Powered by Deep Web Technologies
Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Gravity and magnetic data of Midway Valley, southwest Nevada  

SciTech Connect (OSTI)

Detailed gravity and ground magnetic data collected along five traverses across Midway Valley on the eastern flank of Yucca Mountain in southwest Nevada are described. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley.

Ponce, D.A.; Langenheim, V.E.; Sikora, R.F. [Geological Survey, Menlo Park, CA (United States)

1993-12-31T23:59:59.000Z

2

Gravity and magnetic anomalies and the deep structure of the Parnaiba cratonic basin, Brazil  

E-Print Network [OSTI]

Gravity and magnetic anomalies and the deep structure of the Parnaiba cratonic basin, Brazil A. B profile across the Parnaiba cratonic basin in NorthEast Brazil. The purpose of this project is to acquire margin of Parnaíba Basin, Brazil. Geophysics 64: 337-356. Ussami N, Cogo de Sa N, Molina EC. 1993

Watts, A. B. "Tony"

3

Preliminary gravity and magnetic models across Midway Valley and Yucca Wash, Yucca Mountain, Nevada  

SciTech Connect (OSTI)

Detailed gravity and ground magnetic data collected along ten traverses across Midway Valley and Yucca Wash on the eastern flank of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley. Gravity and magnetic data across the northwest trending Yucca Wash and the inferred Yucca Wash fault indicate no major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm{sup 3} along the proposed Yucca Wash fault. In addition, a broad magnetic high coincides with the approximate location of the hydrologic gradient and probably reflects moderately magnetic Topopah Spring Tuff or lavas in the Calico Hills Formation.

Ponce, D.A.; Langenheim, V.E.

1994-12-31T23:59:59.000Z

4

Magnetized black holes and black rings in the higher dimensional dilaton gravity  

E-Print Network [OSTI]

In this paper we consider magnetized black holes and black rings in the higher dimensional dilaton gravity. Our study is based on exact solutions generated by applying a Harrison transformation to known asymptotically flat black hole and black ring solutions in higher dimensional spacetimes. The explicit solutions include the magnetized version of the higher dimensional Schwarzschild-Tangherlini black holes, Myers-Perry black holes and five dimensional (dipole) black rings. The basic physical quantities of the magnetized objects are calculated. We also discuss some properties of the solutions and their thermodynamics. The ultrarelativistic limits of the magnetized solutions are briefly discussed and an explicit example is given for the $D$-dimensional magnetized Schwarzschild-Tangherlini black holes.

Stoytcho S. Yazadjiev

2005-11-21T23:59:59.000Z

5

Crustal structure of Guadeloupe Islands and the Lesser Antilles Arc from a new gravity and magnetic synthesis  

E-Print Network [OSTI]

the compilation and processing of available, on-land, airborne and marine, gravity and magnetic data acquired is associated with formations consistent with the low measured density and the underlying hydrothermal system

Paris-Sud XI, Université de

6

On the influence of a magnetic field with circular field lines on the gravity flow of a magnetic fluid film down a thin cylinder  

Science Journals Connector (OSTI)

The gravity-induced flow of a magnetic fluid film down a vertical thin current-carrying cylindrical conductor is considered. The relative thickness of the film is small. A nonlinear equation is derived from a ...

V. M. Korovin

2009-10-01T23:59:59.000Z

7

API Gravity  

Science Journals Connector (OSTI)

n Measure of specific gravity of petroleum and petroleum products, defined by the following equation: $$\\eqalign{{\\rm{API\\,\\,Gravity,\\,\\,degrees }}...

Jan W. Gooch

2011-01-01T23:59:59.000Z

8

Application of magnetic amplitude inversion in exploration for natural gas in volcanics Yaoguo Li, Center for Gravity, Electrical, and Magnetic Studies, Colorado School of Mines  

E-Print Network [OSTI]

Application of magnetic amplitude inversion in exploration for natural gas in volcanics Yaoguo Li basins and have strong remanent magnetization. The appli- cation arises in exploration of natural gas identify the volcanic units at large depths. INTRODUCTION Exploration for natural gas hosted in volcanics

9

Magnetism  

Science Journals Connector (OSTI)

Historically, magnetism is related to rock magnetism, due to a few minerals exhibiting spontaneous magnetization. Attractive properties of magnetite were already known in Antiquity and were used for navigation...

Guillaume Morin

1998-01-01T23:59:59.000Z

10

magnetism  

Science Journals Connector (OSTI)

magnetism [A class of physical phenomena associated with moving electricity, including the mutual mechanical forces among magnets and electric currents] ? Magnetismus m

2014-08-01T23:59:59.000Z

11

Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski...  

Open Energy Info (EERE)

geologically mapped the target area, obtained rock samples for age dating and mineral chemistry, performed gravity and magnetic surveys, and integrated these results to identify...

12

API gravity  

Science Journals Connector (OSTI)

API gravity [The standard American Petroleum Institute method for specifying the density of crude petroleum. The density in degrees API is 141.5/P 131.5...] ? (Roh)ldichte f in API-Graden

2014-08-01T23:59:59.000Z

13

Magnetism  

Science Journals Connector (OSTI)

... dipoles in applied fields". It deals with the classical (Langevin) theory of para-magnetism, anisotropy fields and magnetic measurements. In the next chapter "Atomic structure" the author ... special relevance to ferrites and the inclusion of a quite lengthy discussion of Pauli para-magnetism and of Stoner's treatment of itinerant electron ferromagnetism, though it does much to ...

E. W. LEE

1972-03-31T23:59:59.000Z

14

Magnetism  

Science Journals Connector (OSTI)

... THIS is a good book, and we are glad to see the subject of magnetism fully treated in a popularly written text-book. It is a second edition of ... of importance, accuracy, and exhaustiveness, places the present treatise, as far as terrestrial magnetism is concerned, much before any similar book with which we are acquainted. The correction ...

JAMES STUART

1872-03-07T23:59:59.000Z

15

Quantum Field Theory & Gravity  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Field Theory & Gravity Quantum Field Theory & Gravity Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email...

16

magnets  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

I I Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

17

Magnetic Levitation System The following figure shows the cross section of a magnetic levitation (MAGLEV) train.  

E-Print Network [OSTI]

Magnetic Levitation System The following figure shows the cross section of a magnetic levitation in matched pairs. The magnetic attraction of the vertically paired magnets balances the force of gravity and levitates the vehicle above the guideway. d h z Train Track Magnets Fixed Reference Line Magnets

Hagan, Martin

18

Aeromagnetic and gravity surveys in the Coso Range, California | Open  

Open Energy Info (EERE)

and gravity surveys in the Coso Range, California and gravity surveys in the Coso Range, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Aeromagnetic and gravity surveys in the Coso Range, California Details Activities (2) Areas (1) Regions (0) Abstract: The effect of an underlying magma reservoir cannot be identified within the complex gravity pattern in the Coso Range, California. Rather, linear gravity contours, which suggest a regional tectonic origin, enclose the location of most of the volcanic activity of the Coso Range. Faults along the edges of northwest trending, magnetic blocks probably provided paths of minimum resistance to the ascending viscous magma that was extruded as rhyolite domes. Dense, magnetic rocks associated with a complex mafic pluton 9 km in diameter form a relatively impermeable north border of

19

The Universe Adventure - Gravity  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Gravity: The Main Attraction Gravity: The Main Attraction Gravity Acts on All Matter Gravity's effect is apparent even at the largest scales: just as gravity keeps the Earth orbiting the sun, it holds these two irregular galaxies M32 and M110 in orbit around the larger Andromeda galaxy. In the late 1600s, the English mathematician Sir Isaac Newton gave the first scientific description of gravitation. Gravity is an attractive force existing between any two objects that have mass, causing them to accelerate towards each other. It is the weakest of the four fundamental forces but can act over great distances and is responsible for the formation of planets, stars, galaxies, and even larger scale structures such as groups and superclusters. Gravity is also the force that governs the motion of

20

Gravity Train Project  

E-Print Network [OSTI]

Dec 7, 2013 ... Gravity Train Project. Same page in Romanian, Polish, and in French. Let us drill a straight tunnel from West Lafayette, IN to Paris, France:.

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Counterterms in Lovelock Gravity  

E-Print Network [OSTI]

In this paper, we introduce the counterterms that remove the non-logarithmic divergences of the action in third order Lovelock gravity. We do this by defining the cosmological constant in such a way that the asymptotic form of the metric have the same form in Lovelock and Einstein gravities. Thus, we employ the counterterms of Einstein gravity and show that the power law divergences in the action of Lovelock gravity can be removed by suitable choice of coefficients. We find that the dependence of these coefficients on the dimension in Lovelock gravity is the same as in Einstein gravity. We also introduce the finite energy-momentum tensor and employ these counterterms to calculate the finite action and mass of the black hole solutions of third order Lovelock gravity. We calculate the thermodynamic quantities and show that the entropy calculated through the use of Gibbs-Duhem relation is consistent with the obtained entropy by Wald's formula. We, also, find that in contrast to Einstein gravity in which there ex...

Mehdizadeh, M R; Zangeneh, M Kord

2015-01-01T23:59:59.000Z

22

Gravity perturbed Crapper waves  

Science Journals Connector (OSTI)

...waves are known to have multi-valued height. Using...gravity-capillary waves with multi-valued height. The...of single-valued and multi-valued travelling waves...absence of gravity, a family of exact solutions is...elliptic functions. Building upon the work by Tanveer...

2014-01-01T23:59:59.000Z

23

Selection Rules for the Nonlinear Interactions of Internal Gravity Waves and Inertia-Gravity Waves  

E-Print Network [OSTI]

Internal Gravity Waves . . . . . . . . . . . . . . 3.2.1 Twodimensional inertia-gravity wave physics . . . . . . . . .Three dimensional inertia-gravity wave physics . . . . . .

Jiang, Chung-Hsiang

2010-01-01T23:59:59.000Z

24

MagLab - Pioneers in Electricity and Magnetism: Roland Etvs  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

work involving gravity, but who also made significant studies of capillarity and magnetism. He employed an instrument of his own design commonly referred to as the Etvs...

25

Ground Magnetics At San Francisco Volcanic Field Area (Warpinski...  

Open Energy Info (EERE)

geologically mapped the target area, obtained rock samples for age dating and mineral chemistry, performed gravity and magnetic surveys, and integrated these results to identify...

26

Modifications of gravity  

Science Journals Connector (OSTI)

...requirement of cold dark matter (CDM...gravity|cosmology|dark energy| 1. Introduction...cosmology). The discovery that the expansion...the form of cold dark matter (CDM...and perhaps dark energy (DE) [22-26...

2011-01-01T23:59:59.000Z

27

Purely affine Gravity  

E-Print Network [OSTI]

We develop a topological theory of gravity with torsion where metric has a dynamical rather than a kinematical origin. This approach towards gravity resembles pre-geometrical approaches in which a fundamental metric does not exist, but the affine connection gives place to a local inertial structure. Such feature reminds us of Mach's principle, that assumes the inertial forces should have dynamical origin. Additionally, a Newtonian gravitational force is obtained in the non-relativistic limit of the theory.

Skirzewski, Aureliano

2014-01-01T23:59:59.000Z

28

Purely affine Gravity  

E-Print Network [OSTI]

We develop a topological theory of gravity with torsion where metric has a dynamical rather than a kinematical origin. This approach towards gravity resembles pre-geometrical approaches in which a fundamental metric does not exist, but the affine connection gives place to a local inertial structure. Such feature reminds us of Mach's principle, that assumes the inertial forces should have dynamical origin. Additionally, a Newtonian gravitational force is obtained in the non-relativistic limit of the theory.

Aureliano Skirzewski; Oscar Castillo-Felisola

2014-10-22T23:59:59.000Z

29

Ground Gravity Survey At Mokapu Penninsula Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

Ground Gravity Survey At Mokapu Penninsula Area Ground Gravity Survey At Mokapu Penninsula Area (Thomas, 1986) Exploration Activity Details Location Mokapu Penninsula Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes A separate geophysical analysis performed on the Koolau caldera area (Kauahikaua, 1981 a) synthesized existing self-potential, gravity, seismic and aeromagnetic data with recently acquired resistivity soundings. An analysis of the observed remnant magnetization within the caldera complex suggested that subsurface temperatures ranged from less than 300degrees C to no more than 540degrees C. The resistivity data indicated that the electrical basement, to a depth of 900 m, had resistivities ranging from 42 ohm.m to more than 1000 ohm.m, which is considered to be within the

30

Glossary API Gravity: An  

Gasoline and Diesel Fuel Update (EIA)

5 60 60 131 5 . . The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation Gasoline (Finished): A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in aviation reciprocating engines. Fuel specifi- cations are provided in ASTM Specification D 910 and Military Specification MIL-G-5572. Note: Data on blending components are not counted in data on fin- ished aviation gasoline. Barrel: A volumetric unit of measure for crude oil and petroleum products equivalent to 42 U.S. gallons. Bulk Sales: Wholesale sales of gasoline in individual

31

Glossary API Gravity: An  

Gasoline and Diesel Fuel Update (EIA)

60 60 1315 . . The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation Gasoline (Finished): A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in aviation reciprocating engines. Fuel specifi- cations are provided in ASTM Specification D 910 and Military Specification MIL-G-5572. Note: Data on blending components are not counted in data on fin- ished aviation gasoline. Barrel: A volumetric unit of measure for crude oil and petroleum products equivalent to 42 U.S. gallons. Bulk Sales: Wholesale sales of gasoline in individual

32

Resummation of Massive Gravity  

SciTech Connect (OSTI)

We construct four-dimensional covariant nonlinear theories of massive gravity which are ghost-free in the decoupling limit to all orders. These theories resume explicitly all the nonlinear terms of an effective field theory of massive gravity. We show that away from the decoupling limit the Hamiltonian constraint is maintained at least up to and including quartic order in nonlinearities, hence excluding the possibility of the Boulware-Deser ghost up to this order. We also show that the same remains true to all orders in a similar toy model.

Rham, Claudia de [Department de Physique Theorique, Universite de Geneve, 24 Quai E. Ansermet, CH-1211 Geneve (Switzerland); Gabadadze, Gregory [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York 10003 (United States); Tolley, Andrew J. [Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)

2011-06-10T23:59:59.000Z

33

Phenomenological Quantum Gravity  

E-Print Network [OSTI]

Planck scale physics represents a future challenge, located between particle physics and general relativity. The Planck scale marks a threshold beyond which the old description of spacetime breaks down and conceptually new phenomena must appear. In the last years, increased efforts have been made to examine the phenomenology of quantum gravity, even if the full theory is still unknown.

S. Hossenfelder

2006-11-01T23:59:59.000Z

34

Modified Theories of Gravity  

E-Print Network [OSTI]

The recent observational data in cosmology seem to indicate that the universe is currently expanding in an accelerated way. An intriguing interpretation of these data is that they may just be signalling that Einstein's General Relativity is not the correct description of gravity when we consider distances of the order of the present horizon of the universe. In this thesis we consider two models which modify General Relativity at very large distances, the Cascading DGP and the dRGT massive gravity, and investigate their phenomenological viability. We start with a general introduction to standard cosmology and we introduce the late time acceleration problem and the cosmological constant problem. We then provide a pedagogical introduction to the DGP model, of which the Cascading DGP is an extension, and to the dRGT massive gravity. Concerning the Cascading DGP, we show that the thin limit of the 4D brane inside the (already thin) 5D brane is well defined, at least for the class of configurations that we consider, and confirm that gravity is regularized in these set-ups. We give a geometrical interpretation of the presence of the critical tension, and comment on the difference between the results in the literature and our results, which we support with a numerical calculation. Regarding the dRGT massive gravity, we focus on the branch of solutions in which the Vainshtein mechanism can occur. We determine analytically the number and properties of local solutions which exist asymptotically on large scales (but still below the gravitational Compton wavelength), and of local (inner) solutions which exist on small scales. We characterize exactly the properties of global solutions in every point of the phase space, and characterize precisely in which regions the Vainshtein mechanism takes place. We also provide numerical solutions which confirm our analysis.

Fulvio Sbisa'

2014-07-09T23:59:59.000Z

35

Viscosity in modified gravity  

E-Print Network [OSTI]

A bulk viscosity is introduced in the formalism of modified gravity. It is shown that, on the basis of a natural scaling law for the viscosity, a simple solution can be found for quantities such as the Hubble parameter and the energy density. These solutions may incorporate a viscosity-induced Big Rip singularity. By introducing a phase transition in the cosmic fluid, the future singularity can nevertheless in principle be avoided.

Iver Brevik

2012-11-12T23:59:59.000Z

36

Unimodular Gravity and Averaging  

E-Print Network [OSTI]

The question of the averaging of inhomogeneous spacetimes in cosmology is important for the correct interpretation of cosmological data. In this paper we suggest a conceptually simpler approach to averaging in cosmology based on the averaging of scalars within unimodular gravity. As an illustration, we consider the example of an exact spherically symmetric dust model, and show that within this approach averaging introduces correlations (corrections) to the effective dynamical evolution equation in the form of a spatial curvature term.

A. Coley; J. Brannlund; J. Latta

2011-02-16T23:59:59.000Z

37

Gravity, Dimension, Equilibrium, & Thermodynamics  

E-Print Network [OSTI]

Is it actually possible to interpret gravitation as space's property in a pure classical way. Then, we note that extended self-gravitating system equilibrium depends directly on the number of dimension of the space in which it evolves. Given those precisions, we review the principal thermodynamical knowledge in the context of classical gravity with arbitrary dimension of space. Stability analyses for bounded 3D systems, namely the Antonov instability paradigm, are then rapproched to some amazing properties of globular clusters and galaxies.

Jerome Perez

2006-03-30T23:59:59.000Z

38

Modified Theories of Gravity  

E-Print Network [OSTI]

The recent observational data in cosmology seem to indicate that the universe is currently expanding in an accelerated way. An intriguing interpretation of these data is that they may just be signalling that Einstein's General Relativity is not the correct description of gravity when we consider distances of the order of the present horizon of the universe. In this thesis we consider two models which modify General Relativity at very large distances, the Cascading DGP and the dRGT massive gravity, and investigate their phenomenological viability. We start with a general introduction to standard cosmology and we introduce the late time acceleration problem and the cosmological constant problem. We then provide a pedagogical introduction to the DGP model, of which the Cascading DGP is an extension, and to the dRGT massive gravity. Concerning the Cascading DGP, we show that the thin limit of the 4D brane inside the (already thin) 5D brane is well defined, at least for the class of configurations that we consider...

Sbis, Fulvio

2014-01-01T23:59:59.000Z

39

Gravity Methods | Open Energy Information  

Open Energy Info (EERE)

Gravity Methods Gravity Methods Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gravity Methods Details Activities (0) Areas (0) Regions (0) NEPA(3) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Gravity Methods: No definition has been provided for this term. Add a Definition References No exploration activities found. Document # Analysis Type Applicant Geothermal Area Lead Agency District Office Field Office Mineral Manager Surface Manager Development Phase(s) Techniques NVN-084630 CU Vulcan Energy Patua Geothermal Area BLM Nevada State Office BLM Winnemucca District Office BLM Humboldt River Field Office BLM BLM Geothermal/Exploration Gravity Methods

40

Geometric scalar theory of gravity  

SciTech Connect (OSTI)

We present a geometric scalar theory of gravity. Our proposal will be described using the ''background field method'' introduced by Gupta, Feynman, Deser and others as a field theory formulation of general relativity. We analyze previous criticisms against scalar gravity and show how the present proposal avoids these difficulties. This concerns not only the theoretical complaints but also those related to observations. In particular, we show that the widespread belief of the conjecture that the source of scalar gravity must be the trace of the energy-momentum tensor which is one of the main difficulties to couple gravity with electromagnetic phenomenon in previous models does not apply to our geometric scalar theory. From the very beginning this is not a special relativistic scalar gravity. The adjective ''geometric'' pinpoints its similarity with general relativity: this is a metric theory of gravity. Some consequences of this new scalar theory are explored.

Novello, M.; Bittencourt, E.; Goulart, E.; Salim, J.M.; Toniato, J.D. [Instituto de Cosmologia Relatividade Astrofisica ICRA - CBPF Rua Dr. Xavier Sigaud 150 - 22290-180 Rio de Janeiro - Brazil (Brazil); Moschella, U., E-mail: novello@cbpf.br, E-mail: eduhsb@cbpf.br, E-mail: Ugo.Moschella@uninsubria.it, E-mail: egoulart@cbpf.br, E-mail: jsalim@cbpf.br, E-mail: toniato@cbpf.br [Universit degli Studi dell'Insubria - Dipartamento di Fisica e Matematica Via Valleggio 11 - 22100 Como - Italy (Italy)

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Dual gravity and E11  

E-Print Network [OSTI]

We consider the equation of motion in the gravity sector that arises from the non-linear realisation of the semi-direct product of E11 and its first fundamental representation, denoted by l1, in four dimensions. This equation is first order in derivatives and at low levels relates the usual field of gravity to a dual gravity field. When the generalised space-time is restricted to be the usual four dimensional space-time we show that this equation does correctly describe Einstein's theory at the linearised level. We also comment on previous discussions of dual gravity.

Peter West

2014-11-04T23:59:59.000Z

42

Dual gravity and E11  

E-Print Network [OSTI]

We consider the equation of motion in the gravity sector that arises from the non-linear realisation of the semi-direct product of E11 and its first fundamental representation, denoted by l1, in four dimensions. This equation is first order in derivatives and at low levels relates the usual field of gravity to a dual gravity field. When the generalised space-time is restricted to be the usual four dimensional space-time we show that this equation does correctly describe Einstein's theory at the linearised level. We also comment on previous discussions of dual gravity.

West, Peter

2014-01-01T23:59:59.000Z

43

Relativistic Gravity and Non-Relativistic Effective Field Theories  

E-Print Network [OSTI]

There has been great interest recently in formulating non-relativistic effective field theories in a general coordinate invariant way. We show that relativistic gravity theories can offer such a framework. We focus on the parity violating case in 2+1 dimensions which is particularly appropriate for the study on quantum Hall effects and chiral superfluids. We discuss how the non-relativistic spacetime structure emerges from relativistic gravity. We present covariant maps and constraints that relate the field contents in the two theories, which also serve as holographic dictionary in context of gauge/gravity duality. A low energy effective action for fractional quantum Hall states is constructed and captures universal geometric properties and generates non-universal corrections systematically. We give another holographic example with dyonic black brane background to calculate thermodynamic and transport properties of strongly coupled non-relativistic fluids in magnetic field. Our formalism has a good projection...

Wu, Chaolun

2014-01-01T23:59:59.000Z

44

Echoes of Gravity  

E-Print Network [OSTI]

The study of anisotropies in the Cosmic Microwave Background radiation is progressing at a phenomenal rate, both experimentally and theoretically. These anisotropies can teach us an enormous amount about the way that fluctuations were generated and the way they subsequently evolved into the clustered galaxies which are observed today. In particular, on sub-degree scales the rich structure in the anisotropy spectrum is the consequence of gravity-driven acoustic oscillations occurring before the matter in the universe became neutral. The frozen-in phases of these sound waves imprint a dependence on many cosmological parameters, that we may be on the verge of extracting.

Douglas Scott; Martin White

1995-05-22T23:59:59.000Z

45

Fluid Gravity Engineering Rocket motor flow analysis  

E-Print Network [OSTI]

Fluid Gravity Engineering Capability · Rocket motor flow analysis -Internal (performance) -External young scientists/engineers Fluid Gravity Engineering Ltd #12;

Anand, Mahesh

46

Reduced models for quantum gravity  

E-Print Network [OSTI]

The preceding talks given at this conference have dealt mainly with general ideas for, main problems of and techniques for the task of quantizing gravity canonically. Since one of the major motivations to arrange for this meeting was that it should serve as a beginner's introduction to canonical quantum gravity, we regard it as important to demonstrate the usefulness of the formalism by means of applying it to simplified models of quantum gravity, here formulated in terms of Ashtekar's new variables. From the various, completely solvable, models that have been discussed in the literature we choose those that we consider as most suitable for our pedagogical reasons, namely 2+1 gravity and the spherically symmetric model. The former model arises from a dimensional, the latter from a Killing reduction of full 3+1 gravity. While 2+1 gravity is usually treated in terms of closed topologies without boundary of the initial data hypersurface, the toplogy for the spherically symmetric system is chosen to be asymptotically flat. Finally, 2+1 gravity is more suitably quantized using the loop representation while spherically symmetric gravity is easier to quantize via the self-dual representation. Accordingly, both types of reductions, both types of topologies and both types of representations that are mainly employed in the literature in the context of the new variables come into practice. What makes the discussion especially clear is the fact that for both models the reduced phase space turns out to be finitely dimensional.

T. Thiemann

1999-10-04T23:59:59.000Z

47

Gravity Waves in the Sun  

E-Print Network [OSTI]

We present numerical simulations of penetrative convection and gravity wave excitation in the Sun. Gravity waves are self-consistently generated by a convective zone overlying a radiative interior. We produce power spectra for gravity waves in the radiative region as well as estimates for the energy flux of gravity waves below the convection zone. We calculate a peak energy flux in waves below the convection zone to be three orders of magnitude smaller than previous estimates for m=1. The simulations show that the linear dispersion relation is a good approximation only deep below the convective-radiative boundary. Both low frequency propagating gravity waves as well as higher frequency standing modes are generated; although we find that convection does not continually drive the standing g-mode frequencies.

Tamara M. Rogers; Gary A. Glatzmaier

2005-08-25T23:59:59.000Z

48

Gravity Techniques | Open Energy Information  

Open Energy Info (EERE)

Gravity Techniques Gravity Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gravity Techniques Details Activities (0) Areas (0) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Geophysical Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. Stratigraphic/Structural: Delineation of steeply dipping formations, geological discontinuities and faults, intrusions and the deposition of silicates due to hydrothermal activity. Hydrological: Density of sedimentary rocks are strongly influenced by fluid contained within pore space. Dry bulk density refers to the rock with no moisture, while the wet bulk density accounts for water saturation; fluid content may alter density by up to 30%.(Sharma, 1997)

49

residual magnetism  

Science Journals Connector (OSTI)

The magnetization, i.e., the magnetic polarization, that remains in a magnetized material after all attempts to remove the magnetization have been made. Note: An example of residual magnetization is the magnetiza...

2001-01-01T23:59:59.000Z

50

Ground Gravity Survey At Lightning Dock Area (Warpinski, Et Al., 2002) |  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Ground Gravity Survey At Lightning Dock Area (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Lightning Dock Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Lightning Dock Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes As a foundation for successful siting and drilling a deep test well, additional geophysical work has been completed including gravity, resistivity, and airborne magnetic surveys. Several new seismic profiles

51

Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et Al., 2002) |  

Open Energy Info (EERE)

Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et Al., 2002) Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location. References N. R. Warpinski, A. R. Sattlerl, D. A. Sanchez (2002) Geothermal

52

Designing surveys for tests of gravity  

Science Journals Connector (OSTI)

...Bean and Andrew Taylor Designing surveys for tests of gravity Bhuvnesh Jain * * bjain@physics...that the observational programme developed to test dark energy needs to be augmented to capture new tests of gravity on astrophysical scales. Several...

2011-01-01T23:59:59.000Z

53

Kerr geometry in f(T) gravity  

E-Print Network [OSTI]

Null tetrads are shown to be a valuable tool in teleparallel theories of modified gravity. We use them to prove that Kerr geometry remains a solution for a wide family of f(T) theories of gravity.

Cecilia Bejarano; Rafael Ferraro; Mara Jos Guzmn

2014-12-01T23:59:59.000Z

54

Modified gravity and the CMB  

Science Journals Connector (OSTI)

We consider the effect of modified gravity on the peak structure of the cosmic microwave background (CMB) spectrum. We focus on simple models of modified gravity mediated by a massive scalar field coupled to both baryons and cold dark matter. This captures the features of chameleon, symmetron, dilaton, and f(R) models. We find that the CMB peaks can be affected in three independent ways provided the Compton radius of the massive scalar is not far-off the sound horizon at last scattering. When the coupling of the massive scalar to cold dark matter is large, the anomalous growth of the cold dark matter perturbation inside the Compton radius induces a change in the peak amplitudes. When the coupling to baryons is moderately large, the speed of sound is modified and the peaks shifted to higher momenta. Finally when both couplings are nonvanishing, a new contribution proportional to the Newton potential appears in the Sachs-Wolfe temperature and increases the peak amplitudes. We also show how, given any temporal evolution of the scalar field mass, one can engineer a corresponding modified gravity model of the chameleon type. This opens up the possibility of having independent constraints on modified gravity from the CMB peaks and large scale structures at low redshifts.

Philippe Brax and Anne-Christine Davis

2012-01-10T23:59:59.000Z

55

Multiple Ising Spins Coupled to 2d Quantum Gravity  

E-Print Network [OSTI]

We study a model in which p independent Ising spins are coupled to 2d quantum gravity (in the form of dynamical planar phi-cubed graphs). Consideration is given to the p tends to infinity limit in which the partition function becomes dominated by certain graphs; we identify most of these graphs. A truncated model is solved exactly providing information about the behaviour of the full model in the limit of small beta. Finally, we derive a bound for the critical value of the coupling constant, beta_c and examine the magnetization transition in the limit p tends to zero.

M. G. Harris; J. F. Wheater

1994-04-28T23:59:59.000Z

56

Magnetic Fields in the Formation of Sun-Like Stars  

E-Print Network [OSTI]

We report high-angular-resolution measurements of polarized dust emission toward the low-mass protostellar system NGC 1333 IRAS 4A. We show that in this system the observed magnetic field morphology is in agreement with the standard theoretical models of the formation of Sun-like stars in magnetized molecular clouds at scales of a few hundred astronomical units; gravity has overcome magnetic support, and the magnetic field traces a clear hourglass shape. The magnetic field is substantially more important than turbulence in the evolution of the system, and the initial misalignment of the magnetic and spin axes may have been important in the formation of the binary system.

Josep M. Girart; Ramprasad Rao; Daniel P. Marrone

2006-09-06T23:59:59.000Z

57

Ising-link Regge gravity  

Science Journals Connector (OSTI)

We define a simplified version of Regge quantum gravity where the link lengths can take on only two possible values, both always compatible with the triangle inequalities. This is therefore equivalent to a model of Ising spins living on the links of a regular lattice with somewhat complicated, yet local interactions. The measure corresponds to the natural sum over all 2?links configurations, and numerical simulations can be efficiently implemented by means of look-up tables. In three dimensions we find a peak in the curvature susceptibility which grows with increasing system size. The value of the corresponding critical exponent appears to vary with the cosmological constant ?, agreeing with Regge gravity for at least one value of ?. However, the curvature does not go to zero at the transition.

Tom Fleming; Mark Gross; Ray Renken

1994-12-15T23:59:59.000Z

58

Dynamical 3-Space: Emergent Gravity  

E-Print Network [OSTI]

The laws of gravitation devised by Newton, and by Hilbert and Einstein, have failed many experimental and observational tests, namely the bore hole g anomaly, flat rotation curves for spiral galaxies, supermassive black hole mass spectrum, uniformly expanding universe, cosmic filaments, laboratory G measurements, galactic EM bending, precocious galaxy formation,.. The response has been the introduction of the new epicycles: ``dark matter", ``dark energy", and others. To understand gravity we must restart with the experimental discoveries by Galileo, and following a heuristic argument we are led to a uniquely determined theory of a dynamical 3-space. That 3-space exists has been missed from the beginning of physics, although it was 1st directly detected by Michelson and Morley in 1887. Uniquely generalising the quantum theory to include this dynamical 3-space we deduce the response of quantum matter and show that it results in a new account of gravity, and explains the above anomalies and others. The dynamical...

Cahill, Reginald T

2011-01-01T23:59:59.000Z

59

Supersymmetry in 5D gravity  

Science Journals Connector (OSTI)

We study a 5d gravity theory with a warped metric and show that two N=2 supersymmetric quantum-mechanical systems are hidden in the 4d spectrum. The supersymmetry can be regarded as a remnant of higher-dimensional general coordinate invariance and turns out to become a powerful tool to determine the physical 4d spectrum and the allowed boundary conditions. Possible extensions of the N=2 supersymmetry are briefly discussed.

C. S. Lim; Tomoaki Nagasawa; Satoshi Ohya; Kazuki Sakamoto; Makoto Sakamoto

2008-02-15T23:59:59.000Z

60

Supersymmetry in 5d Gravity  

E-Print Network [OSTI]

We study a 5d gravity theory with a warped metric and show that two N = 2 supersymmetric quantum-mechanical systems are hidden in the 4d spectrum. The supersymmetry can be regarded as a remnant of higher-dimensional general coordinate invariance and turns out to become a powerful tool to determine the physical 4d spectrum and the allowed boundary conditions. Possible extensions of the N = 2 supersymmetry are briefly discussed.

C. S. Lim; Tomoaki Nagasawa; Satoshi Ohya; Kazuki Sakamoto; Makoto Sakamoto

2007-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Supersymmetry in 5d Gravity  

E-Print Network [OSTI]

We study a 5d gravity theory with a warped metric and show that two N = 2 supersymmetric quantum-mechanical systems are hidden in the 4d spectrum. The supersymmetry can be regarded as a remnant of higher-dimensional general coordinate invariance and turns out to become a powerful tool to determine the physical 4d spectrum and the allowed boundary conditions. Possible extensions of the N = 2 supersymmetry are briefly discussed.

Lim, C S; Ohya, Satoshi; Sakamoto, Kazuki; Sakamoto, Makoto

2007-01-01T23:59:59.000Z

62

Magnetic Spinner  

Science Journals Connector (OSTI)

A science toy sometimes called the magnetic spinner is an interesting class demonstration to illustrate the principles of magnetic levitation. It can also be used to demonstrate Faraday's law and a horizontally suspended physical pendulum. The levitated part contains two circular magnets encased in a plastic housing. Each magnet stays above two triangular magnets fixed to the base. The magnetic repulsive force experienced by the circular magnets is independent of their orientation; therefore the holder of these magnets can be rotated without affecting its stability. The holder with the circular magnets can be oscillated up and down as a horizontally suspended physical pendulum.

P. J. Ouseph

2006-01-01T23:59:59.000Z

63

Magnetism Digest  

Science Journals Connector (OSTI)

... and Institute of Electrical and Electronic Engineers, on the occasion of their annual conferences on magnetism and magnetic materials in the United States, have sponsored the production of a Magnetic ... references, drawn from a large number of sources, to work in the field of magnetism and magnetic materials published in the preceding year. They therefore provide a very convenient ...

J. H. PHILLIPS

1966-06-25T23:59:59.000Z

64

Regional North American gravity and magnetic anomaly correlations  

Science Journals Connector (OSTI)

......volcanic rocks of the Snake River Plain, Idaho...A. , 1964. Developments in Solid Earth...combined with lateral temperature perturbations are...regionally higher temperatures are associated...volcanic rocks of the Snake River Plain, Idaho...A., 1964. Developments in Solid Earth......

R. R. B. von Frese; W. J. Hinze; L. W. Braile

1982-06-01T23:59:59.000Z

65

Growth histories in bimetric massive gravity  

SciTech Connect (OSTI)

We perform cosmological perturbation theory in Hassan-Rosen bimetric gravity for general homogeneous and isotropic backgrounds. In the de Sitter approximation, we obtain decoupled sets of massless and massive scalar gravitational fluctuations. Matter perturbations then evolve like in Einstein gravity. We perturb the future de Sitter regime by the ratio of matter to dark energy, producing quasi-de Sitter space. In this more general setting the massive and massless fluctuations mix. We argue that in the quasi-de Sitter regime, the growth of structure in bimetric gravity differs from that of Einstein gravity.

Berg, Marcus; Buchberger, Igor [Department of Physics, Karlstad University, 651 88 Karlstad (Sweden); Enander, Jonas; Mrtsell, Edvard; Sjrs, Stefan, E-mail: marcus.berg@kau.se, E-mail: igor.buchberger@kau.se, E-mail: enander@fysik.su.se, E-mail: edvard@fysik.su.se, E-mail: stefans@fysik.su.se [Oskar Klein Center, Stockholm University, Albanova University Center, 106 91 Stockholm (Sweden)

2012-12-01T23:59:59.000Z

66

Cosmological Acceleration: Dark Energy or Modified Gravity?  

E-Print Network [OSTI]

We review the evidence for recently accelerating cosmological expansion or "dark energy", either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any Dark Energy constituent. If constituent Dark Energy does not exist, so that our universe is now dominated by pressure-free matter, Einstein gravity must be modified at low curvature. The vacuum symmetry of any Robertson-Walker universe then characterizes Dark Gravity as low- or high-curvature modifications of Einstein gravity. The dynamics of either kind of "dark energy" cannot be derived from the homogeneous expansion alone, but requires also observing the growth of inhomogeneities. Present and projected observations are all consistent with a small fine tuned cosmological constant, with nearly static Dark Energy, or with gravity modified at cosmological scales. The growth of cosmological fluctuations will potentially distinguish static "dark energy" from dynamic "dark energy" with equation of state $w(z)$ either changing rapidly or tracking the background matter. But to cosmologically distinguish $\\Lambda$CDM from modified gravity will require a weak lensing shear survey more ambitious than any now projected. Dvali-Gabadadze-Porrati modifications of Einstein gravity may also be detected in refined bservations in the solar system or at the intermediate Vainstein scale. Dark Energy's epicyclic character, failure to explain the original Cosmic Coincidence ("Why now?") without fine tuning, inaccessibility to laboratory or solar system tests, along with braneworld theories, now motivate future precision solar system, Vainstein-scale and cosmological-scale studies of Dark Gravity.

Sidney Bludman

2006-05-08T23:59:59.000Z

67

Bouguer gravity map | Open Energy Information  

Open Energy Info (EERE)

Bouguer gravity map. Map. Denver, Colorado. U.S. Geological Survey. () . Black & White. Scale 1:500,000. Retrieved from "http:en.openei.orgwindex.php?titleBouguergravi...

68

Doubly Special Relativity and quantum gravity phenomenology  

E-Print Network [OSTI]

I review the conceptual, algebraical, and geometrical structure of Doubly Special Relativity. I also speculate about the possible relevance of DSR for quantum gravity phenomenology.

J. Kowalski-Glikman

2003-12-12T23:59:59.000Z

69

Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski, Et  

Open Energy Info (EERE)

4) 4) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski, Et Al., 2004) Exploration Activity Details Location San Francisco Volcanic Field Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Northern Arizona University has re-assessed the existing exploration data, geologically mapped the target area, obtained rock samples for age dating and mineral chemistry, performed gravity and magnetic surveys, and integrated these results to identify potential drilling targets and sites. Further work may occur in 2004 or 2005. References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal Resource Exploration And Definition Projects

70

Ground Gravity Survey At Chocolate Mountains Area (Alm, Et Al., 2010) |  

Open Energy Info (EERE)

Chocolate Mountains Area (Alm, Et Al., 2010) Chocolate Mountains Area (Alm, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Chocolate Mountains Area (Alm, Et Al., 2010) Exploration Activity Details Location Chocolate Mountains Area Exploration Technique Ground Gravity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Gravity and ground-based magnetics surveys were conducted during the summer of 2008. This data was acquired to aid in the identification of structures without fair surface expression, obscured by recent deposition. References Steve Alm, S. Bjornstad, M. Lazaro, A. Sabin1, D. Meade, J. Shoffner, W. C. Huang, J. Unruh, M. Strane, H. Ross (2010) Geothermal Energy Resource Investigations, Chocolate Mountains Aerial Gunnery Range,

71

Generalized second law in the modified theory of gravity  

SciTech Connect (OSTI)

In the context of modified theory of gravity [f(R) gravity], we try to study the conditions needed for validity of the generalized second law.

Mohseni Sadjadi, H. [Department of Physics, University of Tehran, P.O. Box 14395-547, Tehran 14399-55961 (Iran, Islamic Republic of)

2007-11-15T23:59:59.000Z

72

Conserved charges in 3D gravity  

Science Journals Connector (OSTI)

The covariant canonical expression for the conserved charges, proposed by Nester, is tested on several solutions in three-dimensional gravity with or without torsion and topologically massive gravity. In each of these cases, the calculated values of energy momentum and angular momentum are found to satisfy the first law of black hole thermodynamics.

M. Blagojevi? and B. Cvetkovi?

2010-06-09T23:59:59.000Z

73

Quantum Gravity Phenomenology and Lorentz Violation  

E-Print Network [OSTI]

If quantum gravity violates Lorentz symmetry, the prospects for observational guidance in understanding quantum gravity improve considerably. This article briefly reviews previous work on Lorentz violation (LV) and discusses aspects of the effective field theory framework for parametrizing LV effects. Current observational constraints on LV are then summarized, focusing on effects in QED at order E/M_Planck.

Ted Jacobson; Stefano Liberati; David Mattingly

2004-04-15T23:59:59.000Z

74

Conserved charges in 3D gravity  

SciTech Connect (OSTI)

The covariant canonical expression for the conserved charges, proposed by Nester, is tested on several solutions in three-dimensional gravity with or without torsion and topologically massive gravity. In each of these cases, the calculated values of energy momentum and angular momentum are found to satisfy the first law of black hole thermodynamics.

Blagojevic, M.; Cvetkovic, B. [University of Belgrade, Institute of Physics, P. O. Box 57, 11001 Belgrade (Serbia)

2010-06-15T23:59:59.000Z

75

Quantum Gravity Phenomenology, Lorentz Invariance and Discreteness  

E-Print Network [OSTI]

Quantum Gravity Phenomenology, Lorentz Invariance and Discreteness Fay Dowker #3; , Joe Henson y invariant, and we recall the reasons why. For illustration, we introduce a phenomenological model of massive { LLI violating phenomenological e#11;ects of quantum gravity { has grown up around this idea

Sorkin, Rafael Dolnick

76

Gravity's Rainbow induces Topology Change  

E-Print Network [OSTI]

In this work, we explore the possibility that quantum fluctuations induce a topology change, in the context of Gravity's Rainbow. A semi-classical approach is adopted, where the graviton one-loop contribution to a classical energy in a background spacetime is computed through a variational approach with Gaussian trial wave functionals. The energy density of the graviton one-loop contribution, or equivalently the background spacetime, is then let to evolve, and consequently the classical energy is determined. More specifically, the background metric is fixed to be Minkowskian in the equation governing the quantum fluctuations, which behaves essentially as a backreaction equation, and the quantum fluctuations are let to evolve; the classical energy, which depends on the evolved metric functions, is then evaluated. Analysing this procedure, a natural ultraviolet (UV) cutoff is obtained, which forbids the presence of an interior spacetime region, and may result in a multipy-connected spacetime. Thus, in the context of Gravity's Rainbow, this process may be interpreted as a change in topology, and in principle results in the presence of a Planckian wormhole.

Remo Garattini; Francisco S. N. Lobo

2014-08-20T23:59:59.000Z

77

Threat Mitigation: The Gravity Tractor  

E-Print Network [OSTI]

The Gravity Tractor (GT) is a fully controlled asteroid deflection concept using the mutual gravity between a robotic spacecraft and an asteroid to slowly accelerate the asteroid in the direction of the "hovering" spacecraft. Based on early warning, provided by ground tracking and orbit prediction, it would be deployed a decade or more prior to a potential impact. Ion engines would be utilized for both the rendezvous with the asteroid and the towing phase. Since the GT does not dock with or otherwise physically contact the asteroid during the deflection process there is no requirement for knowledge of the asteroid's shape, composition, rotation state or other "conventional" characteristics. The GT would first reduce the uncertainty in the orbit of the asteroid via Earth tracking of its radio transponder while station keeping with the asteroid. If, after analysis of the more precise asteroid orbit a deflection is indeed indicated, the GT would "hover" above the surface of the asteroid in the direction of the required acceleration vector for a duration adequate to achieve the desired velocity change. The orbit of the asteroid is continuously monitored throughout the deflection process and the end state is known in real time. The performance envelope for the GT includes most NEOs which experience close gravitational encounters prior to impact and those below 150-200 meters in diameter on a direct Earth impact trajectory.

Russell Schweickart; Clark Chapman; Dan Durda; Piet Hut

2006-08-15T23:59:59.000Z

78

Gravity Dual of Superconformal Anomaly  

E-Print Network [OSTI]

The supergravity dual of superconformal anomaly in a four-dimensional supersymmetric gauge theory is investigated. We consider a well-established dual correspondence between the ${\\cal N}=1$ $SU(N+M)\\times SU(N)$ supersymmetric gauge theory with two flavors of matter fields in the bifundamental representation of gauge group and the type IIB superstring in the space-time background furnished by the Klebanov-Strassler (K-S) solution. The D-brane configuration for these two dual theories consists of N D3 branes and M fractional $D3$ branes in the singular space-time composed of a direct product of M^4 and a six-dimensional conifold ${\\cal C}_6$ with the base $T^{1,1}$. The superconformal anomaly originate from fractional branes frozen at the apex of ${\\cal C}_6$. While on the gravity side, the fractional branes deform the $AdS_5\\times T^{1,1}$ space-time background and partially break local supersymmetry of type IIB supergravity. We find that the deformation on $AdS_5\\times T^{1,1}$ leads to the spontaneous breaking local symmetries in gauged AdS_5 supergravity and consequently a super-Higgs mechanism arises. We thus conclude that the super-Higgs mechanism in gauged supergravity is dual to the superconformal anomaly of supersymmetric gauge theory in terms of gauge/gravity correspondence.

W. F. Chen

2005-08-16T23:59:59.000Z

79

Airborne Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Airborne Gravity Survey Airborne Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Airborne Gravity Survey Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Gravity Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. Stratigraphic/Structural: Delineation of steeply dipping formations, geological discontinuities and faults, intrusions and the deposition of silicates due to hydrothermal activity. Hydrological: Density of sedimentary rocks are strongly influenced by fluid contained within pore space. Dry bulk density refers to the rock with no moisture, while the wet bulk density accounts for water saturation; fluid content may alter density by up to 30%.(Sharma, 1997)

80

Definition: Ground Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Ground Gravity Survey Jump to: navigation, search Dictionary.png Ground Gravity Survey The ground gravitational method is the study of the distribution of mass in the subsurface with the observation point at the earth's surface.[1] View on Wikipedia Wikipedia Definition A gravity anomaly is the difference between the observed acceleration of a planet's gravity and a value predicted from a model. A location with a positive anomaly exhibits more gravity than predicted, while a negative anomaly exhibits a lower value than predicted. References ↑ http://www.amazon.com/Geophysical-Field-Theory-Three-Volume-Gravitational/dp/0124020410 Ret Like Like You like this.Sign Up to see what your friends like.

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Ground Gravity Survey | Open Energy Information  

Open Energy Info (EERE)

Ground Gravity Survey Ground Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Gravity Survey Details Activities (48) Areas (34) Regions (2) NEPA(2) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Gravity Techniques Parent Exploration Technique: Gravity Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. Stratigraphic/Structural: Delineation of steeply dipping formations, geological discontinuities and faults, intrusions and large-scale deposition of silicates due to hydrothermal activity. Hydrological: Density of sedimentary rocks are strongly influenced by fluid contained within pore space. Dry bulk density refers to the rock with no moisture, while the wet bulk density accounts for water saturation; fluid content may alter density by up to 30%.(Sharma, 1997)

82

Magnetism.1  

Science Journals Connector (OSTI)

... each complete magnets with a pair of poles. The general character of the earth's magnetism has long been knownthat the earth behaves with regard to magnets as though it ... and that these poles have a slow secular motion. For many years the earth's magnetism has been the subject of careful study by the most powerful minds. Gauss organized ...

1890-01-16T23:59:59.000Z

83

Earths magnetism  

Science Journals Connector (OSTI)

Earths magnetism, geomagnetism, terrestrial magnetism [The magnetism of the Earth] ? Erdmagnetismus m, Geomagnetismus

2014-08-01T23:59:59.000Z

84

Testing Relativistic Gravity with Radio Pulsars  

E-Print Network [OSTI]

Before the 1970s, precision tests for gravity theories were constrained to the weak gravitational fields of the Solar system. Hence, only the weak-field slow-motion aspects of relativistic celestial mechanics could be investigated. Testing gravity beyond the first post-Newtonian contributions was for a long time out of reach. The discovery of the first binary pulsar by Russell Hulse and Joseph Taylor in the summer of 1974 initiated a completely new field for testing the relativistic dynamics of gravitationally interacting bodies. For the first time the back reaction of gravitational wave emission on the binary motion could be studied. Furthermore, the Hulse-Taylor pulsar provided the first test bed for the orbital dynamics of strongly self-gravitating bodies. To date there are a number of pulsars known, which can be utilized for precision test of gravity. Depending on their orbital properties and their companion, these pulsars provide tests for various different aspects of relativistic dynamics. Besides tests of specific gravity theories, like general relativity or scalar-tensor gravity, there are pulsars that allow for generic constraints on potential deviations of gravity from general relativity in the quasi-stationary strong-field and the radiative regime. This article presents a brief overview of this modern field of relativistic celestial mechanics, reviews some of the highlights of gravity tests with radio pulsars, and discusses their implications for gravitational physics and astronomy, including the upcoming gravitational wave astronomy.

Norbert Wex

2014-02-23T23:59:59.000Z

85

Dimensional Reduction in Quantum Gravity  

E-Print Network [OSTI]

The requirement that physical phenomena associated with gravitational collapse should be duly reconciled with the postulates of quantum mechanics implies that at a Planckian scale our world is not 3+1 dimensional. Rather, the observable degrees of freedom can best be described as if they were Boolean variables defined on a two-dimensional lattice, evolving with time. This observation, deduced from not much more than unitarity, entropy and counting arguments, implies severe restrictions on possible models of quantum gravity. Using cellular automata as an example it is argued that this dimensional reduction implies more constraints than the freedom we have in constructing models. This is the main reason why so-far no completely consistent mathematical models of quantum black holes have been found. Essay dedicated to Abdus Salam.

G. 't Hooft

2009-03-20T23:59:59.000Z

86

Loop Quantum Gravity 1. Classical framework : Ashtekar-Barbero connection  

E-Print Network [OSTI]

gravity Why Quantum Gravity ? Gravitation vs. Quantum Physics : the two infinities Gravitation : large Quantum Gravity ? Gravitation vs. Quantum Physics : the two infinities Gravitation : large scales-perturbative renormalization Gravity is not a fundamental theory but it is effective (law energy) · it has to be modified

Sart, Remi

87

Dynamical variables in Gauge-Translational Gravity  

E-Print Network [OSTI]

Assuming that the natural gauge group of gravity is given by the group of isometries of a given space, for a maximally symmetric space we derive a model in which gravity is essentially a gauge theory of translations. Starting from first principles we verify that a nonlinear realization of the symmetry provides the general structure of this gauge theory, leading to a simple choice of dynamical variables of the gravity field corresponding, at first order, to a diagonal matrix, whereas the non-diagonal elements contribute only to higher orders.

J. Julve; A. Tiemblo

2010-07-02T23:59:59.000Z

88

Investigations in massive 3D gravity  

SciTech Connect (OSTI)

Some interesting gravitational properties of the Bergshoeff-Hohm-Townsend model (massive 3D gravity), such as the presence of a short-range gravitational force in the nonrelativistic limit and the existence of an impact-parameter-dependent gravitational deflection angle, are studied. Interestingly enough, these phenomena have no counterpart in the usual Einstein 3D gravity. In order to better understand the two aforementioned gravitational properties, they are also analyzed in the framework of 3D higher-derivative gravity with the Einstein-Hilbert term with the 'wrong sign'.

Accioly, Antonio [Laboratorio de Fisica Experimental (LAFEX), Centro Brasileiro de Pesquisas Fisicas (CBPF), Rua Dr. Xavier Sigaud 150, Urca, 22290-180, Rio de Janeiro, RJ (Brazil); Instituto de Fisica Teorica (IFT), Sao Paulo State University (UNESP), Rua Dr. Bento Teobaldo Ferraz 271, Bloco II-Barra Funda, 01140-070, Sao Paulo, SP (Brazil); Helayeel-Neto, Jose; Morais, Jefferson; Turcati, Rodrigo [Laboratorio de Fisica Experimental (LAFEX), Centro Brasileiro de Pesquisas Fisicas (CBPF), Rua Dr. Xavier Sigaud 150, Urca, 22290-180, Rio de Janeiro, RJ (Brazil); Scatena, Eslley [Instituto de Fisica Teorica (IFT), Sao Paulo State University (UNESP), Rua Dr. Bento Teobaldo Ferraz 271, Bloco II-Barra Funda, 01140-070, Sao Paulo, SP (Brazil)

2011-05-15T23:59:59.000Z

89

Reduced Gravity Education Flight Opportunity for Students at Minority  

Broader source: Energy.gov (indexed) [DOE]

Reduced Gravity Education Flight Opportunity for Students at Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions March 21, 2013 - 5:21pm Addthis Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions NASA is offering undergraduate students from Minority Serving Institutions an opportunity to test experiments in microgravity aboard NASA's reduced gravity aircraft. This opportunity is a partnership between the Minority University Research and Education Program and NASA's Reduced Gravity Education Flight Program, which gives aspiring explorers a chance to propose, design and fabricate a reduced-gravity experiment. Selected teams will test and evaluate their

90

Reduced Gravity Education Flight Opportunity for Students at Minority  

Broader source: Energy.gov (indexed) [DOE]

Reduced Gravity Education Flight Opportunity for Students at Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions March 21, 2013 - 5:21pm Addthis Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions NASA is offering undergraduate students from Minority Serving Institutions an opportunity to test experiments in microgravity aboard NASA's reduced gravity aircraft. This opportunity is a partnership between the Minority University Research and Education Program and NASA's Reduced Gravity Education Flight Program, which gives aspiring explorers a chance to propose, design and fabricate a reduced-gravity experiment. Selected teams will test and evaluate their

91

Gravity Duals of Lifshitz-Like Fixed Points  

SciTech Connect (OSTI)

We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our theories are characterized by a dynamical critical exponent z, which governs the anisotropy between spatial and temporal scaling t {yields} {lambda}{sup z}t, x {yields} {lambda}x; we focus on the case with z = 2. Such theories describe multicritical points in certain magnetic materials and liquid crystals, and have been shown to arise at quantum critical points in toy models of the cuprate superconductors. This work can be considered a small step towards making useful dual descriptions of such critical points.

Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Liu, Xiao; /Perimeter Inst. Theor. Phys.; Mulligan, Michael; /Stanford U., Phys. Dept. /SLAC

2008-11-05T23:59:59.000Z

92

The Branching of Graphs in 2-d Quantum Gravity  

E-Print Network [OSTI]

The branching ratio is calculated for three different models of 2d gravity, using dynamical planar phi-cubed graphs. These models are pure gravity, the D=-2 Gaussian model coupled to gravity and the single spin Ising model coupled to gravity. The ratio gives a measure of how branched the graphs dominating the partition function are. Hence it can be used to estimate the location of the branched polymer phase for the multiple Ising model coupled to 2d gravity.

M. G. Harris

1996-07-16T23:59:59.000Z

93

Modern Magnetism  

Science Journals Connector (OSTI)

... BATESS "Modern Magnetism", first published in 1939, is widely appreciated as a general survey in which ... grateful to the author for collecting together so much interesting information about recent work in magnetism. ...

E. C. S.

1948-06-05T23:59:59.000Z

94

Test particle motion in modified gravity theories  

E-Print Network [OSTI]

We derive the equations of motion of an electrically neutral test particle for modified gravity theories in which the covariant divergence of the ordinary matter energy-momentum tensor dose not vanish (i.e. $\

Mahmood Roshan

2013-02-05T23:59:59.000Z

95

2D gravity and the extended formalism  

Science Journals Connector (OSTI)

The role of SL(2,R) symmetry in two-dimensional gravity is investigated in the context of the extended Hamiltonian formalism. Using our results we clarify previous works on the subject.

Fernando P. Devecchi

1998-07-10T23:59:59.000Z

96

Energy conditions in f(R)-gravity  

E-Print Network [OSTI]

In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework are derived from the Raychaudhuri's equation along with the requirement that gravity is attractive, whereas the weak and dominant energy conditions are stated from a comparison with the energy conditions that can be obtained in a direct approach via an effective energy-momentum tensor for f(R)-gravity. As a concrete application of the energy conditions to locally homogeneous and isotropic f(R)-cosmology, the recent estimated values of the deceleration and jerk parameters are used to examine the bounds from the weak energy condition on the parameters of two families of f(R)-gravity theories.

J. Santos; J. S. Alcaniz; M. J. Reboucas; F. C. Carvalho

2007-09-06T23:59:59.000Z

97

SUSY QM meets 5d Gravity  

E-Print Network [OSTI]

We report hidden quantum mechanical supersymmetry structure in five-dimensional gravity with the Randall-Sundrum background. We show that two N=2 supersymmetries are hidden in the spectrum.

Ohya, Satoshi

2010-01-01T23:59:59.000Z

98

SUSY QM Meets 5d Gravity  

E-Print Network [OSTI]

We report hidden quantum mechanical supersymmetry structure in five-dimensional gravity with the Randall-Sundrum background. We show that two N=2 supersymmetries are hidden in the spectrum.

Satoshi Ohya

2010-12-01T23:59:59.000Z

99

Gravity waves from vortex dipoles and jets  

E-Print Network [OSTI]

The dissertation first investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Several initially balanced and localized jets induced by vortex dipoles are examined here...

Wang, Shuguang

2009-05-15T23:59:59.000Z

100

Testing Modified Gravity with Gravitational Wave Astronomy  

E-Print Network [OSTI]

The emergent area of gravitational wave astronomy promises to provide revolutionary discoveries in the areas of astrophysics, cosmology, and fundamental physics. One of the most exciting possibilities is to use gravitational-wave observations to test alternative theories of gravity. In this contribution we describe how to use observations of extreme-mass-ratio inspirals by the future Laser Interferometer Space Antenna to test a particular class of theories: Chern-Simons modified gravity.

Carlos F. Sopuerta; Nicolas Yunes

2010-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Relativistic Gravity With a Dynamical Preferred Frame  

E-Print Network [OSTI]

While general relativity possesses local Lorentz invariance, both canonical quantum gravity and string theory suggest that Lorentz invariance may be broken at high energies. Broken Lorentz invariance has also been postulated as an explanation for astrophysical anomalies such as the missing GZK cutoff. Therefore, we seek an effective field theory description of gravity where Lorentz invariance is broken. We will construct a candidate theory and then briefly discuss some of the implications.

David Mattingly; Ted Jacobson

2001-12-07T23:59:59.000Z

102

Migratory magnetism  

Science Journals Connector (OSTI)

... in tune with the Earth's magnetic field. But how, exactly, do creatures sense magnetism? This is one of the most intriguing questions in modern biology - and also ... move preferentially in a north-south direction. This finding hints at the possible influence of magnetism on their movements. ...

Henry Gee

1999-10-06T23:59:59.000Z

103

Magnetic Testing of Bonded Magnets  

Science Journals Connector (OSTI)

Many techniques exist to characterize the magnetic properties of bonded magnets. We will review the common and not so common techniques in use, with emphasis on the advantages and disadvantages of each one, an...

S. R. Trout

2003-01-01T23:59:59.000Z

104

Universality of Gravity from Entanglement  

E-Print Network [OSTI]

The entanglement "first law" in conformal field theories relates the entanglement entropy for a ball-shaped region to an integral over the same region involving the expectation value of the CFT stress-energy tensor, for infinitesimal perturbations to the CFT vacuum state. In recent work, this was exploited at leading order in $N$ in the context of large N holographic CFTs to show that any geometry dual to a perturbed CFT state must satisfy Einstein's equations linearized about pure AdS. In this note, we investigate the implications of the leading 1/N correction to the exact CFT result. We show that these corrections give rise to the source term for the gravitational equations: for semiclassical bulk states, the expectation value of the bulk stress-energy tensor appears as a source in the linearized equations. In particular, the CFT first law leads to Newton's Law of gravitation and the fact that all sources of stress-energy source the gravitational field. In our derivation, this universality of gravity comes directly from the universality of entanglement (the fact that all degrees of freedom in a subsystem contribute to entanglement entropy).

Brian Swingle; Mark Van Raamsdonk

2014-05-12T23:59:59.000Z

105

Ground Magnetics At Marysville Mt Area (Blackwell) | Open Energy  

Open Energy Info (EERE)

Ground Magnetics At Marysville Mt Area (Blackwell) Ground Magnetics At Marysville Mt Area (Blackwell) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Magnetics At Marysville Mt Area (Blackwell) Exploration Activity Details Location Marysville Mt Area Exploration Technique Ground Magnetics Activity Date Usefulness not useful DOE-funding Unknown Notes A ground magnetic survey located no anomaly with an amplitude of more than 20 or 30 gammas that could be associated with the thermal anomaly, however the magnetic data did outline the Cretaceous stock in great detail and allow the removal from the gravity field of the effect of the stock. References D. D. Blackwell (Unknown) Exploration In A Blind Geothermal Area Near Marysville, Montana, Usa Retrieved from "http://en.openei.org/w/index.php?title=Ground_Magnetics_At_Marysville_Mt_Area_(Blackwell)&oldid=389390"

106

Introduction to Modified Gravity: From the Cosmic Speedup Problem to Quantum Gravity Phenomenology  

E-Print Network [OSTI]

These notes represent a summary of the introductory part of a course on modified gravity delivered at several Spanish Universities (Granada, Valencia, and Valladolid), at the University of Wisconsin-Milwaukee (WI, USA), and at the Karl-Franzens Universitaet (Graz, Austria) during the period 2008-2011. We begin with a discussion of the classical Newtonian framework and how special relativity boosted the interest on new theories of gravity. Then we focus on Nordstrom's scalar theories of gravity and their influence on Einstein's theory of general relativity. We comment on the meaning of the Einstein equivalence principle and its implications for the construction of alternative theories of gravity. We present the cosmic speedup problem and how $f(R)$ theories can be constrained attending to their weak-field behavior. We conclude by showing that Palatini f(R) and f(R,Q) theories can be used to address different aspects of quantum gravity phenomenology and singularity problems.

Gonzalo J. Olmo

2011-12-09T23:59:59.000Z

107

Newton-Cartan Gravity in Noninertial Reference Frames  

E-Print Network [OSTI]

We study properties of Newton-Cartan gravity under transformations into all noninertial, nonrelativistic reference frames. The set of these transformations has the structure of an infinite dimensional Lie group, called the Galilean line group, which contains as a subgroup the Galilei group. We show that the fictitious forces of noninertial reference frames are naturally encoded in the Cartan connection transformed under the Galilean line group. These noninertial forces, which are coordinate effects, do not contribute to the Ricci tensor which describes the curvature of Newtonian spacetime. We show that only the $00$-component of the Ricci tensor is non-zero and equal to ($4\\pi$ times) the matter density in any inertial or noninetial reference frame and that it leads to what may be called Newtonian ADM mass. While the Ricci field equation and Gauss law are both fulfilled by the same physical matter density in inertial and linearly accelerating reference frames, there appears a discrepancy between the two in rotating reference frames in that Gauss law holds for an effective mass density that differs from the physical matter density. This effective density has its origin in the simulated magnetic field that appears in rotating frames, highlighting a rather striking difference between linearly and rotationally accelerating reference frames. We further show that the dynamical equations that govern the simulated gravitational and magnetic fields have the same form as Maxwell's equations, a surprising conclusion given that these equations are well-known to obey special relativity (and $U(1)$-gauge symmetry), rather than Galilean symmetry.

Leo Rodriguez; James St. Germaine-Fuller; Sujeev Wickramasekara

2014-12-26T23:59:59.000Z

108

Massive Gravity Wrapped in the Cosmic Web  

Science Journals Connector (OSTI)

We study how the filamentary pattern of the cosmic web changes if the true gravity deviates from general relativity (GR) on a large scale. The f(R) gravity, whose strength is controlled to satisfy the current observational constraints on the cluster scale, is adopted as our fiducial model and a large, high-resolution N-body simulation is utilized for this study. By applying the minimal spanning tree algorithm to the halo catalogs from the simulation at various epochs, we identify the main stems of the rich superclusters located in the most prominent filamentary section of the cosmic web and determine their spatial extents per member cluster to be the degree of their straightness. It is found that the f(R) gravity has the effect of significantly bending the superclusters and that the effect becomes stronger as the universe evolves. Even in the case where the deviation from GR is too small to be detectable by any other observables, the degree of the supercluster straightness exhibits a conspicuous difference between the f(R) and the GR models. Our results also imply that the supercluster straightness could be a useful discriminator of f(R) gravity from the coupled dark energy since it is shown to evolve differently between the two models. As a final conclusion, the degree of the straightness of the rich superclusters should provide a powerful cosmological test of large scale gravity.

Junsup Shim; Jounghun Lee; Baojiu Li

2014-01-01T23:59:59.000Z

109

Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2002) | Open  

Open Energy Info (EERE)

Jump to: navigation, search Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location. References N. R. Warpinski, A. R. Sattlerl, D. A. Sanchez (2002) Geothermal Resource Exploration And Definition Project

110

Magnetic shielding  

DOE Patents [OSTI]

A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines. 3 figs.

Kerns, J.A.; Stone, R.R.; Fabyan, J.

1987-10-06T23:59:59.000Z

111

Magnetic shielding  

DOE Patents [OSTI]

A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

Kerns, John A. (Livermore, CA); Stone, Roger R. (Walnut Creek, CA); Fabyan, Joseph (Livermore, CA)

1987-01-01T23:59:59.000Z

112

Strange Magnetism  

E-Print Network [OSTI]

We present an analytic and parameter-free expression for the momentum dependence of the strange magnetic form factor of the nucleon and its corresponding radius which has been derived in Heavy Baryon Chiral Perturbation Theory. We also discuss a model-independent relation between the isoscalar magnetic and the strange magnetic form factors of the nucleon based on chiral symmetry and SU(3) only. These limites are used to derive bounds on the strange magnetic moment of the proton from the recent measurement by the SAMPLE collaboration.

Thomas R. Hemmert; Ulf-G. Meissner; Sven Steininger

1998-11-09T23:59:59.000Z

113

Optical Magnetism  

Science Journals Connector (OSTI)

Magnetic dipole radiation one fourth as intense as electric dipole radiation, as well as a novel nonlinear magneto-optical effect are reported in dielectric media.

Oliveira, Samuel L; Rand, Stephen C

114

Magnetic Field Safety Magnetic Field Safety  

E-Print Network [OSTI]

Magnetic Field Safety Training #12;Magnetic Field Safety Strong Magnetic Fields exist around energized magnets. High magnetic fields alone are a recognized hazard only for personnel with certain medical conditions such as pacemakers, magnetic implants, or embedded shrapnel. In addition, high magnetic

McQuade, D. Tyler

115

Magnetic Field Safety Training  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Safety Training Magnetic Field Safety Strong Magnetic Fields exist around energized magnets. High magnetic fields alone are a recognized hazard only for personnel with certain...

116

Cosmological perturbations in f(T) gravity  

SciTech Connect (OSTI)

We investigate the cosmological perturbations in f(T) gravity. Examining the pure gravitational perturbations in the scalar sector using a diagonal vierbein, we extract the corresponding dispersion relation, which provides a constraint on the f(T) Ansaetze that lead to a theory free of instabilities. Additionally, upon inclusion of the matter perturbations, we derive the fully perturbed equations of motion, and we study the growth of matter overdensities. We show that f(T) gravity with f(T) constant coincides with General Relativity, both at the background as well as at the first-order perturbation level. Applying our formalism to the power-law model we find that on large subhorizon scales (O(100 Mpc) or larger), the evolution of matter overdensity will differ from {Lambda}CDM cosmology. Finally, examining the linear perturbations of the vector and tensor sectors, we find that (for the standard choice of vierbein) f(T) gravity is free of massive gravitons.

Chen, Shih-Hung; Dent, James B. [Department of Physics and School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287-1404 (United States); Dutta, Sourish [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States); Saridakis, Emmanuel N. [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China)

2011-01-15T23:59:59.000Z

117

Emergence in Holographic Scenarios for Gravity  

E-Print Network [OSTI]

'Holographic' relations between theories have become an important theme in quantum gravity research. These relations entail that a theory without gravity is equivalent to a gravitational theory with an extra spatial dimension. The idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis of his studies of evaporating black holes. Soon afterwards the holographic 'AdS/CFT' duality was introduced, which since has been intensively studied in the string theory community and beyond. Recently, Erik Verlinde has proposed that even Newton's law of gravitation can be related holographically to the 'thermodynamics of information' on screens. We discuss these scenarios, with special attention to the status of the holographic relation in them and to the question of whether they make gravity and spacetime emergent. We conclude that only Verlinde's scheme straightfowardly instantiates emergence. However, assuming a non-standard interpretation of AdS/CFT may create room for the emergence of spacetime and ...

Dieks, Dennis; de Haro, Sebastian

2015-01-01T23:59:59.000Z

118

Quantum gravity effects in the Kerr spacetime  

SciTech Connect (OSTI)

We analyze the impact of the leading quantum gravity effects on the properties of black holes with nonzero angular momentum by performing a suitable renormalization group improvement of the classical Kerr metric within quantum Einstein gravity. In particular, we explore the structure of the horizons, the ergosphere, and the static limit surfaces as well as the phase space available for the Penrose process. The positivity properties of the effective vacuum energy-momentum tensor are also discussed and the 'dressing' of the black hole's mass and angular momentum are investigated by computing the corresponding Komar integrals. The pertinent Smarr formula turns out to retain its classical form. As for their thermodynamical properties, a modified first law of black-hole thermodynamics is found to be satisfied by the improved black holes (to second order in the angular momentum); the corresponding Bekenstein-Hawking temperature is not proportional to the surface gravity.

Reuter, M. [Institute of Physics, University of Mainz, Staudingerweg 7, D-55099 Mainz (Germany); Tuiran, E. [Departamento de Fisica, Universidad del Norte, Km 5 via a Puerto Colombia, AA-1569 Barranquilla (Colombia)

2011-02-15T23:59:59.000Z

119

Photonic Crystal Beads from Gravity-Driven Microfluidics  

Science Journals Connector (OSTI)

Photonic Crystal Beads from Gravity-Driven Microfluidics ... Compared to traditional methods, the droplet templates of the PCBs are generated by using the ultrastable gravity as the driving force for the microfluidics, thus the PCBs are formed with minimal polydispersity. ...

Hongcheng Gu; Fei Rong; Baocheng Tang; Yuanjin Zhao; Degang Fu; Zhongze Gu

2013-05-29T23:59:59.000Z

120

API gravity ranges of EIA-182 crude streams  

Gasoline and Diesel Fuel Update (EIA)

API Gravity Ranges of Selected Crude Streams, EIA-182 Gravity 20 or less Alabama Heavy Ca - Coalinga Ca - Cymric Ca - Kern River Ca - Lost Hills Ca - Midway-Sunset Ca OCS - Hondo...

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The generalized second law of thermodynamics in generalized gravity theories  

E-Print Network [OSTI]

We investigate the generalized second law of thermodynamics (GSL) in generalized theories of gravity. We examine the total entropy evolution with time including the horizon entropy, the non-equilibrium entropy production, and the entropy of all matter, field and energy components. We derive a universal condition to protect the generalized second law and study its validity in different gravity theories. In Einstein gravity, (even in the phantom-dominated universe with a Schwarzschild black hole), Lovelock gravity, and braneworld gravity, we show that the condition to keep the GSL can always be satisfied. In $f(R)$ gravity and scalar-tensor gravity, the condition to protect the GSL can also hold because the gravity is always attractive and the effective Newton constant should be approximate constant satisfying the experimental bounds.

Shao-Feng Wu; Bin Wang; Guo-Hong Yang; Peng-Ming Zhang

2008-01-17T23:59:59.000Z

122

Gravity data as a tool for landfill study  

Science Journals Connector (OSTI)

This paper shows the potential of gravity data to map a buried landfill bottom topography. To this end, a ... gravity inversion method is presented for estimating the landfills bottom depths at discrete points a...

Joo B. C. Silva; Wlamir A. Teixeira; Valria C. F. Barbosa

2009-04-01T23:59:59.000Z

123

Inertia and gravitation in teleparallel gravity  

E-Print Network [OSTI]

Using the fact that teleparallel gravity allows a separation between gravitation and inertia, explicit expressions for the gravitational and the inertial energy-momentum densities are obtained. It is shown that, like all other fields of nature, gravitation alone has a tensorial energy-momentum density which in a general frame is conserved in the covariant sense. Together with the inertial energy-momentum density, they form a pseudotensor which is conserved in the ordinary sense. An analysis of the role played by the gravitational and the inertial densities in the computation of the total energy and momentum of gravity is presented.

R. Aldrovandi; Tiago Gribl Lucas; J. G. Pereira

2009-08-14T23:59:59.000Z

124

Geodesic distances in Liouville quantum gravity  

E-Print Network [OSTI]

In order to study the quantum geometry of random surfaces in Liouville gravity, we propose a definition of geodesic distance associated to a Gaussian free field on a regular lattice. This geodesic distance is used to numerically determine the Hausdorff dimension associated to shortest cycles of 2d quantum gravity on the torus coupled to conformal matter fields, showing agreement with a conjectured formula by Y. Watabiki. Finally, the numerical tools are put to test by quantitatively comparing the distribution of lengths of shortest cycles to the corresponding distribution in large random triangulations.

Jan Ambjorn; Timothy Budd

2014-11-12T23:59:59.000Z

125

Differential geometry, Palatini gravity and reduction  

SciTech Connect (OSTI)

The present article deals with a formulation of the so called (vacuum) Palatini gravity as a general variational principle. In order to accomplish this goal, some geometrical tools related to the geometry of the bundle of connections of the frame bundle LM are used. A generalization of Lagrange-Poincar reduction scheme to these types of variational problems allows us to relate it with the Einstein-Hilbert variational problem. Relations with some other variational problems for gravity found in the literature are discussed.

Capriotti, S., E-mail: santiago.capriotti@uns.edu.ar [Departamento de Matemtica, Universidad Nacional del Sur, 8000 Baha Blanca (Argentina)

2014-01-15T23:59:59.000Z

126

A perturbation approach to Translational Gravity  

E-Print Network [OSTI]

Within a gauge formulation of 3+1 gravity relying on a nonlinear realization of the group of isometries of space-time, a natural expansion of the metric tensor arises and a simple choice of the gravity dynamical variables is possible. We show that the expansion parameter can be identified with the gravitational constant and that the first order depends only on a diagonal matrix in the ensuing perturbation approach. The explicit first order solution is calculated in the static isotropic case, and its general structure is worked out in the harmonic gauge.

J. Julve; A. Tiemblo

2013-01-09T23:59:59.000Z

127

Gravity as a Gauge Theory of Translations  

E-Print Network [OSTI]

The Poincar\\'e group can be interpreted as the group of isometries of a minkowskian space. This point of view suggests to consider the group of isometries of a given space as the suitable group to construct a gauge theory of gravity. We extend these ideas to the case of maximally symmetric spaces to reach a realistic theory including the presence of a cosmological constant. Introducing the concept of "minimal tetrads" we deduce Einstein gravity in the vacuum as a gauge theory of translations.

J. Martin-Martin; A. Tiemblo

2009-07-16T23:59:59.000Z

128

Standard Model and Gravity from Spinors  

E-Print Network [OSTI]

We propose to unify the Gravity and Standard Model gauge groups by using algebraic spinors of the standard four-dimensional Clifford algebra, in left-right symmetric fashion. This generates exactly a Standard Model family of fermions, and a Pati-Salam unification group emerges, at the Planck scale, where (chiral) self-dual gravity decouples. As a remnant of the unification, isospin-triplets spin-two particles may naturally appear at the weak scale, providing a striking signal at the LHC.

F. Nesti

2008-06-20T23:59:59.000Z

129

Asymptotic freedom in Horava-Lifshitz gravity  

E-Print Network [OSTI]

We use the Wetterich equation for foliated spacetimes to study the RG flow of projectable Horava-Lifshitz gravity coupled to n Lifshitz scalars. Using novel results for anisotropic heat kernels, the matter-induced beta functions for the gravitational couplings are computed explicitly. The RG flow exhibits an UV attractive anisotropic Gaussian fixed point where Newton's constant vanishes and the extra scalar mode decouples. This fixed point ensures that the theory is asymptotically free in the large-n expansion, indicating that projectable Horava-Lifshitz gravity is perturbatively renormalizable. Notably, the fundamental fixed point action does not obey detailed balance.

D'Odorico, Giulio; Schutten, Marrit

2014-01-01T23:59:59.000Z

130

Asymptotic freedom in Horava-Lifshitz gravity  

E-Print Network [OSTI]

We use the Wetterich equation for foliated spacetimes to study the RG flow of projectable Horava-Lifshitz gravity coupled to n Lifshitz scalars. Using novel results for anisotropic heat kernels, the matter-induced beta functions for the gravitational couplings are computed explicitly. The RG flow exhibits an UV attractive anisotropic Gaussian fixed point where Newton's constant vanishes and the extra scalar mode decouples. This fixed point ensures that the theory is asymptotically free in the large-n expansion, indicating that projectable Horava-Lifshitz gravity is perturbatively renormalizable. Notably, the fundamental fixed point action does not obey detailed balance.

Giulio D'Odorico; Frank Saueressig; Marrit Schutten

2014-06-17T23:59:59.000Z

131

Higher curvature gravity at the LHC  

Science Journals Connector (OSTI)

We investigate brane-world models in different viable F(R) gravity theories where the Lagrangian is an arbitrary function of the curvature scalar. Deriving the warped metric for this model, resembling Randal-Sundrum (RS)-like solutions, we determine the graviton KK modes. The recent observations at the LHC, which constrain the RS graviton KK modes to a mass range greater than 3TeV, are incompatible with RS model predictions. It is shown that the models with F(R) gravity in the bulk address the issue, which in turn constrains the F(R) model itself.

Sumanta Chakraborty and Soumitra SenGupta

2014-08-08T23:59:59.000Z

132

Higher curvature gravity at the LHC  

E-Print Network [OSTI]

We investigate brane-world models in different viable $F(R)$ gravity theories where the Lagrangian is an arbitrary function of the curvature scalar. Deriving the warped metric for this model, resembling Randal-Sundrum (RS) like solutions, we determine the graviton KK modes. The recent observations at the LHC, which constrain the RS graviton KK modes to a mass range greater than 3 TeV, are incompatible to RS model predictions. It is shown that the models with $F(R)$ gravity in the bulk address the issue which in turn constrains the $F(R)$ model itself.

Sumanta Chakraborty; Soumitra SenGupta

2014-03-13T23:59:59.000Z

133

Magnetic insulation  

Science Journals Connector (OSTI)

... by Winterberg1, led me to look into the background of the idea of 'magnetic insulation'. The purpose of this letter is to point out that the scheme described in ... were presented earlier in a longer article2. In that article he suggested that 'magnetic insulation' might make possible a transformer for 109 V. A year later the same objections ...

JOHN P. BLEWETT

1974-06-28T23:59:59.000Z

134

Magnetism1  

Science Journals Connector (OSTI)

... is reached, the rate of diminution becomes very rapid indeed, until, finally, the magnetism of the iron disappears at the same time as for small forces. Instead of ... a lower maximum, and its rise is less rapid. The critical temperature at which magnetism disappears changes rapidly with the composition of the steel. For very soft charcoal iron ...

1890-01-23T23:59:59.000Z

135

Magnetism Group  

Science Journals Connector (OSTI)

... of the Institute of Physics and the Physical Society has announced the establishment of a Magnetism Group. The aim of the new Group is to further interest in ... Group. The aim of the new Group is to further interest in magnetism by holding regular discussion meetings and in other ways. It is intended that these ...

1965-09-04T23:59:59.000Z

136

Terrestrial Magnetism*  

Science Journals Connector (OSTI)

... A similar investigation of the effect of the moon's action on terrestrial magnetism requires a series of observations made at much less distant intervals than the monthly ones ... heat, from the central body of our system, or merely having its own inherent magnetism modified by solar action, then we must choose as our unit the lunation, or ...

1873-01-09T23:59:59.000Z

137

Terrestrial Magnetism*  

Science Journals Connector (OSTI)

... IN bringing before you this evening, gentlemen, the subject of terrestrial magnetism, it is not my intention to attempt to present you with an exhaustive paper ... clearly as I am able, what is the actual condition of our knowledge respecting the magnetism of the globe, and what the nature of its complex variations, without, however, ...

1873-01-02T23:59:59.000Z

138

Terrestrial Magnetism  

Science Journals Connector (OSTI)

... THE present activity of the department of terrestrial magnetism of the Carnegie Institution of Washington and the largeness of its future aims are alike ... a progress report which he contributes to the latest (March) number of Terrestrial Magnetism. The department, which has lately entered on its eleventh year, has under construetion ...

C. CHREE

1914-07-23T23:59:59.000Z

139

Remanent Magnetism  

Science Journals Connector (OSTI)

... STUDY of the natural remanent magnetism of rocks is becoming a familiar method for determining the direction of the Earth's ... the geomagnetic poles or of the continents themselves. An alternative use for measurements of remanent magnetism, namely, the determination of the temperature of formation of pyroclastic deposits, is described ...

1958-03-22T23:59:59.000Z

140

Magnetic shielding  

DOE Patents [OSTI]

A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

Kerns, J.A.; Stone, R.R.; Fabyan, J.

1985-02-12T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Superconducting Magnets  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mit Hilfe der Technologie supraleitender Magnete lassen sich in Mit Hilfe der Technologie supraleitender Magnete lassen sich in Ringbeschleunigern höhere Energien erreichen. Weil supraleitende Spulen keinen elektrischen Widerstand aufweisen, können damit stärkere Magnetfelder erzeugt werden. In normal leitenden Elektromagneten wird - wegen des elektrischen Widerstands der Drähte - die Spule aufgeheizt. Auf diese Weise geht sehr viel Energie in Form von Wärme verloren, was die Energiekosten dieser Magnete in die Höhe treibt. Supraleitende Spulen erlauben es, Magnete grosser Feldstärke unter günstigen Bedingungen zu betreiben und damit die Energiekosten zu senken. Durch den Einbau supraleitender Spulen in den Ringbeschleuniger von Fermilab konnte dessen Energie verdoppelt werden.Auch der im Bau befindliche "Large Hadron Collider" am CERN wird supraleitende Magnete

142

Magnetic nanotubes  

DOE Patents [OSTI]

A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.

Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

2010-11-16T23:59:59.000Z

143

Observing ocean heat content using satellite gravity and altimetry  

E-Print Network [OSTI]

: ocean heat content, altimetry, satellite gravity, steric height, remote sensing Citation: Jayne, S. RObserving ocean heat content using satellite gravity and altimetry Steven R. Jayne1,2 and John M with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat

Jayne, Steven

144

The Mars Gravity Biosatellite as an innovative partial gravity research platform  

E-Print Network [OSTI]

The Mars Gravity Biosatellite is an unprecedented independent spaceflight platform for gravitational biology research. With a projected first launch after 2010, the low Earth orbit satellite will support a cohort of fifteen ...

Fulford-Jones, Thaddeus R. F

2008-01-01T23:59:59.000Z

145

Gravity and the Quantum: Are they Reconcilable?  

E-Print Network [OSTI]

General relativity and quantum mechanics are conflicting theories. The seeds of discord are the fundamental principles on which these theories are grounded. General relativity, on one hand, is based on the equivalence principle, whose strong version establishes the local equivalence between gravitation and inertia. Quantum mechanics, on the other hand, is fundamentally based on the uncertainty principle, which is essentially nonlocal in the sense that a particle does not follow one trajectory, but infinitely many trajectories, each one with a different probability. This difference precludes the existence of a quantum version of the strong equivalence principle, and consequently of a quantum version of general relativity. Furthermore, there are compelling experimental evidences that a quantum object in the presence of a gravitational field violates the weak equivalence principle. Now it so happens that, in addition to general relativity, gravitation has an alternative, though equivalent description, given by teleparallel gravity, a gauge theory for the translation group. In this theory torsion, instead of curvature, is assumed to represent the gravitational field. These two descriptions lead to the same classical results, but are conceptually different. In general relativity, curvature geometrizes the interaction, while torsion in teleparallel gravity acts as a force, similar to the Lorentz force of electrodynamics. Because of this peculiar property, teleparallel gravity describes the gravitational interaction without requiring any of the equivalence principles. The replacement of general relativity by teleparallel gravity may, in consequence, lead to a conceptual reconciliation of gravitation with quantum mechanics.

R. Aldrovandi; J. G. Pereira; K. H. Vu

2005-09-14T23:59:59.000Z

146

MODIFIED GRAVITY SPINS UP GALACTIC HALOS  

SciTech Connect (OSTI)

We investigate the effect of modified gravity on the specific angular momentum of galactic halos by analyzing the halo catalogs at z = 0 from high-resolution N-body simulations for a f(R) gravity model that meets the solar-system constraint. It is shown that the galactic halos in the f(R) gravity model tend to acquire significantly higher specific angular momentum than those in the standard {Lambda}CDM model. The largest difference in the specific angular momentum distribution between these two models occurs for the case of isolated galactic halos with mass less than 10{sup 11} h {sup -1} M {sub Sun }, which are likely least shielded by the chameleon screening mechanism. As the specific angular momentum of galactic halos is rather insensitive to other cosmological parameters, it can in principle be an independent discriminator of modified gravity. We speculate a possibility of using the relative abundance of low surface brightness galaxies (LSBGs) as a test of general relativity given that the formation of the LSBGs occurs in fast spinning dark halos.

Lee, Jounghun [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of); Zhao, Gong-Bo [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China)] [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China); Li, Baojiu [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)] [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Koyama, Kazuya, E-mail: jounghun@astro.snu.ac.kr [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)] [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)

2013-01-20T23:59:59.000Z

147

Unified description of screened modified gravity  

Science Journals Connector (OSTI)

We consider modified gravity models driven by a scalar field whose effects are screened in high density regions due to the presence of nonlinearities in its interaction potential and/or its coupling to matter. Our approach covers chameleon, f(R) gravity, dilaton and symmetron models and allows a unified description of all these theories. We find that the dynamics of modified gravity are entirely captured by the time variation of the scalar field mass and its coupling to matter evaluated at the cosmological minimum of its effective potential, where the scalar field has sat since an epoch prior to big bang nucleosynthesis. This new parametrization of modified gravity allows one to reconstruct the potential and coupling to matter and therefore to analyze the full dynamics of the models, from the scale dependent growth of structures at the linear level to nonlinear effects requiring N-body simulations. This procedure is illustrated with explicit examples of reconstruction for chameleon, dilaton, f(R) and symmetron models.

Philippe Brax; Anne-Christine Davis; Baojiu Li; Hans A. Winther

2012-08-08T23:59:59.000Z

148

The diffeomorphism algebra approach to quantum gravity  

E-Print Network [OSTI]

The representation theory of non-centrally extended Lie algebras of Noether symmetries, including spacetime diffeomorphisms and reparametrizations of the observer's trajectory, has recently been developped. It naturally solves some long-standing problems in quantum gravity, e.g. the role of diffeomorphisms and the causal structure, but some new questions also arise.

T. A. Larsson

1999-09-13T23:59:59.000Z

149

Landscape versus Swampland for Higher Derivative Gravity  

E-Print Network [OSTI]

We survey recent studies of Gauss-Bonnet gravity and its dual conformal field theories, including their relation to the violation of the Kovtun-Starinets-Son viscosity bound. Via holography, we can also study properties such as microcausality and unitarity of boundary field theory duals. Such studies in turn supply constraints on bulk gravitational theories, consigning some of them to the swampland.

Sho Yaida

2009-02-10T23:59:59.000Z

150

Gravitomagnetism and the Speed of Gravity  

E-Print Network [OSTI]

Experimental discovery of the gravitomagnetic fields generated by translational and/or rotational currents of matter is one of primary goals of modern gravitational physics. The rotational (intrinsic) gravitomagnetic field of the Earth is currently measured by the Gravity Probe B. The present paper makes use of a parametrized post-Newtonian (PN) expansion of the Einstein equations to demonstrate how the extrinsic gravitomagnetic field generated by the translational current of matter can be measured by observing the relativistic time delay caused by a moving gravitational lens. We prove that measuring the extrinsic gravitomagnetic field is equivalent to testing relativistic effect of the aberration of gravity caused by the Lorentz transformation of the gravitational field. We unfold that the recent Jovian deflection experiment is a null-type experiment testing the Lorentz invariance of the gravitational field (aberration of gravity), thus, confirming existence of the extrinsic gravitomagnetic field associated with orbital motion of Jupiter with accuracy 20%. We comment on erroneous interpretations of the Jovian deflection experiment given by a number of researchers who are not familiar with modern VLBI technique and subtleties of JPL ephemeris. We propose to measure the aberration of gravity effect more accurately by observing gravitational deflection of light by the Sun and processing VLBI observations in the geocentric frame with respect to which the Sun is moving with velocity 30 km/s.

Sergei M. Kopeikin

2005-06-30T23:59:59.000Z

151

Linear chain magnetism  

Science Journals Connector (OSTI)

Linear chain magnetism ... A brief introduction to this concept, which is also called lower dimensional magnetism. ...

Richard L. Carlin

1991-01-01T23:59:59.000Z

152

Gravity modeling of Cenozoic extensional basins, offshore Vietnam  

E-Print Network [OSTI]

. . . 78 . . . 81 LIST OF FIGURES Figure 1 Southeast Asian study area location map 2 Major tectonic features of Southeast Asia 3 Mekong basin sediment isopach map . 4 Mekong basin generalized stratigraphy . Page . . . . 1 0 5 Mekong basin... gravity model 2 17 Mekong 2D forward gravity model 3 18 Mekong 2D forward gravity model 4 19 Mekong 2D forward gravity model 5 32 34 . . . 35 . . . 36 Page 20 Schematic 3D forward gravity model of Yinggehai basin sediment . . . 21 3D forward...

Mauri, Steven Joseph

2012-06-07T23:59:59.000Z

153

Low dimensional magnetism  

E-Print Network [OSTI]

Magnetism in Ultracold Gases 4 Magnetic phase diagram of aMagnetism . . . . . . . . . . . .1.3 Magnetism in condensedIntroduction 1 Brief introduction to magnetism 1.1 Classic

Kjall, Jonas Alexander

2012-01-01T23:59:59.000Z

154

Ground Gravity Survey At Coso Geothermal Area (1990) | Open Energy  

Open Energy Info (EERE)

Coso Geothermal Area (1990) Coso Geothermal Area (1990) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Coso Geothermal Area (1990) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1990 Usefulness not indicated DOE-funding Unknown Exploration Basis To identify features related to the heat source and to seek possible evidence for an underlying magma chamber Notes 2D and 3D gravity modeling was done using gridded Bouguer gravity data covering a 45 by 45 km region over the Coso geothermal area. Isostatic and terrain corrected Bouguer gravity data for about 1300 gravity stations were obtained from the US Geological Survey. After the data were checked, the gravity values were gridded at 1 km centers for the area of interest

155

Magnetic Viscosity  

Science Journals Connector (OSTI)

1 January 1893 research-article Magnetic Viscosity J. Hopkinson E. Wilson F. Lydall The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings of the Royal Society of London. www.jstor.org

1893-01-01T23:59:59.000Z

156

Rock magnetism  

Science Journals Connector (OSTI)

The past three decades have witnessed a new paradigm, the plate tectonics paradigm, in Earth sciences. The record of the Earth's magnetic field stored in rocks played a major role in the establishment of this par...

Ronald T. Merrill

1989-01-01T23:59:59.000Z

157

Learning About Magnets!  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the the National High Magnetic Field Laboratory Learning About Name A magnet is a material or object that creates a magnetic fi eld. This fi eld is invisible, but it creates a force that can "attract" or "repel" other magnets and magnetic materials, like iron or nickel. What is a Magnet? This bar magnet is a permanent magnet. Permanent magnets can be found in the Earth as rocks and metals. Magnets have

158

Controlling Magnetism at the Nanoscale  

E-Print Network [OSTI]

Manipulation of Magnetism - External148 Conclusion A The Magnetism Cheat Sheet A.1 Magnetic157 A.2 Magnetism Unit Conversion

Wong, Jared

2012-01-01T23:59:59.000Z

159

The String Landscape, Black Holes and Gravity as the Weakest Force  

E-Print Network [OSTI]

We conjecture a general upper bound on the strength of gravity relative to gauge forces in quantum gravity. This implies, in particular, that in a four-dimensional theory with gravity and a U(1) gauge field with gauge coupling g, there is a new ultraviolet scale Lambda=g M_{Pl}, invisible to the low-energy effective field theorist, which sets a cutoff on the validity of the effective theory. Moreover, there is some light charged particle with mass smaller than or equal to Lambda. The bound is motivated by arguments involving holography and absence of remnants, the (in) stability of black holes as well as the non-existence of global symmetries in string theory. A sharp form of the conjecture is that there are always light "elementary" electric and magnetic objects with a mass/charge ratio smaller than the corresponding ratio for macroscopic extremal black holes, allowing extremal black holes to decay. This conjecture is supported by a number of non-trivial examples in string theory. It implies the necessary presence of new physics beneath the Planck scale, not far from the GUT scale, and explains why some apparently natural models of inflation resist an embedding in string theory.

Nima Arkani-Hamed; Lubos Motl; Alberto Nicolis; Cumrun Vafa

2006-01-02T23:59:59.000Z

160

Neutrino magnetic moment in a magnetized plasma  

E-Print Network [OSTI]

The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.

N. V. Mikheev; E. N. Narynskaya

2010-11-08T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Detecting individual gravity modes in the Sun  

E-Print Network [OSTI]

Many questions are still open regarding the structure and the dynamics of the solar core. By constraining more this region in the solar evolution models, we can reduce the incertitudes on some physical processes and on momentum transport mechanisms. A first big step was made with the detection of the signature of the dipole-gravity modes in the Sun, giving a hint of a faster rotation rate inside the core. A deeper analysis of the GOLF/SoHO data unveils the presence of a pattern of peaks that could be interpreted as dipole gravity modes. In that case, those modes can be characterized, thus bringing better constraints on the rotation of the core as well as some structural parameters such as the density at these very deep layers of the Sun interior.

Garcia, R A; Eff-Darwich, A; Garrido, R; Jimenez, A; Mathis, S; Moya, A; Palle, P L; Regulo, C; Salabert, D; Suarez, J C; Turck-Chieze, S

2009-01-01T23:59:59.000Z

162

Viscosity bound violation in higher derivative gravity  

SciTech Connect (OSTI)

Motivated by the vast string landscape, we consider the shear viscosity to entropy density ratio in conformal field theories dual to Einstein gravity with curvature square corrections. After field redefinitions these theories reduce to Gauss-Bonnet gravity, which has special properties that allow us to compute the shear viscosity nonperturbatively in the Gauss-Bonnet coupling. By tuning of the coupling, the value of the shear viscosity to entropy density ratio can be adjusted to any positive value from infinity down to zero, thus violating the conjectured viscosity bound. At linear order in the coupling, we also check consistency of four different methods to calculate the shear viscosity, and we find that all of them agree. We search for possible pathologies associated with this class of theories violating the viscosity bound.

Brigante, Mauro; Liu Hong; Myers, Robert C.; Shenker, Stephen; Yaida, Sho [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada) and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Department of Physics, Stanford University, Stanford, CA 94305 (United States)

2008-06-15T23:59:59.000Z

163

Quantum gravity at a Lifshitz point  

SciTech Connect (OSTI)

We present a candidate quantum field theory of gravity with dynamical critical exponent equal to z=3 in the UV. (As in condensed-matter systems, z measures the degree of anisotropy between space and time.) This theory, which at short distances describes interacting nonrelativistic gravitons, is power-counting renormalizable in 3+1 dimensions. When restricted to satisfy the condition of detailed balance, this theory is intimately related to topologically massive gravity in three dimensions, and the geometry of the Cotton tensor. At long distances, this theory flows naturally to the relativistic value z=1, and could therefore serve as a possible candidate for a UV completion of Einstein's general relativity or an infrared modification thereof. The effective speed of light, the Newton constant and the cosmological constant all emerge from relevant deformations of the deeply nonrelativistic z=3 theory at short distances.

Horava, Petr [Berkeley Center for Theoretical Physics and Department of Physics, University of California, Berkeley, California, 94720-7300 (United States) and Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8162 (United States)

2009-04-15T23:59:59.000Z

164

Chaotic inflation in higher derivative gravity theories  

E-Print Network [OSTI]

In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar $R^2$, the contraction of the Ricci tensor $P$, and the contraction of the Riemann tensor $Q$. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the $e$-folds number, and the spectral indexes. Several explicit examples are furnished, namely we will consider the cases of massive scalar field and scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. Viable inflation according with observations is analyzed.

Myrzakul, Shynaray; Sebastiani, Lorenzo

2015-01-01T23:59:59.000Z

165

Auxiliary fields representation for modified gravity models  

SciTech Connect (OSTI)

We consider tensor-multiscalar representations for several types of modified gravity actions. The first example is the theory with the action representing an arbitrary smooth function of the scalar curvature R and {open_square}R, the integrand of the Gauss-Bonnet term and the square of the Weyl tensor. We present a simple procedure leading to an equivalent theory of a space-time metric and four auxiliary scalars and especially discuss the calibration of a cosmological constant and the condition of the existence of de Sitter-like solutions in the case of an empty universe. The condition for obtaining a smaller number of independent scalar fields is derived. The second example is the Eddington-like gravity action. In this case we show, in particular, the equivalence of the theory to general relativity with the cosmological constant term, with or without use of the first-order formalism, and also discuss some possible generalizations.

Rodrigues, Davi C.; Salles, Filipe de O; Shapiro, Ilya L.; Starobinsky, Alexei A. [Departamento de Fisica, CCE, Universidade Federal do Espirito Santo, 29075-910, Vitoria, ES (Brazil); Departamento de Fisica, ICE, Universidade Federal de Juiz de Fora, 36036-330, MG (Brazil); Landau Institute for Theoretical Physics, Moscow, 119334 (Russian Federation); RESCEU, Graduate School of Science, University of Tokyo, Tokyo 113-0033 (Japan)

2011-04-15T23:59:59.000Z

166

Lorentz violation and higher-derivative gravity  

E-Print Network [OSTI]

In this work, we analyze a gravity model with higher derivatives including a CPT-even Lorentz-violating term. In principle, the model could be a low-energy limit of a Lorentz-invariant theory presenting the violation of Lorentz symmetry as a consequence of a spontaneous symmetry-breaking mechanism if a decoupling between the metric and the Nambu-Goldstone modes is assumed. We have set up a convenient operator basis for the expansion of wave operators for symmetric second-rank tensors in the presence of a background vector. By using this set of operators, the particle content is obtained, and its consistency, regarding the conditions for stability and unitarity, is discussed. We conclude that this extra Lorentz noninvariant contribution is unable to address the problems of stability and unitarity of higher-derivative gravity models.

Hernaski, C

2014-01-01T23:59:59.000Z

167

Hydrogen atom in Palatini theories of gravity  

E-Print Network [OSTI]

We study the effects that the gravitational interaction of $f(R)$ theories of gravity in Palatini formalism has on the stationary states of the Hydrogen atom. We show that the role of gravity in this system is very important for lagrangians $f(R)$ with terms that grow at low curvatures, which have been proposed to explain the accelerated expansion rate of the universe. We find that new gravitationally induced terms in the atomic Hamiltonian generate a strong backreaction that is incompatible with the very existence of bound states. In fact, in the 1/R model, Hydrogen disintegrates in less than two hours. The universe that we observe is, therefore, incompatible with that kind of gravitational interaction. Lagrangians with high curvature corrections do not lead to such instabilities.

Gonzalo J. Olmo

2008-06-03T23:59:59.000Z

168

Correlation Functions in the Multiple Ising Model Coupled to Gravity  

E-Print Network [OSTI]

The model of p Ising spins coupled to 2d gravity, in the form of a sum over planar phi-cubed graphs, is studied and in particular the two-point and spin-spin correlation functions are considered. We first solve a toy model in which only a partial summation over spin configurations is performed and, using a modified geodesic distance, various correlation functions are determined. The two-point function has a diverging length scale associated with it. The critical exponents are calculated and it is shown that all the standard scaling relations apply. Next the full model is studied, in which all spin configurations are included. Many of the considerations for the toy model apply for the full model, which also has a diverging geometric correlation length associated with the transition to a branched polymer phase. Using a transfer function we show that the two-point and spin-spin correlation functions decay exponentially with distance. Finally, by assuming various scaling relations, we make a prediction for the critical exponents at the transition between the magnetized and branched polymer phases in the full model.

M. G. Harris; J. Ambjorn

1996-02-06T23:59:59.000Z

169

Gravitational lensing in metric theories of gravity  

Science Journals Connector (OSTI)

Gravitational lensing in metric theories of gravity is discussed. I introduce a generalized approximate metric element, inclusive of both post-post-Newtonian contributions and a gravitomagnetic field. Following Fermats principle and standard hypotheses, I derive the time delay function and deflection angle caused by an isolated mass distribution. Several astrophysical systems are considered. In most of the cases, the gravitomagnetic correction offers the best perspectives for an observational detection. Actual measurements distinguish only marginally different metric theories from each other.

Mauro Sereno

2003-03-24T23:59:59.000Z

170

Non-metric gravity: A status report  

E-Print Network [OSTI]

We review the status of a certain (infinite) class of four-dimensional generally covariant theories propagating two degrees of freedom that are formulated without any direct mention of the metric. General relativity itself (in its Plebanski formulation) belongs to the class, so these theories are examples of modified gravity. We summarize the current understanding of the nature of the modification, of the renormalizability properties of these theories, of their coupling to matter fields, and describe some of their physical properties.

Kirill Krasnov

2007-11-05T23:59:59.000Z

171

The Hausdorff dimension in polymerized quantum gravity  

E-Print Network [OSTI]

We calculate the Hausdorff dimension, $d_H$, and the correlation function exponent, $\\eta$, for polymerized two dimensional quantum gravity models. If the non-polymerized model has correlation function exponent $\\eta_0 >3$ then $d_H=\\gamma^{-1}$ where $\\gamma$ is the susceptibility exponent. This suggests that these models may be in the same universality class as certain non-generic branched polymer models.

Martin G. Harris; John F. Wheater

1998-11-24T23:59:59.000Z

172

Gravity dual of the Ising model  

Science Journals Connector (OSTI)

We evaluate the partition function of three-dimensional theories of gravity in the quantum regime, where the antideSitter (AdS) radius is Planck scale and the central charge is of order one. The contribution from the AdS vacuum sector canwith certain assumptionsbe computed and equals the vacuum character of a minimal model conformal field theory. The torus partition function is given by a sum over geometries which is finite and computable. For generic values of Newtons constant G and the AdS radius ?, the result has no Hilbert space interpretation, but in certain cases it agrees with the partition function of a known conformal field theory. For example, the partition function of pure Einstein gravity with G=3? equals that of the Ising model, providing evidence that these theories are dual. We also present somewhat weaker evidence that the three-state and tricritical Potts models are dual to pure higher spin theories of gravity based on SL(3) and E6, respectively.

Alejandra Castro; Matthias R. Gaberdiel; Thomas Hartman; Alexander Maloney; Roberto Volpato

2012-01-19T23:59:59.000Z

173

Cosmology with Coupled Gravity and Dark Energy  

E-Print Network [OSTI]

Dark energy is a fundamental constituent of our universe, its status in the cosmological field equation should be equivalent to that of gravity. Here we construct a dark energy and matter gravity coupling (DEMC) model of cosmology in a way that dark energy and gravity are introduced into the cosmological field equation in parallel with each other from the beginning. The DEMC universe possesses a composite symmetry from global Galileo invariance and local Lorentz invariance. The observed evolution of the universe expansion rate at redshift z>1 is in tension with the standard LCDM model, but can be well predicted by the DEMC model from measurements of only nearby epochs. The so far most precise measured expansion rate at high z is quite a bit slower than the expectations from LCDM, but remarkably consistent with that from DEMC. It is hoped that the DEMC scenario can also help to solve other existing challenges to cosmology: large scale anomalies in CMB maps and large structures up to about 10^3 Mpc of a quasar group. The DEMC universe is a well defined mechanical system. From measurements we can quantitatively evaluate its total rest energy, present absolute radius and expanding speed.

Ti-Pei Li

2015-01-13T23:59:59.000Z

174

Cosmology with Coupled Gravity and Dark Energy  

E-Print Network [OSTI]

Dark energy is a fundamental constituent of our universe, its status in the cosmological field equation should be equivalent to that of gravity. Here we construct a dark energy and matter gravity coupling (DEMC) model of cosmology in a way that dark energy and gravity are introduced into the cosmological field equation in parallel with each other from the beginning. The DEMC universe possesses a composite symmetry from global Galileo invariance and local Lorentz invariance. The observed evolution of the universe expansion rate at redshift z>1 is in tension with the standard LCDM model, but can be well predicted by the DEMC model from measurements of only nearby epochs. The so far most precise measured expansion rate at high z is quite a bit slower than the expectations from LCDM, but remarkably consistent with that from DEMC. It is hoped that the DEMC scenario can also help to solve other existing challenges to cosmology: large scale anomalies in CMB maps and large structures up to about 10^3 Mpc of a quasar group. The DEMC universe is a well defined mechanical system. From measurements we can quantitatively evaluate its total rest energy, present absolute radius and expanding speed.

Ti-Pei Li

2014-09-01T23:59:59.000Z

175

Lorentz Invariance Violation in Modified Gravity  

E-Print Network [OSTI]

We consider an environmentally dependent violation of Lorentz invariance in scalar-tensor models of modified gravity where General Relativity is retrieved locally thanks to a screening mechanism. We find that fermions have a modified dispersion relation and would go faster than light in an anisotropic and space-dependent way along the scalar field lines of force. Phenomenologically, these models are tightly restricted by the amount of Cerenkov radiation emitted by the superluminal particles, a constraint which is only satisfied by chameleons. Measuring the speed of neutrinos emitted radially from the surface of the earth and observed on the other side of the earth would probe the scalar field profile of modified gravity models in dense environments. We argue that the test of the equivalence principle provided by the Lunar ranging experiment implies that a deviation from the speed of light, for natural values of the coupling scale between the scalar field and fermions, would be below detectable levels, unless gravity is modified by camouflaged chameleons where the field normalisation is environmentally dependent.

Philippe Brax

2012-02-03T23:59:59.000Z

176

MAXIMIZING MAGNETIC ENERGY STORAGE IN THE SOLAR CORONA  

SciTech Connect (OSTI)

The energy that drives solar eruptive events such as coronal mass ejections (CMEs) almost certainly originates in coronal magnetic fields. Such energy may build up gradually on timescales of days or longer before its sudden release in an eruptive event, and the presence of free magnetic energy capable of rapid release requires nonpotential magnetic fields and associated electric currents. For magnetic energy to power a CME, that energy must be sufficient to open the magnetic field to interplanetary space, to lift the ejecta against solar gravity, and to accelerate the material to speeds of typically several hundred km s{sup -1}. Although CMEs are large-scale structures, many originate from relatively compact active regions on the solar surface-suggesting that magnetic energy storage may be enhanced when it takes place in smaller magnetic structures. This paper builds on our earlier work exploring energy storage in large-scale dipolar and related bipolar magnetic fields. Here we consider two additional cases: quadrupolar fields and concentrated magnetic bipoles intended to simulate active regions. Our models yield stored energies whose excess over that of the corresponding open field state can be greater than 100% of the associated potential field energy; this contrasts with maximum excess energies of only about 20% for dipolar and symmetric bipolar configurations. As in our previous work, energy storage is enhanced when we surround a nonpotential field with a strong overlying potential field that acts to 'hold down' the nonpotential flux as its magnetic energy increases.

Wolfson, Richard; Drake, Christina; Kennedy, Max, E-mail: wolfson@middlebury.edu [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)

2012-05-01T23:59:59.000Z

177

Maximizing Magnetic Energy Storage in the Solar Corona  

Science Journals Connector (OSTI)

The energy that drives solar eruptive events such as coronal mass ejections (CMEs) almost certainly originates in coronal magnetic fields. Such energy may build up gradually on timescales of days or longer before its sudden release in an eruptive event, and the presence of free magnetic energy capable of rapid release requires nonpotential magnetic fields and associated electric currents. For magnetic energy to power a CME, that energy must be sufficient to open the magnetic field to interplanetary space, to lift the ejecta against solar gravity, and to accelerate the material to speeds of typically several hundred km s1. Although CMEs are large-scale structures, many originate from relatively compact active regions on the solar surfacesuggesting that magnetic energy storage may be enhanced when it takes place in smaller magnetic structures. This paper builds on our earlier work exploring energy storage in large-scale dipolar and related bipolar magnetic fields. Here we consider two additional cases: quadrupolar fields and concentrated magnetic bipoles intended to simulate active regions. Our models yield stored energies whose excess over that of the corresponding open field state can be greater than 100% of the associated potential field energy; this contrasts with maximum excess energies of only about 20% for dipolar and symmetric bipolar configurations. As in our previous work, energy storage is enhanced when we surround a nonpotential field with a strong overlying potential field that acts to "hold down" the nonpotential flux as its magnetic energy increases.

Richard Wolfson; Christina Drake; Max Kennedy

2012-01-01T23:59:59.000Z

178

Petroglyphs, Lighting, and Magnetism  

E-Print Network [OSTI]

1950 Electricity and Magnetism: Theory and Applications.I Petroglyphs, Lightning, and Magnetism | Walker Figure 8.I Petroglyphs, Lightning, and Magnetism | Walker Figure IL

Walker, Merle F

2007-01-01T23:59:59.000Z

179

Using precision gravity data in geothermal reservoir engineering modeling studies  

SciTech Connect (OSTI)

Precision gravity measurements taken at various times over a geothermal field can be used to derive information about influx into the reservoir. Output from a reservoir simulation program can be used to compute surface gravity fields and time histories. Comparison of such computer results with field-measured gravity data can add confidence to simulation models, and provide insight into reservoir processes. Such a comparison is made for the Bulalo field in the Philippines.

Atkinson, Paul G.; Pederseen, Jens R.

1988-01-01T23:59:59.000Z

180

Solar System experiments do not yet veto modified gravity models  

E-Print Network [OSTI]

The dynamical equivalence between modified and scalar-tensor gravity theories is revisited and it is concluded that it breaks down in the limit to general relativity. A gauge-independent analysis of cosmological perturbations in both classes of theories lends independent support to this conclusion. As a consequence, the PPN formalism of scalar-tensor gravity and Solar System experiments do not veto modified gravity, as previously thought.

Valerio Faraoni

2006-07-05T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Current Speed in a Magnetic Annular Shock Tube  

Science Journals Connector (OSTI)

A parametric study of the speeds of the current sheet and center?of?gravity of current in a magnetic annular shock tube has been carried out. The parameters varied include: (1) the drive current (2) the polarity of the inner electrode (3) the gas pressure (4) the nature of the gas (5) the radius of the inner electrode and (6) the material of the inner electrode. The most interesting result of the investigation was the observation of limiting speeds for the current sheet and center?of?gravity of current of approximately 8 cm/?sec and 3 cm/?sec respectively. These speeds were not exceeded even under conditions where the magnetic pressure exceeded the dynamic pressure by a factor of 10. The most probable explanation of the limiting speed is that it is due to the inertial drag of material ablated from the insulator at the driver end of the shock tube.

James Keck

1964-01-01T23:59:59.000Z

182

Magnetic Catalysis vs Magnetic Inhibition  

E-Print Network [OSTI]

We discuss the fate of chiral symmetry in an extremely strong magnetic field B. We investigate not only quark fluctuations but also neutral meson effects. The former would enhance the chiral-symmetry breaking at finite B according to the Magnetic Catalysis, while the latter would suppress the chiral condensate once B exceeds the scale of the hadron structure. Using a chiral model we demonstrate how neutral mesons are subject to the dimensional reduction and the low dimensionality favors the chiral-symmetric phase. We point out that this effect, the Magnetic Inhibition, can be a feasible explanation for recent lattice-QCD data indicating the decreasing behavior of the chiral-restoration temperature with increasing B.

Kenji Fukushima; Yoshimasa Hidaka

2012-09-06T23:59:59.000Z

183

Magnetic Stereoscopy  

E-Print Network [OSTI]

The space mission STEREO will provide images from two viewpoints. An important aim of the STEREO mission is to get a 3D view of the solar corona. We develop a program for the stereoscopic reconstruction of 3D coronal loops from images taken with the two STEREO spacecraft. A pure geometric triangulation of coronal features leads to ambiguities because the dilute plasma emissions complicates the association of features in image 1 with features in image 2. As a consequence of these problems the stereoscopic reconstruction is not unique and multiple solutions occur. We demonstrate how these ambiguities can be resolved with the help of different coronal magnetic field models (potential, linear and non-linear force-free fields). The idea is that, due to the high conductivity in the coronal plasma, the emitting plasma outlines the magnetic field lines. Consequently the 3D coronal magnetic field provides a proxy for the stereoscopy which allows to eliminate inconsistent configurations. The combination of stereoscopy and magnetic modelling is more powerful than one of these tools alone. We test our method with the help of a model active region and plan to apply it to the solar case as soon as STEREO data become available.

Thomas Wiegelmann; Bernd Inhester

2006-12-21T23:59:59.000Z

184

Ground Gravity Survey At Dixie Valley Geothermal Area (Schaefer...  

Open Energy Info (EERE)

Area (Schaefer, 1983) Exploration Activity Details Location Dixie Valley Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1983 - 1983 Usefulness...

185

Gravity Survey of the Carson Sink - Data and Maps  

SciTech Connect (OSTI)

A detailed gravity survey was carried out for the entire Carson Sink in western Nevada (Figure 1) through a subcontract to Zonge Engineering, Inc. The Carson Sink is a large composite basin containing three known, blind high?temperature geothermal systems (Fallon Airbase, Stillwater, and Soda Lake). This area was chosen for a detailed gravity survey in order to characterize the gravity signature of the known geothermal systems and to identify other potential blind systems based on the structural setting indicated by the gravity data. Data: Data were acquired at approximately 400, 800, and 1600 meter intervals for a total of 1,243 stations. The project location and station location points are presented in Figure 14. The station distribution for this survey was designed to complete regional gravity coverage in the Carson Sink area without duplication of available public and private gravity coverage. Gravity data were acquired using a Scintrex CG?5 gravimeter and a LaCoste and Romberg (L&R) Model?G gravimeter. The CG?5 gravity meter has a reading resolution of 0.001 milligals and a typical repeatability of less than 0.005 milligals. The L&R gravity meter has a reading resolution of 0.01 milligals and a typical repeatability of 0.02 milligals. The basic processing of gravimeter readings to calculate through to the Complete Bouguer Anomaly was made using the Gravity and Terrain Correction software version 7.1 for Oasis Montaj by Geosoft LTD. Results: The gravity survey of the Carson Sink yielded the following products. Project location and station location map (Figure 14). Complete Bouguer Anomaly @ 2.67 gm/cc reduction density. Gravity Complete Bouguer Anomaly at 2.50 g/cc Contour Map (Figure 15). Gravity Horizontal Gradient Magnitude Shaded Color Contour Map. Gravity 1st Vertical Derivative Color Contour Map. Interpreted Depth to Mesozoic Basement (Figure 16), incorporating drill?hole intercept values. Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south?central, east?central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step?overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.

Faulds, James E.

2013-12-31T23:59:59.000Z

186

Ground Gravity Survey At Coso Geothermal Area (1980) | Open Energy...  

Open Energy Info (EERE)

Range, California. Rather, linear gravity contours, which suggest a regional tectonic origin, enclose the location of most of the volcanic activity of the Coso Range. References...

187

Gravity fields of eight north Pacific seamounts: implications for density  

E-Print Network [OSTI]

121 122 124 126 127 LIST OF FIGURES Figure Location map for seamounts Page 10 2 Structure of a typical seamount. 3a Bathymetry of Kaluakalana seamount (KK) 3b Gravity anomaly oi Kaluakalana seamount (KK) 4a Bathymetry of Finch seamount (FI...). 4b Gravity anomaly of Finch seamount (FI) ~ ~ ~ ~ ~ 5a Bathymetry of Paumakua seamount (PA). . 5b Gravity anomaly of Paumakua seamount (PA) . . 6a Bathymetry of Handel seamount (HA) . 6b Gravity anomaly of Handel seamount (HA). . 7a Bathymetry...

Freitag, Helen Clare

2012-06-07T23:59:59.000Z

188

Ground Gravity Survey At Walker Lake Valley Area (Shoffner, Et...  

Open Energy Info (EERE)

N. Hinz, A. Sabin, M. Lazaro, S. Alm (2010) Understanding Fault Characteristics And Sediment Depth For Geothermal Exploration Using 3D Gravity Inversion In Walker Valley, Nevada...

189

What kind of noncommutative geometry for quantum gravity ?  

E-Print Network [OSTI]

We give a brief account of the description of the standard model in noncommutative geometry as well as the thermal time hypothesis, questioning their relevance for quantum gravity.

Pierre Martinetti

2005-01-07T23:59:59.000Z

190

Ground Gravity Survey At Long Valley Caldera Geothermal Area...  

Open Energy Info (EERE)

Battaglia, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Long Valley Caldera Geothermal Area (Battaglia,...

191

Ground Gravity Survey At Under Steamboat Springs Area (Warpinski...  

Open Energy Info (EERE)

Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Under Steamboat Springs Area (Warpinski,...

192

Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...  

Open Energy Info (EERE)

Vapor (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...

193

Unification of Gravity and Electromagnetism II A Geometric Theory  

E-Print Network [OSTI]

It is shown that unification of gravity and electromagnetism can be achieved using an affine non-symmetric connection $\\Gamma^\\lambda_{\\mu\

Partha Ghose

2014-08-05T23:59:59.000Z

194

Precisely mapping the magnetic field gradient in vacuum with an atom interferometer  

SciTech Connect (OSTI)

The magnetic field gradient has been measured with an atom interferometer using the magnetic sublevels of {sup 87}Rb atoms. The Doppler-insensitive measurement effectively eliminates the contribution from gravity and background vibration noise, and the differential measurement also can reject some systematic errors. A resolution of 300 pT/mm has been demonstrated with a 90-s integration time and a spatial resolution of 1.4 mm. The gradiometer was then used to measure the magnetic field gradient in an ultrahigh-vacuum environment. The technique will also be very useful to subtract the systematic error arising from the magnetic field inhomogeneity in precision atom-interferometry experiments, such as gravity measurement.

Zhou Minkang; Hu Zhongkun; Duan Xiaochun; Sun Buliang; Zhao Jinbo; Luo Jun [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-12-15T23:59:59.000Z

195

Gravity anomalies derived from Seasat, Geosat, ERS-1 and TOPEX/POSEIDON altimetry and ship gravity: a case study over the Reykjanes Ridge  

Science Journals Connector (OSTI)

......should be added to the ship gravity anomalies to account for the atmospheric effect before comparison with...satellite gravity and ship gravity anomalies resulting...was subtracted from the ship gravity. Table 3 lists...represent the total effect of the different error......

Cheinway Hwang; Barry Parsons

1995-09-01T23:59:59.000Z

196

The JPL lunar gravity field to spherical harmonic degree 660 from the GRAIL Primary Mission  

E-Print Network [OSTI]

The lunar gravity field and topography provide a way to probe the interior structure of the Moon. Prior to the Gravity Recovery and Interior Laboratory (GRAIL) mission, knowledge of the lunar gravity was limited mostly to ...

Konopliv, Alex S.

197

Gravity Measurements in Panama with the IMGC-02 Transportable Absolute Gravimeter  

Science Journals Connector (OSTI)

The work hereafter described was designed to determine the gravity datum at the Centro Nacional de Metrologa de Panam CENAMEP AIP through absolute measurement of the gravity acceleration, and settle a gravity n...

G. DAgostino; A. Germak; D. Quagliotti; O. Pinzon

2010-01-01T23:59:59.000Z

198

Note on the relationship between the speed of light and gravity in the bi-metric theory of gravity  

E-Print Network [OSTI]

Relationship between the speed of gravity c_g and the speed of light c_e in the bi-metric theory of gravity is discussed. We reveal that the speed of light is a function of the speed of gravity which is a primary fundamental constant. Thus, experimental measurement of relativistic bending of light propagating in time-dependent gravitational field directly compares the speed of gravity versus the speed of light and tests if there is any aether associated with the gravitational field considered as a transparent `medium' with the constant refraction index.

Sergei Kopeikin

2005-12-30T23:59:59.000Z

199

Perturbations of Nested Branes With Induced Gravity  

E-Print Network [OSTI]

We study the behaviour of weak gravitational fields in models where a 4D brane is embedded inside a 5D brane equipped with induced gravity, which in turn is embedded in a 6D spacetime. We consider a specific regularization of the branes internal structures where the 5D brane can be considered thin with respect to the 4D one. We find exact solutions corresponding to pure tension source configurations on the thick 4D brane, and study perturbations at first order around these background solutions. To perform the perturbative analysis, we adopt a bulk-based approach and we express the equations in terms of gauge invariant and master variables using a 4D scalar-vector-tensor decomposition. We then propose an ansatz on the behaviour of the perturbation fields when the thickness of the 4D brane goes to zero, which corresponds to configurations where gravity remains finite everywhere in the thin limit of the 4D brane. We study the equations of motion using this ansatz, and show that they give rise to a consistent set of differential equations in the thin limit, from which the details of the internal structure of the 4D brane disappear. We conclude that the thin limit of the "ribbon" 4D brane inside the (already thin) 5D brane is well defined (at least when considering first order perturbations around pure tension configurations), and that the gravitational field on the 4D brane remains finite in the thin limit. We comment on the crucial role of the induced gravity term on the 5D brane.

Fulvio Sbisa'; Kazuya Koyama

2014-06-06T23:59:59.000Z

200

Hall viscosity from gauge/gravity duality  

E-Print Network [OSTI]

In (2+1)-dimensional systems with broken parity, there exists yet another transport coefficient, appearing at the same order as the shear viscosity in the hydrodynamic derivative expansion. In condensed matter physics, it is referred to as "Hall viscosity". We consider a simple holographic realization of a (2+1)-dimensional isotropic fluid with broken spatial parity. Using techniques of fluid/gravity correspondence, we uncover that the holographic fluid possesses a nonzero Hall viscosity, whose value only depends on the near-horizon region of the background. We also write down a Kubo's formula for the Hall viscosity. We confirm our results by directly computing the Hall viscosity using the formula.

Omid Saremi; Dam Thanh Son

2011-03-24T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Gamma Ray Burst Neutrinos Probing Quantum Gravity  

E-Print Network [OSTI]

Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.

M. C. Gonzalez-Garcia; F. Halzen

2006-11-28T23:59:59.000Z

202

New solutions in 3D gravity  

Science Journals Connector (OSTI)

We study gravitational theory in 1+2 spacetime dimensions which is determined by the Lagrangian constructed as a sum of the Einstein-Hilbert term plus the two (translational and rotational) gravitational Chern-Simons terms. When the corresponding coupling constants vanish, we are left with purely Einstein theory of gravity. We obtain new exact solutions for the gravitational field equations with nontrivial material sources. Special attention is paid to plane-fronted gravitational waves (in case of the Maxwell field source) and to the circularly symmetric as well as the anisotropic cosmological solutions which arise for the ideal fluid matter source.

Yuri N. Obukhov

2003-12-19T23:59:59.000Z

203

Dualities of 3D dilaton gravity  

Science Journals Connector (OSTI)

We investigate Brans-Dicke dilaton gravity theories in 2+1 dimensions. We show that the reduced field equations for solutions with a diagonal metric and depending only on one spacetime coordinate have a continuous O(2) symmetry. Using this symmetry we derive general static and cosmological solutions of the theory. The action of the discrete group O(2,Z) on the space of the solutions is discussed. Three-dimensional string effective theory and three-dimensional general relativity are discussed in detail. In particular, we find that the previously discovered black string solution is dual to a spacetime with a conical singularity.

Mariano Cadoni

1996-12-15T23:59:59.000Z

204

Cosmological Solutions of Emergent Noncommutative Gravity  

SciTech Connect (OSTI)

Matrix models of the Yang-Mills type lead to an emergent gravity theory, which does not require fine-tuning of a cosmological constant. We find cosmological solutions of the Friedmann-Robertson-Walker type. They generically have a big bounce, and an early inflationlike phase with graceful exit. The mechanism is purely geometrical; no ad hoc scalar fields are introduced. The solutions are stabilized through vacuum fluctuations and are thus compatible with quantum mechanics. This leads to a Milne-like universe after inflation, which appears to be in remarkably good agreement with observation and may provide an alternative to standard cosmology.

Klammer, Daniela; Steinacker, Harold [Fakultaet fuer Physik, Universitaet Wien, A-1090 Wien (Austria)

2009-06-05T23:59:59.000Z

205

Robust approach to f(R) gravity  

SciTech Connect (OSTI)

We consider metric f(R) theories of gravity without mapping them to their scalar-tensor counterpart, but using the Ricci scalar itself as an ''extra'' degree of freedom. This approach avoids then the introduction of a scalar-field potential that might be ill defined (not single valued). In order to explicitly show the usefulness of this method, we focus on static and spherically symmetric spacetimes and deal with the recent controversy about the existence of extended relativistic objects in certain class of f(R) models.

Jaime, Luisa G. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Apartado Postal 50-542, Mexico Distrito Federal 04510 (Mexico); Patino, Leonardo [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Apartado Postal 50-542, Mexico Distrito Federal 04510 (Mexico); Salgado, Marcelo [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico)

2011-01-15T23:59:59.000Z

206

Loop quantum gravity - a short review  

E-Print Network [OSTI]

In this article we review the foundations and the present status of loop quantum gravity. It is short and relatively non-technical, the emphasis is on the ideas, and the flavor of the techniques. In particular, we describe the kinematical quantization and the implementation of the Hamilton constraint, as well as the quantum theory of black hole horizons, semiclassical states, and matter propagation. Spin foam models and loop quantum cosmology are mentioned only in passing, as these will be covered in separate reviews to be published alongside this one.

Sahlmann, Hanno

2010-01-01T23:59:59.000Z

207

Gravity with a dynamical preferred frame  

E-Print Network [OSTI]

We study a generally covariant model in which local Lorentz invariance is broken "spontaneously" by a dynamical unit timelike vector field $u^a$---the "aether". Such a model makes it possible to study the gravitational and cosmological consequences of preferred frame effects, such as ``variable speed of light" or high frequency dispersion, while preserving a generally covariant metric theory of gravity. In this paper we restrict attention to an action for an effective theory of the aether which involves only the antisymmetrized derivative $\

Ted Jacobson; David Mattingly

2001-06-02T23:59:59.000Z

208

Gravity, Cosmic Rays and the LHC  

E-Print Network [OSTI]

The high energy proton beams expected when the Large Hadron Collider (LHC) comes online should provide a pass/fail test for a gravity-related explanation of ultrahigh energy cosmic rays. The model predicts that particles have two kinds energies, equal for null gravitational potentials and, in the potential at the Earth, differing significantly above one TeV. If correct, a 7 TeV trajectory energy proton at the LHC would deliver a 23.5 TeV particle state energy in a collision.

Richard Shurtleff

2008-01-20T23:59:59.000Z

209

The Ising Model on a Dynamically Triangulated Disk with a Boundary Magnetic Field  

E-Print Network [OSTI]

We use Monte Carlo simulations to study a dynamically triangulated disk with Ising spins on the vertices and a boundary magnetic field. For the case of zero magnetic field we show that the model possesses three phases. For one of these the boundary length grows linearly with disk area, while the other two phases are characterized by a boundary whose size is on the order of the cut-off. A line of continuous magnetic transitions separates the two small boundary phases. We determine the critical exponents of the continuous magnetic phase transition and relate them to predictions from continuum 2-d quantum gravity. This line of continuous transitions appears to terminate on a line of discontinuous phase transitions dividing the small boundary phases from the large boundary phase. We examine the scaling of bulk magnetization and boundary magnetization as a function of boundary magnetic field in the vicinity of this tricritical point.

Scott McGuire; Simon Catterall; Mark Bowick; Simeon Warner

2001-05-02T23:59:59.000Z

210

Magnetic Bianchi type II string cosmological model in loop quantum cosmology  

E-Print Network [OSTI]

The loop quantum cosmology of the Bianchi type II string cosmological model in the presence of a homogeneous magnetic field is studied. We present the effective equations which provide modifications to the classical equations of motion due to quantum effects. The numerical simulations confirm that the big bang singularity is resolved by quantum gravity effects.

Victor Rikhvitsky; Bijan Saha; Mihai Visinescu

2013-12-09T23:59:59.000Z

211

Interaction of p modes with a collection of thin magnetic tubes  

Science Journals Connector (OSTI)

......plane-parallel atmosphere with constant...assumption is that the plasma beta is constant...neutrally stable atmosphere for which acoustic-gravity...between 3 and 4 mHz followed by a decrease beyond 4 mHz. Azimuthal averaging...field-free atmosphere. Also, is the...magnetic flux and plasma beta parameter......

R. Jain; A. Gascoyne; B. W. Hindman

2011-08-01T23:59:59.000Z

212

magnets2  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

II II Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

213

Magnetic Reconnection  

SciTech Connect (OSTI)

We review the fundamental physics of magnetic reconnection in laboratory and space plasmas, by discussing results from theory, numerical simulations, observations from space satellites, and the recent results from laboratory plasma experiments. After a brief review of the well-known early work, we discuss representative recent experimental and theoretical work and attempt to interpret the essence of significant modern findings. In the area of local reconnection physics, many significant findings have been made with regard to two- uid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and micro-turbulence are discussed to understand the fundamental processes in a local reconnection layer both in space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also brie y discussed.

Masaaki Yamada, Russell Kulsrud and Hantao Ji

2009-09-17T23:59:59.000Z

214

E-Print Network 3.0 - artificial gravity reveals Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

line is required. This value is computed from the surface gravity... focuses on different error sources, which influence the gravity ... Source: Schuh, Harald - Institut fr...

215

E-Print Network 3.0 - artificial gravity countermeasure Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the benefits of an artificial gravity countermeasure coupled with exercise and vibration Summary: Modeling the benefits of an artificial gravity countermeasure coupled with...

216

E-Print Network 3.0 - artificial gravity hope Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of the Elements, 2003 Summary: spectrum, the ionization equilibrium could only be applied to derive upper limits on the gravity. We hope... on a universal gravity...

217

Ground Gravity Survey At Glass Buttes Area (DOE GTP) | Open Energy...  

Open Energy Info (EERE)

Ground Gravity Survey At Glass Buttes Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Glass Buttes Area...

218

PROTOSTELLAR ACCRETION FLOWS DESTABILIZED BY MAGNETIC FLUX REDISTRIBUTION  

SciTech Connect (OSTI)

Magnetic flux redistribution lies at the heart of the problem of star formation in dense cores of molecular clouds that are magnetized to a realistic level. If all of the magnetic flux of a typical core were to be dragged into the central star, the stellar field strength would be orders of magnitude higher than the observed values. This well-known magnetic flux problem can in principle be resolved through non-ideal MHD effects. Two-dimensional (axisymmetric) calculations have shown that ambipolar diffusion, in particular, can transport magnetic flux outward relative to matter, allowing material to enter the central object without dragging the field lines along. We show through simulations that such axisymmetric protostellar accretion flows are unstable in three dimensions to magnetic interchange instability in the azimuthal direction. The instability is driven by the magnetic flux redistributed from the matter that enters the central object. It typically starts to develop during the transition from the prestellar phase of star formation to the protostellar mass accretion phase. In the latter phase, the magnetic flux is transported outward mainly through advection by strongly magnetized low-density regions that expand against the collapsing inflow. The tussle between the gravity-driven infall and magnetically driven expansion leads to a highly filamentary inner accretion flow that is more disordered than previously envisioned. The efficient outward transport of magnetic flux by advection lowers the field strength at small radii, making the magnetic braking less efficient and the formation of rotationally supported disks easier in principle. However, we find no evidence for such disks in any of our rotating collapse simulations. We conclude that the inner protostellar accretion flow is shaped to a large extent by the flux redistribution-driven magnetic interchange instability. How disks form in such an environment is unclear.

Krasnopolsky, Ruben; Shang, Hsien [Academia Sinica, Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Li Zhiyun; Zhao Bo [University of Virginia, Astronomy Department, Charlottesville (United States)

2012-09-20T23:59:59.000Z

219

Cosmological evolutions of F(R) nonlinear massive gravity  

Science Journals Connector (OSTI)

Recently a new extended nonlinear massive gravity model has been proposed which includes the F(R) modifications to the de RhamGabadadzeTolley model. We follow the F(R) nonlinear massive gravity and study its implications on cosmological evolutions. We derive the critical points of the cosmic system and study the corresponding kinetics by performing the phase-plane analysis.

De-Jun Wu

2014-08-25T23:59:59.000Z

220

Inverted gravity, not inverted shape impairs biological motion perception  

E-Print Network [OSTI]

Inverted gravity, not inverted shape impairs biological motion perception Nikolaus Trojetroje. Scrambling should therefore impair perception even more than inversion. Upright and inverted scrambled motion). Is the cause of the inversion effect inverted gravity? If this is the case upright scrambled motion should

Troje, Nikolaus

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Solar System tests of Ho?avaLifshitz gravity  

Science Journals Connector (OSTI)

...research-article Research articles 1000 162 169 138 Solar System tests of Horava-Lifshitz gravity...constraining Horava gravity at the scale of the Solar System, by considering the classical tests...classical tests of general relativity|solar system| 1. Introduction Recently, a...

2011-01-01T23:59:59.000Z

222

Remarks on Pure Spin Connection Formulations of Gravity  

E-Print Network [OSTI]

In the derivation of a pure spin connection action functional for gravity two methods have been proposed. The first starts from a first order lagrangian formulation, the second from a hamiltonian formulation. In this note we show that they lead to identical results for the specific cases of pure gravity with or without a cosmological constant.

Riccardo Capovilla; Ted Jacobson

1992-07-21T23:59:59.000Z

223

The Gravity of Annual Freight and Logistics Symposium  

E-Print Network [OSTI]

The Gravity of Logistics 17th Annual Freight and Logistics Symposium A Summary Report | December 6 to those who want them --the "gravity" of logistics--depends on infrastructure that can support and sustainth Annual State of Logistics Report--IsThis the New Normal? Rosalyn Wilson, Senior Business Analyst

Minnesota, University of

224

Phenomenological Quantum Gravity: the birth of a new frontier?  

E-Print Network [OSTI]

In the last years a general consensus has emerged that, contrary to intuition, quantum-gravity effects may have relevant consequences for the propagation and interaction of high energy particles. This has given birth to the field of ``Phenomenological Quantum Gravity'' We review some of the aspects of this new, very exciting frontier of Physics.

R. Aloisio; P. Blasi; A. Galante; P. L. Ghia; A. F. Grillo; F. Mendez

2005-02-01T23:59:59.000Z

225

Disformal Transformations, Veiled General Relativity and Mimetic Gravity  

E-Print Network [OSTI]

In this Note we show that Einstein's equations for gravity are generically invariant under 'disformations'. We also show that the particular subclass when this is not true yields the equations of motion of 'Mimetic Gravity'. Finally we give the 'mimetic' generalization of the Schwarzschild solution.

Nathalie Deruelle; Josephine Rua

2014-07-03T23:59:59.000Z

226

Nonlinear Energy Transfer in a Narrow Gravity-Wave Spectrum  

Science Journals Connector (OSTI)

...research-article Nonlinear Energy Transfer in a Narrow Gravity-Wave Spectrum J. C...calculation of the rate of energy transfer due to...a narrow gravity wave spectrum according...typical narrow wind wave spectrum on the nonlinear energy transfer are very...

1979-01-01T23:59:59.000Z

227

ccsd00000548 COMMENTS ON "MEASURING THE GRAVITY SPEED BY VLBI"  

E-Print Network [OSTI]

ccsd­00000548 (version 1) : 18 Aug 2003 COMMENTS ON "MEASURING THE GRAVITY SPEED BY VLBI" H. ASADA the light speed. Such a di#11;erence may play a vital role in the primordial universe. In recent, Kopeikin and Fomalont claimed the #12;rst measurement of the gravity speed by VLBI. However, the measurement has

228

Perturbations of Nested Branes With Induced Gravity  

E-Print Network [OSTI]

We study the behaviour of weak gravitational fields in models where a 4D brane is embedded inside a 5D brane equipped with induced gravity, which in turn is embedded in a 6D spacetime. We consider a specific regularization of the branes internal structures where the 5D brane can be considered thin with respect to the 4D one. We find exact solutions corresponding to pure tension source configurations on the thick 4D brane, and study perturbations at first order around these background solutions. To perform the perturbative analysis, we adopt a bulk-based approach and we express the equations in terms of gauge invariant and master variables using a 4D scalar-vector-tensor decomposition. We then propose an ansatz on the behaviour of the perturbation fields when the thickness of the 4D brane goes to zero, which corresponds to configurations where gravity remains finite everywhere in the thin limit of the 4D brane. We study the equations of motion using this ansatz, and show that they give rise to a consistent set...

Sbisa', Fulvio

2014-01-01T23:59:59.000Z

229

Analogue model for quantum gravity phenomenology  

E-Print Network [OSTI]

So called "analogue models" use condensed matter systems (typically hydrodynamic) to set up an "effective metric" and to model curved-space quantum field theory in a physical system where all the microscopic degrees of freedom are well understood. Known analogue models typically lead to massless minimally coupled scalar fields. We present an extended "analogue space-time" programme by investigating a condensed-matter system - in and beyond the hydrodynamic limit - that is in principle capable of simulating the massive Klein-Gordon equation in curved spacetime. Since many elementary particles have mass, this is an essential step in building realistic analogue models, and an essential first step towards simulating quantum gravity phenomenology. Specifically, we consider the class of two-component BECs subject to laser-induced transitions between the components, and we show that this model is an example for Lorentz invariance violation due to ultraviolet physics. Furthermore our model suggests constraints on quantum gravity phenomenology in terms of the "naturalness problem" and "universality issue".

Silke Weinfurtner; Stefano Liberati; Matt Visser

2005-11-18T23:59:59.000Z

230

Magnetic Reconnection in Astrophysical and  

E-Print Network [OSTI]

Magnetic Reconnection in Astrophysical and Laboratory Plasmas Ellen G. Zweibel1 and Masaaki Yamada2 astrophysics, magnetic fields, magnetic reconnection Abstract Magnetic reconnection is a topological rearrangement of magnetic field that converts magnetic energy to plasma energy. Astrophysical flares, from

231

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Wednesday, 29 November 2006 00:00...

232

National High Magnetic Field Laboratory Audio Dictionary: Magnetic...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Links Magnets from Mini to Mighty Meet the Magnets How to Make an Electromagnet (audio slideshow) Compasses in Magnetic Fields (interactive tutorial) Magnetic Field Around a...

233

Magnetic Fields in High-Mass Infrared Dark Clouds  

E-Print Network [OSTI]

High-mass Stars are cosmic engines known to dominate the energetics in the Milky Way and other galaxies. However, their formation is still not well understood. Massive, cold, dense clouds, often appearing as Infrared Dark Clouds (IRDCs), are the nurseries of massive stars. No measurements of magnetic fields in IRDCs in a state prior to the onset of high-mass star formation (HMSF) have previously been available, and prevailing HMSF theories do not consider strong magnetic fields. Here, we report observations of magnetic fields in two of the most massive IRDCs in the Milky Way. We show that IRDCs G11.11-0.12 and G0.253+0.016 are strongly magnetized and that the strong magnetic field is as important as turbulence and gravity for HMSF. The main dense filament in G11.11-0.12 is perpendicular to the magnetic field, while the lower density filament merging onto the main filament is parallel to the magnetic field. The implied magnetic field is strong enough to suppress fragmentation sufficiently to allow HMSF. Other ...

Pillai, Thushara; Tan, Jonathan; Goldsmith, Paul; Carey, Sean; Menten, Karl

2014-01-01T23:59:59.000Z

234

Gravity-anti-Gravity Symmetric Mini-Superspace: Quantum Entanglement and Cosmological Scale Factor Grid  

E-Print Network [OSTI]

A gravity-anti-gravity (GaG) odd linear dilaton action offers an eternal inflation evolution governed by the unified (cosmological constant plus radiation) equation of state $\\rho-3P=4\\Lambda$. At the mini superspace level, a 'two-particle' variant of the no-boundary proposal, notably 'one-particle' energy dependent, is encountered. While a GaG-odd wave function can only host a weak Big Bang boundary condition, albeit for any $k$, a strong Big Bang boundary condition requires a GaG-even entangled wave function, and singles out $k=0$ flat space. The locally most probable values for the cosmological scale factor and the dilaton field form a grid $\\{a^2,a\\phi\\}\\sim\\sqrt{4n_1+1}\\pm\\sqrt{4n_2+1}$.

Aharon Davidson; Tomer Ygael

2014-10-13T23:59:59.000Z

235

Gravity-anti-Gravity Symmetric Mini-Superspace: Quantum Entanglement and Cosmological Scale Factor Grid  

E-Print Network [OSTI]

A gravity-anti-gravity (GaG) odd linear dilaton action offers an eternal inflation evolution governed by the unified (cosmological constant plus radiation) equation of state $\\rho-3P=4\\Lambda$. At the mini superspace level, a 'two-particle' variant of the no-boundary proposal, notably 'one-particle' energy dependent, is encountered. While a GaG-odd wave function can only host a weak Big Bang boundary condition, albeit for any $k$, a strong Big Bang boundary condition requires a GaG-even entangled wave function, and singles out $k=0$ flat space. The locally most probable values for the cosmological scale factor and the dilaton field form a grid $\\{a^2,a\\phi\\}\\sim\\sqrt{4n_1+1}\\pm\\sqrt{4n_2+1}$.

Davidson, Aharon

2014-01-01T23:59:59.000Z

236

Superconducting magnet  

DOE Patents [OSTI]

A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

Satti, John A. (Naperville, IL)

1980-01-01T23:59:59.000Z

237

Solar system tests of Ho?ava-Lifshitz gravity  

E-Print Network [OSTI]

Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Ho\\v{r}ava. The theory reduces to Einstein gravity with a non-vanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(A)dS solution, has also been obtained for the Ho\\v{r}ava-Lifshitz theory. The exact asymptotically flat Schwarzschild type solution of the gravitational field equations in Ho\\v{r}ava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR modified Ho\\v{r}ava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Ho\\v{r}ava gravity at the scale of the Solar System, by considering the classical tests of general relativity (perihelion precession of the planet Mercury, deflection of light by the Sun and the radar echo delay) for the spherically symmetric black hole solution of Ho\\v{r}ava-Lifshitz gravity. All these gravitational effects can be fully explained in the framework of the vacuum solution of the gravity. Moreover, the study of the classical general relativistic tests also constrain the free parameter of the solution.

Tiberiu Harko; Zoltan Kovcs; Francisco S. N. Lobo

2010-10-28T23:59:59.000Z

238

From thermodynamics to the solutions in gravity theory  

E-Print Network [OSTI]

In a recent work, we present a new point of view to the relation of gravity and thermodynamics, in which we derive the \\sch~solution through thermodynamic laws by the aid of the Misner-Sharp mass in an adiabatic system. In this paper 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 Guass-Bonnet gravity. Using this gravi-thermodynamics thought, we obtain a NEW class of solution in $F(R)$ gravity in an $n$-dimensional (n$\\geq$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.

Zhang, Hongsheng

2014-01-01T23:59:59.000Z

239

More on massive 3D gravity  

Science Journals Connector (OSTI)

We explore the space of static solutions of the recently discovered three-dimensional new massive gravity (NMG), allowing for either sign of the Einstein-Hilbert term and a cosmological term parametrized by a dimensionless constant ?. For ?=-1 we find black hole solutions asymptotic (but not isometric) to the unique (anti) deSitter [(A)dS] vacuum, including extremal black holes that interpolate between this vacuum and (A)dS2S1. We also investigate unitarity of linearized NMG in (A)dS vacua. We find unitary theories for some dS vacua, but (bulk) unitarity in AdS implies negative central charge of the dual conformal field theories (CFT), except for ?=3 where the central charge vanishes and the bulk gravitons are replaced by massive photons. A similar phenomenon is found in the massless limit of NMG, for which the linearized equations become equivalent to Maxwells equations.

Eric A. Bergshoeff; Olaf Hohm; Paul K. Townsend

2009-06-26T23:59:59.000Z

240

Semiclassical approximation to supersymmetric quantum gravity  

SciTech Connect (OSTI)

We develop a semiclassical approximation scheme for the constraint equations of supersymmetric canonical quantum gravity. This is achieved by a Born-Oppenheimer type of expansion, in analogy to the case of the usual Wheeler-DeWitt equation. The formalism is only consistent if the states at each order depend on the gravitino field. We recover at consecutive orders the Hamilton-Jacobi equation, the functional Schroedinger equation, and quantum gravitational correction terms to this Schroedinger equation. In particular, the following consequences are found: (i) the Hamilton-Jacobi equation and therefore the background spacetime must involve the gravitino, (ii) a (many-fingered) local time parameter has to be present on super Riem {sigma} (the space of all possible tetrad and gravitino fields) (iii) quantum supersymmetric gravitational corrections affect the evolution of the very early Universe. The physical meaning of these equations and results, in particular, the similarities to and differences from the pure bosonic case, are discussed.

Kiefer, Claus; Lueck, Tobias; Moniz, Paulo [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Cologne (Germany); Astronomy Unit, School of Mathematical Sciences, Queen Mary College, University of London, Mile End Road, London E1 4NS (United Kingdom)

2005-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

CPT Violation and Decoherence in Quantum Gravity  

E-Print Network [OSTI]

In this brief review I discuss ways and tests of CPT-Violation in the context of quantum gravity theories with space-time foam vacua, which entail quantum decoherence of matter propagating in such backgrounds. I cover a wide variety of sensitive probes, ranging from cosmic neutrinos to meson factories. I pay particular emphasis on associating the latter with specific, probably unique ("smoking-gun"), effects of this type of CPT Violation, related to a modification of Einstein-Podolsky-Rosen (EPR) correlations in the entangled states of the relevant neutral mesons. I also present some semi-microscopic estimates of these latter effects, in the context of a specific string-inspired model of space-time foam ("D-particle foam").

Mavromatos, Nick E

2009-01-01T23:59:59.000Z

242

Gravity with a dynamical preferred frame  

Science Journals Connector (OSTI)

We study a generally covariant model in which local Lorentz invariance is broken by a dynamical unit timelike vector field uathe aether. Such a model makes it possible to study the gravitational and cosmological consequences of preferred frame effects, such as variable speed of light or high frequency dispersion, while preserving a generally covariant metric theory of gravity. In this paper we restrict attention to an action for an effective theory of the aether which involves only the antisymmetrized derivative ?[aub]. Without matter this theory is equivalent to a sector of the Einstein-Maxwell-charged dust system. The aether has two massless transverse excitations, and the solutions of the model include all vacuum solutions of general relativity (as well as other solutions). However, the aether generally develops gradient singularities which signal a breakdown of this effective theory. Including the symmetrized derivative in the action for the aether field may cure this problem.

Ted Jacobson and David Mattingly

2001-06-26T23:59:59.000Z

243

What is faster -- light or gravity?  

E-Print Network [OSTI]

General relativity lacks the notion of the speed of gravity. This is inconvenient and the present paper is aimed at filling this gap up. To that end I introduce the concept of the "alternative" and argue that its variety called the "superluminal alternative" describes exactly what one understands by the "superluminal gravitational signal". Another, closely related, object called the "semi-superluminal alternative" corresponds to the situation in which a massive (and therefore gravitating) body reaches its destination sooner than a photon \\emph{would}, be the latter sent \\emph{instead} of the body. I prove that in general relativity constrained by the condition that only globally hyperbolic spacetimes are allowed 1) semi-superluminal alternatives are absent and 2) under some natural conditions and conventions admissible superluminal alternative are absent too.

S. Krasnikov

2014-08-28T23:59:59.000Z

244

Nonsymmetric Gravity Theories: Inconsistencies and a Cure  

E-Print Network [OSTI]

Motivated by the apparent dependence of string $\\sigma$--models on the sum of spacetime metric and antisymmetric tensor fields, we reconsider gravity theories constructed from a nonsymmetric metric. We first show that all such "geometrical" theories homogeneous in second derivatives violate standard physical requirements: ghost-freedom, absence of algebraic inconsistencies or continuity of degree-of-freedom content. This no-go result applies in particular to the old unified theory of Einstein and its recent avatars. However, we find that the addition of nonderivative, ``cosmological'' terms formally restores consistency by giving a mass to the antisymmetric tensor field, thereby transmuting it into a fifth-force-like massive vector but with novel possible matter couplings. The resulting macroscopic models also exhibit ``van der Waals''-type gravitational effects, and may provide useful phenomenological foils to general relativity.

T. Damour; S. Deser; J. McCarthy

1992-07-22T23:59:59.000Z

245

Gravitational Waves in Ghost Free Bimetric Gravity  

E-Print Network [OSTI]

We obtain a set of exact gravitational wave solutions for the ghost free bimetric theory of gravity. With a flat reference metric, the theory admits the vacuum Brinkmann plane wave solution for suitable choices of the coefficients of different terms in the interaction potential. An exact gravitational wave solution corresponding to a massive scalar mode is also admitted for arbitrary choice of the coefficients with the reference metric being proportional to the spacetime metric. The proportionality factor and the speed of the wave are calculated in terms of the parameters of the theory. We also show that a F(R) extension of the theory admits similar solutions but in general is plagued with ghost instabilities.

Morteza Mohseni

2012-11-15T23:59:59.000Z

246

A length operator for canonical quantum gravity  

E-Print Network [OSTI]

We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator obtained after regularization is densely defined, does not suffer from factor ordering singularities and does not require any renormalization. We show that the length operator admits self-adjoint extensions and compute part of its spectrum which like its companions, the volume and area operators already constructed in the literature, is purely discrete and roughly is quantized in units of the Planck length. The length operator contains full and direct information about all the components of the metric tensor which faciliates the construction of a new type of weave states which approximate a given classical 3-geometry.

T. Thiemann

1996-06-29T23:59:59.000Z

247

Bi-metric Gravity and "Dark Matter"  

E-Print Network [OSTI]

We present a bi-metric theory of gravity containing a length scale of galactic size. For distances less than this scale the theory satisfies the standard tests of General Relativity. For distances greater than this scale the theory yields an effective gravitational constant much larger than the locally observed value of Newton's constant. The transition from one regime to the other through the galactic scale can explain the observed rotation curves of galaxies and hence the effects normally attributed to the presence of dark matter. Phenomena on an extragalactic scale such as galactic clusters and the expansion of the universe are controlled by the enhanced gravitational coupling. This provides an explanation of the missing matter normally invoked to account for the observed value of Hubble's constant in relation to observed matter.

I. T. Drummond

2000-08-18T23:59:59.000Z

248

Serendipitous discoveries in nonlocal gravity theory  

Science Journals Connector (OSTI)

We present a class of generally covariant nonlocal gravity models which have a flat-space general relativistic limit and also possess a stable deSitter or anti-deSitter (AdS) background with an arbitrary value of its cosmological constant. The nonlocal action of the theory is formulated in the Euclidean signature spacetime and is understood as an approximation to the quantum effective action (generating functional of one-particle irreducible diagrams) originating from fundamental quantum gravity theory. Using the known relation between the Schwinger-Keldysh technique for quantum expectation values and the Euclidean quantum field theory we derive from this action the causal effective equations of motion for mean value of the metric field in the physical Lorentzian-signature spacetime. Thus we show that the (A)dS background of the theory carries as free propagating modes massless gravitons having two polarizations identical to those of the Einstein theory with a cosmological term. The on-shell action of the theory is vanishing both for the flat-space and (A)dS backgrounds which play the role of stable vacua underlying, respectively, the ultraviolet and infrared phases of the theory. We also obtain linearized gravitational potentials of compact matter sources and show that in the infrared (A)dS phase their effective gravitational coupling Geff can be essentially different from the Newton gravitational constant GN of the short-distance general relativistic phase. When Geff?GN the (A)dS phase can be regarded as a strongly coupled infrared modification of Einstein theory not only describing the dark energy mechanism of cosmic acceleration but also simulating the dark matter phenomenon by enhanced gravitational attraction at long distances.

A. O. Barvinsky

2012-05-09T23:59:59.000Z

249

Gravity Anomalies Seaward of Deep-Sea Trenches and their Tectonic Implications  

Science Journals Connector (OSTI)

......trenches we consider the gravity effect of a downgoing slab is likely...trench. Undoubtedly the gravity effect of the dense downgoing slab...local gravity highs on surface ship measurements. If the gravity effect of the downgoing slab is small......

A. B. Watts; M. Talwani

1974-01-01T23:59:59.000Z

250

PHYSICS OF FLUIDS 25, 086604 (2013) Gravity currents shoaling on a slope  

E-Print Network [OSTI]

water rivers into the saline ocean form surface gravity currents. The study of gravity currents is also spills in the ocean.6 Gravity currents in a channel have been well studied through lockPHYSICS OF FLUIDS 25, 086604 (2013) Gravity currents shoaling on a slope Bruce R. Sutherland,1,2,a

Sutherland, Bruce

251

ccsd-00000548(version1):18Aug2003 COMMENTS ON "MEASURING THE GRAVITY SPEED BY VLBI"  

E-Print Network [OSTI]

ccsd-00000548(version1):18Aug2003 COMMENTS ON "MEASURING THE GRAVITY SPEED BY VLBI" H. ASADA or alternative gravity theories might suggest that the gravity propagation speed can be different from the light and Fomalont claimed the first measurement of the gravity speed by VLBI. However, the measurement has

Paris-Sud XI, Université de

252

Energy conditions in f(R, Lm) gravity  

Science Journals Connector (OSTI)

In order to constrain f(R, Lm) gravity from theoretical aspects, its energy conditions are derived in this paper. These energy conditions given by us are quite general and can be degenerated to the well-known energy conditions in general relativity and f(R) theories of gravity with arbitrary coupling, non-minimal coupling and non-coupling between matter and geometry, respectively, as special cases. To exemplify how to use these energy conditions to restrict f(R, Lm) gravity, we consider a special model in the FRW cosmology and give some corresponding results by using astronomical observations.

Jun Wang; Kai Liao

2012-01-01T23:59:59.000Z

253

Three-dimensional geologic structures from inversion of gravity anomalies  

E-Print Network [OSTI]

from an analysis of the sampling interval. 39 100 80 z0= 7km p = 1gm/cra R, /R6= 2 ~ 10 60 mgal . ~ ~ Numerical Integration Parker Method 40 20 64 56 48 40 32 km 10 a) 24 16 8 mgal ! km 10b) 16 8 Figure 10. Gravity profile across.... The input was the gravity profile shown in Figure 5. The model parameters are the same used by Oldenburg (1974, Figure 2, p. 533) for the case Z =6km. . . . . . . . . . . . . . . . 33 Comparison of gravity profiles from the cosine model and from...

Hinson, Charles Alvin

2012-06-07T23:59:59.000Z

254

Learning About Magnets!  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by the National High Magnetic Field Laboratory Learning About Name A magnet is a material or object that creates a magnetic fi eld. This fi eld is invisible, but it creates a...

255

Interface Magnetism in Multiferroics  

E-Print Network [OSTI]

1.2.1 Magnetism . . . . . . . . . . . . . . . . . . . 1.2.2domain walls . . . . . 3 Magnetism of domain walls in BiFeOof electrical control of magnetism in mixed phase BiFeO 3

He, Qing

2011-01-01T23:59:59.000Z

256

Ground Magnetics At San Francisco Volcanic Field Area (Warpinski, Et Al.,  

Open Energy Info (EERE)

Warpinski, Et Al., Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Magnetics At San Francisco Volcanic Field Area (Warpinski, Et Al., 2004) Exploration Activity Details Location San Francisco Volcanic Field Area Exploration Technique Ground Magnetics Activity Date Usefulness not indicated DOE-funding Unknown Notes Northern Arizona University has re-assessed the existing exploration data, geologically mapped the target area, obtained rock samples for age dating and mineral chemistry, performed gravity and magnetic surveys, and integrated these results to identify potential drilling targets and sites. Further work may occur in 2004 or 2005. References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J.

257

Nonlinear Electrodynamics in $f(T)$ Gravity and Generalized Second Law of Thermodynamics  

E-Print Network [OSTI]

In this paper, we study the nonlinear electrodynamics in the framework of $f(T)$ gravity for FRW universe along with dust matter, magnetic and torsion contributions. We evaluate the equation of state and deceleration parameters to explore the accelerated expansion of the universe. The validity of generalized second law of thermodynamics for Hubble and event horizons is also investigated in this scenario. For this purpose, we assume pole-like and power-law forms of scale factor and construct $f(T)$ models. The graphical behavior of the cosmological parameters versus smaller values of redshift $z$ represent the accelerated expansion of the universe. It turns out that the generalized second law of thermodynamics holds for all values of $z$ with event horizon for power-law scale factor whereas it holds in a specific range of $z$ with Hubble horizon for power-law and both horizons in pole-like scale factors.

Sharif, M

2014-01-01T23:59:59.000Z

258

Nonlinear Electrodynamics in $f(T)$ Gravity and Generalized Second Law of Thermodynamics  

E-Print Network [OSTI]

In this paper, we study the nonlinear electrodynamics in the framework of $f(T)$ gravity for FRW universe along with dust matter, magnetic and torsion contributions. We evaluate the equation of state and deceleration parameters to explore the accelerated expansion of the universe. The validity of generalized second law of thermodynamics for Hubble and event horizons is also investigated in this scenario. For this purpose, we assume pole-like and power-law forms of scale factor and construct $f(T)$ models. The graphical behavior of the cosmological parameters versus smaller values of redshift $z$ represent the accelerated expansion of the universe. It turns out that the generalized second law of thermodynamics holds for all values of $z$ with event horizon for power-law scale factor whereas it holds in a specific range of $z$ with Hubble horizon for power-law and both horizons in pole-like scale factors.

M. Sharif; Shamaila Rani

2013-12-03T23:59:59.000Z

259

Local support against gravity in magnetoturbulent fluids  

Science Journals Connector (OSTI)

......the MHD simulations, but the turbulence energy is higher. Moreover, in contrast to...of the thermal, turbulent and magnetic energy densities (see, for instance, Lequeux...Space Plasma Flows-Pogorelov N. V., Audit E., Zank G. P., eds. (2010) San......

W. Schmidt; D. C. Collins; A. G. Kritsuk

2013-01-01T23:59:59.000Z

260

Femtosecond Opto-Magnetism  

Science Journals Connector (OSTI)

We demonstrate that circularly polarized laser pulses may selectively excite different modes of magnetic resonance, realize quantum control of magnons, trigger magnetic phase...

Kimel, Alexey; Kirilyuk, A; Rasing, Th

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Effective temperature and compactivity of a lattice gas under gravity  

Science Journals Connector (OSTI)

The notion of longitudinal effective temperature and its relation with the Edwards compactivity are investigated in an abstract lattice gas model of granular material compacting under gravity and weak thermal vibration.

Mauro Sellitto

2002-10-10T23:59:59.000Z

262

Extended Theories of Gravity and their Cosmological and Astrophysical Applications  

E-Print Network [OSTI]

We review Extended Theories of Gravity in metric and Palatini formalism pointing out their cosmological and astrophysical application. The aim is to propose an alternative approach to solve the puzzles connected to dark components.

Salvatore Capozziello; Mauro Francaviglia

2007-06-08T23:59:59.000Z

263

Geodesic multiplication as a tool for classical and quantum gravity  

E-Print Network [OSTI]

Algebraic systems called the local geodesic loops and their tangent Akivis algebras are considered. Their possible role in theory of gravity is considered. Quantum conditions for the infinitesimal quantum events are proposed.

Piret Kuusk; Eugen Paal

2008-03-08T23:59:59.000Z

264

Gravity assist maneuvers of a spacecraft in Jupiter system  

Science Journals Connector (OSTI)

Low cost tours in the Jovian system using gravity assist maneuvers near its large bodies are considered. Limited dynamic capabilities of the application of such maneuvers require multiple flybys of these bodies. Clearly, it is important to regularly ...

Yu. F. Golubev, A. V. Grushevskii, V. V. Koryanov, A. G. Tuchin

2014-05-01T23:59:59.000Z

265

Mixed convection and heat management in the Mars gravity biosatellite  

E-Print Network [OSTI]

The Mars Gravity Biosatellite will house fifteen mice in a low Earth orbit satellite spinning about its longitudinal axis. The satellite's payload thermal control system will reject heat through the base of the payload ...

Marsh, Jesse B. (Jesse Benjamin)

2007-01-01T23:59:59.000Z

266

The evolution of miscible gravity currents in horizontal porous layers  

E-Print Network [OSTI]

Gravity currents of miscible fluids in porous media are important to understand because they occur in important engineering projects, such as enhanced oil recovery and geologic CO[subscript 2] sequestration. These flows ...

Szulczewski, Michael Lawrence

267

Costs of Imported Crude Oil by API Gravity  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

Crude Oil Acquisition Report," July 1984 to present. 26. F.O.B. Costs of Imported Crude Oil by API Gravity 48 Energy Information Administration Petroleum Marketing Annual 1996...

268

Costs of Imported Crude Oil by API Gravity  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

Crude Oil Acquisition Report," July 1984 to present. 26. F.O.B. Costs of Imported Crude Oil by API Gravity 48 Energy Information Administration Petroleum Marketing Annual 1997...

269

Gravity and its Mysteries: Some Thoughts and Speculations  

E-Print Network [OSTI]

I gave a rambling talk about gravity and its many mysteries at Chen-Ning Yang's 85th Birthday Celebration held in November 2007. I don't have any answers.

A. Zee

2008-05-14T23:59:59.000Z

270

An alternative derivation of the Minimal massive 3D gravity  

E-Print Network [OSTI]

By using the algebra of exterior forms and the first order formalism with constraints, an alternative derivation of the field equations for the Minimal massive 3D gravity model is presented.

Ahmet Baykal

2014-08-22T23:59:59.000Z

271

Gravity assist maneuvers of a spacecraft in Jupiter system  

Science Journals Connector (OSTI)

Low cost tours in the Jovian system using gravity assist maneuvers near its large bodies are considered. Limited dynamic capabilities of the application of such maneuvers require multiple flybys of these bodie...

Yu. F. Golubev; A. V. Grushevskii

2014-05-01T23:59:59.000Z

272

Ground Gravity Survey At Dixie Valley Geothermal Area (Iovenitti...  

Open Energy Info (EERE)

project area. These data were used in conjunction with past gravity data reported in by Smith et al (2001) and Blackwell et al (2005). The analysis of these data had not been...

273

Constraints and Solutions of Quantum Gravity in Metric Representation  

E-Print Network [OSTI]

We construct the regularised Wheeler-De Witt operator demanding that the algebra of constraints of quantum gravity is anomaly free. We find that for a subset of all wavefunctions being integrals of scalar densities this condition can be satisfied. We proceed to finding exact solutions of quantum gravity being of the form of functionals of volume and average curvature of compact three-manifold.

A. B?aut; J. Kowalski-Glikman

1997-10-07T23:59:59.000Z

274

Gravity Effects on Antimatter in the Standard-Model Extension  

E-Print Network [OSTI]

The gravitational Standard-Model Extension (SME) is the general field-theory based framework for the analysis of CPT and Lorentz violation. In this work we summarize the implications of Lorentz and CPT violation for antimatter gravity in the context of the SME. Implications of various attempts to place indirect limits on anomalous antimatter gravity are considered in the context of SME-based models.

Tasson, Jay D

2015-01-01T23:59:59.000Z

275

Differentiating dark energy and modified gravity with galaxy redshift surveys  

Science Journals Connector (OSTI)

The observed cosmic acceleration today could be due to an unknown energy component (dark energy), or a modification to general relativity (modified gravity). If dark energy models and modified gravity models are required to predict the same cosmic expansion history H(z), they will predict different growth rates for cosmic large scale structure, fg(z). If gravity is not modified, the measured H(z) leads to a unique prediction for fg(z), fgH(z), if dark energy and dark matter are separate. Comparing fgH(z) with the measured fg(z) provides a transparent and straightforward test of gravity. We show that a simple ?2 test provides a general figure of merit for our ability to distinguish between dark energy and modified gravity given the measured H(z) and fg(z). We find that a magnitude-limited NIR galaxy redshift survey covering >10?000(deg)2 and a redshift range of 0.5zH(z) to 12% accuracy via baryon acoustic oscillation measurements, and fg(z) to the accuracy of a few per cent via the measurement of redshift-space distortions and the bias factor which describes how light traces mass. We show that if the H(z) data are fitted by both a DGP gravity model and an equivalent dark energy model that predict the same H(z), a survey area of 11?931(deg)2 is required to rule out the DGP gravity model at the 99.99% confidence level. It is feasible for such a galaxy redshift survey to be carried out by the next generation space missions from NASA and ESA, and it will revolutionize our understanding of the universe by differentiating between dark energy and modified gravity.

Yun Wang

2008-01-01T23:59:59.000Z

276

Loop Quantum Gravity Phenomenology: Linking Loops to Observational Physics  

E-Print Network [OSTI]

Research during the last decade demonstrates that effects originating on the Planck scale are currently being tested in multiple observational contexts. In this review we discuss quantum gravity phenomenological models and their possible links to loop quantum gravity. Particle frameworks, including kinematic models, broken and deformed Poincar\\'e symmetry, non-commutative geometry, relative locality and generalized uncertainty principle, and field theory frameworks, including Lorentz violating operators in effective field theory and non-commutative field theory, are discussed. The arguments relating loop quantum gravity to models with modified dispersion relations are reviewed, as well as, arguments supporting the preservation of local Lorentz invariance. The phenomenology related to loop quantum cosmology is briefly reviewed, with a focus on possible effects that might be tested in the near future. As the discussion makes clear, there remains much interesting work to do in establishing the connection between the fundamental theory of loop quantum gravity and these specific phenomenological models, in determining observational consequences of the characteristic aspects of loop quantum gravity, and in further refining current observations. Open problems related to these developments are highlighted. characteristic aspects of loop quantum gravity, and in further refining current observations. Open problems related to these developments are highlighted.

Florian Girelli; Franz Hinterleitner; Seth A. Major

2012-12-13T23:59:59.000Z

277

Dynamical horizon entropy and equilibrium thermodynamics of generalized gravity theories  

SciTech Connect (OSTI)

We study the relation between the thermodynamics and field equations of generalized gravity theories on the dynamical trapping horizon with sphere symmetry. We assume the entropy of a dynamical horizon as the Noether charge associated with the Kodama vector and point out that it satisfies the second law when a Gibbs equation holds. We generalize two kinds of Gibbs equations to Gauss-Bonnet gravity on any trapping horizon. Based on the quasilocal gravitational energy found recently for f(R) gravity and scalar-tensor gravity in some special cases, we also build up the Gibbs equations, where the nonequilibrium entropy production, which is usually invoked to balance the energy conservation, is just absorbed into the modified Wald entropy in the Friedmann-Robertson-Walker spacetime with slowly varying horizon. Moreover, the equilibrium thermodynamic identity remains valid for f(R) gravity in a static spacetime. Our work provides an alternative treatment to reinterpret the nonequilibrium correction and supports the idea that the horizon thermodynamics is universal for generalized gravity theories.

Wu Shaofeng; Ge Xianhui; Yang Guohong [Department of Physics, Shanghai University, Shanghai, 200444 (China); Shanghai Key Lab of Astrophysics, Shanghai, 200234 (China); Zhang Pengming [Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); Institute of Modern Physics, Lanzhou, 730000 (China)

2010-02-15T23:59:59.000Z

278

Quadrupole magnets measurement  

SciTech Connect (OSTI)

A rotating coil setup is designed for quadrupole magnet measurement at the Accelerator Test Facility (ATF); Hall probe measurement was also performed for one of each type of quadrupole magnet. Both mechanical and magnetic properties of the quadrupole magnets were measured, the results are reported here. 5 refs., 12 figs., 12 tabs.

Wang, Xijie (California Univ., Los Angeles, CA (USA). Center for Advanced Accelerators Physics); Sylvester, C. (Brookhaven National Lab., Upton, NY (USA))

1991-01-01T23:59:59.000Z

279

Magnetic Imaging Wolfgang Kuch  

E-Print Network [OSTI]

Magnetic Imaging Wolfgang Kuch Freie Universit¨at Berlin, Institut f¨ur Experimentalphysik, Arnimallee 14, 14195 Berlin, Germany kuch@physik.fu-berlin.de Abstract. Imaging of magnetic domains has- ern techniques is used nowadays routinely for magnetic imaging of magnetic ma- terials

Kuch, Wolfgang

280

Magnetism in Nanocrystalline Gold  

Science Journals Connector (OSTI)

Magnetism in Nanocrystalline Gold ... Bridging the current gap in experimental study of magnetism in bare gold nanomaterials, we report here on magnetism in gold nanocrystalline films produced by cluster deposition in the aggregate form that can be considered as a crossover state between a nanocluster and a continuous film. ... gold; nanocrystalline film; magnetism; cluster deposition; SQUID magnetometry ...

Vladimir Tuboltsev; Alexander Savin; Alexandre Pirojenko; Jyrki Risnen

2013-07-07T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Magnetism of spiral galaxies  

Science Journals Connector (OSTI)

... magnetic fields of spiral galaxies has taken a special place in the study of cosmic magnetism, but magnetic fields are a universal property of all galactic-type objects, as is ... . The past ten years have been notable for rapid, qualitative progress in understanding the magnetism of spiral galaxies, a result of both theoretical and observational developments. A few decades ...

Alexander Ruzmaikin; Dmitry Sokoloff; Anvar Shukurov

1988-11-24T23:59:59.000Z

282

Magnetism in microquasars  

Science Journals Connector (OSTI)

...Lynden-Bell, E. R. Priest and N. O. Weiss Magnetism in microquasars I. F. Mirabel Centre...binaries|magnetic field|plasma physics| Magnetism in microquasars By I. F. Mirabel Centre...Trans. R. Soc. Lond. A (2000) Magnetism in microquasars 843 At rst glance it...

2000-01-01T23:59:59.000Z

283

Early History of Magnetism  

Science Journals Connector (OSTI)

... 2, Dr. J. B. Kramer read a paper on The Early History of Magnetism, in which he discussed the various accounts of the first discovery of a magnet ... accounts of the first discovery of a magnet, and the development of the science of magnetism down to A.D. 1600. His remarks were divided into five sections, the ...

1932-03-19T23:59:59.000Z

284

Growth factor parametrization and modified gravity  

SciTech Connect (OSTI)

The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining the cosmic acceleration. The growth rate is parametrized by the growth index {gamma}. We discuss the dependence of {gamma} on the matter energy density {omega} and its current value {omega}{sub 0} for a more accurate approximation of the growth factor. The observational data, including the data of the growth rate, are used to fit different models. The data strongly disfavor the Dvali-Gabadadze-Porrati model. For the dark energy model with a constant equation of state, we find that {omega}{sub 0}=0.27{+-}0.02 and w=-0.97{+-}0.09. For the {lambda}CDM model, we find that {gamma}=0.64{sub -0.15}{sup +0.17}. For the Dvali-Gabadadze-Porrati model, we find that {gamma}=0.55{sub -0.13}{sup +0.14}.

Gong Yungui [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China)

2008-12-15T23:59:59.000Z

285

Characterising Vainshtein Solutions in Massive Gravity  

E-Print Network [OSTI]

We study static, spherically symmetric solutions in a recently proposed ghost-free model of non-linear massive gravity. We focus on a branch of solutions where the helicity-0 mode can be strongly coupled within certain radial regions, giving rise to the Vainshtein effect. We truncate the analysis to scales below the gravitational Compton wavelength, and consider the weak field limit for the gravitational potentials, while keeping all non-linearities of the helicity-0 mode. We determine analytically the number and properties of local solutions which exist asymptotically on large scales, and of local (inner) solutions which exist on small scales. We find two kinds of asymptotic solutions, one of which is asymptotically flat, while the other one is not, and also two types of inner solutions, one of which displays the Vainshtein mechanism, while the other exhibits a self-shielding behaviour of the gravitational field. We analyse in detail in which cases the solutions match in an intermediate region. The asymptotically flat solutions connect only to inner configurations displaying the Vainshtein mechanism, while the non asymptotically flat solutions can connect with both kinds of inner solutions. We show furthermore that there are some regions in the parameter space where global solutions do not exist, and characterise precisely in which regions of the phase space the Vainshtein mechanism takes place.

Fulvio Sbisa'; Gustavo Niz; Kazuya Koyama; Gianmassimo Tasinato

2014-06-17T23:59:59.000Z

286

Symmetry and Evolution in Quantum Gravity  

E-Print Network [OSTI]

We propose an operator constraint equation for the wavefunction of the Universe that admits genuine evolution. While the corresponding classical theory is equivalent to the canonical decomposition of General Relativity, the quantum theory makes predictions that are distinct from Wheeler-DeWitt cosmology. Furthermore, the local symmetry principle - and corresponding observables - of the theory have a direct interpretation in terms of a conventional gauge theory, where the gauge symmetry group is that of spatial conformal diffeomorphisms (that preserve the spatial volume of the Universe). The global evolution is in terms of an arbitrary parameter that serves only as an unobservable label for successive states of the Universe. Our proposal follows unambiguously from a suggestion of York whereby the independently specifiable initial data in the action principle of General Relativity is given by a conformal geometry and the spatial average of the York time on the spacelike hypersurfaces that bound the variation. Remarkably, such a variational principle uniquely selects the form of the constraints of the theory so that we can establish a precise notion of both symmetry and evolution in quantum gravity.

Sean Gryb; Karim Thebault

2014-03-25T23:59:59.000Z

287

Exploring Cartan gravity with dynamical symmetry breaking  

E-Print Network [OSTI]

It has been known for some time that General Relativity can be regarded as a Yang-Mills-type gauge theory in a symmetry broken phase. In this picture the gravity sector is described by an $SO(1,4)$ or $SO(2,3)$ gauge field $A^{a}_{\\phantom{a}b\\mu}$ and Higgs field $V^{a}$ which acts to break the symmetry down to that of the Lorentz group $SO(1,3)$. This symmetry breaking mirrors that of electroweak theory. However, a notable difference is that while the Higgs field $\\Phi$ of electroweak theory is taken as a genuine dynamical field satisfying a Klein-Gordon equation, the gauge independent norm $V^2\\equiv \\eta_{ab}V^{a}V^{b}$ of the Higgs-type field $V^a$ is typically regarded as non-dynamical. Instead, in many treatments $V^a$ does not appear explicitly in the formalism or is required to satisfy $V^2 = \\mathrm{const.} \

H. F. Westman; T. G. Zlosnik

2014-03-24T23:59:59.000Z

288

A gravity model for the Coso geothermal area, California | Open Energy  

Open Energy Info (EERE)

gravity model for the Coso geothermal area, California gravity model for the Coso geothermal area, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: A gravity model for the Coso geothermal area, California Details Activities (1) Areas (1) Regions (0) Abstract: Two- and three-dimensional gravity modeling was done using gridded Bouguer gravity data covering a 45 x 45 km region over the Coso geothermal area in an effort to identify features related to the heat source and to seek possible evidence for an underlying magma chamber. Isostatic and terrain corrected Bouguer gravity data for about 1300 gravity stations were obtained from the US Geological Survey. After the data were checked, the gravity values were gridded at 1 km centers for the area of interest centered on the Coso volcanic field. Most of the gravity

289

Magnetic Fields Analogous to electric field, a magnet  

E-Print Network [OSTI]

characteristic of elementary particles such as an electron #12;Magnetic Fields Magnetic field lines Direction;Magnetic Fields Magnetic field lines enter one end (south) of magnet and exit the other end (north) Opposite magnetic poles attract like magnetic poles repel #12;Like the electric field lines

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

290

The Search for a Primordial Magnetic Field  

E-Print Network [OSTI]

Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments of the big bang. Such a primordial magnetic field (PMF) would be expected to arise from and/or influence a variety of cosmological phenomena such as inflation, cosmic phase transitions, big bang nucleosynthesis, the cosmic microwave background (CMB) temperature and polarization anisotropies, the cosmic gravity wave background, and the formation of large-scale structure. In this review, we summarize the development of theoretical models for analyzing the observational consequences of a PMF. We also summarize the current state of the art in the search for observational evidence of a PMF. In particular we review the framework needed to calculate the effects of a PMF power spectrum on the CMB and the development of large scale structure. We summarize the current constraints on the PMF amplitude $B_\\lambda$ and the power spectral index $n_B$ and discuss prospects for better determining these quantities in the near future.

Dai G. Yamazaki; Toshitaka Kajino; Grant J. Mathew; Kiyotomo Ichiki

2012-04-16T23:59:59.000Z

291

Oil gravity segregation in the Monterey formation, California  

SciTech Connect (OSTI)

The Monterey Formation is a fractured siliceous shale that is the principal reservoir and source rock for oil fields in the Santa Maria basin and the western Santa Barbara Channel. Monterey crudes in producing offshore fields are high-sulfur oils that range from 10[degrees] to 35[degrees] API. The oils in Monterey fractured reservoirs display a systematic increase in API gravity with increasing height above the oil-water contact. The rate of change in API gravity with depth in Monterey oil fields generally ranges from 0.5[degrees] to 1.2[degrees] API/100 ft. The oil-water contact usually occurs at an oil gravity of 10[degrees] API (the gravity at which the density of the oil and the water is equal). The maximum API gravity in a Monterey oil field is related to the level of thermal exposure experienced by the formation in the adjacent depocenter. Monterey oils are sourced by high-sulfur kerogens that generate heavy oils at low levels of thermal exposure, but generate progressively higher gravity oils at higher levels of thermal maturity. Comparison of the maximum API gravity found in 33 Monterey-sourced oil fields with the maximum temperature experienced by the Monterey Formation within three miles of the field (the most likely migration distance) suggests that a temperature of 260[degrees]F (127[degrees]C) is required to generate 20[degrees] API oil, and a temperature of 330[degrees]F (166[degrees]C) is required to generate 30[degrees] API oil.

Hornafius, J.S. (Mobil Exploration and Producing, Bakersfield, CA (United States))

1994-04-01T23:59:59.000Z

292

Differentiating dark energy and modified gravity with galaxy redshift surveys  

E-Print Network [OSTI]

The observed cosmic acceleration today could be due to an unknown energy component (dark energy), or a modification to general relativity (modified gravity). If dark energy models and modified gravity models are required to predict the same cosmic expansion history H(z), they will predict different growth rate for cosmic large scale structure, f_g(z)=d\\ln \\delta/d\\ln a (\\delta=(\\rho_m-\\bar{\\rho_m})/\\bar{\\rho_m}), a is the cosmic scale factor). If gravity is not modified, the measured H(z) leads to a unique prediction for f_g(z), f_g^H(z). Comparing f_g^H(z) with the measured f_g(z) provides a transparent and straightforward test of gravity. We show that a simple \\chi^2 test provides a general figure-of-merit for our ability to distinguish between dark energy and modified gravity given the measured H(z) and f_g(z). We study a magnitude-limited NIR galaxy redshift survey covering >10,000 (deg)^2 and the redshift range of 0.5dark energy model that predict the same expansion history, a survey area of 11,931 (deg)^2 is required to rule out the DGP gravity model at the 99.99% confidence level. It is feasible for such a galaxy redshift survey to be carried out by the next generation space missions from NASA and ESA, and it will revolutionize our understanding of the universe by differentiating between dark energy and modified gravity.

Yun Wang

2007-10-21T23:59:59.000Z

293

HTS Magnet Program | Superconducting Magnet Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

HTS Magnet Program HTS Magnet Program High Temperature Superconductors (HTS) have the potential to revolutionize the field of superconducting magnets for particle accelerators, energy storage and medical applications. This is because of the fact that as compared to the conventional Low Temperature Superconductors (LTS), the critical current density (Jc ) of HTS falls slowly both: as a function of increasing field, and as a function of increasing temperature These unique properties can be utilized to design and build: HTS magnets that produce very high fields (20 - 50 T) HTS magnets that operate at elevated temperatures (20 - 77 K) This is a significant step forward over the convention LTS magnets which generally operate at a temperature of ~4 K and with field usually limited

294

Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets  

SciTech Connect (OSTI)

Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.

None

2010-10-01T23:59:59.000Z

295

Waste Isolation Pilot Plant (WIPP) site gravity survey and interpretation  

SciTech Connect (OSTI)

A portion of the WIPP site has been extensively surveyed with high-precision gravity. The main survey (in T22S, R31E) covered a rectangular area 2 by 4-1/3 mi encompassing all of WIPP site Zone II and part of the disturbed zone to the north of the site. Stations were at 293-ft intervals along 13 north-south lines 880 ft apart. The data are considered accurate to within a few hundredths of a milligal. Long-wavelength gravity anomalies correlate well with seismic time structures on horizons below the Castile Formation. Both the gravity anomalies and the seismic time structures are interpreted as resulting from related density and velocity variations within the Ochoan Series. Shorter wavelength negative gravity anomalies are interpreted as resulting from bulk density alteration in the vicinity of karst conduits. The WIPP gravity survey was unable to resolve low-amplitude, long-wavelength anomalies that should result from the geologic structures within the disturbed zone. It did indicate the degree and character of karst development within the surveyed area.

Barrows, L.J.; Fett, J.D.

1983-04-01T23:59:59.000Z

296

Unscreening modified gravity in the matter power spectrum  

E-Print Network [OSTI]

Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k Solar System tests or distance indicators in unscreened dwarf galaxies.

Lucas Lombriser; Fergus Simpson; Alexander Mead

2015-01-20T23:59:59.000Z

297

Unscreening modified gravity in the matter power spectrum  

E-Print Network [OSTI]

Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k < 0.3 h...

Lombriser, Lucas; Mead, Alexander

2015-01-01T23:59:59.000Z

298

Eustatic control of gravity tectonics: Concept, mechanism and limits  

SciTech Connect (OSTI)

Gravity tectonics over a ductile decollement characterizes deformation of the Albian to Recent section in the West African margin, from Gabon to Angola. Largely studied during the past 20 years as a prolific petroleum play, it is now well known that three mains factors will control gravity driven deformation: the ductile layer, the slope as a response to the crustal activity and the overlying sedimentary loading. For the West African passive margin, the slope effect at the first glance can be considered as constant and gravity driven deformation as a result of salt layer distribution (in time and space) and sedimentary loading. If previous papers have already shown that the type and distribution of the deposits control the development of the classical structural domains : updip extensional to downdip contractional, this study will focused on the factor which control the sedimentary loading. Based on several natural examples combining seismic stratigraphy, sequential stratigraphy and structural studies and also analogical modelling, it is demonstrated that: (1) as sediment distribution and then sedimentary loading is controlled by relative sea level changes, thus sea level changes can be directly related to gravity driven deformation : large sea level fall will provide an important increase of clastics supply which will enhanced gravity gliding. On the contrary, relative sea level high will stop the deformation because of the decreasing amount of detritics and their homogeneous distribution. (2) the salt downdip withdrawal during extension will enhance the eustatic effect. (3) episodic crustal activity, materialized by westward tilting of the margin will interfere on this mechanism.

Raillard, S.; Allix, P.; Guerin, G.; Lecanu, H. [Elf Aquitaine Production, Pau (France)] [and others

1996-12-31T23:59:59.000Z

299

Eustatic control of gravity tectonics: Concept, mechanism and limits  

SciTech Connect (OSTI)

Gravity tectonics over a ductile decollement characterizes deformation of the Albian to Recent section in the West African margin, from Gabon to Angola. Largely studied during the past 20 years as a prolific petroleum play, it is now well known that three mains factors will control gravity driven deformation: the ductile layer, the slope as a response to the crustal activity and the overlying sedimentary loading. For the West African passive margin, the slope effect at the first glance can be considered as constant and gravity driven deformation as a result of salt layer distribution (in time and space) and sedimentary loading. If previous papers have already shown that the type and distribution of the deposits control the development of the classical structural domains : updip extensional to downdip contractional, this study will focused on the factor which control the sedimentary loading. Based on several natural examples combining seismic stratigraphy, sequential stratigraphy and structural studies and also analogical modelling, it is demonstrated that: (1) as sediment distribution and then sedimentary loading is controlled by relative sea level changes, thus sea level changes can be directly related to gravity driven deformation : large sea level fall will provide an important increase of clastics supply which will enhanced gravity gliding. On the contrary, relative sea level high will stop the deformation because of the decreasing amount of detritics and their homogeneous distribution. (2) the salt downdip withdrawal during extension will enhance the eustatic effect. (3) episodic crustal activity, materialized by westward tilting of the margin will interfere on this mechanism.

Raillard, S.; Allix, P.; Guerin, G.; Lecanu, H. (Elf Aquitaine Production, Pau (France)) (and others)

1996-01-01T23:59:59.000Z

300

Tamper resistant magnetic stripes  

DOE Patents [OSTI]

This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.

Naylor, Richard Brian (Albuquerque, NM); Sharp, Donald J. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

STABILITY OF THE TOROIDAL MAGNETIC FIELD IN STELLAR RADIATION ZONES  

SciTech Connect (OSTI)

The stability of the magnetic field in radiation zones is of crucial importance for mixing, angular momentum transport, etc. We consider the stability properties of a star containing a predominant toroidal field in spherical geometry by means of a linear stability in the Boussinesq approximation taking into account the effect of thermal conductivity. We calculate the growth rate of instability and analyze in detail the effects of stable stratification and heat transport. We argue that the stabilizing influence of gravity can never entirely suppress the instability caused by electric currents in radiation zones. However, the stable stratification can essentially decrease the growth rate of instability.

Bonanno, Alfio [INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania (Italy); Urpin, Vadim, E-mail: alfio.bonanno@inaf.it, E-mail: vadim.urpin@uv.es [INFN, Sezione di Catania, Via S. Sofia 72, 95123 Catania (Italy)

2012-03-10T23:59:59.000Z

302

Resonant detection of axion mediated forces with Nuclear Magnetic Resonance  

E-Print Network [OSTI]

We describe a method based on precision magnetometry that can extend the search for axion-mediated spin-dependent forces by several orders of magnitude. By combining techniques used in nuclear magnetic resonance and short-distance tests of gravity, our approach can substantially improve upon current experimental limits set by astrophysics, and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. Our method is sensitive to PQ axion decay constants between 10^9 and 10^12 GeV or axion masses between 10^-6 and 10^-3 eV, independent of the cosmic axion abundance.

Asimina Arvanitaki; Andrew A. Geraci

2014-03-05T23:59:59.000Z

303

Ground Gravity Survey At Truckhaven Area (Layman Energy Associates, 2009) |  

Open Energy Info (EERE)

Truckhaven Area (Layman Energy Associates, 2009) Truckhaven Area (Layman Energy Associates, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Truckhaven Area (Layman Energy Associates, 2009) Exploration Activity Details Location Truckhaven Area Exploration Technique Ground Gravity Survey Activity Date Usefulness useful DOE-funding Unknown Notes The area of coverage for the DOE-funded geophysical surveys is shown in Figure 9. The 95 magnetotelluric (MT) soundings cover a central area of about 80 square kilometers. The 126 gravity stations extend over a broader area of about 150 square kilometers, centered on the same area covered by the MT soundings. A detailed description of the instrumentation and data acquisition procedures used for both surveys is provided in GSY-USA, Inc.

304

Viscosity bound for anisotropic superfluids in higher derivative gravity  

E-Print Network [OSTI]

In the present paper, based on the principles of gauge/gravity duality we analytically compute the shear viscosity to entropy ratio corresponding to the superfluid phase in Einstein Gauss-Bonnet gravity. From our analysis we note that the ratio indeed receives a finite temperature correction below certain critical temperature. This proves the non universality of shear viscosity to entropy ratio in higher derivative theories of gravity. We also compute the upper bound for the Gauss-Bonnet coupling corresponding to the symmetry broken phase and note that the upper bound on the coupling does not seem to change as long as we are close to the critical point of the phase diagram. However the corresponding lower bound of the shear viscosity to entropy ratio seems to get modified due to the finite temperature effects.

Bhattacharyya, Arpan

2014-01-01T23:59:59.000Z

305

Viscosity bound for anisotropic superfluids in higher derivative gravity  

E-Print Network [OSTI]

In the present paper, based on the principles of gauge/gravity duality we analytically compute the shear viscosity to entropy ratio corresponding to the superfluid phase in Einstein Gauss-Bonnet gravity. From our analysis we note that the ratio indeed receives a finite temperature correction below certain critical temperature. This proves the non universality of shear viscosity to entropy ratio in higher derivative theories of gravity. We also compute the upper bound for the Gauss-Bonnet coupling corresponding to the symmetry broken phase and note that the upper bound on the coupling does not seem to change as long as we are close to the critical point of the phase diagram. However the corresponding lower bound of the shear viscosity to entropy ratio seems to get modified due to the finite temperature effects.

Arpan Bhattacharyya; Dibakar Roychowdhury

2014-10-13T23:59:59.000Z

306

Will multiple probes of dark energy find modified gravity?  

SciTech Connect (OSTI)

One of the most pressing issues in cosmology is whether general relativity (GR) plus a dark sector is the underlying physical theory or whether a modified gravity model is needed. Upcoming dark energy experiments designed to probe dark energy with multiple methods can address this question by comparing the results of the different methods in constraining dark energy parameters. Disagreement would signal the breakdown of the assumed model (GR plus dark energy). We study the power of this consistency test by projecting constraints in the w{sub 0}-w{sub a} plane from the four different techniques of the Dark Energy Survey in the event that the underlying true model is modified gravity. We find that the standard technique of looking for overlap has some shortcomings, and we propose an alternative, more powerful Multidimensional Consistency Test. We introduce the methodology for projecting whether a given experiment will be able to use this test to distinguish a modified gravity model from GR.

Shapiro, Charles [Institute of Cosmology and Gravitation, Portsmouth, PO1 3FX (United Kingdom); Dodelson, Scott [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States); Kavli Institute for Cosmological Physics, Chicago, Illinois 60637 (United States); Hoyle, Ben [Institut de Ciencies del Cosmos, Barcelona (Spain); Samushia, Lado [Institute of Cosmology and Gravitation, Portsmouth, PO1 3FX (United Kingdom); National Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, GE-0160 Tbilisi (Georgia); Flaugher, Brenna [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

2010-08-15T23:59:59.000Z

307

On the UV structure of quantum unimodular gravity  

E-Print Network [OSTI]

It is a well known result that any formulation of unimodular gravity is classically equivalent to General Relativity (GR), however a debate exists in the literature about this equivalence at the quantum level. In this work, we investigate the UV quantum structure of a diffeomorphism invariant formulation of unimodular gravity using functional renormalisation group methods in a Wilsonian context. We show that the effective action of the unimodular theory acquires essentially the same form with that of GR in the UV, as well as that both theories share similar UV completions within the framework of the asymptotic safety scenario for quantum gravity. Furthermore, we find that in this context the unimodular theory can appear to be non--predictive due to an increasing number of relevant couplings at high energies, and explain how this unwanted feature is in the end avoided.

Ippocratis D. Saltas

2014-12-13T23:59:59.000Z

308

Rapidly rotating neutron stars in $R$-squared gravity  

E-Print Network [OSTI]

$f(R)$ theories of gravity are one of the most popular alternative explanations for dark energy and therefore studying the possible astrophysical implications of these theories is an important task. In the present paper we make a substantial advance in this direction by considering rapidly rotating neutron stars in $R^2$ gravity. The results are obtained numerically and the method we use is non-perturbative and self-consistent. The neutron star properties, such as mass, radius and moment of inertia, are studied in detail and the results show that rotation magnifies the deviations from general relativity and the maximum mass and moment of inertia can reach very high values. This observation is similar to previous studies of rapidly rotating neutron stars in other alternative theories of gravity, such as the scalar-tensor theories, and it can potentially lead to strong astrophysical manifestations.

Yazadjiev, Stoytcho S; Kokkotas, Kostas D

2015-01-01T23:59:59.000Z

309

Will multiple probes of dark energy find modified gravity?  

Science Journals Connector (OSTI)

One of the most pressing issues in cosmology is whether general relativity (GR) plus a dark sector is the underlying physical theory or whether a modified gravity model is needed. Upcoming dark energy experiments designed to probe dark energy with multiple methods can address this question by comparing the results of the different methods in constraining dark energy parameters. Disagreement would signal the breakdown of the assumed model (GR plus dark energy). We study the power of this consistency test by projecting constraints in the w0-wa plane from the four different techniques of the Dark Energy Survey in the event that the underlying true model is modified gravity. We find that the standard technique of looking for overlap has some shortcomings, and we propose an alternative, more powerful Multidimensional Consistency Test. We introduce the methodology for projecting whether a given experiment will be able to use this test to distinguish a modified gravity model from GR.

Charles Shapiro; Scott Dodelson; Ben Hoyle; Lado Samushia; Brenna Flaugher

2010-08-17T23:59:59.000Z

310

National High Magnetic Field Laboratory: An Introduction to Magnets...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

resistive magnet is here at the Magnet Lab: It can generate a sustained magnetic field of 35 tesla. (Were not counting here our world-record hybrid magnet or the stronger,...

311

3D analysis of magnetization distribution magnetized by capacitor-discharge impulse magnetizer  

Science Journals Connector (OSTI)

Method for calculating the magnetization distribution magnetized by capacitor-discharge impulse magnetizer is expanded to 3D, and the calculated flux distribution is compared with measured one.

Norio Takahashi

2001-01-01T23:59:59.000Z

312

Spin and orbital magnetization loops obtained using magnetic Compton scattering  

SciTech Connect (OSTI)

We present an application of magnetic Compton scattering (MCS) to decompose a total magnetization loop into spin and orbital magnetization contributions. A spin magnetization loop of SmAl{sub 2} was measured by recording the intensity of magnetic Compton scattering as a function of applied magnetic field. Comparing the spin magnetization loop with the total magnetization one measured by a vibrating sample magnetometer, the orbital magnetization loop was obtained. The data display an anti-coupled behavior between the spin and orbital magnetizations and confirm that the orbital part dominates the magnetization.

Itou, M.; Sakurai, Y. [Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Koizumi, A. [Graduate School of Materials Science, University of Hyogo, Hyogo 678-1297 (Japan)] [Graduate School of Materials Science, University of Hyogo, Hyogo 678-1297 (Japan)

2013-02-25T23:59:59.000Z

313

E-Print Network 3.0 - assisted gravity drainage Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

, by gravity drainage in a core sample positioned vertically. The 1 m long core had a permeability of 7000 md... and a porosity of 41%. Pedrera et al. (2002) conducted gravity...

314

Visualization of flow boiling in an annular heat exchanger under reduced gravity conditions  

E-Print Network [OSTI]

creating unique visual and quantitative data. These data were then analyzed using a resistance type heat transfer model and five different zero gravity flow regime maps. Results from this analysis included: (i) presenting zero gravity data that correlated...

Westheimer, David Thomas

2012-06-07T23:59:59.000Z

315

E-Print Network 3.0 - altered gravity conditions Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ren a, , Su Xu b , Shin-Tson Wu b... 2010 Keywords: Liquid droplet Droplet surface Surface tension Focal length Gravity effect We report... the gravity effects on the shape...

316

Constraints on gravity on cosmic scales with upcoming large-scale structure surveys  

Science Journals Connector (OSTI)

...acceleration: large-scale structure surveys, such as Dark Energy Survey, the Large Synoptic Survey Telescope...modified gravity models. We consider the survey's ability to constrain dark energy EoS and modified gravity parameters by...

2011-01-01T23:59:59.000Z

317

Recent lunar magnetism  

E-Print Network [OSTI]

The magnetization of young lunar samples (magnetic fields (e.g. core dynamo and long-lived impact plasma fields) have not been present within the last 1.5 Ga. To better ...

Buz, Jennifer

2011-01-01T23:59:59.000Z

318

Metallic Magnetic Hetrostructures  

E-Print Network [OSTI]

This work studied sputter deposited conventional spin valves (SV) and related structures. In SV layered structures, two ferromagnetic layers are separated by a non-magnetic spacer. Under an external magnetic field, the relative orientation...

Leung, Chi Wah

319

Plasma Magnetic Insulation  

Science Journals Connector (OSTI)

29 June 1987 research-article Plasma Magnetic Insulation B. B. Kadomtsev Theoretically the strong magnetic field of a tokamak should confine electrons and ions in a high-temperature...

1987-01-01T23:59:59.000Z

320

Magnetic assisted statistical assembly  

E-Print Network [OSTI]

The objective of this thesis is to develop a process using magnetic forces to assemble micro-components into recesses on silicon based integrated circuits. Patterned SmCo magnetic thin films at the bottom of recesses are ...

Cheng, Diana I

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Magnetic Nanoparticle NANOMATERIALS  

E-Print Network [OSTI]

Magnetic Nanoparticle Metrology NANOMATERIALS We are developing best practice metrology for characterization of magnetic nanoparticle systems (e.g. blocking temperature, anisotropy, property distributions, T nanoparticles and provide guidelines to the FDA to properly compare systems when approving nanoparticle systems

322

Uranium Monochalcogenides: Magnetic Form Factor and Magnetic Neutron Scattering  

Science Journals Connector (OSTI)

Fig. R.66. UY. (A) Magnetic form factor. The radial ?j i? integrals, which contribute to the neutron magnetic fo...

R. Tro?

2009-01-01T23:59:59.000Z

323

LHC Magnet Program | Superconducting Magnet Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnet Program Magnet Program The Superconducting Magnet Division is building a number of dipole magnets for the Large Hadron Collider (LHC), which is now under construction at CERN in Geneva, Switzerland. Scheduled to begin operation in 2007, this machine will collide beams of protons with the unprecedented energy of 7 TeV per beam to explore the nature of matter at its most basic level (RHIC can collide beams of protons with energies of 0.25 TeV, but is mostly used to collide heavy ions with energies of 0.1 TeV per nucleon). The magnets are being built as part of the US program, recommended by the High Energy Physics Advisory Panel (HEPAP) and approved by Congress, to contribute to the construction and, later, use of that frontier machine by the US high energy physics community. Fermi National Accelerator Laboratory (FNAL) and

324

Magnetic and gravity signatures and structural history of the Tas-mantid Seamounts  

E-Print Network [OSTI]

area. Brisbane -6000 -5000 -4000 -3000 -2000 -1000 0 1000 2000 3000 Meters Selected References Weissel

Watts, A. B. "Tony"

325

Geodesic Structure of the Schwarzschild Black Hole in Rainbow Gravity  

E-Print Network [OSTI]

In this paper we study the geodesic structure of the Schwarzschild black hole in rainbow gravity analyzing the behavior of null and time-like geodesic. We find that the structure of the geodesics essentially does not change when the semi-classical effects are included. However, we can distinguish different scenarios if we take into account the effects of rainbow gravity. Depending on the type of rainbow functions under consideration, inertial and external observers see very different situations in radial and non radial motion of a test particles.

Carlos Leiva; Joel Saavedra; Jose Villanueva

2008-12-09T23:59:59.000Z

326

Gravity Survey of the Carson Sink - Data and Maps  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south?central, east?central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step?overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.

Faulds, James E.

327

CP violation and gravity as the weakest force  

E-Print Network [OSTI]

We argue that CP violation has rather dramatic impact on the "gravity as the weakest force" conjecture. Namely we find that new ultraviolet scale must be $\\Lambda \\lesssim \\theta g^3 M_P$, where $\\theta$ is an effective parameter describing CP violation and $g$ is the gauge coupling constant. The bound implies that CP-conserving limit is discontinuous, and possibly indicates that the class of effective theories with strict CP conservation is inconsistent with a fundamental theory incorporating quantum gravity. At the same time, the mass hierarchy problem can be explained due to the smallness of the CP violation, $\\theta \\sim 10^{-15}$ or so.

Archil Kobakhidze

2008-07-03T23:59:59.000Z

328

Spherically symmetric static spacetimes in vacuum f(T) gravity  

SciTech Connect (OSTI)

We show that Schwarzschild geometry remains as a vacuum solution for those four-dimensional f(T) gravitational theories behaving as ultraviolet deformations of general relativity. In the gentler context of three-dimensional gravity, we also find that the infrared-deformed f(T) gravities, like the ones used to describe the late cosmic speed up of the Universe, have as the circularly symmetric vacuum solution a Deser-de Sitter or a Banados, Teitelboim and Zanelli-like spacetime with an effective cosmological constant depending on the infrared scale present in the function f(T).

Ferraro, Rafael [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Fiorini, Franco [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina)

2011-10-15T23:59:59.000Z

329

Neutron stars in f(R) gravity with perturbative constraints  

SciTech Connect (OSTI)

We study the structure of neutron stars in f(R) gravity theories with perturbative constraints. We derive the modified Tolman-Oppenheimer-Volkov equations and solve them for a polytropic equation of state. We investigate the resulting modifications to the masses and radii of neutron stars and show that observations of surface phenomena alone cannot break the degeneracy between altering the theory of gravity versus choosing a different equation of state of neutron-star matter. On the other hand, observations of neutron-star cooling, which depends on the density of matter at the stellar interior, can place significant constraints on the parameters of the theory.

Cooney, Alan; DeDeo, Simon; Psaltis, Dimitrios [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, New Mexico 87501 (United States); Departments of Astronomy and Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2010-09-15T23:59:59.000Z

330

Time machines and traversable wormholes in modified theories of gravity  

E-Print Network [OSTI]

We review recent work on wormhole geometries in the context of modified theories of gravity, in particular, in f(R) gravity and with a nonminimal curvature-matter coupling, and in the recently proposed hybrid metric-Palatini theory. In principle, the normal matter threading the throat can be shown to satisfy the energy conditions and it is the higher order curvatures terms that sustain these wormhole geometries. We also briefly review the conversion of wormholes into time-machines, explore several of the time travel paradoxes and possible remedies to these intriguing side-effects in wormhole physics.

Francisco S. N. Lobo

2012-12-05T23:59:59.000Z

331

Ising Model Coupled to Three-Dimensional Quantum Gravity  

E-Print Network [OSTI]

We have performed Monte Carlo simulations of the Ising model coupled to three-dimensional quantum gravity based on a summation over dynamical triangulations. These were done both in the microcanonical ensemble, with the number of points in the triangulation and the number of Ising spins fixed, and in the grand canoncal ensemble. We have investigated the two possible cases of the spins living on the vertices of the triangulation (``diect'' case) and the spins living in the middle of the tetrahedra (``dual'' case). We observed phase transitions which are probably second order, and found that the dual implementation more effectively couples the spins to the quantum gravity.

C. F. Baillie

1992-05-09T23:59:59.000Z

332

Quantum-Gravity Phenomenology and the DSR Ether Theories  

E-Print Network [OSTI]

Guided primarily by versions of a theoretical framework called Doubly Special Relativity, or DSR, that are supposed to entail speeds of light that vary with energy while preserving the relativity of inertial frames, quantum-gravity phenomenologists have recently been seeking clues to quantum gravity, in hoped-for differing times of arrival, for light of differing energies, from cosmologically distant sources. However, it has long been known that signals, of arbitrarily high speed in opposing directions, could be used to observe the translational state of (absolute) rest, as could signals of a fixed speed different from c. Consequently, the above versions of DSR are nonviable.

Kenneth M. Sasaki

2010-09-20T23:59:59.000Z

333

Geological structures from downward continuation of gravity anomalies  

E-Print Network [OSTI]

operator and two grid spacings (2 and 4 km), the depth to the upper surface of the source is about 4 km, with the center of' mass located at about 8 km. Comparison of these results with those for a sphere yield a density contrast of 0. 3 g/cc . Both... km 18. Downward-continuation residual gravity map and profile at the depth of 6 km. Contours in mGals. Grid spacing 4 km by 4 km 19. Downward-continuation residual gravity map and profile at the depth of 8 km. Contours in mGals. Grid spacing 4 km...

Yao, Chia-Chi George

2012-06-07T23:59:59.000Z

334

Power-counting renormalizability of generalized Horava gravity  

E-Print Network [OSTI]

In an earlier article [arXiv:0902.0590 [hep-th], Phys. Rev D80 (2009) 025011], I discussed the potential benefits of allowing Lorentz symmetry breaking in quantum field theories. In particular I discussed the perturbative power-counting finiteness of the normal-ordered :P(phi)^{z>=d}_{d+1}: scalar quantum field theories, and sketched the implications for Horava's model of quantum gravity. In the current rather brief addendum, I will tidy up some dangling issues and fill out some of the technical details of the argument indicating the power-counting renormalizability of a z>=d variant of Horava gravity in (d+1) dimensions.

Matt Visser

2009-12-24T23:59:59.000Z

335

Generalized Second Law of Thermodynamics in Extended Theories of Gravity  

E-Print Network [OSTI]

By employing the general expression of temperature $T_{h}=|\\kappa|/2\\pi = \\frac{1}{2\\pi \\tilde{r}_{A}}(1-\\frac{\\dot{\\tilde{r}}_{A}}{2H\\tilde{r}_{A}})$ associated with the apparent horizon of a FRW universe and assuming a region of FRW universe enclosed by the apparent horizon as a thermal system in equilibrium, we are able to show that the generalized second law of thermodynamics holds in Gauss-Bonnet gravity and in more general Lovelock gravity.

M. Akbar

2008-08-25T23:59:59.000Z

336

On Solutions of Minimal Massive 3D Gravity  

E-Print Network [OSTI]

We look at solutions of Minimal Massive Gravity (MMG), a generalisation of Topologically Massive Gravity (TMG) that improves upon its holographic properties. It is shown that generically (in MMG parameter space) all conformally flat solutions of vacuum MMG are locally isometric to one of the two (A)dS vacua of the theory. We then couple a scalar field, and find that domain wall solutions can only interpolate between these two vacua precisely when the bulk graviton is tachyonic. Finally, we find a non-BTZ AdS black hole solution satisfying Brown-Henneaux boundary conditions, which lies within the "bulk/ boundary unitarity region".

Arvanitakis, Alex S

2015-01-01T23:59:59.000Z

337

Complete Classification of 1+1 Gravity Solutions  

E-Print Network [OSTI]

A classification of the maximally extended solutions for 1+1 gravity models (comprising e.g. generalized dilaton gravity as well as models with non-trivial torsion) is presented. No restrictions are placed on the topology of the arising solutions, and indeed it is found that for generic models solutions on non-compact surfaces of arbitrary genus with an arbitrary non-zero number of holes can be obtained. The moduli space of classical solutions (solutions of the field equations with fixed topology modulo gauge transformations) is parametrized explicitly.

T. Kloesch; T. Strobl

1997-11-25T23:59:59.000Z

338

Classical and Quantum Aspects of 1+1 Gravity  

E-Print Network [OSTI]

We present a classification of all global solutions (with Lorentzian signature) for any general 2D dilaton gravity model. For generic choices of potential-like terms in the Lagrangian one obtains maximally extended solutions on arbitrary non-compact two-manifolds, including various black-hole and kink configurations. We determine all physical quantum states in a Dirac approach. In some cases the spectrum of the (black-hole) mass operator is found to be sensitive to the signature of the theory, which may be relevant in view of current attempts to implement a generalized Wick-rotation in 4D quantum gravity.

T. Kloesch; P. Schaller; T. Strobl

1996-08-02T23:59:59.000Z

339

Magnetic susceptibility in QCD  

E-Print Network [OSTI]

Magnetic susceptibility in the deconfined phase of QCD is calculated in a closed form using a recent general expression for the quark gas pressure in magnetic field. Quark selfenergies are entering the result via Polyakov line factors and ensure the total paramagnetic effect, increasing with temperature. A generalized form of magnetic susceptibility in nonzero magnetic field suitable for experimental and lattice measurements is derived, showing a good agreement with available lattice data.

V. D. Orlovsky; Yu. A. Simonov

2014-05-12T23:59:59.000Z

340

A perturbative approach for the study of compatibility between nonminimally coupled gravity and Solar System experiments  

E-Print Network [OSTI]

We develop a framework for constraining a certain class of theories of nonminimally coupled (NMC) gravity with Solar System observations.

Orfeu Bertolami; Riccardo March; Jorge Pramos

2014-03-18T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Magnetism Theory Group / POSTECH Magnetism Theory Group / POSTECH  

E-Print Network [OSTI]

Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH J.H . Park et al. #12;'s of FeinCsm e tal The chargeandorbitalordering geom etryin YB a C o 2 O 5 S. K. Kwon etal .Magnetism Theory

Min, Byung Il

342

RESEARCH: Argonne's Super Magnet  

Science Journals Connector (OSTI)

RESEARCH: Argonne's Super Magnet ... The world's largest superconducting magnet has been successfully built and operated by Argonne National Laboratory, at Argonne, Ill. ... The magnet will be part of Argonne's bubble chamber, also the world's largest, which should be completed on schedule this summer. ...

1969-02-03T23:59:59.000Z

343

Noble gas magnetic resonator  

DOE Patents [OSTI]

Precise measurements of a precessional rate of noble gas in a magnetic field is obtained by constraining the time averaged direction of the spins of a stimulating alkali gas to lie in a plane transverse to the magnetic field. In this way, the magnetic field of the alkali gas does not provide a net contribution to the precessional rate of the noble gas.

Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

2014-04-15T23:59:59.000Z

344

Magnetism in transition metals  

Science Journals Connector (OSTI)

By using the Hubbard tight-binding-type Hamiltonian and the cluster Bethe-lattice approximation we calculate for Fe the Curie temperature TC=2250 K and the temperature dependence of the magnetic moments and the magnetization. Moreover, we show how previous theories for itinerant magnets may be extended to include short-range spin correlations.

J. L. Morn-Lpez; K. H. Bennemann; M. Avignon

1981-06-01T23:59:59.000Z

345

A Study in Magnetism  

Science Journals Connector (OSTI)

... this century, for the simple comprehensiveness and original beauty of his researches in electricity and magnetism; chiefly, perhaps, for his discovery of magneto-electricitythe kind of electricity that ... space surrounding a magnet was thrown into a peculiar condition by the presence of the magnetism. Two centuries previously another Englishman, as uniquely great if not greater, Dr. Gilbert ...

SILVANUS P. THOMPSON

1878-11-28T23:59:59.000Z

346

An optimizing reduced order FDS for the tropical Pacific Ocean reduced gravity model  

E-Print Network [OSTI]

An optimizing reduced order FDS for the tropical Pacific Ocean reduced gravity model Zhendong Luoa) for the tropical Pacific Ocean reduced gravity model. Ensembles of data are compiled from transient solutions computed from the discrete equation system derived by FDS for the tropical Pacific Ocean reduced gravity

Aluffi, Paolo

347

Complete Bouguer gravity map of the Nevada Test Site and vicinity, Nevada  

SciTech Connect (OSTI)

About 15,000 gravity stations were used to create the gravity map. Gravity studies at the Nevada Test Site were undertaken to help locate geologically favorable areas for underground nuclear tests and to help characterize potential high-level nuclear waste storage sites. 48 refs. (TEM)

Healey, D.L.; Harris, R.N.; Ponce, D.A.; Oliver, H.W.

1987-12-31T23:59:59.000Z

348

Canonical quantization of a minisuperspace model for gravity using self-dual variables  

E-Print Network [OSTI]

The present article summarizes the work of the papers \\cite{1} dealing with the quantization of pure gravity and gravity coupled to a Maxwell field and a cosmological constant in presence of spherical symmetry. The class of models presented is intended as an interesting testing ground for the quantization of full 3+1 gravity. We are working in Ashtekar's self-dual representation.

T. Thiemann

1999-10-04T23:59:59.000Z

349

Nonlinear force-free modeling of the solar coronal magnetic field  

E-Print Network [OSTI]

The coronal magnetic field is an important quantity because the magnetic field dominates the structure of the solar corona. Unfortunately direct measurements of coronal magnetic fields are usually not available. The photospheric magnetic field is measured routinely with vector magnetographs. These photospheric measurements are extrapolated into the solar corona. The extrapolated coronal magnetic field depends on assumptions regarding the coronal plasma, e.g. force-freeness. Force-free means that all non-magnetic forces like pressure gradients and gravity are neglected. This approach is well justified in the solar corona due to the low plasma beta. One has to take care, however, about ambiguities, noise and non-magnetic forces in the photosphere, where the magnetic field vector is measured. Here we review different numerical methods for a nonlinear force-free coronal magnetic field extrapolation: Grad-Rubin codes, upward integration method, MHD-relaxation, optimization and the boundary element approach. We briefly discuss the main features of the different methods and concentrate mainly on recently developed new codes.

T. Wiegelmann

2008-01-18T23:59:59.000Z

350

Combined passive magnetic bearing element and vibration damper  

DOE Patents [OSTI]

A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium and dampen transversely directed vibrations. Mechanical stabilizers are provided to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. In a improvement over U.S. Pat. No. 5,495,221, a magnetic bearing element is combined with a vibration damping element to provide a single upper stationary dual-function element. The magnetic forces exerted by such an element, enhances levitation of the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations, and suppresses the effects of unbalance or inhibits the onset of whirl-type rotor-dynamic instabilities. Concurrently, this equilibrium is made stable against displacement-dependent drag forces of the rotating object from its equilibrium position.

Post, Richard F. (Walnut Creek, CA)

2001-01-01T23:59:59.000Z

351

Magnetically attached sputter targets  

DOE Patents [OSTI]

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

Makowiecki, D.M.; McKernan, M.A.

1994-02-15T23:59:59.000Z

352

In-situ magnetization of NdFeB magnets for permanent magnet machines  

SciTech Connect (OSTI)

In-situ magnetizers are needed to facilitate the assembly of permanent magnet machines and to remagnetize the magnets after weakening due to a fault condition. The air-core magnetizer in association with the silicon steel lamination structure of the rotor has advantages over its iron-core counterpart. This novel method has been used to magnetize the NdFeB magnets in a 30-hp permanent magnet synchronous motor. The magnetizing capability for different magnetizer geometries was investigated for the magnetization of NdFeB material. The design, testing, and operation of this magnetizer are reported in this paper.

Chang, L.; Eastham, T.R.; Dawson, G.E. (Dept. of Electrical Engineering, Queen's Univ., Kingston, Ontario K7L 3N6 (CA))

1991-09-01T23:59:59.000Z

353

math.QA/0006228 Combinatorial quantisation of Euclidean gravity  

E-Print Network [OSTI]

MS­00­007 math.QA/0006228 Combinatorial quantisation of Euclidean gravity in three dimensions B the combinatorial quantisation program developed for 1 address after 1.09.2000: Department of Mathematics, Heriot by Alekseev, Grosse and Schomerus, see [1][2] and also [3]. We shall show how to implement the main steps

Schroers, Bernd J.

354

Ionospheric detection of gravity waves induced by tsunamis  

Science Journals Connector (OSTI)

......waves in the atmosphere, because...ionospheric plasma through different...hour and larger scales than...and 0.5 mHz, corresponding...couple with atmospheric gravity wave...ionospheric plasma at high altitude...ionosphere over large areas, in particular...description of the atmospheric-ionospheric......

Juliette Artru; Vesna Ducic; Hiroo Kanamori; Philippe Lognonn; Makoto Murakami

2005-03-01T23:59:59.000Z

355

Self-gravity and quasi-stellar object discs  

Science Journals Connector (OSTI)

......large radius. Under standard assumptions, the Toomre...been made to modify the standard alpha-disc model so...extended discs. The plan of the paper is as follows. In Section 2 we review self-gravity in steady...these alternatives to the standard alpha disc face severe......

Jeremy Goodman

2003-03-11T23:59:59.000Z

356

Testing Gravity Against Early Time Integrated Sachs-Wolfe Effect  

E-Print Network [OSTI]

A generic prediction of general relativity is that the cosmological linear density growth factor $D$ is scale independent. But in general, modified gravities do not preserve this signature. A scale dependent $D$ can cause time variation in gravitational potential at high redshifts and provides a new cosmological test of gravity, through early time integrated Sachs-Wolfe (ISW) effect-large scale structure (LSS) cross correlation. We demonstrate the power of this test for a class of $f(R)$ gravity, with the form $f(R)=-\\lambda_1 H_0^2\\exp(-R/\\lambda_2H_0^2)$. Such $f(R)$ gravity, even with degenerate expansion history to $\\Lambda$CDM, can produce detectable ISW effect at $z\\ga 3$ and $l\\ga 20$. Null-detection of such effect would constrain $\\lambda_2$ to be $\\lambda_2>1000$ at $>95%$ confidence level. On the other hand, robust detection of ISW-LSS cross correlation at high $z$ will severely challenge general relativity.

Pengjie Zhang

2005-11-08T23:59:59.000Z

357

Peeling and Multi-critical Matter Coupled to Quantum Gravity  

E-Print Network [OSTI]

We show how to determine the unknown functions arising when the peeling decomposition is applied to multi-critical matter coupled to two-dimensional quantum gravity and compute the loop-loop correlation functions. The results that $\\eta=2+2/(2K-3)$ and $\

Martin G. Harris; John F. Wheater

1999-11-24T23:59:59.000Z

358

The quadratic symmetric teleparallel gravity in two dimensions  

Science Journals Connector (OSTI)

A 2D symmetric teleparallel gravity model is given by a generic 4-parameter action that is quadratic in the non-metricity tensor. Variational field equations are derived. A class of conformally flat solutions are found. We also give static or cosmological solutions that need not be in this class.

M. Adak; T. Dereli

2008-01-01T23:59:59.000Z

359

No Open or Flat Bouncing Cosmologies in Einstein Gravity  

E-Print Network [OSTI]

We show that bouncing open or flat Friedmann-Robertson-Walker cosmologies are inconsistent with worldsheet string theory to first approximation. Specifically, the Virasoro constraint translates to the null energy condition in spacetime at leading order in the alpha-prime expansion. Thus one must go beyond minimally-coupled Einstein gravity in order to find bounce solutions.

Parikh, Maulik K

2015-01-01T23:59:59.000Z

360

The relationship between gravity and bathymetry in the Pacific Ocean  

Science Journals Connector (OSTI)

......gravity and bathymetry in the Pacific Ocean A. B. Watts D. P. McKenzie...and geoid anomaly maps of the Pacific Ocean basin and its margin. The maps...The resulting maps show the Pacific ocean basin is associated with a number......

A. B. Watts; D. P. McKenzie; B. E. Parsons; M. Roufosse

1985-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Testing gravity with halo density profiles observed through gravitational lensing  

SciTech Connect (OSTI)

We present a new test of the modified gravity endowed with the Vainshtein mechanism with the density profile of a galaxy cluster halo observed through gravitational lensing. A scalar degree of freedom in the galileon modified gravity is screened by the Vainshtein mechanism to recover Newtonian gravity in high-density regions, however it might not be completely hidden on the outer side of a cluster of galaxies. Then the modified gravity might yield an observational signature in a surface mass density of a cluster of galaxies measured through gravitational lensing, since the scalar field could contribute to the lensing potential. We investigate how the transition in the Vainshtein mechanism affects the surface mass density observed through gravitational lensing, assuming that the density profile of a cluster of galaxies follows the original Navarro-Frenk-White (NFW) profile, the generalized NFW profile and the Einasto profile. We compare the theoretical predictions with observational results of the surface mass density reported recently by other researchers. We obtain constraints on the amplitude and the typical scale of the transition in the Vainshtein mechanism in a subclass of the generalized galileon model.

Narikawa, Tatsuya; Yamamoto, Kazuhiro, E-mail: narikawa@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

2012-05-01T23:59:59.000Z

362

Gravity monitoring of CO2 movement during sequestration: Model studies  

SciTech Connect (OSTI)

We examine the relative merits of gravity measurements as a monitoring tool for geological CO{sub 2} sequestration in three different modeling scenarios. The first is a combined CO{sub 2} enhanced oil recovery (EOR) and sequestration in a producing oil field, the second is sequestration in a brine formation, and the third is for a coalbed methane formation. EOR/sequestration petroleum reservoirs have relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and CO{sub 2}), whereas brine formations usually have much thicker injection intervals and only two components (brine and CO{sub 2}). Coal formations undergoing methane extraction tend to be thin (3-10 m), but shallow compared to either EOR or brine formations. The injection of CO{sub 2} into the oil reservoir produced a bulk density decrease in the reservoir. The spatial pattern of the change in the vertical component of gravity (G{sub z}) is directly correlated with the net change in reservoir density. Furthermore, time-lapse changes in the borehole G{sub z} clearly identified the vertical section of the reservoir where fluid saturations are changing. The CO{sub 2}-brine front, on the order of 1 km within a 20 m thick brine formation at 1900 m depth, with 30% CO{sub 2} and 70% brine saturations, respectively, produced a -10 Gal surface gravity anomaly. Such anomaly would be detectable in the field. The amount of CO{sub 2} in a coalbed methane test scenario did not produce a large enough surface gravity response; however, we would expect that for an industrial size injection, the surface gravity response would be measurable. Gravity inversions in all three scenarios illustrated that the general position of density changes caused by CO{sub 2} can be recovered, but not the absolute value of the change. Analysis of the spatial resolution and detectability limits shows that gravity measurements could, under certain circumstances, be used as a lower-cost alternative to seismic measurements.

Gasperikova, E.; Hoversten, G.M.

2008-07-15T23:59:59.000Z

363

Stability of Interfaces with Self-Gravity, Relative Flow, and {ital B} Field  

SciTech Connect (OSTI)

Observations with the {ital Hubble} {ital Space} {ital T}{ital elescope} (Hester et al.) of spectacular {open_quotes}fingers{close_quotes} or {open_quotes}elephant trunks{close_quotes} of gas protruding from a large star-forming cloud in the Eagle Nebula stimulate renewed interest in the stability of interfaces between different media in molecular clouds. Instability and nonlinear growth of crenelations of interfaces can lead to mass concentrations that in turn lead to star formation. In an earlier study of the stability of interfaces, we took into account the important physical effects{emdash}the different densities and temperatures of the media, the relative motion (Kelvin-Helmholtz instability), the gravitational acceleration perpendicular to the interface (Rayleigh-Taylor instability), and self-gravity. A new {ital self}-{ital gravitational} {ital instability} of an interface was found that was independent of the wavelength of the perturbation. At short wavelengths, the perturbations are essentially distortional, but compression becomes important as the Jeans length is approached from below. The {ital e}-folding time for the instability is comparable with the free-fall collapse time for the denser fluid. In the present work, we generalize our earlier theory in two ways: by including ordered magnetic fields parallel to the interface, and by examining the stability of long cylindrical interfaces. We show that dynamically important magnetic fields in the media can quench instabilities if the fields are oriented in different directions (that is, crossed); however, for astronomically plausible geometries in which the fields are closer to being parallel, but of different strengths in the two media, instabilities are free to grow in directions normal to the fields. A cylindrical interface between an interior medium of density {rho}{sub 1} and an exterior medium of density {rho}{sub 2} provides a model for the long filaments of dense gas observed in some molecular clouds. We show that such an interface with {rho}{sub 1} {gt} {rho}{sub 2} is stable to {open_quotes}kink modes{close_quotes} but unstable to {open_quotes}sausage modes{close_quotes} owing to self-gravity for long axial wavelengths, {lambda}{sub {ital z}} {gt} 3.8{ital d}, where {ital d} is the diameter of the cylinder. This instability will tend to form prolate ellipsoidal density concentrations aligned with the cylinder axis. {copyright} {ital {copyright} .} {ital The American Astronomical Society}

Hunter, J.H. Jr. [Department of Astronomy, University of Florida, PO Box 112005, Gainesville, FL 32611-2055 (United States)] [Department of Astronomy, University of Florida, PO Box 112005, Gainesville, FL 32611-2055 (United States); Whitaker, R.W. [Los Alamos National Laboratory, EES-8, MS F659, Los Alamos, NM 87545 (United States)] [Los Alamos National Laboratory, EES-8, MS F659, Los Alamos, NM 87545 (United States); Lovelace, R.V. [Department of Astronomy, Cornell University, Ithaca, NY 14853-6801 (United States)] [Department of Astronomy, Cornell University, Ithaca, NY 14853-6801 (United States)

1998-12-01T23:59:59.000Z

364

Permanent magnet steam generator  

SciTech Connect (OSTI)

This patent describes a system for magnetic heating of a fluid by motor rotation of a permanent magnet rotor adjacent an assembly of ferro-magnetic condensing plate and of copper heat absorber plate with protrusions through the ferro-magnetic condensing plate into an enclosure with the fluid therein and having fluid inlet and fluid outlet. The assembly has a first shaft and a second shaft coaxially spaced therefrom, a respective the motor connected to the outer end of each shaft, and a respective the permanent magnet rotor connected to the inner end of each shaft, adjacent a the heat absorber plate. The improvement described here comprises: the enclosure including a steel boiler with a first the ferro-magnetic condensing plate closing off a first end thereof and a second the ferro-magnetic condensing plate closing off a second end thereof, a the copper heat absorbing plate affixed on each ferro-magnetic plate; means, free of pockets, for promoting turbulent flow of the fluid with uniformly good heat transfer including the protrusion being a plurality of heat sinks, each heat sink of the plurality of heat sinks comprising an integral elongate member with an alternately large diameter and smaller diameter portions regularly spaced therealong. The elongate members through the first the ferro-magnetic condensing plate are coaxially aligned with the elongate members through the second the ferro-magnetic condensing plate.

Gerard, F.; Gerard, F.J.

1986-09-30T23:59:59.000Z

365

Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood & Mabey,  

Open Energy Info (EERE)

Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood & Mabey, Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood & Mabey, 1978) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood & Mabey, 1978) Exploration Activity Details Location Baltazor Hot Springs Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The gravity map of the Baltazor KGRA (Fig. 2) shows a gravity low within the valley area that presumably is related to low-density Cenozoic sediments. The steep gravity gradient along the east side of the valley suggests a north-trending normal fault. The thickness of low-density fill is estimated to be about 300 m in the southwestern part of the KGRA and

366

Geodesic Deviation Equation in GR equivalent theory of $f(T)$ gravity  

E-Print Network [OSTI]

In this work, we show that it is possible to study the GR equivalent notion of geodesic deviation in $f(T)$ gravity, in spite of the fact that in teleparallel gravity there is no notion of geodesics, and the torsion is responsible for the appearance of gravitational interaction. In this regard, we obtain the GR equivalent of $f(T)$ gravity whose equations are in the modified gravity form such as $f(R)$ gravity. Then, we obtain the GDE within the context of this modified gravity. In this way, the obtained geodesic deviation equation will correspond to the $f(T)$ gravity. Eventually, we extend the calculations to obtain the modification of Matting relation.

Darabi, F; Atazadeh, K

2015-01-01T23:59:59.000Z

367

Geodesic Deviation Equation in GR equivalent theory of $f(T)$ gravity  

E-Print Network [OSTI]

In this work, we show that it is possible to study the GR equivalent notion of geodesic deviation in $f(T)$ gravity, in spite of the fact that in teleparallel gravity there is no notion of geodesics, and the torsion is responsible for the appearance of gravitational interaction. In this regard, we obtain the GR equivalent of $f(T)$ gravity whose equations are in the modified gravity form such as $f(R)$ gravity. Then, we obtain the GDE within the context of this modified gravity. In this way, the obtained geodesic deviation equation will correspond to the $f(T)$ gravity. Eventually, we extend the calculations to obtain the modification of Matting relation.

F. Darabi; M. Mousavi; K. Atazadeh

2014-12-31T23:59:59.000Z

368

Multi-gravity separator: an alternate gravity concentrator to process coal fines  

SciTech Connect (OSTI)

The multi-gravity separator (MGS) is a novel piece of equipment for the separation of fine and ultra-fine minerals. However, the published literature does not demonstrate its use in the separation of coal fines. Therefore, an attempt was made to study the effects of different process variables on the performance of an MGS for the beneficiation of coal fines. The results obtained from this study revealed that among the parameters studied, drum rotation and feed solids concentration play dominating roles in controlling the yield and ash content of the clean coal. Mathematical modeling equations that correlate the variables studied and the yield and ash contents of the clean coal were developed to predict the performance of an MGS under different operating and design conditions. The entire exercise revealed that the MGS could produce a clean coal with an ash content of 14.67% and a yield of 71.23% from a feed coal having an ash content of 24.61 %.

Majumder, A.K.; Bhoi, K.S.; Barnwal, J.P. [Regional Research Laboratories, Bhopal (India)

2007-08-15T23:59:59.000Z

369

High Field Magnet R&D |Superconducting Magnet Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

High Field Magnet R&D High Field Magnet R&D The Superconducting Magnet Division is developing advanced magnet designs and magnet-related technologies for high field accelerator magnets. We are currently working on magnets for three inter-related programs: High Field Magnets for Muon Collider Papers, Presentations Common Coil Magnets Papers, Presentations Interaction Region Magnets Papers, Presentations High Temperature Superconductor (HTS) Magnets Papers, Presentations This is part of a multi-lab superconducting magnet development program for new accelerator facilities that would be part of the U.S. High Energy Physics program. These programs (@BNL, @FNAL, @LBNL) are quite complimentary to each other, so that magnet designs and technologies developed at one laboratory can be easily transferred to another. The BNL

370

Cool Magnetic Molecules  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cool Magnetic Molecules Cool Magnetic Molecules Cool Magnetic Molecules Print Wednesday, 25 May 2011 00:00 Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

371

Passive magnetic bearing system  

DOE Patents [OSTI]

An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

Post, Richard F.

2014-09-02T23:59:59.000Z

372

CHAPTER 3. STRUCTURE OF MAGNETIC FIELDS 1 Structure of Magnetic  

E-Print Network [OSTI]

CHAPTER 3. STRUCTURE OF MAGNETIC FIELDS 1 Chapter 3 Structure of Magnetic Fields Many of the most interesting plasmas are permeated by or imbedded in magnetic fields.1 As shown in Fig. 3.1, the magnetic field properties of magnetic fields in plasmas can be discussed without specifying a model for the plasma

Callen, James D.

373

Pulse magnetic welder  

DOE Patents [OSTI]

A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.

Christiansen, D.W.; Brown, W.F.

1984-01-01T23:59:59.000Z

374

Brownian motion and magnetism  

Science Journals Connector (OSTI)

We present an interesting connection between Brownian motion and magnetism. We use this to determine the distribution of areas enclosed by the path of a particle diffusing on a sphere. In addition, we find a bound on the free energy of an arbitrary system of spinless bosons in a magnetic field. The work presented here is expected to shed light on polymer entanglement, depolarized light scattering, and magnetic behavior of spinless bosons.

Supurna Sinha and Joseph Samuel

1994-11-01T23:59:59.000Z

375

The Virtues of Magnetism  

Science Journals Connector (OSTI)

The Virtues of Magnetism ... In Mozarts late opera Cos fan tutte from 1790, Despina, the accomplice of thread puller Don Alfonso, instantly heals the two male characters who are pretending to be dying by using the virtues of magnetism. ... Although magnetism had been known for centuries, its scientific sources were not yet understood at the end of the 18th century, when Lorenzo da Ponte wrote the libretto. ...

Jan-Ole Joswig; Tommy Lorenz; Gotthard Seifert

2013-12-23T23:59:59.000Z

376

Magnetic properties of holographic multiquarks in the quark-gluon plasma  

E-Print Network [OSTI]

We study the magnetic properties of the coloured multiquark states in the quark-gluon plasma where the gluons are deconfined and the chiral symmetry is still broken, using the Sakai-Sugimoto model. There are two possible magnetized multiquark configurations. Both configurations converge to the same configuration at the critical field and temperature before they dissociate altogether either into less coloured multiquarks or into other phases for a fixed density. It is also found that the multiquarks with higher colour charges respond more to the external magnetic field in both the magnetization and the degree of chiral symmetry breaking. Magnetic field also makes it more difficult for multiquark states with large colour charges to satisfy the equilibrium condition of the configuration in the gravity dual picture. As long as the chemical potential $\\mu > \\mu_{onset}$, the magnetized multiquarks phase is thermodynamically preferred over the magnetized vacuum. Pure pion gradient and the chiral-symmetric quark-gluon plasma ($\\chi_S$-QGP) phase for the general Sakai-Sugimoto model are discussed and compared with the multiquark phase in the presence of the magnetic field. It is found that at large densities and moderate fields, the mixed phase of multiquarks and the pion gradient is thermodynamically preferred over the $\\chi_S$-QGP.

Piyabut Burikham

2009-09-03T23:59:59.000Z

377

Magnetic differential torque sensor  

SciTech Connect (OSTI)

A new torque sensor structure is presented. The basic idea is a simple torque sensor with a variable magnetic circuit excited by an axially magnetized permanent magnet ring. The circuit is constituted by iron toothed rings, whose teeth relative position changes whenever an applied torque twists the rotating shaft. A Hall probe measures the induction in an airgap where the induction is uniform. The new structure is an association of two previous ones, thus creating a differential system with the related advantages: diminution of thermal drifts, zero mean value for the signal. The new magnetic circuit is studied by calculating equivalent reluctances through energy calculations and by using electrical analogies.

Lemarquand, V.; Lemarquand, G. [Univ. de Savoie, Annecy-le-Vieux (France)] [Univ. de Savoie, Annecy-le-Vieux (France)

1995-11-01T23:59:59.000Z

378

Holographic Magnetic Phase Transition  

E-Print Network [OSTI]

We study four-dimensional interacting fermions in a strong magnetic field, using the holographic Sakai-Sugimoto model of intersecting D4 and D8 branes in the deconfined, chiral-symmetric parallel phase. We find that as the magnetic field is varied, while staying in the parallel phase, the fermions exhibit a first-order phase transition in which their magnetization jumps discontinuously. Properties of this transition are consistent with a picture in which some of the fermions jump to the lowest Landau level. Similarities to known magnetic phase transitions are discussed.

Gilad Lifschytz; Matthew Lippert

2009-06-21T23:59:59.000Z

379

Nuclear magnetic resonance imaging  

Science Journals Connector (OSTI)

Nuclear magnetic resonance imaging (NMRI) is a powerful imaging modality having a range of important applications to medicine and industry. The basic principles of NMRI are reviewed in...

Rothwell, William P

1985-01-01T23:59:59.000Z

380

Magnetic Field Viewing Cards  

Science Journals Connector (OSTI)

For some years now laminated cards containing a green magnetically sensitive film have been available from science education suppliers. When held near a magnet these cards appear dark green in regions where the field is perpendicular to the card and light green where the field is parallel to the card. The cards can be used to explore the magnetic field near a variety of magnets as well as near wire loops. In this paper we describe how to make these cards and how we have used them in our physics classrooms and labs.

Stephen Kanim; John R. Thompson

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Recycling Magnets | Jefferson Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Recycling Magnets July 15, 2013 The cost of a nuclear or particle physics experiment can be enormous, several hundred million dollars for the Large Hadron Collider Experiments,...

382

Nuclear Magnetic Moments  

Science Journals Connector (OSTI)

This paper contains approximate formulas (Eqs. (5) and (6) for the calculation of nuclear magnetic moments from observed hyperfine structure separations.

S. Goudsmit

1933-04-15T23:59:59.000Z

383

Magnetism in hafnium dioxide  

Science Journals Connector (OSTI)

Thin films of HfO2 produced by pulsed-laser deposition on sapphire, yttria-stabilized zirconia, or silicon substrates show ferromagnetic magnetization curves with little hysteresis and extrapolated Curie temperatures far in excess of 400K. The moment does not scale with film thickness, but in terms of substrate area it is typically in the range 150400?Bnm?2. The magnetization exhibits a remarkable anisotropy, which depends on texture and substrate orientation. Pure HfO2 powder develops a weak magnetic moment on heating in vacuum, which is eliminated on annealing in oxygen. Lattice defects are the likely source of the magnetism.

J. M. D. Coey; M. Venkatesan; P. Stamenov; C. B. Fitzgerald; L. S. Dorneles

2005-07-22T23:59:59.000Z

384

Transverse Optical Magnetism  

Science Journals Connector (OSTI)

Magnetic interactions with light are usually so small that they are ignored, even in nonlinear optics. Scientists have discovered that parametric processes can drive the interactions...

Rand, Stephen

2010-01-01T23:59:59.000Z

385

Magnetism and Electricity  

Science Journals Connector (OSTI)

... of the mariner's compass being especially good; indeed, the whole chapter on terrestrial magnetism is the best elementary account of the subject which has come under our notice. ...

1889-11-14T23:59:59.000Z

386

Magnetic Braids Anthony Yeates  

E-Print Network [OSTI]

flux function Main result Conclusion 2. Thermonuclear confinement devices. ITER (Internat'l Thermonuclear Experimental Reactor). Inside the KSTAR tokamak. Correspond to periodic magnetic braids. 4 / 22

Dundee, University of

387

Magnetism Highlights| Neutron Science | ORNL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetism Magnetism SHARE Magnetism Highlights 1-5 of 5 Results ARCS maps collaborative magnetic spin behavior in iron telluride December 01, 2011 - Researchers have long thought that magnetism and superconductivity are mutually exclusive. The former typically involves localized atomic electrons. The latter requires freely propagating, itinerant electrons. Unexpected Magnetic Excitations in Doped Insulator Surprise Researchers October 01, 2011 - When doping a disordered magnetic insulator material with atoms of a nonmagnetic material, the conventional wisdom is that the magnetic interactions between the magnetic ions in the material will be weakened. Neutron Analysis Reveals Unique Atomic-Scale Behavior of "Cobalt Blue" September 01, 2011 - Neutron scattering studies of "cobalt blue," a

388

BEPC-II Magnet Project | Superconducting Magnet Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

BEPC-II Magnet Project BEPC-II Magnet Project Project Overview The BEPC-II magnets are Interaction Region magnets to be used as part of an upgrade to the Beijing Electron Positron Collider. Two magnets will be produced, both of which will be inserted within the solenoidal detector at one of the collision points. Since the best use of the quadrupole focusing in this case requires placing the magnet as close to the collision point as possible, these magnets will be used within the magnetic field of the detector. This constrains the materials that can be used for construction to only non-magnetic materials. It also places severe demands on the structure of the magnet and it's holding supports due to the reaction forces between the solenoid and the magnet. To create the coil pattern for the final magnet, the coils will be

389

National High Magnetic Field Laboratory: An Introduction to Magnets...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

is a magnet); opposite poles attract, like poles repel. In all magnets, the magnetic field lines run from south to north, and these fields are what produce forces on other...

390

Momentum and Energy Transport by Gravity Waves in Stochastically Driven Stratified Flows. Part I: Radiation of Gravity Waves from a Shear Layer  

Science Journals Connector (OSTI)

In this paper, the emission of internal gravity waves from a local westerly shear layer is studied. Thermal and/or vorticity forcing of the shear layer with a wide range of frequencies and scales can lead to strong emission of gravity waves in ...

Nikolaos A. Bakas; Petros J. Ioannou

2007-05-01T23:59:59.000Z

391

Relativistic Scalar Gravity: A Laboratory for Numerical Relativity  

E-Print Network [OSTI]

We present here a relativistic theory of gravity in which the spacetime metric is derived from a single scalar field $\\Phi$. The field equation, derived from a simple variational principle, is a non-linear flat-space four-dimensional wave equation which is particularly suited for numerical evolution. We demonstrate that while this theory does not generate results which are exactly identical quantitatively to those of general relativity (GR), many of the qualitative features of the full GR theory are reproduced to a reasonable approximation. The advantage of this formulation lies in the fact that 3D numerical grids can be numerically evolved in minutes or hours instead of the days and weeks required by GR, thus drastically reducing the development time of new relativistic hydrodynamical codes. Scalar gravity therefore serves as a meaningful testbed for the development of larger routines destined for use under the full theory of general relativity.

Keith Watt; Charles W. Misner

1999-10-10T23:59:59.000Z

392

D-branes in Standard Model building, Gravity and Cosmology  

E-Print Network [OSTI]

D-branes are by now an integral part of our toolbox towards understanding nature. In this review we will describe recent progress in their use to realize fundamental interactions. The realization of the Standard Model and relevant physics and problems will be detailed. New ideas on realizing 4-dimensional gravity use the brane idea in an important way. Such approaches will be reviewed and compared to the standard paradigm of compactification. Branes can play a pivotal role both in early- and late-universe cosmology mainly via the brane-universe paradigm. Brane realizations of various cosmological ideas (early inflation, sources for dark matter and dark energy, massive gravity etc) will be also reviewed.

Elias Kiritsis

2004-05-14T23:59:59.000Z

393

Symmetric Teleparallel Gravity: Some exact solutions and spinor couplings  

E-Print Network [OSTI]

In this paper we elaborate on the symmetric teleparallel gravity (STPG) written in a non-Riemannian spacetime with nonzero nonmetricity, but zero torsion and zero curvature. Firstly we give a prescription for obtaining the nonmetricity from the metric in a peculiar gauge. Then we state that under a novel prescription of parallel transportation of a tangent vector in this non-Riemannian geometry the autoparallel curves coincides with those of the Riemannian spacetimes. Subsequently we represent the symmetric teleparallel theory of gravity by the most general quadratic and parity conserving lagrangian with lagrange multipliers for vanishing torsion and curvature. We show that our lagrangian is equivalent to the Einstein-Hilbert lagrangian for certain values of coupling coefficients. Thus we arrive at calculating the field equations via independent variations. Then we obtain in turn conformal, spherically symmetric static, cosmological and pp-wave solutions exactly. Finally we discuss a minimal coupling of a spin-1/2 field to STPG.

Muzaffer Adak; zcan Sert; Mestan Kalay; Murat Sar?

2008-10-14T23:59:59.000Z

394

Cloud of strings for radiating black holes in Lovelock gravity  

E-Print Network [OSTI]

We present exact spherically symmetric null dust solutions in the third order Lovelock gravity with a string cloud background in arbitrary $N$ dimensions,. This represents radiating black holes and generalizes the well known Vaidya solution to Lovelock gravity with a string cloud in the background. We also discuss the energy conditions and horizon structures, and explicitly bring out the effect of the string clouds on the horizon structure of black hole solutions for the higher dimensional general relativity and Einstein-Gauss-Bonnet theories. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms and/or background string clouds completely changes the structure of the horizon and this may lead to a naked singularity. We recover known spherically symmetric radiating models as well as static black holes in the appropriate limits.

Sushant G. Ghosh; Sunil D. Maharaj

2014-09-28T23:59:59.000Z

395

Stability of AdS in Einstein Gauss Bonnet Gravity  

E-Print Network [OSTI]

Recently it has been argued that in Einstein gravity Anti-de Sitter spacetime is unstable against the formation of black holes for a large class of arbitrarily small perturbations. We examine the effects of including a Gauss-Bonnet term. In five dimensions, spherically symmetric Einstein-Gauss-Bonnet gravity has two key features: Choptuik scaling exhibits a radius gap, and the mass function goes to a finite value as the horizon radius vanishes. These suggest that black holes will not form dynamically if the total mass/energy content of the space-time is too small, thereby restoring the stability of AdS spacetime. We support this claim with numerical simulations and uncover a rich structure in horizon radii and formation times as a function of perturbation amplitude.

Deppe, Nils; Frey, Andrew; Kunstatter, Gabor

2014-01-01T23:59:59.000Z

396

Gravity of Accelerations on Quantum Scales and its Consequences  

E-Print Network [OSTI]

Gravity stands apart from other fundamental interactions in that it is locally equivalent to an accelerated frame and can be transformed away. Again it is indistinguishable from the geometry of space-time (which is an arena for all other basic interactions), its strength being linked with the curvature. This is a major reason why it has so far not been amenable to quantisation like other interactions. It is also evident that new ideas are required to resolve several conundrums in areas like cosmology, black hole physics, and particles at high energies. That gravity can have strong coupling at microscales has also been suggested in several contexts earlier. Here we develop some of these ideas, especially in connection with the high accelerations experienced by particles at microscales, which would be interpreted as strong local gravitational fields. The consequences are developed for various situations and possible experimental manifestations are discussed.

C Sivaram; Kenath Arun; Kiren O V; B N Sreenath

2013-12-18T23:59:59.000Z

397

Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames  

SciTech Connect (OSTI)

We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (?g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in ?g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in ?g flames, which reduces the time to gel for nanoparticles by ?10{sup 6}?s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.

Chakrabarty, Rajan K., E-mail: rajan.chakrabarty@gmail.com [Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 (United States); Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Novosselov, Igor V. [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Enertechnix Inc., Maple Valley, Washington 98068 (United States); Beres, Nicholas D.; Moosmller, Hans [Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Sorensen, Christopher M. [Condensed Matter Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States); Stipe, Christopher B. [TSI Incorporated, 500 Cardigan Rd, Shoreview, Minnesota 55126 (United States)

2014-06-16T23:59:59.000Z

398

Generalized quantum gravity condensates for homogeneous geometries and cosmology  

E-Print Network [OSTI]

We construct a generalized class of quantum gravity condensate states, that allows the description of continuum homogeneous quantum geometries within the full theory. They are based on similar ideas already applied to extract effective cosmological dynamics from the group field theory formalism, and thus also from loop quantum gravity. However, they represent an improvement over the simplest condensates used in the literature, in that they are defined by an infinite superposition of graph-based states encoding in a precise way the topology of the spatial manifold. The construction is based on the definition of refinement operators on spin network states, written in a second quantized language. The construction lends itself easily to be applied also to the case of spherically symmetric quantum geometries.

Daniele Oriti; Daniele Pranzetti; James P. Ryan; Lorenzo Sindoni

2015-01-05T23:59:59.000Z

399

Measuring the Balmer Jump and Effective Gravity in FGK Stars  

E-Print Network [OSTI]

It is difficult to accurately measure the effective gravity (log g) in late-type stars using broadband (eg. UBV or SDSS) or intermediate-band (uvby) photometric systems, especially when the stars can cover a range of metallicities and reddenings. However, simple spectroscopic observational and data reduction techniques can yield accurate values for log g through comparison of the Balmer jumps of low-resolution spectra with recent grids of synthetic flux spectra.

Bessell, Michael S

2007-01-01T23:59:59.000Z

400

Electric field in 3D gravity with torsion  

E-Print Network [OSTI]

It is shown that in static and spherically symmetric configurations of the system of Maxwell field coupled to 3D gravity with torsion, at least one of the Maxwell field components has to vanish. Restricting our attention to the electric sector of the theory, we find an interesting exact solution, corresponding to the azimuthal electric field. Its geometric structure is to a large extent influenced by the values of two different central charges, associated to the asymptotic AdS structure of spacetime.

M. Blagojevi?; B. Cvetkovi?

2008-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Solar system constraints on f(G) gravity models  

E-Print Network [OSTI]

We discuss solar system constraints on f(G) gravity models, where f is a function of the Gauss-Bonnet term G. We focus on cosmologically viable f(G) models that can be responsible for late-time cosmic acceleration. These models generally give rise to corrections of the form epsilon*(r/rs)^p to the vacuum Schwarzschild solution, where epsilon = H^2 rs^2 solar system constraints for a wide range of model parameters.

Antonio De Felice; Shinji Tsujikawa

2009-07-10T23:59:59.000Z

402

Extended Ho?ava gravity and Einstein-aether theory  

Science Journals Connector (OSTI)

Einstein-aether theory is general relativity coupled to a dynamical, unit timelike vector. If this vector is restricted in the action to be hypersurface orthogonal, the theory is identical to the IR limit of the extension of Ho?ava gravity proposed by Blas, Pujols and Sibiryakov. Hypersurface orthogonal solutions of Einstein-aether theory are solutions to the IR limit of this theory, hence numerous results already obtained for Einstein-aether theory carry over.

Ted Jacobson

2010-05-19T23:59:59.000Z

403

Towards a new approach to quantum gravity phenomenology  

E-Print Network [OSTI]

The idea that quantum gravity manifestations would be associated with a violation of Lorentz invariance is very strongly bounded and faces serious theoretical challenges. This leads us to consider an alternative line of thought for such phenomenological search. We discuss the underlying viewpoint and briefly mention its possible connections with current theoretical ideas. We also outline the challenges that the experimental search of the effects would seem to entail.

Alejandro Corichi; Daniel Sudarsky

2005-05-17T23:59:59.000Z

404

Torsion-Gravity for Dirac fields and their effective phenomenology  

E-Print Network [OSTI]

We will consider the torsional completion of gravity for a background filled with Dirac matter fields, studying the weak-gravitational non-relativistic approximation, in view of an assessment about their effective phenomenology: we discuss how the torsionally-induced non-linear interactions among fermion fields in this limit are compatible with all experiments, and remarks on the role of torsion to suggest new physics are given.

Luca Fabbri

2014-09-01T23:59:59.000Z

405

Static charged distributions in 2+1 gravity  

SciTech Connect (OSTI)

Circularly symmetric charged perfect-fluid distributions are studied in three-dimensional gravity with a cosmological constant. We derive the Tolman-Oppenheimer-Volkoff equation of hydroelectrostatic equilibrium, and we discuss its applicability. A class of charged fluid distributions for p=-{rho} is considered. In this case, a particular model is obtained which represents a charged distribution whose mass is entirely of electromagnetic origin.

Cataldo, Mauricio; Cruz, Norman [Departamento de Fisica, Facultad de Ciencias, Universidad del Bio-Bio, Avenida Collao 1202, Casilla 5-C, Concepcion (Chile); Departamento de Fisica, Facultad de Ciencia, Universidad de Santiago, Casilla 307, Santiago (Chile)

2006-05-15T23:59:59.000Z

406

Thermodynamics in f(R) gravity in the Palatini formalism  

SciTech Connect (OSTI)

We investigate thermodynamics of the apparent horizon in f(R) gravity in the Palatini formalism with non-equilibrium and equilibrium descriptions. We demonstrate that it is more transparent to understand the horizon entropy in the equilibrium framework than that in the non-equilibrium one. Furthermore, we show that the second law of thermodynamics can be explicitly verified in both phantom and non-phantom phases for the same temperature of the universe outside and inside the apparent horizon.

Bamba, Kazuharu; Geng, Chao-Qiang, E-mail: bamba@phys.nthu.edu.tw, E-mail: geng@phys.nthu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu, 300 Taiwan (China)

2010-06-01T23:59:59.000Z

407

Three-graviton vertex function in thermal quantum gravity  

Science Journals Connector (OSTI)

The high-temperature limit of the three-graviton vertex function is studied in thermal quantum gravity, to one-loop order. The leading (T4) contributions arising from internal gravitons are calculated and shown to be twice the ones associated with internal scalar particles, in correspondence with the two helicity states of the graviton. The gauge invariance of this result follows as a consequence of the Ward and Weyl identities obeyed by the thermal loops, which are verified explicitly.

F. T. Brandt and J. Frenkel

1993-05-15T23:59:59.000Z

408

Comments on Cahill's Quantum Foam Inflow Theory of Gravity  

E-Print Network [OSTI]

We reveal an underlying flaw in Reginald T. Cahill's recently promoted quantum foam inflow theory of gravity. It appears to arise from a confusion of the idea of the Galilean invariance of the acceleration of an individual flow with what is obtained as an acceleration when a homogeneous flow is superposed with an inhomogeneous flow. We also point out that the General Relativistic covering theory he creates by substituting a generalized Painleve-Gullstrand metric into Einstein's field equations leads to absurd results.

T. D. Martin

2004-07-20T23:59:59.000Z

409

Solar system tests do not rule out 1/R gravity  

E-Print Network [OSTI]

We argue that Solar system tests do not rule out 1/R gravity at least due to the reason addressed in Phys. Rev. D 74 (2006) 121501 [astro-ph/0610483] (ref. [1]) and subsequent published papers. Ref. [1] has not only modified the Einstein-Hilbert action but also has changed the boundary conditions since they altered the equations of motion. In Einstein-Hilbert action equations are second order, so the fall off of the fields suffices to single out a unique solution. In 1/R gravity the equations are fourth order, so we should impose additional boundary conditions. Perhaps the boundary condition we must impose is that the abrupt change in the second derivative of the metric near the surface of the Sun remains intact by adding `1/R' corrections to the equations of motion. The solution of 1/R gravity with this boundary condition remains consistent with the solar system tests. Ref. [1] assumes that as soon as they perturbatively modified the equations then the Ricci scalar becomes smooth on the surface of the Sun. This assumption is simply wrong because the boundary conditions and equations of motions are two different entities.

Qasem Exirifard

2009-12-28T23:59:59.000Z

410

Power counting renormalizability of quantum gravity in Lifshitz spacetime  

E-Print Network [OSTI]

We analyse the power counting renormalizability of the quantum field theory of Einstein or Einstein-Gauss-Bonnet gravity in D+2 dimensional Lifshitz spacetime. We show the spectral dimension becomes 2+(D/z) at the UV region where z is the critical exponent. Since it is larger than two, the quantum theory of Einstein gravity is not power counting renormalizable. For the pure Einstein-Gauss-Bonnet gravity, where Lifshitz spacetime is allowed only when the parameters are fine tuned, it happens that the graviton modes do not propagate and the quantum field theory is accidentally renormalizable when z>=D. Another method is discretizing the radial coordinate which changes the spectral dimension to 1+(D/z) at the UV region. Since our four dimensional spacetime is continuous, the four dimensional Lorentz symmetry is recovered at the low energy and the power counting renormalizability is still kept for z>=D, if the spacetime near the null singularity in Lifshitz spacetime is modified into AdS spacetime and the discrete radial direction is compactified like a brane world scenario. We also comment on the AdS/CFT correspondence.

Takayuki Hirayama

2012-10-25T23:59:59.000Z

411

Vibrating Black Holes in f(R) gravity  

E-Print Network [OSTI]

We consider general perturbations of a Schwarzschild black holes in the context of f(R) gravity. A reduced set of frame independent master variables are determined, which obey two closed wave equations - one for the transverse, trace-free (tensor) perturbations and the other for the additional scalar degree of freedom which characterise fourth-order theories of gravity. We show that for the tensor modes, the underlying dynamics in f(R) gravity is governed by a modified Regge-Wheeler tensor which obeys the same Regge-Wheeler equation as in General Relativity. We find that the possible sources of scalar quasinormal modes that follow from scalar perturbations for the lower multipoles result from primordial black holes, while higher mass, stellar black holes are associated with extremely high multipoles, which can only be produced in the first stage of black hole formation. Since scalar quasi-normal modes are short ranged, this scenario makes their detection beyond the range of current experiments.

Anne Marie Nzioki; Rituparno Goswami; Peter K. S. Dunsby

2014-08-01T23:59:59.000Z

412

Domestic Crude Oil First Purchase Prices by API Gravity  

U.S. Energy Information Administration (EIA) Indexed Site

API Gravity API Gravity (Dollars per Barrel) Period: Monthly Annual Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes API Gravity Apr-13 May-13 Jun-13 Jul-13 Aug-13 Sep-13 View History 20.0º or Less 98.76 98.37 96.70 102.63 102.06 101.99 1993-2013 20.1º to 25.0º 99.08 99.72 98.54 104.51 105.09 104.96 1993-2013 25.1º to 30.0º 92.00 92.67 90.95 98.83 98.56 98.41 1993-2013 30.1º to 35.0º 99.63 98.18 97.56 103.78 106.39 106.16 1993-2013 35.1º to 40.0º 93.89 94.99 94.59 103.04 104.77 104.20 1993-2013 40.0º or Greater 93.16 93.61 92.04 100.24 101.89 100.83 1993-2013 - = No Data Reported; -- = Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data.

413

Velocity and gravity effects in relative permeability measurements  

SciTech Connect (OSTI)

There have been several studies on the effects of gravity and flowrate on laboratory relative permeability measurements. Most of these studies have concentrated on the effect of these parameters on the flooding front. Miller's (1983) data showed that the influence of these and other variables are not understood. The study found that the calculated recovery at breakthrough was different than the observed recovery at breakthrough. The calculated recovery at breakthrough was based on theory derived from Buckley-Leverett piston-like displacement. This study attempted to determine how gravity or core positioning and flowrate of the displacing fluid might be used to achieve a stable flooding front. A relative permeameter with unsteady-state flow was used for the apparatus. The core material was an unconsolidated silica sand. The core was 2 in. in diameter and 20 in. long. The fluids were refined white mineral oil and salt water. All measurements were done at room temperature. This study found that gravity had no significant effect on the difference between calculated and observed recovery at breakthrough. It also observed that an increase in flowrate would increase the flooding front instabilities. Therefore as flowrate decreased the calculated and observed breakthrough approach a single value. 23 refs., 56 figs., 25 tabs.

Beal, B.A.; Nunes, C.S.

1984-06-01T23:59:59.000Z

414

Neutral Hydrogen Tully Fisher Relation: The case for Newtonian Gravity  

E-Print Network [OSTI]

Intrinsic luminosities are related to rotation velocities of disk galaxies by Tully Fisher (TF) relations. The Baryonic TF (BTF) relation has recently been explained with Dark Matter and Newtonian Gravity as well as Modified Newtonian Dynamics (MOND). However, recent work has pointed out that the currently used BTF relation ignores the contribution from hot gas and oversimplifies complex galaxy-scale physics. In this Letter, we advocate the use of the Neutral Hydrogen TF (HITF) relationship, which is free from dust obscuration and stellar evolution effects, as a clean probe of gravity and dynamics in the weak field regime. We incorporate the physics of hot gas from supernova feedback which drives the porosity of the Interstellar Medium (ISM). A simple model that includes supernovae feedback, is generalized to include a parametrized effective gravitational force law. We test our model against a catalogue of galaxies, spanning the full range of disks from dwarf galaxies to giant spirals, to demonstrate that a Kennicutt-Schmidt (KS) law for star formation and simple Newtonian gravity is adequate for explaining the observed HI scaling relations. The data rules out MOND-like theories, within the scope of this model.

Sayan Chakraborti; Satej Khedekar

2011-09-02T23:59:59.000Z

415

Journal of Magnetism and Magnetic Materials 252 (2002) 159161 Magnetically induced alignment of FNS  

E-Print Network [OSTI]

Journal of Magnetism and Magnetic Materials 252 (2002) 159­161 Magnetically induced alignment the observation of magnetically controlled anchoring of ferro-nematic suspensions. We found that application of a weak magnetic field to a cell with the ferro-suspension induces an easy orientation axis with weak

Reznikov, Yuri

416

Journal of Magnetism and Magnetic Materials 225 (2001) 337345 Irreversible magnetization in nickel nanoparticles  

E-Print Network [OSTI]

in this magnetic nanoparticle system. # 2001 Elsevier Science B.V. All rights reserved. PACS: 75.10.Nr; 75.50.KjJournal of Magnetism and Magnetic Materials 225 (2001) 337­345 Irreversible magnetization in nickel in revised form 20 October 2000 Abstract We report magnetic studies on nickel nanoparticle films of average

Zuo, Fulin

417

EXOTIC MAGNETS FOR ACCELERATORS.  

SciTech Connect (OSTI)

Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

WANDERER, P.

2005-09-18T23:59:59.000Z

418

Streched Magnetic Moments  

E-Print Network [OSTI]

We note that for a system of 2 nucleons in a stretched case (J=J1+J2) the magnetic moment of the combined system is the sum of the magnetic moments of the 2 constituents. We compile other simple formulas.

Larry Zamick; Yitzhak Sharon

2012-07-12T23:59:59.000Z

419

Magnetic insulation (reply)  

Science Journals Connector (OSTI)

... DR WINTERBERG REPLIES: Contrary to Blewett's belief, magnetic insulation has not only been experimentally confirmed2 since I proposed it several years ago1, but ... generators (for example, the MJ Aurora machine). The magnetic field needed for the insulation effect in this case is generated by the strong azimuthal self-induced field of the ...

F. WINTERBERG

1974-06-28T23:59:59.000Z

420

Magnetic reconnection in space  

SciTech Connect (OSTI)

Models of magnetic reconnection in space plasmas generally consider only a segment of the magnetic field lines. The consideration of only a segment of the lines is shown to lead to paradoxical results in which reconnection can be impossible even in a magnetic field constrained to be curl free or can be at an Alfven rate even when the plasma is a perfect conductor. A model of reconnecting magnetic fields is developed which shows the smallness of the interdiffusion distance {delta}{sub d} of magnetic field lines does not limit the speed of reconnection but does provide a reconnection trigger. When the reconnection region has a natural length L{sub r}, the spatial scale of the gradient of magnetic field across the magnetic field lines must reach L{sub g} Almost-Equal-To 0.3L{sub r}/ln(L{sub r}/{delta}{sub d}) for fast reconnection to be triggered, which implies a current density j Almost-Equal-To B/{mu}{sub 0}L{sub g} that is far lower than that usually thought required for fast reconnection. The relation between magnetic reconnection in space and in toroidal laboratory plasmas is also discussed.

Boozer, Allen H. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

2012-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Itinerant-electron magnetism  

Science Journals Connector (OSTI)

... A conference on Itinerant-Electron Magnetism was held in Oxford on September 13?15, 1976. It was sponsored by the ... was held in Oxford on September 13?15, 1976. It was sponsored by the Magnetism Section of the European Physical Society and the Institute of Physics. The Proceedings will ...

E. P. Wohlfarth

1976-11-18T23:59:59.000Z

422

Treatise on Terrestrial Magnetism  

Science Journals Connector (OSTI)

... and from which the writer also attempts to deduce some of the other phenomena of magnetism. There seems to us to be some ambiguity in the writer's method of ... , to arrive at laws, that we may hope to form a theory of terrestrial magnetism, than from making an hypothesis,and then attempting to apply it to facts. ...

J. S.

1872-01-04T23:59:59.000Z

423

Remarks on Terrestrial Magnetism  

Science Journals Connector (OSTI)

... auror are secondary currents produced by rapid, though small, changes in the earth's magnetism. In this hypothesis the earth was viewed as similar to the soft iron core ... conductors in which secondary currents would be generated whenever any change took place in the magnetism of the core.

B. STEWART

1870-01-06T23:59:59.000Z

424

A Treatise on Magnetism  

Science Journals Connector (OSTI)

... principle expressed by Newton when he said Hypotheses non fingo. The elementary laws of magnetism are deduced by rigorous induction from particular cases and are then applied to explain phenomena ... the mathematics employed throughout are of a simple character, so that the first principles of magnetism are thus thrown open to one who has gone no great way in mathematical reading ...

JAMES STUART

1871-12-14T23:59:59.000Z

425

Magnetism and Matter  

Science Journals Connector (OSTI)

... DR. STONER and all physicists interested in magnetism are to be congratulated on the appearance of this admirable monograph. In 1926, the ... admirable monograph. In 1926, the author published a book on the same subject, Magnetism and Atomic Structure. The present treatise, far from being merely a revised edition ...

H. A. K.

1935-07-20T23:59:59.000Z

426

Magnetism: Managed mess  

Science Journals Connector (OSTI)

... crime-fighting gadgetry (Fig. 1) noted long ago that he who controls magnetism controls the Universe. And efforts to control ... controls the Universe. And efforts to control magnetism continue to make progress, as Silevitch et al. ably demonstrate in this issue ( ...

Zachary Fisk

2007-08-01T23:59:59.000Z

427

Molecular and Cosmical Magnetism  

Science Journals Connector (OSTI)

... RECENT researches on magnetism tend to suggest that the negative electron may be a magneton or unitary electromagnet as ... previously considered and observed in relation to ferromagnetic bodies on the assumption that the ferro-magnetism is due to electrons in orbital motion as a whole. Wider conclusions can be ...

S. CHAPMAN

1920-11-25T23:59:59.000Z

428

Electricity and Magnetism  

Science Journals Connector (OSTI)

... and practical applications; or, speaking briefly, theory and practice. In the theoretical part, magnetism is first treated, then electricity, in the order statical electricity, electro-chemistry, and ... first treated, then electricity, in the order statical electricity, electro-chemistry, and electro-magnetism. In the practical part are comprised telegraphy and telephony, electric lighting and transmission of ...

A. GRAY

1891-11-05T23:59:59.000Z

429

Progress in Magnetism  

Science Journals Connector (OSTI)

... HISTORIES of physics and magnetism have much in common, beginning with the discovery of the lode-stone by the ... , beginning with the discovery of the lode-stone by the Greeks. Modern texts on magnetism tend to overlook the work of past philosophers and it is very refreshing to find ...

C. A. BATES

1965-11-13T23:59:59.000Z

430

Magnetism and Atomic Structure  

Science Journals Connector (OSTI)

... the information with regard to the atom has been obtained by studying spectra; chemistry, magnetism, X-ray scattering, etc., play only a subsidiary part. We must admit, ... for fresh sources of information. Much may be said in support of the opinion that magnetism will open a new way by which to approach the study of the structure of ...

P. KAPITZA

1927-06-04T23:59:59.000Z

431

Magnetism and Electricity  

Science Journals Connector (OSTI)

... WRITTEN in colloquial language, this book, which is a first-year course on magnetism and electricity, will appeal to many beginners besides the students in technical institutions, for ... have almost forgotten that their jargon is not that of the man in the street. Magnetism is first dealt with, and then the ideas of static and current electricity are ...

1922-11-11T23:59:59.000Z

432

The Origin of Magnetism  

Science Journals Connector (OSTI)

... A of the British Association at Hull this year a discussion on The Origin of Magnetism, it was met with the criticism from eminent quarters that the time was not ... to one another nor providing an answer to the essential question of the origin of magnetism. In spite of the comparative failure of the discussion in its wider aspects, one ...

A. O. RANKINE

1922-11-04T23:59:59.000Z

433

Gravitation and Magnetism  

Science Journals Connector (OSTI)

......1 August 1950 research-article Articles Gravitation and Magnetism E. A. Milne It is shown by the methods of kinematic relativity that there should be a connection between gravitation and magnetism of the type suggested by the empirical formulae of Blackett......

E. A. Milne

1950-08-01T23:59:59.000Z

434

National High Magnetic Field Laboratory Slideshow: Seeing Magnetic...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

more about magnets You can start here with a straightforward rundown. Compasses in Magnetic Fields Experiment with the compass in this tutorial to see how it responds to...

435

Superconducting Magnet Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 - 6/13/06 3 - 6/13/06 Superconducting Magnet Division S&T Committee Program Review June 22-23, 2006 Conference Room A, Bldg. 725, BNL DRAFT AGENDA Thursday, June 22 0830 Executive Session to address the charge S. Aronson (25 min) 0855 Welcome S. Aronson (5 min) 0900 Superconducting Magnet Division Status & M. Harrison (45 + 15 min) Issues - mission statement, core competencies, themes, program, problems, etc. 1000 Themes - Nb3Sn, HTS, Direct wind, Accelerator integration, P. Wanderer (20 + 10 min) rapid cycling Core Competencies 1030 Superconducting Materials A. Ghosh (20 + 5 min) 1055 Break 1110 Magnetic Design R. Gupta (20 + 5 min) 1135 Magnet Construction M. Anerella (20 + 5 min) 1200 Magnet Testing G. Ganetis (20 + 5 min)

436

Cool Magnetic Molecules  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

437

Cool Magnetic Molecules  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

438

Cool Magnetic Molecules  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

439

Cool Magnetic Molecules  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

440

Magnet pole tips  

DOE Patents [OSTI]

An improved magnet more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

Thorn, C.E.; Chasman, C.; Baltz, A.J.

1981-11-19T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Cryogenic permanent magnet undulators  

Science Journals Connector (OSTI)

In order to obtain high magnetic fields in a short period undulator, superconductive undulators have been actively investigated in recent years. In this paper, however, we propose a new approach, the cryogenic permanent magnet undulator (CPMU) design, using permanent magnets at the cryogenic temperature of liquid nitrogen or higher. This cryogenic scheme can be easily adapted to currently existing in-vacuum undulators and it improves the magnetic field performance by 30%50%. Unlike superconductive undulators operating around the liquid helium temperature, there is no big technological difficulty such as the thermal budget problem. In addition, existing field correction techniques are applicable to the CPMUs. Since there is no quench in the CPMUs, the operation of the CPMUs has the same reliability as conventional permanent magnet undulators.

Toru Hara; Takashi Tanaka; Hideo Kitamura; Teruhiko Bizen; Xavier Marchal; Takamitsu Seike; Tsutomu Kohda; Yutaka Matsuura

2004-05-18T23:59:59.000Z

442

Cool Magnetic Molecules  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

443

Sources and Magnetic Charge  

Science Journals Connector (OSTI)

A beginning is made on a phenomenological reconstruction of the theory of magnetic charge. The concept is introduced by reference to a new kind of photon source. It is shown that photon exchange between different source types is relativistically invariant. The space-time generalization of this coupling involves an arbitrary vector. The only way to remove a corresponding arbitrariness of physical predictions is to recognize the localization of charge and impose a charge quantization condition. The consideration of particles that carry both kinds of charge loosens the charge restrictions. The great strength of magnetic attraction indicated by g24?=4(137) suggests that ordinary matter is a magnetically neutral composite of magnetically charged particles that carry fractional electric charge. There is a brief discussion of such a magnetic model of strongly interacting particles, which makes contact with empirical classification schemes. Additional remarks on notation, and on the general nature of the source description, are appended.

Julian Schwinger

1968-09-25T23:59:59.000Z

444

Ground Gravity Survey At Valles Caldera - Redondo Area (Wilt & Haar, 1986)  

Open Energy Info (EERE)

Gravity Survey At Valles Caldera - Redondo Area (Wilt & Haar, 1986) Gravity Survey At Valles Caldera - Redondo Area (Wilt & Haar, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Valles Caldera - Redondo Area (Wilt & Haar, 1986) Exploration Activity Details Location Valles Caldera - Redondo Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting gravity observations along profiles A--A' and B--B' (Talwani et al., 1959). Densities of 2.12, 2.40, and 2.65 g/cm a were used for modeling the near-surface caldera fill, the underlying volcanics, and the basement sections, respectively (Fig. 8). Although correlation with

445

Ground Gravity Survey At Dixie Valley Geothermal Field Area (Blackwell, Et  

Open Energy Info (EERE)

Blackwell, Et Blackwell, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Dixie Valley Geothermal Field Area (Blackwell, Et Al., 2009) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Ground Gravity Survey Activity Date Usefulness useful DOE-funding Unknown Notes "The gravity data are described by (Blackwell et al., 1999; 2002). On a basin-wide scale the gravity low in Dixie Valley is strongly asymmetrical from east to west. The west side is relatively well-defined by rapid horizontal changes in the gravity anomaly value, whereas along the east side horizontal changes are more subdued and often consist of several steps. The horizontal gradient of the gravity field has proved most useful

446

Ground Gravity Survey At Clear Lake Area (Skokan, 1993) | Open Energy  

Open Energy Info (EERE)

Ground Gravity Survey At Clear Lake Area (Skokan, 1993) Ground Gravity Survey At Clear Lake Area (Skokan, 1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Clear Lake Area (Skokan, 1993) Exploration Activity Details Location Clear Lake Area Exploration Technique Ground Gravity Survey Activity Date Usefulness useful DOE-funding Unknown Notes A detailed gravity survey (Isherwood, 1975) was undertaken as a follow-up to a regional gravity survey of the area in order to detail a low in the Clear Lake volcanics. The low (Fig. 5 ) was thought to be caused by an intrusion of molten rock which would be mass deficient. Modeling and interpretation indicated a+K139 chamber-like feature with a radius of approximately 7 km within 7-8 km of the surface. References

447

Ground Gravity Survey At Raft River Geothermal Area (1957-1961) | Open  

Open Energy Info (EERE)

Ground Gravity Survey At Raft River Geothermal Area (1957-1961) Ground Gravity Survey At Raft River Geothermal Area (1957-1961) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Raft River Geothermal Area (1957-1961) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1957 - 1961 Usefulness not indicated DOE-funding Unknown Notes From 1957 to 1961 a regional gravity survey was made over the northern part of the Great Salt Lake Desert and adjacent areas in Utah, eastern Nevada, and southeastern Idaho. A total of 1040 stations were taken over an area of about 7000 square miles. The results were compiled as a Bouguer gravity anomaly map with a contour interval of 2 mgal. The Bouguer values ranged

448

SP - 19 Magnetic Field Safety  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

19 Page 1 Revision 02 August 6, 2007 NATIONAL HIGH MAGNETIC FIELD LABORATORY NHMFL FLORIDA STATE UNIVERSITY SAFETY PROCEDURE SP-19 MAGNETIC FIELD SAFETY ...

449

On the Connection Between 2d Topological Gravity and the Reduced Hermitian Matrix Model  

E-Print Network [OSTI]

We discuss how concepts such as geodesic length and the volume of space-time can appear in 2d topological gravity. We then construct a detailed mapping between the reduced Hermitian matrix model and 2d topological gravity at genus zero. This leads to a complete solution of the counting problem for planar graphs with vertices of even coordination number. The connection between multi-critical matrix models and multi-critical topological gravity at genus zero is studied in some detail.

J. Ambjorn; M. G. Harris; M. Weis

1997-02-26T23:59:59.000Z

450

E-Print Network 3.0 - asymptotically safe gravity Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- Instytut Fizyki, Uniwersytet Jagiellonski Collection: Physics 6 DARK MATTER AND DARK ENERGY AS EFFECTS OF QUANTUM GRAVITY Max I. Fomitchev1 Summary: DARK MATTER AND DARK ENERGY...

451

A Finite Volume Implementation of the Shallow Water Equations for Boussinesq Gravity Currents.  

E-Print Network [OSTI]

??The shallow water equations (SWE) are a powerful tool for modeling the propagation of gravity currents (GC) because of their relative simplicity, computational efficiency and (more)

Hatcher, Thomas Jr

2012-01-01T23:59:59.000Z

452

E-Print Network 3.0 - affine quantum gravity Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

gravity. We explore the issue ... Source: Wthrich, Christian - Department of Philosophy, University of California at San Diego Collection: Multidisciplinary Databases and...

453

E-Print Network 3.0 - atmospheric gravity waves Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Centre de mathmatiques Collection: Mathematics 58 SMLTM simulations of the diurnal tide: comparison with UARS observations Summary: ., 1997). Small-scale gravity waves...

454

E-Print Network 3.0 - averaged gravity fields Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

field while the short wavelength components... with wavelengths as short as 25 km. marine gravity ... Source: Sandwell, David T. - Institute of Geophysics and Planetary...

455

Table 27. Landed Costs of Imported Crude Oil by API Gravity  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

Crude Oil Acquisition Report," July 1984 to present. 27. Landed Costs of Imported Crude Oil by API Gravity Energy Information Administration Petroleum Marketing Annual 1997...

456

Table 27. Landed Costs of Imported Crude Oil by API Gravity  

Gasoline and Diesel Fuel Update (EIA)

Crude Oil Acquisition Report," July 1984 to present. 27. Landed Costs of Imported Crude Oil by API Gravity Energy Information Administration Petroleum Marketing Annual 1996...

457

Table 28. Percentages of Total Imported Crude Oil by API Gravity  

U.S. Energy Information Administration (EIA) Indexed Site

Oil Acquisition Report," July 1984 to present. 28. Percentages of Total Imported Crude Oil by API Gravity 50 Energy Information Administration Petroleum Marketing Annual 1996...

458

Table 23. Domestic Crude Oil First Purchase Prices by API Gravity  

U.S. Energy Information Administration (EIA) Indexed Site

EIA-182, "Domestic Crude Oil First Purchase Report." 23. Domestic Crude Oil First Purchase Prices by API Gravity Energy Information Administration Petroleum Marketing Annual 1996...

459

Table 23. Domestic Crude Oil First Purchase Prices by API Gravity  

Gasoline and Diesel Fuel Update (EIA)

"Domestic Crude Oil First Purchase Report." 23. Domestic Crude Oil First Purchase Prices by API Gravity Energy Information Administration Petroleum Marketing Annual 1997...

460

Table 28. Percentages of Total Imported Crude Oil by API Gravity  

U.S. Energy Information Administration (EIA) Indexed Site

Oil Acquisition Report," July 1984 to present. 28. Percentages of Total Imported Crude Oil by API Gravity 50 Energy Information Administration Petroleum Marketing Annual 1997...

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Generalized Vaidya spacetime in Lovelock gravity and thermodynamics on the apparent horizon  

SciTech Connect (OSTI)

We present a kind of generalized Vaidya solutions in a generic Lovelock gravity. This solution generalizes the simple case in Gauss-Bonnet gravity reported recently by some authors. We study the thermodynamics of apparent horizon in this generalized Vaidya spacetime. Treating those terms except for the Einstein tensor as an effective energy-momentum tensor in the gravitational field equations, and using the unified first law in Einstein gravity theory, we obtain an entropy expression for the apparent horizon. We also obtain an energy expression of this spacetime, which coincides with the generalized Misner-Sharp energy proposed by Maeda and Nozawa in Lovelock gravity.

Cai Ronggen [Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China); Cao Liming [Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Hu Yapeng [Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Kim, Sang Pyo [Department of Physics, Kunsan National University, Kunsan 573-701 (Korea, Republic of); Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

2008-12-15T23:59:59.000Z

462

Next steps in understanding the asymptotics of $3d$ quantum gravity  

E-Print Network [OSTI]

Based on a combinatorial approach and random matrix theory, we show a central limit theorem that gives important insight into causally triangulated $3d$ quantum gravity.

Maria Simonetta Bernabei; Horst Thaler

2014-12-10T23:59:59.000Z

463

Ground Gravity Survey At Fort Bliss Area (DOE GTP) | Open Energy...  

Open Energy Info (EERE)

Exploration Activity Details Location Fort Bliss Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown References (1 January...

464

Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition  

Broader source: Energy.gov [DOE]

Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition presentation at the April 2013 peer review meeting held in Denver, Colorado.

465

Tailoring Magnetic Properties in Bulk Nanostructured Solids  

E-Print Network [OSTI]

permanent magnets). Under specific temperature and applied magnetic field conditions, exchange coupling

Morales, Jason R.

2011-01-01T23:59:59.000Z

466

Magnetically catalyzed fusion  

Science Journals Connector (OSTI)

We calculate the reaction cross sections for the fusion of hydrogen and deuterium in strong magnetic fields as are believed to exist in the atmospheres of neutron stars. We find that in the presence of a strong magnetic field (B?1012 G), the reaction rates are many orders of magnitude higher than in the unmagnetized case. The fusion of both protons and deuterons is important over a neutron stars lifetime for ultrastrong magnetic fields (B?1016 G). The enhancement may have dramatic effects on thermonuclear runaways and bursts on the surfaces of neutron stars. 1996 The American Physical Society.

Jeremy S. Heyl and Lars Hernquist

1996-11-01T23:59:59.000Z

467

Mesoscopic Spin Magnetism  

Science Journals Connector (OSTI)

We investigate the spin magnetism of mesoscopic metallic grains. In the average response of an ensemble of grains there are corrections to macroscopic behavior due to both spectral fluctuations and electron-electron interactions. These corrections are a nonlinear function of the magnetic field. Their temperature dependence is calculated numerically and analytically. An experiment is proposed to measure the unknown interaction coupling constant in the Cooper channel. For a single sample the magnetization is found to fluctuate reproducibly about the mean. These fluctuations directly probe the energy level statistics.

H. Mathur; M. Gkeda?; A. Douglas Stone

1995-03-06T23:59:59.000Z

468

Reversed magnetization A NOVEL DEVICE FOR CONTINUOUS FLOW MAGNETIC TRAPPING  

E-Print Network [OSTI]

1. 3 µm5 µm Reversed magnetization A NOVEL DEVICE FOR CONTINUOUS FLOW MAGNETIC TRAPPING AND SORTING Martin d'hères, France ABSTRACT The manipulation of magnetically labeled bio-objects of nano or micrometer sizes is now realizable by combining the magnetic forces with microfluidics. This paper reports

Paris-Sud XI, Université de

469

Force and Stiffness of Passive Magnetic Bearings Using Permanent Magnets.  

E-Print Network [OSTI]

1 Force and Stiffness of Passive Magnetic Bearings Using Permanent Magnets. Part 2 : Radial Magnetization R. Ravaud, G. Lemarquand, V. Lemarquand Abstract This paper deals with the calculation of the force and the stiffness between two ring permanent magnets whose polarization is radial

Boyer, Edmond

470

Ground Magnetics At Chocolate Mountains Area (Alm, Et Al., 2010) | Open  

Open Energy Info (EERE)

Chocolate Mountains Area (Alm, Et Al., 2010) Chocolate Mountains Area (Alm, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Magnetics At Chocolate Mountains Area (Alm, Et Al., 2010) Exploration Activity Details Location Chocolate Mountains Area Exploration Technique Ground Magnetics Activity Date Usefulness useful DOE-funding Unknown Notes Gravity and ground-based magnetics surveys were conducted during the summer of 2008. This data was acquired to aid in the identification of structures without fair surface expression, obscured by recent deposition. References Steve Alm, S. Bjornstad, M. Lazaro, A. Sabin1, D. Meade, J. Shoffner, W. C. Huang, J. Unruh, M. Strane, H. Ross (2010) Geothermal Energy Resource Investigations, Chocolate Mountains Aerial Gunnery Range,

471

Seismometer using a vertical long natural-period rotational pendulum with magnetic levitation  

SciTech Connect (OSTI)

We have demonstrated a highly sensitive/wideband vertical-component seismometer using an astatic rotational pendulum to obtain a long natural period. This seismometer employs magnetic levitation for removing any parasitic resonances of a spring to support a weight due to gravity and the thermal dependence of the spring constant. The pendulum has a cylindrical plunger-type permanent magnet that has a weight at one side of its end edge. The plunger magnet is inserted into a uniform magnetic field generated by a window-frame-type permanent magnet, and attached to two crossed-leaf spring hinges as a rotational axis outside of the bore of the magnet. Magnetic forces applied to the plunger magnet counterbalance the gravitational force at the weight. To realize stable operation of the rotational pendulum without any unnecessary movements of the plunger magnet, a tilt of lines of the magnetic force in the bore of the window-frame magnet was compensated by a tilted magnetic-pole surface near to its opening. The field uniformity reached 10{sup -4} owing to this compensation. The thermal dependence of a magnetic field strength of about 10{sup -3}/K was also compensated by as much as 9x10{sup -5}/K by Ni-Fe metal having a negative permeability coefficient. The metal was attached along the sidewalls of the window-frame magnet. To determine the feedback control parameters for a feedback control seismometer, the natural period of a prototype rotational pendulum was measured. It was more than 8 s, and was able to be changed from 5 to 8 s by using an additional magnetic spring, similar to the voice coil actuator of a speaker. This change was in accordance with theoretical calculations, and showed that the pendulum movement did not include a big nonlinearity caused by the tilt of the lines of the magnetic force. No parasitic resonances were found during experiments. A velocity feedback-control circuit and a capacitance position detector to measure the weight position were applied to the rotational pendulum for building a feedback control seismometer. Observations showed that the noise level of the seismometer was less than about 10{sup -8} m/s at 1 Hz. This fruitful value is close to the specifications of the most sensitive seismometer, such as STS-I. However, low-frequency noise of about 10{sup -7} m/s, caused by a buoyancy change at the pendulum weight arising from atmospheric pressure variation, could be recognized. To decrease the noise, a vacuum chamber to isolate the atmospheric pressure variation should be employed in the next step of the study.

Otake, Yuji; Araya, Akito; Hidano, Kazuo [ERI, Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

2005-05-15T23:59:59.000Z

472

MagneticsLab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetics Laboratory Magnetics Laboratory Manufacturing Technologies The Magnetics Lab provides customers with design, prototyping, packaging solutions and production of unique magnetic and resistive components from millivolts to extremely high voltage (250KV) components. Capabilities * Design review of specification and requirements * Design and develop from sketches, verbal ideas, or circuit design parameters * Coil windings of any size or configuration * Coil diameter from 0.1 to 24 inches * Low temperature and high temperature coils * Precision resistors from 0.1 ohms to 2 megaohms (non-inductive) * Special high voltage transformers (2KV to 250KV) and high voltage loads (38K ohms to 100K ohms and 2KV to 250KV) Resources * Computer Aided Mechanical Design (Solid Works 3D CAD System) for mechanical

473

AFRD - Superconducting Magnets  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Superconducting Magnets Superconducting Magnets Home Organization Diversity Safety Links Gallery/History Updated July 2008 Ever-stronger magnets (which must be cost-effective as well) are a key to building tomorrow's high-energy accelerators and upgrading today's. Our role— not only a leading R&D group but also the administrators of the multi-institutional National Conductor Development Program— to create both evolutionary improvements and paradigm shifts in the application of accelerator magnets, providing innovative technology that enables new science. Improvements in conductor, innovative structures to solve the challenges of high fields and brittle superconductors, and integration of computerized design and analysis tools are key. The performance requirements of modern accelerators continue to press the

474

Fundamentals of Magnetic Recording  

Science Journals Connector (OSTI)

In recent years magnetic recording has become a preferred medium for storing information such as printed language, mathematics, sound, and pictures. It is compact, economical, easily updated, and instantly ret...

Marvin Camras

1988-01-01T23:59:59.000Z

475

Modular tokamak magnetic system  

DOE Patents [OSTI]

A modular tokamak system comprised of a plurality of interlocking moldules. Each module is comprised of a vacuum vessel section, a toroidal field coil, moldular saddle coils which generate a poloidal magnetic field and ohmic heating coils.

Yang, Tien-Fang (Wayland, MA)

1988-01-01T23:59:59.000Z

476

Magnetic gripper device  

DOE Patents [OSTI]

A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.

Meyer, R.E.

1993-03-09T23:59:59.000Z

477

Magnetic gripper device  

DOE Patents [OSTI]

A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.

Meyer, Ross E. (Los Alamos, NM)

1993-01-01T23:59:59.000Z

478

NEW MAGNETIC MATERIALS  

Science Journals Connector (OSTI)

New, sophisticated magnetic materials can be found as essential components in computers, sensors, and actuators, and in a variety of telecommunications devices ranging from telephones to satellites. Some of th...

STANOJA STOIMENOV

2006-01-01T23:59:59.000Z

479

Nonlinear magnetization of graphene  

Science Journals Connector (OSTI)

We compute the magnetization of graphene in a magnetic field, taking into account for generality the possibility of a mass gap. We concentrate on the physical regime where quantum oscillations are not observed due to the effect of the temperature or disorder and show that the magnetization exhibits nonlinear behavior as a function of the applied field, reflecting the strong nonanalyticity of the two-dimensional effective action of Dirac electrons. The necessary values of the magnetic field to observe this nonlinearity vary from a few teslas for very clean suspended samples to 2030 T for good samples on substrate. In the light of these calculations, we discuss the effects of disorder and interactions as well as the experimental conditions under which the predictions can be observed.

Sergey Slizovskiy and Joseph J. Betouras

2012-09-24T23:59:59.000Z

480

USe: Magnetic Neutron Scattering  

Science Journals Connector (OSTI)

This document is part of subvolume B6b?Actinide Monochalcogenides of Volume 27 Magnetic properties of non-metallic inorganic compounds based on transition elements of Landolt-Brnstein - Group III Condens...

R. Tro?

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gravity magnetic electncal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Intrinsic Magnetic Fields  

Science Journals Connector (OSTI)

Emission theory of electromagnetic fields.(1) Intrinsic magnetic field. The intrinsic magnetic field of a point charge is defined as that portion of the field which cannot be annihilated by the Lorentz transformation. It is shown that the intrinsic field can be represented by lines of force carried by the same moving elements as carry the electric field, and a potential is given for it. (2) Frequency of emission of moving elements. A relation between the frequency of emission of moving elements and the number of lines of force to a tube is deduced on the assumption that the latter number is the same for the electric and magnetic fields and that each moving element marks the intersection of an electric and magnetic line of force.

Leigh Page

1923-08-01T23:59:59.000Z

482

MOON: Magnetism and interior  

Science Journals Connector (OSTI)

The internal structure and magnetic field of the Moon are two basic properties of our nearest planetary body that may or may not be related. For the Earth, these properties are closely related because the geom...

Lon L. Hood

1997-01-01T23:59:59.000Z

483

Some Experiments in Magnetism  

Science Journals Connector (OSTI)

1 January 1904 research-article Some Experiments in Magnetism T. C. Porter The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings of the Royal Society of London. www.jstor.org

1904-01-01T23:59:59.000Z

484

Saturn's mysterious magnetism  

Science Journals Connector (OSTI)

... 2014 Royal Astronomical Society February 2014 research-article Features Saturn's mysterious magnetism D J Southwood D J Southwood, Blackett Laboratory, Imperial College, London, UK. In his 2013 RAS Presidential Address, David......

D J Southwood

2014-02-01T23:59:59.000Z

485

Magnetism and Recalescence  

Science Journals Connector (OSTI)

1 January 1890 research-article Magnetism and Recalescence J. Hopkinson The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings of the Royal Society of London. www.jstor.org

1890-01-01T23:59:59.000Z

486

Geometrically frustrated quantum magnets  

E-Print Network [OSTI]

(cont.) more general lessons on frustrated quantum magnetism. At the end, we demonstrate some new mathematical tools on two other frustrated two-dimensional systems, and summarize our conclusions, with an outlook to remaining ...

Nikoli‡ , Predrag, 1974-

2004-01-01T23:59:59.000Z

487

Large Superconducting Magnet Systems  

E-Print Network [OSTI]

The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb?Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 1320 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

Vdrine, P

2014-01-01T23:59:59.000Z

488

Turbulent Magnetic Reconnection Near a  

E-Print Network [OSTI]

Turbulent Magnetic Reconnection Near a 3D Magnetic Null C. S. Ng Space Science Center Institute for the Study of Earth, Oceans, and Space University of New Hampshire, Durham, NH 03824 #12;Turbulent Magnetic Reconnection Near a 3D Magnetic Null C. S. Ng, chung-sang.ng@unh.edu, Space Science Center, Institute

Ng, Chung-Sang

489

Magnetism and the Maxwellian Theory  

Science Journals Connector (OSTI)

... 31 that he is satisfied with my reply to his query concerning the place of magnetism in fundamental electrical theory. Of course there can be no question of annihilating magnetic ... and properties of permanent magnets; but, as regards the understanding of fundamental physical phenomena, magnetism appears to have played a part similar to that of money in economicsa useful ...

C. V. DRYSDALE

1939-02-18T23:59:59.000Z

490

Rock Magnetism To-Day  

Science Journals Connector (OSTI)

... ROCK magnetism is that branch of geophysics that deals with the origin of magnetization in rocks and ... that deals with the origin of magnetization in rocks and its stability. Workers in rock magnetism are also interested in the phenomenon of self-reversal, that is, a rock acquiring ...

SUBIR K. BANERJEE

1966-02-12T23:59:59.000Z

491

Reverse Thermo-Remanent Magnetism  

Science Journals Connector (OSTI)

... In this communication a particular case of thermo-remanent magnetism, the direction of which is opposite to that of the applied magnetic field under ... to room temperature in a magnetic field of 0-5 Oersteds, it takes a remanent magnetism of 0-12 e.m.u./c.c. in intensity, and the direction ...

TAKESI NAGATA

1952-04-26T23:59:59.000Z

492

Magnetic fluorescent lamp  

DOE Patents [OSTI]

The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

Berman, S.M.; Richardson R.W.

1983-12-29T23:59:59.000Z

493

Magnetism of nickel  

Science Journals Connector (OSTI)

A previously developed theory of the magnetism of iron, based upon notion of a randomized exchange field, has now been applied to calculate the properties of nickel. We obtained a Curie temperature of 1200 K, about twice the observed value. The magnetization curve, the paramagnetic susceptibility (a Curie-Weiss law), and the distribution of spin lengths are also calculated. Both similarities and differences from the results of the iron calculations are noted.

J. Hubbard

1981-06-01T23:59:59.000Z

494

Magnetic coupling device  

DOE Patents [OSTI]

A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.

Nance, Thomas A. (Aiken, SC)

2009-08-18T23:59:59.000Z

495

Percentages of Total Imported Crude Oil by API Gravity  

U.S. Energy Information Administration (EIA) Indexed Site

Percentages of Total Imported Crude Oil by API Gravity Percentages of Total Imported Crude Oil by API Gravity (Percent by Interval) Period: Monthly Annual Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes API Gravity Apr-13 May-13 Jun-13 Jul-13 Aug-13 Sep-13 View History 20.0º or Less 16.07 17.25 17.35 14.65 17.17 19.70 1983-2013 20.1º to 25.0º 34.75 32.07 33.66 33.41 32.73 35.52 1983-2013 25.1º to 30.0º 9.35 8.59 8.61 11.45 8.98 7.73 1983-2013 30.1º to 35.0º 25.99 30.03 26.36 28.73 29.89 26.56 1983-2013 35.1º to 40.0º 11.94 10.60 12.42 9.74 9.89 8.80 1983-2013 40.1º to 45.0º 1.62 1.23 1.13 1.70 1.14 W 1983-2013 45.1º or Greater 0.28 0.23 0.48 0.31 0.20 W 1983-2013 - = No Data Reported; -- = Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data.

496

Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization  

DOE Patents [OSTI]

In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.

Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

2000-12-19T23:59:59.000Z

497

Magnetism of nanosized metallic particles  

Science Journals Connector (OSTI)

The magnetism of a small cluster of magnetic atoms at finite temperatures is numerically investigated. The evolution of the system towards thermal equilibrium is studied, and the possibility of occurrence of vortexlike excitations in the arrangement of the magnetic moments within the cluster is pointed out. The magnetization curve as a function of temperature, of a small magnetic particle, suggests that magnetic clusters in granular metals are not saturated even at room temperature. The relevance of the present results to the understanding of the magnetic behavior of granular metals is discussed.

P. Vargas; J. dAlbuquerque e Castro; D. Altbir

1999-09-01T23:59:59.000Z

498

One-loop divergences in massive gravity theory  

E-Print Network [OSTI]

The one-loop divergences are calculated for the recently proposed ghost-free version of massive gravity, where the action depends on both metric and external tensor field f. The non-polynomial structure of the massive term is reduced to a more standard form by means of auxiliary tensor field, which is settled on-shell after quantum calculations are performed. As one should expect, the counterterms do not reproduce the form of the classical action. Moreover, the result has the form of the power series in f.

Ioseph L. Buchbinder; Dante D. Pereira; Ilya L. Shapiro

2012-01-16T23:59:59.000Z

499

Zero curvature condition and 2D gravity theories  

SciTech Connect (OSTI)

In this paper, the authors propose interpreting the zero curvature condition associated with an integrable model as an anomaly equation. This can lead to the WZWN action and the associated current algebra quite readily and clarifies further the connections found between the integrable models and 2D gravity theories. The authors analyze, in detail, the cases SL(2,R) (KdV hierarchy), OSp(2/1) (sKdV hierarchy) and SL(3,R) (Boussinesq hierarchy) and obtain the operator product expansions of the appropriate fields. The authors also make some observations on the generalization of our method to SL(n,R).

Das, A.; Huang, W.J.; Roy, S. (Dept. of Physics and Astronomy, Univ. of Rochester, Rochester, NY (US))

1992-06-20T23:59:59.000Z

500

Rapid Thermalization by Baryon Injection in Gauge/Gravity Duality  

E-Print Network [OSTI]

Using the AdS/CFT correspondence for strongly coupled gauge theories, we calculate thermalization of mesons caused by a time-dependent change of a baryon number chemical potential. On the gravity side, the thermalization corresponds to a horizon formation on the probe flavor brane in the AdS throat. Since heavy ion collisions are locally approximated by a sudden change of the baryon number chemical potential, we discuss implication of our results to RHIC and LHC experiments, to find a rough estimate of rather rapid thermalization time-scale t_{th} < 1 [fm/c]. We also discuss universality of our analysis against varying gauge theories.

Koji Hashimoto; Norihiro Iizuka; Takashi Oka

2011-08-26T23:59:59.000Z