Reconsidering Schwarzschild's original solution
Antoci, S; Liebscher, D. -E.
2001-01-01
We analyse the Schwarzschild solution in the context of the historical development of its present use, and explain the invariant definition of a singular surface at the Schwarzschild's radius, that can be applied to the Kerr-Newman solution too.
Analytical Solution Of Complete Schwarzschild\\'s Planetary Equation
African Journals Online (AJOL)
It is well known how to solve the Einstein\\'s planetary equation of motion by the method of successive approximation for the corresponding orbit solution. In this paper, we solve the complete schwarzschild\\'s planetary equation of motion by an exact analytical method. The result reveals that there are actually eight exact ...
The Schwarzschild solution in the DGP model
Middleton, Chad; Siopsis, George
2003-01-01
We discuss the Schwarzschild solution in the Dvali-Gabadadze-Porrati (DGP) model. We obtain a perturbative expansion and find the explicit form of the lowest-order contribution. By keeping off-diagonal terms in the metric, we arrive at a perturbative expansion which is valid both far from and near the Schwarzschild radius. We calculate the lowest-order contribution explicitly and obtain the form of the metric both on the brane and in the bulk. As we approach the Schwarzschild radius, the pert...
On Quantum Deformation of the Schwarzschild Solution
Kazakov, D.I.; Solodukhin, S. N.
1993-01-01
We consider the deformation of the Schwarzschild solution in general relativity due to spherically symmetric quantum fluctuations of the metric and the matter fields. In this case, the 4D theory of gravity with Einstein action reduces to the effective two-dimensional dilaton gravity. We have found that the Schwarzschild singularity at $r=0$ is shifted to the finite radius $r_{min} \\sim r_{Pl}$, where the scalar curvature is finite, so that the space-time looks regular and consists of two asym...
The solution of complete Schwarzschild's planetary equation with ...
African Journals Online (AJOL)
The Einstein's solution of the planetary equation of motion from Schwarzschild's line element is well known. In this paper, we solve the complete Schwarzschild's planetary equation with the method of successive approximation for the corresponding precession and compare the result with that from the line element.
On analytic solutions of wave equations in regular coordinate systems on Schwarzschild background
Philipp, Dennis
2015-01-01
The propagation of (massless) scalar, electromagnetic and gravitational waves on fixed Schwarzschild background spacetime is described by the general time-dependent Regge-Wheeler equation. We transform this wave equation to usual Schwarzschild, Eddington-Finkelstein, Painleve-Gullstrand and Kruskal-Szekeres coordinates. In the first three cases, but not in the last one, it is possible to separate a harmonic time-dependence. Then the resulting radial equations belong to the class of confluent Heun equations, i.e., we can identify one irregular and two regular singularities. Using the generalized Riemann scheme we collect properties of all the singular points and construct analytic (local) solutions in terms of the standard confluent Heun function HeunC, Frobenius and asymptotic Thome series. We study the Eddington-Finkelstein case in detail and obtain a solution that is regular at the black hole horizon. This solution satisfies causal boundary conditions, i.e., it describes purely ingoing radiation at $r=2M$. ...
Zou, Li; Li, Fang-Yu; Li, Tao
2014-11-01
In this paper, we first deduce the Tolman-Oppenheimer-Volkoff (TOV) equations and Schwarzschild-de Sitter (SdS) constant-density interior solutions of perfect fluid spheres in hydrostatic equilibrium by the Einstein equations with a nonzero cosmological constant. The TOV equations and the spacetime properties of exact solutions inside uniform perfect fluid spheres with different spatial curvature and cosmological constants will be respectively analyzed in detail. Moreover, a brief comparison between the internal static solutions of the SdS type and the dynamical Einstein-Strauss-de Sitter (ESdS) vacuole spacetime is obtained.
Averaging Schwarzschild spacetime
Tegai, S. Ph.; Drobov, I. V.
2017-07-01
We tried to average the Schwarzschild solution for the gravitational point source by analogy with the same problem in Newtonian gravity or electrostatics. We expected to get a similar result, consisting of two parts: the smoothed interior part being a sphere filled with some matter content and an empty exterior part described by the original solution. We considered several variants of generally covariant averaging schemes. The averaging of the connection in the spirit of Zalaletdinov's macroscopic gravity gave unsatisfactory results. With the transport operators proposed in the literature it did not give the expected Schwarzschild solution in the exterior part of the averaged spacetime. We were able to construct a transport operator that preserves the Newtonian analogy for the outward region but such an operator does not have a clear geometrical meaning. In contrast, using the curvature as the primary averaged object instead of the connection does give the desired result for the exterior part of the problem in a fine way. However for the interior part, this curvature averaging does not work because the Schwarzschild curvature components diverge as 1 /r3 near the center and therefore are not integrable.
The Lemaitre-Schwarzschild problem revisited
Fuzfa, A.; Gérard, Jean-Marc; Lambert, Didier
2001-01-01
The Lemaitre and Schwarzschild analytical solutions for a relativistic spherical body of constant density are linked together through the use of the Weyl quadratic invariant. The critical radius for gravitational collapse of an incompressible fluid is shown to vary continuously from 9/8 of the Schwarzschild radius to the Schwarzschild radius itself while the internal pressures become locally anisotropic. Comment: Final version as accepted by GR&G (to appear in vol. 34, sept...
Slowly rotating supercompact Schwarzschild stars
Posada, Camilo
2017-06-01
The Schwarzschild interior solution, or 'Schwarzschild star', which describes a spherically symmetric homogeneous mass with a constant energy density, shows a divergence in pressure when the radius of the star reaches the Schwarzschild-Buchdahl bound. Recently, Mazur and Mottola showed that this divergence is integrable through the Komar formula, inducing non-isotropic transverse stresses on a surface of some radius R0. When this radius approaches the Schwarzschild radius Rs = 2 M, the interior solution becomes one of negative pressure evoking a de Sitter space-time. This gravitational condensate star, or gravastar, is an alternative solution to the idea of a black hole as the ultimate state of gravitational collapse. Using Hartle's model to calculate equilibrium configurations of slowly rotating masses, we report results of surface and integral properties for a Schwarzschild star in the very little studied region Rs < R < (9/8)Rs. We found that in the gravastar limit, the angular velocity of the fluid relative to the local inertial frame tends to zero, indicating rigid rotation. Remarkably, the normalized moment of inertia I/MR2 and the mass quadrupole moment Q approach the corresponding values for the Kerr metric to second order in Ω. These results provide a solution to the problem of the source of a slowly rotating Kerr black hole.
Doppleraj efikoj \\^ce Schwarzschild
Paiva, F M
2009-01-01
Motion of bodies and light rays are studied in the gravitational field of Schwarzschild. Several Doppler effects are described. ----- Movado de korpoj kaj lumo estas studitaj en gravita kampo de Schwarzschild. Pluraj Doppleraj efikoj estas priskribitaj.
Martin Schwarzschild (1912-1997)
Trimble, V.
1997-12-01
Martin Schwarzschild, the ASP Bruce Medalist for 1965, died on 10 April 1997. A refugee from Hitler's Germany who firmly embraced his adopted country, Schwarzschild not only solved a number of fundamental problems in stellar structure and evolution but also taught the rest of the astronomical community how to do so with his 1958 text, Structure and Evolution of the Stars. At about the time of his 1979 retirement, he turned to a completely different question of how to model spheroidal galaxies self-consistently and sent another generation of students and collaborators forward toward the still somewhat distant solution. It is impossible for anyone who ever interacted with Schwarzschild to remain entirely solemn when remembering him. (SECTION: Obituary)
TRANSFER PANAS LUBANG HITAM SCHWARZSCHILD
Directory of Open Access Journals (Sweden)
Y Tiandho
2015-07-01
Full Text Available Mekanika kuantum menunjukkan bahwa lubang hitam memiliki temperatur sebagai indikasi dapat mengemisikan partikel. Persamaan transfer panas secara general mengandung operator Laplacian yang sifatnya dipengaruhi oleh ruang. Kelengkungan ruang-waktu di daerah sekitar lubang hitam sangat besar sehingga operator Laplacian untuk menghitung distribusi temperaturnya merupakan Laplacian ruang lengkung. Persamaan Fourier untuk lubang hitam Schwarzschild bergantung pada jarak dan radius Schwarzschild. Pada keadaan tunak solusi dari komponen radius mengandung polinomial Legendre dan solusi dari komponen sudut ruang mengadung fungsi spherical harmonics. Untuk kasus dengan persamaan diferensial terhadap waktu bernilai konstan solusi menyimpulkan bahwa temperatur bertambah seiring waktu. Hasil yang telah didapatkan secara umum dapat digunakan untuk menentukan distribusi temperatur pada ruang lengkung akibat suatu objek bermassa M. Koreksi ini sekaligus menggambarkan peristiwa transfer panas dalam konteks relativitas umum.Quantum mechanics show that black hole has temperature that indicated that black hole can emit particles.<0} {0>Persamaan transfer panas secara general mengandung operator Laplacian yang sifatnya dipengaruhi oleh ruang.<}0{>Generally the heat transfer equation contains Laplacian operators that is influenced by space.<0} {0>Kelengkungan ruang-waktu di daerah sekitar lubang hitam sangat besar sehingga operator Laplacian untuk menghitung distribusi temperaturnya merupakan Laplacian ruang lengkung.<}0{>The space-time arch in the surrounding of black hole is very big so that Laplacian operators to calculate the temperature distribution is the arch space Laplacian.<0} {0>Persamaan Fourier untuk lubang hitam Schwarzschild bergantung pada jarak dan radius Schwarzschild.<}0{>Fourier equation for Schwarzschild black hole is depended on the distance and radius of Schwarzschild.<0} {0>Pada keadaan tunak solusi dari komponen radius mengandung polinomial
Quantum corrections to Schwarzschild black hole
Energy Technology Data Exchange (ETDEWEB)
Calmet, Xavier; El-Menoufi, Basem Kamal [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)
2017-04-15
Using effective field theory techniques, we compute quantum corrections to spherically symmetric solutions of Einstein's gravity and focus in particular on the Schwarzschild black hole. Quantum modifications are covariantly encoded in a non-local effective action. We work to quadratic order in curvatures simultaneously taking local and non-local corrections into account. Looking for solutions perturbatively close to that of classical general relativity, we find that an eternal Schwarzschild black hole remains a solution and receives no quantum corrections up to this order in the curvature expansion. In contrast, the field of a massive star receives corrections which are fully determined by the effective field theory. (orig.)
Radiation memory, boosted Schwarzschild spacetimes and supertranslations
Mädler, Thomas; Winicour, Jeffrey
2017-06-01
We investigate gravitational radiation memory and its corresponding effect on the asymptotic symmetries of a body whose exterior is a boosted Schwarzschild spacetime. First, in the context of linearized theory, we consider such a Schwarzschild body which is initially at rest, then goes through a radiative stage and finally emerges as a boosted Schwarzschild body. We show that the proper retarded solution of the exterior Schwarzschild spacetime for this process can be described in terms of the ingoing Kerr-Schild form of the Schwarzschild metric for both the initial and final states. An outgoing Kerr-Schild or time symmetric metric does not give the proper solution. The special property of Kerr-Schild metrics that their linearized and nonlinear forms are identical allows us to extend this result to processes in the nonlinear regime. We then discuss how the nonlinear memory effect, and its associated supertranslation, affect angular momentum conservation. Our approach provides a new framework for studying nonlinear aspects of the memory effect.
Stability of Schwarzschild singularity in non-local gravity
Calcagni, Gianluca; Modesto, Leonardo
2017-10-01
In a previous work, it was shown that all Ricci-flat spacetimes are exact solutions for a large class of non-local gravitational theories. Here we prove that, for a subclass of non-local theories, the Schwarzschild singularity is stable under linear perturbations. Thus, non-locality may be not enough to cure all the singularities of general relativity. Finally, we show that the Schwarzschild solution can be generated by the gravitational collapse of a thin shell of radiation.
Gravitational field of Schwarzschild soliton
Directory of Open Access Journals (Sweden)
Musavvir Ali
2015-01-01
Full Text Available The aim of this paper is to study the gravitational field of Schwarzschild soliton. Use of characteristic of λ-tensor is given to determine the kinds of gravitational fields. Through the cases of two and three dimension for Schwarzschild soliton, the Gaussian curvature is expressed in terms of eigen values of the characteristic equation.
Dynamics of particles around time conformal Schwarzschild black hole
Jawad, Abdul; Ali, Farhad; Shahzad, M. Umair; Abbas, G.
2016-11-01
In this work, we present the new technique for discussing the dynamical motion of neutral as well as charged particles in the absence/presence of a magnetic field around the time conformal Schwarzschild black hole. Initially, we find the numerical solutions of geodesics of the Schwarzschild black hole and the time conformal Schwarzschild black hole. We observe that the Schwarzschild spacetime admits the time conformal factor e^{ɛ f(t)}, where f( t) is an arbitrary function and ɛ is very small, which causes a perturbation in the spacetimes. This technique also re-scales the energy content of spacetime. We also investigate the thermal stability, horizons and energy conditions corresponding to time conformal Schwarzschild spacetime. Also, we examine the dynamics of a neutral and charged particle around a time conformal Schwarzschild black hole. We investigate the circumstances under which the particle can escape from the vicinity of a black hole after collision with another particle. We analyze the effective potential and effective force of a particle in the presence of a magnetic field with angular momentum graphically.
Traversable Schwarzschild-like wormholes
Cataldo, Mauricio; Liempi, Luis; Rodríguez, Pablo
2017-11-01
In this paper we study relativistic static traversable wormhole solutions which are a slight generalization of Schwarzschild wormholes. In order to do this we assume a shape function with a linear dependence on the radial coordinate r. This linear shape function generates wormholes whose asymptotic spacetime is not flat: they are asymptotically locally flat, since in the asymptotic limit r → ∞ spacetimes exhibiting a solid angle deficit (or excess) are obtained. In particular, there exist wormholes which connect two asymptotically non-flat regions with a solid angle deficit. For these wormholes the size of their embeddings in a three-dimensional Euclidean space extends from the throat to infinity. A new phantom zero-tidal-force wormhole exhibiting such asymptotic is obtained. On the other hand, if a solid angle excess is present, the size of the wormhole embeddings depends on the amount of this angle excess, and the energy density is negative everywhere. We discuss the traversability conditions and study the impact of the β -parameter on the motion of a traveler when the wormhole throat is crossed. A description of the geodesic behavior for the wormholes obtained is also presented.
Stability of Schwarzschild singularity in non-local gravity
Directory of Open Access Journals (Sweden)
Gianluca Calcagni
2017-10-01
Full Text Available In a previous work, it was shown that all Ricci-flat spacetimes are exact solutions for a large class of non-local gravitational theories. Here we prove that, for a subclass of non-local theories, the Schwarzschild singularity is stable under linear perturbations. Thus, non-locality may be not enough to cure all the singularities of general relativity. Finally, we show that the Schwarzschild solution can be generated by the gravitational collapse of a thin shell of radiation.
Complete Schwarzschild\\'s planetary equation | Howusu | Journal of ...
African Journals Online (AJOL)
In this paper we derive the complete planetary equation from the Schwarzschild's equations of motion and compare it with the corresponding well-known planetary equation from the Schwarzchild's line element. Journal of the Nigerian Association of Mathematical Physics Vol. 8 2004: pp. 265-268 ...
Schwarzschild instanton in emergent gravity
Chanda, Sumanto; Guha, Partha; Roychowdhury, Raju
2017-09-01
In the bottom-up approach of emergent gravity, we attempt to find symplectic gauge fields emerging from Euclidean Schwarzschild instanton, which is studied as electromagnetism defined on the symplectic space (M,ω). Geometrical engineering with the emergent metric sets up the Seiberg-Witten map between commutative and non-commutative gauge fields, preparing the ground for the evaluation of topological invariants in terms of the underlying gauge theory quantities.
Quantum corrected Schwarzschild thin-shell wormhole
Jusufi, Kimet
2016-01-01
Recently, Ali and Khalil (Nucl Phys B, 909, 173–185, 2016 ), based on Bohmian quantum mechanics, derived a quantum corrected version of the Schwarzschild metric. In this paper, we construct a quantum corrected Schwarzschild thin-shell wormhole (QSTSW) and investigate the stability of this wormhole. First we compute the surface stress at the wormhole throat by applying the Darmois–Israel formalism to the modified Schwarzschild metric and show that exotic matter is required at the throat to kee...
On the Ramifications of the Schwarzschild Space-Time Metric
Directory of Open Access Journals (Sweden)
Crothers S. J.
2005-04-01
Full Text Available In a previous paper I derived the general solution for the simple point-mass in a true Schwarzschild space. I extend that solution to the point-charge, the rotating point-mass, and the rotating point-charge, culminating in a single expression for the general solution for the point-mass in all its configurations when Λ = 0. The general exact solution is proved regular everywhere except at the arbitrary location of the source of the gravitational field. In no case does the black hole manifest. The conventional solutions giving rise to various black holes are shown to be inconsistent with General Relativity.
Dynamical scalar hair formation around a Schwarzschild black hole
Benkel, Robert; Sotiriou, Thomas P.; Witek, Helvi
2016-12-01
Scalar fields coupled to the Gauss-Bonnet invariant evade the known no-hair theorems and have nontrivial configurations around black holes. We focus on a scalar field that couples linearly to the Gauss-Bonnet invariant and hence exhibits shift symmetry. We study its dynamical evolution and the formation of scalar hair in a Schwarzschild background. We show that the evolution eventually settles to the known static hairy solutions in the appropriate limit.
Caustic echoes from a Schwarzschild black hole
Zenginoğlu, Anıl
2012-01-01
We present the first numerical construction of the scalar Schwarzschild Green function in the time-domain, which reveals several universal features of wave propagation in black hole spacetimes. We demonstrate the trapping of energy near the photon sphere and confirm its exponential decay. The trapped wavefront propagates through caustics resulting in echoes that propagate to infinity. The arrival times and the decay rate of these caustic echoes are consistent with propagation along null geodesics and the large l-limit of quasinormal modes. We show that the four-fold singularity structure of the retarded Green function is due to the well-known action of a Hilbert transform on the trapped wavefront at caustics. A two-fold cycle is obtained for degenerate source-observer configurations along the caustic line, where the energy amplification increases with an inverse power of the scale of the source. Finally, we discuss the tail piece of the solution due to propagation within the light cone, up to and including nu...
Quantum Corrected Schwarzschild Thin Shell Wormhole
Jusufi, Kimet
2016-01-01
Recently, Ali and Khalil \\cite{ahmed}, based on the Bohmian quantum mechanics derived a quantum corrected version of the Schwarzschild metric. In this paper, we construct a quantum corrected Schwarzschild thin shell wormhole (QSTSW) and investigate the stability of this wormhole. First we compute the surface stress at the wormhole throat by applying the Darmois-Israel formalism to the modified Schwarzschild metric and show that exotic matter is required at the throat to keep the wormhole stable. We then study the stability analysis of the wormhole by considering phantom-energy for the exotic matter, generalized Chaplygin gas (GCG), and the linearized stability analysis. It is argued that, quantum corrections can affect the stability domain of the wormhole.
Quantum corrected Schwarzschild thin-shell wormhole
Energy Technology Data Exchange (ETDEWEB)
Jusufi, Kimet [State University of Tetovo, Physics Department, Tetovo (Macedonia, The Former Yugoslav Republic of)
2016-11-15
Recently, Ali and Khalil (Nucl Phys B, 909, 173-185, 2016), based on Bohmian quantum mechanics, derived a quantum corrected version of the Schwarzschild metric. In this paper, we construct a quantum corrected Schwarzschild thin-shell wormhole (QSTSW) and investigate the stability of this wormhole. First we compute the surface stress at the wormhole throat by applying the Darmois-Israel formalism to the modified Schwarzschild metric and show that exotic matter is required at the throat to keep the wormhole stable. We then study the stability analysis of the wormhole by considering phantom-energy for the exotic matter, generalized Chaplygin gas (GCG), and the linearized stability analysis. It is argued that quantum corrections can affect the stability domain of the wormhole. (orig.)
Properties of gravity near the Schwarzschild radius
Verozub, Leonid
2014-01-01
The radius of the observable region of the Universe is of the order of its Schwarzschild radius. Due to the spherical symmetry, this allows to check the properties of the gravitational force in the vicinity of the Schwarzschild radius by comparing the theoretical and observed Hubble diagram at high redshifts. This can be done in a simple model that fellows from projective-invariant equations of gravitation.This paper shows that the Hubble diagram up to $z=8$ testifies in favor of the specific...
da Rocha, R.; Sobreiro, R. F.; Tomaz, A. A.
2017-12-01
Sound waves on a fluid stream, in a de Laval nozzle, are shown to correspond to quasinormal modes emitted by black holes that are physical solutions in a quadratic curvature gravity with cosmological constant. Sound waves patterns in transsonic regimes at a laboratory are employed here to provide experimental data regarding generalized theories of gravity, comprised by the exact de Sitter-like solution and a perturbative solution around the Schwarzschild-de Sitter standard solution as well. Using the classical tests of General Relativity to bound free parameters in these solutions, acoustic perturbations on fluid flows in nozzles are then regarded, to study quasinormal modes of these black holes solutions, providing deviations of the de Laval nozzle cross-sectional area, when compared to the Schwarzschild solution. The fluid sonic point in the nozzle, for sound waves in the fluid, is shown to implement the acoustic event horizon corresponding to quasinormal modes.
Features and stability analysis of non-Schwarzschild black hole in quadratic gravity
Energy Technology Data Exchange (ETDEWEB)
Cai, Yi-Fu [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy,University of Science and Technology of China, Chinese Academy of Sciences,Hefei, Anhui, 230026 (China); Department of Physics, McGill University,Montréal, Quebec, H3A 2T8 (Canada); School of Physical Sciences, University of Science and Technology of China,Hefei, Anhui, 230026 (China); Zhang, Hezi [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy,University of Science and Technology of China, Chinese Academy of Sciences,Hefei, Anhui, 230026 (China); School of Physical Sciences, University of Science and Technology of China,Hefei, Anhui, 230026 (China); Liu, Junyu [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy,University of Science and Technology of China, Chinese Academy of Sciences,Hefei, Anhui, 230026 (China); School of the Gifted Young, University of Science and Technology of China,Hefei, Anhui, 230026 (China); Cheng, Gong [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy,University of Science and Technology of China, Chinese Academy of Sciences,Hefei, Anhui, 230026 (China); School of Physical Sciences, University of Science and Technology of China,Hefei, Anhui, 230026 (China); Wang, Min [Faculty of Materials and Energy, Southwest University,Chongqing, 400715 (China); CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy,University of Science and Technology of China, Chinese Academy of Sciences,Hefei, Anhui, 230026 (China)
2016-01-19
Black holes are found to exist in gravitational theories with the presence of quadratic curvature terms and behave differently from the Schwarzschild solution. We present an exhaustive analysis for determining the quasinormal modes of a test scalar field propagating in a new class of black hole backgrounds in the case of pure Einstein-Weyl gravity. Our result shows that the field decay of quasinormal modes in such a non-Schwarzschild black hole behaves similarly to the Schwarzschild one, but the decay slope becomes much smoother due to the appearance of the Weyl tensor square in the background theory. We also analyze the frequencies of the quasinormal modes in order to characterize the properties of new back holes, and thus, if these modes can be the source of gravitational waves, the underlying theories may be testable in future gravitational wave experiments. We briefly comment on the issue of quantum (in)stability in this theory at linear order.
Interactive Visualization of a Thin Disc around a Schwarzschild Black Hole
Muller, Thomas; Frauendiener, Jorg
2012-01-01
In a first course in general relativity, the Schwarzschild spacetime is the most discussed analytic solution to Einstein's field equations. Unfortunately, there is rarely enough time to study the optical consequences of the bending of light for some advanced examples. In this paper, we present how the visual appearance of a thin disc around a…
Asymptotic description of a test particle around a Schwarzschild black hole
Rosales-Vera, Marco
2018-03-01
In this paper, the movement of a test particle around a Schwarzschild black hole is revisited. Using matched asymptotic expansions, approximate analytical expressions for the orbit of the test particle in the case of large eccentricity are found. The asymptotic solutions are compared with numerical and analytical results.
Exact Schwarzschild-de Sitter black holes in a family of massive gravity models
Nieuwenhuizen, T.M.
2011-01-01
The Schwarzschild-de Sitter and Reissner-Nordström-de Sitter black hole metrics appear as exact solutions in the recently formulated massive gravity of de Rham, Gabadadze and Tolley, where the mass term sets the curvature scale. They occur within a two-parameter family of de Rham, Gabadadze and
Thermodynamics of Schwarzschild-Beltrami-de Sitter black hole
Liu, Hang; Meng, Xin-He
2017-09-01
In this paper, we investigate the thermodynamical properties of Schwarzschild-Beltrami-de Sitter (S-BdS) black hole introduced by Yan et al. in 2013 by introducing inertial Beltrami coordinates to traditional non-inertial Schwarzschild-de Sitter (S-dS) metric which is the exact static spherical symmetry solution of Einstein equation with a positive cosmological constant Λ. Based on this new metric, we compute entropy on all horizons and we give the entropy bound of the black hole. Hawking temperatures are calculated by considering a perturbation to entropy relations due to that the spacetime described by these inertial coordinates is no longer a stationary spacetime in which surface gravity related to Hawking temperature is defined well on killing horizon. We also get the Smarr relations and the first law of thermodynamics. We find that the S-BdS black hole seems to have similar thermodynamical properties to S-dS black hole in the comparison between their corresponding thermodynamical quantities, although the new black hole metric is described by inertial coordinates which exclude the effects of inertial force.
Classroom reconstruction of the Schwarzschild metric
Kassner, Klaus
2015-01-01
A promising way to introduce general relativity in the classroom is to study the physical predictions that follow from certain given metrics, such as the Schwarzschild one. This involves lower mathematical expenditure than an approach focusing on differential geometry in its full glory and permits to emphasize physical aspects before attacking the field equations. Even so, in terms of motivation, lacking justification of the metric employed may pose an obstacle. The paper discusses how to establish the weak-field limit of the Schwarzschild metric with a minimum of relatively simple physical assumptions. Since this does not appear sufficient to arrive at a form of the metric useful for more than the most basic predictions (gravitational redshift), the determination of a single additional parameter from experiment is admitted. An attractive experimental candidate is the measurement of the perihelion precession of Mercury, because the result was already known before the completion of general relativity. It is sh...
Statistical Entropy of Schwarzschild Black Holes
Englert, F
1998-01-01
The entropy of a seven dimensional Schwarzschild black hole of arbitrary large radius is obtained by a mapping onto a near extremal self-dual three-brane whose partition function can be evaluated. The three-brane arises from duality after submitting a neutral blackbrane, from which the Schwarzschild black hole can be obtained by compactification, to an infinite boost in non compact eleven dimensional space-time and then to a Kaluza-Klein compactification. This limit can be defined in precise terms and yields the Beckenstein-Hawking value up to a factor of order one which can be set to be exactly one with the extra assumption of keeping only transverse brane excitations. The method can be generalized to five and four dimensional black holes.
Quantum correlator outside a Schwarzschild black hole
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Claudia Buss
2018-01-01
Full Text Available We calculate the quantum correlator in Schwarzschild black hole space–time. We perform the calculation for a scalar field in three different quantum states: Boulware, Unruh and Hartle–Hawking, and for points along a timelike circular geodesic. The results show that the correlator presents a global fourfold singularity structure, which is state-independent. Our results also show the different correlations in the three different quantum states arising in-between the singularities.
Quantum correlator outside a Schwarzschild black hole
Buss, Claudia; Casals, Marc
2018-01-01
We calculate the quantum correlator in Schwarzschild black hole space-time. We perform the calculation for a scalar field in three different quantum states: Boulware, Unruh and Hartle-Hawking, and for points along a timelike circular geodesic. The results show that the correlator presents a global fourfold singularity structure, which is state-independent. Our results also show the different correlations in the three different quantum states arising in-between the singularities.
Gravitino perturbations in Schwarzschild black holes
Piedra, Owen Pavel Fernández
2010-01-01
We consider the time evolution of massless gravitino perturbations in Schwarzschild black holes, and show that as in the case of fields of other values of spin, the evolution comes in three stages, after an initial outburst as a first stage, we observe the damped oscillations characteristic of the quasinormal ringing stage, followed by long time tails. Using the sixth order WKB method and Prony fitting of time domain data we determine the quasinormal frequencies. There is a good correspondenc...
Dirac Quasinormal modes of Schwarzschild black hole
Jing, Jiliang
2005-01-01
The quasinormal modes (QNMs) associated with the decay of Dirac field perturbation around a Schwarzschild black hole is investigated by using continued fraction and Hill-determinant approaches. It is shown that the fundamental quasinormal frequencies become evenly spaced for large angular quantum number and the spacing is given by $\\omega_{\\lambda+1}- \\omega_{\\lambda}=0.38490-0.00000i$. The angular quantum number has the surprising effect of increasing real part of the quasinormal frequencies...
The Planck Vacuum and the Schwarzschild Metrics
Directory of Open Access Journals (Sweden)
Daywitt W. C.
2009-07-01
Full Text Available The Planck vacuum (PV is assumed to be the source of the visible universe. So under conditions of sufficient stress, there must exist a pathway through which energy from the PV can travel into this universe. Conversely, the passage of energy from the visible universe to the PV must also exist under the same stressful conditions. The following examines two versions of the Schwarzschild metric equation for compatability with this open-pathway idea.
Gravitating discs around a Schwarzschild black hole: III
Semerak, O
2003-01-01
The properties of exact relativistic spacetimes of a Schwarzschild black hole surrounded by annular thin discs obtained by inversion of the first ten members of the counter-rotating Morgan-Morgan class are studied. Effects of the discs' own gravity are compared, in particular the induced deformation of the horizon and changes in the features of free circular motion in the disc plane. Within the plane of the two relevant parameters of the composite solution (relative disc mass and its inner radius), regions are specified where the discs satisfy basic physical requirements (energetic conditions and possibility, subluminality and stability of circular geodesics in terms of which they are interpreted). In contrast to the first inverted Morgan-Morgan disc, treated in previous papers, the 'higher' members of the family have to be placed farther and farther from the hole in order to remain stable when their mass is increased from zero.
Schwarzschild black holes can wear scalar wigs.
Barranco, Juan; Bernal, Argelia; Degollado, Juan Carlos; Diez-Tejedor, Alberto; Megevand, Miguel; Alcubierre, Miguel; Núñez, Darío; Sarbach, Olivier
2012-08-24
We study the evolution of a massive scalar field surrounding a Schwarzschild black hole and find configurations that can survive for arbitrarily long times, provided the black hole or the scalar field mass is small enough. In particular, both ultralight scalar field dark matter around supermassive black holes and axionlike scalar fields around primordial black holes can survive for cosmological times. Moreover, these results are quite generic in the sense that fairly arbitrary initial data evolve, at late times, as a combination of those long-lived configurations.
Eigentensors of the Lichnerowicz operator in Euclidean Schwarzschild metrics
Energy Technology Data Exchange (ETDEWEB)
Martinez-Morales, J.L. [Instituto de Matematicas, Universidad Nacional Autonoma de Mexico, A. P. 273, Admon. de correos 3, C. P. 62251 Cuernavaca, Morelos (Mexico)
2006-09-01
Properties of the eigentensors of the Lichnerowicz Laplacian for the Euclidean Schwarzschild metric are discussed together with possible applications to the linear stability of higher-dimensional instantons. The main statement of the article is that any eigentensor of the Lichnerowicz operator in a Euclidean (possibly higher-dimensional) Schwarzschild metric is essentially singular at infinity. (Abstract Copyright [2006], Wiley Periodicals, Inc.)
Turning points of massive particles in Schwarzschild geometry
Polonyi, J.; Radosz, A.; Siwek, A.; Ostasiewicz, K.
2009-01-01
The stable geodesics in Schwarzschild geometry can not approach the center closer than the radius of the photon sphere, 3/2 times the Schwarzschild radius. In other words, massive particles moving along geodesics that cross the photon sphere do not escape, they fall into the black hole.
Papadopoulos, Demetrios B; Kokkotas, Kostas D; Stergioulas, Nikolaos
2015-01-01
We obtain an approximate solution for the motion of a charged particle around a Schwarzschild black hole immersed in a weak dipolar magnetic field. We focus on eccentric bound orbits in the equatorial plane of the Schwarzschild black hole and derive an analytic expression for the spectral distribution of the electromagnetic emission from a charged particle on such an orbit. Two sets of harmonic contributions appear, with specific frequency spacing. The expression can be written in compact form, if it is truncated up to the lowest order harmonic contributions.
Sironi, Giorgia
2017-09-01
At the beginning of XX century Karl Schwarzschild defined a method to design large-field aplanatic telescopes based on the use of two aspheric mirrors. The approach was then refined by Couder (1926) who, in order to correct for the astigmatic aberration, introduced a curvature of the focal plane. By the way, the realization of normal-incidence telescopes implementing the Schwarzschild aplanatic configuration has been historically limited by the lack of technological solutions to manufacture and test aspheric mirrors. On the other hand, the Schwarzschild solution was recovered for the realization of coma-free X-ray grazing incidence optics. Wolter-like grazing incidence systems are indeed free of spherical aberration, but still suffer from coma and higher order aberrations degrading the imaging capability for off-axis sources. The application of the Schwarzschild's solution to X-ray optics allowed Wolter to define an optical system that exactly obeys the Abbe sine condition, eliminating coma completely. Therefore these systems are named Wolter-Schwarzschild telescopes and have been used to implement wide-field X-ray telescopes like the ROSAT WFC and the SOHO X-ray telescope. Starting from this approach, a new class of X-ray optical system was proposed by Burrows, Burg and Giacconi assuming polynomials numerically optimized to get a flat field of view response and applied by Conconi to the wide field x-ray telescope (WFXT) design. The Schwarzschild-Couder solution has been recently re-discovered for the application to normal-incidence Cherenkov telescopes, thanks to the suggestion by Vassiliev and collaborators. The Italian Institute for Astrophysics (INAF) realized the first Cherenkov telescope based on the polynomial variation of the Schwarzschild configuration (the so-called ASTRI telescope). Its optical qualification was successfully completed in 2016, demonstrating the suitability of the Schwarzschild-like configuration for the Cherenkov astronomy requirements
Gravitino perturbations in Schwarzschild black holes
Piedra, Owen Pavel Fernández
2010-01-01
We consider the time evolution of massless gravitino perturbations in Schwarzschild black holes, and show that as in the case of fields of other values of spin, the evolution comes in three stages, after an initial outburst as a first stage, we observe the damped oscillations characteristic of the quasinormal ringing stage, followed by long time tails. Using the sixth order WKB method and Prony fitting of time domain data we determine the quasinormal frequencies. There is a good correspondence between the results obtained by the above two methods, and we obtain a considerable improvement with respect to the previously obtained third order WKB results. We also show that the response of a black hole depends crucially on the spin class of the perturbing field: the quality factor becomes a decreasing function of the spin for boson perturbations , whereas the opposite situation appears for fermion ones.
Landau problem in the static schwarzschild universe
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A Jafari
2013-09-01
Full Text Available This paper considers the Landau problem in an elected static space time and the are erased levels shifts which are erased as a metric deviation from the Minkowski space time. This research is based on the Weber’s method. We try to rewrite the equation of motion of particles in the presence of the gravitational effects and consider the regions limited with the tangent spaces conditions. I t would be reasonable to assume the nonrelativistic particles with low speed. We show that due to the Weber’s method, the tangent space is always available. Another assumption of this article is time independent tangent space of Schwarzschild universe and use of Riemann’s normal coordinates.
Dust ball physics and the Schwarzschild metric
Kassner, Klaus
2016-01-01
A physics-first derivation of the Schwarzschild metric is given. Gravitation is described in terms of the effects of tidal forces (or of spacetime curvature) on the volume of a small ball of test particles (a dust ball), freely falling after all particles were at rest with respect to each other initially. The possibility to express Einstein's equation this way and some of its ramifications have been enjoyably discussed by Baez and Bunn [Am. J. Phys. 73, 644 (2005)]. Since the formulation avoids the use of tensors, neither advanced tensor calculus nor sophisticated differential geometry are needed in the calculation. The derivation is not lengthy and it has visual appeal, so it may be useful in teaching.
Counting Schwarzschild and Charged Black Holes
Energy Technology Data Exchange (ETDEWEB)
Rajaraman, Arvind
2003-05-23
We review the arguments that fundamental string states are in one to one correspondence with black hole states. We demonstrate the power of the assumption by showing that it implies that the statistical entropy of a wide class of nonextreme black holes occurring in string theory is proportional to the horizon area. However, the numerical coefficient relating the area and entropy only agrees with the Bekenstein-Hawking formula if the central charge of the string is six which does not correspond to any known string theory. Unlike the current D-brane methods the method used in this paper is applicable for the case of Schwarzschild and highly non-extreme charged black holes.
Resolving the Schwarzschild singularity in both classic and quantum gravity
Zeng, Ding-fang
2017-04-01
The Schwarzschild singularity's resolution has key values in cracking the key mysteries related with black holes, the origin of their horizon entropy and the information missing puzzle involved in their evaporations. We provide in this work the general dynamic inner metric of collapsing stars with horizons and with non-trivial radial mass distributions. We find that static central singularities are not the final state of the system. Instead, the final state of the system is a periodically zero-cross breathing ball. Through 3+1 decomposed general relativity and its quantum formulation, we establish a functional Schrödinger equation controlling the micro-state of this breathing ball and show that, the system configuration with all the matter concentrating on the central point is not the unique eigen-energy-density solution. Using a Bohr-Sommerfield like ;orbital; quantisation assumption, we show that for each black hole of horizon radius rh, there are about e rh2/#x2113;pl 2 allowable eigen-energy-density profiles. This naturally leads to physic interpretations for the micro-origin of horizon entropy, as well as solutions to the information missing puzzle involved in Hawking radiations.
Bose–Einstein graviton condensate in a Schwarzschild black hole
Alfaro, Jorge; Espriu, Domènec; Gabbanelli, Luciano
2018-01-01
We analyze in detail a previous proposal by Dvali and Gómez that black holes could be treated as consisting of a Bose–Einstein condensate of gravitons. In order to do so we extend the Einstein–Hilbert action with a chemical potential-like term, thus placing ourselves in a grand-canonical ensemble. The form and characteristics of this chemical potential-like piece are discussed in some detail. We argue that the resulting equations of motion derived from the action could be interpreted as the Gross–Pitaevskii equation describing a graviton Bose–Einstein condensate trapped by the black hole gravitational field. After this, we proceed to expand the ensuring equations of motion up to second order around the classical Schwarzschild metric so that some non-linear terms in the metric fluctuation are kept. Next we search for solutions and, modulo some very plausible assumptions, we find out that the condensate vanishes outside the horizon but is non-zero in its interior. Inspired by a linearized approximation around the horizon we are able to find an exact solution for the mean-field wave function describing the graviton Bose–Einstein condensate in the black hole interior. After this, we can rederive some of the relations involving the number of gravitons N and the black hole characteristics along the lines suggested by Dvali and Gómez.
Resolving the Schwarzschild singularity in both classic and quantum gravity
Directory of Open Access Journals (Sweden)
Ding-fang Zeng
2017-04-01
Full Text Available The Schwarzschild singularity's resolution has key values in cracking the key mysteries related with black holes, the origin of their horizon entropy and the information missing puzzle involved in their evaporations. We provide in this work the general dynamic inner metric of collapsing stars with horizons and with non-trivial radial mass distributions. We find that static central singularities are not the final state of the system. Instead, the final state of the system is a periodically zero-cross breathing ball. Through 3+1 decomposed general relativity and its quantum formulation, we establish a functional Schrödinger equation controlling the micro-state of this breathing ball and show that, the system configuration with all the matter concentrating on the central point is not the unique eigen-energy-density solution. Using a Bohr–Sommerfield like “orbital” quantisation assumption, we show that for each black hole of horizon radius rh, there are about erh2/ℓpl2 allowable eigen-energy-density profiles. This naturally leads to physic interpretations for the micro-origin of horizon entropy, as well as solutions to the information missing puzzle involved in Hawking radiations.
Quasinormal Modes of a Quantum-Corrected Schwarzschild Black ...
Indian Academy of Sciences (India)
corrected Schwarzschild black hole. The complex frequencies of the quasinormal modes are evaluated by the third-order WKB approximation. The numerical results obtained showed that the complex frequencies depend on the quantum ...
Exact gravitational lensing in conformal gravity and Schwarzschild-de Sitter spacetime
Lim, Yen-Kheng
2016-01-01
An exact solution is obtained for the gravitational bending of light in static, spherically symmetric metrics which includes the Schwarzschild-de Sitter (SdS) spacetime and also the Mannheim-Kazanas (MK) metric of conformal Weyl gravity. From the exact solution, we obtain a small bending-angle approximation for a lens system where the source, lens and observer are co-aligned. This expansion improves previous calculations where we systematically avoid parameter ranges which correspond to non-existent null trajectories. The linear coefficient $\\gamma$ characteristic to conformal gravity is shown to contribute enhanced deflection compared to the angle predicted by General Relativity for small $\\gamma$.
Exact gravitational lensing in conformal gravity and Schwarzschild-de Sitter spacetime
Lim, Yen-Kheng; Wang, Qing-hai
2017-01-01
An exact solution is obtained for the gravitational bending of light in static, spherically symmetric metrics which includes the Schwarzschild-de Sitter spacetime and also the Mannheim-Kazanas metric of conformal Weyl gravity. From the exact solution, we obtain a small-bending-angle approximation for a lens system where the source, lens, and observer are coaligned. This expansion improves previous calculations where we systematically avoid parameter ranges that correspond to nonexistent null trajectories. The linear coefficient γ characteristic to conformal gravity is shown to contribute enhanced deflection compared to the angle predicted by general relativity for small γ .
Hawking radiation inside a Schwarzschild black hole
Hamilton, Andrew J S
2016-01-01
The boundary of any observer's spacetime is the boundary that divides what the observer can see from what they cannot see. The boundary of an observer's spacetime in the presence of a black hole is not the true (future event) horizon of the black hole, but rather the illusory horizon, the dimming, redshifting surface of the star that collapsed to the black hole long ago. The illusory horizon is the source of Hawking radiation seen by observers both outside and inside the true horizon. The perceived acceleration (gravity) on the illusory horizon sets the characteristic frequency scale of Hawking radiation, even if that acceleration varies dynamically, as it must do from the perspective of an infalling observer. The acceleration seen by a non-rotating free-faller both on the illusory horizon below and in the sky above is calculated for a Schwarzschild black hole. Remarkably, as an infaller approaches the singularity, the acceleration becomes isotropic, and diverging as a power law. The isotropic, power-law char...
Gravitino Perturbations in Schwarzschild Black Holes
Fernandez Piedra, Owen Pavel
We consider the time-evolution of massless gravitino perturbations in Schwarzschild black holes, and show that as in the case of fields of other values of spin, the evolution comes in three stages. After an initial outburst as a first stage, we observe the damped oscillations characteristic of the quasinormal ringing stage, followed by long time tails. Using the sixth-order WKB method and Prony fitting of time domain data we determine the quasinormal frequencies. There is a good correspondence between the results obtained by the above two methods, and we obtain a considerable improvement with respect to the previously obtained third-order WKB results. We also show that the response of a black hole depends crucially on the spin class of the perturbing field: the quality factor becomes a decreasing function of the spin for boson perturbations, whereas the opposite situation appears for fermion ones. With respect to the late-time behavior, we found numerical evidence of a faster decay of gravitino perturbations, a result in constrast with what is known for other neutral fields.
Schwarzschild Black Branes and Strings in higher-dimensional Brane Worlds
Kanti, Panagiota; Tamvakis, Kyriakos
2002-01-01
We consider branes embedded in spacetimes of codimension 1 and 2, with a warped metric tensor for the subspace parallel to the brane. We study a variety of brane-world solutions arising by introducing a Schwarzschild-like black hole metric on the brane and we investigate the properties of the corresponding higher-dimensional spacetime. We demonstrate that normalizable bulk modes lead to a vanishing flow of energy through the naked singularities. From this point of view, these singularities are harmless. (28 refs).
How to obtain the Schwarzschild metric before Einstein's field equations
Kassner, Klaus
2016-01-01
As is well-known, there is no way to derive the Schwarzschild metric on the basis of pre-general-relativistic physics alone, which means using only special relativity, the Einstein equivalence principle and the Newtonian limit. It is however possible to encode the additional physics needed in two reasonably plausible postulates allowing to deduce the exact Schwarzschild metric without invoking Einstein's field equations. Since these requirements are designed to apply to the spherically symmmetric case, their union is much less powerful than the postulates from which Einstein obtained his field equations. It is shown that the field equations imply the postulates given here but that the converse is not quite true. The approach provides a fairly fast calculation method for the Schwarzschild metric in arbitrary coordinates exhibiting stationarity.
1st Karl Schwarzschild Meeting on Gravitational Physics
Kaminski, Matthias; Mureika, Jonas; Bleicher, Marcus
2016-01-01
These proceedings collect the selected contributions of participants of the First Karl Schwarzschild Meeting on Gravitational Physics, held in Frankfurt, Germany to celebrate the 140th anniversary of Schwarzschild's birth. They are grouped into 4 main themes: I. The Life and Work of Karl Schwarzschild; II. Black Holes in Classical General Relativity, Numerical Relativity, Astrophysics, Cosmology, and Alternative Theories of Gravity; III. Black Holes in Quantum Gravity and String Theory; IV. Other Topics in Contemporary Gravitation. Inspired by the foundational principle ``By acknowledging the past, we open a route to the future", the week-long meeting, envisioned as a forum for exchange between scientists from all locations and levels of education, drew participants from 15 countries across 4 continents. In addition to plenary talks from leading researchers, a special focus on young talent was provided, a feature underlined by the Springer Prize for the best student and junior presentations.
Cardy-Verlinde Formula of Noncommutative Schwarzschild Black Hole
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G. Abbas
2014-01-01
Full Text Available Few years ago, Setare (2006 has investigated the Cardy-Verlinde formula of noncommutative black hole obtained by noncommutativity of coordinates. In this paper, we apply the same procedure to a noncommutative black hole obtained by the coordinate coherent approach. The Cardy-Verlinde formula is entropy formula of conformal field theory in an arbitrary dimension. It relates the entropy of conformal field theory to its total energy and Casimir energy. In this paper, we have calculated the total energy and Casimir energy of noncommutative Schwarzschild black hole and have shown that entropy of noncommutative Schwarzschild black hole horizon can be expressed in terms of Cardy-Verlinde formula.
Scalar wave scattering from Schwarzschild black holes in modified gravity
Sibandze, Dan B; Maharaj, Sunil D; Nzioki, Anne Marie; Dunsby, Peter K S
2016-01-01
We consider the scattering of gravitational waves off a Schwarzschild Black Hole in $f(R)$ gravity. We find that, while the reflection and transmission coefficients for tensor waves are the same as in General Relativity, a larger fraction of scalar waves are reflected compared to what one obtains for tensors. This may provide a novel observational signature for fourth order gravity.
The golden ratio in Schwarzschild-Kottler black holes
Energy Technology Data Exchange (ETDEWEB)
Cruz, Norman [Universidad de Santiago de Chile, Departamento de Fisica, Facultad de Ciencia, Santiago 2 (Chile); Olivares, Marco [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Villanueva, J.R. [Universidad de Valparaiso, Instituto de Fisica y Astronomia, Valparaiso (Chile)
2017-02-15
In this paper we show that the golden ratio is present in the Schwarzschild-Kottler metric. For null geodesics with maximal radial acceleration, the turning points of the orbits are in the golden ratio Φ = (√(5)-1)/2. This is a general result which is independent of the value and sign of the cosmological constant Λ. (orig.)
Quasinormal Modes of a Quantum-Corrected Schwarzschild Black ...
Indian Academy of Sciences (India)
Chunyan Wang
2017-11-27
Nov 27, 2017 ... Abstract. In this work, we investigate the electromagnetic perturbation around a quantum-corrected. Schwarzschild black hole. The complex frequencies of the quasinormal modes are evaluated by the third- order WKB approximation. The numerical results obtained showed that the complex frequencies ...
Entropy Spectrum of Modified Schwarzschild Black Hole via an ...
Indian Academy of Sciences (India)
2016-01-27
Jan 27, 2016 ... Abstract. The entropy spectrum of a modified Schwarzschild black hole in the gravity's rainbow are investigated. By utilizing an action invariance of the black hole with the help of Bohr–Sommerfield quantization rule, the entropy spectrum for the modified black hole are calculated. The result of the equally ...
Schwarzschild models of the Sculptor dSph galaxy
Breddels, M. A.; Helmi, A.; van den Bosch, R. C. E.; van de Ven, G.; Battaglia, G.; Reyle, C; Robin, A; Schultheis, M
We have developed a spherically symmetric dynamical model of a dwarf spheroidal galaxy using the Schwarzschild method. This type of modelling yields constraints both on the total mass distribution (e.g. enclosed mass and scale radius) as well as on the orbital structure of the system modelled (e.g.
Entropy Spectrum of Modified Schwarzschild Black Hole via an ...
Indian Academy of Sciences (India)
526. Cheng-Zhou Liu where f1 and f2 are two energy functions and by this the present modified. Schwarzschild spacetime is endowed with Planck scale modifications. For the non-charged spherically static symmetric spacetime, the only dynamic degree freedom can be written as qr, the Hamilton's equation ˙r = dr dτ. = dHτ.
Kokkotas, K. D.; Konoplya, R. A.; Zhidenko, A.
2017-09-01
Higher derivative extensions of Einstein gravity are important within the string theory approach to gravity and as alternative and effective theories of gravity. H. Lü, A. Perkins, C. Pope, and K. Stelle [Phys. Rev. Lett. 114, 171601 (2015), 10.1103/PhysRevLett.114.171601] found a numerical solution describing a spherically symmetric non-Schwarzschild asymptotically flat black hole in Einstein gravity with added higher derivative terms. Using the general and quickly convergent parametrization in terms of the continued fractions, we represent this numerical solution in the analytical form, which is accurate not only near the event horizon or far from the black hole, but in the whole space. Thereby, the obtained analytical form of the metric allows one to study easily all the further properties of the black hole, such as thermodynamics, Hawking radiation, particle motion, accretion, perturbations, stability, quasinormal spectrum, etc. Thus, the found analytical approximate representation can serve in the same way as an exact solution.
Directory of Open Access Journals (Sweden)
R. da Rocha
2017-12-01
Full Text Available Sound waves on a fluid stream, in a de Laval nozzle, are shown to correspond to quasinormal modes emitted by black holes that are physical solutions in a quadratic curvature gravity with cosmological constant. Sound waves patterns in transsonic regimes at a laboratory are employed here to provide experimental data regarding generalized theories of gravity, comprised by the exact de Sitter-like solution and a perturbative solution around the Schwarzschildâde Sitter standard solution as well. Using the classical tests of General Relativity to bound free parameters in these solutions, acoustic perturbations on fluid flows in nozzles are then regarded, to study quasinormal modes of these black holes solutions, providing deviations of the de Laval nozzle cross-sectional area, when compared to the Schwarzschild solution. The fluid sonic point in the nozzle, for sound waves in the fluid, is shown to implement the acoustic event horizon corresponding to quasinormal modes. Keywords: Black holes, Fluid branes, Fluid dynamics, Quadratic curvature gravity, de Laval nozzle
Gravitational redshifts in electromagnetic bursts occurring near Schwarzschild horizon
Karkowski, J
2003-01-01
It was suggested earlier that the gravitational redshift formula can be invalid when the effect of the backscattering is strong. It is demonstrated here numerically, for an exemplary electromagnetic pulse that is (i) initially located very close to the horizon of a Schwarzschild black hole and (ii) strongly backscattered, that a mean frequency does not obey the standard redshift formula. Redshifts appear to depend on the frequency and there manifests a backscatter-induced blueshift in the outgoing radiation.
Resolving the Schwarzschild singularity in both classic and quantum gravity
Zeng, Ding-fang
2017-01-01
The Schwarzschild singularity's resolution has key values in cracking the key mysteries related with black holes, the origin of their horizon entropy and the information missing puzzle involved in their evaporations. We provide in this work the general dynamic inner metric of collapsing stars with horizons and with non-trivial radial mass distributions. We find that static central singularities are not the final state of the system. Instead, the final state of the system is a periodically zer...
A comparative study of background flow geometries in Schwarzschild metric with shock
Tarafdar, Pratik
2016-01-01
We study the effects of discontinuity in general relativistic axially symmetric background fluid flow in the Schwarzschild metric. The discontinuities, or 'shocks', are incorporated using general relativistic Rankine-Hugoniot conditions. A general shock-invariant quantity is thus derived analytically for three distinct geometric configurations of the background fluid flow, viz., constant height discs, quasi-spherical discs and discs in hydrostatic equilibrium in the vertical direction. As already pointed out in our previous works, even identical initial conditions may lead to completely different phase-space behaviour of the stationary solutions for separate flow geometries. Hence it is then useful to investigate and compare the influence of geometric configuration of the flow described by various thermodynamic equations of state, on different important properties and manifestations of such physical discontinuities.
Accretion of a relativistic, collisionless kinetic gas into a Schwarzschild black hole
Rioseco, Paola
2016-01-01
We provide a systematic study for the accretion of a collisionless, relativistic kinetic gas into a nonrotating black hole. To this end, we first solve the relativistic Liouville equation on a Schwarzschild background spacetime. The most general solution for the distribution function is given in terms of appropriate symplectic coordinates on the cotangent bundle, and the associated observables, including the particle current density and stress energy-momentum tensor, are determined. Next, we explore the case where the flow is steady-state and spherically symmetric. Assuming that in the asymptotic region the gas is described by an equilibrium distribution function, we determine the relevant parameters of the accretion flow as a function of the particle density and the temperature of the gas at infinity. In particular, we find that in the low temperature limit the tangential pressure at the horizon is about an order of magnitude larger than the radial one, showing explicitly that a collisionless gas, despite ex...
Loop quantization of the Schwarzschild black hole.
Gambini, Rodolfo; Pullin, Jorge
2013-05-24
We quantize spherically symmetric vacuum gravity without gauge fixing the diffeomorphism constraint. Through a rescaling, we make the algebra of Hamiltonian constraints Abelian, and therefore the constraint algebra is a true Lie algebra. This allows the completion of the Dirac quantization procedure using loop quantum gravity techniques. We can construct explicitly the exact solutions of the physical Hilbert space annihilated by all constraints. New observables living in the bulk appear at the quantum level (analogous to spin in quantum mechanics) that are not present at the classical level and are associated with the discrete nature of the spin network states of loop quantum gravity. The resulting quantum space-times resolve the singularity present in the classical theory inside black holes.
Accretion processes in magnetically and tidally perturbed Schwarzschild black holes
Kovács, Zoltán; Vasúth, Mátyás
2011-01-01
We study the accretion process in the region of the Preston-Poisson space-time describing a Schwarzschild black hole perturbed by asymptotically uniform magnetic field and axisymmetric tidal structures. We find that the accretion disk shrinks and the marginally stable orbit shifts towards the black hole with the perturbation. The radiation intensity of the accretion disk increases, while the radius where radiation is maximal remains unchanged. The spectrum is blue-shifted. Finally, the conversion efficiency of accreting mass into radiation is decreased by both the magnetic and the tidal perturbations.
Drude-Schwarzschild Metric and the Electrical Conductivity of Metals
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Silva P. R.
2014-07-01
Full Text Available Starting from a string with a length equal to the electron mean free path and having a unit cell equal to the Compton length of the electron, we construct a Schwarzschild-like metric. We found that this metric has a surface horizon with radius equal to the electron mean free path and its Bekenstein-like entropy is proportional to the number of squared unit cells contained in this spherical surface. The Hawking temperature is inversely proportional to the perimeter of the maximum circle of this sphere. Also, interesting analogies on some features of the particle physics are examined.
von-Neumann stability and singularity resolution in loop quantized Schwarzschild black hole
Yonika, Alec; Khanna, Gaurav; Singh, Parampreet
2018-02-01
Though loop quantization of several spacetimes has exhibited existence of a bounce via an explicit evolution of states using numerical simulations, the question about the way central singularity is resolved in the black hole interior has remained open. The quantum Hamiltonian constraint in loop quantization turns out to be a finite difference equation whose stability is important to understand to gain insights on the viability of the underlying quantization and resulting physical implications. We take first steps towards addressing these issues for a loop quantization of the Schwarzschild interior recently given by Corichi and Singh. Von-Neumann stability analysis is performed using separability of solutions as well as a full two dimensional quantum difference equation. This results in a stability condition for black holes which have a very large mass compared to the Planck mass. For black holes of smaller masses evidence of numerical instability is found. In addition, stability analysis for macroscopic black holes leads to a constraint on the choice of the allowed states in numerical evolution. States which are not sharply peaked in accordance with this constraint result in instabilities. With the caveat of using kinematical norm, sharply peaked Gaussian states are evolved using the quantum difference equation and singularity resolution is obtained. A bounce is found for one of the triad variables, but for the other triad variable singularity resolution amounts to a non-singular passage through the zero volume. States are found to be peaked at the classical trajectory for a long time before and after the singularity resolution, and retain their semi-classical character across the zero volume. Our main result is that quantum bounce occurs in loop quantized Schwarzschild interior at least for macroscopic black holes. Instability of small black holes which can be a result of using kinematical norm nevertheless signifies the need of further understanding of the
Rigorous construction and Hadamard property of the Unruh state in Schwarzschild spacetime
Energy Technology Data Exchange (ETDEWEB)
Dappiaggi, Claudio; Pinamonti, Nicola [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Moretti, Valter [Trento Univ., Povo (Italy). Dipt. di Matematica; Istituto Nazionale di Fisica Nucleare, Povo (Italy); Istituto Nazionale di Alta Matematica ' ' F. Severi' ' , GNFM, Sesto Fiorentino (Italy)
2009-07-15
The discovery of the radiation properties of black holes prompted the search for a natural candidate quantum ground state for a massless scalar field theory on Schwarzschild spacetime, here considered in the Eddington-Finkelstein representation. Among the several available proposals in the literature, an important physical role is played by the so-called Unruh state which is supposed to be appropriate to capture the physics of a black hole formed by spherically symmetric collapsing matter. Within this respect, we shall consider a massless Klein-Gordon field and we shall rigorously and globally construct such state, that is on the algebra of Weyl observables localised in the union of the static external region, the future event horizon and the non-static black hole region. Eventually, out of a careful use of microlocal techniques, we prove that the built state fulfils, where defined, the so-called Hadamard condition; hence, it is perturbatively stable, in other words realizing the natural candidate with which one could study purely quantum phenomena such as the role of the back reaction of Hawking's radiation. From a geometrical point of view, we shall make a profitable use of a bulk-to-boundary reconstruction technique which carefully exploits the Killing horizon structure as well as the conformal asymptotic behaviour of the underlying background. From an analytical point of view, our tools will range from Hoermander's theorem on propagation of singularities, results on the role of passive states, and a detailed use of the recently discovered peeling behaviour of the solutions of the wave equation in Schwarzschild spacetime. (orig.)
Schwarzschild models of the Sculptor dSph galaxy
Directory of Open Access Journals (Sweden)
van de Ven G.
2012-02-01
Full Text Available We have developed a spherically symmetric dynamical model of a dwarf spheroidal galaxy using the Schwarzschild method. This type of modelling yields constraints both on the total mass distribution (e.g. enclosed mass and scale radius as well as on the orbital structure of the system modelled (e.g. velocity anisotropy. Therefore not only can we derive the dark matter content of these systems, but also explore possible formation scenarios. Here we present preliminary results for the Sculptor dSph. We find that the mass of Sculptor within 1 kpc is 8.5 × 107±0.05 M๏, its anisotropy profile is tangentially biased and slightly more isotropic near the center. For an NFW profile, the preferred concentration (~15 is compatible with cosmological models. Very cuspy density profiles (steeper than NFW are strongly disfavoured for Sculptor.
On the twin paradox in static spacetimes: I. Schwarzschild metric
Sokołowski, Leszek M.
2012-05-01
Motivated by a conjecture put forward by Abramowicz and Bajtlik we reconsider the twin paradox in static spacetimes. According to a well known theorem in Lorentzian geometry the longest timelike worldline between two given points is the unique geodesic line without points conjugate to the initial point on the segment joining the two points. We calculate the proper times for static twins, for twins moving on a circular orbit (if it is a geodesic) around a centre of symmetry and for twins travelling on outgoing and ingoing radial timelike geodesics. We show that the twins on the radial geodesic worldlines are always the oldest ones and we explicitly find the the conjugate points (if they exist) outside the relevant segments. As it is of its own mathematical interest, we find general Jacobi vector fields on the geodesic lines under consideration. In the first part of the work we investigate Schwarzschild geometry.
On the twin paradox in static spacetimes: I. Schwarzschild metric
Sokolowski, Leszek M
2012-01-01
Motivated by a conjecture put forward by Abramowicz and Bajtlik we reconsider the twin paradox in static spacetimes. According to a well known theorem in Lorentzian geometry the longest timelike worldline between two given points is the unique geodesic line without points conjugate to the initial point on the segment joining the two points. We calculate the proper times for static twins, for twins moving on a circular orbit (if it is a geodesic) around a centre of symmetry and for twins travelling on outgoing and ingoing radial timelike geodesics. We show that the twins on the radial geodesic worldlines are always the oldest ones and we explicitly find the conjugate points (if they exist) outside the relevant segments. As it is of its own mathematical interest, we find general Jacobi vector fields on the geodesic lines under consideration. In the first part of the work we investigate Schwarzschild geometry.
The Compton-Schwarzschild correspondence from extended de Broglie relations
Energy Technology Data Exchange (ETDEWEB)
Lake, Matthew J. [The Institute for Fundamental Study, “The Tah Poe Academia Institute' ,Naresuan University, Phitsanulok 65000 (Thailand); Thailand Center of Excellence in Physics, Ministry of Education,Bangkok 10400 (Thailand); Carr, Bernard [School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom)
2015-11-17
The Compton wavelength gives the minimum radius within which the mass of a particle may be localized due to quantum effects, while the Schwarzschild radius gives the maximum radius within which the mass of a black hole may be localized due to classial gravity. In a mass-radius diagram, the two lines intersect near the Planck point (l{sub P},m{sub P}), where quantum gravity effects become significant. Since canonical (non-gravitational) quantum mechanics is based on the concept of wave-particle duality, encapsulated in the de Broglie relations, these relations should break down near (l{sub P},m{sub P}). It is unclear what physical interpretation can be given to quantum particles with energy E≫m{sub P}c{sup 2}, since they correspond to wavelengths λ≪l{sub P} or time periods τ≪t{sub P} in the standard theory. We therefore propose a correction to the standard de Broglie relations, which gives rise to a modified Schrödinger equation and a modified expression for the Compton wavelength, which may be extended into the region E≫m{sub P}c{sup 2}. For the proposed modification, we recover the expression for the Schwarzschild radius for E≫m{sub P}c{sup 2} and the usual Compton formula for E≪m{sub P}c{sup 2}. The sign of the inequality obtained from the uncertainty principle reverses at m≈m{sub P}, so that the Compton wavelength and event horizon size may be interpreted as minimum and maximum radii, respectively. We interpret the additional terms in the modified de Broglie relations as representing the self-gravitation of the wave packet.
The stable problem of the black-hole connected region in the Schwarzschild black hole
Tian, Guihua
2005-01-01
The stability of the Schwarzschild black hole is studied. Using the Painlev\\'{e} coordinate, our region can be defined as the black-hole-connected region(r>2m, see text) of the Schwarzschild black hole or the white-hole-connected region(r>2m, see text) of the Schwarzschild black hole. We study the stable problems of the black-hole-connected region. The conclusions are: (1) in the black-hole-connected region, the initially regular perturbation fields must have real frequency or complex frequen...
Null and timelike geodesics of the Schwarzschild black hole with string cloud background
Batool, Mahwish; Hussain, Ibrar
The trajectories of the time-like and null geodesics for radial and circular motion of the Schwarzschild black hole with string cloud background are investigated and compared with the Schwarzschild case without string clouds. It is found that in the presence of the string cloud parameter, the radius of the orbits is larger than the radius of the orbits in the case of the Schwarzschild black hole without string cloud parameter. Effective potential is calculated and it is observed that as the value of string cloud parameter increases the particle can more easily escape to infinity. Stability of the circular orbits is also discussed.
Transformation optics that mimics the system outside a Schwarzschild black hole
Chen, Huanyang; Miao, Rong-Xin; Li, Miao
2009-01-01
We applied the transformation optics to mimic a black hole of Schwarzschild form. Similar properties of photon sphere were also found numerically for the metamaterial black hole. Several reduced versions of the black hole systems were proposed for easier implementations.
Analytic solutions in nonlinear massive gravity.
Koyama, Kazuya; Niz, Gustavo; Tasinato, Gianmassimo
2011-09-23
We study spherically symmetric solutions in a covariant massive gravity model, which is a candidate for a ghost-free nonlinear completion of the Fierz-Pauli theory. There is a branch of solutions that exhibits the Vainshtein mechanism, recovering general relativity below a Vainshtein radius given by (r(g)m(2))(1/3), where m is the graviton mass and r(g) is the Schwarzschild radius of a matter source. Another branch of exact solutions exists, corresponding to de Sitter-Schwarzschild spacetimes where the curvature scale of de Sitter space is proportional to the mass squared of the graviton.
The Compton-Schwarzschild correspondence from extended de Broglie relations
Lake, Matthew J
2015-01-01
The Compton wavelength gives the minimum radius within which the mass of a particle may be localized due to quantum effects, while the Schwarzschild radius gives the maximum radius within which the mass of a black hole may be localized due to classial gravity. In a mass-radius diagram, the two lines intersect near the Planck point $(l_P,m_P)$, where quantum gravity effects become significant. Since canonical (non-gravitational) quantum mechanics is based on the concept of wave-particle duality, encapsulated in the de Broglie relations, these relations should break down near $(l_P,m_P)$. It is unclear what physical interpretation can be given to quantum particles with energy $E \\gg m_Pc^2 $, since they correspond to wavelengths $\\lambda \\ll l_P$ or time periods $T \\ll t_P$ in the standard theory. We therefore propose a correction to the standard de Broglie relations, which gives rise to a modified Schr{\\" o}dinger equation and a modified expression for the Compton wavelength, which may be extended into the reg...
Khayrul, Hasan, M.; Sultana, Kausari; Shahjalal, Md.
2017-10-01
We probe the plausibility of weak equivalence principle for a circular motion at the radial distance of photon sphere of the Schwarzschild?(Anti-)de Sitter black hole. We switch the static Schwarzschild?(Anti-)de Sitter space-time to rotational by means of the transformation with constant angular velocity. The fiducial observers revolving along the trajectory of photon orbit of the Schwarzschild?(Anti-)de Sitter black hole are supposed to agree on the result of any physical experiment when their angular velocities are uniform, which give rise to the constancy in their accelerations, meaning the observers are equivalent. Our study, in contrast, finds that the observers do not measure similar results, claiming the invalidity of the principle of weak equivalence. However, the aim of our work is not to defy the principle absolutely, rather we focus our attention on the very cause for which the dispute arises, namely the rotational motion.
Quantum-mechanical corrections to the Schwarzschild black-hole metric
Bargueño, P.; Bravo Medina, S.; Nowakowski, M.; Batic, D.
2017-03-01
Motivated by quantum-mechanical corrections to the Newtonian potential, which can be translated into a {\\hbar} -correction to the g 00 component of the Schwarzschild metric, we construct a quantum-mechanically corrected metric assuming -g00=grr . We show how the Bekenstein black-hole entropy S receives its logarithmic contribution provided the quantum-mechanical corrections to the metric are negative. In this case the standard horizon at the Schwarzschild radius r S increases by small terms proportional to {\\hbar} and a remnant of the order of Planck mass emerges.
First optical validation of a Schwarzschild Couder telescope: the ASTRI SST-2M Cherenkov telescope
Giro, E.; Canestrari, R.; Sironi, G.; Antolini, E.; Conconi, P.; Fermino, C. E.; Gargano, C.; Rodeghiero, G.; Russo, F.; Scuderi, S.; Tosti, G.; Vassiliev, V.; Pareschi, G.
2017-12-01
Context. The Cherenkov Telescope Array (CTA) represents the most advanced facility designed for Cherenkov Astronomy. ASTRI SST-2M has been developed as a demonstrator for the Small Size Telescope in the context of the upcoming CTA. Its main innovation consists in the optical layout which implements the Schwarzschild-Couder configuration and is fully validated for the first time. The ASTRI SST-2M optical system represents the first qualified example of a two-mirror telescope for Cherenkov Astronomy. This configuration permits us to (i) maintain high optical quality across a large field of view; (ii) demagnify the plate scale; and (iii) exploit new technological solutions for focal plane sensors. Aims: The goal of the paper is to present the optical qualification of the ASTRI SST-2M telescope. The qualification has been obtained measuring the point spread function (PSF) sizes generated in the focal plane at various distances from the optical axis. These values have been compared with the performances expected by design. Methods: After an introduction on Gamma-ray Astronomy from the ground, the optical design of ASTRI SST-2M and how it has been implemented is discussed. Moreover, the description of the set-up used to qualify the telescope over the full field of view is shown. Results: We report the results of the first-light optical qualification. The required specification of a flat PSF of 10 arcmin in a large field of view ( 10°) has been demonstrated. These results validate the design specifications, opening a new scenario for Cherenkov Gamma-ray Astronomy and, in particular, for the detection of high-energy (5-300 TeV) gamma rays and wide-field observations with CTA.
Static Solutions of Einstein's Equations with Cylindrical Symmetry
Trendafilova, C. S.; Fulling, S. A.
2011-01-01
In analogy with the standard derivation of the Schwarzschild solution, we find all static, cylindrically symmetric solutions of the Einstein field equations for vacuum. These include not only the well-known cone solution, which is locally flat, but others in which the metric coefficients are powers of the radial coordinate and the spacetime is…
Augousti, A. T.; Gawelczyk, M.; Siwek, A.; Radosz, A.
2012-01-01
The problem of communication between observers in the vicinity of a black hole in a Schwarzschild metric is considered. The classic example of an infalling observer Alice and a static distant mother station (MS) is extended to include a second infalling observer Bob, who follows Alice in falling towards the event horizon. Kruskal coordinates are…
Rayimbaev, J. R.
2016-09-01
The motion of a magnetized particle orbiting around non-Schwarzschild black hole immersed in an external uniform magnetic field is considered. The influence of deformation parameter h to effective potential of the radial motion of the magnetized particle around non-Schwarzschild black hole using Hamilton-Jacobi formalism is studied. We have obtained numerical values of area Δ ρ where magnetized particles can move which is expanding (narrowing) due to the effect of the negative (positive) deformation. Finally, we have studied the collision of two particles (magnetized-neutral, magnetized-magnetized, magnetized-charged) in non-Schwarzschild spacetime and got the center-of-mass energy (E_{c.m}) for the particles. Moreover, we have found the capture radius (r_{cap}) - the distance from the central object to the point where particles collide and fall down to the central compact object. It is shown that non-Schwarzschild black holes could also act as particle accelerators with arbitrarily high center-of-mass energy.
Vossos, Spyridon; Vossos, Elias
2017-12-01
Schwarzschild Metric is the first and the most important solution of Einstein vacuum field equations. This is associated with Lorentz metric of flat spacetime and produces the relativistic potential (Φ) and the field strength (g) outside a spherically symmetric mass or a non-rotating black hole. It has many applications such as gravitational red shift, the precession of Mercury’s orbit, Shapiro time delay etc. However, it is inefficient to explain the rotation curves in large galaxies and clusters of them, causing the necessity for dark matter. On the other hand, Modified Newtonian Dynamics (MOND) has already explained these rotation curves in many cases, using suitable interpolating function (μ) in Milgrom’s Law. In this presentation, we initially produce a Generalized Schwarzschild potential and the corresponding Metric of spacetime, in order to be in accordance with any isotropic metric of flat spacetime (including Galilean Metric of spacetime which is associated with Galilean Transformation of spacetime). From this Generalized Schwarzschild potential (Φ), we calculate the corresponding field strength (g), which is associated with the interpolating function (μ). In this way, a new relativistic potential is obtained (let us call 2nd Generalized Schwarzschild potential) which describes the gravitational interaction at any distance and for any metric of flat spacetime. Thus, not only the necessity for Dark Matter is eliminated, but also MOND becomes a pure Relativistic Theory of Gravitational Interaction. Then, we pass to the case of flat spacetime with Lorentz metric (Minkowski space), because the experimental data have been extracted using the Relativistic Doppler Shift and the gravitational red shift of Classic Relativity (CR). Thus, we Explain the Rotation Curves in Galaxies (e.g. NGC 3198) and Clusters of them as well as the Solar system, eliminating Dark Matter. This relativistic potential and the corresponding metric of spacetime have been obtained
Numerical solutions of Einstein field equations with radial dark matter
Klimenko, Stanislav; Nikitin, Igor; Nikitina, Lialia
We study a static spherically symmetric problem with a black hole and radially directed geodesic flows of dark matter. The obtained solutions have the following properties. At large distances, the gravitational field produces constant velocities of circular motion, i.e. flat rotation curves. At smaller distances, the field switches to Newtonian regime, then to Schwarzschild regime. Deviations from Schwarzschild regime start below the gravitational radius. The dark matter prevents the creation of event horizon, instead, a spherical region possessing extremely large redshift is created. The structure of space-time for the obtained solutions is investigated and the implications for the models of the galaxies are discussed.
Thermodynamic stability of modified Schwarzschild-AdS black hole in rainbow gravity
Energy Technology Data Exchange (ETDEWEB)
Kim, Yong-Wan [Chonbuk National University, Research Institute of Physics and Chemistry, Jeonju (Korea, Republic of); Kim, Seung Kook [Seonam University, Department of Physical Therapy, Namwon (Korea, Republic of); Park, Young-Jai [Sogang University, Department of Physics, Seoul (Korea, Republic of)
2016-10-15
In this paper, we have extended the previous study of the thermodynamics and phase transition of the Schwarzschild black hole in the rainbow gravity to the Schwarzschild-AdS black hole where metric depends on the energy of a probe. Making use of the Heisenberg uncertainty principle and the modified dispersion relation, we have obtained the modified local Hawking temperature and thermodynamic quantities in an isothermal cavity. Moreover, we carry out the analysis of constant temperature slices of a black hole. As a result, we have shown that there also exists another Hawking-Page-like phase transition in which case a locally stable small black hole tunnels into a globally stable large black hole as well as the standard Hawking-Page phase transition from a hot flat space to a black hole. (orig.)
Slowly decaying resonances of massive scalar fields around Schwarzschild-de Sitter black holes
Toshmatov, Bobir; Stuchlík, Zdeněk
2017-07-01
We study in special limiting cases quasinormal modes of massive scalar fields in the Schwarzschild-de Sitter black hole backgrounds. We determine the lower limit on the mass parameter of the scalar field that allows the waves with quasinormal frequencies to propagate to infinity, showing that it depends on the spacetime parameters only. Then we discuss in the large multipole number limit quasinormal modes, whose frequencies can be directly related to the unstable circular photon geodesics. In the large scalar mass approximation, we demonstrate the new interesting phenomenon of slowly decaying resonances, that are strongly related to the maximum of the effective potential of the massive scalar field, which is located at the static radius of the Schwarzschild-de Sitter spacetimes, where the cosmic repulsion is just balanced by the black hole attraction.
Scattering of Ricci scalar perturbations from Schwarzschild black holes in modified gravity
Energy Technology Data Exchange (ETDEWEB)
Sibandze, Dan B.; Goswami, Rituparno; Maharaj, Sunil D.; Nzioki, Anne Marie [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics Statistics and Computer Science, Private Bag X54001, Durban (South Africa); Dunsby, Peter K.S. [University of Cape Town, Department of Mathematics and Applied Mathematics and ACGC, Cape Town (South Africa)
2017-06-15
It has already been shown that the gravitational waves emitted from a Schwarzschild black hole in f(R) gravity have no signatures of the modification of gravity from General Relativity, as the Regge-Wheeler equation remains invariant. In this paper we consider the perturbations of Ricci scalar in a vacuum Schwarzschild spacetime, which is unique to higher order theories of gravity and is absent in General Relativity. We show that the equation that governs these perturbations can be reduced to a Volterra integral equation. We explicitly calculate the reflection coefficients for the Ricci scalar perturbations, when they are scattered by the black hole potential barrier. Our analysis shows that a larger fraction of these Ricci scalar waves are reflected compared to the gravitational waves. This may provide a novel observational signature for fourth order gravity. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Feng, Z.W.; Zu, X.T. [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Li, H.L. [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Shenyang Normal University, College of Physics Science and Technology, Shenyang (China); Yang, S.Z. [China West Normal University, Physics and Space Science College, Nanchong (China)
2016-04-15
We investigate the thermodynamics of Schwarzschild-Tangherlini black hole in the context of the generalized uncertainty principle (GUP). The corrections to the Hawking temperature, entropy and the heat capacity are obtained via the modified Hamilton-Jacobi equation. These modifications show that the GUP changes the evolution of the Schwarzschild-Tangherlini black hole. Specially, the GUP effect becomes susceptible when the radius or mass of the black hole approaches the order of Planck scale, it stops radiating and leads to a black hole remnant. Meanwhile, the Planck scale remnant can be confirmed through the analysis of the heat capacity. Those phenomena imply that the GUP may give a way to solve the information paradox. Besides, we also investigate the possibilities to observe the black hole at the Large Hadron Collider (LHC), and the results demonstrate that the black hole cannot be produced in the recent LHC. (orig.)
Ridho, Almizan
2017-01-01
130801028 Jika suatu bintang masif dengan massa M berbentuk bola, maka kita dapat menghitung radius bola yang mengungkung massa M tersebut. Kemudian untuk mengubah bintang masif tersebut menjadi lubang hitam kita harus mengubah radius ini menjadi sedemikian rupa. Radius yang menjadikan suatu bintang masif menjadi lubang hitam inilah yang kemudian dinamakan Radius Schwarzschild. Dengan demikian, kita juga dapat mendefinisikan lubang hitam sebagai suatu bintang masif bermassa M yang seluruh ...
Formation of the remnant close to Planck scale and the Schwarzschild black hole with global monopole
Li, Hui-Ling; Chen, Shuai-Ru
2017-10-01
In this paper, we use the generalized uncertainty principle (GUP) and quantum tunneling method to research the formation of the remnant from a Schwarzschild black hole with global monopole. Based on the corrected Hamilton-Jacobi equation, the corrections to the Hawking temperature, heat capacity and entropy are calculated. We not only find the remnant close to Planck scale by employing GUP, but also research the thermodynamic stability of the black hole remnant according to the phase transition and heat capacity.
Gravitational Self Force in a Schwarzschild Background and the Effective One Body Formalism
Damour, Thibault
2009-01-01
We discuss various ways in which the computation of conservative Gravitational Self Force (GSF) effects on a point mass moving in a Schwarzschild background can inform us about the basic building blocks of the Effective One-Body (EOB) Hamiltonian. We display the information which can be extracted from the recently published GSF calculation of the first-GSF-order shift of the orbital frequency of the last stable circular orbit, and we combine this information with the one recently obtained by ...
Real Scalar Field Scattering with Polynomial Approximation around Schwarzschild-de Sitter Black-hole
Liu, Molin; Liu, Hongya; Zhang, Jingfei; Yu, Fei
2008-01-01
As one of the fitting methods, the polynomial approximation is effective to process sophisticated problem. In this paper, we employ this approach to handle the scattering of scalar field around the Schwarzschild-de Sitter black-hole. The complex relationship between tortoise coordinate and radial coordinate is replaced by the approximate polynomial. The Schr$\\ddot{o}$dinger-like equation, the real boundary conditions and the polynomial approximation construct a full Sturm-Liouville type probl...
Schwarzschild-de Sitter spacetimes, McVittie coordinates, and trumpet geometries
Dennison, Kenneth A.; Baumgarte, Thomas W.
2017-12-01
Trumpet geometries play an important role in numerical simulations of black hole spacetimes, which are usually performed under the assumption of asymptotic flatness. Our Universe is not asymptotically flat, however, which has motivated numerical studies of black holes in asymptotically de Sitter spacetimes. We derive analytical expressions for trumpet geometries in Schwarzschild-de Sitter spacetimes by first generalizing the static maximal trumpet slicing of the Schwarzschild spacetime to static constant mean curvature trumpet slicings of Schwarzschild-de Sitter spacetimes. We then switch to a comoving isotropic radial coordinate which results in a coordinate system analogous to McVittie coordinates. At large distances from the black hole the resulting metric asymptotes to a Friedmann-Lemaître-Robertson-Walker metric with an exponentially-expanding scale factor. While McVittie coordinates have another asymptotically de Sitter end as the radial coordinate goes to zero, so that they generalize the notion of a "wormhole" geometry, our new coordinates approach a horizon-penetrating trumpet geometry in the same limit. Our analytical expressions clarify the role of time-dependence, boundary conditions and coordinate conditions for trumpet slices in a cosmological context, and provide a useful test for black hole simulations in asymptotically de Sitter spacetimes.
Wang, Mengjie; Herdeiro, Carlos; Jing, Jiliang
2017-11-01
We study Dirac quasinormal modes of Schwarzschild-anti-de Sitter (Schwarzschild-AdS) black holes, following the generic principle for allowed boundary conditions proposed in [M. Wang, C. Herdeiro, and M. O. P. Sampaio, Phys. Rev. D 92, 124006 (2015)., 10.1103/PhysRevD.92.124006]. After deriving the equations of motion for Dirac fields on the aforementioned background, we impose vanishing energy flux boundary conditions to solve these equations. We find a set of two Robin boundary conditions are allowed. These two boundary conditions are used to calculate Dirac normal modes on empty AdS and quasinormal modes on Schwarzschild-AdS black holes. In the former case, we recover the known normal modes of empty AdS; in the latter case, the two sets of Robin boundary conditions lead to two different branches of quasinormal modes. The impact on these modes of the black hole size, the angular momentum quantum number and the overtone number are discussed. Our results show that vanishing energy flux boundary conditions are a robust principle, applicable not only to bosonic fields but also to fermionic fields.
Directory of Open Access Journals (Sweden)
Maria de Hoyos Guajardo, Ph.D. Candidate, M.Sc., B.Eng.
2004-11-01
Full Text Available The theory that is presented below aims to conceptualise how a group of undergraduate students tackle non-routine mathematical problems during a problem-solving course. The aim of the course is to allow students to experience mathematics as a creative process and to reflect on their own experience. During the course, students are required to produce a written ‘rubric’ of their work, i.e., to document their thoughts as they occur as well as their emotionsduring the process. These ‘rubrics’ were used as the main source of data.Students’ problem-solving processes can be explained as a three-stage process that has been called ‘solutioning’. This process is presented in the six sections below. The first three refer to a common area of concern that can be called‘generating knowledge’. In this way, generating knowledge also includes issues related to ‘key ideas’ and ‘gaining understanding’. The third and the fourth sections refer to ‘generating’ and ‘validating a solution’, respectively. Finally, once solutions are generated and validated, students usually try to improve them further before presenting them as final results. Thus, the last section deals with‘improving a solution’. Although not all students go through all of the stages, it may be said that ‘solutioning’ considers students’ main concerns as they tackle non-routine mathematical problems.
Geometric Description of the Thermodynamics of the Noncommutative Schwarzschild Black Hole
Directory of Open Access Journals (Sweden)
Alexis Larrañaga
2013-01-01
Full Text Available The thermodynamics of the noncommutative Schwarzschild black hole is reformulated within the context of the recently developed formalism of geometrothermodynamics (GTD. Using a thermodynamic metric which is invariant with respect to Legendre transformations, we determine the geometry of the space of equilibrium states and show that phase transitions, which correspond to divergencies of the heat capacity, are represented geometrically as singularities of the curvature scalar. This further indicates that the curvature of the thermodynamic metric is a measure of thermodynamic interaction.
Self-consistent orbital evolution of a particle around a Schwarzschild black hole.
Diener, Peter; Vega, Ian; Wardell, Barry; Detweiler, Steven
2012-05-11
The motion of a charged particle is influenced by the self-force arising from the particle's interaction with its own field. In a curved spacetime, this self-force depends on the entire past history of the particle and is difficult to evaluate. As a result, all existing self-force evaluations in curved spacetime are for particles moving along a fixed trajectory. Here, for the first time, we overcome this long-standing limitation and present fully self-consistent orbits and waveforms of a scalar charged particle around a Schwarzschild black hole.
Quasinormal Modes of a Quantum-Corrected Schwarzschild Black Hole for Electromagnetic Perturbation
Wang, Chunyan; Gao, Yajun; Ding, Wenbo; Yu, Qingxu
2017-12-01
In this work, we investigate the electromagnetic perturbation around a quantum-corrected Schwarzschild black hole. The complex frequencies of the quasinormal modes are evaluated by the third-order WKB approximation. The numerical results obtained showed that the complex frequencies depend on the quantum correction parameter a of a black hole, which the real parts and the magnitudes of the imaginary parts of quasinormal modes decrease with the increase in factor a. These conclusions show that the electromagnetic perturbation around the black hole oscillate and damp more slowly owing to the presence of the quantum correction parameter.
Barack, Leor; Sago, Norichika
2009-05-15
The innermost stable circular orbit (ISCO) of a test particle around a Schwarzschild black hole of mass M has (areal) radius r_{isco}=6MG/c;{2}. If the particle is endowed with mass micro(radius and frequency, at leading order in the mass ratio micro/M. We obtain, in the Lorenz gauge, Deltar_{isco}=-3.269(+/-0.003)microG/c;{2} and DeltaOmega_{isco}/Omega_{isco}=0.4870(+/-0.0006)micro/M. We discuss the implications of our result within the context of the extreme-mass-ratio binary inspiral problem.
Mishra, Subodha
2007-01-01
Using a single particle density distribution for a system of self-gravitating particles which ultimately forms a black hole, we from a condensed matter point of view derive the Schwarzschild radius and by including the quantum mechanical exchange energy we find a small correction to the Schwarzschild radius, which we designate as the skin of the black hole.
Rousselle, J.; Byrum, K.; Cameron, R.; Connaughton, V.; Errando, M.; Guarino, V.; Humensky, T.; Jenke, P.; Kieda, D.; Mukherjee, R.; Nieto, D.; Okumura, A.; Petrashyk, A; Vassiliev, V.
2015-01-01
We present the design and the status of procurement of the optical system of the prototype Schwarzschild-Couder telescope (pSCT), for which construction is scheduled to begin in fall at the Fred Lawrence Whipple Observatory in southern Arizona, USA. The Schwarzschild-Couder telescope is a candidate for the medium-sized telescopes of the Cherenkov Telescope Array, which utilizes imaging atmospheric Cherenkov techniques to observe gamma rays in the energy range of 60Gev-60TeV. The pSCT novel ap...
Perturbation of a Schwarzschild Black Hole Due to a Rotating Thin Disk
Čížek, P.; Semerák, O.
2017-09-01
Will, in 1974, treated the perturbation of a Schwarzschild black hole due to a slowly rotating, light, concentric thin ring by solving the perturbation equations in terms of a multipole expansion of the mass-and-rotation perturbation series. In the Schwarzschild background, his approach can be generalized to perturbation by a thin disk (which is more relevant astrophysically), but, due to rather bad convergence properties, the resulting expansions are not suitable for specific (numerical) computations. However, we show that Green’s functions, represented by Will’s result, can be expressed in closed form (without multipole expansion), which is more useful. In particular, they can be integrated out over the source (a thin disk in our case) to yield good converging series both for the gravitational potential and for the dragging angular velocity. The procedure is demonstrated, in the first perturbation order, on the simplest case of a constant-density disk, including the physical interpretation of the results in terms of a one-component perfect fluid or a two-component dust in a circular orbit about the central black hole. Free parameters are chosen in such a way that the resulting black hole has zero angular momentum but non-zero angular velocity, as it is just carried along by the dragging effect of the disk.
Proper temperature of the Schwarzschild AdS black hole revisited
Eune, Myungseok; Kim, Wontae
2017-10-01
The Unruh temperature calculated by using the global embedding of the Schwarzschild AdS spacetime into the Minkowski spacetime was identified with the local proper temperature; however, it became imaginary in a certain region outside the event horizon. So, the temperature was assumed to be zero of non-thermal radiation for that region. In this work, we revisit this issue in an exactly soluble two-dimensional Schwarzschild AdS black hole and present an alternative resolution to this problem in terms of the Tolman's procedure. However, the process appears to be non-trivial in the sense that the original procedure assuming the traceless energy-momentum tensor should be extended in such a way that it should cover the non-vanishing case of the energy-momentum tensor in the presence of the trace anomaly. Consequently, we show that the proper temperature turns out to be real everywhere outside the event horizon without any imaginary value, in particular, it vanishes at both the horizon and the asymptotic infinity.
Kanti, P.; Pappas, T.
2017-07-01
The absence of a true thermodynamical equilibrium for an observer located in the causal area of a Schwarzschild-de Sitter spacetime has repeatedly raised the question of the correct definition of its temperature. In this work, we consider five different temperatures for a higher-dimensional Schwarzschild-de Sitter black hole: the bare T0, the normalized TBH, and three effective ones given in terms of both the black-hole and cosmological horizon temperatures. We find that these five temperatures exhibit similarities but also significant differences in their behavior as the number of extra dimensions and the value of the cosmological constant are varied. We then investigate their effect on the energy emission spectra of Hawking radiation. We demonstrate that the radiation spectra for the normalized temperature TBH—proposed by Bousso and Hawking over twenty years ago—leads to the dominant emission curve, while the other temperatures either support a significant emission rate only in a specific Λ regime or have their emission rates globally suppressed. Finally, we compute the bulk-over-brane emissivity ratio and show that the use of different temperatures may lead to different conclusions regarding the brane or bulk dominance.
Recovering the mass profile and orbit anisotropy of mock dwarf galaxies with Schwarzschild modelling
Kowalczyk, Klaudia; Łokas, Ewa L.; Valluri, Monica
2017-10-01
We present a new study concerning the application of the Schwarzschild orbit superposition method to model spherical galaxies. The method aims to recover the mass and the orbit anisotropy parameter profiles of the objects using measurements of positions and line-of-sight velocities usually available for resolved stellar populations of dwarf galaxies in the Local Group. To test the reliability of the method, we used different sets of mock data extracted from four numerical realizations of dark matter haloes. The models shared the same density profile but differed in anisotropy profiles, covering a wide range of possibilities, from constant to increasing and decreasing with radius. The tests were done in two steps, first assuming that the mass profile of the dwarf is known and employing the method to retrieve the anisotropy only, and then varying also the mass distribution. We used two kinds of data samples: unrealistically large ones based on over 270 000 particles from the numerical realizations and small ones matching the amount of data available for the Fornax dwarf. For the large data samples, we recover both the mass and the anisotropy profiles with very high accuracy. For the realistically small ones, we also find a reasonably good agreement between the fitted and the input anisotropies, however the total density profiles can be significantly biased as a result of their oversensitivity to the available data. Our results therefore provide convincing evidence in favour of the applicability of the Schwarzschild method to break the mass-anisotropy degeneracy in dwarf galaxies.
(Non-adiabatic) string creation on nice slices in Schwarzschild black holes
Puhm, Andrea; Rojas, Francisco; Ugajin, Tomonori
2017-04-01
Nice slices have played a pivotal role in the discussion of the black hole information paradox as they avoid regions of strong spacetime curvature and yet smoothly cut through the infalling matter and the outgoing Hawking radiation, thus, justifying the use of low energy field theory. To avoid information loss it has been argued recently, however, that local effective field theory has to break down at the horizon. To assess the extent of this breakdown in a UV complete framework we study string-theoretic effects on nice slices in Schwarzschild black holes. Our purpose is two-fold. First, we use nice slices to address various open questions and caveats of [1] where it was argued that boost-enhanced non-adiabatic string-theoretic effects at the horizon could provide a dynamical mechanism for the firewall. Second, we identify two non-adiabatic effects on nice slices in Schwarzschild black holes: pair production of open strings near the horizon enhanced by the presence of the infinite tower of highly excited string states and a late-time non-adiabatic effect intrinsic to nice slices.
Directory of Open Access Journals (Sweden)
Sergio Mendoza
2009-01-01
Full Text Available We present heuristic arguments suggesting that if EM waves with wavelengths somewhat larger than the Schwarzschild radius of a black hole were fully absorbed by it, the second law of thermodynamics would be violated, under the Bekenstein interpretation of the area of a black hole as a measure of its entropy. Thus, entropy considerations make the well known fact that large wavelengths are only marginally absorbed by black holes, a natural consequence of thermodynamics. We also study numerically the ingoing radial propagation of a scalar field wave in a Schwarzschild metric, relaxing the standard assumption which leads to the eikonal equation, that the wave has zero spatial extent. We find that if these waves have wavelengths larger that the Schwarzschild radius, they are very substantially reflected, fully to numerical accuracy. Interestingly, this critical wavelength approximately coincides with the one derived from entropy considerations of the EM field, and is consistent with well known limit results of scattering in the Schwarzschild metric. The propagation speed is also calculated and seen to differ from the value c, for wavelengths larger than Rs, in the vicinity of Rs. As in all classical wave phenomena, whenever the wavelength is larger or comparable to the physical size of elements in the system, in this case changes in the metric, the zero extent Ã¢Â€Â™particleÃ¢Â€Â™ description fails, and the wave nature becomes apparent.
From the Schwarzschild Anti-de Sitter Black Hole to the Conformal Field Theory
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Akram Sadat Sefiedgar
2015-01-01
Full Text Available The emergence of the quantum gravitational effects in a very high energy regime necessitates some corrections to the thermodynamics of black holes. In this letter, we investigate a possible modification to the thermodynamics of Schwarzschild anti-de Sitter (SAdS black holes due to rainbow gravity model. Using the correspondence between a (d+1-dimensional SAdS black hole and a conformal filed theory in d-dimensional spacetime, one may find the corrections to the Cardy-Verlinde formula from the modified thermodynamics of the black hole. Furthermore, we show that the corrected Cardy-Verlinde formula can also be derived by redefining the Virasoro operator and the central charge.
Hawking radiation as tunneling in Schwarzschild anti-de Sitter black hole
Sefiedgar, A. S.; Ashrafinejad, A.
2017-08-01
The Hawking radiation from a (d+1) -dimensional Schwarzschild Anti-de Sitter (SAdS) black hole is investigated within rainbow gravity. Based on the method proposed by Kraus, Parikh and Wilczek, the Hawking radiation is considered as a tunneling process across the horizon. The emission rate of massless particles which are tunneling across the quantum-corrected horizon is calculated. Enforcing the energy conservation law leads to a dynamical geometry. Both the dynamical geometry and the quantum effects of space-time yield some corrections to the emission rate. The corrected radiation spectrum is not purely thermal. The emission rate is related to the changes of modified entropy in rainbow gravity and the corrected thermal spectrum may be consistent with an underlying unitary quantum theory. The correlations between emitted particles are also investigated in order to address the recovery of information.
Toward the construction of a medium size prototype Schwarzschild-Couder telescope for CTA
Rousselle, J.; Byrum, K.; Cameron, R.; Connaughton, V.; Errando, M.; Griffiths, S.; Guarino, V.; Humensky, T. B.; Jenke, P.; Kaaret, P.; Kieda, D.; Limon, M.; Mognet, I.; Mukherjee, R.; Nieto, D.; Okumura, A.; Peck, A.; Petrashyk, A.; Ribeiro, D.; Stevenson, B.; Vassiliev, V.; Yu, P.
2015-09-01
The construction of a prototype Schwarzschild-Couder telescope (pSCT) started in early June 2015 at the Fred Lawrence Whipple Observatory in Southern Arizona, as a candidate medium-sized telescope for the Cherenkov Telescope Array (CTA). Compared to current Davies-Cotton telescopes, this novel instrument with an aplanatic two-mirror optical system will offer a wider field-of-view and improved angular resolution. In addition, the reduced plate scale of the camera allows the use of highly-integrated photon detectors such as silicon photo multipliers. As part of CTA, this design has the potential to greatly improve the performance of the next generation ground-based observatory for very high-energy (E>60 GeV) gamma-ray astronomy. In this contribution we present the design and performance of both optical and alignment systems of the pSCT.
Accretion of a symmetry-breaking scalar field by a Schwarzschild black hole.
Traykova, Dina; Braden, Jonathan; Peiris, Hiranya V
2018-03-06
We simulate the behaviour of a Higgs-like field in the vicinity of a Schwarzschild black hole using a highly accurate numerical framework. We consider both the limit of the zero-temperature Higgs potential and a toy model for the time-dependent evolution of the potential when immersed in a slowly cooling radiation bath. Through these numerical investigations, we aim to improve our understanding of the non-equilibrium dynamics of a symmetry-breaking field (such as the Higgs) in the vicinity of a compact object such as a black hole. Understanding this dynamics may suggest new approaches for studying properties of scalar fields using black holes as a laboratory.This article is part of the Theo Murphy meeting issue 'Higgs Cosmology'. © 2018 The Author(s).
General theories of linear gravitational perturbations to a Schwarzschild black hole
Tattersall, Oliver J.; Ferreira, Pedro G.; Lagos, Macarena
2018-02-01
We use the covariant formulation proposed by Tattersall, Lagos, and Ferreira [Phys. Rev. D 96, 064011 (2017), 10.1103/PhysRevD.96.064011] to analyze the structure of linear perturbations about a spherically symmetric background in different families of gravity theories, and hence study how quasinormal modes of perturbed black holes may be affected by modifications to general relativity. We restrict ourselves to single-tensor, scalar-tensor and vector-tensor diffeomorphism-invariant gravity models in a Schwarzschild black hole background. We show explicitly the full covariant form of the quadratic actions in such cases, which allow us to then analyze odd parity (axial) and even parity (polar) perturbations simultaneously in a straightforward manner.
Gravitational self-force effects on a point mass moving around a Schwarzschild black hole
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Sago, Norichika [School of Mathematics, University of Southampton, University Road, Southampton, SO17 1BJ (United Kingdom)
2009-05-07
We consider the effects of the gravitational self-force on a point mass moving in a generic (eccentric) orbit around a Schwarzschild black hole. We developed a numerical code to solve the metric perturbation equations in the time domain, under the Lorenz gauge condition, and to implement the so-called 'mode sum' scheme to obtain the self-force. We use our numerical results to investigate both dissipative and conservative self-force effects on the particle's orbits. To check the consistency of our calculation, we (1) compare our results with independent calculations based on a different gauge, in the special case of a circular orbit (by considering gauge-invariant quantities); (2) derive the energy and angular momentum fluxes of emitted gravitational waves and compare with results from standard Teukolsky-based calculations.
Marginally Stable Circular Orbits in Schwarzschild Black Hole Surrounded by Quintessence Matter
Hussain, Ibrar
2016-01-01
Marginally stable circular orbits (MSCOs) of a massive test particle are investigated in the spacetime geometry of Schwarzschild black hole surrounded by quintessence. For that matter we consider three important scenarios where the equation of state parameter $\\omega_{q}$, has one of the following forms (i) $\\omega_q=-1$ (ii) $\\omega_q=-2/3$ and (iii) $\\omega_q= -1/3$. The existence of such marginally stable circular orbits in these scenarios depend on the range of normalization factor $\\alpha$. Briefly, we show that in the first case such orbits exist only if $0<\\alpha<4/16875$. Moreover in the second case which is a special Kiselev black hole it is found that MSCOs exist when the value of the normalization factor satisfy $0<\\alpha\\leq 0.00536165238$. In the last case the MSCOs are also shown to exist.
Schwarzschild-de Sitter spacetime: The role of temperature in the emission of Hawking radiation
Pappas, Thomas; Kanti, Panagiota
2017-12-01
We consider a Schwarzschild-de Sitter (SdS) black hole, and focus on the emission of massless scalar fields either minimally or non-minimally coupled to gravity. We use six different temperatures, two black-hole and four effective ones for the SdS spacetime, as the question of the proper temperature for such a background is still debated in the literature. We study their profiles under the variation of the cosmological constant, and derive the corresponding Hawking radiation spectra. We demonstrate that only few of these temperatures may support significant emission of radiation. We finally compute the total emissivities for each temperature, and show that the non-minimal coupling constant of the scalar field to gravity also affects the relative magnitudes of the energy emission rates.
Tripartite nonlocality for an open Dirac system in the background of Schwarzschild space–time
Ding, Zhi-Yong; Shi, Jia-Dong; Wu, Tao; He, Juan
2017-12-01
In this paper, the behavior of the tripartite nonlocality for a Dirac system in the background of Schwarzschild space–time is studied. It is shown that the nonlocality of the ultimate physical accessible state always decreases as the Hawking effect increases monotonically, which is independent of the number of particles located near the event horizon. Besides, the more particles there are located near the event horizon, the more difficult the violation of the Svetlichny inequality becomes. Furthermore, we investigate the property of these particles suffering from a non-Markovian environment, and derive that the nonlocality decreases quickly with the increasing decoherence time accompanied by damping revivals. To preserve tripartite nonlocality in the non-Markovian environment, we propose a scheme by means of prior weak measurement and post measurement reversal. It is worth noticing that the effect is better for larger measurement strengths, while it induces smaller success probability.
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El-Menoufi, Basem Kamal [Department of Physics, University of Massachusetts,Amherst, MA 01003 (United States)
2016-05-05
In the context of effective field theory, we consider quantum gravity with minimally coupled massless particles. Fixing the background geometry to be of the Kerr-Schild type, we fully determine the one-loop effective action of the theory whose finite non-local part is induced by the long-distance portion of quantum loops. This is accomplished using the non-local expansion of the heat kernel in addition to a non-linear completion technique through which the effective action is expanded in gravitational curvatures. Via Euclidean methods, we identify a logarithmic correction to the Bekenstein-Hawking entropy of Schwarzschild black hole. Using dimensional transmutation the result is shown to exhibit an interesting interplay between the UV and IR properties of quantum gravity.
Accretion of a symmetry-breaking scalar field by a Schwarzschild black hole
Traykova, Dina; Braden, Jonathan; Peiris, Hiranya V.
2018-01-01
We simulate the behaviour of a Higgs-like field in the vicinity of a Schwarzschild black hole using a highly accurate numerical framework. We consider both the limit of the zero-temperature Higgs potential and a toy model for the time-dependent evolution of the potential when immersed in a slowly cooling radiation bath. Through these numerical investigations, we aim to improve our understanding of the non-equilibrium dynamics of a symmetry-breaking field (such as the Higgs) in the vicinity of a compact object such as a black hole. Understanding this dynamics may suggest new approaches for studying properties of scalar fields using black holes as a laboratory. This article is part of the Theo Murphy meeting issue `Higgs Cosmology'.
Al-Badawi, A.
2018-02-01
The Dirac equation is considered in a spacetime that represents a Schwarzschild metric coupled to a uniform external electromagnetic field. Due to the presence of electromagnetic field from the surroundings, the interaction with the spin-1/2 massive charged particle is considered. The equations of the spin-1/2 massive charged particle are separated into radial and angular equations by adopting the Newman-Penrose formalism. The angular equations obtained are similar to the Schwarzschild geometry. For the radial equations we manage to obtain the one dimensional Schrödinger-type wave equations with effective potentials. Finally, we study the behavior of the potentials by plotting them as a function of radial distance and expose the effect of the external parameter, charge and the frequency of the particle on them.
Ng, Keith K.; Mann, Robert B.; Martín-Martínez, Eduardo
2017-10-01
The RP3 geon and the Schwarzschild black hole are two black hole spacetimes which differ only behind the event horizon. We show that the thermal Hawking radiation emanating from the two black holes contains nontrivial correlations, that these correlations contain information about their interiors, and demonstrate that a particle detector can recover these correlations. In this manner, a simple particle detector can determine the structure behind the event horizon of an eternal black hole.
Alvarez-Gaumé, Luís; Marino, M; Wadia, S R; Alvarez-Gaume, Luis; Basu, Pallab; Marino, Marcos; Wadia, Spenta R.
2006-01-01
In this paper we discuss the blackhole-string transition of the small Schwarzschild blackhole of $AdS_5 \\times S^5$ using the AdS/CFT correspondence at finite temperature. The finite temperature gauge theory effective action, at weak {\\it and} strong coupling, can be expressed entirely in terms of constant Polyakov lines which are $SU (N)$ matrices. In showing this we have taken into account that there are no Nambu-Goto modes associated with the fact that the 10 dimensional blackhole solution sits at a point in $S^5$. We show that the phase of the gauge theory in which the eigenvalue spectrum has a gap corresponds to supergravity saddle points in the bulk theory. We identify the third order $N = \\infty$ phase transition with the blackhole-string transition. This singularity can be resolved using a double scaling limit in the transition region where the large N expansion is organized in terms of powers of $N^{-2/3}$. The $N = \\infty$ transition now becomes a smooth crossover in terms of a renormalized string c...
Gravitational self-force on a particle in eccentric orbit around a Schwarzschild black hole
Barack, Leor
2010-01-01
We present a numerical code for calculating the local gravitational self-force acting on a pointlike particle in a generic (bound) geodesic orbit around a Schwarzschild black hole. The calculation is carried out in the Lorenz gauge: For a given geodesic orbit, we decompose the Lorenz-gauge metric perturbation equations (sourced by the delta-function particle) into tensorial harmonics, and solve for each harmonic using numerical evolution in the time domain (in 1+1 dimensions). The physical self-force along the orbit is then obtained via mode-sum regularization. The total self-force contains a dissipative piece as well as a conservative piece, and we describe a simple method for disentangling these two pieces in a time-domain framework. The dissipative component is responsible for the loss of orbital energy and angular momentum through gravitational radiation; as a test of our code we demonstrate that the work done by the dissipative component of the computed force is precisely balanced by the asymptotic fluxe...
Thermodynamics of the Schwarzschild-AdS Black Hole with a Minimal Length
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Yan-Gang Miao
2017-01-01
Full Text Available Using the mass-smeared scheme of black holes, we study the thermodynamics of black holes. Two interesting models are considered. One is the self-regular Schwarzschild-AdS black hole whose mass density is given by the analogue to probability densities of quantum hydrogen atoms. The other model is the same black hole but whose mass density is chosen to be a rational fractional function of radial coordinates. Both mass densities are in fact analytic expressions of the δ-function. We analyze the phase structures of the two models by investigating the heat capacity at constant pressure and the Gibbs free energy in an isothermal-isobaric ensemble. Both models fail to decay into the pure thermal radiation even with the positive Gibbs free energy due to the existence of a minimal length. Furthermore, we extend our analysis to a general mass-smeared form that is also associated with the δ-function and indicate the similar thermodynamic properties for various possible mass-smeared forms based on the δ-function.
Transformation Groups for a Schwarzschild-Type Geometry in f(R Gravity
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Emre Dil
2016-01-01
Full Text Available We know that the Lorentz transformations are special relativistic coordinate transformations between inertial frames. What happens if we would like to find the coordinate transformations between noninertial reference frames? Noninertial frames are known to be accelerated frames with respect to an inertial frame. Therefore these should be considered in the framework of general relativity or its modified versions. We assume that the inertial frames are flat space-times and noninertial frames are curved space-times; then we investigate the deformation and coordinate transformation groups between a flat space-time and a curved space-time which is curved by a Schwarzschild-type black hole, in the framework of f(R gravity. We firstly study the deformation transformation groups by relating the metrics of the flat and curved space-times in spherical coordinates; after the deformation transformations we concentrate on the coordinate transformations. Later on, we investigate the same deformation and coordinate transformations in Cartesian coordinates. Finally we obtain two different sets of transformation groups for the spherical and Cartesian coordinates.
Hanada, Masanori; Miwa, Akitsugu; Nishimura, Jun; Takeuchi, Shingo
2009-05-08
In the string-gauge duality it is important to understand how the space-time geometry is encoded in gauge theory observables. We address this issue in the case of the D0-brane system at finite temperature T. Based on the duality, the temporal Wilson loop W in gauge theory is expected to contain the information of the Schwarzschild radius RSch of the dual black hole geometry as log(W)=RSch/(2pialpha'T). This translates to the power-law behavior log(W)=1.89(T/lambda 1/3)-3/5, where lambda is the 't Hooft coupling constant. We calculate the Wilson loop on the gauge theory side in the strongly coupled regime by performing Monte Carlo simulations of supersymmetric matrix quantum mechanics with 16 supercharges. The results reproduce the expected power-law behavior up to a constant shift, which is explainable as alpha' corrections on the gravity side. Our conclusion also demonstrates manifestly the fuzzball picture of black holes.
Holographic entanglement entropies for Schwarzschild and Reisner-Nordstr\\"om spacetimes
Sun, Yuan
2016-01-01
The holographic entanglement entropies (HEE) associated with four dimensional Schwarzschild and Reisner-Nordstr\\"om spacetimes are investigated. Unlike the cases of asymptotically AdS spacetimes for which the boundaries are always taken at (timelike) conformal infinities, we take the boundaries at either large but finite radial coordinate (far boundary) or very close to the black hole event horizons (near horizon boundary). The reason for such choices is that such boundaries are similar to the conformal infinity of AdS spacetime in that they are all timelike, so that there may be some hope to define dual systems with ordinary time evolution on such boundaries. Our results indicate that, in the case of far boundaries, the leading order contribution to the HEEs come from the background Minkowski spacetime, however, the next to leading order contribution which arises from the presence of the black holes is always proportional to the black hole mass, which constitutes a version of the first law of the HEE for asy...
Gravitational self-force in a Schwarzschild background and the effective one-body formalism
Damour, Thibault
2010-01-01
We discuss various ways in which the computation of conservative gravitational self-force (GSF) effects on a point mass moving in a Schwarzschild background can inform us about the basic building blocks of the effective one-body (EOB) Hamiltonian. We display the information which can be extracted from the recently published GSF calculation of the first-GSF-order shift of the orbital frequency of the last stable circular orbit, and we combine this information with the one recently obtained by comparing the EOB formalism to high-accuracy numerical relativity data on coalescing binary black holes. The information coming from GSF data helps to break the degeneracy (among some EOB parameters) which was left after using comparable-mass numerical relativity data to constrain the EOB formalism. We suggest various ways of obtaining more information from GSF computations: either by studying eccentric orbits, or by focusing on a special zero-binding zoom-whirl orbit. We show that logarithmic terms start entering the post-Newtonian expansions of various (EOB and GSF) functions at the fourth post-Newtonian level, and we analytically compute the first logarithm entering a certain, gauge-invariant “redshift” GSF function (defined along the sequence of circular orbits).
Gravitational Self Force in a Schwarzschild Background and the Effective One Body Formalism
Damour, Thibault
2009-01-01
We discuss various ways in which the computation of conservative Gravitational Self Force (GSF) effects on a point mass moving in a Schwarzschild background can inform us about the basic building blocks of the Effective One-Body (EOB) Hamiltonian. We display the information which can be extracted from the recently published GSF calculation of the first-GSF-order shift of the orbital frequency of the last stable circular orbit, and we combine this information with the one recently obtained by comparing the EOB formalism to high-accuracy numerical relativity (NR) data on coalescing binary black holes. The information coming from GSF data helps to break the degeneracy (among some EOB parameters) which was left after using comparable-mass NR data to constrain the EOB formalism. We suggest various ways of obtaining more information from GSF computations: either by studying eccentric orbits, or by focussing on a special zero-binding zoom-whirl orbit. We show that logarithmic terms start entering the post-Newtonian ...
Merlin, Cesar
2014-01-01
We present a first numerical implementation of a new scheme by Pound et al. that enables the calculation of the gravitational self-force in Kerr spacetime from a reconstructed metric-perturbation in a radiation gauge. The numerical task of the metric reconstruction essentially reduces to solving the fully separable Teukolsky equation, rather than having to tackle the linearized Einstein's equations themselves. The method offers significant computational saving compared to existing methods in the Lorenz gauge, and we expect it to become a main workhorse for precision self-force calculations in the future. Here we implement the method for circular orbits on a Schwarzschild background, in order to illustrate its efficacy and accuracy. We use two independent methods for solving the Teukolsky equation, one based on a direct numerical integration, and the other on the analytical approach of Mano, Suzuki, and Takasugi. The relative accuracy of the output self-force is at least $10^{-7}$ using the first method, and a...
Kim, Jinho; Garain, Sudip K.; Balsara, Dinshaw S.; Chakrabarti, Sandip K.
2017-11-01
We study time evolution of sub-Keplerian transonic accretion flows on to black holes using a general relativistic numerical simulation code. We perform simulations in Schwarzschild space-time. We first compare one-dimensional simulation results with theoretical results and validate the performance of our code. Next, we present results of axisymmetric, two-dimensional simulation of advective flows. We find that even in this case, for which no complete theoretical analysis is present in the literature, steady-state shock formation is possible.
Saha, T. T.
1984-01-01
An equation similar to the Abbe sine condition is derived for a Wolter type II telescope. This equation and the sine condition are then combined to produce a so called generalized sine condition. Using the law of reflection, Fermat's principle, the generalized sine condition, and simple geometry the surface equations for a Wolter type II telescope and an equivalent Wolter-Schwarzschild telescope are calculated. The performances of the telescopes are compared in terms of rms blur circle radius at the Gaussian focal plane and at best focus.
Relativity solution for ``Twin paradox'': a comprehensive solution
Sfarti, A.
2012-10-01
We have provided a complete and realistic solution to the problem of Twin Paradox, for the first time, in the frame work of general relativity. Some of the inspiration for this paper has come from the well known papers by Linet and Teyssandier (Phys Rev D 66:024045, 2002) discussing objects moving on geodesics for more general metrics than Schwarzschild. The subject of the "Twin paradox" is encountered frequently in relativity classes but a complete solution in the general relativity framework is not being taught. Our approaches have covered all the cases, starting with inertial motion in flat space time, going through hyperbolic motion in flat space time and ending with the treatment for curved space time.
Global structure of static spherically symmetric solutions surrounded by quintessence
Cruz, Miguel; Ganguly, Apratim; Gannouji, Radouane; Leon, Genly; Saridakis, Emmanuel N.
2017-06-01
We investigate all static spherically symmetric solutions in the context of general relativity surrounded by a minimally-coupled quintessence field, using dynamical system analysis. Applying the 1 + 1 + 2 formalism and introducing suitable normalized variables involving the Gaussian curvature, we were able to reformulate the field equations as first order differential equations. In the case of a massless canonical scalar field we recovered all known black hole results, such as the Fisher solution, and we found that apart from the Schwarzschild solution all other solutions are naked singularities. Additionally, we identified the symmetric phase space which corresponds to the white hole part of the solution and in the case of a phantom field, we were able to extract the conditions for the existence of wormholes and define all possible classes of solutions such as cold black holes, singular spacetimes and wormholes such as the Ellis wormhole, for example. For an exponential potential, we found that the black hole solution which is asymptotically flat is unique and it is the Schwarzschild spacetime, while all other solutions are naked singularities. Furthermore, we found solutions connecting to a white hole through a maximum radius, and not a minimum radius (throat) such as wormhole solutions, therefore violating the flare-out condition. Finally, we have found a necessary and sufficient condition on the form of the potential to have an asymptotically AdS spacetime along with a necessary condition for the existence of asymptotically flat black holes.
Akcay, Sarp
2010-01-01
Fast, reliable orbital evolutions of compact objects around massive black holes will be needed as input for gravitational wave search algorithms in the data stream generated by the planned Laser Interferometer Space Antenna (LISA). Currently, the state of the art is a time-domain code by [Phys. Rev. D{\\bf 81}, 084021, (2010)] that computes the gravitational self-force on a point-particle in an eccentric orbit around a Schwarzschild black hole. Currently, time-domain codes take up to a few days to compute just one point in parameter space. In a series of articles, we advocate the use of a frequency-domain approach to the problem of gravitational self-force (GSF) with the ultimate goal of orbital evolution in mind. Here, we compute the GSF for a particle in a circular orbit in Schwarzschild spacetime. We solve the linearized Einstein equations for the metric perturbation in Lorenz gauge. Our frequency-domain code reproduces the time-domain results for the GSF up to $\\sim 1000$ times faster for small orbital rad...
A static axisymmetric exact solution of f(R)-gravity
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Gutierrez-Pineres, Antonio C., E-mail: acgutierrez@correo.nucleares.unam.mx [Facultad de Ciencias Basicas, Universidad Tecnologica de Bolivar, CO 131001 Cartagena de Indias (Colombia); Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Lopez-Monsalvo, Cesar S., E-mail: cesar.slm@correo.nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico)
2013-01-29
We present an exact, axially symmetric, static, vacuum solution for f(R)-gravity in Weyl's canonical coordinates. We obtain a general explicit expression for the dependence of df(R)/dR upon the r and z coordinates and then the corresponding explicit form of f(R), which must be consistent with the field equations. We analyze in detail the modified Schwarzschild solution in prolate spheroidal coordinates. Finally, we study the curvature invariants and show that, in the case of f(R){ne}R, this solution corresponds to a naked singularity.
Schwarzschildâde Sitter spacetime: The role of temperature in the emission of Hawking radiation
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Thomas Pappas
2017-12-01
Full Text Available We consider a Schwarzschildâde Sitter (SdS black hole, and focus on the emission of massless scalar fields either minimally or non-minimally coupled to gravity. We use six different temperatures, two black-hole and four effective ones for the SdS spacetime, as the question of the proper temperature for such a background is still debated in the literature. We study their profiles under the variation of the cosmological constant, and derive the corresponding Hawking radiation spectra. We demonstrate that only few of these temperatures may support significant emission of radiation. We finally compute the total emissivities for each temperature, and show that the non-minimal coupling constant of the scalar field to gravity also affects the relative magnitudes of the energy emission rates.
The self-force on a non-minimally coupled static scalar charge outside a Schwarzschild black hole
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Cho, Demian H J; Tsokaros, Antonios A; Wiseman, Alan G [Department of Physics, University of Wisconsin-Milwaukee, PO Box 413, Milwaukee, WI 53201 (United States)
2007-03-07
The finite part of the self-force on a static, non-minimally coupled scalar test charge outside a Schwarzschild black hole is zero. This result is determined from the work required to slowly raise or lower the charge through an infinitesimal distance. Unlike similar force calculations for minimally-coupled scalar charges or electric charges, we find that we must account for a flux of field energy that passes through the horizon and changes the mass and area of the black hole when the charge is displaced. This occurs even for an arbitrarily slow displacement of the non-minimally coupled scalar charge. For a positive coupling constant, the area of the hole increases when the charge is lowered and decreases when the charge is raised. The fact that the self-force vanishes for a static, non-minimally coupled scalar charge in Schwarzschild spacetime agrees with a simple prediction of the Quinn-Wald axioms. However, Zel'nikov and Frolov computed a non-vanishing self-force for a non-minimally coupled charge. Our method of calculation closely parallels the derivation of Zel'nikov and Frolov, and we show that their omission of this unusual flux is responsible for their (incorrect) result. When the flux is accounted for, the self-force vanishes. This correction eliminates a potential counter example to the Quinn-Wald axioms. The fact that the area of the black hole changes when the charge is displaced brings up two interesting questions that did not arise in similar calculations for static electric charges and minimally coupled scalar charges. (1) How can we reconcile a decrease in the area of the black hole horizon with the area theorem which concludes that {delta}Area{sub horizon} {>=} 0? The key hypothesis of the area theorem is that the stress-energy tensor must satisfy a null-energy condition T{sup {alpha}}{sup {beta}}l{sub {alpha}}l{sub {beta}} {>=} 0 for any null vector l{sub {alpha}}. We explicitly show that the stress-energy associated with a non
Conical Stream of the Two-Sided Jets in NGC 4261 over the Range of 103–109 Schwarzschild Radii
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Satomi Nakahara
2016-12-01
Full Text Available We report the jet width profile of of the nearby ( ∼ 30 Mpc AGN NGC 4261 for both the approaching jet and the counter jet at radial distances ranging from ∼ 10 3 – 10 9 Schwarzschild radius ( R S from the central engine. Our Very Large Array (VLA and Very Long Baseline Array (VLBA observations reveal that the jets maintain a conical structure on both sides over the range 10 3 – 10 9 R S without any structural transition (i.e., parabolic to conical like in the approaching jet in M87. Thus, NGC 4261 will provide a unique opportunity to examine the conical jet hypothesis in blazars, while it may require some additional consideration on the acceleration and collimation process in AGN jets.
Tarafdar, Pratik; Majumdar, Archan S
2013-01-01
In black hole evaporation process, the mass of the hole anti-correlates with the Hawking temperature enabling us to infer that the smaller mass holes will have higher surface gravity. For analogue Hawking effects, however, the acoustic surface gravity is determined by the local value of the dynamical velocity of the stationary background fluid flow and the speed of propagation of the characteristic perturbation embedded in the background fluid, as well as their space derivatives evaluated along the direction normal to the acoustic horizon, respectively. The mass of the analogue system - whether classical or quantum - does not directly contribute to extremise the value of the associated acoustic surface gravity. For general relativistic axisymmetric background fluid flow in the Schwarzschild metric, we show that the initial boundary conditions describing such axisymmetrically accreting matter flow influence the maximization scheme of the acoustic surface gravity as well as the corresponding characteristic temp...
Kundu, Prasun K.
2017-11-01
In a comment published several years ago in this journal, Mitra [J. Math. Phys. 50, 042502 (2009)] has claimed to prove that a neutral point particle in general relativity as described by the Schwarzschild metric must have zero gravitational mass, i.e., the mass parameter M0 of a Schwarzschild black hole necessarily vanishes. It is shown that the purported proof is incorrect. The error stems from a basic misunderstanding of the mathematical description of coordinate volume element in a differentiable manifold.
Analytic solution for a static black hole in the RSII model
Dai, De-Chang; Stojkovic, Dejan
2011-10-01
We present here a static solution for a large black hole (whose horizon radius is larger than the AdS radius) located on the brane in RSII model. According to some arguments based on the AdS/CFT conjecture, a solution for the black hole located on the brane in RSII model must encode quantum gravitational effects and therefore cannot be static. We demonstrated that a static solution can be found if the bulk is not empty. The stress energy tensor of the matter distribution in the bulk for the solution we found is physical (i.e. it is non-singular with the energy density and pressure not violating any energy conditions). The scale of the solution is given by a parameter “a”. For large values of the parameter “a” we have a limit of an almost empty AdS bulk. It is interesting that the solution cannot be transformed into the Schwarzschild-like form and does not reduce to the Schwarzschild solution on the brane. We also present two other related static solutions. At the end, we discuss why the numerical methods failed so far in finding static solutions in this context, including the solutions we found analytically here.
Analytic solution for a static black hole in the RSII model
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Dai Dechang [Department of Physics, SUNY at Buffalo, Buffalo, NY 14260-1500 (United States); Stojkovic, Dejan, E-mail: ds77@buffalo.edu [Department of Physics, SUNY at Buffalo, Buffalo, NY 14260-1500 (United States)
2011-10-19
We present here a static solution for a large black hole (whose horizon radius is larger than the AdS radius) located on the brane in RSII model. According to some arguments based on the AdS/CFT conjecture, a solution for the black hole located on the brane in RSII model must encode quantum gravitational effects and therefore cannot be static. We demonstrated that a static solution can be found if the bulk is not empty. The stress energy tensor of the matter distribution in the bulk for the solution we found is physical (i.e. it is non-singular with the energy density and pressure not violating any energy conditions). The scale of the solution is given by a parameter 'a'. For large values of the parameter 'a' we have a limit of an almost empty AdS bulk. It is interesting that the solution cannot be transformed into the Schwarzschild-like form and does not reduce to the Schwarzschild solution on the brane. We also present two other related static solutions. At the end, we discuss why the numerical methods failed so far in finding static solutions in this context, including the solutions we found analytically here.
Relativistic electrons and magnetic fields of the M87 jet on the ∼10 Schwarzschild radii scale
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Kino, M. [Korea Astronomy and Space Science Institute, 776 Daedukdae-ro, Yusong, Daejon 305-348 (Korea, Republic of); Takahara, F. [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan); Hada, K. [INAF—Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Doi, A. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, 229-8510 Sagamihara (Japan)
2014-05-01
We explore energy densities of the magnetic fields and relativistic electrons in the M87 jet. Since the radio core at the jet base is identical to the optically thick surface against synchrotron self-absorption (SSA), the observing frequency is identical to the SSA turnover frequency. As a first step, we assume the radio core has a simple uniform sphere geometry. Using the observed angular size of the radio core measured by the Very Long Baseline Array at 43 GHz, we estimate the energy densities of magnetic fields (U{sub B} ) and relativistic electrons (U{sub e} ) on the basis of the standard SSA formula. Imposing the condition that the Poynting power and kinetic power of relativistic electrons should be smaller than the total power of the jet, we find that (1) the allowed range of the magnetic field strength (B {sub tot}) is 1 G ≤ B {sub tot} ≤ 15 G and that (2) 1 × 10{sup –5} ≤ U{sub e} /U{sub B} ≤ 6 × 10{sup 2} holds. The uncertainty of U{sub e} /U{sub B} comes from the strong dependence on the angular size of the radio core and the minimum Lorentz factor of non-thermal electrons (γ {sub e,min}) in the core. It is still unsettled whether resultant energetics are consistent with either the magnetohydrodynamic jet or the kinetic power dominated jet even on the ∼10 Schwarzschild radii scale.
Otte, A N; Dickinson, H.; Funk, S.; Jogler, T.; Johnson, C.A.; Karn, P.; Meagher, K.; Naoya, H.; Nguyen, T.; Okumura, A.; Santander, M.; Sapozhnikov, L.; Stier, A.; Tajima, H.; Tibaldo, L.; Vandenbroucke, J.; Wakely, S.; Weinstein, A.; Williams, D.A.
2015-01-01
We present the development of a novel 11328 pixel silicon photomultiplier (SiPM) camera for use with a ground-based Cherenkov telescope with Schwarzschild-Couder optics as a possible medium-sized telescope for the Cherenkov Telescope Array (CTA). The finely pixelated camera samples air-shower images with more than twice the optical resolution of cameras that are used in current Cherenkov telescopes. Advantages of the higher resolution will be a better event reconstruction yielding improved background suppression and angular resolution of the reconstructed gamma-ray events, which is crucial in morphology studies of, for example, Galactic particle accelerators and the search for gamma-ray halos around extragalactic sources. Packing such a large number of pixels into an area of only half a square meter and having a fast readout directly attached to the back of the sensors is a challenging task. For the prototype camera development, SiPMs from Hamamatsu with through silicon via (TSV) technology are used. We give ...
Zakharov, Alexander F.
2018-01-01
Recently, Liu et al published a paper (2016 Class. Quantum Grav. 33 175014). In the abstract, the authors claimed as a key result of the paper that a particle sphere is found for the Schwarzschild black hole (BH), with its radius as a simple function of the particle velocity and proportional to the BH mass. Usually, if there are no references for the result it is assumed that the result was obtained originally in the paper; but this is not the case for the quoted paper. The concept of a particle sphere was introduced by Mielnik and Plebański (1962 Acta Phys. Pol. 21 239) and a simple derivation of the critical impact parameter was given in Zakharov A F (1988 Sov. Astron. 32 456 and Zakharov A F 1994 Class. Quantum Grav. 11 1027). We show that in slightly different notations, equation (17) for the critical impact parameter in Liu X et al (2016 Class. Quantum Grav. 33 175014) coincides with equation (12) in Zakharov (1994 Class. Quantum Grav. 11 1027) and with the corresponding equation (10.10) in Mielnik and Plebański (1962 Acta Phys. Pol. 21 239).
Kanti, P.; Pappas, T.; Pappas, N.
2014-12-01
In this paper, we consider the propagation of scalar particles in a higher-dimensional Schwarzschild-de Sitter black-hole spacetime, both on the brane and in the bulk. Our analysis applies for arbitrary partial modes and for both minimal and nonminimal coupling of the scalar field. A general expression for the greybody factor is analytically derived in each case, and its low-energy behavior is studied in detail. Its profile in terms of scalar properties (angular-momentum number and nonminimal coupling parameter) and spacetime properties (number of extra dimensions and cosmological constant) is thoroughly investigated. In contrast to previous studies, the effect of the cosmological constant is taken into account both close to and far away from the black-hole horizon. The dual role of the cosmological constant, that may act either as a helping agent to the emission of scalar particles or as a deterring effect depending on the value of the nonminimal coupling parameter, is also demonstrated.
Energy Technology Data Exchange (ETDEWEB)
He, Juan [School of Physics and Material Science, Anhui University, Hefei 230039 (China); School of Physics and Electronics Science, Fuyang Normal College, Fuyang 236037 (China); Xu, Shuai; Yu, Yang [School of Physics and Material Science, Anhui University, Hefei 230039 (China); Ye, Liu, E-mail: yeliu@ahu.edu.cn [School of Physics and Material Science, Anhui University, Hefei 230039 (China)
2015-01-05
We explore the performance of various correlation measures for open Dirac system with Hawking effect in Schwarzschild space–time. Our results indicate that the impact of Hawking effect on physical accessible entanglement is weaker than that of decoherence. For generalized amplitude damping (GAD) channel, the entanglement sudden death (ESD) is analyzed in detail, and the inequivalence of quantization for Dirac particles in the black hole and Kruskal space–time is verified via quantum discord measure. In addition, as an example for interpreting Bell non-locality, we study the GAD channel with Hawking effect. It can be noticed that there is a boundary line of Bell violation for physically accessible states. That is, quantum non-locality would disappear when Hawking temperature exceeds a certain value. This critical temperature increases as a decoherence parameter decreases. In the case of phase damping (PD) channel, the interaction between the particle and noise environment does not produce bipartite system–environment entanglement. Then we discuss entanglement distributions, and find that the reduced physically accessible entanglement can be redistributed to physical inaccessible region. At last, we extend our investigation to an N-qubit system, and obtain a universal expression of the physical accessible entanglement.
Barack, Leor
2011-01-01
We study conservative finite-mass corrections to the motion of a particle in a bound (eccentric) strong-field orbit around a Schwarzschild black hole. We assume the particle's mass $\\mu$ is much smaller than the black hole mass $M$, and explore post-geodesic corrections of $O(\\mu/M)$. Our analysis uses numerical data from a recently developed code that outputs the Lorenz-gauge gravitational self-force (GSF) acting on the particle along the eccentric geodesic. First, we calculate the $O(\\mu/M)$ conservative correction to the periastron advance of the orbit, as a function of the (gauge dependent) semi-latus rectum and eccentricity. A gauge-invariant description of the GSF precession effect is made possible in the circular-orbit limit, where we express the correction to the periastron advance as a function of the invariant azimuthal frequency. We compare this relation with results from fully nonlinear numerical-relativistic simulations. In order to obtain a gauge-invariant measure of the GSF effect for fully ecc...
Barack, Leor; Sago, Norichika
2010-01-01
Using a recently presented numerical code for calculating the Lorenz-gauge gravitational self-force (GSF), we compute the $O(m)$ conservative correction to the precession rate of the small-eccentricity orbits of a particle of mass $m$ moving around a Schwarzschild black hole of mass ${\\mathsf M}\\gg m$. Specifically, we study the gauge-invariant function $\\rho(x)$, where $\\rho$ is defined as the $O(m)$ part of the dimensionless ratio $(\\hat\\Omega_r/\\hat\\Omega_{\\varphi})^2$ between the squares of the radial and azimuthal frequencies of the orbit, and where $x=[Gc^{-3}({\\mathsf M}+m)\\hat\\Omega_{\\varphi}]^{2/3}$ is a gauge-invariant measure of the dimensionless gravitational potential (mass over radius) associated with the mean circular orbit. Our GSF computation of the function $\\rho(x)$ in the interval $0
Cavalcanti, R. T.; Goncalves da Silva, A.; da Rocha, Roldão
2016-11-01
In this paper we apply the strong deflection limit approach to investigate the gravitational lensing phenomena beyond general relativity. This is accomplished by considering the lensing effects related to black hole solutions that emerge out of the domain of Einstein gravity, namely, the ones acquired from the method of geometric deformation and the Casadio-Fabbri-Mazzacurati (CFM) brane-world black holes. The lensing observables, for those brane-world black hole metrics, are compared with the standard ones for the Schwarzschild case. We prove that brane-world black holes could have significantly different observational signatures, compared to the Schwarzschild black hole, with terms containing the post-Newtonian parameter, for the case of the CFM, and terms with variable brane-world tension, for the method of geometric deformation.
Electrically charged black hole solutions in generalized gauge field theories
Diaz-Alonso, J.; Rubiera-Garcia, D.
2011-09-01
We summarize the main features of a class of anomalous (asymptotically flat, but non Schwarzschild-like) gravitational configurations in models of gravitating non-linear electrodynamics (G-NED) whose Lagrangian densities are defined as arbitrary functions of the two field invariants and constrained by several physical admissibility conditions. This class of models and their associated electrostatic spherically symmetric black hole (ESSBH) solutions are characterized by the behaviours of the Lagrangian densities around the vacuum and at the boundary of their domain of definition.
Electrically charged black hole solutions in generalized gauge field theories
Energy Technology Data Exchange (ETDEWEB)
Diaz-Alonso, J; Rubiera-Garcia, D, E-mail: joaquin.diaz@obspm.fr, E-mail: diego.rubiera-garcia@obspm.fr [LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot. 5 Place Jules Janssen, 92190 Meudon (France); Departamento de Fisica, Universidad de Oviedo. Avda. Calvo Sotelo 18, 33007 Oviedo, Asturias (Spain)
2011-09-22
We summarize the main features of a class of anomalous (asymptotically flat, but non Schwarzschild-like) gravitational configurations in models of gravitating non-linear electrodynamics (G-NED) whose Lagrangian densities are defined as arbitrary functions of the two field invariants and constrained by several physical admissibility conditions. This class of models and their associated electrostatic spherically symmetric black hole (ESSBH) solutions are characterized by the behaviours of the Lagrangian densities around the vacuum and at the boundary of their domain of definition.
Sterken, C.; Dick, W. R.; Hamel, J.
2002-12-01
astronomers in his days, when his working place at Altona still belonged to the kingdom of Denmark. This paper is followed by a second one by the same author and deals with the correspondence of H. C. Schumacher and H C. Oersted (1777-1851) and shows how intense and diverse their cooperation was. In a subsequent paper, Wolfgang Kokott describes the role of the Astronomisches Jahrbuch (published from 1776 by the Royal Academy of Sciences at Berlin), a ranking international publication, with Bode's modest Berlin Observatory serving as a clearinghouse of information originating from virtually all European countries. "Karl Schwarzschild and the professionalisation of Astrophysics" is the title of Theodor Schmidt-Kaler's contribution and presents Schwarzschild's contributions to professionalization of astronomy: establishment of course lectures and a permanent astrophysical laboratory, a tight connection between teaching and research, stimulations and suggestions for astronomy at high school and for the formation of high school teachers, international organisation, and the planning of a southern observatory. Peter Habison describes the contribution of Leo de Ball (1853-1916, Director of the Kuffner Observatory in Vienna) to international astronomy. Internationalization in astronomy is also discussed in a following paper by Gudrun Wolfschmidt on the establishment of the Vereinigte Astronomische Gesellschaft, the international Astronomische Gesellschaft in 1863 and finally the International Astronomical Union in 1919. In the second but last paper of the book, Hilmar Duerbeck describes the history of the Chilean National Observatory, beginning with its origins out of Gilliss' US Naval Expedition to the Southern Hemisphere in 1849, over its directors Moesta, Vergara, Obrecht and Ristenpart, to the middle of the 20th century. The paper also includes the astronomical development at the Universidad Catolica and various international expeditions, which aimed at the observations of solar
Huang, ChunYu; Ma, Wen-chao; Wang, Dong; Ye, Liu
2018-01-01
In this work, the effect of Hawking radiation on the quantum Fisher information (QFI) of Dirac particles is investigated in the background of a Schwarzschild black hole. Interestingly, it has been verified that the QFI with respect to the weight parameter θ of a target state is always independent of the Hawking temperature T. This implies that if we encode the information on the weight parameter, then we can affirm that the corresponding accuracy of the parameter estimation will be immune to the Hawking effect. Besides, it reveals that the QFI with respect to the phase parameter φ exhibits a decay behavior with the increase in the Hawking temperature T and converges to a nonzero value in the limit of infinite Hawking temperature T. Remarkably, it turns out that the function F_φ on θ =π \\big /4 symmetry was broken by the influence of the Hawking radiation. Finally, we generalize the case of a three-qubit system to a case of a N-qubit system, i.e., |ψ > _{1,2,3,\\ldots ,N} =(cos θ | 0 > ^{⊗ N}+sin θ e^{iφ }| 1 > ^{⊗ N}) and obtain an interesting result: the number of particles in the initial state does not affect the QFI F_θ , nor the QFI F_φ . However, with the increasing number of particles located near the event horizon, F_φ will be affected by Hawking radiation to a large extent, while F_θ is still free from disturbance resulting from the Hawking effects.
Kowalczyk, Klaudia; Łokas, Ewa L.; Valluri, Monica
2018-02-01
In our previous work we confirmed the reliability of the spherically symmetric Schwarzschild orbit-superposition method to recover the mass and velocity anisotropy profiles of spherical dwarf galaxies. Here we investigate the effect of its application to intrinsically non-spherical objects. For this purpose we use a model of a dwarf spheroidal galaxy formed in a numerical simulation of a major merger of two disky dwarfs. The shape of the stellar component of the merger remnant is axisymmetric and prolate which allows us to identify and measure the bias caused by observing the spheroidal galaxy along different directions, especially the longest and shortest principal axis. The modelling is based on mock data generated from the remnant that are observationally available for dwarfs: projected positions and line-of-sight velocities of the stars. In order to obtain a reliable tool while keeping the number of parameters low we parametrize the total mass distribution as a radius-dependent mass-to-light ratio with just two free parameters we aim to constrain. Our study shows that if the total density profile is known, the true, radially increasing anisotropy profile can be well recovered for the observations along the longest axis whereas the data along the shortest axis lead to the inference an incorrect, isotropic model. On the other hand, if the density profile is derived from the method as well, the anisotropy is always underestimated but the total mass profile is well recovered for the data along the shortest axis whereas for the longest axis the mass content is overestimated.
Ribeiro, Deivid; Humensky, Brian; Nieto, Daniel; V Vassiliev Group in UCLA division of Astronomy and Astrophysics, P Kaaret Group at Iowa University Department of Physics and Astronomy, CTA Consortium
2016-01-01
The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. The Schwarzschild-Couder design is a candidate 9-m diameter medium-sized telescope featuring a novel aplanatic two-mirror optical design capable of a wide field of view with significantly improved imaging resolution as compared to the traditional Davies-Cotton optical design. Achieving this imaging resolution imposes strict mirror alignment requirements that necessitate a sophisticated alignment system. This system uses a collection of position sensors between panels to determine the relative position of adjacent panels; each panel is mounted on a Stewart platform to allow motion control with six degrees of freedom, facilitating the alignment of the optical surface for the segmented primary and secondary mirrors. Alignments of the primary and secondary mirrors and the camera focal plane with respect to each other are performed utilizing a set of CCD cameras which image LEDs placed on the mirror panels to measure relative translation, and custom-built auto-collimators to measure relative tilt between the primary and secondary mirrors along the optical axis of the telescope. In this contribution we present the status of the development of the SC optical alignment system, soon to be materialized in a full-scale prototype SC medium-size telescope (pSCT) at the Fred Lawrence Whipple Observatory in southern Arizona.
Addazi, Andrea; Nojiri, Shin'ichi; Odintsov, Sergei
2017-06-01
We study the problem of a four-dimensional brane lying in the five-dimensional degenerate Schwarzschild-de Sitter (Nariai) black hole in five-dimensional F (R ) gravity. We show that there cannot exist the brane in the Nariai bulk space except for the case where the brane tension vanishes. We demonstrate that the five-dimensional Nariai bulk is unstable in a large region of the parameter space. In particular, the Nariai bulk can have classical (anti)evaporation instabilities. The bulk instability backreacts on the four-dimensional brane, in that case, the brane tension vanishes, and the unstable modes propagate in their world volume.
Bezerra, V. B.; Christiansen, H. R.; Cunha, M. S.; Muniz, C. R.
2017-07-01
We obtain the exact (confluent Heun) solutions to the massive scalar field in a gravity's rainbow Schwarzschild metric. With these solutions at hand, we study the Hawking radiation resulting from the tunneling rate through the event horizon. We show that the emission spectrum obeys nonextensive statistics and is halted when a certain mass remnant is reached. Next, we infer constraints on the rainbow parameters from recent LHC particle physics experiments and Hubble STIS astrophysics measurements. Finally, we study the low frequency limit in order to find the modified energy spectrum around the source.
Gamal, G. L. Nashed
2011-11-01
A theory of (4+1)-dimensional gravity is developed on the basis of the teleparallel theory equivalent to general relativity. The fundamental gravitational field variables are the five-dimensional vector fields (pentad), defined globally on a manifold M, and gravity is attributed to the torsion. The Lagrangian density is quadratic in the torsion tensor. We then give the exact five-dimensional solution. The solution is a generalization of the familiar Schwarzschild and Kerr solutions of the four-dimensional teleparallel equivalent of general relativity. We also use the definition of the gravitational energy to calculate the energy and the spatial momentum.
Black hole solutions in mimetic Born-Infeld gravity.
Chen, Che-Yu; Bouhmadi-López, Mariam; Chen, Pisin
2018-01-01
The vacuum, static, and spherically symmetric solutions in the mimetic Born-Infeld gravity are studied. The mimetic Born-Infeld gravity is a reformulation of the Eddington-inspired-Born-Infeld (EiBI) model under the mimetic approach. Due to the mimetic field, the theory contains non-trivial vacuum solutions different from those in Einstein gravity. We find that with the existence of the mimetic field, the spacelike singularity inside a Schwarzschild black hole could be altered to a lightlike singularity, even though the curvature invariants still diverge at the singularity. Furthermore, in this case, the maximal proper time for a timelike radially-infalling observer to reach the singularity is found to be infinite.
Energy Technology Data Exchange (ETDEWEB)
Wang, Mingzhi [Hunan Normal University, Department of Physics, Institute of Physics, Changsha, Hunan (China); Hunan Normal University, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha, Hunan (China); Chen, Songbai; Jing, Jiliang [Hunan Normal University, Department of Physics, Institute of Physics, Changsha, Hunan (China); Hunan Normal University, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha, Hunan (China); Hunan Normal University, Synergetic Innovation Center for Quantum Effects and Applications, Changsha, Hunan (China)
2017-04-15
We present firstly the equation of motion for a test scalar particle coupling to the Einstein tensor in the Schwarzschild-Melvin black hole spacetime through the short-wave approximation. Through analyzing Poincare sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram, we investigate the effects of the coupling parameter on the chaotic behavior of the particles. With the increase of the coupling strength, we find that the motion of the coupled particle for the chosen parameters becomes more regular and order for the negative couple constant. While, for the positive one, the motion of the coupled particles first undergoes a series of transitions betweens chaotic motion and regular motion and then falls into horizon or escapes to spatial infinity. Our results show that the coupling brings about richer effects for the motion of the particles. (orig.)
Lemos, José P. S.; Zanchin, Vilson T.
2017-05-01
We show that Guilfoyle's exact solutions of the Einstein-Maxwell equations for spherical symmetric static electrically charged matter with a Reissner-Nordström exterior possess a bewildering plethora of different types of solutions. For the parameter space of the solutions we use two normalized variables, q2/R2 and r0/R , where q is the total electric charge, r0 is the radius of the object, and R is a length representing the square root of the inverse energy density of the matter. The two other parameters, the mass m and the Guilfoyle parameter a , both dependent on q , r0 and R , are analyzed in detail. The full parameter space of solutions q2/R2×r0/R is explored with the corresponding types of solutions being identified and analyzed. The different types of solutions are regular charged stars, including charged dust stars and stars saturating the Buchdahl-Andréasson bound, quasiblack holes, regular charged black holes with a de Sitter core, regular black holes with a core of phantom charged matter, other exotic regular black holes, Schwarzschild stars, Schwarzschild black holes, Kasner spacetimes, pointlike and planar naked singularities, and the Minkowski spacetime. Allowing for q2<0 , in which case it is not possible to interpret q as electric charge, also yields new solutions, some of which are interesting and regular, others are singular. Some of these types of solutions as well as the matter properties have been previously found and studied, here the full spectrum being presented in a unified manner.
Fluid/gravity correspondence and the CFM black brane solutions
Energy Technology Data Exchange (ETDEWEB)
Casadio, R. [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); I.N.F.N., Sezione di Bologna, Bologna (Italy); Cavalcanti, R.T. [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); Universidade Federal do ABC-UFABC, Centro de Ciencias Naturais e Humanas, Santo Andre (Brazil); Rocha, Roldao da [Universidade Federal do ABC-UFABC, Centro de Matematica, Computacao e Cognicao, Santo Andre (Brazil)
2016-10-15
We consider the lower bound for the shear viscosity-to-entropy density ratio, obtained from the fluid/gravity correspondence, in order to constrain the post-Newtonian parameter of brane-world metrics. In particular, we analyse the Casadio-Fabbri-Mazzacurati (CFM) effective solutions for the gravity side of the correspondence and argue that including higher-order terms in the hydrodynamic expansion can lead to a full agreement with the experimental bounds, for the Eddington-Robertson-Schiff post-Newtonian parameter in the CFM metrics. This lends further support to the physical relevance of the viscosity-to-entropy ratio lower bound and fluid/gravity correspondence. Hence we show that CFM black branes are, effectively, Schwarzschild black branes. (orig.)
Fluid/gravity correspondence and the CFM black brane solutions
Casadio, R.; Cavalcanti, R. T.; da Rocha, Roldão
2016-10-01
We consider the lower bound for the shear viscosity-to-entropy density ratio, obtained from the fluid/gravity correspondence, in order to constrain the post-Newtonian parameter of brane-world metrics. In particular, we analyse the Casadio-Fabbri-Mazzacurati (CFM) effective solutions for the gravity side of the correspondence and argue that including higher-order terms in the hydrodynamic expansion can lead to a full agreement with the experimental bounds, for the Eddington-Robertson-Schiff post-Newtonian parameter in the CFM metrics. This lends further support to the physical relevance of the viscosity-to-entropy ratio lower bound and fluid/gravity correspondence. Hence we show that CFM black branes are, effectively, Schwarzschild black branes.
Weyl Conformal Gravity: Mannheim-Kazanas Solution
Bhattacharya, Amrita; Scalia, Massimo; Cattani, Carlo; Nandi, Kamal K
2009-01-01
In this paper, we first point out certain interesting features of the Mannheim-Kazanas solution of Weyl conformal gravity. Next, we adopt the viewpoint that physical effects in Weyl gravity should be determined by the combined effect of both the constants $\\gamma$ and k appearing in the solution, and not by $\\gamma$ alone. This idea is supported by the effect of tidal forces as well as by the required stability of circular orbits of massive particles. To deal with massless particles, we employ the Rindler-Ishak method for calculating the bending of light rays up to second order, which at once reveals the exact Schwarzschild terms as well as the combined effect of $\\gamma$ and k. The enhanced light bending in the attractive halo gravity then provides a positive lower bound for $\\gamma$. A certain reported discrepancy in the literature is also resolved. It turns out that even the first order light bending is modified by Weyl gravity. This is a new effect though too minuscule to be observed at present.
From thermodynamics to the solutions in gravity theory
Directory of Open Access Journals (Sweden)
Hongsheng Zhang
2014-10-01
Full Text Available In a recent work, we present a new point of view to the relation of gravity and thermodynamics, in which we derive the Schwarzschild solution through thermodynamic considerations by the aid of the Misner–Sharp mass in an adiabatic system. In this Letter we continue to investigate the relation between gravity and thermodynamics for obtaining solutions via thermodynamics. We generalize our studies on gravi-thermodynamics in Einstein gravity to modified gravity theories. By using the first law with the assumption that the Misner–Sharp mass is the mass for an adiabatic system, we reproduce the Boulware–Deser–Cai solution in Gauss–Bonnet gravity. Using this gravi-thermodynamic thought, we obtain a NEW class of solution in F(R gravity in an n-dimensional (n≥3 spacetime which permits three-type (n−2-dimensional maximally symmetric subspace, as an extension of our recent three-dimensional black hole solution, and four-dimensional Clifton–Barrow solution in F(R gravity.
Baranski, Maciej; Passilly, Nicolas; Bargiel, Sylwester; Froehly, Luc; Gorecki, Christophe
2016-04-01
This paper presents the conception of a new micro-optical component fabricated within the wafer-level approach: a micromachined reflective objective, the so-called micro-Schwarzschild objective, characterized by superior optical performances than widespread microlenses. The system, made of two vertically integrated mirrors, works in transmission similarly as microlenses. While the specific geometric configuration of the two-mirrors allows elimination of most common optical aberrations, the reflective architecture provides inherent achromaticity. This paper presents in detail the optical design and analyzes fabrication tolerances. It also describes a fabrication flow chart based on silicon micromachining done at the wafer level that could allow production of thousands of such micro-optical devices within a single fabrication run. The realized prototype employs the two-step KOH etching process to generate the micromirror pairs followed by glass reflow for the secondary mirror generation and selective metallic deposition. Despite an insufficient mirror quality attributed to this specific silicon etching technique and highlighted by the reflective configuration, the objective fabrication in terms of alignment, bonding, and coating is shown as feasible.
Linet, Bernard
2015-01-01
We present a complete analysis of the light rays within the linearized, weak-field approximation of a Schwarzschild-like metric describing the gravitational field of an isolated, spherically symmetric body. We prove in this context the existence of two time transfer functions and we obtain these functions in an exact closed-form. We are led to distinguish two regimes. In the first regime, the two time transfer functions correspond to rays which are confined in regions of spacetime where the weak-field approximation is valid. Such a regime occurs in gravitational lensing configurations with double images of a given source. We find the general expressions of the angular separation and the difference in light travel time between the two images. In the second regime, there exists only one time transfer function corresponding to a light ray remaining in a region of weak field. Performing a Taylor expansion of this function with respect to the gravitational constant, we obtain the Shapiro time delay completed by a ...
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Xu, Shuai; Song, Xue-ke; Shi, Jia-dong; Ye, Liu, E-mail: yeliu@ahu.edu.cn
2014-06-02
In this Letter, we analytically explore the effect of the Hawking radiation on the quantum correlation and Bell non-locality for Dirac particles in the background of Schwarzschild black hole. It is shown that when the Hawking effect is almost nonexistent, corresponding to the case of an almost extreme black hole, the quantum properties of physically accessible state are the same for the initial situation. For finite Hawking temperature T, the accessible quantum correlation monotonously decreases along with increasing T owing to the thermal fields generated by the Hawking effect, and the accessible quantum non-locality will be disappeared when the Hawking temperature is more than a fixed value which increases with the parameter r of Werner state growing. Then we analyze the redistribution of quantum correlation, and find that for the case of the Hawking temperature being infinite, corresponding to the case of the black hole evaporating completely, the quantum correlation of physically accessible state is equal to the one of the inaccessible states. Moreover, due to the Pauli exclusion principle and the differences between Fermi–Dirac and Bose–Einstein statistics, for the Dirac fields the accessible classical correlation decreases with increase of the Hawking temperature, which is different for the scalar fields. For Bell non-locality, we also find that the quantum non-locality is always extinct for physically inaccessible states, and the strength of the non-locality decreases with enlarging intensity of Hawking effect when the non-locality is existent in physically accessible state.
Energy Technology Data Exchange (ETDEWEB)
Hada, Kazuhiro; Giroletti, Marcello; Giovannini, Gabriele [INAF Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Doi, Akihiro [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara 252-5210 (Japan); Nagai, Hiroshi; Honma, Mareki [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Inoue, Makoto [Academia Sinica Institute for Astronomy and Astrophysics, 11F Astronomy-Mathematics Building, National Taiwan University, No. 1, Roosevelt Road, Sec. 4, Taipei 10617, Taiwan R.O.C. (China)
2013-12-10
The Sombrero galaxy (M 104, NGC 4594) is associated with one of the nearest low-luminosity active galactic nuclei (AGNs). We investigated the detailed radio structure of the Sombrero nucleus using high-resolution, quasi-simultaneous, multi-frequency, phase-referencing Very Long Baseline Array observations. We obtained high-quality images of this nucleus at seven frequencies, where those at 15, 24, and 43 GHz are the first clear very long baseline interferometry detections. At 43 GHz, the nuclear structure was imaged on a linear scale under 0.01 pc or 100 Schwarzschild radii, revealing a compact, high-brightness-temperature (≳ 3 × 10{sup 9} K) radio core. We discovered the presence of the extended structure emanating from the core on two sides in the northwest and southeast directions. The nuclear radio spectra show a clear spatial gradient, which is similar to that seen in more luminous AGNs with powerful relativistic jets. Moreover, the size and position of the core tend to be frequency dependent. These findings provide evidence that the central engine of the Sombrero is powering radio jets and the jets are overwhelming the emission from the underlying radiatively inefficient accretion flow over the observed frequencies. Based on these radio characteristics, we constrained the following physical parameters for the M 104 jets: (1) the northern side is approaching, whereas the southern one is receding; (2) the jet viewing angle is relatively close to our line-of-sight (≲ 25°); and (3) the intrinsic jet velocity is highly sub-relativistic (≲ 0.2c). The derived pole-on nature of the M 104 jets is consistent with the previous argument that this nucleus contains a true type II AGN, i.e., the broad line region is actually absent or intrinsically weak if the plane of the circumnuclear torus is perpendicular to the jet axis.
Camilli, Fabio; Prados, Emmanuel
2011-01-01
International audience; Viscosity solution is a notion of weak solution for a class of partial differential equations of Hamilton-Jacobi type. The range of applications of the notions of viscosity solution and Hamilton-Jacobi equations is enormous, including common class of partial differential equations such as evolutive problems and problems with boundary conditions, equations arising in optimal control theory, differential games, second-order equations arising in stochastic optimal control...
Energy Technology Data Exchange (ETDEWEB)
Seitz, M.G.
1982-01-01
Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results.
Geodesics of simultaneity in Schwarzschild
Paiva, F M
2010-01-01
Geodesic of simultaneity is a spacelike geodesic in which every pair of neighbour events are simultaneous ($g_{0\\mu}\\dd x^\\mu=0$). These geodesics are studied in the exterior region of \\Sch's metric.
Christov, Ivan C
2012-01-01
In classical continuum physics, a wave is a mechanical disturbance. Whether the disturbance is stationary or traveling and whether it is caused by the motion of atoms and molecules or the vibration of a lattice structure, a wave can be understood as a specific type of solution of an appropriate mathematical equation modeling the underlying physics. Typical models consist of partial differential equations that exhibit certain general properties, e.g., hyperbolicity. This, in turn, leads to the possibility of wave solutions. Various analytical techniques (integral transforms, complex variables, reduction to ordinary differential equations, etc.) are available to find wave solutions of linear partial differential equations. Furthermore, linear hyperbolic equations with higher-order derivatives provide the mathematical underpinning of the phenomenon of dispersion, i.e., the dependence of a wave's phase speed on its wavenumber. For systems of nonlinear first-order hyperbolic equations, there also exists a general ...
DEFF Research Database (Denmark)
Efeoglu, Arkin; Møller, Charles; Serie, Michel
2013-01-01
This paper outlines an artifact building and evaluation proposal. Design Science Research (DSR) studies usually consider encapsulated artifact that have relationships with other artifacts. The solution prototype as a composed artifact demands for a more comprehensive consideration in its systematic...... environment. The solution prototype that is composed from blending product and service prototype has particular impacts on the dualism of DSR’s “Build” and “Evaluate”. Since the mix between product and service prototyping can be varied, there is a demand for a more agile and iterative framework. Van de Ven...
Geoghegan, Michael W
2005-01-01
Podcasting is the art of recording radio show style audio tracks, then distributing them to listeners on the Web via podcasting software such as iPodder. From downloading podcasts to producing a track for fun or profit, ""Podcast Solutions"" covers the entire world of podcasting with insight, humor, and the unmatched wisdom of experience.
Regular Solutions in Vacuum Brans-Dicke Theory Compared to Vacuum Einstein Theory
Directory of Open Access Journals (Sweden)
Alina Khaybullina
2013-01-01
Full Text Available We will confront some static spherically symmetric vacuum Brans-Dicke solutions in the Jordan and Einstein Frames with the Robertson parameters. While the regular solution in the vacuum Einstein theory is just the Schwarzschild black hole, the same in the Jordan frame Brans-Dicke theory is shown to represent not a black hole but a traversable wormhole. But, in this case, the valid range of ω becomes too narrow to yield the observed weak field Robertson parameters at the positive mass mouth. The corresponding solution in the Einstein frame also provides a regular wormhole, and it yields the correct parametric values but only up to “one and half order.” We argue that a second-order contribution can in principle distinguish between the signatures of the regular wormhole and the singular Buchdahl solution in the Einstein frame. Thus, at the level of regular solutions, Brans-Dicke theory in each frame predicts effects very different from those of Einstein's theory. To our knowledge, these theoretical distinctions seem not to have received adequate attention so far.
Thermodynamic analysis of black hole solutions in gravitating nonlinear electrodynamics
Diaz-Alonso, J.; Rubiera-Garcia, D.
2013-10-01
We perform a general study of the thermodynamic properties of static electrically charged black hole solutions of nonlinear electrodynamics minimally coupled to gravitation in three space dimensions. The Lagrangian densities governing the dynamics of these models in flat space are defined as arbitrary functions of the gauge field invariants, constrained by some requirements for physical admissibility. The exhaustive classification of these theories in flat space, in terms of the behaviour of the Lagrangian densities in vacuum and on the boundary of their domain of definition, defines twelve families of admissible models. When these models are coupled to gravity, the flat space classification leads to a complete characterization of the associated sets of gravitating electrostatic spherically symmetric solutions by their central and asymptotic behaviours. We focus on nine of these families, which support asymptotically Schwarzschild-like black hole configurations, for which the thermodynamic analysis is possible and pertinent. In this way, the thermodynamic laws are extended to the sets of black hole solutions of these families, for which the generic behaviours of the relevant state variables are classified and thoroughly analyzed in terms of the aforementioned boundary properties of the Lagrangians. Moreover, we find universal scaling laws (which hold and are the same for all the black hole solutions of models belonging to any of the nine families) running the thermodynamic variables with the electric charge and the horizon radius. These scale transformations form a one-parameter multiplicative group, leading to universal "renormalization group"-like first-order differential equations. The beams of characteristics of these equations generate the full set of black hole states associated to any of these gravitating nonlinear electrodynamics. Moreover the application of the scaling laws allows to find a universal finite relation between the thermodynamic variables
A Non-anthropic Solution to the Cosmological Constant Problem
Directory of Open Access Journals (Sweden)
Spivey R. J.
2016-01-01
Full Text Available Accelerating cosmological expansion is driven by a minuscule vacuum energy density possibly seeking opportunities to decay to a true ground state. Quasar characteristics imply their central engines possess an intrinsic magnetic field compatible with the pres- ence of an electrically charged toroidal dark hole, an eternally collapsing structure lack- ing an event horizon. The possibility is consistent with the inability of black holes to capture particles in a universe of finite age, Einstein’s dismissal of the Schwarzschild metric as unphysical and the implausibility of the various paradoxes invoked by black hole existence. The uncloaked innards of these dark holes would expose immense vac- uum accelerations at their cores, inevitably tempered by Planck scale physics. The Unruh effect predicts that intense yet highly localised heating should occur there. As thermal energy gradually amasses and dissipates, radiation would eventually start to escape into the surrounding environment. Virtual from the d ark hole perspective, the emissions could not decrease the dark hole’s mass: the energy source must instead be the universal vacuum, the likely repository of dark energy. In analogy with core- collapse supernovae, neutrinos should dominate the cooling flows. Red-shifting to low energies upon escape, quantum degenerate haloes should for m predominantly around the largest galaxies. This mechanism is promising from the perspective of enabling the future universe to efficiently sustain aquatic life before stars become scarce, offering a biological yet decidedly non-anthropic solution to the cosmological constant problem.
Alloy solution hardening with solute pairs
Mitchell, John W.
1976-08-24
Solution hardened alloys are formed by using at least two solutes which form associated solute pairs in the solvent metal lattice. Copper containing equal atomic percentages of aluminum and palladium is an example.
Klijn, F.; Slikker, M.; Tijs, S.H.
2000-01-01
In this note we introduce an egalitarian solution, called the dual egalitarian solution, that is the natural counterpart of the egalitarian solution of Dutta and Ray (1989).We prove, among others, that for a convex game the egalitarian solution coincides with the dual egalitarian solution for its
Pant, Neeraj; Pradhan, N.; Murad, Mohammad Hassan
2014-11-01
We present a spherically symmetric solution of the general relativistic field equations in isotropic coordinates for perfect charged fluid, compatible with a super dense star modeling. The solution is well behaved for all the values of Schwarzschild parameter u lying in the range 0 < u < 0.1727 for the maximum value of charge parameter K = 0.08163. The maximum mass of the fluid distribution is calculated by using stellar surface density as ρ b = 4.6888×1014g cm-3. Corresponding to K = 0.08 and u max = 0.1732, the resulting well behaved solution has a maximum mass M = 0.9324 M ⊙ and radius R = 8.00 and by assuming ρ b = 2×1014g cm-3 the solution results a stellar configuration with maximum mass M = 1.43 M ⊙ and radius R b = 12.25 km. The maximum mass is found increasing with increasing K up to 0.08. The well behaved class of relativistic stellar models obtained in this work might has astrophysical significance in the study of internal structure of compact star such as neutron star or self-bound strange quark star like Her X-1.
Exact solution for the interior of a black hole
Nieuwenhuizen, T.M.
2008-01-01
Within the Relativistic Theory of Gravitation it is shown that the equation of state p = rho holds near the center of a black hole. For the stiff equation of state p = rho - rho(c) the interior metric is solved exactly. It is matched with the Schwarzschild metric, which is deformed in a narrow range
National Research Council Canada - National Science Library
White S.A; Goldhill D.R
1997-01-01
As Hartmann's solution is commonly used by anaesthetists, we surveyed a group of Part III FRCA candidates to establish their knowledge of its constituents and the purpose and metabolism of the lactate in solution...
Energy Technology Data Exchange (ETDEWEB)
Aftanas, B.L.
1996-04-30
This Functional Design Criteria (FDC) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.
Multicapillary mixer of solutions.
Moskowitz, G W; Bowman, R L
1966-07-22
A mixer made from a bundle of glass tubules can mix two solutions within 30 microseconds, with a total-solution flow rate of 1.33 milliliters per second. One solution passes through the interstices of the bundle; the other moves through the lumens of the tubes.
Solutions to Organizational Paradox
DEFF Research Database (Denmark)
Li, Xin; Worm, Verner; Peihong, Xie
Organizations face all kinds of paradoxical problems. There exist various solutions to organizational paradoxes. We develop a typology that lists nine possible logical approaches to understanding the relationship between paradoxical opposites, out of which we identify five types of solutions...... to organizational paradox. Four of the five solutions are explicitly associated with four prominent philosophies. We show the relevance of the five solutions to the real world by applying our scheme to understand different solutions to the generic strategy paradox. Finally, we address the question whether...
Solution phase combinatorial chemistry.
Merritt, A T
1998-06-01
Combinatorial chemistry and parallel array synthesis techniques are now used extensively in the drug discovery process. Although published literature has been dominated by solid phase chemistry approaches, the use of solution phase techniques has also been widely explored. This review considers the advantages and disadvantages of choosing solution phase approaches in the various stages of drug discovery and optimisation, and assesses the practical issues related to these approaches. The uses of standard solution chemistry, the related liquid phase approach, and of supported materials to enhance solution phase chemistry are all illustrated by a comprehensive review of the published literature over the past three years.
Solute-solute interactions in intermetallic compounds
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Debashis; Murray, Ryan; Collins, Gary S., E-mail: collins@wsu.edu [Washington State University, Department of Physics and Astronomy (United States); Zacate, Matthew O. [Northern Kentucky University, Department of Physics and Geology (United States)
2017-11-15
Experiments were carried out on highly ordered GdAl{sub 2} samples containing extremely dilute mole fractions of{sup 111}In/Cd probe-atom solutes (about 10{sup −11}), intrinsic antisite atoms Al{sub Gd} having mole fractions of order 0-10{sup −2}, and doped with Ag solutes at mole fractions of order 10{sup −2}. Three types of defect interactions were investigated. (1) Quadrupole interactions caused by Ag-solute atoms neighboring{sup 111}In/Cd solute probe atoms were detected using the method of perturbed angular correlation of gamma rays (PAC). Three complexes of pairs of In-probes and Ag-solutes occupying neighboring positions on Gd- and Al-sublattices were identified by comparing site fractions in Gd-poor and Gd-rich GdAl{sub 2}(Ag) samples and from the symmetry of the quadrupole interactions. Interaction enthalpies between solute-atom pairs were determined from temperature dependences of observed site fractions. Repulsive interactions were observed for close-neighbor complexes In{sub Gd}+Ag{sub Gd} and In{sub Gd}+Ag{sub Al} pairs, whereas a slightly attractive interaction was observed for In{sub Al}+Ag{sub Al}. Interaction enthalpies were all small, in the range ±0.15 eV. (2) Quadrupole interactions caused by intrinsic antisite atoms Al{sub Gd} neighboring In{sub Gd} probes were also detected and site fractions measured as a function of temperature, as in previous work on samples not doped with Ag-solutes [Temperature- and composition-driven changes in site occupation of solutes in Gd{sub 1+3x}Al{sub 2−3x}, Zacate and Collins (Phys. Rev. B69, 174202 (1))]. However, the effective binding enthalpy between In{sub Gd} probe and Al{sub Gd} antisite was found to change sign from -0.12 eV (attractive interaction) in undoped samples to + 0.24 eV (repulsive) in Ag-doped samples. This may be attributed to an attractive interaction between Al{sub Gd} antisite atoms and Ag-dopants that competes with the attractive interaction between In{sub Gd} and Al{sub Gd
The procedural egalitarian solution
Dietzenbacher, Bas; Borm, Peter; Hendrickx, Ruud
2017-01-01
In this paper we introduce and analyze the procedural egalitarian solution for transferable utility games. This new concept is based on the result of a coalitional bargaining procedure in which egalitarian considerations play a central role. The procedural egalitarian solution is the first
The Procedural Egalitarian Solution
Dietzenbacher, Bas; Borm, Peter; Hendrickx, Ruud
2016-01-01
In this paper we introduce and analyze the procedural egalitarian solution for transferable utility games. This new concept is based on the result of a coalitional bargaining procedure in which egalitarian considerations play a central role. The procedural egalitarian solution is the first
Directory of Open Access Journals (Sweden)
Schaefer Philip W
2002-01-01
Full Text Available Rotationally symmetric solutions are derived for some nonlinear equations of the form in the title in terms of elementary functions. Under suitable assumptions, the nonexistence of entire solutions is also proved for the inequality in the title as well as some radial upper bounds are obtained. These results are the consequence of an appropriate differential inequality.
Cromolyn Sodium Nasal Solution
Cromolyn comes as a solution to use with a special nasal applicator. It usually is inhaled three to six times a day to prevent allergy ... first time, read the instructions provided with the solution. Ask your doctor, pharmacist, or respiratory therapist to ...
White, S A; Goldhill, D R
1997-05-01
As Hartmann's solution is commonly used by anaesthetists, we surveyed a group of Part III FRCA candidates to establish their knowledge of its constituents and the purpose and metabolism of the lactate in solution. Of the 82 candidates surveyed only three (4%) accurately recorded the electrolytes and their concentrations in Hartmann's solution. Lactate was stated to be a source of bicarbonate by 52 (63%) and a source of glucose by 17 (21%). The descriptions of lactate metabolism were largely imprecise, none was complete and 24 (29%) of candidates offered no explanation. The constituents of Hartmann's solution and their concentrations are designed to match those of plasma, reducing ion and fluid shifts postinfusion. The lactate in Hartmann's solution is metabolised by both oxidation and gluconeogenesis, predominantly in the liver, and bicarbonate is generated by both processes over 1-2 h.
A cosmic solution to the twin paradox
Grøn, Ø
2009-01-01
Recently Abramowicz and Bajtlik [arXiv:0905.2428 (2009)] have studied the twin paradox in Schwarzschild spacetime. Considering circular motion they showed that the twin with a non-vanishing 4-acceleration is older than his brother at the reunion and argued that in spaces that are asymptotically Minkowskian there exists an absolute standard of rest determining which twin is oldest at the reunion. Here we show that with vertical motion in Schwarzschild spacetime the result is opposite: The twin with a non-vanishing 4-acceleration is younger. Moreover, by invoking the strong principle of relativity we also deduce the existence of a new relativistic time effect, that there is either a time dilation or an increased rate of time associated with a clock moving in a rotating frame. This is in fact a first order effect in the velocity of the clock, and must be taken into account if the situation presented by Abramowicz and Bajtlik is described from the rotating rest frame of one of the twins. Our analysis shows that t...
Lublinsky, Boris; Yakubovich, Alexey
2013-01-01
The go-to guidebook for deploying Big Data solutions with Hadoop Today's enterprise architects need to understand how the Hadoop frameworks and APIs fit together, and how they can be integrated to deliver real-world solutions. This book is a practical, detailed guide to building and implementing those solutions, with code-level instruction in the popular Wrox tradition. It covers storing data with HDFS and Hbase, processing data with MapReduce, and automating data processing with Oozie. Hadoop security, running Hadoop with Amazon Web Services, best practices, and automating Hadoop processes i
Convergent Aeronautics Solutions Project
National Aeronautics and Space Administration — The Convergent Aeronautics Solutions (CAS) Project uses short-duration activities to establish early-stage concept and technology feasibility for high-potential...
Directory of Open Access Journals (Sweden)
TUTUNEA MIHAELA FILOFTEIA
2012-09-01
Full Text Available The integration of activities, the business processes as well as their optimization, bring the perspective of profitable growth and create significant and competitive advantages in any company. The adoption of some ERP integrated software solutions, from SMEs’ perspective, must be considered as a very important management decision in medium and long term. ERP solutions, along with the transparent and optimized management of all internal processes, also offer an intra and inter companies collaborative platform, which allows a rapid expansion of activities towards e- business and mobile-business environments. This material introduces ERP solutions for SMEs from commercial offer and open source perspective; the results of comparative analysis of the solutions on the specific market, can be an useful aid to the management of the companies, in making the decision to integrate business processes, using ERP as a support.
The Conductivity of Solutions.
Rayner-Canham, Geoff
1993-01-01
Presents historical background and modern explanations for the popular demonstration of showing conductivity of solutions through the insertion of a light-bulb conductivity tester into deionized water and water with salt in it. (PR)
Piezoelectric Energy Harvesting Solutions
Caliò, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria
2014-01-01
This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions. PMID:24618725
Piezoelectric Energy Harvesting Solutions
Directory of Open Access Journals (Sweden)
Renato Caliò
2014-03-01
Full Text Available This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions.
Piezoelectric energy harvesting solutions.
Caliò, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria
2014-03-10
This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions.
Energy Technology Data Exchange (ETDEWEB)
Strom, I.; Joosten, L.; Boonstra, C. [DHV Sustainability Consultants, Eindhoiven (Netherlands)
2006-05-15
PEP stands for 'Promotion of European Passive Houses' and is a consortium of European partners, supported by the European Commission, Directorate General for Energy and Transport. In this working paper an overview is given of Passive House solutions. An inventory has been made of Passive House solutions for new build residences applied in each country. Based on this, the most common basic solutions have been identified and described in further detail, including the extent to which solutions are applied in common and best practice and expected barriers for the implementation in each country. An inventory per country is included in the appendix. The analysis of Passive House solutions in partner countries shows high priority with regard to the performance of the thermal envelope, such as high insulation of walls, roofs, floors and windows/ doors, thermal bridge-free construction and air tightness. Due to the required air tightness, special attention must be paid to indoor air quality through proper ventilation. Finally, efficient ((semi-)solar) heating systems for combined space and DHW heating still require a significant amount of attention in most partner countries. Other basic Passive House solutions show a smaller discrepancy with common practice and fewer barriers have been encountered in partner countries. In the next section, the general barriers in partner countries have been inventoried. For each type of barrier a suggested approach has been given. Most frequently encountered barriers in partner countries are: limited know-how; limited contractor skills; and acceptation of Passive Houses in the market. Based on the suggested approaches to overcoming barriers, this means that a great deal of attention must be paid to providing practical information and solutions to building professionals, providing practical training to installers and contractors and communication about the Passive House concept to the market.
Deconstructing graphite: graphenide solutions.
Pénicaud, Alain; Drummond, Carlos
2013-01-15
Growing interest in graphene over past few years has prompted researchers to find new routes for producing this material other than mechanical exfoliation or growth from silicon carbide. Chemical vapor deposition on metallic substrates now allows researchers to produce continuous graphene films over large areas. In parallel, researchers will need liquid, large scale, formulations of graphene to produce functional graphene materials that take advantage of graphene's mechanical, electrical, and barrier properties. In this Account, we describe methods for creating graphene solutions from graphite. Graphite provides a cheap source of carbon, but graphite is insoluble. With extensive sonication, it can be dispersed in organic solvents or water with adequate additives. Nevertheless, this process usually creates cracks and defects in the graphite. On the other hand, graphite intercalation compounds (GICs) provide a means to dissolve rather than disperse graphite. GICS can be obtained through the reaction of alkali metals with graphite. These compounds are a source of graphenide salts and also serve as an excellent electronic model of graphene due to the decoupling between graphene layers. The graphenide macroions, negatively charged graphene sheets, form supple two-dimensional polyelectrolytes that spontaneously dissolve in some organic solvents. The entropic gain from the dissolution of counterions and the increased degrees of freedom of graphene in solution drives this process. Notably, we can obtain graphenide solutions in easily processable solvents with low boiling points such as tetrahydrofuran or cyclopentylmethylether. We performed a statistical analysis of high resolution transmission electronic micrographs of graphene sheets deposited on grids from GICs solution to show that the dissolved material has been fully exfoliated. The thickness distribution peaks with single layers and includes a few double- or triple-layer objects. Light scattering analysis of the
Jorgensen, Adam; Welch, John; Clark, Dan; Price, Christopher; Mitchell, Brian
2014-01-01
Tap the power of Big Data with Microsoft technologies Big Data is here, and Microsoft's new Big Data platform is a valuable tool to help your company get the very most out of it. This timely book shows you how to use HDInsight along with HortonWorks Data Platform for Windows to store, manage, analyze, and share Big Data throughout the enterprise. Focusing primarily on Microsoft and HortonWorks technologies but also covering open source tools, Microsoft Big Data Solutions explains best practices, covers on-premises and cloud-based solutions, and features valuable case studies. Best of all,
Calculus problems and solutions
Ginzburg, Abraham
2011-01-01
Ideal for self-instruction as well as for classroom use, this text helps students improve their understanding and problem-solving skills in analysis, analytic geometry, and higher algebra. More than 1,200 problems appear in the text, with concise explanations of the basic notions and theorems to be used in their solution. Many are followed by complete answers; solutions for the others appear at the end of the book. Topics include sequences, functions of a single variable, limit of a function, differential calculus for functions of a single variable, fundamental theorems and applications of dif
Phenomenology of polymer solution dynamics
National Research Council Canada - National Science Library
Phillies, George D. J
2011-01-01
... solutions, not dilute solutions or polymer melts. From centrifugation and solvent dynamics to viscosity and diffusion, experimental measurements and their quantitative representations are the core of the discussion...
Aliteracy : causes and solutions
Nielen, Thijs Martinus Johannes
2016-01-01
The reading motivation of the majority of students declines in the upper half of primary school, which implies a risk for aliteracy: Students can read but, due to lack of practice, their skills remain underdeveloped (Chapter 2). In this thesis we have explored causes and solutions for this important
School Solutions for Cyberbullying
Sutton, Susan
2009-01-01
This article offers solutions and steps to prevent cyberbullying. Schools can improve their ability to handle cyberbullying by educating staff members, students, and parents and by implementing rules and procedures for how to handle possible incidents. Among the steps is to include a section about cyberbullying and expectations in the student…
Antisocial Personalities, Antidemocractic Solutions.
Schneiderman, Howard G.
1996-01-01
Provides critical analysis of David T. Lykken's article "Psychopathy, Sociopathy, and Crime" (1996) and its correlation between unstable families and sociopathy and the use of parental licensing as a solution. Discusses reasons for the appeal of parental licensing as well as the issue of state control replacing social control. (GR)
Cells and Hypotonic Solutions.
Bery, Julia
1985-01-01
Describes a demonstration designed to help students better understand the response of plant and animal cells to hypotonic solutions. The demonstration uses a balloon inside a flexible, thin-walled cardboard box. Air going in corresponds to water entering by osmosis, and, like real cells, if stretched enough, the balloon will burst. (DH)
Glycosylation of solute carriers
DEFF Research Database (Denmark)
Pedersen, Nis Borbye; Carlsson, Michael C; Pedersen, Stine Helene Falsig
2016-01-01
Solute carriers (SLCs) are one of the largest groups of multi-spanning membrane proteins in mammals and include ubiquitously expressed proteins as well as proteins with highly restricted tissue expression. A vast number of studies have addressed the function and organization of SLCs as well...
Stiff fluid spike solutions from Bianchi type V seed solutions
Gregoris, D.; Lim, W. C.; Coley, A. A.
2017-12-01
In this paper we expand upon our previous work Coley et al (2016 Class. Quantum Grav. 33 215010) by using the entire family of Bianchi type V stiff fluid solutions as seed solutions of the Stephani transformation. Among the new exact solutions generated, we observe a number of important physical phenomena. The most interesting phenomenon is exact solutions with intersecting spikes. Other interesting phenomena are solutions with saddle states and a close-to-FL epoch.
DEFF Research Database (Denmark)
Chakkol, Mehmet; Johnson, Mark; Raja, Jawwad
2014-01-01
Purpose – This paper aims to adopt service-dominant logic (SDL) to empirically explore network configurations resulting from the provision of goods, goods and services, and solutions. Design/methodology/approach – This paper uses a single, in-depth, exploratory case study in a truck manufacturer...... different value propositions and the resulting network configurations are discussed. In so doing, evidence is provided of a more complex, tetradic network configuration for solutions, with varying degrees of interplay between actors in the flow of operand and operant resources to create value....... and its supply network. An abductive approach is adopted. In total, 54 semi-structured interviews were conducted. Findings – Three value propositions are clearly discernible within the truck provider. These range from a truck to a “solution”. These propositions have different supply network configurations...
Earnest Rutherford, the solution
2003-01-01
If you did not make it to the Science & Society talk by John Campbell last week and are still wondering about the spelling of "Earnest", here is the solution: Two months after the birth of his fourth child on 30 August 1871 in Spring Grove, New Zealand, James Rutherford registered his son, who was recorded as "Earnest" in the Birth Register. Presumably the Registrar wrote the name down as it sounded and the father failed to notice the mistake when signing the Register.
Solution Processing - Rodlike Polymers
1979-08-01
side it necessary and identify by block number) Para-ordered Polymers High Modulus Fibers and Films Polybenzobisoxazoles Polybenzobisthiazoles 20...considerations important in solution processing are considered, with special emphasis on the dry-jet wet spinning process used to form fibers . Pertinent...Company, Summit, N.J. iii TABLE OF CONTENTS 1. INTRODUCTION ................ .......................... .. 1 2. REMARKS ON DRY-JET WET SPUN FIBER
Shuttle Wastewater Solution Characterization
Adam, Niklas; Pham, Chau
2011-01-01
During the 31st shuttle mission to the International Space Station, STS-129, there was a clogging event in the shuttle wastewater tank. A routine wastewater dump was performed during the mission and before the dump was completed, degraded flow was observed. In order to complete the wastewater dump, flow had to be rerouted around the dump filter. As a result, a basic chemical and microbial investigation was performed to understand the shuttle wastewater system and perform mitigation tasks to prevent another blockage. Testing continued on the remaining shuttle flights wastewater and wastewater tank cleaning solutions. The results of the analyses and the effect of the mitigation steps are detailed in this paper.
Integrated multiphase solutions
Energy Technology Data Exchange (ETDEWEB)
Jiskoot, Mark A. [Jiskoot Autocontrol, Kent (United Kingdom)
1998-07-01
Everyone accepts that multiphase metering provides substantial cost advantages over conventional test separator methods. However the complexity of the flow regimes and process ensures that there is no single applicable technology currently available for all conditions. Numerous optimistic and ill-founded have been made for accuracy. Because of the commercial opportunities, the market is a technology minefield for the potential specifier and user! Jiskoot has introduced an Integarated approach to provision of Multiphase Solutions (IMS) and is the licensee of two distinctly different technologies. This paper outlines a few multiphase measurements problems and the IMS approach using the Mixmeter and Smartstar technologies. (author)
Denschlag, Robert; Lingenheil, Martin; Tavan, Paul; Mathias, Gerald
2009-10-13
For the enhanced conformational sampling in molecular dynamics (MD) simulations, we present "simulated solute tempering" (SST) which is an easy to implement variant of simulated tempering. SST extends conventional simulated tempering (CST) by key concepts of "replica exchange with solute tempering" (REST, Liu et al. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 13749). We have applied SST, CST, and REST to molecular dynamics (MD) simulations of an alanine octapeptide in explicit water. The weight parameters required for CST and SST are determined by two different formulas whose performance is compared. For SST only one of them yields a uniform sampling of the temperature space. Compared to CST and REST, SST provides the highest exchange probabilities between neighboring rungs in the temperature ladder. Concomitantly, SST leads to the fastest diffusion of the simulation system through the temperature space, in particular, if the "even-odd" exchange scheme is employed in SST. As a result, SST exhibits the highest sampling speed of the investigated tempering methods.
Rational homoclinic solution and rogue wave solution for the ...
Indian Academy of Sciences (India)
In this paper, a rational homoclinic solution is obtained via the classical homoclinicsolution for the coupled long-wave–short-wave system. Based on the structures of ratinal homoclinic solution, the characteristics of homoclinic solution are discussed which might provide us with useful information on the dynamics of the ...
Solution of IVP of Second Order ODE with Oscillatory Solutions ...
African Journals Online (AJOL)
A Numerical method for solution of IVP of second order with oscillatory solutions using VIM is developed. The method is applied to solve some initial value problems of second order ODE with oscillatory solutions. The results are compared with some existing methods and found to compete favourably with existing methods.
Solute-Filled Syringe For Formulating Intravenous Solution
Owens, Jim; Bindokas, AL; Dudar, Tom; Finley, Mike; Scharf, Mike
1993-01-01
Prefilled syringe contains premeasured amount of solute in powder or concentrate form used to deliver solute to sterile interior of large-volume parenteral (LVP) bag. Predetermined amount of sterile water also added to LVP bag through sterilizing filter, and mixed with contents of syringe, yielding sterile intravenous solution of specified concentration.
Strong nonlinear oscillators analytical solutions
Cveticanin, Livija
2017-01-01
This book outlines an analytical solution procedure of the pure nonlinear oscillator system, offering a solution for free and forced vibrations of the one-degree-of-freedom strong nonlinear system with constant and time variable parameter. Includes exercises.
Persistent Self-Association of Solute Molecules in Solution.
Tang, Weiwei; Mo, Huaping; Zhang, Mingtao; Parkin, Sean; Gong, Junbo; Wang, Jingkang; Li, Tonglei
2017-11-02
The structural evolvement of a solute determines the crystallization outcome. The self-association mechanism leading to nucleation, however, remains poorly understood. Our current study explored the solution chemistry of a model compound, tolfenamic acid (TFA), in three different solvents mainly by solution NMR. It was found that hydrogen-bonded pairs of solute-solute or solute-solvent stack with each through forming a much weaker π-π interaction as the concentration increases. Depending on the solvent, configurations of the solution species may be retained in the resultant crystal structure or undergo rearrangement. Yet, the π-π stacking is always retained in the crystal regardless of the solvent used for the crystallization. The finding suggests that nucleation not only involves the primary intermolecular interaction (hydrogen bonding) but also engages the secondary forces in the self-assembly process.
Exact Solutions to Maccari's System
Pan, Jun-Ting; Gong, Lun-Xun
2007-07-01
Based on the generalized Riccati relation, an algebraic method to construct a series of exact solutions to nonlinear evolution equations is proposed. Being concise and straightforward, the method is applied to Maccari's system, and some exact solutions of the system are obtained. The method is of important significance in exploring exact solutions for other nonlinear evolution equations.
2010 Water & Aqueous Solutions
Energy Technology Data Exchange (ETDEWEB)
Dor Ben-Amotz
2010-08-13
Water covers more than two thirds of the surface of the Earth and about the same fraction of water forms the total mass of a human body. Since the early days of our civilization water has also been in the focus of technological developments, starting from converting it to wine to more modern achievements. The meeting will focus on recent advances in experimental, theoretical, and computational understanding of the behavior of the most important and fascinating liquid in a variety of situations and applications. The emphasis will be less on water properties per se than on water as a medium in which fundamental dynamic and reactive processes take place. In the following sessions, speakers will discuss the latest breakthroughs in unraveling these processes at the molecular level: Water in Solutions; Water in Motion I and II; Water in Biology I and II; Water in the Environment I and II; Water in Confined Geometries and Water in Discussion (keynote lecture and poster winners presentations).
Griscom, Bronson W.; Adams, Justin; Ellis, Peter W.; Houghton, Richard A.; Lomax, Guy; Miteva, Daniela A.; Schlesinger, William H.; Shoch, David; Siikamäki, Juha V.; Smith, Pete; Woodbury, Peter; Zganjar, Chris; Blackman, Allen; Campari, João; Conant, Richard T.; Delgado, Christopher; Elias, Patricia; Gopalakrishna, Trisha; Hamsik, Marisa R.; Herrero, Mario; Kiesecker, Joseph; Landis, Emily; Laestadius, Lars; Leavitt, Sara M.; Minnemeyer, Susan; Polasky, Stephen; Potapov, Peter; Putz, Francis E.; Sanderman, Jonathan; Silvius, Marcel; Wollenberg, Eva; Fargione, Joseph
2017-10-01
Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify “natural climate solutions” (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS—when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams of CO2 equivalent (PgCO2e) y‑1 (95% CI 20.3–37.4). This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO2e y‑1) represents cost-effective climate mitigation, assuming the social cost of CO2 pollution is ≥100 USD MgCO2e‑1 by 2030. Natural climate solutions can provide 37% of cost-effective CO2 mitigation needed through 2030 for a >66% chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO2‑1. Most NCS actions—if effectively implemented—also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change.
Enthalpy of solution of biuret in various aqueous electrolyte solutions and in an urea solution
Energy Technology Data Exchange (ETDEWEB)
Nishimura, Hisashi; Murakami, Sachio (Osaka City Univ. (Japan))
1989-06-30
Enthalpies of biuret which is simplest amido acid and does not have hydrophobic group, in various aqueous solutions and in urea solution were measured at 298.15K to clarify the influence of salt on polymer conformal changes of organism or structure and functions of membrane. The isoperibol calorimeter where the quartz thermometer was used as the thermal sensor, was used in the measurement. The performance of this calorimeter was tested by comparing measurements with values in references. From the analysis of enthalpies of biuret solutions, following results of solute-solute-solvent interactions could be obtained: the rate where biuret destroys water structure is smaller in salt solutions than in aqueous solutions and the tendency depends on the ion size; ion-water interaction weakens owing to the ion-biuret interaction in salt solution of biuret; and water molecules are made free. 25 refs., 4 figs., 5 tabs.
Future climate. Engineering solutions
Energy Technology Data Exchange (ETDEWEB)
Ferdinand, J.F.; Hagedorn-Rasmussen, P.; Fonnesbech, B.
2009-09-15
Future Climate Engineering Solutions - Joint Report is the common output and a documentation of more than 1 year's effort by 13 engineering associations - in 12 countries - to demonstrate how technologies can combat climate change. The report consists of three parts: Summaries of 10 national climate plans and technology prospects, 5 Key Common Findings, and a Climate Call from Engineers to create a new global climate treaty. The basic assumption of the project is recognition that GHG emissions, and their concentration in the atmosphere, must be reduced to a sustainable level. The project definition of a sustainable level is equivalent to the best-case stabilisation scenario which was presented in the 4th Assessment Report (AR4) by the UN Intergovernmental Panel on Climate Change (IPCC), whereby the global mean temperature is most likely to stabilise at 2.0-2.4 deg. C. The Future Climate website www.futureclimate.info holds more information about the project, including possibility to download project material, including the full national climate plans.
Directory of Open Access Journals (Sweden)
Brahim DENNAI
2011-08-01
Full Text Available Mixing rate is characterized by the diffusion flux given by the Fick’s law. A passive mixing strategy is proposed to enhance mixing of two fluids through perturbed jet flow. A numerical study of passive mixers has been presented. This paper is focused on the modeling of a micro-injection systems composed of passive amplifier without mechanical part. The micro-system modeling is based on geometrical oscillators form. An asymmetric micro-oscillator design based on a monostable fluidic amplifier is proposed. The characteristic size of the channels is generally about a few hundred of microns. The numerical results indicate that the mixing performance can be as high as 92 % within a typical mixing chamber of 2.25 mm diameter and 0.20 mm length when the Reynolds number is Re = 490. In addition, the results confirm that self-rotation in the circular mixer significantly enhances the mixing performance. The novel micro mixing method presented in this study provides a simple solution to mixing problems in micro system.
2003-01-01
From the company that brought the world an integral heating and cooling food service system after originally developing it for NASA's Apollo Program, comes yet another orbital offshoot: a product that can be as thin as paper and as strong as steel. Nextel Ceramic Textiles and Composites from 3M Company offer space-age protection and innovative solutions for hot situations, ranging from NASA to NASCAR. With superior thermal protection, Nextel fabrics, tape, and sleevings outperform other high temperature textiles such as aramids, carbon, glass, and quartz, permitting engineers and manufacturers to handle applications up to 2,500 F (1,371 C). The stiffness and strength of Nextel Continuous Ceramic Fibers make them a great match for improving the rigidity of aluminum in metal matrix composites. Moreover, the fibers demonstrate low shrinkage at operating temperatures, which allow for the manufacturing of a dimensionally stable product. These novel fibers also offer excellent chemical resistance, low thermal conductivity, thermal shock resistance, low porosity, and unique electrical properties.
Properties of scintillator solutes
Energy Technology Data Exchange (ETDEWEB)
Fluornoy, J.M.
1998-06-01
This special report summarizes measurements of the spectroscopic and other properties of the solutes that were used in the preparation of several new liquid scintillators developed at EG and G/Energy Measurements/Santa Barbara Operations (the precursor to Bechtel Nevada/Special Technologies Laboratory) on the radiation-to-light converter program. The data on the individual compounds are presented in a form similar to that used by Prof. Isadore Berlman in his classic handbook of fluorescence spectra. The temporal properties and relative efficiencies of the new scintillators are presented in Table 1, and the efficiencies as a function of wavelength are presented graphically in Figure 1. In addition, there is a descriptive glossary of the abbreviations used herein. Figure 2 illustrates the basic structures of some of the compounds and of the four solvents reported in this summary. The emission spectra generally exhibit more structure than the absorption spectra, with the result that the peak emission wavelength for a given compound may lie several nm away from the wavelength, {lambda}{sub avg}, at the geometric center of the emission spectrum. Therefore, the author has chosen to list absorption peaks, {lambda}{sub max}, and emission {lambda}{sub avg} values in Figures 3--30, as being most illustrative of the differences between the compounds. The compounds, BHTP, BTPB, ADBT, and DPTPB were all developed on this program. P-terphenyl, PBD, and TPB are commercially available blue emitters. C-480 and the other longer-wavelength emitters are laser dyes available commercially from Exciton Corporation. 1 ref., 30 figs.
Iodine addition using triiodide solutions
Rutz, Jeffrey A.; Muckle, Susan V.; Sauer, Richard L.
1992-01-01
The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.
Solute diffusion in liquid metals
Bhat, B. N.
1973-01-01
A gas model of diffusion in liquid metals is presented. In this model, ions of liquid metals are assumed to behave like the molecules in a dense gas. Diffusion coefficient of solute is discussed with reference to its mass, ionic size, and pair potential. The model is applied to the case of solute diffusion in liquid silver. An attempt was made to predict diffusion coefficients of solutes with reasonable accuracy.
Colligative properties of simple solutions.
Andrews, F C
1976-11-05
Vapor pressure lowering, osmotic pressure, boiling point elevation, and freezing point depression are all related quantitatively to the decrease in micro(1)(soln) upon the addition of solute in forming a solution. In any equilibrium system, regardless of whether it is in a gravitational field or whether it contains walls, semipermeable membranes, phase transitions, or solutes, all equilibria are maintained locally, in the small region of the equilibrium, by the equality of micro(1)(soln). If there are several subsystems in a gravitational field, at any fixed height, microi will have the same value in each subsystem into which substance i can get, and microi + M(i)gh is constant throughout the entire system. In a solution, there is no mechanism by which solvent and solute molecules could sustain different pressures. Both the solvent and solute are always under identical pressures in a region of solution, namely, the pressure of the solution in that region. Since nature does not know which component we call the solvent and which the solute, equations should be symmetric in the two (acknowledging that the nonvolatile component, if any, is commonly chosen to be solute). Simple molecular pictures illustrate what is happening to cause pressure (positive or negative) in liquids, vapor pressure of liquids, and the various colligative properties of solutions. The only effect of solute involved in these properties is that it dilutes the solvent, with the resulting increase in S and decrease in micro(1)(soln). Water can be driven passively up a tree to enormous heights by the difference between its chemical potential in the roots and the ambient air. There is nothing mysterious about the molecular bases for any of these phenomena. Biologists can use the well-understood pictures of these phenomena with confidence to study what is happening in the complicated living systems they consider.
Structure and dynamics of solutions
Ohtaki, H
2013-01-01
Recent advances in the study of structural and dynamic properties of solutions have provided a molecular picture of solute-solvent interactions. Although the study of thermodynamic as well as electronic properties of solutions have played a role in the development of research on the rate and mechanism of chemical reactions, such macroscopic and microscopic properties are insufficient for a deeper understanding of fast chemical and biological reactions. In order to fill the gap between the two extremes, it is necessary to know how molecules are arranged in solution and how they change their pos
High conductivity electrolyte solutions and rechargeable cells incorporating such solutions
Angell, Charles Austen; Zhang, Sheng-Shui; Xu, Kang
1998-01-01
This invention relates generally to electrolyte solvents for use in liquid or rubbery polymer electrolyte solutions as are used, for example, in electrochemical devices. More specifically, this invention relates to sulfonyl/phospho-compound electrolyte solvents and sulfonyl/phospho-compound electrolyte solutions incorporating such solvents.
Viscosity Control of Protein Solution by Small Solutes: A Review.
Hong, Taehun; Iwashita, Kazuki; Shiraki, Kentaro
2017-12-12
Viscosity of protein solution is one of the most troublesome issues for the high-concentration formulation of protein drugs. In this review, we summarize the practical methods that suppress the viscosity of protein solution using small molecular additives. The small amount of salts decreases the viscosity that results from electrostatic repulsion and attraction. The chaotrope suppresses the hydrophobic attraction and cluster formation, which can lower the solution viscosity. Arginine hydrochloride (ArgHCl) also suppresses the solution viscosity due to the hydrophobic and aromatic interactions between protein molecules. The small molecular additives are the simplest resolution of the high viscosity of protein solution as well as understanding of the primary cause in complex phenomena of protein interactions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Nutrient solutions for soilless cultures
Sonneveld, C.; Voogt, W.
2009-01-01
Nutrient solutions intended for plant growth are already used from the middle of the 19th century, when the importance of mineral elements for plant growth was made clear by Justus von Liebig. In advance, the nutrient solutions used to grow plants in so called “water cultures” had a simple
Evaluation of ITRF2014 Solutions
Dach, Rolf; Grahsl, Andrea; Susnik, Andreja; Villiger, Arturo; Arnold, Daniel; Jäggi, Adrian
2017-04-01
For the most recent International Terrestrial Reference Frame (ITRF) realization three candidates have been provided, namely an ITRF2014 solution by IGN, DTRF2014 by DGFI-TUM, and JTRF2014 by JPL. There are significant differences in the way how these solutions have been generated, which parametrization has been applied, and how the solutions from the different space-geodetic techniques are combined. The most recent GNSS reprocessing solution generated in the frame of the EGSIEM project (European Gravity Service for Improved Emergency Management; funded by EC in the frame of Horizon 2020) was used to generate time series of GNSS-based solutions from 2000 to the end of 2014 using these reference frame realizations. The solution contains station coordinates, GNSS satellite orbits, Earth rotation parameters, and troposphere parameters. In order to evaluate the consistency of the contributions from the IGS (GNSS) and ILRS (SLR) in the reference frame solutions, the SLR measurements to the GNSS satellites can be used. Since the microwave-based GNSS satellite orbits obtained in the different reference frames are consistent regarding the orbit modeling differences in the SLR residuals may be interpreted to assess the consistency of the station coordinates between the SLR and GNSS sites in the reference frame solutions. With this contribution we hope to provide an independent contribution to the discussion about the advantages and disadvantages of the different methods to generate the IERS-TRF.
Solution of Finite Element Equations
DEFF Research Database (Denmark)
Krenk, Steen
An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...
Enclosing Solutions of Integral Equations
DEFF Research Database (Denmark)
Madsen, Kaj; NA NA NA Caprani, Ole; Stauning, Ole
1996-01-01
We present a method for enclosing the solution of an integral equation. It is assumed that a solution exists and that the corresponding integral operator T is a contraction near y. When solving the integral equation by iteration we obtain a result which is normally different from y because...
Solutions of equations in languages
Hesselink, Wim H.
A context-free grammar corresponds to a system of equations in languages. The language generated by the grammar is the smallest solution of the system. We give a necessary and sufficient condition for an arbitrary solution to be the smallest one. We revive an old criterion to decide that a grammar
Requirements Engineering: Solutions and Trends
Ebert, C.; Wieringa, Roelf J.; Aurum, A.; Wohlin, C.
2005-01-01
This last chapter of the book describes solutions and trends in the discipline of RE. Starting from a wrap-up of what was presented throughout this book, it suggests a framework of requirements engineering and indicates what current solutions are available in this framework. Beyond providing a short
Interior Design: Challenges and Solutions.
School Planning and Management, 1999
1999-01-01
Presents solutions to architectural challenges in school interior design; these solutions made the indoor environments more conducive and attractive for learning. Addresses four challenges: making a long corridor look less like a tunnel; maintaining tradition and minimizing cost in a new athletic facility; designing a kindergarten that is secure…
Vainshtein solutions without superluminal modes
Gabadadze, Gregory; Kimura, Rampei; Pirtskhalava, David
2015-06-01
The Vainshtein mechanism suppresses the fifth force at astrophysical distances, while enabling it to compete with gravity at cosmological scales. Typically, Vainshtein solutions exhibit superluminal perturbations. However, a restricted class of solutions with special boundary conditions was shown to be devoid of the faster-than-light modes. Here we extend this class by finding solutions in a theory of quasidilaton, amended by derivative terms consistent with its symmetries. Solutions with Minkowski asymptotics are not stable, while the ones that exhibit the Vainshtein mechanism by transitioning to cosmological backgrounds are free of ghosts, tachyons, gradient instability, and superluminality, for all propagating modes present in the theory. These solutions require a special choice of the strength and signs of nonlinear terms, as well as a choice of asymptotic cosmological boundary conditions.
TREATMENT OF AMMONIUM NITRATE SOLUTIONS
Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.
1958-06-10
The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.
Solutions for the food processing industry; Shokuhin seizogyo solution
Energy Technology Data Exchange (ETDEWEB)
Toda, T.; Iwami, N. [Fuji Electric Co. Ltd., Tokyo (Japan)
1999-09-10
To improve quality control and maintain stable operation, the food processing industry requires problem solutions in total, including not only processing and operation control divisions but also quality control, design and production technology, and maintenance divisions. This paper describes solutions for HACCP (hazard analysis critical control point) support, quality control, and maintenance, in order to improve the quality level, ensure traceability and realize stable processing operations. (author)
Business process solution `Joint MEISTER`; Gyomu shien solution `Joint MEISTER`
Energy Technology Data Exchange (ETDEWEB)
Watanabe, Y.; Ito, S. [Fuji Electric Co. Ltd., Tokyo (Japan)
1998-12-10
The business process solution `Joint{sub M}EISTER` can be ranked among computer systems represented by groupware and WWW applications. This paper describes its typical system, ExchangeUSE work flow solution, and the effect of its introduction, citing a concrete case. The Company A introduced the ExchangeUSE work flow for traveling expenses adjustment and attendance, and has gained a reduction of 7 man-months/month. (author)
Ormancey, Emmanuel
2008-01-01
The need for Single Sign On has always been restricted by the absence of cross platform solutions: a single sign on working only on one platform or technology is nearly useless. The recent improvements in Web Services Federation (WS-Federation) standard enabling federation of identity, attribute, authentication and authorization information can now provide real extended Single Sign On solutions. Various solutions have been investigated at CERN and now, a Web SSO solution using some parts of WS-Federation technology is available. Using the Shibboleth Service Provider module for Apache hosted web sites and Microsoft ADFS as the identity provider linked to Active Directory user, users can now authenticate on any web application using a single authentication platform, providing identity, user information (building, phone...) as well as group membership enabling authorization possibilities. A typical scenario: a CERN user can now authenticate on a Linux/Apache website using Windows Integrated credentials, and his ...
Adolescents: Health Risks and Solutions
... sheets Fact files Questions & answers Features Multimedia Contacts Adolescents: health risks and solutions Fact sheet Updated May ... adolescents in some high-income countries. Rights of adolescents The rights of children (people under 18 years ...
Solutions of Nonlocal -Laplacian Equations
Directory of Open Access Journals (Sweden)
Mustafa Avci
2013-01-01
Full Text Available In view of variational approach we discuss a nonlocal problem, that is, a Kirchhoff-type equation involving -Laplace operator. Establishing some suitable conditions, we prove the existence and multiplicity of solutions.
Solute diffusivity in undisturbed soil
DEFF Research Database (Denmark)
Lægdsmand, Mette; Møldrup, Per; Schjønning, Per
2012-01-01
Solute diffusivity in soil plays a major role in many important processes with relation to plant growth and environmental issues. Soil solute diffusivity is affected by the volumetric water content as well as the morphological characteristics of water-filled pores. The solute diffusivity in intact...... tracers) for a better determination of the diffusivity. The diffusivity was higher in the below-till soil than the plowed soil at the same soil water matric potential due to higher water content but also due to higher continuity and lower tortuosity of the soil pores. We measured identical solute...... diffusivities independent of the tracer set used. We analyzed the whole data set using Archie's law and found a linear relation between Archie's exponent and the logarithm of the soil water matric suction in centimeters of water (pF). An analysis of seven data sets from the literature showed...
Transnistria: Prospects for a Solution
National Research Council Canada - National Science Library
Urse, Cristian
2007-01-01
.... After the conclusion of the agreement that ended the armed conflict, Chisinau and Tiraspol made efforts to find a political solution, under the supervision of a negotiation mechanism that included...
Clean Energy Solutions Center Services
Energy Technology Data Exchange (ETDEWEB)
2016-03-01
The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Exact cosmological solutions for MOG
Energy Technology Data Exchange (ETDEWEB)
Roshan, Mahmood [Ferdowsi University of Mashhad, Department of Physics, P.O. Box 1436, Mashhad (Iran, Islamic Republic of)
2015-09-15
We find some new exact cosmological solutions for the covariant scalar-tensor-vector gravity theory, the so-called modified gravity (MOG). The exact solution of the vacuum field equations has been derived. Also, for non-vacuum cases we have found some exact solutions with the aid of the Noether symmetry approach. More specifically, the symmetry vector and also the Noether conserved quantity associated to the point-like Lagrangian of the theory have been found. Also we find the exact form of the generic vector field potential of this theory by considering the behavior of the relevant point-like Lagrangian under the infinitesimal generator of the Noether symmetry. Finally, we discuss the cosmological implications of the solutions. (orig.)
Exact solution for generalized pairing
Pan, Feng; Draayer, J. P.
1997-01-01
An infinite dimensional algebra, which is useful for deriving exact solutions of the generalized pairing problem, is introduced. A formalism for diagonalizing the corresponding Hamiltonian is also proposed. The theory is illustrated with some numerical examples.
Spherically symmetric perfect fluid solutions
Energy Technology Data Exchange (ETDEWEB)
Hajj-Boutros, J.
1985-04-01
Many exact solutions for the spherically symmetric perfect fluid distribution of matter with shear, acceleration, and expansion are obtained. One of them is expressed in terms of Painleve's third transcendent.
Cesium recovery from aqueous solutions
Goodhall, C. A.
1960-09-13
A process for recovering cesium from aqueous solutions is given in which precipitation on zinc ferricyanide is used. The precipitation is preferably carried out in solutions containing at least 0.0004M zinc ferricyanide, an acidity ranging from 0.2N mineral acid to 0.61N acid deficiency, and 1 to 2.5M aluminum nitrate. (D.L.C.)
Reuse of hydroponic waste solution.
Kumar, Ramasamy Rajesh; Cho, Jae Young
2014-01-01
Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.
Approximative solutions of difference equations
Directory of Open Access Journals (Sweden)
Janusz Migda
2014-03-01
\\Delta^m x_n=a_nf(n,x_{\\sigma(n}+b_n $$ are studied. Using the iterated remainder operator and fixed point theorems we obtain sufficient conditions under which for any solution $y$ of the equation $\\Delta^my=b$ and for any real $s\\leq 0$ there exists a solution $x$ of the above equation such that $\\Delta^kx=\\Delta^ky+\\mathrm{o}(n^{s-k}$ for any nonnegative integer $k\\leq m$. Using a discrete variant of the Bihari lemma and a certain new technique we give also sufficient conditions under which for a given real $s\\leq m-1$ all solutions $x$ of the equation satisfy the condition $x=y+\\mathrm{o}(n^s$ where $y$ is a solution of the equation $\\Delta^my=b$. Moreover, we give sufficient conditions under which for a given natural $k
Technetium recovery from high alkaline solution
Energy Technology Data Exchange (ETDEWEB)
Nash, Charles A.
2016-07-12
Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.
One-soliton solutions from Laplace's seed
Indian Academy of Sciences (India)
One-soliton solutions of axially symmetric vacuum Einstein ﬁeld equations are presented in this paper. Two sets of Laplace's solutions are used as seed and it is shown that the derived solutions reduce to some already known solutions when the constants are properly adjusted. An analysis of the solutions in terms of the ...
One-soliton solutions from Laplace's seed
Indian Academy of Sciences (India)
Abstract. One-soliton solutions of axially symmetric vacuum Einstein field equations are pre- sented in this paper. Two sets of Laplace's solutions are used as seed and it is shown that the derived solutions reduce to some already known solutions when the constants are properly adjusted. An analysis of the solutions in ...
Stability of aflatoxins in solution.
Diaz, Gonzalo J; Cepeda, Sandra M; Martos, Perry A
2012-01-01
The stability of aflatoxins B1, B2, G1, and G2 was studied in solutions containing different concentrations of water, acetonitrile, and/or methanol, and in autosampler vials treated with nitric acid or silanized. When stored at room temperature (20 degrees C) for 24 h, aflatoxins G1 and G2 were stable only in solutions containing 100% organic solvent, whereas aflatoxins B1 and B2 were stable in solutions of methanol-water and acetonitrile-water at greater than 60 and 40% organic content, respectively. At 5 degrees C, aflatoxins G1 and G2 showed a significant decrease in concentration only when kept in less than 20% aqueous organic solvent. Significant loss of aflatoxins was realized in standard, commercially available amber type I borosilicate autosampler vials, but chemical etching of the vials with nitric acid or with silanization prevented aflatoxin degradation. These results indicate that aflatoxins are unstable in aqueous solutions and that this instability can be counteracted by the presence of at least 20% organic solvent and keeping the solutions at 5 degrees C or by the use of treated vials.
Plagiarism Detection by Online Solutions.
Masic, Izet; Begic, Edin; Dobraca, Amra
2017-01-01
The problem of plagiarism represents one of the burning issues of the modern scientific world. Detection of plagiarism is a problem that the Editorial Board encounters in their daily work. Software solutions represent a good solution for the detection of plagiarism. The problem of plagiarism will become most discussed topic of the modern scientific world, especially due to the development of standard measures, which rank the work of one author. Investment in education, education of young research personnel about the importance of scientific research, with paying particular attention on ethical behavior, becomes an imperative of academic staff. Editors have to invest additional effort in the development of the base of reviewers team as well as in their proper guidance, because after all, despite the software solutions, they are the best weapon to fight plagiarism. Peer review process should be a key of successful operation of each journal.
Automatic validation of numerical solutions
DEFF Research Database (Denmark)
Stauning, Ole
1997-01-01
differential equations, but in this thesis, we describe how to use the methods for enclosing iterates of discrete mappings, and then later use them for discretizing solutions of ordinary differential equations. The theory of automatic differentiation is introduced, and three methods for obtaining derivatives...... is the possiblility to combine the three methods in an extremely flexible way. We examine some applications where this flexibility is very useful. A method for Taylor expanding solutions of ordinary differential equations is presented, and a method for obtaining interval enclosures of the truncation errors incurred......, using this method has been developed. (ADIODES is an abbreviation of `` Automatic Differentiation Interval Ordinary Differential Equation Solver''). ADIODES is used to prove existence and uniqueness of periodic solutions to specific ordinary differential equations occuring in dynamical systems theory...
Ions in hyaluronic acid solutions
Horkay, Ferenc; Basser, Peter J.; Londono, David J.; Hecht, Anne-Marie; Geissler, Erik
2009-11-01
Hyaluronic acid (HA) is an anionic biopolymer that is almost ubiquitous in biological tissues. An attempt is made to determine the dominant features that account for both its abundance and its multifunctional role, and which set it apart from other types of biopolymers. A combination of osmotic and scattering techniques is employed to quantify its dynamic and static properties in near-physiological solution conditions, where it is exposed both to mono- and divalent counterions. An equation of state is derived for the osmotic pressure Π in the semidilute concentration region, in terms of two variables, the polymer concentration c and the ionic strength J of the added salt, according to which Π =1.4×103c9/4/J3/4 kPa, where c and J are expressed in mole. Over the physiological ion concentration range, the effect of the sodium chloride and calcium chloride on the osmotic properties of HA solutions is fully accounted for by their contributions to the ionic strength. The absence of precipitation, even at high CaCl2 concentrations, distinguishes this molecule from other biopolymers such as DNA. Dynamic light scattering measurements reveal that the collective diffusion coefficient in HA solutions exceeds that in aqueous solutions of typical neutral polymers by a factor of approximately 5. This property ensures rapid adjustment to, and recovery from, stress applied to HA-containing tissue. Small angle x-ray scattering measurements confirm the absence of appreciable structural reorganization over the observed length scale range 10-1000 Å, as a result of calcium-sodium ion exchange. The scattered intensity in the transfer momentum range q >0.03 Å-1 varies as 1/q, indicating that the HA chain segments in semidilute solutions are linear over an extended concentration range. The osmotic compression modulus c ∂Π/∂c, a high value of which is a prerequisite in structural biopolymers, is several times greater than in typical neutral polymer solutions.
Fluid mechanics problems and solutions
Spurk, Joseph H
1997-01-01
his collection of over 200 detailed worked exercises adds to and complements the textbook Fluid Mechanics by the same author, and illustrates the teaching material through examples. In the exercises the fundamental concepts of Fluid Mechanics are applied to obtaining the solution of diverse concrete problems, and in doing this the student's skill in the mathematical modeling of practical problems is developed. In addition, 30 challenging questions without detailed solutions have been included, and while lecturers will find these questions suitable for examinations and tests, the student himself can use them to check his understanding of the subject.
Hybrid Solution for Integrated Trading
Directory of Open Access Journals (Sweden)
Vlad DIACONITA
2010-01-01
Full Text Available Integrated applications are complex solutions, whose complexity are determined by the economic processes they implement, the amount of data employed (millions of records grouped in hundreds of tables, databases, hundreds of GB and the number of users. Service oriented architecture (SOA, is now the most talked-about integration solution in mainstream journals, addressing both simple applications, for a department but also at enterprise level. SOA can refer to software architecture or to a way of standardizing the technical architecture of an enterprise and it shows its value when operating in several distinct and heterogeneous environments.
Electrodialysis operation with buffer solution
Hryn, John N [Naperville, IL; Daniels, Edward J [Orland Park, IL; Krumdick, Greg K [Crete, IL
2009-12-15
A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.
Teaching sustainable solutions in engineering
DEFF Research Database (Denmark)
Olsen, Stig Irving; Nielsen, Susanne Balslev; Ejlertsen, Marina
2015-01-01
The increasing societal and industrial emphasis on sustainability requests that the next generation engineers needs to be trained in the context of sustainability. One of the means to address students at DTU is the establishment of a course aimed at bachelor students from all of the university......'s study lines. The objectives of the course 'Sustainability in engineering solutions', is for the participants to understand the basic concept of sustainability and its three dimensions (people, profit, planet), as well as to analyse problems and synthesise solutions that are sustainable throughout...
Analytical Solution for Reactive Solute Transport Considering Incomplete Mixing
Bellin, A.; Chiogna, G.
2013-12-01
The laboratory experiments of Gramling et al. (2002) showed that incomplete mixing at the pore scale exerts a significant impact on transport of reactive solutes and that assuming complete mixing leads to overestimation of product concentration in bimolecular reactions. We consider here the family of equilibrium reactions for which the concentration of the reactants and the product can be expressed as a function of the mixing ratio, the concentration of a fictitious non reactive solute. For this type of reactions we propose, in agreement with previous studies, to model the effect of incomplete mixing at scales smaller than the Darcy scale assuming that the mixing ratio is distributed within an REV according to a Beta distribution. We compute the parameters of the Beta model by imposing that the mean concentration is equal to the value that the concentration assumes at the continuum Darcy scale, while the variance decays with time as a power law. We show that our model reproduces the concentration profiles of the reaction product measured in the Gramling et al. (2002) experiments using the transport parameters obtained from conservative experiments and an instantaneous reaction kinetic. The results are obtained applying analytical solutions both for conservative and for reactive solute transport, thereby providing a method to handle the effect of incomplete mixing on multispecies reactive solute transport, which is simpler than other previously developed methods. Gramling, C. M., C. F. Harvey, and L. C. Meigs (2002), Reactive transport in porous media: A comparison of model prediction with laboratory visualization, Environ. Sci. Technol., 36(11), 2508-2514.
Point massive particle in General Relativity
Katanaev, M. O.
2013-10-01
It is well known that the Schwarzschild solution describes the gravitational field outside compact spherically symmetric mass distribution in General Relativity. In particular, it describes the gravitational field outside a point particle. Nevertheless, what is the exact solution of Einstein's equations with -type source corresponding to a point particle is not known. In the present paper, we prove that the Schwarzschild solution in isotropic coordinates is the asymptotically flat static spherically symmetric solution of Einstein's equations with -type energy-momentum tensor corresponding to a point particle. Solution of Einstein's equations is understood in the generalized sense after integration with a test function. Metric components are locally integrable functions for which nonlinear Einstein's equations are mathematically defined. The Schwarzschild solution in isotropic coordinates is locally isometric to the Schwarzschild solution in Schwarzschild coordinates but differs essentially globally. It is topologically trivial neglecting the world line of a point particle. Gravity attraction at large distances is replaced by repulsion at the particle neighborhood.
COMPOSITE SOLUTIONS IN RAILROAD ENGINEERING
Directory of Open Access Journals (Sweden)
Panfilova Marina Ivanovna
2012-10-01
Full Text Available Present-day methods of recovery of used wooden railway ties, including burial, chemical neutralization, gasification and subsequent burning, utilization in the capacity of composite materials, are expensive and unsafe for the environment. The authors propose a new method of their utilization. Ash generated in the course of their burning may replace a portion of cement in composite solutions and act as an additive to grouting mortars designated for the filling of the annulus space of manifold tunnels. The chemical composition of the ash was identified by the x-ray method applied to three samples taken during various periods of time from out of a dry-type dust collector. The level of human health/environmental hazard of the ash is based on its chemical composition. Changes in the rheological properties of composite solutions that contained concrete fractions, various ratios of ash, and 5% of liquid glass were studied in the course of the research. The experiments have proven that in the event of replacement of 20% of cement by ash, the strength of the composite solution is approximately the same as the one of the benchmark sample; therefore, this ash content ratio is deemed acceptable. The finding demonstrate that the ash has no toxic effect, and the ecological safety of this solution is thus confirmed. The authors have proven that 20% of cement may be replaced by the ash generated in the course of burning of waste railway ties.
Components of Geometric Analogy Solution.
Mulholland, Timothy M.; And Others
1980-01-01
Adults' geometric analogy solution was investigated as a function of systematic variations in the information structure of items. Latency data from verification of true and false items were recorded. A model incorporating assumptions about the form of item representation, working memory factors, and processing components and strategies was…
Aqueous Solution Chemistry of Plutonium
Energy Technology Data Exchange (ETDEWEB)
Clark, David L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-01-28
Things I have learned working with plutonium: Chemistry of plutonium is complex; Redox equilibria make Pu solution chemistry particularly challenging in the absence of complexing ligands; Understanding this behavior is key to successful Pu chemistry experiments; There is no suitable chemical analog for plutonium.
Lump solutions in SFT. Complements
Bonora, L.; Giaccari, S.; Tolla, D. D.
2011-01-01
Recently a possible violation of the equation of motion for the recently proposed lump solutions in open SFT has been pointed out in the literature. In this paper we argue that, when the issue is considered in the appropriate mathematical setting of distribution theory, no violations to the equation of motion occur.
Archival storage solutions for PACS
Chunn, Timothy
1997-05-01
While they are many, one of the inhibitors to the wide spread diffusion of PACS systems has been robust, cost effective digital archive storage solutions. Moreover, an automated Nearline solution is key to a central, sharable data repository, enabling many applications such as PACS, telemedicine and teleradiology, and information warehousing and data mining for research such as patient outcome analysis. Selecting the right solution depends on a number of factors: capacity requirements, write and retrieval performance requirements, scaleability in capacity and performance, configuration architecture and flexibility, subsystem availability and reliability, security requirements, system cost, achievable benefits and cost savings, investment protection, strategic fit and more.This paper addresses many of these issues. It compares and positions optical disk and magnetic tape technologies, which are the predominant archive mediums today. Price and performance comparisons will be made at different archive capacities, plus the effect of file size on storage system throughput will be analyzed. The concept of automated migration of images from high performance, high cost storage devices to high capacity, low cost storage devices will be introduced as a viable way to minimize overall storage costs for an archive. The concept of access density will also be introduced and applied to the selection of the most cost effective archive solution.
Solute carrier transporters: Pharmacogenomics research ...
African Journals Online (AJOL)
Aghogho
substrates. The growing number of publications reporting genetic population data for the solute carrier transporters in particular shows ... almost all diseases is also determined to some extent by genetic variation (Brockmoller and .... bile acids, amino acids, ions, xenobiotics, drugs, and other biologically active compounds, ...
Solute strengthening at high temperatures
Leyson, G. P. M.; Curtin, W. A.
2016-08-01
The high temperature behavior of solute strengthening has previously been treated approximately using various scaling arguments, resulting in logarithmic and power-law scalings for the stress-dependent energy barrier Δ E(τ ) versus stress τ. Here, a parameter-free solute strengthening model is extended to high temperatures/low stresses without any a priori assumptions on the functional form of Δ E(τ ) . The new model predicts that the well-established low-temperature, with energy barrier Δ {{E}\\text{b}} and zero temperature flow stress {τy0} , transitions to a near-logarithmic form for stresses in the regime 0.2intermediate-temperature and the associated transition for the activation volume. Overall, the present analysis unifies the different qualitative models in the literature and, when coupled with the previous parameter-free solute strengthening model, provides a single predictive model for solute strengthening as a function of composition, temperature, and strain rate over the full range of practical utility.
Solution properties of hydrophobically modified
Directory of Open Access Journals (Sweden)
A.M. Al-Sabagh
2016-12-01
Full Text Available We tested nine hydrophobically modified polyacrylamides with molecular weights situated between 1.58 and 0.89 × 106 g/mol for enhanced oil recovery applications. Their solution properties were investigated in the distilled water, brine solution, formation water and sea water. Their critical association concentrations were determined from the relationship between their concentrations and the corresponding apparent viscosities (ηapp at 30 °C at shear rate 6 s−1. They were between 0.4 and 0.5 g/dl. The brine solutions of 0.5 g/dl of HM-PAMs were investigated at different conditions regarding their apparent viscosities. Such conditions were mono and divalent cations, temperature ranging from 30 to 90 °C, the shear rate ranging from 6 to 30 s−1 and the aging time for 45 days. The surface and interfacial tensions for the HM-PAMs were measured for concentration range from 0.01 to 1 g/dl brine solutions at 30 °C and their emulsification efficiencies were investigated for 7 days. The discrepancy in the properties and efficiencies of the tested copolymers was discussed in the light of their chemical structure.
Graphical Solution of Polynomial Equations
Grishin, Anatole
2009-01-01
Graphing utilities, such as the ubiquitous graphing calculator, are often used in finding the approximate real roots of polynomial equations. In this paper the author offers a simple graphing technique that allows one to find all solutions of a polynomial equation (1) of arbitrary degree; (2) with real or complex coefficients; and (3) possessing…
A charged spherically symmetric solution
Indian Academy of Sciences (India)
By setting the charge contribution to zero we regain an (uncharged) perfect ﬂuid solution found previously with the equation of state =+ constant, which is a generalisation of a stiff equation of state. Our class of ... Govinder1. School of Mathematical and Statistical Sciences, University of Natal, Durban 4041, South Africa ...
Looking to nature for solutions
Turner, Will R.
2018-01-01
Completely stopping fossil fuel use may not be enough to avoid dangerous climate change. Recent research on the mitigation potential of conservation, restoration, and improved land management demonstrates that natural solutions can reduce emissions and remove atmospheric CO2 while safeguarding food security and biodiversity.
Cosmological solutions with massive gravitons
Energy Technology Data Exchange (ETDEWEB)
Chamseddine, Ali H. [Physics Department, American University of Beirut (Lebanon); Laboratoire de Mathematiques et Physique Theorique CNRS-UMR 6083, Universite de Tours, Parc de Grandmont, 37200 Tours (France); LE STUDIUM, Loire Valley Institute for Advanced Studies, Tours and Orleans (France); I.H.E.S., F-91440 Bures-sur-Yvette (France); Volkov, Mikhail S., E-mail: volkov@lmpt.univ-tours.fr [Laboratoire de Mathematiques et Physique Theorique CNRS-UMR 6083, Universite de Tours, Parc de Grandmont, 37200 Tours (France)
2011-10-25
We present solutions describing spatially closed, open, or flat cosmologies in the massive gravity theory within the recently proposed tetrad formulation. We find that the effect of the graviton mass is equivalent to introducing to the Einstein equations a matter source that can consist of several different matter types - a cosmological term, quintessence, gas of cosmic strings, and non-relativistic cold matter.
Authorized Duplication: A Timely Solution.
Curatilo, Joe
1997-01-01
Asks how a music teacher can supply enough sheet music to ensure resources for every student while meeting restrictions of slender budgets and copyright laws. Explores the concept of authorized duplication, similar to software licensing, as a solution. Provides sources of music with authorized duplication agreements. (DSK)
Grover, Saurabh
2015-01-01
This book is aimed at IT admins, consultants, and architects alike who wish to deploy, manage, and maintain Hyper-V solutions in organizations of various sizes. You are expected to have a working knowledge of managing Windows Server and a fair understanding of networking and storage concepts.
Peritoneal dialysis solution and nutrition.
Verger, Christian
2012-01-01
20-70% of peritoneal dialysis patients have some signs of malnutrition. Anorexia, protein and amino acid losses in dialysate, advanced age of elderly patients, inflammation and cardiac failure are among the main causes. Modern dialysis solutions aim to reduce these causes, but none of them is without side effects: glucose is relatively safe and brings additional energy but induces anorexia and lipid abnormalities, amino acids compensate dialysate losses but may increase uremia and acidosis, icodextrin helps control hyperhydration and chronic heart failure and minimizes glucose side effects, but may sometimes cause inflammation, and poly chamber bags allow the replacement of lactate by bicarbonate and are more biocompatible, decrease GDP, induce less inflammation and have a better effect on nutritional status. However, it appears that the management of nutrition with the different solutions available nowadays necessitates various combinations of solutions adapted to different patient profiles and there is not actually a single universal solution to minimize malnutrition in peritoneal dialysis patients. Copyright © 2012 S. Karger AG, Basel.
Solute carrier transporters: Pharmacogenomics research ...
African Journals Online (AJOL)
... genomic variation in South Africa and sub-Saharan Africa, especially with regards to health applications. Genomic diversity in this region is indeed relatively under-studied despite being home to significant portion of human genomic diversity. Keywords: Solute carrier transporters, pharmacogenomics, pharmacogenetics ...
Microheterogeneity in frozen protein solutions.
Twomey, Alan; Kurata, Kosaku; Nagare, Yutaka; Takamatsu, Hiroshi; Aksan, Alptekin
2015-06-20
In frozen and lyophilized systems, the biological to be stabilized (e.g. therapeutic protein, biomarker, drug-delivery vesicle) and the cryo-/lyo-protectant should be co-localized for successful stabilization. During freezing and drying, many factors cause physical separation of the biological from the cryo-/lyo-protectant, called microheterogeneity (MH), which may result in poor stabilization efficiency. We have developed a novel technique that utilized confocal Raman microspectroscopy in combination with counter-gradient freezing to evaluate the effect of a wide range of freezing temperatures (-20
Entropy corresponding to the interior of a Schwarzschild black hole
Majhi, Bibhas Ranjan; Samanta, Saurav
2017-07-01
Interior volume within the horizon of a black hole is a non-trivial concept which turns out to be very important to explain several issues in the context of quantum nature of black hole. Here we show that the entropy, contained by the maximum interior volume for massless modes, is proportional to the Bekenstein-Hawking expression. The proportionality constant is less than unity implying the horizon bears maximum entropy than that by the interior. The derivation is very systematic and free of any ambiguity. To do so the precise value of the energy of the modes, living in the interior, is derived by constraint analysis. Finally, the implications of the result are discussed.
Canonical Ensemble Model for Black Hole Horizon of Schwarzschild ...
Indian Academy of Sciences (India)
In this paper, we use the canonical ensemble model to discuss the radiation of a Schwarzschild–de Sitter black hole on the black hole horizon. Using this model, we calculate the probability distribution from function of the emission shell. And the statistical meaning which compare with the distribution function is used to ...
Canonical Ensemble Model for Black Hole Horizon of Schwarzschild ...
Indian Academy of Sciences (India)
Abstract. In this paper, we use the canonical ensemble model to discuss the radiation of a Schwarzschild–de Sitter black hole on the black hole horizon. Using this model, we calculate the probability distribution from function of the emission shell. And the statistical meaning which compare with the distribution function is ...
Post-Newtonian Circular Restricted 3-Body Problem: Schwarzschild primaries
Dubeibe, F. L.; Lora-Clavijo, F. D.; González, G. A.
2017-07-01
The restricted three-body problem (RTBP) has been extensively studied to investigate the stability of the solar system, extra-solar subsystems, asteroid capture, and the dynamics of two massive black holes orbited by a sun. In the present work, we study the stability of the planar circular restricted three-body problem in the context of post-Newtonian approximations. First of all, we review the results obtained from the post-Newtonian equations of motion calculated in the framework of the Einstein-Infeld-Hoffmann formalism (EIH). Therefore, using the Fodor-Hoenselers-Perjes formalism (FHP), we have performed an expansion of the gravitational potential for two primaries, deriving a new system of equations of motion, which unlike the EIH-approach, preserves the Jacobian integral of motion. Additionally, we have obtained approximate expressions for the Lagrange points in terms of a mass parameter μ, where it is found that the deviations from the classical regime are larger for the FHP than for the EIH equations.
Evolution of inspiral orbits around a Schwarzschild black hole
Warburton, Niels; Akcay, Sarp; Barack, Leor; Gair, Jonathan R; Sago, Norichika
2011-01-01
We present results from calculations of the orbital evolution in eccentric binaries of nonrotating black holes with extreme mass-ratios. Our inspiral model is based on the method of osculating geodesics, and is the first to incorporate the full gravitational self-force (GSF) effect, including conservative corrections. The GSF information is encapsulated in an analytic interpolation formula based on numerical GSF data for over a thousand sample geodesic orbits. We assess the importance of incl...
Evolution of inspiral orbits around a Schwarzschild black hole
Warburton, Niels; Barack, Leor; Gair, Jonathan R; Sago, Norichika
2011-01-01
We present results from calculations of the orbital evolution in eccentric binaries of nonrotating black holes with extreme mass-ratios. Our inspiral model is based on the method of osculating geodesics, and is the first to incorporate the full gravitational self-force (GSF) effect, including conservative corrections. The GSF information is encapsulated in an analytic interpolation formula based on numerical GSF data for over a thousand sample geodesic orbits. We assess the importance of including conservative GSF corrections in waveform models for gravitational-wave searches.
Infinite derivative gravity: non-singular cosmology & blackhole solutions
Mazumdar, A.
Both Einstein’s theory of General Relativity and Newton’s theory of gravity possess a short distance and small time scale catastrophe. The blackhole singularity and cosmological Big Bang singularity problems highlight that current theories of gravity are incomplete description at early times and small distances. I will discuss how one can potentially resolve these fundamental problems at a classical level and quantum level. In particular, I will discuss infinite derivative theories of gravity, where gravitational interactions become weaker in the ultraviolet, and therefore resolving some of the classical singularities, such as Big Bang and Schwarzschild singularity for compact non-singular objects with mass up to 1025 grams. In this lecture, I will discuss quantum aspects of infinite derivative gravity and discuss few aspects which can make the theory asymptotically free in the UV.
Plasma generation in aqueous solution containing volatile solutes
Mizukoshi, Yoshiteru; Hatanaka, Shin-ichi; Okitsu, Kenji; Iseki, Yoshikazu; Iwasaki, Ryouhei; Sakamoto, Tomokazu; Yamaguchi, Susumu; Tanaka, Hirohisa; Tanabe, Shuji
2018-01-01
When high and short-pulse voltage was applied with a high repetition frequency to tungsten electrodes placed in water containing ammonia and water containing 2-methyl-2-propanol, gas evolved vigorously from the plasma generated between the electrodes. The main gas evolved was H2 in both aqueous solutions. Decomposition of ammonia provided N2 in addition to H2. In the decomposition of aqueous 2-methyl-2-propanol solution, CO, CO2, methane, ethane, ethylene, and acetylene were generated in addition to H2. The “temperature” deduced by kinetic consideration using the yields of C2 products (ethane, ethylene, and acetylene) formed by the recombination of two methyl radicals was calculated to be ca. 4200 K.
Zielinski, Michal W; McGann, Locksley E; Nychka, John A; Elliott, Janet A W
2014-10-01
Thermodynamic solution theories allow the prediction of chemical potentials in solutions of known composition. In cryobiology, such models are a critical component of many mathematical models that are used to simulate the biophysical processes occurring in cells and tissues during cryopreservation. A number of solution theories, both thermodynamically ideal and non-ideal, have been proposed for use with cryobiological solutions. In this work, we have evaluated two non-ideal solution theories for predicting water chemical potential (i.e. osmolality) in multi-solute solutions relevant to cryobiology: the Elliott et al. form of the multi-solute osmotic virial equation, and the Kleinhans and Mazur freezing point summation model. These two solution theories require fitting to only single-solute data, although they can make predictions in multi-solute solutions. The predictions of these non-ideal solution theories were compared to predictions made using ideal dilute assumptions and to available literature multi-solute experimental osmometric data. A single, consistent set of literature single-solute solution data was used to fit for the required solute-specific coefficients for each of the non-ideal models. Our results indicate that the two non-ideal solution theories have similar overall performance, and both give more accurate predictions than ideal models. These results can be used to select between the non-ideal models for a specific multi-solute solution, and the updated coefficients provided in this work can be used to make the desired predictions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
Zielinski, Michal W; McGann, Locksley E; Nychka, John A; Elliott, Janet A W
2017-11-22
The prediction of nonideal chemical potentials in aqueous solutions is important in fields such as cryobiology, where models of water and solute transport-that is, osmotic transport-are used to help develop cryopreservation protocols and where solutions contain many varied solutes and are generally highly concentrated and thus thermodynamically nonideal. In this work, we further the development of a nonideal multisolute solution theory that has found application across a broad range of aqueous systems. This theory is based on the osmotic virial equation and does not depend on multisolute data. Specifically, we derive herein a novel solute chemical potential equation that is thermodynamically consistent with the existing model, and we establish the validity of a grouped solute model for the intracellular space. With this updated solution theory, it is now possible to model cellular osmotic behavior in nonideal solutions containing multiple permeating solutes, such as those commonly encountered by cells during cryopreservation. In addition, because we show here that for the osmotic virial equation the grouped solute approach is mathematically equivalent to treating each solute separately, multisolute solutions in other applications with fixed solute mass ratios can now be treated rigorously with such a model, even when all of the solutes cannot be enumerated.
Crystallisation of materials from aqueous solutions
Witkamp, G.J.; Vrijenhoef, J.P.; De Graauw, J.; Van der Ham, F.
2001-01-01
The invention is directed to a process for recovering a crystalline material from an aqueous solution, which solution also contains organic contaminants, in which process the material is crystallised from the aqueous solution by freeze crystallising at a eutectic freezing point of the solution.
On exact solutions of the Bogoyavlenskii equation
Indian Academy of Sciences (India)
Abstract. Exact solutions for the Bogoyavlenskii equation are studied by the travelling wave method and the singular manifold method. It is found that the linear superposition of the shock wave solution and the complex solitary wave solution for the physical field is still a solution of the equation of interest, except for a ...
REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS
Schulz, W.W.
1959-08-01
The removal of chlorides from aqueons solutions is described. The process involves contacting the aqueous chloride containing solution with a benzene solution about 0.005 M in phenyl mercuric acetate whereby the chloride anions are taken up by the organic phase and separating the organic phase from the aqueous solutions.
21 CFR 522.690 - Dinoprost solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dinoprost solution. 522.690 Section 522.690 Food... Dinoprost solution. (a) Specifications. Each milliliter (mL) of solution contains dinoprost tromethamine.... (v) Dinoprost solution as provided by No. 000009 in § 510.600(c) of this chapter may be used...
21 CFR 522.914 - Fenprostalene solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fenprostalene solution. 522.914 Section 522.914... Fenprostalene solution. (a) Specifications—(1) Cattle. Each milliliter of sterile solution contains 0.5 milligram of fenprostalene. (2) Swine. Each milliliter of sterile solution contains 0.25 milligram of...
27 CFR 21.119 - Nicotine solution.
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent.... One ml of the nicotine solution (previously agitated in the presence of air) is measured into 100 ml...
Fissile solution dynamics: Student research
Energy Technology Data Exchange (ETDEWEB)
Hetrick, D.L.
1994-09-01
There are two research projects in criticality safety at the University of Arizona: one in dynamic simulation of hypothetical criticality accidents in fissile solutions, and one in criticality benchmarks using transport theory. We have used the data from nuclear excursions in KEWB, CRAC, and SILENE to help in building models for solution excursions. An equation of state for liquids containing gas bubbles has been developed and coupled to point-reactor dynamics in an attempt to predict fission rate, yield, pressure, and kinetic energy. It appears that radiolytic gas is unimportant until after the first peak, but that it does strongly affect the shape of the subsequent power decrease and also the dynamic pressure.
Health solutions for the poor.
Castro, J L; Fujiwara, P I; Bhambal, P; Emaille-Léotard, N; Harries, A D
2014-03-21
The International Union Against Tuberculosis and Lung Disease (The Union) is the oldest international non-governmental organisation involved in the fight against tuberculosis. In 2008, the Institute of The Union was challenged to think boldly about the future and to develop a diverse work portfolio covering a wide spectrum of lung health and other disease-related problems. The vision adopted by The Union at that time was 'Health solutions for the poor'. More recently, there has been lengthy debate about the need for the Union to concentrate just on its core mandate of tuberculosis and lung health and for the Union's vision to reflect this narrower spectrum of activity as 'Lung health solutions for the poor'. In this viewpoint article we outline our reasons for believing that this narrower vision is incompatible with The Union's mission statement, and we argue that making such a change would be a mistake.
DNA denaturation in ionic solution
Maity, Arghya; Singh, Amar; Singh, Navin
2016-05-01
Salt or cations, present in solution play an important role in DNA denaturation and folding kinetics of DNA helix. In this work we study the thermal melting of double stranded DNA (dsDNA) molecule using Peyrard Bishop Dauxois (PBD) model. We modify the potential of H-bonding between the bases of the complimentary strands to introduce the salt and solvent effect. We choose different DNA sequences having different contents of GC pairs and calculate the melting temperatures. The melting temperature increases logarithmically with the salt concentration of the solution. The more GC base pairs in the chain enhance the stability of DNA chain at a fix salt concentration. The obtained results are in good accordance with experimental findings.
Solution landscapes in nematic microfluidics
Crespo, M.; Majumdar, A.; Ramos, A. M.; Griffiths, I. M.
2017-08-01
We study the static equilibria of a simplified Leslie-Ericksen model for a unidirectional uniaxial nematic flow in a prototype microfluidic channel, as a function of the pressure gradient G and inverse anchoring strength, B. We numerically find multiple static equilibria for admissible pairs (G , B) and classify them according to their winding numbers and stability. The case G = 0 is analytically tractable and we numerically study how the solution landscape is transformed as G increases. We study the one-dimensional dynamical model, the sensitivity of the dynamic solutions to initial conditions and the rate of change of G and B. We provide a physically interesting example of how the time delay between the applications of G and B can determine the selection of the final steady state.
Ahmed's Integral: the maiden solution
Ahmed, Zafar
2014-01-01
In 2001-2002, I happened to have proposed a new definite integral in the American Mthematical Monthly (AMM),which later came to be known in my name (Ahmed). In the meantime, this integral has been mentioned in mathematical encyclopedias and dictionaries and further it has also been cited and discussed in several books and journals. In particular, a google search with the key word "Ahmed's Integral" throws up more than 60 listings. Here I present the maiden solution for this integral.
Radar Absorbing Colloidal Solutions (RACS)
2007-08-01
calibrated up to the conmoctons with- open , short ,and load In order to validate the expe ment another mesrm a usqme ing u ma etc particles (Fe;0 4...hydrophobic tolkiene solution and begin t# chlst without the cappihg nibledukw, tis forihh"dg the lag" nanoparticle aggregate. Conversely , the nanopartieles...to control the aggregation of particles using sequec speciity [11]. dsDNA meling transitions are well defined and cotrelate f the DRA ui.leotide sequen
Clean Energy Solutions Center (Presentation)
Energy Technology Data Exchange (ETDEWEB)
Reategui, S.
2012-07-01
The Clean Energy Ministerial launched the Clean Energy Solutions Center in April, 2011 for major economy countries, led by Australia and U.S. with other CEM partners. Partnership with UN-Energy is extending scope to support all developing countries: 1. Enhance resources on policies relating to energy access, small to medium enterprises (SMEs), and financing programs; 2. Offer expert policy assistance to all countries; 3. Expand peer to peer learning, training, and deployment and policy data for developing countries.
Viscoelasticity of Concentrated Proteoglycan Solutions
Meechai, Nispa; Jamieson, Alex; Blackwell, John; Carrino, David
2001-03-01
Proteoglycan Aggregate (PGA) is the principal macromolecular component of the energy-absorbing matrix of cartilage and tendon. Its brush-like supramolecular structure consists of highly-ionic subunits, non-covalently bound to a hyaluronate chain. We report viscoelastic behavior of concentrated solutions of PGA, purified by column fractionation to remove free subunits. At physiological ionic strength, these preparations exhibit a sol-to-gel transition when the concentration is increased above molecular overlap. The strain dependence of concentrated solutions shows a pronounced non-linearity above a critical strain, at which the storage modulus decreases suddenly, and the loss modulus exhibits a maximum. This response is similar to that observed for close-packed dispersions of soft spheres, when the applied strain is sufficient to move a sphere past its neighbors. At low and high ionic strength, the elasticity of solutions near the overlap concentration decreases. The former is interpreted as due to a decrease in intramolecular and intermolecular electrostatic repulsions, because of strong trapping of counterions within the PGA brush, the latter to salt-induced brush collapse.
Step Bunching and Solution Flow
Chernov, A. A.
2003-01-01
Imagine a sequence of equidistant steps parallel to one another on a crystal face growing from solution. Steps may be one or part of a lattice spacing high. With such ideal morphology, the most perfect material is expected to be produced. Sometimes this happens. Much more often, however, steps form bunches, acquire wavy shapes and interlace. With time, these spontaneous perturbations may be increased in amplitude, i.e. the stepped surface becomes morphologically unstable. Interferometric studies of Y.G. Kuznetsov, L.N. Rashkovich, P.G. Vekilov and N.A. Booth and the author demonstrated that the step bunching depends at least on direction and rate of solution flow over the interface, supersaturation and presence of impurities. In particular, if solution and step flow are parallel to one another, the steps convene into bunches. If these flows are antiparallel, the bunches disappear. As the step train propagates, the overall bunch height often increases infinitely. However, we have found recently that if the flow rate is large enough, (approximately 1 meter per second), the bunch height may be limited. All these phenomena come from interaction between steps. The interaction mechanisms are still not fully understood. I plan to overview major approaches to the still unresolved problem on how these dissipative structures on growing crystal face appear and evolve.
Pollen Aquaporins: The Solute Factor.
Pérez Di Giorgio, Juliana A; Soto, Gabriela C; Muschietti, Jorge P; Amodeo, Gabriela
2016-01-01
In the recent years, the biophysical properties and presumed physiological role of aquaporins (AQPs) have been expanded to specialized cells where water and solute exchange are crucial traits. Complex but unique processes such as stomatal movement or pollen hydration and germination have been addressed not only by identifying the specific AQP involved but also by studying how these proteins integrate and coordinate cellular activities and functions. In this review, we referred specifically to pollen-specific AQPs and analyzed what has been assumed in terms of transport properties and what has been found in terms of their physiological role. Unlike that in many other cells, the AQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which are extensively studied for their high water capacity exchange. Instead, a variety of TIPs and NIPs are expressed in pollen. These findings have altered the initial understanding of AQPs and water exchange to consider specific and diverse solutes that might be critical to sustaining pollen's success. The spatial and temporal distribution of the pollen AQPs also reflects a regulatory mechanism that allowing a properly adjusting water and solute exchange.
Solution Focused Approach and Usage of Nursing
Nurcan AKGÜL GÜNDOÐDU; Handan ZÝNCÝR; Nuran GÜLER
2016-01-01
"Problem talk creates problems; solution talk creates solutions " Steve de Shazer In recent years, concern for solution-oriented approach has increased in nursing practice. In this review it is aimed to give information about nursing application of solution-oriented approach whose efficacy has been proved with many studies. In addition, solution-oriented approach is what how it turned out, the answer to the question of principle, and that is what the management strategy and what the n...
Commercial Lighting Solutions Webtool Peer Review Report, Office Solutions
Energy Technology Data Exchange (ETDEWEB)
Beeson, Tracy A.; Jones, Carol C.
2010-02-01
The Commercial Lighting Solutions (CLS) project directly supports the U.S. Department of Energy’s Commercial Building Energy Alliance efforts to design high performance buildings. CLS creates energy efficient best practice lighting designs for widespread use, and they are made available to users via an interactive webtool that both educates and guides the end user through the application of the Lighting Solutions. This report summarizes the peer review of the CLS webtool for offices. The methodology for the peer review process included data collection (stakeholder input), analysis of the comments, and organization of the input into categories for prioritization of the comments against a set of criteria. Based on this process, recommendations were developed for the release of version 2.0 of the webtool at the Lightfair conference in Las Vegas in May 2010. The report provides a list of the top ten most significant and relevant improvements that will be made within the webtool for version 2.0 as well as appendices containing the comments and short-term priorities in additional detail. Peer review comments that are considered high priority by the reviewers and the CLS team but cannot be completed for Version 2.0 are listed as long-term recommendations.
Exploring manufacturing solutions for SMEs
DEFF Research Database (Denmark)
Radziwon, Agnieszka; Blichfeldt, Henrik; Bilberg, Arne
This exploratory study provides an overview over current state of manufacturing solutions in small and medium sized enterprises (SMEs) in region of Southern Denmark. Building on manufacturing paradigms, this paper reveals relevant aspects for the development and implementation of improving SMEs......’ automation processes. The paper presents an embedded case study based on 10 low- and medium-tech Danish companies. Based on the development of production paradigms and the presented study, this research helps to understand key determinants and processes for SMEs’ exploration of future directions...
Mobile authentication problems and solutions
Jakobsson, Markus
2012-01-01
Mobile Authentication: Problems and Solutions looks at human-to-machine authentication, with a keen focus on the mobile scenario. Human-to-machine authentication is a startlingly complex issue. In the old days of computer security-before 2000, the human component was all but disregarded. It was either assumed that people should and would be able to follow instructions, or that end users were hopeless and would always make mistakes. The truth, of course, is somewhere in between, which is exactly what makes this topic so enticing. We cannot make progress with human-to-machine authentication with
Numerical Solution of Parabolic Equations
DEFF Research Database (Denmark)
Østerby, Ole
These lecture notes are designed for a one-semester course on finite-difference methods for parabolic equations. These equations which traditionally are used for describing diffusion and heat-conduction problems in Geology, Physics, and Chemistry have recently found applications in Finance Theory...... approximations which depend on a step size, such as numerical integration and solution of ordinary and partial differential equations. An integral part of the error estimation is the estimation of the order of the method and can thus satisfy the inquisitive mind: Is the order what we expect it to be from theopry...
New wormhole solutions on the brane
Parsaei, F.; Riazi, N.
2015-01-01
In this paper, static wormholes in the brane-world scenario are studied. We show that the existence of extra terms coming from the bulk help construct exact solutions that satisfy the null energy condition. Two important classes of solutions found earlier are analyzed in more depth in order to determine the conditions necessary for consistent solutions. Two new classes of solutions with different asymptotic behavior are also introduced. We focus on the conservation of the stress-energy tensor to achieve new solutions which have the important property of asymptotic flatness. Some main mathematical and physical properties of the solutions are addressed.
Disentangling entanglements in biopolymer solutions.
Lang, Philipp; Frey, Erwin
2018-02-05
Reptation theory has been highly successful in explaining the unusual material properties of entangled polymer solutions. It reduces the complex many-body dynamics to a single-polymer description, where each polymer is envisaged to be confined to a tube through which it moves in a snake-like fashion. For flexible polymers, reptation theory has been amply confirmed by both experiments and simulations. In contrast, for semiflexible polymers, experimental and numerical tests are either limited to the onset of reptation, or were performed for tracer polymers in a fixed, static matrix. Here, we report Brownian dynamics simulations of entangled solutions of semiflexible polymers, which show that curvilinear motion along a tube (reptation) is no longer the dominant mode of dynamics. Instead, we find that polymers disentangle due to correlated constraint release, which leads to equilibration of internal bending modes before polymers diffuse the full tube length. The physical mechanism underlying terminal stress relaxation is rotational diffusion mediated by disentanglement rather than curvilinear motion along a tube.
Research on cloud computing solutions
Directory of Open Access Journals (Sweden)
Liudvikas Kaklauskas
2015-07-01
Full Text Available Cloud computing can be defined as a new style of computing in which dynamically scala-ble and often virtualized resources are provided as a services over the Internet. Advantages of the cloud computing technology include cost savings, high availability, and easy scalability. Voas and Zhang adapted six phases of computing paradigms, from dummy termi-nals/mainframes, to PCs, networking computing, to grid and cloud computing. There are four types of cloud computing: public cloud, private cloud, hybrid cloud and community. The most common and well-known deployment model is Public Cloud. A Private Cloud is suited for sensitive data, where the customer is dependent on a certain degree of security.According to the different types of services offered, cloud computing can be considered to consist of three layers (services models: IaaS (infrastructure as a service, PaaS (platform as a service, SaaS (software as a service. Main cloud computing solutions: web applications, data hosting, virtualization, database clusters and terminal services. The advantage of cloud com-puting is the ability to virtualize and share resources among different applications with the objective for better server utilization and without a clustering solution, a service may fail at the moment the server crashes.DOI: 10.15181/csat.v2i2.914
Holographic cosmology from BIonic solutions
Sepehri, Alireza; Faizal, Mir; Setare, Mohammad Reza; Ali, Ahmed Farag
2017-02-01
In this paper, we will use a BIonic solution for analyzing the holographic cosmology. A BIonic solution is a configuration of a D3-brane and an anti-D3-brane connected by a wormhole, and holographic cosmology is a recent proposal to explain cosmic expansion by using the holographic principle. In our model, a BIonic configuration will be produced by the transition of fundamental black strings. The formation of a BIonic configuration will cause inflation. As the D3-brane moves away from the anti-D3-brane, the wormhole will get annihilated, and the inflation will end with the annihilation of this wormhole. However, it is possible for a D3-brane to collide with an anti-D3-brane. Such a collision will occur if the distance between the D3-brane and the anti-D3-brane reduces, and this will create tachyonic states. We will demonstrate that these tachyonic states will lead to the formation of a new wormhole, and this will cause acceleration of the universe before such a collision.
Directory of Open Access Journals (Sweden)
Eliana Henriques de Brito
1990-01-01
Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.
INTERCULTURAL MISUNDERSTANDINGS: CAUSES AND SOLUTIONS
Directory of Open Access Journals (Sweden)
Майкл Б Хиннер
2017-12-01
Full Text Available Intercultural misunderstandings involve a number of complex causes which can easily escalate into conflicts. Since conflicts are also complex, it is not easy to find solutions because there is no one solution for all problems. Systems Theory, transdisciplinarity, and the social ecological model take a holistic approach in investigating complex phenomena. They permit the creation of a theoretical framework based on previous empirical research and theories across scientific disciplines to identify the relevant elements of complex phenomena and to understand the interrelationship of these elements. Intercultural misunderstandings and conflicts are very complex phenomena because they include culture, perception, identity, ethnocentrism, relationships, trust building and conflict management as well as intercultural commu-nication competence which entails cognition, metacognition, and social metacognition. Since most em-pirical studies focus on isolated, individual elements in specific contexts, this article describes the theoretical framework of how the various findings and theories developed in different scientific disciplines can be used to form a cohesive framework to help circumvent intercultural misunderstandings and conflicts. In so doing, it follows the general principles of Systems Theory, transdisciplinarity, and the social ecological model.
Uniqueness of large positive solutions
López-Gómez, Julián; Maire, Luis
2017-08-01
We establish the uniqueness of the positive solution of the singular problem (1.1) through some standard comparison techniques involving the maximum principle. Our proofs do not invoke to the blow-up rates of the solutions, as in most of the specialized literature. We give two different types of results according to the geometrical properties of Ω and the regularity of partial Ω . Even in the autonomous case, our theorems are extremely sharp extensions of all existing results. Precisely, when a(x)≡ 1, it is shown that the monotonicity and superadditivity of f( u) with constant C≥ 0 entail the uniqueness; f is said to be superadditive with constant C≥ 0 if f(a+b) ≥ f(a) + f(b) - C \\quad for all a, b ≥ 0. This condition, introduced by Marcus and Véron (J Evol Equ 3:637-652, 2004), weakens all previous sufficient conditions for uniqueness, as it will become apparent in this paper.
Solution structure of human prolactin
DEFF Research Database (Denmark)
Teilum, Kaare; Hoch, Jeffrey C; Goffin, Vincent
2005-01-01
We report the solution structure of human prolactin determined by NMR spectroscopy. Our result is a significant improvement over a previous structure in terms of number and distribution of distance restraints, regularity of secondary structure, and potential energy. More significantly, the struct......We report the solution structure of human prolactin determined by NMR spectroscopy. Our result is a significant improvement over a previous structure in terms of number and distribution of distance restraints, regularity of secondary structure, and potential energy. More significantly......, the structure is sufficiently different that it leads to different conclusions regarding the mechanism of receptor activation and initiation of signal transduction. Here, we compare the structure of unbound prolactin to structures of both the homologue ovine placental lactogen and growth hormone. The structures...... of unbound and receptor bound prolactin/placental lactogen are similar and no noteworthy structural changes occur upon receptor binding. The observation of enhanced binding at the second receptor site when the first site is occupied has been widely interpreted to indicate conformational change induced...
Numerical Solution for an Epicycloid Crack
Directory of Open Access Journals (Sweden)
Nik Mohd Asri Nik Long
2014-01-01
linear equations. Numerical solution for the shear stress intensity factors, maximum stress intensity, and strain energy release rate is obtained. Our results give an excellent agreement to the existing asymptotic solutions.
Silver recovery from spent photographic solutions
Energy Technology Data Exchange (ETDEWEB)
Kunda, W.; Etsell, T.H.
1991-04-12
A process is disclosed for recovering silver sulfide from a silver-containing spent photographic fixer solution. The process is particularly suited for treating the fixer solution in a manner which enables recycling of the solution, and does not have the inefficiencies and high costs of alternative processes such as electrolysis. The process comprises introducing hydrosulfide ion into the silver-containing spent fixer solution to precipitate silver sulfide. The resultant precipitate is isolated from the fixer solution in order to remove silver from the solution. The process is especially suited for treating spent solutions which contain thiosulfate, in particular sodium or ammonium thiosulfate. The preferred hydrosulfide is either a sodium or ammonium hydrosulfide for precipitating silver in the form of silver sulfide. The quantity of hydrosulfide used is in the range of greater than 0.5 mole per mole of silver in the fixer solution. Experiments are described to illustrate the process of the invention. 3 figs., 5 tabs.
Engineering report (conceptual design) PFP solution stabilization
Energy Technology Data Exchange (ETDEWEB)
Witt, J.B.
1997-07-17
This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.
Gold and Silver Extraction from Leach Solutions
Directory of Open Access Journals (Sweden)
Bagdaulet K. Kenzhaliyev
2014-03-01
Full Text Available There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.
Solute Partitioning and Hindered Diffusion in Hydrogels
Liu, David Ezra
2016-01-01
Solute uptake and release govern the efficacy of hydrogels in controlled drug delivery, tissue engineering, and chromatographic separations. In soft contact lenses, uptake and release of wetting, packaging, and care-solution agents is extensively employed to improve on-eye lens performance. Key physical parameters are the equilibrium solute partition coefficient and the solute diffusion coefficient in the gel that dictate the amounts and rates of uptake/release, respectively. To investigate t...
A new algorithm for anisotropic solutions
Indian Academy of Sciences (India)
Abstract. We establish a new algorithm that generates a new solution to the Einstein field equations, with an anisotropic matter distribution, from a seed isotropic solution. The new solution is expressed in terms of integrals of an isotropic gravitational potential; and the integration can be completed exactly for particular ...
Clean Energy Solutions Center Services (Fact Sheet)
Energy Technology Data Exchange (ETDEWEB)
2014-04-01
The Clean Energy Solutions Center (Solutions Center) helps governments, advisors and analysts create policies and programs that advance the deployment of clean energy technologies. The Solutions Center partners with international organizations to provide online training, expert assistance, and technical resources on clean energy policy.
Subharmonic Solutions of Order One-Third
Fay, Temple H.
2005-01-01
Finding a periodic solution to a nonlinear ordinary differential equation is in general a difficult task. Only in a very few cases can direct methods be applied to an equation to find initial values leading to a solution of the corresponding initial value problem that is periodic. Oscillatory periodic solutions have such practical importance that…
An axiomatization of the Euclidean compromise solution
Voorneveld, M.; Nouweland, A. van den
2000-01-01
The Euclidean compromise solution in multicriteria optimization is a solution concept that assigns to a feasible set the alternative with minimal Euclidean distance to the utopia point The purpose of this paper is to provide a characterization of the Euclidean compromise solution
21 CFR 522.900 - Euthanasia solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Euthanasia solution. 522.900 Section 522.900 Food... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg.... For humane, painless, and rapid euthanasia. (2) Amount. One mL per 10 pounds of body weight. (3...
Positive Integer Solutions of Certain Diophantine Equations
Indian Academy of Sciences (India)
29
An important area of number theory is devoted to finding solutions of equations where the solutions are restricted to the set of integers. Diophantine equations get their name from Diophantus of. Alexandria and they are algebraic equations for which rational or integer solutions are sought. Many researchers considered the ...
21 CFR 520.447 - Clindamycin solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Clindamycin solution. 520.447 Section 520.447 Food... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.447 Clindamycin solution. (a) Specifications. Each milliliter of solution contains the equivalent of 25 milligrams (mg) clindamycin as the...
21 CFR 522.1450 - Moxidectin solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Moxidectin solution. 522.1450 Section 522.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Moxidectin solution. (a) Specifications. Each milliliter of solution contains 10 milligrams (mg) moxidectin...
21 CFR 520.1454 - Moxidectin solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Moxidectin solution. 520.1454 Section 520.1454... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1454 Moxidectin solution. (a) Specifications. Each milliliter (mL) of solution contains 1 milligram (mg) moxidectin. (b) Sponsor. See No...
21 CFR 522.2012 - Prostalene solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prostalene solution. 522.2012 Section 522.2012 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Prostalene solution. (a) Specifications. Each milliliter of sterile solution contains 1 milligram of...
21 CFR 522.1020 - Gelatin solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gelatin solution. 522.1020 Section 522.1020 Food... Gelatin solution. (a) Specifications. It is sterile and each 100 cubic centimeters contains 8 grams of gelatin in an 0.85 percent sodium chloride solution. (b) Sponsor. See No. 000856 in § 510.600(c) of this...
21 CFR 522.1225 - Ketoprofen solution.
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ketoprofen solution. 522.1225 Section 522.1225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Ketoprofen solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 100 milligrams...
Estimating the Cost of Heterogeneous Solutions
Poort, Eltjo; Vliet, Eric van der
2014-01-01
Existing estimation methods have severe limitations when it comes to estimating the delivery cost of heterogeneous IT-based solutions. In this experience report we present Solution-Based Estimation, a new approach that explicitly links a solution's architecture to its delivery cost model.
Mobility needs and wireless solutions
DEFF Research Database (Denmark)
Saugstrup, Dan; Henten, Anders
The main purpose of this report is to spell out a methodological approach to the analysis of user needs with respect to mobility. Furthermore, this methodological approach is used in an exemplary analysis of the relationship between user needs and technology solutions offered by different wireless...... technologies. The report is based on a research approach, emphasizing important aspects in relation to developing more user oriented mobile services and applications in a heterogeneous network environment. As a staring point, Scandinavian research within the field of social science concerning mobility...... is described and discussed. Furthermore different wireless technologies are briefly described and discussed in relation to possible transmission capacities and coverage areas. In addition to this, a preliminary framework regarding the implications of mobility on the use and development of mobile services...
Solution synthesis of germanium nanocrystals
Gerung, Henry [Albuquerque, NM; Boyle, Timothy J [Kensington, MD; Bunge, Scott D [Cuyahoga Falls, OH
2009-09-22
A method for providing a route for the synthesis of a Ge(0) nanometer-sized material from. A Ge(II) precursor is dissolved in a ligand heated to a temperature, generally between approximately 100.degree. C. and 400.degree. C., sufficient to thermally reduce the Ge(II) to Ge(0), where the ligand is a compound that can bond to the surface of the germanium nanomaterials to subsequently prevent agglomeration of the nanomaterials. The ligand encapsulates the surface of the Ge(0) material to prevent agglomeration. The resulting solution is cooled for handling, with the cooling characteristics useful in controlling the size and size distribution of the Ge(0) materials. The characteristics of the Ge(II) precursor determine whether the Ge(0) materials that result will be nanocrystals or nanowires.
Nanoplasmonic solution for nonlinear optics
DEFF Research Database (Denmark)
Bache, Morten; Lavrinenko, Andrei; Lysenko, Oleg
2014-01-01
Nonlinear optical properties of dielectric waveguides are well known and are widely used in moderntelecommunication systems [1]. However, the fundamental law of diffraction imposes physical limitation for integration of dielectric photonics and semiconductor electronics [2]. A possible way...... to combine the high speed of a photonic device with the compact size of an electronic device is to produce ananoplasmonic device based on metal waveguides. The successful solutions can be used for future sustainable technologies. In meantime, nonlinear optics of metal waveguides is not fully understood...... and is being under investigation in recent years [3].The purpose of our research is to study nonlinear optical properties of gold waveguides embedded intodielectric medium (silicon dioxide) using picosecond laser spectroscopy. The work includes modeling ofoptical properties of gold waveguides, fabrication...
African Solutions to African Problems?
DEFF Research Database (Denmark)
Emmanuel, Nikolas G.; Schwartz, Brendan
2017-01-01
. The emergence of Déby’s Chad depends both on its ability to accomplish sub-imperial tasks encouraged by these actors, while obfuscating undemocratic governance and human rights abuses at home. Nonetheless, Déby’s role in regional security has helped him achieve a certain degree of agency in his relationship......—tenuous position at home and abroad. Chad is the current representation of the hackneyed phrase, “African solutions to African problems”. However, one must not forget that Chad’s meteoric rise has been facilitated by important states in the international system, mainly France but also the United States...... of apparently competing liberal and illiberal interests. This will lead us to a better explanation of Déby’s recent rise at home and abroad....
Intuitive Solutions to Relativistic Paradoxes
Hewett, Lionel D.
2010-10-01
Einstein's special theory of relativity is filled with so many apparent paradoxes that many people simply cannot accept its validity. They cannot believe that any theory filled with so many conceptual inconsistencies could possibly correlate with true reality. However, it is not the Theory of Relativity that is filled with paradoxes and inconsistencies but a person's intuitive interpretation of that theory. By simply changing one's perspective or viewpoint it is possible to acquire intuitive solutions to many of relativity's apparent paradoxes and to remove various conceptual inconsistencies commonly associated with the theory. This presentation illustrates how that intuition can be applied to such apparent paradoxes as the twin paradox, the pole-and-barn paradox, and even various paradoxes associated with spacetime itself.
Multivariate statistics exercises and solutions
Härdle, Wolfgang Karl
2015-01-01
The authors present tools and concepts of multivariate data analysis by means of exercises and their solutions. The first part is devoted to graphical techniques. The second part deals with multivariate random variables and presents the derivation of estimators and tests for various practical situations. The last part introduces a wide variety of exercises in applied multivariate data analysis. The book demonstrates the application of simple calculus and basic multivariate methods in real life situations. It contains altogether more than 250 solved exercises which can assist a university teacher in setting up a modern multivariate analysis course. All computer-based exercises are available in the R language. All R codes and data sets may be downloaded via the quantlet download center www.quantlet.org or via the Springer webpage. For interactive display of low-dimensional projections of a multivariate data set, we recommend GGobi.
Regional Transmission Projects: Finding Solutions
Energy Technology Data Exchange (ETDEWEB)
The Keystone Center
2005-06-15
The Keystone Center convened and facilitated a year-long Dialogue on "Regional Transmission Projects: Finding Solutions" to develop recommendations that will help address the difficult and contentious issues related to expansions of regional electric transmission systems that are needed for reliable and economic transmission of power within and across regions. This effort brought together a cross-section of affected stakeholders and thought leaders to address the problem with the collective wisdom of their experience and interests. Transmission owners sat at the table with consumer advocates and environmental organizations. Representatives from regional transmission organizations exchanged ideas with state and federal regulators. Generation developers explored common interests with public power suppliers. Together, the Dialogue participants developed consensus solutions about how to begin unraveling some of the more intractable issues surrounding identification of need, allocation of costs, and reaching consensus on siting issues that can frustrate the development of regional transmission infrastructure. The recommendations fall into three broad categories: 1. Recommendations on appropriate institutional arrangements and processes for achieving regional consensus on the need for new or expanded transmission infrastructure 2. Recommendations on the process for siting of transmission lines 3. Recommendations on the tools needed to support regional planning, cost allocation, and siting efforts. List of Dialogue participants: List of Dialogue Participants: American Electric Power American Transmission Company American Wind Energy Association California ISO Calpine Corporation Cinergy Edison Electric Institute Environmental Defense Federal Energy Regulatory Commission Great River Energy International Transmission Company ISO-New England Iowa Public Utility Board Kanner & Associates Midwest ISO National Association of Regulatory Utility Commissioners National Association
Thermodynamic stability of radioactivity standard solutions
Energy Technology Data Exchange (ETDEWEB)
Iroulard, M.G
2007-04-15
The basic requirement when preparing radioactivity standard solutions is to guarantee the concentration of a radionuclide or a radioelement, expressed in the form of activity concentration (Ac = A/m (Bq/g), with A: activity and m: mass of solution). Knowledge of the law of radioactive decay and the half-life of a radionuclide or radioelement makes it possible to determine the activity concentration at any time, and this must be confirmed subsequently by measurement. Furthermore, when radioactivity standard solutions are prepared, it is necessary to establish optimal conditions of thermodynamic stability of the standard solutions. Radioactivity standard solutions are prepared by metrology laboratories from original solutions obtained from a range of suppliers. These radioactivity standard solutions must enable preparation of liquid and/or solid radioactivity standard sources of which measurement by different methods can determine, at a given instant, the activity concentration of the radionuclide or radioelement present in the solution. There are a number of constraints associated with the preparation of such sources. Here only those that relate to the physical and chemical properties of the standard solution are considered, and therefore need to be taken into account when preparing a radioactivity standard solution. These issues are considered in this document in accordance with the following plan: - A first part devoted to the chemical properties of the solutions: - the solubilization media: ultra-pure water and acid media, - the carriers: concentration, oxidation state of the radioactive element and the carrier element. - A second part describing the methodology of the preparation, packaging and storage of standard solutions: - glass ampoules: the structure of glasses, the mechanisms of their dissolution, the sorption phenomenon at the solid-solution interface, - quartz ampoules, - cleaning and packaging: cleaning solutions, internal surface coatings and
Solution Focused Approach and Usage of Nursing
Directory of Open Access Journals (Sweden)
Nurcan AKGÜL GÜNDOÐDU
2016-12-01
Full Text Available "Problem talk creates problems; solution talk creates solutions " Steve de Shazer In recent years, concern for solution-oriented approach has increased in nursing practice. In this review it is aimed to give information about nursing application of solution-oriented approach whose efficacy has been proved with many studies. In addition, solution-oriented approach is what how it turned out, the answer to the question of principle, and that is what the management strategy and what the nursing relationship will be sought. [JCBPR 2016; 5(3.000: 145-152
Multicomponent integrable wave equations: II. Soliton solutions
Energy Technology Data Exchange (ETDEWEB)
Degasperis, A [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , and Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome (Italy); Lombardo, S [School of Mathematics, University of Manchester, Alan Turing Building, Upper Brook Street, Manchester M13 9EP (United Kingdom)], E-mail: antonio.degasperis@roma1.infn.it, E-mail: sara.lombardo@manchester.ac.uk, E-mail: sara@few.vu.nl
2009-09-25
The Darboux-dressing transformations developed in Degasperis and Lombardo (2007 J. Phys. A: Math. Theor. 40 961-77) are here applied to construct soliton solutions for a class of boomeronic-type equations. The vacuum (i.e. vanishing) solution and the generic plane wave solution are both dressed to yield one-soliton solutions. The formulae are specialized to the particularly interesting case of the resonant interaction of three waves, a well-known model which is of boomeronic type. For this equation a novel solution which describes three locked dark pulses (simulton) is introduced.
Oscillating instanton solutions in curved space
Lee, Bum-Hoon; Lee, Chul H.; Lee, Wonwoo; Oh, Changheon
2012-01-01
We investigate oscillating instanton solutions of a self-gravitating scalar field between degenerate vacua. We show that there exist O(4)-symmetric oscillating solutions in a de Sitter background. The geometry of this solution is finite and preserves the Z2 symmetry. The nontrivial solution corresponding to tunneling is possible only if the effect of gravity is taken into account. We present numerical solutions of this instanton, including the phase diagram of solutions in terms of the parameters of the present work and the variation of energy densities. Our solutions can be interpreted as solutions describing an instanton-induced domain wall or braneworld-like object rather than a kink-induced domain wall or braneworld. The oscillating instanton solutions have a thick wall and the solutions can be interpreted as a mechanism providing nucleation of the thick wall for topological inflation. We remark that Z2 invariant solutions also exist in a flat and anti-de Sitter background, though the physical significance is not clear.
Exact solutions in three-dimensional gravity
Garcia-Diaz, Alberto A
2017-01-01
A self-contained text, systematically presenting the determination and classification of exact solutions in three-dimensional Einstein gravity. This book explores the theoretical framework and general physical and geometrical characteristics of each class of solutions, and includes information on the researchers responsible for their discovery. Beginning with the physical character of the solutions, these are identified and ordered on the basis of their geometrical invariant properties, symmetries, and algebraic classifications, or from the standpoint of their physical nature, for example electrodynamic fields, fluid, scalar field, or dilaton. Consequently, this text serves as a thorough catalogue on 2+1 exact solutions to the Einstein equations coupled to matter and fields, and on vacuum solutions of topologically massive gravity with a cosmological constant. The solutions are also examined from different perspectives, enabling a conceptual bridge between exact solutions of three- and four-dimensional gravit...
Colloid solutions for fluid resuscitation.
Bunn, Frances; Trivedi, Daksha
2012-06-13
Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy. To compare the effects of different colloid solutions in patients thought to need volume replacement. We searched the Cochrane Injuries Specialised Register (searched 1 Dec 2011), Cochrane Central Register of Controlled Trials 2011, issue 4 (The Cochrane Library); MEDLINE (Ovid) (1948 to November Week 3 2011); EMBASE (Ovid) (1974 to 2011 Week 47); ISI Web of Science: Science Citation Index Expanded (1970 to 1 Dec 2011); ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to 1 Dec 2011); CINAHL (EBSCO) (1982 to 1 Dec 2011); National Research Register (2007, Issue 1) and PubMed (searched 1 Dec 2011). Bibliographies of trials retrieved were searched, and for the initial version of the review drug companies manufacturing colloids were contacted for information (1999). Randomised controlled trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement. Two authors independently extracted the data and assessed the quality of the trials. The outcomes sought were death, amount of whole blood transfused, and incidence of adverse reactions. Ninety trials, with a total of 5678 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 35 trials and poor or uncertain in the rest.Deaths were obtained in 61 trials. For albumin or PPF versus hydroxyethyl starch (HES) 32 trials (n = 1769) reported mortality. The pooled relative risk (RR) was 1.07 (95% CI 0.87 to 1.32). When the trials by Boldt were removed from the analysis the pooled RR was 0.90 (95% CI 0.68 to 1.20). For albumin or PPF versus gelatin, nine trials (n = 824) reported
Pollution! Find a STEM solution!
Takač, Danijela; Moćan, Marina
2016-04-01
Primary and secondary school Pantovčak is an innovative school in downtown Zagreb, Croatia. The school is involved in many projects concerning STEM education. Pollution! Find a STEM solution! is a two year long cross-curricular project that grew out of identified need to develop STEM and ICT skills more. Pisa results make evident that students' knowledge is poor and motivation for math and similar subjects is low. Implying priorities of European Commission, like e-learning, raises motivation and also develops basic skills and improves knowledge in science, math, physic, ICT. Main objectives are to increase students' interest in STEM education and careers and introduce them to all available new trends in technology, engineering and science in their region by visiting clean technology industries and strengthening links with them, to introduce some future digital jobs and prepare students for rapid technological changes by integrating ICT into classroom practice more, to highlight the importance of global environmental issues and improve the knowledge in the areas of sustainable development and renewable energy, to develop collaborative partnership between schools and the wider community in formal, non-formal and informal learning, to support multilingualism by publishing Open Educational Resources in 8 different languages and to strengthen the professional profile of the teaching profession. The project brings together 231 teachers and 2729 students from five different European countries in learning to think globally and work on activities that contribute to the community's well-being. There are altogether 33 activities, divided in 4 categories. STEM activities are focused on students building the devices for measuring air, light and noise pollution in their school and homes. They use the scientific method to analyze the data and compare the results with their peers to find a solution. Eskills, digital literacy and digital jobs are focused on introducing career
Innovative Solution to Video Enhancement
2001-01-01
Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.
Software Solutions for Agile Business
Directory of Open Access Journals (Sweden)
Viorel LUPU
2006-01-01
Full Text Available Businesses, like people, are continuously evolving and as such face rapid and continual change. As markets and customer needs evolve, enterprises must respond with new ways to attract and retain customers and partners, increase operational efficiency, and achieve greater visibility into their business processes. IT staff see business processes through the lens of the low-level parts of the flow, rather than at the business level. As a result, they aren't capable of implementing the processes so that they will meet continuously changing business requirements, thus impeding business agility. Business users are increasingly demanding that they have control over their own business processes - and so, are requiring systems that put control of the flow and logic into their hands, not those of IT. An Enterprise Service Bus based on a Service Oriented Architecture could be a solution and tie together the notions of service oriented process, service oriented integration and event-driven, message based interaction into a single environment that enables users to combine their assets and information from multiple points of view.
Aeromedical solutions for aerospace safety.
Kapoor, Pawan; Gaur, Deepak
2017-10-01
All facets of activity in the speciality of Aviation Medicine are essentially aimed at enhancing aerospace safety. This paper highlights some innovative changes brought about by Aerospace Medicine in the three major fields of the speciality namely, medical evaluation, aeromedical training and research. Based on lab and field studies, military aircrew are now permitted flying with Modifinil as 'Go' Pill and Zolpidem as 'No-Go' Pill during sustained operations. Several other drugs for disabilities like Hypertension and CAD are now permitted for aviators. Comprehensive revision of policy permitting early return to flying is an on-going process. OPRAM courses for all three streams of aircrew in IAF have contributed to reduce aircraft accident rates. Human Engineering Consultancy and expert advice is provided by specialists at IAM as well as those in the field. In future, the country needs to provide better post-service opportunities to aerospace medicine specialists. This, in turn, will attract bright young minds to the specialty. The ISRO Humanin-Space programme will be an exciting challenge for all in this unique field. Aerospace Medicine continues to provide aerospace safety solutions to the IAF and the aviation industry. The nation needs to continue to utilize and support this specialty.
Turbulence of Dilute Polymer Solution
Xi, Heng-Dong; Xu, Haitao
2013-01-01
In fully developed three dimensional fluid turbulence the fluctuating energy is supplied at large scales, cascades through intermediate scales, and dissipates at small scales. It is the hallmark of turbulence that for intermediate scales, in the so called inertial range, the average energy flux is constant and independent of viscosity [1-3]. One very important question is how this range is altered, when an additional agent that can also transport energy is added to the fluid. Long-chain polymers dissolved at very small concentrations in the fluid are such an agent [4,5]. Based on prior work by de Gennes and Tabor [6,7] we introduce a theory that balances the energy flux through the turbulent cascade with that of the energy flux into the elastic degrees of freedom of the dilute long-chain polymer solution. We propose a refined elastic length scale, $r_\\varepsilon$, which describes the effect of polymer elasticity on the turbulence energy cascade. Our experimental results agree excellently with this new energy ...
Energy Technology Data Exchange (ETDEWEB)
Setoguchi, T.; Manchu, Y.; Katsumata, M. [Toshiba Corp., Tokyo (Japan)
2000-04-01
Toshiba provides a range of information technology (IT) solutions called SmartEC Solution, which includes business-to-business electronic commerce systems and services based on international standards and industrial know-how, especially our electronic data interchange (EDI) know-how as a manufacturer. These IT solutions are supplied as services covering strategy planning, system integration, and application service provider based on five types of business-to-business electronic commerce. (author)
Technical solutions to nonproliferation challenges
Energy Technology Data Exchange (ETDEWEB)
Satkowiak, Lawrence [Director, Nonproliferation, Safeguards and Security Programs, Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States)
2014-05-09
The threat of nuclear terrorism is real and poses a significant challenge to both U.S. and global security. For terrorists, the challenge is not so much the actual design of an improvised nuclear device (IND) but more the acquisition of the special nuclear material (SNM), either highly enriched uranium (HEU) or plutonium, to make the fission weapon. This paper provides two examples of technical solutions that were developed in support of the nonproliferation objective of reducing the opportunity for acquisition of HEU. The first example reviews technologies used to monitor centrifuge enrichment plants to determine if there is any diversion of uranium materials or misuse of facilities to produce undeclared product. The discussion begins with a brief overview of the basics of uranium processing and enrichment. The role of the International Atomic Energy Agency (IAEA), its safeguard objectives and how the technology evolved to meet those objectives will be described. The second example focuses on technologies developed and deployed to monitor the blend down of 500 metric tons of HEU from Russia's dismantled nuclear weapons to reactor fuel or low enriched uranium (LEU) under the U.S.-Russia HEU Purchase Agreement. This reactor fuel was then purchased by U.S. fuel fabricators and provided about half the fuel for the domestic power reactors. The Department of Energy established the HEU Transparency Program to provide confidence that weapons usable HEU was being blended down and thus removed from any potential theft scenario. Two measurement technologies, an enrichment meter and a flow monitor, were combined into an automated blend down monitoring system (BDMS) and were deployed to four sites in Russia to provide 24/7 monitoring of the blend down. Data was downloaded and analyzed periodically by inspectors to provide the assurances required.
Technical solutions to nonproliferation challenges
Satkowiak, Lawrence
2014-05-01
The threat of nuclear terrorism is real and poses a significant challenge to both U.S. and global security. For terrorists, the challenge is not so much the actual design of an improvised nuclear device (IND) but more the acquisition of the special nuclear material (SNM), either highly enriched uranium (HEU) or plutonium, to make the fission weapon. This paper provides two examples of technical solutions that were developed in support of the nonproliferation objective of reducing the opportunity for acquisition of HEU. The first example reviews technologies used to monitor centrifuge enrichment plants to determine if there is any diversion of uranium materials or misuse of facilities to produce undeclared product. The discussion begins with a brief overview of the basics of uranium processing and enrichment. The role of the International Atomic Energy Agency (IAEA), its safeguard objectives and how the technology evolved to meet those objectives will be described. The second example focuses on technologies developed and deployed to monitor the blend down of 500 metric tons of HEU from Russia's dismantled nuclear weapons to reactor fuel or low enriched uranium (LEU) under the U.S.-Russia HEU Purchase Agreement. This reactor fuel was then purchased by U.S. fuel fabricators and provided about half the fuel for the domestic power reactors. The Department of Energy established the HEU Transparency Program to provide confidence that weapons usable HEU was being blended down and thus removed from any potential theft scenario. Two measurement technologies, an enrichment meter and a flow monitor, were combined into an automated blend down monitoring system (BDMS) and were deployed to four sites in Russia to provide 24/7 monitoring of the blend down. Data was downloaded and analyzed periodically by inspectors to provide the assurances required.
Osmosis and thermodynamics explained by solute blocking.
Nelson, Peter Hugo
2017-01-01
A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.
Osmosis and thermodynamics explained by solute blocking
Nelson, Peter Hugo
2016-01-01
A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult’s law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation. PMID:27225298
Summer confort solutions in mediterranean areas
Coch Roura, Helena; Serra Florensa, Rafael
1996-01-01
The climate of Mediterranean countries is characterized by its complexity. Rapidly changing conditions mean that both cold and heat can be a problem. In architectural practice the design solutions that must be applied in buildings are complex. Solutions for summer comfort in Mediterranean areas also reflect this complexity. The causes of summer discomfort will be described and some examples of solutions against these will be showed and analized. Peer Reviewed
Exact Solutions in Modified Gravity Models
Directory of Open Access Journals (Sweden)
Valery V. Obukhov
2012-06-01
Full Text Available We review the exact solutions in modified gravity. It is one of the main problems of mathematical physics for the gravity theory. One can obtain an exact solution if the field equations reduce to a system of ordinary differential equations. In this paper we consider a number of exact solutions obtained by the method of separation of variables. Some applications to Cosmology and BH entropy are briefly mentioned.
Colligative properties of solutions: I. Fixed concentrations
Alexander, Kenneth; Biskup, Marek; Chayes, Lincoln
2004-01-01
Using the formalism of rigorous statistical mechanics, we study the phenomena of phase separation and freezing-point depression upon freezing of solutions. Specifically, we devise an Ising-based model of a solvent-solute system and show that, in the ensemble with a fixed amount of solute, a macroscopic phase separation occurs in an interval of values of the chemical potential of the solvent. The boundaries of the phase separation domain in the phase diagram are characterized and shown to asym...
Supersymmetric solutions for non-relativistic holography
Energy Technology Data Exchange (ETDEWEB)
Donos, Aristomenis [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gauntlett, Jerome P. [Blackett Laboratory, Imperial College, London (United Kingdom)]|[Institute for Mathematical Sciences, Imperial College, London (United Kingdom)
2009-01-15
We construct families of supersymmetric solutions of type IIB and D=11 supergravity that are invariant under the non-relativistic conformal algebra for various values of dynamical exponent z{>=}4 and z{>=}3, respectively. The solutions are based on five- and seven-dimensional Sasaki-Einstein manifolds and generalise the known solutions with dynamical exponent z=4 for the type IIB case and z=3 for the D=11 case, respectively. (orig.)
Real-Time Ada Problem Solution Study
1989-03-24
Method - Tools Solution Timeframe - Short-term Solution Approach - Remedial Solution 2 - Use a compiler which provides "fast" interrupt procesoing . A...applications will experience timing overhead impacts due to tasking features like task allocation, task activation/ termination , task switching...overhead compared to the processing done within the task itself: 26 Task Normal Description Overhead Proc. (usec) (usec) 1. Task activation and termination
Exact Solutions for Some Fractional Differential Equations
Sonmezoglu, Abdullah
2015-01-01
The extended Jacobi elliptic function expansion method is used for solving fractional differential equations in the sense of Jumarie’s modified Riemann-Liouville derivative. By means of this approach, a few fractional differential equations are successfully solved. As a result, some new Jacobi elliptic function solutions including solitary wave solutions and trigonometric function solutions are established. The proposed method can also be applied to other fractional differential e...
Partnering for A Solution: A Case Study
Jimenez-Smith, Deyrah
2003-01-01
A material-related issue has been identified, which has the potential of impacting the Space Program. Although "in-house" efforts have been underway to solve the problem, a solution has not yet been reached. This presentation shows how a GIDEP member organization is using a Problem Advisory as a solution approach in an effort to receive information from other industry and/or government organizations that may contribute in finding a solution.
Sterilization potential of contact lens solutions
Dada Vijay; Mehta Manoj
1988-01-01
In a dynamic field of Contact Lens Solutions maintenance of high standards of anti-microbial activity is a must Resterilization Activity Time′ is a universally accepted yardstick for such an evaluation. In this study eight brands of indigenous popular solutions alongwith two FDA approved solutions were tested for their sterilization efficacy: Standardized suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus were used for the purpose. ...
Vaidya-like exact solutions with torsion
Blagojević, M
2015-01-01
Starting from the Oliva-Tempo-Troncoso black hole, a solution of the Bergshoeff-Hohm-Townsend massive gravity, a new class of the Vaidya-like exact solutions with torsion is constructed in the three-dimensional Poincar\\'e gauge theory. A particular subclass of these solutions is shown to possess the asymptotic conformal symmetry. The related canonical energy contains a contribution stemming from torsion.
Molecular thermodynamics using fluctuation solution theory
DEFF Research Database (Denmark)
Ellegaard, Martin Dela
to relevant experimental data is limited. This thesis addresses the issue of generating and using simple thermodynamic models within a rigorous statistical mechanical framework, the so-called fluctuation solution theory, from which relations connecting properties and phase equilibria can be obtained....... The framework relates thermodynamic variables to molecular pair correlation functions of liquid mixtures. In this thesis, application of the framework is illustrated using two approaches: 1. Solubilities of solid solutes in mixed solvent systems are determined from fluctuation solution theory application...
A numerical solution for a telegraph equation
Ashyralyev, Allaberen; Modanli, Mahmut
2014-08-01
In this study, the initial value problem for a telegraph equation in a Hilbert space is considered. The stability estimate for the solution of this problem is given. A first and a second order of approximation difference schemes approximately solving the initial value problem are presented. The stability estimates for the solution of these difference schemes are given. The theoretical statements for the solution of these difference schemes are supported by the results of numerical experiments.
On IR solutions in Horava gravity theories
Nastase, Horatiu
2009-01-01
In this note we search for large distance solutions of Horava gravity. In the case of the "detailed balance" action, gravity solutions asymptote to IR only above the cosmological constant ($\\sim$horizon) scale. However, if one adds IR dominant terms $\\alpha R^{(3)}+\\beta \\Lambda_W$, one can recover general relativity solutions on usual scales in the real Universe, provided one fine-tunes the cosmological constant, reobtaining the usual cosmological constant problem. We comment on pp wave solu...
Anodizing And Sealing Aluminum In Nonchromated Solutions
Emmons, John R.; Kallenborn, Kelli J.
1995-01-01
Improved process for anodizing and sealing aluminum involves use of 5 volume percent sulfuric acid in water as anodizing solution, and 1.5 to 2.0 volume percent nickel acetate in water as sealing solution. Replaces process in which sulfuric acid used at concentrations of 10 to 20 percent. Improved process yields thinner coats offering resistance to corrosion, fatigue life, and alloy-to-alloy consistency equal to or superior to those of anodized coats produced with chromated solutions.
Geometrical and Graphical Solutions of Quadratic Equations.
Hornsby, E. John, Jr.
1990-01-01
Presented are several geometrical and graphical methods of solving quadratic equations. Discussed are Greek origins, Carlyle's method, von Staudt's method, fixed graph methods and imaginary solutions. (CW)
Processing Solutions for Big Data in Astronomy
Fillatre, L.; Lepiller, D.
2016-09-01
This paper gives a simple introduction to processing solutions applied to massive amounts of data. It proposes a general presentation of the Big Data paradigm. The Hadoop framework, which is considered as the pioneering processing solution for Big Data, is described together with YARN, the integrated Hadoop tool for resource allocation. This paper also presents the main tools for the management of both the storage (NoSQL solutions) and computing capacities (MapReduce parallel processing schema) of a cluster of machines. Finally, more recent processing solutions like Spark are discussed. Big Data frameworks are now able to run complex applications while keeping the programming simple and greatly improving the computing speed.
Sterilization potential of contact lens solutions
Directory of Open Access Journals (Sweden)
Dada Vijay
1988-01-01
Full Text Available In a dynamic field of Contact Lens Solutions maintenance of high standards of anti-microbial activity is a must Resterilization Activity Time′ is a universally accepted yardstick for such an evaluation. In this study eight brands of indigenous popular solutions alongwith two FDA approved solutions were tested for their sterilization efficacy: Standardized suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus were used for the purpose. It was observed that the contact lens solutions available ir, the domestic market were not upto the mark Suggestions for improvement have also been made.
Dislocation Etching Solutions for Mercury Cadmium Selenide
2014-09-01
mercury cadmium telluride (Hg1–xCdxTe) for infrared (IR) sensor applications, but etch pit density ( EPD ) measurements are required to measure...dislocations that affect device performance. No EPD solutions have been reported for Hg1–xCdxSe, and standard EPD solutions for Hg1–xCdxTe have proved...ineffective. Thus, a new etching solution is required for EPD measurements of Hg1–xCdxSe. Samples were etched in various solutions and the resulting pits
Scaling solutions for dilaton quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Henz, T.; Pawlowski, J.M., E-mail: j.pawlowski@thphys.uni-heidelberg.de; Wetterich, C.
2017-06-10
Scaling solutions for the effective action in dilaton quantum gravity are investigated within the functional renormalization group approach. We find numerical solutions that connect ultraviolet and infrared fixed points as the ratio between scalar field and renormalization scale k is varied. In the Einstein frame the quantum effective action corresponding to the scaling solutions becomes independent of k. The field equations derived from this effective action can be used directly for cosmology. Scale symmetry is spontaneously broken by a non-vanishing cosmological value of the scalar field. For the cosmology corresponding to our scaling solutions, inflation arises naturally. The effective cosmological constant becomes dynamical and vanishes asymptotically as time goes to infinity.
Scaling solutions for dilaton quantum gravity
Henz, T.; Pawlowski, J. M.; Wetterich, C.
2017-06-01
Scaling solutions for the effective action in dilaton quantum gravity are investigated within the functional renormalization group approach. We find numerical solutions that connect ultraviolet and infrared fixed points as the ratio between scalar field and renormalization scale k is varied. In the Einstein frame the quantum effective action corresponding to the scaling solutions becomes independent of k. The field equations derived from this effective action can be used directly for cosmology. Scale symmetry is spontaneously broken by a non-vanishing cosmological value of the scalar field. For the cosmology corresponding to our scaling solutions, inflation arises naturally. The effective cosmological constant becomes dynamical and vanishes asymptotically as time goes to infinity.
Solution space assessment for mass customization
DEFF Research Database (Denmark)
Brunø, Thomas Ditlev; Nielsen, Kjeld; Jørgensen, Kaj Asbjørn
2012-01-01
literature study and analysis of solution space characteristics a number of metrics are described which can be used for solution space assessment. They are divided into five caterories: Profitability, Utilization, Variety Demand satisfaction, Architecture and Responsiveness. The metrics and be applied as KPI......In mass customization, the capability solution space development is essential to offer a variety of products which satisfies the idiosyncratic needs of the customers. We argue that there is a need for methods which can assess a company’s solution space and their capability to develop it. Through...
Supergravity solutions for Born-Infeld dyons
Youm, D
1999-01-01
We construct partially localized supergravity counterpart solutions to the 1/2 supersymmetric nonthreshold and the 1/4 supersymmetric threshold bound state BI dyons in the D3-brane Dirac-Born-Infeld theory. Such supergravity solutions have all the parameters of the BI dyons. By applying the type-IIA-type-IIB T-duality transformations to these supergravity solutions, we obtain the supergravity counterpart solutions to 1/2 and 1/4 supersymmetric bions carrying electric and magnetic charges of the world volume U(1) gauge field in the Dirac- Born-Infeld theory in other dimensions. (70 refs).
Risk transfer solutions for the insurance industry
Directory of Open Access Journals (Sweden)
Njegomir Vladimir
2009-01-01
Full Text Available The paper focuses on the traditional and alternative mechanisms for insurance risk transfer that are available to global as well as to domestic insurance companies. The findings suggest that traditional insurance risk transfer solutions available to insurance industry nowadays will be predominant in the foreseeable future but the increasing role of alternative solutions is to be expected as the complementary rather than supplementary solution to traditional transfer. Additionally, findings suggest that it is reasonable to expect that future development of risk transfer solutions in Serbia will follow the path that has been passed by global insurance industry.
Supersaturated Electrolyte Solutions: Theory and Experiment
Izmailov, Alexander F.; Myerson, Allan S.; Na, Han-Soo
1995-01-01
Highly supersaturated electrolyte solutions can be prepared and studied employing an electrodynamic levitator trap (ELT) technique. The ELT technique involves containerless suspension of a microdroplet thus eliminating dust, dirt, and container walls which normally cause heterogeneous nucleation. This allows very high supersaturations to be achieved. A theoretical study of the experimental results obtained for the water activity in microdroplets of various electrolyte solutions is based on the development of the Cahn-Hilliard formalism for electrolyte solutions. In the approach suggested the metastable state for electrolyte solutions is described in terms of the conserved order parameter omega(r,t) associated with fluctuations of the mean solute concentration n(sub 0). Parameters of the corresponding Ginzburg-Landau free energy functional which defines the dynamics of metastable state relaxation are determined and expressed through the experimentally measured quantities. A correspondence of 96-99 % between theory and experiment for all solutions studied was achieved and allowed the determination of an analytical expression for the spinodal concentration n(sub spin), and its calculation for various electrolyte solutions at 298 K. The assumption that subcritical solute clusters consist of the electrically neutral Bjerrum pairs has allowed both analytical and numerical investigation of the number-size N(sub c) of nucleation monomers (aggregates of the Bjerrum pairs) which are elementary units of the solute critical clusters. This has also allowed estimations for the surface tension Alpha, and equilibrium bulk energy Beta per solute molecule in the nucleation monomers. The dependence of these properties on the temperature T and on the solute concentration n(sub 0) through the entire metastable zone (from saturation concentration n(sub sat) to spinodal n(sub spin) is examined. It has been demonstrated that there are the following asymptotics: N(sub c), = I at spinodal
Solute Migration from the Aquifer Matrix into a Solution Conduit and the Reverse.
Li, Guangquan; Field, Malcolm S
2016-09-01
A solution conduit has a permeable wall allowing for water exchange and solute transfer between the conduit and its surrounding aquifer matrix. In this paper, we use Laplace Transform to solve a one-dimensional equation constructed using the Euler approach to describe advective transport of solute in a conduit, a production-value problem. Both nonuniform cross-section of the conduit and nonuniform seepage at the conduit wall are considered in the solution. Physical analysis using the Lagrangian approach and a lumping method is performed to verify the solution. Two-way transfer between conduit water and matrix water is also investigated by using the solution for the production-value problem as a first-order approximation. The approximate solution agrees well with the exact solution if dimensionless travel time in the conduit is an order of magnitude smaller than unity. Our analytical solution is based on the assumption that the spatial and/or temporal heterogeneity in the wall solute flux is the dominant factor in the spreading of spring-breakthrough curves, and conduit dispersion is only a secondary mechanism. Such an approach can lead to the better understanding of water exchange and solute transfer between conduits and aquifer matrix. Euler and Lagrangian approaches are used to solve transport in conduit. Two-way transfer between conduit and matrix is investigated. The solution is applicable to transport in conduit of persisting solute from matrix. © 2016, National Ground Water Association.
Hausdorff continuous solutions of nonlinear partial differentail ...
African Journals Online (AJOL)
It was shown in [15] that very large classes of nonlinear partial differential equations (PDE's) have solutions which can be assimilated with usual measurable functions on the Euclidean domains of definition of the respective equations. In this paper the regularity of these solutions is improved significantly by showing that they ...
Clean Energy Solutions Center Services (Vietnamese Translation)
Energy Technology Data Exchange (ETDEWEB)
2016-03-01
This is a Vietnamese translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
An Enlarged Profile of Uremic Solutes.
Directory of Open Access Journals (Sweden)
Hisae Tanaka
Full Text Available Better knowledge of the uremic solutes that accumulate when the kidneys fail could lead to improved renal replacement therapy. This study employed the largest widely available metabolomic platform to identify such solutes. Plasma and plasma ultrafiltrate from 6 maintenance hemodialysis (HD patients and 6 normal controls were first compared using a platform combining gas and liquid chromatography with mass spectrometry. Further studies compared plasma from 6 HD patients who had undergone total colectomy and 9 with intact colons. We identified 120 solutes as uremic including 48 that had not been previously reported to accumulate in renal failure. Combination of the 48 newly identified solutes with those identified in previous reports yielded an extended list of more than 270 uremic solutes. Among the solutes identified as uremic in the current study, 9 were shown to be colon-derived, including 6 not previously identified as such. Literature search revealed that many uremic phenyl and indole solutes, including most of those shown to be colon-derived, come from plant foods. Some of these compounds can be absorbed directly from plant foods and others are produced by colon microbial metabolism of plant polyphenols that escape digestion in the small intestine. A limitation of the metabolomic method was that it underestimated the elevation in concentration of uremic solutes which were measured using more quantitative assays.
Solution Kinetics Database on the Web
SRD 40 NDRL/NIST Solution Kinetics Database on the Web (Web, free access) Data for free radical processes involving primary radicals from water, inorganic radicals and carbon-centered radicals in solution, and singlet oxygen and organic peroxyl radicals in various solvents.
Clean Energy Solutions Center Services (Arabic Translation)
Energy Technology Data Exchange (ETDEWEB)
2016-03-01
This is an Arabic translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Clean Energy Solutions Center Services (French Translation)
Energy Technology Data Exchange (ETDEWEB)
2016-03-01
This is a French translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Rheological characterization of nephila spidroin solution.
Chen, Xin; Knight, David P; Vollrath, Fritz
2002-01-01
We report the results of an investigation into the rheology of solutions of natural spider silk dope (spinning solution). We demonstrate that dilute dope solutions showed only shear thinning as the shear rate increased while more concentrated solutions showed an initial shear thinning followed by a shear thickening and a subsequent decline in viscosity. The critical shear rate for shear thickening depended on dope concentration and was very low in concentrated solutions. This helps to explain how spiders are able to spin silk at very low draw rates and why they use a very concentrated dope solution. We also show that the optimum shear rate for shear thickening in moderately concentrated solutions occurred at pH 6.3 close to the observed pH at the distal end of the spider's spinning duct. Finally, we report that the addition of K(+) ions to dilute dope solutions produced a spontaneous formation of nanofibrils that subsequently aggregated and precipitated. This change was not seen after the addition of other common cations. Taken together, these observations support the hypothesis that the secretion of H(+) and K(+) by the spider's duct together with moderate strain rates produced during spinning induce a phase separation in the silk dope in which the silk protein (spidroin) molecules are converted into insoluble nanofibrils.
The Pizza Problem: A Solution with Sequences
Shafer, Kathryn G.; Mast, Caleb J.
2008-01-01
This article addresses the issues of coaching and assessing. A preservice middle school teacher's unique solution to the Pizza problem was not what the professor expected. The student's solution strategy, based on sequences and a reinvention of Pascal's triangle, is explained in detail. (Contains 8 figures.)
Asymptotically periodic solutions of Volterra integral equations
Directory of Open Access Journals (Sweden)
Muhammad N. Islam
2016-03-01
Full Text Available We study the existence of asymptotically periodic solutions of a nonlinear Volterra integral equation. In the process, we obtain the existence of periodic solutions of an associated nonlinear integral equation with infinite delay. Schauder's fixed point theorem is used in the analysis.
Numerical Solution of Differential Algebraic Equations
DEFF Research Database (Denmark)
Thomsen, Per Grove; Bendtsen, Claus
1999-01-01
Lecture notes for a PhD-course on the numerical solution of DAE's. The course was held at IMM in the autumn of 1998 and the early spring of 1999.......Lecture notes for a PhD-course on the numerical solution of DAE's. The course was held at IMM in the autumn of 1998 and the early spring of 1999....
Power Series Solution to the Pendulum Equation
Benacka, Jan
2009-01-01
This note gives a power series solution to the pendulum equation that enables to investigate the system in an analytical way only, i.e. to avoid numeric methods. A method of determining the number of the terms for getting a required relative error is presented that uses bigger and lesser geometric series. The solution is suitable for modelling the…
Manager, Human Resources Business Solutions | IDRC ...
International Development Research Centre (IDRC) Digital Library (Canada)
Job Summary The Manager, Human Resources (HR) Business Solutions is responsible for the delivery of integrated HR business solutions to clients ensuring ... Work with the Director Human Resources, Manager, Global Compensation and Manager Employee and Labour Relations to develop objectives, set priorities and ...
Super Darboux-Egoroff equations and solutions
Kersten, P.H.M.; Martini, Ruud
1998-01-01
Super Darboux-Egoroff equations are discussed. First of all linearity of the potential $\\varphi$ with respect to odd variables is proved. Solutions of Darboux-Egoroff equations in dimension $(2|2)$ including flatness of the unit vector field are constructed. Moreover solutions of Darboux-Egoroff
IMCCE planetary solution: overview and prospects
Fienga, A.; Simon, J.-L.
2004-09-01
The VSOP solutions of the planetary motions are analytical solutions of the planets of the solar system, from Mercury to Neptune. These solutions have to give highly accurate ephemerides on long time intervals, about several thousand years for the inner planets and 1000 years of the outer planets. VSOP2002 (Bretagnon, 2002), the last unfinished VSOP version processed by P.Bretagnon, will be presented and its current accuracy will be discussed. A new analytical solution, VSOP2003, based on VSOP2002, is under development: Pluto perturbations based on the new analytical description of its motion (Simon 2003) are added, we introduce the developments of the mean short periods based on TOP (Simon, 2000), perturbations of the 300 asteroids are added with a one angular parameter model. In parallel, numerical solutions are also under development. Compared to VSOP solutions, these solutions will give more accurate positions and velocities of planets over shorter periods of time. Two types of solutions are considered: i) one follows the JPL integrator and algorithm. Its current status of development as well as the accuracies achieved by this version under process will be given during the talk. ii) one is based on the symplectic integrators developed by Laskar and Robutel (2001). It will be very accurate on short period of time (ten years) but also on very long period of time (several millions of years).
LHCb: DIRAC A community grid solution
Tsaregorodtsev, A
2007-01-01
The DIRAC project began as a solution for the LHCb experiment at CERN to carry out massive Monte Carlo simulation and data processing on various distributed computing resources. Now it is evolving to a complete Grid solution for community of users such as LHCb.
Clean Energy Solutions Center Services (Portuguese Translation)
Energy Technology Data Exchange (ETDEWEB)
2016-03-01
This is a Portuguese translation of the Clean Energy Solutions Center Services fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
NUMERICAL SOLUTIONS OF SOME PARAMETRIC EFFECTS DUE ...
African Journals Online (AJOL)
Dr A.B.Ahmed
ISSN 1597-6343. Numerical Solutions of Some Parametric Effects Due to Electromagnetic Wave. Scattering by an Infinite Circular Cylinder. NUMERICAL SOLUTIONS OF SOME PARAMETRIC EFFECTS DUE. TO ELECTROMAGNETIC WAVE SCATTERING BY AN INFINITE. CIRCULAR CYLINDER. *1 Suleiman A. B. and 1 ...
Analytical solution of one dimensional temporally dependent ...
African Journals Online (AJOL)
... chemically non-reactive. The first order decay term which is inversely proportional to the dispersion coefficient is also considered. Initially the porous domain is considered solute free. Analytical solutions are obtained by using Laplace transform technique for continuous uniform and increasing input source concentration.
Mixed Solutions of Electrical Energy Storage
Directory of Open Access Journals (Sweden)
Chioncel Cristian Paul
2012-01-01
Full Text Available The paper presents electrical energy storage solutions using electricbatteries and supercapacitors powered from photovoltaic solarmodules, with possibilities of application in electric and hybrid vehicles.The future development of electric cars depends largely on electricalenergy storage solutions that should provide a higher range of roadand operating parameters comparable to those equipped with internalcombustion engines, that eliminate pollution.
Exercises and solutions manual - course 72241
DEFF Research Database (Denmark)
Christensen, Georg Kronborg; Bucka-Christensen, E. Thomas
1996-01-01
A collection of excercises for group-work and examin tasks for the cource: "Measurement and Instrumentation Techniques". 72241. Solution are provided for the examination tasks.......A collection of excercises for group-work and examin tasks for the cource: "Measurement and Instrumentation Techniques". 72241. Solution are provided for the examination tasks....
Analytic solutions of nonlinear Cournot duopoly game
Directory of Open Access Journals (Sweden)
Akio Matsumoto
2005-01-01
Full Text Available We construct a Cournot duopoly model with production externality in which reaction functions are unimodal. We consider the case of a Cournot model which has a stable equilibrium point. Then we show the existence of analytic solutions of the model. Moreover, we seek general solutions of the model in the form of nonlinear second-order difference equation.
Surface tension of aqueous electrolyte solutions. Thermodynamics
Drzymala, J.; Lyklema, J.
2012-01-01
A thermodynamic theory is developed for obtaining the enthalpic and entropic contributions to the surface excess Gibbs energy of electrolyte solutions from the dependence of the surface tension on concentration and temperature. For elaboration, accurate activity coefficients in solution as functions
Clinical advantages of new peritoneal dialysis solutions
Krediet, Raymond T.; van Westrhenen, Roos; Zweers, Machteld M.; Struijk, Dirk G.
2002-01-01
A review is given of the various mechanisms by which conventional glucose/lactate-based peritoneal dialysis solutions can induce damage to the peritoneal membrane. The potential advantages of newly developed dialysis solutions and the results of recent studies on their use in patients are discussed
Femtosecond reactivity of electron in aqueous solutions
Gauduel, Yann; Migus, A.; Chambaret, J. P.; Antonetti, A.
1987-01-01
Femtosecond optical techniques allowing the generation of intense optical pulses from the near ultraviolet to the near infrared are used in the monitoring of ultrafast photophysical and photochemical reactions in aqueous solutions. Selected examples for dynamics of electron solvation in water and aqueous solution of ferrocyanide are discussed.
Exact solutions for the biadjoint scalar field
Energy Technology Data Exchange (ETDEWEB)
White, C.D., E-mail: Christopher.White@glasgow.ac.uk [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Centre for Research in String Theory, Queen Mary University of London, London E1 4NS (United Kingdom)
2016-12-10
Biadjoint scalar theories are novel field theories that arise in the study of non-abelian gauge and gravity amplitudes. In this short paper, we present exact nonperturbative solutions of the field equations, and compare their properties with monopole-like solutions in non-abelian gauge theory. Our results may pave the way for nonperturbative studies of the double copy.
AdS solutions through transgression
Energy Technology Data Exchange (ETDEWEB)
Donos, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Gauntlett, J.P. [Imperial College, London (United Kingdom). Blackett Lab.]|[Imperial College, London (United Kingdom). The Institute for Mathematical Sciences; Kim, Nakwoo [Kyung Hee Univ., Seoul (Korea). Dept. of Physics and Research Inst. of Basic Science
2008-07-15
We present new classes of explicit supersymmetric AdS{sub 3} solutions of type IIB supergravity with non-vanishing five-form flux and AdS{sub 2} solutions of D=11 supergravity with electric four-form flux. The former are dual to two-dimensional SCFTs with (0,2) supersymmetry and the latter to supersymmetric quantum mechanics with two supercharges. We also investigate more general classes of AdS{sub 3} solutions of type IIB supergravity and AdS{sub 2} solutions of D=11 supergravity which in addition have non-vanishing three-form flux and magnetic four-form flux, respectively. The construction of these more general solutions makes essential use of the Chern-Simons or ''transgression'' terms in the Bianchi identity or the equation of motion of the field strengths in the supergravity theories. We construct infinite new classes of explicit examples and for some of the type IIB solutions determine the central charge of the dual SCFTs. The type IIB solutions with non-vanishing three-form flux that we construct include a two-torus, and after two T-dualities and an S-duality, we obtain new AdS3 solutions with only the NS fields being non-trivial. (orig.)
PERIODIC-SOLUTIONS IN SPONTANEOUSLY BROKEN THEORIES
BRIHAYE, Y; KUNZ, J
A class of spontaneously broken field theories is proposed, and the occurrence of their periodic, classical solutions is investigated in detail. The emergence of multiple solutions is observed, their normal modes of oscillation are studied, and the bifurcations of the classical energy functional are
New stiff matter solutions to Einstein equations
Energy Technology Data Exchange (ETDEWEB)
Hajj-Boutros, J.
1989-01-01
New exact solutions are presented to the Einstein field equations which are spherically symmetric and static, with a perfect fluid distribution of matter satisfying the equation of state /rho/ = p. One of the obtained solutions may only be used locally, the other represents the stellar interior globally and is singularity-free.
New exact wave solutions for Hirota equation
Indian Academy of Sciences (India)
... integrals in polynomial form with a high accuracy for two-dimensional plane autonomous systems. Exact soliton solution is constructed through the established first integrals. This method is a powerful tool for searching exact travelling solutions of nonlinear partial differential equations (NPDEs) in mathematical physics.
My #safecities solution campaign | IDRC - International ...
International Development Research Centre (IDRC) Digital Library (Canada)
2017-05-19
May 19, 2017 ... The conference, organized with IDRC by the African Leadership Centre, will offer many opportunities for online participation, including webcasts. my safe cities solutions posters. IDRC is running a campaign on Facebook and Twitter to highlight the many solutions generated by SAIC research and other ...
Euclidean supergravity and multi-centered solutions
Sabra, W. A.
2017-04-01
In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein-Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D = 5, N = 2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein-Maxwell multi-centered solutions are also presented.
Euclidean supergravity and multi-centered solutions
Directory of Open Access Journals (Sweden)
W.A. Sabra
2017-04-01
Full Text Available In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein–Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D=5, N=2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein–Maxwell multi-centered solutions are also presented.
Analytical solution methods for geodesic motion
Hackmann, Eva
2015-01-01
The observation of the motion of particles and light near a gravitating object is until now the only way to explore and to measure the gravitational field. In the case of exact black hole solutions of the Einstein equations the gravitational field is characterized by a small number of parameters which can be read off from the observables related to the orbits of test particles and light rays. Here we review the state of the art of analytical solutions of geodesic equations in various space--times. In particular we consider the four dimensional black hole space--times of Pleba\\'nski--Demia\\'nski type as far as the geodesic equation separates, as well as solutions in higher dimensions, and also solutions with cosmic strings. The mathematical tools used are elliptic and hyperelliptic functions. We present a list of analytic solutions which can be found in the literature.
Exact solution to fractional logistic equation
West, Bruce J.
2015-07-01
The logistic equation is one of the most familiar nonlinear differential equations in the biological and social sciences. Herein we provide an exact solution to an extension of this equation to incorporate memory through the use of fractional derivatives in time. The solution to the fractional logistic equation (FLE) is obtained using the Carleman embedding technique that allows the nonlinear equation to be replaced by an infinite-order set of linear equations, which we then solve exactly. The formal series expansion for the initial value solution of the FLE is shown to be expressed in terms of a series of weighted Mittag-Leffler functions that reduces to the well known analytic solution in the limit where the fractional index for the derivative approaches unity. The numerical integration to the FLE provides an excellent fit to the analytic solution. We propose this approach as a general technique for solving a class of nonlinear fractional differential equations.
Corundum dissolution in concentrated sodium hydroxide solution
Directory of Open Access Journals (Sweden)
u-sheng Wu
2016-11-01
Full Text Available The corundum (α-alumina core has been considered as a suitable candidate for investment casting of hollow, high pressure turbine engine airfoils due to its excellent properties. However, the efficiency of removing alumina cores in concentrated caustic solution cannot meet the needs of industrial production. In this paper, the effects of temperature and initial solution concentration on dissolution of α-alumina were studied by the classical weight-loss method. The fractal kinetic model was developed in order to describe α-alumina dissolution, assuming that the nonporous particles shrank during reaction process. The results show that the dissolution rate increases with increasing reaction temperature and initial solution concentration. Especially, the initial solution concentration has a significant influence on α-alumina dissolution rate at a higher reaction temperature. The activation energies decrease with increasing initial solution concentration, and the chemical reaction is the rate-controlling step.
Radiation Driven Wind Solutions and Applications
Curé, M.
2016-11-01
The standard modified-CAK equation of motion is a non-linear differential equation that possesses many singular points and therefore many solutions. Apart from the standard solution, we have found three other physical solutions: i) when the rotational velocity is higher than 3/4 of the critical rotational speed; ii) when there is a high ionization change throughout the wind; and iii) when the k line force parameter is very high (k is the fraction of the total stellar flux which would be blocked in the photosphere if all lines were optically thick). We also show some applications of these solutions, e.g., the wind of a B[e] supergiant, the oblate wind of a Be star, and the winds of BA supergiants. Furthermore, we calculate synthetic spectra with FASTWIND, where we have used our new hydrodynamical solutions as input to the code.
Transition between vortex rings and MAP solutions for electrically charged magnetic solutions
Wong, Khai-Ming; Soltanian, Amin; Teh, Rosy
2014-03-01
We consider the bifurcation and transition of axially symmetric monopole-antimonopole pair (MAP) and vortex ring solutions in the presence of electric charge for the SU(2) Yang-Mills-Higgs field theory. Here we investigate the properties of MAP/vortex ring solutions with n = 3,η = 0.65, for different Higgs field strength λ. For λ ring solution, but at the critical value of λb = 4.93, branching happens and 2 sets of new solutions appeared. The new branch with less energy is a full MAP solution while the branch with higher energy contains MAP at the beginning and separation between poles of MAP on the z-axis reduces gradually and at another critical value of λt = 14.852, they merge together at z = 0. Beyond this point the solutions change to the vortex ring solutions and a transitions between MAP and vortex ring solutions happens at this branch.
Stability of tacrolimus solutions in polyolefin containers.
Lee, Jun H; Goldspiel, Barry R; Ryu, Sujung; Potti, Gopal K
2016-02-01
Results of a study to determine the stability of tacrolimus solutions stored in polyolefin containers under various temperature conditions are reported. Triplicate solutions of tacrolimus (0.001, 0.01, and 0.1 mg/mL) in 0.9% sodium chloride injection or 5% dextrose injection were prepared in polyolefin containers. Some samples were stored at room temperature (20-25 °C); others were refrigerated (2-8 °C) for 20 hours and then stored at room temperature for up to 28 hours. The solutions were analyzed by stability-indicating high-performance liquid chromatography (HPLC) assay at specified time points over 48 hours. Solution pH was measured and containers were visually inspected at each time point. Stability was defined as retention of at least 90% of the initial tacrolimus concentration. All tested solutions retained over 90% of the initial tacrolimus concentration at all time points, with the exception of the 0.001-mg/mL solution prepared in 0.9% sodium chloride injection, which was deemed unstable beyond 24 hours. At all evaluated concentrations, mean solution pH values did not change significantly over 48 hours; no particle formation was detected. During storage in polyolefin bags at room temperature, a 0.001-mg/mL solution of tacrolimus was stable for 24 hours when prepared in 0.9% sodium chloride injection and for at least 48 hours when prepared in 5% dextrose injection. Solutions of 0.01 and 0.1 mg/mL prepared in either diluent were stable for at least 48 hours, and the 0.01-mg/mL tacrolimus solution was also found to be stable throughout a sequential temperature protocol. Copyright © 2016 by the American Society of Health-System Pharmacists, Inc. All rights reserved.
Periodic Solutions and S-Asymptotically Periodic Solutions to Fractional Evolution Equations
Directory of Open Access Journals (Sweden)
Jia Mu
2017-01-01
Full Text Available This paper deals with the existence and uniqueness of periodic solutions, S-asymptotically periodic solutions, and other types of bounded solutions for some fractional evolution equations with the Weyl-Liouville fractional derivative defined for periodic functions. Applying Fourier transform we give reasonable definitions of mild solutions. Then we accurately estimate the spectral radius of resolvent operator and obtain some existence and uniqueness results.
Perturbation Solutions of the Quintic Duffing Equation with Strong Nonlinearities
Directory of Open Access Journals (Sweden)
Mehmet Pakdemirli
Full Text Available The quintic Duffing equation with strong nonlinearities is considered. Perturbation solutions are constructed using two different techniques: The classical multiple scales method (MS and the newly developed multiple scales Lindstedt Poincare method (MSLP. The validity criteria for admissible solutions are derived. Both approximate solutions are contrasted with the numerical solutions. It is found that MSLP provides compatible solution with the numerical solution for strong nonlinearities whereas MS solution fail to produce physically acceptable solution for large perturbation parameters.
Oyelami, Benjamin Oyediran
2013-01-01
In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.
Directory of Open Access Journals (Sweden)
Oyelami, Benjamin Oyediran
2013-09-01
Full Text Available In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.
Americium separations from high salt solutions
Energy Technology Data Exchange (ETDEWEB)
Mary E. Barr; Gordon D. Jarvinen; Louis D. Schulte; Peter C. Stark; Rebecca M. Chamberlin; Kent D. Abney; Thomas E. Ricketts; Yvette E. Valdez; Richard A. Bartsch
2000-03-01
Americium (III) exhibits an unexpectedly high affinity for anion-exchange material from the high-salt evaporator bottoms solutions--an effect which has not been duplicated using simple salt solutions. Similar behavior is observed for its lanthanide homologue, Nd(III), in complex evaporator bottoms surrogate solutions. There appears to be no single controlling factor--acid concentration, total nitrate concentration or solution ionic strength--which accounts for the approximately 2-fold increase in retention of the trivalent ions from complex solutions relative to simple solutions. Calculation of species activities (i.e., water, proton and nitrate) in such concentrated mixed salt solutions is difficult and of questionable accuracy, but it is likely that the answer to forcing formation of anionic nitrate complexes of americium lies in the relative activities of water and nitrate. From a practical viewpoint, the modest americium removal needs (ca. 50--75%) from nitric acid evaporator bottoms allow sufficient latitude for the use of non-optimized conditions such as running existing columns filled with older, well-used Reillex HPQ. Newer materials, such as HPQ-100 and the experimental bifunctional resins, which exhibit higher distribution coefficients, would allow for either increased Am removal or the use of smaller columns. It is also of interest that one of the experimental neutral-donor solid-support extractants, DHDECMP, exhibits a similarly high level of americium (total alpha) removal from EV bottoms and is much less sensitive to total acid content than commercially-available material.
Disintegration of brown coal using alkaline solution
Energy Technology Data Exchange (ETDEWEB)
Vydra, J.; Skalicka, J.
1985-01-01
Investigations carried out by the Institute of Geology and Geotechnics of the Academy of Sciences of Czechoslovakia are discussed. The investigations were aimed at determining the optimum conditions for in situ solution mining of brown coal using alkaline solutions. Twelve brown coal samples with carbon content ranging from 64.5 to 90.7% were treated with sodium hydroxide solution with concentration ranging from 1 to 5%. Effects of hydrogen peroxide (15%) and ethanolamine (5%) also were investigated. Proportion of the 3 compounds in water was the following: 500 ml sodium hydroxide, 100 ml ethanolamine and 20 ml hydrogen peroxide. Effects of coal grain size on its disintegration in the alkaline solution also were analyzed. Conditions of in situ solution mining were simulated in the laboratory. Investigations showed that the optimum coal grain size was 2 mm, in which case disintegration efficiency depended on carbon content in coal. The lower the carbon content was, the more efficient was the alkaline disintegration. Alkaline solutions did not influence brown coal with carbon content higher than 85%. The optimum concentration of sodium hydroxide was 3%. Addition of hydrogen peroxide and ethanolamine did not influence disintegration. When alkaline solution was pumped 96 h long into a borehole, it penetrated coal to a depth of 2 mm causing swelling of the borehole walls but not coal disintegration. 8 references.
Ions, solutes and solvents, oh my!
Energy Technology Data Exchange (ETDEWEB)
Kemp, Daniel David [Iowa State Univ., Ames, IA (United States)
2009-08-01
Modern methods in ab initio quantum mechanics have become efficient and accurate enough to study many gas-phase systems. However, chemists often work in the solution phase. The presence of solvent molecules has been shown to affect reaction mechanisms1, lower reaction energy barriers2, participate in energy transfer with the solute3 and change the physical properties of the solute4. These effects would be overlooked in simple gas phase calculations. Careful study of specific solvents and solutes must be done in order to fully understand the chemistry of the solution phase. Water is a key solvent in chemical and biological applications. The properties of an individual water molecule (a monomer) and the behavior of thousands of molecules (bulk solution) are well known for many solvents. Much is also understood about aqueous microsolvation (small clusters containing ten water molecules or fewer) and the solvation characteristics when bulk water is chosen to solvate a solute. However, much less is known about how these properties behave as the cluster size transitions from the microsolvated cluster size to the bulk. This thesis will focus on species solvated with water clusters that are large enough to exhibit the properties of the bulk but small enough to consist of fewer than one hundred solvent molecules. New methods to study such systems will also be presented.
The Krafft temperature of surfactant solutions
Directory of Open Access Journals (Sweden)
Manojlović Jelena Ž.
2012-01-01
Full Text Available Our main motivation to revisit the solution properties of cetyltrimethylammonium bromide is related to the clear requirement for better control of the adsorption parameters to form uniform self-assembled monolayers on muscovite mica substrates. To readily monitor the temporal evolution of structural details in cetyltrimethylammonium bromide solutions, we realized a rather simple conductivity experiment. Conductivity measurements were carried out as a function of temperature, to look closer into the Krafft temperature behavior of this surfactant. We measured the electrical conductivity of different concentrations of aqueous cetyltrimethylammonium bromide solutions, below and above the critical micells concentration.
Membrane separation of ionic liquid solutions
Energy Technology Data Exchange (ETDEWEB)
Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart
2015-09-01
A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.
Pole solutions for flame front propagation
Kupervasser, Oleg
2015-01-01
This book deals with solving mathematically the unsteady flame propagation equations. New original mathematical methods for solving complex non-linear equations and investigating their properties are presented. Pole solutions for flame front propagation are developed. Premixed flames and filtration combustion have remarkable properties: the complex nonlinear integro-differential equations for these problems have exact analytical solutions described by the motion of poles in a complex plane. Instead of complex equations, a finite set of ordinary differential equations is applied. These solutions help to investigate analytically and numerically properties of the flame front propagation equations.
Colligative Properties of Solutions: I. Fixed Concentrations
Alexander, Kenneth S.; Biskup, Marek; Chayes, Lincoln
2005-05-01
Using the formalism of rigorous statistical mechanics, we study the phenomena of phase separation and freezing-point depression upon freezing of solutions. Specifically, we devise an Ising-based model of a solvent--solute system and show that, in the ensemble with a fixed amount of solute, a macroscopic phase separation occurs in an interval of values of the chemical potential of the solvent. The boundaries of the phase separation domain in the phase diagram are characterized and shown to asymptotically agree with the formulas used in heuristic analyses of freezing-point depression. The limit of infinitesimal concentrations is described in a subsequent paper.
Solutions of the coupled Higgs field equations
Talukdar, Benoy; Ghosh, Swapan K.; Saha, Aparna; Pal, Debabrata
2013-07-01
By an appropriate choice for the phase of the complex nucleonic field and going over to the traveling coordinate, we reduce the coupled Higgs equations to the Hamiltonian form and treat the resulting equation using the dynamical system theory. We present a phase-space analysis of its stable points. The results of our study demonstrate that the equation can support both traveling- and standing-wave solutions. The traveling-wave solution appears in the form of a soliton and resides in the midst of doubly periodic standing-wave solutions.
Terahertz absorption of dilute aqueous solutions.
Heyden, Matthias; Tobias, Douglas J; Matyushov, Dmitry V
2012-12-21
Absorption of terahertz (THz) radiation by aqueous solutions of large solutes reports on the polarization response of their hydration shells. This is because the dipolar relaxation of the solute is dynamically frozen at these frequencies, and most of the solute-induced absorption changes, apart from the expulsion of water, are caused by interfacial water. We propose a model expressing the dipolar response of solutions in terms of a single parameter, the interface dipole moment induced in the interfacial water by electromagnetic radiation. We apply this concept to experimental THz absorption of hydrated sugars, amino acids, and proteins. None of the solutes studied here follow the expectations of dielectric theories, which predict a negative projection of the interface dipole on the external electric field. We find that this prediction is not able to describe the available experimental data, which instead suggests a nearly zero interface dipole for sugars and a more diverse pattern for amino acids. Hydrophobic amino acids, similarly to sugars, give rise to near zero interface dipoles, while strongly hydrophilic ones are best described by a positive projection of the interface dipole on the external field. The sign of the interface dipole is connected to the slope of the absorption coefficient with the solute concentration. A positive slope, implying an increase in the solution polarity relative to water, mirrors results frequently reported for protein solutions. We therefore use molecular dynamics simulations of hydrated glucose and lambda repressor protein to calculate the interface dipole moments of these solutes and the concentration dependence of the THz absorption. The absorption at THz frequencies increases with increasing solute concentration in both cases, implying a higher polarity of the solution compared to bulk water. The structure of the hydration layer, extracted from simulations, is qualitatively similar in both cases, with spatial correlations
Adsorption from solutions of non-electrolytes
Kipling, J J
1965-01-01
Adsorption from Solutions of Non-Electrolytes provides a general discussion of the subject, which has so far been given little or no attention in current textbooks of physical chemistry. A general view of the subject is particularly needed at a time when we wish to see how far it will be possible to use theories of solutions to explain the phenomena of adsorption. The book opens with an introductory chapter on the types of interface, aspects of adsorption from solution, types of adsorption, and classification of systems. This is followed by separate chapters on experimental methods, adsorption
Approximate solution for Fokker-Planck equation
Directory of Open Access Journals (Sweden)
M.T. Araujo
2015-12-01
Full Text Available In this paper, an approximate solution to a specific class of the Fokker-Planck equation is proposed. The solution is based on the relationship between the Schrödinger type equation with a partially confining and symmetrical potential. To estimate the accuracy of the solution, a function error obtained from the original Fokker-Planck equation is suggested. Two examples, a truncated harmonic potential and non-harmonic polynomial, are analyzed using the proposed method. For the truncated harmonic potential, the system behavior as a function of temperature is also discussed.
Pro SharePoint 2010 Solution Development
Hild, E
2010-01-01
This book takes a practical problem-solution approach to common business challenges. You'll not only encounter interesting code samples, but also see how to combine these examples with the Microsoft collaboration platform's services. The book's solutions focus on using Visual Studio 2008 and its built-in Office development tools to construct the user interface layer. And solutions can interact with SharePoint as a service provider, taking advantage of SharePoint's many collaboration features like document repositories, collaboration sites, and search functions. This book is unique because it s
Extended solutions for the biadjoint scalar field
De Smet, Pieter-Jan; White, Chris D.
2017-12-01
Biadjoint scalar field theories are increasingly important in the study of scattering amplitudes in various string and field theories. Recently, some first exact nonperturbative solutions of biadjoint scalar theory were presented, with a pure power-like form corresponding to isolated monopole-like objects located at the origin of space. In this paper, we find a novel family of extended solutions, involving non-trivial form factors that partially screen the divergent field at the origin. All previous solutions emerge as special cases.
Mechatronics ideas, challenges, solutions and applications
Kaliński, Krzysztof; Szewczyk, Roman; Kaliczyńska, Małgorzata
2016-01-01
This book presents recent advances and developments in control, automation, robotics, and measuring techniques. It presents contributions of top experts in the fields, focused on both theory and industrial practice. In particular the book is devoted to new ideas, challenges, solutions and applications of Mechatronics. The particular chapters present a deep analysis of a specific technical problem which is in general followed by a numerical analysis and simulation, and results of an implementation for the solution of a real world problem. The presented theoretical results, practical solutions and guidelines will be useful for both researchers working in the area of engineering sciences and for practitioners solving industrial problems. .
Removal of cadmium from acidic phosphatic solutions
Energy Technology Data Exchange (ETDEWEB)
Frankenfeld, K.; Brodt, P.; Eich, G.; Ruschke, P.
1985-01-08
The invention is concerned with a process of removing cadmium from acid, especially P/sub 2/O/sub 5/-containing solutions by liquid/liquid extraction with the aid of alkyl amine salts that are dissolved in an inert, organic solvent. The cadmium ions are removed from the acid, aqueous phase and are enriched in the organic phase. The cadmium-containing organic phase, subsequently, is re-extracted with an aqueous salt solution, with the cadmium ions migrating from the organic phase into the aqueous phase. The process is particularly suitable for extracting cadmium from concentrated, highly acid aqueous solutions.
Zhang, Zhizeng; Zhao, Zhao; Li, Yongtao
2016-06-01
This paper attempts to verify the correctness of the analytical displacement solution in transversely isotropic rock mass, and to determine the scope of its application. The analytical displacement solution of a circular tunnel in transversely isotropic rock mass was derived firstly. The analytical solution was compared with the numerical solution, which was carried out by FLAC3D software. The results show that the expression of the analytical displacement solution is correct, and the allowable engineering range is that the dip angle is less than 15 degrees.
HCl, KCl and KOH solvation resolved solute-solvent interactions and solution surface stress
Zhang, Xi; Xu, Yan; Zhou, Yong; Gong, Yinyan; Huang, Yongli; Sun, Chang Q.
2017-11-01
An incorporation of the hydrogen bond (O:Hsbnd O or HB) cooperativity notion, contact angle detection, and the differential phonon spectrometrics (DPS) has enabled us to gain refined information on the HCl, KCl and KOH solvation resolved solute-solvent molecular interactions and the solution surface stresses. Results show that ionic polarization stiffens the solvent Hsbnd O bond phonon from 3200 to 3480 cm-1 in the hydration shells. The HO- in alkaline solution, however, shares not only the same Hsbnd O phonon redshift of compressed water from 3200 to bonds of H2O surface featured at 3610 cm-1. Salt and alkaline solvation enhances the solution surface stress by K+ and Cl- ionic polarization. The excessive H+ proton in acid solution forms a H↔H anti-HB that depresses the solution surface stress, instead. The solute capability of transforming the fraction of the O:Hsbnd O bonds of the solvent matrix is featured by: fH = 0 and fx ∝ 1-exp(-C/C0) (x = HO-, K+ and Cl-) towards saturation. Exercises not only confirm the presence of the H↔H anti-HB point fragilization, the O:⇔:O super-HB point compression, and ionic polarization dominating the performance of the respective HCl, KOH, and KCl solutions, but also demonstrate the power of the DPS that enables high resolution of solute-solute-solvent interactions and correlation between HB relaxation and solution surface stress.
Sun, Xiang; Ladanyi, Branka M; Stratt, Richard M
2015-07-23
Experimental studies of solvation dynamics in liquids invariably ask how changing a solute from its electronic ground state to an electronically excited state affects a solution's dynamics. With traditional time-dependent-fluorescence experiments, that means looking for the dynamical consequences of the concomitant change in solute-solvent potential energy. But if one follows the shift in the dynamics through its effects on the macroscopic polarizability, as recent solute-pump/solvent-probe spectra do, there is another effect of the electronic excitation that should be considered: the jump in the solute's own polarizability. We examine the spectroscopic consequences of this solute polarizability change in the classic example of the solvation dye coumarin 153 dissolved in acetonitrile. After demonstrating that standard quantum chemical methods can be used to construct accurate multisite models for the polarizabilities of ground- and excited-state solvation dyes, we show via simulation that this polarizability change acts as a contrast agent, significantly enhancing the observable differences in optical-Kerr spectra between ground- and excited-state solutions. A comparison of our results with experimental solute-pump/solvent-probe spectra supports our interpretation and modeling of this spectroscopy. We predict, in particular, that solute-pump/solvent-probe spectra should be sensitive to changes in both the solvent dynamics near the solute and the electronic-state-dependence of the solute's own rotational dynamics.
Jawor-Baczynska, Anna; Moore, Barry D; Lee, Han Seung; McCormick, Alon V; Sefcik, Jan
2013-01-01
Aqueous solutions of highly soluble substances such as small amino acids are usually assumed to be essentially homogenous systems with some degree of short range local structuring due to specific interactions on the sub-nanometre scale (e.g. molecular clusters, hydration shells), usually not exceeding several solute molecules. However, recent theoretical and experimental studies have indicated the presence of much larger supramolecular assemblies or mesospecies in solutions of small organic and inorganic molecules as well as proteins. We investigated both supersaturated and undersaturated aqueous solutions of two simple amino acids (glycine and DL-alanine) using Dynamic Light Scattering (DLS), Brownian Microscopy/Nanoparticles Tracking Analysis (NTA) and Cryogenic Transmission Electron Microscopy (Cryo-TEM). Colloidal scale mesospecies (nanodroplets) were previously reported in supersaturated solutions of these amino acids and were implicated as intermediate species on non-classical crystallization pathways. Surprisingly, we have found that the mesospecies are also present in significant numbers in undersaturated solutions even when the solute concentration is well below the solid-liquid equilibrium concentration (saturation limit). Thus, mesopecies can be observed with mean diameters ranging from 100 to 300 nm and a size distribution that broadens towards larger size with increasing solute concentration. We note that the mesospecies are not a separate phase and the system is better described as a thermodynamically stable mesostructured liquid containing solute-rich domains dispersed within bulk solute solution. At a given temperature, solute molecules in such a mesostructured liquid phase are subject to equilibrium distribution between solute-rich mesospecies and the surrounding bulk solution.
Considerations Regarding Designing and Administrating SOA Solutions
Directory of Open Access Journals (Sweden)
Vlad DIACONITA
2011-06-01
Full Text Available Solutions like SOA, Cloud, SaaS, Iaas or PaaS are not only buzzwords, they became a business reality because they are relative cheap and easy to use. SOA and Cloud are tightly linked because most cloud solutions are being defined using SOA making them feasible from the business perspective, because it’s hard to move to cloud when you are using a tightly coupled architecture. Big companies such as Oracle, Microsoft, IBM or Amazon offer many commercial solutions providing software as a service, as well as hosted and managed alternatives to classical deployment. For firms that are building private clouds and for service providers that are building public clouds, diverse solutions are offered by the big players for platform as a service and infrastructure as a service.
Periodic Solution of the Hematopoiesis Equation
Directory of Open Access Journals (Sweden)
Ji-Huan He
2013-01-01
Full Text Available Wu and Liu (2012 presented some results for the existence and uniqueness of the periodic solutions for the hematopoiesis model. This paper gives a simple approach to find an approximate period of the model.
Multimodal Solutions for Large Scale Evacuation
2009-12-30
In this research, a multimodal transportation model was developed attending the needs of emergency situations, and the solutions provided by the model could be used to moderate congestion during such events. The model incorporated features such as la...
Multimodal solutions for large scale evacuations.
2009-12-30
In this research, a multimodal transportation model was developed attending the needs of emergency situations, : and the solutions provided by the model could be used to moderate congestion during such events. : The model incorporated features such a...
On oscillatory solutions of certain difference equations
Directory of Open Access Journals (Sweden)
Grzegorz Grzegorczyk
2006-01-01
Full Text Available Some difference equations with deviating arguments are discussed in the context of the oscillation problem. The aim of this paper is to present the sufficient conditions for oscillation of solutions of the equations discussed.
Database of magnetochemistry in solutions (abstract)
Tarasov, O. Ju.; Vinogradov, A. G.
1994-05-01
The database (DB) of magnetochemistry in solutions was created to systematize and to critically review data of the magnetic susceptibility of liquids, solutions, and substances in solutions. The database ``MagChemSol 1.0'' was made on a mfoxplus base and may be supported by dbaseiii plus or higher. Search fields include substances, solvent, condition and method of investigation, critical magnetochemistry characteristics, and references to literature. All material is printable and the database can change and expand itself. System requirements include IBM PC or compatible with 640 Kb of RAM, 5 in. and 3 in. diskette drive or hard-disk, and dos 3.30 or higher; printers are Epson or compatible. The DB ``MagChemSol 1.0'' version includes about 1000 data entries according to the magnetochemical properties, the majority solvents in general use some diamagnetic and paramagnetic salts, and also the complex compounds of d and f elements in the solutions.
Cosmological solutions with charged black holes
Bibi, Rashida; Clifton, Timothy; Durk, Jessie
2017-07-01
We consider the problem of constructing cosmological solutions of the Einstein-Maxwell equations that contain multiple charged black holes. By considering the field equations as a set of constraint and evolution equations, we construct exact initial data for N charged black holes on a hypersphere. This corresponds to the maximum of expansion of a cosmological solution, and provides sufficient information for a unique evolution. We then consider the specific example of a universe that contains eight charged black holes, and show that the existence of non-zero electric charge reduces the scale of the cosmological region of the space. These solutions generalize the Majumdar-Papapetrou solutions away from the extremal limit of charged black holes, and provide what we believe to be some of the first relativistic calculations of the effects of electric charge on cosmological backreaction.
Dynamic Selection Screen Generation for SAP Solutions
National Research Council Canada - National Science Library
Cornelia Muntean
2017-01-01
This paper presents an application for generating a dynamic selection screen in ABAP and the need and advantages of this solution instead of the manual modification of the coding itself for adding one...
Mixing, entropy and reactive solute transport
Chiogna, Gabriele; Hochstetler, David L.; Bellin, Alberto; Kitanidis, Peter K.; Rolle, Massimo
2012-10-01
Mixing processes significantly affect reactive solute transport in fluids. For example, contaminant degradation in environmental aquatic systems can be limited either by the availability of one or more reactants, brought into contact by physical mixing, or by the kinetics of the (bio)chemical transformations. Appropriate metrics are needed to accurately quantify the interplay between mixing and reactive processes. The exponential of the Shannon entropy of the concentration probability distribution has been proposed and applied to quantify the dilution of conservative solutes either in a given volume (dilution index) or in a given water flux (flux-related dilution index). In this work we derive the transport equation for the entropy of a reactive solute. Adopting a flux-related framework, we show that the degree of uniformity of the solute mass flux distribution for a reactive species and its rate of change are informative measures of physical and (bio)chemical processes and their complex interaction.
Coordination chemistry in fused-salt solutions
Gruen, D. M.
1969-01-01
Spectrophotometric work on structural determinations with fused-salt solutions is reviewed. Constraints placed on the method, as well as interpretation of the spectra, are discussed with parallels drawn to aqueous spectrophotometric curves of the same materials.
Exercises and solutions in statistical theory
Kupper, Lawrence L; O'Brien, Sean M
2013-01-01
""I have found the book useful in preparing homework and exam questions in my current course, and I could see students benefiting from such a trove of problems with solutions.""-The American Statistician, February 2015
International young physicists' tournament problems & solutions 2014
Gao, Wenli
2016-01-01
International Young Physicists' Tournament (Iypt), is one of the most prestigious international physics contests among high school students. This book is based on the solutions of 2014 Iypt problems. The authors are undergraduate students who participated in the Cupt (Chinese Undergraduate Physics Tournament). It is intended as a college level solution to the challenging open-ended problems. It provides original, quantitative solutions in fulfilling seemingly impossible tasks. This book is not limited to the tasks required by the problems and it is not confined to the models and methods in present literatures. Many of the articles include modification and extension to existing models in references, or derivation and computation based on fundamental physics. This book provides quantitative solutions to practical problems in everyday life. This is a good reference book for undergraduates, advanced high-school students, physics educators and curious public interested in the intriguing phenomena in daily life.
An approximation of solutions of variational inequalities
Directory of Open Access Journals (Sweden)
B. E. Rhoades
2005-10-01
Full Text Available We use a Mann-type iteration scheme and the metric projection operator (the nearest-point projection operator to approximate the solutions of variational inequalities in uniformly convex and uniformly smooth Banach spaces.
Rayco Development Solutions, Inc. Information Sheet
Rayco Development Solutions, Inc. (the Company) is located in Hayward, California. The settlement involves renovation activities conducted at property constructed prior to 1978, located in several cities in California.
Calorimetric studies of macromolecular aqueous solutions
Blandamer, M.J; Cullis, P.M.; Engberts, J.B.F.N.
Both titration and differential scanning microcalorimetric techniques are shown to yield important information concerning the properties of macromolecules in aqueous solution. Application of titration calorimetry is examined in me context of deaggregation of canonic micelles (e.g.
DNA nanopore translocation in glutamate solutions
Plesa, C.; Van Loo, N.; Dekker, C.
2015-01-01
Nanopore experiments have traditionally been carried out with chloride-based solutions. Here we introduce silver/silver-glutamate-based electrochemistry as an alternative, and study the viscosity, conductivity, and nanopore translocation characteristics of potassium-, sodium-, and lithium-glutamate
Aggregation of sodium alkylbenzenesulfonates in aqueous solution
Energy Technology Data Exchange (ETDEWEB)
Magid, L.J.; Shaver, R.J.; Gulari, E.; Bedwell, B.; Alkhafaji, S.
1981-01-01
The surfactant 6 phenyl C/sub 12/SNa forms small spherical micelles in aqueous solution, having an aggregation number of 20 to 30 and a fractional charge of 0.45. These micelles are hydrated to the extent of approximately 18 moles H/sub 2/O per moles of surfactant. A second larger aggregate is also present in 6 phenyl C/sub 12/SNa solutions; its importance increases with solution age. Addition of NaCl causes both aggregates to apparently increase modestly in size. The surfactant 8 phenyl C/sub 16/SNa also contains both aggregates in its solutions; the larger one is relatively more important here. The larger aggregate does not correspond to dispersed bits of a liquid crystalline mesophase.
Numerical and approximate solutions for plume rise
Krishnamurthy, Ramesh; Gordon Hall, J.
Numerical and approximate analytical solutions are compared for turbulent plume rise in a crosswind. The numerical solutions were calculated using the plume rise model of Hoult, Fay and Forney (1969, J. Air Pollut. Control Ass.19, 585-590), over a wide range of pertinent parameters. Some wind shear and elevated inversion effects are included. The numerical solutions are seen to agree with the approximate solutions over a fairly wide range of the parameters. For the conditions considered in the study, wind shear effects are seen to be quite small. A limited study was made of the penetration of elevated inversions by plumes. The results indicate the adequacy of a simple criterion proposed by Briggs (1969, AEC Critical Review Series, USAEC Division of Technical Information extension, Oak Ridge, Tennesse).
Generating geodesic flows and supergravity solutions
Energy Technology Data Exchange (ETDEWEB)
Bergshoeff, E. [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)], E-mail: e.a.bergshoeff@rug.nl; Chemissany, W. [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)], E-mail: w.chemissany@rug.nl; Ploegh, A. [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)], E-mail: a.r.ploegh@rug.nl; Trigiante, M. [Dipartimento di Fisica Politecnico di Torino, C.so Duca degli Abruzzi, 24, I-10129 Torino (Italy)], E-mail: mario.trigiante@polito.it; Van Riet, T. [Institute for Theoretical Physics, K.U. Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Departamento de Fisica Teorica y del Cosmos and Centro Andaluz de Fisica de Particulas Elementales, Universidad de Granada, 18071 Granada (Spain)], E-mail: thomasvr@itf.fys.kuleuven.ac.be
2009-05-11
We consider the geodesic motion on the symmetric moduli spaces that arise after timelike and spacelike reductions of supergravity theories. The geodesics correspond to timelike respectively spacelike p-brane solutions when they are lifted over a p-dimensional flat space. In particular, we consider the problem of constructing the minimal generating solution: A geodesic with the minimal number of free parameters such that all other geodesics are generated through isometries. We give an intrinsic characterization of this solution in a wide class of orbits for various supergravities in different dimensions. We apply our method to three cases: (i) Einstein vacuum solutions, (ii) extreme and non-extreme D=4 black holes in N=8 supergravity and their relation to N=2 STU black holes and (iii) Euclidean wormholes in D{>=}3. In case (iii) we present an easy and general criterium for the existence of regular wormholes for a given scalar coset.
Fashion design solutions for environmentally conscious consumers
Wagner, M.; Chen, Y.; Curteza, A.; Thomassey, S.; Perwuelz, A.; Zeng, X.
2017-10-01
This paper intends to give an overview of the design solutions in fashion for environmentally conscious consumers, presenting green and ethical practices in contemporary clothing design. The results introduce the concept of slow fashion and discuss available fashion design solutions, giving most prominent examples of sustainable products and brands, these contain one or more design features. By this, the discussion extracts the main contemporary ideas. The presented examples of current offers are all envisioning less impact on the environment and society. Sustainable design solutions use more environmentally friendly materials such as organic cotton, incorporate circular design or design for recycling, e.g., replacing button closures with alternative closing possibilities or leather labels with printed versions, or ensure long product life through durability, among other methods. There are differing designs due to creators’ individuality. This overview can be beneficial for the future development of new solutions for more environmentally friendly fashion.
Renewable energy integration challenges and solutions
Hossain, Jahangir
2014-01-01
This book examines challenges involved in the integration of renewable energy into existing electricity grids. It provides models of power systems to show how the integration will effect conventional grids and various solutions to minimize the impacts.
Remediation of Aqueous Solution of Cypermethrin and ...
African Journals Online (AJOL)
ADOWIE PERE
288. Okeola, OF; Odebunmi EO; Ameen OM; Adebayo. GB (2011). “Adsorption of Iron (III) ion. Aqueous Solution Using Jatrophacurcas Seed. Coat Activated Carbon”, Proceedings of the 34th. Annual International Conference of the Chemical.
An approximation of solutions of variational inequalities
Directory of Open Access Journals (Sweden)
Rhoades BE
2005-01-01
Full Text Available We use a Mann-type iteration scheme and the metric projection operator (the nearest-point projection operator to approximate the solutions of variational inequalities in uniformly convex and uniformly smooth Banach spaces.
Mean-field learning for satisfactory solutions
Tembine, Hamidou
2013-12-01
One of the fundamental challenges in distributed interactive systems is to design efficient, accurate, and fair solutions. In such systems, a satisfactory solution is an innovative approach that aims to provide all players with a satisfactory payoff anytime and anywhere. In this paper we study fully distributed learning schemes for satisfactory solutions in games with continuous action space. Considering games where the payoff function depends only on own-action and an aggregate term, we show that the complexity of learning systems can be significantly reduced, leading to the so-called mean-field learning. We provide sufficient conditions for convergence to a satisfactory solution and we give explicit convergence time bounds. Then, several acceleration techniques are used in order to improve the convergence rate. We illustrate numerically the proposed mean-field learning schemes for quality-of-service management in communication networks. © 2013 IEEE.
Quantum corrections for a cosmological string solution
Energy Technology Data Exchange (ETDEWEB)
Behrndt, K.
1994-08-01
The author investigates quantum corrections for a cosmological solution of the string effective action. Starting point is a classical solution containing an antisymmetric tensor field, a dilaton and a modulus field which has singularities in the scalar fields. As a first step he quantizes the scalar fields near the singularity with the result that the singularities disappear and that in general non-perturbative quantum corrections form a potential in the scalar fields.
Cusped Bubbles Rising through Polyelectrolyte Solutions
Belmonte, Andrew; Sostarecz, Michael
2000-11-01
It is well known that a bubble rising in a polymer fluid can have a cusp-like tail. We report on an experimental study of bubbles rising through solutions of glycerol/water with the addition of the polymer xanthan gum, a polyelectrolyte which becomes more rigid as the free ion concentration is increased. The addition of salt also decreases the elasticity of the xanthan gum solutions, and we observe its effects on the velocity and shape of the cusped bubble.
New generalized nonspherical black hole solutions
Kleihaus, Burkhard; Radu, Eugen; Rodriguez, Maria J
2010-01-01
We present numerical evidence for the existence of several types of static black hole solutions with a nonspherical event horizon topology in $d\\geq 6$ spacetime dimensions. These asymptotically flat configurations are found for a specific metric ansatz and can be viewed as higher dimensional counterparts of the $d=5$ static black rings, dirings and black Saturn. Similar to that case, they are supported against collapse by conical singularities. The issue of rotating generalizations of these solutions is also considered.
Missing solution in a Cornell potential
Energy Technology Data Exchange (ETDEWEB)
Castro, L.B., E-mail: luis.castro@pgfsc.ufsc.br [Departamento de Física, CFM, Universidade Federal de Santa Catarina, 88040-900, Florianópolis - SC (Brazil); Castro, A.S. de, E-mail: castro@pq.cnpq.br [Departamento de Física e Química, Campus de Guaratinguetá, Universidade Estadual Paulista, 12516-410, Guaratinguetá - SP (Brazil)
2013-11-15
Missing bound-state solutions for fermions in the background of a Cornell potential consisting of a mixed scalar–vector–pseudoscalar coupling is examined. Charge-conjugation operation, degeneracy and localization are discussed. -- Highlights: •The Dirac equation with scalar–vector–pseudoscalar Cornell potential is investigated. •The isolated solution from the Sturm–Liouville problem is found. •Charge-conjugation operation, degeneracy and localization are discussed.
A solution defined by fine vectors
Xu, G.; Sun, H.; Sun, H.; Hoede, C.; Driessen, Theo
Bumb and Hoede have shown that a cooperative game can be split into two games, the reward game and the fine game, by considering the sign of quantities $c_v^S$ in the c-diagram of the game. One can then define a solution $x$ for the original game as $x = x_r - x_f$ , where $x_r$ is a solution for
Piecewise polynomial solutions to linear inverse problems
DEFF Research Database (Denmark)
Hansen, Per Christian; Mosegaard, K.
1996-01-01
We have presented a new algorithm PP-TSVD that computes piecewise polynomial solutions to ill-posed problems, without a priori knowledge about the positions of the break points. In particular, we can compute piecewise constant functions that describe layered models. Such solutions are useful, e.g.......g., in seismological problems, and the algorithm can also be used as a preprocessor for other methods where break points/discontinuities must be incorporated explicitly....