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1

Hard, infrared black coating with very low outgassing  

SciTech Connect (OSTI)

Infrared astronomical instruments require absorptive coatings on internal surfaces to trap scattered and stray photons. This is typically accomplished with any one of a number of black paints. Although inexpensive and simple to apply, paint has several disadvantages. Painted surfaces can be fragile, prone to shedding particles, and difficult to clean. Most importantly, the vacuum performance is poor. Recently a plasma enhanced chemical vapor deposition (PECVD) process was developed to apply thick (30 {micro}m) diamond-like carbon (DLC) based protective coatings to the interior of oil pipelines. These DLC coatings show much promise as an infrared black for an ultra high vacuum environment. The coatings are very robust with excellent cryogenic adhesion. Their total infrared reflectivity of < 10% at normal incidence approaches that of black paints. We measured outgas rates of <10{sup -12} Torr liter/sec cm{sup 2}, comparable to bare stainless steel.

Kuzmenko, P J; Behne, D M; Casserly, T; Boardman, W; Upadhyaya, D; Boinapally, K; Gupta, M; Cao, Y

2008-06-02T23:59:59.000Z

2

Variable Hard X-ray Emission from the Candidate Accreting Black Hole in Dwarf Galaxy Henize 2-10  

E-Print Network [OSTI]

We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2-10. Recent observations suggest that this galaxy hosts an actively accreting black hole with mass ~10^6 M_sun. The presence of an AGN in a low-mass starburst galaxy marks a new environment for active galactic nuclei (AGNs), with implications for the processes by which "seed" black holes may form in the early Universe. In this paper, we analyze four epochs of X-ray observations of Henize 2-10, to characterize the long-term behavior of its hard nuclear emission. We analyze observations with Chandra from 2001 and XMM-Newton from 2004 and 2011, as well as an earlier, less sensitive observation with ASCA from 1997. Based on detailed analysis of the source and background, we find that the hard (2-10 keV) flux of the putative AGN has decreased by approximately an order of magnitude between the 2001 Chandra observation and exposures with XMM-Newton in 2004 and 2011. The observed variability confirms th...

Whalen, Thomas J; Reines, Amy E; Greene, Jenny E; Sivakoff, Gregory R; Johnson, Kelsey E; Alexander, David M; Goulding, Andy D

2015-01-01T23:59:59.000Z

3

Gravitational infall in the hard wall model  

E-Print Network [OSTI]

An infalling shell in the hard wall model provides a simple holographic model for energy injection in a confining gauge theory. Depending on its parameters, a scalar shell either collapses into a large black brane, or scatters between the hard wall and the anti-de Sitter boundary. In the scattering regime, we find numerical solutions that keep oscillating for as long as we have followed their evolution, and we provide an analytic argument that shows that a black brane can never be formed. This provides examples of states in infinite-volume field theory that never thermalize. We find that the field theory expectation value of a scalar operator keeps oscillating, with an amplitude that undergoes modulation.

B. Craps; E. J. Lindgren; A. Taliotis; J. Vanhoof; H. Zhang

2014-12-15T23:59:59.000Z

4

Gravitational collapse and thermalization in the hard wall model  

E-Print Network [OSTI]

We study a simple example of holographic thermalization in a confining field theory: the homogeneous injection of energy in the hard wall model. Working in an amplitude expansion, we find black brane formation for sufficiently fast energy injection and a scattering wave solution for sufficiently slow injection. We comment on our expectations for more sophisticated holographic QCD models.

Ben Craps; Elias Kiritsis; Christopher Rosen; Anastasios Taliotis; Joris Vanhoof; Hongbao Zhang

2014-03-03T23:59:59.000Z

5

Black Holes  

E-Print Network [OSTI]

Lecture notes for a 'Part III' course 'Black Holes' given in DAMTP, Cambridge. The course covers some of the developments in Black Hole physics of the 1960s and 1970s.

P. K. Townsend

1997-07-04T23:59:59.000Z

6

The high energy emission from black holes  

E-Print Network [OSTI]

The origin of the high energy emission (X-rays and gamma-rays) from black holes is still a matter of debate. We present new evidence that hard X-ray emission in the low/hard state may not be dominated by thermal Comptonization. We present an alternative scenario for the origin of the high energy emission that is well suited to explain the high energy emission from GRO J1655-40.

M. D. Caballero-Garcia; J. M. Miller; E. Kuulkers

2007-11-06T23:59:59.000Z

7

SUPER HARD SURFACED POLYMERS  

SciTech Connect (OSTI)

High energy ion beam surface treatments were applied to a selected group of polymers. Of the six materials in the present study, four were thermoplastics (polycarbonate, polyethylene, polyethylene terephthalate, and polystyrene) and two were thermosets (epoxy and polyimide). The particular epoxy evaluated in this work is one of the resins used in formulating fiber reinforced composites for military helicopter blades. Measures of mechanical properties of the near surface regions were obtained by nanoindentation hardness and pin on disk wear. Attempts were also made to measure erosion resistance by particle impact. All materials were hardness tested. Pristine materials were very soft, having values in the range of approximately 0.1 to 0.5 GPa. Ion beam treatment increased hardness by up to 50 times compared to untreated materials. For reference, all materials were hardened to values higher than those typical of stainless steels. Wear tests were carried out on three of the materials, PET, PI and epoxy. On the ion beam treated epoxy no wear could be detected, whereas the untreated material showed significant wear.

Mansur, Louis K [ORNL] [ORNL; Bhattacharya, R [UES, Incorporated, Dayton, OH] [UES, Incorporated, Dayton, OH; Blau, Peter Julian [ORNL] [ORNL; Clemons, Art [ORNL] [ORNL; Eberle, Cliff [ORNL] [ORNL; Evans, H B [UES, Incorporated, Dayton, OH] [UES, Incorporated, Dayton, OH; Janke, Christopher James [ORNL] [ORNL; Jolly, Brian C [ORNL] [ORNL; Lee, E H [Consultant, Milpitas, CA] [Consultant, Milpitas, CA; Leonard, Keith J [ORNL] [ORNL; Trejo, Rosa M [ORNL] [ORNL; Rivard, John D [ORNL] [ORNL

2010-01-01T23:59:59.000Z

8

Hard physics in PHENIX  

E-Print Network [OSTI]

We review recent results on hard observables in p+p, d+A and A+A collisions obtained by the PHENIX experiment. Emphasis is put on those measurements that provide insight into the properties of hot QCD media expected to be created in nucleus-nucleus collisions at RHIC energies. Direct photon spectra, jet properties and heavy quarks production measured in p+p and d+Au collisions are compared to the same observables extracted in heavy ion collisions to find modifications due to the presence of hot QCD matter.

D. Peressounko; for the PHENIX collaboration

2005-12-08T23:59:59.000Z

9

Hard metal composition  

DOE Patents [OSTI]

A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 wt % boron carbide and the remainder a metal mixture comprising from 70 to 90% tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 and 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

Sheinberg, H.

1983-07-26T23:59:59.000Z

10

Hard metal composition  

DOE Patents [OSTI]

A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 weight percent boron carbide and the remainder a metal mixture comprising from 70 to 90 percent tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 to 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

Sheinberg, Haskell (Los Alamos, NM)

1986-01-01T23:59:59.000Z

11

KT Monograph Black and White Photos 3  

E-Print Network [OSTI]

D5:2 - 672: neck and handle of Red Lustrous Wheel-made ware pilgrim flask D6:1 - 693-698: Pilgrim flasks and other storage vessels from Rm 20 destruc- tion debris D5:3 - Interiors of libation arm fragments from unit 4211, to show manu- facturing... and 1595 E2:12 - 1532: perforated clay disc E2:14 -1596: decorated clay ball E2:15 - 1623: re-used sherd with incised design E2:17 - 1625: horned clay support E2:16 - 1624: Ottoman pipe bowl E2:18 - 1627: clay spit support E2:19 - clay crescents 1634...

Douglas, B; Densham, M; Thomas, D C; Postgate, J N

2005-03-16T23:59:59.000Z

12

Rapidity gap survival in the black-disk regime  

SciTech Connect (OSTI)

We summarize how the approach to the black-disk regime (BDR) of strong interactions at TeV energies influences rapidity gap survival in exclusive hard diffraction pp -> p + H + p (H = dijet, Qbar Q, Higgs). Employing a recently developed partonic description of such processes, we discuss (a) the suppression of diffraction at small impact parameters by soft spectator interactions in the BDR; (b) further suppression by inelastic interactions of hard spectator partons in the BDR; (c) correlations between hard and soft interactions. Hard spectator interactions substantially reduce the rapidity gap survival probability at LHC energies compared to previously reported estimates.

Leonid Frankfurt; Charles Hyde; Mark Strikman; Christian Weiss

2007-04-16T23:59:59.000Z

13

Black Hole Chromosphere at the LHC  

E-Print Network [OSTI]

If the scale of quantum gravity is near a TeV, black holes will be copiously produced at the LHC. In this work we study the main properties of the light descendants of these black holes. We show that the emitted partons are closely spaced outside the horizon, and hence they do not fragment into hadrons in vacuum but more likely into a kind of quark-gluon plasma. Consequently, the thermal emission occurs far from the horizon, at a temperature characteristic of the QCD scale. We analyze the energy spectrum of the particles emerging from the "chromosphere", and find that the hard hadronic jets are almost entirely suppressed. They are replaced by an isotropic distribution of soft photons and hadrons, with hundreds of particles in the GeV range. This provides a new distinctive signature for black hole events at LHC.

Luis Anchordoqui; Haim Goldberg

2003-02-26T23:59:59.000Z

14

Materials science Nanotubes get hard  

E-Print Network [OSTI]

Materials science Nanotubes get hard under pressure Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0405877101 (2004) When Zhongwu Wang et al. squeezed carbon nanotubes in a diamond anvil cell, they made nanotubes into diamond itself: the carbon material formed under compression at room temperature seems

Downs, Robert T.

15

Ultrasonic material hardness depth measurement  

DOE Patents [OSTI]

The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part.

Good, Morris S. (Richland, WA); Schuster, George J. (Kennewick, WA); Skorpik, James R. (Kennewick, WA)

1997-01-01T23:59:59.000Z

16

Hard X-ray observations of Cygnus X-1 with the Miso telescope  

SciTech Connect (OSTI)

The black hole candidate Cygnus X-1 was observed in the hard X-ray - soft gamma-ray energy range by the Miso telescope on two different occasions: in September 1979 and May 1980. Two hard X-ray states of the source have beem measured: in 1979 the observed spectrum confirms the superlow state measured in the same period by the HEAO-3 satellite, while in 1980 the Miso X-ray data are consistent with the so-called low state of Cygnus X-1. In both occasions, no gamma-ray excess has been observed above 200 keV. 9 references.

Perotti, F.; Della Ventura, A.; Villa, G.

1984-01-01T23:59:59.000Z

17

Microwave assisted hard rock cutting  

DOE Patents [OSTI]

An apparatus for the sequential fracturing and cutting of subsurface volume of hard rock (102) in the strata (101) of a mining environment (100) by subjecting the volume of rock to a beam (25) of microwave energy to fracture the subsurface volume of rock by differential expansion; and , then bringing the cutting edge (52) of a piece of conventional mining machinery (50) into contact with the fractured rock (102).

Lindroth, David P. (Apple Valley, MN); Morrell, Roger J. (Bloomington, MN); Blair, James R. (Inver Grove Heights, MN)

1991-01-01T23:59:59.000Z

18

Black Pine Engineering  

Broader source: Energy.gov [DOE]

Black Pine Engineering is commercializing a disruptive technology in the turbomachinery industry. Using a patented woven composite construction, Black Pine Engineering can make turbomachines (turbines, compressors) that are cheaper and lighter than competing technologies. Using this technology, Black Pine Engineering will sell turbo-compressors which solve the problem of wasted steam in geothermal power plants.

19

Hardness and microstructural response to thermal annealing of irradiated ASTM A533B class 1 plate steel  

SciTech Connect (OSTI)

Hardness measurements were used to determine the post-irradiation annealing response of A533B class 1 plate steel irradiated to a fluence of 1 {times} 10{sup 19} n/cm{sup 2} (E > 1 MeV) at 150 C. Rockwell hardness measurements indicated that the material had hardened by 6.6 points on the B scale after irradiation. The irradiation induced hardness increase was associated with a decrease in upper shelf energy from 63.4 J to 5-1.8 J and a temperature shift in the Charpy curve at the 41 J level from 115 C to 215 C. Specimens were annealed after irradiation at temperatures of 343 C (650 F), 399 C (750 F), and 454 C (850 F) for durations of up to one week (168 h). Hardness measurements were made to chart recovery of hardness as a function of time and temperature. Specimens annealed at the highest temperature 454 C recovered the fastest, fully recovering within 144 h. Specimens annealed at 399 C recovered completely within 168 h. Specimens annealed at the lowest temperature, 343 C recovered only {approximately}70% after 168 h of annealing. After neutron irradiation, a new feature of black spot damage was found to be superimposed on the unirradiated microstructure. The density of black spots was found to vary from 2.3 {times} 10{sup 15}/cm{sup 3} to 1.1 {times} 10{sup 16}/cm{sup 3} with an average diameter of 2.85 nm. Following annealing at 454 C for 24 h the black spot damage was completely annealed out. It was concluded that the black spot damage was responsible for 70% of the irradiation-induced hardness.

Reinhart, D.E. [SMS Concast, Inc., Pittsburgh, PA (United States); Kumar, A.S. [Univ. of Missouri, Rolla, MO (United States); Gelles, D.S.; Hamilton, M.L. [Pacific Northwest Lab., Richland, WA (United States); Rosinski, S.T. [Electric Power Research Inst., Charlotte, NC (United States)

1999-10-01T23:59:59.000Z

20

Black Hole Chemistry  

E-Print Network [OSTI]

The mass of a black hole has traditionally been identified with its energy. We describe a new perspective on black hole thermodynamics, one that identifies the mass of a black hole with chemical enthalpy, and the cosmological constant as thermodynamic pressure. This leads to an understanding of black holes from the viewpoint of chemistry, in terms of concepts such as Van der Waals fluids, reentrant phase transitions, and triple points. Both charged and rotating black holes exhibit novel chemical-type phase behaviour, hitherto unseen.

David Kubiznak; Robert B. Mann

2014-04-08T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Development of radiation hard scintillators  

SciTech Connect (OSTI)

Substantial improvements have been made in the radiation hardness of plastic scintillators. Cylinders of scintillating materials 2.2 cm in diameter and 1 cm thick have been exposed to 10 Mrads of gamma rays at a dose rate of 1 Mrad/h in a nitrogen atmosphere. One of the formulations tested showed an immediate decrease in pulse height of only 4% and has remained stable for 12 days while annealing in air. By comparison a commercial PVT scintillator showed an immediate decrease of 58% and after 43 days of annealing in air it improved to a 14% loss. The formulated sample consisted of 70 parts by weight of Dow polystyrene, 30 pbw of pentaphenyltrimethyltrisiloxane (Dow Corning DC 705 oil), 2 pbw of p-terphenyl, 0.2 pbw of tetraphenylbutadiene, and 0.5 pbw of UVASIL299LM from Ferro.

Markley, F.; Woods, D.; Pla-Dalmau, A.; Foster, G. (Fermi National Accelerator Lab., Batavia, IL (United States)); Blackburn, R. (Michigan Univ., Nuclear Reactor Lab., Ann Arbor, MI (United States))

1992-05-01T23:59:59.000Z

22

Hard-gapped Holographic Superconductors  

E-Print Network [OSTI]

In this work we discuss the zero temperature limit of a "p-wave" holographic superconductor. The bulk description consists of a non-Abelian SU(2) gauge fields minimally coupled to gravity. We numerically construct the zero temperature solution which is the gravity dual of the superconducting ground state of the "p-wave" holographic superconductors. The solution is a smooth soliton with zero horizon size and shows an emergent conformal symmetry in the IR. We found the expected superconducting behavior. Using the near horizon analysis we show that the system has a "hard gap" for the relevant gauge field fluctuations. At zero temperature the real part of the conductivity is zero for an excitation frequency less than the gap frequency. This is in contrast with what has been observed in similar scalar- gravity-gauge systems (holographic superconductors). We also discuss the low but finite temperature behavior of our solution.

Pallab Basu; Jianyang He; Anindya Mukherjee; Hsien-Hang Shieh

2009-12-05T23:59:59.000Z

23

Hardness Standardization Our objective is to standardize and improve hardness measurement  

E-Print Network [OSTI]

by Standard Development Organizations (SDOs) such as ASTM International and the International Organization and Measures (BIPM) during the development of international test method standards, by those performing hardnessHardness Standardization METALS Our objective is to standardize and improve hardness measurement

24

Bicycling Black Rings  

E-Print Network [OSTI]

We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. Such limits exist for both types of solutions; for the bi-rings it is obtained when the two rings drag each other to extremality through the effect of gravitational frame-dragging. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

Elvang, Henriette

2008-01-01T23:59:59.000Z

25

Bicycling Black Rings  

E-Print Network [OSTI]

We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

Henriette Elvang; Maria J. Rodriguez

2008-01-25T23:59:59.000Z

26

BLACK HISTORY MONTH  

Broader source: Energy.gov [DOE]

Black History Month is an annual celebration of achievements by black Americans and a time for recognizing the central role of African Americans in U.S. history. The event grew out of “Negro History Week,” created by historian Carter G. Woodson and other prominent African Americans. Other countries around the world, including Canada and the United Kingdom, also devote a month to celebrating black history.

27

A Black Hole Levitron  

E-Print Network [OSTI]

We study the problem of spatially stabilising four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes kept in external fields we find that taking a continuum limit of Denef et al's multi-center solutions provides a supergravity description of such backgrounds within which a black hole can be trapped in a given volume. This is realised by levitating a black hole over a magnetic dipole base. We comment on how such a construction resembles a mechanical Levitron.

Xerxes D. Arsiwalla; Erik P. Verlinde

2009-02-02T23:59:59.000Z

28

Dynamics of black holes  

E-Print Network [OSTI]

This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping horizon which manifests temporally as separate horizons.

Sean A. Hayward

2009-02-28T23:59:59.000Z

29

Revisit of interfacial free energy of the hard sphere system near hard wall  

E-Print Network [OSTI]

We propose a simple Monte Carlo method to calculate the interfacial free energy between the substrate and the material. Using this method we investigate the interfacial free energys of the hard sphere fluid and solid phases near a smooth hard wall. According to the obtained interfacial free energys of the coexisting fluid and solid phases and the Young equation we are able to determine the contact angle with high accuracy, cos$\\theta$ = 1:010(31), which indicates that a smooth hard wall can be wetted completely by the hard sphere crystal at the interface between the wall and the hard sphere fluid.

Mingcheng Yang; Hongru Ma

2008-06-23T23:59:59.000Z

30

"Hybrid" Black Holes  

E-Print Network [OSTI]

We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

Valeri P. Frolov; Andrei V. Frolov

2014-12-30T23:59:59.000Z

31

Hardness of approximation for quantum problems  

E-Print Network [OSTI]

The polynomial hierarchy plays a central role in classical complexity theory. Here, we define a quantum generalization of the polynomial hierarchy, and initiate its study. We show that not only are there natural complete problems for the second level of this quantum hierarchy, but that these problems are in fact hard to approximate. Using these techniques, we also obtain hardness of approximation for the class QCMA. Our approach is based on the use of dispersers, and is inspired by the classical results of Umans regarding hardness of approximation for the second level of the classical polynomial hierarchy [Umans, FOCS 1999]. The problems for which we prove hardness of approximation for include, among others, a quantum version of the Succinct Set Cover problem, and a variant of the local Hamiltonian problem with hybrid classical-quantum ground states.

Sevag Gharibian; Julia Kempe

2012-09-05T23:59:59.000Z

32

Novel hard compositions and methods of preparation  

DOE Patents [OSTI]

Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value.

Sheinberg, H.

1981-02-03T23:59:59.000Z

33

Hard x-ray imaging from explorer  

SciTech Connect (OSTI)

Coded aperture X-ray detectors were applied to obtain large increases in sensitivity as well as angular resolution. A hard X-ray coded aperture detector concept is described which enables very high sensitivity studies persistent hard X-ray sources and gamma ray bursts. Coded aperture imaging is employed so that approx. 2 min source locations can be derived within a 3 deg field of view. Gamma bursts were located initially to within approx. 2 deg and X-ray/hard X-ray spectra and timing, as well as precise locations, derived for possible burst afterglow emission. It is suggested that hard X-ray imaging should be conducted from an Explorer mission where long exposure times are possible.

Grindlay, J.E.; Murray, S.S.

1981-11-01T23:59:59.000Z

34

Hard X-ray Fluorescence Measurements of Heteroepitaxial Solid...  

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

Hard X-ray Fluorescence Measurements of Heteroepitaxial Solid Oxide Fuel Cell Cathode Materials. Hard X-ray Fluorescence Measurements of Heteroepitaxial Solid Oxide Fuel Cell...

35

Charging Black Saturn?  

E-Print Network [OSTI]

We construct new charged static solutions of the Einstein-Maxwell field equations in five dimensions via a solution generation technique utilizing the symmetries of the reduced Lagrangian. By applying our method on the multi-Reissner-Nordstrom solution in four dimensions, we generate the multi-Reissner-Nordstrom solution in five dimensions. We focus on the five-dimensional solution describing a pair of charged black objects with general masses and electric charges. This solution includes the double Reissner-Nordstrom solution as well as the charged version of the five-dimensional static black Saturn. However, all the black Saturn configurations that we could find present either a conical singularity or a naked singularity. We also obtain a non-extremal configuration of charged black strings that reduces in the extremal limit to a Majumdar-Papapetrou like solution in five dimensions.

Brenda Chng; Robert Mann; Eugen Radu; Cristian Stelea

2008-10-28T23:59:59.000Z

36

Charged Schrodinger black holes  

E-Print Network [OSTI]

We construct charged and rotating asymptotically Schrödinger black hole solutions of type IIB supergravity. We begin by obtaining a closed-form expression for the null Melvin twist of a broad class of type IIB backgrounds, ...

Adams, Allan

37

Helical superconducting black holes  

E-Print Network [OSTI]

We construct novel static, asymptotically $AdS_5$ black hole solutions with Bianchi VII$_0$ symmetry that are holographically dual to superconducting phases in four spacetime dimensions with a helical p-wave order. We calculate the precise temperature dependence of the pitch of the helical order. At zero temperature the black holes have vanishing entropy and approach domain wall solutions that reveal homogenous, non-isotropic dual ground states with emergent scaling symmetry.

Aristomenis Donos; Jerome P. Gauntlett

2012-05-17T23:59:59.000Z

38

Hard x-ray observations of Cygnus X-1 with the MISO telescope  

SciTech Connect (OSTI)

The results of hard x-ray, soft gamma-ray observations of the galactic black hole candidate, Cyg X-1, taken with the MISO telescope in October 1979 and May 1980 are presented, confirming the superlow state measured during September-October 1979 by the HEAO 3 satellite. The 1980 observation coincides with a low- to high-state transition and is consistent with HEAO 3 observations taken at the same epoch. No gamma-ray counting-rate excess above 200 keV was recorded in either observation. Apart from these two measurements, the observation of the Crab Nebula as an a posteriori calibration source is also described. 15 references.

Perotti, F.; Della Ventura, A.; Villa, G.; Bassani, L.; Butler, R.C.

1986-01-01T23:59:59.000Z

39

Mass without radiation: heavily obscured AGN, the X-ray Background and the Black Hole Mass Density  

E-Print Network [OSTI]

A recent revision of black hole scaling relations (Kormendy & Ho 2013), indicates that the local mass density in black holes should be increased by up to a factor of five with respect to previously determined values. The local black hole mass density is connected to the mean radiative efficiency of accretion through the time integral of the AGN volume density and a significant increase of the local black holes mass density would have interesting consequences on AGN accretion properties and demography. One possibility to explain a large black hole mass density is that most of the Black Hole growth is via radiatively inefficient channels such as super Eddington accretion, however, given the intrinsic degeneracies in the Soltan argument, this solution is not unique. Here we show how it is possible to accommodate a larger fraction of heavily buried, Compton thick AGN, without violating the limit imposed by the hard X-ray and mid-infrared backgrounds spectral energy density.

Comastri, A; Marconi, A; Risaliti, G; Salvati, M

2015-01-01T23:59:59.000Z

40

On Black Hole Entropy  

E-Print Network [OSTI]

Two techniques for computing black hole entropy in generally covariant gravity theories including arbitrary higher derivative interactions are studied. The techniques are Wald's Noether charge approach introduced recently, and a field redefinition method developed in this paper. Wald's results are extended by establishing that his local geometric expression for the black hole entropy gives the same result when evaluated on an arbitrary cross-section of a Killing horizon (rather than just the bifurcation surface). Further, we show that his expression for the entropy is not affected by ambiguities which arise in the Noether construction. Using the Noether charge expression, the entropy is evaluated explicitly for black holes in a wide class of generally covariant theories. Further, it is shown that the Killing horizon and surface gravity of a stationary black hole metric are invariant under field redefinitions of the metric of the form $\\bar{g}_{ab}\\equiv g_{ab} + \\Delta_{ab}$, where $\\Delta_{ab}$ is a tensor field constructed out of stationary fields. Using this result, a technique is developed for evaluating the black hole entropy in a given theory in terms of that of another theory related by field redefinitions. Remarkably, it is established that certain perturbative, first order, results obtained with this method are in fact {\\it exact}. The possible significance of these results for the problem of finding the statistical origin of black hole entropy is discussed.}

Ted Jacobson; Gungwon Kang; Robert C. Myers

1994-01-03T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Novel hard compositions and methods of preparation  

DOE Patents [OSTI]

Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value. Photomicrographs show that the shapes of the grains of the alloy mixture with which the minor amount of carbide (or carbide-formers) is mixed are radically altered from large, rounded to small, very angular by the addition of the carbide. Superiority of one of these hard compositions of matter over cobalt-bonded tungsten carbide for ultra-high pressure anvil applications was demonstrated. 3 figs.

Sheinberg, H.

1983-08-23T23:59:59.000Z

42

Novel hard compositions and methods of preparation  

DOE Patents [OSTI]

Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value. Photomicrographs show that the shapes of the grains of the alloy mixture with which the minor amount of carbide (or carbide-formers) is mixed are radically altered from large, rounded to small, very angular by the addition of the carbide. Superiority of one of these hard compositions of matter over cobalt-bonded tungsten carbide for ultra-high pressure anvil applications was demonstrated.

Sheinberg, Haskell (Los Alamos, NM)

1983-08-23T23:59:59.000Z

43

Hard-thermal-loop QED thermodynamics  

E-Print Network [OSTI]

The weak-coupling expansion for thermodynamic quantities in thermal field theories is poorly convergent unless the coupling constant is tiny. We discuss the calculation of the free energy for a hot gas of electrons and photons to three-loop order using hard-thermal-loop perturbation theory (HTLpt). We show that the hard-thermal-loop perturbation reorganization improves the convergence of the successive approximations to the QED free energy at large coupling, e ~ 2. The reorganization is gauge invariant by construction, and due to the cancellations among various contributions, we obtain a completely analytic result for the resummed thermodynamic potential at three loops.

Nan Su; Jens O. Andersen; Michael Strickland

2009-11-24T23:59:59.000Z

44

Entangled games are hard to approximate  

E-Print Network [OSTI]

We establish the first hardness results for the problem of computing the value of one-round games played by a verifier and a team of provers who can share quantum entanglement. In particular, we show that it is NP-hard to approximate within an inverse polynomial the value of a one-round game with (i) quantum verifier and two entangled provers or (ii) classical verifier and three entangled provers. Previously it was not even known if computing the value exactly is NP-hard. We also describe a mathematical conjecture, which, if true, would imply hardness of approximation to within a constant. We start our proof by describing two ways to modify classical multi-prover games to make them resistant to entangled provers. We then show that a strategy for the modified game that uses entanglement can be ``rounded'' to one that does not. The results then follow from classical inapproximability bounds. Our work implies that, unless P=NP, the values of entangled-prover games cannot be computed by semidefinite programs that are polynomial in the size of the verifier's system, a method that has been successful for more restricted quantum games.

Julia Kempe; Hirotada Kobayashi; Keiji Matsumoto; Ben Toner; Thomas Vidick

2007-11-21T23:59:59.000Z

45

HARD CLAM HYBRIDS FOR FLORIDAAQUACULTURE: HATCHERY CULTURE  

E-Print Network [OSTI]

Florida have reported higher than expected mortality, which may be caused by high water temperatures by thermal stimulation. Southern hard clams seemed to spawn as water cooled from peak temperature, or other stressors (e.g., rapid salinity changes caused by excessive rain), during the prolonged hot

Florida, University of

46

Party hard! The maths of connections  

E-Print Network [OSTI]

problem Question How many people need to come to a party, to guarantee that at least three of them all! With this group of 6 people, we succeeded in finding a trio. What can we say, in general? Colva Roney-Dougal Party hard! #12;Introducing graphs We'll represent the people as dots, called vertices. If two people know

47

Hard Thresholding Pursuit Algorithms: Number of Iterations  

E-Print Network [OSTI]

algorithms do provide alternative methods. We consider here the hard thresholding pursuit (HTP) algorithm [6 us now recall that (HTP) consists in constructing a sequence (xn) of s-sparse vectors, starting absolute entries of xn-1 + A (y - Axn-1 ),(HTP1) xn := argmin{ y - Az 2, supp(z) Sn },(HTP2) until

Hitczenko, Pawel

48

Hard thermal loops in static external fields  

E-Print Network [OSTI]

We study, in the imaginary-time formalism, the high temperature behavior of n-point thermal loops in static Yang-Mills and gravitational fields. We show that in this regime, any hard thermal loop gives the same leading contribution as the one obtained by evaluating the loop at zero external energies and momenta.

J. Frenkel; S. H. Pereira; N. Takahashi

2009-02-04T23:59:59.000Z

49

Gasification of black liquor  

SciTech Connect (OSTI)

A process is described for treating a concentrated aqueous black liquor carbonaceous material and alkali metal sulfur compounds to form a combustible gas and a sulfide-rich melt comprising: (a) providing a gasifier vessel maintained at a pressure of from about 1 to 50 atmospheres and containing a relatively shallow molten salt pool at its bottom within a sump equipped with an overflow discharge; (b) introducing into the top of the drying zone the concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds; (c) evaporating water from the concentrated aqueous black liquor in the drying zone by direct contact of the aqueous black liquor with the hot gas rising from the gasification zone to produce dried black liquor solids; (d) introducing a first portion of an oxygen-containing gas into the gas space in the gasification zone located below the drying zone immediately above the molten salt pool to partially oxidize and gasify a fraction of the carbonaceous material in the dried black liquor solids falling through the zone to form a hot combustible gas; (e) introducing a second portion of the oxygen-containing gas beneath the surface of the molten salt pool in an amount sufficient to cause gasification of essentially all carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool; (f) withdrawing the cooled combustible gas having a higher heating value of at least about 90 Btu/scf (dry basis) from an upper portion of the drying zone; and (g) withdrawing from the overflow discharge in the molten salt reduction zone a melt in which the sulfur content is predominantly in the form of alkali metal sulfide.

Kohl, A.L.

1987-07-28T23:59:59.000Z

50

Black holes at accelerators.  

E-Print Network [OSTI]

ar X iv :h ep -p h/ 05 11 12 8v 3 6 A pr 2 00 6 Black Holes at Accelerators Bryan Webber Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK In theories with large extra dimensions and TeV-scale gravity, black holes... 2000 3000 Missing ET (GeV) Ar bi tra ry S ca le p p ? QCD SUSY 5 TeV BH (n=6) 5 TeV BH (n=2) (PT > 600 GeV) (SUGRA point 5) Figure 10: Missing transverse energy for various processes at the LHC. 4.2. Event Characteristics Turning from single...

Webber, Bryan R

51

Extremal black disks in QCD  

E-Print Network [OSTI]

We argue that in the high energy QCD a true black disk wave function necessarily contains many quarks. This corresponds to necessity of non-vacuum reggeon loops in formation of a black disk. The result comes from decomposition of the black disk S-matrix in characters on group manifold.

Alexey V. Popov

2008-05-12T23:59:59.000Z

52

Black holes and black strings in plane waves  

E-Print Network [OSTI]

We investigate the construction of black holes and black strings in vacuum plane wave spacetimes using the method of matched asymptotic expansions. We find solutions of the linearised equations of motion in the asymptotic region for a general source on a plane wave background. We observe that these solutions do not satisfy our previously defined conditions for being asymptotically plane wave. Hence, the space of asymptotically plane wave solutions is restricted. We consider the solution in the near region, treating the plane wave as a perturbation of a black object, and find that there is a regular black string solution but no regular black hole solution.

Julian Le Witt; Simon F. Ross

2009-10-30T23:59:59.000Z

53

Gasification of black liquor  

DOE Patents [OSTI]

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

Kohl, Arthur L. (Woodland Hills, CA)

1987-07-28T23:59:59.000Z

54

Gasification of black liquor  

DOE Patents [OSTI]

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

Kohl, A.L.

1987-07-28T23:59:59.000Z

55

Black Hole Thermodynamics Today  

E-Print Network [OSTI]

A brief survey of the major themes and developments of black hole thermodynamics in the 1990's is given, followed by summaries of the talks on this subject at MG8 together with a bit of commentary, and closing with a look towards the future.

Ted Jacobson

1998-01-07T23:59:59.000Z

56

Combustion of black liquor  

SciTech Connect (OSTI)

This patent describes an improvement in the combustion of black liquor in an existing Tomlison recovery boiler unit in which black liquor is sprayed into a furnace in which it is successively dried, pyrolyzed and converted to a bed of solid carbonaceous residue, using a primary air stream and a secondary air stream and the residue is subsequently converted to a smelt. The improvement comprises: the addition of between an effective amount up to 5% oxygen by volume to the primary air stream directed at the bed of solid carbonaceous residue, the amount of oxygen added being sufficient to increase the adiabatic flame temperature, the combustion rate of the solid carbonaceous material, the rate of pyrolysis, the temperature in the lower portion of the furnace, the the drying rate of black liquor droplets, and to decrease the temperature of the gases entering the heat transfer surfaces in the upper portion of the furnace and the rate of deposit formation on the surfaces and wherein the amount of black liquor combusted is increased as compared with the amount combusted in the same furnace operated without the addition of oxygen to the primary air.

Mullen, W.T.

1989-08-15T23:59:59.000Z

57

Quantum black hole inflation  

E-Print Network [OSTI]

In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the gravitational field red-shifts the frequency modes of the vacuum, a condition on the minimum stregth of the gravitational field required to achieve real particle creation is derived. Application of this requirement on a Schwartzchid black hole resulted in deducing an upper limit on the region, outside the event horizon, where real particles can be created. Using this regional upper limit, and considering particle creation by black holes as a consequence of the Casimir effect, with the assumption that the created quanta are to be added to the initial energy, we deduce a natural power law for the development of the event horizon, and consequently a logarithmic law for the area spectrum of an inflating black hole. Application of the results on a cosmological model shows that if we start with a Planck-dimensional black hole, then through the process of particle creation we end up with a universe having the presently estimated critical density. Such a universe will be in a state of eternal inflation.

M. B. Altaie

2001-05-07T23:59:59.000Z

58

Black brane steady states  

E-Print Network [OSTI]

We follow the evolution of an asymptotically AdS black brane with a fixed temperature gradient at spatial infinity until a steady state is formed. The resulting energy density and energy flux of the steady state in the boundary theory are compared to a conjecture on the behavior of steady states in conformal field theories. Very good agreement is found.

Amado, Irene

2015-01-01T23:59:59.000Z

59

Laser ablated hard coating for microtools  

DOE Patents [OSTI]

Wear-resistant coatings composed of laser ablated hard carbon films, are deposited by pulsed laser ablation using visible light, on instruments such as microscope tips and micro-surgical tools. Hard carbon, known as diamond-like carbon (DLC), films produced by pulsed laser ablation using visible light enhances the abrasion resistance, wear characteristics, and lifetimes of small tools or instruments, such as small, sharp silicon tips used in atomic probe microscopy without significantly affecting the sharpness or size of these devices. For example, a 10-20 nm layer of diamond-like carbon on a standard silicon atomic force microscope (AFM) tip, enables the useful operating life of the tip to be increased by at least twofold. Moreover, the low inherent friction coefficient of the DLC coating leads to higher resolution for AFM tips operating in the contact mode.

McLean, II, William (Oakland, CA); Balooch, Mehdi (Berkeley, CA); Siekhaus, Wigbert J. (Berkeley, CA)

1998-05-05T23:59:59.000Z

60

Laser ablated hard coating for microtools  

DOE Patents [OSTI]

Wear-resistant coatings composed of laser ablated hard carbon films, are deposited by pulsed laser ablation using visible light, on instruments such as microscope tips and micro-surgical tools. Hard carbon, known as diamond-like carbon (DLC), films produced by pulsed laser ablation using visible light enhances the abrasion resistance, wear characteristics, and lifetimes of small tools or instruments, such as small, sharp silicon tips used in atomic probe microscopy without significantly affecting the sharpness or size of these devices. For example, a 10--20 nm layer of diamond-like carbon on a standard silicon atomic force microscope (AFM) tip, enables the useful operating life of the tip to be increased by at least twofold. Moreover, the low inherent friction coefficient of the DLC coating leads to higher resolution for AFM tips operating in the contact mode. 12 figs.

McLean, W. II; Balooch, M.; Siekhaus, W.J.

1998-05-05T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Fixed target electroweak and hard scattering physics  

SciTech Connect (OSTI)

The possibilities for future physics and experiments involving weak and electromagnetic interactions, neutrino oscillations, general hard scattering and experiments involving nuclear targets were explored. The studies were limited to the physics accessible using fixed target experimentation. While some of the avenues explored turn out to be relatively unrewarding in the light of competition elsewhere in the world, there are a number of positive conclusions reached about experimentation in the energy range available to the Main Injector and Tevatron. Some of the experiments would benefit from the increased intensity available from the Tevatron utilizing the Main Injector, while some require this increase. Finally, some of the experiments would use the Main Injector low energy, high intensity extracted beams directly. A program of electroweak and hard scattering experiments at fixed target energies retains the potential for important contributions to physics. The key to major parts of this program would appear to be the existence of the Main Injector. 115 refs, 17 figs.

Brock, R. (Michigan State Univ., East Lansing, MI (USA)); Brown, C.N.; Montgomery, H.E. (Fermi National Accelerator Lab., Batavia, IL (USA)); Corcoran, M.D. (eds.) (Rice Univ., Houston, TX (USA))

1990-02-01T23:59:59.000Z

62

Exploring electronic structure through high-resolution hard x...  

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

Laboratory Modern high brilliance beamlines coupled with recent advances in hard-x-ray optics are establishing high-resolution hard x-ray spectroscopies as a powerful analytical...

63

Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm  

E-Print Network [OSTI]

Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2003 #12;Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2003 Published: 14 May 2004

64

Refining the fundamental plane of accreting black holes  

E-Print Network [OSTI]

The idea of a unified description of supermassive and stellar black holes has been supported by the extension of the empirical radio/X-ray correlation from X-ray binaries to active galactic nuclei through the inclusion of a mass term. This has lead to the so-called fundamental plane of black hole activity in the black hole mass, radio and X-ray luminosity space. Two incarnations of this fundamental plane have so far been suggested using different underlying models and using two different samples of accreting black holes. We present revised samples for both studies together with a refined statistical analysis using measured errors of the observables. This method is used to compare the two samples, discuss selection effects, and infer parameters for the fundamental plane in a homogeneous way. We show that strongly sub-Eddington objects in a state equivalent to the low/hard state of X-ray binaries follow the fundamental plane very tightly; the scatter is comparable to the measurement errors. However, we find that the estimated parameters depend strongly on the assumptions made on the sources of scatter and the relative weight of the different AGN classes in the sample. Using only hard state objects, the fundamental plane is in agreement with the prediction of a simple uncooled synchrotron/jet model for the emitted radiation. Inclusion of high-state objects increases the scatter and moves the correlation closer to a disk/jet model. This is qualitatively consistent with a picture where low-state objects are largely dominated by jet emission while high-state objects have a strong contribution from an accretion disk.

Elmar Koerding; Heino Falcke; Sephane Corbel

2006-03-05T23:59:59.000Z

65

Constraints on jet X-ray emission in low/hard state X-ray binaries  

E-Print Network [OSTI]

We show that the combination of the similarities between the X-ray properties of low luminosity accreting black holes and accreting neutron stars, combined with the differences in their radio properties argues that the X-rays from these systems are unlikely to be formed in the relativistic jets. Specifically, the spectra of extreme island state neutron stars and low/hard state black holes are known to be indistinguishable, while the power spectra from these systems are known to show only minor differences beyond what would be expected from scaling the characteristic variability frequencies by the mass of the compact object. The spectral and temporal similarities thus imply a common emission mechanism that has only minor deviations from having all key parameters scaling linearly with the mass of the compact object, while we show that this is inconsistent with the observations that the radio powers of neutron stars are typically about 30 times lower than those of black holes at the same X-ray luminosity. We also show that an abrupt luminosity change would be expected when a system makes a spectral state transition from a radiatively inefficient jet dominated accretion flow to a thin disk dominated flow, but that such a change is not seen.

Thomas J. Maccarone

2005-03-31T23:59:59.000Z

66

BLACK HOLE AURORA POWERED BY A ROTATING BLACK HOLE  

SciTech Connect (OSTI)

We present a model for high-energy emission sources generated by a standing magnetohydrodynamical (MHD) shock in a black hole magnetosphere. The black hole magnetosphere would be constructed around a black hole with an accretion disk, where a global magnetic field could be originated by currents in the accretion disk and its corona. Such a black hole magnetosphere may be considered as a model for the central engine of active galactic nuclei, some compact X-ray sources, and gamma-ray bursts. The energy sources of the emission from the magnetosphere are the gravitational and electromagnetic energies of magnetized accreting matters and the rotational energy of a rotating black hole. When the MHD shock generates in MHD accretion flows onto the black hole, the plasma's kinetic energy and the black hole's rotational energy can convert to radiative energy. In this Letter, we demonstrate the huge energy output at the shock front by showing negative energy postshock accreting MHD flows for a rapidly rotating black hole. This means that the extracted energy from the black hole can convert to the radiative energy at the MHD shock front. When an axisymmetric shock front is formed, we expect a ring-shaped region with very hot plasma near the black hole; this would look like an 'aurora'. The high-energy radiation generated from there would carry to us the information for the curved spacetime due to the strong gravity.

Takahashi, Masaaki [Department of Physics and Astronomy, Aichi University of Education, Kariya, Aichi 448-8542 (Japan); Takahashi, Rohta, E-mail: takahasi@phyas.aichi-edu.ac.j [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2010-05-15T23:59:59.000Z

67

Design of Hard Water Stable Emulsifier Systems for Petroleum-  

E-Print Network [OSTI]

Design of Hard Water Stable Emulsifier Systems for Petroleum- and Bio-based Semi for petroleum and bio-based MWFs that improve fluid lifetime by providing emulsion stability under hard water. The newly developed petroleum and bio-based formulations with improved hard water stability are competitive

Clarens, Andres

68

Supermassive Black Holes  

E-Print Network [OSTI]

Supermassive black holes have generally been recognized as the most destructive force in nature. But in recent years, they have undergone a dramatic shift in paradigm. These objects may have been critical to the formation of structure in the early universe, spawning bursts of star formation and nucleating proto-galactic condensations. Possibly half of all the radiation produced after the Big Bang may be attributed to them, whose number is now known to exceed 300 million. The most accessible among them is situated at the Center of Our Galaxy. In the following pages, we will examine the evidence that has brought us to this point, and we will understand why many expect to actually image the event horizon of the Galaxy's central black hole within this decade.

Fulvio Melia

2007-05-10T23:59:59.000Z

69

Shape of black holes  

E-Print Network [OSTI]

It is well known that celestial bodies tend to be spherical due to gravity and that rotation produces deviations from this sphericity. We discuss what is known and expected about the shape of black holes' horizons from their formation to their final, stationary state. We present some recent results showing that black hole rotation indeed manifests in the widening of their central regions, limits their global shapes and enforces their whole geometry to be close to the extreme Kerr horizon geometry at almost maximal rotation speed. The results depend only on the horizon area and angular momentum. In particular they are entirely independent of the surrounding geometry of the spacetime and of the presence of matter satisfying the strong energy condition. We also discuss the the relation of this result with the Hoop conjecture.

Clement, María E Gabach

2015-01-01T23:59:59.000Z

70

Black Pine Circle Project  

SciTech Connect (OSTI)

A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

Mytko, Christine

2014-03-31T23:59:59.000Z

71

Black Pine Circle Project  

ScienceCinema (OSTI)

A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

Mytko, Christine

2014-09-15T23:59:59.000Z

72

Red-black Tree Jingjing Xia  

E-Print Network [OSTI]

Advanced Algorithm Design Red-black Tree Jingjing Xia #12;Red-Black Tree A red-black tree is a binary search tree, and each node contains one extra field: its color, it can be either black or red of the binary search tree. If a binary search tree satisfies all the following red-black properties, it is a red

Chen, Yangjun

73

Black holes in massive gravity  

E-Print Network [OSTI]

We review the black hole solutions of the ghost-free massive gravity theory and its bimetric extension and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact black hole solutions, analogous to those of General Relativity. In addition to these solutions, hairy black holes -- solutions with no correspondent in General Relativity -- have been found numerically, whose existence is a natural consequence of the absence of the Birkhoff's theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these black holes richer and more complex than those of General Relativity. In particular, the bi-Schwarzschild black hole exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical black holes are described by these solutions, the superradiant instability o...

Babichev, Eugeny

2015-01-01T23:59:59.000Z

74

Black Hole's 1/N Hair  

E-Print Network [OSTI]

According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

Gia Dvali; Cesar Gomez

2012-03-29T23:59:59.000Z

75

Effect of tungsten addition on the toughness and hardness of Fe{sub 2}B in wear-resistant Fe-B-C cast alloy  

SciTech Connect (OSTI)

The effects of tungsten additions of 0%, 1.12%, 2.04%, and 3.17% (in wt.%) on the morphology, fracture toughness and micro-hardness of Fe{sub 2}B in Fe-B-C cast alloy were investigated. The results indicate that, with the increase of tungsten addition, the morphology and distribution of Fe{sub 2}B have no change and a new W-containing phase, except the (Fe, W){sub 2}B with a certain tungsten solution, does not form, and that the fracture toughness of Fe{sub 2}B increases first and then decreases, while the hardness increases first and then has a little change. Compared with the fracture toughness (3.8 MPa{center_dot}m{sup 1/2}) of Fe{sub 2}B without tungsten addition, the toughness at 2.04 wt.% tungsten can be improved by about above 80% and achieves about 6.9 MPa{center_dot}m{sup 1/2}, and variation characteristics of hardness and toughness of Fe{sub 2}B were also testified by viewing the indentation marks and cracks on the Fe{sub 2}B, respectively. - Highlights: Black-Right-Pointing-Pointer Poor toughness of Fe2B decreases obviously the wear resistance of the alloy. Black-Right-Pointing-Pointer As W content increases, Fe2B's toughness increases first and then decreases. Black-Right-Pointing-Pointer As W content increases, Fe2B's hardness first increases and then has little change. Black-Right-Pointing-Pointer The toughness at 2.04 % W can be improved by above 80% more than that at 0% W.

Huang, Zhifu, E-mail: hzf@mail.xjtu.edu.cn; Xing, Jiandong; Lv, Liangliang

2013-01-15T23:59:59.000Z

76

Observational Evidence for Black Holes  

E-Print Network [OSTI]

Astronomers have discovered two populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with masses in the range 10^6 to 10^{10} solar masses, one each in the nucleus of every galaxy. There is strong circumstantial evidence that all these objects are true black holes with event horizons. The measured masses of supermassive black hole are strongly correlated with properties of their host galaxies, suggesting that these black holes, although extremely small in size, have a strong influence on the formation and evolution of entire galaxies. Spin parameters have recently been measured for a handful of black holes. Based on the data, there is an indication that the kinetic power of at least one class of relativistic jet ejected from accreting black holes may be correlated with black hole spin. If verified, it would suggest that these jets are powered by a generalized Penrose process mediated by magnetic fields.

Ramesh Narayan; Jeffrey E. McClintock

2014-07-20T23:59:59.000Z

77

Why Blue-Collar Blacks Help Less  

E-Print Network [OSTI]

In Hispanics in the Why Blacks Help Less U.S. Economy, eds.71(1):42-71. Why Blacks Help Less Fernandez, Roberto M. andProblems 49 (1): 11- Why Blacks Help Less Heflin, Coleen M.

Smith, Sandra Susan; Young, Kara Alexis

2013-01-01T23:59:59.000Z

78

Black-white asymmetry in visual perception  

E-Print Network [OSTI]

tion of black and white in human vision. Investi- gativeneural responses to black and white ments are balanced, weand observers. The black– white asymmetry with a ¼ 1.28 is

Lu, Z.-L.; Sperling, G.

2012-01-01T23:59:59.000Z

79

Why Blue-Collar Blacks Help Less  

E-Print Network [OSTI]

Exclude Black Men from Blue-Collar Jobs. Berkeley, CA:How Black and Latino Blue Collar Workers Make Decisionsof Sample Respondents Blue-Collar Latinos Blue-Collar Black

Smith, Sandra Susan; Young, Kara Alexis

2013-01-01T23:59:59.000Z

80

RHIC | Black Holes?  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar HomePromising Science for1 20115, 2001 MediaBrookhavenBlack Holes at

Note: This page contains sample records for the topic "hard black lustrous" 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

ARM - Black Forest News  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies |NovemberARMContactsARM Engineering6,GermanyBlack Forest News

82

RHIC | Black Holes?  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, and 323 K.Office ofMayPVREPORTPortalPriceA/4Black

83

Black Stars and Gamma Ray Bursts  

E-Print Network [OSTI]

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

Tanmay Vachaspati

2007-06-08T23:59:59.000Z

84

Black hole entanglement entropy regularized in a freely falling frame  

E-Print Network [OSTI]

We compute the black hole horizon entanglement entropy S_E for a massless scalar field, first with a hard cutoff and then with high frequency dispersion, both imposed in a frame that falls freely across the horizon. Using WKB methods, we find that S_E is finite for a hard cutoff or super-luminal dispersion, because the mode oscillations do not diverge at the horizon and the contribution of high transverse momenta is cut off by the angular momentum barrier. For sub-luminal dispersion the entropy depends on the behavior at arbitrarily high transverse momenta. In all cases it scales with the horizon area. For the hard cutoff it is linear in the cutoff, rather than quadratic. This discrepancy from the familiar result arises from the difference between the free-fall frame and the static frame in which a cutoff is usually imposed. In the super-luminal case the entropy scales with a fractional power of the cutoff that depends on the index of the dispersion relation. Implications for the possible relation between regularized entanglement entropy and the Bekenstein-Hawking entropy are discussed.

Ted Jacobson; Renaud Parentani

2007-07-09T23:59:59.000Z

85

Effect of Nd:YAG laser welding on microstructure and hardness of an Al-Li based alloy  

SciTech Connect (OSTI)

Butt joints of 3.0 mm thick sheets of an Al-Li based alloy have been produced using Nd:YAG laser welding without filler metals. The hardness distribution and microstructure of the alloy and welded joints were investigated. The changes in the grain shapes, grain orientations, microtexture, and precipitates of the fusion zone were analyzed using optical microscope, electron back scattered diffraction (EBSD) and transmission electron microscopy (TEM). The results show that Nd:YAG laser welding leads to a change of the microhardness, grain shape, grain orientations, and a disappearance of the microtexture and precipitates. A narrow band of EQZ along the fusion boundary and a predominantly equiaxed dendritic structure are developed in the fusion zone. The formation of the predominately equiaxed dendritic grains is due to a heterogeneous nucleation mechanism aided by equilibrium A1{sub 3}Zr phases as well as the growth of pre-existing nuclei created by dendrite fragmentation, or by grain detachment resulted from Nd:YAG laser welding processes. In addition, Nd:YAG laser welding produces lower Vickers hardness than that of the base metal due to the decrease in the in quantity of {delta} Prime precipitates in the fusion zone. - Graphical Abstract: The grain shapes, grain orientations, microtexture, and precipitates of the solidified fusion zone were investigated and compared with the base metal using optical microscope, electron back scattered diffraction (EBSD) and transmission electron microscope (TEM). EBSD orientation map of laser welded joint in 5A90 alloys is presented in Fig. 3. It clearly shows that a narrow band EQZ along the fusion boundary and the predominantly equiaxed grains have been developed in the fusion zone of 5A90 alloys. Also, it is clear that the microstructure of the base metal is characterized by laminated grains with preferred orientations, whereas the fusion zone is predominately equiaxed grains in different colors having random orientations. Highlights: Black-Right-Pointing-Pointer The predominantly equiaxed dendritic structure is developed in the fusion zone. Black-Right-Pointing-Pointer The fusion zone with equiaxed grains shows random orientations and microtexture. Black-Right-Pointing-Pointer The loss in hardness in the fusion zone is due to the decrease in {delta} Prime precipitates. Black-Right-Pointing-Pointer The non-epitaxial growth occurs at fusion boundary. Black-Right-Pointing-Pointer The equilibrium A1{sub 3}Zr phases maybe the nuclei of new grains in the fusion zone.

Cui, Li, E-mail: cuili@bjut.edu.cn [Beijing University of Technology (China)] [Beijing University of Technology (China); Li, Xiaoyan, E-mail: xyli@bjut.edu.cn [Beijing University of Technology (China)] [Beijing University of Technology (China); He, Dingyong, E-mail: dyhe@bjut.edu.cn [Beijing University of Technology (China)] [Beijing University of Technology (China); Chen, Li, E-mail: ouchenxi@163.com [AVIC Beijing Aeronautical Manufacturing Technology Research Institute (China)] [AVIC Beijing Aeronautical Manufacturing Technology Research Institute (China); Gong, Shuili, E-mail: gongshuili@sina.com [AVIC Beijing Aeronautical Manufacturing Technology Research Institute (China)] [AVIC Beijing Aeronautical Manufacturing Technology Research Institute (China)

2012-09-15T23:59:59.000Z

86

Magnetized Hypermassive Neutron Star Collapse: a candidate central engine for short-hard GRBs  

E-Print Network [OSTI]

Hypermassive neutron stars (HMNSs) are equilibrium configurations supported against collapse by rapid differential rotation and likely form as transient remnants of binary neutron star mergers. Though HMNSs are dynamically stable, secular effects such as viscosity or magnetic fields tend to bring HMNSs into uniform rotation and thus lead to collapse. We simulate the evolution of magnetized HMNSs in axisymmetry using codes which solve the Einstein-Maxwell-MHD system of equations. We find that magnetic braking and the magnetorotational instability (MRI) both contribute to the eventual collapse of HMNSs to rotating black holes surrounded by massive, hot accretion tori and collimated magnetic fields. Such hot tori radiate strongly in neutrinos, and the resulting neutrino-antineutrino annihilation could power short-hard GRBs.

Branson C. Stephens; Matthew D. Duez; Yuk Tung Liu; Stuart L. Shapiro; Masaru Shibta

2007-02-02T23:59:59.000Z

87

Optical black holes and solitons  

E-Print Network [OSTI]

We exhibit a static, cylindrically symmetric, exact solution to the Euler-Heisenberg field equations (EHFE) and prove that its effective geometry contains (optical) black holes. It is conjectured that there are also soliton solutions to the EHFE which contain black hole geometries.

Shawn Westmoreland

2010-12-21T23:59:59.000Z

88

Entropy of Lovelock Black Holes  

E-Print Network [OSTI]

A general formula for the entropy of stationary black holes in Lovelock gravity theories is obtained by integrating the first law of black hole mechanics, which is derived by Hamiltonian methods. The entropy is not simply one quarter of the surface area of the horizon, but also includes a sum of intrinsic curvature invariants integrated over a cross section of the horizon.

Ted Jacobson; Robert C. Myers

1993-05-06T23:59:59.000Z

89

Black Holes of Negative Mass  

E-Print Network [OSTI]

I demonstrate that, under certain circumstances, regions of negative energy density can undergo gravitational collapse into a black hole. The resultant exterior black hole spacetimes necessarily have negative mass and non-trivial topology. A full theory of quantum gravity, in which topology-changing processes take place, could give rise to such spacetimes.

R. B. Mann

1997-05-06T23:59:59.000Z

90

Feedback Limits Rapid Growth of Seed Black Holes at High Redshift  

E-Print Network [OSTI]

Seed black holes formed in the collapse of population III stars have been invoked to explain the presence of supermassive black holes at high redshift. It has been suggested that a seed black hole can grow up to $10^{5\\sim 6}\\sunm$ through highly super-Eddington accretion for a period of $\\sim 10^{6\\sim 7}$ yr between redshift $z=20\\sim 24$. We studied the feedback of radiation pressure, Compton heating and outflow during the seed black hole growth. It is found that its surrounding medium fueled to the seed hole is greatly heated by Compton heating. For a super-critical accretion onto a $10^3\\sunm$ seed hole, a Compton sphere (with a temperature $\\sim 10^6$K) forms in a timescale of $1.6\\times 10^3$yr so that the hole is only supplied by a rate of $10^{-3}$ Eddington limit from the Compton sphere. Beyond the Compton sphere, the kinetic feedback of the strong outflow heats the medium at large distance, this leads to a dramatical decrease of the outer Bondi accretion onto the black hole and avoid the accumulation of the matter. The highly super-critical accretion will be rapidly halted by the strong feedback. The seed black holes hardly grow up at the very early universe unless the strong feedback can be avoided.

J. -M. Wang; Y. -M. Chen; C. Hu

2005-12-17T23:59:59.000Z

91

STOCHASTIC VARIABILITY IN X-RAY EMISSION FROM THE BLACK HOLE BINARY GRS 1915+105  

SciTech Connect (OSTI)

We examine stochastic variability in the dynamics of X-ray emission from the black hole system GRS 1915+105, a strongly variable microquasar commonly used for studying relativistic jets and the physics of black hole accretion. The analysis of sample observations for 13 different states in both soft (low) and hard (high) energy bands is performed by flicker-noise spectroscopy (FNS), a phenomenological time series analysis method operating on structure functions and power spectrum estimates. We find the values of FNS parameters, including the Hurst exponent, flicker-noise parameter, and characteristic timescales, for each observation based on multiple 2500 s continuous data segments. We identify four modes of stochastic variability driven by dissipative processes that may be related to viscosity fluctuations in the accretion disk around the black hole: random (RN), power-law (1F), one-scale (1S), and two-scale (2S). The variability modes are generally the same in soft and hard energy bands of the same observation. We discuss the potential for future FNS studies of accreting black holes.

Polyakov, Yuriy S. [USPolyResearch, Ashland, PA 17921 (United States); Neilsen, Joseph [MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Timashev, Serge F., E-mail: ypolyakov@uspolyresearch.com [Karpov Institute of Physical Chemistry, Moscow 103064 (Russian Federation)

2012-06-15T23:59:59.000Z

92

Radiation Hard AlGaN Detectors and Imager  

SciTech Connect (OSTI)

Radiation hardness of AlGaN photodiodes was tested using a 65 MeV proton beam with a total proton fluence of 3x10{sup 12} protons/cm{sup 2}. AlGaN Deep UV Photodiode have extremely high radiation hardness. These new devices have mission critical applications in high energy density physics (HEDP) and space explorations. These new devices satisfy radiation hardness requirements by NIF. NSTec is developing next generation AlGaN optoelectronics and imagers.

None

2012-05-01T23:59:59.000Z

93

Hard turning micro-machine tool  

DOE Patents [OSTI]

A micro-scale apparatus for supporting a tool for hard turning comprises a base, a pivot coupled to the base, an actuator coupled to the base, and at least one member coupled to the actuator at one end and rotatably coupled to the pivot at another end. A tool mount is disposed on the at least one member. The at least one member defines a first lever arm between the pivot and the tool mount, and a second lever arm between the pivot and the actuator. The first lever arm has a length that is less than a length of the second lever arm. The actuator moves the tool mount along an arc.

DeVor, Richard E; Adair, Kurt; Kapoor, Shiv G

2013-10-22T23:59:59.000Z

94

Nanomechanics of hard films on compliant substrates.  

SciTech Connect (OSTI)

Development of flexible thin film systems for biomedical, homeland security and environmental sensing applications has increased dramatically in recent years [1,2,3,4]. These systems typically combine traditional semiconductor technology with new flexible substrates, allowing for both the high electron mobility of semiconductors and the flexibility of polymers. The devices have the ability to be easily integrated into components and show promise for advanced design concepts, ranging from innovative microelectronics to MEMS and NEMS devices. These devices often contain layers of thin polymer, ceramic and metallic films where differing properties can lead to large residual stresses [5]. As long as the films remain substrate-bonded, they may deform far beyond their freestanding counterpart. Once debonded, substrate constraint disappears leading to film failure where compressive stresses can lead to wrinkling, delamination, and buckling [6,7,8] while tensile stresses can lead to film fracture and decohesion [9,10,11]. In all cases, performance depends on film adhesion. Experimentally it is difficult to measure adhesion. It is often studied using tape [12], pull off [13,14,15], and peel tests [16,17]. More recent techniques for measuring adhesion include scratch testing [18,19,20,21], four point bending [22,23,24], indentation [25,26,27], spontaneous blisters [28,29] and stressed overlayers [7,26,30,31,32,33]. Nevertheless, sample design and test techniques must be tailored for each system. There is a large body of elastic thin film fracture and elastic contact mechanics solutions for elastic films on rigid substrates in the published literature [5,7,34,35,36]. More recent work has extended these solutions to films on compliant substrates and show that increasing compliance markedly changes fracture energies compared with rigid elastic solution results [37,38]. However, the introduction of inelastic substrate response significantly complicates the problem [10,39,40]. As a result, our understanding of the critical relationship between adhesion, properties, and fracture for hard films on compliant substrates is limited. To address this issue, we integrated nanomechanical testing and mechanics-based modeling in a program to define the critical relationship between deformation and fracture of nanoscale films on compliant substrates. The approach involved designing model film systems and employing nano-scale experimental characterization techniques to isolate effects of compliance, viscoelasticity, and plasticity on deformation and fracture of thin hard films on substrates that spanned more than two orders of compliance magnitude exhibit different interface structures, have different adhesion strengths, and function differently under stress. The results of this work are described in six chapters. Chapter 1 provides the motivation for this work. Chapter 2 presents experimental results covering film system design, sample preparation, indentation response, and fracture including discussion on the effects of substrate compliance on fracture energies and buckle formation from existing models. Chapter 3 describes the use of analytical and finite element simulations to define the role of substrate compliance and film geometry on the indentation response of thin hard films on compliant substrates. Chapter 4 describes the development and application of cohesive zone model based finite element simulations to determine how substrate compliance affects debond growth. Chapter 5 describes the use of molecular dynamics simulations to define the effects of substrate compliance on interfacial fracture of thin hard tungsten films on silicon substrates. Chapter 6 describes the Workshops sponsored through this program to advance understanding of material and system behavior.

Reedy, Earl David, Jr. (Sandia National Laboratories, Albuquerque, NM); Emerson, John Allen (Sandia National Laboratories, Albuquerque, NM); Bahr, David F. (Washington State University, Pullman, WA); Moody, Neville Reid; Zhou, Xiao Wang; Hales, Lucas (University of Minnesota, Minneapolis, MN); Adams, David Price (Sandia National Laboratories, Albuquerque, NM); Yeager,John (Washington State University, Pullman, WA); Nyugen, Thao D. (Johns Hopkins University, Baltimore, MD); Corona, Edmundo (Sandia National Laboratories, Albuquerque, NM); Kennedy, Marian S. (Clemson University, Clemson, SC); Cordill, Megan J. (Erich Schmid Institute, Leoben, Austria)

2009-09-01T23:59:59.000Z

95

Shock compression synthesis of hard materials  

SciTech Connect (OSTI)

The purpose of this research was to adapt the high explosives technology that was developed in conjunction with nuclear weapons programs to subjecting materials to ultra-high pressures and to explore the utility of this technique for the synthesis of hard materials. The research was conducted in collaboration with researchers at the University of Texas, Texas Tech University and Pantex (Mason and Hanger Corp.). The group designed, modeled, built, and tested a new device that allows quantitative recovery of grams of material that have been subjected to unprecedented pressures. The modeling work was done at Texas Tech and Pantex. The metal parts and material samples were made at the University of Texas, and Pantex machined the explosives, assembled the devices and conducted the detonations. Sample characterization was carried out at the University of Texas and Texas Tech.

Willson, C.G. [Univ. of Texas, Austin, TX (United States). Dept. of Chemistry

1999-03-01T23:59:59.000Z

96

amorphous hard carbon: Topics by E-print Network  

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

in hard and elastic amorphous carbon nitride films investigated H NMR spectroscopy Materials Science Websites Summary: Received 14 February 2003; published 5 November 2003 The...

97

EXIST A High Sensitivity Hard X-ray Imaging Sky Survey Mission for ISS  

E-Print Network [OSTI]

A deep all-sky imaging hard x-ray survey and wide-field monitor is needed to extend soft (ROSAT) and medium (ABRIXAS2) x-ray surveys into the 10-100 keV band (and beyond) at comparable sensitivity (~0.05 mCrab). This would enable discovery and study of >3000 obscured AGN, which probably dominate the hard x-ray background; detailed study of spectra and variability of accreting black holes and a census of BHs in the Galaxy; Gamma-ray bursts and associated massive star formation (PopIII) at very high redshift and Soft Gamma-ray Repeaters throughout the Local Group; and a full galactic survey for obscured supernova remnants. The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed array of 8 x 1m^2 coded aperture telescopes fixed on the International Space Station (ISS) with 160deg x 40deg field of view which images the full sky each 90 min orbit. EXIST has been included in the most recent NASA Strategic Plan as a candidate mission for the next decade. An overview of the science goals and mission concep...

Grindlay, J; Chakraborty, D; Elvis, M; Fabian, A C; Fiore, F; Gehrels, N; Hailey, C J; Harrison, F; Hartmann, D; Prince, T A; Ramsey, B; Rothschild, R; Skinner, G K; Woosley, S

1999-01-01T23:59:59.000Z

98

Integral detection of hard X-ray emission from the Galactic nuclear region  

E-Print Network [OSTI]

This letter presents the first results of an observational campaign to study the Galactic Centre with INTEGRAL. The mosaicked images obtained with the IBIS/ISGRI coded aperture instrument in the energy ranges 20-40 and 40-100 keV, give a yet unseen view of the high-energy sources of this region in hard X- and gamma-rays with an angular resolution of 12 arcmin (FWHM). We report on the discovery of a source, IGR J17456-2901, coincident with the Galactic Nucleus SgrA* to within 0.9 arcmin. Located at R.A.(J2000.0) = 17h45m38.5s, Dec.(J2000.0) = -29:01:15, the source is visible up to about 100 keV with a 20-100 keV luminosity at 8 kpc of (2.89 +/- 0.41) x 10^35 ergs/s. Although the new INTEGRAL source cannot unequivocally be associated to the Galactic Nucleus, this is the first report of significant hard X-ray emission from within the inner 10 arcming of the Galaxy and a contribution from the galactic supermassive black hole itself cannot be excluded.

Bélanger, G; Goldoni, P; Paul, J; Terrier, R; Falanga, M; Ubertini, P; Bazano, A; Santo, M D; Winkler, C; Parmar, A N; Kuulkers, E; Ebisawa, K; Roques, J P; Lund, N; Melia, F

2004-01-01T23:59:59.000Z

99

Black optic display  

DOE Patents [OSTI]

An optical display includes a plurality of stacked optical waveguides having first and second opposite ends collectively defining an image input face and an image screen, respectively, with the screen being oblique to the input face. Each of the waveguides includes a transparent core bound by a cladding layer having a lower index of refraction for effecting internal reflection of image light transmitted into the input face to project an image on the screen, with each of the cladding layers including a cladding cap integrally joined thereto at the waveguide second ends. Each of the cores is beveled at the waveguide second end so that the cladding cap is viewable through the transparent core. Each of the cladding caps is black for absorbing external ambient light incident upon the screen for improving contrast of the image projected internally on the screen.

Veligdan, James T. (Manorville, NY)

1997-01-01T23:59:59.000Z

100

The Simplified Partial Digest Problem: Hardness and a Probabilistic Analysis  

E-Print Network [OSTI]

The Simplified Partial Digest Problem: Hardness and a Probabilistic Analysis Zoë Abrams1 and Ho site locations of the enzyme. Two common approaches are the Double Digest Problem and the Partial Digest Problem. The Double Digest Problem is known to be NP-Complete[4], but the hardness of the Partial

Pratt, Vaughan

Note: This page contains sample records for the topic "hard black lustrous" 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

Thermodynamics of regular black hole  

E-Print Network [OSTI]

We investigate thermodynamics for a magnetically charged regular black hole (MCRBH), which comes from the action of general relativity and nonlinear electromagnetics, comparing with the Reissner-Norstr\\"om (RN) black hole in both four and two dimensions after dimensional reduction. We find that there is no thermodynamic difference between the regular and RN black holes for a fixed charge $Q$ in both dimensions. This means that the condition for either singularity or regularity at the origin of coordinate does not affect the thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$ thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim theory. We also identify the near-horizon entropy as the statistical entropy by using the AdS$_2$/CFT$_1$ correspondence.

Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

2008-09-21T23:59:59.000Z

102

Black Hole Interior Mass Formula  

E-Print Network [OSTI]

We argue by explicit computations that, although the area product, horizon radii product, entropy product and \\emph {irreducible mass product} of the event horizon and Cauchy horizon are universal, the \\emph{surface gravity product}, \\emph{surface temperature product} and \\emph{Komar energy product} of the said horizons do not seem to be universal for Kerr-Newman (KN) black hole space-time. We show the black hole mass formula on the \\emph{Cauchy horizon} following the seminal work by Smarr\\cite{smarr} for the outer horizon. We also prescribed the \\emph{four} laws of black hole mechanics for the \\emph{inner horizon}. New definition of the extremal limit of a black hole is discussed.

Parthapratim Pradhan

2014-05-06T23:59:59.000Z

103

Lattice Black Holes  

E-Print Network [OSTI]

We study the Hawking process on lattices falling into static black holes. The motivation is to understand how the outgoing modes and Hawking radiation can arise in a setting with a strict short distance cutoff in the free-fall frame. We employ two-dimensional free scalar field theory. For a falling lattice with a discrete time-translation symmetry we use analytical methods to establish that, for Killing frequency $\\omega$ and surface gravity $\\kappa$ satisfying $\\kappa\\ll\\omega^{1/3}\\ll 1$ in lattice units, the continuum Hawking spectrum is recovered. The low frequency outgoing modes arise from exotic ingoing modes with large proper wavevectors that "refract" off the horizon. In this model with time translation symmetry the proper lattice spacing goes to zero at spatial infinity. We also consider instead falling lattices whose proper lattice spacing is constant at infinity and therefore grows with time at any finite radius. This violation of time translation symmetry is visible only at wavelengths comparable to the lattice spacing, and it is responsible for transmuting ingoing high Killing frequency modes into low frequency outgoing modes.

Steven Corley; Ted Jacobson

1998-03-26T23:59:59.000Z

104

Fishing in Black Holes  

E-Print Network [OSTI]

The coordinate system $(\\bar{x},\\bar{t})$ defined by $r = 2m + K\\bar{x}- c K \\bar{t}$ and $t=\\bar{x}/cK - 1 /cK \\int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \\[ds^2=c^2 d\\bar{t}^2 + (W^2/K^2 - 2W/K) d\\bar{x}^2 + 2c (1 + W/K) d\\bar{x}d\\bar{t} - r^2 (d\\theta^2 + cos^2\\theta d\\phi^2)\\] with $W=(1 - 2m/r + K^2)^{1/2}$, in which the coefficients' pathologies are moved to $r_K = 2m/(1+K^2)$. This new coordinate system is used to study the entrance into a black hole of a rigid line (a line in which the shock waves propagate with velocity c).

A. Brotas

2006-09-01T23:59:59.000Z

105

Red-Black Trees 1 2004 Goodrich, Tamassia Red-Black Trees  

E-Print Network [OSTI]

Red-Black Trees 1© 2004 Goodrich, Tamassia Red-Black Trees 6 3 8 4 v z #12;Red-Black Trees 2© 2004 Goodrich, Tamassia From (2,4) to Red-Black Trees A red-black tree is a representation of a (2,4) tree by means of a binary tree whose nodes are colored red or black In comparison with its associated (2,4) tree

Alechina, Natasha

106

Kraft black liquor delivery systems  

SciTech Connect (OSTI)

Improvement of spray nozzles for black liquor injection into kraft recovery furnaces is expected to result from obtaining a controlled, well-defined droplet size distribution. Work this year has centered on defining the capabilities of commercial black liquor nozzles currently in use. Considerations of the observed mechanism of droplet formation suggest a major revision is needed in the theory of how droplets form from these nozzles. High resolution, high sensitivity video has been shown to be superior to flash x-ray as a technique for measuring the droplet size distribution as well as the formation history. An environmentally sound spray facility capable of spraying black liquor at temperatures up to normal firing conditions is being constructed before data acquisition continues. Preliminary correlations have been developed between liquor properties, nozzle design, and droplet size. Three aspects of nozzle design have been investigated: droplet size distribution, fluid sheet thickness, and flow and pressure drop characteristics. The standard deviation about the median droplet size for black liquor is nearly the same as the for a wide variety of other fluids and nozzle types. Preliminary correlation for fluid sheet thickness on the plate of a splashplate nozzle show the strong similarities of black liquor to other fluids. The flow and pressure drop characteristic of black liquor nozzle, follow a simple two-term relationship similar to other flow devices. This means that in routine mill operation of black liquor nozzles only the fluid acceleration in the nozzle is important, viscous losses are quiet small. 21 refs., 53 figs., 10 tabs.

Adams, T.N.; Empie, H.L.; Obuskovic, N.; Spielbauer, T.M.

1990-02-01T23:59:59.000Z

107

Pool resolution is NP-hard to recognize  

E-Print Network [OSTI]

2004) 5. Buss, S.R. , Hoffmann, J. : The NP-hardness of ?276 (2008) 6. Buss, S.R. , Hoffmann, J. , Johannsen, J. :Article 13 (2008) 7. Hoffmann, J. : Finding a tree structure

Buss, Samuel R.

2009-01-01T23:59:59.000Z

108

Innovation incentives and competition in the hard disk drive industry  

E-Print Network [OSTI]

Firms in the hard disk drive industry are continually engaging in R & D and improving the quality of their products. We explore various determinants of the product innovation incentives for firms concerned with both their ...

Wu, Xiaohua Sherry

2011-01-01T23:59:59.000Z

109

Improving the polishing process for Rockwell hardness test block  

E-Print Network [OSTI]

Inefficiencies in a Rockwell hardness test block manufacturing process were analyzed. The polishing stage was identified to be the bottleneck with a high reworking rate. An understanding based on the physics of polishing ...

Imani Nejad, Mohammad

2009-01-01T23:59:59.000Z

110

Why Are Bad Products So Hard to Kill?  

E-Print Network [OSTI]

It is puzzling that firms often continue to invest in product development projects when they should know that demand will be low. We argue that bad products are hard to kill because firms face an inherent conflict when ...

Simester, Duncan

111

On the Hardness of Optimal Auctions (Extended Abstract)  

E-Print Network [OSTI]

On the Hardness of Optimal Auctions (Extended Abstract) Amir Ronen #3; Amin Saberi y Abstract We Berkeley. Email: saberi@cc.gatech.edu. problem which is perhaps the most basic in optimal auction design

Saberi, Amin

112

How to estimate hardness of crystals on a pocket calculator  

SciTech Connect (OSTI)

A generalization of the semiempirical microscopic model of hardness is presented and applied to currently studied borides, carbides, and nitrides of heavy transition metals. The hardness of OsB, OsC, OsN, PtN, RuC, RuB{sub 2}, ReB{sub 2}, OsB{sub 2}, IrN{sub 2}, PtN{sub 2}, and OsN{sub 2} crystals in various structural phases is predicted. It is found that none of the transition metal crystals is superhard, i.e., with hardness greater than 40 GPa. The presented method provides materials researchers with a practical tool in the search for new hard materials.

Simunek, Antonin [Institute of Physics v.v.i., Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague (Czech Republic)

2007-05-01T23:59:59.000Z

113

Soft Pion Emission in Hard Exclusive Pion Production  

E-Print Network [OSTI]

We investigate hard exclusive reactions on the nucleon with soft pion emission. A parametrization of corresponding hadronic matrix elements in terms of parton distributions for final pion-nucleon state is provided. These distributions are calculated in terms of nucleon and pion GPDs and the pion distribution amplitude via soft-pion theorems. Some observables for the process of hard charged pion production on the proton with soft pion emission are computed.

Maxim V. Polyakov; Simone Stratmann

2006-09-05T23:59:59.000Z

114

Energy on black hole spacetimes  

E-Print Network [OSTI]

We consider the issue of defining energy for test particles on a background black hole spacetime. We revisit the different notions of energy as defined by different observers. The existence of a time-like isometry allows for the notion of a total conserved energy to be well defined, and subsequently the notion of a gravitational potential energy is also meaningful. We then consider the situation in which the test particle is adsorbed by the black hole, and analyze the energetics in detail. In particular, we show that the notion of horizon energy es defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle's conserved energy. As another example, we comment a recent proposal to define energy of the black hole as seen by an observer at rest. This account is intended to be pedagogical and is aimed at the level of and as a complement to the standard textbooks on the subject.

Alejandro Corichi

2012-07-18T23:59:59.000Z

115

Call for Papers and Panels Unleashing the Black Erotic  

E-Print Network [OSTI]

and the Hypersexuality of Black Women Alternative Modes of Black Love and Family The Politics and Economics of Porn

Kunkle, Tom

116

Black Hills Energy- Solar Power Program  

Broader source: Energy.gov [DOE]

Black Hills Energy has a performance-based incentive (PBI) for photovoltaic (PV) systems up to 100 kilowatts (kW) in capacity. In exchange for these incentives, Black Hills Energy earns the right...

117

Black Literary Suite: Kansas Authors Edition  

E-Print Network [OSTI]

authors were born or lived in the Sunflower State, and their work often reflects their time in Kansas. This Black Literary Suite exhibit highlights four important black writers—Langston Hughes, Gwendolyn Brooks, Frank Marshall Davis, and Kevin Young...

Wiggins, Meredith Joan

2015-03-04T23:59:59.000Z

118

Black brane entropy and hydrodynamics  

SciTech Connect (OSTI)

Recent advances in holography have led to the formulation of fluid-gravity duality, a remarkable connection between the hydrodynamics of certain strongly coupled media and dynamics of higher dimensional black holes. This paper introduces a correspondence between phenomenologically defined entropy currents in relativistic hydrodynamics and 'generalized horizons' of near-equilibrium black objects in a dual gravitational description. A general formula is given, expressing the divergence of the entropy current in terms of geometric objects which appear naturally in the gravity dual geometry. The proposed definition is explicitly covariant with respect to boundary diffeomorphisms and reproduces known results when evaluated for the event horizon.

Booth, Ivan; Heller, Michal P.; Spalinski, Michal [Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, A1C 5S7 (Canada); Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland) and Physics Department, University of Bialystok, 15-424 Bialystok (Poland)

2011-03-15T23:59:59.000Z

119

Hawking Emission and Black Hole Thermodynamics  

E-Print Network [OSTI]

A brief review of Hawking radiation and black hole thermodynamics is given, based largely upon hep-th/0409024.

Don N. Page

2006-12-18T23:59:59.000Z

120

On the nature of black hole entropy  

E-Print Network [OSTI]

I argue that black hole entropy counts only those states of a black hole that can influence the outside, and attempt (with only partial success) to defend this claim against various objections, all but one coming from string theory. Implications for the nature of the Bekenstein bound are discussed, and in particular the case for a holographic principle is challenged. Finally, a generalization of black hole thermodynamics to "partial event horizons" in general spacetimes without black holes is proposed.

Ted Jacobson

2000-01-13T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

6, 34193463, 2006 Black carbon or  

E-Print Network [OSTI]

ACPD 6, 3419­3463, 2006 Black carbon or brown carbon M. O. Andreae and A. Gelencs´er Title Page Chemistry and Physics Discussions Black carbon or brown carbon? The nature of light-absorbing carbonaceous;ACPD 6, 3419­3463, 2006 Black carbon or brown carbon M. O. Andreae and A. Gelencs´er Title Page

Paris-Sud XI, Université de

122

White holes and eternal black holes  

E-Print Network [OSTI]

We investigate isolated white holes surrounded by vacuum, which correspond to the time reversal of eternal black holes that do not evaporate. We show that isolated white holes produce quasi- thermal Hawking radiation. The time reversal of this radiation, incident on a black hole precursor, constitutes a special preparation that will cause the black hole to become eternal.

Stephen D. H. Hsu

2011-11-16T23:59:59.000Z

123

Conservation Assessment for Bloodroot in the Black  

E-Print Network [OSTI]

Conservation Assessment for Bloodroot in the Black Hills National Forest, South Dakota and Wyoming Forest Service Rocky Mountain Region Black Hills National Forest Custer, South Dakota April 2003 #12;Species Assessment of Bloodroot in the Black Hills National Forest, South Dakota and Wyoming J. Hope

124

Absorption cross section in Lifshitz black hole  

E-Print Network [OSTI]

We derive the absorption cross section of a minimally coupled scalar in the Lifshitz black hole obtained from the new massive gravity. The absorption cross section reduces to the horizon area in the low energy and massless limit of s-wave mode propagation, indicating that the Lifshitz black hole also satisfies the universality of low energy absorption cross section for black holes.

Taeyoon Moon; Yun Soo Myung

2012-10-05T23:59:59.000Z

125

Donald Byrne (white) vs. Robert James "Bobby" Fischer (black) 1956 White Black  

E-Print Network [OSTI]

Donald Byrne (white) vs. Robert James "Bobby" Fischer (black) 1956 White Black 1. Nf3 Nf6 comments here are called "annotation" 2. c4 g6 3. Nc3 Bg7 black bishop sits on long diagonal 4. d4 0-0 white black threatens the queen 7. Qxc4 c6 8. e4 Nbd7 black's knight on b moves to d7 9. Rd1 Nb6 white's rook

Zirbel, Craig L.

126

Proceedings of the Tungsten Workshop for Hard Target Weapons Program  

SciTech Connect (OSTI)

The purpose of this meeting was to review and exchange information and provide technical input for improving technologies relevant to the Hard Target Weapons Program. This workshop was attended by representatives from 17 organizations, including 4 Department of Defense (DoD) agencies, 8 industrial companies, and 5 laboratories within DOE. Hard targets are defined as reinforced underground structures that house enemy forces, weapon systems, and support equipment. DOE-ORO and Martin Marietta Energy Systems, Inc. (Energy Systems) have been involved in advanced materials research and development (R&D) for several DOE and DoD programs. These programs are conducted in close collaboration with Eglin AFB, Department of the Army`s Picatinny Arsenal, and other DoD agencies. As part of this ongoing collaboration, Eglin AFB and Oak Ridge National Laboratory planned and conducted this workshop to support the Hard Target Weapons Program. The objectives of this workshop were to (1) review and identify the technology base that exists (primarily due to anti-armor applications) and assess the applicability of this technology to the Hard Target Weapons Program requirements; (2) determine future directions to establish the W materials, processing, and manufacturing technologies suitable for use in fixed, hard target penetrators; and (3) identify and prioritize the potential areas for technical collaboration among the participants.

Mackiewicz-Ludtka, G.; Hayden, H.W.; Davis, R.M.

1995-06-01T23:59:59.000Z

127

Black Hole Evaporation as a Nonequilibrium Process  

E-Print Network [OSTI]

When a black hole evaporates, there arises a net energy flow from the black hole into its outside environment due to the Hawking radiation and the energy accretion onto black hole. Exactly speaking, due to the net energy flow, the black hole evaporation is a nonequilibrium process. To study details of evaporation process, nonequilibrium effects of the net energy flow should be taken into account. In this article we simplify the situation so that the Hawking radiation consists of non-self-interacting massless matter fields and also the energy accretion onto the black hole consists of the same fields. Then we find that the nonequilibrium nature of black hole evaporation is described by a nonequilibrium state of that field, and we formulate nonequilibrium thermodynamics of non-self-interacting massless fields. By applying it to black hole evaporation, followings are shown: (1) Nonequilibrium effects of the energy flow tends to accelerate the black hole evaporation, and, consequently, a specific nonequilibrium phenomenon of semi-classical black hole evaporation is suggested. Furthermore a suggestion about the end state of quantum size black hole evaporation is proposed in the context of information loss paradox. (2) Negative heat capacity of black hole is the physical essence of the generalized second law of black hole thermodynamics, and self-entropy production inside the matter around black hole is not necessary to ensure the generalized second law. Furthermore a lower bound for total entropy at the end of black hole evaporation is given. A relation of the lower bound with the so-called covariant entropy bound conjecture is interesting but left as an open issue.

Hiromi Saida

2008-11-11T23:59:59.000Z

128

BSW process of the slowly evaporating charged black hole  

E-Print Network [OSTI]

In this paper, we study the BSW process of the slowly evaporating charged black hole. It can be found that the BSW process will also arise near black hole horizon when the evaporation of charged black hole is very slow. But now the background black hole does not have to be an extremal black hole, and it will be approximately an extremal black hole unless it is nearly a huge stationary black hole.

Liancheng Wang; Feng He; Xiangyun Fu

2015-02-09T23:59:59.000Z

129

Free volume distribution of nearly jammed hard sphere packings  

E-Print Network [OSTI]

We calculate the free volume distributions of nearly jammed packings of monodisperse and bidisperse hard sphere configurations. These distributions differ qualitatively from those of the fluid, displaying a power law tail at large free volumes, which constitutes a distinct signature of nearly jammed configurations, persisting for moderate degrees of decompression. We reproduce and explain the observed distribution by considering the pair correlation function within the first coordination shell for jammed hard sphere configurations. We analyze features of the equation of state near jamming, and discuss the significance of observed asphericities of the free volumes to the equation of state.

Moumita Maiti; Srikanth Sastry

2014-07-25T23:59:59.000Z

130

Vacancy-stabilized crystalline order in hard cubes  

E-Print Network [OSTI]

We examine the effect of vacancies on the phase behavior and structure of systems consisting of hard cubes using event-driven molecular dynamics and Monte Carlo simulations. We find a first-order phase transition between a fluid and a simple cubic crystal phase that is stabilized by a surprisingly large number of vacancies, reaching a net vacancy concentration of ~6.4% near bulk coexistence. Remarkably, we find that vacancies increase the positional order in the system. Finally, we show that the vacancies are delocalized and therefore hard to detect.

Frank Smallenburg; Laura Filion; Matthieu Marechal; Marjolein Dijkstra

2012-09-16T23:59:59.000Z

131

Wide Field Hard X-ray Survey Telescope: ProtoEXIST1  

E-Print Network [OSTI]

We report our progress on the development of pixellated imaging CZT detector arrays for our first-generation balloon-borne wide-field hard X-ray (20 - 600 keV) telescope, ProtoEXIST1. Our ProtoEXIST program is a pathfinder for the High Energy Telescope (HET) on the Energetic X-ray Imaging Survey telescope (EXIST), a proposed implementation of the Black Hole Finder Probe. ProtoEXIST1 consists of four independent coded-aperture telescopes with close-tiled (~0.4 mm gaps) CZT detectors that preserve their 2.5mm pixel pitch. Multiple shielding/field-of-view configurations are planned to identify optimal geometry for the HET in EXIST. The primary technical challenge in ProtoEXIST is the development of large area, close-tiled modules of imaging CZT detectors (1000 cm2 for ProtoEXIST1), with all readout and control systems for the ASIC readout vertically stacked. We describe the overall telescope configuration of ProtoEXIST1 and review the current development status of the CZT detectors, from individual detector crys...

Hong, J; Chammas, N; Allen, B; Copete, A; Said, B; Burke, M; Howell, J; Gauron, T; Baker, R G; Barthelmy, S D; Sheikh, S; Gehrels, N; Cook, W R; Burnham, J A; Harrison, F A; Collins, J; Labov, S; Garson, A; Krawczynski, H

2007-01-01T23:59:59.000Z

132

Origin of black string instability  

SciTech Connect (OSTI)

It is argued that many nonextremal black branes exhibit a classical Gregory-Laflamme (GL) instability. Why does the universal instability exist? To find an answer to this question and explore other possible instabilities, we study stability of black strings for all possible types of gravitational perturbation. The perturbations are classified into tensor-, vector-, and scalar-types, according to their behavior on the spherical section of the background metric. The vector and scalar perturbations have exceptional multipole moments, and we have paid particular attention to them. It is shown that for each type of perturbations there is no normalizable negative (unstable) modes, apart from the exceptional mode known as s-wave perturbation which is exactly the GL mode. We discuss the origin of instability and comment on the implication for the correlated-stability conjecture.

Kudoh, Hideaki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2006-05-15T23:59:59.000Z

133

Accelerating and rotating black holes  

E-Print Network [OSTI]

An exact solution of Einstein's equations which represents a pair of accelerating and rotating black holes (a generalised form of the spinning C-metric) is presented. The starting point is a form of the Plebanski-Demianski metric which, in addition to the usual parameters, explicitly includes parameters which describe the acceleration and angular velocity of the sources. This is transformed to a form which explicitly contains the known special cases for either rotating or accelerating black holes. Electromagnetic charges and a NUT parameter are included, the relation between the NUT parameter $l$ and the Plebanski-Demianski parameter $n$ is given, and the physical meaning of all parameters is clarified. The possibility of finding an accelerating NUT solution is also discussed.

J. B. Griffiths; J. Podolsky

2005-07-06T23:59:59.000Z

134

Charged spinning black holes as particle accelerators  

SciTech Connect (OSTI)

It has recently been pointed out that the spinning Kerr black hole with maximal spin could act as a particle collider with arbitrarily high center-of-mass energy. In this paper, we will extend the result to the charged spinning black hole, the Kerr-Newman black hole. The center-of-mass energy of collision for two uncharged particles falling freely from rest at infinity depends not only on the spin a but also on the charge Q of the black hole. We find that an unlimited center-of-mass energy can be approached with the conditions: (1) the collision takes place at the horizon of an extremal black hole; (2) one of the colliding particles has critical angular momentum; (3) the spin a of the extremal black hole satisfies (1/{radical}(3)){<=}(a/M){<=}1, where M is the mass of the Kerr-Newman black hole. The third condition implies that to obtain an arbitrarily high energy, the extremal Kerr-Newman black hole must have a large value of spin, which is a significant difference between the Kerr and Kerr-Newman black holes. Furthermore, we also show that, for a near-extremal black hole, there always exists a finite upper bound for center-of-mass energy, which decreases with the increase of the charge Q.

Wei Shaowen; Liu Yuxiao; Guo Heng; Fu Chune [Institute of Theoretical Physics, Lanzhou University, Lanzhou 730000 (China)

2010-11-15T23:59:59.000Z

135

Dave Kaminsky Charles L. Black  

E-Print Network [OSTI]

Edwin D. McKay Thomas L. McNeely Jean C. Persons Neysa P. Pickens Armant C. Touchy Jack S. Zoller 19511935 $50.00 Dave Kaminsky 1938 $200.00 Charles L. Black 1940 $50.00 Harold S. Miropol 1941 $67. Tennison Ben Thompson 1945 $250.00 Paul Finkelstein Harold J. Jacobs Lawrence Kahn 1946 $2,250.00 David W

136

Black Hole Thermodynamics and Electromagnetism  

E-Print Network [OSTI]

We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

Burra G. Sidharth

2005-07-15T23:59:59.000Z

137

ARM - Measurement - Black carbon concentration  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Related InformationAcid RainTheimagegovMeasurementsBlack carbon

138

Red-Black Trees 11/26/2007 11:09 AM Red-Black Trees 1 2004 Goodrich, Tamassia  

E-Print Network [OSTI]

Red-Black Trees 11/26/2007 11:09 AM 1 Red-Black Trees 1© 2004 Goodrich, Tamassia Red-Black Trees 6 3 8 4 v z Red-Black Trees 2© 2004 Goodrich, Tamassia From (2,4) to Red-Black Trees A red-black tree is a representation of a (2,4) tree by means of a binary tree whose nodes are colored red or black In comparison

Alechina, Natasha

139

Red-Black Trees 11/11/2004 10:02 AM Red-Black Trees 1 2004 Goodrich, Tamassia  

E-Print Network [OSTI]

Red-Black Trees 11/11/2004 10:02 AM 1 Red-Black Trees 1© 2004 Goodrich, Tamassia Red-Black Trees 6 3 8 4 v z Red-Black Trees 2© 2004 Goodrich, Tamassia From (2,4) to Red-Black Trees A red-black tree is a representation of a (2,4) tree by means of a binary tree whose nodes are colored red or black In comparison

Alechina, Natasha

140

Entanglement entropy of black holes  

E-Print Network [OSTI]

The entanglement entropy is a fundamental quantity which characterizes the correlations between sub-systems in a larger quantum-mechanical system. For two sub-systems separated by a surface the entanglement entropy is proportional to the area of the surface and depends on the UV cutoff which regulates the short-distance correlations. The geometrical nature of the entanglement entropy calculation is particularly intriguing when applied to black holes when the entangling surface is the black hole horizon. I review a variety of aspects of this calculation: the useful mathematical tools such as the geometry of spaces with conical singularities and the heat kernel method, the UV divergences in the entropy and their renormalization, the logarithmic terms in the entanglement entropy in 4 and 6 dimensions and their relation to the conformal anomalies. The focus in the review is on the systematic use of the conical singularity method. The relations to other known approaches such as 't Hooft's brick wall model and the Euclidean path integral in the optical metric are discussed in detail. The puzzling behavior of the entanglement entropy due to fields which non-minimally couple to gravity is emphasized. The holographic description of the entanglement entropy of the black hole horizon is illustrated on the two- and four-dimensional examples. Finally, I examine the possibility to interpret the Bekenstein-Hawking entropy entirely as the entanglement entropy.

Sergey N. Solodukhin

2011-04-19T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Quantum Geometry and Black Holes  

E-Print Network [OSTI]

We present an overall picture of the advances in the description of black hole physics from the perspective of loop quantum gravity. After an introduction that discusses the main conceptual issues we present some details about the classical and quantum geometry of isolated horizons and their quantum geometry and then use this scheme to give a natural definition of the entropy of black holes. The entropy computations can be neatly expressed in the form of combinatorial problems solvable with the help of methods based on number theory and the use of generating functions. The recovery of the Bekenstein-Hawking law and corrections to it is explained in some detail. After this, due attention is paid to the discussion of semiclassical issues. An important point in this respect is the proper interpretation of the horizon area as the energy that should appear in the statistical-mechanical treatment of the black hole model presented here. The chapter ends with a comparison between the microscopic and semiclassical app...

G., J Fernando Barbero

2015-01-01T23:59:59.000Z

142

Characterizing the acoustic noise generated by hard disk drives and a scheme for detecting noisy hard drives  

E-Print Network [OSTI]

of the requirements for the degree of MASTER OF SCIENCE August 1992 Major Subject: Electrical Engineering s nah7 CHARACTERIZING THE ACOUSTIC NOISE GENERATED BY HARD DISK DRIVES AND A SCHEME FOR DETECTING NOISY HARD DRIVES A Thesis by SEUK BO KIM Approved... 48 48 49 52 53 55 APPENDIX A 58 VITA LIST OF TABLES TABLE Page I Disk Drive Sample Set 16 II Subjective Human Response: Original Noise 22 IH Leq Measured by MIC1 IV Leq Measured by ACC V Leq Grouping of Tv o Sensors 24 26 26 VI...

Kim, Seuk Bo

1992-01-01T23:59:59.000Z

143

GRB 060313: A New Paradigm for Short-Hard Bursts?  

E-Print Network [OSTI]

We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray bands by the Swift-BAT and the KONUS-Wind instruments of the short-hard burst, GRB 060313. The observations reveal multiple peaks in both the gamma-ray and hard X-ray suggesting a highly variable outflow from the central explosion. We also describe the early-time observations of the X-ray and UV/Optical afterglows by the Swift XRT and UVOT instruments. The combination of the X-ray and UV/Optical observations provide the most comprehensive lightcurves to date of a short-hard burst at such an early epoch. The afterglows exhibit complex structure with different decay indices and flaring. This behavior can be explained by the combination of a structured jet, radiative loss of energy, and decreasing microphysics parameters occurring in a circum-burst medium with densities varying by a factor of approximately two on a length scale of 10^17 cm. These density variations are normally associated with the environment of a mass...

Roming, P W A; Palshin, V D; Pagani, C; Norris, J; Kumar, P; Krimm, H; Holland, S T; Gronwall, C; Blustin, A J; Zhang, B; Schady, P; Sakamoto, T; Osborne, J P; Nousek, J A; Marshall, F E; Mészáros, P; Golenetskii, S V; Gehrels, N; Frederiks, D D; Campana, S; Burrows, D N; Boyd, P T; Barthelmy, S; Aptekar, R L; Roming, Peter W. A.; Berk, Daniel Vanden; Palshin, Valentin; Pagani, Claudio; Norris, Jay; Kumar, Pawan; Krimm, Hans; Holland, Stephen T.; Gronwall, Caryl; Zhang, Bing; Schady, Patricia; Sakamoto, Takanori; Osborne, Julian P.; Nousek, John A.; Marshall, Frank E.; Meszaros, Peter; Golenetskii, Sergey V.; Gehrels, Neil; Frederiks, Dmitry D.; Campana, Sergio; Burrows, David N.; Boyd, Patricia T.; Barthelmy, Scott

2006-01-01T23:59:59.000Z

144

Educing GPDs from amplitudes of hard exclusive processes  

E-Print Network [OSTI]

The dual parametrization of generalized parton distributions (GPDs) is considered in details. We discuss which part of information about hadron structure encoded in GPDs [part of total GPD image] can be restored from the known amplitude of a hard exclusive process. The physics content of this partial image is analyzed.

M. V. Polyakov

2007-11-12T23:59:59.000Z

145

Direct Imaging of Soft-Hard Interfaces Enabled by Graphene  

E-Print Network [OSTI]

Direct Imaging of Soft-Hard Interfaces Enabled by Graphene Zonghoon Lee,*, Ki-Joon Jeon,*, Albert. We show that graphene, a single atomic layer of sp2 -bonded carbon atoms, can be employed capability. Our findings reveal the unique potential of graphene as an ideal support film for atomic

Frenklach, Michael

146

SpinybotII: Climbing Hard Walls with Compliant Microspines  

E-Print Network [OSTI]

of these approaches is suitable for porous and typically dusty exterior surfaces such as brick, concrete, stucco, hard vertical surfaces including concrete, brick, stucco and masonry without using suction or adhesives demonstrated on brick and concrete walls [11] with considerable success. However, this approach consumes

Provancher, William

147

Optimal Fractal Coding is NP-Hard1 (Extended Abstract)  

E-Print Network [OSTI]

Optimal Fractal Coding is NP-Hard1 (Extended Abstract) Matthias Ruhl, Hannes Hartenstein Institut f,hartenst@informatik.uni-freiburg.de Abstract In fractal compression a signal is encoded by the parameters of a contractive trans- formation whose fixed point (attractor) is an approximation of the original data. Thus fractal coding can

Reiterer, Harald

148

Radiation-Hard ASICs for LHC Optical Data Transmission  

E-Print Network [OSTI]

Radiation-Hard ASICs for LHC Optical Data Transmission K.K. Gan, H.P. Kagan, R.D. Kass, J.R. Moore damage. We have designed three ASICs for possible applications in the optical links for the new pixel, D.S. Smith Abstract­We have designed three ASICs for possible applications in the optical links

Gan, K. K.

149

Why is hard to patent an invention? , W. Bein 2  

E-Print Network [OSTI]

Why is hard to patent an invention? D. Bein 1 , W. Bein 2 , M. P. Brut 3 and A. M. Cazacu 4 1 employment situations. A patent is a government-granted monopoly given to an inventor as both a reward for the intellectual and financial investment, and a stimulus to innovate. As a monopoly, the patent has legal power

Bein, Wolfgang

150

Component mixers and a hardness result for counterfeiting quantum money  

E-Print Network [OSTI]

In this paper we give the first proof that, under reasonable assumptions, a problem related to counterfeiting quantum money from knots [Farhi et al. 2010] is hard. Along the way, we introduce the concept of a component mixer, define three new classical query problems and associated complexity classes related to graph isomorphism and group membership, and conjecture an oracle separating QCMA from QMA.

Andrew Lutomirski

2011-07-01T23:59:59.000Z

151

Combustion properties of Kraft Black Liquors  

SciTech Connect (OSTI)

In a previous study of the phenomena involved in the combustion of black liquor droplets a numerical model was developed. The model required certain black liquor specific combustion information which was then not currently available, and additional data were needed for evaluating the model. The overall objectives of the project reported here was to provide experimental data on key aspects of black liquor combustion, to interpret the data, and to put it into a form which would be useful for computational models for recovery boilers. The specific topics to be investigated were the volatiles and char carbon yields from pyrolysis of single black liquor droplets; a criterion for the onset of devolatilization and the accompanying rapid swelling; and the surface temperature of black liquor droplets during pyrolysis, combustion, and gasification. Additional information on the swelling characteristics of black liquor droplets was also obtained as part of the experiments conducted.

Frederick, W.J. Jr.; Hupa, M. (Aabo Akademi, Turku (Finland))

1993-04-01T23:59:59.000Z

152

Dirac Quasinormal modes of MSW black holes  

E-Print Network [OSTI]

In this paper we study the Dirac quasinormal modes of an uncharged 2 + 1 black hole proposed by Mandal et. al and referred to as MSW black hole in this work. The quasi- normal mode is studied using WKB approximation method. The study shows that the imaginary part of quasinormal frequencies increases indicating that the oscillations are damping and hence the black hole is stable against Dirac perturbations.

Sebastian, Saneesh

2014-01-01T23:59:59.000Z

153

Dirac Quasinormal modes of MSW black holes  

E-Print Network [OSTI]

In this paper we study the Dirac quasinormal modes of an uncharged 2 + 1 black hole proposed by Mandal et. al and referred to as MSW black hole in this work. The quasi- normal mode is studied using WKB approximation method. The study shows that the imaginary part of quasinormal frequencies increases indicating that the oscillations are damping and hence the black hole is stable against Dirac perturbations.

Saneesh Sebastian; V. C. Kuriakose

2014-01-15T23:59:59.000Z

154

Black hole entropy: inside or out?  

E-Print Network [OSTI]

A trialogue. Ted, Don, and Carlo consider the nature of black hole entropy. Ted and Carlo support the idea that this entropy measures in some sense ``the number of black hole microstates that can communicate with the outside world.'' Don is critical of this approach, and discussion ensues, focusing on the question of whether the first law of black hole thermodynamics can be understood from a statistical mechanics point of view.

Ted Jacobson; Donald Marolf; Carlo Rovelli

2005-01-14T23:59:59.000Z

155

Spinning Black Holes as Particle Accelerators  

E-Print Network [OSTI]

It has recently been pointed out that particles falling freely from rest at infinity outside a Kerr black hole can in principle collide with arbitrarily high center of mass energy in the limiting case of maximal black hole spin. Here we aim to elucidate the mechanism for this fascinating result, and to point out its practical limitations, which imply that ultra-energetic collisions cannot occur near black holes in nature.

Ted Jacobson; Thomas P. Sotiriou

2010-01-21T23:59:59.000Z

156

Probing the Constituent Structure of Black Holes  

E-Print Network [OSTI]

We calculate the cross section for scattering processes between graviton emitters on the near side of a Schwarzschild surface and absorbers on its far side, that is black hole constituents. We show that these scatterings allow to directly extract structural observables such as the momentum distribution of black hole constituents. For this we employ a quantum bound state description originally developed in quantum chromodynamics and recently applied to general relativity that allows to consider black holes in a relativistic Hartree like framework.

Lukas Gruending; Stefan Hofmann; Sophia Müller; Tehseen Rug

2014-12-12T23:59:59.000Z

157

Remarks on Renormalization of Black Hole Entropy  

E-Print Network [OSTI]

We elaborate the renormalization process of entropy of a nonextremal and an extremal Reissner-Nordstr\\"{o}m black hole by using the Pauli-Villars regularization method, in which the regulator fields obey either the Bose-Einstein or Fermi-Dirac distribution depending on their spin-statistics. The black hole entropy involves only two renormalization constants. We also discuss the entropy and temperature of the extremal black hole.

Sang Pyo Kim; Sung Ku Kim; Kwang-Sup Soh; Jae Hyung Yee

1996-07-07T23:59:59.000Z

158

Absorption cross section of RN black hole  

E-Print Network [OSTI]

The behavior of a charged scalar field in the RN black hole space time is studied using WKB approximation. In the present work it is assumed that matter waves can get reflected from the event horizon. Using this effect, the Hawking temperature and the absorption cross section for RN black hole placed in a charged scalar field are calculated. The absorption cross section $\\sigma _{abs}$ is found to be inversely proportional to square of the Hawking temperature of the black hole.

Sini R.; V. C. Kuriakose

2007-08-23T23:59:59.000Z

159

Black holes with massive graviton hair  

E-Print Network [OSTI]

No-hair theorems exclude the existence of nontrivial scalar and massive vector hair outside four-dimensional, static, asymptotically flat black-hole spacetimes. We show, by explicitly building nonlinear solutions, that black holes can support massive graviton hair in theories of massive gravity. These hairy solutions are, most likely, the generic end state of the recently discovered monopole instability of Schwarzschild black holes in massive graviton theories.

Richard Brito; Vitor Cardoso; Paolo Pani

2013-09-03T23:59:59.000Z

160

Red-black Trees To know what a red-black tree is (10.1).  

E-Print Network [OSTI]

809 CHAPTER 10 Red-black Trees Objectives · To know what a red-black tree is (§10.1). · To convert a red-black tree to a 2-4 tree and vice versa (§10.2). · To design the RBTree class that extends the BinaryTree class (§10.3). · To insert an element in a red-black tree and resolve the double red problem

Liang, Y. Daniel

Note: This page contains sample records for the topic "hard black lustrous" 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

Destroying black holes with test bodies  

E-Print Network [OSTI]

If a black hole can accrete a body whose spin or charge would send the black hole parameters over the extremal limit, then a naked singularity would presumably form, in violation of the cosmic censorship conjecture. We review some previous results on testing cosmic censorship in this way using the test body approximation, focusing mostly on the case of neutral black holes. Under certain conditions a black hole can indeed be over-spun or over-charged in this approximation, hence radiative and self-force effects must be taken into account to further test cosmic censorship.

Ted Jacobson; Thomas P. Sotiriou

2010-06-09T23:59:59.000Z

162

Black Liquor Research Program symposium: proceedings  

SciTech Connect (OSTI)

In the paper pulp industry's recovery boilers, black liquor is sprayed in through nozzle guns near the top of the furnace. This report includes eight papers. (DLC)

Emerson, D.B.; Whitworth, B.A.

1985-03-01T23:59:59.000Z

163

Black Hills Power- Commercial Energy Efficiency Programs  

Broader source: Energy.gov [DOE]

Black Hills Power provides rebates for its commercial customers who install energy efficient heat pumps, motors, variable frequency drives, lighting, and water heaters. Custom rebates for approved...

164

Black Hills Power- Residential Customer Rebate Program  

Broader source: Energy.gov [DOE]

Black Hills Power offers cash rebates to residential customers who purchase and install energy efficient equipment in their homes. Incentives exist for water heaters, demand control units, air...

165

Lower Dimensional Black Holes: Inside and Out  

E-Print Network [OSTI]

I survey the physics of black holes in two and three spacetime dimensions, with special attention given to an understanding of their exterior and interior properties.

R. B. Mann

1995-01-27T23:59:59.000Z

166

International House Collection / William Black (collector)  

E-Print Network [OSTI]

International House Collection / William Black (collector) Revised by Erwin Wodarczak (2010 (collector). ­ 1950-1953. 45 p. of textual records. Biographical Sketch Born in London, England, William

Handy, Todd C.

167

Black Holes: from Speculations to Observations  

E-Print Network [OSTI]

This paper provides a brief review of the history of our understanding and knowledge of black holes. Starting with early speculations on ``dark stars'' I discuss the Schwarzschild "black hole" solution to Einstein's field equations and the development of its interpretation from "physically meaningless" to describing the perhaps most exotic and yet "most perfect" macroscopic object in the universe. I describe different astrophysical black hole populations and discuss some of their observational evidence. Finally I close by speculating about future observations of black holes with the new generation of gravitational wave detectors.

Thomas W. Baumgarte

2006-04-13T23:59:59.000Z

168

Superconducting Hair on Charged Black String Background  

E-Print Network [OSTI]

Behaviour of Dirac fermions in the background of a charged black string penetrated by an Abelian Higgs vortex is elaborated. One finds the evidence that the system under consideration can support fermion fields acting like a superconducting cosmic string in the sence that a nontrivial Dirac fermion field can be carried by the system in question. The case of nonextremal and extremal black string vortex systems were considered. The influence of electric and Higgs charge, the winding number and the fermion mass on the fermion localization near the black string event horizon was studied. It turned out that the extreme charged black string expelled fermion fields more violently comparing to the nonextremal one.

Lukasz Nakonieczny; Marek Rogatko

2012-01-25T23:59:59.000Z

169

A new spin on black hole hair  

E-Print Network [OSTI]

We show that scalar hair can be added to rotating, vacuum black holes of general relativity. These hairy black holes (HBHs) clarify a lingering question concerning gravitational solitons: if a black hole can be added at the centre of a boson star, as it typically can for other solitons. We argue that it can, but only if it is spinning. The existence of such HBHs is related to the Kerr superradiant instability triggered by a massive scalar field. This connection leads to the following conjecture: a (hairless) black hole which is afflicted by the superradiant instability of a given field must allow hairy generalizations with that field.

Herdeiro, Carlos A R

2014-01-01T23:59:59.000Z

170

Black Swans, Dragons-Kings and Prediction Black Swan (Cygnus atratus)  

E-Print Network [OSTI]

Black Swans, Dragons-Kings and Prediction Black Swan (Cygnus atratus) www.er.ethz.ch Didier hurricanes normalized to 1995 dollars by inflation, personal property increases and coastal county population;12 2008 FINANCIAL CRISIS #12;Crises are not but "Dragon-kings" Dragon-king hypothesis #12;Black Swan story

171

National Society of Black EngineersNational Society of Black Engineers Columbia University Chapter  

E-Print Network [OSTI]

National Society of Black EngineersNational Society of Black Engineers Columbia University Chapter #12;Columbia University Greetings NSBE Family and Friends! My name is Ken Yearwood, the 2008-2009 Columbia University NSBE (National Society of Black Engineers) Chapter President. On behalf of the Columbia

Hone, James

172

Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling  

SciTech Connect (OSTI)

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill ''faster and deeper'' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energy and loads. The significance of the ''ultra-high rotary speed drilling system'' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm-usually well below 5,000 rpm. This document details the progress at the end of Phase 1 on the program entitled ''Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling'' for the period starting 1 March 2006 and concluding 30 June 2006. (Note: Results from 1 September 2005 through 28 February 2006 were included in the previous report (see Judzis, Black, and Robertson)). Summarizing the accomplished during Phase 1: {lg_bullet} TerraTek reviewed applicable literature and documentation and convened a project kickoff meeting with Industry Advisors in attendance (see Black and Judzis). {lg_bullet} TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Some difficulties continued in obtaining ultra-high speed motors. Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed. {lg_bullet} TerraTek concluded Task 3 ''Small-scale cutting performance tests.'' {sm_bullet} Significant testing was performed on nine different rocks. {sm_bullet} Five rocks were used for the final testing. The final tests were based on statistical design of experiments. {sm_bullet} Two full-faced bits, a small diameter and a large diameter, were run in Berea sandstone. {lg_bullet} Analysis of data was completed and indicates that there is decreased specific energy as the rotational speed increases (Task 4). Data analysis from early trials was used to direct the efforts of the final testing for Phase I (Task 5). {lg_bullet} Technology transfer (Task 6) was accomplished with technical presentations to the industry (see Judzis, Boucher, McCammon, and Black).

Arnis Judzis; Homer Robertson; Alan Black

2006-06-22T23:59:59.000Z

173

Deep Frames, White Men's Discourse, and Black Female Bodies  

E-Print Network [OSTI]

In this qualitative study, I examine the persistent trend of black women as an excluded relationship partner for white men. Integral to understanding the exclusion of black women as relationship partners is the construction of black female bodies...

Slatton, Brittany C.

2012-02-14T23:59:59.000Z

174

Causticizing for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The cost-benefit outlook of black liquor gasification (BLG) could be greatly improved if the smelt causticization step could be achieved in situ during the gasification step. Or, at a minimum, the increase in causticizing load associated with BLG could be mitigated. A number of chemistries have been proven successful during black liquor combustion. In this project, three in situ causticizing processes (titanate, manganate, and borate) were evaluated under conditions suitable for high temperature entrained flow BLG, and low temperature steam reforming of black liquor. The evaluation included both thermodynamic modeling and lab experimentation. Titanate and manganate were tested for complete direct causticizing (to thus eliminate the lime cycle), and borates were evaluated for partial causticizing (to mitigate the load increase associated with BLG). Criteria included high carbonate conversion, corresponding hydroxide recovery upon hydrolysis, non process element (NPE) removal, and economics. Of the six cases (three chemistries at two BLG conditions), only two were found to be industrially viable: titanates for complete causticizing during high temperature BLG, and borates for partial causticizing during high temperature BLG. These two cases were evaluated for integration into a gasification-based recovery island. The Larsen [28] BLG cost-benefit study was used as a reference case for economic forecasting (i.e. a 1500 tpd pulp mill using BLG and upgrading the lime cycle). By comparison, using the titanate direct causticizing process yielded a net present value (NPV) of $25M over the NPV of BLG with conventional lime cycle. Using the existing lime cycle plus borate autocausticizing for extra capacity yielded a NPV of $16M.

Scott Sinquefeld; James Cantrell; Xiaoyan Zeng; Alan Ball; Jeff Empie

2009-01-07T23:59:59.000Z

175

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. This report covers Task 1.3, Simulative corrosion of candidate materials developed by refractory producers and in the laboratory based on the results of Task 1.1 and Task 1.2. Refractories provided by in-kind sponsors were tested by cup testing, density/porosity determinations, chemical analysis and microscopy. The best performing materials in the cup testing were fused cast materials. However, 2 castables appear to outperforming any of the previously tested materials and may perform better than the fused cast materials in operation. The basis of the high performance of these materials is the low open porosity and permeability to black liquor smelt.

William L. Headrick Jr; Musa Karakus; Jun Wei

2005-03-01T23:59:59.000Z

176

IS THE LATE NEAR-INFRARED BUMP IN SHORT-HARD GRB 130603B DUE TO THE LI-PACZYNSKI KILONOVA?  

SciTech Connect (OSTI)

Short-hard gamma-ray bursts (GRBs) are widely believed to be produced by the merger of two binary compact objects, specifically by two neutron stars or by a neutron star orbiting a black hole. According to the Li-Paczynski kilonova model, the merger would launch sub-relativistic ejecta and a near-infrared/optical transient would then occur, lasting up to days, which is powered by the radioactive decay of heavy elements synthesized in the ejecta. The detection of a late bump using the Hubble Space Telescope (HST) in the near-infrared afterglow light curve of the short-hard GRB 130603B is indeed consistent with such a model. However, as shown in this Letter, the limited HST near-infrared light curve behavior can also be interpreted as the synchrotron radiation of the external shock driven by a wide mildly relativistic outflow. In such a scenario, the radio emission is expected to peak with a flux of ?100 ?Jy, which is detectable for current radio arrays. Hence, the radio afterglow data can provide complementary evidence on the nature of the bump in GRB 130603B. It is worth noting that good spectroscopy during the bump phase in short-hard bursts can test the validity of either model above, analogous to spectroscopy of broad-lined Type Ic supernova in long-soft GRBs.

Jin, Zhi-Ping; Fan, Yi-Zhong; Wei, Da-Ming [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Science, Nanjing 210008 (China)] [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Science, Nanjing 210008 (China); Xu, Dong [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark)] [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Wu, Xue-Feng, E-mail: yzfan@pmo.ac.cn [Chinese Center for Antarctic Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)] [Chinese Center for Antarctic Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2013-09-20T23:59:59.000Z

177

Hard Excluseive $?$ and $J/?$ Photoproduction off a Proton  

E-Print Network [OSTI]

We study the photoproduction of the vector mesons $\\Phi$ and $J/\\Psi$ off a proton in the kinematical regime of large energies and scattering angles within the framework of perturbative QCD. Our investigations are based on the hard scattering approach. This means that the hadrons are replaced by their valence Fock states and scattering on the partonic level is described by tree graphs in which the large transferred momentum is redistributed between the valence partons via the exchange of hard gluons. We find that the unpolarized photoproduction cross sections are dominated by Compton-scattering-like graphs in which the photon couples to the proton, whereas vector-meson-dominance-like graphs, in which the photon fluctuates into the heavy quark-antiquark pair which then exchanges two gluons with the proton, play a minor role. We give explicit predictions for unpolarized scattering cross sections and compare them with experimental data where possible.

A. T. Goritschnig; B. Melic; K. Passek-Kumericki; W. Schweiger

2014-11-04T23:59:59.000Z

178

Hard Sphere Dynamics for Normal and Granular Fluids  

E-Print Network [OSTI]

A fluid of N smooth, hard spheres is considered as a model for normal (elastic collisions) and granular (inelastic collisions) fluids. The potential energy is discontinuous for hard spheres so the pairwise forces are singular and the usual forms of Newtonian and Hamiltonian mechanics do not apply. Nevertheless, particle trajectories in the N particle phase space are well defined and the generators for these trajectories can be identified. The first part of this presentation is a review of the generators for the dynamics of observables and probability densities. The new results presented in the second part refer to applications of these generators to the Liouville dynamics for granular fluids. A set of eigenvalues and eigenfunctions of the generator for this Liouville dynamics is identified in a special "stationary representation". This provides a class of exact solutions to the Liouville equation that are closely related to hydrodynamics for granular fluids.

James W. Dufty; Aparna Baskaran

2005-03-08T23:59:59.000Z

179

Does The 3N-Force Have A Hard Core?  

E-Print Network [OSTI]

The meson-nucleon dynamics that generates the hard core of the RuhrPot two-nucleon interaction is shown to vanish in the irreducible 3N force. This result indicates a small 3N force dominated by conventional light meson-exchange dynamics and holds for an arbitrary meson-theoretic Lagrangian. The resulting RuhrPot 3N force is defined in the appendix. A completely different result is expected when the Tamm-Dancoff/Bloch-Horowitz procedure is used to define the NN and 3N potentials. In that approach, (e.g. full Bonn potential) both the NN {\\it and} 3N potentials contain non-vanishing contributions from the coherent sum of meson-recoil dynamics and the possibility of a large hard core requiring explicit calculation cannot be ruled out.

J. A. Eden; M. F. Gari

1996-01-17T23:59:59.000Z

180

Probing the evolution and morphology of hard carbon spheres  

SciTech Connect (OSTI)

Monodispersed hard carbon spheres can be synthesized quickly and reproducibly by autogenic reactions of hydrocarbon precursors, notably polyethylene (including plastic waste), at high temperature and pressure. The carbon microparticles formed by this reaction have a unique spherical architecture, with a dominant internal nanometer layered motif, and they exhibit diamond-like hardness and electrochemical properties similar to graphite. In the present study, in-situ monitoring by X-ray diffraction along with electron microscopy, Raman spectroscopy, neutron pair-distribution function analysis, and computational modeling has been used to elucidate the morphology and evolution of the carbon spheres that form from the autogenic reaction of polyethylene at high temperature and pressure. A mechanism is proposed on how polyethylene evolves from a linear chain-based material to a layered carbon motif. Heating the spheres to 2400-2800 °C under inert conditions increases their graphitic character, particularly at the surface, which enhances their electrochemical and tribological properties.

Pol, Vilas G.; Wen, Jianguo; Lau, Kah Chun; Callear, Samantha; Bowron, Daniel T.; Lin, Chi-Kai; Deshmukh, Sanket A.; Sankaranarayanan, Subramanian; Curtiss, Larry A.; David, William; Miller, Dean J.; Thackeray, Michael M.

2014-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Infrared Safety in Factorized Hard Scattering Cross-Sections  

E-Print Network [OSTI]

The rules of soft-collinear effective theory can be used naively to write hard scattering cross-sections as convolutions of separate hard, jet, and soft functions. One condition required to guarantee the validity of such a factorization is the infrared safety of these functions in perturbation theory. Using e+e- angularity distributions as an example, we propose and illustrate an intuitive method to test this infrared safety at one loop. We look for regions of integration in the sum of Feynman diagrams contributing to the jet and soft functions where the integrals become infrared divergent. Our analysis is independent of an explicit infrared regulator, clarifies how to distinguish infrared and ultraviolet singularities in pure dimensional regularization, and demonstrates the necessity of taking zero-bins into account to obtain infrared-safe jet functions.

Andrew Hornig; Christopher Lee; Grigory Ovanesyan

2009-05-13T23:59:59.000Z

182

Role of bit patterned media in future of hard disk drives  

E-Print Network [OSTI]

The hard disk industry has traditionally stayed competitive by competing on the means of price alone by cutting down aggressively on cost via increase of areal density. Continuing increases in the areal density of hard ...

Aravindakshan, Vibin

2007-01-01T23:59:59.000Z

183

Congressional Black Caucus Foundation, Inc. Meet/Match Procurement...  

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

Congressional Black Caucus Foundation, Inc. MeetMatch Procurement Forum Congressional Black Caucus Foundation, Inc. MeetMatch Procurement Forum Presented by Congresswoman Sheila...

184

White House Initiative on Historically Black Colleges and Universities...  

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

White House Initiative on Historically Black Colleges and Universities White House Initiative on Historically Black Colleges and Universities How WHI-HBCU are ran White House...

185

Austin E. Quigley Black Box Theater Proposal Form  

E-Print Network [OSTI]

-1- Austin E. Quigley Black Box Theater Proposal Form Sponsoring Organization indicate that you have read the Austin E. Quigley Black Box Theatre Policy and Procedure Guidelines

Hone, James

186

Energy conservation for dynamical black holes  

E-Print Network [OSTI]

An energy conservation law is described, expressing the increase in mass-energy of a general black hole in terms of the energy densities of the infalling matter and gravitational radiation. For a growing black hole, this first law of black-hole dynamics is equivalent to an equation of Ashtekar & Krishnan, but the new integral and differential forms are regular in the limit where the black hole ceases to grow. An effective gravitational-radiation energy tensor is obtained, providing measures of both ingoing and outgoing, transverse and longitudinal gravitational radiation on and near a black hole. Corresponding energy-tensor forms of the first law involve a preferred time vector which plays the role for dynamical black holes which the stationary Killing vector plays for stationary black holes. Identifying an energy flux, vanishing if and only if the horizon is null, allows a division into energy-supply and work terms, as in the first law of thermodynamics. The energy supply can be expressed in terms of area increase and a newly defined surface gravity, yielding a Gibbs-like equation, with a similar form to the so-called first law for stationary black holes.

Sean A. Hayward

2004-08-03T23:59:59.000Z

187

Quantum Entropy of Charged Rotating Black Holes  

E-Print Network [OSTI]

I discuss a method for obtaining the one-loop quantum corrections to the tree-level entropy for a charged Kerr black hole. Divergences which appear can be removed by renormalization of couplings in the tree-level gravitational action in a manner similar to that for a static black hole.

R. B. Mann

1996-07-10T23:59:59.000Z

188

Black holes cannot support conformal scalar hair  

E-Print Network [OSTI]

It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.

T. Zannias

1994-09-14T23:59:59.000Z

189

The Kansas Black Bass Tournament Monitoring Program  

E-Print Network [OSTI]

The Kansas Black Bass (Micropterus spp.) Tournament Monitoring Program was begun by the Kansas Fish and Game program of the Kansas Fish and Game Commission avoids both of these prob- lems. The Kansas Black Bass annually to each of the bass clubs in Kansas before the bulk of fishing begins, and clubs are asked

190

Topological Black Holes in Quantum Gravity  

E-Print Network [OSTI]

We derive the black hole solutions with horizons of non-trivial topology and investigate their properties in the framework of an approach to quantum gravity being an extension of Bohm's formulation of quantum mechanics. The solutions we found tend asymptotically (for large $r$) to topological black holes. We also analyze the thermodynamics of these space-times.

J. Kowalski-Glikman; D. Nowak-Szczepaniak

2000-07-31T23:59:59.000Z

191

Cooking with Black-Eyed Peas  

E-Print Network [OSTI]

the most protein from the peas, serve them with grain foods such as corn, rice or wheat. A serving size is ? cup. Uses Use black-eyed peas as a tasty side dish or include it in casseroles, soups, and salads. Black-eyed peas are often packaged in 1- or 2...

Anding, Jenna

2008-12-09T23:59:59.000Z

192

Relaxation dynamics in a binary hard-ellipse liquid  

E-Print Network [OSTI]

Structural relaxation in binary hard spherical particles has been shown recently to exhibit a wealth of remarkable features when size disparity or mixture's composition is varied. In this paper, we test whether or not similar dynamical phenomena occur in glassy systems composed of binary hard ellipses. We demonstrate via event-driven molecular dynamics simulation that a binary hard-ellipse mixture with an aspect ratio of two and moderate size disparity displays characteristic glassy dynamics upon increasing density in both the translational and the rotational degrees of freedom. The rotational glass transition density is found to be close to the translational one for the binary mixtures investigated. More importantly, we assess the influence of size disparity and mixture's composition on the relaxation dynamics. We find that an increase of size disparity leads, both translationally and rotationally, to a speed up of the long-time dynamics in the supercooled regime so that both the translational and the rotational glass transition shift to higher densities. By increasing the number concentration of the small particles, the time evolution of both translational and rotational relaxation dynamics at high densities displays two qualitatively different scenarios, i.e., both the initial and the final part of the structural relaxation slow down for small size disparity, while the short-time dynamics still slows down but the final decay speeds up in the binary mixture with large size disparity. These findings are reminiscent of those observed in binary hard spherical particles. Therefore, our results suggest a universal mechanism for the influence of size disparity and mixture's composition on the structural relaxation in both isotropic and anisotropic particle systems.

Wen-Sheng Xu; Zhao-Yan Sun; Li-Jia An

2014-12-01T23:59:59.000Z

193

Distortion of Schwarzschild-anti-de Sitter black holes to black strings  

E-Print Network [OSTI]

Motivated by the existence of black holes with various topologies in four-dimensional spacetimes with a negative cosmological constant, we study axisymmetric static solutions describing any large distortions of Schwarzschild-anti-de Sitter black holes parametrized by the mass $m$. Under the approximation such that $m$ is much larger than the anti-de Sitter radius, it is found that a cylindrically symmetric black string is obtained as a special limit of distorted spherical black holes. Such a prolonged distortion of the event horizon connecting a Schwarzschild-anti-de Sitter black hole to a black string is allowed without violating both the usual black hole thermodynamics and the hoop conjecture for the horizon circumference.

A. Tomimatsu

2005-06-25T23:59:59.000Z

194

Density functional theory for Baxter's sticky hard spheres in confinement  

E-Print Network [OSTI]

It has recently been shown that a free energy for Baxter's sticky hard sphere fluid is uniquely defined within the framework of fundamental measure theory (FMT) for the inhomogeneous hard sphere fluid, provided that it obeys scaled-particle theory and the Percus-Yevick (PY) result for the direct correlation function [Hansen-Goos and Wettlaufer, J. Chem. Phys. {\\bf 134}, 014506 (2011)]. Here, combining weighted densities from common versions of FMT with a new vectorial weighted density, we derive a regularization of the divergences of the associated strongly confined limit. Moreover, the simple free energy that emerges is exact in the zero-dimensional limit, leaves the underlying equation of state unaffected, and yields a direct correlation function distinct from the PY expression. Comparison with simulation data for both the bulk pair correlation function and the density profiles in confinement shows that the new theory is significantly more accurate than the PY-based results. Finally, the resulting free energy is applicable to a glass of adhesive hard spheres.

Hendrik Hansen-Goos; Mark A. Miller; J. S. Wettlaufer

2011-12-15T23:59:59.000Z

195

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-10-01T23:59:59.000Z

196

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO2 and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick; Musa Karakus; Alireza Rezaie

2004-03-30T23:59:59.000Z

197

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-07-01T23:59:59.000Z

198

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected/developed that either react with the gasifier environment to form protective surfaces in-situ; and were functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development were divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-10-01T23:59:59.000Z

199

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr.; Alireza Rezaie

2004-04-01T23:59:59.000Z

200

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-07-01T23:59:59.000Z

202

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO{sub 2} and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-01-01T23:59:59.000Z

203

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Alireza Rezaie

2003-12-01T23:59:59.000Z

204

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected or developed that reacted with the gasifier environment to form protective surfaces in-situ; and were functionally-graded to give the best combination of thermal, mechanical and physical properties and chemical stability; and are relatively inexpensive, reliable repair materials. Material development was divided into 2 tasks: Task 1 was development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO2 and SiC. Task 2 was finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Alireza Rezaie; Xiaoting Liang; Musa Karakus; Jun Wei

2005-12-01T23:59:59.000Z

205

REFRACTORY FOR BLACK LIQUOR GASIFIERS  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr.; Alireza Rezaie

2003-12-01T23:59:59.000Z

206

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

William L. Headrick Jr; Alireza Rezaie

2003-08-01T23:59:59.000Z

207

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for black liquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing black liquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

Robert E. Moore; William L. Headrick; Alireza Rezaie

2003-03-31T23:59:59.000Z

208

Diagnostics of quark-gluon plasma in ultrarelativistic heavy ion collisions by hard QCD-processes  

E-Print Network [OSTI]

We analyze the possibilities for studying properties of dense QCD-matter, created in ultrarelativistic nuclear collisions, by hard QCD-production processes, so-called "hard" probes -- heavy quarkonia, hard jets, high mass dimuons. Special attention is paid to the potential of coming heavy ion experiments on Large Hadron Collider to observe the rescattering and energy losses of hard partons in quark-gluon plasma.

I. P. Lokhtin

2000-12-01T23:59:59.000Z

209

Black hole and holographic dark energy  

E-Print Network [OSTI]

We discuss the connection between black hole and holographic dark energy. We examine the issue of the equation of state (EOS) for holographic energy density as a candidate for the dark energy carefully. This is closely related to the EOS for black hole, because the holographic dark energy comes from the black hole energy density. In order to derive the EOS of a black hole, we may use its dual (quantum) systems. Finally, a regular black hole without the singularity is introduced to describe an accelerating universe inside the cosmological horizon. Inspired by this, we show that the holographic energy density with the cosmological horizon as the IR cutoff leads to the dark energy-dominated universe with $\\omega_{\\rm \\Lambda}=-1$.

Yun Soo Myung

2007-04-11T23:59:59.000Z

210

Black Hole Thermodynamics Based on Unitary Evolutions  

E-Print Network [OSTI]

In this paper, we try to construct black hole thermodynamics based on the fact that, the formation and evaporation of a black hole can be described by quantum unitary evolutions. First, we show that the Bekenstein-Hawking entropy $S_{BH}$ cannot be a Boltzmann or thermal entropy. To confirm this statement, we show that the original black hole's "first law" cannot be treated as the first law of thermodynamics formally, due to some missing metric perturbations caused by matter. Then, by including those (quantum) metric perturbations, we show that the black hole formation and evaporation can be described in a unitary manner effectively, through a quantum channel between the exterior and interior of the event horizon. In this way, the paradoxes of information loss and firewall can be resolved effectively. Finally, we show that black hole thermodynamics can be constructed in an ordinary way, by constructing statistical mechanics.

Feng, Yu-Lei

2015-01-01T23:59:59.000Z

211

An electromagnetic black hole made of metamaterials  

E-Print Network [OSTI]

Traditionally, a black hole is a region of space with huge gravitational field in the means of general relativity, which absorbs everything hitting it including the light. In general relativity, the presence of matter-energy densities results in the motion of matter propagating in a curved spacetime1, which is similar to the electromagnetic-wave propagation in a curved space and in an inhomogeneous metamaterial2. Hence one can simulate the black hole using electromagnetic fields and metamaterials. In a recent theoretical work, an optical black hole has been proposed based on metamaterials, in which the numerical simulations showed a highly efficient light absorption3. Here we report the first experimental demonstration of electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can absorb electromagnetic waves efficiently coming from all directions due to the local control of electromagnetic fields. Hence the elect...

Cheng, Qiang

2009-01-01T23:59:59.000Z

212

Black holes in Asymptotically Safe Gravity  

E-Print Network [OSTI]

Black holes are among the most fascinating objects populating our universe. Their characteristic features, encompassing spacetime singularities, event horizons, and black hole thermodynamics, provide a rich testing ground for quantum gravity ideas. In this note we observe that the renormalization group improved Schwarzschild black holes constructed by Bonanno and Reuter within Weinberg's asymptotic safety program constitute a prototypical example of a Hayward geometry used to model non-singular black holes within quantum gravity phenomenology. Moreover, they share many features of a Planck star: their effective geometry naturally incorporates the one-loop corrections found in the effective field theory framework, their Kretschmann scalar is bounded, and the black hole singularity is replaced by a regular de Sitter patch. The role of the cosmological constant in the renormalization group improvement process is briefly discussed.

Saueressig, Frank; D'Odorico, Giulio; Vidotto, Francesca

2015-01-01T23:59:59.000Z

213

Black Hole Superradiance in Dynamical Spacetime  

E-Print Network [OSTI]

We study the superradiant scattering of gravitational waves by a nearly extremal black hole (dimensionless spin $a=0.99$) by numerically solving the full Einstein field equations, thus including backreaction effects. This allows us to study the dynamics of the black hole as it loses energy and angular momentum during the scattering process. To explore the nonlinear phase of the interaction, we consider gravitational wave packets with initial energies up to $10%$ of the mass of the black hole. We find that as the incident wave energy increases, the amplification of the scattered waves, as well as the energy extraction efficiency from the black hole, is reduced. During the interaction the apparent horizon geometry undergoes sizable nonaxisymmetric oscillations. The largest amplitude excitations occur when the peak frequency of the incident wave packet is above where superradiance occurs, but close to the dominant quasinormal mode frequency of the black hole.

William E. East; Fethi M. Ramazano?lu; Frans Pretorius

2014-03-14T23:59:59.000Z

214

Transition of an X-ray binary to the hard ultraluminous state in the blue compact dwarf galaxy VII Zw 403  

E-Print Network [OSTI]

We examine the X-ray spectra of VII Zw 403, a nearby low-metallicity blue compact dwarf (BCD) galaxy. The galaxy has been observed to contain an X-ray source, likely a high mass X-ray binary (HMXB), with a luminosity of 1.3-23x10^38 erg s^-1 in the 0.3-8 keV energy range. A new Suzaku observation shows a transition to a luminosity of 1.7x10^40 erg s^-1 [0.3-8 keV], higher by a factor of 7-130. The spectra from the high flux state are hard, best described by a disk plus Comptonization model, and exhibit curvature at energies above 5 keV. This is consistent with many high-quality ultraluminous X-ray source spectra which have been interpreted as stellar mass black holes (StMBH) accreting at super-Eddington rates. However, this lies in contrast to another HMXB in a low-metallicity BCD, I Zw 18, that exhibits a soft spectrum at high flux, similar to Galactic black hole binaries and has been interpreted as a possible intermediate mass black hole. Determining the spectral properties of HMXBs in BCDs has important im...

Brorby, Matthew; Feng, Hua

2015-01-01T23:59:59.000Z

215

Young Collapsed Supernova Remnants: Similarities and Differences in Neutron Stars, Black Holes, and More Exotic Objects  

E-Print Network [OSTI]

Type Ia supernovae are thought to explode completely, leaving no condensed remnant, only an expanding shell. Other types of supernovae are thought to involve core collapse and are expected to leave a condensed remnant, which could be either a neutron star or a black hole, or just possibly, something more exotic, such as a quark orstrange star, a naked singularity, a frozen star, a wormhole or a red hole. It has proven surprisingly difficult to determine which type of condensed remnant has been formed in those cases where the diagnostic highly regular pulsar signature of a neutron star is absent. We consider possible observational differences between the two standard candidates, as well as the more speculative alternatives. We classify condensed remnants according to whether they do or do not possess three major features: 1)a hard surface, 2)an event horizon, and 3)a singularity. Black holes and neutron stars differ on all three criteria. Some of the less frequently considered alternatives are "intermediate," in the sense that they possess some of the traits of a black hole and some of the traits of a neutron star. This possibility makes distinguishing the various possibilities even more difficult.

James S. Graber

2000-12-09T23:59:59.000Z

216

GRB 060313: A NEW PARADIGM FOR SHORT-HARD BURSTS? Peter W. A. Roming,1  

E-Print Network [OSTI]

of the prompt emission in the gamma-ray and hard X-ray bands by the Swift BAT and the Konus-Wind instruments of the short-hard burst, GRB 060313. The observations reveal multiple peaks in both the gamma-ray and hard X: gamma rays: bursts Online material: color figures 1. INTRODUCTION Gamma-ray bursts (GRBs) are generally

Zhang, Bing

217

Ductile Binder Phase For Use With Almgb14 And Other Hard Ceramic Materials  

DOE Patents [OSTI]

This invention relates to a ductile binder phase for use with AlMgB14 and other hard materials. The ductile binder phase, a cobalt-manganese alloy, is used in appropriate quantities to tailor good hardness and reasonable fracture toughness for hard materials so they can be used suitably in industrial machining and grinding applications.

Cook, Bruce A. (Ankeny, IA); Russell, Alan (Ames, IA); Harringa, Joel (Ames, IA)

2005-07-26T23:59:59.000Z

218

Refractory for Black Liquor Gasifiers  

SciTech Connect (OSTI)

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. This report covers Task 1.4, Industrial Trial of candidate materials developed by refractory producers and in the laboratory based on the results of Task 1.1, 1.2 and 1.3. Refractories provided by in-kind sponsors to industrial installations tested by cup testing, density/porosity determinations, chemical analysis and microscopy. None of the materials produced in this program have been tried in high temperature gasifiers, but the mortar developed Morcocoat SP-P is outperforming other mortars tested at ORNL. MORCO PhosGun M-90-O has shown in laboratory testing to be an acceptable candidate for hot and cold repairs of existing high temperature gasifiers. It may prove to be an acceptable lining material.

William L. Headrick Jr; Musa Karakus; Xiaoting Laing

2005-10-01T23:59:59.000Z

219

ENERGY-DEPENDENT POWER SPECTRAL STATES AND ORIGIN OF APERIODIC VARIABILITY IN BLACK HOLE BINARIES  

SciTech Connect (OSTI)

We found that the black hole candidate MAXI J1659-152 showed distinct power spectra, i.e., power-law noise (PLN) versus band-limited noise (BLN) plus quasi-periodic oscillations (QPOs) below and above about 2 keV, respectively, in observations with Swift and the Rossi X-ray Timing Explorer during the 2010 outburst, indicating a high energy cutoff of the PLN and a low energy cutoff of the BLN and QPOs around 2 keV. The emergence of the PLN and the fading of the BLN and QPOs initially took place below 2 keV when the source entered the hard intermediate state and settled in the soft state three weeks later. The evolution was accompanied by the emergence of the disk spectral component and decreases in the amplitudes of variability in the soft and hard X-ray bands. Our results indicate that the PLN is associated with an optically thick disk in both hard and intermediate states, and the power spectral state is independent of the X-ray energy spectral state in a broadband view. We suggest that in the hard or intermediate state, the BLN and QPOs emerge from the innermost hot flow subjected to Comptonization, while the PLN originates from the optically thick disk farther out. The energy cutoffs of the PLN and the BLN or QPOs then follow the temperature of the seed photons from the inner edge of the optically thick disk, while the high frequency cutoff of the PLN follows the orbital frequency of the inner edge of the optically thick disk as well.

Yu Wenfei; Zhang Wenda, E-mail: wenfei@shao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

2013-06-20T23:59:59.000Z

220

Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling  

SciTech Connect (OSTI)

The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill 'faster and deeper' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energy and loads. The significance of the 'ultra-high rotary speed drilling system' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm - usually well below 5,000 rpm. This document provides the progress through two phases of the program entitled 'Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling' for the period starting 30 June 2003 and concluding 31 March 2009. The accomplishments of Phases 1 and 2 are summarized as follows: (1) TerraTek reviewed applicable literature and documentation and convened a project kick-off meeting with Industry Advisors in attendance (see Black and Judzis); (2) TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed; (3) TerraTek concluded small-scale cutting performance tests; (4) Analysis of Phase 1 data indicated that there is decreased specific energy as the rotational speed increases; (5) Technology transfer, as part of Phase 1, was accomplished with technical presentations to the industry (see Judzis, Boucher, McCammon, and Black); (6) TerraTek prepared a design concept for the high speed drilling test stand, which was planned around the proposed high speed mud motor concept. Alternative drives for the test stand were explored; a high speed hydraulic motor concept was finally used; (7) The high speed system was modified to accommodate larger drill bits than originally planned; (8) Prototype mud turbine motors and the high speed test stand were used to drive the drill bits at high speed; (9) Three different rock types were used during the testing: Sierra White granite, Crab Orchard sandstone, and Colton sandstone. The drill bits used included diamond impregnated bits, a polycrystalline diamond compact (PDC) bit, a thermally stable PDC (TSP) bit, and a hybrid TSP and natural diamond bit; and (10) The drill bits were run at rotary speeds up to 5500 rpm and weight on bit (WOB) to 8000 lbf. During Phase 2, the ROP as measured in depth of cut per bit revolution generally increased with increased WOB. The performance was mixed with increased rotary speed, with the depth cut with the impregnated drill bit generally increasing and the TSP and hybrid TSP drill bits generally decreasing. The ROP in ft/hr generally increased with all bits with increased WOB and rotary speed. The mechanical specific energy generally improved (decreased) with increased WOB and was mixed with increased rotary speed.

TerraTek, A Schlumberger Company

2008-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Thermodynamics of Dyonic Lifshitz Black Holes  

E-Print Network [OSTI]

Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.

Tobias Zingg

2011-07-15T23:59:59.000Z

222

Some remarks on black hole thermodynamics  

E-Print Network [OSTI]

Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

R. Y. Chiao

2011-02-04T23:59:59.000Z

223

Spectroscopy and Thermodynamics of MSW Black Hole  

E-Print Network [OSTI]

We study the thermodynamics and spectroscopy of a 2+1 dimensional black hole pro- posed by Mandal et. al1 . We put the background space time in Kruskal like co-ordinate and find period with respect to Euclidean time. Different thermodynamic quantities like entropy, specific heat, temperature etc are obtained. The adiabatic invariant for the black hole is found out and quantized using Bohr-Sommerfeld quantization rule. The study shows that the area spectrum of MSW black hole is equally spaced and the value of spacing is found to be h bar

Sebastian, Saneesh

2013-01-01T23:59:59.000Z

224

Spectroscopy and Thermodynamics of MSW Black Hole  

E-Print Network [OSTI]

We study the thermodynamics and spectroscopy of a 2+1 dimensional black hole pro- posed by Mandal et. al1 . We put the background space time in Kruskal like co-ordinate and find period with respect to Euclidean time. Different thermodynamic quantities like entropy, specific heat, temperature etc are obtained. The adiabatic invariant for the black hole is found out and quantized using Bohr-Sommerfeld quantization rule. The study shows that the area spectrum of MSW black hole is equally spaced and the value of spacing is found to be h bar

Saneesh Sebastian; V. C. Kuriakose

2013-09-02T23:59:59.000Z

225

Tunable optical properties of multilayers black phosphorus  

E-Print Network [OSTI]

We calculated the optical conductivity tensor of multilayers black phosphorus using the Kubo formula within an effective low-energy Hamiltonian. The optical absorption spectra of multilayers black phosphorus are shown to vary sensitively with thickness, doping, and light polarization. In conjunction with experimental spectra obtained from infrared absorption spectroscopy, we discuss the role of interband coupling and disorder on the observed anisotropic absorption spectra. Multilayers black phosphorus might offer attractive alternatives to narrow gap compound semiconductors for optoelectronics across mid- to near-infrared frequencies.

Low, Tony; Carvalho, A; Jiang, Yongjin; Wang, Han; Xia, Fengnian; Neto, A H Castro

2014-01-01T23:59:59.000Z

226

CHARYBDIS: A Black hole event generator.  

E-Print Network [OSTI]

model of black hole production and decay which can be interfaced to existing Monte Carlo programs using the Les Houches accord [4]. The major new theoretical input to the generator is the inclusion of the recently calculated ‘grey-body’ factors for black... ? TH geometric arguments show that ?l,m? ? (?rh)2 in any number of dimensions, which means that at high energies the shape of the spectrum is like that of a black body. However the low energy behaviour of the grey-body factors is spin-dependent and also...

Harris, Chris M; Richardson, P; Webber, Bryan R

227

Black hole hair in higher dimensions  

E-Print Network [OSTI]

We study the property of matter in equilibrium with a static, spherically symmetric black hole in D-dimensional spacetime. It requires this kind of matter has an equation of state (\\omega\\equiv p_r/\\rho=-1/(1+2kn), k,n\\in \\mathbb{N}), which seems to be independent of D. However, when we associate this with specific models, some interesting limits on space could be found: (i)(D=2+2kn) while the black hole is surrounded by cosmic strings; (ii)the black hole can be surrounded by linear dilaton field only in 4-dimensional spacetime. In both cases, D=4 is special.

Chao Cao; Yi-Xin Chen; Jian-Long Li

2008-04-02T23:59:59.000Z

228

Morphology of PolyethyleneCarbon Black Composites G. BEAUCAGE,1  

E-Print Network [OSTI]

Morphology of Polyethylene­Carbon Black Composites G. BEAUCAGE,1 S. RANE,1 D. W. SCHAEFER,1 G. LONG-ray scattering (SAXS) study of a conductive grade of carbon black and carbon black­polymer composites(methyl methacrylate); carbon black; filler; composite; conductivity; percolation INTRODUCTION The morphology

Beaucage, Gregory

229

Phase transitions and Geometrothermodynamics of Regular black holes  

E-Print Network [OSTI]

In this paper we study the thermodynamics and state space geometry of regular black hole solutions such as Bardeen black hole, Ay\\'{o}n-Beato and Garc\\'{i}a black hole, Hayward black hole and Berej-Matyjasek-Trynieki-Wornowicz black hole. We find that all these black holes show second order thermodynamic phase transitions(SOTPT) by observing discontinuities in heat capacity-entropy graphs as well as the cusp type double point in free energy-temperature graph. Using the formulation of geometrothermodynamics we again find the singularities in the heat capacity of the black holes by calculating the curvature scalar of the Legendre invariant metric.

R. Tharanath; Jishnu Suresh; V. C. Kuriakose

2014-06-16T23:59:59.000Z

230

Grinding tool for making hemispherical bores in hard materials  

DOE Patents [OSTI]

A grinding tool for forming hemispherical bores in hard materials such as boron carbide. The tool comprises a hemicircular grinding bit, formed of a metal bond diamond matrix, which is mounted transversely on one end of a tubular tool shaft. The bit includes a spherically curved outer edge surface which is the active grinding surface of the tool. Two coolant fluid ports on opposite sides of the bit enable introduction of coolant fluid through the bore of the tool shaft so as to be emitted adjacent the opposite sides of the grinding bit, thereby providing optimum cooling of both the workpiece and the bit.

Duran, E.L.

1985-04-03T23:59:59.000Z

231

Radiation hardness of WLS fibres for the ATLAS Tile Calorimeter  

E-Print Network [OSTI]

In this document we present the data obtained in the irradiation in a Co-60 source of WLS fibers for the TileCal calorimeter. The optical, mechanical and radiation hardness properties of these fibers were developed in close contact with three producers: Bicron, Kuraray and Pol.Hi.Tech. The results on the degradation of the light output and attenuation length from five irradiations are presented. The fibers were irradiated with a total dose at least 3 times higher than the dose predicted for 10 years of operation of LHC at nominal luminosity.

David, M; Maio, A

2007-01-01T23:59:59.000Z

232

Quantum model of an autonomous oscillator in hard excitation regime  

E-Print Network [OSTI]

We propose the simple quantum model of nonlinear autonomous oscillator in hard excitation regime. We originate from classical equations of motion for similar oscillator and quantize them using the Lindblad master equation for the density matrix of this system. The solution for the populations of the stationary states of such oscillator may be explicitly found in the case when nonlinearity parameters of the problem are small. It was shown that in this situation there are three distinct regimes of behavior of the model. We compare properties of this model with corresponding ones of close open system, namely quantum oscillator in soft excitation regime. We discuss a possible applications of the results obtained.

E. D. Vol; M. A. Ialovega

2014-12-01T23:59:59.000Z

233

One dimensional Brownian motion in hard rods: adiabatic piston problem  

E-Print Network [OSTI]

We have investigated the motion characteristics of a movable piston immersed in a one dimensional gas of hard rods by event-oriented molecular dynamics in the absence of thermal noise. Periodic and reflecting boundary conditions are explored. It is shown that the piston undergoes systematic oscillations with decaying amplitudes in short times before it comes to global thermodynamic equilibrium. Moreover, the diffusion of the piston is explored and analytical expressions for its equilibrium mean-squared displacement is obtained. It is shown that MSD of the piston does not differ much from the normal rods despite its mass and length are significantly larger.

M. Ebrahim Foulaadvand; M. Mehdi Shafiee

2014-09-11T23:59:59.000Z

234

Anisotropic flow generated by hard partons in medium  

E-Print Network [OSTI]

Hard partons which are produced copiously in nuclear collisions at the LHC, deposit most of their energy and momentum into the surrounding quark-gluon plasma. We show that this generates streams in the plasma and contributes importantly to flow anisotropies. With the help of event-by-event three-dimensional perfect hydrodynamic simulations we calculate the observable azimuthal anisotropies of hadronic distributions and show that the proposed mechanism is capable of generating non-negligible part of the observed signal. Hence, it must be taken into account in quantitative studies in which one tries to extract the values of viscosities from the comparison of simulated results with measured data.

Tomasik, Boris

2015-01-01T23:59:59.000Z

235

Harding County, South Dakota: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation,Ohio:Greer County is8584°, -79.954985°isEnergyHardeeAda,Harding County is

236

Harding-Birch Lakes, Alaska: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation,Ohio:Greer County is8584°, -79.954985°isEnergyHardeeAda,Harding County

237

Flash Memory Garbage Collection in Hard Real-Time Systems  

E-Print Network [OSTI]

collection and compare it to that of more proactive schemes. I develop formulas to assess the schedulability of hard real- time periodic task sets under simpli ed memory consumption models. Results show that I prove the proactive schemes achieve the larger... work in the area of ash memory management. Moreover, we review the previous research about garbage collection in real-time system. In Chapter III we will describe a simpli ed ash memory model that will be used throughout the rest of the thesis...

Lai, Chien-An

2012-10-19T23:59:59.000Z

238

Sandia National Laboratories: Rad-Hard Electronics and Trusted Services  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErik SpoerkeSolar Regional Test CenterCMCNational LaboratoriesRFRORad-Hard

239

Multi-Scale Indentation Hardness Testing; A Correlation and Model  

E-Print Network [OSTI]

. This test is performed by applying a steady load to an indenter (most commonly a diamond pyramid, diamond spheroconical, or a tungsten carbide ball) and then calculating the hardness from the area or depth of the 5 indentation. A dynamic indentation test... 6 variants are the indenter tip and the load applied. A tungsten carbide sphere or a diamond cone or pyramid is used to prevent the indenter tip from being damaged by the test piece. This consideration is made because test pieces have unique values...

Bennett, Damon W.

2010-01-20T23:59:59.000Z

240

Reclaiming Blackness: (Counter) Narratives of Racial Kinship in Black Gay Men‘s Sexual Stories  

E-Print Network [OSTI]

and Prevention CME Christian Methodist Episcopal church DL Down Low GLBT Gay, Lesbian, Bisexual and Transgendered HIV Human Immunodeficiency Virus MCC Metropolitan Community Church MSM Men Who Have Sex with Men NCBLG National Coalition of Black Lesbians... and Gays SBM Super Black Man SGL Same Gender Loving STDs Sexually Transmitted Diseases The Forum National Black Gay and Lesbian Leadership Forum TVC Traditional Values Coalition x TABLE OF CONTENTS Page ABSTRACT...

Chambers, Christopher Scott

2012-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Thermodynamics of Schwarzschild-de Sitter black hole: thermal stability of Nariai black hole  

E-Print Network [OSTI]

We study thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalizations. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization, and does not favor the Bousso-Hawking normalization.

Yun Soo Myung

2008-03-28T23:59:59.000Z

242

Relativistic simulations of black hole-neutron star coalescence: the jet emerges  

E-Print Network [OSTI]

We perform magnetohydrodynamic simulations in full general relativity of an initially quasiequilibrium binary black hole-neutron star on a quasicircular orbit that undergoes merger. The binary mass ratio is $3:1$, the black hole has initial spin parameter $a/m=0.75$ aligned with the orbital angular momentum, and the neutron star is modeled as an irrotational $\\Gamma=2$ polytrope. About two orbits prior to merger (at time $t=t_B$), we seed the neutron star with a dynamically weak dipolar magnetic field [${B}_{pole}\\sim 10^{14}(1.4M_\\odot/M_{\\rm NS})$ G] that extends from the stellar interior into the exterior. At $t=t_B$ the exterior is characterized by a low density atmosphere with constant plasma parameter $\\beta\\equiv P_{\\rm gas}/P_{\\rm mag}$. Varying $\\beta$ at $t_B$ in the exterior from $0.1$ to $0.01$, we find that at $\\sim 4000M \\sim 100(M_{\\rm NS}/1.4M_\\odot)$ms following the onset of accretion of tidally disrupted debris, magnetic field winding above the remnant black hole poles builds up the magnetic field sufficiently to launch a mildly relativistic, collimated outflow - an incipient jet. The duration of the accretion and the lifetime of the jet is $\\Delta t\\sim 0.5(M_{\\rm NS}/1.4M_\\odot)$s. Our simulations are the first self-consistent calculations in full general relativity that provide theoretical corroboration that mergers of black hole-neutron stars can launch jets and be the central engines that power short-hard gamma ray bursts.

Vasileios Paschalidis; Milton Ruiz; Stuart L. Shapiro

2014-10-27T23:59:59.000Z

243

Thermodynamics and evaporation of the noncommutative black hole  

E-Print Network [OSTI]

We investigate the thermodynamics of the noncommutative black hole whose static picture is similar to that of the nonsingular black hole known as the de Sitter-Schwarzschild black hole. It turns out that the final remnant of extremal black hole is a thermodynamically stable object. We describe the evaporation process of this black hole by using the noncommutativity-corrected Vaidya metric. It is found that there exists a close relationship between thermodynamic approach and evaporation process.

Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

2007-01-21T23:59:59.000Z

244

Black hole evolution: I. Supernova-regulated black hole growth  

E-Print Network [OSTI]

The growth of a supermassive black hole (BH) is determined by how much gas the host galaxy is able to feed it, which in turn is controlled by the cosmic environment, through galaxy mergers and accretion of cosmic flows that time how galaxies obtain their gas, but also by internal processes in the galaxy, such as star formation and feedback from stars and the BH itself. In this paper, we study the growth of a 10^12 Msun halo at z=2, which is the progenitor of an archetypical group of galaxies at z=0, and of its central BH by means of a high-resolution zoomed cosmological simulation, the Seth simulation. We study the evolution of the BH driven by the accretion of cold gas in the galaxy, and explore the efficiency of the feedback from supernovae (SNe). For a relatively inefficient energy input from SNe, the BH grows at the Eddington rate from early times, and reaches self-regulation once it is massive enough. We find that at early cosmic times z>3.5, efficient feedback from SNe forbids the formation of a settled...

Dubois, Yohan; Silk, Joseph; Devriendt, Julien; Slyz, Adrianne; Teyssier, Romain

2015-01-01T23:59:59.000Z

245

Ethnic identification among blacks and whites  

E-Print Network [OSTI]

Two central questions drive this research: (1) Are there trends in ethnic identification among blacks and whites; and (2) Are there meaningful differences between groups that identify differently? I use descriptive and regression analysis...

Glass, Teresa Gail

1996-01-01T23:59:59.000Z

246

Energy of 4-Dimensional Black Hole, etc  

E-Print Network [OSTI]

In this letter I suggest possible redefinition of mass density, not depending on speed of the mass element, which leads to a more simple stress-energy for an object. I calculate energy of black hole.

Dmitriy Palatnik

2011-07-18T23:59:59.000Z

247

Topological Black Holes -- Outside Looking In  

E-Print Network [OSTI]

I describe the general mathematical construction and physical picture of topological black holes, which are black holes whose event horizons are surfaces of non-trivial topology. The construction is carried out in an arbitrary number of dimensions, and includes all known special cases which have appeared before in the literature. I describe the basic features of massive charged topological black holes in $(3+1)$ dimensions, from both an exterior and interior point of view. To investigate their interiors, it is necessary to understand the radiative falloff behaviour of a given massless field at late times in the background of a topological black hole. I describe the results of a numerical investigation of such behaviour for a conformally coupled scalar field. Significant differences emerge between spherical and higher genus topologies.

R. B. Mann

1997-09-15T23:59:59.000Z

248

Horizon Operator Approach to Black Hole Quantization  

E-Print Network [OSTI]

The $S$-matrix Ansatz for the construction of a quantum theory of black holes is further exploited. We first note that treating the metric tensor $g_{\\m\

G. 't Hooft

1994-02-21T23:59:59.000Z

249

Towards Black Hole Entropy in Shape Dynamics  

E-Print Network [OSTI]

Shape dynamics is classical theory of gravity which agrees with general relativity in many important cases, but possesses different gauge symmetries and constraints. Rather than spacetime diffeomorphism invariance, shape dynamics takes spatial diffeomorphism invariance and spatial Weyl invariance as the fundamental gauge symmetries associated with the gravitational field. Since the area of the event horizon of a black hole transforms under a generic spatial Weyl transformation, there has been some doubt that one can speak sensibly about the thermodynamics of black holes in shape dynamics. The purpose of this paper is to show that by treating the event horizon of a black hole as an interior boundary, one can recover familiar notions of black hole thermodynamics in shape dynamics and define a gauge invariant entropy that agrees with general relativity.

Gabriel Herczeg; Vasudev Shyam

2014-10-21T23:59:59.000Z

250

BLACK ENGLISH AND THE AMERICAN VALUE SYSTEM  

E-Print Network [OSTI]

The strategy of enlightened bi-dialectalism used by the schools in the United States to deal with the problem of Black English is a significant attempt at social engineering. This attempt is motivated by basic linguistic ...

Drake, Glendon F.

1973-10-01T23:59:59.000Z

251

The structure of the carbon black flame  

E-Print Network [OSTI]

THE STRUCTURE OF THE CARBON BLACK FLAME A Dissertation By W1 111 ami Kermit Anderson THEHSR UCOF Approval as to style and content recommended Head of tiie Department of Chemistry A Dissertation Submitted to the Faculty of the Agricultural... and Mechanical College of. Texas in Parti ail Fulfilment of the Requirements for the Degree of Doctor of Philosophy THE STRUCTURE OF THE CARBON BLACK FLAME Major Subject: Chemistry AB William Hermit Anderson:\\ t * August 1945 THE STRUCTURE OF THE. CARBON...

Anderson, W. Kermi

1945-01-01T23:59:59.000Z

252

Notes on Black Hole Fluctuations and Backreaction  

E-Print Network [OSTI]

In these notes we prepare the ground for a systematic investigation into the issues of black hole fluctuations and backreaction by discussing the formulation of the problem, commenting on possible advantages and shortcomings of existing works, and introducing our own approach via a stochastic semiclassical theory of gravity based on the Einstein-Langevin equation and the fluctuation-dissipation relation for a self-consistent description of metric fluctuations and dissipative dynamics of the black hole with backreaction of its Hawking radiance.

B. L. Hu; Alpan Raval; Sukanya Sinha

1999-01-05T23:59:59.000Z

253

Electromagnetic Beams Overpass the Black Hole Horizon  

E-Print Network [OSTI]

We show that the electromagnetic excitations of the Kerr black hole have very strong back reaction on metric. In particular, the electromagnetic excitations aligned with the Kerr congruence form the light-like beams which overcome horizon, forming the holes in it, which allows matter to escape interior. So, there is no information lost inside the black hole. This effect is based exclusively on the analyticity of the algebraically special solutions.

Alexander Burinskii

2008-06-16T23:59:59.000Z

254

Local order variations in confined hard-sphere fluids  

E-Print Network [OSTI]

Pair distributions of fluids confined between two surfaces at close distance are of fundamental importance for a variety of physical, chemical, and biological phenomena, such as interactions between macromolecules in solution, surface forces, and diffusion in narrow pores. However, in contrast to bulk fluids, properties of inhomogeneous fluids are seldom studied at the pair-distribution level. Motivated by recent experimental advances in determining anisotropic structure factors of confined fluids, we analyze theoretically the underlying anisotropic pair distributions of the archetypical hard-sphere fluid confined between two parallel hard surfaces using first-principles statistical mechanics of inhomogeneous fluids. For this purpose, we introduce an experimentally accessible ensemble-averaged local density correlation function and study its behavior as a function of confining slit width. Upon increasing the distance between the confining surfaces, we observe an alternating sequence of strongly anisotropic versus more isotropic local order. The latter is due to packing frustration of the spherical particles. This observation highlights the importance of studying inhomogeneous fluids at the pair-distribution level.

Kim Nygård; Sten Sarman; Roland Kjellander

2013-10-31T23:59:59.000Z

255

Tritium level along Romanian Black Sea Coast  

SciTech Connect (OSTI)

Establishing the tritium level along the Romanian Black Sea Coast, after 10 years of exploitation of the nuclear power plant from Cernavoda, is a first step in evaluating its impact on the Black Sea ecosystem. The monitoring program consists of tritium activity concentration measurement in sea water and precipitation from Black Sea Coast between April 2005 and April 2006. The sampling points were spread over the Danube-Black Sea Canal - before the locks Agigea and Navodari, and Black Sea along the coast to the Bulgarian border. The average tritium concentration in sea water collected from the sampling locations had the value of 11.1 {+-} 2.1 TU, close to tritium concentration in precipitation. Although an operating nuclear power plant exists in the monitored area, the values of tritium concentration in two locations are slightly higher than those recorded elsewhere. To conclude, it could be emphasized that until now, Cernavoda NPP did not had any influence on the tritium concentration of the Black Sea Shore. (authors)

Varlam, C.; Stefanescu, I.; Popescu, I.; Faurescu, I. [National Inst. for Cryogenic and Isotopic Technologies, PO Box 10, Rm. Valcea, 24050 (Romania)

2008-07-15T23:59:59.000Z

256

Black liquor gasifier/gas turbine cogeneration  

SciTech Connect (OSTI)

The kraft process dominates pulp and paper production worldwide. Black liquor, a mixture of lignin and inorganic chemicals, is generated in this process as fiber is extracted from wood. At most kraft mills today, black liquor is burned in Tomlinson boilers to produce steam for on-site heat and power and to recover the inorganic chemicals for reuse in the process. Globally, the black liquor generation rate is about 85,000 MW{sub fuel} (or 0.5 million tonnes of dry solids per day), with nearly 50% of this in North America. The majority of presently installed Tomlinson boilers will reach the end of their useful lives during the next 5 to 20 years. As a replacement for Tomlinson-based cogeneration, black liquor-gasifier/gas turbine cogeneration promises higher electrical efficiency, with prospective environmental, safety, and capital cost benefits for kraft mills. Several companies are pursuing commercialization of black liquor gasification for gas turbine applications. This paper presents results of detailed performance modeling of gasifier/gas turbine cogeneration systems using different black liquor gasifiers modeled on proposed commercial designs.

Consonni, S. [Politecnico di Milano (Italy). Dept. di Energetica; Larson, E.D.; Keutz, T.G. [Princeton Univ., NJ (United States); Berglin, N. [Chalmers Univ. of Technology, Goteborg (Sweden). Dept. of Heat and Power Technology

1998-07-01T23:59:59.000Z

257

Asymptotically Lifshitz brane-world black holes  

SciTech Connect (OSTI)

We study the gravity dual of a Lifshitz field theory in the context of a RSII brane-world scenario, taking into account the effects of the extra dimension through the contribution of the electric part of the Weyl tensor. We study the thermodynamical behavior of such asymptotically Lifshitz black holes. It is shown that the entropy imposes the critical exponent z to be bounded from above. This maximum value of z corresponds to a positive infinite entropy as long as the temperature is kept positive. The stability and phase transition for different spatial topologies are also discussed. - Highlights: Black-Right-Pointing-Pointer Studying the gravity dual of a Lifshitz field theory in the context of brane-world scenario. Black-Right-Pointing-Pointer Studying the thermodynamical behavior of asymptotically Lifshitz black holes. Black-Right-Pointing-Pointer Showing that the entropy imposes the critical exponent z to be bounded from above. Black-Right-Pointing-Pointer Discussing the phase transition for different spatial topologies.

Ranjbar, Arash, E-mail: a_ranjbar@sbu.ac.ir; Sepangi, Hamid Reza, E-mail: hr-sepangi@sbu.ac.ir; Shahidi, Shahab, E-mail: s_shahidi@sbu.ac.ir

2012-12-15T23:59:59.000Z

258

Black Carbon’s Properties and Role in the Environment: A Comprehensive Review  

E-Print Network [OSTI]

H. Can reducing black carbon emissions counteract globalinventory of black carbon emissions. Atmos. Environ. 1993,commonly studied form of carbon emissions. Black carbon (BC)

Shrestha, Gyami

2010-01-01T23:59:59.000Z

259

The synchrotron boiler and the spectral states of black hole binaries  

E-Print Network [OSTI]

We study the effects of synchrotron self-absorption on the Comptonising electron distribution in the magnetised corona of accreting black holes. We solve the kinetic equations assuming that power is supplied to the coronal electrons through Coulomb collisions with a population of hot protons and/or through the injection of non-thermal energetic electrons by some unspecified acceleration process. We compute numerically the steady state particle distributions and escaping photon spectra. These numerical simulations confirm that synchrotron self-absorption, together with e-e Coulomb collisions, constitute an efficient thermalising mechanism for the coronal electrons. When compared to the data, they allow us to constrain the magnetic field and temperature of the hot protons in the corona independently of any dynamical accretion flow model or geometry. A preliminary comparison with the Low Hard State (LHS) spectrum of Cygnus X-1 indicates a magnetic field below equipartition with radiation, suggesting that the cor...

Malzac, Julien

2008-01-01T23:59:59.000Z

260

Accretion disk and ionized absorber of the 9.7-hour dipping black hole binary MAXI J1305-704  

E-Print Network [OSTI]

We report the results from X-ray studies of the newly discovered black hole candidate MAXI J1305-704 based on Suzaku and Swift observations in the low/hard and high/soft states, respectively. The long Suzaku observation shows two types of clear absorption dips, both of which recur on a dip interval of 9.74 +- 0.04 hours, which we identify with the orbital period. There is also partially ionized absorption in the non-dip (persistent) emission in both the high/soft state and, very unusually, the low/hard state. However, this absorption (in both states) has substantially lower ionization than that seen in other high inclination systems, where the material forms a homogeneous disk wind. Here instead the absorption is most probably associated with clumpy, compact structures associated with the dipping material, which we see uniquely in this source likely because we view it at a very large inclination angle. A large inclination angle is also favored, together with a low black hole mass, to explain the high disk tem...

Shidatsu, Megumi; Nakahira, Satoshi; Done, Chris; Morihana, Kumiko; Sugizaki, Mutsumi; Mihara, Tatehiro; Hori, Takafumi; Negoro, Hitoshi; Kawai, Nobuyuki; Yamaoka, Kazutaka; Ebisawa, Ken; Matsuoka, Masaru; Serino, Motoko; Yoshikawa, Tatsuhito; Nagayama, Takahiro; Matsunaga, Noriyuki

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Hard and low friction nitride coatings and methods for forming the same  

DOE Patents [OSTI]

An improved coating material possessing super-hard and low friction properties and a method for forming the same. The improved coating material includes the use of a noble metal or soft metal homogeneously distributed within a hard nitride material. The addition of small amounts of such metals into nitrides such as molybdenum nitride, titanium nitride, and chromium nitride results in as much as increasing of the hardness of the material as well as decreasing the friction coefficient and increasing the oxidation resistance.

Erdemir, Ali (Naperville, IL); Urgen, Mustafa (Istanbul, TR); Cakir, Ali Fuat (Istanbul, TR); Eryilmaz, Osman Levent (Bolingbrook, IL); Kazmanli, Kursat (Istanbul, TR); Keles, Ozgul (Istanbul, TR)

2007-05-01T23:59:59.000Z

262

Theory of angular dispersive imaging hard x-ray spectrographs  

E-Print Network [OSTI]

A spectrograph is an optical instrument that disperses photons of different energies into distinct directions and space locations, and images photon spectra on a position-sensitive detector. Spectrographs consist of collimating, angular dispersive, and focusing optical elements. Bragg reflecting crystals arranged in an asymmetric scattering geometry are used as the dispersing elements. A ray-transfer matrix technique is applied to propagate x-rays through the optical elements. Several optical designs of hard x-ray spectrographs are proposed and their performance is analyzed. Spectrographs with an energy resolution of 0.1 meV and a spectral window of imaging up to a few tens of meVs are shown to be feasible for inelastic x-ray scattering (IXS) spectroscopy applications. In another example, a spectrograph with a 1-meV spectral resolution and 85-meV spectral window of imaging is considered for Cu K-edge resonant IXS (RIXS).

Shvyd'ko, Yuri

2015-01-01T23:59:59.000Z

263

Towards hard X-ray imaging at GHz frame rate  

SciTech Connect (OSTI)

Gigahertz (GHz) imaging using hard X-rays ({approx}> 10 keV) can be useful to high-temperature plasma experiments, as well as research using coherent photons from synchrotron radiation and X-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one X-ray photon is detected per pixel, are given. Two possible paths towards X-ray imaging at GHz frame rates using a single camera are (a) Avalanche photodiode arrays of high-Z materials and (b) Microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Kwiatkowski, Kris K. [Los Alamos National Laboratory; Kapustinsky, Jon S. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

264

Towards hard x-ray imaging at GHz frame rate  

SciTech Connect (OSTI)

Gigahertz (GHz) imaging using hard x-rays ( Greater-Than-Or-Equivalent-To 10 keV) can be useful to high-temperature plasma experiments, as well as research and applications using coherent photons from synchrotron radiation and x-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one x-ray photon is detected per pixel, are given. Two possible paths towards x-ray imaging at GHz frame rates using a single camera are: (a) avalanche photodiode arrays of high-Z materials and (b) microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang Zhehui; Morris, C. L.; Kapustinsky, J. S.; Kwiatkowski, K.; Luo, S.-N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

265

Phase diagram of two-dimensional hard ellipses  

E-Print Network [OSTI]

We report the phase diagram of two-dimensional hard ellipses as obtained from replica exchange Monte Carlo simulations. The replica exchange is implemented by expanding the isobaric ensemble in pressure. The phase diagram shows four regions: isotropic, nematic, plastic, and solid (letting aside the hexatic phase at the isotropic-plastic two-step transition [PRL 107, 155704 (2011)]). At low anisotropies, the isotropic fluid turns into a plastic phase which in turn yields a solid for increasing pressure (area fraction). Intermediate anisotropies lead to a single first order transition (isotropic-solid). Finally, large anisotropies yield an isotropic-nematic transition at low pressures and a high-pressure nematic-solid transition. We obtain continuous isotropic-nematic transitions. For the transitions involving quasi-long-range positional ordering, i. e. isotropic-plastic, isotropic-solid, and nematic-solid, we observe bimodal probability density functions. This supports first order transition scenarios.

Gustavo Bautista-Carbajal; Gerardo Odriozola

2014-05-09T23:59:59.000Z

266

Goldstone modes in Lyapunov spectra of hard sphere systems  

E-Print Network [OSTI]

In this paper, we demonstrate how the Lyapunov exponents close to zero of a system of many hard spheres can be described as Goldstone modes, by using a Boltzmann type of approach. At low densities, the correct form is found for the wave number dependence of the exponents as well as for the corresponding eigenvectors in tangent-space. The predicted values for the Lyapunov exponents belonging to the transverse mode are within a few percent of the values found in recent simulations, the propagation velocity for the longitudinal mode is within 1%, but the value for the Lyapunov exponent belonging to the longitudinal mode deviates from the simulations by 30%. For higher densities, the predicted values deviate more from the values calculated in the simulations. These deviations may be due to contributions from ring collisions and similar terms, which, even at low densities, can contribute to the leading order.

Astrid S. de Wijn; Henk van Beijeren

2004-04-29T23:59:59.000Z

267

Bent-housing turbodrills improve hard-formation directional drilling  

SciTech Connect (OSTI)

Improvements in the design of turbine-powered downhole motors allowed steerable drilling in a hard formation at a high rate of penetration (ROP). Drilling in this dolomite formation with the rotary or with positive-displacement motors (PDMs) was slow during steering operations. Shell's solution to the steering penetration rate problems was to change the well plans if suitable directional drilling tools weren't available. Where possible, the wells were designed with the Zechstein interval drilled as a tangent section with non-steerable turbodrills. However, a better solution was the use of a steerable turbodrill-a tool unavailable on the market at that time. The paper describes motor development, a field test, and the design and operation of the motor.

Koot, L.; Koole, K. (Shell U.K. Exploration and Production, Lowestoft (United Kingdom)); Gaynor, T. (Neyrfor-Weir Ltd., Aberdeen (United Kingdom))

1993-02-15T23:59:59.000Z

268

Rolling friction for hard cylinder and sphere on viscoelastic solid  

E-Print Network [OSTI]

We calculate the friction force acting on a hard cylinder or spherical ball rolling on a flat surface of a viscoelastic solid. The rolling friction coefficient depends non-linearly on the normal load and the rolling velocity. For a cylinder rolling on a viscoelastic solid characterized by a single relaxation time Hunter has obtained an exact result for the rolling friction, and our result is in very good agreement with his result for this limiting case. The theoretical results are also in good agreement with experiments of Greenwood and Tabor. We suggest that measurements of rolling friction over a wide range of rolling velocities and temperatures may constitute an useful way to determine the viscoelastic modulus of rubber-like materials.

B. N. J. Persson

2010-08-26T23:59:59.000Z

269

Effective interaction approach to the Fermi hard-sphere system  

E-Print Network [OSTI]

The formalism based on correlated basis functions and the cluster expansion technique has been recently employed to derive an effective interaction from a realistic nuclear hamiltonian. To gauge the reliability of this scheme, we perform a systematic comparison between the results of its application to the Fermi hard-sphere system and the predictions obtained from low-density expansions, as well as from other many-body techniques. The analysis of a variety of properties, including the ground state energy, the effective mass and the momentum distribution, shows that the effective interaction approach is remarkably accurate, thus suggesting that it may be employed to achieve a consistent description of the structure and dynamics of nuclear matter in the density region relevant to astrophysical applications.

Angela Mecca; Alessandro Lovato; Omar Benhar; Artur Polls

2014-10-31T23:59:59.000Z

270

Method for producing hard-surfaced tools and machine components  

DOE Patents [OSTI]

In one aspect, the invention comprises a method for producing tools and machine components having superhard crystalline-ceramic work surfaces. Broadly, the method comprises two steps: a tool or machine component having a ceramic near-surface region is mounted in ion-implantation apparatus. The region then is implanted with metal ions to form, in the region, a metastable alloy of the ions and said ceramic. The region containing the alloy is characterized by a significant increase in hardness properties, such as microhardness, fracture-toughness, and/or scratch-resistance. The resulting improved article has good thermal stability at temperatures characteristic of typical tool and machine-component uses. The method is relatively simple and reproducible.

McHargue, C.J.

1981-10-21T23:59:59.000Z

271

Method for producing hard-surfaced tools and machine components  

DOE Patents [OSTI]

In one aspect, the invention comprises a method for producing tools and machine components having superhard crystalline-ceramic work surfaces. Broadly, the method comprises two steps: A tool or machine component having a ceramic near-surface region is mounted in ion-implantation apparatus. The region then is implanted with metal ions to form, in the region, a metastable alloy of the ions and said ceramic. The region containing the alloy is characterized by a significant increase in hardness properties, such as microhardness, fracture-toughness, and/or scratch-resistance. The resulting improved article has good thermal stability at temperatures characteristic of typical tool and machine-component uses. The method is relatively simple and reproducible.

McHargue, Carl J. (Farragut, TN)

1985-01-01T23:59:59.000Z

272

Study of the Radiation-Hardness of VCSEL and PIN  

E-Print Network [OSTI]

The silicon trackers of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN (Geneva) use optical links for data transmission. An upgrade of the trackers is planned for the Super LHC (SLHC), an upgraded LHC with ten times higher luminosity. We study the radiation-hardness of VCSELs (Vertical-Cavity Surface-Emitting Laser) and GaAs and silicon PINs using 24 GeV/c protons at CERN for possible application in the data transmission upgrade. The optical power of VCSEL arrays decreases significantly after the irradiation but can be partially annealed with high drive currents. The responsivities of the PIN diodes also decrease significantly after irradiation, but can be recovered by operating at higher bias voltage. This provides a simple mechanism to recover from the radiation damage.

Gan, K K; Fernando, W; Kagan, H P; Kass, R D; Lebbai, M R M; Merritt, H; Moore, J R; Nagarkar, A; Rizatdinova, F; Skubic, P L; Smith, D S; Strang, M

2009-01-01T23:59:59.000Z

273

Radiation-hard electrical coil and method for its fabrication  

DOE Patents [OSTI]

A radiation-hard insulated electrical coil and method for making the same are disclosed. In accordance with the method, a conductor, preferably copper, is wrapped with an aluminum strip and then tightly wound into a coil. The aluminum-wrapped coil is then annealed to relax the conductor in the coiled configuration. The annealed coil is then immersed in an alkaline solution to dissolve the aluminum strip, leaving the bare conductor in a coiled configuration with all of the windings closely packed yet uniformly spaced from one another. The coil is then insulated with a refractory insulating material. In the preferred embodiment, the coil is insulated by coating it with a vitreous enamel and subsequently potting the enamelled coil in a castable ceramic concrete. The resulting coil is substantially insensitive to radiation and may be operated continuously in high radiation environments for long periods of time.

Grieggs, R.J.; Blake, R.D.; Gac, F.D.

1982-06-29T23:59:59.000Z

274

Dynamic Scheduling of Hard RealTime Applications in Open System Environment  

E-Print Network [OSTI]

Dynamic Scheduling of Hard Real­Time Applications in Open System Environment Z. Deng J. W.­S. Liu J

275

E-Print Network 3.0 - aespoe hard rock Sample Search Results  

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

Collection: Mathematics 75 JUST OUTSIDE OUR DOOR by Dave Shinkle Summary: in boots and gloves Worked hard along the way Doing all the other things. Their sweat stained...

276

Holographic superconductor in the exact hairy black hole  

E-Print Network [OSTI]

We study the charged black hole of hyperbolic horizon with scalar hair (charged Martinez-Troncoso-Zanelli: CMTZ black hole) as a model of analytic hairy black hole for holographic superconductor. For this purpose, we investigate the second order phase transition between CMTZ and hyperbolic Reissner-Nordstr\\"om-AdS (HRNAdS) black holes. However, this transition unlikely occur. As an analytic treatment for holographic superconductor, we develop superconductor in the bulk and superfluidity on the boundary using the CMTZ black hole below the critical temperature. The presence of charge destroys the condensates around the zero temperature, which is in accord with the thermodynamic analysis of the CMTZ black hole.

Yun Soo Myung; Chanyong Park

2011-09-13T23:59:59.000Z

277

Perturbative String Thermodynamics near Black Hole Horizons  

E-Print Network [OSTI]

We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work JHEP 1403 (2014) 086. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of $\\alpha'$-corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large $k$ limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O'Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in $g_s$) to compute thermodynamical quantities in black hole spacetimes.

Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov

2014-10-29T23:59:59.000Z

278

The Environmental Impact of Supermassive Black Holes  

E-Print Network [OSTI]

The supermassive black holes observed at the centers of almost all present-day galaxies, had a profound impact on their environment. I highlight the principle of self-regulation, by which supermassive black holes grow until they release sufficient energy to unbind the gas that feeds them from their host galaxy. This principle explains several observed facts, including the correlation between the mass of a central black hole and the depth of the gravitational potential well of its host galaxy, and the abundance and clustering properties of bright quasars in the redshift interval of z~2-6. At lower redshifts, quasars might have limited the maximum mass of galaxies through the suppression of cooling flows in X-ray clusters. The seeds of supermassive black holes were likely planted in dwarf galaxies at redshifts z>10, through the collapse of massive or supermassive stars. The minimum seed mass can be identified observationally through the detection of gravitational waves from black hole binaries by Advanced LIGO or LISA. Aside from shaping their host galaxies, quasar outflows filled the intergalactic medium with magnetic fields and heavy elements. Beyond the reach of these outflows, the brightest quasars at z>6 have ionized exceedingly large volumes of gas (tens of comoving Mpc) prior to global reionization, and must have suppressed the faint end of the galaxy luminosity function in these volumes before the same occurred through the rest of the universe.

Abraham Loeb

2004-08-10T23:59:59.000Z

279

Investigating Dark Energy with Black Hole Binaries  

E-Print Network [OSTI]

The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.

Laura Mersini-Houghton; Adam Kelleher

2009-06-08T23:59:59.000Z

280

Black Holes with Flavors of Quantum Hair?  

E-Print Network [OSTI]

We show that black holes can posses a long-range quantum hair of super-massive tensor fields, which can be detected by Aharonov-Bohm tabletop interference experiments, in which a quantum-hairy black hole, or a remnant particle, passes through the loop of a magnetic solenoid. The long distance effect does not decouple for an arbitrarily high mass of the hair-providing field. Because Kaluza-Klein and String theories contain infinite number of massive tensor fields, we study black holes with quantum Kaluza-Klein hair. We show that in five dimensions such a black hole can be interpreted as a string of `combed' generalized magnetic monopoles, with their fluxes confined along it. For the compactification on a translation-invariant circle, this substructure uncovers hidden flux conservation and quantization of the monopole charges, which constrain the quantum hair of the resulting four-dimensional black hole. For the spin-2 quantum hair this result is somewhat unexpected, since the constituent `magnetic' charges have no `electric' counterparts. Nevertheless, the information about their quantization is encoded in singularity.

Gia Dvali

2006-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

New Evidence for High Activity of the Super-Massive Black Hole in our Galaxy  

E-Print Network [OSTI]

Prominent K-shell emission lines of neutral iron (hereafter, FeI-K) and hard-continuum X-rays were found from molecular clouds (MCs) in the Sagittarius B (Sgr B) region with the two separate Suzaku observations in 2005 and 2009. The X-ray flux of FeI-K decreased in correlation to the hard-continuum flux by factor of 0.4-0.5 in 4 years, which is nearly equal to the light-travelling across the MCs. The rapid and correlated time-variability, the equivalent width of FeI-K, and the K-edge absorption depth of FeI are consistently explained by "X-ray echoes" due to the fluorescent and Thomson-scattering of an X-ray flare from an external source. The required flux of the X-ray flare depends on the distance to the MCs and the duration time. The flux, even in the minimum case, is larger than those of the brightest Galactic X-ray sources. Based on these facts, we conclude that the super-massive black hole, Sgr A*, exhibited a big-flare about a few hundred years ago and the luminosity of higher than 4x10^39 erg s^{-1}. T...

Nobukawa, Masayoshi; Tsuru, Takeshi Go; Koyama, Katsuji

2011-01-01T23:59:59.000Z

282

General relativistic simulations of black hole-neutron star mergers: Effects of magnetic fields  

E-Print Network [OSTI]

As a neutron star (NS) is tidally disrupted by a black hole (BH) companion at the end of a BH-NS binary inspiral, its magnetic fields will be stretched and amplified. If sufficiently strong, these magnetic fields may impact the gravitational waveforms, merger evolution and mass of the remnant disk. Formation of highly-collimated magnetic field lines in the disk+spinning BH remnant may launch relativistic jets, providing the engine for a short-hard GRB. We analyze this scenario through fully general relativistic, magnetohydrodynamic (GRMHD) BHNS simulations from inspiral through merger and disk formation. Different initial magnetic field configurations and strengths are chosen for the NS interior for both nonspinning and moderately spinning (a/M=0.75) BHs aligned with the orbital angular momentum. Only strong interior (Bmax~10^17 G) initial magnetic fields in the NS significantly influence merger dynamics, enhancing the remnant disk mass by 100% and 40% in the nonspinning and spinning BH cases, respectively. However, detecting the imprint of even a strong magnetic field may be challenging for Advanced LIGO. Though there is no evidence of mass outflows or magnetic field collimation during the preliminary simulations we have performed, higher resolution, coupled with longer disk evolutions and different initial magnetic field configurations, may be required to definitively assess the possibility of BHNS binaries as short-hard GRB progenitors.

Zachariah B. Etienne; Yuk Tung Liu; Vasileios Paschalidis; Stuart L. Shapiro

2012-05-15T23:59:59.000Z

283

Neutrino Majorana Mass from Black Hole  

E-Print Network [OSTI]

We propose a new mechanism to generate the neutrino Majorana mass in TeV-scale gravity models. The black hole violates all non-gauged symmetries and can become the origin of lepton number violating processes. The fluctuation of higher-dimensional spacetime can result in the production of a black hole, which emits 2 neutrinos. If neutrinos are Majorana particles, this process is equivalent to the free propagation of a neutrino with the insertion of the black hole. From this fact, we derive the neutrino Majorana mass. The result is completely consistent with the recently observed evidence of neutrinoless double beta decay. And the obtained neutrino Majorana mass satisfies the constraint from the density of the neutrino dark matter, which affects the cosmic structure formation. Furthermore, we can explain the ultrahigh energy cosmic rays by the Z-burst scenario with it.

Yosuke Uehara

2002-05-25T23:59:59.000Z

284

Black Hole Complementarity in Gravity's Rainbow  

E-Print Network [OSTI]

We calculate the required energy for duplication of information in the context of black hole complementarity in the rainbow Schwarzschild black hole. The resultant energy can be written as the well-defined limit given by the conventional result for the vanishing rainbow parameter which characterizes the deformation of the relativistic dispersion relation in the freely falling frame. It shows that the duplication of information in quantum mechanics could be not allowed below a certain critical value of the rainbow parameter; however, it could be possible above the critical value of the rainbow parameter, so that the consistent formulation in the rainbow Schwarzschild black hole requires additional constraints or any other resolutions for the latter case.

Gim, Yongwan

2015-01-01T23:59:59.000Z

285

Extremal limits and black hole entropy  

E-Print Network [OSTI]

Taking the extremal limit of a non-extremal Reissner-Nordstr\\"om black hole (by externally varying the mass or charge), the region between the inner and outer event horizons experiences an interesting fate -- while this region is absent in the extremal case, it does not disappear in the extremal limit but rather approaches a patch of $AdS_2\\times S^2$. In other words, the approach to extremality is not continuous, as the non-extremal Reissner-Nordstr\\"om solution splits into two spacetimes at extremality: an extremal black hole and a disconnected $AdS$ space. We suggest that the unusual nature of this limit may help in understanding the entropy of extremal black holes.

Sean M. Carroll; Matthew C. Johnson; Lisa Randall

2009-01-08T23:59:59.000Z

286

Legendary Tuskegee Airmen to Speak at Jefferson Lab's Black History...  

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

Lab's Black History Month Event February 3, 2004 Three members of the legendary, World War II era Tuskegee Airmen will speak at Jefferson Lab's Black History Month celebration at...

287

Improved recovery of tall oil from black liquors  

SciTech Connect (OSTI)

Applying a d.c. of less than 15 V to acidified black liquor separates a significant amount of tall oil remaining in the black liquor sludge. An apparatus with graphite electrodes for this process is described.

Zucker, J.

1980-12-09T23:59:59.000Z

288

Topological black holes in Horava-Lifshitz gravity  

SciTech Connect (OSTI)

We find topological (charged) black holes whose horizon has an arbitrary constant scalar curvature 2k in Horava-Lifshitz theory. Without loss of generality, one may take k=1, 0, and -1. The black hole solution is asymptotically anti-de Sitter with a nonstandard asymptotic behavior. Using the Hamiltonian approach, we define a finite mass associated with the solution. We discuss the thermodynamics of the topological black holes and find that the black hole entropy has a logarithmic term in addition to an area term. We find a duality in Hawking temperature between topological black holes in Horava-Lifshitz theory and Einstein's general relativity: the temperature behaviors of black holes with k=1, 0, and -1 in Horava-Lifshitz theory are, respectively, dual to those of topological black holes with k=-1, 0, and 1 in Einstein's general relativity. The topological black holes in Horava-Lifshitz theory are thermodynamically stable.

Cai Ronggen [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China) and Kavli Institute for Theoretical Physics China (KITPC), 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); Ohta, Nobuyoshi [Department of Physics, Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan)

2009-07-15T23:59:59.000Z

289

Black Hills Energy (Gas)- Residential Energy Efficiency Rebate Programs  

Broader source: Energy.gov [DOE]

Black Hills Energy offers its residential Iowa customers incentives to encourage energy efficiency in their homes. Black Hills Energy offers a free home energy evaluation to customers (both owners...

290

The Development of the Emerald Programming Language Andrew P. Black  

E-Print Network [OSTI]

The Development of the Emerald Programming Language Andrew P. Black Portland State University black@cs.pdx.edu Norman C. Hutchinson University of British Columbia norm@cs.ubc.ca Eric Jul University of Copenhagen eric

Black, Andrew P.

291

Dynamics of galaxy cores and supermassive black holes  

E-Print Network [OSTI]

Recent work on the dynamical evolution of galactic nuclei containing supermassive black holes is reviewed. Topics include galaxy structural properties; collisionless and collisional equilibria; loss-cone dynamics; and dynamics of binary and multiple supermassive black holes.

David Merritt

2006-05-02T23:59:59.000Z

292

CHARYBDIS: A Black Hole Event Generator  

E-Print Network [OSTI]

CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.

C. M. Harris; P. Richardson; B. R. Webber

2003-07-24T23:59:59.000Z

293

Might black holes reveal their inner secrets?  

E-Print Network [OSTI]

Black holes harbor a spacetime singularity of infinite curvature, where classical spacetime physics breaks down, and current theory cannot predict what will happen. However, the singularity is invisible from the outside because strong gravity traps all signals, even light, behind an event horizon. In this essay we discuss whether it might be possible to destroy the horizon, if a body is tossed into the black hole so as to make it spin faster and/or have more charge than a certain limit. It turns out that one could expose a "naked" singularity if effects of the body's own gravity can be neglected. We suspect however that such neglect is unjustified.

Ted Jacobson; Thomas P. Sotiriou

2010-06-09T23:59:59.000Z

294

BLACK HOLE ENTROPY IN HIGHER CURVATURE GRAVITY  

E-Print Network [OSTI]

We discuss some recent results on black hole thermodynamics within the context of effective gravitational actions including higher-curvature interactions. Wald's derivation of the First Law demonstrates that black hole entropy can always be expressed as a local geometric density integrated over a space-like cross-section of the horizon. In certain cases, it can also be shown that these entropy expressions satisfy a Second Law. One such simple example is considered from the class of higher curvature theories where the Lagrangian consists of a polynomial in the Ricci scalar.

TED JACOBSON; GUNGWON KANG; ROBERT C. MYERS

1995-02-27T23:59:59.000Z

295

How red is a quantum black hole?  

E-Print Network [OSTI]

Radiating black holes pose a number of puzzles for semiclassical and quantum gravity. These include the transplanckian problem -- the nearly infinite energies of Hawking particles created near the horizon, and the final state of evaporation. A definitive resolution of these questions likely requires robust inputs from quantum gravity. We argue that one such input is a quantum bound on curvature. We show how this leads to an upper limit on the redshift of a Hawking emitted particle, to a maximum temperature for a black hole, and to the prediction of a Planck scale remnant.

Viqar Husain; Oliver Winkler

2005-05-30T23:59:59.000Z

296

Black nickel selective absorber, optimization of parameters  

SciTech Connect (OSTI)

Electroplated black nickel selective absorber is one of the most commercially used element of solar energy systems. Electrodeposition parameters such as time of deposition, pH, current density, electrolyte temperature should be optimized to produce the most efficient selective absorber. The topology of the substrate material is very effective on selectivity and it should also be optimized. In this study, by controlling the conditions of electrodeposition black nickel selective absorbers are produced and their reflectivities are measured. The effects of the electrodeposition parameters together with the topology of the substrate, on the selective properties are investigated.

Akinoglu, B.; Cercioglu, V.; Ecevit, A.

1983-12-01T23:59:59.000Z

297

Tachyon Perturbation on Two Dimensional Black Hole  

E-Print Network [OSTI]

We study the black hole geometry in the presence of tachyonic perturbations, and solve for the form of allowed tachyonic hair in the presence of back reaction, and for the form of the metric under the assumption that only the metric is perturbed but not the dilaton. We evaluate the Kretschmann scalar and argue that the horizon becomes singular in the presence of tachyons, implying that the black hole has turned into a naked singularity. A form of the allowed tachyon potential emerges as a requirement of self-consistency of our solution.

Aniket Basu

2014-07-03T23:59:59.000Z

298

Chaotic Information Processing by Extremal Black Holes  

E-Print Network [OSTI]

We review an explicit regularization of the AdS$_2$/CFT$_1$ correspondence, that preserves all isometries of bulk and boundary degrees of freedom. This scheme is useful to characterize the space of the unitary evolution operators that describe the dynamics of the microstates of extremal black holes in four spacetime dimensions. Using techniques from algebraic number theory to evaluate the transition amplitudes, we remark that the regularization scheme expresses the fast quantum computation capability of black holes as well as its chaotic nature.

Axenides, Minos; Nicolis, Stam

2015-01-01T23:59:59.000Z

299

BlackGold Biofuels | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectricEnergyCTBarre BiomassTHIS PAGE ISJump to: navigation,BlackBlackGold

300

Hard quark-quark scattering with exclusive reactions  

SciTech Connect (OSTI)

We have begun a program designed to study hard quark-quark scattering with exclusive reactions, focusing on quasi-elastic two-body reactions with all possible quark flavor exchanges. Examples are ..pi../sup -/p ..-->.. ..pi../sup -/p, rho/sup -/p, ..pi../sup +/..delta../sup -/, K/sup +/..sigma../sup -/, or K..lambda... Of the two-body exclusives, only elastic scattering had been measured at such large t previous to our experiment. By comparing the relative importance of different final states, the energy dependence of the production ratios of these states, the prominence of resonances such as rho/sup -/ over background in this region, and measuring polarizations where accessible, we have collected a large body of data on hard scattering in a completely new domain. Previously, essential all short distance QCD tests have been for inclusive processes. We have taken data with both negative and positive incident beam at 10 GeV/c on a hydrogen target and will present the first results, for ..pi../sup -/p ..-->.. ..pi../sup -/p and rho/sup -/p at THETA/sub cm/ = 90/sup 0/, -t = 9 GeV/sup 2//c/sup 2/. The apparatus consists of a magnetic spectrometer, with Cerenkov particle identification, which selects stable charged particles (protons in this case) at high momentum near 90/sup 0/ in the center-of-mass. A large aperture array of PWCs observes the recoil particle or charged decay products. Cross sections are extremely low, approximately a 1 nb/(GeV/c)/sup 2/ for elastic scattering. We will report on a sample of more than 1000 ..pi../sup -/p elastic events, and on rho/sup -/p, where the rho/sup -/ decay distribution was observed. We find a surprisingly large rho/sup -/p cross section in this large momentum transfer region, with rho/sup -/p about half the elastic cross section, and a striking spin alignment of the rho/sup -/.

Barton, D.S.; Bunce, G.M.; Carroll, A.S.; Makdisi, Y.I.; Baller, B.; Blazey, G.C.; Courant, H.; Heller, K.J.; Heppelmann, S.; Marshak, M.L.

1984-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Isotope Biogeochemistry of Diagenesis caused by a Black  

E-Print Network [OSTI]

the coasts of Surinam and French Guyana #12;µ Black shales in Leg 207 sediments and pore water response depth

302

Can the fluctuations of a black hole be treated thermodynamically?  

E-Print Network [OSTI]

Since the temperature of a typical Schwarzschild black hole is very low, some doubts are raised about whether the fluctuations of the black hole can be treated thermodynamically. It is shown that this is not the case: the thermodynamic fluctuations of a black hole are considerably larger than the corresponding quantum fluctuations. Moreover the ratio of the mean square thermodynamic fluctuation to the corresponding quantum fluctuation can be interpreted as a number of the effective constituents of a black hole.

Kostyantyn Ropotenko

2008-03-31T23:59:59.000Z

303

A Note on Black Hole Temperature and Entropy  

E-Print Network [OSTI]

We propose intuitive derivations of the Hawking temperature and the Bekenstein-Hawking entropy of a Schwarzschild black hole.

P. R. Silva

2006-05-09T23:59:59.000Z

304

Black holes in Born-Infeld extended new massive gravity  

SciTech Connect (OSTI)

In this paper we find different types of black holes for the Born-Infeld extended new massive gravity. Our solutions include (un)charged warped (anti-)de Sitter black holes for four and six derivative expanded action. We also look at the black holes in unexpanded Born-Infeld action. In each case we calculate the entropy, angular momentum and mass of the black holes. We also find the central charges for the conformal field theory duals.

Ghodsi, Ahmad; Yekta, Davood Mahdavian [Department of Physics, Ferdowsi University of Mashhad, P.O. Box 1436, Mashhad (Iran, Islamic Republic of)

2011-05-15T23:59:59.000Z

305

Particles and scalar waves in noncommutative charged black hole spacetime  

E-Print Network [OSTI]

In this paper we have discussed geodesics and the motion of test particle in the gravitational field of noncommutative charged black hole spacetime. The motion of massive and massless particle have been discussed seperately. A comparative study of noncommutative charged black hole and usual Reissner-Nordstrom black hole has been done. The study of effective potential has also been included. Finally, we have examined the scattering of scalar waves in noncommutative charged black hole spacetime.

Bhar, Piyali; Biswas, Ritabrata; Mondal, U F

2015-01-01T23:59:59.000Z

306

Entropy and Area of Black Holes in Loop Quantum Gravity  

E-Print Network [OSTI]

Simple arguments related to the entropy of black holes strongly constrain the spectrum of the area operator for a Schwarzschild black hole in loop quantum gravity. In particular, this spectrum is fixed completely by the assumption that the black hole entropy is maximum. Within the approach discussed, one arrives in loop quantum gravity at a quantization rule with integer quantum numbers $n$ for the entropy and area of a black hole.

I. B. Khriplovich

2002-03-31T23:59:59.000Z

307

Liquid metal feeding through dendritic region in Ni-Hard white iron  

SciTech Connect (OSTI)

Liquid permeability in the dendritic regions is one of the factors that determine porosity formation and macro segregation in castings. Permeability in the dendritic structure of Ni-Hard white iron was measured as a function of temperature. Effect of microstructural coarsening on the permeability was also investigated. Permeability increased with coarsening dendritic structure in Ni-Hard white iron.

Oryshchyn, Danylo B.; Dogan, Omer N.

2005-01-01T23:59:59.000Z

308

Regularized reconstruction of the differential emission measure from solar flare hard X-ray spectra  

E-Print Network [OSTI]

Regularized reconstruction of the differential emission measure from solar flare hard X-ray spectra for solar flare hard X-rays, it is currently unclear whether the electron distribution responsible between (T) and J( ). However, in the last years, two issues have made this inversion problem more

Piana, Michele

309

Computational Investigation of Hardness Evolution During Friction-Stir Welding of AA5083 and AA2139  

E-Print Network [OSTI]

Computational Investigation of Hardness Evolution During Friction-Stir Welding of AA5083 and AA2139 coupled thermo-mechanical finite-element analysis of the friction-stir welding (FSW) process developed, finite-element analysis, friction- stir welding, hardness prediction 1. Introduction Having a more mobile

Grujicic, Mica

310

K.K. Gan RD07 1 Radiation-Hard Optical Link for SLHC  

E-Print Network [OSTI]

spliced SIMM-GRIN fiber Radiation hardness of PIN/VCSEL arrays Results on MT-style optical packages irradiation? What is optical power after irradiation? What current is needed for annealing? #12;K.K. Gan RDK.K. Gan RD07 1 Radiation-Hard Optical Link for SLHC June 28, 2007 W. Fernando, K.K. Gan, A. Law, H

Gan, K. K.

311

K.K. Gan HEP2007 1 Radiation-Hard Optical Link for SLHC  

E-Print Network [OSTI]

of fusion spliced SIMM-GRIN fiber Radiation hardness of PIN/VCSEL arrays Results on MT-style optical What is rise/fall time after irradiation? What is optical power after irradiation? What currentK.K. Gan HEP2007 1 Radiation-Hard Optical Link for SLHC July 20, 2007 W. Fernando, K.K. Gan, A. Law

Gan, K. K.

312

Estimating the Economic Impact for the Commercial Hard Clam Culture Industry on the Economy of  

E-Print Network [OSTI]

1 Estimating the Economic Impact for the Commercial Hard Clam Culture Industry on the Economy that the economic impact of the cultured hard clam industry on the economy of Florida was approximately $34 million communities and the statewide economy Florida. A follow-up study to the 2000 study was recently funded

Florida, University of

313

A Framework for Dynamic Hard/Soft Fusion David L. Hall  

E-Print Network [OSTI]

/asymmetric warfare cases where the observational capabilities and opportunities for traditional electronic ("Hard on the ongoing development ofa research framework for dynamic integration of information from hard (electronic" henceforth) sensors is limited. This is especially related to the urban warfare case

Mullen, Tracy

314

The Extended Power Law as Intrinsic Signature For a Black Hole  

E-Print Network [OSTI]

We analyze the exact general relativistic exact integro-differential equation of radiative transfer describing the interaction of low energy photons with a Maxwellian distribution of hot electrons in gravitational field of a Schwarzschild black hole. We prove that due to Comptonization an initial arbitrary spectrum of low energy photons unavoidably results in spectra characterized by an extended power-law feature. We examine the spectral index by using both analytical and numerical methods for a variety of physical parameters as such the plasma temperature and the mass accretion rate. The presence of the event horizon as well as the behaviour of the null geodesics in its vicinity largely determine the dependence of the spectral index on the flow parameters. We come to the conclusion that the bulk motion of a converging flow is more efficient in upscattering photons than thermal Comptonization provided that the electron temperature in the flow is of order of a few keV or less. In this case, the spectrum observed at infinity consists of a soft component produced by those input photons that escape after a few scatterings without any significant energy change and of hard component (described by a power law) produced by the photons that underwent significant upscattering. The luminosity of the power-law component is relatively small compared to that of the soft component. For accretion into black hole the spectral energy index of the power-law is always higher than one for plasma temperature of order of a few keV. This result suggests that the bulk motion Comptonization might be responsible for the power-law spectra seen in the black-hole X-ray sources.

Lev Titarchuk; Thomas Zannias

1997-08-27T23:59:59.000Z

315

Emission of scalar particles from cylindrical black holes  

E-Print Network [OSTI]

We study quantum tunneling of scalar particles from black strings. For this purpose we apply WKB approximation and Hamilton-Jacobi method to solve the Klein-Gordon equation for outgoing trajectories. We find the tunneling probability of outgoing charged and uncharged scalars from the event horizon of black strings, and hence the Hawking temperature for these black configurations.

H. Gohar; K. Saifullah

2011-09-27T23:59:59.000Z

316

Are black holes with hair a normal state of matter?  

SciTech Connect (OSTI)

Recent observations put forward that quasars are black holes with a magnetic dipole moment and no event horizon. To model hairy black holes a quantum field for hydrogen is considered in curved space, coupled to the scalar curvature. An exact, regular solution for the interior metric occurs for supermassive black holes. The equation of state is p = -{rho}c{sup 2}/3.

Nieuwenhuizen, Th. M. [Institute for Theoretical Physics, Science Park 904, P. O. Box 94485, 1090 GL Amsterdam (Netherlands)

2011-03-28T23:59:59.000Z

317

A Link Between Black Holes and the Golden Ratio  

E-Print Network [OSTI]

We consider a variational formalism to describe black holes solution in higher dimensions. Our procedure clarifies the arbitrariness of the radius parameter and, in particular, the meaning of the event horizon of a black hole. Moreover, our formalism enables us to find a surprising link between black holes and the golden ratio.

J. A. Nieto

2011-06-02T23:59:59.000Z

318

Location and Geology Fig 1. The Macasty black shale  

E-Print Network [OSTI]

, Quebec, is organic-rich black shale and hosting oil and gas. It is equivalent to the Ithaca shaleLocation and Geology Fig 1. The Macasty black shale in the Anticosti Island in the Gulf of St. d13C for calcite disseminated in the black shale range from 2.6o to 2.8 / The values are lower

319

Refractive Optics for Hard X-ray Transmission Microscopy  

SciTech Connect (OSTI)

For hard x-ray transmission microscopy at photon energies higher than 15 keV we design refractive condenser and imaging elements to be used with synchrotron light sources as well as with x-ray tube sources. The condenser lenses are optimized for low x-ray attenuation--resulting in apertures greater than 1 mm--and homogeneous intensity distribution on the detector plane, whereas the imaging enables high-resolution (<100 nm) full-field imaging. To obtain high image quality at reasonable exposure times, custom-tailored matched pairs of condenser and imaging lenses are being developed. The imaging lenses (compound refractive lenses, CRLs) are made of SU-8 negative resist by deep x-ray lithography. SU-8 shows high radiation stability. The fabrication technique enables high-quality lens structures regarding surface roughness and arrangement precision with arbitrary 2D geometry. To provide point foci, crossed pairs of lenses are used. Condenser lenses have been made utilizing deep x-ray lithographic patterning of thick SU-8 layers, too, whereas in this case, the aperture is limited due to process restrictions. Thus, in terms of large apertures, condenser lenses made of structured and rolled polyimide film are more attractive. Both condenser types, x-ray mosaic lenses and rolled x-ray prism lenses (RXPLs), are considered to be implemented into a microscope setup. The x-ray optical elements mentioned above are characterized with synchrotron radiation and x-ray laboratory sources, respectively.

Simon, M.; Last, A.; Mohr, J.; Nazmov, V.; Reznikova, E. [Institute for Microstructure Technology, Karlsruhe Institute of Technology Kaiserstrasse 12, 76131 Karlsruhe (Germany); Ahrens, G.; Voigt, A. [Microresist Technology, Koepenikerstrasse 325, 12555 Berlin (Germany)

2011-09-09T23:59:59.000Z

320

Lyapunov instability of rough hard-disk fluids  

E-Print Network [OSTI]

The dynamical instability of rough hard-disk fluids in two dimensions is characterized through the Lyapunov spectrum and the Kolmogorov-Sinai entropy, $h_{KS}$, for a wide range of densities and moments of inertia $I$. For small $I$ the spectrum separates into translation-dominated and rotation-dominated parts. With increasing $I$ the rotation-dominated part is gradually filled in at the expense of translation, until such a separation becomes meaningless. At any density, the rate of phase-space mixing, given by $h_{KS}$, becomes less and less effective the more the rotation affects the dynamics. However, the degree of dynamical chaos, measured by the maximum Lyapunov exponent, is only enhanced by the rotational degrees of freedom for high-density gases, but is diminished for lower densities. Surprisingly, no traces of Lyapunov modes were found in the spectrum for larger moments of inertia. The spatial localization of the perturbation vector associated with the maximum exponent however persists for any $I$.

Jacobus A. van Meel; Harald A. Posch

2009-04-02T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Isotropic-nematic phase behavior of length polydisperse hard rods  

E-Print Network [OSTI]

The isotropic-nematic phase behavior of length polydisperse hard rods with arbitrary length distributions is calculated. Within a numerical treatment of the polydisperse Onsager model using the Gaussian trial function Ansatz we determine the onset of isotropic-nematic phase separation, coming from a dilute isotropic phase and a dense nematic phase. We focus on parent systems whose lengths can be described by either a Schulz or a `fat-tailed' log-normal distribution with appropriate lower and upper cutoff lengths. In both cases, very strong fractionation effects are observed for parent polydispersities larger than roughly 50 %. In these regimes, the isotropic and nematic phases are completely dominated by respectively the shortest and the longest rods in the system. Moreover, for the log-normal case, we predict triphasic isotropic-nematic-nematic equilibria to occur above a certain threshold polydispersity. By investigating the properties of the coexisting phases across the coexistence region for a particular set of cutoff lengths we explicitly show that the region of stable triphasic equilibria does not extend up to very large parent polydispersities but closes off at a consolute point located not far above the threshold polydispersity. The experimental relevance of the phenomenon is discussed.

H. H. Wensink; G. J. Vroege

2003-04-18T23:59:59.000Z

322

West Short Pine Hills field, Harding County, South Dakota  

SciTech Connect (OSTI)

The West Short Pine Hills field is a shallow gas field that produces from the Shannon Sandstone Member, on the Camp Crook anticline in southwestern Harding County, South Dakota. The Alma McCutchin 1-17 Heikkila discovery was drilled in the NW1/4, Sec. 17, T16N, R2E, to a depth of 1600 ft and completed in October 1977 for 600 MCFGD from perforations at 1405-1411 ft. To date, 40 gas wells have been completed with total estimated reserves of more than 20 bcf. The field encompasses 12,000 ac, with a current drill-site spacing unit of 160 ac. The field boundaries are fairly well defined, except on the south edge of the field. The wells range in depth from 1250 to 2200 ft, and cost $60,000-$85,000 to drill and complete. Core and log analyses indicate that the field has 70 ft of net pay, with average porosity of 30% and average permeability of 114 md. Most wells have been completed with nitrogen-sand frac. Williston Basin Interstate Pipeline Company of Bismarck, North Dakota, operates a compressor station and 2.5 mi of 4-in. line that connects the field to their 160 in. north-south transmission line to the Rapid City area. Currently, producers are netting $1.10-$1.25/million Btu. The late Mathew T. Biggs of Casper, Wyoming, was the geologist responsible for mapping and finding this gas deposit.

Strothman, B.

1988-07-01T23:59:59.000Z

323

Method and apparatus for micromachining using hard X-rays  

DOE Patents [OSTI]

An X-ray source such as a synchrotron which provides a significant spectral content of hard X-rays is used to expose relatively thick photoresist such that the portions of the photoresist at an exit surface receive at least a threshold dose sufficient to render the photoresist susceptible to a developer, while the entrance surface of the photoresist receives an exposure which does not exceed a power limit at which destructive disruption of the photoresist would occur. The X-ray beam is spectrally shaped to substantially eliminate lower energy photons while allowing a substantial flux of higher energy photons to pass through to the photoresist target. Filters and the substrate of the X-ray mask may be used to spectrally shape the X-ray beam. Machining of photoresists such as polymethylmethacrylate to micron tolerances may be obtained to depths of several centimeters, and multiple targets may be exposed simultaneously. The photoresist target may be rotated and/or translated in the beam to form solids of rotation and other complex three-dimensional structures.

Siddons, David Peter (Shoreham, NY); Johnson, Erik D. (Ridge, NY); Guckel, Henry (Madison, WI); Klein, Jonathan L. (Madison, WI)

1997-10-21T23:59:59.000Z

324

Method and apparatus for micromachining using hard X-rays  

DOE Patents [OSTI]

An X-ray source such as a synchrotron which provides a significant spectral content of hard X-rays is used to expose relatively thick photoresist such that the portions of the photoresist at an exit surface receive at least a threshold dose sufficient to render the photoresist susceptible to a developer, while the entrance surface of the photoresist receives an exposure which does not exceed a power limit at which destructive disruption of the photoresist would occur. The X-ray beam is spectrally shaped to substantially eliminate lower energy photons while allowing a substantial flux of higher energy photons to pass through to the photoresist target. Filters and the substrate of the X-ray mask may be used to spectrally shape the X-ray beam. Machining of photoresists such as polymethylmethacrylate to micron tolerances may be obtained to depths of several centimeters, and multiple targets may be exposed simultaneously. The photoresist target may be rotated and/or translated in the beam to form solids of rotation and other complex three-dimensional structures. 21 figs.

Siddons, D.P.; Johnson, E.D.; Guckel, H.; Klein, J.L.

1997-10-21T23:59:59.000Z

325

Quantum Searches in a Hard 2SAT Ensemble  

E-Print Network [OSTI]

Using a recently constructed ensemble of hard 2SAT realizations, that has a unique ground-state we calculate for the quantized theory the median gap correlation length values $\\xi_{GAP}$ along the direction of the quantum adiabatic control parameter $\\lambda$. We use quantum annealing (QA) with transverse field and a linear time schedule in the adiabatic control parameter $\\lambda$. The gap correlation length diverges exponentially $\\xi_{\\rm GAP} \\propto {\\rm exp} [+r_{\\rm GAP}N]$ in the median with a rate constant $r_{\\rm GAP}=0.553(6)$, while the run time diverges exponentially $\\tau_{\\rm QA} \\propto {\\rm exp} [+r_{\\rm QA}N]$ with $r_{\\rm QA}=1.184(16)$. Simulated classical annealing (SA) exhibits a run time rate constant $r_{\\rm SA}=0.340(5)$ that is small and thus finds ground-states exponentially faster than QA. There are no quantum speedups in ground state searches on constant energy surfaces that have exponentially large volume. We also determine gap correlation length distribution functions $P(\\xi_{\\rm GAP})d\\xi_{\\rm GAP} \\approx W_k$ over the ensemble that at $N=18$ are close to Weibull functions $W_k$ with $k \\approx 1.2$ i.e., the problems show thin catastrophic tails in $\\xi_{\\rm GAP}$. The inferred success probability distribution functions of the quantum annealer turn out to be bimodal.

Neuhaus Thomas

2014-12-17T23:59:59.000Z

326

T-534: Vulnerability in the PDF distiller of the BlackBerry Attachment Service for the BlackBerry Enterprise Server  

Broader source: Energy.gov [DOE]

BlackBerry advisory describes a security issue that the BlackBerry Attachment Service component of the BlackBerry Enterprise Server is susceptible to. The issue relates to a known vulnerability in the PDF distiller component of the BlackBerry Attachment Service that affects how the BlackBerry Attachment Service processes PDF files.

327

Black Holes and Sub-millimeter Dimensions  

E-Print Network [OSTI]

Recently, a new framework for solving the hierarchy problem was proposed which does not rely on low energy supersymmetry or technicolor. The fundamental Planck mass is at a TeV and the observed weakness of gravity at long distances is due the existence of new sub-millimeter spatial dimensions. In this letter, we study how the properties of black holes are altered in these theories. Small black holes---with Schwarzschild radii smaller than the size of the new spatial dimensions---are quite different. They are bigger, colder, and longer-lived than a usual $(3+1)$-dimensional black hole of the same mass. Furthermore, they primarily decay into harmless bulk graviton modes rather than standard-model degrees of freedom. We discuss the interplay of our scenario with the holographic principle. Our results also have implications for the bounds on the spectrum of primordial black holes (PBHs) derived from the photo-dissociation of primordial nucleosynthesis products, distortion of the diffuse gamma-ray spectrum, overcl...

Argyres, Philip C; March-Russell, John David; Argyres, Philip C.; Dimopoulos, Savas; March-Russell, John

1998-01-01T23:59:59.000Z

328

Black Holes in Einstein-Aether Theory  

E-Print Network [OSTI]

We study black hole solutions in general relativity coupled to a unit timelike vector field dubbed the "aether". To be causally isolated a black hole interior must trap matter fields as well as all aether and metric modes. The theory possesses spin-0, spin-1, and spin-2 modes whose speeds depend on four coupling coefficients. We find that the full three-parameter family of local spherically symmetric static solutions is always regular at a metric horizon, but only a two-parameter subset is regular at a spin-0 horizon. Asymptotic flatness imposes another condition, leaving a one-parameter family of regular black holes. These solutions are compared to the Schwarzschild solution using numerical integration for a special class of coupling coefficients. They are very close to Schwarzschild outside the horizon for a wide range of couplings, and have a spacelike singularity inside, but differ inside quantitatively. Some quantities constructed from the metric and aether oscillate in the interior as the singularity is approached. The aether is at rest at spatial infinity and flows into the black hole, but differs significantly from the the 4-velocity of freely-falling geodesics.

Christopher Eling; Ted Jacobson

2010-03-28T23:59:59.000Z

329

Geodesic study of a charged black hole  

E-Print Network [OSTI]

The behavior of the timelike and null geodesics of charged E. Ay$\\acute{o}$n-Beato and A. Garcia (ABG) black hole are investigated. For circular and radial geodesics, we investigate all the possible motions by plotting the effective potentials for different parameters. In conclusion, we have shown that there is no phenomenon of \\textit{superradiance} in this case.

Mehedi Kalam; Nur Farhad; Sk. Monowar Hossein

2013-03-17T23:59:59.000Z

330

Limits on New Physics from Black Holes  

E-Print Network [OSTI]

Black holes emit high energy particles which induce a finite density potential for any scalar field $\\phi$ coupling to the emitted quanta. Due to energetic considerations, $\\phi$ evolves locally to minimize the effective masses of the outgoing states. In theories where $\\phi$ resides at a metastable minimum, this effect can drive $\\phi$ over its potential barrier and classically catalyze the decay of the vacuum. Because this is not a tunneling process, the decay rate is not exponentially suppressed and a single black hole in our past light cone may be sufficient to activate the decay. Moreover, decaying black holes radiate at ever higher temperatures, so they eventually probe the full spectrum of particles coupling to $\\phi$. We present a detailed analysis of vacuum decay catalyzed by a single particle, as well as by a black hole. The former is possible provided large couplings or a weak potential barrier. In contrast, the latter occurs much more easily and places new stringent limits on theories with hierarchical spectra. Finally, we comment on how these constraints apply to the standard model and its extensions, e.g. metastable supersymmetry breaking.

Clifford Cheung; Stefan Leichenauer

2014-08-02T23:59:59.000Z

331

Pulsed combustion process for black liquor gasification  

SciTech Connect (OSTI)

The objective of this project is to test an energy efficient, innovative black liquor recovery system on an industrial scale. In the MTCI recovery process, black liquor is sprayed directly onto a bed of sodium carbonate solids which is fluidized by steam. Direct contact of the black liquor with hot bed solids promotes high rates of heating and pyrolysis. Residual carbon, which forms as a deposit on the particle surface, is then gasified by reaction with steam. Heat is supplied from pulse combustor resonance tubes which are immersed within the fluid bed. A portion of the gasifier product gas is returned to the pulse combustors to provide the energy requirements of the reactor. Oxidized sulfur species are partially reduced by reaction with the gasifier products, principally carbon monoxide and hydrogen. The reduced sulfur decomposed to solid sodium carbonate and gaseous hydrogen sulfide (H{sub 2}S). Sodium values are recovered by discharging a dry sodium carbonate product from the gasifier. MTCI's indirectly heated gasification technology for black liquor recovery also relies on the scrubbing of H{sub 2}S for product gases to regenerate green liquor for reuse in the mill circuit. Due to concerns relative to the efficiency of sulfur recovery in the MTCI integrated process, an experimental investigation was undertaken to establish performance and design data for this portion of the system.

Durai-Swamy, K.; Mansour, M.N.; Warren, D.W.

1991-02-01T23:59:59.000Z

332

Schwarzschild black hole in dark energy background  

E-Print Network [OSTI]

In this paper we present an exact solution of Einstein's field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type $D$ in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole.

Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

2014-09-27T23:59:59.000Z

333

4, 871891, 2007 Mobility of black  

E-Print Network [OSTI]

BGD 4, 871­891, 2007 Mobility of black carbon J. Leifeld et al. Title Page Abstract Introduction Discussion EGU Biogeosciences Discuss., 4, 871­891, 2007 www.biogeosciences-discuss.net/4/871/2007/ © Author ­ Published: 23 March 2007 Correspondence to: J. Leifeld (jens.leifeld@art.admin.ch) 871 #12;BGD 4, 871

Paris-Sud XI, Université de

334

Supermassive Black Hole Binaries: The Search Continues  

E-Print Network [OSTI]

Gravitationally bound supermassive black hole binaries (SBHBs) are thought to be a natural product of galactic mergers and growth of the large scale structure in the universe. They however remain observationally elusive, thus raising a question about characteristic observational signatures associated with these systems. In this conference proceeding I discuss current theoretical understanding and latest advances and prospects in observational searches for SBHBs.

Tamara Bogdanovic

2014-06-19T23:59:59.000Z

335

Typechecking Polymorphism in Emerald Andrew P. Black  

E-Print Network [OSTI]

Typechecking Polymorphism in Emerald Andrew P. Black Digital Equipment Corporation Norman, distributed programming. c Digital Equipment Corporation and Norman Hutchinson 1991. All rights reserved by the National Science Foundation under Grant CCR-8701516. Norman Hutchinson was with the University of Arizona

Black, Andrew P.

336

Six Sigma Black Belts Fight For Quality  

E-Print Network [OSTI]

Six Sigma Black Belts Fight For Quality Ron Scott Ross Finnestad Rodney Kalsow IE 361 mini-paper 9/22/00 #12;Six Sigma is a breakthrough management strategy that is revolutionizing the world's top corporations. So what is Six Sigma? "It is a business process that allows companies to drastically improve

Vardeman, Stephen B.

337

Brief review on higher spin black holes  

E-Print Network [OSTI]

We review some relevant results in the context of higher spin black holes in three-dimensional spacetimes, focusing on their asymptotic behaviour and thermodynamic properties. For simplicity, we mainly discuss the case of gravity nonminimally coupled to spin-3 fields, being nonperturbatively described by a Chern-Simons theory of two independent sl(3,R) gauge fields. Since the analysis is particularly transparent in the Hamiltonian formalism, we provide a concise discussion of their basic aspects in this context; and as a warming up exercise, we briefly analyze the asymptotic behaviour of pure gravity, as well as the BTZ black hole and its thermodynamics, exclusively in terms of gauge fields. The discussion is then extended to the case of black holes endowed with higher spin fields, briefly signaling the agreements and discrepancies found through different approaches. We conclude explaining how the puzzles become resolved once the fall off of the fields is precisely specified and extended to include chemical potentials, in a way that it is compatible with the asymptotic symmetries. Hence, the global charges become completely identified in an unambiguous way, so that different sets of asymptotic conditions turn out to contain inequivalent classes of black hole solutions being characterized by a different set of global charges.

Alfredo Perez; David Tempo; Ricardo Troncoso

2014-05-12T23:59:59.000Z

338

Repackaging SRS Black Box TRU Waste  

SciTech Connect (OSTI)

Historically, large items of TRU Waste, which were too large to be packaged in drums for disposal have been packaged in various sizes of custom made plywood boxes at the Savannah River Site (SRS), for many years. These boxes were subsequently packaged into large steel ''Black Boxes'' for storage at SRS, pending availability of Characterization and Certification capability, to facilitate disposal of larger items of TRU Waste. There are approximately 107 Black Boxes in inventory at SRS, each measuring some 18' x 12' x 7', and weighing up to 45,000 lbs. These Black Boxes have been stored since the early 1980s. The project to repackage this waste into Standard Large Boxes (SLBs), Standard Waste Boxes (SWB) and Ten Drum Overpacks (TDOP), for subsequent characterization and WIPP disposal, commenced in FY04. To date, 10 Black Boxes have been repackaged, resulting in 40 SLB-2's, and 37 B25 overpack boxes, these B25's will be overpacked in SLB-2's prior to shipping to WIPP. This paper will describe experience to date from this project.

Swale, D. J.; Stone, K.A.; Milner, T. N.

2006-01-09T23:59:59.000Z

339

Ecology, Silviculture, and Management of Black Hills  

E-Print Network [OSTI]

. Battaglia United States Department of Agriculture Forest Service Rocky Mountain Research Station General Technical Report RMRS-GTR-97 September 2002 #12;Shepperd, Wayne D.; Battaglia, Michael A. 2002. Ecology in Arizona, and the Black Hills of South Dakota. Michael A. Battaglia is a research associate with METI

Fried, Jeremy S.

340

Geodesics and Geodesic Deviation in static Charged Black Holes  

E-Print Network [OSTI]

The radial motion along null geodesics in static charged black hole space-times, in particular, the Reissner-Nordstr\\"om and stringy charged black holes are studied. We analyzed the properties of the effective potential. The circular photon orbits in these space-times are investigated. We found that the radius of circular photon orbits in both charged black holes are different and differ from that given in Schwarzschild space-time. We studied the physical effects of the gravitational field between two test particles in stringy charged black hole and compared the results with that given in Schwarzschild and Reissner-Nordstr\\"om black holes.

Ragab M. Gad

2010-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Entropy spectra of single horizon black holes in two dimensions  

E-Print Network [OSTI]

The Hod conjecture proposes that the asymptotic quasinormal frequencies determine the entropy quantum of a black hole. Considering the Maggiore modification of this conjecture we calculate the entropy spectra of general, single horizon, asymptotically flat black holes in two-dimensional dilaton gravity. We also compute the entropy quanta of the two-dimensional Witten and AdS(2) black holes. Using the results for the entropy quanta of these two-dimensional black holes we discuss whether the produced values are generic. Finally we extend the results on the entropy spectra of other black holes.

A. Lopez-Ortega

2011-12-29T23:59:59.000Z

342

Quantum spectrum and statistic entropy of black hole  

E-Print Network [OSTI]

Taking the horizon surface of the black hole as a compact membrane and solving the oscillation equation of this membrane by Klein-Gordon equation, we derive the frequencies of oscillation modes of the horizon surface, which are proportional to the radiation temperature of the black hole. However, the frequencies of oscillation modes are not equidistant. Using the distribution of obtained frequencies of oscillation mode we compute the statistic entropy of the black hole and obtain that the statistic entropy of the black hole is proportional to the area of the horizon. Therefore, it is proven that the quantum statistic entropy of the black hole is consistent with Bekenstein-Hawking entropy.

Zhao Ren; Li Huaifan; Zhang Shengli

2006-10-16T23:59:59.000Z

343

Wave packet autocorrelation functions for quantum hard-disk and hard-sphere billiards in the high-energy, diffraction regime  

E-Print Network [OSTI]

We consider the time evolution of a wave packet representing a quantum particle moving in a geometrically open billiard that consists of a number of fixed hard-disk or hard-sphere scatterers. Using the technique of multiple collision expansions we provide a first-principle analytical calculation of the time-dependent autocorrelation function for the wave packet in the high-energy diffraction regime, in which the particle's de Broglie wave length, while being small compared to the size of the scatterers, is large enough to prevent the formation of geometric shadow over distances of the order of the particle's free flight path. The hard-disk or hard-sphere scattering system must be sufficiently dilute in order for this high-energy diffraction regime to be achievable. Apart from the overall exponential decay, the autocorrelation function exhibits a generally complicated sequence of relatively strong peaks corresponding to partial revivals of the wave packet. Both the exponential decay (or escape) rate and the revival peak structure are predominantly determined by the underlying classical dynamics. A relation between the escape rate, and the Lyapunov exponents and Kolmogorov-Sinai entropy of the counterpart classical system, previously known for hard-disk billiards, is strengthened by generalization to three spatial dimensions. The results of the quantum mechanical calculation of the time-dependent autocorrelation function agree with predictions of the semiclassical periodic orbit theory.

Arseni Goussev; J. R. Dorfman

2006-07-18T23:59:59.000Z

344

Fate of black branes in Einstein-Gauss-Bonnet gravity  

SciTech Connect (OSTI)

Black branes are studied in Einstein-Gauss-Bonnet gravity. Evaporation drives black branes toward one of two singularities depending on the sign of {alpha}, the Gauss-Bonnet coupling. For positive {alpha} and sufficiently large ratio {radical}({alpha})/L, where L/2{pi} is the radius of compactification, black branes avoid the Gregory-Laflamme (GL) instability before reaching a critical state. No black branes with the radius of horizon smaller than the critical value can exist. Approaching the critical state branes have a nonzero Hawking temperature. For negative {alpha} all black branes encounter the GL instability. No black branes may exist outside of the interval of the critical values 0{<=}{beta}<3, where {beta}=1-8{alpha}/r{sub h}{sup 2} and r{sub h} is the radius of horizon of the black brane. The first order phase transition line of GL transitions ends in a second order phase transition point at {beta}=0.

Suranyi, P.; Wijewardhana, L. C. R. [Department of Physics, University of Cincinnati, Cincinnati, Ohio, 45221-0011 (United States); Vaz, C. [Department of Physics, University of Cincinnati, Cincinnati, Ohio, 45221-0011 (United States); RWC, University of Cincinnati, Cincinnati, Ohio, 45221 (United States)

2009-06-15T23:59:59.000Z

345

Acoustic clouds: standing sound waves around a black hole analogue  

E-Print Network [OSTI]

Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

Carolina L. Benone; Luis C. B. Crispino; Carlos Herdeiro; Eugen Radu

2015-01-28T23:59:59.000Z

346

Acoustic clouds: standing sound waves around a black hole analogue  

E-Print Network [OSTI]

Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

Benone, Carolina L; Herdeiro, Carlos; Radu, Eugen

2014-01-01T23:59:59.000Z

347

Nanopatterned ferroelectrics for ultrahigh density rad-hard nonvolatile memories.  

SciTech Connect (OSTI)

Radiation hard nonvolatile random access memory (NVRAM) is a crucial component for DOE and DOD surveillance and defense applications. NVRAMs based upon ferroelectric materials (also known as FERAMs) are proven to work in radiation-rich environments and inherently require less power than many other NVRAM technologies. However, fabrication and integration challenges have led to state-of-the-art FERAMs still being fabricated using a 130nm process while competing phase-change memory (PRAM) has been demonstrated with a 20nm process. Use of block copolymer lithography is a promising approach to patterning at the sub-32nm scale, but is currently limited to self-assembly directly on Si or SiO{sub 2} layers. Successful integration of ferroelectrics with discrete and addressable features of {approx}15-20nm would represent a 100-fold improvement in areal memory density and would enable more highly integrated electronic devices required for systems advances. Towards this end, we have developed a technique that allows us to carry out block copolymer self-assembly directly on a huge variety of different materials and have investigated the fabrication, integration, and characterization of electroceramic materials - primarily focused on solution-derived ferroelectrics - with discrete features of {approx}20nm and below. Significant challenges remain before such techniques will be capable of fabricating fully integrated NVRAM devices, but the tools developed for this effort are already finding broader use. This report introduces the nanopatterned NVRAM device concept as a mechanism for motivating the subsequent studies, but the bulk of the document will focus on the platform and technology development.

Brennecka, Geoffrey L.; Stevens, Jeffrey; Scrymgeour, David; Gin, Aaron V.; Tuttle, Bruce Andrew

2010-09-01T23:59:59.000Z

348

Critical issues in measuring the mechanical properties of hard films on soft substrates by nanoindentation techniques  

SciTech Connect (OSTI)

This study explores the difficulties encountered when using conventional nanoindentation techniques to measure the Young`s modulus and hardness of hard films on soft substrates. In general, the indentation measurement of film/substrate systems is affected by four material properties: the Young`s modulus and hardness of the film, and the Young`s modulus and hardness of the substrate. For the particular case of a hard film on a soft substrate, there is a tendency for the material around the hardness impression to sink-in which results from the large difference in yielding of the two materials. In this study, a model system consisting of NiP on annealed Cu was used to explore the behavior. This system is interesting because the film and substrate have similar Young`s moduli, minimizing the elastic behavior as a variable. In contrast, the hardness of NiP is approximately 7--8 GPa, and that of the annealed copper is less than 1 GPa, providing a factor of 10 difference in the plastic flow characteristics. Experimental results indicate that standard analytical methods for determining the contact depth, hardness and Young`s modulus do not work well for the case of a hard film on a soft substrate. At shallow contact depths, the measured indentation modulus is close to that of the film, but at larger depths sink-in phenomena result in an overestimation of the contact area, and an indentation modulus which is less than the Young`s modulus of both the film and substrate. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) provide critical details of the physical processes involved, and illustrate how the standard data analyses overestimate the true contact area.

Hay, J.C. [Oak Ridge National Lab., TN (United States); Pharr, G.M. [Rice Univ., Houston, TX (United States). Dept. of Materials Science

1997-12-31T23:59:59.000Z

349

Surface tension of isotropic-nematic interfaces: Fundamental Measure Theory for hard spherocylinders  

E-Print Network [OSTI]

A fluid constituted of hard spherocylinders is studied using a density functional theory for non-spherical hard particles, which can be written as a function of weighted densities. This is based on an extended deconvolution of the Mayer $f$-function for arbitrarily shaped convex hard bodies in tensorial weight functions, which depend each only on the shape and orientation of a single particle. In the course of an examination of the isotropic- nematic interface at coexistence the functional is applied to anisotropic and inhomogeneous problems for the first time. We find good qualitative agreement with other theoretical predictions and also with Monte-Carlo simulations.

René Wittmann; Klaus Mecke

2014-03-10T23:59:59.000Z

350

Automated measurement system employing eddy currents to adjust probe position and determine metal hardness  

DOE Patents [OSTI]

A system for measuring the hardness of cartridge cases employs an eddy current probe for inducing and sensing eddy currents in each cartridge case. A first component of the sensed signal is utilized in a closed loop system for accurately positioning the probe relative to the cartridge case both in the lift off direction and in the tangential direction, and a second component of the sensed signal is employed as a measure of the hardness. The positioning and measurement are carried out under closed loop microprocessor control facilitating hardness testing on a production line basis. 14 figs.

Prince, J.M.; Dodson, M.G.; Lechelt, W.M.

1989-07-18T23:59:59.000Z

351

Rholography, Black Holes and Scherk-Schwarz  

E-Print Network [OSTI]

We present both the macroscopic and microscopic description of a class of near-extremal asymptotically flat black hole solutions in four (or five) dimensional gauged supergravity with R-symmetry gaugings obtained from Scherk-Schwarz reductions on a circle. The entropy of these black holes is counted holographically by the well known MSW (or D1/D5) system, with certain twisted boundary conditions labeled by a twist parameter \\rho. We find that the corresponding (0,4) (or (4,4)) superconformal algebras are exactly those studied by Schwimmer and Seiberg, using a twist on the outer automorphism group. The interplay between R-symmetries, \\rho-algebras and holography leads us to name our construction "Rholography".

Nava Gaddam; Alessandra Gnecchi; Stefan Vandoren; Oscar Varela

2014-12-23T23:59:59.000Z

352

Black Hole Entropy and Induced Gravity  

E-Print Network [OSTI]

In this short essay we review the arguments showing that black hole entropy is, at least in part, ``entanglement entropy", i.e., missing information contained in correlations between quantum field fluctuations inside and outside the event horizon. Although the entanglement entropy depends upon the matter field content of the theory, it turns out that so does the Bekenstein-Hawking entropy $A/4\\hbar G_{ren}$, in precisely the same way, because the effective gravitational constant $G_{ren}$ is renormalized by the very same quantum fluctuations. It appears most satisfactory if the entire gravitational action is ``induced", in the manner suggested by Sakharov, since then the black hole entropy is purebred entanglement entropy, rather than being hybrid with bare gravitational entropy (whatever that might be.)

Ted Jacobson

1994-04-19T23:59:59.000Z

353

Geometric description of BTZ black holes thermodynamics  

E-Print Network [OSTI]

We study the properties of the space of thermodynamic equilibrium states of the Ba\\~nados-Teitelboim-Zanelli (BTZ) black hole in (2+1)-gravity. We use the formalism of geometrothermodynamics to introduce in the space of equilibrium states a $2-$dimensional thermodynamic metric whose curvature is non-vanishing, indicating the presence of thermodynamic interaction, and free of singularities, indicating the absence of phase transitions. Similar results are obtained for generalizations of the BTZ black hole which include a Chern-Simons term and a dilatonic field. Small logarithmic corrections of the entropy turn out to be represented by small corrections of the thermodynamic curvature, reinforcing the idea that thermodynamic curvature is a measure of thermodynamic interaction.

Hernando Quevedo; Alberto Sanchez

2008-11-15T23:59:59.000Z

354

Quantized black holes, their spectrum and radiation  

SciTech Connect (OSTI)

Under quite natural general assumptions, the following results are obtained. The maximum entropy of a quantized surface is demonstrated to be proportional to the surface area in the classical limit. The general structure of the horizon spectrum is found. In the special case of loop quantum gravity, the value of the Barbero-Immirzi parameter is found. The discrete spectrum of thermal radiation of a black hole fits the Wien profile. The natural widths of the lines are much smaller than the distances between them. The total intensity of the thermal radiation is estimated. If the density of quantized primordial black holes is close to the present upper limit on the dark-matter density in our Solar system, the sensitivity of modern detectors is close to that necessary for detecting this radiation.

Khriplovich, I. B. [Budker Institute of Nuclear Physics (Russian Federation)], E-mail: khriplovich@inp.nsk.su

2008-04-15T23:59:59.000Z

355

Tribological properties of hard carbon films on zirconia ceramics  

SciTech Connect (OSTI)

This study investigated the tribological properties of hard diamondlike carbon (DLC) films on magnesia-partially-stabilized zirconia (MgO-PSZ) substrates over a wide range of loads, speeds, temperatures, and counterface materials. The films were 2 {micro}m-thick and produced on by ion-beam deposition at room temperature. Tribological tests were conducted on a ball-on-disk machine in open air of 30 to 50% relative humidity under contact loads of 1 to 50 N, at sliding velocities of 0.1 to 6 m/s, and at temperatures to 400{degrees}C. A1{sub 2}O{sub 3} and Si{sub 3}N{sub 4} balls were also used and rubbed against the DLC-coated MgO-PSZ disks, primarily to assess and compare their friction and wear performance to that of MgO-PSZ balls. A series of long-duration lifetime tests was run at speeds of 1, 2, and 6 m/s under a 5-N load to assess the durability of these DLC films. Test results showed that the friction coefficients of MgO-PSZ balls sliding against MgO-PSZ disks were in the range of 0.5-0.8, and the average specific wear rates of MgO-PSZ balls ranged from 10{sup {minus}5} to 5 {times} 10{sup {minus}4} mm{sup 3}/N.m, depending on sliding velocity, contact load and ambient temperature. The friction coefficients of MgO-PSZ balls sliding against the DLC-coated-MgO-PSZ disks varied between 0.03 to 0.1. The average specific wear rates of MgO-PSZ balls were reduced by factors of three to four orders of magnitude when rubbed against the DLC coated disks. These DLC films could last 1.5 million to 4 million cycles, depending on sliding velocity. Scanning electron microscopy and micro-laser Raman Spectroscopy were used to elucidate the microstructural and chemical nature of DLC films and worn surfaces.

Erdemir, A.; Bindal, C.; Fenske, G.R. [Argonne National Lab., IL (United States); Wilbur, P. [Colorado State Univ., Fort Collins, CO (United States)

1995-12-31T23:59:59.000Z

356

Economic aspects of black bases in Texas  

E-Print Network [OSTI]

the f easibility of using sand-asphalt stabilized base courses. Gregg reported that the sand-asphalt bases investigated in the field studies performed well under moving traffic. Moduli of resilient deformation of the bitumen-sand mixtures were... Ayron Schoen, B. S. , Texas ARK University Chairman of Advisory Committee: Dr. Jon A. Epps Although black base construction has gained increasing popularity in recent years, the rising costs of asphalt and asphalt materials have demanded that more...

Schoen, Wayne Ayron

1976-01-01T23:59:59.000Z

357

Refined Black Hole Ensembles and Topological Strings  

E-Print Network [OSTI]

We formulate a refined version of the Ooguri-Strominger-Vafa (OSV) conjecture. The OSV conjecture that Z_{BH} = |Z_{top}|^2 relates the BPS black hole partition function to the topological string partition function Z_{top}. In the refined conjecture, Z_{BH} is the partition function of BPS black holes counted with spin, or more precisely the protected spin character. Z_{top} becomes the partition function of the refined topological string, which is itself an index. Both the original and the refined conjecture are examples of large N duality in the 't Hooft sense. The refined conjecture applies to non-compact Calabi-Yau manifolds only, so the black holes are really BPS particles with large entropy, of order N^2. The refined OSV conjecture states that the refined BPS partition function has a large N dual which is captured by the refined topological string. We provide evidence that the conjecture holds by studying local Calabi-Yau threefolds consisting of line bundles over a genus g Riemann surface. We show that the refined topological string partition function on these geometries is computed by a two-dimensional TQFT. We also study the refined black hole partition function arising from N D4 branes on the Calabi-Yau, and argue that it reduces to a (q,t)-deformed version of two-dimensional SU(N) Yang-Mills. Finally, we show that in the large N limit this theory factorizes to the square of the refined topological string in accordance with the refined OSV conjecture.

Mina Aganagic; Kevin Schaeffer

2012-10-05T23:59:59.000Z

358

Density matrix of black hole radiation  

E-Print Network [OSTI]

Hawking's model of black hole evaporation is not unitary and leads to a mixed density matrix for the emitted radiation, while the Page model describes a unitary evaporation process in which the density matrix evolves from an almost thermal state to a pure state. We compare a recently proposed model of semiclassical black hole evaporation to the two established models. In particular, we study the density matrix of the outgoing radiation and determine how the magnitude of the off-diagonal corrections differs for the three frameworks. For Hawking's model, we find power-law corrections to the two-point functions that induce exponentially suppressed corrections to the off-diagonal elements of the full density matrix. This verifies that the Hawking result is correct to all orders in perturbation theory and also allows one to express the full density matrix in terms of the single-particle density matrix. We then consider the semiclassical theory for which the corrections, being non-perturbative from an effective field-theory perspective, are much less suppressed and grow monotonically in time. In this case, the R\\'enyi entropy for the outgoing radiation is shown to grow linearly at early times; but this growth slows down and the entropy eventually starts to decrease at the Page time. In addition to comparing models, we emphasize the distinction between the state of the radiation emitted from a black hole, which is highly quantum, and that of the radiation emitted from a typical classical black body at the same temperature.

Lasma Alberte; Ram Brustein; Andrei Khmelnitsky; A. J. M. Medved

2015-02-09T23:59:59.000Z

359

Entanglement from thermal black body radiation  

E-Print Network [OSTI]

Two non--interacting quantum systems which couple to a common environment with many degrees of freedom initially in thermal equilibrium can become entangled due to the indirect interaction mediated through this heat bath. I examine here the dynamics of reservoir induced entanglement for a heat bath consisting of a thermal electro--magnetic radiation field, such as black body radiation or the cosmic microwave background, and show how the effect can be understood as result of an effective induced interaction.

Daniel Braun

2005-09-06T23:59:59.000Z

360

Comparing quantum black holes and naked singularities  

E-Print Network [OSTI]

There are models of gravitational collapse in classical general relativity which admit the formation of naked singularities as well as black holes. These include fluid models as well as models with scalar fields as matter. Even if fluid models were to be regarded as unphysical in their matter content, the remaining class of models (based on scalar fields) generically admit the formation of visible regions of finite but arbitrarily high curvature. Hence it is of interest to ask, from the point of view of astrophysics, as to what a stellar collapse leading to a naked singularity (or to a visible region of very high curvature) will look like, to a far away observer. The emission of energy during such a process may be divided into three phases - (i) the classical phase, during which matter and gravity can both be treated according to the laws of classical physics, (ii) the semiclassical phase, when gravity is treated classically but matter behaves as a quantum field, and (iii) the quantum gravitational phase. In this review, we first give a summary of the status of naked singularities in classical relativity, and then report some recent results comparing the semiclassical phase of black holes with the semiclassical phase of spherical collapse leading to a naked singularity. In particular, we ask how the quantum particle creation during the collapse leading to a naked singularity compares with the Hawking radiation from a star collapsing to form a black hole. It turns out that there is a fundamental difference between the two cases. A spherical naked star emits only about one Planck energy during its semiclassical phase, and the further evolution can only be determined by the laws of quantum gravity. This contrasts with the semiclassical evaporation of a black hole.

T. P. Singh

2000-12-21T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" from the National Library of EnergyBeta (NLEBeta).
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361

Electromagnetic wave scattering by Schwarzschild black holes  

E-Print Network [OSTI]

We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

2009-05-20T23:59:59.000Z

362

Bibliography Armstrong, T., R. Harding, G. Knorr, and D. Montgomery (1970). Solution of  

E-Print Network [OSTI]

Bibliography Armstrong, T., R. Harding, G. Knorr, and D. Montgomery (1970). Solution of Vlasov's equation by transform methods. In Methods in Computational Physics. New York: Academic Press. Armstrong, T

Hammett, Greg

363

all-sky hard x-ray: Topics by E-print Network  

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

sky coverage each orbit, and full sky coverage each 50 days, hard x-ray studies of gamma-ray bursts, AGN, galactic transients, x-ray binaries and accretion-powered pulsars can be...

364

Support vector machines with the ramp loss and the hard margin loss  

E-Print Network [OSTI]

Nov 4, 2008 ... Support vector machines with the ramp loss and the hard margin loss. J.P. Brooks (jpbrooks ***at*** vcu.edu). Abstract: In the interest of ...

J.P. Brooks

2008-11-04T23:59:59.000Z

365

Hard and tough electrodeposited aluminum-manganese alloys with tailored nanostructures  

E-Print Network [OSTI]

Tailoring the nanostructure of electrodeposited Al-Mn films to achieve high hardness and toughness is the overarching goal of this thesis. Binary Al-Mn alloys are electrodeposited using a conventional current waveform in ...

Ruan, Shiyun

2010-01-01T23:59:59.000Z

366

Next-to-Leading Order Hard Scattering Using Fully Unintegrated Parton Distribution Functions  

E-Print Network [OSTI]

We calculate the next-to-leading order fully unintegrated hard scattering coefficient for unpolarized gluon-induced deep inelastic scattering using the logical framework of parton correlation functions developed in previous work. In our approach, exact four-momentum conservation is maintained throughout the calculation. Hence, all non-perturbative functions, like parton distribution functions, depend on all components of parton four-momentum. In contrast to the usual collinear factorization approach where the hard scattering coefficient involves generalized functions (such as Dirac $\\delta$-functions), the fully unintegrated hard scattering coefficient is an ordinary function. Gluon-induced deep inelastic scattering provides a simple illustration of the application of the fully unintegrated factorization formalism with a non-trivial hard scattering coefficient, applied to a phenomenologically interesting case. Furthermore, the gluon-induced process allows for a parameterization of the fully unintegrated gluon distribution function.

Ted C. Rogers

2008-09-29T23:59:59.000Z

367

Next-to-leading order hard scattering using fully unintegrated parton distribution functions  

SciTech Connect (OSTI)

We calculate the next-to-leading order fully unintegrated hard scattering coefficient for unpolarized gluon-induced deep inelastic scattering using the logical framework of parton correlation functions developed in previous work. In our approach, exact four-momentum conservation is maintained throughout the calculation. Hence, all nonperturbative functions, like parton distribution functions, depend on all components of parton four-momentum. In contrast to the usual collinear factorization approach where the hard scattering coefficient involves generalized functions (such as Dirac {delta} functions), the fully unintegrated hard scattering coefficient is an ordinary function. Gluon-induced deep inelastic scattering provides a simple illustration of the application of the fully unintegrated factorization formalism with a nontrivial hard scattering coefficient, applied to a phenomenologically interesting case. Furthermore, the gluon-induced process allows for a parametrization of the fully unintegrated gluon distribution function.

Rogers, Ted C. [Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2008-10-01T23:59:59.000Z

368

Calculation of the entropy of binary hard sphere mixtures from pair correlation functions  

E-Print Network [OSTI]

We evaluate the entropy of several binary hard sphere fluid mixtures using two approximate expressions that require as input only the pair correlation functions,g ??(r). An approximation based on the incompressible limit ...

Laird, Brian Bostian; Haymet, A. D. J.

1992-06-01T23:59:59.000Z

369

Adaptive Hardness and Composable Security in the Plain Model from Standard Assumptions  

E-Print Network [OSTI]

Adaptive Hardness and Composable Security in the Plain Model from Standard Assumptions Ran Canetti-up or public keys. Tel Aviv University, Email: Canetti@tau.ac.il Cornell University, E-Mail: huijia

Keinan, Alon

370

E-Print Network 3.0 - astronomical hard x-ray Sample Search Results  

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

search results for: astronomical hard x-ray Page: << < 1 2 3 4 5 > >> 1 Reverse Drift Bursts in the 0.8-4.5 GHz Band and their Relation to X-Rays Summary: and causing radio...

371

Thermal hard-photons probing multifragmentation in nuclear collisions around the Fermi energy  

E-Print Network [OSTI]

Hard-photon (E$_{\\gamma} >$ 30 MeV) emission issuing from proton-neutron bremsstrahlung collisions is investigated in four different heavy-ion reactions at intermediate bombarding energies ($^{36}$Ar+$^{197}$Au, $^{107}$Ag, $^{58}$Ni, $^{12}$C at 60{\\it A} MeV) coupling the TAPS photon spectrometer with two charged-particle multidetectors covering more than 80% of the solid angle. The hard-photon spectra of the three heavier targets result from the combination of two distinct exponential distributions with different slope parameters, a result which deviates from the behaviour expected for hard-photon production just in first-chance proton-neutron collisions. The thermal origin of the steeper bremsstrahlung component is confirmed by the characteristics of its slope and angular distribution. Such thermal hard-photons convey undisturbed information of the thermodynamical state of hot and excited nuclear systems undergoing multifragmentation.

D. G. d'Enterria; G. Martínez

2000-07-06T23:59:59.000Z

372

Lowering kraft black liquor viscosity of ultrafiltration  

SciTech Connect (OSTI)

High viscosity is a major factor limiting the percentage total dissolved solids (%TDS) to which kraft black liquor (KBL), a spent pulping liquor, can be concentrated before it is burned to recover its fuel value and its inorganic chemicals. The effect on black liquor viscosity of removing high molecular weight lignin by ultrafiltration of 16% and 24% TDS liquors was studied. Viscosities of ultrafiltration permeates were reduced relative to feed black liquors. When a permeate was concentrated to higher %TDS levels, its viscosity decreased yet further relative to feed samples evaporated to similar solids levels. Retentate viscosity was very high relative to both feed and permeate. Ultrafiltration was carried out at 75/degrees/C using polysulfone membranes in a plate-and-frame or hollow fiber system. Flux rates varied greatly depending upon the specific liquor used. Flux was enhanced by increased temperature and increased linear velocity. The membrane molecular weight cutoff (MWCO) typically used was 50,000; increasing 100,000 or 200,000 did not enhance flux.

Hill, M.K.; Violette, D.A.; Woerner, D.L.

1988-10-01T23:59:59.000Z

373

In Situ Causticizing for Black Liquor Gasification  

SciTech Connect (OSTI)

Black liquor gasification offers a number of attractive incentives to replace Tomlinson boilers but it also leads to an increase in the causticizing load. Reasons for this have been described in previous reports (FY04 ERC, et.al.). The chemistries have also been covered but will be reviewed here briefly. Experimental results of the causticizing reactions with black liquor are presented here. Results of the modeling work were presented in detail in the Phase 1 report. They are included in Table 2 for comparison but will not be discussed in detail. The causticizing agents were added to black liquor in the ratios shown in Table 1, mixed, and then spray-dried. The mixture ratios (doping levels) reflect amount calculated from the stoichiometry above to achieve specified conversions shown in the table. The solids were sieved to 63-90 microns for use in the entrained flow reactors. The firing conditions are shown in Table 2. Pictures and descriptions of the reactors can be found in the Phase 1 annual report. Following gasification, the solids (char) was collected and analyzed by coulometric titration (for carbonate and total carbon), and by inductively coupled plasma emission spectroscopy (ICP) for a wide array of metals.

Scott Alan Sinquefield

2005-10-01T23:59:59.000Z

374

Quantization of rotating linear dilaton black holes  

E-Print Network [OSTI]

In this paper, we firstly prove that the adiabatic invariant quantity, which is commonly used in the literature for quantizing the rotating black holes (BHs) is fallacious. We then show how its corrected form should be. The main purpose of this paper is to study the quantization of 4-dimensional rotating linear dilaton black hole (RLDBH) spacetime describing with an action, which emerges in the Einstein-Maxwell-Dilaton-Axion (EMDA) theory. The RLDBH spacetime has a non-asymptotically flat (NAF) geometry. They reduces to the linear dilaton black hole (LDBH) metric when vanishing its rotation parameter $a$. While studying its scalar perturbations, it is shown that the Schr\\"odinger-like wave equation around the event horizon reduces to a confluent hypergeometric differential equation. Then the associated complex frequencies of the quasinormal modes (QNMs) are computed. By using those QNMs in the true definition of the rotational adiabatic invariant quantity, we obtain the quantum spectra of entropy/area for the RLDBH. It is found out that both spectra are discrete and equidistant. Besides, we reveal that the quantum spectra do not depend on $a$ in spite of the QNMs are modulated by it.

I. Sakalli

2014-06-19T23:59:59.000Z

375

Kerr black holes with scalar hair  

E-Print Network [OSTI]

We present a family of solutions of Einstein's gravity minimally coupled to a complex, massive scalar field, describing asymptotically flat, spinning black holes with scalar hair and a regular horizon. These hairy black holes (HBHs) are supported by rotation and have no static limit. Besides mass M and angular momentum J, they carry a conserved, continuous Noether charge Q measuring the scalar hair. HBHs branch off from the Kerr metric at the threshold of the superradiant instability and reduce to spinning boson stars in the limit of vanishing horizon area. They overlap with Kerr black holes for a set of (M,J) values. A single Killing vector field preserves the solutions, tangent to the null geodesic generators of the event horizon. HBHs can exhibit sharp physical differences when compared to the Kerr solution, such as J/M^2>1, quadrupole moment larger than J^2/M and larger orbital angular velocity at the innermost stable circular orbit. Families of HBHs connected to the Kerr geometry should exist in scalar (...

Herdeiro, Carlos A R

2014-01-01T23:59:59.000Z

376

Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter  

E-Print Network [OSTI]

Ensuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered.

The CMS Electromagnetic Calorimeter Group; P. Adzic; N. Almeida; D. Andelin; I. Anicin; Z. Antunovic; R. Arcidiacono; M. W. Arenton; E. Auffray; S. Argiro; A. Askew; S. Baccaro; S. Baffioni; M. Balazs; D. Bandurin; D. Barney; L. M. Barone; A. Bartoloni; C. Baty; S. Beauceron; K. W. Bell; C. Bernet; M. Besancon; B. Betev; R. Beuselinck; C. Biino; J. Blaha; P. Bloch; A. Borisevitch; A. Bornheim; J. Bourotte; R. M. Brown; M. Buehler; P. Busson; B. Camanzi; T. Camporesi; N. Cartiglia; F. Cavallari; A. Cecilia; P. Chang; Y. H. Chang; C. Charlot; E. A. Chen; W. T. Chen; Z. Chen; R. Chipaux; B. C. Choudhary; R. K. Choudhury; D. J. A. Cockerill; S. Conetti; S. Cooper; F. Cossutti; B. Cox; D. G. Cussans; I. Dafinei; D. R. Da Silva Di Calafiori; G. Daskalakis; A. David; K. Deiters; M. Dejardin; A. De Benedetti; G. Della Ricca; D. Del Re; D. Denegri; P. Depasse; J. Descamps; M. Diemoz; E. Di Marco; G. Dissertori; M. Dittmar; L. Djambazov; M. Djordjevic; L. Dobrzynski; A. Dolgopolov; S. Drndarevic; G. Drobychev; D. Dutta; M. Dzelalija; A. Elliott-Peisert; H. El Mamouni; I. Evangelou; B. Fabbro; J. L. Faure; J. Fay; A. Fedorov; F. Ferri; D. Franci; G. Franzoni; K. Freudenreich; W. Funk; S. Ganjour; S. Gascon; M. Gataullin; F. X. Gentit; A. Ghezzi; A. Givernaud; S. Gninenko; A. Go; B. Gobbo; N. Godinovic; N. Golubev; P. Govoni; N. Grant; P. Gras; M. Haguenauer; G. Hamel de Monchenault; M. Hansen; J. Haupt; H. F. Heath; B. Heltsley; W. Hintz; R. Hirosky; P. R. Hobson; A. Honma; G. W. S. Hou; Y. Hsiung; M. Huhtinen; B. Ille; Q. Ingram; A. Inyakin; P. Jarry; C. Jessop; D. Jovanovic; K. Kaadze; V. Kachanov; S. Kailas; S. K. Kataria; B. W. Kennedy; P. Kokkas; T. Kolberg; M. Korjik; N. Krasnikov; D. Krpic; Y. Kubota; C. M. Kuo; P. Kyberd; A. Kyriakis; M. Lebeau; P. Lecomte; P. Lecoq; A. Ledovskoy; M. Lethuillier; S. W. Lin; W. Lin; V. Litvine; E. Locci; E. Longo; D. Loukas; P. D. Luckey; W. Lustermann; Y. Ma; M. Malberti; J. Malclès; D. Maletic; N. Manthos; Y. Maravin; C. Marchica; N. Marinelli; A. Markou; C. Markou; M. Marone; V. Matveev; C. Mavrommatis; P. Meridiani; P. Milenovic; P. Miné; O. Missevitch; A. K. Mohanty; F. Moortgat; P. Musella; Y. Musienko; A. Nardulli; J. Nash; P. Nedelec; P. Negri; H. B. Newman; A. Nikitenko; F. Nessi-Tedaldi; M. M. Obertino; G. Organtini; T. Orimoto; M. Paganoni; P. Paganini; A. Palma; L. Pant; A. Papadakis; I. Papadakis; I. Papadopoulos; R. Paramatti; P. Parracho; N. Pastrone; J. R. Patterson; F. Pauss; J-P. Peigneux; E. Petrakou; D. G. Phillips II; P. Piroué; F. Ptochos; I. Puljak; A. Pullia; T. Punz; J. Puzovic; S. Ragazzi; S. Rahatlou; J. Rander; P. A. Razis; N. Redaelli; D. Renker; S. Reucroft; P. Ribeiro; C. Rogan; M. Ronquest; A. Rosowsky; C. Rovelli; P. Rumerio; R. Rusack; S. V. Rusakov; M. J. Ryan; L. Sala; R. Salerno; M. Schneegans; C. Seez; P. Sharp; C. H. Shepherd-Themistocleous; J. G. Shiu; R. K. Shivpuri; P. Shukla; C. Siamitros; D. Sillou; J. Silva; P. Silva; A. Singovsky; Y. Sirois; A. Sirunyan; V. J. Smith; F. Stöckli; J. Swain; T. Tabarelli de Fatis; M. Takahashi; V. Tancini; O. Teller; K. Theofilatos; C. Thiebaux; V. Timciuc; C. Timlin; M. Titov; A. Topkar; F. A. Triantis; S. Troshin; N. Tyurin; K. Ueno; A. Uzunian; J. Varela; P. Verrecchia; J. Veverka; T. Virdee; M. Wang; D. Wardrope; M. Weber; J. Weng; J. H. Williams; Y. Yang; I. Yaselli; R. Yohay; A. Zabi; S. Zelepoukine; J. Zhang; L. Y. Zhang; K. Zhu; R. Y. Zhu

2009-12-22T23:59:59.000Z

377

A quantitative model for interpreting nanometer scale hardness measurements of thin films  

SciTech Connect (OSTI)

A model was developed to determine hardness of thin films from hardness versus depth curves, given film thickness and substrate hardness. The model is developed by dividing the measured hardness into film and substrate contributions based on the projected areas of both the film and substrate under the indenter. The model incorporates constraints on the deformation of the film by the surrounding material in the film, the substrate, and friction at the indenter/film and film/substrate interfaces. These constraints increase the pressure that the film can withstand and account for the increase in measured hardness as the indenter approaches the substrate. The model is evaluated by fitting the predicted hardness versus depth curves obtained from titanium and Ta{sub 2}O{sub 5} films of varying thicknesses on sapphire substrates. The model is also able to describe experimental data for Ta{sub 2}O{sub 5} films on sapphire with a carbon layer between the film and the substrate by a reduction in the interfacial strength from that obtained for a film without an interfacial carbon layer.

Poisl, W.H.; Fabes, B.D. [Arizona Univ., Tucson, AZ (United States). Dept. of Materials Science and Engineering; Oliver, W.C. [Oak Ridge National Lab., TN (United States)

1993-09-01T23:59:59.000Z

378

HARD X-RAY OBSERVATIONS OF A JET AND ACCELERATED ELECTRONS IN THE CORONA  

SciTech Connect (OSTI)

We report the first hard X-ray observation of a solar jet on the limb with flare footpoints occulted, so that faint emission from accelerated electrons in the corona can be studied in detail. In this event on 2003 August 21, RHESSI observed a double coronal hard X-ray source in the pre-impulsive phase at both thermal and nonthermal energies. In the impulsive phase, the first of two hard X-ray bursts consists of a single thermal/nonthermal source coinciding with the lower of the two earlier sources, and the second burst shows an additional nonthermal, elongated source, spatially and temporally coincident with the coronal jet. Analysis of the jet hard X-ray source shows that collisional losses by accelerated electrons can deposit enough energy to generate the jet. The hard X-ray time profile above 20 keV matches that of the accompanying Type III and broadband gyrosynchrotron radio emission, indicating both accelerated electrons escaping outward along the jet path and electrons trapped in the flare loop. The double coronal hard X-ray source, the open field lines indicated by Type III bursts, and the presence of a small post-flare loop are consistent with significant electron acceleration in an interchange reconnection geometry.

Glesener, Lindsay; Lin, R. P.; Krucker, Saem, E-mail: glesener@ssl.berkeley.edu [Space Science Laboratory, UC Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States)

2012-07-20T23:59:59.000Z

379

RAPIDLY ACCRETING SUPERGIANT PROTOSTARS: EMBRYOS OF SUPERMASSIVE BLACK HOLES?  

SciTech Connect (OSTI)

Direct collapse of supermassive stars (SMSs) is a possible pathway for generating supermassive black holes in the early universe. It is expected that an SMS could form via very rapid mass accretion with M-dot{sub *} {approx} 0.1-1 M{sub Sun} yr{sup -1} during the gravitational collapse of an atomic-cooling primordial gas cloud. In this paper, we study how stars would evolve under such extreme rapid mass accretion, focusing on the early evolution until the stellar mass reaches 10{sup 3} M{sub Sun }. To this end, we numerically calculate the detailed interior structure of accreting stars with primordial element abundances. Our results show that for accretion rates higher than 10{sup -2} M{sub Sun} yr{sup -1}, stellar evolution is qualitatively different from that expected at lower rates. While accreting at these high rates, the star always has a radius exceeding 100 R{sub Sun }, which increases monotonically with the stellar mass. The mass-radius relation for stellar masses exceeding {approx}100 M{sub Sun} follows the same track with R{sub *}{proportional_to}M {sup 1/2}{sub *} in all cases with accretion rates {approx}> 10{sup -2} M{sub Sun} yr{sup -1}; at a stellar mass of 10{sup 3} M{sub Sun }, the radius is {approx_equal} 7000 R{sub Sun} ({approx_equal} 30 AU). With higher accretion rates, the onset of hydrogen burning is shifted toward higher stellar masses. In particular, for accretion rates exceeding M-dot{sub *}{approx}>0.1 M{sub Sun} yr{sup -1}, there is no significant hydrogen burning even after 10{sup 3} M{sub Sun} have accreted onto the protostar. Such 'supergiant' protostars have effective temperatures as low as T{sub eff} {approx_equal} 5000 K throughout their evolution and because they hardly emit ionizing photons, they do not create an H II region or significantly heat their immediate surroundings. Thus, radiative feedback is unable to hinder the growth of rapidly accreting stars to masses in excess of 10{sup 3} M{sub Sun} as long as material is accreted at rates M-dot{sub *}{approx}>10{sup -2} M{sub Sun} yr{sup -1}.

Hosokawa, Takashi; Yorke, Harold W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Omukai, Kazuyuki, E-mail: Takashi.Hosokawa@jpl.nasa.gov, E-mail: hosokwtk@gmail.com, E-mail: omukai@tap.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)

2012-09-01T23:59:59.000Z

380

Black hole fireworks: quantum-gravity effects outside the horizon spark black to white hole tunneling  

E-Print Network [OSTI]

We show that there is a classical metric satisfying the Einstein equations outside a finite spacetime region where matter collapses into a black hole and then emerges from a white hole. We compute this metric explicitly. We show how quantum theory determines the (long) time for the process to happen. A black hole can thus quantum-tunnel into a white hole. For this to happen, quantum gravity should affect the metric also in a small region outside the horizon: we show that contrary to what is commonly assumed, this is not forbidden by causality or by the semiclassical approximation, because quantum effects can pile up over a long time. This scenario alters radically the discussion on the black hole information puzzle.

Hal M. Haggard; Carlo Rovelli

2014-07-06T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Black Carbon Emissions by Rocket Engines Types of rocket engines Emissions  

E-Print Network [OSTI]

Black Carbon Emissions by Rocket Engines Types of rocket engines Emissions Liquid Hydrogen. Note: Black carbon does not deplete ozone. What happens is the black carbon emissions from the rocket. Other black carbon emissions: The number one contributor to black carbon is burning biomass. Also

Toohey, Darin W.

382

Black holes in extra dimensions can decay on the bulk  

E-Print Network [OSTI]

In the extra dimensional theories, with TeV scale Plank constant, black holes may be produced in the Large Hadron Collider experiments. We have argued that in the d-dimensional black hole, the intrinsically 4-dimensional brane fields do not see the same geometry at the horizon, as in a 4-dimensional space-time. Kaluza-Klein modes invades the brane and surroundings and the brane fields can be considered as a thermal system at the temperature of the black hole. From energy and entropy consideration, we show that whether or not a six-dimensional black hole will decay by emitting Kaluza-Klein modes or the standard model particles, will depend on the length scale of the extra dimensions as well as on the mass of the black hole. For higher dimensional black holes, Kaluza-Klein modes will dominate the decay.

A. K. Chaudhuri

2003-01-08T23:59:59.000Z

383

A toroidal black hole for the AGN phenomenon  

E-Print Network [OSTI]

A new approach to the study of the AGN phenomenon is proposed, in which the nucleus activity is related to the metric of the inner massive black hole. The possibility of a Toroidal Black Hole (TBH), in contrast to the usual Spherical Black Hole (SBH), is discussed as a powerful tool in understanding AGN related phenomena, such as the energetics, the production of jets and the acceleration of particles, the shape of the magnetic field and the lifetime of nucleus activity.

Fulvio Pompilio; S. M. Harun-or-Rashid; Matts Roos

2000-08-30T23:59:59.000Z

384

KKW Analysis for the Dyadosphere of a Charged Black Hole  

E-Print Network [OSTI]

The Keski-Vakkuri, Kraus and Wilczek (KKW) analysis is used to compute the temperature and entropy in the dyadosphere of a charged black hole solution. For our purpose we choose the dyadosphere region of the Reissner-Nordstrom black hole solution. Our results show that the expressions of the temperature and entropy in the dyadosphere of this charged black hole are not the Hawking temperature and the Bekenstein-Hawking entropy, respectively.

I. Radinschi

2005-11-28T23:59:59.000Z

385

Hawking radiation of Dirac particles from black strings  

SciTech Connect (OSTI)

Hawking radiation has been studied as a phenomenon of quantum tunneling in different black holes. In this paper we extend this semi-classical approach to cylindrically symmetric black holes. Using the Hamilton-Jacobi method and WKB approximation we calculate the tunneling probabilities of incoming and outgoing Dirac particles from the event horizon and find the Hawking temperature of these black holes. We obtain results both for uncharged as well as charged particles.

Ahmed, Jamil; Saifullah, K., E-mail: jamil_051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

2011-08-01T23:59:59.000Z

386

Brownian Motion of Black Holes in Dense Nuclei  

E-Print Network [OSTI]

We evaluate the Brownian motion of a massive particle ("black hole") at the center of a galaxy using N-body simulations. Our galaxy models have power-law central density cusps like those observed at the centers of elliptical galaxies. The simulations show that the black hole achieves a steady-state kinetic energy that is substantially different than would be predicted based on the properties of the galaxy model in the absence of the black hole. The reason appears to be that the black hole responds to stars whose velocities have themselves been raised by the presence of the black hole. Over a wide range of density slopes and black hole masses, the black hole's mean kinetic energy is equal to what would be predicted under the assumption that it is in energy equipartition with stars lying within a distance ~r_h/2 from it, where r_h is the black hole's influence radius. The dependence of the Brownian velocity on black hole mass is approximately ~ 1/M^{1/(3-gamma)} with gamma the power-law index of the stellar density profile, rho~1/r^gamma. This is less steep than the 1/M dependence predicted in a model where the effect of the black hole on the stellar velocities is ignored. The influence of a stellar mass spectrum on the black hole's Brownian motion is also evaluated and found to be consistent with predictions from Chandrasekhar's theory. We use these results to derive a probability function for the mass of the Milky Way black hole based on a measurement of its proper motion velocity. Interesting constraints on M will require a velocity resolution exceeding 0.5 km/s.

David Merritt; Peter Berczik; Frederik Laun

2006-10-18T23:59:59.000Z

387

Classical and Quantum Properties of Liouville Black Holes  

E-Print Network [OSTI]

Black hole spacetimes can arise when a Liouville field is coupled to two- dimensional gravity. Exact solutions are obtained both classically and when quantum corrections due to back reaction effects are included. The black hole temperature depends upon the mass and the thermodynamic limit breaks down before evaporation of the black hole is complete, indicating that higher-loop effects must be included for a full description of the process.

R. B. Mann

1994-04-25T23:59:59.000Z

388

A Quantum Material Model of Static Schwarzschild Black Holes  

E-Print Network [OSTI]

A quantum-mechanical prescription of static Einstein field equation is proposed in order to construct the matter-metric eigen-states in the interior of a static Schwarzschild black hole where the signature of space-time is chosen as (--++). The spectrum of the quantum states is identified to be the integral multiples of the surface gravity. A statistical explanation of black hole entropy is given and a quantisation rule for the masses of Schwarzschild black holes is proposed.

S. -T. Sung

1997-03-16T23:59:59.000Z

389

Black Holes as Conformal Field Theories on Horizons  

E-Print Network [OSTI]

We show that any nonextreme black hole can be described by a state with $L_0=E_R$ in a $D=2$ chiral conformal field theory with central charge $c=12E_R$ where $E_R$ is the dimensionless Rindler energy of the black hole. The theory lives in the very near horizon region, i.e. around the origin of Rindler space. Black hole hair is the momentum along the Euclidean dimensionless Rindler time direction. As evidence, we show that $D$--dimensional Schwarzschild black holes and $D=2$ dilatonic ones that are obtained from them by spherical reduction are described by the same conformal field theory states.

Halyo, Edi

2015-01-01T23:59:59.000Z

390

Origin of palladium black by an infrared spectroscopic method  

SciTech Connect (OSTI)

Metal blacks are used as catalysts in a number of organic synthesis processes. Using the method of matrix insulation of blacks obtained from organometallic compounds in the inert atmosphere the IR spectra have been recorded for carbon monoxide adsorbed on actual palladium blacks. The controllable mild conditions for reduction of the initial complex by hydrazine hydrate provide a means of separating the intermediate states of this process. By discontinuing at various stages the reduction of the organometallic complex being investigated the authors have obtained IR spectra of carbon monoxide characterizing the stages of forming the metallic palladium black.

Vozdvizhenskii, V.F.; Levintova, T.D.; Sokol'skii, D.V.

1987-03-01T23:59:59.000Z

391

Improved methods for simulating nearly extremal binary black holes  

E-Print Network [OSTI]

Astrophysical black holes could be nearly extremal (that is, rotating nearly as fast as possible); therefore, nearly extremal black holes could be among the binaries that current and future gravitational-wave observatories will detect. Predicting the gravitational waves emitted by merging black holes requires numerical-relativity simulations, but these simulations are especially challenging when one or both holes have mass $m$ and spin $S$ exceeding the Bowen-York limit of $S/m^2=0.93$. We present improved methods that enable us to simulate merging, nearly extremal black holes more robustly and more efficiently. We use these methods to simulate an unequal-mass, precessing binary black hole coalescence, where the larger black hole has $S/m^2=0.99$. We also use these methods to simulate a non-precessing binary black hole coalescence, where both black holes have $S/m^2=0.994$, nearly reaching the Novikov-Thorne upper bound for holes spun up by thin accretion disks. We demonstrate numerical convergence and estimate the numerical errors of the waveforms; we compare numerical waveforms from our simulations with post-Newtonian and effective-one-body waveforms; we compare the evolution of the black-hole masses and spins with analytic predictions; and we explore the effect of increasing spin magnitude on the orbital dynamics (the so-called "orbital hangup" effect).

Mark A. Scheel; Matthew Giesler; Daniel A. Hemberger; Geoffrey Lovelace; Kevin Kuper; Michael Boyle; Bela Szilagyi; Lawrence E. Kidder

2014-12-04T23:59:59.000Z

392

U-012: BlackBerry Enterprise Server Collaboration Service Bug...  

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

Advisory ID: KB28524 SecurityTracker Alert ID: 1026179 CVE-2011-0290 IMPACT ASSESSMENT: Medium Discussion: A vulnerability exists in the BlackBerry Collaboration Service...

393

Primordial black hole evolution in tensor-scalar cosmology  

E-Print Network [OSTI]

A perturbative analysis shows that black holes do not remember the value of the scalar field $\\phi$ at the time they formed if $\\phi$ changes in tensor-scalar cosmology. Moreover, even when the black hole mass in the Einstein frame is approximately unaffected by the changing of $\\phi$, in the Jordan-Fierz frame the mass increases. This mass increase requires a reanalysis of the evaporation of primordial black holes in tensor-scalar cosmology. It also implies that there could have been a significant magnification of the (Jordan-Fierz frame) mass of primordial black holes.

Ted Jacobson

1999-09-06T23:59:59.000Z

394

Argonne's African American Black Club awards scholarships to...  

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

students July 30, 2014 Tweet EmailPrint The African American Black Club (AABC) at Argonne has awarded four scholarships to promising local Illinois high school students to...

395

National Conference of Black Mayors, Inc. | Department of Energy  

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

Black Mayors, Inc., members' capacity for energy and environmental planning through computer-based technology, Internet access, and a training workshop. National Conference of...

396

Black Pine Engineering Wins Clean Energy Trust Clean Energy Challenge...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

the Energy Innovation Portal Last week the student team of Black Pine Engineering from Michigan State University took top honors at the Eastern Midwest regional competition of...

397

Black Hills Energy (Electric)- Residential Energy Efficiency Program  

Broader source: Energy.gov [DOE]

Black Hills Energy (BHE) offers rebates for residential Colorado customers who purchase energy efficient residential equipment. This program offers rebates for customers who purchase and install...

398

Black Hills Energy (Gas)- Commercial Energy Efficiency Rebate Programs  

Broader source: Energy.gov [DOE]

Black Hills Energy offers commercial and industrial customers incentives to encourage energy efficiency in eligible businesses. Prescriptive rebates are available for furnace and boiler...

399

Black Hills Energy (Gas)- Commercial Energy Efficiency Program  

Broader source: Energy.gov [DOE]

Black Hills Energy offers multiple programs for Colorado commercial and industrial customers to save natural gas in eligible facilities. The commercial prescriptive rebate program provides...

400

Black Hills Energy (Electric)- Commercial Energy Efficiency Program  

Broader source: Energy.gov [DOE]

Black Hills Energy offers multiple programs for its Colorado commercial and industrial customers to save electricity in their facilities. The commercial prescriptive rebate program provides...

Note: This page contains sample records for the topic "hard black lustrous" 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

Black Hills Energy (Gas)- Residential Energy Efficiency Program  

Broader source: Energy.gov [DOE]

Black Hills Energy (BHE) offers a variety of rebates for residential Colorado customers who purchase and install energy efficient natural gas appliances, heating equipment and insulation materials....

402

Small Hairy Black Holes in Global AdS Spacetime  

E-Print Network [OSTI]

We study small charged black holes in global AdS spacetime in the presence of a charged massless minimally coupled scalar field. In a certain parameter range these black holes suffer from well known superradiant instabilities. We demonstrate that the end point of the resultant tachyon condensation process is a hairy black hole which we construct analytically in a perturbative expansion in the black hole radius. At leading order our solution is a small undeformed RNAdS black hole immersed into a charged scalar condensate that fills the AdS `box'. These hairy black hole solutions appear in a two parameter family labelled by their mass and charge. Their mass is bounded from below by a function of their charge; at the lower bound a hairy black hole reduces to a regular horizon free soliton which can also be thought of as a nonlinear Bose condensate. We compute the microcanonical phase diagram of our system at small mass, and demonstrate that it exhibits a second order `phase transition' between the RNAdS black hole and the hairy black hole phases.

Pallab Basu; Jyotirmoy Bhattacharya; Sayantani Bhattacharyya; R. Loganayagam; Shiraz Minwalla; V. Umesh

2010-05-16T23:59:59.000Z

403

Absorption of scalars by extremal black holes in string theory  

E-Print Network [OSTI]

We show that the low frequency absorption cross section of minimally coupled massless scalar fields by extremal spherically symmetric black holes in d dimensions in the presence of string-theoretical alpha' corrections is equal to the horizon area. Classically one has the relation sigma=4GS between the absorption cross section and the black hole entropy. We discuss the validity of such relation in the presence of alpha' corrections for extremal black holes, both nonsupersymmetric and supersymmetric. The examples we consider seem to indicate that this relation is verified in the presence of alpha' corrections for supersymmetric black holes, but not for nonsupersymmetric ones.

Filipe Moura

2014-06-13T23:59:59.000Z

404

Extremal charged rotating dilaton black holes in odd dimensions  

SciTech Connect (OSTI)

Employing higher-order perturbation theory, we find a new class of charged rotating black hole solutions of Einstein-Maxwell-dilaton theory with general dilaton coupling constant. Starting from the Myers-Perry solutions, we use the electric charge as the perturbative parameter, and focus on extremal black holes with equal-magnitude angular momenta in odd dimensions. We perform the perturbations up to 4th order for black holes in 5 dimensions and up to 3rd order in higher odd dimensions. We calculate the physical properties of these black holes and study their dependence on the charge and the dilaton coupling constant.

Allahverdizadeh, Masoud; Kunz, Jutta; Navarro-Lerida, Francisco [Institut fuer Physik, Universitaet Oldenburg, Postfach 2503 D-26111 Oldenburg (Germany); Departamento de Fisica Atomica, Molecular y Nuclear, Ciencias Fisicas Universidad Complutense de Madrid, E-28040 Madrid (Spain)

2010-09-15T23:59:59.000Z

405

Extremal Charged Rotating Dilaton Black Holes in Odd Dimensions  

E-Print Network [OSTI]

Employing higher order perturbation theory, we find a new class of charged rotating black hole solutions of Einstein-Maxwell-dilaton theory with general dilaton coupling constant. Starting from the Myers-Perry solutions, we use the electric charge as the perturbative parameter, and focus on extremal black holes with equal-magnitude angular momenta in odd dimensions. We perform the perturbations up to 4th order for black holes in 5 dimensions and up to 3rd order in higher odd dimensions. We calculate the physical properties of these black holes and study their dependence on the charge and the dilaton coupling constant.

Masoud Allahverdizadeh; Jutta Kunz; Francisco Navarro-Lerida

2010-07-24T23:59:59.000Z

406

Two Different Long-term Behaviors in Black-Hole Candidates: Evidence for Two Accretion Flows?  

E-Print Network [OSTI]

We discuss the results of long-term hard x-ray monitoring of Galactic black-hole candidates 1E 1740.7-2942, GRS 1758-258, Cyg X-1, GX 339-4, and Cyg X-3 with the Rossi X-Ray Timing Explorer (RXTE). The objects divide into two classes. In the first class, exemplified by Cyg X-1, luminosity and spectral hardness evolve simultaneously. In the second class, the relation is more complicated: the softest spectra occur while the count rate is dropping. Most models of accretion, tailored to Cyg X-1, do not predict the second sort of behavior. One interpretation is a simple model with two simultaneous, independent accretion flows: a thin disk and a hot halo. A drop in the accretion rate affecting both flows would propagate through the halo immediately but might take up to several weeks to propagate through the disk. While the inner halo is thus temporarily depleted compared to the disk, a temporary soft state is expected. This picture is supported by the observation that those sources which show delays (1E 1740.7-2942, GRS 1758-258, and GX 339-4) are expected to have low-mass companions, and those which do not (Cyg X-1, Cyg X-3) are known or thought to have high-mass companions. Low-mass companions imply accretion by Roche-lobe overflow, with a high specific angular momentum in the accreting material, and therefore a large disk with a long viscous timescale. Wind accretion from massive companions is expected to result in a much smaller disk, and thus little viscous delay.

D. M. Smith; W. A. Heindl; J. H. Swank

2001-12-20T23:59:59.000Z

407

Homogeneous Einstein Metrics on SU(n) Manifolds, Hoop Conjecture for Black Rings, and Ergoregions in Magnetised Black Hole Spacetimes  

E-Print Network [OSTI]

HOMOGENEOUS EINSTEIN METRICS ON SU(n) MANIFOLDS, HOOP CONJECTURE FOR BLACK RINGS, AND ERGOREGIONS IN MAGNETISED BLACK HOLE SPACETIMES A Dissertation by ABID HASAN MUJTABA Submitted to the O ce of Graduate Studies of Texas A&M University... Subject: Physics Copyright 2013 Abid Hasan Mujtaba ABSTRACT This Dissertation covers three aspects of General Relativity: inequivalent Einstein metrics on Lie Group Manifolds, proving the Hoop Conjecture for Black Rings, and investigating ergoregions...

Mujtaba, Abid Hasan

2013-01-09T23:59:59.000Z

408

A southern black community comes of age: black San Antonio in the Great Depression, 1930-1941  

E-Print Network [OSTI]

A&M University Press, 1984) compares the Depression This thesis follows the format of the Journal of 9 t ~Ht experiences of black, white, and Mexican American women of San Antonio. Judy Kaaz Doyle's "Maury Maverick and Racial Politics in San...A SOUTHERN BLACK COMMUNITY COMES OF AGE: BLACK SAN ANTONIO IN THE GREAT DEPRESSION, 1930-1941 A Thesis by CHARLES CHRISTOPHER JACKSON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

Jackson, Charles Christopher

1989-01-01T23:59:59.000Z

409

RESOLVING THE BONDI ACCRETION FLOW TOWARD THE SUPERMASSIVE BLACK HOLE OF NGC 3115 WITH CHANDRA  

SciTech Connect (OSTI)

Gas undergoing Bondi accretion onto a supermassive black hole (SMBH) becomes hotter toward smaller radii. We searched for this signature with a Chandra observation of the hot gas in NGC 3115, which optical observations show has a very massive SMBH. Our analysis suggests that we are resolving, for the first time, the accretion flow within the Bondi radius of an SMBH. We show that the temperature is rising toward the galaxy center as expected in all accretion models in which the black hole is gravitationally capturing the ambient gas. There is no hard central point source that could cause such an apparent rise in temperature. The data support that the Bondi radius is at about 4''-5'' (188-235 pc), suggesting an SMBH of 2 x 10{sup 9} M{sub sun} that is consistent with the upper end of the optical results. The density profile within the Bondi radius has a power-law index of 1.03{sup +0.23}{sub -0.21}, which is consistent with gas in transition from the ambient medium and the accretion flow. The accretion rate at the Bondi radius is determined to be M-dot{sub B} = 2.2x10{sup -2} M{sub sun} yr{sup -1}. Thus, the accretion luminosity with 10% radiative efficiency at the Bondi radius (10{sup 44} erg s{sup -1}) is about six orders of magnitude higher than the upper limit of the X-ray luminosity of the nucleus.

Wong, Ka-Wah; Irwin, Jimmy A.; Yukita, Mihoko; Million, Evan T. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Mathews, William G. [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Bregman, Joel N., E-mail: kwong@ua.edu [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States)

2011-07-20T23:59:59.000Z

410

Extraneous Carbon Assessments in Radiocarbon Measurements of Black Carbon in Environmental Matrices  

E-Print Network [OSTI]

rived (black/elemental) carbon in soils and sediments usingbon measurements of black carbon in aerosols and oceanMWI, Noack AG. 2000. Black carbon in soils and sediments:

Coppola, Alysha; Ziolkowski, L. A.; Druffel, E. R. M.

2013-01-01T23:59:59.000Z

411

T-602: BlackBerry Enterprise Server Input Validation Flaw in...  

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

02: BlackBerry Enterprise Server Input Validation Flaw in BlackBerry Web Desktop Manager Permits Cross-Site Scripting Attacks T-602: BlackBerry Enterprise Server Input Validation...

412

Entropy: From Black Holes to Ordinary Systems  

E-Print Network [OSTI]

Several results of black holes thermodynamics can be considered as firmly founded and formulated in a very general manner. From this starting point we analyse in which way these results may give us the opportunity to gain a better understanding in the thermodynamics of ordinary systems for which a pre-relativistic description is sufficient. First, we investigated the possibility to introduce an alternative definition of the entropy basically related to a local definition of the order in a spacetime model rather than a counting of microstates. We show that such an alternative approach exists and leads to the traditional results provided an equilibrium condition is assumed. This condition introduces a relation between a time interval and the reverse of the temperature. We show that such a relation extensively used in the black hole theory, mainly as a mathematical trick, has a very general and physical meaning here; in particular its derivation is not related to the existence of a canonical density matrix. Our dynamical approach of thermodynamic equilibrium allows us to establish a relation between action and entropy and we show that an identical relation exists in the case of black holes. The derivation of such a relation seems impossible in the Gibbs ensemble approach of statistical thermodynamics. From these results we suggest that the definition of entropy in terms of order in spacetime should be more general that the Boltzmann one based on a counting of microstates. Finally we point out that these results are obtained by reversing the traditional route going from the Schr\\"{o}dinger equation to statistical thermodynamics.

J. P. Badiali

2005-05-11T23:59:59.000Z

413

Formation of subhorizon black holes from preheating  

E-Print Network [OSTI]

We study the production of primordial black holes (PBHs) during the preheating stage that follows a chaotic inflationary phase. The scalar fields present in the process are evolved numerically using a modified version of the HLATTICE code. From the output of the numerical simulation, we compute the probability distribution of curvature fluctuations, paying particular attention to sub-horizon scales. We find that in some specific models these modes grow to large amplitudes developing highly non-Gaussian probability distributions. We then calculate PBH abundances using the standard Press-Schechter criterion and find that overproduction of PBHs is likely in some regions of the chaotic preheating parameter space.

E. Torres-Lomas; Juan Carlos Hidalgo; Karim A. Malik; L. Arturo Ureña-López

2014-04-29T23:59:59.000Z

414

A black potential for spin less particles  

E-Print Network [OSTI]

We consider the most general non-Hermitian Hulthen potential to study the scattering of spin-less relativistic particles. The conditions for CC, SS and CPA are obtained analytically for this potential. We show that almost total absorption occurs for entire range of incidence energy for certain parameter ranges of the potential and hence term this as `black potential'. Time reversed of the same potential shows perfect emission for the entire range of particle energy. We also present the classical analog of this potential in terms of waveguide cross section.

Ananya Ghatak; Mohammad Hasan; Bhabani Prasad Mandal

2014-12-02T23:59:59.000Z

415

Conformal Invariance of Black Hole Temperature  

E-Print Network [OSTI]

It is shown that the surface gravity and temperature of a stationary black hole are invariant under conformal transformations of the metric that are the identity at infinity. More precisely, we find a conformal invariant definition of the surface gravity of a conformal Killing horizon that agrees with the usual definition(s) for a true Killing horizon and is proportional to the temperature as defined by Hawking radiation. This result is reconciled with the intimate relation between the trace anomaly and the Hawking effect, despite the {\\it non}invariance of the trace anomaly under conformal transformations.

Ted Jacobson; Gungwon Kang

1993-07-06T23:59:59.000Z

416

Black Hole Thermodynamics and Lorentz Symmetry  

E-Print Network [OSTI]

Recent developments point to a breakdown in the generalized second law of thermodynamics for theories with Lorentz symmetry violation. It appears possible to construct a perpetual motion machine of the second kind in such theories, using a black hole to catalyze the conversion of heat to work. Here we describe and extend the arguments leading to that conclusion. We suggest the inference that local Lorentz symmetry may be an emergent property of the macroscopic world with origins in a microscopic second law of causal horizon thermodynamics.

Ted Jacobson; Aron C. Wall

2010-02-04T23:59:59.000Z

417

Geodesic Study of Regular Hayward Black Hole  

E-Print Network [OSTI]

This paper is devoted to study the geodesic structure of regular Hayward black hole. The timelike and null geodesic have been studied explicitly for radial and non-radial motion. For timelike and null geodesic in radial motion there exists analytical solution, while for non-radial motion the effective potential has been plotted, which investigates the position and turning points of the particle. It has been found that massive particle moving along timelike geodesics path are dragged towards the BH and continues move around BH in particular orbits.

G. Abbas; U. Sabiullah

2014-06-03T23:59:59.000Z

418

Fundamental studies of black liquor combustion  

SciTech Connect (OSTI)

The fundamentals of black liquor combustion are being studied in a project being carried out for the US Department of Energy by the Institute of Paper Science Technology (IPST, formerly the Institute of Paper Chemistry) and the National Institute of Science Technology (NIST, formerly the National Bureau of Standards). The project was divided into four phases. This report covers the completion of Phase 1 (in-flight processes), the results of all of the work on Phase 2 (char bed processes), Phase 3 (fume processes), and Phase 4 (furnace simulation). 41 refs., 62 figs., 30 tabs.

Clay, D.T.; Lien, S.J.; Grace, T.M.; Brown, C.A.; Empie, H.L.; Macek, A.; Amin, N.; Charangundla, S.R.

1990-03-01T23:59:59.000Z

419

Black River Electric Coop | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartmentAUDIT REPORTOpenWendeGuo Feng Bio JumpVenturesCoral Capital JumpBlack River

420

Black Warrior Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartmentAUDIT REPORTOpenWendeGuo Feng Bio JumpVenturesCoral Capital JumpBlack

Note: This page contains sample records for the topic "hard black lustrous" 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

Black Diamond Power Co | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin: Energy ResourcesJersey:form ViewBlack Diamond Power Co Jump to: navigation,

422

Black Hills Corporation | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin: Energy ResourcesJersey:form ViewBlack Diamond Power Co JumpHawk County,

423

Black Hills Power Inc | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin: Energy ResourcesJersey:form ViewBlack Diamond Power Co JumpHawk County,Power

424

Black Warrior Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin: Energy ResourcesJersey:form ViewBlack Diamond Power Co JumpHawkIII(Redirected

425

BlackHawk Fund | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin: Energy ResourcesJersey:form ViewBlack Diamond Power CoWolf, Wisconsin:

426

Black Mountain Insulation | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectricEnergyCTBarre BiomassTHIS PAGE ISJump to: navigation,Black Hills Name:

427

Lumens Placard (Black) | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietipDepartmentJuneWhenJulyBadgesSeptemberoflumens_placard-black.eps

428

Timing and Spectral Properties of X-ray Emission from the Converging Flows onto Black hole: Monte-Carlo Simulations  

E-Print Network [OSTI]

We demonstrate that a X-ray spectrum of a converging inflow (CI) onto a black hole is the sum of a thermal (disk) component and the convolution of some fraction of this component with the Comptonization spread (Green's) function. The latter component is seen as an extended power law at energies much higher than the characteristic energy of the soft photons. We show that the high energy photon production (source function) in the CI atmosphere is distributed with the characteristic maximum at about the photon bending radius, 1.5r_S, independently of the seed (soft) photon distribution. We show that high frequency oscillations of the soft photon source in this region lead to the oscillations of the high energy part of the spectrum but not of the thermal component. The high frequency oscillations of the inner region are not significant in the thermal component of the spectrum. We further demonstrate that Doppler and recoil effects (which are responsible for the formation of the CI spectrum) are related to the hard (positive) and soft (negative) time lags between the soft and hard photon energy channels respectively.

Philippe Laurent; Lev Titarchuk

2001-10-11T23:59:59.000Z

429

Thermodynamics of (2+1)-dimensional acoustic black hole based on the generalized uncertainty principle  

E-Print Network [OSTI]

We study thermodynamic quantities of an acoustic black hole and its thermodynamic stability in a cavity based on the generalized uncertainty principle. It can be shown that there is a minimal black hole which can be a stable remnant after black hole evaporation. Moreover, the behavior of the free energy shows that the large black hole is stable too. Therefore, the acoustic black hole can decay into the remnant or the large black hole.

Wontae Kim; Edwin J. Son; Myungseok Yoon

2008-01-09T23:59:59.000Z

430

Density functional theory for colloidal mixtures of hard platelets, rods, and spheres  

E-Print Network [OSTI]

A geometry-based density functional theory is presented for mixtures of hard spheres, hard needles and hard platelets; both the needles and the platelets are taken to be of vanishing thickness. Geometrical weight functions that are characteristic for each species are given and it is shown how convolutions of pairs of weight functions recover each Mayer bond of the ternary mixture and hence ensure the correct second virial expansion of the excess free energy functional. The case of sphere-platelet overlap relies on the same approximation as does Rosenfeld's functional for strictly two-dimensional hard disks. We explicitly control contributions to the excess free energy that are of third order in density. Analytic expressions relevant for the application of the theory to states with planar translational and cylindrical rotational symmetry, e.g. to describe behavior at planar smooth walls, are given. For binary sphere-platelet mixtures, in the appropriate limit of small platelet densities, the theory differs from that used in a recent treatment [L. Harnau and S. Dietrich, Phys. Rev. E 71, 011504 (2004)]. As a test case of our approach we consider the isotropic-nematic bulk transition of pure hard platelets, which we find to be weakly first order, with values for the coexistence densities and the nematic order parameter that compare well with simulation results.

Ansgar Esztermann; Hendrik Reich; Matthias Schmidt

2005-11-18T23:59:59.000Z

431

Hardness of FeB{sub 4}: Density functional theory investigation  

SciTech Connect (OSTI)

A recent experimental study reported the successful synthesis of an orthorhombic FeB{sub 4} with a high hardness of 62(5) GPa [H. Gou et al., Phys. Rev. Lett. 111, 157002 (2013)], which has reignited extensive interests on whether transition-metal borides compounds will become superhard materials. However, it is contradicted with some theoretical studies suggesting transition-metal boron compounds are unlikely to become superhard materials. Here, we examined structural and electronic properties of FeB{sub 4} using density functional theory. The electronic calculations show the good metallicity and covalent Fe–B bonding. Meanwhile, we extensively investigated stress-strain relations of FeB{sub 4} under various tensile and shear loading directions. The calculated weakest tensile and shear stresses are 40 GPa and 25 GPa, respectively. Further simulations (e.g., electron localization function and bond length along the weakest loading direction) on FeB{sub 4} show the weak Fe–B bonding is responsible for this low hardness. Moreover, these results are consistent with the value of Vickers hardness (11.7–32.3 GPa) by employing different empirical hardness models and below the superhardness threshold of 40 GPa. Our current results suggest FeB{sub 4} is a hard material and unlikely to become superhard (>40 GPa)

Zhang, Miao; Du, Yonghui; Gao, Lili [Department of Physics, Beihua University, Jilin 132013 (China)] [Department of Physics, Beihua University, Jilin 132013 (China); Lu, Mingchun [Department of Aeronautical Engineering Professional Technology, Jilin Institute of Chemical Technology, Jilin 132102 (China)] [Department of Aeronautical Engineering Professional Technology, Jilin Institute of Chemical Technology, Jilin 132102 (China); Lu, Cheng [Department of Physics, Nanyang Normal University, Nanyang 473061 (China)] [Department of Physics, Nanyang Normal University, Nanyang 473061 (China); Liu, Hanyu, E-mail: hal420@mail.usask.ca [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)] [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)

2014-05-07T23:59:59.000Z

432

Investigation of the hard x-ray background in backlit pinhole imagers  

SciTech Connect (OSTI)

Hard x-rays from laser-produced hot electrons (>10 keV) in backlit pinhole imagers can give rise to a background signal that decreases signal dynamic range in radiographs. Consequently, significant uncertainties are introduced to the measured optical depth of imaged plasmas. Past experiments have demonstrated that hard x-rays are produced when hot electrons interact with the high-Z pinhole substrate used to collimate the softer He-? x-ray source. Results are presented from recent experiments performed on the OMEGA-60 laser to further study the production of hard x-rays in the pinhole substrate and how these x-rays contribute to the background signal in radiographs. Radiographic image plates measured hard x-rays from pinhole imagers with Mo, Sn, and Ta pinhole substrates. The variation in background signal between pinhole substrates provides evidence that much of this background comes from x-rays produced in the pinhole substrate itself. A Monte Carlo electron transport code was used to model x-ray production from hot electrons interacting in the pinhole substrate, as well as to model measurements of x-rays from the irradiated side of the targets, recorded by a bremsstrahlung x-ray spectrometer. Inconsistencies in inferred hot electron distributions between the different pinhole substrate materials demonstrate that additional sources of hot electrons beyond those modeled may produce hard x-rays in the pinhole substrate.

Fein, J. R., E-mail: jrfein@umich.edu; Holloway, J. P. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Peebles, J. L. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Keiter, P. A.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States)

2014-11-15T23:59:59.000Z

433

AN EVOLVING COMPACT JET IN THE BLACK HOLE X-RAY BINARY MAXI J1836-194  

SciTech Connect (OSTI)

We report striking changes in the broadband spectrum of the compact jet of the black hole transient MAXI J1836-194 over state transitions during its discovery outburst in 2011. A fading of the optical-infrared (IR) flux occurred as the source entered the hard-intermediate state, followed by a brightening as it returned to the hard state. The optical-IR spectrum was consistent with a power law from optically thin synchrotron emission, except when the X-ray spectrum was softest. By fitting the radio to optical spectra with a broken power law, we constrain the frequency and flux of the optically thick/thin break in the jet synchrotron spectrum. The break gradually shifted to higher frequencies as the source hardened at X-ray energies, from {approx}10{sup 11} to {approx}4 Multiplication-Sign 10{sup 13} Hz. The radiative jet luminosity integrated over the spectrum appeared to be greatest when the source entered the hard state during the outburst decay (although this is dependent on the high-energy cooling break, which is not seen directly), even though the radio flux was fading at the time. The physical process responsible for suppressing and reactivating the jet (neither of which are instantaneous but occur on timescales of weeks) is uncertain, but could arise from the varying inner accretion disk radius regulating the fraction of accreting matter that is channeled into the jet. This provides an unprecedented insight into the connection between inflow and outflow, and has implications for the conditions required for jets to be produced, and hence their launching process.

Russell, D. M. [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Russell, T. D.; Miller-Jones, J. C. A.; Soria, R.; Slaven-Blair, T.; Curran, P. A. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); O'Brien, K. [Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Sivakoff, G. R. [Department of Physics, University of Alberta, CCIS 4-181, Edmonton, AB T6G 2E1 (Canada); Lewis, F. [Faulkes Telescope Project, University of Glamorgan, Pontypridd CF37 1DL (United Kingdom); Markoff, S.; Altamirano, D. [Astronomical Institute ''Anton Pannekoek'', University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands); Homan, J. [MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar Street, Cambridge, MA 02139 (United States); Rupen, M. P.; Dhawan, V. [NRAO Domenici Science Operations Center, 1003 Lopezville Road, Socorro, NM 87801 (United States); Belloni, T. M. [INAF - Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Cadolle Bel, M. [European Space Agency, European Space Astronomy Centre, ISOC, Villanueva de la Canada, Madrid (Spain); Casella, P. [INAF - Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy); Corbel, S. [Laboratoire AIM, UMR 7158, CEA/DSM, CNRS, Universite Paris Diderot, IRFU/SAp, Gif-sur-Yvette (France); Fender, R. P. [School of Physics and Astronomy, University of Southampton, Southampton, Hampshire SO17 1BJ (United Kingdom); Gallo, E., E-mail: russell@iac.es [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); and others

2013-05-10T23:59:59.000Z

434

Multi-wavelength observations of the black widow pulsar 2FGL J2339.6-0532 with OISTER and Suzaku  

E-Print Network [OSTI]

Multi-wavelength observations of the black-widow binary system 2FGL J2339.6-0532 are reported. The Fermi gamma-ray source 2FGL J2339.6-0532 was recently categorized as a black widow in which a recycled millisecond pulsar (MSP) is evaporating up the companion star with its powerful pulsar wind. Our optical observations show clear sinusoidal light curves due to the asymmetric temperature distribution of the companion star. Assuming a simple geometry, we constrained the range of the inclination angle of the binary system to 52$^{\\circ}$ < i < 59$^{\\circ}$, which enables us to discuss the interaction between the pulsar wind and the companion in detail. The X-ray spectrum consists of two components: a soft, steady component that seems to originate from the surface of the MSP, and a hard variable component from the wind-termination shock near the companion star. The measured X-ray luminosity is comparable to the bolometric luminosity of the companion, meaning that the heating efficiency is less than 0.5. In t...

Yatsu, Yoichi; Takahashi, Yosuke; Tachibana, Yutaro; Kawai, Nobuyuki; Shibata, Shimpei; Pike, Sean; Yoshii, Taketoshi; Arimoto, Makoto; Saito, Yoshihiko; NakamorI, Takeshi; Sekiguchi, Kazuhiro; Kuroda, Daisuke; Yanagisawa, Kenshi; Hanayama, Hidekazu; Watanabe, Makoto; Hamamoto, Ko; Nakao, Hikaru; Ozaki, Akihito; Motohara, Kentaro; Konishi, Masahiro; Tateuchi, Ken; Matsunaga, Noriyuki; Morokuma, Tomoki; Nagayama, Takahiro; Murata, Katsuhiro; Akitaya, Hiroshi; Yoshida, Michitoshi; Ali, Gamal B; Mohamed, A Essam; Isogai, Mizuki; Arai, Akira; Takahashi, Hidenori; Hashimoto, Osamu; Miyanoshita, Ryo; Omodaka, Toshihiro; Takahashi, Jun; Tokimasa, Noritaka; Matsuda, Kentaro; Okumura, Shin-Ichiro; Nishiyama, Kota; Urakawa, Seitaro; Nogami, Daisaku; Oasa, Yumiko

2015-01-01T23:59:59.000Z

435

Studying the Properties of Accretion Disks and Coronae in Black Hole X-ray Binaries with Monte-Carlo Simulations  

E-Print Network [OSTI]

Understanding the properties of the hot corona is important for studying the accretion disks in black hole X-ray binary systems. Using the Monte-Carlo technique to simulate the inverse Compton scattering between photons emitted from the cold disk and electrons in the hot corona, we have produced two table models in the $XSPEC$ format for the spherical corona case and the disk-like (slab) corona case. All parameters in our table models are physical properties of the system and can be derived from data fitting directly. Applying the models to broad-band spectra of the black hole candidate XTE J2012+381 observed with BeppoSAX, we estimated the size of the corona and the inner radius of the disk. The size of the corona in this system is several tens of gravitational radius, and the substantial increase of the inner disk radius during the transit from hard-state to soft-state is not found.

Yangsen Yao; S. Nan Zhang; Xiaoling Zhang; Yuxin Feng; Craig R. Robinson

2004-10-10T23:59:59.000Z

436

Using the master's tools : representations of blackness and the strategies of stereotype  

E-Print Network [OSTI]

Watermelon, Black Woman with Drumstick, and other-worldlyBlack Woman with Drumstick,” making obvious connotations toWith Watermelon? ” and “With Drumstick? ” I would argue the

Zygmonski, Aimee

2010-01-01T23:59:59.000Z

437

E-Print Network 3.0 - ads schwarzschild black Sample Search Results  

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

spacetime. However, unlike shock matching outside a Black Hole... to infinity along a geodesic of the Schwarzschild metric outside the Black Hole. Thus the OS solution gives... ,...

438

E-Print Network 3.0 - asian black latino Sample Search Results  

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

Ethnic Summary: IndianNative American Asian Black or African American HispanicLatino White Multi-Racial Unspecified... Native American Asian Black or African American Hispanic...

439

Black Carbon’s Properties and Role in the Environment: A Comprehensive Review  

E-Print Network [OSTI]

NOAA/ESRL. Mauna Loa Carbon Dioxide Annual Mean Data.H. Can reducing black carbon emissions counteract globalanalysis of black carbon in soils. Global Biogeochem. Cycle.

Shrestha, Gyami

2010-01-01T23:59:59.000Z

440

Nonrotating black hole in a post-Newtonian tidal environment  

E-Print Network [OSTI]

We examine the motion and tidal dynamics of a nonrotating black hole placed within a post-Newtonian external spacetime. The tidal perturbation created by the external environment is treated as a small perturbation. At a large distance from the black hole, the gravitational field of the external distribution of matter is assumed to be sufficiently weak to be adequately described by the (first) post-Newtonian approximation to general relativity. There, the black hole is treated as a monopole contribution to the total gravitational field. There exists an overlap in the domains of validity of each description, and the black-hole and post-Newtonian metrics are matched in the overlap. The matching procedure produces the equations of motion for the black hole and the gravito-electric and gravito-magnetic tidal fields acting on the black hole. We first calculate the equations of motion and tidal fields by making no assumptions regarding the nature of the post-Newtonian environment; this could contain a continuous distribution of matter or any number of condensed bodies. We next specialize our discussion to a situation in which the black hole is a member of a post-Newtonian two-body system. As an application of our results, we examine the geometry of the deformed event horizon and calculate the tidal heating of the black hole, the rate at which it acquires mass as a result of its tidal interaction with the companion body.

Stephanne Taylor; Eric Poisson

2008-09-11T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Verifying Red-Black Trees Paolo Baldan1  

E-Print Network [OSTI]

Verifying Red-Black Trees Paolo Baldan1 , Andrea Corradini2 , Javier Esparza3 , Tobias Heindel3,heindets,koenigba,koziouvi}@fmi.uni-stuttgart.de Abstract. We show how to verify the correctness of insertion of ele- ments into red-black trees--a form of balanced search trees--using anal- ysis techniques developed for graph rewriting. We first model red

Baldan, Paolo

442

Accelerating and rotating black holes J. B. Griffiths1  

E-Print Network [OSTI]

Accelerating and rotating black holes J. B. Griffiths1 and J. Podolsk´y2 1Department Abstract An exact solution of Einstein's equations which represents a pair of accelerating and rotating which explicitly contains the known special cases for either rotating or accelerating black holes

443

Large rotating AdS black holes from fluid mechanics  

E-Print Network [OSTI]

We use the AdS/CFT correspondence to argue that large rotating black holes in global AdS(D) spaces are dual to stationary solutions of the relativistic Navier-Stokes equations on S**(D-2). Reading off the equation of state of this fluid from the thermodynamics of non-rotating black holes, we proceed to construct the nonlinear spinning solutions of fluid mechanics that are dual to rotating black holes. In all known examples, the thermodynamics and the local stress tensor of our solutions are in precise agreement with the thermodynamics and boundary stress tensor of the spinning black holes. Our fluid dynamical description applies to large non-extremal black holes as well as a class of large non-supersymmetric extremal black holes, but is never valid for supersymmetric black holes. Our results yield predictions for the thermodynamics of all large black holes in all theories of gravity on AdS spaces, for example, string theory on AdS(5) x S**5 and M theory on AdS(4) x S**7 and AdS(7) x S**4.

Sayantani Bhattacharyya; Subhaneil Lahiri; R. Loganayagam; Shiraz Minwalla

2008-07-25T23:59:59.000Z

444

Analysis of spherically symmetric black holes in Braneworld models  

E-Print Network [OSTI]

Research on black holes and their physical proprieties has been active on last 90 years. With the appearance of the String Theory and the Braneworld models as alternative descriptions of our Universe, the interest on black holes, in these context, increased. In this work we studied black holes in Braneworld models. A class of spherically symmetric black holes is investigaded as well its stability under general perturbations. Thermodynamic proprieties and quasi-normal modes are discussed. The black holes studied are the SM (zero mass) and CFM solutions, obtained by Casadio {\\it et al.} and Bronnikov {\\it et al.}. The geometry of bulk is unknown. However the Campbell-Magaard Theorem guarantees the existence of a 5-dimensional solution in the bulk whose projection on the brane is the class of black holes considered. They are stable under scalar perturbations. Quasi-normal modes were observed in both models. The tail behavior of the perturbations is the same. The entropy upper bound of a body absorved by the black holes studied was calculated. This limit turned out to be independent of the black hole parameters.

A. B. Pavan

2010-05-25T23:59:59.000Z

445

Pair Production of Topological anti de Sitter Black Holes  

E-Print Network [OSTI]

The pair creation of black holes with event horizons of non-trivial topology is described. The spacetimes are all limiting cases of the cosmological $C$ metric. They are generalizations of the $(2+1)$ dimensional black hole and have asymptotically anti de Sitter behaviour. Domain walls instantons can mediate their pair creation for a wide range of mass and charge.

R. B. Mann

1996-07-28T23:59:59.000Z

446

Synchronous Black Hole Search in Directed Graphs Adrian Kosowski  

E-Print Network [OSTI]

Synchronous Black Hole Search in Directed Graphs Adrian Kosowski Alfredo Navarra Cristina M called black hole nodes, and once a robot enters in one of them, it is destroyed. The goal is to find supported by the Italian CNR Short-Term Mobility Program. A. Kosowski was supported Polish Ministry Grant N

Paris-Sud XI, Université de

447

Modified Black Hole with Polar Jet and Vortex  

E-Print Network [OSTI]

There are many models relating an accretion disk of Black Hole to jet outflow. The herein heuristic model describes the continuation of an external accretion disk to an internal accretion disk for less than Black Hole horizon, and subsequent polar jet outflow along polar axis out of polar vortex wherein the event horizon is no longer descriptive.

T. Tmmalm

2001-12-06T23:59:59.000Z

448

Electromagnetic extraction of energy from Kerr black holes  

E-Print Network [OSTI]

We elucidate the `right' process for energy extraction from Kerr black holes through `FFDE' magnetospheres, free from causality violation. It is shown that the magnetosphere of a Kerr black hole possesses the double-structure, consisting of the inner and outer magnetospheres with the pair-creation gap between them and with respective unipolar batteries at the inner and outer surfaces of the gap.

Isao Okamoto

2005-06-14T23:59:59.000Z

449

"Black Box" EMC model for Power Electronics Converter Mikael Foissac  

E-Print Network [OSTI]

"Black Box" EMC model for Power Electronics Converter Mikael Foissac Grenoble Electrical be forecasted accurately, in order to avoid disturbance of the complete system. To quantify the EMC behaviour will then illustrate the method on a complete chopper cell. II. BLACK BOX EMC MODEL Any EMC analysis must account

Paris-Sud XI, Université de

450

X] THEPROPAGATIONOF BLACK BASS IN PONDS. BY WILLIAM F. PAGE,  

E-Print Network [OSTI]

X¯] THEPROPAGATIONOF BLACK BASS IN PONDS. BY WILLIAM F. PAGE, Superintendent U.S. Fish Commission to add to the fish supply by broadening the habitat of the black bass. But while fish-culturists were States, engaged in fish-culture were annually, at the period of the bass spawning, devoting every energy

451

Structure and Mass Absorption of Hypothetical Terrestrial Black Holes  

E-Print Network [OSTI]

The prospect of mini black holes, either primordial or in planned experiments at the Large Hadron Collider, interacting with the earth motivate us to examine how they may be detected and the scope of their impact on the earth. We propose that the more massive of these objects may gravitationally bind matter without significant absorption. Since the wave functions of gravitationally bound atoms orbiting a black hole are analogous to those of electrons around a nucleus, we call such an object the Gravitationally Equivalent of an Atom (GEA). Mini black holes are expected to lose mass through quantum evaporation, which has become well accepted on purely theoretical grounds. Since all attempts to directly observe x-rays from an evaporating black hole have failed, we examine the possibility of the inverse test: search for extant mini black holes by looking for emissions from matter bound in a GEA. If quantum evaporation does not occur, then miniature black holes left over from the early universe may be stable, contribute to dark matter, and in principle be detectable through emissions associated with the bound matter. We show that small black holes-with masses below \\sim10^12 kg-can bind matter without readily absorbing it into the black hole but the emissions are too weak to be detected from earth.

A. P. VanDevender; J. Pace VanDevender

2011-05-02T23:59:59.000Z

452

Instabilities of (near) extremal rotating black holes in higher dimensions  

E-Print Network [OSTI]

Recently, Durkee and Reall have conjectured a criterion for linear instability of rotating, extremal, asymptotically Minkowskian black holes in $d\\ge 4$ dimensions, such as the Myers-Perry black holes. They considered a certain elliptic operator, $\\cal A$, acting on symmetric traceless tensors intrinsic to the horizon. Based in part on numerical evidence, they suggested that if the lowest eigenvalue, $\\lambda$, of this operator is less than the critical value $-1/4$ ( called "effective BF-bound"), then the black hole is linearly unstable. In this paper, we prove their conjecture. Our proof uses a combination of methods such as (i) the "canonical energy method" of Hollands-Wald, (ii) algebraically special properties of the near horizon geometries associated with the black hole, and (iii) the structure of the (linearized) constraint equations. Our method of proof is also applicable to rotating, extremal asymptotically Anti-deSitter black holes. In that case, our methods show that "all" such black holes are unstable. Although we explicitly discuss in this paper only extremal black holes, we argue that our methods can be generalized straightforwardly to obtain the same results for "near" extremal black holes.

Stefan Hollands; Akihiro Ishibashi

2014-08-04T23:59:59.000Z

453

Sequencing the Black Aspergilli species complex  

SciTech Connect (OSTI)

The ~15 members of the Aspergillus section Nigri species complex (the "Black Aspergilli") are significant as platforms for bioenergy and bioindustrial technology, as members of soil microbial communities and players in the global carbon cycle, and as food processing and spoilage agents and agricultural toxigens. Despite their utility and ubiquity, the morphological and metabolic distinctiveness of the complex's members, and thus their taxonomy, is poorly defined. We are using short read pyrosequencing technology (Roche/454 and Illumina/Solexa) to rapidly scale up genomic and transcriptomic analysis of this species complex. To date we predict 11197 genes in Aspergillus niger, 11624 genes in A. carbonarius, and 10845 genes in A. aculeatus. A. aculeatus is our most recent genome, and was assembled primarily from 454-sequenced reads and annotated with the aid of >2 million 454 ESTs and >300 million Solexa ESTs. To most effectively deploy these very large numbers of ESTs we developed 2 novel methods for clustering the ESTs into assemblies. We have also developed a pipeline to propose orthologies and paralogies among genes in the species complex. In the near future we will apply these methods to additional species of Black Aspergilli that are currently in our sequencing pipeline.

Kuo, Alan; Salamov, Asaf; Zhou, Kemin; Otillar, Robert; Baker, Scott; Grigoriev, Igor

2011-03-11T23:59:59.000Z

454

Light Loop Echoes and Blinking Black Holes  

E-Print Network [OSTI]

Radiation emitted near a black hole reaches the observer by multiple paths; and when this radiation varies in time, the time-delays between the various paths generate a "blinking" effect in the observed light curve L(t) or its auto-correlation function xi(T)= . For the particularly important "face-on" configuration (in which the hole is viewed roughly along its spin axis, while the emission comes roughly from its equatorial plane -- e.g. from the inner edge of its accretion disk, or from the violent flash of a nearby/infalling star) we calculate the blinking in detail by computing the time delay Delta t_{j}(r,a) and magnification mu_{j}(r,a) of the jth path (j=1,2,3,...), relative to the primary path (j=0), as a function of the emission radius r and black hole spin 0

455

Black holes in f(R) theories  

SciTech Connect (OSTI)

In the context of f(R) theories of gravity, we address the problem of finding static and spherically symmetric black hole solutions. Several aspects of constant curvature solutions with and without electric charge are discussed. We also study the general case (without imposing constant curvature). Following a perturbative approach around the Einstein-Hilbert action, it is found that only solutions of the Schwarzschild-(anti) de Sitter type are present up to second order in perturbations. Explicit expressions for the effective cosmological constant are obtained in terms of the f(R) function. Finally, we have considered the thermodynamics of black holes in anti-de Sitter space-time and found that this kind of solution can only exist provided the theory satisfies R{sub 0}+f(R{sub 0})<0. Interestingly, this expression is related to the condition which guarantees the positivity of the effective Newton's constant in this type of theories. In addition, it also ensures that the thermodynamical properties in f(R) gravities are qualitatively similar to those of standard general relativity.

Cruz-Dombriz, A. de la; Dobado, A.; Maroto, A. L. [Departamento de Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid (Spain)

2009-12-15T23:59:59.000Z

456

Black Hole Instabilities and Exponential Growth  

E-Print Network [OSTI]

Recently, a general analysis has been given of the stability with respect to axisymmetric perturbations of stationary-axisymmetric black holes and black branes in vacuum general relativity in arbitrary dimensions. It was shown that positivity of canonical energy on an appropriate space of perturbations is necessary and sufficient for stability. However, the notions of both "stability" and "instability" in this result are significantly weaker than one would like to obtain. In this paper, we prove that if a perturbation of the form $\\pounds_t \\delta g$---with $\\delta g$ a solution to the linearized Einstein equation---has negative canonical energy, then that perturbation must, in fact, grow exponentially in time. The key idea is to make use of the $t$- or ($t$-$\\phi$)-reflection isometry, $i$, of the background spacetime and decompose the initial data for perturbations into their odd and even parts under $i$. We then write the canonical energy as $\\mathscr E\\ = \\mathscr K + \\mathscr U$, where $\\mathscr K$ and $...

Prabhu, Kartik

2015-01-01T23:59:59.000Z

457

Primordial black holes as biased tracers  

E-Print Network [OSTI]

Primordial black holes (PBHs) are theoretical black holes which may be formed during the radiation dominant era and, basically, caused by the gravitational collapse of radiational overdensities. It has been well known that in the context of the structure formation in our Universe such collapsed objects, e.g., halos/galaxies, could be considered as bias tracers of underlying matter fluctuations and the halo/galaxy bias has been studied well. Employing a peak-background split picture which is known to be a useful tool to discuss the halo bias, we consider the large scale clustering behavior of the PBH and propose an almost mass-independent constraint to the scenario that dark matters (DMs) consist of PBHs. We consider the case where the statistics of the primordial curvature perturbations is almost Gaussian, but with small local-type non-Gaussianity. If PBHs account for the DM abundance, such a large scale clustering of PBHs behaves as nothing but the matter isocurvature perturbation and constrained strictly by...

Tada, Yuichiro

2015-01-01T23:59:59.000Z

458

Black holes can have curly hair  

E-Print Network [OSTI]

We study equilibrium conditions between a static, spherically symmetric black hole and classical matter in terms of the radial pressure to density ratio p_r/\\rho = w(u), where u is the radial coordinate. It is shown that such an equilibrium is possible in two cases: (i) the well-known case w\\to -1 as $u\\to u_h (the horizon), i.e., "vacuum" matter, for which \\rho(u_h) can be nonzero; (ii) w \\to -1/(1+2k) and \\rho \\sim (u-u_h)^k as u\\to u_h, where k>0 is a positive integer (w=-1/3 in the generic case k=1). A non-interacting mixture of these two kinds of matter can also exist. The whole reasoning is local, hence the results do not depend on any global or asymptotic conditions. They mean, in particular, that a static black hole cannot live inside a star with nonnegative pressure and density. As an example, an exact solution for an isotropic fluid with w = -1/3 (that is, a fluid of disordered cosmic strings), with or without vacuum matter, is presented.

K. A. Bronnikov; O. B. Zaslavskii

2008-05-29T23:59:59.000Z

459

Experimental Signature for Black Hole Production in Neutrino Air Showers  

E-Print Network [OSTI]

The existence of extra degrees of freedom beyond the electroweak scale may allow the formation of black holes in nearly horizontal neutrino air showers. In this paper we examine the average properties of the light descendants of these black holes. Our analysis indicates that black hole decay gives rise to deeply penetrating showers with an electromagnetic component which differs substantially from that in conventional neutrino interactions, allowing a good characterization of the phenomenon against background. Naturally occurring black holes in horizontal neutrino showers could be detected and studied with the Auger air shower array. Since the expected black hole production rate at Auger is $> 1$ event/year, this cosmic ray observatory could be potentially powerful in probing models with extra dimensions and TeV-scale gravity.

Luis Anchordoqui; Haim Goldberg

2001-10-15T23:59:59.000Z

460

Quasinormal modes of test fields around regular black holes  

E-Print Network [OSTI]

We study scalar, electromagnetic and gravitational test fields in the Hayward, Bardeen and Ay\\'{o}n-Beato-Garc\\'{i}a regular black hole spacetimes and demonstrate that the test fields are stable in all these spacetimes. Using the sixth order WKB approximation of the linear "axial" perturbative scheme, we determine dependence of the quasinormal mode (QNM) frequencies on the characteristic parameters of the test fields and the spacetime charge parameters of the regular black holes. We give also the greybody factors, namely the transmission and reflection coefficients of scattered scalar, electromagnetic and gravitational waves. We show that damping of the QNMs in regular black hole spacetimes is suppressed in comparison to the case of Schwarzschild black holes, and increasing charge parameter of the regular black holes increases reflection and decreases transmission factor of incident waves for each of the test fields.

Bobir Toshmatov; Ahmadjon Abdujabbarov; Zden?k Stuchlík; Bobomurat Ahmedov

2015-03-19T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Implications of a viscosity bound on black hole accretion  

E-Print Network [OSTI]

Motivated by the viscosity bound in gauge/gravity duality, we consider the ratio of shear viscosity (eta) to entropy density (s) in black hole accretion flows. We use both an ideal gas equation of state and the QCD equation of state obtained from lattice for the fluid accreting onto a Kerr black hole. The QCD equation of state is considered since the temperature of accreting matter is expected to approach 10^{12}K in certain hot flows. We find that in both the cases eta/s is small only for primordial black holes and several orders of magnitude larger than any known fluid for stellar and supermassive black holes. We show that a lower bound on the mass of primordial black holes leads to a lower bound on eta/s and vice versa. Finally we speculate that the Shakura-Sunyaev viscosity parameter should decrease with increasing density and/or temperatures.

Aninda Sinha; Banibrata Mukhopadhyay

2012-02-13T23:59:59.000Z

462

Hypervelocity binary stars: smoking gun of massive binary black holes  

E-Print Network [OSTI]

The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black hole. In this paper, we demonstrate that binary stars can be ejected out of the Galactic center with velocities up to 10^3 km/s, while preserving their integrity, through interactions with a massive binary black hole. Binary stars are unlikely to attain such high velocities via scattering by a single massive black hole or through any other mechanisms. Based on the above theoretical prediction, we propose a search for binary systems among the hypervelocity stars. Discovery of hypervelocity binary stars, even one, is a definitive evidence of the existence of a massive binary black hole in the Galactic center.

Youjun Lu; Qingjuan Yu; D. N. C. Lin

2007-07-22T23:59:59.000Z

463

Black Hole Hair Removal: Non-linear Analysis  

E-Print Network [OSTI]

BMPV black holes in flat transverse space and in Taub-NUT space have identical near horizon geometries but different microscopic degeneracies. It has been proposed that this difference can be accounted for by different contribution to the degeneracies of these black holes from hair modes, -- degrees of freedom living outside the horizon. In this paper we explicitly construct the hair modes of these two black holes as finite bosonic and fermionic deformations of the black hole solution satisfying the full non-linear equations of motion of supergravity and preserving the supersymmetry of the original solutions. Special care is taken to ensure that these solutions do not have any curvature singularity at the future horizon when viewed as the full ten dimensional geometry. We show that after removing the contribution due to the hair degrees of freedom from the microscopic partition function, the partition functions of the two black holes agree.

Dileep P. Jatkar; Ashoke Sen; Yogesh K. Srivastava

2009-07-03T23:59:59.000Z

464

Effects of sequential tungsten and helium ion implantation on nano-indentation hardness of tungsten  

SciTech Connect (OSTI)

To simulate neutron and helium damage in a fusion reactor first wall sequential self-ion implantation up to 13 dpa followed by helium-ion implantation up to 3000 appm was performed to produce damaged layers of {approx}2 {mu}m depth in pure tungsten. The hardness of these layers was measured using nanoindentation and was studied using transmission electron microscopy. Substantial hardness increases were seen in helium implanted regions, with smaller hardness increases in regions which had already been self-ion implanted, thus, containing pre-existing dislocation loops. This suggests that, for the same helium content, helium trapped in distributed vacancies gives stronger hardening than helium trapped in vacancies condensed into dislocation loops.

Armstrong, D. E. J.; Edmondson, P. D.; Roberts, S. G. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)] [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

2013-06-24T23:59:59.000Z

465

Tsallis Fits to p_T Spectra and Multiple Hard Scattering in pp Collisions at LHC  

SciTech Connect (OSTI)

Phenomenological Tsallis fits to the CMS, ATLAS, and ALICE transverse momentum spectra of hadrons for pp collisions at LHC were recently found to extend over a large range of the fitting transverse momentum. We investigate whether the few degrees of freedom in the Tsallis parametrization may arising from the relativistic parton-parton hard-scattering and related hard processes. The effects of multiple hard-scattering and parton showering on the power law are discussed. We find that although the transverse spectra of both hadrons and jets exhibit power-law behaviour of 1/pT^n at high pT, the power indices n for hadrons are categorically greater than those for jets, for which n~4.

Wong, Cheuk-Yin [ORNL; Wilk, Grzegorz [National Centre for Nuclear Research, Warsaw, Poland

2013-01-01T23:59:59.000Z

466

Use of a hard mask for formation of gate and dielectric via nanofilament field emission devices  

DOE Patents [OSTI]

A process for fabricating a nanofilament field emission device in which a via in a dielectric layer is self-aligned to gate metal via structure located on top of the dielectric layer. By the use of a hard mask layer located on top of the gate metal layer, inert to the etch chemistry for the gate metal layer, and in which a via is formed by the pattern from etched nuclear tracks in a trackable material, a via is formed by the hard mask will eliminate any erosion of the gate metal layer during the dielectric via etch. Also, the hard mask layer will protect the gate metal layer while the gate structure is etched back from the edge of the dielectric via, if such is desired. This method provides more tolerance for the electroplating of a nanofilament in the dielectric via and sharpening of the nanofilament.

Morse, Jeffrey D. (Martinez, CA); Contolini, Robert J. (Lake Oswego, OR)

2001-01-01T23:59:59.000Z

467

Hard and soft probe - medium interactions in a 3D hydro+micro approach at RHIC  

E-Print Network [OSTI]

We utilize a 3D hybrid hydro+micro model for a comprehensive and consistent description of soft and hard particle production in ultra-relativistic heavy-ion collisions at RHIC. In the soft sector we focus on the dynamics of (multi-)strange baryons, where a clear strangeness dependence of their collision rates and freeze-out is observed. In the hard sector we study the radiative energy loss of hard partons in a soft medium in the multiple soft scattering approximation. While the nuclear suppression factor $R_{AA}$ does not reflect the high quality of the medium description (except in a reduced systematic uncertainty in extracting the quenching power of the medium), the hydrodynamical model also allows to study different centralities and in particular the angular variation of $R_{AA}$ with respect to the reaction plane, allowing for a controlled variation of the in-medium path-length.

Bass, S A; Ruppert, J; Nonaka, C

2007-01-01T23:59:59.000Z

468

Love isn't always black and white: understanding black-white interracial couples, their challenges, and their dyadic communication  

E-Print Network [OSTI]

of their privileged position in society, whites life situations had never had necessitated that they learn about the black co-culture. The black partners also reported seeing the white community differently by understanding the nuances of racism at a deeper level...

Wilson, Misty Michelle

2009-05-15T23:59:59.000Z

469

Hunter College Black Male Initiative-"Brothers for Excellence"-Summer Pipeline Programs Hunter College Black Male Initiative  

E-Print Network [OSTI]

Hunter College Black Male Initiative-"Brothers for Excellence"- Summer Pipeline Programs 1 Hunter College Black Male Initiative "Brothers for Excellence" Summer Pipeline Programs Table of Contents Page 11 Law Pipeline Programs 1 11 Graduate School, Earning a Ph.D., Conduct Research Pipeline Programs 24 16

Qiu, Weigang

470

Imaging the proton via hard exclusive production in diffractive pp scattering  

SciTech Connect (OSTI)

We discuss the prospects for probing Generalized Parton Distributions (GPDs) via exclusive production of a high-mass system (H = heavy quarkonium, di-photon, di-jet, Higgs boson) in diffractive pp scattering, pp -> p + H + p. In such processes the interplay of hard and soft interactions gives rise to a diffraction pattern in the final-state proton transverse momenta, which is sensitive to the transverse spatial distribution of partons in the colliding protons. We comment on the plans for diffractive pp measurements at RHIC and LHC. Such studies could complement future measurements of GPDs in hard exclusive ep scattering (JLab, COMPASS, EIC).

Charles Hyde; Leonid Frankfurt; Mark Strikman; Christian Weiss

2007-05-21T23:59:59.000Z

471

Reef fish assemblages on hard banks in the northwestern Gulf of Mexico  

E-Print Network [OSTI]

f~C~ h h d banks of the northwestern Gulf based on submersible observations 106 46. Comparison of coloration characters in Holacanthus spp. and their intermediates. Totals for scores on Feddern's patterns 1, 5, and 7 (comparative data from...' Figure 1. Hard banks of the northwestern Gulf of Nexico. eO p+ O 4 cp v+ A +~+~ 0~0 ~4 ~O + ohio+ 50 50 5 Z 100 III 0 100 150 150 Figure 2. Biotic zones known to occur on the hard banks of the northwestern Gulf of Mexico. Broken bar...

Dennis, George David

1985-01-01T23:59:59.000Z

472

Dynamic air deposited coatings for power and black liquor recovery boilers  

SciTech Connect (OSTI)

Dynamic Air Deposition (DyAir) is a novel coating method designed to protect the tubing of power and black liquor recovery boilers against corrosion attack at elevated temperatures. The method utilizes the energy of combustion of gaseous fuel and air to heat the powder material to a temperature just below its melting point and accelerate it over 600 m/s to form a coating. The Ni-Cr and Ni-Cr-Mo DyAir coatings revealed no gas permeability and extremely low oxygen content. Compared to the electric arc and HVOF-sprayed coatings, the DyAir coatings exhibited higher hardness and better crack resistance. During aging at 400 and 700 C the bond strength and crack resistance of the DyAir coatings increased dramatically due to intensive diffusion processes in absence of internal corrosion attack. The DyAir coatings revealed outstanding resistance to corrosion, such as sulfidation attack in presence of hydrochloric acid gas at 400 C, oxidation attack at 700 C and oxidation attack in presence of chlorine at 400 C.

Verstak, A.A.; Baranovski, V.E. [Advanced Surface Technologies Inc., Richmond, VA (United States)

1999-11-01T23:59:59.000Z

473

Coal water suspensions involving carbon black  

SciTech Connect (OSTI)

This patent describes a composition comprising: about 65 to 80% by weight of coal particulates with a particle size distribution within 10% of the value calculated in accordance with a Funk distribution which assumes a maximum coal particle size of about 300 microns and minimum coal particle size of about 0.5 microns; about 0.2 to 2% by weight, as based upon the total weight of dry coal, of carbon black having a primary carbon particle size in the range of about 200 to about 900 Angstroms which primary carbon particles are simultaneously bound together to form primary reticulated chains having lengths in the range of about 500 to 30,000 Angstroms; a carrier liquid comprising 20 to 35 wt % water; and from 0.2 to 2.0 wt % of a dispersant selected from the group consisting of ammonium naphthalene sulfonic acid, hexadecyltrimethylammonium bromide, and ammonium lignosulfonate.

Malone, D.P.; Thompson, D.G.

1988-10-25T23:59:59.000Z

474

Modeling the black hole excision problem  

SciTech Connect (OSTI)

We analyze the excision strategy for simulating black holes. The problem is modeled by the propagation of quasilinear waves in a 1-dimensional spatial region with timelike outer boundary, spacelike inner boundary and a horizon in between. Proofs of well-posed evolution and boundary algorithms for a second differential order treatment of the system are given for the separate pieces underlying the finite-difference problem. These are implemented in a numerical code which gives accurate long term simulations of the quasilinear excision problem. Excitation of long wavelength exponential modes, which are latent in the problem, are suppressed using conservation laws for the discretized system. The techniques are designed to apply directly to recent codes for the Einstein equations based upon the harmonic formulation.

Szilagyi, B.; Winicour, J. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Albert Einstein Institute, Max Planck Gesellschaft, Am Muehlenberg 1, D-14476 Golm (Germany); Kreiss, H.-O. [Albert Einstein Institute, Max Planck Gesellschaft, Am Muehlenberg 1, D-14476 Golm (Germany); NADA, Royal Institute of Technology, 10044 Stockholm (Sweden)

2005-05-15T23:59:59.000Z

475

Char reactions during kraft black liquor pyrolysis  

SciTech Connect (OSTI)

The pyrolysis characteristics of dried black liquor particles were investigated at high heating rates in a laminar entrained-flow reactor at temperatures of 600-1100{degrees}C. Primary pyrolysis of the organic fraction occurred very rapidly, in less 0.5 seconds. Char yields at the end or volatiles evolution were 58-72%. The decreased with increasing reactor temperature to 900{degrees}C but remained constant at higher temperatures. 35-65% of the fuel nitrogen was volatilized, nearly all in less than 0.5 s. Relatively little fuel nitrogen was evolved from the char. Significant alkali metal chloride volatization from the char occurred at all temperatures, while additional sodium volatilization became important above 900{degrees}C. Reduction of sulfur species in the char increased rapidly with increasing temperature. A temperature-dependent delay time in the onset of Na{sub 2}S formation was observed.

Frederick, W.J.; Sricharoenchaikul, V.; Reis, V.V. [Oregon State Univ., Corvallis, OR (United States)

1995-12-01T23:59:59.000Z

476

Generalized uncertainty principle and black hole thermodynamics  

E-Print Network [OSTI]

We study the Schwarzschild and Reissner-Nordstr\\"{o}m black hole thermodynamics using the simplest form of the generalized uncertainty principle (GUP) proposed in the literature. The expressions for the mass-temperature relation, heat capacity and entropy are obtained in both cases from which the critical and remnant masses are computed. Our results are exact and reveal that these masses are identical and larger than the so called singular mass for which the thermodynamics quantities become ill-defined. The expression for the entropy reveals the well known area theorem in terms of the horizon area in both cases upto leading order corrections from GUP. The area theorem written in terms of a new variable which can be interpreted as the reduced horizon area arises only when the computation is carried out to the next higher order correction from GUP.

Sunandan Gangopadhyay; Abhijit Dutta; Anirban Saha

2014-01-08T23:59:59.000Z

477

Polymeric Quantization and Black Hole Thermodynamics  

E-Print Network [OSTI]

Polymer quantization is a non-standard representation of the quantum mechanics that inspired by loop quantum gravity. To study the associated statistical mechanics, one needs to find microstates' energies which are eigenvalues of the Hamiltonian operator in the polymer framework. But, this is not an easy task at all since the Hamiltonian takes a nonlinear form in polymer picture. In this paper, we introduce a semiclassical method in which it is not necessary to solve the eigenvalue problem. Instead, we work with the classical Hamiltonian function and the deformed density of states in the polymeric phase space. Implementing this method, we obtain the canonical partition function for the polymerized systems and we show that our results are in good agreement with those arising from full quantum considerations. Using the partition function, we study the thermodynamics of quantum Schwarzschild black hole and we obtain corrections to the Bekenstein-Hawking entropy due to loop quantum gravity effects.

M. A. Gorji; Kourosh Nozari; B. Vakili

2014-05-18T23:59:59.000Z

478

The Galactic Center Black Hole Laboratory  

E-Print Network [OSTI]

The super-massive 4 million solar mass black hole Sagittarius~A* (SgrA*) shows flare emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a statistical way. The analysis shows that the near-infrared flare amplitudes are dominated by a single state power law, with the low states in SgrA* limited by confusion through the unresolved stellar background. There are several dusty objects in the immediate vicinity of SgrA*. The source G2/DSO is one of them. Its nature is unclear. It may be comparable to similar stellar dusty sources in the region or may consist predominantly of gas and dust. In this case a particularly enhanced accretion activity onto SgrA* may be expected in the near future. Here the interpretation of recent data and ongoing observations are discussed.

Eckart, A; Valencia-S., M; Straubmeier, C; Zensus, J A; Karas, V; Kunneriath, D; Alberdi, A; Sabha, N; Schödel, R; Puetzfeld, D

2015-01-01T23:59:59.000Z

479

Horizon dynamics of distorted rotating black holes  

E-Print Network [OSTI]

We present numerical simulations of a Kerr black hole perturbed by a pulse of ingoing gravitational radiation. For strong perturbations we find up to five concentric marginally outer trapped surfaces. These trapped surfaces appear and disappear in pairs, so that the total number of such surfaces at any given time is odd. The world tubes traced out by the marginally outer trapped surfaces are found to be spacelike during the highly dynamical regime, approaching a null hypersurface at early and late times. We analyze the structure of these marginally trapped tubes in the context of the dynamical horizon formalism, computing the expansion of outgoing and incoming null geodesics, as well as evaluating the dynamical horizon flux law and the angular momentum flux law. Finally, we compute the event horizon. The event horizon is well-behaved and approaches the apparent horizon before and after the highly dynamical regime. No new generators enter the event horizon during the simulation.

Tony Chu; Harald P. Pfeiffer; Michael I. Cohen

2011-04-28T23:59:59.000Z

480

Bubbling the Newly Grown Black Ring Hair  

E-Print Network [OSTI]

New families of BPS black ring solutions with four electric and four dipole magnetic charges have recently been explicitly constructed and uplifted to M-theory. These solutions were found to belong to a CFT with central charge different compared to the one of the STU model. Because of their importance to AdS/CFT, here we give the microstate description of these geometries in terms of topological bubbles and supertubes. The fourth charge results in an additional flux through the topological cycles that resolve the brane singularities. The analog of these solutions in the IIB frame yield a generalized regular supertube with three electric charges and one dipole charge. Direct comparison is also made with the previously-known bubbled geometries.

Orestis Vasilakis

2012-02-08T23:59:59.000Z

Note: This page contains sample records for the topic "hard black lustrous" 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

Higgs Boson Production from Black Holes at the LHC  

E-Print Network [OSTI]

If the fundamental Planck scale is near a TeV, then TeV scale black holes should be produced in proton-proton collisions at the LHC where \\sqrt{s} = 14 TeV. As the temperature of the black holes can be ~ 1 TeV we also expect production of Higgs bosons from them via Hawking radiation. This is a different production mode for the Higgs boson, which would normally be produced via direct pQCD parton fusion processes. In this paper we compare total cross sections and transverse momentum distributions d\\sigma/dp_T for Higgs production from black holes at the LHC with those from direct parton fusion processes at next-to-next-to-leading order and next-to-leading order respectively. We find that the Higgs production from black holes can be larger or smaller than the direct pQCD production depending upon the Planck mass and black hole mass. We also find that d\\sigma/dp_T of Higgs production from black holes increases as a function of p_T which is in sharp contrast with the pQCD predictions where d\\sigma/dp_T decreases so we suggest that the measurement of an increase in d\\sigma/dp_T as p_T increases for Higgs (or any other heavy particle) production can be a useful signature for black holes at the LHC.

Gouranga C. Nayak; J. Smith

2006-06-09T23:59:59.000Z

482

Black Holes with Primary Hair in gauged N=8 Supergravity  

E-Print Network [OSTI]

In this paper, we analyze the static solutions for the $U(1)^{4}$ consistent truncation of the maximally supersymmetric gauged supergravity in four dimensions. Using a new parametrization of the known solutions it is shown that for fixed charges there exist three possible black hole configurations according to the pattern of symmetry breaking of the (scalars sector of the) Lagrangian. Namely a black hole without scalar fields, a black hole with a primary hair and a black hole with a secondary hair respectively. This is the first, exact, example of a black hole with a primary scalar hair, where both the black hole and the scalar fields are regular on and outside the horizon. The configurations with secondary and primary hair can be interpreted as a spontaneous symmetry breaking of discrete permutation and reflection symmetries of the action. It is shown that there exist a triple point in the thermodynamic phase space where the three solution coexist. The corresponding phase transitions are discussed and the free energies are written explicitly as function of the thermodynamic coordinates in the uncharged case. In the charged case the free energies of the primary hair and the hairless black hole are also given as functions of the thermodynamic coordinates.

Andres Anabalon; Fabrizio Canfora; Alex Giacomini; Julio Oliva

2012-03-29T23:59:59.000Z

483

No-hair theorem for Black Holes in Astrophysical Environments  

E-Print Network [OSTI]

According to the no-hair theorem, static black holes are described by a Schwarzschild spacetime provided there are no other sources of the gravitational field. This requirement, however, is in astrophysical realistic scenarios often violated, e.g., if the black hole is part of a binary system or if it is surrounded by an accretion disk. In these cases, the black hole is distorted due to tidal forces. Nonetheless, the subsequent formulation of the no-hair theorem holds: The contribution of the distorted black hole to the multipole moments that describe the gravitational field close to infinity and, thus, all sources is that of a Schwarzschild black hole. It still has no hair. This implies that there is no multipole moment induced in the black hole and that its second Love numbers, which measure some aspects of the distortion, vanish as was already shown in approximations to general relativity. But here we prove this property for astrophysical relevant black holes in full general relativity.

Gürlebeck, Norman

2015-01-01T23:59:59.000Z

484