantowski-Sachs space, and Taub-NUT space. In addition to the earlier explicit solution of the Wheeler-DeWitt equation for Bianchi type IX, describing a virtual wormhole fluctuation, an additional explicit solution is given and identified with the ''no-boundary state.''.
International Nuclear Information System (INIS)
(Dec 1971). United States Ryan, MP Jr. v. 68(2) p. 541-555. cosmological
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... 295 VIII Classification Criteria 305 IX List of Applicable JANAP's 307 X Sample Sheets, Eniwetok Consolidated Telephone Directory 309 ...
2011-05-13
Transition of rotating Bianchi type-IX cosmological model into an inflationary era
Energy Technology Data Exchange (ETDEWEB)
A Bianchi type-IX cosmological model has been found as a solution of Einstien's vacuum field equations with a cosmological constant. The solution represents a rotating generalziation fo the de Sitter universe. This universe shows a transition to exponential expansion and the vorticity begins to decay exponentially at the grand-unified-theory time. The point of time for this transition is independent of the magnitude of the vorticity. During the Guth inflationary era the vorticity decays by a factor of the order 10 US.
1986-02-15
Transition of rotating Bianchi type-IX cosmological model into an inflationary era
International Nuclear Information System (INIS)
A Bianchi type-IX cosmological model has been found as a solution of Einstien's vacuum field equations with a cosmological constant. The solution represents a rotating generalziation fo the de Sitter universe. This universe shows a transition to exponential expansion and the vorticity begins to decay exponentially at the grand-unified-theory time. The point of time for this transition is independent of the magnitude of the vorticity. During the Guth inflationary era the vorticity decays by a factor of the order 10"-"1"4"2.
Quantum cosmological approach to the cosmic no-hair conjecture in the Bianchi type-IX spacetime
Energy Technology Data Exchange (ETDEWEB)
The propriety of the cosmic no-hair conjecture to the Bianchi-type-IX spacetime is discussed from a quantum cosmological point of view. It is shown that most, but not all, classical universes which are created quantum cosmologically are inflationary. The probability of inflation among such universes is also discussed.
1990-02-15
Quantum cosmological approach to the cosmic no-hair conjecture in the Bianchi type-IX spacetime
International Nuclear Information System (INIS)
The propriety of the cosmic no-hair conjecture to the Bianchi-type-IX spacetime is discussed from a quantum cosmological point of view. It is shown that most, but not all, classical universes which are created quantum cosmologically are inflationary. The probability of inflation among such universes is also discussed.
Multidimensional extension of the Bianchi type-IX cosmology
Energy Technology Data Exchange (ETDEWEB)
A higher-dimensional homogeneous spacetime is investigated satisfying the vacuum Einstein equations. It is assumed that the algebra of Killing vectors L admits a non-trivial Levi decomposition L=N+so(3), i.e. that the subalgebras N and so(3) do not commute. It is found that the model behaves in a non-chaotic way and cosmological dimensional reduction inevitably occurs. This model completes all the possible types within the class of higher-dimensional extensions of Bianchi type-IX cosmology.
1988-06-09
Loop quantum cosmology of Bianchi type IX models
International Nuclear Information System (INIS)
The loop quantum cosmology 'improved dynamics' of the Bianchi type IX model are studied. The action of the Hamiltonian constraint operator is obtained via techniques developed for the Bianchi type I and type II models, no new input is required. It is shown that the big bang and big crunch singularities are resolved by quantum gravity effects. We also present effective equations which provide quantum geometry corrections to the classical equations of motion.
2010-08-15
Bianchi type-IX quantum cosmology of the heterotic string
Energy Technology Data Exchange (ETDEWEB)
The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.
1994-01-15
Bianchi type-IX quantum cosmology of the heterotic string
International Nuclear Information System (INIS)
The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.
A multidimensional extension of the Bianchi type-IX cosmology
International Nuclear Information System (INIS)
A higher-dimensional homogeneous spacetime is investigated satisfying the vacuum Einstein equations. It is assumed that the algebra of Killing vectors L admits a non-trivial Levi decomposition L=N+so(3), i.e. that the subalgebras N and so(3) do not commute. It is found that the model behaves in a non-chaotic way and cosmological dimensional reduction inevitably occurs. This model completes all the possible types within the class of higher-dimensional extensions of Bianchi type-IX cosmology. (orig.).
R"2 inflation in anisotropic universes
International Nuclear Information System (INIS)
The evolution of Bianchi type-I and type-IX universes for a theory of gravity with an #epsilon#R"2 term added to the usual Lagrangian is considered. As in the spatially flat Robertson-Walker case considered previously by others, inflation is found to occur. For any amount of initial anisotropy, the anisotropy decays quickly relative to the length of the inflationary epoch, and the amount of expansion is enhanced by the anisotropy. The exceptions are Bianchi type-IX universes near or at isotropy. In these cases a wide range of initial parameters causes the universe to recollapse, thus reducing the phase space in which inflation can occur. The diagonal metric is shown to be the most general form in the R"2 theory for both Bianchi type-I universes with a perfect fluid and vacuum Bianchi type-IX models.
R sup 2 inflation in anisotropic universes
Energy Technology Data Exchange (ETDEWEB)
The evolution of Bianchi type-I and type-IX universes for a theory of gravity with an {epsilon}{ital R}{sup 2} term added to the usual Lagrangian is considered. As in the spatially flat Robertson-Walker case considered previously by others, inflation is found to occur. For any amount of initial anisotropy, the anisotropy decays quickly relative to the length of the inflationary epoch, and the amount of expansion is enhanced by the anisotropy. The exceptions are Bianchi type-IX universes near or at isotropy. In these cases a wide range of initial parameters causes the universe to recollapse, thus reducing the phase space in which inflation can occur. The diagonal metric is shown to be the most general form in the {ital R}{sup 2} theory for both Bianchi type-I universes with a perfect fluid and vacuum Bianchi type-IX models.
1990-08-15
Inhomogeneous mixmaster universes: Some exact solutions
Energy Technology Data Exchange (ETDEWEB)
Algorithms for generating new exact solutions of the Einstein-Klein-Gordon field equations, which describe inhomogeneous universes with S/sup 3/ topology of spatial sections, are developed. The known exact vacuum and still-fluid solutions with S/sup 3/ topology are used as an input. The methods developed are further applied to derive inhomogeneous generalizations of Bianchi type IX solutions and inhomogeneous S/sup 3/ Gowdy models with gravitational and scalar waves. It is shown that the new solutions, which are generalizations of the Bianchi type IX models, permit identification of the scalar field with the velocity potential of the stiff irrotational fluid. The latter result is further used to study the growth rate of density perturbations of the isotropic and anisotropic Bianchi type IX universes in a fully nonlinear relativistic regime. The role of anisotropy on the rate of growth of density perturbations is studied in ...
1983-10-15
Inhomogeneous mixmaster universes: Some exact solutions
International Nuclear Information System (INIS)
Algorithms for generating new exact solutions of the Einstein-Klein-Gordon field equations, which describe inhomogeneous universes with S"3 topology of spatial sections, are developed. The known exact vacuum and still-fluid solutions with S"3 topology are used as an input. The methods developed are further applied to derive inhomogeneous generalizations of Bianchi type IX solutions and inhomogeneous S"3 Gowdy models with gravitational and scalar waves. It is shown that the new solutions, which are generalizations of the Bianchi type IX models, permit identification of the scalar field with the velocity potential of the stiff irrotational fluid. The latter result is further used to study the growth rate of density perturbations of the isotropic and anisotropic Bianchi type IX universes in a fully nonlinear relativistic regime. The role of anisotropy on the rate of growth of density perturbations is studied in detail.
Gravity-wave insights to Bianchi type-IX universes
Energy Technology Data Exchange (ETDEWEB)
Every Bianchi type-IX universe can be interpreted as a closed Friedmann universe on which is superimposed circularly polarized gravitational waves with the longest wavelength that will fit into a closed universe. In this paper, I give a new derivation of this result based on the concept of homogeneous tensor fields on the three-sphere. Every homogeneous symmetric traceless tensor field is shown to be a longest-wavelength three-sphere harmonic. Contrary to previous authors, I show that the wavelength of these gravitational waves is one-half the circumference of the universe. In order to maintain homogeneity, the gravitational waves must all have the same polarization. There are five longest-wavelength modes for each polarization. This interpretation is an {ital exact} description that is valid for every Bianchi type-IX universe---it is in no way limited to first-order perturbations of a Friedmann universe.
1991-10-15
Bianchi type-IX electromagnetic universes
Energy Technology Data Exchange (ETDEWEB)
The dynamical effects of spatially homogeneous electromagnetic fields on anisotropic Bianchi type-IX models are studied. The Lagrangians and Hamiltonians affecting the evolution of anisotropy (including the gravitational and electromagnetic potentials) are obtained for very general spatially homogeneous metrics by means of the Arnowitt-Deser-Misner Hamiltonian formalism. For models having diagonal metrics an exact solution for the electromagnetic fields is obtained. This solution allows a qualitative solution for the gravitational variables. The total solution is similar to that of Brill. For Bianchi type-IX models having symmetric and general metrics, a discussion of the qualitative behavior of the universe point under the influence of the above potentials is given. In particular, it is shown that in some cases the presence of the electromagnetic potential inhibits some types of singularities.
1984-01-15
Bianchi type-IX electromagnetic universes
International Nuclear Information System (INIS)
The dynamical effects of spatially homogeneous electromagnetic fields on anisotropic Bianchi type-IX models are studied. The Lagrangians and Hamiltonians affecting the evolution of anisotropy (including the gravitational and electromagnetic potentials) are obtained for very general spatially homogeneous metrics by means of the Arnowitt-Deser-Misner Hamiltonian formalism. For models having diagonal metrics an exact solution for the electromagnetic fields is obtained. This solution allows a qualitative solution for the gravitational variables. The total solution is similar to that of Brill. For Bianchi type-IX models having symmetric and general metrics, a discussion of the qualitative behavior of the universe point under the influence of the above potentials is given. In particular, it is shown that in some cases the presence of the electromagnetic potential inhibits some types of singularities.
Time-dependent, finite, rotating universes
International Nuclear Information System (INIS)
Three new classes of finite, homogeneous and nonsingular solutions of Einstein's equations which have time-dependent expansion, shear and rotation are presented. The t-constant sections are of Bianchi type IX. The source of these geometries is a fluid which has not been thermalized. (Author).
Quantum chaos in the mixmaster universe
International Nuclear Information System (INIS)
A Monte Carlo simulation of the vacuum Bianchi type-IX (mixmaster) cosmology yields a significant correlation between large universe volume and high anisotropy. An analog of the model's chaotic classical behavior is seen in the break up of the universe wave function at large volume into fingers in the corners of the minisuperspace anisotropy potential.
UK PubMed Central (United Kingdom)
Haemophilia, the commonest hereditary bleeding disorder, arises because of the absence of, decrease in, or deficient functioning of plasma coagulation factor VIII or factor IX. With rare exceptions,...Full Text Available
1991-01-01
Expression of CD1d in human scalp skin and hair follicles: hair cycle related alterations
UK PubMed Central (United Kingdom)
Background: CD1d belongs to a family of antigen presenting molecules that are structurally and distantly related to the classic major histocompatibility complex class I (MHC I00029;...Full Text Available
2005-12-01
Energy-momentum tensor of a spinor field in the mixed universe cosmological model
International Nuclear Information System (INIS)
The energy-momentum tensor of a massless spinor field is constructed and studied based on the previously proposed interpretation of quantum effects of such a field in the anisotropic metric of Bianchi type IX. The characteristic properties of the energy-momentum tensor in the mixed universe model are discussed.
Closed cosmological models that satisfy the strong energy condition but do not recollapse
International Nuclear Information System (INIS)
We show the existence of a rather general class of closed cosmological models of Bianchi type IX that do not exhibit recollapse but expand for all times. This is despite the fact that these models satisfy the strong energy condition by a wide margin.
2010-01-15
Some rotating, time-dependent Bianchi type-IX cosmologies with heat flow
Energy Technology Data Exchange (ETDEWEB)
Solutions are obtained for the Einstein field equations governing 40 rotating and time-dependent Bianchi type-IX cosmologies with thermal and nonthermal perfectly fluid sources. Some general properties of the solutions are discussed, and the exact computational details are given in a companion paper. All the cosmologies have spacelike, timelike or null-like homogeneous hypersurfaces depending on whether the constant alpha is less than or greater than one. The pressure of the cosmologies is assumed to be zero, and the energy density is less than zero. 9 references.
1985-06-01
Cosmic no-hair theorem in power-law inflation
Energy Technology Data Exchange (ETDEWEB)
We prove a cosmic no-hair theorem for Bianchi models in power-law inflation. Provided that the potential of an inflaton {phi} is exp({minus}{lambda}{kappa}{phi}) with 0{le}{lambda}{lt} {radical}2/3 , we find that the isotropic power-law solution is the unique attractor for any initially expanding Bianchi-type models except type IX. For Bianchi type IX, this conclusion is also true if the initial ratio of the vacuum energy to the maximum three-curvature is larger than one half.
1992-02-15
Cosmic no hair for collapsing universes
Energy Technology Data Exchange (ETDEWEB)
It is shown that all contracting, spatially homogeneous, orthogonal Bianchi cosmologies that are sourced by an ultra-stiff fluid with an arbitrary and, in general, varying equation of state asymptote to the spatially flat and isotropic universe in the neighbourhood of the big crunch singularity. This result is employed to investigate the asymptotic dynamics of a collapsing Bianchi type IX universe sourced by a scalar field rolling down a steep, negative exponential potential. A toroidally compactified version of M*-theory that leads to such a potential is discussed and it is shown that the isotropic attractor solution for a collapsing Bianchi type IX universe is supersymmetric when interpreted in an 11-dimensional context.
2006-05-21
Bianchi type IX cosmological models with homogeneous spinor fields
Energy Technology Data Exchange (ETDEWEB)
The diagonal and symmetric Bianchi type IX models are coupled to a homogeneous spinor field. An action for the combined fields is constructed, where the orthonormal basis used is given explicitly in terms of the metric. This allows one to vary the action with respect to the metric and the spinor fields only. Next, a Hamiltonian formulation is given, and a qualitative solution for the problem is presented. We also show that the k = +1 FRW (Friedmann--Robertson--Walker) model is not compatible with a homogeneous spinor field, while the more complicated models are.
1981-03-01
Bianchi type IX cosmological models with homogeneous spinor fields
International Nuclear Information System (INIS)
The diagonal and symmetric Bianchi type IX models are coupled to a homogeneous spinor field. An action for the combined fields is constructed, where the orthonormal basis used is given explicitly in terms of the metric. This allows one to vary the action with respect to the metric and the spinor fields only. Next, a Hamiltonian formulation is given, and a qualitative solution for the problem is presented. We also show that the k = +1 FRW (Friedmann--Robertson--Walker) model is not compatible with a homogeneous spinor field, while the more complicated models are.
Energy Technology Data Exchange (ETDEWEB)
We examine the late-time behavior of initially expanding homogeneous cosmological models satisfying Einstein's equation with a positive cosmological constant ..lambda... It is shown that such models of all Bianchi types except IX exponentially evolve toward the de Sitter solution, with time scale (3/..lambda..)/sup 1/2/. The behavior of Bianchi type-IX universes is similar, provided that ..lambda.. is sufficiently large compared with spatial-curvature terms. Thus, a positive cosmological constant provides an effective means of isotropizing homogeneous universes.
1983-10-15
International Nuclear Information System (INIS)
We examine the late-time behavior of initially expanding homogeneous cosmological models satisfying Einstein's equation with a positive cosmological constant #LAMBDA#. It is shown that such models of all Bianchi types except IX exponentially evolve toward the de Sitter solution, with time scale (3/#LAMBDA#)/sup 1/2/. The behavior of Bianchi type-IX universes is similar, provided that #LAMBDA# is sufficiently large compared with spatial-curvature terms. Thus, a positive cosmological constant provides an effective means of isotropizing homogeneous universes.
Self-Referent Constructs and Medical Sociology: In Search of an Integrative Framework*
UK PubMed Central (United Kingdom)
A theoretical framework centering on four classes of self-referent constructs is offered as a device for integrating the diverse areas constituting medical sociology. Guidance by this framework...Full Text Available
2007-06-01
Homogeneous, anisotropic three-manifolds of topologically massive gravity
Energy Technology Data Exchange (ETDEWEB)
We present a new class of exact solutions of Deser, Jackiw, and Templeton's theory (DJT) of topologically massive gravity which consists of homogeneous, anisotropic manifolds. In these solutions the coframe is given by the left-invariant 1-forms of 3-dimensional Lie algebras up to constant scale factors. These factors are fixed in terms of the DJT coupling constant {mu}m which is the constant of proportionality between the Einstein and Cotton tensors in 3-dimensions. Differences between the scale factors result in anisotropy which is a common feature of topologically massive 3-manifolds. We have found that only Bianchi Types VI, VIII, and IX lead to nontrivial solutions. Among these, a Bianchi Type IX, squashed 3-sphere solution of the Euclideanized DJT theory has finite action, Bianchi Type VIII, IX solutions can variously be embedded in the de Sitter/anti-de Sitter space. That is, some DJT 3-manifolds that we ...
1989-10-01
Homogeneous, anisotropic three-manifolds of topologically massive gravity
International Nuclear Information System (INIS)
We present a new class of exact solutions of Deser, Jackiw, and Templeton's theory (DJT) of topologically massive gravity which consists of homogeneous, anisotropic manifolds. In these solutions the coframe is given by the left-invariant 1-forms of 3-dimensional Lie algebras up to constant scale factors. These factors are fixed in terms of the DJT coupling constant #mu#m which is the constant of proportionality between the Einstein and Cotton tensors in 3-dimensions. Differences between the scale factors result in anisotropy which is a common feature of topologically massive 3-manifolds. We have found that only Bianchi Types VI, VIII, and IX lead to nontrivial solutions. Among these, a Bianchi Type IX, squashed 3-sphere solution of the Euclideanized DJT theory has finite action, Bianchi Type VIII, IX solutions can variously be embedded in the de Sitter/anti-de Sitter space. That is, some DJT 3-manifolds that we shall ...
CP{sup 2} and CP{sup 1} sigma models in supergravity: Bianchi type IX instantons and cosmologies
Energy Technology Data Exchange (ETDEWEB)
We find instanton/cosmological solutions with biaxial Bianchi-IX symmetry, involving nontrivial spatial dependence of the CP{sup 1}-CP{sup 2}-sigma-models coupled to gravity. Such manifolds arise in N = 1, d 4 supergravity with supermatter actions and hence the solutions can be embedded in supergravity. There is a natural way in which the standard coordinates of these manifolds can be mapped into the four-dimensional physical space. Due to its special symmetry, we start with CP{sup 2} with its corresponding scalar ansatz; this further requires the spacetime to be SU(2) x U(1)-invariant. The problem then reduces to a set of ordinary differential equations whose analytical properties and solutions are discussed. Among the solutions there is a surprising, special family of exact solutions which owe their existence to the nontrivial topology of CP{sup 2} and are in 1-1 correspondence with matter-free Bianchi-IX metrics. These solutions can also be ...
2004-05-07
CP"2 and CP"1 sigma models in supergravity: Bianchi type IX instantons and cosmologies
International Nuclear Information System (INIS)
We find instanton/cosmological solutions with biaxial Bianchi-IX symmetry, involving nontrivial spatial dependence of the CP"1-CP"2-sigma-models coupled to gravity. Such manifolds arise in N = 1, d 4 supergravity with supermatter actions and hence the solutions can be embedded in supergravity. There is a natural way in which the standard coordinates of these manifolds can be mapped into the four-dimensional physical space. Due to its special symmetry, we start with CP"2 with its corresponding scalar ansatz; this further requires the spacetime to be SU(2) x U(1)-invariant. The problem then reduces to a set of ordinary differential equations whose analytical properties and solutions are discussed. Among the solutions there is a surprising, special family of exact solutions which owe their existence to the nontrivial topology of CP"2 and are in 1-1 correspondence with matter-free Bianchi-IX metrics. These solutions can also be found by coupling ...
2004-05-07
Numerical solutions of high-frequency perturbations in Bianchi type IX models
International Nuclear Information System (INIS)
The problem in perturbation theory in general relativity is finding a natural gauge which simplifies the equations considerably. We solved the first and second order perturbation equations in the ''Lorentz gauge'' using the two-timing method. The equations were deduced from the equations of Einstein in the presence of a matter energy-momentum tensor of a perfect fluid with equation of state p = (#gamma#-1) rho. It is found that the 0--0 component of the first order equations together with the gauge conditions are consistent with the Bianchi type V model, without axial symmetry. It represents a ''ground state'' situation of the Bianchi type IX model (Mixmaster model.) The second order equations, describing the reaction back of the gravitational waves on the slowly varying background, give rise to rotation and will disturb the isotropization mechanism. The numerical solutions show all the features which are expected to appear. Moreover, it is found that the frequency ...
Energy Technology Data Exchange (ETDEWEB)
We consider the dynamics towards the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. Surprisingly few facts are known about the 'Mixmaster' dynamics of these models, while at the same time most of the commonly held beliefs are rather vague. In this paper, we use Mixmaster facts as a base to build an infrastructure that makes it possible to sharpen the main Mixmaster beliefs. We formulate explicit conjectures concerning (i) the past asymptotic states of type IX solutions and (ii) the relevance of the Mixmaster/Kasner map for generic past asymptotic dynamics. The evidence for the conjectures is based on a study of the stochastic properties of this map in conjunction with dynamical systems techniques. We use a dynamical systems formulation, since this approach has so far been the only successful path to obtain theorems, but we also make comparisons with the ...
2009-04-07
A Stress-Dependent Hysteresis Model for Ferroelectric ...
... Attributes and limitations of the charac- terization framework are illustrated through comparison with experimental PLZT data. ...
2011-05-13
Transfer of semantics from argumentation frameworks to logic programming A preliminary report
There are various interesting semantics' (extensions) designed for argumentation frameworks. They enable to assign a meaning, e.g., to odd-length cycles. Our main motivation is to transfer semantics' proposed by Baroni, Giacomin and Guida for argumetation frameworks with odd-length cycles to logic programs with odd-length cycles through default negation. The developed construction is even stronger. For a given logic program an argumentation framework is defined. The construction enables to transfer each semantics of the resulting argumentation framework to a semantics of the given logic program. Weak points of the construction are discussed and some future continuations of this approach are outlined.
2011-01-01
Subcriticality calculations for the FFTF reverse approach to critical experiment
The reverse approach to critical (RAC) experiments were performed in the ZPR-IX critical facility at Argonne National Laboratory. One of the major objectives of this project is to determine the adequacy of the low-level flux monitor (LLFM) detectors for initial loading of the Fast Flux Test Facility (FFTF). 5 references. (auth)
1975-01-01
Size of a bouncing mixmaster universe
Energy Technology Data Exchange (ETDEWEB)
An analysis is given of the evolution of a massive scalar field in a closed mixmaster universe of Bianchi type IX. Although the scalar field violates the strong energy condition, the probability of the model ''bouncing'' at a very early time is infinitesimally small; of the order of the ratio of the minimum to maximum sizes of the universe approx. 10/sup -40/.
1980-01-15
International Nuclear Information System (INIS)
We demonstrate the existence of shear-free cosmological models with rotation and expansion which support inflationary scenarios. The corresponding metrics belong to the family of spatially homogeneous models with the geometry of the closed universe (Bianchi type IX). We show that the global vorticity does not prevent inflation and can even accelerate it.
2002-08-15
Energy Technology Data Exchange (ETDEWEB)
We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant)
2003-03-21
International Nuclear Information System (INIS)
We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant).
2003-03-21
Quantum chaos in the mixmaster universe
Energy Technology Data Exchange (ETDEWEB)
A Monte Carlo simulation of the vacuum Bianchi type-IX (mixmaster) cosmology yields a significant correlation between large universe volume and high anisotropy. An analog of the model's chaotic classical behavior is seen in the break up of the universe wave function at large volume into fingers in the corners of the minisuperspace anisotropy potential.
1989-04-15
International Nuclear Information System (INIS)
Gadolinium removal during the first approach to criticality of TAPP-4 540 MWe reactor using mixed bed resin (strong acid cation resin and weak base anion resin) topped with strong acid cation exchange resin yielded IX column outlet pH of >6 during the first 6 h of run during which [Gd] decreased from 2.1 to 1 mg/kg. However, the main moderator system pH was between 5.0-5.5. Technical specification for pH of moderator is in the range 5.0-5.5 as long as Gd is present. This is to avoid any precipitation of Gd in the core and a pH of 5.8 or even a pH of 5.6 when carbonate is present is specified as the upper limit of the moderator system pH for this purpose. The situation of IX column outlet pH being #>=# 6 mixing with a system water having Gd results in local mixing zone pH in the range of 6- 5.4. In order to have an iso-pH regime (5-5.5) both with respect to the IX outlet as well as in the system, studies were conducted ...
2005-11-01
Kaluza-Klein mixmaster universes
Energy Technology Data Exchange (ETDEWEB)
We analyze the behavior of some Bianchi type-IX, mixmaster cosmological models possessing extra dimensions. We find that, unlike the three-dimensional case, they do not exhibit chaotic behavior on approach to their initial singularity. A finite sequence of stochastic mixmaster oscillations is, in general, replaced by monotonic contraction of the three-space scale factors on approach to a singularity whenever additional spatial dimensions exist with the metric form we consider.
1985-09-15
Kaluza-Klein mixmaster universes
International Nuclear Information System (INIS)
We analyze the behavior of some Bianchi type-IX, mixmaster cosmological models possessing extra dimensions. We find that, unlike the three-dimensional case, they do not exhibit chaotic behavior on approach to their initial singularity. A finite sequence of stochastic mixmaster oscillations is, in general, replaced by monotonic contraction of the three-space scale factors on approach to a singularity whenever additional spatial dimensions exist with the metric form we consider.
Influence of rotation on the initial state of the Universe
Energy Technology Data Exchange (ETDEWEB)
We apply Hawking's proposal for the initial state of the Universe to a rotating Bianchi type-IX minisuperspace model in order to examine the problem of rotation in a closed cosmology. Using the Feynman path-integral techniques instead of the Wheeler-DeWitt equation, we are able to say that for a small angular velocity the closed Friedmann-Robertson-Walker model is indeed the most probable initial state for the Universe.
1989-12-15
Influence of rotation on the initial state of the Universe
International Nuclear Information System (INIS)
We apply Hawking's proposal for the initial state of the Universe to a rotating Bianchi type-IX minisuperspace model in order to examine the problem of rotation in a closed cosmology. Using the Feynman path-integral techniques instead of the Wheeler-DeWitt equation, we are able to say that for a small angular velocity the closed Friedmann-Robertson-Walker model is indeed the most probable initial state for the Universe.
Inflation in a renormalizable cosmological model and the cosmic no-hair conjecture
Energy Technology Data Exchange (ETDEWEB)
The possibility of having inflation in a renormalizable cosmological model is investigated. The cosmic no-hair conjecture is proved to hold for all Bianchi types except Bianchi type IX. By the use of a conformal transformation on the metric we show that these models are equivalent to the ones described by the Einstein-Hilbert action for gravity minimally coupled to a set of scalar fields with inflationary potentials. Henceforth, we prove that inflationary solutions behave as attractors in solution space, making it a natural event in the evolution of such models.
1989-05-15
Inflation in a renormalizable cosmological model and the cosmic no-hair conjecture
International Nuclear Information System (INIS)
The possibility of having inflation in a renormalizable cosmological model is investigated. The cosmic no-hair conjecture is proved to hold for all Bianchi types except Bianchi type IX. By the use of a conformal transformation on the metric we show that these models are equivalent to the ones described by the Einstein-Hilbert action for gravity minimally coupled to a set of scalar fields with inflationary potentials. Henceforth, we prove that inflationary solutions behave as attractors in solution space, making it a natural event in the evolution of such models.
Inflation in Bianchi models and the cosmic no hair theorem in a brane world
International Nuclear Information System (INIS)
The cosmic no hair theorem is studied in anisotropic brane worlds. Assuming anisotropic Bianchi models with an inflaton field it is shown that, during slow-roll inflation, anisotropy in all Bianchi models except a Bianchi type-IX universe washes out. Brane worlds admit both exponential and power law inflation. We consider here only exponential expansion of the universe. It is found that isotropization occurs much faster in a brane world than in the general theory of relativity.
2002-12-15
Amplitude-real-phase exact solutions for quantum mixmaster universes
Energy Technology Data Exchange (ETDEWEB)
We present a set of exact solutions for quantum Bianchi type-IX anisotropic cosmological models (including the Taub model) of the form {Psi}={ital We}{sup {minus}{ital S}}. These solutions are spread over all values of anisotropy near the singularity, but at larger values of the radius of the universe they are strongly peaked around the {ital k}=+1 Friedmann-Robertson-Walker model.
1991-10-15
A new solution of the Wheeler-De Witt equation
Energy Technology Data Exchange (ETDEWEB)
We consider the problem of rotation in a homogeneous Bianchi type IX cosmological model. Studying the Wheeler-De Witt equation corresponding to this minisuperspace, and adopting a particular choice of the factor ordering, we are able to find a particular solution which is strongly peaked about isotropy. This result confirms all the previous investigations in this field, and suggests the conclusion that the machian nature of our universe is the natural, i.e. most likely, outcome of the Planck epoch. (orig.).
1991-06-06
A new solution of the Wheeler-De Witt equation
International Nuclear Information System (INIS)
We consider the problem of rotation in a homogeneous Bianchi type IX cosmological model. Studying the Wheeler-De Witt equation corresponding to this minisuperspace, and adopting a particular choice of the factor ordering, we are able to find a particular solution which is strongly peaked about isotropy. This result confirms all the previous investigations in this field, and suggests the conclusion that the machian nature of our universe is the natural, i.e. most likely, outcome of the Planck epoch. (orig.).
Theoretical Models and Operational Frameworks in Public Health Ethics
UK PubMed Central (United Kingdom)
The article is divided into three sections: (i) an overview of the main ethical models in public health (theoretical foundations); (ii) a summary of several published frameworks for public health ethics...Full Text Available
2010-01-01
Performance assessment for EEG-based neonatal seizure detectors
UK PubMed Central (United Kingdom)
ObjectiveThis study discusses an appropriate framework to measure system performance for the task of neonatal seizure detection using EEG. The framework is used to present an extended...Full Text Available
2011-03-01
UK PubMed Central (United Kingdom)
ObjectivesTo assess Croatian community pharmacists' patient care competencies using the General Level Framework (GLF).MethodsThe competencies of...Full Text Available
2011-03-10
Evaluation of Conceptual Framework for Recruitment of African American Patients With Breast Cancer
UK PubMed Central (United Kingdom)
Purpose/ObjectivesTo describe the Heiney-Adams Recruitment Framework (H-ARF); to delineate a recruitment plan for a randomized, behavioral trial (RBT) based on H-ARF;...Full Text Available
2010-05-01
UK PubMed Central (United Kingdom)
Evaluation of the impact and effectiveness of courses is necessary so that strengths and weaknesses can be identified and improvements made. This article uses Kirkpatrick's evaluation framework to present...Full Text Available
UK PubMed Central (United Kingdom)
We develop a statistical framework to study the relationship between chromatin features and gene expression. This can be used to predict gene expression of protein coding genes, as well as microRNAs....Full Text Available
2011-01-01
A classification-based framework for predicting and analyzing gene regulatory response
UK PubMed Central (United Kingdom)
BackgroundWe have recently introduced a predictive framework for studying gene transcriptional regulation in simpler organisms using a novel supervised learning algorithm called...Full Text Available
Towards a dissipativity framework for power system stabilizer design
Energy Technology Data Exchange (ETDEWEB)
This paper describes a dissipativity-based framework for the study of low-frequency oscillations in power systems and for power system stabilizer design. This framework leads to a robust controller design formulation, amenable to both H{sub {infinity}} and QFT tools. An illustrating numerical example presents QFT based design for a widely used benchmark two area, four machine power system.
1996-11-01
Numerical solutions of high-frequency perturbations in Bianchi type IX models
Energy Technology Data Exchange (ETDEWEB)
The problem in perturbation theory in general relativity is finding a natural gauge which simplifies the equations considerably. We solved the first and second order perturbation equations in the ''Lorentz gauge'' using the two-timing method. The equations were deduced from the equations of Einstein in the presence of a matter energy-momentum tensor of a perfect fluid with equation of state p = (..gamma..-1) rho. It is found that the 0--0 component of the first order equations together with the gauge conditions are consistent with the Bianchi type V model, without axial symmetry. It represents a ''ground state'' situation of the Bianchi type IX model (Mixmaster model.) The second order equations, describing the reaction back of the gravitational waves on the slowly varying background, give rise to rotation and will disturb the isotropization mechanism. The numerical solutions show all the ...
1983-05-15
Homoclinic chaos in the dynamics of a general Bianchi type-IX model
International Nuclear Information System (INIS)
The dynamics of a general Bianchi type-IX model with three scale factors is examined. The matter content of the model is assumed to be comoving dust plus a positive cosmological constant. The model presents a critical point of saddle-center-center type in the finite region of phase space. This critical point engenders in the phase space dynamics the topology of stable and unstable four dimensional tubes RxS"3, where R is a saddle direction and S"3 is the manifold of unstable periodic orbits in the center-center sector. A general characteristic of the dynamical flow is an oscillatory mode about orbits of an invariant plane of the dynamics which contains the critical point and a Friedmann-Robertson-Walker (FRW) singularity. We show that a pair of tubes (one stable, one unstable) emerging from the neighborhood of the critical point towards the FRW singularity have homoclinic transversal crossings. The homoclinic intersection manifold has topology RxS"2 and is ...
2002-04-15
Biaxial Bianchi type IX quantum cosmology
Energy Technology Data Exchange (ETDEWEB)
We investigate the quantum cosmology of spatially homogeneous models with compact spatial sections admitting a u(2) isometry algebra. The metric ansatz in these models is that of Bianchi type IX with two scale factors set to be equal. We apply the Hartle-Hawking no-boundary path integral prescription and find the semi-classical contributions to the wave function. Exact formulae are obtainable for certain contributions and otherwise the limits of large and small anisotropy (for the pure vacuum case) and large spatial volume or small anisotropy (for the case with a positive cosmological constant) are considered. For the pure vacuum case we find no rapidly oscillating semiclassical components in the wave function, and hence do not recover lorentzian space-time as a prediction of the no-boundary proposal. For the case with a cosmological constant the wave function does contain rapidly oscillating components and thus predicts approximately lorentzian space-times; ...
1991-03-11
Biaxial Bianchi type IX quantum cosmology
International Nuclear Information System (INIS)
We investigate the quantum cosmology of spatially homogeneous models with compact spatial sections admitting a u(2) isometry algebra. The metric ansatz in these models is that of Bianchi type IX with two scale factors set to be equal. We apply the Hartle-Hawking no-boundary path integral prescription and find the semi-classical contributions to the wave function. Exact formulae are obtainable for certain contributions and otherwise the limits of large and small anisotropy (for the pure vacuum case) and large spatial volume or small anisotropy (for the case with a positive cosmological constant) are considered. For the pure vacuum case we find no rapidly oscillating semiclassical components in the wave function, and hence do not recover lorentzian space-time as a prediction of the no-boundary proposal. For the case with a cosmological constant the wave function does contain rapidly oscillating components and thus predicts approximately lorentzian space-times; ...
Two-dimensional Kaehler Einstein spaces and gravitational instantons
International Nuclear Information System (INIS)
A new class of solutions of the euclidean Einstein equations with #LAMBDA#-term ( A-class ) is found by solving the complex two-dimensional Kaehler Einstein equations with the following realization of complex metrics. The A-Class includes two gravitational instantons already known: the CP"2 and the Eguchi-Hanson metric, and allows a U(1)-generalized spin structure. It is shown that all Einstein euclidean two-axial Bianchi type IX metrics are exhausted by the Taub-NUT-de Sitter family and the A-class. (orig.).
Towards the entropy of gravity time-dependent models via the Cardy-Verlinde formula
International Nuclear Information System (INIS)
For models with several time-dependent components, generalized entropies can be defined. This is shown for the Bianchi type IX model. We first derive the Cardy-Verlinde formula under the assumption that the first law of thermodynamics is valid. This leads to an explicit expression of the total entropy associated with this type of universe. Assuming the validity of the Cardy entropy formula, we obtain expressions for the corresponding Bekenstein, Bekenstein-Hawking and Hubble entropies. We discuss the validity of the Cardy-Verlinde formula and possible extensions of the outlined procedure to other time-dependent models.
2003-07-15
International Nuclear Information System (INIS)
The symposium covers papers under different sections namely, (i) Core physics and Fuel management, (ii) Commissioning of facilities and systems, (iii) Operational experience and Human resource development, (iv) Fuel handling, Maintenance management and Surveillance, (v) Instrumentation and Control and Power supply systems, (vi) Analysis, modifications and developments for enhancing operational safety, (vii) Chemistry control and Effluent management, (viii) Radiation and industrial safety and (ix) Steam generators, Turbo-generators and other auxiliaries. Papers relevant to INIS are indexed separately. (author)
2006-11-13
On the stability of the Einstein static universe
Energy Technology Data Exchange (ETDEWEB)
We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c{sup 2}{sub s} > 1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilize an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed. (letter to the editor)
2003-06-07
On the stability of the Einstein static universe
International Nuclear Information System (INIS)
We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c"2_s > 1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilize an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed. (letter to the editor)
2003-06-07
No chaos in brane-world cosmology
Energy Technology Data Exchange (ETDEWEB)
We discuss the asymptotic dynamical evolution of spatially homogeneous brane-world cosmological models close to the initial singularity. We find that generically the cosmological singularity is isotropic in Bianchi type IX brane-world models and consequently these models do not exhibit Mixmaster or chaotic-like behaviour close to the initial singularity. We argue that this is typical of more general cosmological models in the brane-world scenario. In particular, we show that an isotropic singularity is a past-attractor in all orthogonal Bianchi models and is a local past-attractor in a class of inhomogeneous brane-world models. (letter to the editor)
2002-04-21
Kasner asymptotics of mixmaster Horava-Witten and pre-big-bang cosmologies
Energy Technology Data Exchange (ETDEWEB)
We discuss various superstring effective actions and, in particular, their common sector which leads to the so-called pre-big-bang cosmology (cosmology in a weak coupling limit of heterotic superstring theory). Using the conformal relationship between these two theories we present Kasner asymptotic solutions of Bianchi type IX geometries within these theories and make predictions about possible emergence of chaos. Finally, we present a possible method of generating Horava-Witten cosmological solutions out of the well-known general relativistic or pre-big-bang solutions.
2001-09-01
Kasner asymptotics of mixmaster Horava-Witten and pre-big-bang cosmologies
International Nuclear Information System (INIS)
We discuss various superstring effective actions and, in particular, their common sector which leads to the so-called pre-big-bang cosmology (cosmology in a weak coupling limit of heterotic superstring theory. Using the conformal relationship between these two theories we present Kasner asymptotic solutions of Bianchi type IX geometries within these theories and make predictions about possible emergence of chaos. Finally, we present a possible method of generating Horava-Witten cosmological solutions out of the well-known general relativistic or pre-big-bang solutions.
2001-09-01
Emission Line Spectra in the Soft X-Ray Region 20-75 (Angstrom)
Energy Technology Data Exchange (ETDEWEB)
As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.
2002-06-18
Energy Technology Data Exchange (ETDEWEB)
Dose-response studies of the radiosensitivity of spermatogonial stem cells in various epithelial stages after irradiation with graded doses of fission neutrons of 1 MeV mean energy were carried out in the Cpb-N mouse. These studies on the stem cell population in stages IX-XI yielded simple exponential lines characterized by an average D0 value of 0.76 +/- 0.02 Gy. In the subsequent epithelial stages XII-III, a significantly lower D0 value of 0.55 +/- 0.02 Gy was found. In contrast to the curves obtained for stem cells in stages IX-III, the curves obtained in stages IV-VIII indicated the presence of a mixture of radioresistant and radiosensitive stem cells. In stage VII, almost no radioresistant stem cells appeared to be present and a D0 value for the radiosensitive stem cells of 0.22 +/- 0.01 Gy was derived. Previously, data were obtained on the size of colonies (in number of spermatogonia) derived from surviving stem cells. Combining these ...
1986-12-01
Dynamics of multidimensional generalization of Bianchi type-IX cosmological models
Energy Technology Data Exchange (ETDEWEB)
We investigate the dynamics of an 11-dimensional homogeneous cosmological model. We assume that the t = const hypersurfaces are products of a 3-dimensional Bianchi type-IX space and a 7-dimensional torus. Most results of our investigation hold when the 7-dimensional torus is replaced by an m-dimensional torus T/sup m/. We show that for a large class of vacuum solutions the physical space expands while the microspace contracts providing a natural mechanism of dimensional reduction. Matter satisfying a simple barotropic equation of state always breaks the process of dynamical dimensional reduction. With special attention we study the behavior of our model close to the initial singularity. In contrast with the 4-dimensional Bianchi type-IX cosmological model the Kasner solution always describes an approach to the initial singularity. We study the transition from the Kasner regime to the oscillatory regime. We show that matter does not ...
1987-11-15
Dynamics of multidimensional generalization of Bianchi type-IX cosmological models
International Nuclear Information System (INIS)
We investigate the dynamics of an 11-dimensional homogeneous cosmological model. We assume that the t = const hypersurfaces are products of a 3-dimensional Bianchi type-IX space and a 7-dimensional torus. Most results of our investigation hold when the 7-dimensional torus is replaced by an m-dimensional torus T/sup m/. We show that for a large class of vacuum solutions the physical space expands while the microspace contracts providing a natural mechanism of dimensional reduction. Matter satisfying a simple barotropic equation of state always breaks the process of dynamical dimensional reduction. With special attention we study the behavior of our model close to the initial singularity. In contrast with the 4-dimensional Bianchi type-IX cosmological model the Kasner solution always describes an approach to the initial singularity. We study the transition from the Kasner regime to the oscillatory regime. We show that matter does not ...
Configurable Middleware-Level Intrusion Detection for Embedded Systems
Energy Technology Data Exchange (ETDEWEB)
Embedded systems have become integral parts of a diverse range of systems from automobiles to critical infrastructure applications such as gas and electric power distribution. Unfortunately, research on computer security in general and intrusion detection in particular, has not kept pace. Furthermore, embedded systems, by their very nature, are application specific and therefore frameworks for developing application-specific intrusion detection systems for distributed embedded systems must be researched, designed, and implemented. In this paper, we present a configurable middleware-based intrusion detection framework. In particular, this paper presents a system model and a concrete implementation of a highly configurable intrusion detection framework that is integrated into MicroQoSCORBA, a highly configurable middleware framework developed for embedded systems. By exploiting the application-specific ...
2005-06-20
Developing a strategic framework of key account performance
British Library Electronic Table of Contents (United Kingdom)
Strategic management of key accounts has become an important component of many companies' sales efforts. This research introduces a strategic framework of key account performance that integrates theory from relationship marketing, key account management, and customer equity. Using the three drivers of customer equity - value equity, brand equity, and relationship equity - the framework captures both the relational outcomes (relationship commitment and trust) and financial performance outcomes (profitability and share of spend) of strategic decisions made in key account programs. Implications and future research are then discussed.
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
Development of an assessment framework and indicators can be used to evaluate effectiveness of wetland restoration. Example of these include index of biotic integrity and the hydrogeomorphic method. Both approaches provide qualitative ranks. We propose a new method based on the EPA wetland research program. Similar to other methods, indexes are compared to reference communities; however, the comparisons are quantitative. In this paper we discuss the results of our framework using the Pen Branch riparian wetland system as an example.
2000-10-01
A framework for the establishment of organizational risk indicators
International Nuclear Information System (INIS)
Organizational risk indicators are proposed as a tool for risk control during operation of offshore installations, as a complement to QRA-based indicators. An organizational factor framework is developed based on a review of existing organizational factor frameworks, research on safety performance indicators, and previous work on QRA-based indicators. The results comprise a qualitative organizational model, proposed organizational risk indicators, and a quantification methodology for assessing the impact of the organization on risk. The risk indicators, when validated, will aid in a frequent control of the risk in the periods between the updating of the quantitative risk assessments.
2001-11-01
integrates multiple fisheries information systems to obtain a view of U.S. freshwater fish distribution. Information about NFDI National Framework for Early Detection, Rapid...
2011-06-23
The effect of metal ceramic restoration framework design on tooth color
British Library Electronic Table of Contents (United Kingdom)
Statement of problem The opacity of the metal framework in metal ceramic restorations results in reduced light transmission through the tooth that diminishes the esthetics of the tooth. Purpose The purpose of this study was to investigate the color change that occurs apically to a metal ceramic restoration as a result of altering the metal framework design. Material and methods Color change relative to the unprepared tooth (DE) between various metal ceramic restorations was determined using computer imaging and CIELAB coordinates and compared to previously determined levels of clinical acceptability. Color change was evaluated by examining 2 conditions (the metal copings and the completed metal ceramic restorations), 4 framework designs (metal collar and porcelain margins with 0-mm, 1-mm, ...
2008-01-01
International Nuclear Information System (INIS)
Russian 2004 p. 53 Russian Federation Kotsarev, AV Nikonov, SP FGU
2004-03-01
Saturation effects at LHC energies
Within the framework of a modified Balitsky-Kovchegov equation, we calculated and provide estimates of non-linear saturation effects expected in the LHC range of energies.
2005-01-01
On the A-dependence of the nuclear structure functions
International Nuclear Information System (INIS)
The A-dependence of the nuclear structure functions is described rather well within the framework of the quark-parton-flucton model of nucleus. 16 refs. (author).
Modern theory of nuclear forces: status and perspectives
Energy Technology Data Exchange (ETDEWEB)
I present and discuss recent results on nuclear forces and few-nucleon systems obtained in the framework of chiral effective nuclear field theory.
2007-06-15
Model checking for network security requirements via a flexible modeling framework
This paper proposes an approach that mitigates the problem of verification of network security system properties over concurrent processes.
2001-01-01
Model checking for network security requirements via a flexible ...
Jan 22, 2011 ... Title: Model checking for network security requirements via a flexible modeling framework. Authors: Powell, J. Gilliam, D. ...
Means for transferring knowledge in the relocation of manufacturing units
DEFF Research Database (Denmark)
Based on case studies and action research, this paper investigates and discusses appropriate means for transfer knowledge when relocating manufacturing units. The cases include relocations both within the country and overseas. A framework for identifying suitable means is developed based on the situations which are extracted from the cases. Two parameters are used to classify the situation: the complexity of knowledge, and the environment for transferring the knowledge. Four different groups of means are identified from the case studies; 1) Documents or manuals and peer-to-peer training, 2) Scenarios on real systems, 3) Prototypes and games, and 4) Emulation. These means are evaluated based on the parameters in the framework and proper means are positioned in the framework. This framework can be used to support learning to develop knowledge in the new manufacturing unit.
2008-01-01
Knowledge Encapsulation Framework for Collaborative Social Modeling
Energy Technology Data Exchange (ETDEWEB)
This paper describes the Knowledge Encapsulation Framework (KEF), a suite of tools to enable knowledge inputs (relevant, domain-specific facts) to modeling and simulation projects, as well as other domains that require effective collaborative workspaces for knowledge-based task. This framework can be used to capture evidence (e.g., trusted material such as journal articles and government reports), discover new evidence (covering both trusted and social media), enable discussions surrounding domain-specific topics and provide automatically generated semantic annotations for improved corpus investigation. The current KEF implementation is presented within a wiki environment, providing a simple but powerful collaborative space for team members to review, annotate, discuss and align evidence with their modeling frameworks. The novelty in this approach lies in the combination of automatically tagged and user-vetted resources, ...
2009-03-24
How Can Political Campaign Strategy be Adopted to Support ...
... WHS- Washington Headquarters Service ... present a framework based on political campaigns theory for both the Joint Task Force Commander down ...
2010-10-27
Guidelines for the Management of Soft Tissue Sarcomas
UK PubMed Central (United Kingdom)
These guidelines were drawn up following a consensus meeting of UK sarcoma specialists convened under the auspices of the British Sarcoma Group and are intended to provide a framework for the multidisciplinary...Full Text Available
2010-01-01
Google Android: A State-of-the-Art Review of Security Mechanisms
Google's Android is a comprehensive software framework for mobile communication devices (i.e., smartphones, PDAs). The Android framework includes an operating system, middleware and a set of key applications. The incorporation of integrated access services to the Internet on such mobile devices, however, increases their exposure to damages inflicted by various types of malware. This paper provides a comprehensive security assessment of the Android framework and the security mechanisms incorporated into it. A methodological qualitative risk analysis that we conducted identifies the high-risk threats to the framework and any potential danger to information or to the system resulting from vulnerabilities that have been uncovered and exploited. Our review of current academic and commercial solutions in the area of smartphone security yields a list of applied and recommended defense mechanisms for hardening ...
2009-01-01
Development of a business-to-business critical success factors (B2B CSFs) framework for Chinese SMEs
British Library Electronic Table of Contents (United Kingdom)
Purpose - The purpose of this paper is to critically explore business-to-business critical success factors (B2B CSFs) for small and medium-sized enterprises (SMEs) operating in the Chinese B2B marketplace, evaluate the findings, and use the generated CSFs to propose a framework to assist in the marketing management of B2B in China. The proposed framework provides a guideline for academics and practitioners and highlights the significant role of each factor in developing and sustaining effective B2B electronic commerce (B2B e-commerce) practice for SMEs. Design/methodology/approach - The proposed framework is constructed by combining the empirical findings and B2B literature. The quantitative (online survey) was targeted at, proprietors, chief executive officers, managing directors, general...
2011-01-01
Anxiety and Cancer Treatment: Response to Stressful Radiotherapy
UK PubMed Central (United Kingdom)
Previous research with individuals undergoing surgery or diagnostic procedures provided a conceptual framework for analysis of radiation therapy, a common form of cancer treatment. The present...Full Text Available
1984-01-01
A framework for evolutionary systems biology
UK PubMed Central (United Kingdom)
BackgroundMany difficult problems in evolutionary genomics are related to mutations that have weak effects on fitness, as the consequences of mutations with large effects are often...Full Text Available
A common framework for aspect mining based on crosscutting concern sorts
The increasing number of aspect mining techniques proposed in literature calls for a methodological way of comparing and combining them in order to assess, and improve on, their quality. This paper addresses this situation by proposing a common framework based on crosscutting concern sorts which allows for consistent assessment, comparison and combination of aspect mining techniques. The framework identifies a set of requirements that ensure homogeneity in formulating the mining goals, presenting the results and assessing their quality. We demonstrate feasibility of the approach by retrofitting an existing aspect mining technique to the framework, and by using it to design and implement two new mining techniques. We apply the three techniques to a known aspect mining benchmark and show how they can be consistently assessed and combined to increase the quality of the results. The techniques and combinations are implemented ...
2006-01-01
A Mediation Framework for Mobile Web Service Provisioning
Web Services and mobile data services are the newest trends in information systems engineering in wired and wireless domains, respectively. Web Services have a broad range of service distributions while mobile phones have large and expanding user base. To address the confluence of Web Services and pervasive mobile devices and communication environments, a basic mobile Web Service provider was developed for smart phones. The performance of this Mobile Host was also analyzed in detail. Further analysis of the Mobile Host to provide proper QoS and to check Mobile Host's feasibility in the P2P networks, identified the necessity of a mediation framework. The paper describes the research conducted with the Mobile Host, identifies the tasks of the mediation framework and then discusses the feasible realization details of such a mobile Web Services mediation framework.
2010-01-01
A Human-Centered Design and Evaluation Framework for Information Search
UK PubMed Central (United Kingdom)
Information search in a distributed environment is an interactive process between the user and the artifact. How the information is distributed across the user and the artifact determines the efficacy...Full Text Available
2005-01-01
Ultrafast resonance energy transfer in bio-molecular systems
British Library Electronic Table of Contents (United Kingdom)
In this article, we present our consistent efforts to explore the dynamical pathways of the migration of electronic radiation by using ultrafast (picosecond/femtosecond time scales) F?rster resonance energy transfer (FRET) technique. The ultrafast non-radiative energy migration from an intrinsic donor fluorophore (Tryptophan, Trp214) present in domain IIA of a transporter protein human serum albumin (HSA) to various non-covalently/covalently attached organic/inorganic chromophores including photoporphyrin IX (PPIX), polyoxovanadate [V15As6O42(H2O)]-6 clusters (denoted as V15) and CdS quantum dots (QDs) has been explored. We have also used other covalently/non-covalently attached extrinsic fluorogenic donors (NPA, ANS) in order to exploit the dynamics of resonance energy migration of an enz...
2010-01-01
Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,{tau}) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe{sup 8+}. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe{sup 8+} transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)
2004-11-30
International Nuclear Information System (INIS)
Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,?) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe8+. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe8+ transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)
2004-11-30
Supergravity solutions without triholomorphic U(1) isometries
International Nuclear Information System (INIS)
We investigate the construction of five-dimensional supergravity solutions that do not have any triholomorphic U(1) isometries. We construct a class of solutions that in various limits of parameters reduces to many of previously constructed five-dimensional supergravity solutions based on both hyper-Kaehler base spaces that can be put into a Gibbons-Hawking form and hyper-Kaehler base spaces that cannot be put into a Gibbons-Hawking form. We find a new solution which is over triaxial Bianchi type IX Einstein-hyper-Kaehler base space with no triholomorphic U(1) symmetry. One special case of this solution corresponds to a five-dimensional solution based on Eguchi-Hanson type II geometry.
2008-12-15
Neutrinos and long-range weak forces in cosmology
International Nuclear Information System (INIS)
The Lorentz and coordinate covariant calculus of spinors in Riemannian spacetime, which is the mathematical model for the description of the quantum mechanics of elementary particles with spin interacting with the classical gravitation field, is explored. The Dirac equation describing the interaction of neutrinos with the gravitational fields of the Robertson-Walker cosmological world models is separated, and the spectrum of eigenfunctions and eigenvalues for particular choices of the set of quantum numbers is given explicitly for the k = 0 and k = +1 models, although only the radial equations determining the final quantum number are given for the k = -1 model. The mathematical theory of the motion of a perfect fluid whose elements interact via long-range neutrino-exchange forces, as well as gravitationally, is developed. The formalism for calculating, by calculating the Bogoliubov transformation of the Fock space operators that instantaneously diagonalize their quantized field ...
Homoclinic chaos and energy condition violation
International Nuclear Information System (INIS)
In this letter we discuss the connection between so-called homoclinic chaos and the violation of energy conditions in locally rotationally symmetric Bianchi type IX models, where the matter is assumed to be nontilted dust and a positive cosmological constant. We show that homoclinic chaos in these models is an artifact of unphysical assumptions: it requires that there exist solutions with positive matter energy density #rho#>0 that evolve through the singularity and beyond as solutions with negative matter energy density #rho#<0. Homoclinic chaos is absent when it is assumed that the dust particles always retain their positive mass. In addition, we discuss more general models: for solutions that are not locally rotationally symmetric we demonstrate that the construction of extensions through the singularity, which is required for homoclinic chaos, is not possible in general.
2006-09-15
International Nuclear Information System (INIS)
We consider perturbations of a particular type (homogeneous of Bianchi type IX) from a closed Friedmann-Robertson-Walker model. By considering a perfect fluid, we obtain closed-form solutions for the perturbations in three interesting cases: stiff matter, radiation, and dust. As a cosmological application, we obtain an upper limit on the relative shear, (sigma/theta)_0 < b/sub 0exp/, if the microwave background radiation was last scattered at a mean red-shift
Biaxial Bianchi type 9 quantum cosmology
Energy Technology Data Exchange (ETDEWEB)
We investigate the quantum cosmology of spatially homogeneous models with compact spatial sections admitting a u(2) isometry algebra. The metric ansatz in these models is that of Bianchi type IX with two scale factors set to be equal. We apply the Hartle-Hawking no-boundary path integral prescription and find the semi-classical contributions to the wave function. Exact formulae are obtainable for certain contributions and otherwise the limits of large and small anisotropy (for the pure vacuum case) and large spatial volume or small anisotropy (for the case with a positive cosmological constant) are considered. For the pure vacuum case we find no semiclassical components which would correspond to Lorentzian universes. For the case with a cosmological constant the Hartle-Hawking boundary conditions formally constrain one of the parameters in the Lorentzian solutions to be purely imaginary. Possible interpretations of this imaginary parameter are discussed. 27 refs.
1990-04-01
Biaxial Bianchi type 9 quantum cosmology
International Nuclear Information System (INIS)
We investigate the quantum cosmology of spatially homogeneous models with compact spatial sections admitting a u(2) isometry algebra. The metric ansatz in these models is that of Bianchi type IX with two scale factors set to be equal. We apply the Hartle-Hawking no-boundary path integral prescription and find the semi-classical contributions to the wave function. Exact formulae are obtainable for certain contributions and otherwise the limits of large and small anisotropy (for the pure vacuum case) and large spatial volume or small anisotropy (for the case with a positive cosmological constant) are considered. For the pure vacuum case we find no semiclassical components which would correspond to Lorentzian universes. For the case with a cosmological constant the Hartle-Hawking boundary conditions formally constrain one of the parameters in the Lorentzian solutions to be purely imaginary. Possible interpretations of this imaginary parameter are discussed. 27 refs.
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...In 2000, the Water Framework Directive (WFD) came into force, introducing a comprehensive, river basin based water management for Europe. The aim of the Directive is ...In 2000, the Water Framework Directive (WFD) came into force, introducing a comprehensive, river basin based water management for Europe. The aim of the Directive ...
Energy Technology Data Exchange (ETDEWEB)
Assessing the potential environmental and human effects of deploying renewable energy on private and public lands, along our coasts, on the Outer Continental Shelf (OCS), and in the Great Lakes requires a new way of evaluating potential environmental and human impacts. The author argues that deployment of renewables requires a framework risk paradigm that underpins effective future siting decisions and public policies.
2010-04-01
Forum: Science and Innovation for Sustainable Development - Framework
... Studies People Projects Opportunities Framework Critical Sectors Development Goals Geographic Region Geographic Scale Research Themes Printer-Friendly Center for Ocean Solutions Early Career Fellowship Program Location: Stanford, California Source: The Center for Ocean Solutions (“Ocean Solutions”) seeks one or more recent graduates who have received a JD, MBA or PhD in the natural, physical or social sciences in the last five years, and who ...
Energy Technology Data Exchange (ETDEWEB)
The present report outlines the background and issues supporting the national strategy which was developed to deploy U.S. Government resources most effectively to increase environmental technologies exports and to enhance the trade competitiveness of the U.S. environmental technologies sector. The document is a supplement to the strategic framework.
1994-04-01
The hurried development of multimedia and internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information. In additional, digital document is also easy to copy and distribute, therefore it may face many threats. It became necessary to find an appropriate protection due to the significance, accuracy and sensitivity of the information. Furthermore, there is no formal method to be followed to discover a hidden data. In this paper, a new information hiding framework is presented.The proposed framework aim is implementation of framework computation between advance encryption standard (AES) and distortion technique (DT) which embeds information in image page within executable file (EXE file) to find a secure solution to cover file without change the size of cover file. The framework includes two main functions; first is the hiding of the ...
2009-01-01
International Nuclear Information System (INIS)
Addition of Gadolinium Nitrate as chemical shim to moderator heavy water of 540 MWe PHWR, at 15 mg/kg level (at a pH of 5.0) is practiced for reactor shutdown purposes. Presently a strong acid cation exchanger column is used for this purpose. During this operation, the moderator pH of 3.8, with the IX column outlet pH of ?3.5-3.6 was observed against the technical specification demand that when Gd is present, the pH of moderator must be in the range of 5.0-5.5. In order to achieve an iso-pH regime during Gd removal, studies were conducted using a mixed bed of strong acid cation resin plus a weak base anion resin (loaded in the volume ratio of 1 : 6), backed up in the same column (bottom most layer) by a 5 % nitric acid loaded weak base resin and topped by a strong acid cation resin (uppermost layer) simulating system flow velocity and percentage loading of resin. Using such a column it is demonstrated that Gd removal could be achieved simultaneously maintaining the ...
2006-11-13
Gadolinium removal from the moderator system of TAPP - 3 using the three layer bed
International Nuclear Information System (INIS)
Nitric acid leaching from the weak base anion (WBA) exchanger had been evaluated and based on this a 5% mixture of nitric acid loaded weak base anion exchanger with fresh weak base anion exchanger (NLWBA) at the bottom of the ion exchange column has been devised to maintain an outlet pH in the range of 5.0 to 5.5 during Gd removal from the moderator system of TAPP - 3 and 4. A three layered bed had been constituted wherein strong acid cation (SAC) exchanger is placed as the top layer while a mixed bed of SAC and WBA or pure WBA is used as the middle layer and the 5% NLWBA was used as the bottom most layer. This bed configuration would result in an iso-pH regime in the moderator system during the Gd removal along with quantitative removal of Gd. Two three-layer bed columns were prepared at TAPS - 3 and 4 in July 07. The resin was loaded in batches and after preparing the column, the column was deuterated with heavy water (> 99.75 % w/w) at a steady flow rate of 280 ml/min. After ...
2008-12-01
Renewable Energy in Danish Municipalities - an Evaluation of The Planning Framework for Wind Power
DEFF Research Database (Denmark)
Wind power is a maturing technology that in a number of countries is likely to contribute a major share to fully renewable energy systems. Denmark has a comparably long history of wind power development and is planning to continue expanding the existing capacity. If a large-scale penetration of wind power is to be achieved, an integrated framework is needed that can respond to the associated challenges. This paper argues for adopting an integrated macro perspective when evaluating and building frameworks to support wind power development. This macro perspective is applied to the case of Denmark, and more specifically to concrete wind power projects in the region of Northern Jutland. The results suggest although certain elements in the legislation have been improved, the feasibility of wind power projects cannot be guaranteed, and there is a tendency to exclude smaller turbines from the development.
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
In 2009, following approval of the European Marine Strategy Framework Directive (MSFD, 2008/56/EC), the European Commission (EC) created task groups to develop guidance for eleven quality descriptors that form the basis for evaluating ecosystem function. The objective was to provide European countries with practical guidelines for implementing the MSFD, and to produce a Commission Decision that encapsulated key points of the work in a legal framework. This paper presents a review of work carried out by the eutrophication task group, and reports our main findings to the scientific community. On the basis of an operational, management-oriented definition, we discuss the main methodologies that could be used for coastal and marine eutrophication assessment. Emphasis is placed on integrated ap...
2011-01-01
Northeast coal study: resource planning framework, resource development status report. 3 Vols
Energy Technology Data Exchange (ETDEWEB)
The objective of this study was to provide a framework for land use and resource allocation decisions in the Northeast Coal Block of British Columbia. The area was divided into a number of sites, and information gathered in two main areas, 1) status of the resource base, and 2) resource management/planning/development. A map and physical description of each site is provided as well as such information as - air quality, soils, vegetation, water resources, petroleum and natural gas resources, coal resources, and gravel resources, agricultural resources, timber resources, fisheries and wildlife resources, recreatational and aesthetic (visual) resources. The appendix volume provides a summary of the institutional management framework and approval procedures for all significant resource sectors. Provincial legislation and government acts are identified.
1982-01-01
How can supply networks increase firm value? A causal framework to structure the answer
British Library Electronic Table of Contents (United Kingdom)
The recent literature in the field of supply chain management emphasizes the role of inter-organizational networks and the integration of vertical reproduction networks (supply chains) in particular as a key factor for value creation. However, the literature includes little empirical evidence. This situation suggests the need to appraise investments in such networks or supply chains carefully. How can a decision maker reliably assess the effect of investing in inter-organizational network arrangements on firm value? This article takes up this issue and suggests a framework consisting of five components to help answer the question. The task of the framework is to support the structuring and revelation of the causal chain between investments in the network on the one hand and the effect of t...
2009-01-01
Framework for high-resolution climate change impact assessment on grapevines at a regional scale
British Library Electronic Table of Contents (United Kingdom)
Understanding the impacts of climate change on viticulture is especially essential in those areas producing high-quality wines. In this work, we create an operational framework to investigate climate change impact on viticulture in the Tuscany region (central Italy) the viticulture industry of which relies on producing high-quality wines to compete in a global market. The framework includes (i) statistical downscaling of General Circulation Model (GCM) outputs for the period 1975?2099 to a local scale; (ii) the use of downscaling outputs as driving variables in specific simulation models; (iii) the spatial interpolation of model outputs to feed an economic and (iv) a quality model. The results show that as a consequence of a progressive increase in temperature and a decrease in rainfall, (...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
An Environmental Impact Assessment (EIA) study for any project is a time- consuming process because it has a large number of dependent and independent variables that must be taken into account. Although EIAs are dependent on geo-spatial information in order to make an assessment, there are no standard rules for conducting an environmental assessment. In addition, each assessment objective is case-dependent, based on what information is available. This paper presents a new framework for the analysis phase of the Environmental Impact Assessment (EIA) for projects, based on the integration between remote sensing technology, geographic information systems, and spatial modeling. The framework comprehensively analyzes the environmental vulnerability around the project areas and its impact on the...
2010-01-01
Ensuring GRID resource availability with the SAM framework in LHCb
The LHCb experiment has chosen to use the SAM framework (Service Availability Monitoring Environment from EGEE-II) [1] make extensive tests of the LHCb environment at all the accessible grid resources. The availability and the proper definition of the local Computing and Storage Elements, user interfaces as well as the WLCG software environment are checked. The SAM framework is also used to pre-install the LHCb applications in the shared software area provided by each site. The deployment of the LHCb applications is based on a python tool developed inside the experiment. It is used for software management including incremental installation of interdependent packages and clean package removal. After the application software is installed a validation test of the whole MC chain is run. According to the results of the experiment specific SAM tests, the sites are (re)integrated into the LHCb production system managed by DIRAC [2]. The possibility of ...
2008-01-01
Asymptotics and Hamiltonians in a First order formalism
We consider 4-dimensional space-times which are asymptotically flat at spatial infinity and show that, in the first order framework, action principle is well-defined \\emph{without the need of infinite counter terms.} It naturally leads to a covariant phase space in which the Hamiltonians generating asymptotic symmetries provide the total energy-momentum and angular momentum of the space-time. We address the subtle but important problems that arise because of logarithmic translations and super-translations both in the Langrangian and Hamiltonian frameworks. As a forthcoming paper will show, the treatment of higher dimensions is considerably simpler. Our first order framework also suggests a new direction for generalizing the spectral action of non-commutative geometry.
2008-01-01
International Nuclear Information System (INIS)
In the analysis of power systems security, recently a new concern related to possible malicious attacks caught much attention. Coordination among different transmission system operators (TSO) in an interconnected power system to counteract such attacks has become an important problem. This paper presents a general framework for describing the physical, cyber and decision-making aspects of the problem and their interrelations; within this framework, an analytic tool for the assessment of information impacts in handling on-line security after a malicious attack is proposed and discussed. The model is based on the socially rational multi-agent systems and the equilibrium of a fictitious play is considered to analyze the impacts of various levels of information available to the interconnected system operators on the outcomes of the decision-making process under attack. A 34-buses test system, with 3 systems interconnected by tie-lines, is presented ...
2009-06-01
Assembly of a water-insoluble strontium metal-organic framework with luminescent properties
British Library Electronic Table of Contents (United Kingdom)
A new strontium metal-organic framework, [Sr2(BTEC)(H2O)4] 2H2O (1) (H4BTEC=benzene-1,2,4,5-tetracarboxylic acid), has been successfully synthesized by mixing the starting reagents. The single-crystal structure analysis showed that compound 1 displayed three-dimensional structures containing inorganic motifs with two-dimensional layers pillar-connected through organic linkers and forming water-coordinated neutral framework. Further studies revealed that compound 1 was insoluble in water and that it emitted strong luminescence at approximately 437nm after dehydration.
2011-01-01
Application research on three-dimensional virtual mine in the framework of internet of things
British Library Electronic Table of Contents (United Kingdom)
Based on the information system characteristics of mine, proposed network architecture design of the mine property. And in this framework based on the design of three-dimensional virtual mine described the application of intelligent management platform. Three-dimensional virtual underground mine that shows the situation, the core application is through remote monitoring system of information exchange between devices (material object communication). Internet of things in the framework of mining three-dimensional virtual reconstruction of mine. On coal mine safety in the production process of human, machine and environment, control elements and their harmony and unity. 3D virtual mine management platform integrates personnel positioning, dust control, gas monitoring, roof pressure monitoring...
2011-01-01
International Nuclear Information System (INIS)
An integrated beam optics-nuclear processes framework is essential for accurate simulation of fragment separator beam dynamics. The code COSY INFINITY provides powerful differential algebraic methods for modeling and beam dynamics simulations in absence of beam-material interactions. However, these interactions are key for accurately simulating the dynamics of heavy ion fragmentation and fission. We have developed an extended version of the code that includes these interactions, and a set of new tools that allow efficient and accurate particle transport: by transfer map in vacuum and by Monte Carlo methods in materials. The new framework is presented, along with several examples from a preliminary layout of a fragment separator for a facility for rare isotope beams.
2010-12-01
An analytical framework for capacity development in EIA ? The case of Yemen
British Library Electronic Table of Contents (United Kingdom)
Most countries worldwide nowadays apply Environmental Assessment (EA) as an ex ante tool to evaluate environmental impacts of policies, plans, programmes, and projects. However, the application and performance of EA differ significantly. Scientific analysis of how EA performs mainly focuses on two levels: the micro (or project) level and the macro (or system) level. Macro level analysis usually focuses on institutions for EA and the organisation of stakeholder interaction in EA. This article proposes a more comprehensive framework for analysing EA systems that combines other approaches with a capacity approach and an explicit consideration of the context in which EA systems are developed and performed. In order to illustrate the value of our framework, we apply it to the Republic of Yemen,...
2010-01-01
A second gradient theoretical framework for hierarchical multiscale modeling of materials
Energy Technology Data Exchange (ETDEWEB)
A theoretical framework for the hierarchical multiscale modeling of inelastic response of heterogeneous materials has been presented. Within this multiscale framework, the second gradient is used as a non local kinematic link between the response of a material point at the coarse scale and the response of a neighborhood of material points at the fine scale. Kinematic consistency between these scales results in specific requirements for constraints on the fluctuation field. The wryness tensor serves as a second-order measure of strain. The nature of the second-order strain induces anti-symmetry in the first order stress at the coarse scale. The multiscale ISV constitutive theory is couched in the coarse scale intermediate configuration, from which an important new concept in scale transitions emerges, namely scale invariance of dissipation. Finally, a strategy for developing meaningful kinematic ISVs and the proper free energy functions and ...
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
IntroductionFocusing on people and organizations, this paper aims to contribute to offshore safety assessment by proposing a methodology to model causal relationships.MethodThe methodology is proposed in a general sense that it will be capable of accommodating modeling of multiple risk factors considered in offshore operations and will have the ability to deal with different types of data that may come from different resources. Reason's ?Swiss cheese?? model is used to form a generic offshore safety assessment framework, and Bayesian Network (BN) is tailored to fit into the framework to construct a causal relationship model. The proposed framework uses a five-level-structure model to address latent failures within the causal sequence of events. The five levels include Root causes level, Tr...
2008-01-01
The SysMES framework: System management for networked embedded systems and clusters
Energy Technology Data Exchange (ETDEWEB)
The ALICE heavy-ion particle physics experiment is currently being built at CERN near Geneva. It will use a PC cluster of 900 dual-processor machines for the last stages of the data readout process and a network of 400 microcomputers for the configuration and control of the cluster nodes. One of the most important objectives to be achieved in such experiments is to guarantee the utilized devices are running correctly during the experiment life-time. A second aspect is the extremely high availability and reliability requirements of the applications being run, the so called high level trigger (HLT). The SysMES framework is a scalable, decentralized, fault tolerant, dynamic, rule based tool set for the monitoring of networks of target systems and applications. The management algorithms consist of the following steps: system and application monitoring, recognition of undesirable states, event (message) generation, local event handling on the target, event forwarding to ...
2008-07-01
Strategic planning for information management: what are the deliverables?
UK PubMed Central (United Kingdom)
This paper describes the deliverables framework developed by Vanderbilt University Medical Center (VUMC) in its IAIMS planning process. The key deliverables include: visions for the future; mission,...Full Text Available
1995-01-01
Relativistic Feynman-type integrals
Energy Technology Data Exchange (ETDEWEB)
It is shown that within the framework of the Kershaw stochastic model generalized by the author to the relativistic case a Feynman-type process may be constructed which can formally be understood as a diffusion phenomenon in Euclidean space. This makes it possible to introduce a real probability measure in the scheme of quantum mechanics proposed by Feynman.
1980-05-01
Online social support for individuals concerned with heart disease: observing gender differences.
UK PubMed Central (United Kingdom)
Using a theoretical framework of social support, and content analysis, the content and pattern of support in messages posted in a 4-week period on a commercial health network for individuals concerned...Full Text Available
1999-01-01
Network Security Versus Network Connectivity: A Framework ...
Page 1. Page 2. Page 3. Page 4. Page 5. Page 6. Page 7. Page 8. Page 9. Page 10. Page 11. Page 12. Page 13. Page 14. Page 15. Page 16. Page ...
1999-12-01
Mechanistic fracture criteria for the failure of human cortical bone
Energy Technology Data Exchange (ETDEWEB)
A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.
2002-12-13
Investigations into the nature of a silicoaluminophosphate with the faujasite structure
Energy Technology Data Exchange (ETDEWEB)
The physicochemical nature of a silicoaluminophosphate with the faujasite structure has been studied. The molecular sieve framework contains a homogeneous distribution of silicon, aluminum, and phosphorus and is negatively charged. Combustion in air of the charge-compensating organic cations produces hydroxyl groups which exhibit Broensted acidity.
1987-04-29
UK PubMed Central (United Kingdom)
All ceramic fixed partial dentures (FPD)s exhibit enhanced biocompatibility and esthetics as compared to metal-ceramic restorations. However, framework fractures are frequently reported especially when...Full Text Available
2008-01-01
Integrating diverse databases into an unified analysis framework: a Galaxy approach
UK PubMed Central (United Kingdom)
Recent technological advances have lead to the ability to generate large amounts of data for model and non-model organisms. Whereas, in the past, there have been a relatively small number of central...Full Text Available
Independent Vector Analysis for Source Separation Using a Mixture of Gaussians Prior
UK PubMed Central (United Kingdom)
Convolutive mixtures of signals, which are common in acoustic environments, can be difficult to separate into their component sources. Here we present a uniform probabilistic framework to separate...Full Text Available
2010-06-01
UK PubMed Central (United Kingdom)
Recently, G. C. Van Orden, J. G. Holden, and M. T. Turvey (2003) proposed to abandon the conventional framework of cognitive psychology in favor of the...Full Text Available
2005-02-01
UK PubMed Central (United Kingdom)
BackgroundMany interventions found to be effective in health services research studies fail to translate into meaningful patient care outcomes across multiple contexts. Health services...Full Text Available
Exactly solvable field-theoretical model with tachyons
Energy Technology Data Exchange (ETDEWEB)
Explicit soliton solutions describing the inelastic interaction between sub- and superluminal particles are found within the framework of a new integrable model of relativistic classical field theory. The corresponding energies are nonnegative irrespective of the choice of reference frame.
1988-09-01
Evaluating noncancer effects of trichloroethylene: dosimetry, mode of action, and risk assessment.
UK PubMed Central (United Kingdom)
Alternatives for developing chronic exposure limits for noncancer effects of trichloroethylene (TCE) were evaluated. These alternatives were organized within a framework for dose-response assessment--exposure:dosimetry...Full Text Available
2000-05-01
EXPONENTIAL TENSORS: A FRAMEWORK FOR EFFICIENT HIGHER-ORDER DT-MRI COMPUTATIONS
UK PubMed Central (United Kingdom)
In Diffusion Tensor Magnetic Resonance Image (DT-MRI) processing a 2nd order tensor has been commonly used to approximate the diffusivity function at each lattice...Full Text Available
2007-05-15
UK PubMed Central (United Kingdom)
BackgroundChina has had no effective and systematic information system to provide guidance for strengthening PHC (Primary Health Care) or account to citizens on progress. We report...Full Text Available
Corporate Power and Social Policy: The Political Economy of the Transnational Tobacco Companies
UK PubMed Central (United Kingdom)
Drawing on published tobacco document research and related sources, this article applies Farnsworth and Holden's conceptual framework for the analysis of corporate power and corporate involvement...Full Text Available
2009-12-01
Continuum Polarizable Force Field within the Poisson-Boltzmann Framework
UK PubMed Central (United Kingdom)
We have developed and tested a complete set of nonbonded parameters for a continuum polarizable force field. Our analysis shows that the new continuum polarizable model is consistent with B3LYP/cc-pVTZ...Full Text Available
2008-06-26
Challenges, Dilemmas, Drivers and Initiatives for the Finance Sector
Energy Technology Data Exchange (ETDEWEB)
The objectives for the financial sector with regard to climate change investments are to regard to sustainability policies, not just for itself, but also for borrowers and investment portfolios, and to assist in developing frameworks and products that will enable shareholders and clients to invest in commercial solutions to mitigate the impacts of climate change.
2006-02-15
Chagas disease: an impediment in achieving the Millennium Development Goals in Latin America
UK PubMed Central (United Kingdom)
BackgroundAchieving sustainable economic and social growth through advances in health is crucial in Latin America within the framework of the United Nations Millennium Development...Full Text Available
Energy Technology Data Exchange (ETDEWEB)
This article outlines research and progress into the liquefaction of coal by solvent treatment, being conducted at the National Research Institute for Pollution and Resources, Japan. (In Japanese)
1980-01-01
Analysis of data on cumulative antiproton production by 10-GeV protons
International Nuclear Information System (INIS)
The data are analyzed on cumulative antiproton production on Be, Al, Cu, and Ta nuclei induced by 10 GeV protons. The analysis is carried out in the framework of the flucton quark fragmentation model.
An ounce of prevention or a pound of cure: bioeconomic risk analysis of invasive species.
UK PubMed Central (United Kingdom)
Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks,...Full Text Available
2002-12-07
A Software System for Data Analysis in Automated DNA?Sequencing
UK PubMed Central (United Kingdom)
Software for gel image analysis and base-calling in fluorescence-based sequencing consisting of two primary programs, BaseFinder and GelImager, is described. BaseFinder is a framework for trace processing,...Full Text Available
1998-06-01
A Computational Framework Discovers New Copy Number Variants with Functional Importance
UK PubMed Central (United Kingdom)
Structural variants which cause changes in copy numbers constitute an important component of genomic variability. They account for 0.7% of genomic differences in two individual genomes, of which...Full Text Available
Technology shocks under varying degrees of financial openness
British Library Electronic Table of Contents (United Kingdom)
The objective of this paper is to analyze the implications of varying degrees of financial openness for the impact of technology shocks on a real, small open economy with financial and informational frictions. Aggregate fluctuations and propagation mechanisms under increasing financial openness are investigated in a dynamic, stochastic, general equilibrium framework in the case of positive technology shocks. The imperfections in the economy in the form of informational asymmetries among the agents and uncertainty in the production process necessitate financial intermediation and collateralized borrowing in the economy. The reason to abstract from money in the setup of the framework is to be able to concentrate on the real implications of increasing financial openness for the effect of tech...
2012-01-01
TOGAF is a framework - a detailed method and a set of supporting tools - for developing an enterprise architecture, developed by members of The Open Group Architecture Forum.TOGAF Version 9 provides a wide-ranging set of revisions to the TOGAF specification to improve the value of the TOGAF framework. It is an evolution from TOGAF 8.1.1, thereby preserving existing investment in TOGAF, and adds further detail and clarification to what is already proven.It may be used freely by any organization wishing to develop an enterprise architecture for use within that organization (subject to the Condit
2008-01-01
International Nuclear Information System (INIS)
The ore-hosting Yaojia Formation is composed of a set of braided stream medium-fine grained sediments. Guided by the basic theory of high-resolution sequence stratigraphy, and based on the core observation, the analysis of chemical composition of rocks, and data of natural potential logging and apparent resistivity logging, the authors have set up the high-resolution sequence stratigraphy framework of the ore-hosting Yaojia Formation, and discussed the relation of the stratigraphic structure of the middle cycle, as well as the paleotopography, the micro-facies to the formation of uranium deposit. (authors)
2005-07-01
Structure functions of nuclei and #pi#-meson production in cumulative region
International Nuclear Information System (INIS)
The structure functions (SF) of nuclei determined within the framework of the flucton model with rescaling (FMR) are compared with new experimental data of the ITEP on cumulative #pi#-meson yield in a wide range of the scale variable X (1
PARALLEL 3-D SPACE CHARGE CALCULATIONS IN THE UNIFIED ACCELERATOR LIBRARY.
Energy Technology Data Exchange (ETDEWEB)
The paper presents the integration of the SIMBAD space charge module in the UAL framework. SIMBAD is a Particle-in-Cell (PIC) code. Its 3-D Parallel approach features an optimized load balancing scheme based on a genetic algorithm. The UAL framework enhances the SIMBAD standalone version with the interactive ROOT-based analysis environment and an open catalog of accelerator algorithms. The composite package addresses complex high intensity beam dynamics and has been developed as part of the FAIR SIS 100 project.
2006-06-26
Energy Technology Data Exchange (ETDEWEB)
This paper presents a framework for creating a common spatial canvass that can bring together considerations of resource availability, infrastructure reliability, and development costs while strategizing renewable energy investment. We describe the underlying models and methodologies that annotate an investment plan for potential sites over a time-period with costs and constraints which may be imposed on distance from infrastructure, system impact on infrastructure, and policy incentives. The framework is intended as an enabler for visualization, optimization and decision making across diverse dimensions while searching for lucrative investment-plans.
2010-09-01
Microeconomics of the ideal gas like market models
We develop a framework based on microeconomic theory from which the ideal gas like market models can be addressed. A kinetic exchange model based on that framework is proposed and its distributional features have been studied by considering its moments. Next, we derive the moments of the CC model (Eur. Phys. J. B 17 (2000) 167) as well. Some precise solutions are obtained which conform with the solutions obtained earlier. Finally, an output market is introduced with global price determination in the model with some necessary modifications.
2009-01-01
International Nuclear Information System (INIS)
The paper demonstrates an application of advanced decision support tools within the framework of the environmental information system of the Province of Milan. These tools include environmental simulation models, multi criteria analysis, risk analysis and environmental accounting for marketable emission permits. After describing the general structure of the system, three demonstrational case studies are introduced concerning: groundwater pollution management; atmospheric pollution management; urban environmental quality perception and management. In the conclusion, potential use of tools like the ones implemented by the province of Milan within the framework of Local Agenda 21 processes is recalled.
2006-03-01
A New Fuzzy MCDM Framework to Evaluate E-Government Security Strategy
Ensuring security of e-government applications and infrastructures is crucial to maintain trust among stakeholders to store, process and exchange information over the e-government systems. Due to dynamic and continuous threats on e-government information security, policy makers need to perform evaluation on existing information security strategy as to deliver trusted e-government services. This paper presents an information security evaluation framework based on new fuzzy multi criteria decision making (MCDM) to help policy makers conduct comprehensive assessment of e-government security strategy.
2010-01-01
A Framework for Understanding Golfing Visitors to a Destination
British Library Electronic Table of Contents (United Kingdom)
The purpose of this study is to determine whether there are differences among visitors to a destination based on their golfing frequency in the previous year. By constructing a framework for understanding the golf traveller, golf and tourism industry representatives can better understand the contribution that golfers make to a destination based on factors such as satisfaction, perceived value received from the golfing experience, trip length, expenditures, travel decisions, and motivations. The results indicate that there are significant differences between golfers based on golfing frequency. Dedicated golfers are very different from infrequent and moderate golfers on three of the four variables used to profile these visitors. Findings from this research may provide golf and tourism market...
2008-01-01
The mixmaster universe in Horava-Lifshitz gravity
Energy Technology Data Exchange (ETDEWEB)
We consider spatially homogeneous (but generally non-isotropic) cosmologies in the recently proposed Horava-Lifshitz gravity and compare them to those of general relativity using Hamiltonian methods. In all cases, the problem is described by an effective point particle moving in a potential well with exponentially steep walls. Focusing on the closed-space cosmological model (Bianchi type IX), the mixmaster dynamics is now completely dominated by the quadratic Cotton tensor potential term for a very small volume of the universe. Unlike general relativity, where the evolution toward the initial singularity always exhibits chaotic behavior with alternating Kasner epochs, the anisotropic universe in Horava-Lifshitz gravity (with parameter lambda > 1/3) is described by a particle moving in a frozen potential well with fixed (but arbitrary) energy E. Alternating Kasner epochs still provide a good description of the early universe for very large E, but the ...
2010-02-21
The mixmaster universe in Horava-Lifshitz gravity
International Nuclear Information System (INIS)
We consider spatially homogeneous (but generally non-isotropic) cosmologies in the recently proposed Horava-Lifshitz gravity and compare them to those of general relativity using Hamiltonian methods. In all cases, the problem is described by an effective point particle moving in a potential well with exponentially steep walls. Focusing on the closed-space cosmological model (Bianchi type IX), the mixmaster dynamics is now completely dominated by the quadratic Cotton tensor potential term for a very small volume of the universe. Unlike general relativity, where the evolution toward the initial singularity always exhibits chaotic behavior with alternating Kasner epochs, the anisotropic universe in Horava-Lifshitz gravity (with parameter #lambda# > 1/3) is described by a particle moving in a frozen potential well with fixed (but arbitrary) energy E. Alternating Kasner epochs still provide a good description of the early universe for very large E, but the evolution ...
2010-02-21
The Dixmier-Moeglin equivalence and a Gel'fand-Kirillov problem for Poisson polynomial algebras
The structure of Poisson polynomial algebras of the type obtained as semiclassical limits of quantized coordinate rings is investigated. Sufficient conditions for a rational Poisson action of a torus on such an algebra to leave only finitely many Poisson prime ideals invariant are obtained. Combined with previous work of the first-named author, this establishes the Poisson Dixmier-Moeglin equivalence for large classes of Poisson polynomial rings, such as semiclassical limits of quantum matrices, quantum symplectic and euclidean spaces, quantum symmetric and antisymmetric matrices. For a similarly large class of Poisson polynomial rings, it is proved that the quotient field of the algebra (respectively, of any Poisson prime factor ring) is a rational function field $F(x_1,...,x_n)$ over the base field (respectively, over an extension field of the base field) with $\\{x_i,x_j\\}= \\lambda_{ij} x_ix_j$ for suitable scalars $\\lambda_{ij}$, thus establishing a ...
2007-01-01
International Nuclear Information System (INIS)
The first-step formation constants of UO_2"2"+-complexes of some N-hydroxysuccinamic acids viz. N-phenyl N-hydroxysuccinamic acid (Rsub(p)H(sub(2))), N-o-toyl N-hydroxysuccinamic acid(Rsub(t)oHsub(2)) and N-m-tolyl N-hydroxysuccinamic acid (Rsub(t)mHsub(2)) have been determined spectrophotometrically. Stabilities are in the ligand order Risup(m)Hsub(2)>Rsub(t)oHsub(2)>Rsub(p)Hsub(2). The first-step hydrolysis constant k' of UO_2"2"+ ion has been determined spectrophotometrically and found to be pk'=4.00 at a constant ionic strength (#mu#=0.5) at 30deg-+0.5deg and the molar extinction coefficients of the species UO_2"2"+ and UO_2(OH)"+ at #LAMBDA#=385 nm are found to be 2.0 and 13.0 respectively. (author).
1976-01-01
Matter and dynamics in closed cosmologies
International Nuclear Information System (INIS)
To systematically analyze the dynamical implications of the matter content in cosmology, we generalize earlier dynamical systems approaches so that perfect fluids with a general barotropic equation of state can be treated. We focus on locally rotationally symmetric Bianchi type IX and Kantowski-Sachs orthogonal perfect fluid models, since such models exhibit a particularly rich dynamical structure and also illustrate typical features of more general cases. For these models, we recast Einstein's field equations into a regular system on a compact state space, which is the basis for our analysis. We prove that models expand from a singularity and recollapse to a singularity when the perfect fluid satisfies the strong energy condition. When the matter source admits Einstein's static model, we present a comprehensive dynamical description, which includes the qualitative asymptotic behavior, of models in the neighborhood of the Einstein model; the results refute earlier ...
2005-04-15
Holomorphic wave function of the Universe
Energy Technology Data Exchange (ETDEWEB)
The quantum behavior of the vacuum Bianchi type-IX universe with the cosmological constant is investigated in terms of the Ashtekar variables. An exact solution to the quantum Hamiltonian constraint in the holomorphic representation is given. This solution reduces to the Hartle-Hawking wave function in the spatially isotropic sector and extends in the triad representation to the classically forbidden region where the determinant of the spatial metric becomes negative. The analysis of the quantum Robertson-Walker universe indicates that if the superspace is extended to such a classically forbidden region, the holomorphic representation picks up some restricted class of solutions in general. This observation leads to a new ansatz on the boundary condition of the Universe. In particular, the behavior of the Lorentzian and Euclidean WKB orbits corresponding to the solution suggests a new picture on the semiclassical behavior of the quantum Universe: that the Universe ...
1990-10-15
Holomorphic wave function of the Universe
International Nuclear Information System (INIS)
The quantum behavior of the vacuum Bianchi type-IX universe with the cosmological constant is investigated in terms of the Ashtekar variables. An exact solution to the quantum Hamiltonian constraint in the holomorphic representation is given. This solution reduces to the Hartle-Hawking wave function in the spatially isotropic sector and extends in the triad representation to the classically forbidden region where the determinant of the spatial metric becomes negative. The analysis of the quantum Robertson-Walker universe indicates that if the superspace is extended to such a classically forbidden region, the holomorphic representation picks up some restricted class of solutions in general. This observation leads to a new ansatz on the boundary condition of the Universe. In particular, the behavior of the Lorentzian and Euclidean WKB orbits corresponding to the solution suggests a new picture on the semiclassical behavior of the quantum Universe: that the Universe ...
Generalized quantum theory of recollapsing homogeneous cosmologies
International Nuclear Information System (INIS)
A sum-over-histories generalized quantum theory is developed for homogeneous minisuperspace type A Bianchi cosmological models, focusing on the particular example of the classically recollapsing Bianchi type-IX universe. The decoherence functional for such universes is exhibited. We show how the probabilities of decoherent sets of alternative, coarse-grained histories of these model universes can be calculated. We consider in particular the probabilities for classical evolution defined by a suitable coarse graining. For a restricted class of initial conditions and coarse grainings we exhibit the approximate decoherence of alternative histories in which the universe behaves classically and those in which it does not. For these situations we show that the probability is near unity for the universe to recontract classically if it expands classically. We also determine the relative probabilities of quasiclassical trajectories for initial states of WKB form, recovering ...
2004-06-15
Gauge invariant perturbation theory in spatially homogeneous cosmology
International Nuclear Information System (INIS)
The perturbations of the L.R.S. class A spatially homogeneous spacetimes are treated using Hamiltonian methods in conjunction with techniques from the theory of Lie group harmonic analysis. These latter techniques lead to a simple way of handling any set of tensor equations on these background spacetimes which has the same symmetry group as the space-time metric. Once this approach is developed, the Hamiltonian formulation is used to recover in a clean way the Bonanos equations for the perturbations of the perfect fluid models of the class of spacetimes under consideration. The conserved quantities associated with the four-dimensional symmetry group are evaluated and their role in the linearized Hamiltonian dynamics is discussed. The time-dependent linear canonical transformation of the linearized vacuum gravitational phase space adapted to Moncrief's gauge invariant decomposition is described in general for these models and evaluated explicitly for a class of lower dimensional ...
Energy Technology Data Exchange (ETDEWEB)
The increasing complexity of the real-time data acquisition and processing systems (TDAQ: the so called Trigger and Data AcQuisition systems) in high energy physics calls for an appropriate evolution of development tools. This work is about the interplay between in principle specifications of TDAQ systems and their actual design and realization on a concrete hardware and software platform. The basis of our work is to define a methodology for the development of TDAQ systems that meets the specific demands for the development of such systems. The result is the detailed specification of a 'methodological framework' based on the Unified Modeling Language (UML) and designed to manage a development process. The use of this UML-based methodological framework progressively leads to the setting up of a 'home-made' framework, i.e. a development tool that comprises reusable components and generic ...
2002-09-01
Nanoheterostructure Cation Exchange: Anionic Framework Conservation
Energy Technology Data Exchange (ETDEWEB)
In ionic nanocrystals the cationic sub-lattice can be replaced with a different metal ion via a fast, simple, and reversible place-exchange, allowing post-synthetic modification of the composition of the nanocrystal, while preserving its size and shape. Here, we demonstrate for the first time that during such an exchange, the anionic framework of the crystal is preserved. When applied to nanoheterostructures, this phenomenon ensures that compositional interfaces within the heterostructure are conserved throughout the transformation. For instance, a morphology composed of a CdSe nanocrystal embedded in a CdS rod (CdSe/CdS) was exchanged to a PbSe/PbS nanorod via a Cu2Se/Cu2S structure. During every exchange cycle, the seed size and position within the nanorod were preserved, as evident by excitonic features, Z-contrast imaging, and elemental line-scans. Anionic framework conservation extends the domain of cation exchange to the design of more ...
2010-05-11
International Nuclear Information System (INIS)
Ordered mesoporous C-TiO2 nanocomposites with crystalline framework were prepared by the evaporation-induced triconstituent co-assembly method. The products were characterized by XRD, TEM, N2 adsorption-desorption and TG. Their microwave absorption properties were investigated by mixing the product and epoxy resin. It is found that the peak with minimum reflection loss value moves to lower frequencies and the ordered mesoporous C-TiO2 nanocomposite possesses an excellent microwave absorbing property with the maximum reflection loss of -25.4 dB and the bandwidth lower than -10 dB is 6.6 GHz. The attenuation of microwave can be attributed to dielectric loss and their absorption mechanism is discussed in detail. The mesoporous C-TiO2 nanocomposites also exhibit a lower infrared emissivity in the wavelength from 8 to 14 ?m than that of TiO2-free powder. -- Graphical abstract: Ordered mesoporous C-TiO2 nanocomposite with crystalline framework ...
2010-12-01
FastFlow: Efficient Parallel Streaming Applications on Multi-core
Shared memory multiprocessors come back to popularity thanks to rapid spreading of commodity multi-core architectures. As ever, shared memory programs are fairly easy to write and quite hard to optimise; providing multi-core programmers with optimising tools and programming frameworks is a nowadays challenge. Few efforts have been done to support effective streaming applications on these architectures. In this paper we introduce FastFlow, a low-level programming framework based on lock-free queues explicitly designed to support high-level languages for streaming applications. We compare FastFlow with state-of-the-art programming frameworks such as Cilk, OpenMP, and Intel TBB. We experimentally demonstrate that FastFlow is always more efficient than all of them in a set of micro-benchmarks and on a real world application; the speedup edge of FastFlow over other solutions might be bold for fine grain tasks, as an example +35% ...
2009-01-01
We present a theoretical framework for formal study of systematic effects in Supernovae Type Ia (SN Ia) that utilizes 2-d simulations to implement a form of the deflagration-detonation transition (DDT) explosion scenario. The framework is developed from a randomized initial condition that leads to a sample of simulated SN Ia whose Ni56 masses have a similar average and range to those observed, and have many other modestly realistic features such as the velocity extent of intermediate mass elements. The intended purpose is to enable statistically well-defined studies of both physical and theoretical parameters of the SN Ia explosion simulation. We present here a thorough description of the outcome of the SN Ia explosions produced by our current simulations. A first application of this framework is utilized to study the dependence of the SN Ia on the Ne22 content, which is known to be directly influenced by the progenitor ...
2009-01-01
Electroweak Supersymmetry with an Approximate U(1)_PQ
A new predictive framework for supersymmetry at the TeV scale is presented. The \\mu parameter of the MSSM is replaced by (\\lambda S), where S is a singlet field, and the axion becomes a heavy pseudoscalar, G, by adding a mass, m_G, by hand. The explicit breaking of Peccei--Quinn (PQ) symmetry is assumed to be sufficiently weak at the TeV scale that the only observable consequence is the mass m_G. Three models for the explicit PQ breaking are given; but the utility of this framework is that the predictions for all physics at the electroweak scale are independent of the particular model for PQ breaking. The MSSM parameters \\mu, B are replaced by \\lambda, A_\\lambda. Taking the scalar mass m_S^2 to be sufficiently small and \\lambda = A_\\lambda \\sin (2 \\beta) /2. Our framework leads to a theory similar to the MSSM, except that \\mu is predicted and there are light, weakly-coupled states that lie dominantly in the ...
2004-01-01
Energy Technology Data Exchange (ETDEWEB)
This report presents estimates of the annual anthropogenic UK emissions of greenhouse gases for the years 1990-93 for submission under the Framework Convention on Climate Change. The gases considered are carbon dioxide, methane, nitrous oxide, nitrogen oxides, carbon monoxide and non-methane volatile organic compounds. Emissions of all the gases have declined since 1990. In particular, those of carbon dioxide have fallen by 4%; those of methane by 8% and those of nitrous oxide by 28%. Emission estimates are reported in the IPCC Standard Tables format disaggregated by source category and fuel. The methodology used for the estimates and how they relate to the UK National Atmospheric Emissions Inventory is discussed in an appendix. (author)
1995-10-01
Energy Technology Data Exchange (ETDEWEB)
Within the framework of efforts to optimize state-of-the-art waste disposal methods, this research project makes a theoretical analysis of the propagation behaviour of pollutants from landfills and waste incineration plants into the immediate vicinity of such plants. In order to judge the propagation of pollutants near the above-mentioned waste disposal facilities, a calculation program was developed within the framework of this research project which permits simulation of the propagation of such emissions in a three-dimensional space by application of an Eulerian grid model. It is capable of realistically representing fluid flow conditions and pollutant concentrations for certain points of times within the complex building patterns of such plants, for randomly chosen atmospheric conditions. (orig.)
1992-01-01
Target space duality I: general theory
Energy Technology Data Exchange (ETDEWEB)
We develop a systematic framework for studying target space duality at the classical level. We show that target space duality between manifolds M and M-tilde arises because of the existence of a very special symplectic manifold. This manifold locally looks like MxM-tilde and admits a double fibration. We analyze the local geometric requirements necessary for target space duality and prove that both manifolds must admit flat orthogonal connections. We show how abelian duality, nonabelian duality and Poisson-Lie duality are all special cases of a more general framework. As an example we exhibit new (nonlinear) dualities in the case M=M-tilde=R{sup n}.
2000-09-25
Strengthening Clean Energy Technology Cooperation under the UNFCCC: Steps toward Implementation
Energy Technology Data Exchange (ETDEWEB)
Development of a comprehensive and effective global clean technology cooperation framework will require years of experimenting and evaluation with new instruments and institutional arrangements before it is clear what works on which scale and in which region or country. In presenting concrete examples, this paper aims to set the first step in that process by highlighting successful models and innovative approaches that can inform efforts to ramp up clean energy technology cooperation. This paper reviews current mechanisms and international frameworks for global cooperation on clean energy technologies, both within and outside of the UNFCCC, and provides selected concrete options for scaling up global cooperation on clean energy technology RD&D, enabling environment, and financing.
2010-08-01
Staging Transformations for Multimodal Web Interaction Management
Multimodal interfaces are becoming increasingly ubiquitous with the advent of mobile devices, accessibility considerations, and novel software technologies that combine diverse interaction media. In addition to improving access and delivery capabilities, such interfaces enable flexible and personalized dialogs with websites, much like a conversation between humans. In this paper, we present a software framework for multimodal web interaction management that supports mixed-initiative dialogs between users and websites. A mixed-initiative dialog is one where the user and the website take turns changing the flow of interaction. The framework supports the functional specification and realization of such dialogs using staging transformations -- a theory for representing and reasoning about dialogs based on partial input. It supports multiple interaction interfaces, and offers sessioning, caching, and co-ordination functions through the use of an ...
2003-01-01
Seesaw mechanism in the sneutrino sector and its consequences
The seesaw-extended MSSM provides a framework in which the observed light neutrino masses and mixing angles can be generated in the context of a natural theory for the TeV-scale. Sneutrino-mixing phenomena provides valuable tools for connecting the physics of neutrinos and supersymmetry. We examine the theoretical structure of the seesaw-extended MSSM, retaining the full complexity of three generations of neutrinos and sneutrinos. In this general framework, new flavor-changing and CP-violating sneutrino processes are allowed, and are parameterized in terms of two $3\\times 3$ matrices that respectively preserve and violate lepton number. The elements of these matrices can be bounded by analyzing the rate for rare flavor-changing decays of charged leptons and the one-loop contribution to neutrino masses. In the former case, new contributions arise in the seesaw extended model which are not present in the ordinary MSSM. In the latter case, ...
2007-01-01
Negotiating equity for management of DOE wastes
Energy Technology Data Exchange (ETDEWEB)
One important factor frustrating optimal management of Department of Energy (DOE)-complex wastes is the inability to use licensed and permitted facilities systematically. Achieving the goal of optimal use of DOE`s waste management facilities is politically problematic for two reasons. First, no locale wants to bear a disproportionate burden from DOE wastes. Second, the burden imposed by additional wastes transported from one site to another is difficult to characterize. To develop a viable framework for equitably distributing these burdens while achieving efficient use of all DOE waste management facilities, several implementation and equity issues must be addressed and resolved. This paper discusses stakeholder and equity issues and proposes a framework for joint research and action that could facilitate equity negotiations among stakeholder and move toward a more optimal use of DOE`s waste management capabilities.
1994-09-01
Magic-angle-spinning NMR studies of acid sites in zeolite H-ZSM-5
{sup 1}H, {sup 13}C, {sup 27}Al, and {sup 29}Si magic-angle-spinning (MAS) NMR was used to elucidate the nature of the catalytic activity of zeolite H-ZSM-5. {sup 1}H MAS NMR of sealed samples after mild hydrothermal dealumination shows that the enhanced activity for n-hexane cracking is not due to an enhanced Bronstead acidity. The concentrations of the various OH groups and aluminous species suggest that the reason for the enhanced catalytic activity is the interaction of the n-hexane molecule with a bridging hydroxyl group and with extra-framework aluminium species, which give rise to the enhanced activity, cannot be easily removed from their positions, and are therefore immobilized by the zeolitic framework.
1991-01-01
Impedance Spectra of Mixed Conductors: a 2D Study of Ceria
In this paper we develop an analytical framework for the study of electrochemical impedance of mixed ionic and electronic conductors (MIEC). The framework is based on first-principles and it features the coupling of electrochemical reactions, surface transport and bulk transport processes. We utilize this work to analyze two dimensional systems relevant for fuel cell science via finite element method (FEM). Alternate current Impedance Spectroscopy (IS) of a ceria symmetric cell is simulated near equilibrium condition (zero bias) for a wide array of working conditions including variations of temperature and $H_2$ partial pressure on a two dimensional fuel cell sample with patterned metal electrodes. The model shows agreement of IS curves with the experimental literature with the relative error on the impedance being consistently below 2%. Important two-dimensional effects such the effects of thickness decrease and the influence of variable ...
2009-01-01
How do mathematicians learn math?: resources and acts for constructing and understanding mathematics
British Library Electronic Table of Contents (United Kingdom)
In this paper, we present an analytic framework for investigating expert mathematical learning as the process of building a network of mathematical resources by establishing relationships between different components and properties of mathematical ideas. We then use this framework to analyze the reasoning of ten mathematicians and mathematics graduate students that were asked to read and make sense of an unfamiliar, but accessible, mathematical proof in the domain of geometric topology. We find that experts are more likely to refer to definitions when questioning or explaining some aspect of the focal mathematical idea and more likely to refer to specific examples or instantiations when making sense of an unknown aspect of that idea. However, in general, they employ a variety of types of m...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The framework of time-sequence stratigraphy was established according to the point of view of high-resolution sequence stratigraphy. The development characteristic of the sequence, the distribution pattern of strata, the basin evolution and filling, and the relationship between variations of base level and coal accumulation of epicontinental basin were expounded based on the base-level cycles. The result shows that the C-P coal measures in Hebei is a series of basin deposit of inner epicontinental sea. The formation and evolution and sedimentation of the basin is intimately related to the changes of the basin base-level, which controls the development of the coal-accumulation, forming a clear coal-bearing sequence in the cycle. 9 refs., 3 figs.
2001-07-01
British Library Electronic Table of Contents (United Kingdom)
Although a large number of different organisations offer various forest education programmes within Germany, specific information (i.e., sectoral and programme content and provision at a state level) is lacking. This study used a survey of all 61 forest education organisations (43 respondents) in the state of North Rhine-Westphalia, Germany, to evaluate its forest education sector, with a specific focus on the organisations, demand for its services, forest educational programmes and framework conditions. Input from expert interviews was also used to develop recommendations. The study indicates that, especially with children as the main target group, many non-formal programmes are offered to support the formal environmental education sector and to promote leisure activities in the forest. Y...
2011-01-01
Data Mining for Actionable Knowledge: A Survey
The data mining process consists of a series of steps ranging from data cleaning, data selection and transformation, to pattern evaluation and visualization. One of the central problems in data mining is to make the mined patterns or knowledge actionable. Here, the term actionable refers to the mined patterns suggest concrete and profitable actions to the decision-maker. That is, the user can do something to bring direct benefits (increase in profits, reduction in cost, improvement in efficiency, etc.) to the organization's advantage. However, there has been written no comprehensive survey available on this topic. The goal of this paper is to fill the void. In this paper, we first present two frameworks for mining actionable knowledge that are inexplicitly adopted by existing research methods. Then we try to situate some of the research on this topic from two different viewpoints: 1) data mining tasks and 2) adopted framework. Finally, we ...
2005-01-01
Asymmetric Totally-corrective Boosting for Real-time Object Detection
Real-time object detection is one of the core problems in computer vision. The cascade boosting framework proposed by Viola and Jones has become the standard for this problem. In this framework, the learning goal for each node is asymmetric, which is required to achieve a high detection rate and a moderate false positive rate. We develop new boosting algorithms to address this asymmetric learning problem. We show that our methods explicitly optimize asymmetric loss objectives in a totally corrective fashion. The methods are totally corrective in the sense that the coefficients of all selected weak classifiers are updated at each iteration. In contract, conventional boosting like AdaBoost is stage-wise in that only the current weak classifier's coefficient is updated. At the heart of the totally corrective boosting is the column generation technique. Experiments on face detection show that our methods outperform the state-of-the-art asymmetric ...
2010-01-01
Analysis of heterogeneous cell populations: A density-based modeling and identification framework
British Library Electronic Table of Contents (United Kingdom)
Abstract: In many biological processes heterogeneity within clonal cell populations is an important issue. One of the most striking examples is a population of cancer cells in which after a common, identical death signal some cells die whereas others survive. The reason for this heterogeneity is intrinsic and extrinsic noise. In this paper we present a mechanistic multi-scale modeling framework for cell populations, in which the dynamics of every individual cell is captured by a parameter dependent stochastic differential equation (SDE). Heterogeneity among individual cells is accounted for by differences in parameter values, modeling extrinsic influences. Based on the statistical properties of the extrinsic noise and the SDE model for the individual cell, a partial differential equation (...
2011-01-01
An analytical framework for data stream mining techniques based on challenges and requirements
A growing number of applications that generate massive streams of data need intelligent data processing and online analysis. Real-time surveillance systems, telecommunication systems, sensor networks and other dynamic environments are such examples. The imminent need for turning such data into useful information and knowledge augments the development of systems, algorithms and frameworks that address streaming challenges. The storage, querying and mining of such data sets are highly computationally challenging tasks. Mining data streams is concerned with extracting knowledge structures represented in models and patterns in non stopping streams of information. Generally, two main challenges are designing fast mining methods for data streams and need to promptly detect changing concepts and data distribution because of highly dynamic nature of data streams. The goal of this article is to analyze and classify the application of diverse data mining techniques in ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
Restructuring of power system has changed the traditional planning objectives and introduced challenges in the field of Transmission Expansion Planning (TEP). Due to these changes, new approaches and criteria are needed for transmission planning in deregulated environment. Therefore, in this paper, a dynamic expansion methodology is presented using a multi-objective optimization framework. Investment cost, congestion cost and reliability are considered in the optimization as three objectives. To overcome the difficulties in solving the non-convex and mixed integer nature of the optimization problems, a Non-Dominated Sorting Genetic Algorithm (NSGA II) approach is used followed by a fuzzy decision making analysis to obtain the final optimal solution. The planning methodology has been demonstrated on the IEEE 24-bus test system and north-east of Iran national 400 kV transmission grid to show the feasibility and capabilities of the proposed algorithm in electricity ...
2010-10-15
British Library Electronic Table of Contents (United Kingdom)
In this work, we propose a conceptual distributed control framework for electrical grid integrated with distributed renewable energy generation systems in order to enable the development of the so-called ''smart electrical grid''. First, we introduce the key elements and their interactions in the proposed control architecture and discuss the design of the distributed control systems which are able to coordinate their actions to account for optimization considerations on the system operation. Subsequently, we focus on a specific wind/solar energy generation system connected to a reverse osmosis water desalination system and the electrical grid and design two supervisory predictive controllers via model predictive control to operate the integrated system taking into account short-term and lo...
2011-01-01
This paper gives a concise overview of evolutionary algorithms for multiobjective optimization. A substantial number of evolutionary computation methods for multiobjective problem solving has been proposed so far, and an attempt of unifying existing approaches is here presented. Based on a fine-grained decomposition and following the main issues of fitness assignment, diversity preservation and elitism, a conceptual global model is proposed and is validated by regarding a number of state-of-the-art algorithms as simple variants of the same structure. The presented model is then incorporated into a general-purpose software framework dedicated to the design and the implementation of evolutionary multiobjective optimization techniques: ParadisEO-MOEO. This package has proven its validity and flexibility by enabling the resolution of many real-world and hard multiobjective optimization problems.
2009-01-01
A Progressive Network Management Architecture Enabled By Java Technology
This paper proposes a framework based completely on Java technology. The advantages brought about by the use of Java in network management answer some critical problems existing in current systems. With this work we address several factors concerning interoperability and security in heterogeneous network environments. Specifically, we present a manager application and a multithreaded agent engine that make use of a lightweight communication mechanism for message exchange. A MIB parser is introduced to accelerate handling of incoming management requests, and the RSA public-key cryptosystem is implemented to provide both encryption and authentication features. Results, measured in terms of response time, compare favourably with other published work and standard management frameworks.
2010-01-01
A Neuro-Fuzzy Multi Swarm FastSLAM Framework
FastSLAM is a framework for simultaneous localization using a Rao-Blackwellized particle filter. In FastSLAM, particle filter is used for the mobile robot pose (position and orientation) estimation, and an Extended Kalman Filter (EKF) is used for the feature location's estimation. However, FastSLAM degenerates over time. This degeneracy is due to the fact that a particle set estimating the pose of the robot loses its diversity. One of the main reasons for loosing particle diversity in FastSLAM is sample impoverishment. It occurs when likelihood lies in the tail of the proposal distribution. In this case, most of particle weights are insignificant. Another problem of FastSLAM relates to the design of an extended Kalman filter for landmark position's estimation. The performance of the EKF and the quality of the estimation depends heavily on correct a priori knowledge of the process and measurement noise covariance matrices (Q and R) that are in most applications ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Properties of the multi-species electromagnetic Weibel and electrostatic two-stream instabilities are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters.
2004-04-09
Environmental Research Database
DescriptionThis project investigates in silico the interactive consequences of breeding for parasite resistance and nutritional environment on livestock productivity. The thesis of the work is that conflicting evidence regarding the consequences of breeding for parasite resistance arises from the failure to consider the interactions between host genetics and nutritional environment. Starting with a framework that accounts for the consequences of host nutrition on the development of parasitism, we will (1 [continued...
2007-01-31
International Nuclear Information System (INIS)
Methods of preparation, stability in solutions and in the solid phase, composition of orthophosphate crystallohydrates and condensed uranyl- and uranium (4) phosphates, are considered. Structures of these compounds are discussed; it is shown that they are steric polymers with an uranylphosphate framework. The problem of phosphate-anion polymerization in the process of thermal decomposition is discussed. It is established that condensed uranyl polyphosphates are not stable during storage, capable of degradation, its degree increasing with the phosphate chain length and uranium content.
The software for the USB-based multi-channel analyzer system
International Nuclear Information System (INIS)
A new type of multi-channel analyzer system is introduced, which takes advantage of Universal Serial Bus to communicate with computer and gets the merit of fast speed, universality and Plug and Play. The authors discussed the framework of the system, primary functions, display of spectrum date and the way of communication with hardware. The environment of the program is Visual Basic 6.0
2002-07-01
The research agenda in ICU telemedicine: a statement from the Critical Care Societies Collaborative.
ICU telemedicine uses audiovisual conferencing technology to provide critical care from a remote location. Research is needed to best define the optimal use of ICU telemedicine, but efforts are hindered by methodological challenges and the lack of an organized delivery approach. We convened an interdisciplinary working group to develop a research agenda in ICU telemedicine, addressing both methodological and knowledge gaps in the field. To best inform clinical decision-making and health policy, future research should be organized around a conceptual framework that enables consistent descriptions of both the study setting and the telemedicine intervention. The framework should include standardized methods for assessing the preimplementation ICU environment and describing the telemedicine program. This framework will facilitate comparisons across studies and improve generalizability by permitting context-specific ...
2011-07-01
The form factors of the nucleon at small momentum transfer
Energy Technology Data Exchange (ETDEWEB)
We study the low energy expansion of the nucleon`s electroweak form factors in the framework of an effective chiral Lagrangian including pions, nucleons and the {Delta}(1232). We work to third order in the so-called small scale expansion and compare the results with the ones previously obtained in the chiral expansion. In addition, these calculations serve as a first exploratory study of renormalization and decoupling within the small scale expansion. (orig.) 35 refs.
1998-05-25
The dipole picture in DIS: saturation and heavy quarks
Energy Technology Data Exchange (ETDEWEB)
We discuss the description of the proton structure function within the dipole factorization framework. We parameterize the forward dipole amplitude to account for saturation as predicted by the small-x QCD evolution equations. Contrarily to previous models, the saturation scale does not decrease when taking heavy quarks into account. We show that the same dipole amplitude also allows to reproduce diffractive data and exclusive vector meson production.
2008-04-07
Target space duality II: applications
Energy Technology Data Exchange (ETDEWEB)
We apply the framework developed in Target space duality I: general theory. We show that both nonabelian duality and Poisson-Lie duality are examples of the general theory. We propose how the formalism leads to a systematic study of duality by studying few scenarios that lead to open questions in the theory of Lie algebras. We present evidence that there are probably new examples of irreducible target space duality.
2000-09-25
Studying the triple-Higgs vertex in the process. gamma. gamma. yields HH at TeV energies
Energy Technology Data Exchange (ETDEWEB)
In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process {gamma}{gamma}{yields}HH are calculated. It is shown that the cross section is measurable at TeV {gamma}{gamma} colliders and is marginally sensitive to the triple-Higgs variation. (orig.).
1992-06-04
Studying the triple-Higgs vertex in the process #gamma##gamma##->#HH at TeV energies
International Nuclear Information System (INIS)
In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process #gamma##gamma##->#HH are calculated. It is shown that the cross section is measurable at TeV #gamma##gamma# colliders and is marginally sensitive to the triple-Higgs variation. (orig.).
Strength evaluation of bellows subjected to torsion
Energy Technology Data Exchange (ETDEWEB)
In this paper the stress due to torsion and the torsional buckling behavior of bellows are investigated through both theoretical and numerical analyses. The numerical solutions agree with the theoretical results very well in a wide range of dimensions and the number of convolutions. Based on these results, the framework of the design rule related to the torsion of bellows is proposed. (J.P.N.).
1992-11-01
Stored light and released fiction
It is shown that the interpretation of the experimental results reported in the publication "Storage of Light in Atomic Vapor" by D.F.Phillips et al., Phys. Rev.Lett. 86, 783 (2001) [quant-ph/0012138] is incorrect. The experimental observation of this paper can be consistently explained in the framework of standard concepts of the physics of optical pumping and has nothing to do with "storage of light", or "dynamic reduction of the group velocity", or "light pulse compression".
2003-01-01
Spin polarization and structure of the sup(181, 182, 187)Re and "1"7"7Ta states
International Nuclear Information System (INIS)
The properties of "1"7"7Ta and sup(181, 182, 187)Re states are discussed in the framework of the rotational model with the Coriolis coupling. The relations are obtained for calculating magnetic moments by this model in the jlK representation. The valent-nucleon spin polarization found on the basis of a comparison of the experimental values of magnetic moments with the calculated ones, is shown to depend on the number of nucleons of the same type.
1978-03-01
Energy Technology Data Exchange (ETDEWEB)
This thesis presents the work achieved to instrument the ATLAS software framework, ATHENA, with a library of tools and utensils for the physics analysis as well as the extraction of the jet energy scale using physics events (in-situ calibration). The software part presents the various components of the ATHENA framework which handles the simulated and reconstructed data flow as well as the different stages of this process, before and during the data taking. The building of a library of tools easing the reconstruction of physics objects, their association with Monte-Carlo particles and their API is then explained. The need for common language and collaboration-wide utensils is emphasised as it allows to share the workload of validating these tools and to get reproducible physics results. The analysis part deals with the implementation of a light jet energy scale calibration algorithm within the C++ framework. This calibration ...
2006-07-01
Simplification of the scheme - Department of Energy and Climate Change
...Simplification of the scheme - Department of Energy and Climate Change simplification, crc energy efficiency scheme Simplification of the scheme Simplification of the CRC Energy ...Efficiency Scheme The Government is considering the simplification of the CRC in the light of experience since the scheme began in April 2010. ...will take into account feedback from stakeholders including: the effectiveness of the CRC framework for driving energy efficiency in large private and public sector ... The perceived complexity of the CRC scheme and hence the administrative burden on: - those organisations that are subject to ...
Residential applliance data, assumptions and methodology for end-use forecasting with EPRI-REEPS 2.1
Energy Technology Data Exchange (ETDEWEB)
This report details the data, assumptions and methodology for end-use forecasting of appliance energy use in the US residential sector. Our analysis uses the modeling framework provided by the Appliance Model in the Residential End-Use Energy Planning System (REEPS), which was developed by the Electric Power Research Institute. In this modeling framework, appliances include essentially all residential end-uses other than space conditioning end-uses. We have defined a distinct appliance model for each end-use based on a common modeling framework provided in the REEPS software. This report details our development of the following appliance models: refrigerator, freezer, dryer, water heater, clothes washer, dishwasher, lighting, cooking and miscellaneous. Taken together, appliances account for approximately 70% of electricity consumption and 30% of natural gas consumption in the US residential sector. Appliances are thus ...
1994-05-01
Process e/sup -/. -->. e/sup -/(. nu. nu-bar) in the field of a circularly polarized plane wave
Energy Technology Data Exchange (ETDEWEB)
The e/sup -/..-->..e/sup -/(..nu..nu-bar) process in the field of a circularly polarized plane wave is studied in the framework of the Glashow-Weinberg-Salam model. General expressions for the probability of creation of neutrino pairs are obtained, and the case of a low-intensity wave is studied in detail. The effects of asymmetry of emission of electron and muon neutrinos are estimated, and comparison with previous results is performed.
1987-12-01
International Nuclear Information System (INIS)
Field reversed configuration (FRC) is a prospective high ? magnetic system for high efficiency D- 3He fusion reactor. Self-consistent FRC plasma profiles and static electric field for reactor calculations are discussed in framework of the model including flow equilibrium and collisionless transport equations. The extrapolations to reactor regimes of plasma confinement scaling laws are considered.
2006-01-01
Phenomenological implications of supersymmetry in left-right electroweak model
International Nuclear Information System (INIS)
The basics of a supersymmetric SU(2)_L x SU(2)_R x U(1)_B-I, model are reviewed. The production and subsequent decays of the doubly charged triplet higgsino #DELTA##+-##+-# in the Next Linear Collider are discussed. The slepton pair production in the framework of this model is also analyzed. (author)
1994-08-21
Performance estimates for attached-sunspace passive solar heated buildings
Energy Technology Data Exchange (ETDEWEB)
Performance predictions have been made for attached-sunspace types of passively solar heated buildings. The predictions are based on hour-by-hour computer simulations using computer models developed in the framework of PASOLE, the Los Alamos Scientific Laboratory (LASL) passive solar energy simulation program. The models have been validated by detailed comparison with actual hourly temperature measurements taken in attached-sunspace test rooms at LASL.
1980-01-01
P-odd asymmetries in deep inelastic scatterings of polarized leptons on nuclei
International Nuclear Information System (INIS)
The P-odd asymmetries in deep inelastic scattering (DIS) of polarized leptons on nuclei are considered in the framework of the standard model and the parton-flucton model. The model predictions, within the experimental errors,agree well with the present data. 13 refs., 2 figs., 2 tabs. (author).
Energy Technology Data Exchange (ETDEWEB)
Governments around the world will soon make decisions on policies that could determine the fate of the ozone layer-the Earth's shield from harmful ultraviolet radiation. The Vienna Convention for the Protection of the Ozone Layer, signed on March 22, 1985, created a framework for scientific cooperation and information exchange that will form the basis for a protocol for controlling substances thought to threaten the ozone layer. As of mid-1987, 29 countries had signed the Convention, including the major producers and users of chlorofluorocarbons (CFCs), the most important of suspect chemicals.
1987-12-01
On a new model for deep inelastic lepton-nuclei scatterings. I
International Nuclear Information System (INIS)
An approach to high energy nuclear reactions (relativistic nuclear physics) is developed on the basis of the quark-parton-flucton concept. The main assumptions underlying the known parton chain model are briefly reformulated, modified and generalized to the flucton case. This new model is used to investigate electron-nuclei and muon-nuclei inclusive reactions within the framework of quantum electrodynamics. The theoretical results are fitted well with existing data. (Auth.).
On Measurement and Computation
Inspired by the work of Feynman, Deutsch, We formally propose the theory of physical computability and accordingly, the physical complexity theory. To achieve this, a framework that can evaluate almost all forms of computation using various physical mechanisms is discussed. Here, we focus on using it to review the theory of Quantum Computation. As a preliminary study on more general problems, some examples of other physical mechanism are also given in this paper.
2011-01-01
Noncommutative tachyons and K-theory
Energy Technology Data Exchange (ETDEWEB)
We show that the relation between D-branes and noncommutative tachyons leads very naturally to the relation between D-branes and K-theory. We also discuss some relations between D-branes and K-homology, provide a noncommutative generalization of the ABS construction, and give a simple physical interpretation of Bott periodicity. In addition, a framework for constructing Neveu--Schwarz fivebranes as noncommutative solitons is proposed.
2001-07-01
Neutron-proton mass difference in isospin-asymmetric nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Isospin-breaking effects in the baryonic sector are studied in the framework of a medium-modified Skyrme model. The neutron-proton mass difference in infinite, asymmetric nuclear matter is discussed. In order to describe the influence of the nuclear environment on the skyrmions, we include energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it strongly decreases in neutron matter. (orig.)
2007-06-15
Moving Forward with Lessons Learned About Long-term Radioactive Waste Management
Energy Technology Data Exchange (ETDEWEB)
A range of lessons have been identified from previous attempts to implement long term radioactive waste management policy in the UK and internationally. Many of these relate to the way the decision-making process is undertaken and the fact that there needs to be an open, transparent process that enables continuous stakeholder involvement. Nirex believes that using the SEA and EIA frameworks will help to incorporate the lessons learned into the future decision-making process relating to long-term radioactive waste management.
2006-09-15
Marsden-Ratiu reduction and W_3"2 algebra
International Nuclear Information System (INIS)
The W_3"2 algebra is deduced by the Marsden-Ratiu reduction in the bi-Hamiltonian framework proposed by Magri et al and compared with the usual derivations via the Drinfeld-Sokolov formalism. It is observed that the choice of A in the first Poisson tensor must be different for W_3"2 algebra. (orig.).
1997-01-01
UK PubMed Central (United Kingdom)
An (Awassi × Merino) × Merino backcross family of 172 ewes was used to map quantitative trait loci (QTL) for different milk production traits on a framework map of 200 loci across all...Full Text Available
sinensis), the otter (Lutra lutra) and the grey seal (Halichoerus grypus) can be mentioned as ...conflict relates to damage caused by the grey seal to coastal fisheries, whereas in Germany damages ...For example species like the grey seal involved in the conflicts may benefit from the by-catch regulation.
Investigation of lifetimes in the dipole band of {sup 139}Sm
Energy Technology Data Exchange (ETDEWEB)
Lifetimes have been measured for a dipole band in {sup 139}Sm using DSAM. The deduced B(M1) and B(E2) values as well as B(M1)/B(E2) ratios are compared with calculations in the framework of the TAC (Tilted Axis Cranking) and SPAC (Shears mechanism with Principal Axis Cranking) models. The dipole band in {sup 139}Sm can be considered as a magnetic rotational band with a prolate or triaxial nuclear deformation. (orig.)
2008-09-15
Investigation of lifetimes in dipole bands of {sup 142}Gd
Energy Technology Data Exchange (ETDEWEB)
Lifetimes have been measured for dipole bands in {sup 142}Gd using DSAM. The deduced B(M1) and B(E2) values as well as B(M1)/B(E2) ratios are compared with calculations in the framework of the TAC (Tilted Axis Cranking) and SPAC (shears mechanism with Principal Axis Cranking) models. The dipole bands DB1 to DB4 can be interpreted as magnetic rotational bands. (orig.)
2005-02-01
International Nuclear Information System (INIS)
The cross sections for proton-proton elastic scattering at Fermilab and ISR energies are investigated in the framework of the multiple constituent scattering formalism, including the contributions of the inelastic intermediate states. We find that the higher-order multiple scattering amplitudes are strongly suppressed due to the presence of the inelastic intermediate states. The calculated cross sections reproduce the high energy experimental data fairly well. (author).
Generic design framework pile foundations (fixed steel structures)
Energy Technology Data Exchange (ETDEWEB)
To assist in attaining the HSE's objective of providing perspective and focus for Safety Case Assessment, a generic model of the structural design process for the foundations of pile supported fixed steel structures has been developed. Interfaces between the foundation design team and other stakeholders have been identified and assessments made of both the magnitude and the potential significance of the uncertainties associated with key elements of the design process. (author)
2001-07-01
Forum: Science and Innovation for Sustainable Development
...Studies People Projects Opportunities Framework Critical Sectors Development Goals Geographic Region Geographic Scale Research Themes Printer-Friendly MSU Environmental Science and Policy Program Michigan State University East Lansing , Michigan Type: Program Education Level: Graduate Event Duration: Ongoing Philosophy of the doctoral specialization: In the ...
Flux mapping system for TAPS 3 and 4: software perspective
International Nuclear Information System (INIS)
The Flux Mapping System (FMS) of 540 MWe PHWR is a system, which is first of its kind used in Indian PHWRs. It is used to compute a detailed flux/power distribution of the reactor core using modal synthesis method .The paper brings out the high availability features of FMS and the software design philosophy. The paper emphasizes on framework based reusable architectural design, which simplifies and speeds up the development of data acquisition systems. (author)
2010-02-01
Engineering Assistance and sustainable development; Ingenierie conseil et developpement durable
Energy Technology Data Exchange (ETDEWEB)
Since many years, people take care of hazardous consequences of a non controlled economic growth and the sustainable development concept gains on one. This situation leads to consequences in the building industry and in the energy policy: buildings insulation in consideration, demand of consultants. In this framework, the partnership between Gaz De France and CICF has to be built. (A.L.B.)
2002-07-01
Electronic structure of the Ru(0001) surface
Energy Technology Data Exchange (ETDEWEB)
This paper deals with the electronic structure of ruthenium. Synchrotron radiation in the range from 15 to 45 eV and angle-resolved ultraviolet photoemission are used to map the energies of the electronic states. The Fermi surface of Ru is determined using angle-resolved ultraviolet photoemission spectroscopy. The experimental results are compared with calculated photoemission spectra obtained within the framework of the one-step model of photoemission. (author)
2000-03-13
EUROPA-Site on LCA Tools, Services and Data -
...htm Waste Framework Directive 75/442/EEC (amended by Directive 91/156/EEC) and Waste Management Planning http://ec.europa.eu/environment/waste/plans/index.htm Selected EC commissioned/supported projects including LCA IPP Pilot Product exercise on mobile phones and on tropical garden furniture http://ec.europa.eu/environment/ipp/pilot.htm \\
The internal-tracking-system (ITS) of the ALICE detector at LHC, consists of six concentrical barrels of silicon detectors. The outmost two layers are made of double-sided strip detectors (SSD). In the framework of a R and D, the characteristics and performances of these devices, manufactured by two different companies, associated with their designed read-out electronics, have been studied off- and in-beam at the SPS (CERN). The results are presented and discussed.
1999-01-01
Development of breeder reactors in Japan
Energy Technology Data Exchange (ETDEWEB)
In the framework of a global analysis of the various available sources of energy, Japan has reserved a prominent place to the nuclear energy, and in the long-term view, to the breeder reactor which will be due for commercial deployment in 2010. To achieve these objectives, three stages are envisaged, one of the experimental reactor Joyo (in service), one of the demonstration reactor Monju (its construction has been decided), and one of the pre-commercial reactor (due to be taken in hand at the beginning of the Nineties). Efforts will be made in parallel concerning the fuel cycle.
1984-01-01
Density of states of ordered and disordered A-15 phase
International Nuclear Information System (INIS)
Within the tight binding framework, a study is made of how the disorder affects the electronic properties of A-15 compounds. In particular it is shown that for compounds of two transition metals in the A-15 structure, the vacancy formation affects the density of states only in the low energy region or in the high energy region, in opposition with the isolated chain model of Labbe and Friedel. It is concluded that interchain interactions are important. (U.K.).
Data Qualification guidelines. Task number 90-053-0
Energy Technology Data Exchange (ETDEWEB)
Data Qualification (DQ) is a formal, technical process whose objective is to affirm that experimental data are suitable for their intended use. Although it is not possible to develop a fixed recipe for the DQ process to cover all test situations, these general guidelines have been developed for the Nuclear Engineering Section to establish a framework for qualifying data from steady-state processing. These guidelines outline the role of the DQ team providing insight into the planning and conducting of the DQ process.
1992-09-02
Current ventilation and air conditioning systems and strategies
Energy Technology Data Exchange (ETDEWEB)
The report examines common ventilation and air conditioning systems and strategies for both domestic and commercial buildings; and covers issues such as energy conservation, indoor air quality and occupant comfort. Drawing data from many countries in Europe and the United States of America, various natural, mechanical and air conditioning systems were compared using criteria such as climate, level of occupant interaction, and level of system comfort. This classification system is evaluated and seen as a valuable framework for further research. (U.K.)
1994-02-01
Critical concentrations in France; Les charges critiques en France
Energy Technology Data Exchange (ETDEWEB)
The critical concentrations correspond to contamination thresholds of environments over which noxious effects can occur and deteriorate soils, water and vegetation. They are defined according to the type of pollutants and their mode of action. The aim of this document is to provide a scientific framework to the policies of reduction of atmospheric pollution negotiated at Geneva`s convention. The methodology of evaluation, the results obtained for surface waters and forest soils, the perspectives of French research and the integration of French knowledge in the European database are presented. (J.S.)
1997-12-31
Computing Networks: A General Framework to Contrast Neural and Swarm Architectures
Computing Networks (CNs) are defined. These are used to generalize neural and swarm architectures, namely artificial neural networks, ant colony optimization, and particle swarm optimization. The description of these architectures as CNs allows their comparison, distinguishing which properties enable them to perform complex computations and exhibit complex cognitive abilities. In this context, the most relevant characteristics of CNs are the existence multiple dynamical and functional scales.
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
We analyze large diffusion-limited aggregates and uncover a {ital discrete} scaling invariance in their inner structure, which can be quantified by the introduction of a set of {ital complex} fractal dimensions. We provide a theoretical framework and prediction of their values based on renormalization group theory and a previous wavelet analysis. {copyright} {ital 1996 The American Physical Society.}
1996-01-01
International Nuclear Information System (INIS)
Coherent oscillator radiation is considered. A comparison is made with classical particle radiation with gauss distribution. Decay probability for coherent state in spontaneous radiation is estimated. The method suggested for describing harmonic oscillator allows to separate the effect of classical field radiation from quantum description of particle state within the framework of a self-consistent quantum mechanical problem.
1982-04-01
Bistability and hysteresis in tilted sandpiles
We show that tilting a model sandpile that has dynamic disorder leads to bistability and hysteresis at the angle of repose. Also the distribution of {\\it local slopes} shows an interesting dependence on the amount of tilt - weakly tilted sandpiles retain the quasi-continuous distributions of the steady state, while large tilt makes the distribution more discrete, with local slopes clustered round particular values. These observations are used to explain recent experimental results on avalanche shapes; we give a theoretical framework in terms of directed percolation.
2000-01-01
International Nuclear Information System (INIS)
We present a method for obtaining the quasi-exact solutions of the Rabi Hamiltonian in the framework of the asymptotic iteration method (AIM). The energy eigenvalues, the eigenfunctions and the associated Bender-Dunne orthogonal polynomials are deduced. We show (i) that orthogonal polynomials are generated from the upper limit (i.e., truncation limit) of polynomial solutions deduced from AIM, and (ii) prove to have nonpositive norm. (authors)
2011-08-01
Atlas of room air flow; Raumstroemungsatlas
Energy Technology Data Exchange (ETDEWEB)
Within the framework of the IEA project Annex 20 - Airflow patters within buildings , an airflow data base was built up as a prototype. It enables airflow profiles, comfort and interior air quality to be studied without having to carry out a 1:1 experiment or having to run an expensive simulation code. The data base contains a number of pre-calculated room airflow profiles with their associated depictions of air quality and risks of drafts for given premises and for different ventilation systems. figs., tabs., refs.
1994-12-31
Antiproton production of propagating cosmic rays under distributed reacceleration
Energy Technology Data Exchange (ETDEWEB)
The available measurements on the cosmic-ray antiproton/proton ratio show an excess of antiprotons above predictions derived in the framework of the standard picture of cosmic-ray origin and propagation. Calculations are performed of the production from collisions of cosmic rays with the interstellar gas under the condition of distributed reacceleration. It could be shown that the calculated antiproton/proton ratio is enhanced compared to that derived from the leaky box model, but it remains difficult to bring it into agreement with the data by reasonable astrophysical assumptions. 15 references.
1987-09-01
Analysis of Computer Experiments with Multiple Noise Sources
DEFF Research Database (Denmark)
In this paper we present a modeling framework for analyzing computer models with two types of variations. The paper is based on a case study of an orthopedic surgical unit, which has both controllable and uncontrollable factors. Our results show that this structure of variation can be modeled effectively with linear mixed effects models and generalized additive models. Copyright (C) 2009 John Wiley & Sons, Ltd.
2010-01-01
This report provides an initial survey of the domestic and international safeguards requirements and provides a general framework on which future studies may be based. Additional studies are needed to evaluate the activities required to implement effective safeguards within the civilian waste management system and to ensure compliance with all safeguards requirements. 16 refs.
Energy Technology Data Exchange (ETDEWEB)
The development of emmissions, the measures planned and carried out and the present state of research in the Federal Republic of Germany into air pollution effects and abatement technology is reported. Possible starting points and solutions for air pollution abatement measures are explored within the legal framework.
1981-01-01
Agent-Based Evolutionary Search
The performance of Evolutionary Algorithms can be enhanced by integrating the concept of agents. Agents and Multi-agents can bring many interesting features which are beyond the scope of traditional evolutionary process and learning. This book presents the state-of-the art in the theory and practice of Agent Based Evolutionary Search and aims to increase the awareness on this effective technology. This includes novel frameworks, a convergence and complexity analysis, as well as real-world applications of Agent Based Evolutionary Search, a design of multi-agent architectures and a design of age
2010-01-01
A_2 Toda theory in reduced WZNW framework and the representations of the W-algebra
International Nuclear Information System (INIS)
Using the reduced WZNW formulation we analyse the classical W-orbit content of the space of classical solutions of the A_2 Toda theory. We define the quantized Toda field as a periodic primary field of the W-algebra satisfying the quantized equations of motion. We show that this local operator can be constructed consistently only in Hilbert space consisting of the representation corresponding to the minimal models of the W-algebra. (orig.).
1992-10-01
A phenomenological interpretation of trace impurity transport
Energy Technology Data Exchange (ETDEWEB)
An interpretive theory of trace impurity transport in tokamaks is presented. It is based on an earlier phenomenological approach developed by the authors for describing tokamak plasma transport experiments. The present model is used to explain disparate phenomena observed in ALCATOR C and DITE in a unified phenomenological framework. Predictive numerical calculations are presented for DITE conditions. If experimentally confirmed, the model could be used to correlate plasma properties with trace impurity behaviour. (orig.)
1989-10-01
Cosmologies with quasiregular singularities. II. Stability considerations
Energy Technology Data Exchange (ETDEWEB)
The stability properties of a class of spacetimes with quasiregular singularities is discussed. Quasiregular singularities are the end points of incomplete, inextendible geodesics at which the Riemann tensor and its derivatives remain at least bounded in all parallel-propagated orthonormal (PPON) frames; observers approaching such a singularity would find that their world lines come to an end in a finite proper time. The Taub-NUT (Newman-Unti-Tamburino)-type cosmologies investigated are R/sup 1/ x T/sup 3/ and R/sup 3/ x S/sup 1/ flat Kasner spacetimes, the two-parameter family of spatially homogeneous but anisotropic Bianchi type-IX Taub-NUT spacetimes, and an infinite-dimensional family of Einstein-Rosen-Gowdy spacetimes studied by Moncrief. The behavior of matter near the quasiregular singularity in each of these spacetimes is explored through an examination of the behavior of the stress-energy tensors and scalars for conformally coupled and minimally coupled, ...
1985-03-15
Cosmologies with quasiregular singularities. II. Stability considerations
International Nuclear Information System (INIS)
The stability properties of a class of spacetimes with quasiregular singularities is discussed. Quasiregular singularities are the end points of incomplete, inextendible geodesics at which the Riemann tensor and its derivatives remain at least bounded in all parallel-propagated orthonormal (PPON) frames; observers approaching such a singularity would find that their world lines come to an end in a finite proper time. The Taub-NUT (Newman-Unti-Tamburino)-type cosmologies investigated are R"1 x T"3 and R"3 x S"1 flat Kasner spacetimes, the two-parameter family of spatially homogeneous but anisotropic Bianchi type-IX Taub-NUT spacetimes, and an infinite-dimensional family of Einstein-Rosen-Gowdy spacetimes studied by Moncrief. The behavior of matter near the quasiregular singularity in each of these spacetimes is explored through an examination of the behavior of the stress-energy tensors and scalars for conformally coupled and minimally coupled, massive and massless ...
An accident of misidentification has brought to light the interesting system HD 191588, a new RS CVn-type spectroscopic binary. A radial-velocity study of the primary star, the only seen component, carried out at the Observatoire de Haute-Provence with the Coravel instrument and subsequently at the Cambridge Observatories with a similar one, reveals two orbital motions: a short-period orbit (60 days) and a long-period one (about 4.5 years), so this star is a triple system. The following orbital elements are obtained: (1) for the long-period orbit P = 1667+/-17 days, T = 50901 +/-67 MJD, Gamma = +2.09 +/-0.07 km/s, K = 2.51 +/-0.13 km/s, e = 0.18 +/-0.04, omega = 228deg +/- 14 deg, a1 sin i = 56.7 +/- 3.0 Gm, f(m) = 0.0026 +/-0.0004 M_sun, and (2) for the short-period orbit P = 60.0269 +/-0.0016 days, T = 50482.6 +/-3.3 MJD, gamma is var., K = 24.03 +/- 0.09 km/s, e = 0.012 +/-0.004, omega = 233 deg +/-19deg, a1 sin i = 19.83 +/-0.07 Gm, f(m) = 0.0865 +/-0.0009 M_sun. From near-infrared ...
2003-01-01
Energy Technology Data Exchange (ETDEWEB)
The emission isolation flux chamber (EIFC) methodology was applied to Superfund investigations at the Lawrence Livermore National Laboratory Site 300 to determine if on-site workers were exposed to VOCs volatilizing from the subsurface and what, if any, health risks could be attributed to the inhalation of the VOCs volatilizing from the subsurface. During July and August of 1996, twenty, eighteen, and twenty six VOC soil vapor flux samples were collected in the Building 830, 832, and 854 areas, respectively using EIFCS. The VOC concentrations in the vapor samples were used to calculate soil flux rates which were used as input into an air dispersion model to calculate ambient air exposure-point concentrations. The exposure-point concentrations were compared to EPA Region IX Preliminary Remediation Goals (PRGs). Buildings 830 and 832 exposure-point concentrations were less then the PRGs therefore no cancer risks were calculated. The cancer risks for Building 854 ...
1998-02-01
Accelerator technology program. Progress report, April-December 1978
This report presents highlights of activities in the Acceleartor Technology (AT) Division from April through December 1978. The report is divided into 10 sections to cover work done by the four groups that make up AT Division (AT-1, AT-2, AT-3, and AT-4). Section I is a brief summary of the whole report. Sections II through VI describe work done by At-1, the Linac Technology Group. Subjects covered are the Pion Generation for Medical Irradiation Program, the Electronuclear Fuel-Producing Accelerator Program, the Gyrocon rf Amplifier Program, the Electron Linear Accelerator Program, and the Free Electron Laser Program. Section VII covers the Linear Accelerator Beam Dynamics development, and Sec. VIII deals with work with the H/sup -/ Ion Source. Most of the work in Secs. VII and VIII was done by AT-2, the Special Projects Group, although work on factors influencing emittance growth was done by MP-9, and results on emittance growth in the new European Council for Nuclear Research (CERN) ...
1980-05-01
US Department of Energy investments in natural gas R&D: An analysis of the gas industry proposal
Energy Technology Data Exchange (ETDEWEB)
The natural gas industry has proposed an increase in the DOE gas R&D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R&D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE`s (1991) National Energy Strategy. This framework would assist the DOE in constructing an R&D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on grounds of economic efficiency and environmental quality. The fuel cell program is supported on grounds of ...
1992-04-13
Energy Technology Data Exchange (ETDEWEB)
This paper presents the conceptual framework that is being used to define quantification of margins and uncertainties (QMU) for application in the nuclear weapons (NW) work conducted at Sandia National Laboratories. The conceptual framework addresses the margins and uncertainties throughout the NW life cycle and includes the definition of terms related to QMU and to figures of merit. Potential applications of QMU consist of analyses based on physical data and on modeling and simulation. Appendix A provides general guidelines for addressing cases in which significant and relevant physical data are available for QMU analysis. Appendix B gives the specific guidance that was used to conduct QMU analyses in cycle 12 of the annual assessment process. Appendix C offers general guidelines for addressing cases in which appropriate models are available for use in QMU analysis. Appendix D contains an example that highlights the consequences of different ...
2007-12-01
A stellar evolution computer model has been used to determine changes in the luminosity L and effective temperature T(e) of single stars during their time on the main sequence. The range of stellar masses investigated was from 0.5 to 1.5 times that of the Sun, each with a mass fraction of metals (metallicity, Z) from 0.008 to 0.05. The extent of each star's habitable zone (HZ) has been determined from its values of L and T(e). These stars form a reference framework for other main sequence stars. All of the 104 main sequence stars known to have one or more giant planets have been matched to their nearest stellar counterpart in the framework, in terms of mass and metallicity, hence closely approximating their HZ limits. The limits of HZ, for each of these stars, have been compared to its giant planet(s)'s range of strong gravitational influence. This allows a quick assessment as to whether Earth-mass planets could exist in stable orbits within ...
2003-01-01
Structural transformation of Li{sub 2}CoPO{sub 4}F upon Li-deintercalation
Energy Technology Data Exchange (ETDEWEB)
Electrochemical performance and structural properties of the high-voltage cathode material Li{sub 2}CoPO{sub 4}F have been investigated. The cyclic voltammetry and coulometry under potential step mode in the voltage range 3.0-5.1 V vs. Li revealed a structural transformation at potentials above 4.8 V. This transformation occurring upon Li-extraction appears to be irreversible: the subsequent Li-insertion does not result in restoration of the initial structure, but takes place within a new ''modified'' framework. According to the structure refinement this modification involves the mutual rotations of (CoO{sub 4}F{sub 2}) octahedra and (PO{sub 4}) tetrahedra accompanied by the considerable unit cell expansion which is expected to enhance the Li-transport upon subsequent cycling. The new framework demonstrates a reversible Li-insertion/extraction in a solid-solution regime with stabilized discharge capacity at ...
2011-01-01
Skip-webs: Efficient distributed data structures for multi-dimensional data sets
DEFF Research Database (Denmark)
We present a framework for designing efficient distributed data structures for multi-dimensional data. Our structures, which we call skip-webs, extend and improve previous randomized distributed data structures, including skipnets and skip graphs. Our framework applies to a general class of data querying scenarios, which include linear (one-dimensional) data, such as sorted sets, as well as multi-dimensional data, such as d-dimensional octrees and digital tries of character strings defined over a fixed alphabet. We show how to perform a query over such a set of n items spread among n hosts using O(log n / log log n) messages for one-dimensional data, or O(log n) messages for fixed-dimensional data, while using only O(log n) space per host. We also show how to make such structures dynamic so as to allow for insertions and deletions in O(log n) messages for quadtrees, octrees, and digital tries, and O(log n / log log n) messages for ...
2005-01-01
Ranking Scientific Publications Based on Their Citation Graph
CDS Invenio is the web-based integrated digital library system developed at CERN. It is a suite of applications which provides the framework and tools for building and managing an autonomous digital library server. Within this framework, the goal of this project is to implement new ranking methods based on the bibliographic citation graph extracted from the CDS Invenio database. As a first step, we implemented the Citation Count as a baseline ranking method. The major disadvantage of this method is that all citations are treated equally, disregarding their importance and their publication date. To overcome this drawback, we consider two different approaches: a link-based approach which extends the PageRank model to the bibliographic citation graph and a time-dependent approach which takes into account time in the citation counts. In addition, we also combined these two approaches in a hybrid model based on a time-dependent PageRank. In the ...
2009-01-01
Quantum Teleportation with Continuous Variables: a survey
Very recently we have assisted to a new development of quantum information, the so-called continuous variable (CV) quantum information theory. Such a further development has been mainly due to the experimental and theoretical advantages offered by CV systems, i.e., quantum systems described by a set of observables, like position and momentum, which have a continuous spectrum of eigenvalues. According to this novel trend, quantum information protocols like quantum teleportation have been suitably extended to the CV framework. Here, we briefly review some mathematical tools relative to CV systems and we consequently develop the concepts of quantum entanglement and teleportation in the CV framework, by analogy with the qubit-based approach. Some connections between teleportation fidelity and entanglement properties of the underlying quantum channel are inspected. Next, we face the study of CV quantum teleportation networks where more users share a ...
2006-01-01
Probabilistic seismic and geotechnical evaluation at a dam site
Energy Technology Data Exchange (ETDEWEB)
This report examines the use of probabilistic methods in dealing with the problem of potential earthquake-induced liquefaction of foundation soils at an example dam site located in the central United States, near the New Madrid earthquake zone. The example dam is assumed to be a 1-mile long rolled-filled embankment founded on a 100-ft deep deposit of interbedded alluvial gravels, sands, silts, and clays. The study is seen as an opportunity to examine probabilistic concepts and procedures in the framework of an example engineering project. In this context, the main practical value of a probabilistic approach is that it permits more informed decision making about further data acquisition, additional engineering analysis, and if necessary, remedial action. The specific aim of the study is to show how probabilistic procedures complement and help to reinterpret the results of deterministic (earthquake-induced) liquefaction analysis. The procedures focus on evaluating ...
1983-09-01
Energy Technology Data Exchange (ETDEWEB)
The analysis described demonstrates the use of benefit/cost sensitivity analysis in examining the wide range of potential damages and savings associated with converting oil-fired electric utility boilers to burn coal in Florida. This model, for the first time incorporates, in quantitative terms, environmental economic externalities into a benefit/cost ratio sensitivity analysis framework. Five different dose-response estimates of morbidity and mortality costs, property devaluation, and willing-to-pay estimates are used in combination with four acid rain dose-response models to estimate the net present worth of externality costs. The model estimates the net present worth of benefits by incorporating into a dynamic framework all relevant construction, O + M, and fuel costs of converting an electrical generation facility from using oil to coal. These benefits of fuel savings are then weighted against various combinations of externality costs ...
1984-01-01
Phenomenological 3D and 1D consistent models for shape-memory alloy materials
The paper deals with the modeling and the development of a numerical procedure for the analysis of shape-memory alloy (SMA) elements in order to predict the main features of SMA devices. A 3D SMA model in the framework of small strain theory is developed starting from the thermo-mechanical model proposed by Souza et al. (Eur J Mech A/Solids 17:789-806, 1998) and modified by Auricchio and Petrini (Int J Numer Methods Eng 55:1255-1284, 2002). The aim of this paper is to propose some more modifications to the original model, to derive its consistent 1D formulation, to clarify the mechanical meaning of the material parameters governing the constitutive model. A robust time integration algorithm is developed in the framework of the finite element method and a new beam finite element is proposed. Some numerical applications and a comparison with experimental data available in literature are carried out in order to assess the ability of the proposed ...
2009-08-01
Online processing in the ALICE DAQ The detector algorithms
ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Some specific calibration tasks are performed regularly for each of the 18 ALICE sub-detectors in order to achieve most accurate physics measurements. These procedures involve events analysis in a wide range of experimental conditions, implicating various trigger types, data throughputs, electronics settings, and algorithms, both during short sub-detector standalone runs and long global physics runs. A framework was designed to collect statistics and compute some of the calibration parameters directly online, using resources of the Data Acquisition System (DAQ), and benefiting from its inherent parallel architecture to process events. This system has been used at the experimental area for one year, and includes more than 30 calibration routines in production. This paper ...
2010-01-01
Microlocal analysis of asymptotically hyperbolic and Kerr-de Sitter spaces
In this paper we develop a general, systematic, microlocal framework for the Fredholm analysis of non-elliptic problems, including high energy (or semiclassical) estimates, which is stable under perturbations. This framework is relatively simple given modern microlocal analysis, and only takes a bit over a dozen pages after the statement of notation. It resides on a compact manifold without boundary, hence in the standard setting of microlocal analysis, including semiclassical analysis. The rest of the paper is devoted to applications. Many natural applications arise in the setting of non-Riemannian b-metrics in the context of Melrose's b-structures. These include asymptotically Minkowski metrics, asymptotically de Sitter-type metrics on a blow-up of the natural compactification and Kerr-de Sitter-type metrics. The simplest application, however, is to provide a new approach to analysis on Riemannian or Lorentzian (or indeed, possibly of other ...
2010-01-01
International Nuclear Information System (INIS)
This study develops a statistical model of industrial US natural gas consumption based upon historical data for the 1958-2003 period. The model specifically addresses interfuel substitution possibilities and changes in the industrial economic base. Using a relatively simple approach, the framework can be simulated repeatedly with little effort over a range of different conditions. It may also provide a valuable input into larger modeling exercises where an organization wants to determine long-run natural gas prices based upon supply and demand conditions. Projections based upon this demand framework indicate that industrial natural gas consumption may grow more slowly over the next 20 yr than being projected by the U.S. Energy Information Administration (EIA). This conclusion is based upon the assumption that natural gas prices will follow oil prices, as they have done over recent decades. If natural gas prices should lag well below oil prices, ...
2007-07-01
Energy Technology Data Exchange (ETDEWEB)
This paper is a result of a research with the primary purpose of extending Probabilistic Risk Assessment (PRA) modeling frameworks to include the effects of organizational factors as the deeper, more fundamental causes of accidents and incidents. There have been significant improvements in the sophistication of quantitative methods of safety and risk assessment, but the progress on techniques most suitable for organizational safety risk frameworks has been limited. The focus of this paper is on the choice of 'representational schemes' and 'techniques.' A methodology for selecting appropriate candidate techniques and their integration in the form of a 'hybrid' approach is proposed. Then an example is given through an integration of System Dynamics (SD), Bayesian Belief Network (BBN), Event Sequence Diagram (ESD), and Fault Tree (FT) in order to demonstrate the feasibility and value of hybrid ...
2009-05-15
Energy Technology Data Exchange (ETDEWEB)
Cooperation for low carbon and energy efficient development is a high priority for France, in line with the United Nations Framework Convention on Climate Change. France contributes to tackling climate change by working with its partners on all continents to implement projects both to mitigate greenhouse gas emissions and to adapt to climate change. Within the framework of the Marrakech Accords, France also encourages the implementation of the Kyoto Protocol Clean Development Mechanism, in particular between French business and non-Annex I countries; this mechanism will facilitate the financing of mitigation projects and contribute to the sustainable development of host countries in the South. At multilateral level, France is a major donor. At a bilateral level, an initial analysis of cooperation projects which are strongly linked to tackling climate change identified public support of 136 millions euros per year, as an average over the past ...
2004-07-01
Energy Technology Data Exchange (ETDEWEB)
Although the Federal Facility Agreement (FFA) addresses the entire Oak Ridge Reservation, specific requirements are set forth for the liquid low-level radioactive waste (LLLW) storage tanks and their associated piping and equipment, tank systems, at ORNL. The stated objected of the FFA as it relates to these tank systems is to ensure that structural integrity, containment and detection of releases, and source control are maintained pending final remedial action at the site. The FFA requires that leaking LLLW tank systems be immediately removed from service. It also requires the LLLW tank systems that do not meet the design and performance requirements established for secondary containment and leak detection be either upgraded or replaced. The FFA establishes a procedural framework for implementing the environmental laws. For the LLLW tank systems, this framework requires the specified plans and schedules be submitted to EPA and TDEC for ...
1992-03-01
Energy Technology Data Exchange (ETDEWEB)
Within the framework of the German Federal-State 1000 Roofs Photovoltaic Programme monthly measuring data and verbal comments on the PV system operation (reports on failures and defects) have been collected, stored in a databank and evaluated for the period 1991 to 1997 for a differing number of PV systems. In addition to this came along data of initially 100, then 40 intensively measured systems. The results of the measuring data evaluation as well as the results of further accompanying research projects to the Federal-State 1000 Roofs Photovoltaic Programme (e.g. low energy yield analysis, on-site inspections and measuring of nominal powers) are summarised. Starting from the gained results, conclusions and recommendations are given for the design, installation and operation for future grid-connected PV-systems. Also it is pointed to the remaining need for optimisation and R and D. Additional part of the report are the Annual Journal (published in a large print ...
1998-10-16
Energy Technology Data Exchange (ETDEWEB)
To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations of relevant processes must first be identified, and then reduced. This endeavor demands that the GCM parameterizations of unresolved processes, in particular, should be tested over a wide range of time scales, not just in climate simulations. Thus, a numerical weather prediction (NWP) methodology for evaluating model parameterizations and gaining insights into their behavior may prove useful, provided that suitable adaptations are made for implementation in climate GCMs. This method entails the generation of short-range weather forecasts by a realistically initialized climate GCM, and the application of six-hourly NWP analyses and observations of parameterized variables to evaluate these forecasts. The behavior of the parameterizations in such a weather-forecasting framework can provide insights on how these schemes might be improved, and ...
2004-05-06
This study compares the spatial characteristics of industrial R&D networks to those of public research R&D networks (i.e. universities and research organisations). The objective is to measure the impact of geographical separation effects on the constitution of cross-region R&D collaborations for both types of collaboration. We use data on joint research projects funded by the 5th European Framework Programme (FP) to proxy cross-region collaborative activities. The study area is composed of 255 NUTS-2 regions that cover the EU-25 member states (excluding Malta and Cyprus) as well as Norway and Switzerland. We adopt spatial interaction models to analyse how the variation of cross-region industry and public research networks is affected by geography. The results of the spatial analysis provide evidence that geographical factors significantly affect patterns of industrial R&D collaboration, while in the public research sector effects of geography are ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Concerns over the environment and energy security have recently prompted renewed interest in the U.S. in nuclear energy. Recognizing this, the U.S. Dept. of Energy has launched an initiative to revamp and modernize the role that modeling and simulation plays in the development and operation of nuclear facilities. This Nuclear Energy Advanced Modeling and Simulation (NEAMS) program represents a major investment in the development of new software, with one or more large multi-scale multi-physics capabilities in each of four technical areas associated with the nuclear fuel cycle, as well as additional supporting developments. In conjunction with this, we are designing a software architecture, computational environment, and component framework to integrate the NEAMS technical capabilities and make them more accessible to users. In this report of work very much in progress, we lay out the 'problem' we are addressing, describe the model-driven system ...
2009-11-01
Cost analysis of the ownership and use of traditional and innovative cooking appliances
Energy Technology Data Exchange (ETDEWEB)
This study develops a framework for analysis and assessment of the cost of ownership and use of major cooking appliances. This involved an assessment of the monetary cost as well as the cost of human resources required to maintain and operate cooking systems. The goal was to provide information useful in making purchase decisions within a framework that can be used to organize information about cost beyond the initial purchase price. Five cooktops - conventional electric oil, induction, solid element with thermostatic control, solid element with thermal limiter, and gas - and a microwave oven were used to develop a decision-making matrix. Results were used to assign weights in the matrix used to develop a 10-point scale that represented the total cost of owning and using a cooking system in food preparation. Based on the matrix, the microwave oven received the highest score followed by gas, conventional electric coil, solid element with ...
1988-01-01
Convolution powers in the operator-valued framework
We consider the framework of an operator-valued noncommutative probability space over a unital C*-algebra B. We show how for a B-valued distribution \\mu one can define convolution powers with respect to free additive convolution and with respect to Boolean convolution, where the exponent considered in the power is a suitably chosen linear map \\eta from B to B, instead of being a non-negative real number. More precisely, the Boolean convolution power is defined whenever \\eta is completely positive, while the free additive convolution power is defined whenever \\eta - 1 is completely positive (where 1 stands for the identity map on B). In connection to these convolution powers we define an evolution semigroup related to the Boolean Bercovici-Pata bijection. We prove several properties of this semigroup, including its connection to the B-valued free Brownian motion. We also obtain two results on the operator-valued analytic function theory related to the free ...
2011-01-01
Conceptual Framework of Economic Evaluation on SMRs
International Nuclear Information System (INIS)
Korea Atomic Energy Research Institute(KAERI) launched a project to develop an integral reactor in 1996. The reactor called as System Integrated Modular Advanced Reactor(SMART) which is a kind of small modular reactors (SMRs). Since the early 1990s, there has been renewed interest in the development and application of small and medium sized integral reactors. 2009 assessment by the IAEA under its Innovative Nuclear Power Reactor and Fuel Cycle (INPRO) program concluded that there could be 96 SMRs in operation around the world by 2030 in its 'high' case, and 43 units in the 'low' case, none of them in the USA. The reason of the increased demand mostly comes from the fact that SMRs are thought to be more suitable for developing countries with small electrical grid capacity, insufficient infrastructure and limited investment capability than developed ones. However, it has disadvantage in the point of scale of economy. So, it should be compared the amount of this advantage and disadvantage ...
2010-10-01
Breakup of 96 MeV #alpha#-particles in the "5"8","6"4Ni niclei fields
International Nuclear Information System (INIS)
The aim of the paper is to investigate the process of #alpha#-particle breakup into two deuterons and to estimate the applicability of data on breakup for extraction of diffusivity parameter (a) in the framework of the diffraction approach. Measurements of absolute values of differential cross sections (DCS) of 96 MeV #alpha#-particle breakup on "5"8","6"4Ni are carried out in the limited angular range: #THETA#_1=22.5 deg, #THETA#_2=50, 55, 60, -50, -60 deg. Wide maxima typical for the process of incident #alpha#-particle breakup are observed in deuteron energy spectra. Measured DCS for #alpha#-particle breakup show distinct difference for "5"8Ni and "6"4Ni. The calculations describe satisfactorily this difference in the framework of the diffraction approach, if it is supposed that the diffusivity parameter for "5"8Ni nucleus has the value a=0.65 fm, and for "6"4Ni - a=0.85 fm.
Energy Technology Data Exchange (ETDEWEB)
The failure of the standard Growth Approach to economic development to solve the problems of underdevelopment in LDCs has caused an alternative approach, Basic Needs Approach (BNA), to attain prominence in development thought. BNA emphasizes poverty-minimizing growth. Its strategy of direct attack on poverty has better potential for LDCs' development and fulfillment of their populations' basic needs than the trickle-down mechanism of the Growth Approach. BNA requires, among other things, (a) suitable rural financial markets (RFMs) as parts of the overall financial system, and (b) indigenous technological capabilities. The financial system, if it functions as a central element in an institutionalized technology policy, can link technology-related institutions that generate, evaluate, and promote appropriate technologies (ATs) with RFMs that can support adoption and diffusion of ATs in the agro-rural sector. The above argument uses Bangladesh as a case for illustration. ...
1988-01-01
International Nuclear Information System (INIS)
The connections between several studies of the off-shell amplitude, based on apparently different criteria, are first clarified and expressed through more coincise operator notion. In all cases the resolution of the underlying dynamical relations is reduced to a two-step procedure. Underconditions which are discussed, the latter implies only Volterra-like integral equations followed by simple quadratures and algebraic operations. Then it is shown that the off-shell generalizations of the Jost formalism which are defined by such approaches can as well be introduced without reference to any explicit dynamical framework. Examples are given specifying in such model independent ways the main properties of the associated Jost-type functions. The relative interest of different representations built with these functions is also examined, and on this occasion new three-separable-term approximations are a useful guideline for introducing similar formalisms in other ...
Kohn-Sham density functional theory is one of the most widely used electronic structure theories. Uniform discretization of the Kohn-Sham Hamiltonian generally results in a large number of basis functions per atom in order to resolve the rapid oscillations of the Kohn-Sham orbitals around the nuclei. Previous attempts to reduce the number of basis functions per atom include the usage of atomic orbitals and similar objects, but the atomic orbitals generally require fine tuning in order to reach the chemical accuracy. We present a novel discretization scheme that adaptively and systematically builds the rapid oscillations of the Kohn-Sham orbitals around the nuclei as well as environmental effects into the basis functions. The resulting basis functions are localized in the real space, and are discontinuous in the global domain. The continuous Kohn-Sham orbitals and the electron density are evaluated from the discontinuous basis functions using the discontinuous Galerkin (DG) ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
We develop a general framework for the formulation of the action principle and the noether theorem for classical noncommutative field theories. We give a concrete example of an algebra that fits into this framework. It describes a scalar field theory on noncommutative minkowski space. We develop a notion of locality for this algebra and investigate the locality properties of localised interaction terms. This leads us to the definition of local functionals on the field algebra. We propose a scheme for the quantisation of these functionals. (orig.) [German] Wir entwickeln eine allgemeinen rahmen, der es erlaubt, das wirkungsprinzip und das noether-theorem fuer klassische nichtkommutative feldtheorien zu formulieren. Als ein konkretes beispiel betrachten wir eine algebra, die sich in diesem rahmen einfuegt, und die eine skalare feldtheorie auf dem nichtkommutativen minkowski-raum beschreibt. Fuer diese algebra wird ein lokalitaetsbegriff ...
2003-12-01
International Nuclear Information System (INIS)
Until recent years, those involved in the design, operation and regulation of nuclear power systems devoted more resources to forward movement than to the back end of the fuel cycle. Now, though, concerted thought and international cooperation have been devoted to the question of nuclear waste management. The expert consensus is that sufficient knowledge exists to make e.g. disposal decisions with an acceptable level of confidence. In the first phases of research, decision processes were adapted to the tasks at hand. However, at some point in each nuclearized country, there came a time when waste management implied finding repository sites. At that time management abruptly entered the social sphere - where unfortunate experience has shown time and time again that classical decision processes are not adapted to facilitating societal acceptance of management solutions. This paper recounts the various management frameworks that have been tested in a number of ...
1999-12-01
A Systematic Framework for the Construction of Optimal Complete Complementary Codes
The complete complementary code (CCC) is a sequence family with ideal correlation sums which was proposed by Suehiro and Hatori. Numerous literatures show its applications to direct-spread code-division multiple access (DS-CDMA) systems for inter-channel interference (ICI)-free communication with improved spectral efficiency. In this paper, we propose a systematic framework for the construction of CCCs based on $N$-shift cross-orthogonal sequence families ($N$-CO-SFs). We show theoretical bounds on the size of $N$-CO-SFs and CCCs, and give a set of four algorithms for their generation and extension. The algorithms are optimal in the sense that the size of resulted sequence families achieves theoretical bounds and, with the algorithms, we can construct an optimal CCC consisting of sequences whose lengths are not only almost arbitrary but even variable between sequence families. We also discuss the family size, alphabet size, and lengths of constructible CCCs based ...
2010-01-01
Zero-motion flucton correlations in high-energy proton elastic scattering on /sup 40/C
Energy Technology Data Exchange (ETDEWEB)
The 1.04 GeV-proton elastic scattering from /sup 40/Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data.
1985-03-01
Zero-motion flucton correlations in high-energy proton elastic scattering on "4"0C
International Nuclear Information System (INIS)
The 1.04 GeV-proton elastic scattering from "4"0Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data. (orig.).
Energy Technology Data Exchange (ETDEWEB)
Yucca Mountain in Nevada represents the proposed solution to what has been a lengthy national effort to dispose of high-level radioactive waste, waste which must be isolated from the biosphere for tens of thousands of years. This chapter reviews the background of that national effort and includes some discussion of international work in order to provide a more complete framework for the problem of waste disposal. Other chapters provide the regional geologic setting, the geology of the Yucca Mountain site, the tectonics, and climate (past, present, and future). These last two chapters are integral to prediction of long-term waste isolation.
2006-09-25
Washington: a guide to geothermal energy development
Energy Technology Data Exchange (ETDEWEB)
A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)
1980-01-01
Energy Technology Data Exchange (ETDEWEB)
The House Committee report describes the purpose, background, committee considerations and findings, and correspondence relating to H. Con. Res. 50, which is intended to encourage the president to pursue international negotiations relating to the ozone layer. The intent is to develop an international protocol and regulatory framework that will protect the stratosphere from the effects of chlorofluorocarbons. The report notes that some nations have already taken unilateral remedial steps, but argues the benefits of a negotiated agreement worldwide.
1987-01-01
Value creation through relationship closeness
British Library Electronic Table of Contents (United Kingdom)
Globalization and technological innovation are creating dynamic networks or chains of interconnected players, often known as value delivery networks or supply chains, in which a firm, whether manufacturing or service, holds the key to creating and delivering value in the form of offerings to the customers. This idea of value creation and exchange is the foundation stone of relationship marketing and it is considered successful when closeness is said to have been established in the relationship which subsequently leads toward the achievement of objectives. In order to study and understand the creation of value through relationship closeness in a value delivery network particularly at the backward end, a literature review is conducted. A framework is further developed with the help of Interp...
2010-01-01
Uncertainties of radionuclide migration parameter values obtained from in-situ tracer experiments
International Nuclear Information System (INIS)
One of the key issues in safety assessment of high-level nuclear waste disposal is evaluating the effects of uncertainty inherent in radionuclide migration parameter values. In this paper, radionuclide transport parameter values and error variances (uncertainties) from in-situ tracer experiments, carried out in a single fracture at the Aespoe Hard Rock Laboratory (HRL) in Sweden, are identified by solving the inverse problem in a framework of the maximum likelihood theory. From the results, it is found that the parameter value uncertainty caused by a conceptual model of radionuclide migration is greater than that caused by a fluctuation in the observed breakthrough curve data. (author)
2005-10-03
Triangle identity and free differential algebra of massless higher spins
International Nuclear Information System (INIS)
In terms of Berezins's theory of symbols of operators, the integral formulation is suggested for the free differential algebra which gives rise to consistent equations of motion of interacting massless fields of all spins 0#<=#s<#infinity# in the frameworks of gravity. In the first nontrivial order of the expansion in powers of curvatures, Frobenius consistency conditions for higher-spin equations of motion are shown to reduce to the simple geometrical fast that there are two ways for splitting any quadrangle in two triangles. To clarify our construction, we illustrate how it works in the simplest case of pure gravity. (orig.).
1989-09-01
Transport effect on He II film under conditions of weak interaction with the substrate
Energy Technology Data Exchange (ETDEWEB)
The properties of a helium film on the surface of solid parahydrogen are investigated. It is shown that wetting of the solid hydrogen by the liquid helium occurs. The transport velocities along the He II film on the solid parahydrogen surface are measured in broad temperature, film height, and level difference ranges. It is shown that the transport velocity in this case has the least value as compared with its value on other substrates. The thickness of the helium-saturated film is determined on the solid hydrogen surface on the basis of the data obtained, and the value is in good agreement with the results of a computation performed within the framework of the Frenkel' theory.
1980-10-01
Topological Defects in the Moduli Sector of String Theory
We point out that the moduli sector of the $(2,2)$ string compactification with its nonperturbatively preserved non-compact symmetries is a fertile framework to study global topological defects, thus providing a natural source for the large scale structure formation. Based on the target space modular invariance of the nonperturbative superpotential of the four-dimensional N=1 supersymmetric string vacua, topologically stable stringy domain walls are found. They are supersymmetric solutions, thus saturating the Bogomolnyi bound. It is also shown that there are moduli sectors that allow for the global monopole-type and texture-type configurations whose radial stability is ensured by higher derivative terms.
1991-01-01
DEFF Research Database (Denmark)
The thermodynamic framework that was developed in a previous work [Vrachnos et al. Ind. Eng. Chem. Res. 2004, 43, 2798] for the description of chemical and vapor-liquid equilibria of carbon dioxide, hydrogen sulfide, and their mixtures in aqueous methyldiethanolamine (MDEA) solutions is revised and extended in this study to the absorption of carbon dioxide into aqueous monoethanolamine (MEA) solutions and aqueous MDEA-MEA blends. The results of the model are compared with experimental data taken from the literature. Very satisfactory predictions of acidic gas vapor-liquid equilibrium over MDEA, MEA, and their blends at various concentrations, acidic gas loadings, and temperatures are obtained.
2006-01-01
The river Elbe. A case study for the ecological and economical chain of sediments
Energy Technology Data Exchange (ETDEWEB)
Industrial activities in the river basin of the Elbe have a very long tradition, and have been resulting in the contamination of sediments for centuries. Contamination lasted until the fall of the iron curtain; since then, the situation has improved significantly. In the transition zone between freshwater systems and the marine environment, ports like Hamburg still have to bear this burden of history. An overall (contaminated) management strategy should be developed in the context of the European Water Framework Directive with the emphasis on source control. (orig.)
2002-07-01
British Library Electronic Table of Contents (United Kingdom)
Purpose - The purpose of this research is to investigate the influence of psychological contracts on the adjustment and organisational commitment of expatriates during international business assignments. The study also aims to investigate the influence of psychological barriers to expatriate adjustment. Design/methodology/approach - A unique survey questionnaire was developed to collect data from 219 Taiwanese business expatriates during the first quarter of 2007. A LISREL analysis is used to test the hypotheses of the research framework. Findings - The study finds that: perceived fulfilment of the psychological contracts of expatriates significantly influences both their adjustment to foreign situations and their organisational commitment; psychological barriers to adjustment have a negat...
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
Due to changed operational conditions and because of the increasing age of several hydro power plant components, there is an increasing risk of damages and the control of degradation mechanisms is of increasing significance. Therefore lifetime considerations for safety relevant components in pumped-storage plants become more and more important. The development of a lifetime management system, in conjunction with monitoring systems and specific surveillance for a group of pumped-storage power plants of different ages and in a wide range of power output is presented. The special focus is on the impact of fatigue strength considerations within this framework. The applied procedure will be described for typical mechanical components in pumped-storage plants exemplarily. (orig.)
2010-07-01
The Ethics and Practice of Islamic Medieval Charity
British Library Electronic Table of Contents (United Kingdom)
Abstract Charity is deeply embedded in the religious thought and teachings of the three monotheistic religions. This article, while focusing on medieval Islam, is set in a wider framework with references to both Jewish and Christian parallels. Three main topics are examined: the religious meaning of charity, the social and political ramifications of almsgiving, and the impact of the institutional form of charity (the pious endowment system, waqf pl. awqaf) on Muslim medieval society. In the course of this examination, the article deals with the motives and attitudes of the donors (mainly people of the ruling class and the wealthy) and with the recipients of charity (the poor as well as the learned class). The article equally provides an overview of the charitable institutions and functions...
2007-01-01
The CDMS II data acquisition system
Energy Technology Data Exchange (ETDEWEB)
The Data Acquisition System for the CDMS II dark matter experiment was designed and built when the experiment moved to its new underground installation at the Soudan Lab. The combination of remote operation and increased data load necessitated a completely new design. Elements of the original LabView system remained as stand-alone diagnostic programs, but the main data processing moved to a VME-based system with custom electronics for signal conditioning, trigger formation and buffering. The data rate was increased 100-fold and the automated cryogenic system was linked to the data acquisition. A modular server framework with associated user interfaces was implemented in Java to allow control and monitoring of the entire experiment remotely.
2011-01-01
System reliability of timber structures with ductile behaviour
British Library Electronic Table of Contents (United Kingdom)
The present paper considers the evaluation of timber structures with the focus on robustness due to connection ductility. The robustness analysis is based on the structural reliability framework applied to a simplified mechanical system. The structural timber system is depicted as a parallel system. An evaluation method of the ductile behaviour is introduced. For different ductile behaviours, the system reliability is estimated based on Monte Carlo simulation. A correlation between the strength of the structural elements is introduced. The results indicate that the reliability of a structural timber system can be significantly increased due to the ductile behavior.
2011-01-01
Study of the influence of surface carbon on the tribological properties of ion-treated steels
Energy Technology Data Exchange (ETDEWEB)
Samples of 100Cr6 steel were treated by different ion beams in order to study the evolution of their tribological properties. A strong correlation was found between the amount of surface carbon, whatever its origin (contamination, direct C implantation or ion-beam mixing of a deposited carbon layer), and the reduction of the friction coefficient as well as the improvement of the wear resistance. These results are discussed in the framework of a recent statistical model founded on the asperity concept and describing the tribological behaviour of bilayer systems.
1999-01-02
Space activities in the Bolivarian Republic of Venezuela
British Library Electronic Table of Contents (United Kingdom)
This paper summarizes the establishment and current development of space activities in the Bolivarian Republic of Venezuela. Space activities in Venezuela are focused on the areas of telecommunications, Earth observation and research on the physical properties of the Earth, and have as a primary goal the satisfaction of social needs. Current development of space activities started in 1999 when the new National Constitution recognized the value of outer space as the common heritage of mankind, and the key role of science and technology in promoting human welfare. The Bolivarian Agency for Space Activities (ABAE) was created in 2007. Its legal framework recognizes three key elements that drive its policy: the participation of society, capacity building and human training, and international c...
2011-01-01
Solar cells in architecture; Solceller i arkitekturen
Energy Technology Data Exchange (ETDEWEB)
This book contains the results of an architectural evaluation of building examples with integrated photovoltaic. Danish Building and Urban Research and Danish Technological Institute conducted the work within the framework of Solar Energy Centre Denmark. Seven examples are selected to inspire Danish architects and building owners to use PV in the building environment. The examples come from Denmark and countries (the Netherlands and Germany) with similar building traditions, climate and solar conditions. All the examples demonstrate architectural concepts that integrate photovoltaic as a natural part of the building envelope. (BA)
2002-07-01
Energy Technology Data Exchange (ETDEWEB)
We investigate the formation of nanostructures in 2D strained alloys on face centered cubic (111) surfaces by means of equilibrium Monte Carlo simulations. In the framework of an off-lattice model, we consider one monolayer of two bulk-immiscible adsorbates A and B with negative and positive misfit relative to the substrate, respectively. Simulations show that the adsorbates partly self-organize into island or stripe-like patterns. We show how these structures depend on the relative misfits, interaction, and concentration of components. The morphology is quite different for phase separation and intermixing regimes.
2008-07-02
Energy Technology Data Exchange (ETDEWEB)
This report is published in the framework of the 1991 French law for the nuclear waste management. The state of the art reported here concerns the long term evolution of spent fuel in the various environmental conditions corresponding to dry storage and geological disposal: closed system, air and water saturated medium. This review is based on the results of the french PRECCI project (Research Program on Long term Evolution of Spent Nuclear Fuel) and on literature data. (authors)
2005-03-15
Revisiting light neutralino scenarios in the MSSM
We revisit the case of a light neutralino LSP in the framework of the MSSM. We consider a model with eleven free parameters. We show that all scenarios where the annihilation of light neutralinos rely mainly on the exchange of a light pseudoscalar are excluded by direct detection searches and by Fermi measurements of the gamma-flux from dwarf spheroidal galaxies. On the other hand, we find scenarios with light sleptons that satisfy all collider and astroparticle physics constraints. In this case, the lower limit on the LSP mass is 12.6 GeV. We discuss how the parameter space of the model will be further probed by new physics searches at the LHC.
2011-01-01
Redefining the issues of risk and public acceptance
International Nuclear Information System (INIS)
A conceptual framework is proposed within which the notion of risk as normally used in risk assessment (RA) could be enlarged in line with the real substance of social issues of technology policy, to help avoid RA's threatened irrelevance to social decision making. It is argued that the frequent organizational incoherence and thus the unviability of modern technology arises from 'social alienation' between the innovation-commitment phase and the implementation of the technology in society. The roles of technical elites and of particular concepts of technology in this alienation are emphasized. One of the case studies deals with 'Nuclear power - myths of scientific and organizational realism' and discusses the UK nuclear 'programme' and the Three Mile Island accident. (author).
Quark-hadron duality in structure functions
Energy Technology Data Exchange (ETDEWEB)
I review recent developments in quark-hadron duality in inclusive electron-nucleon scattering. Matrix elements of twist-4 operators extracted from moments of the spin-dependent g1 structure function suggest that duality violating higher twists are small above Q2 {approx} 1 GeV2. The x dependence of local duality is analyzed within a quark model framework, and mechanisms are identified for spin-flavor symmetry breaking which underpin the behavior of structure functions at large x.
2004-10-01
Pumped storage plants in a new framework - challenges and consequences
Energy Technology Data Exchange (ETDEWEB)
Originally designed exclusively for peak load covering, pumped storage plants are now faced with new challenges brought about by the deregulation of the electricity market and the substantial growth of wind power capacity. Today's pumped storage plants are started more frequently and often for shorter periods of time. The grid controlling tasks have increased the importance of the role played by this type of power plant and improved sales considerably. But the operational demands have grown substantially as well. This paper discusses the ensuing adaptation of power plant operation as well as options available to power plant operators. (orig.)
2006-07-01
Prospective cognition in animals.
The debate about whether or not animals have foresight has focused on whether animals can be shown to have episodic future thinking, that is the ability to travel mentally in time and see themselves in the future. This focus has distracted from consideration of other forms of foresight that animals demonstrate. We propose a framework for examining future-oriented behaviours and then discuss the evidence for future thinking in animals. In the final section we examine some perspectives of future thinking and suggest that there are future-oriented capabilities of animals that do not involve mental time travel but may yet involve future thinking which deserve further investigation. PMID:20522320
2009-03-01
Practical Ext JS Projects with Gears
Discover Ext JS, one of today's most powerful and highly regarded JavaScript frameworks, with perhaps the best set of GUI widgets around, and a whole host of components that make developing client--side applications a breeze. Using a pragmatic approach, you'll dissect seven full--fledged applications, covering *How Ext JS allows you to create these applications with a slick user interface with a minimum of effort*How the other parts of Ext JS aside from the GUI widgets provide many of the capabilities modern applications need, such as Ajax and data mechanisms *How other technologies such as Ge
2009-01-01
Power system stabilizer design based on structured singular values
Energy Technology Data Exchange (ETDEWEB)
In this paper, power system stabilizer design for multi-machine power systems is translated into an equivalent problem of decentralized controller design for Multi-Output Multi-Input (MIMO) control systems. Subject to a condition based on the structured singular values, each stabilizer can be designed independently. Within this general framework, the conventional stabilizer design methodology based on the concept of synchronous and damping torques is used to decide the design details of each stabilizer. The suggested design method is applied to a model of a practical 10 machine power system. (author)
1998-12-31
Place of technical support organizations in nuclear energy development
International Nuclear Information System (INIS)
Significant changes in Energy Generation industry and as a consequence in Nuclear Energy put new challenges and extend the tasks that need to be resolved by Technical Support Organisations. Political and economical changes in Bulgaria put also significant influence on Nuclear sector. During the last decade the main challenges for Bulgarian TSO's and for Risk Engineering Ltd in particular came from renovation of nuclear legislative framework, wide modernization programs of Kozloduy NPP Units and decision of Bulgarian Government for construction of Belene NPP. (author)
2007-08-01
We investigate several varying-mass dark-matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and dark matter densities of the same order. Imposing exponential or power-law potentials and exponential or power-law mass dependence, we conclude that the coincidence problem cannot be solved or even alleviated. Thus, if dark energy is attributed to the phantom paradigm, varying-mass dark matter models cannot fulfill the basic requirement that led to their construction.
2009-01-01
Perturbed Chern-Simons theory, fractional statistics, and Yang-Baxter algebra
International Nuclear Information System (INIS)
Topological Chern-Simons theory coupled to matter fields is analysed in the framework of Dirac's method of quantising constrained systems in a general class of linear, non-local gauges. We show that in the weak coupling limit gauge invariant operators in the theory transform under an exchange according to a higher dimensional representation of the braid group which is built out of the fundamental representation matrices of the gauge group and thus behave like anyons. We also discover new solutions of the Yang-Baxter equation which emerges as a consistency condition on the structure functions of the operator algebra of the matter fields. (orig.).
1992-04-01
On measuring vulnerability to poverty
British Library Electronic Table of Contents (United Kingdom)
There is a growing interest on dynamic and broader concepts of deprivation such as vulnerability, which takes in to account the destitution of individuals from future shocks. We use the framework of decision making under uncertainty to arrive at a new measure of vulnerability to poverty. We highlight the importance of current standard of living to better capture the notion of vulnerability. In conceptualizing the new class of measures of vulnerability, we thus move beyond the standard expected poverty measures that is commonly found in the literature. We also axiomatically characterize the new class of measure and discuss some of its properties.
2011-01-01
On endogenous order of moves in a trade embargo game
International Nuclear Information System (INIS)
Hung and Quyen's model (analysis of strategic interactions between players in the game theoretic framework) is first recapitulated. Solutions to the embargo game with the seller acting as the Stackelberg leader in both periods. Then the timing coordination issue is discussed and perfect equilibrium outcomes under different structures of leader-follower in the game are compared. Numerical simulations show that the structure corresponding to alternated leadership from one period to the other yields the perfect equilibrium outcome that is Pareto improving with respect to the structure where the buyer is first mover in both periods and Pareto dominant for some specific values of the parameters embedded in the game.
Nucleon momentum distributions of 39(K), 40(Ca) and 48(Ca)
Energy Technology Data Exchange (ETDEWEB)
The proton momentum distributions of (39)K,(40)Ca and (48)Ca are calculated from the model-independent charge distributions obtained from analyses of electron elastic scattering and muonic atoms, and also from the charge distributions calculated from the single-particle potential method in the framework of the flucton model. The sensitivities of the momentum distribution to different regions of the charge distribution are determined. The analysis is extended to the neutron distributions using the single-particle potential method, and the differences between the proton and neutron momentum distributions are examined. The resulting momentum distribution in the case of (40)Ca is used for analyzing the quasielastic electron scattering.
1983-01-01
Nuclear magnetic resonance on oriented XVTa and XXTa
Energy Technology Data Exchange (ETDEWEB)
XVTa and XXTa nuclei were oriented at low temperature as dilute impurities in Fe. The magnetic hyperfine splitting frequencies = B sub(HF)/Ih of the XVTa and XXTa ground states have been measured to be 320.45(11) and 317.552(55) MHz by using the technique of NMR-ON. Taking the known hyperfine field of Y Ta in Fe, the magnetic moments have been deduced: ( XVTa, 7/2 ) =2.270(45) and ( XXTa, 7/2 ) =2.250(45) sub(N). These values of the magnetic moments are discussed in the framework of the rotational model.
1984-08-01
Nuclear magnetic moments of "1"7"5Ta and "1"7"7Ta
International Nuclear Information System (INIS)
"1"7"5Ta and "1"7"7Ta nuclei as dilute impurities in Fe were oriented at low temperatures. Using the technique of NMR/ON the magnetic moments have been measured: "+#mu#("1"7"5Ta, 7/2"+,"+=2.270(45) #mu# sub(N) and "+#mu#("1"7"5Ta, 7/2"+)"+=2.250(45) #mu# sub(N). These values are discussed in the framework of the rotational model. (author).
... John Cannaday and Ken Weddle present the framework for a Product Design Engineering project (http://engineering.dartmouth.edu/~teps/images/ProductDesign.pdf) for high school students which may have relevance at a more advanced level. David Price has created a Mechanical Engineering Design (http://www.soton.ac.uk/~cds/) site containing engineering design notes. The Virtual Reality Engineering Library Home Page at the University of Bristol (http://www.dig.bris.ac.uk/virtual_lib/) is a library ...
New aspects for the evaluation of radioactive waste disposal methods
International Nuclear Information System (INIS)
For the performance assessment of radioactive and hazardous waste disposal sites, risk assessments are usually performed for the long term, i.e., over an interval in space and time for which one can predict movement and behavior of toxic agents in the environment. This approach is based on at least three implicit assumptions: One, that the engineering layout will take care of the immediate endangerment of potential receptors; two, that one has carefully evaluated just how far out in space and time the models can be extrapolated, and three, that one can evaluate potential health effects for very low exposures. A few of these aspects will be discussed here in the framework of the scientific method.
1996-08-18
NMR study of one-dimensional ionic conductor with hollandite-type structure (IV) Rb-priderite
International Nuclear Information System (INIS)
Conduction properties of Rb"+ ion in Rb-Al-priderite and K"+ ion and Rb"+ ion in (K,Rb)-Al-priderite, were investigated by NMR using "2"7Al in the framework as a probe. Size effect was observed remarkably in the activation energies. Frequency dependence of T_1 in Rb-Al-priderite at a low temperature indicates that the relaxation behavior of "2"7Al in Rb-Al-priderite can be described by the continuum model. Barrier height distributions and 'attempt frequencies' in both samples obtained by a curve-fitting method are discussed in comparison with those of K-Al-priderite. (orig.).
1985-08-18
British Library Electronic Table of Contents (United Kingdom)
There is proposed the nonlinear model of dose dependence saturation of the yield strength on the base of the vacancy and interstitial barrier interaction in this work. Processes of mutual recombination of vacancy and interstitial barriers and formation of vacancy and interstitial clusters are taken into consideration. In the framework of the model, the analytical equations corresponding to the evolution of the barrier densities and yield strength are obtained. It is shown that the yield strength of irradiated materials decreases with the increasing intensity of barrier recombination processes, the dependence being nonlinear. Also it is shown that the model is valid both for low doses and large doses on the stage of radiation hardening.
2009-01-01
Molecular dynamics study of reaction kinetics in viscous media
British Library Electronic Table of Contents (United Kingdom)
Predicted by stochastic models and observed experimentally in a number of isomerization reactions, viscosity-induced solvent effects manifest themselves in a significant departure of the reaction rates from the values expected on the basis of transition state theory. These effects are well understood within the framework of stochastic models; however, the predictive power of such models is limited by the fact that their parameters are not readily available. Experiment and molecular dynamics (MD) simulations can provide such information and can serve as the testing grounds for various stochastic models. In real solvents, a change in viscosity is inevitably associated with variation of at least one of the three factors - temperature, pressure, or solvent identity, resulting in different solv...
2011-01-01
The authors suggest a method of calculation of the isotherms of the spinodal and the heterogeneous equilibria in four-component systems in the framework of a unified thermodynamic model of the solution. The results of their calculations predict the existence of extended regions of immiscibility in the solid phase in the interval of temperatures usually used to obtain epitaxial layers of InAs/sub x/P/sub y/Sb/sub 1-x-y/ and AlAs/sub x/P/sub y/Sb/sub 1-x-y/.
1987-01-01
MIMO APP Receiver Processing with Performance-Determined Complexity
Typical receiver processing, targeting always the best achievable bit error rate performance, can result in a waste of resources, especially, when the transmission conditions are such that the best performance is orders of magnitude better than the required. In this work, a processing framework is proposed which allows adjusting the processing requirements to the transmission conditions and the required bit error rate. It applies a-posteriori probability receivers operating over multiple-input multiple-output channels. It is demonstrated that significant complexity savings can be achieved both at the soft, sphere-decoder based detector and the channel decoder with only minor modifications.
2010-01-01
MACROSCOPIC ONTOLOGY IN EVERETTIAN QUANTUM MECHANICS
British Library Electronic Table of Contents (United Kingdom)
Abstract Simon Saunders and David Wallace have proposed an attractive semantics for interpreting linguistic communities embedded in an Everettian multiverse. It provides a charitable interpretation of our ordinary talk about the future, and allows us to retain a principle of bivalence for propositions and to retain the law of excluded middle in the logic of propositions about the future. But difficulties arise when it comes to providing an appropriate account of the metaphysics of macroscopic objects and events. I evaluate various metaphysical frameworks which might be combined with the Saunders-Wallace semantics. I conclude that the most appropriate metaphysics to underwrite the semantics renders Everettian quantum mechanics a theory of non-overlapping worlds.
2011-01-01
Lossless Coding with Generalised Criteria
This paper presents prefix codes which minimize various criteria constructed as a convex combination of maximum codeword length and average codeword length or maximum redundancy and average redundancy, including a convex combination of the average of an exponential function of the codeword length and the average redundancy. This framework encompasses as a special case several criteria previously investigated in the literature, while relations to universal coding is discussed. The coding algorithm derived is parametric resulting in re-adjusting the initial source probabilities via a weighted probability vector according to a merging rule. The level of desirable merging has implication in applications where the maximum codeword length is bounded.
2011-01-01
Level structure of the doubly-odd /sup 242/Am nucleus
Energy Technology Data Exchange (ETDEWEB)
The level structure of the doubly-odd /sup 242/Am nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and ..beta.. spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.
1988-06-01
International cooperation - Information Centre - Research & Innovation - European Commission
... Removal of this layer facilitates the unreeling of cocoons into long strands of silk comparable to those derived from the domesticated mulberry silkworm (Bombyx mori, B. mori). The research was funded in part by the SABIP ('Silks as biomimetic ideals for polymers) project, which has clinched a European Research Council (ERC) grant worth almost EUR 2.3 million under the EU's Seventh Framework Programme (FP7). Presented in the journal Biomacromolecules, the findings could lead to the development of new silk industries in ...
Energy Technology Data Exchange (ETDEWEB)
In the framework of the negotiations on the climatic changes, beginning at Rio in 1992, the France received an UN conference from the 4 to 15 of september 2000. This conference determined the necessary actions for the Kyoto protocol validation. This document presents in two part the program of these days. The first part is devoted to the world government policy and the second part defines the french actions decided to fight against the climatic change. A glossary of the main terms adapted to the climatic change domain, is also provided. (A.L.B.)
2000-07-01
British Library Electronic Table of Contents (United Kingdom)
The increasing environmental concern and promotion of ''green processes'' are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real ''green'' catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures...
2011-01-01
Information processing, computation, and cognition
British Library Electronic Table of Contents (United Kingdom)
Computation and information processing are among the most fundamental notions in cognitive science. They are also among the most imprecisely discussed. Many cognitive scientists take it for granted that cognition involves computation, information processing, or both ? although others disagree vehemently. Yet different cognitive scientists use ?computation? and ?information processing? to mean different things, sometimes without realizing that they do. In addition, computation and information processing are surrounded by several myths; first and foremost, that they are the same thing. In this paper, we address this unsatisfactory state of affairs by presenting a general and theory-neutral account of computation and information processing. We also apply our framework by analyzing the relatio...
2011-01-01
Industrial hazardous waste in the framework of EU and international legislation
British Library Electronic Table of Contents (United Kingdom)
Purpose - The aim of the present study is to present in a systematic way the subject of industrial hazardous waste from the point-of-view of definitions in engineering, science and legislation. This analysis is necessary, as many different approaches and overlapping definitions are used for the classification of waste, leading to different results, a situation that often complicates the collection and interpretation of data on waste. Design/methodology/approach - The study is conducted by bringing together the extended experience of the authors and other experts in the field of environmental legislation and a wide variety of scientific and legislative sources as well as articles and research reports. The focus is the European Union, while several approaches from the international area are ...
2011-01-01
In vivo magnetic resonance techniques and drug discovery
International Nuclear Information System (INIS)
The long and resource intensive process of drug discovery and development is confronted with the basic challenge of providing effective and safe therapies at reasonably low costs. The better the mechanism of a disease is known, the higher the probability to find an appropriate therapy. Also, the better and earlier a disease can be diagnosed and characterized, the higher the chance to be able to interfere in this process with a chemical entity. This reasoning sets the framework for the use of imaging in drug discovery. We discuss the relevance of magnetic resonance imaging and spectroscopy to derive anatomical, functional, metabolic and target-related information in the context of pharmacological research in vivo. (author)
2006-03-01
Energy Technology Data Exchange (ETDEWEB)
In the framework of the carbon storage two forestry methods are analyzed by the author: the standing capitalization (slowing of the crops) and the spices substitution (slow growing species by fast growing species). The construction of a model taking into account the all stage of the carbon implication (biomass, soil, forest products) offers simulation and quantitative results on these methods. (A.L.B.)
2005-10-15
Global Value Chains and Open Networks: The Case of Italian Industrial Districts
British Library Electronic Table of Contents (United Kingdom)
Italian district small and medium enterprises (SMEs) developed aggressive strategies to extend their sales networks and supply chains abroad. Literature on districts offered alternative explanations about the impacts of internationalization on local manufacturing systems. The authors consider the evolution of Italian districts in the framework of global value chain approach, focusing on the role of leading firms. Based on a survey of 650 Italian SMEs and financial indicators, the paper describes the rise of a new district firm model, the open network, which becomes a key node of global value chains. The paper also analyses the relationships among internationalization, innovation strategies and performance of SMEs.
2010-01-01
International Nuclear Information System (INIS)
The Gamma Physics (GaP) program of physical phenomena investigation is proposed on #gamma#p, #gamma#e and #gamma##gamma# colliders at TeV energies. The program contains specialized software (CompHEP system) created for automation of particle interaction processes calculations in the framework of various gauge models. Preliminary physical results are presented (heavy quark production, W, Z production, supersymmetry etc.), and further software development is suggested. (R.P.) 22 refs., 8 figs., 4 tabs.
From recreational mathematics to recreational programming, and back
British Library Electronic Table of Contents (United Kingdom)
Recreational Programming (RecPro) is the discipline that encourages the study of computer programming through ludic problems. Problems that are typically studied within this discipline are similar to those of Recreational Mathematics (RecMat), which sometimes leads to the confusion of these two disciplines. The objective for RecPro is to write programs, while RecMat practitioners can use these programs to state (and prove if possible) conjectures about the solution. This interaction leads to a mathematical quality production. In an educational framework, problems in elemental number theory (those that are formulated with a basic knowledge of arithmetic) are very interesting, leading to the revision of classical unsolved problems. One of these problems is the general form of Zumkeller numbe...
2011-01-01
Finite element stress analysis of the CMS magnet coil
The Compact Muon Solenoid (CMS) is one of the experiments which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.38 m and the aperture is 6.36 m. This is achieved with a 4 layer-5 module superconducting Al-stabilized coil energised at a nominal current of 20 kA. The finite element analysis (FEA) carried out is axisymmetric elasto-plastic. FEA has also been carried out on the suspension system and on the conductor. (8 refs).
2000-01-01
Field emission dark current of technical metallic electrodes
International Nuclear Information System (INIS)
In the framework of the Low Emittance Gun (LEG) project, high gradient acceleration of a low emittance electron beam will be necessary. In order to achieve this acceleration, a -500 kV, 250 ns FWHM, pulse will be applied between two electrodes. Those electrodes should sustain the pulsed field without arcing, must not outgas and must not emit electrons. Ion back bombardment, and dark current will be damaging to the electron source as well as for the low emittance beam. Electrodes of commercially available OFE copper, aluminium, stainless steel (SS), titanium and molybdenum were tested, following different procedures including plasma glow discharge cleaning.
2007-04-21
Energy Technology Data Exchange (ETDEWEB)
We have developed EOS7M, a ferrofluid flow and transport module for TOUGH2. EOS7M calculates the magnetic forces on ferrofluid caused by an external magnetic field and allows simulation of flow and advective transport of ferrofluid-water mixtures through porous media. Such flow problems are strongly coupled and well suited to the TOUGH2 framework. Preliminary applications of EOS7M to some simple pressure and flow problems for which experiments were carried out in the lab show good qualitative agreement with the laboratory results.
1998-03-24
Energy Technology Data Exchange (ETDEWEB)
The legal basis to be provided is a licence for decommissioning work, issued for a particular reactor, including activities for recycling of disassembled, radioactive components and materials, subject to radioactivity measurements and exemption from radiological control of materials not exceeding the legally defined maximum level of contamination. (HP) [Deutsch] Es genuegt eine Stillegungsgenehmigung zu einem konkreten Abbauauftrag mit Verwertung radioaktiver Reststoffe nach Freigabe durch Radioaktivitaetsgrenzwertsfestsetzung. (HP)
1995-12-31
European Commission - Environment
...Species - see CITES Trade of Dangerous Chemicals Transport and Environment U Urban Environment Use of natural resources V Volatile Organic Compounds W Waste Landfills Waste electrical and electronic equipment - see WEEE Waste incineration Waste legislation - reporting Waste management planning Waste oils Waste shipments Waste water - see Urban waste water Water Bathing Water Drinking water Floods Marine environment Urban waste water Water Framework Directive WEEE - Waste Electric and Electronic Equipment Wildlife ...
Environmental Research Database
DescriptionFarm-level estimates of the financial impact of regulation are important indicators of the effect that a regulation have. Such estimates should be included in RIA, particularly within the Small Firms Impact Test. This farm-level analysis can be used in the RIA to inform judgements of the affordability of the regulation proposal. It will help to identify which farm types are likely to be financially had-hit from the regulation. Farm-level cost estimates for each regulation are also required t [continued...
2007-01-23
Enhancing employability in the "ME generation"
British Library Electronic Table of Contents (United Kingdom)
Purpose - The purpose of this paper is to place all of the contributions to this special issue into a theoretical framework and to highlight the role that the so-called "information age mindset" has in the facilitation of employability skills. Design/methodology/approach - The paper discusses the major themes of this special issue. Findings - Undergraduate students do see the importance of technological innovation in the classroom but they see the development of experiential or work-based skills to be more important. Practical implications - Future curriculum design should consider the expectations and attitudes of the modern day undergraduate student to ensure that potential employability is maximised. Originality/value - The findings are placed into the wider context of the emerging fiel...
2010-01-01
Energy production: institutional and legislative scenario
Energy Technology Data Exchange (ETDEWEB)
Brief comments are given on the evolution of the institutional nature of ENEL (Italian Electricity Board) as it relates to the framework of legislation for the nationalization of the utility in December, 1962. Special attention is given to the development of legislative criteria to allow the creation of a rate structure, in the case of autoproduction by industry, that would stimulate national economic growth. A discussion is also made of the changing role of ENEL as it responds to the planning objectives cited in the Italian National Energy Plan which calls for a more integrated effort by the regional governments and the Electricity Board in the management of natural resources.
1989-05-01
Emerging logics of competition: paradigm shift, fantasy, or reality check?
British Library Electronic Table of Contents (United Kingdom)
Purpose - The purpose of this paper is to elicit the subtle but progressive shift in organizational/institutional interaction with its rivals within a competitive framework, and thereby discusses and analyses paradigm shifts in competition and competitiveness. The paper argues that interorganizational networks and the recent concept of supply chain management may have induced a change in how competitiveness is viewed at the national, industry, and firm levels of interaction. Design/methodology/approach - The paper conceptualizes extant literature into distinct themes of (organizational and institutional) analysis - micro, macro, and meso - and based on this review the paper seeks to identify emerging logics and shifts within mainstream competitiveness literature over the last decade. Findi...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
A typical incident response pits technicians against networks that aren't prepared forensically. [1, 2] If practitioners do consider collecting network forensic data, they face a choice between expending extraordinary effort (time and money) collecting forensically sound data, or simply restoring the network as quickly as possible. In this context, the concept of organizational network forensic readiness has emerged. This paper proposes a methodology for "operationalizing" organizational network forensic readiness. The methodology, and the theoretical analysis that led to its development, are offered as a conceptual framework for thinking about more efficient, proactive approaches to digital forensics on networks.
2006-08-01
Effective mass of heavy holes in diamond-like semiconductors
Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account according to the Loewdin procedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of Gamma/sub 15c/ and Gamma/sub 12c/ bands) and the inverse dependence on the magnitude of the spin-orbit splittiing is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semiconductors, except for materials with a very strong nonparabolicity of the band of silicon type
1987-08-01
Effective mass of heavy holes in diamond-like semiconductors
International Nuclear Information System (INIS)
Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account according to the Loewdin procedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of Gamma/sub 15c/ and Gamma/sub 12c/ bands) and the inverse dependence on the magnitude of the spin-orbit splittiing is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semiconductors, except for materials with a very strong nonparabolicity of the band of silicon type.
Effective Constraints for Quantum Systems
An effective formalism for quantum constrained systems is presented which allows manageable derivations of solutions and observables, including a treatment of physical reality conditions without requiring full knowledge of the physical inner product. Instead of a state equation from a constraint operator, an infinite system of constraint functions on the quantum phase space of expectation values and moments of states is used. The examples of linear constraints as well as the free non-relativistic particle in parameterized form illustrate how standard problems of constrained systems can be dealt with in this framework.
2008-01-01
Duality in nonsupersymmetric M-theory QCD
Energy Technology Data Exchange (ETDEWEB)
The curves that describe the M-theoretic extension of type IIA string configurations with non-supersymmetric field theories on their surface exhibit a duality map. The map suggests a continued link between an SU(N) gauge theory with F flavors and an SU(F{minus}N) gauge theory with F flavors (the duality of supersymmetric QCD) even when the gaugino mass is taken to infinity. Within the context of the field theory such a duality only continues to make sense if the scalar fields remain light. We discuss the difficulties of decoupling the scalars within this framework. thinsp {copyright} {ital 1998} {ital The American Physical Society}
1998-10-01
Distribution amplitudes of {sigma} and {lambda} and their electromagnetic form factors
Energy Technology Data Exchange (ETDEWEB)
Based on QCD conformal partial wave expansion to leading order conformal spin accuracy, we present the light-cone distribution amplitudes (DAs) of {sigma} and {lambda} baryons up to twist 6. It is concluded that fourteen independent DAs are needed to describe the valence three-quark states of the baryons at small transverse separations. The nonperturbative parameters relevant to the DAs are determined within the framework of QCD sum rule method. With the obtained DAs, a simple investigation on the electromagnetic form factors of these baryons are given. The magnetic moments of the baryons are estimated by fitting the magnetic form factor with the dipole formula.
2009-04-15
If fourth family condensates are responsible for electroweak symmetry breaking then they may also break approximate global symmetries. Among the resulting pseudo-Goldstone bosons are those that can have diquark quantum numbers. We describe the variety of diquarks and their decay modes, and we find aspects that are particular to the fourth family framework. Spectacular signatures at the LHC appear and are explored for color sextet diquarks with 600 GeV mass. We consider a simple search strategy which avoids diquark reconstruction. We also consider 350 GeV mass diquarks that are accessible at the Tevatron.
2011-01-01
Development of a polymer fuel cell system for naval surface ship applications
Energy Technology Data Exchange (ETDEWEB)
In the framework of the development of new generations of surface ships, the Royal Netherlands Navy is studying the option of the all-electric ship concept. Background is the growing demand of electric power on board of naval ships for various services (including weapons and sensors). Important features of such an all-electric ship concept are decentralized electric energy generation and storage. In such an all-electric ship concept, fuel cells are expected to play an important role in the future, not only for reasons of energy efficiency and low emissions, but also because of their potential military advantages. Especially polymer electrolyte fuel cell systems appear to be very interesting for this application.
1996-12-31
International Nuclear Information System (INIS)
Within the framework of the EU power plant conceptual study (PPCS), a modular He-cooled divertor concept with integrated pin array (HEMP) is being developed at the Forschungszentrum Karlsruhe. The design goal is to achieve a high heat flux of at least about 10-15 MW/m"2, which is proposed for a near-term reactor model like DEMO. The development and optimization of the divertor concept require a close link between the main issues: design, analyses, materials and fabrication technology, and experiments with feedbacks between them to be accounted for. Design-specific requirements on materials and fabrication issues will be discussed.
2004-08-01
Energy Technology Data Exchange (ETDEWEB)
The aim of this research is the design and implementation of a decentralized power system stabilizer (PSS) capable of performing well for a wide range of variations in system parameters and/or loading conditions. The framework of the design is based on Fuzzy Logic Control (FLC). In particular, the neuro-fuzzy control rules are derived from training three classical PSSs; each is tuned using GA so as to perform optimally at one operating point. The effectiveness and robustness of the designed stabilizer, after implementing it to the laboratory model, is investigated. The results of real-time implementation prove that the proposed PSS offers a superior performance in comparison with the conventional stabilizer. (author)
2010-09-15
Description of odd-A nuclei in the Pt region in the interacting boson-fermion model
Energy Technology Data Exchange (ETDEWEB)
Properties of unique parity states in odd-proton (/sub 77/Ir, /sub 79/Au) and odd-neutron nuclei (/sub 78/Pt) are investigated in the framework of the interacting boson-fermion approximation model. The core (boson)-particle (fermion) interaction is represented by a quadrupole-quadrupole interaction and an exchange term, which takes into account the effects of the Pauli exclusion principle. The even-even core nucleus is described in terms of the IBA-1 hamiltonian. The change in the properties of the corresponding odd-A nuclei can be interpreted in terms of a transition of the core hamiltonian between the O(6) and SU(3) limiting cases.
1982-05-03
Description of odd-A nuclei in the Pt region in the interacting boson-fermion model
International Nuclear Information System (INIS)
Properties of unique parity states in odd-proton (_7_7Ir, _7_9Au) and odd-neutron nuclei (_7_8Pt) are investigated in the framework of the interacting boson-fermion approximation model. The core (boson)-particle (fermion) interaction is represented by a quadrupole-quadrupole interaction and an exchange term, which takes into account the effects of the Pauli exclusion principle. The even-even core nucleus is described in terms of the IBA-1 hamiltonian. The change in the properties of the corresponding odd-A nuclei can be interpreted in terms of a transition of the core hamiltonian between the O(6) and SU(3) limiting cases. (orig.).
Contract pricing of electric and telephone service: Current practice and policy
Energy Technology Data Exchange (ETDEWEB)
Due mainly to competitive pressures, the practice of offering electric and telephone service under contracts or special tariffs negotiated individually between a utility and its customers has increased in importance in recent years. Moreover, the practice is likely to become still more widespread in the future. This creates questions of public policy that are of interest to regulators and ratepayers alike such as how to supervise the practice, how to encourage utilities to compete while preventing cross-subsidization and anticompetitive behavior, and how the practice will ultimately affect utilities and ratepayers. This report sheds light on the topic by describing approaches that have been taken by the various regulatory commissions and by providing a framework for analyzing such contractors.
1992-04-01
Conjugate parallel-flowing free and forced convection boundary layers on vertical wall sides
Energy Technology Data Exchange (ETDEWEB)
The paper describes an analytical study of two parallel-flowing boundary layers of free and forced convection modes on the facing sides of a vertical thin wall. The two layers are analyzed separately within the framework of boundary layer theory, and coupled by the matching conditions at wall. Numerical data are obtained for a wide range of a dimensionless conjugation parameter {zeta} relating the heat transfer effectiveness of two convection modes. Based on these data, an expression for calculating the conjugate mean Nusselt number as a function of {zeta}-parameter is found by means of a curve-fitting method. (orig.)
2003-02-01
Energy Technology Data Exchange (ETDEWEB)
In this book the notion of time in classical physics and relativity theory is discussed. After a criticism of the absolute time some alternative measures of time in mechanics are considered. Thereafter the problem of equal time at different points of the space as well as the time in different inertial systems are considered. In this framework the clock paradox is discussed. Then the Lorentz transformation is considered. Thereafter the reconstruction of the absolute time in relativity theory is described. Finally the notion of time in general relativity theory is considered.
1980-01-01
Competencies of Employment Specialists for Effective Job Development
British Library Electronic Table of Contents (United Kingdom)
A scant body of literature addresses competencies needed for successful job development. This study aimed to identify competencies needed for this role. In this analysis, we observed employment specialists identified as successful in helping consumers obtain employment perform job development duties. We supplemented observations with interviews. Employment specialists possessed competencies in six domains: time management, advocacy, building partnerships with consumers, working as part of a team, face-to-face communication, and networking. The conceptual framework derived from this study can inform supported employment supervisors and researchers about the competencies that can strengthen supported employment teams.
2011-01-01
Comparison of the TESLA, NLC and CLIC Beam-Collimation System Performance
This report describes studies performed in the framework of the Collimation Task Force organized to support the work of the second International Linear Collider Technical Review Committee. The post-linac beam-collimation systems in the TESLA, JLC/NLC and CLIC linear-collider designs are compared using the same computer code under the same assumptions. Their performance is quantified in terms of beam-halo and synchrotron-radiation collimation efficiency. The performance of the current designs varies across projects, and does not always meet the original design goals. But these comparisons suggest that achieving the required performance in a future linear collider is feasible.
2004-01-01
Collectivity at N=40 in neutron-rich "6"4Cr
International Nuclear Information System (INIS)
"9Be-induced inelastic scattering of "6"2","6"4","6"6Fe and "6"0","6"2","6"4Cr was performed at intermediate beam energies. Excited states in "6"4Cr were measured for the first time. Energies and population patterns of excited states in these neutron-rich Fe and Cr nuclei are compared and interpreted in the framework of large-scale shell-model calculations in different model spaces. Evidence for increased collectivity and for distinct structural changes between the neighboring Fe and Cr isotopic chains near N=40 is presented.
2010-05-01
Cluster-phonon model applied to the [sup 91]Zr nucleus
Energy Technology Data Exchange (ETDEWEB)
The structure of the low-lying levels of the [sup 91]Zr nucleus is discussed in a framework of the cluster-phonon coupling model. In order to describe simultaneously positive- and negative-parity states, octupole as well as quadrupole vibrations of the [sup 88]Sr core are allowed. The cluster states include two single protons coupled to a single neutron. The residual interaction among the cluster particles is assumed to be the modified surface [delta] interaction. Energy levels and electromagnetic properties are calculated and compared with the experimental data.
1993-07-01
Chargino production at high energy {gamma}{gamma} colliders with polarized beams
Energy Technology Data Exchange (ETDEWEB)
We investigate the chargino production process {gamma}{gamma} {yields} (W-tilde){sup +}(W-tilde){sup -} at high energy {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy {gamma} beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background {gamma}{gamma} {yields} W{sup +}W{sup -}. (author).
1995-05-01
Chargino production at high energy #gamma##gamma# colliders with polarized beams
International Nuclear Information System (INIS)
We investigate the chargino production process #gamma##gamma# #-># (W-tilde)"+(W-tilde)"- at high energy #gamma##gamma# colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy #gamma# beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background #gamma##gamma# #-># W"+W"-. (author).
1995-05-01
International Nuclear Information System (INIS)
A radioactively contaminated marine sediment core stemming from Irish Sea has been characterized by radiometric and mass spectrometric techniques as for "2"3"7Np, "2"4"1Am, "2"3"9Pu, "2"4"0Pu, "2"4"1Pu, "1"3"7Cs and "1"5"4Eu. The data obtained with independent methods in the framework of a QA/QC program as compared with the source term discharges, as well as with those reported in literature, are in good agreement. (author)
2005-02-01
British Library Electronic Table of Contents (United Kingdom)
Background: We consider cells as biological systems that process information by means of molecular codes. Many studies analyze cellular information processing exclusively in syntactic terms (e.g., by measuring Shannon entropy of sets of macromolecules), and abstract completely from semantic aspects that are related to the meaning of molecular information. Methods: This mini-review focusses on semantic aspects of molecular information, particularly on codes that organize the semantic dimension of molecular information. First, a general conceptual framework for describing molecular information is proposed. Second, some examples of molecular codes are presented. Third, a mathematical approach that makes the identification of molecular codes in reaction networks possible, is developed. Results...
2011-01-01
The open source Scala language is a Java--based dynamic scripting, functional programming language. Moreover, this highly scalable scripting language lends itself well to building Cloud--based/deliverable Software as a Service (SaaS) online applications. Written by Lift Scala web framework founder and lead Dave Pollak, Beginning Scala takes a down--to--earth approach to teaching Scala that leads you through simple examples that can be combined to build complex, scalable systems and applications. This book introduces you to the Scala programming language and then guides you through Scala constr
2009-01-01
An overview of FFTF [Fast Flux Test Facility] contributions to Liquid Metal Reactor Safety
International Nuclear Information System (INIS)
The Fast Flux Test Facility has provided a very useful framework for testing the advances in Liquid Metal Reactor Safety Technology. During the licensing phase, the switch from a nonmechanistic bounding technique to the mechanistic approach was developed and implemented. During the operational phase, the consideration of new tests and core configurations led to use of the anticipated-transients-without-scram approach for beyond design basis events and the move towards passive safety. The future role of the Fast Flux Test Facility may involve additional passive safety and waste transmutation tests. 26 refs.
1990-11-11
An analysis of convective losses from cavity solar central receivers
Energy Technology Data Exchange (ETDEWEB)
A simple analytical model has been developed in order to provide a framework for designing experimental programs for convective loss determinations, for analyzing available experimental data from solar receiver test programs, and for estimating the convective loss at a relatively small cost. Analytical results and experimental evidence indicate that the convective loss from cavity receivers is appreciable, while the effects of wind on the convective loss under normal operating conditions are minimal. The proposed analytical model provides a means of determining the relative importance of the internal resistances and predicting the bulk air temperature within the convective zone inside the cavity.
1981-01-01
Alaska: a guide to geothermal energy development
Energy Technology Data Exchange (ETDEWEB)
A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)
1980-06-01
ALOHA: Automatic Libraries Of Helicity Amplitudes for Feynman diagram computations
We present an application that automatically writes the Helas library corresponding to the Feynman rules of any Lagrangian, renormalizable or not, in quantum field theory. The code, written in Python, takes the Universal FeynRules Output as an input and produces the complete set of routines (wave-functions and amplitudes) that are needed for the computation of Feynman diagrams at leading as well as at higher orders. The representation is language independent and outputs in Fortran, C++, Python are currently available. A few key sample applications implemented in the MadGraph5 framework are presented.
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The work is devoted to the construction of a viable of locally anisotropic, i.e. Finslerian, space-time and to the generalization, on this basis, of the relativistic theory of gravitation. Arguments in favour of this model are considered. From physical considerations the concrete form of the Finslerian metric has been reconstructed and within the framework of the correspondence principle a formalism of the theory has been developed. The approach suggested is aimed at developing unified gauge theories of all fundamental interactions. Much attention is given to the nontrivial physical manifestations of local space anisotropy and to the possibility of its experimental detection. (orig.)
1994-01-01
A study for good regulation of the CANDU's in Korea
Energy Technology Data Exchange (ETDEWEB)
The objective of project is to derive the policy recommendations to improve the efficiency of CANDU plants regulation. These policy recommendations will eventually contribute to the upgrading of Korean nuclear regulatory system and safety enhancement. During the second phase of this 2 years study, following research activities were done. Review the technical basis and framework of the new Canadian Regulation System and IAEA. Analysis on the interview of Wolsung operation staffs to identify important safety issues and regulation problems experienced at operation. Providing a plan of CANDU regulation system enhancement program.
2002-03-15
British Library Electronic Table of Contents (United Kingdom)
This essay focuses on the major industrial changes from the late 1950s onwards in the industrial basins from the Nord/Pas-de-Calais to the Ruhrgebiet. The notion of industrial redeployment (reconversion industrielle) is critically analysed in the framework of European integration. The comparative approach highlights the importance of the time-space dimension which differs from one basin to the other. The diverse individual and collective actors also were in command of different power resources according to the various state traditions. The European Community, however, appears to have played an increasing role, culminating at the time of the steel industry crisis (1975-1985).
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
Regular physical activity (PA) decreases the risk of several chronic diseases including some cancers, type II diabetes, obesity, and cardiovascular disease; however, the majority of US adults are not meeting the recommended levels to experience these benefits. To address this public health concern, the underlying mechanisms for behavior change need to be understood, translated and disseminated into appropriately tailored interventions. The Transtheoretical Model (TTM) provides a framework for both the conceptualization and the measurement of behavior change, as well as facilitating promotion strategies that are individualized and easily adapted. The purpose of this manuscript is to present the constructs of the TTM as they relate to PA behavior change. We begin with a brief synopsis of rec...
2011-01-01
A light charged Higgs boson in two-Higgs doublet model for CDF $Wjj$ anomaly
Motivated by recent anomalous CDF data on $Wjj$ events, we study a possible explanation within the framework of the two-Higgs doublet model. We find that a charged Higgs boson of mass $\\sim$ 140 GeV with appropriate couplings can account for the observed excess. In addition, we consider the flavor-changing neutral current effects induced at loop level by the charged Higgs boson on the $B$ meson system to further constrain the model. Our study shows that the like-sign charge asymmetry $A_{s\\ell}^b$ can be of ${\\cal O}(10^{-3})$ in this scenario.
2011-01-01
A framework for the financial evaluation of household biogas plants in India
Energy Technology Data Exchange (ETDEWEB)
A generalised procedure for quantifying the benefits of household biogas plants is presented. The sensitivity of the procedure to the uncertainty in input prices is reduced through the assumption of incremental benefits from the biogas plant. These benefits are quantified in terms of the quantity of fuelwood for which the biogas substitutes in cooking, the quantity of kerosene replaced through the use of biogas for lighting and the diesel fuel displaced through the use of a biogas fuelled dual-fuel engine for motive power. Sensitivity of the monetary benefits for these parameters is examined in order to identify variables which influence the viability of the technology to the end user. (author).
1990-01-01
A Hamiltonian Formulation of the BKL Conjecture
The Belinskii, Khalatnikov and Lifshitz conjecture \\cite{bkl1} posits that on approach to a space-like singularity in general relativity the dynamics are well approximated by `ignoring spatial derivatives in favor of time derivatives.' In \\cite{ahs1} we examined this idea from within a Hamiltonian framework and provided a new formulation of the conjecture in terms of variables well suited to loop quantum gravity. We now present the details of the analytical part of that investigation. While our motivation came from quantum considerations, thanks to some of its new features, our formulation should be useful also for future analytical and numerical investigations within general relativity.
2011-01-01
A Deflationary Metaphysics of Morality
British Library Electronic Table of Contents (United Kingdom)
The metaphysical dispute between moral realists and antirealists is cast in terms of properties: the realist holds that moral properties exist, the antirealist denies this claim. There is a longstanding philosophical dispute over the nature of properties, and the obscurity of properties may make the realist/antirealist dispute even more obscure. In the spirit of deflationary theories of truth, we can turn to a deflationary theory of properties in order to clarify this issue. One might reasonably worry that such an account of properties would not be capable of properly characterizing disputes regarding the existence or nonexistence of genuine moral properties. In this paper, I will show that, within this framework, the traditional disputes over the existence of moral properties can be chara...
2010-01-01
International Nuclear Information System (INIS)
A new iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P21/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, ?=92.11(1)o, V=879.0(3) A3). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO4) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO4)3(OH)2F2], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic exchange below TN=17 K, consistent with ...
2010-12-01
Report of activity, 1995 - 1996; Rapport d`activite, 1995 - 1996
Energy Technology Data Exchange (ETDEWEB)
This Report of activity displays the work developed at Centre d`Etude Nucleaires de Bordeaux-Gradignan (CENBG) in the period 1995-1996. A number of 68 short progress notes are presented in the fields of Cosmic particles (3), Nuclear Astrophysics (4), High Spins-Large Deformations (8), Basic Interactions (9), Exotic Nuclei (10), Hybrid Systems (4), Theoretical Physics (28), Cellular Microanalysis by means of Nuclear Probes (3) and Technical Development (3). The main problems attacked at CENBG, established as orientations by scientific board of IN2P3 (CENBG is a UMR of Bordeaux-1 Univ. and CNRS-IN2P3) are the following: the research of Majorana/Dirac nature of neutrino (in the framework of NEMO Experiment) in relation with the problem of origin of mass in the Universe and the cosmological puzzle of dark matter, the investigation of the origin of high energy (20 to 200 GeV) cosmic radiation (in the framework of CELESTE Experiment), the study of ...
1997-06-01
Public perceptions of wind energy developments: Case studies from New Zealand
Energy Technology Data Exchange (ETDEWEB)
Although the public generally hold positive attitudes towards wind energy, proposals for the construction of new wind farms are often met with strong resistance. In New Zealand, where the government has recently introduced ambitious policy targets for renewable energy generation, negative perceptions of wind farms are increasingly evident and have the potential to prevent the achievement of these targets. This research sets out to examine what influences social resistance to wind farms in New Zealand. Drawing from public submissions on three wind farm proposals, a framework developed by Devine-Wright [Devine-Wright, P., 2005a. Beyond NIMBYism: towards an integrated Framework for Understanding Public Perceptions of Wind Energy. Wind Energy 8, 125-139.] was used as the basis for identification of factors affecting public perceptions of wind farms. The research found firstly that there was no apparent relationship between the proximity of ...
2009-09-15
Public perceptions of wind energy developments. Case studies from New Zealand
Energy Technology Data Exchange (ETDEWEB)
Although the public generally hold positive attitudes towards wind energy, proposals for the construction of new wind farms are often met with strong resistance. In New Zealand, where the government has recently introduced ambitious policy targets for renewable energy generation, negative perceptions of wind farms are increasingly evident and have the potential to prevent the achievement of these targets. This research sets out to examine what influences social resistance to wind farms in New Zealand. Drawing from public submissions on three wind farm proposals, a framework developed by Devine-Wright [Devine-Wright, P., 2005a. Beyond NIMBYism: towards an integrated Framework for Understanding Public Perceptions of Wind Energy. Wind Energy 8, 125-139.] was used as the basis for identification of factors affecting public perceptions of wind farms. The research found firstly that there was no apparent relationship between the proximity of ...
2009-09-15
Organization and safety in nuclear power plants
International Nuclear Information System (INIS)
Perspectives from industry, academe, and the NRC are brought together in this report and used to develop a logical framework that links management and organization factors and safety in nuclear power plant performance. The framework focuses on intermediate outcomes which can be predicted by organizational and management factors, and which are subsequently linked to safety. The intermediate outcomes are efficiency, compliance, quality, and innovation. The organization and management factors can be classified in terms of environment, context, organizational governance, organizational design, and emergent processes. Initial empirical analyses were conducted on a limited set of hypotheses derived from the framework. One set of hypotheses concerned the relationships between one of the intermediate outcome variables, efficiency, as measured by critical hours and outage rate, and safety, as measured by 5 NRC indicators. Results of ...
Online grocery retailing: What do consumers think?
DEFF Research Database (Denmark)
Purpose: To use the theory of planned behavior (TPB) as a theoretical framework to explore in depth the range of beliefs held by consumers about internet shopping in general and internet grocery shopping in particular. Design/methodology/approach: Seven focus group interviews, four in the United Kingdom and three in Denmark, were conducted among consumers with different degrees of experience with internet grocery shopping. This diversification of respondents was chosen to capture a broad range of the consumer beliefs that predict intentions to buy groceries online or not. The TPB framework was used to construct the interview guide that was followed in all focus groups. Findings: An unexpected result of the explorative study was that the seven groups consisting of more or less experienced internet shoppers differed only little in their pool of beliefs (outcome and control beliefs). Beliefs about internet grocery shopping, positive as well as ...
2005-01-01
A Virtual Engineering Framework for Simulating Advanced Power System
Energy Technology Data Exchange (ETDEWEB)
In this report is described the work effort performed to provide NETL with VE-Suite based Virtual Engineering software and enhanced equipment models to support NETL's Advanced Process Engineering Co-simulation (APECS) framework for advanced power generation systems. Enhancements to the software framework facilitated an important link between APECS and the virtual engineering capabilities provided by VE-Suite (e.g., equipment and process visualization, information assimilation). Model enhancements focused on improving predictions for the performance of entrained flow coal gasifiers and important auxiliary equipment (e.g., Air Separation Units) used in coal gasification systems. In addition, a Reduced Order Model generation tool and software to provide a coupling between APECS/AspenPlus and the GE GateCycle simulation system were developed. CAPE-Open model interfaces were employed where needed. The improved simulation capability is ...
2008-06-18
Energy Technology Data Exchange (ETDEWEB)
(I)Results are given for photoproduction of the D{sup *} at 103 GeV. Clean signals are seen for the decay D{sup *{+-}} {yields} {pi}{sup {+-}}D{sup 0} with the D{sup 0} decaying into both K{sup {-+}}{pi}{sup {+-}} and K{sup {-+}}{pi}{sup {+-}}{pi}{sup 0}. Analysis of the Dalitz plot for the K{pi}{pi} mode gives branching fractions (BFs) for K{sup {minus}}{rho}{sup +}, K{sup *{minus}}{pi}{sup +}, and {anti K}{sup *0}{pi}{sup 0} final states. The BF for D{sup 0} {yields} K{sup {minus}}{rho}{sup +}, much lower than a previous result, is in approximate agreement with the value expected for an l=1/2 final state. (II)Inelastic and elastic J/{psi} photoproduction on H is investigated at 103 GeV. The inelastic cross section with E{sub {psi}}/E{sub {gamma}} {lt} 0.9 is significantly lower than the corresponding result for muoproduction on Fe targets, but consistent with second-order perturbative QCD calculation. The mean p{sub +} of inelastic events is larger than that of elastic events. ...
1984-12-31
Target Diagnostic Instrument-Based Controls Framework for the National Ignition Facility
Energy Technology Data Exchange (ETDEWEB)
NIF target diagnostics are being developed to observe and measure the extreme physics of targets irradiated by the 192-beam laser. The response time of target materials can be on the order of 100ps--the time it takes light to travel 3 cm--temperatures more than 100 times hotter than the surface of the sun, and pressures that exceed 109 atmospheres. Optical and x-ray diagnostics were developed and fielded to observe and record the results of the first 4-beam experiments at NIF. Hard and soft x-ray spectra were measured, and time-integrated and gated x-ray images of hydrodynamics experiments were recorded. Optical diagnostics recorded backscatter from the target, and VISAR laser velocimetry measurements were taken of laser-shocked target surfaces. Additional diagnostics are being developed and commissioned to observe and diagnose ignition implosions, including various neutron and activation diagnostics. NIF's diagnostics are being developed at LLNL and with collaborators at ...
2007-05-07
International Nuclear Information System (INIS)
Due to current social and economical framework, in last years many nuclear power plant owners started a program for the Long Term Operation (LTO)/PLIM (Plant Life Management) of their older nuclear facilities. PLIM/PLEX has already been implemented in many countries (USA, Russia, etc.). This process has many nuclear safety implications, other than strategic and political ones. The need for tailoring the available safety assessment tools to such applications has become urgent in recent years and triggered many research actions. In particular, a PLIM framework requires both a detailed review of the features of the main safety programs (Maintenance, ISI, Surveillance) and a complete integration of these programs into the general management system of the plant. New external factors, such as: large use of subcontractors, need for efficient management of spare parts, request for heavy plant refurbishment programs demand for updated techniques in the ...
2007-10-15
Working with activity theory: Context, technology, and information behavior
British Library Electronic Table of Contents (United Kingdom)
Abstract Over the last 7 years, the AIMTech Research Group in the University of Leeds has used cultural-historical activity theory (CHAT) to inform a range of research activities in the fields of information behavior and information systems. In this article, we identify certain openings and theoretical challenges in the field of information behavior, which sparked our initial interest in CHAT: context, technology, and the link between practice and policy. We demonstrate the relevance of CHAT in studying information behavior and addressing the identified openings and argue that by providing a framework and hierarchy of activity-action-operation and semantic tools, CHAT is able to overcome many of the uncertainties concerning information behavior research. In particular, CHAT provides resear...
2011-01-01
Towards a quantum theory of chiral magnetic effect
We discuss three possible ways to address quantum physics behind chiral magnetic effect and electric charge fluctuation patterns in heavy ion collisions. The first one makes use of P-parity violation probed by local order parameters, the second considers CME in quantum measurement theory framework and the third way is to study P-odd * P-odd contributions to P-even observables. In the latter approach relevant form-factor is extracted and computed for weak magnetic field in confinement region and for free quarks in strong field regime. It is shown that the effect is negligible in the former case. We also discuss saturation effect - charge fluctuation asymmetry for free fermions reaches constant value at asymptotically large fields.
2010-01-01
Total synthesis of solanoeclepin A
British Library Electronic Table of Contents (United Kingdom)
Cyst nematodes are troublesome parasites that live on, and destroy, a range of important host vegetable plants. Damage caused by the potato cyst nematode has now been reported in over 50 countries. One approach to eliminating the problem is to stimulate early hatching of the nematodes, but key hatching stimuli are not naturally available in sufficient quantities to do so. Here, we report the first chemical synthesis of solanoeclepin A, the key hatch-stimulating substance for potato cyst nematode. The crucial steps in our synthesis are an intramolecular cyclization reaction for construction of the highly strained tricyclo[5.2.1.01,6]decane skeleton (DEF ring system) and an intramolecular Diels???Alder reaction of a furan derivative for the synthesis of the ABC carbon framework. The present ...
2011-01-01
The geometry emerging from the symmetries of a quantum system
We investigate the relation between the symmetries of a quantum system and its topological quantum numbers, in a general C*-algebraic framework. We prove that, under suitable assumptions on the symmetry algebra, there exists a generalization of the Bloch-Floquet transform which induces a direct-integral decomposition of the algebra of observables. Such generalized transform selects uniquely the set of "continuous sections" in the direct integral, thus yielding a Hilbert bundle. The emerging geometric structure provides some topological invariants of the quantum system. Two running examples provide an Ariadne's thread through the paper. For the sake of completeness, we review two related theorems by von Neumann and Maurin and compare them with our result.
2009-01-01
The ?Non-cuttable? Space in Between: Context, Boundaries and Their Natural Fluidity
British Library Electronic Table of Contents (United Kingdom)
The inherent open-ended nature of socio-cultural phenomena makes it necessary to create new theoretical frameworks that enable us to understand the fluidity of the relations between different parts of the dynamic system. Recent advance in modern biology seems to provide a set of heuristic concepts useful to investigate the complexity and fluidity of the relationship between different contexts. One of these is the Rayner?s logic of natural inclusionality. According whit Rayner?s evolutionary standpoint any living system is constantly in dialogue with its natural neighbourhood on the basis of an interdependent and co-evolutive process involved both the context and the organism. The aim of this paper is to evaluate the model proposed by Rayner in light of contextual perspective in development...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The article has three sections. The first discusses the environmental problems the tanker traffic poses to the Norwegian coastal waters and shores. Various precautionary measures and requirements are briefly presented. The size of the present marine transportation and the future Russian marine petroleum activity in the Barents area are briefly mentioned. The second named, conflicting exploration drilling, presents the conflicting interests regarding exploratory drilling in the Barents Sea in Norway. The environmental problems are large and have lead to an on-going reevaluation. Some pollution abatement measures are mentioned. The regional economic development is briefly outlined. The third deals with the Norwegian governmental safety activities and presents a brief survey of the official safety activities in the petroleum sector in Norway and the international cooperation particularly with the Russian Federation. The emphasis is on the maritime security, the safety of the maritime ...
2003-07-01
Shallow groundwater nitrogen and denitrification in a newly afforested, subirrigated riparian buffer
British Library Electronic Table of Contents (United Kingdom)
Summary 1. The EU -Nitrates Directive- (Directive 91/676/EEC) and the WFD (Water Framework Directive 2000/60/EEC) introduced a series of measures designed to reduce and prevent water pollution caused or induced by nitrates from agricultural sources. Therefore, there is an urgent requirement to control the nitrate concentration in freshwater. The objective of this paper was to verify the potential capacity of a specifically designed afforested riparian zone in removing the excess of nitrogen from river water. 2. A buffer zone was set with irrigation ditches, to produce a subsurface water flow carrying water from the study river through the buffer strip to drainage ditches. This experimental system enables the co-occurrence of two main processes: vegetation/microbial nitrogen uptake and deni...
2011-01-01
Sequential development of correlated projects: an application to coal liquefaction
Energy Technology Data Exchange (ETDEWEB)
A sequential research and development programme is considered for which several categories of related technologies are available to develop, each having the potential to produce some final product. At each stage of the programme, an optimal portfolio of technologies is chosen given the information acquired from the previous stages, and those contingent optimal plans are followed in all subsequent stages. The model is applied to coal liquefaction technologies to emphasize the costs that may be incurred by erroneously approaching the development programme as a once-and-for-all endeavour rather than in a sequential framework. The results of the synthetic oil application indicate that the acceleration of the programme may be optimal when the probability of successful development decreases. Under these conditions, adoption of a 'crash programme' in which all projects are researched simultaneously, may lead to deferral of synthetic oil development. (13 ...
1983-01-01
British Library Electronic Table of Contents (United Kingdom)
The use of indigenous bacterial root endophytes with biocontrol activity against soil-borne phytopathogens is an environmentally-friendly and ecologically-efficient action within an integrated disease management framework. The earliest steps of olive root colonization by Pseudomonas fluorescens PICF7 and Pseudomonas putida PICP2, effective biocontrol agents (BCAs) against Verticillium wilt of olive (Olea europaea L.) caused by the fungus Verticillium dahliae Kleb., are here described. A gnotobiotic study system using in vitro propagated olive plants, differential fluorescent-protein tagging of bacteria, and confocal laser scanning microscopy analysis have been successfully used to examine olive roots?Pseudomonas spp. interactions at the single-cell level. In vivo simultaneous visualization...
2011-01-01
Risk trade-off linked to temporary storage function in road transports
British Library Electronic Table of Contents (United Kingdom)
Today?s demand on high supply chain performance requires higher awareness about supply chain risks and uncertainty. The purpose of this paper is to analyse the role of temporary storage in the transport network in a supply chain perspective. The primary research question concerns the purpose or role of temporary storage and whether management of temporary storage can contribute to reducing risks and uncertainty in the supply chain. The research is based on a system-theoretical approach, which emphasizes a holistic view instead of the characteristics of the different parts. The research method used in this paper is abductive. Existing theories are used to formulate a framework which leads to a conceptual model description of the temporary storage function. This model is then supported and v...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Research on and with ethnic minority students is characterised by a growing international literature that privileges 'liberal multiculturalism' as a lens through which to understand their experiences, yet ethnic diversity is constructed and responded to in many societies that are not underpinned by liberal democratic values. In this paper we use Joppke's binary to show how researching ethnic minority students outside of a liberal democratic framework requires methodologies that enable researchers to see beyond the invisibility that is often attached to ethnic minorities. We show how invisibility (i.e. antidiscrimination) can also be further culturally constructed, confounding even more any broader multicultural project. We canvass four broad areas including the role of legally binding legi...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
Simple frameworks have been developed for estimating the utilization potential of: (a) solar photovoltaic (SPV) pumps; (b) windmill pumps; (c) producer gas based dual fuel engine pumps; and (d) biogas based dual fuel engine pumps for irrigation water pumping in India. The approach takes into account factors such as: solar radiation intensity, wind speed, availability of bovine dung and agri-residues, and their alternative uses, ground water requirements for irrigation and its availability, affordability, and propensity of the users to invest in renewable energy devices, etc. SPV pumps are estimated to have the maximum utilization potential in India, followed by windmill pumps. (author)
2007-05-15
Reliability-based robustness analysis for a Croatian sports hall
British Library Electronic Table of Contents (United Kingdom)
This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.
2011-01-01
Regulation of naturally occurring radioactive materials in Australia
British Library Electronic Table of Contents (United Kingdom)
In order to promote uniformity between jurisdictions, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has developed the National Directory for Radiation Protection, which is a regulatory framework that all Australian governments have agreed to adopt. There is a large and diverse range of industries involved in mining or mineral processing, and the production of fossil fuels in Australia. Enhanced levels of naturally occurring radionuclides can be associated with mineral extraction and processing, other industries (e.g. metal recycling) and some products (e.g. plasterboard). ARPANSA, in conjunction with industry and State regulators, has undertaken a review and assessment of naturally occurring radioactive material (NORM) management in Australian industries. This rev...
2011-01-01
Reducing barriers to energy efficiency in the German higher education sector. Final report
Energy Technology Data Exchange (ETDEWEB)
This report describes the empirical research into barriers to energy efficiency in the German higher education (HE) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of six case studies of energy management in German universities. The results are analysed using the theoretical framework developed for the BARRIERS project (Sorrell et al., 2000). The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the sector may be improved. The results of the study for the higher education sector in Germany are summarised in this executive summary under the following headings: - Characterising the higher education sector; - Case studies of energy management in the German higher education sector; - Evidence of barriers in the German higher education sector; - The role of energy service companies in the higher education ...
2000-12-01
Quantum probabilities: an information-theoretic interpretation
This Chapter develops a realist information-theoretic interpretation of the nonclassical features of quantum probabilities. On this view, what is fundamental in the transition from classical to quantum physics is the recognition that \\emph{information in the physical sense has new structural features}, just as the transition from classical to relativistic physics rests on the recognition that space-time is structurally different than we thought. Hilbert space, the event space of quantum systems, is interpreted as a kinematic (i.e., pre-dynamic) framework for an indeterministic physics, in the sense that the geometric structure of Hilbert space imposes objective probabilistic or information-theoretic constraints on correlations between events, just as the geometric structure of Minkowski space in special relativity imposes spatio-temporal kinematic constraints on events. The interpretation of quantum probabilities is more subjectivist in spirit than other ...
2010-01-01
Proposed roadmap for overcoming legal and financial obstacles to carbon capture and sequestration
Energy Technology Data Exchange (ETDEWEB)
Many existing proposals either lack sufficient concreteness to make carbon capture and geological sequestration (CCGS) operational or fail to focus on a comprehensive, long term framework for its regulation, thus failing to account adequately for the urgency of the issue, the need to develop immediate experience with large scale demonstration projects, or the financial and other incentives required to launch early demonstration projects. We aim to help fill this void by proposing a roadmap to commercial deployment of CCGS in the United States.This roadmap focuses on the legal and financial incentives necessary for rapid demonstration of geological sequestration in the absence of national restrictions on CO2 emissions. It weaves together existing federal programs and financing opportunities into a set of recommendations for achieving commercial viability of geological sequestration.
2009-03-01
Energy Technology Data Exchange (ETDEWEB)
The author investigates whether the international law regime so far has developed any legal principles dealing with the problem of the dumping of radioactive waste in the sub-seabed, and whether any of such provisions available adequately tackle the problem in the light of the gravity of danger emanating from radioactive waste. The study covers over 30 different texts of international treaties and protocols. Points of main interest are the London Dumping Convention and the Montego Bay Convention on the Law of the Sea. The author concludes that the disposal of radioactive waste into the seabed belongs to the permissible, although not specially allowed activities within the framework of the freedom of the high seas, and therefore urgently calls for establishing an international regulatory system pertaining to the planning and accomplishment of such activities. An outline legal concept of a regulatory system is explained. (orig./HSCH).
1986-01-01
Numerical modeling of a Global Navigation Satellite System in a general relativistic framework
In this article we model a Global Navigation Satellite System (GNSS) in a Schwarzschild space-time, as a first approximation of the relativistic geometry around the Earth. The closed time-like and scattering light-like geodesics are obtained analytically, describing respectively trajectories of satellites and electromagnetic signals. We implement an algorithm to calculate Schwarzschild coordinates of a GNSS user who receives proper times sent by four satellites, knowing their orbital parameters; the inverse procedure is implemented to check for consistency. The constellation of satellites therefore realizes a geocentric inertial reference system with no \\emph{a priori} realization of a terrestrial reference frame. We show that the calculation is very fast and could be implemented in a real GNSS, as an alternative to usual post-Newtonian corrections. Effects of non-gravitational perturbations on positioning errors are assessed, and methods to reduce them are sketched. In particular, ...
2010-01-01
This essay aims to summarize the main physical features arising from a new supersymmetric theory of gravitation. Based on preliminary discussions about classical field theory, cosmology, algebra and group theory, and taking formal results and theoretical considerations in comparison with several contributions from great authors, present work deals with gravity inside the limits of a meta-field theory, that is, a non-quantized but consistent representation of supergravity, the supersymmetry between gravitons and gravitinos. The introduction of meta-fields furnishes an independent framework for the study of gravity despite of constraints of quantization, treating the supersymmetric partners as deterministic actors of gravitation and not simply probabilistic entities. I explain my belief that gravitational field, by its own nature, is not quantizable in the same foot as the other fields, what does not means that we can not understand gravity by similar formal veins. ...
2011-01-01
Neutrino tagging through secondary beam scraping
We discuss an experimental technique aimed at tagging electron neutrinos in multi-GeV artificial sources on an event-by-event basis. It exploits in a novel manner calorimetric and tracking technologies developed in the framework of the LHC experiments and of rare kaon decay searches. The setup is based on an instrumented decay tunnel equipped with tagging units that intercept secondary and tertiary leptons from the bulk of undecayed pi+ and protons. We show that the taggers are able to reduce the nue contamination originating from K_e3 decays by about one order of magnitude. Only a limited suppression (~60%) is achieved for nue produced by the decay-in-flight of muons; for moderate beam powers, similar performance as for K_e3 can be reached supplementing the tagging system with an instrumented beam dump.
2010-01-01
Network Security Mechanisms Utilizing Dynamic Network Address Translation LDRD Project
A new protocol technology is just starting to emerge from the laboratory environment. Its stated purpose is to provide an additional means in which networks, and the services that reside on them, can be protected from adversarial compromise. This report has a two-fold objective. First is to provide the reader with an overview of this emerging Dynamic Defenses technology using Dynamic Network Address Translation (Dynat). This ''structure overview'' is concentrated in the body of the report, and describes the important attributes of the technology. The second objective is to provide a framework that can be used to help in the classification and assessment of the different types of dynamic defense technologies along with some related capabilities and limitations. This information is primarily contained in the appendices.
2002-11-01
International Nuclear Information System (INIS)
The MCNPE-BO and MCNP4 Monte Carlo electron-photon codes were used to calculate the dose equivalent per unit fluence at various depths in tissue-equivalent slab phantoms for broad parallel beams of monoenergetic electrons with energies from 50 keV to 10 MeV. The study was carried out in the framework of the activities of a ICRP/ICRU Joint Task Group with the support of EURADOS WG4 (Numerical Dosimetry). Some preliminary results and comparisons as well as a general discussion on the performances of the codes are presented, demonstrating quite a satisfactory agreement among the results obtained using the two codes and those of other authors. (author).
Magnetic properties of ErPd_2Si_2 from magnetization Moessbauer and neutron diffraction measurements
International Nuclear Information System (INIS)
Magnetization, neutron diffraction and "1"6"6Er Moessbauer measurements on ErPd_2Si_2 are reported. Below 4.8 K ErPd_2Si_2 orders AF with complex modulated magnetic structures, where the Er moments are aligned along the c-axis. At 1.5 K a squared structure with #mu#_E_r #approx# 7.8(1)#mu#_B is found while a saturation Er moment of 8.2(2)#mu#_B is inferred from the hyperfine field data. The temperature dependence of the Moessbauer spectra in the paramagnetic region is explained in the framework of a relaxation model implying excited crystal field levels. Its analysis is used to estimate the B"m_n CEF parameters. (orig.).
Machine condition monitoring - the way ahead
Energy Technology Data Exchange (ETDEWEB)
During the last fifteen years a variety of instruments and transducers, such as voltage plugs, power transducers, flow and pressure transducers, recorders and tensometers, have been developed for underground use in measuring the performance and technical parameters of prototype machines. The equipment, until recently, has been in a portable form and was found useful by the industry generally, in fault finding and trouble-shooting exercises and in commissioning procedures performed by small teams on a call-out basis. Over the last five years the test equipment has been adapted and the techniques modified to suit individual colliery-based operations with more permanent machine mounted and built-in transducers. At the moment these techniques operate within the framework of a statutory planned preventive maintenance scheme for each mine. This paper discusses the merits of changing from preventive maintenance to condition-based maintenance and the practical steps being ...
1984-11-01
Insights into the ASME PRA Standard-based Quality Evaluation on the Existing KSNP LERF Model
Energy Technology Data Exchange (ETDEWEB)
The current Risk-informed Regulation (RIR) framework employs both a Level 1 Core Damage Frequency (CDF) and a Level 2 Large Early Release Frequency (LERF) as two surrogate measures for the plant risk. For their use in making regulatory decisions for the plant risk, it has been required to maintain an appropriate level of quality for the plant risk models. The first step for this purpose is to evaluate the quality of the PSA model in a qualitative or quantitative manner. Recently, a similar type of quality evaluation has been made for the KSNP Level 1 PSA model based on an ASME PRA Standard for the RIR application, but not for the corresponding LERF model. The main objective of this paper is to provide the ASME PRA Standard-based evaluation result for the existing KSNP Level 2 LERF model and the insights obtained from the evaluation process.
2005-07-01
Insights into the ASME PRA Standard-based Quality Evaluation on the Existing KSNP LERF Model
International Nuclear Information System (INIS)
The current Risk-informed Regulation (RIR) framework employs both a Level 1 Core Damage Frequency (CDF) and a Level 2 Large Early Release Frequency (LERF) as two surrogate measures for the plant risk. For their use in making regulatory decisions for the plant risk, it has been required to maintain an appropriate level of quality for the plant risk models. The first step for this purpose is to evaluate the quality of the PSA model in a qualitative or quantitative manner. Recently, a similar type of quality evaluation has been made for the KSNP Level 1 PSA model based on an ASME PRA Standard for the RIR application, but not for the corresponding LERF model. The main objective of this paper is to provide the ASME PRA Standard-based evaluation result for the existing KSNP Level 2 LERF model and the insights obtained from the evaluation process
2005-10-27
Hydrodynamics induced vibration to trash-racks
International Nuclear Information System (INIS)
In conventional power plants trash-racks are provided at the intakes to protect the turbines. In pumped storage plants, the draft tube or tailrace must also have trash-racks to protect the units while pumping. Because the loads believed to cause many failures of trash-racks are dynamic in nature, it is important to understand the dynamic characteristics of trash-racks structures in general and a single rack in particular. The classical added-mass solution structure-fluid dynamic interaction is known as an approximate solution procedure. An accurate added-mass approach mixed with implementation in finite element framework is proposed. In this proposal, experimental conclusions, supported by theory, led to presentation of more accurate results in vibration of trash-racks. This numerical solution as a powerful method to solve such a complex problem can be employed to carry out dynamic characteristics of these structures while vibrating in water.
2002-12-01
Energy Technology Data Exchange (ETDEWEB)
Consultant and advanced practice are relatively new concepts in radiography. There is evidence to show that as the career progression framework is being adopted the numbers of consultant and advanced practitioners in radiography are growing with the latter growing at a faster rate. The article considers the concept of advanced and consultant practice and the education requirements to support development. Preparation for an advanced practice role begins at the practitioner stage. Masters' level programmes are available to support the development of advanced practice. Education needs to be flexible as new advanced practice roles emerge. It is necessary to take practitioners beyond a defined modality to include leadership and people skills. These are essential for those aspiring to become consultants. Consultants require a high level of clinical knowledge for expert practice but also strategic vision and interpersonal intelligence to facilitate leadership and ...
2008-12-15
From Whitney Forms to Metamaterials: a Rigorous Homogenization Theory
A rigorous homogenization theory of metamaterials -- artificial periodic structures judiciously designed to control the propagation of electromagnetic waves -- is developed. All coarse-grained fields are unambiguously defined and effective parameters are then derived without any heuristic assumptions. The theory is an amalgamation of two concepts: Smith & Pendry's physical insight into field averaging and the mathematical framework of Whitney-Nedelec-Bossavit-Kotiuga interpolation. All coarse-grained fields are defined via Whitney forms and satisfy Maxwell's equations exactly. The new approach is illustrated with several analytical and numerical examples and agrees well with the established results (e.g. the Maxwell-Garnett formula and the zero cell-size limit) within the range of applicability of the latter. The sources of approximation error and the respective suitable error indicators are clearly identified, along with systematic routes for improving the ...
2010-01-01
Financial evaluation of renewable energy technologies for irrigation water pumping in India
International Nuclear Information System (INIS)
An attempt to develop a simple framework for financial evaluation of renewable energy technologies (RETs) such as photovoltaic (PV) pump, windmill pump, biogas and producer gas-driven dual fuel engine pumps for irrigation water pumping has been made. The unit cost of water and unit cost of useful energy delivered by the RETs have been estimated. The monetary benefits that accrued to the end-user have been quantified in terms of the amount of diesel or electricity saved. Financial figures of merit for the investments made in the RETs have been estimated. The effect of fuel price escalation on these measures of financial performance has also been evaluated along with the estimation of the break-even prices of fuels likely to be substituted by RETs. Results of some exemplifying calculations are presented and briefly discussed.
2007-06-01
Energy Technology Data Exchange (ETDEWEB)
This book is mainly a comparison of the cost of pollution with the cost of environmental protection. As to the causes of pollution, a difference is made between pollutants that accumulate and pollutants that do not accumulate. Because of pollutant accumulation it is necessary to carry out both subsequent pollution abatement measures and to take preventive action which helps to avoid pollutant emission. Growth models serve to substantiate why such preventive action is both ecologically and economically useful as a rule. Finally the study makes a comparison between some tools of environmental protection. It stresses in particular that, if a duty on emissions is levied, the polluter has to bear all the cost of the pollution, while at the same time the quality of the environment can be more successfully improved than by emission standards alone.
1986-01-01
Embodied energy and emergy evaluation of a typical biodiesel production chain in China
British Library Electronic Table of Contents (United Kingdom)
Biodiesel from non-grain feedstock has been considered as one of the proper substitutes for fossil fuels associated with a series of activities emerging in China in order to meet the resource shortage and develop the energy crops. This paper presents an ecological accounting framework based on embodied energy, emergy, and CO2 emission for the whole production chain of biodiesel made from Jatropha curcas L. (JCL) oil. The energy and materials invested in and CO2 emission from the whole process, including cropping, transportation, extraction, and production, are accounted and calculated. Also, EmCO2, the ratio of real CO2 released to the emergy-based sustainability indicator per joule biodiesel, is proposed in this paper to present a new goal function for low-carbon system optimization. Fina...
2011-01-01
International Nuclear Information System (INIS)
The absorption spectra of an unoriented single crystal of the title compound (1) have been measured at room and at low temperatures. Assuming a similar sequence of crystal field (CF) levels as for the previously analyzed Nd[N(SiMe_3)_2]_3 (2) a truncated CF splitting pattern is derived from the spectra obtained. The parameters of an empirical Hamiltonian are fitted to the energies of 71 levels to give an r.m.s. deviation of 24.2 cm"-"1. The parameters obtained are compared with those of 2 and Nd[N(SiMe_3)_2]_3(CNC_6H_1_1)_2 (3). The observed trends of CF parameters are consistent with the results of simple model calculations in the framework of the angular overlap model. (orig.)
1998-07-24
Energy Technology Data Exchange (ETDEWEB)
Incomplete convergence in numerical simulation such as computational physics simulations and/or Monte Carlo simulations can enter into the calculation of the objective function in an optimization problem, producing noise, bias, and topo- graphical inaccuracy in the objective function. These affect accuracy and convergence rate in the optimization problem. This paper is concerned with global searching of a diverse parameter space, graduating to accelerated local convergence to a (hopefully) global optimum, in a framework that acknowledges convergence uncertainty and manages model resolu- tion to efficiently reduce uncertainty in the final optimum. In its own right, the global-to-local optimization engine employed here (devised for noise tolerance) performs better than other classical and contemporary optimization approaches tried individually and in combination on the "industrial" test problem to be presented.
1999-05-18
A new mathematical framework is formulated to derive the effective equations of motion for the constrained quantum system which possesses an internal clock. In the realm close to classical behavior, the quantum evolution is approximated by a finite system of coupled but ordinary differential equations adhered to the weakly imposed Hamiltonian constraint. For the simplified version of loop quantum cosmology in the Bianchi I model with a free massless scalar filed, the resulting effective equations of motion affirm the bouncing scenario predicted by the previous studies: The big bang singularity is resolved and replaced by the big bounces, which take place up to three times, once in each diagonal direction, whenever the directional density approaches the critical value in the regime of Planckian density. It is also revealed that back-reaction arises from the quantum corrections and modifies the precise value of the directional density at the bouncing epoch. ...
2008-01-01
Did Lobachevsky Have A Model Of His "imaginary Geometry"?
The invention of non-Euclidean geometries is often seen through the optics of Hilbertian formal axiomatic method developed later in the 19th century. However such an anachronistic approach fails to provide a sound reading of Lobachevsky's geometrical works. Although the modern notion of model of a given theory has a counterpart in Lobachevsky's writings its role in Lobachevsky's geometrical theory turns to be very unusual. Lobachevsky doesn't consider various models of Hyperbolic geometry, as the modern reader would expect, but uses a non-standard model of Euclidean plane (as a particular surface in the Hyperbolic 3-space). In this paper I consider this Lobachevsky's construction, and show how it can be better analyzed within an alternative non-Hilbertian foundational framework, which relates the history of geometry of the 19th century to some recent developments in the ?eld.
2010-01-01
Demand Analysis with Partial Predicates
In order to alleviate the inefficiencies caused by the interaction of the logic and functional sides, integrated languages may take advantage of \\emph{demand} information -- i.e. knowing in advance which computations are needed and, to which extent, in a particular context. This work studies \\emph{demand analysis} -- which is closely related to \\emph{backwards strictness analysis} -- in a semantic framework of \\emph{partial predicates}, which in turn are constructive realizations of ideals in a domain. This will allow us to give a concise, unified presentation of demand analysis, to relate it to other analyses based on abstract interpretation or strictness logics, some hints for the implementation, and, more important, to prove the soundness of our analysis based on \\emph{demand equations}. There are also some innovative results. One of them is that a set constraint-based analysis has been derived in a stepwise manner using ideas taken from the area of program ...
2006-01-01
British Library Electronic Table of Contents (United Kingdom)
Summary Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act required the US Environmental Protection Agency to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures of chemicals to elucidate mechanisms of joint action at the systemic level with the goal of providing a framework for assessing the cumulative effects of reproductive toxicants. Previous mixture studies conducted with antiandrogenic chemicals are reviewed briefly and two new studies are described. In all binary mixture studies, rats were dosed during pregnancy with chemicals, singly or in pairs, at dosage levels equivalent to approximately one-half of the ED50 for hypospadias or e...
2010-01-01
Conformity, political participation, and economic rewards: The case of Chinese private entrepreneurs
British Library Electronic Table of Contents (United Kingdom)
Using institutional and resource dependence theories as the conceptual framework, this study identifies three forms of conformity?political, economic, and social?that can affect the level of private entrepreneurs? formal political participation in a transition economy. Data from a 2004 national-wide survey of 3,012 private firms in China show that political conformity (indicated by membership in the ruling party), economic conformity (amount of taxes paid), and social conformity (amount of charity donated) are each antecedents to private entrepreneurs? formal political participation. Moreover, political conformity negatively moderates the relationship between social conformity and private entrepreneurs? formal political participation?for party members, a lesser amount of charity is associa...
2011-01-01
Comparative planetology, climatology and biology of Venus, Earth and Mars
British Library Electronic Table of Contents (United Kingdom)
Spacecraft studies of the three terrestrial planets with atmospheres have made it possible to make meaningful comparisons that shed light on their common origin and divergent evolutionary paths. Early in their histories, all three apparently had oceans and extensive volcanism; Mars and Earth, at least, had magnetic fields, and Earth, at least, had life. All three currently have climates determined by energy balance relationships involving carbon dioxide, water and aerosols, regulated by solar energy deposition, atmospheric and ocean circulation, composition, and cloud physics and chemistry. This paper addresses the extent to which current knowledge allows us to explain the observed state of each planet, its planetology, climatology and biology, within a common framework. Areas of ignorance...
2011-01-01
International Nuclear Information System (INIS)
Measurements of absolute differential cross sections for H"+-H_2 direct, single-, and double-charge-transfer scattering at 0.5, 1.5, and 5.0 keV are reported at laboratory scattering angles less than 1 degree with an angular resolution of approximately 0.02 degree. The cross sections exhibit deep interference oscillations in single-charge-transfer scattering, but no such oscillations are present in direct and double-charge-transfer scattering. Theoretical cross sections derived using the diatoms-in-molecules method to describe the molecular states in a semiclassical molecular-orbital three-state close-coupling model within a semiclassical framework agree satisfactorily with the experimental results.
Australian experience with herbicide tolerant (HT) and Bacillus thuringiensis (Bt) cotton
British Library Electronic Table of Contents (United Kingdom)
Australia?s nationally consistent framework for gene technology regulation is underpinned by the Gene Technology Act 2000, administered by an independent decision-maker, the Gene Technology Regulator. The object of the Act is ?to protect the health and safety of people, and to protect the environment, by identifying risks posed by or as a result of gene technology, and by managing those risks through regulating certain dealings with genetically modified organisms?. Marketing and trade impacts are outside the scope of assessments required by the Act. Since 2001, seven licences have been issued for the commercial cultivation of genetically modified (GM) cotton with insect resistance and/or herbicide tolerance. Licences have also been issued for 32 GM cotton field trials with a broader range ...
2011-01-01
An historical view of the pineal gland and mental disorders
British Library Electronic Table of Contents (United Kingdom)
Since Classical Antiquity numerous authors have linked the origin of some mental disorders to physical and functional changes in the pineal gland because of its attributed role in humans as the connection between the material and the spiritual world. The pineal organ was seen as a valve-like structure that regulated the flow of animal spirits through the ventricular system, a hypothesis that took on more vigour during the Middle Ages and the Renaissance. The framework for this theory was ''the three cells of the brain'', in which the pineal gland was even called the ''appendix of thought''. The pineal gland could also be associated with the boom, during this period, of certain legends about the ''stone of folly''. But the most relevant psychopathological role of this organ arrived with Des...
2011-01-01
Advanced Monitoring and Control of Multi monomer System in Emulsion Polymerization
British Library Electronic Table of Contents (United Kingdom)
Abstract A control framework was developed for real time implementation of optimal control of emulsion polymerization with multiple monomers by integrating model based algorithms with software engines. The developed system was applied for controlling conversion, particle size, molar mass, and polymer composition using model predictive control (MPC) based on mechanistic models for emulsion polymerization. The control formulation was extended to account for existing process constraints on the input, input moves, and solids content. On experimental testing, the developed control scheme was found to achieve the desired objectives without violating the process constraints and showed good robustness in rejecting disturbances. Improvements in the process operation and polymer property control wer...
2010-01-01
Adaptive Waveform Correlation Detectors for Arrays: Algorithms for Autonomous Calibration
Energy Technology Data Exchange (ETDEWEB)
Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the individual channel correlation traces to achieve significant array gain. In previous ...
2009-07-23
Ab initio relativistic many-body calculation of hyperfine splitting of ^{113}Cd^+
This work presents accurate ab initio determination of the hyperfine splitting for the ground state and few low-lying excited states of 113Cd+; important candidates for the frequency standard in the microwave region, using coupled-cluster theory (CC) in the relativistic framework. The calculated hyperfine splitting are well in agreement with recent experimental results. We have also carried out the lifetimes of the 5p2P1=2 and 5p2P3=2 states, which are in well agreement with recent experimental result (Moehring et al., PRA 73 023413, 2006). The roles of different electron correlation effects in the determination of these quantities are discussed and their contributions are presented in the CC terms.
2007-01-01
A unified framework for biological evolution and stochastic quantization
We investigate the profound relation between the equations of biological evolution and quantum mechanics by writing a biologically inspired equation for the stochastic dynamics of an ensemble of particles. Interesting behavior is observed which is related to a new type of stochastic quantization. We find that the probability distribution of the ensemble of particles can be decomposed into eigenfunctions associated to a discrete spectrum of eigenvalues. In absence of interactions between the particles, the out-of-equilibrium dynamics asymptotically relaxes towards the fundamental state. This phenomenon can be related with the Fisher theorem in biology. On the contrary, in presence of scattering processes the evolution reaches a steady state in which the distribution of the ensemble of particles is characterized by a Bose-Einstein statistics. In order to show a concrete example of this stochastic quantization we have solved explicitly the case in which the potential energy has the ...
2010-01-01
A study of the Teachers` Academy for Mathematics and Science
Energy Technology Data Exchange (ETDEWEB)
The Teachers` Academy for Mathematics and Science in Chicago (TAMS) is a freestanding institution founded in 1989 by scientists and a variety of other stakeholders, to advance the systemic reform of mathematics and science education in Chicago`s public schools. It focuses on the ``re-tooling`` of its elementary level teachers. The TAMS program, which has been funded in part by the DOE, contributes to strategic goals two through five of the Office of University and Science Education (OUSE). This evaluation of TAMS by the National Center for Improving Science Education is primarily a qualitative study that summarizes the history and current status of the organization and its programs. Data was obtained through extensive interviews, observations, and document review, using a framework of templates to guide data collection and analyses. The findings are organized around a series of lessons learned from the first three years of TAMS and conclusions about its current ...
1994-09-15
We introduce a new formulation of asset trading games in continuous time in the framework of the game-theoretic probability established by Shafer and Vovk (2001). In our formulation, the market moves continuously but an investor trades in discrete times, which can depend on the past path of the market. We prove that an investor can essentially force that the asset price path behaves with the variation exponent exactly equal to two. Our proof is based on embedding high-frequency discrete time games into the continuous time game and the use of the Bayesian strategy of Kumon, Takemura and Takeuchi (2007b) for discrete time coin-tossing games. We also clarify that the main growth part of the investor's capital processes is lucidly described by the information quantities, which are derived from the Kullback-Leibler information with respect to the empirical fluctuation of the asset price.
2007-01-01
A neutrino-nucleon interaction generator for the FLUKA Monte Carlo code
Event generators that handle neutrino-nucleon interaction have been developed for the FLUKA code [1]. In earlier FLUKA versions only quasi-elastic (QEL) interactions were included, and the code relied on external event generators for the resonance (RES) and deep inelastic scattering (DIS). The new DIS+RES event generator is fully integrated in FLUKA and uses the same hadronization routines as those used for simulating hadron-nucleon interactions. Nuclear effects in neutrino-nucleus interactions are simulated within the same framework as in the FLUKA hadron-nucleus interaction model (PEANUT), thus profiting from its detailed physics modelling and longstanding benchmarking. The generators are available in the standard FLUKA distribution. They are presently under development and several improvements are planned to be implemented. The physics relevant to the neutrino-nucleon interactions and the results of comparisons with experimental data are discussed.
2010-01-01
A complete census of AGN and their hosts from optical surveys?
Large optical surveys provide an unprecedented census of galaxies in the local Universe, forming an invaluable framework into which more detailed studies of objects can be placed. But how useful are optical surveys for understanding the co-evolution of black holes and galaxies, given their limited wavelength coverage, selection criteria, and depth? In this conference paper I present work-in-progress comparing optical and mid-IR diagnostics of three "unusual" low redshift populations (luminous Seyferts, dusty Balmer-strong AGN, ULIRGs) with a set of ordinary star-forming galaxies from the SDSS. I address the questions: How well do the mid-infrared and optical diagnostics of star formation and AGN strength agree? To what extent do optical surveys allow us to include extreme, dusty, morphologically disturbed galaxies in our "complete" census of black hole-galaxy co-evolution?
2010-01-01
A New Spin Foam Model for 4d Gravity
Starting from the Plebanski formulation of gravity as a constrained BF theory we propose a new spin foam model for 4d Riemmanian quantum gravity that generalises the well-known model of Barrett-Crane and resolves the ultralocality problem that this model is known to possess. It is well known that the BF formulation of 4d gravity possesses two sectors: one corresponding to gravity and the other topological. The model presented here is shown to give a quantisation of the gravitational sector. The present model is dual to the recently proposed spin foam model of Engle et al. which, we show, corresponds to the topological sector of the theory. One important outcome of our approach is that it also allow us to introduce the Immirzi parameter into the framework of spin foam quantisation. We generalize some of our considerations to the Lorentzian setting and obtain a new spin foam model in that context as well.
2007-01-01
A Network Coding Approach to Loss Tomography
Network tomography aims at inferring internal network characteristics based on measurements at the edge of the network. In loss tomography, in particular, the characteristic of interest is the loss rate of individual links. There is a significant body of work dedicated to this problem using multicast and/or unicast end-to-end probes. Independently, recent advances in network coding have shown that there are several advantages from allowing intermediate nodes to process and combine, in addition to just forward, packets. In this paper, we pose the problem of loss tomography in networks that have network coding capabilities. We design a framework for estimating link loss rates, which leverages network coding capabilities and we show that it improves several aspects of tomography, including the identifiability of links, the tradeoff between estimation accuracy and bandwidth efficiency, and the complexity of probe path selection. We discuss the cases of inferring: the ...
2010-01-01
A Bayesian approach to analyze energy balance data from lactating dairy cows
British Library Electronic Table of Contents (United Kingdom)
The objective of the present investigation was to develop a Bayesian framework for updating and integrating covariate information into key parameters of metabolizable energy (ME) systems for dairy cows. The study addressed specifically the effects of genetic improvements and feed quality on key parameters in current ME systems. These are net and metabolizable energy for maintenance (NEM and MEM, respectively), efficiency of utilization of ME for milk production (kL) and growth (kG), and efficiency of utilization of body stores for milk production (kT). Data were collated from 38 studies, yielding 701 individual cow observations on milk energy, ME intake, and tissue gain and loss. A function based on a linear relationship between milk energy and ME intake and correcting for tissue energy lo...
2011-01-01
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