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1

Mode Conversion Heating Scenarios for the National Compact Stellarator Experiment  

DOE Green Energy (OSTI)

Radio-frequency heating scenarios for the National Compact Stellarator eXperiment (NCSX) are considered. The focus here is on mode conversion from the fast to the slow ion Bernstein wave as either an electron or ''bulk'' ion heating technique, using a high-field side launch to directly access the ion-ion hybrid layer. Modeling for the planned parameters of NCSX [R(subscript ave) {approximately} 1.4 m, a(subscript ave) {approximately} 0.4 m, B(subscript T)(0) {approximately} 1.2-2 T, n(subscript e)(0) {approximately} 2-5 x 10(superscript19) m(superscript -3), T(subscript e)(0) {approximately} T(subscript i)(0) {approximately} 1-2 keV] for mode conversion in D-H and D-3He plasmas is presented. Possible types of high-field side antennas are also briefly discussed.

Majeski, R.; Wilson, J.R.; and Zarnstorff, M.

2001-05-18T23:59:59.000Z

2

The National Compact Stellarator Experiment at the Princeton Plasma Physics Laboratory  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Finding of No Significant Impact Finding of No Significant Impact Proposed National Compact Stellarator Experiment Princeton Plasma Physics Laboratory, New Jersey AGENCY: U.S. Department of Energy ACTION: Finding of No Significant Impact SUMMARY: The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1437, evaluating the environmental effects of the proposed fabrication, assembly and operation of a National Compact Stellarator Experiment (NCSX) within the existing C- Stellarator (CS) Building at C-Site of the Princeton Plasma Physics Laboratory (PPPL), Princeton, New Jersey. The purpose of the NCSX is to provide an experimental device to investigate the attractiveness of a compact stellarator as the basis for a fusion power reactor. Fusion energy has the potential to help compensate for dwindling supplies of fossil fuels, the

3

Comparing Linear Microinstability of the National Compact Stellarator Expriment and a Shaped Tokamak  

SciTech Connect

One metric for comparing con nement properties of di erent magnetic fusion energy con gurations is the linear critical gradient of drift wave modes. The critical gradient scale length determines the ratio of the core to pedestal temperature when a plasma is limited to marginal stability in the plasma core. The gyrokinetic turbulence code GS2 was used to calculate critical temperature gradients for the linear, collisionless ion tem- perature gradient (ITG) mode in the National Compact Stellarator Experiment (NCSX) and a prototypical shaped tokamak, based on the pro les of a JET H-mode shot and the stronger shaping of ARIES-AT. While a concern was that the narrow cross section of NCSX at some toroidal locations would result in steep gradients that drive instabilities more easily, it is found that other stabilizing e ects of the stellarator con guration o set this so that the normalized critical gradients for NCSX are competitive with or even better than for the tokamak. For the adiabatic ITG mode, NCSX and the tokamak had similar critical gradients, though beyond marginal stability, NCSX had larger growth rates. However, for the kinetic ITG mode, NCSX had a higher critical gradient and lower growth rates until a/LT ?#25; 1:5 a/LT;crit, when it surpassed the tokamak's. A discussion of the results presented with respect to a/LT vs R/LT is included.

J.A. Baumgaertel, G.W. Hammett and D.R. Mikkelsen

2012-11-20T23:59:59.000Z

4

Results of Compact Stellarator Engineering Trade Studies  

SciTech Connect

number of technical requirements and performance criteria can drive stellarator costs, e.g., tight tolerances, accurate coil positioning, low aspect ratio (compactness), choice of assembly strategy, metrology, and complexity of the stellarator coil geometry. With the completion of a seven-year design and construction effort of the National Compact Stellarator Experiment (NCSX) it is useful to interject the NCSX experience along with the collective experiences of the NCSX stellarator community to improving the stellarator configuration. Can improvements in maintenance be achieved by altering the stellarator magnet configuration with changes in the coil shape or with the combination of trim coils? Can a mechanical configuration be identified that incorporates a partial set of shaped fixed stellarator coils along with some removable coil set to enhance the overall machine maintenance? Are there other approaches that will simplify the concepts, improve access for maintenance, reduce overall cost and improve the reliability of a stellarator based power plant? Using ARIES-CS and NCSX as reference cases, alternative approaches have been studied and developed to show how these modifications would favorably impact the stellarator power plant and experimental projects. The current status of the alternate stellarator configurations being developed will be described and a comparison made to the recently designed and partially built NCSX device and the ARIES-CS reactor design study.

Tom Brown, L. Bromberg, M. Cole

2009-05-27T23:59:59.000Z

5

Gyrokinetic studies of the effect of {beta} on drift-wave stability in the National Compact Stellarator Experiment  

Science Conference Proceedings (OSTI)

The gyrokinetic turbulence code GS2 was used to investigate the effects of plasma {beta} on linear, collisionless ion temperature gradient (ITG) modes and trapped electron modes (TEM) in National Compact Stellarator Experiment (NCSX) geometry. Plasma {beta} affects stability in two ways: through the equilibrium and through magnetic fluctuations. The first was studied here by comparing ITG and TEM stability in two NCSX equilibria of differing {beta} values, revealing that the high {beta} equilibrium was marginally more stable than the low {beta} equilibrium in the adiabatic-electron ITG mode case. However, the high {beta} case had a lower kinetic-electron ITG mode critical gradient. Electrostatic and electromagnetic ITG and TEM mode growth rate dependencies on temperature gradient and density gradient were qualitatively similar. The second {beta} effect is demonstrated via electromagnetic ITG growth rates' dependency on GS2's {beta} input parameter. A linear benchmark with gyrokinetic codes GENE and GKV-X is also presented.

Baumgaertel, J. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Hammett, G. W.; Mikkelsen, D. R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Nunami, M. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Xanthopoulos, P. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstr. 1, 17491 Greifswald (Germany)

2012-12-15T23:59:59.000Z

6

THE ARIES-CS COMPACT STELLARATOR FUSION POWER PLANT  

E-Print Network (OSTI)

, Fliederweg 3, D 76351 Linkenheim-Hochstetten, Germany k Idaho National Laboratory, Idaho Falls, Idaho l

California at San Diego, University of

7

National Compact Stellarator Experiment COST AND SCHEDULE ESTIMATING GUIDE  

E-Print Network (OSTI)

) design, project engineering, and management and oversight; o Manufacturing Development (formerly called R and schedule estimate. Whenever feasible, bottoms-up estimates should be utilized, using manufacturing. In addition, the NCSX Project Control Manager will provide you a timeline for developing your estimate

Princeton Plasma Physics Laboratory

8

PDC (polycrystalline diamond compact) bit research at Sandia National Laboratories  

DOE Green Energy (OSTI)

From the beginning of the geothermal development program, Sandia has performed and supported research into polycrystalline diamond compact (PDC) bits. These bits are attractive because they are intrinsically efficient in their cutting action (shearing, rather than crushing) and they have no moving parts (eliminating the problems of high-temperature lubricants, bearings, and seals.) This report is a summary description of the analytical and experimental work done by Sandia and our contractors. It describes analysis and laboratory tests of individual cutters and complete bits, as well as full-scale field tests of prototype and commercial bits. The report includes a bibliography of documents giving more detailed information on these topics. 26 refs.

Finger, J.T.; Glowka, D.A.

1989-06-01T23:59:59.000Z

9

Resonant-plane locking and spin alignment in stellar-mass black-hole binaries: a diagnostic of compact-binary formation  

E-Print Network (OSTI)

We study the influence of astrophysical formation scenarios on the precessional dynamics of spinning black-hole binaries by the time they enter the observational window of second- and third-generation gravitational-wave detectors, such as Advanced LIGO/Virgo, LIGO-India, KAGRA and the Einstein Telescope. Under the plausible assumption that tidal interactions are efficient at aligning the spins of few-solar mass black-hole progenitors with the orbital angular momentum, we find that black-hole spins should be expected to preferentially lie in a plane when they become detectable by gravitational-wave interferometers. This "resonant plane" is identified by the conditions \\Delta\\Phi=0{\\deg} or \\Delta\\Phi=+/-180{\\deg}, where \\Delta\\Phi is the angle between the components of the black-hole spins in the plane orthogonal to the orbital angular momentum. If the angles \\Delta \\Phi can be accurately measured for a large sample of gravitational-wave detections, their distribution will constrain models of compact binary formation. In particular, it will tell us whether tidal interactions are efficient and whether a mechanism such as mass transfer, stellar winds, or supernovae can induce a mass-ratio reversal (so that the heavier black hole is produced by the initially lighter stellar progenitor). Therefore our model offers a concrete observational link between gravitational-wave measurements and astrophysics. We also hope that it will stimulate further studies of precessional dynamics, gravitational-wave template placement and parameter estimation for binaries locked in the resonant plane.

Davide Gerosa; Michael Kesden; Emanuele Berti; Richard O'Shaughnessy; Ulrich Sperhake

2013-02-18T23:59:59.000Z

10

Stellar Populations in Compact Galaxy Groups: a Multi-Wavelength Study of HCGs 16, 22, and 42, their Star Clusters and Dwarf Galaxies  

E-Print Network (OSTI)

We present a multi-wavelength analysis of three compact galaxy groups, HCGs 16, 22, and 42, which describe a sequence in terms of gas richness, from space- (Swift, HST, Spitzer) and ground-based (LCO, CTIO) imaging and spectroscopy. We study various signs of past interactions including a faint, dusty tidal feature about HCG 16A, which we tentatively age-date at <1 Gyr. This represents the possible detection of a tidal feature at the end of its phase of optical observability. Our HST images also resolve what were thought to be double nuclei in HCG 16C and D into multiple, distinct sources, likely to be star clusters. Beyond our phenomenological treatment, we focus primarily on contrasting the stellar populations across these three groups. The star clusters show a remarkable intermediate-age population in HCG 22, and identify the time at which star formation was quenched in HCG 42. We also search for dwarf galaxies at accordant redshifts. The inclusion of 33 members and 27 'associates' (possible members) rad...

Konstantopoulos, I S; Charlton, J C; Fedotov, K; Durrell, P R; Mulchaey, J S; English, J; Desjardins, T D; Gallagher, S C; Walker, L M; Johnson, K E; Tzanavaris, P; Gronwall, C

2013-01-01T23:59:59.000Z

11

Stellarator Coil Design and Plasma Sensitivity  

SciTech Connect

The rich information contained in the plasma response to external magnetic perturbations can be used to help design stellarator coils more effectively. We demonstrate the feasibility by first devel- oping a simple, direct method to study perturbations in stellarators that do not break stellarator symmetry and periodicity. The method applies a small perturbation to the plasma boundary and evaluates the resulting perturbed free-boundary equilibrium to build up a sensitivity matrix for the important physics attributes of the underlying configuration. Using this sensitivity information, design methods for better stellarator coils are then developed. The procedure and a proof-of-principle application are given that (1) determine the spatial distributions of external normal magnetic field at the location of the unperturbed plasma boundary to which the plasma properties are most sen- sitive, (2) determine the distributions of external normal magnetic field that can be produced most efficiently by distant coils, (3) choose the ratios of the magnitudes of the the efficiently produced magnetic distributions so the sensitive plasma properties can be controlled. Using these methods, sets of modular coils are found for the National Compact Stellarator Experiment (NCSX) that are either smoother or can be located much farther from the plasma boundary than those of the present design.

Long-Poe Ku and Allen H. Boozer

2010-11-03T23:59:59.000Z

12

THE MASS-LOSS-INDUCED ECCENTRIC KOZAI MECHANISM: A NEW CHANNEL FOR THE PRODUCTION OF CLOSE COMPACT OBJECT-STELLAR BINARIES  

SciTech Connect

Over a broad range of initial inclinations and eccentricities, an appreciable fraction of hierarchical triple star systems with similar masses are essentially unaffected by the Kozai-Lidov mechanism (KM) until the primary in the central binary evolves into a compact object. Once it does, it may be much less massive than the other components in the ternary, enabling the 'eccentric Kozai mechanism (EKM)': the mutual inclination between the inner and outer binaries can flip signs driving the inner binary to very high eccentricity, leading to a close binary or collision. We demonstrate this 'mass-loss-induced eccentric Kozai' (MIEK) mechanism by considering an example system and defining an ad hoc minimal separation between the inner two members at which tidal effects become important. For fixed initial masses and semimajor axes, but uniform distributions of eccentricity and cosine of the mutual inclination, {approx}10% of systems interact tidally or collide while the primary is on the main sequence (MS) due to the KM or EKM. Those affected by the EKM are not captured by earlier quadrupole-order secular calculations. We show that fully {approx}30% of systems interact tidally or collide for the first time as the primary swells to AU scales, mostly as a result of the KM. Finally, {approx}2% of systems interact tidally or collide for the first time after the primary sheds most of its mass and becomes a white dwarf (WD), mostly as a result of the MIEK mechanism. These findings motivate a more detailed study of mass loss in triple systems and the formation of close neutron star (NS)/WD-MS and NS/WD-NS/WD binaries without an initial common envelope phase.

Shappee, Benjamin J.; Thompson, Todd A., E-mail: shappee@astronomy.ohio-state.edu, E-mail: thompson@astronomy.ohio-state.edu [Center for Cosmology, and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210 (United States)

2013-03-20T23:59:59.000Z

13

Physics Basis for High-Beta, Low-Aspect-Ratio Stellarator Experiments  

SciTech Connect

High-beta, low-aspect-ratio (compact) stellarators are promising solutions to the problem of developing a magnetic plasma configuration for magnetic fusion power plants that can be sustained in steady-state without disrupting. These concepts combine features of stellarators and advanced tokamaks and have aspect ratios similar to those of tokamaks (2-4). They are based on computed plasma configurations that are shaped in three dimensions to provide desired stability and transport properties. Experiments are planned as part of a program to develop this concept. A beta = 4% quasi-axisymmetric plasma configuration has been evaluated for the National Compact Stellarator Experiment (NCSX). It has a substantial bootstrap current and is shaped to stabilize ballooning, external kink, vertical, and neoclassical tearing modes without feedback or close-fitting conductors. Quasi-omnigeneous plasma configurations stable to ballooning modes at beta = 4% have been evaluated for the Quasi-Omnigeneous Stellarator (QOS) experiment. These equilibria have relatively low bootstrap currents and are insensitive to changes in beta. Coil configurations have been calculated that reconstruct these plasma configurations, preserving their important physics properties. Theory- and experiment-based confinement analyses are used to evaluate the technical capabilities needed to reach target plasma conditions. The physics basis for these complementary experiments is described.

A. Brooks; A.H. Reiman; G.H. Neilson; M.C. Zarnstorff; et al

1999-11-01T23:59:59.000Z

14

Compact Fluorescent Lamps : Technologies : From the Lab to the...  

NLE Websites -- All DOE Office Websites (Extended Search)

process. (Left) Compact Fluorescent Lamp; (Right) Cover of the 'Lighting Retrofit Workbook' (Left) Compact Fluorescent Lamp (CFL) (Right) Retrofitting national parks...

15

VIBRATION COMPACTION  

DOE Patents (OSTI)

A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

Hauth, J.J.

1962-07-01T23:59:59.000Z

16

STELLARATOR INJECTOR  

DOE Patents (OSTI)

A method and means are described for injecting energetic neutral atoms or molecular ions into dense magnetically collimated plasma columns of stellarators and the like in such a manner that the atoms or ions are able to significantly penetrate the column before being ionized by collision with the plasma constituent particles. Penetration of the plasma column by the neutral atoms or molecular ions is facilitated by superposition of two closely spaced magnetic mirrors on the plasma confinement field. The mirrors are moved apart to magnetically sweep plasma from a region between the mirrors and establish a relatively low plasma density therein. By virture of the low density, neutral atoms or molecular ions injected into the region significantly penetrate the plasma column before being ionized. Thereafter, the mirrors are diminished to permit the injected material to admix with the plasma in the remainder of the column. (AEC)

Post, R.F.

1962-09-01T23:59:59.000Z

17

Superconductivity with deformed Fermi surfaces and compact stars  

E-Print Network (OSTI)

I discuss the deformed Fermi surface superconductivity (DFS) and some of its alternatives in the context of nucleonic superfluids and two flavor color superconductors that may exist in the densest regions of compact stellar objects.

Armen Sedrakian

2003-12-15T23:59:59.000Z

18

Compact accelerator  

DOE Patents (OSTI)

A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Kirbie, Hugh C. (Los Alamos, NM)

2007-02-06T23:59:59.000Z

19

Pecos River Compact (Texas)  

Energy.gov (U.S. Department of Energy (DOE))

This legislation authorizes the state's entrance into the Pecos River Compact, a joint agreement between the states of New Mexico and Texas. The compact is administered by the Pecos River Compact...

20

Stellar science unveiled at space conference  

NLE Websites -- All DOE Office Websites (Extended Search)

Stellar science unveiled at space conference Stellar science unveiled at space conference Stellar science unveiled at space conference The Laboratory will be represented in more than 20 papers to be given at the 42nd Lunar and Planetary Science Conference in Houston. March 8, 2011 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

Note: This page contains sample records for the topic "national compact stellarator" 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

SAFETY ASSESSMENT OF THE ARIES COMPACT STELLARATOR DESIGN  

E-Print Network (OSTI)

to use RESRAD, which exists as NUREG and DOE publication, to justify the release or recycling of material

Raffray, A. René

22

SAFETY ASSESSMENT OF THE ARIES COMPACT STELLARATOR DESIGN  

E-Print Network (OSTI)

, 780 Creston Hatchery Road, Kalispell, Montana 59901 D.W. Garfield 3489 Trails End Road, Missoula decline (Jeppson and Platts 1959; Bjornn 1961; Martin and Olver 1980; Fraley and Shepard 1989; Spencer et for adult lake trout and bull trout (Jeppson and Platts 1959; Bjornn 1961; Martin and Olver 1980; Fraley

California at San Diego, University of

23

Gluon Vortices and Induced Magnetic Field in Compact Stars  

E-Print Network (OSTI)

The natural candidates for the realization of color superconductivity are the extremely dense cores of compact stars, many of which have very large magnetic fields, especially the so-called magnetars. In this paper we discuss how a color superconducting core can serve to generate and enhance the stellar magnetic field without appealing to a magnetohydrodynamic dynamo mechanism.

Efrain J. Ferrer

2007-08-12T23:59:59.000Z

24

Gluon Vortices and Induced Magnetic Field in Compact Stars  

SciTech Connect

The natural candidates for the realization of color superconductivity are the extremely dense cores of compact stars, many of which have very large magnetic fields, especially the so called magnetars. In this paper we discuss how a color superconducting core can serve to generate and enhance the stellar magnetic field without appealing to a magnetohydrodynamic dynamo mechanism.

Ferrer, Efrain J. [Department of Physics, Western Illinois University, Macomb, IL 61455 (United States)

2007-10-26T23:59:59.000Z

25

Plants and Dirt Compaction  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirt Compaction Name: Conor Location: NA Country: NA Date: NA Question: When growing corn and soybean plants does the compaction of dirt effect the growth of the plant? Replies:...

26

Red River Compact (Texas)  

Energy.gov (U.S. Department of Energy (DOE))

The Red River Compact Commission administers the Red River Compact to ensure that Texas receives its equitable share of quality water from the Red River and its tributaries as apportioned by the...

27

Testing of Compact Bolted Fasteners with Insulation and Friction-Enhanced Shims for NCSX  

SciTech Connect

The fastening of the National Compact Stellarator Experiment's (NCSX) modular coils presented a number of engineering and manufacturing challenges due to the high magnetic forces, need to control induced currents, tight tolerances and restrictive space envelope. A fastening method using high strength studs, jack nuts, insulating spacers, bushings and alumina coated shims was developed which met the requirements. A test program was conducted to verify the design. The tests included measurements of flatness of the spacers, determination of contact area, torque vs. tension of the studs and jack nuts, friction coefficient tests on the alumina and G-10 insulators, electrical tests, and tension relaxation tests due to temperature excursions from room temperature to liquid nitrogen temperatures. This paper will describe the design and the results of the test program.

L. E. Dudek, J.H. Chrzanowski, G. Gettelfinger, P. Heitzenroeder, S. Jurczynski, M. Viola and K. Freudenberg

2009-02-04T23:59:59.000Z

28

Compact models with regular charge distributions  

E-Print Network (OSTI)

We model a compact relativistic body with anisotropic pressures in the presence of an electric field. The equation of state is barotropic with a linear relationship between the radial pressure and the energy density. Simple exact models of the Einstein-Maxwell equations are generated. A graphical analysis indicates that the matter and electromagnetic variables are well behaved. In particular the proper charge density is regular for certain parameter values at the stellar centre unlike earlier anisotropic models in the presence of charge. We show that the electric field affects the mass of stellar objects and the observed mass for a particular binary pulsar is regained. Our models contain previous results of anisotropic charged matter with a linear equation of state for special parameter values.

P. Mafa Takisa; S. D. Maharaj

2013-10-01T23:59:59.000Z

29

Midwest Nuclear Compact (Iowa)  

Energy.gov (U.S. Department of Energy (DOE))

The Midwest Nuclear Compact establishes a Midwest Nuclear Board to cooperatively evaluate and make recommendations regarding the development of nuclear technology, distribute information about...

30

UNIFYING THE ZOO OF JET-DRIVEN STELLAR EXPLOSIONS  

Science Conference Proceedings (OSTI)

We present a set of numerical simulations of stellar explosions induced by relativistic jets emanating from a central engine sitting at the center of compact, dying stars. We explore a wide range of durations of the central engine activity, two candidate stellar progenitors, and two possible values of the total energy release. We find that even if the jets are narrowly collimated, their interaction with the star unbinds the stellar material, producing a stellar explosion. We also find that the outcome of the explosion can be very different depending on the duration of the engine activity. Only the longest-lasting engines result in successful gamma-ray bursts. Engines that power jets only for a short time result in relativistic supernova (SN) explosions, akin to observed engine-driven SNe such as SN2009bb. Engines with intermediate durations produce weak gamma-ray bursts, with properties similar to nearby bursts such as GRB 980425. Finally, we find that the engines with the shortest durations, if they exist in nature, produce stellar explosions that lack sizable amounts of relativistic ejecta and are therefore dynamically indistinguishable from ordinary core-collapse SNe.

Lazzati, Davide; Blackwell, Christopher H. [Department of Physics, NC State University, 2401 Stinson Drive, Raleigh, NC 27695-8202 (United States); Morsony, Brian J. [Department of Astronomy, University of Wisconsin-Madison, 2535 Sterling Hall, 475 N. Charter Street, Madison WI 53706-1582 (United States); Begelman, Mitchell C. [JILA, University of Colorado, 440 UCB, Boulder, CO 80309-0440 (United States)

2012-05-01T23:59:59.000Z

31

Death of Stellar Baryonic Dark Matter Candidates  

E-Print Network (OSTI)

The nature of the dark matter in the Universe is one of the outstanding questions in astrophysics. In this talk, I address possible stellar baryonic contributions to the 50-90% of our Galaxy that is made of unknown dark matter. First I show that faint stars and brown dwarfs constitute only a few percent of the mass of the Galaxy. Next, I show that stellar remnants, including white dwarfs and neutron stars, are also insufficient in abundance to explain all the dark matter of the Galaxy. High energy gamma-rays observed in HEGRA data place the most robust constraints, $\\Omega_{WD} < 3 \\times 10^{-3} h^{-1}$, where $h$ is the Hubble constant in units of 100 km s$^{-1}$ Mpc$^{-1}$. Overproduction of chemical abundances (carbon, nitrogen, and helium) provide the most stringent constraints, $\\Omega_{WD} < 2 \\times 10^{-4} h^{-1}$. Comparison with recent updates of microlensing data are also made. According to the gamma-ray limit, all Massive Compact Halo Objects seen by the experiments (Machos) can be white dwarfs if one takes the extreme numbers; however, from chemical overproduction limits, NOT all Machos can be white dwarfs. Comments on recent observations of the infrared background and of white dwarfs are also made. In conclusion, a nonbaryonic component in the Halo seems to be required.

Katherine Freese; Brian Fields; David Graff

2000-07-28T23:59:59.000Z

32

Stellar Astrophysics Requirements NERSC Forecast  

NLE Websites -- All DOE Office Websites (Extended Search)

Requirements for Requirements for m461:Stellar Explosions in Three Dimensions Tomek Plewa (Florida State University) + 3 graduate students, Artur Gawryszczak (Warsaw), Konstantinos Kifonidis (Munich), Andrzej Odrzywolek (Cracow), Ju Zhang (FIT), Andrey Zhiglo (Kharkov) 1. m461: Stellar Explosions in Three Dimensions * Summarize your projects and expected scientific objectives through 2014 * Modeling and simulations of transient phenomena in stellar astrophysics driven by either radiation or thermonuclear processes * Numerical solution of a coupled system of PDEs and ODEs * Tame nonlinearity! * Our goal is to ... * Explain observed properties of exploding stellar objects * Present focus is ... * Neutrino-driven core-collapse supernova explosions * In the next 3 years we expect to ...

33

Compact baby Skyrmions  

Science Conference Proceedings (OSTI)

For the baby Skyrme model with a specific potential, compacton solutions, i.e., configurations with a compact support and parabolic approach to the vacuum, are derived. Specifically, in the nontopological sector, we find spinning Q-balls and Q-shells, as well as peakons. Moreover, we obtain compact baby skyrmions with nontrivial topological charge. All these solutions may form stable multisoliton configurations provided they are sufficiently separated.

Adam, C. [Departamento de Fisica de Particulas, Universidad de Santiago and Instituto Galego de Fisica de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Klimas, P. [Instituto de Fisica de Sao Carlos, Universidade de Sao Carlos, Caixa Postal 369, CEP 13560-970, Sao Carlos-SP (Brazil); Sanchez-Guillen, J. [Departamento de Fisica de Particulas, Universidad de Santiago and Instituto Galego de Fisica de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Reymonta 4, Krakow (Poland)

2009-11-15T23:59:59.000Z

34

The Build-Up of Nuclear Stellar Cusps in Extreme Starburst Galaxies and Major Mergers  

E-Print Network (OSTI)

Nuclear stellar cusps are defined as central excess light component in the stellar light profiles of galaxies and are suggested to be stellar relics of intense compact starbursts in the central ~100-500 pc region of gas-rich major mergers. Here we probe the build-up of nuclear cusps during the actual starburst phase for a complete sample of Luminous Infrared Galaxy systems (85 LIRGs, with 11.4stellar light imaged in the near-infrared by the Hubble Space Telescope and have been combined with mid-IR diagnostics for AGN/starburst characterization. We find that nuclear stellar cusps are resolved in 76% of LIRGs (merger and non-interacting galaxies). The cusp strength and luminosity increases with far-IR luminosity (excluding AGN) and merger stage, confirming theoretical models that starburst activity is associated with the build-up of nuclear stellar cusps. Evidence for ultra compact nuclear starb...

Haan, S; Surace, J A; Charmandaris, V; Evans, A S; Diaz-Santos, T; Melbourne, J L; Mazzarella, J M; Howell, J H; Stierwalt, S; Kim, D C; Vavilkin, T; Sanders, D B; Petric, A; Murphy, E J; Braun, R; Bridge, C R; Inami, H

2013-01-01T23:59:59.000Z

35

Compaction Scale Up and Optimization of Cylindrical Fuel Compacts for the Next Generation Nuclear Plant  

Science Conference Proceedings (OSTI)

Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of designed experiments have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel. Results from these experiments are included. The scale-up effort is nearing completion with the process installed and operational using nuclear fuel materials. The process is being certified for manufacture of qualification test fuel compacts for the AGR-5/6/7 experiment at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL).

Jeffrey J. Einerson; Jeffrey A. Phillips; Eric L. Shaber; Scott E. Niedzialek; W. Clay Richardson; Scott G. Nagley

2012-10-01T23:59:59.000Z

36

Compactly supported cohomology of buildings  

E-Print Network (OSTI)

We compute the compactly supported cohomology of the standard realization of any locally finite building.

Davis, Michael; Januszkiewicz, Tadeusz; Meier, John; Okun, Boris

2008-01-01T23:59:59.000Z

37

Compact Neutron Generators - Lawrence Berkeley National Laboratory  

For Industry; For Researchers ... Energy Storage and Recovery; ... ion beam accelerator with a titanium tubing target that oscillates to minimize heat ...

38

The Dense Stellar Systems Around Galactic Massive Black Holes  

E-Print Network (OSTI)

The central regions of galaxies show the presence of massive black holes and/or dense stellar systems. The question about their modes of formation is still under debate. A likely explanation of the formation of the central dense stellar systems in both spiral and elliptical galaxies is based on the orbital decay of massive globular clusters in the central region of galaxies due to kinetic energy dissipation by dynamical friction. Their merging leads to the formation of a nuclear star cluster, like that of the Milky Way, where a massive black hole (Sgr A*) is also present. Actually, high precision N-body simulations (Antonini, Capuzzo-Dolcetta et al. 2012, ApJ, 750, 111) show a good fit to the observational characteristics of the Milky Way nuclear cluster, giving further reliability to the cited `migratory' model for the formation of compact systems in the inner galaxy regions.

Capuzzo-Dolcetta, R; Spera, M

2013-01-01T23:59:59.000Z

39

Blackbody radiation with compact and non-compact extra dimensions  

E-Print Network (OSTI)

The problem of blackbody radiation in flat space with non-compact extra dimensions was analysed recently. In the present article we reanalyse this problem with compact (and non-compact) extra dimensions in flat space to observe the consequences of this approach upon Wien's displacement and Stefan-Boltzmann law.

Ramaton Ramos; Henrique Boschi-Filho

2009-10-08T23:59:59.000Z

40

Progress in Compact Toroid Experiments  

SciTech Connect

The term "compact toroids" as used here means spherical tokamaks, spheromaks, and field reversed configurations, but not reversed field pinches. There are about 17 compact toroid experiments under construction or operating, with approximate parameters listed in Table 1.

Dolan, Thomas James

2002-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

The Evolution of Galaxies in Compact Groups  

E-Print Network (OSTI)

We present the analysis of the spectra of 62 galaxies in 15 compact groups. The galaxies were classified in four activity classes: galaxies without emission, starburst nucleus galaxies (SBNGs), luminous AGNs and low-luminosity AGNs (LLAGNs). The star formation in the HCG starbursts is more intense than in normal spirals, but comparable to those in the field SBNGs. Their mean gas metallicity is solar and they do not follow the metallicity-luminosity relation traced by the early-type SBNGs in the field, suggesting that most of them are late-type SBNGs. This morphology preference coupled to the observation that the HCG starbursts are predominantly in the halo of the groups is consistent with the idea that compact groups are embedded in sparser structures. The stellar metallicities of the non starburst galaxies are relatively high for their luminosities. In these galaxies the equivalent widths of the metal absorption lines are slightly narrower than normal while the Balmer absorption lines are relatively strong. All these galaxies could be ``post-starburst'' at an advanced stage of evolution. Our observations are supporting a scenario where the core of the groups are slowly collapsing evolved systems embedded in more extended structures (Ribeiro et al. 1998). In the core of the groups, the interactions were more frequent and the galaxies evolved at a more rapid rate than in their halos.

Roger Coziol; Reinaldo R. de Carvalho; Hugo V. Capelato; Andre L. B. Ribeiro

1998-05-30T23:59:59.000Z

42

Microsoft Windows Embedded Compact Cryptographic ...  

Science Conference Proceedings (OSTI)

Page 1. Microsoft Windows Cryptographic Primitives Library (bcrypt.dll) Security Policy Document ... Microsoft Windows Embedded Compact ...

2013-08-07T23:59:59.000Z

43

Interstate Oil and Gas Conservation Compact (Multiple States) | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Interstate Oil and Gas Conservation Compact (Multiple States) Interstate Oil and Gas Conservation Compact (Multiple States) Interstate Oil and Gas Conservation Compact (Multiple States) < Back Eligibility Commercial Developer Industrial Investor-Owned Utility Municipal/Public Utility Utility Program Info State Alabama Program Type Environmental Regulations Provider Interstate Oil and Gas Compact Commission The Interstate Oil and Gas Compact Commission assists member states efficiently maximize oil and natural gas resources through sound regulatory practices while protecting the nation's health, safety and the environment. The Commission serves as the collective voice of member governors on oil and gas issues and advocates states' rights to govern petroleum resources within their borders. The Commission formed the Geological CO2 Sequestration Task Force, which

44

CYANATE ION IN COMPACT AMORPHOUS WATER ICE  

SciTech Connect

The 4.62 {mu}m infrared (2164.5 cm{sup -1}) absorption band, observed in ice mantels toward many young stellar objects, has been mostly attributed to the {nu}{sub 3} (CN stretch) band of OCN{sup -} ions. We present in this work a spectroscopic study of OCN{sup -} ions embedded in compact amorphous ice in a range of concentrations and temperatures relevant to astronomical observations together with quantum mechanical calculations of the {nu}{sub 3} band of OCN{sup -} in various H{sub 2}O environments. The ice samples containing the ions are prepared through hyperquenching of liquid droplets of K{sup +}OCN{sup -} solutions on a substrate at 14 K. The {nu}{sub 3} OCN{sup -} band appears as a broad feature peaking at 4.64 {mu}m with a secondary maximum at 4.54 {mu}m and is much weaker than the corresponding peak in the liquid solution or in the solid salt. A similar weakening is observed for other OCN{sup -} absorption peaks at 7.66 {mu}m (2{nu}{sub 2}) and 8.20 {mu}m ({nu}{sub 1}). The theoretical calculations for the {nu}{sub 3} vibration lead to a range of frequencies spanning the experimentally observed width. This frequency spread could help explain the pronounced drop in the band intensity in the ice. The OCN{sup -} {nu}{sub 3} band in the present compact ices is also broader and much weaker than that reported in the literature for OCN{sup -} ions obtained by variously processing porous ice samples containing suitable neutral precursors. The results of this study indicate that the astronomical detection of OCN{sup -} in ice mantels could be significantly impaired if the ion is embedded in a compact water network.

Mate, Belen; Herrero, Victor J.; Rodriguez-Lazcano, Yamilet; Moreno, Miguel A.; Escribano, Rafael [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, E-28006 Madrid (Spain); Fernandez-Torre, Delia [Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, E-28050 Madrid (Spain); Gomez, Pedro C. [Departamento de Quimica Fisica I, Universidad Complutense, Unidad Asociada UCM-CSIC, E-28040 Madrid (Spain)

2012-11-10T23:59:59.000Z

45

Electronic Compact Fluorescent Lamps  

Science Conference Proceedings (OSTI)

This EPRI Technical Update addresses the fastest growing energy efficient light source the electronic compact fluorescent lamp (CFL). Business and technical market factors (Chapter 2) explain the past and future growth of the CFL market while emphasizing future technical improvements along with discussion of the importance of utility involvement in helping their customers make the switch from incandescent lamps to CFLs. The basic CFL technology is covered in Chapter 3 including test results for selected ...

2007-12-18T23:59:59.000Z

46

Compact power reactor  

DOE Patents (OSTI)

There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

Wetch, Joseph R. (Woodland Hills, CA); Dieckamp, Herman M. (Canoga Park, CA); Wilson, Lewis A. (Canoga Park, CA)

1978-01-01T23:59:59.000Z

47

Compact superradiant Cerenkov source  

Science Conference Proceedings (OSTI)

An economical, coherent, and widely tunable source does not exist spanning the far-infrared electromagnetic spectral range of 50-1000 {mu}m in wavelength. The Cerenkov free-electron laser (CFEL) is a promising candidate. This report describes an experimental investigation of a compact CFEL driven by a high-quality low-energy electron beam. Cerenkov emission and strong gain but remarkably low output coupling were observed.

Owens, I.J.; Brownell, J.H. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755-3528 (United States)

2005-05-15T23:59:59.000Z

48

Compact Fluorescent Lamps  

Science Conference Proceedings (OSTI)

Electric lighting constitutes approximately 21-23 % of the electric grid load in the United States. The higher energy and maintenance costs of incandescent lamps, combined with the favorable economics of high-efficiency compact fluorescent lamps (CFLs), are making CFLs the increasingly popular choice for both residential and commercial lighting. Utility incentive and rebate programs to stimulate CFL use and the beginnings of a ban on incandescent lamps are enhancing CFL penetration levels in these enviro...

2009-12-17T23:59:59.000Z

49

Compact proton spectrometers for measurements of shock  

Science Conference Proceedings (OSTI)

The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign (NIC) diagnostic. The WRF measures the spectrum of protons from D-{sup 3}He reactions in tuning-campaign implosions containing D and {sup 3}He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total {rho}R through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

Mackinnon, A; Zylstra, A; Frenje, J A; Seguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M G; Casey, D T; Sinenian, N; Manuel, M; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G; Dewald, E; Doeppner, T; Edwards, M J; Glenzer, S H; Hicks, D; Landen, O L; London, R; Meezan, N B

2012-05-02T23:59:59.000Z

50

Seismological challenges for stellar structure  

E-Print Network (OSTI)

Helioseismology has provided very detailed information about the solar interior, and extensive data on a large number of stars, although at less detail, are promised by the ongoing and upcoming asteroseismic projects. In the solar case there remain serious challenges in understanding the inferred solar structure, particularly in the light of the revised determinations of the solar surface composition. Also, a secure understanding of the origins of solar rotation as inferred from helioseismology, both in the radiative interior and in the convection zone, is still missing. In the stellar case challenges are certain to appear as the data allow more detailed inferences of the properties of stellar cores. Large remaining uncertainties in modelling concerns the properties of convective cores and other processes that may cause mixing. As a result of developing asteroseismic signatures addressing these and other issues, we can look forward to a highly challenging, and hence exciting, era of stellar astrophysics.

Christensen-Dalsgaard, J

2010-01-01T23:59:59.000Z

51

Electric fields and transport in optimized stellarators  

E-Print Network (OSTI)

Recent stellarator experiments have been designed with one of two types of neoclassical optimization: quasisymmetry or quasi-isodynamism. Both types of stellarator have perfectly confined collisionless particle orbits as ...

Landreman, Matthew Joseph

2011-01-01T23:59:59.000Z

52

Compact gate valve  

DOE Patents (OSTI)

This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

Bobo, Gerald E. (Knoxville, TN)

1977-01-01T23:59:59.000Z

53

Compact laser amplifier system  

DOE Patents (OSTI)

A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

Carr, R.B.

1974-02-26T23:59:59.000Z

54

Magnetic Fields in Stellar Astrophysics  

E-Print Network (OSTI)

This is a white paper submitted to the Stars and Stellar Evolution (SSE) Science Frontier Panel (SFP) of the NRC's 2010 Astronomy and Astrophysics Decadal Survey. The white paper is endorsed by the NSF Physics Frontier Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas (CMSO).

Uzdensky, Dmitri; Ji, Hantao; Townsend, Richard; Yamada, Masaaki

2009-01-01T23:59:59.000Z

55

A mean field theory for the cold quark gluon plasma applied to stellar structure  

SciTech Connect

An equation of state based on a mean-field approximation of QCD is used to describe the cold quark gluon plasma and also to study the structure of compact stars. We obtain stellar masses compatible with the pulsar PSR J1614-2230 that was determined to have a mass of (1.97 {+-} 0.04 M{sub Circled-Dot-Operator }), and the corresponding radius around 10-11 km.

Fogaca, D. A.; Navarra, F. S.; Franzon, B. [Instituto de Fisica, Universidade de Sao Paulo Rua do Matao, Travessa R, 187, 05508-090 Sao Paulo, SP (Brazil); Horvath, J. E. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao, 1226, 05508-090, Sao Paulo, SP (Brazil)

2013-03-25T23:59:59.000Z

56

Compact electrostatic comb actuator  

DOE Patents (OSTI)

A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

Rodgers, M. Steven (Albuquerque, NM); Burg, Michael S. (Albuquerque, NM); Jensen, Brian D. (Albuquerque, NM); Miller, Samuel L. (Albuquerque, NM); Barnes, Stephen M. (Albuquerque, NM)

2000-01-01T23:59:59.000Z

57

Accretion in Compact Binaries  

E-Print Network (OSTI)

Compact binaries have long been a paradigm for accretion theory. Much of our present view of how accretion occurs comes directly from the comparison of theory with observations of these sources. Since theory differs little for other objects such as active galaxies, increasing efforts have recently gone into searching for correspondences in observed behaviour. This chapter aims at giving a concise summary of the field, with particular emphasis on new developments since the previous edition of this book. These developments have been significant. Much of the earlier literature implicitly assumed that accreting binaries were fairly steady sources accreting most of the mass entering their vicinity, often with main-sequence companions, and radiating the resulting accretion luminosity in rough isotropy. We shall see that in reality these assumptions fail for the majority of systems. Most are transient; mass ejection in winds and jets is extremely common; a large (sometimes dominant) fraction of even short-period systems have evolved companions whose structure deviates significantly from the zero-age main sequence; and the radiation pattern of many objects is significantly anisotropic. It is now possible to give a complete characterization of the observed incidence of transient and persistent sources in terms of the disc instability model and formation constraints. X-ray populations in external galaxies, particularly the ultraluminous sources, are revealing important new insights into accretion processes and compact binary evolution.

Andrew R. King

2003-01-07T23:59:59.000Z

58

Susquehanna River Basin Compact (Maryland)  

Energy.gov (U.S. Department of Energy (DOE))

This legislation enables the state's entrance into the Susquehanna River Basin Compact, which provides for the conservation, development, and administration of the water resources of the...

59

METHOD OF FORMING ELONGATED COMPACTS  

DOE Patents (OSTI)

A powder compacting procedure and apparatus which produces elongated compacts of Be is described. The powdered metal is placed in a thin metal tube which is chemically compatible to lubricant, powder, atmosphere, and die material and will undergo a high degree of plastic deformation and have intermediate hardness. The tube is capped and placed in the die, and punches are applied to the ends. During the compacting stroke the powder seizes the tube and a thickening and shortening of the tube occurs. The tube is easily removed from the die, split, and peeled from the compact. (T.R.H.)

Larson, H.F.

1959-05-01T23:59:59.000Z

60

Available Technologies: Compact Hyperspectral Imager  

Scientists have developed a compact and lightweight optical device that can perform spatially resolved spectroscopy at low levels of visible light. The team — led ...

Note: This page contains sample records for the topic "national compact stellarator" 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

CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS?  

Science Conference Proceedings (OSTI)

The discovery of supernovae associated with long-duration gamma-ray burst observations is primary evidence that the progenitors of these outbursts are massive stars. One of the principle mysteries in understanding these progenitors has been the fact that all of these gamma-ray-burst-associated supernovae are Type Ic supernovae with no evidence of helium in the stellar atmosphere. Many studies have focused on whether or not this helium is simply hidden from spectral analyses. In this Letter, we show results from recent stellar models using new convection algorithms based on our current understanding of stellar mixing. We demonstrate that enhanced convection may lead to severe depletion of stellar helium layers, suggesting that the helium is not observed simply because it is not in the star. We also present light curves and spectra of these compact helium-depleted stars compared to models with more conventional helium layers.

Frey, Lucille H. [HPC-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Young, Patrick A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85276 (United States)

2013-08-10T23:59:59.000Z

62

CIM - compact intensity modulation.  

SciTech Connect

Compact intensity modulation (CIM), a new method to modulate the intensity of a neutron beam is demonstrated. CIM allows the production of arbitrary signals where the focus point can be chosen and changed without any constraints. A novel feature in this technique compared to spin echo techniques is that the neutron polarization is kept parallel or anti-parallel to the static fields during the passage through the magnetic fields and the beating pattern at the detector is produced by an amplitude modulation (AM) of the adiabatic RF-spin flippers rather than Larmor precession like in neutron spin echo (NSE) instruments; thus, the achievable contrast is very high and the instrument resolution can be changed very quickly. This gives the fascinating possibility at pulsed neutron sources to sweep the modulation frequency of the flippers in order to increase dynamic resolution range during the same neutron pulse.

Bleuel, M.; Lang, E.; Gahler, G.; Lal, J.; Intense Pulsed Neutron Source; Inst. Lau Langevin

2008-07-21T23:59:59.000Z

63

Compact acoustic refrigerator  

DOE Patents (OSTI)

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

Bennett, G.A.

1992-11-24T23:59:59.000Z

64

Compact vacuum insulation embodiments  

DOE Patents (OSTI)

An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

Benson, D.K.; Potter, T.F.

1992-04-28T23:59:59.000Z

65

Compact acoustic refrigerator  

DOE Patents (OSTI)

This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

Bennett, G.A.

1991-12-31T23:59:59.000Z

66

Compact acoustic refrigerator  

DOE Patents (OSTI)

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

Bennett, Gloria A. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

67

Compact vacuum insulation  

DOE Patents (OSTI)

An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

Benson, D.K.; Potter, T.F.

1993-01-05T23:59:59.000Z

68

Compact vacuum insulation embodiments  

DOE Patents (OSTI)

An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1992-01-01T23:59:59.000Z

69

Compact vacuum insulation  

DOE Patents (OSTI)

An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1993-01-01T23:59:59.000Z

70

Stellar Energy Solutions Inc | Open Energy Information  

Open Energy Info (EERE)

Stellar Energy Solutions Inc Stellar Energy Solutions Inc Jump to: navigation, search Name Stellar Energy Solutions Inc Place Healdsburg, California Zip 95448 Sector Renewable Energy, Solar Product Turn-key renewable energy solutions provider specializing in solar electric roofing. References Stellar Energy Solutions Inc[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Stellar Energy Solutions Inc is a company located in Healdsburg, California . References ↑ "Stellar Energy Solutions Inc" Retrieved from "http://en.openei.org/w/index.php?title=Stellar_Energy_Solutions_Inc&oldid=351700" Categories: Clean Energy Organizations Companies Organizations Stubs What links here Related changes

71

Aspects of stellarator confinement scaling  

DOE Green Energy (OSTI)

Extensive discussion has been made concerning stellarator experimental confinement scaling and the extrapolation to reactor systems. Two features are discussed here: (1) The role of hydrogen-impurity interactions. (2) The neoclassical (bootstrap) current has been invoked as an argument against the possibility of optimizing the stellarator magnetic configuration to reach high ..beta... It is felt that significant bootstrap current production under conditions of high ..beta.. will dominate the vacuum fields. In this regard, a brief summary is presented of a comparison made between ISX-B high-..beta.. data and the neoclassical predictions. The non-neoclassical rates of electron pitch-angle scattering serve to destroy this current, and are evidently responsible for a lack of evidence for the bootstrap current under conditions in tokamaks where a large effect is expected.

Hogan, J.

1981-01-01T23:59:59.000Z

72

Compact vacuum insulation  

DOE Patents (OSTI)

Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and variious laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1992-01-01T23:59:59.000Z

73

Compact vacuum insulation  

DOE Patents (OSTI)

Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

Benson, D.K.; Potter, T.F.

1992-10-27T23:59:59.000Z

74

Canadian River Compact (Texas) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Administration Other Agencies You are here Home Savings Canadian River Compact (Texas) Canadian River Compact (Texas) Eligibility Utility Fed. Government Commercial...

75

Rio Grande Compact (Texas) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Rio Grande Compact (Texas) Rio Grande Compact (Texas) Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility StateProvincial Govt Industrial...

76

DRAFT STELLAR White paper Early Years and Technology. March 2011 STELLAR 2nd  

E-Print Network (OSTI)

DRAFT STELLAR White paper ­ Early Years and Technology. March 2011 - 1 and evaluation of technologies to support young children's learning White paper hal-00722846,version1-5Aug2012 #12;DRAFT STELLAR White paper ­ Early Years

Paris-Sud XI, Université de

77

Nuclear Star Clusters - Structure and Stellar Populations  

E-Print Network (OSTI)

This is an overview of nuclear star cluster observations, covering their structure, stellar populations, kinematics and possible connection to black holes at the centers of galaxies.

Neumayer, Nadine

2012-01-01T23:59:59.000Z

78

Helical-axis stellarator with helical windings  

SciTech Connect

The equilibrium and stability of the plasma in a stellarator with a helical geometric axis and with helical external fields are analyzed.

Mikhailov, M.I.; Pustovitov, V.D.

1981-10-05T23:59:59.000Z

79

Helical axis stellarator with noninterlocking planar coils  

DOE Patents (OSTI)

A helical axis stellarator using only noninterlocking planar, non-circular coils, generates magnetic fields having a magnetic well and large rotational transform with resultant large equilibrium beta.

Reiman, Allan (Princeton, NJ); Boozer, Allen H. (Rocky Hill, NJ)

1987-01-01T23:59:59.000Z

80

New considerations for compact cyclotrons  

E-Print Network (OSTI)

A compact cyclotron built with superconducting magnets could be a transformative solution to many scientific problems facing the defense, medical, and energy industries today. This thesis discusses three potential applications ...

Marshall, Eric S. (Eric Scott)

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

High flux compact neutron generators  

E-Print Network (OSTI)

This work was supported by Sandia National Laboratory andThis Work was supported by Sandia National Laboratory and

Reijonen, J.; Lou, T.-P.; Tolmachoff, B.; Leung, K.-N.; Verbeke, J.; Vujic, J.

2001-01-01T23:59:59.000Z

82

Interstate Mining Compact (Maryland) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

You are here You are here Home » Interstate Mining Compact (Maryland) Interstate Mining Compact (Maryland) < Back Eligibility Commercial Developer Investor-Owned Utility Municipal/Public Utility Rural Electric Cooperative Utility Program Info State Maryland Program Type Environmental Regulations Provider Interstate Mining Compact Commission This legislation authorizes the state's entrance into the Interstate Mining Compact, a multi-state governmental agency / organization that represents the natural resource and related environmental protection interests of its member states. Currently, 23 states are members to the compact, and 6 additional states are associate members. The compact is administered by the Interstate Mining Compact Commission, which does not possess regulatory

83

Stellarators | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Join Our Mailing List A Collaborative National Center for Fusion & Plasma Research Search form Search Search Home About Overview Learn More Visiting PPPL History...

84

Compact orthogonal NMR field sensor  

DOE Patents (OSTI)

A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

Gerald, II, Rex E. (Brookfield, IL); Rathke, Jerome W. (Homer Glen, IL)

2009-02-03T23:59:59.000Z

85

A Massive Pulsar in a Compact Relativistic Binary  

E-Print Network (OSTI)

Many physically motivated extensions to general relativity (GR) predict significant deviations in the properties of spacetime surrounding massive neutron stars. We report the measurement of a 2.01 +/- 0.04 solar mass pulsar in a 2.46-hr orbit with a 0.172 +/- 0.003 solar mass white dwarf. The high pulsar mass and the compact orbit make this system a sensitive laboratory of a previously untested strong-field gravity regime. Thus far, the observed orbital decay agrees with GR, supporting its validity even for the extreme conditions present in the system. The resulting constraints on deviations support the use of GR-based templates for ground-based gravitational wave detectors. Additionally, the system strengthens recent constraints on the properties of dense matter and provides insight to binary stellar astrophysics and pulsar recycling.

John Antoniadis; Paulo C. C. Freire; Norbert Wex; Thomas M. Tauris; Ryan S. Lynch; Marten H. van Kerkwijk; Michael Kramer; Cees Bassa; Vik S. Dhillon; Thomas Driebe; Jason W. T. Hessels; Victoria M. Kaspi; Vladislav I. Kondratiev; Norbert Langer; Thomas R. Marsh; Maura A. McLaughlin; Timothy T. Pennucci; Scott M. Ransom; Ingrid H. Stairs; Joeri van Leeuwen; Joris P. W. Verbiest; David G. Whelan

2013-04-25T23:59:59.000Z

86

Electric Transmission Line Siting Compact  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Electric Transmission Line Siting Compact Electric Transmission Line Siting Compact 1 ______________________________________________________________________________ 2 ARTICLE I 3 PURPOSE 4 5 Siting electric transmission lines across state borders and federal lands is an issue for states, the 6 federal government, transmission utilities, consumers, environmentalists, and other stakeholders. 7 The current, multi-year application review process by separate and equal jurisdictions constitutes 8 a sometimes inefficient and redundant process for transmission companies and complicates the 9 efforts of state and federal policy-makers and other stakeholders to develop more robust 10 economic opportunities, increase grid reliability and security, and ensure the consumers have the 11 lowest cost electricity possible. 12

87

Compact monolithic capacitive discharge unit  

DOE Patents (OSTI)

A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

Roesler, Alexander W. (Tijeras, NM); Vernon, George E. (Rio Rancho, NM); Hoke, Darren A. (Albuquerque, NM); De Marquis, Virginia K. (Tijeras, NM); Harris, Steven M. (Albuquerque, NM)

2007-06-26T23:59:59.000Z

88

Equilibrium and Stablity for the ARIES Compact Stellarator Reactor (A24758)  

E-Print Network (OSTI)

Proc. Of 31st Euro. Conf. On Plasma Phys. And Controlled Fusion, London, United Kingdom, 2004, To Be Published31st EPS Conference on Controlled Fusion and Plasma Physics London, UK, 2004999609795

Turnbull, A.D.

2004-07-30T23:59:59.000Z

89

Compact Stellarator Power Plants Prospects, Technical Issue, and R&D Directions  

E-Print Network (OSTI)

with different coil aspect ratio, Ac=/min were produced. In addition, the coil cross section (shape and size for assembly and maintenance; and feasibility and cost of manufacturing. The 3-D shape of the plasma is due to manufacturing process (and not the cost of the raw material), it is expected

Najmabadi, Farrokh

90

Robustness and Flexibility in Compact Quasiaxial Stellarators: Global Ideal MHD Stability and Energetic Particle Transport  

E-Print Network (OSTI)

, making use of advanced computer packages as well as high performance computing platforms. Although

91
92

What are Machos? Limits on Stellar Objects as the Dark Matter of our Halo  

E-Print Network (OSTI)

The nature of the Massive Compact Halo objects seen in microlensing experiments and interpreted as dark matter in the Halo of our Galaxy remains a mystery. Arguments are presented that these events are probably not ordinary stellar or substellar objects, i.e., they are probably not faint stars, brown dwarfs, white dwarfs, or neutron stars. On theoretical grounds one is then pushed to either exotic explanations or a "no-Macho" Halo (in which the Machos reside elsewhere than in the Halo). Indeed a nonbaryonic component in the Halo seems to be required.

Katherine Freese; Brian Fields; David Graff

1999-01-13T23:59:59.000Z

93

Compact Totally Disconnected Moufang Buildings  

E-Print Network (OSTI)

Let $\\Delta$ be a spherical building each of whose irreducible components is infinite, has rank at least 2 and satisfies the Moufang condition. We show that $\\Delta$ can be given the structure of a topological building that is compact and totally disconnected precisely when $\\Delta$ is the building at infinity of a locally finite affine building.

Grundhofer, T; Van Maldeghem, H; Weiss, R M

2010-01-01T23:59:59.000Z

94

Supernova rates and stellar populations  

E-Print Network (OSTI)

We discuss the results about the nature of type Ia Supernovae that can be derived by studying their rates in different stellar populations. While the evolution of SN photometry and spectra can constrain the explosion mechanism, the SN rate depends on the progenitor system. We review the current available data on rates as a function of parent galaxy color, morphology, star formation rate, radio luminosity and environment. By studying the variation of the rates with the color of the parent galaxy, a strong evidence was established that type Ia SNe come from both young and old stars. The dependence of the rates with the radio power of the parent galaxy is best reproduced by a bimodal distribution of delay time between the formation of the progenitor and its explosion as a SN. Cluster early-type galaxies show higher type Ia SN rate with respect to field galaxies, and this effect can be due either to traces of young stars or to differences in the delay time distribution.

F. Mannucci

2007-08-03T23:59:59.000Z

95

SPALL FRACTURE AND SPALL FRACTURE AND COMPACTION COMPACTION  

National Nuclear Security Administration (NNSA)

SPALL FRACTURE AND SPALL FRACTURE AND SPALL FRACTURE AND SPALL FRACTURE AND COMPACTION COMPACTION IN NATURAL URANIUM IN NATURAL URANIUM UNDER SHOCK UNDER SHOCK - - WAVE LOADING WAVE LOADING O.A. O.A. Tyupanova Tyupanova , S.S. , S.S. Nadezhin Nadezhin , A.N. , A.N. Malyshev Malyshev , , O.N. O.N. Ignatova Ignatova , V.I. , V.I. Skokov Skokov , V.N. , V.N. Knyazev Knyazev , , V.A. V.A. Raevsky Raevsky , N.A. , N.A. Yukina Yukina Russian Federal Nuclear Center Russian Federal Nuclear Center - - VNIIEF, VNIIEF, Sarov Sarov , Russia , Russia Introduction Introduction  Nucleation and growth of defects inside a solid under pulse tensile stresses signify a necessity to consider it as a damaged medium.  A certain volume of experimental data, obtained in correct tests, which are sensitive to a characteristic under study, is necessary

96

Charlton Compact Power Ltd | Open Energy Information  

Open Energy Info (EERE)

Charlton Compact Power Ltd Charlton Compact Power Ltd Jump to: navigation, search Name Charlton Compact Power Ltd Place Frome, England, United Kingdom Zip BA11 2RH Sector Biomass Product A joint venture between A. J. Charlton & Sons and Compact Power to develop a 3.6MW to 4.5MW biomass plant in Somerset. References Charlton Compact Power Ltd[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Charlton Compact Power Ltd is a company located in Frome, England, United Kingdom . References ↑ "Charlton Compact Power Ltd" Retrieved from "http://en.openei.org/w/index.php?title=Charlton_Compact_Power_Ltd&oldid=343457" Categories: Clean Energy Organizations Companies Organizations

97

Compact High-Temperature Superconducting Cable Wins ' ...  

Science Conference Proceedings (OSTI)

Compact High-Temperature Superconducting Cable Wins 'R&D 100' Award. From NIST Tech Beat: June 22, 2011. ...

2011-07-06T23:59:59.000Z

98

Compact magnetic energy storage module  

DOE Patents (OSTI)

A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module. 4 figures.

Prueitt, M.L.

1994-12-20T23:59:59.000Z

99

Compact magnetic energy storage module  

DOE Patents (OSTI)

A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module.

Prueitt, Melvin L. (Los Alamos, NM)

1994-01-01T23:59:59.000Z

100

Compact portable diffraction moire interferometer  

DOE Patents (OSTI)

A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observation means including film and video cameras may be used to view and record the resultant fringe patterns.

Deason, Vance A. (Shelley, ID); Ward, Michael B. (Idaho Falls, ID)

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Compact portable diffraction moire interferometer  

DOE Patents (OSTI)

A compact and portable moire interferometer used to determine surface deformations of an object. The improved interferometer is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent wave splitters, and collimating lenses directing the split beam at one or more specimen gratings. Observations means including film and video cameras may be used to view and record the resultant fringe patterns. 7 figs.

Deason, V.A.; Ward, M.B.

1988-05-23T23:59:59.000Z

102

Thixoforming of Stellite Powder Compacts  

SciTech Connect

Thixoforming involves processing metallic alloys in the semi-solid state. The process requires the microstructure to be spheroidal when part-solid and part-liquid i.e. to consist of solid spheroids surrounded by liquid. The aim of this work was to investigate whether powder compacts can be used as feedstock for thixoforming and whether the consolidating pressure in the thixoformer can be used to remove porosity from the compact. The powder compacts were made from stellite 6 and stellite 21 alloys, cobalt-based alloys widely used for e.g. manufacturing prostheses. Isothermal heat treatments of small samples in the consolidated state showed the optimum thixoforming temperature to be in the range 1340 deg. C-1350 deg. C for both materials. The alloys were thixoformed into graphite dies and flowed easily to fill the die. Porosity in the thixoformed components was lower than in the starting material. Hardness values at various positions along the radius of the thixoformed demonstrator component were above the specification for both alloys.

Hogg, S. C. [Institute of PolymerTechnology and Materials Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom); Atkinson, H. V. [Department of Engineering, University of Leicester, University Rd., Leicester LE1 7RH (United Kingdom); Kapranos, P. [Department of Engineering Materials, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

2007-04-07T23:59:59.000Z

103

Canadian River Compact (Texas) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Canadian River Compact (Texas) Canadian River Compact (Texas) Canadian River Compact (Texas) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Residential Installer/Contractor Rural Electric Cooperative Tribal Government Low-Income Residential Schools Retail Supplier Institutional Multi-Family Residential Systems Integrator Fuel Distributor Nonprofit General Public/Consumer Transportation Savings Category Water Buying & Making Electricity Home Weatherization Program Info State Texas Program Type Siting and Permitting Provider Canadian River Compact Commission The Canadian River Commission administers the Canadian River Compact which includes the states of New Mexico, Oklahoma, and Texas. Signed in 1950 by

104

Software Development for a CompactRIO-Based Wire Scanner Control and Data Acquisition SYstem  

SciTech Connect

The Beam Diagnostics and Instrumentation Team at the Los Alamos Neutron Science Center is developing a wire scanner data acquisition and control system with a National Instrument's compactRIO at its core. For this application, the compactRIO controller not only requires programming the FPGA and RT computer internal to the compactRIO, but also requires programming a client computer and a touch panel display. This article will summarize the hardware interfaces and describe the software design approach utilized for programming and interfacing the four systems together in order to fulfill the design requirements and promote reliable interoperability.

Sedillo, James Daniel [Los Alamos National Laboratory

2012-05-16T23:59:59.000Z

105

Prediction of reservoir compaction and surface subsidence  

SciTech Connect

A new loading-rate-dependent compaction model for unconsolidated clastic reservoirs is presented that considerably improves the accuracy of predicting reservoir rock compaction and surface subsidence resulting from pressure depletion in oil and gas fields. The model has been developed on the basis of extensive laboratory studies and can be derived from a theory relating compaction to time-dependent intergranular friction. The procedure for calculating reservoir compaction from laboratory measurements with the new model is outlined. Both field and laboratory compaction behaviors appear to be described by one single normalized, nonlinear compaction curve. With the new model, the large discrepancies usually observed between predictions based on linear compaction models and actual (nonlinear) field behavior can be explained.

De Waal, J.A.; Smits, R.M.M.

1988-06-01T23:59:59.000Z

106

The Stellar Populations of Seyfert 2 Nuclei  

E-Print Network (OSTI)

We present a preliminary analysis of the stellar populations in the central parsecs of a sample of 22 Seyfert 2 galaxies, based on a careful separation of nebular emission and stellar light in high-spatial resolution HST-STIS spectra. 10% of the surveyed nuclei display stellar populations of intermediate age, 1-2 Gyr old, whereas the remaining targets appear to be evenly split between objects showing only very old stellar populations and nuclei requiring also an additional blue featureless component, which we characterise by means of very young, few-Myr-old stars. The small fraction of stellar population of intermediate age seems to argue against the presence of such a young component, however, since the short lifetime of O-stars would imply recurrent star-formation episodes and the build-up over the last 1-2 Gyr of a detectable intermediate-age population. Additionally, a correlation between the luminosity of such a blue component and the emission from highly-ionised species, together with the general absence of Wolf-Rayet features, further suggests that the featureless continuum arises from the central engine rather than from star-forming regions. We discuss our results in the framework of the unification paradigm and of models for star formation close to supermassive black holes.

Marc Sarzi; Joe Shields; Rick Pogge; Paul Martini

2007-03-30T23:59:59.000Z

107

Residual Stress Tensor in a Compact Tension Weld Specimen  

Science Conference Proceedings (OSTI)

Presentation Title, Residual Stress Tensor in a Compact Tension Weld Specimen ... austenitic stainless steel (Esshete 1250) compact tension weld specimen.

108

Recent Advances in Modeling Stellar Interiors  

E-Print Network (OSTI)

Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: 1) updates to input physics of stellar models; 2) progress in two and three-dimensional evolution and hydrodynamic models; 3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid gamma Dor/delta Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as eta Car and P Cyg, and the solar abundance problem.

Guzik, Joyce Ann

2010-01-01T23:59:59.000Z

109

The Cosmic Stellar Birth and Death Rates  

E-Print Network (OSTI)

The cosmic stellar birth rate can be measured by standard astronomical techniques. It can also be probed via the cosmic stellar death rate, though until recently, this was much less precise. However, recent results based on measured supernova rates, and importantly, also on the attendant diffuse fluxes of neutrinos and gamma rays, have become competitive, and a concordant history of stellar birth and death is emerging. The neutrino flux from all past core-collapse supernovae, while faint, is realistically within reach of detection in Super-Kamiokande, and a useful limit has already been set. I will discuss predictions for this flux, the prospects for neutrino detection, the implications for understanding core-collapse supernovae, and a new limit on the contribution of type-Ia supernovae to the diffuse gamma-ray background.

John F. Beacom

2006-02-05T23:59:59.000Z

110

Recent advances in modeling stellar interiors (u)  

Science Conference Proceedings (OSTI)

Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: (1) updates to input physics of stellar models; (2) progress in two and three-dimensional evolution and hydrodynamic models; (3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid {gamma} Dor/{delta} Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as {eta} Car and P Cyg, and the solar abundance problem.

Guzik, Joyce Ann [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

111

IRAS 04000+5052: A not so compact, not so metal-poor HII region  

E-Print Network (OSTI)

We present new observations of IRAS 04000+5052, a Galactic HII region associated with a young stellar cluster and possibly located at the Perseus arm. Contrary to previous claims, we have found that this object is not a compact metal-poor HII region. The electron density and chemical composition of the nebula are similar to those of normal HII regions of the Galactic disk. The radial velocity of the ionized gas coincides with that obtained from CO observations, indicating that the nebula is associated with a molecular cloud. Probably, the ionizing source of the HII region is a Herbig Be star of B0.5 spectral type.

Cesar Esteban; Luis Lopez-Martin; Angel R. Lopez-Sanchez; Bernabe Cedres; Jorge Garcia-Rojas

2004-06-07T23:59:59.000Z

112

IRAS 04000+5052: A not so compact, not so metal-poor HII region  

E-Print Network (OSTI)

We present new observations of IRAS 04000+5052, a Galactic HII region associated with a young stellar cluster and possibly located at the Perseus arm. Contrary to previous claims, we have found that this object is not a compact metal-poor HII region. The electron density and chemical composition of the nebula are similar to those of normal HII regions of the Galactic disk. The radial velocity of the ionized gas coincides with that obtained from CO observations, indicating that the nebula is associated with a molecular cloud. Probably, the ionizing source of the HII region is a Herbig Be star of B0.5 spectral type.

Esteban, C; Lopez-Sanchez, A R; Cedres, B; Garcia-Rojas, J; Esteban, Cesar; Lopez-Martin, Luis; Lopez-Sanchez, Angel R.; Cedres, Bernabe; Garcia-Rojas, Jorge

2004-01-01T23:59:59.000Z

113

Compacted carbon for electrochemical cells  

DOE Patents (OSTI)

This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (i) an x-ray density of at least 2.00 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 47%; and (b) graphite having the following properties: (i) an x-ray density of at least 2.20 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counterelectrode.

Greinke, Ronald Alfred (Medina, OH); Lewis, Irwin Charles (Strongsville, OH)

1997-01-01T23:59:59.000Z

114

Compacted carbon for electrochemical cells  

DOE Patents (OSTI)

This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (1) an x-ray density of at least 2.00 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 47%; and (b) graphite having the following properties: (1) an x-ray density of at least 2.20 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counter electrode. 10 figs.

Greinke, R.A.; Lewis, I.C.

1997-10-14T23:59:59.000Z

115

UNIVERSITY of CALIFORNIA A COMPARISON OF SOLAR AND GALACTIC STELLAR  

E-Print Network (OSTI)

UNIVERSITY of CALIFORNIA SANTA CRUZ A COMPARISON OF SOLAR AND GALACTIC STELLAR PROPERTIES TO SOLVE;Abstract A Comparison of Solar and Galactic Stellar Properties to Solve the Mystery of Excess Chromospheric

Belanger, David P.

116

Method for preparing porous metal hydride compacts  

DOE Patents (OSTI)

A method for preparing porous metallic-matrix hydride compacts which can be repeatedly hydrided and dehydrided without disintegration. A mixture of a finely divided metal hydride and a finely divided matrix metal is contacted with a poison which prevents the metal hydride from dehydriding at room temperature and atmospheric pressure. The mixture of matrix metal and poisoned metal hydride is then compacted under pressure at room temperature to form porous metallic-matrix hydride compacts.

Ron, M.; Gruen, D.M.; Mendelsohn, M.H.; Sheft, I.

1980-01-21T23:59:59.000Z

117

Compact Solid State Cooling Systems: Compact MEMS Electrocaloric Module  

SciTech Connect

BEETIT Project: UCLA is developing a novel solid-state cooling technology to translate a recent scientific discovery of the so-called giant electrocaloric effect into commercially viable compact cooling systems. Traditional air conditioners use noisy, vapor compression systems that include a polluting liquid refrigerant to circulate within the air conditioner, absorb heat, and pump the heat out into the environment. Electrocaloric materials achieve the same result by heating up when placed within an electric field and cooling down when removed—effectively pumping heat out from a cooler to warmer environment. This electrocaloric-based solid state cooling system is quiet and does not use liquid refrigerants. The innovation includes developing nano-structured materials and reliable interfaces for heat exchange. With these innovations and advances in micro/nano-scale manufacturing technologies pioneered by semiconductor companies, UCLA is aiming to extend the performance/reliability of the cooling module.

None

2010-10-01T23:59:59.000Z

118

Helical axis stellarator with noninterlocking planar coils  

DOE Patents (OSTI)

The present invention generates stellarator fields having favorable properties (magnetic well and large rotational transform) by a simple coil system consisting only of unlinked planar non-circular coils. At large rotational transform toroidal effects on magnetic well and rotational transform are small and can be ignored. We do so herein, specializing in straight helical systems.

Reiman, A.; Boozer, A.H.

1984-03-06T23:59:59.000Z

119

Stellar Sources of Gamma-ray Bursts  

E-Print Network (OSTI)

Correlation analysis of Swift gamma-ray burst coordinates and nearby star locations (catalog Gliese) reveals 4 coincidences with good angular accuracy. The random probability is 4\\times 10^{-5}, so evidencing that coincident stars are indeed gamma-ray burst sources. Some additional search of stellar gamma-ray bursts is discussed.

Luchkov, B I

2011-01-01T23:59:59.000Z

120

The Evolution of Stellar Exponential Discs  

E-Print Network (OSTI)

Models of disc galaxies which invoke viscosity-driven radial flows have long been known to provide a natural explanation for the origin of stellar exponential discs, under the assumption that the star formation and viscous timescales are comparable. We present models which invoke simultaneous star formation, viscous redistribution of gas and cosmologically-motivated gaseous infall and explore the predictions such models make for the scale length evolution and radial star formation history of galactic stellar discs. While the inclusion of viscous flows is essential for ensuring that the stellar disc is always exponential over a significant range in radius, we find that such flows play essentially no role in determining the evolution of the disc scale length. In models in which the main infall phase precedes the onset of star formation and viscous evolution, we find the exponential scale length to be rather invariant with time. On the other hand, models in which star formation/viscous evolution and infall occur concurrently result in a smoothly increasing scale length with time, reflecting the mean angular momentum of material which has fallen in at any given epoch. The disc stellar populations in these models are predominantly young (ie. ages history predicted by our infall model and the recent observational determination of this quantity by Rocha-Pinto et al (2000).

Annette Ferguson; Cathie Clarke

2001-03-14T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

NUCLEAR ASPECTS OF STELLAR AND EXPLOSIVE NUCLEOSYNTHESIS  

E-Print Network (OSTI)

NUCLEAR ASPECTS OF STELLAR AND EXPLOSIVE NUCLEOSYNTHESIS Thomas Rauscher 1 , Friedrich. of Astron. and Astroph., Univ. of California, Santa Cruz, CA 95064 Abstract The majority of nuclear­Feshbach). The global parametrizations of the nuclear properties needed for predictions far off stability probe our

Rauscher, Thomas

122

Dedicated Compact Refinery - Programmaster.org  

Science Conference Proceedings (OSTI)

Meeting, 2013 TMS Annual Meeting & Exhibition ... capital cost per tonne of alumina (tA) capacity; * Compact plant production capacity, resulting in a simple and ...

123

Compact Absorption Chiller - Energy Innovation Portal  

The Compact Absorption Chiller uses microchannel technologies in an absorption heat pump which produces cooling using heat as the primary energy source.

124

Compact submanifolds supporting singular interactions  

E-Print Network (OSTI)

A quantum particle moving under the influence of singular interactions on embedded surfaces furnish an interesting example from the spectral point of view. In these problems, the possible occurrence of a bound state is perhaps the most important aspect. Such systems can be introduced as quadratic forms and generically they do not require renormalization. Yet an alternative path through the resolvent is also beneficial to study various properties. In the present work, we address these issues for compact surfaces embedded in a class of ambient manifolds. We discover that there is an exact bound state solution written in terms of the heat kernel of the ambient manifold for a range of coupling strengths. Moreover, we develop techniques to estimate bounds on the ground state energy when several surfaces, each of which admits a bound state solution, coexist.

Kaynak, Burak Tevfik

2013-01-01T23:59:59.000Z

125

Compact submanifolds supporting singular interactions  

E-Print Network (OSTI)

A quantum particle moving under the influence of singular interactions on embedded surfaces furnish an interesting example from the spectral point of view. In these problems, the possible occurrence of a bound state is perhaps the most important aspect. Such systems can be introduced as quadratic forms and generically they do not require renormalization. Yet an alternative path through the resolvent is also beneficial to study various properties. In the present work, we address these issues for compact surfaces embedded in a class of ambient manifolds. We discover that there is an exact bound state solution written in terms of the heat kernel of the ambient manifold for a range of coupling strengths. Moreover, we develop techniques to estimate bounds on the ground state energy when several surfaces, each of which admits a bound state solution, coexist.

Burak Tevfik Kaynak; O. Teoman Turgut

2013-05-24T23:59:59.000Z

126

Compactness of the space of causal curves  

E-Print Network (OSTI)

We prove that the space of causal curves between compact subsets of a separable globally hyperbolic poset is itself compact in the Vietoris topology. Although this result implies the usual result in general relativity, its proof does not require the use of geometry or differentiable structure.

Keye Martin

2004-08-19T23:59:59.000Z

127

Compaction within the South Belridge diatomite  

SciTech Connect

Compaction is incorporated into a field-scale finite-difference thermal simulator to allow practical engineering analysis of reservoir compaction caused by fluid withdrawal. Capabilities new to petroleum applications include hysteresis in the form of limited rebound during fluid injection and the concept of relaxation time (i.e., creep).

Chase C.A. Jr.; Dietrich, J.K. (Todd, Dietrich and Chase Inc., Durango, CO (US))

1989-11-01T23:59:59.000Z

128

Compact Process Development at Babcock & Wilcox  

Science Conference Proceedings (OSTI)

Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of compaction trials have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel at packing fractions exceeding 46% by volume. Results from these trials are included. The scale-up effort is nearing completion with the process installed and operable using nuclear fuel materials. Final process testing is in progress to certify the process for manufacture of qualification test fuel compacts in 2012.

Eric Shaber; Jeffrey Phillips

2012-03-01T23:59:59.000Z

129

Compact approach to monitored retrievable storage of spent fuel  

Science Conference Proceedings (OSTI)

Recent federal waste-management legislation has raised national interest in monitored retrievable storage (MRS) of unprocessed spent fuel from civilian nuclear power plants. We have reviewed the current MRS design approaches, and we have examined an alternative concept that is extremely compact in terms of total land use. This approach may offer substantial advantages in the areas of monitoring and in safeguards against theft, as well as in reducing the chances of groundwater contamination. Total facility costs are roughly estimated and found to be generally competitive with other MRS concepts. 4 references, 3 figures, 3 tables.

Muir, D.W.

1984-09-01T23:59:59.000Z

130

The distribution of stellar population age in galactic bars  

E-Print Network (OSTI)

Recent analysis of stellar populations in barred galaxies have focused on the spatial distribution of stellar population ages and metallicities. However, barred galaxies are complex objects where dynamical instabilities play a leading role in shaping any spatial distribution. The age distribution of stellar populations should thus be analyzed from the two points of view of stellar population evolution and dynamical secular evolution. Chemodynamical simulations of single barred galaxies with simple but realistic star formation and feedback recipes are used to produce face-on mass-weighted maps of stellar population ages. Luminosity-weighted maps in V-band are also displayed after calibrating the simulation with mass-to-light ratios provided by a synthesis population model. It is shown that inside a stellar bar two persistent diametrically opposed regions display a mean age lower than the surrounding average. These two low-age regions are due to the accumulation of young stellar populations trapped on elliptica...

Wozniak, H

2007-01-01T23:59:59.000Z

131

Antitruncated Stellar Disks via Minor Mergers  

E-Print Network (OSTI)

We use hydrodynamic simulations of minor mergers of galaxies to investigate the nature of surface brightness excesses at large radii observed in some spiral galaxies: antitruncated stellar disks. We find that this process can produce the antitruncation via two competing effects: (1) merger-driven gas inflows that concentrate mass in the center of the primary galaxy and contract its inner density profile; and (2) angular momentum transferred outwards by the interaction, causing the outer disk to expand. In our experiments, this requires both a significant supply of gas in the primary disk, and that the encounter be prograde with moderate orbital angular momentum. The stellar surface mass density profiles of our remnants both qualitatively and quantitatively resemble the broken exponentials observed in local face--on spirals that display antitruncations. Moreover, the observed trend towards more frequent antitruncation relative to classical truncation in earlier Hubble types is consistent with a merger-driven scenario.

Joshua D. Younger; T. J. Cox; Anil C. Seth; Lars Hernquist

2007-07-30T23:59:59.000Z

132

On multimode pulsations of degenerate stellar models  

Science Conference Proceedings (OSTI)

Nonlinear dissipative radial oscillations of partially and completely degenerate stellar models have been studied. The general mathematical framework for the study of interaction between various radial modes of oscillation has been presented. The dynamical tools, e.g., Poincare surface of section and the spectrum of Liapunov exponents, have been used to investigate the nature of pulsation in the phase space. For simplicity, numerical computations have been made to study the interaction of only the first three modes, including the fundamental mode for both partially and completely degenerate stellar masses. For these models, with varying degrees of central degeneracy, the possible occurrence of quasi-periodic motions with as many as three irrationally related frequencies has been established in the dissipative regime. 56 refs.

Das, M.K.; Singh, H.P.; Tandon, J.N. (Delhi Univ. (India))

1989-11-01T23:59:59.000Z

133

Streams in the Aquarius stellar haloes  

E-Print Network (OSTI)

We use the very high resolution, fully cosmological simulations from the Aquarius project, coupled to a semi-analytical model of galaxy formation, to study the phase-space distribution of halo stars in "solar neighbourhood"-like volumes. We find that this distribution is very rich in substructure in the form of stellar streams for all five stellar haloes we have analysed. These streams can be easily identified in velocity space, as well as in spaces of pseudo-conserved quantities such as E vs. Lz. In our best-resolved local volumes, the number of identified streams ranges from ~ 300 to 600, in very good agreement with previous analytical predictions, even in the presence of chaotic mixing. The fraction of particles linked to (massive) stellar streams in these volumes can be as large as 84%. The number of identified streams is found to decrease as a power-law with galactocentric radius. We show that the strongest limitation to the quantification of substructure in our poorest-resolved local volumes is particle...

Gómez, Facundo A; Cooper, Andrew P; Frenk, Carlos S; Navarro, Julio F; White, Simon D M

2013-01-01T23:59:59.000Z

134

On the Evolution of Helium in Blue Compact Galaxies  

E-Print Network (OSTI)

We discuss the chemical evolution of dwarf irregular and blue compact galaxies in light of recent data, new stellar yields and chemical evolution models. We examine the abundance data for evidence of HII region self-enrichment effects, which would lead to correlations in the scatter of helium, nitrogen, and oxygen abundances around their mean trends. The observed helium abundance trends show no such correlations, though the nitrogen--oxygen trend does show strong evidence for real scatter beyond observational error. We construct simple models for the chemical evolution of these galaxies, using the most recent yields of \\he4, C, N and O in intermediate- and high-mass stars. The effects of galactic outflows, which can arise both from bulk heating and evaporation of the ISM, and from the partial escape of enriched supernova ejecta are included. In agreement with other studies, we find that supernova-enriched outflows can roughly reproduce the observed He, C, N, and O trends; however, in models that fit N versus O, the slopes $\\Delta Y/\\Delta$O and $\\Delta Y/\\Delta$N consistently fall more than $2\\sigma$ below the fit to observations. We discuss the role of the models and their uncertainties in the extrapolation of primordial helium from the data. We also explore the model dependence arising nucleosynthesis uncertainties associated with nitrogen yields in intermediate mass stars, the fate of $8-11 \\msol$ stars, and massive star winds.

Brian D. Fields; Keith A. Olive

1998-03-25T23:59:59.000Z

135

Compact Cross-Dipole Sonic (CXD) | Open Energy Information  

Open Energy Info (EERE)

2010 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Compact Cross-Dipole Sonic (CXD) Citation Weatherford. Compact Cross-Dipole...

136

Southeast Interstate Low-Level Radioactive Waste Management Compact...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Southeast Interstate Low-Level Radioactive Waste Management Compact (multi-state) Southeast Interstate Low-Level Radioactive Waste Management Compact (multi-state) Eligibility...

137

Simulation of Powder Compact Forging Process for Producing a ...  

Science Conference Proceedings (OSTI)

Presentation Title, Simulation of Powder Compact Forging Process for Producing a ... Powder compact forging is a recently developed manufacturing process to ...

138

Northwest Interstate Compact on Low-Level Radioactive Waste Management...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Northwest Interstate Compact on Low-Level Radioactive Waste Management (Multiple States) Northwest Interstate Compact on Low-Level Radioactive Waste Management (Multiple States)...

139

Atlantic Interstate Low-Level Radioactive Waste Management Compact...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Atlantic Interstate Low-Level Radioactive Waste Management Compact (South Carolina) Atlantic Interstate Low-Level Radioactive Waste Management Compact (South Carolina) Eligibility...

140

Compact Filter Design for Gas Treatment Centers - Programmaster.org  

Science Conference Proceedings (OSTI)

An Innovative Compact Heat Exchanger Solution for Aluminium Off-Gas Cooling and Heat Recovery · Autonomous Vehicle and Smelter Technologies · Compact ...

Note: This page contains sample records for the topic "national compact stellarator" 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

Electric Pulse Method for Compaction of the Mononitride Uranium ...  

Science Conference Proceedings (OSTI)

Presentation Title, Electric Pulse Method for Compaction of the Mononitride ... reactors and also the advantages of the electric pulse compaction method.

142

NERSC and CRD Help Decipher Science from Compact Accelerator...  

NLE Websites -- All DOE Office Websites (Extended Search)

and CRD Help Decipher Science from Compact Accelerator Simulations NERSC and CRD Help Decipher Science from Compact Accelerator Simulations May 26, 2009 3D Particle Surfing :...

143

Belle Fourche River Compact (South Dakota) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Other Agencies You are here Home Savings Belle Fourche River Compact (South Dakota) Belle Fourche River Compact (South Dakota) Eligibility Agricultural...

144

The effects of stellar dynamics on the evolution of young dense stellar systems  

E-Print Network (OSTI)

In the present paper we report on first results of a project in Brussels where we study the effects of stellar dynamics on the evolution of young dense stellar systems using the 3 decades expertise in massive star evolution and our population (number and spectral) synthesis code. We highlight an unconventionally formed object scenario (UFO-scenario) for Wolf Rayet binaries and study the effects of a luminous blue variable-type instability wind mass loss formalism on the formation of intermediate mass black holes.

Belkus, H; Vanbeveren, D

2004-01-01T23:59:59.000Z

145

The effects of stellar dynamics on the evolution of young dense stellar systems  

E-Print Network (OSTI)

In the present paper we report on first results of a project in Brussels where we study the effects of stellar dynamics on the evolution of young dense stellar systems using the 3 decades expertise in massive star evolution and our population (number and spectral) synthesis code. We highlight an unconventionally formed object scenario (UFO-scenario) for Wolf Rayet binaries and study the effects of a luminous blue variable-type instability wind mass loss formalism on the formation of intermediate mass black holes.

H. Belkus; J. Van Bever; D. Vanbeveren

2004-10-21T23:59:59.000Z

146

Compact Spatial Differencing Techniques in Numerical Modeling  

Science Conference Proceedings (OSTI)

The accuracies of the usual centered differencing, compact differencing and finite element methods are compared linearly with a geostrophic adjustment problem and nonlinearly with a vorticity advection problem. The finite element method provides ...

Hai-Ru Chang; Hampton N. Shirer

1985-04-01T23:59:59.000Z

147

Steady state compact toroidal plasma production  

DOE Patents (OSTI)

Apparatus and method for maintaining steady state compact toroidal plasmas. A compact toroidal plasma is formed by a magnetized coaxial plasma gun and held in close proximity to the gun electrodes by applied magnetic fields or magnetic fields produced by image currents in conducting walls. Voltage supply means maintains a constant potential across the electrodes producing an increasing magnetic helicity which drives the plasma away from a minimum energy state. The plasma globally relaxes to a new minimum energy state, conserving helicity according to Taylor's relaxation hypothesis, and injecting net helicity into the core of the compact toroidal plasma. Controlling the voltage so as to inject net helicity at a predetermined rate based on dissipative processes maintains or increases the compact toroidal plasma in a time averaged steady state mode.

Turner, William C. (Livermore, CA)

1986-01-01T23:59:59.000Z

148

A CMOS-compatible compact display  

E-Print Network (OSTI)

Portable information devices demand displays with high resolution and high image quality that are increasingly compact and energy-efficient. Microdisplays consisting of a silicon CMOS backplane integrated with light ...

Chen, Andrew R. (Andrew Raymond)

2005-01-01T23:59:59.000Z

149

Roller-Compacted Concrete for Dams  

Science Conference Proceedings (OSTI)

Placing mass concrete by the roller-compacted method improves the economics of hydroelectric dam construction. Many sites previously considered uneconomical for embankment or conventional concrete construction may now prove feasible.

1986-09-29T23:59:59.000Z

150

Pharmaceutical tablet compaction : product and process design  

E-Print Network (OSTI)

This thesis explores how tablet performance is affected by microstructure, and how microstructure can be controlled by selection of excipients and compaction parameters. A systematic strategy for formulation and process ...

Pore, Mridula

2009-01-01T23:59:59.000Z

151

Compact reflective imaging spectrometer utilizing immersed gratings  

DOE Patents (OSTI)

A compact imaging spectrometer comprising an entrance slit for directing light, a first mirror that receives said light and reflects said light, an immersive diffraction grating that diffracts said light, a second mirror that focuses said light, and a detector array that receives said focused light. The compact imaging spectrometer can be utilized for remote sensing imaging spectrometers where size and weight are of primary importance.

Chrisp, Michael P. (Danville, CA)

2006-05-09T23:59:59.000Z

152

Reservoir compaction loads on casings and liners  

Science Conference Proceedings (OSTI)

Pressure drawdown due to production from a reservoir causes compaction of the reservoir formation which induces axial and radial loads on the wellbore. Reservoir compaction loads increase during the production life of a well, and are greater for deviated wells. Presented here are casing and liner loads at initial and final pressure drawdowns for a particular reservoir and at well deviation angles of 0 to 45 degrees.

Wooley, G.R.; Prachner, W.

1984-09-01T23:59:59.000Z

153

Compact binary mergers: an astrophysical perspective  

E-Print Network (OSTI)

This paper reviews the current understanding of double neutron star and neutron star black hole binaries. It addresses mainly (nuclear) astrophysics aspects of compact binary mergers and thus complements recent reviews that have emphasized the numerical relativity viewpoint. In particular, the paper discusses different channels to release neutron-rich matter into the host galaxy, connections between compact binary mergers and short Gamma-ray bursts and accompanying electromagnetic signals.

S. Rosswog

2010-12-04T23:59:59.000Z

154

THE ORIGIN OF THE VIRGO STELLAR SUBSTRUCTURE  

Science Conference Proceedings (OSTI)

We present three-dimensional space velocities of stars selected to be consistent with membership in the Virgo stellar substructure. Candidates were selected from SA 103, a single 40' Multiplication-Sign 40' field from our proper-motion (PM) survey in Kapteyn's Selected Areas (SAs), based on the PMs, Sloan Digital Sky Survey (SDSS) photometry, and follow-up spectroscopy of 215 stars. The signature of the Virgo substructure is clear in the SDSS color-magnitude diagram (CMD) centered on SA 103, and 16 stars are identified that have high Galactocentric-frame radial velocities (V{sub GSR} > 50 km s{sup -1}) and lie near the CMD locus of Virgo. The implied distance to the Virgo substructure from the candidates is 14 {+-} 3 kpc. We derive mean kinematics from these 16 stars, finding a radial velocity V{sub GSR} = 153 {+-} 22 km s{sup -1} and proper motions ({mu}{sub {alpha}}cos {delta}, {mu}{sub {delta}}) = (- 5.24, -0.91) {+-} (0.43, 0.46) mas yr{sup -1}. From the mean kinematics of these members, we determine that the Virgo progenitor was on an eccentric (e {approx} 0.8) orbit that recently passed near the Galactic center (pericentric distance R{sub p} {approx} 6 kpc). This destructive orbit is consistent with the idea that the substructure(s) in Virgo originated in the tidal disruption of a Milky Way satellite. N-body simulations suggest that the entire cloud-like Virgo substructure (encompassing the 'Virgo Overdensity' and the 'Virgo Stellar Stream') is likely the tidal debris remnant from a recently disrupted massive ({approx}10{sup 9} M{sub Sun }) dwarf galaxy. The model also suggests that some other known stellar overdensities in the Milky Way halo (e.g., the Pisces Overdensity and debris near NGC 2419 and SEGUE 1) are explained by the disruption of the Virgo progenitor.

Carlin, Jeffrey L.; Yam, William; Willett, Benjamin A.; Newberg, Heidi J. [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Casetti-Dinescu, Dana I.; Girard, Terrence M. [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Majewski, Steven R., E-mail: carlij@rpi.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2012-07-10T23:59:59.000Z

155

THE SPITZER ATLAS OF STELLAR SPECTRA (SASS)  

SciTech Connect

We present the Spitzer Atlas of Stellar Spectra, which includes 159 stellar spectra (5-32 {mu}m; R {approx} 100) taken with the Infrared Spectrograph on the Spitzer Space Telescope. This Atlas gathers representative spectra of a broad section of the Hertzsprung-Russell diagram, intended to serve as a general stellar spectral reference in the mid-infrared. It includes stars from all luminosity classes, as well as Wolf-Rayet (WR) objects. Furthermore, it includes some objects of intrinsic interest, such as blue stragglers and certain pulsating variables. All of the spectra have been uniformly reduced, and all are available online. For dwarfs and giants, the spectra of early-type objects are relatively featureless, characterized by the presence of hydrogen lines in A spectral types. Besides these, the most noticeable photospheric features correspond to water vapor and silicon monoxide in late-type objects and methane and ammonia features at the latest spectral types. Most supergiant spectra in the Atlas present evidence of circumstellar gas and/or dust. The sample includes five M supergiant spectra, which show strong dust excesses and in some cases polycyclic aromatic hydrocarbon features. Sequences of WR stars present the well-known pattern of lines of He I and He II, as well as forbidden lines of ionized metals. The characteristic flat-top shape of the [Ne III] line is evident even at these low spectral resolutions. Several Luminous Blue Variables and other transition stars are present in the Atlas and show very diverse spectra, dominated by circumstellar gas and dust features. We show that the [8]-[24] Spitzer colors (IRAC and MIPS) are poor predictors of spectral type for most luminosity classes.

Ardila, David R. [NASA Herschel Science Center, California Institute of Technology, Mail Code 100-22, Pasadena, CA 91125 (United States); Van Dyk, Schuyler D.; Makowiecki, Wojciech; Stauffer, John; Rho, Jeonghee; Fajardo-Acosta, Sergio; Hoard, D. W.; Wachter, Stefanie [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Song, Inseok, E-mail: ardila@ipac.caltech.ed [Department of Physics and Astronomy, University of Georgia at Athens, GA 30602-2451 (United States)

2010-12-15T23:59:59.000Z

156

Dynamic compaction of tungsten carbide powder.  

Science Conference Proceedings (OSTI)

The shock compaction behavior of a tungsten carbide powder was investigated using a new experimental design for gas-gun experiments. This design allows the Hugoniot properties to be measured with reasonably good accuracy despite the inherent difficulties involved with distended powders. The experiments also provide the first reshock state for the compacted powder. Experiments were conducted at impact velocities of 245, 500, and 711 m/s. A steady shock wave was observed for some of the sample thicknesses, but the remainder were attenuated due to release from the back of the impactor or the edge of the sample. The shock velocity for the powder was found to be quite low, and the propagating shock waves were seen to be very dispersive. The Hugoniot density for the 711 m/s experiment was close to ambient crystal density for tungsten carbide, indicating nearly complete compaction. When compared with quasi-static compaction results for the same material, the dynamic compaction data is seen to be significantly stiffer for the regime over which they overlap. Based on these initial results, recommendations are made for improving the experimental technique and for future work to improve our understanding of powder compaction.

Gluth, Jeffrey Weston; Hall, Clint Allen; Vogler, Tracy John; Grady, Dennis Edward

2005-04-01T23:59:59.000Z

157

Technology Selections for Cylindrical Compact Fabrication  

SciTech Connect

A variety of process approaches are available and have been used historically for manufacture of cylindrical fuel compacts. The jet milling, fluid bed overcoating, and hot press compacting approach being adopted in the U.S. AGR Fuel Development Program for scale-up of the compacting process involves significant paradigm shifts from historical approaches. New methods are being pursued because of distinct advantages in simplicity, yield, and elimination of process mixed waste. Recent advances in jet milling technology allow simplified dry matrix powder preparation. The matrix preparation method is well matched with patented fluid bed powder overcoating technology recently developed for the pharmaceutical industry and directly usable for high density fuel particle matrix overcoating. High density overcoating places fuel particles as close as possible to their final position in the compact and is matched with hot press compacting which fully fluidizes matrix resin to achieve die fill at low compacting pressures and without matrix end caps. Overall the revised methodology provides a simpler process that should provide very high yields, improve homogeneity, further reduce defect fractions, eliminate intermediate grading and QC steps, and allow further increases in fuel packing fractions.

Jeffrey A. Phillips

2010-10-01T23:59:59.000Z

158

Compact fission counter for DANCE  

SciTech Connect

The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF{sub 2} crystals with equal solid-angle coverage. DANCE is a 4{pi} {gamma}-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed {gamma}-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture {gamma} rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to {alpha} particles, which is important for experiments with {alpha}-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from {alpha}'s. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed counter and still be able to maintain a stable operation under extreme radioactivity and the ability to separate fission fragments from {alpha}'s. In the following sections, the description is given for the design and performance of this new compact PPAC, for studying the neutron-induced reactions on actinides using DANCE at LANL.

Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

2010-11-06T23:59:59.000Z

159

Accretion-Powered Stellar Winds II: Numerical Solutions for Stellar Wind Torques  

E-Print Network (OSTI)

[Abridged] In order to explain the slow rotation observed in a large fraction of accreting pre-main-sequence stars (CTTSs), we explore the role of stellar winds in torquing down the stars. For this mechanism to be effective, the stellar winds need to have relatively high outflow rates, and thus would likely be powered by the accretion process itself. Here, we use numerical magnetohydrodynamical simulations to compute detailed 2-dimensional (axisymmetric) stellar wind solutions, in order to determine the spin down torque on the star. We explore a range of parameters relevant for CTTSs, including variations in the stellar mass, radius, spin rate, surface magnetic field strength, the mass loss rate, and wind acceleration rate. We also consider both dipole and quadrupole magnetic field geometries. Our simulations indicate that the stellar wind torque is of sufficient magnitude to be important for spinning down a ``typical'' CTTS, for a mass loss rate of $\\sim 10^{-9} M_\\odot$ yr$^{-1}$. The winds are wide-angle, self-collimated flows, as expected of magnetic rotator winds with moderately fast rotation. The cases with quadrupolar field produce a much weaker torque than for a dipole with the same surface field strength, demonstrating that magnetic geometry plays a fundamental role in determining the torque. Cases with varying wind acceleration rate show much smaller variations in the torque suggesting that the details of the wind driving are less important. We use our computed results to fit a semi-analytic formula for the effective Alfv\\'en radius in the wind, as well as the torque. This allows for considerable predictive power, and is an improvement over existing approximations.

Sean Matt; Ralph E. Pudritz

2008-01-02T23:59:59.000Z

160

Strategy Guideline: Compact Air Distribution Systems  

SciTech Connect

This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

Burdick, A.

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Binary populations and stellar dynamics in young clusters  

E-Print Network (OSTI)

We first summarize work that has been done on the effects of binaries on theoretical population synthesis of stars and stellar phenomena. Next, we highlight the influence of stellar dynamics in young clusters by discussing a few candidate UFOs (unconventionally formed objects) like intermediate mass black holes, Eta Carinae, Zeta Puppis, Gamma Velorum and WR 140.

D. Vanbeveren; H. Belkus; J. Van Bever; N. Mennekens

2008-01-17T23:59:59.000Z

162

Binary populations and stellar dynamics in young clusters  

E-Print Network (OSTI)

We first summarize work that has been done on the effects of binaries on theoretical population synthesis of stars and stellar phenomena. Next, we highlight the influence of stellar dynamics in young clusters by discussing a few candidate UFOs (unconventionally formed objects) like intermediate mass black holes, Eta Carinae, Zeta Puppis, Gamma Velorum and WR 140.

Vanbeveren, D; Van Bever, J; Mennekens, N

2008-01-01T23:59:59.000Z

163

Stellar Burning Falk Herwig, Alexander Heger, and Frank  

E-Print Network (OSTI)

Stellar Burning and Mixing Falk Herwig, Alexander Heger, and Frank Timmes (T-6); and Rob Hueckstaedt and Rob Coker (X-2); fherwig@lanl.gov D uring most phases of stellar evolution, nuclear burning nuclear burning in convective regions in which mixing and nuclear energy release proceeds on comparable

Herwig, Falk

164

Gas Feedback on Stellar Bar Evolution  

E-Print Network (OSTI)

We analyze evolution of live disk-halo systems in the presence of various gas fractions, f_gas less than 8% in the disk. We addressed the issue of angular momentum (J) transfer from the gas to the bar and its effect on the bar evolution. We find that the weakening of the bar, reported in the literature, is not related to the J-exchange with the gas, but is caused by the vertical buckling instability in the gas-poor disks and by a steep heating of a stellar velocity dispersion by the central mass concentration (CMC) in the gas-rich disks. The gas has a profound effect on the onset of the buckling -- larger f_gas brings it forth due to the more massive CMCs. The former process leads to the well-known formation of the peanut-shaped bulges, while the latter results in the formation of progressively more elliptical bulges, for larger f_gas. The subsequent (secular) evolution of the bar differs -- the gas-poor models exhibit a growing bar while gas-rich models show a declining bar whose vertical swelling is driven by a secular resonance heating. The border line between the gas-poor and -rich models lies at f_gas ~ 3% in our models, but is model-dependent and will be affected by additional processes, like star formation and feedback from stellar evolution. The overall effect of the gas on the evolution of the bar is not in a direct J transfer to the stars, but in the loss of J by the gas and its influx to the center that increases the CMC. The more massive CMC damps the vertical buckling instability and depopulates orbits responsible for the appearance of peanut-shaped bulges. The action of resonant and non-resonant processes in gas-poor and gas-rich disks leads to a converging evolution in the vertical extent of the bar and its stellar dispersion velocities, and to a diverging evolution in the bulge properties.

Ingo Berentzen; Isaac Shlosman; Inma Martinez-Valpuesta; Clayton Heller

2007-03-01T23:59:59.000Z

165

Thermonuclear inverse magnetic pumping power cycle for stellarator reactor  

DOE Patents (OSTI)

The plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energy is obtained from this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure. The cycle can be made self-sustaining by operating a system of two stellarator reactors in tandem. Part of the energy derived from the expansion phase of a first stellarator reactor is used to compress the plasma in a second stellarator reactor.

Ho, Darwin D. (Pleasanton, CA); Kulsrud, Russell M. (Princeton, NJ)

1991-01-01T23:59:59.000Z

166

Compact Power Inc CPI | Open Energy Information  

Open Energy Info (EERE)

Compact Power Inc CPI Compact Power Inc CPI Jump to: navigation, search Name Compact Power Inc (CPI) Place Troy, Michigan Zip 48083 Sector Vehicles Product Producer of lithium-ion batteries for Hybrid Electric Vehicles (HEV) and non-automotive (commercial and military) markets. Coordinates 39.066587°, -80.768578° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.066587,"lon":-80.768578,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

167

Compaction and Sintering of Mo Powders  

SciTech Connect

To support the development of Mo-99 production by NorthStar Medical Technologies, LLC, Mo metal powders were evaluated for compaction and sintering characteristics as they relate to Mo-100 accelerator target disk fabrication. Powders having a natural isotope distribution and enriched Mo-100 powder were examined. Various powder characteristics are shown to have an effect on both the compaction and sintering behavior. Natural Mo powders could be cold pressed directly to >90% density. All of the powders, including the Mo-100 samples, could be sintered after cold pressing to >90% density. As an example, a compacted Mo-100 disk reached 89.7% density (9.52 g/cm3) after sintering at 1000 C for 1 hr. in flowing Ar/4%H2. Higher sintering temperatures were required for other powder samples. The relationships between processing conditions and the resulting densities of consolidated Mo disks will be presented.

Nunn, Stephen D [ORNL; Kiggans, Jim [ORNL; Bryan, Chris [ORNL

2013-01-01T23:59:59.000Z

168

Lab Spotlight: Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Lab Spotlight: Argonne National Laboratory Lab Spotlight: Argonne National Laboratory ultrananocrystalline diamond (UNCD) technology Researchers John Carlisle (left) and Orlando Auciello (right) are developing an ultrathin biocompatible coating for the device. Creating Diamond Coatings for the Retinal Implant Argonne National Laboratory (ANL) plays a critical role in the success of the electrode implants used in the Artificial Retina Project. That's where researchers Orlando Auciello and colleague John Carlisle are using their patented ultrananocrystalline diamond (UNCD) technology to apply a revolutionary new coating to the retinal prosthetic device. The new packaging promises to provide a very thin, ultrasmooth film that will be far more compact and biocompatible than the bulky materials used to encase

169

A Pure Geometric Approach to Stellar Structure  

E-Print Network (OSTI)

The present work represents a step to deal with stellar structure using a pure geometric approach. A geometric field theory is used to construct a model for a spherically symmetric configuration. The model obtained can be considered as a pure geometric one in the sense that the tensor describing the material distributions is not a phenomenological object, but a part of the geometric structure used. A general equation of state is obtained from, and not imposed on, the model. The solution obtained shows that there are different zones characterizing the configuration: a central radiation dominant zone, a probable convection zone as a physical interpretation of the singularity of the model and a corona like zone. The model may represent a type of main sequence stars. The present work shows that Einstein's geometerization scheme can be extended to gain more physical information within material distribution, with some advantages.

M. I. Wanas; Samah A. Ammar

2009-06-25T23:59:59.000Z

170

Stellar Wind Bubbles: H-Deficient . . .  

E-Print Network (OSTI)

We present simplified one-dimensional numerical models for stellar wind bubbles (SWB), investigating two aspects: the effect of H-deicient winds, such as observed in [WR]-type centrals stars of planetary nebulae (PN) and massive Wolf-Rayet stars (WR), and the X-ray spectra produced by SWBs. For the H-deficient winds, we find that the extra cooling caused by the extremely high metal abundances influences the structure and evolution of their SWBs, although they remain mostly energy-driven. For the X-ray spectra we find that a standard SWB model cannot explain the observed spectra, and some extra physical effect is needed. We show that thermal conduction with low efficiency can be this effect.

G. Mellema

2003-01-01T23:59:59.000Z

171

Momentum compaction and phase slip factor  

SciTech Connect

Section 2.3.11 of the Handbook of Accelerator Physics and Engineering on Landau damping is updated. The slip factor and its higher orders are given in terms of the various orders of the momentum compaction. With the aid of a simplified FODO lattice, formulas are given for the alteration of the lower orders of the momentum compaction by various higher multipole magnets. The transition to isochronicity is next demonstrated. Formulas are given for the extraction of the first three orders of the slip factor from the measurement of the synchrotron tune while changing the rf frequency. Finally bunch-length compression experiments in semi-isochronous rings are reported.

Ng, K.Y.; /Fermilab

2010-10-01T23:59:59.000Z

172

Remote vacuum compaction of compressible hazardous waste  

DOE Patents (OSTI)

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

1996-12-31T23:59:59.000Z

173

Remote vacuum compaction of compressible hazardous waste  

DOE Patents (OSTI)

A system for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

Coyne, Martin J. (Pittsburgh, PA); Fiscus, Gregory M. (McMurray, PA); Sammel, Alfred G. (Pittsburgh, PA)

1998-01-01T23:59:59.000Z

174

Remote vacuum compaction of compressible hazardous waste  

DOE Patents (OSTI)

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut. 8 figs.

Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

1998-10-06T23:59:59.000Z

175

FODO-Supercell Based Compact Ring Design with Tunable Momentum Compaction and Optimized Dynamic Aperture  

Science Conference Proceedings (OSTI)

A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and predamping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

Sun, Yipeng; /SLAC

2012-05-03T23:59:59.000Z

176

FODO-Supercell Based Compact Ring Design with Tunable Momentum Compaction and Optimized Dynamic Aperture  

Science Conference Proceedings (OSTI)

A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and pre-damping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

Sun, Yipeng; /SLAC

2012-05-11T23:59:59.000Z

177

New Jersey | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

July 1, 2002 EA-1437: Finding of No Significant Impact Proposed National Compact Stellarator Equipment Princeton Plasma Physics Laboratory, New Jersey December 1, 1995 EA-1108:...

178

Interstate Mining Compact Commission (multi-state) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

You are here You are here Home » Interstate Mining Compact Commission (multi-state) Interstate Mining Compact Commission (multi-state) < Back Eligibility Commercial Construction Developer Industrial Investor-Owned Utility Local Government Municipal/Public Utility Rural Electric Cooperative Systems Integrator Tribal Government Utility Program Info Start Date 1970 State Alabama Program Type Safety and Operational Guidelines Siting and Permitting Provider Interstate Mining Compact Commission The Interstate Mining Compact is a multi-state governmental agency / organization that represents the natural resource and related environmental protection interests of its member states. Currently, 23 states are members to the compact, and 6 additional states are associate members. The compact

179

The impact of pollution on stellar evolution models  

E-Print Network (OSTI)

An approach is introduced for incorporating the concept of stellar pollution into stellar evolution models. The approach involves enhancing the metal content of the surface layers of stellar models. In addition, the surface layers of stars in the mass range of 0.5-2.0 Solar masses are mixed to an artificial depth motivated by observations of lithium abundance. The behavior of polluted stellar evolution models is explored assuming the pollution occurs after the star has left the fully convective pre main sequence phase. Stellar models polluted with a few Earth masses of iron are significantly hotter than stars of the same mass with an equivalent bulk metallicity. Polluted stellar evolution models can successfully reproduce the metal-rich, parent star tau Bootis and suggest a slightly lower mass than standard evolution models. Finally, the possibility that stars in the Hyades open cluster have accreted an average of 0.5 Earth masses of iron is explored. The results indicate that it is not possible to rule out stellar pollution on this scale from the scatter of Hyades stars on a color-magnitude diagram. The small amount of scatter in the observational data set does rule out pollution on the order of 1.5 Earth masses of iron. Pollution effects at the low level of 0.5 Earth masses of iron do not produce substantial changes in a star's evolution.

Aaron Dotter; Brian Chaboyer

2003-08-15T23:59:59.000Z

180

Compact Ultradense Objects in the Solar System  

E-Print Network (OSTI)

We describe properties and gravitational interactions of meteor-mass and greater compact ultra dense objects with nuclear density or greater (CUDO s). We discuss possible enclosure of CUDO s in comets, stability of these objects on impact with the Earth and Sun and show that the hypothesis of a CUDO core helps resolve issues challenging the understanding of a few selected cometary impacts.

J. Rafelski; Ch. Dietl; L. Labun

2013-03-19T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Energy Performance of Compact Fluorescent Lamps  

Science Conference Proceedings (OSTI)

This power quality (PQ) case study presents the results of tests performed at the Worcester Polytechnic Institute, in contract with the EPRI Power Electronics Applications Center (PEAC), to determine the light output, power consumption, efficiency, and power factor of off-the-shelf electronic and magnetic compact fluorescent lamps.

2003-12-31T23:59:59.000Z

182

Duke Power Compact PHOCUS Boresonic System Evaluation  

Science Conference Proceedings (OSTI)

Reliable and repeatable boresonic inspection of turbine rotors and generators is critical for accurately predicting remaining life. EPRI's boresonic system evaluation program provides utilities with insight into commercial boresonic system performance capabilities. This report, one in a series of boresonic system evaluations, features an assessment of Duke Power Company's compact PHOCUS boresonic inspection system.

1994-05-07T23:59:59.000Z

183

Compact upwind schemes on adaptive octrees  

Science Conference Proceedings (OSTI)

Compact high-order upwind schemes using reconstruction from cell-averages are derived for application with the compressible three-dimensional Navier-Stokes equations. An adaptive-octree mesh, combined with the Adams-Bashforth-Moulton family of predictor-corrector ... Keywords: Finite-volume, High-order, Navier-Stokes, Predictor-corrector

Scott M. Murman

2010-02-01T23:59:59.000Z

184

Compact range for variable-zone measurements  

DOE Patents (OSTI)

A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector. 2 figs.

Burnside, W.D.; Rudduck, R.C.; Yu, J.S.

1987-02-27T23:59:59.000Z

185

Compact range for variable-zone measurements  

DOE Patents (OSTI)

A compact range for testing antennas or radar targets includes a source for directing energy along a feedline toward a parabolic reflector. The reflected wave is a spherical wave with a radius dependent on the distance of the source from the focal point of the reflector.

Burnside, Walter D. (Columbus, OH); Rudduck, Roger C. (Columbus, OH); Yu, Jiunn S. (Albuquerque, NM)

1988-01-01T23:59:59.000Z

186

A Compact Lightweight Aerosol Spectrometer Probe (CLASP)  

Science Conference Proceedings (OSTI)

The Compact Lightweight Aerosol Spectrometer Probe (CLASP) is an optical particle spectrometer capable of measuring size-resolved particle concentrations in 16 user-defined size bins spanning diameters in the range 0.24 < D < 18.5 ?m at a rate of ...

Martin K. Hill; Barbara J. Brooks; Sarah J. Norris; Michael H. Smith; Ian M. Brooks; Gerrit de Leeuw

2008-11-01T23:59:59.000Z

187

Plasma-enhanced gasification of low-grade coals for compact power plants  

Science Conference Proceedings (OSTI)

A high temperature of a steam torch ensures an efficient gasification of low-grade coals, which is comparable to that of high-grade coals. Therefore, the coal gasification system energized by microwaves can serve as a moderately sized power plant due to its compact and lightweight design. This plasma power plant of low-grade coals would be useful in rural or sparsely populated areas without access to a national power grid.

Uhm, Han S. [Department of Electrophysics, Kwangwoon University, 447-1 Wolgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Hong, Yong C.; Shin, Dong H.; Lee, Bong J. [Convergence Plasma Research Center, National Fusion Research Institute, 113 Gwahangno, Yuseong-Gu, Daejeon 305-333 (Korea, Republic of)

2011-10-15T23:59:59.000Z

188

Southeast Interstate Low-Level Radioactive Waste Management Compact (multi-state)  

Energy.gov (U.S. Department of Energy (DOE))

The Southeast Interstate Low-Level Radioactive Waste Management Compact is administered by the Compact Commission. The Compact provides for rotating responsibility for the region's low-level...

189

Federal Energy Management Program: Energy Cost Calculator for Compact  

NLE Websites -- All DOE Office Websites (Extended Search)

Compact Fluorescent Lamps to someone by E-mail Compact Fluorescent Lamps to someone by E-mail Share Federal Energy Management Program: Energy Cost Calculator for Compact Fluorescent Lamps on Facebook Tweet about Federal Energy Management Program: Energy Cost Calculator for Compact Fluorescent Lamps on Twitter Bookmark Federal Energy Management Program: Energy Cost Calculator for Compact Fluorescent Lamps on Google Bookmark Federal Energy Management Program: Energy Cost Calculator for Compact Fluorescent Lamps on Delicious Rank Federal Energy Management Program: Energy Cost Calculator for Compact Fluorescent Lamps on Digg Find More places to share Federal Energy Management Program: Energy Cost Calculator for Compact Fluorescent Lamps on AddThis.com... Energy-Efficient Products Federal Requirements Covered Product Categories

190

Classification of linearly compact simple Jordan and generalized Poisson superalgebras  

E-Print Network (OSTI)

We classify all linearly compact simple Jordan superalgebras over an algebraically closed field of characteristic zero. As a corollary, we deduce the classification of all linearly compact unital simple generalized Poisson superalgebras.

Nicoletta Cantarini; Victor G. Kac; To Ernest; Borisovich Vinberg

2006-01-01T23:59:59.000Z

191

The pressure confined wind of the massive and compact superstar cluster M82-A1  

E-Print Network (OSTI)

The observed parameters of the young superstar cluster M82-A1 and its associated compact HII region are here shown to indicate a low heating efficiency or immediate loss, through radiative cooling, of a large fraction of the energy inserted by stellar winds and supernovae during the early evolution of the cluster. This implies a bimodal hydrodynamic solution which leads to a reduced mass deposition rate into the ISM, with a much reduced outflow velocity. Furthermore, to match the observed parameters of the HII region associated to M82-A1, the resultant star cluster wind is here shown to ought to be confined by a high pressure interstellar medium. The cluster wind parameters, as well as the location of the reverse shock, its cooling length and the radius of the standing outer HII region are derived analytically. All of these properties are then confirmed with a semi-analytical integration of the flow equations, which provides us also with the run of the hydrodynamic variables as a function of radius. The impact of the results is discussed and extended to other massive and young superstar clusters surrounded by a compact HII region.

Sergiy Silich; Guillermo Tenorio-Tagle; Casiana Munoz-Tunon

2007-07-18T23:59:59.000Z

192

Physicist Zoe Martin's fusion quest: a stellar future  

NLE Websites -- All DOE Office Websites (Extended Search)

Zoe Martin's fusion quest: a stellar future Zoe Martin's fusion quest: a stellar future Physicist Zoe Martin's fusion quest: a stellar future From revealing radiation hydrodynamics to creating energy, physics student pursues science's boundaries. August 27, 2013 Zoe Martin's fusion quest: a stellar future From revealing radiation hydrodynamics to creating energy, physics student pursues science's boundaries. She also pursues gravity-defying dance in her spare time. Martin said her mentor, physicist Leslie Sherrill, takes the time to explain and teaches her relevant and applicable science-and she's helping her get published, a rare but career-changing feat for an undergrad. » Return to homepage From revealing radiation hydrodynamics to creating energy, physics student pursues science's boundaries Today, internships are a valuable career launching tool; but many college

193

Cape Light Compact - Commercial, Industrial and Municipal Buildings...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Industrial and Municipal Buildings Energy Efficiency Rebate Program Cape Light Compact - Commercial, Industrial and Municipal Buildings Energy Efficiency Rebate Program...

194

Preliminary Investigation into the Effect of Green Compact ...  

Science Conference Proceedings (OSTI)

May 1, 2007 ... Preliminary Investigation into the Effect of Green Compact Microstructural Design on the Density of Combustion Synthesized Aluminide ...

195

Application of two-time methods in stellar pulsations  

Science Conference Proceedings (OSTI)

The method of two-time expansions is extended to include the effects of the outer, non-adiabatic layers in stellar pulsation. The evolution of pulsating stellar models can be examined, including the approach to limit cycle behavior. The method is demonstrated by a calculation of the eigenvectors for a ..beta.. Cepheid model. It is argued that the method is promising as a practical tool for treating the approach to limiting oscillations, as well as resonant and multimode behavior.

Pesnell, W.D.; Regev, O.; Buchler, J.R.

1982-07-28T23:59:59.000Z

196

The history and development of nonlinear stellar pulsation codes  

SciTech Connect

This review is limited to the history and development of nonlinear stellar pulsation codes and methods. The narrative includes examples of practical interest in the application of these numerical methods to problems in stellar pulsation such as Cepheid mass discrepancy, the delineation of the RR Lyrae instability strip, and the question of the development of double-mode pulsation as observed in Cepheids, RR Lyrae and other variable stars. 15 refs.

Davis, C.G.

1987-01-01T23:59:59.000Z

197

Review: Sensor systems for measuring soil compaction: Review and analysis  

Science Conference Proceedings (OSTI)

Spatially variable soil compaction often causes inconsistent growing conditions in many fields. Various soil compaction sensor systems have been deployed to obtain georeferenced maps of certain state and behavioral properties (e.g., soil strength, water ... Keywords: Air permeability, Penetrometer, Sensor fusion, Soil compaction, Soil mechanical resistance, Soil mechanics, Water content

A. Hemmat; V. I. Adamchuk

2008-10-01T23:59:59.000Z

198

THE MERGER HISTORY, ACTIVE GALACTIC NUCLEUS, AND DWARF GALAXIES OF HICKSON COMPACT GROUP 59  

Science Conference Proceedings (OSTI)

Compact group galaxies often appear unaffected by their unusually dense environment. Closer examination can, however, reveal the subtle, cumulative effects of multiple galaxy interactions. Hickson Compact Group (HCG) 59 is an excellent example of this situation. We present a photometric study of this group in the optical (Hubble Space Telescope), infrared (Spitzer), and X-ray (Chandra) regimes aimed at characterizing the star formation and nuclear activity in its constituent galaxies and intra-group medium. We associate five dwarf galaxies with the group and update the velocity dispersion, leading to an increase in the dynamical mass of the group of up to a factor of 10 (to 2.8 Multiplication-Sign 10{sup 13} M{sub Sun }), and a subsequent revision of its evolutionary stage. Star formation is proceeding at a level consistent with the morphological types of the four main galaxies, of which two are star-forming and the other are two quiescent. Unlike in some other compact groups, star-forming complexes across HCG 59 closely follow mass-radius scaling relations typical of nearby galaxies. In contrast, the ancient globular cluster populations in galaxies HCG 59A and B show intriguing irregularities, and two extragalactic H II regions are found just west of B. We age-date a faint stellar stream in the intra-group medium at {approx}1 Gyr to examine recent interactions. We detect a likely low-luminosity active galactic nucleus in HCG 59A by its {approx}10{sup 40} erg s{sup -1} X-ray emission; the active nucleus rather than star formation can account for the UV+IR spectral energy distribution. We discuss the implications of our findings in the context of galaxy evolution in dense environments.

Konstantopoulos, I. S.; Charlton, J. C.; Brandt, W. N.; Eracleous, M.; Gronwall, C. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Gallagher, S. C.; Fedotov, K.; Hill, A. R. [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada); Durrell, P. R. [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States); Tzanavaris, P.; Hornschemeier, A. E. [Laboratory for X-ray Astrophysics, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Zabludoff, A. I. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Maier, M. L. [Gemini Observatory, Casilla 603, Colina el Pino S/N, La Serena (Chile); Elmegreen, D. M. [Department of Physics and Astronomy, Vassar College, Poughkeepsie, NY 12604 (United States); Johnson, K. E.; Walker, L. M. [Department of Astronomy, University of Virginia, P. O. Box 400325, Charlottesville, VA 22904 (United States); Maybhate, A. [Space Telescope Science Institute, Baltimore, MD (United States); English, J. [University of Manitoba, Winnipeg, MN (Canada); Mulchaey, J. S., E-mail: iraklis@astro.psu.edu [Carnegie Observatories, Pasadena, CA 91101 (United States)

2012-01-20T23:59:59.000Z

199

Compact fast analyzer of rotary cuvette type  

DOE Patents (OSTI)

A compact fast analyzer of the rotary cuvette type is provided for simultaneously determining concentrations in a multiplicity of discrete samples using either absorbance or fluorescence measurement techniques. A rigid, generally rectangular frame defines optical passageways for the absorbance and fluorescence measurement systems. The frame also serves as a mounting structure for various optical components as well as for the cuvette rotor mount and drive system. A single light source and photodetector are used in making both absorbance and fluorescence measurements. Rotor removal and insertion are facilitated by a swing-out drive motor and rotor mount. BACKGROUND OF THE INVENTION The invention relates generally to concentration measuring instruments and more specifically to a compact fast analyzer of the rotary cuvette type which is suitable for making either absorbance or fluorescence measurements. It was made in the course of, or under, a contract with the U.S. Atomic Energy Commission.

Thacker, Louis H. (Knoxville, TN)

1976-01-01T23:59:59.000Z

200

A compact high voltage pulse generator  

SciTech Connect

A compact, easily transportable, pulse generator has been developed for a variety of applications that require a pulse duration in the range of 1 {mu} sec., voltages from 150 to 300 KV and current levels from 2,000 to 3,000 amps. The generator has a simple cylindrical configuration and modular construction to facilitate assembly and service. The generator may be operated single-pulse or repetitively at pulse repetition rates to 50 Hz in a burst mode.

Rohwein, G.J.; Babcock, S.R.

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

THE COUNCIL OF STATE GOVERNMENTS THE ELECTRIC TRANSMISSION LINE SITING COMPACT  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

COUNCIL OF STATE GOVERNMENTS COUNCIL OF STATE GOVERNMENTS THE ELECTRIC TRANSMISSION LINE SITING COMPACT LEGISLATIVE BRIEFING Background and Summary Background and Need The siting of interstate transmission lines has long been a problem that has vexed both states and the federal government. With the expected growth in electricity demand, coupled with the need to bring renewable energy to market and the necessity to enhance and secure the nation's energy infrastructure, the need for added transmission capacity has never been more apparent. National need and parochial interests, however, often do not align and have led to an underdeveloped and overstressed electricity transmission system.

202

Compact x-ray source and panel  

SciTech Connect

A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

203

The Size of Compact Extra Dimensions from Blackbody Radiation Laws  

E-Print Network (OSTI)

In this work we generalize the Stefan-Boltzmann and Wien's displacement laws for a D-dimensional spacetime composed by 4 non-compact dimensions and D-4 compact dimensions. The electromagnetic field is assumed to pervade all compact and non-compact dimensions. In particular, the total radiated power becomes R(T) = \\sigma_B T^4 + \\sigma_D (a) T^D, where a is the size of compact extra dimensions. For D=10, predicted from String Theory, and D=11, from M-Theory, the outcomes agree with available experimental data for a as high as 2 x 10^{-7} m.

Ramaton Ramos; Henrique Boschi-Filho

2011-11-10T23:59:59.000Z

204

The Size of Compact Extra Dimensions from Blackbody Radiation Laws  

E-Print Network (OSTI)

In this work we generalize the Stefan-Boltzmann and Wien's displacement laws for a D-dimensional spacetime composed by 4 non-compact dimensions and D-4 compact dimensions. The electromagnetic field is assumed to pervade all compact and non-compact dimensions. In particular, the total radiated power becomes R(T) = \\sigma_B T^4 + \\sigma_D (a) T^D, where a is the size of compact extra dimensions. For D=10, predicted from String Theory, and D=11, from M-Theory, the outcomes agree with available experimental data for a as high as 2 x 10^{-7} m.

Ramos, Ramaton

2011-01-01T23:59:59.000Z

205

Compact Dielectric Wall Accelerator Development For Intensity Modulated Proton Therapy And Homeland Security Applications  

Science Conference Proceedings (OSTI)

Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory. The DWA accelerator uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. Its high electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The DWA concept can be applied to accelerate charge particle beams with any charge to mass ratio and energy. Based on the DWA system, a novel compact proton therapy accelerator is being developed. This proton therapy system will produce individual pulses that can be varied in intensity, energy and spot width. The system will be capable of being sited in a conventional linac vault and provide intensity modulated rotational therapy. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, SiC photoconductive switches and compact proton sources. Applications of the DWA accelerator to problems in homeland security will also be discussed.

Chen, Y -; Caporaso, G J; Guethlein, G; Sampayan, S; Akana, G; Anaya, R; Blackfield, D; Cook, E; Falabella, S; Gower, E; Harris, J; Hawkins, S; Hickman, B; Holmes, C; Horner, A; Nelson, S; Paul, A; Pearson, D; Poole, B; Richardson, R; Sanders, D; Stanley, J; Sullivan, J; Wang, L; Watson, J; Weir, J

2009-06-17T23:59:59.000Z

206

Interstate Oil and Gas Conservation Compact (Maryland) | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Interstate Oil and Gas Conservation Compact (Maryland) Interstate Oil and Gas Conservation Compact (Maryland) Interstate Oil and Gas Conservation Compact (Maryland) < Back Eligibility Commercial Construction Fed. Government Industrial Institutional Investor-Owned Utility Local Government Municipal/Public Utility Retail Supplier Rural Electric Cooperative Systems Integrator Tribal Government Utility Program Info State Maryland Program Type Siting and Permitting Provider Interstate Oil and Gas Compact Commission This legislation authorizes the State to join the Interstate Compact for the Conservation of Oil and Gas. The Compact is an agreement that has been entered into by 30 oil- and gas-producing states, as well as eight associate states and 10 international affiliates (including seven Canadian provinces). Members participate in the Interstate Oil and Gas Compact

207

EVIDENCE FOR TWO DISTINCT STELLAR INITIAL MASS FUNCTIONS  

Science Conference Proceedings (OSTI)

We present velocity dispersion measurements of 20 Local Group stellar clusters (7 < log(age [yr]) <10.2) from integrated light spectra and examine the evolution of the stellar mass-to-light ratio, Y{sub *}. We find that the clusters deviate from the evolutionary tracks corresponding to simple stellar populations drawn from standard stellar initial mass functions (IMFs). The nature of this failure, in which Y{sub *} is at first underestimated and then overestimated with age, invalidates potential simple solutions involving a rescaling of either the measured masses or modeled luminosities. A range of possible shortcomings in the straightforward interpretation of the data, including subtleties arising from cluster dynamical evolution on the present-day stellar mass functions and from stellar binarity on the measured velocity dispersions, do not materially affect this conclusion given the current understanding of those effects. Independent of further conjectures regarding the origin of this problem, this result highlights a basic failing of our understanding of the integrated stellar populations of these systems. We propose the existence of two distinct IMFs, one primarily, but not exclusively, valid for older, metal-poor clusters and the other for primarily, but not exclusively, younger, metal-rich clusters. The young (log(age [yr]) < 9.5) clusters are well described by a bottom-heavy IMF, such as a Salpeter IMF, while the older clusters are better described by a top-heavy IMF, such as a light-weighted Kroupa IMF, although neither of these specific forms is a unique solution. The sample is small, with the findings currently depending on the results for four key clusters, but doubling the sample is within reach.

Zaritsky, Dennis [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Colucci, Janet E.; Bernstein, Rebecca A. [Department of Astronomy and Astrophysics, 1156 High Street, UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Pessev, Peter M. [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile); Chandar, Rupali, E-mail: dzaritsky@as.arizona.edu [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States)

2012-12-20T23:59:59.000Z

208

Accretion-Powered Stellar Winds III: Spin Equilibrium Solutions  

E-Print Network (OSTI)

We compare the stellar wind torque calculated in a previous work (Paper II) to the spin-up and spin-down torques expected to arise from the magnetic interaction between a slowly rotating ($\\sim 10$% of breakup) pre-main-sequence star and its accretion disk. This analysis demonstrates that stellar winds can carry off orders of magnitude more angular momentum than can be transferred to the disk, provided that the mass outflow rates are greater than the solar wind. Thus, the equilibrium spin state is simply characterized by a balance between the angular momentum deposited by accretion and that extracted by a stellar wind. We derive a semi-analytic formula for predicting the equilibrium spin rate as a function only of the ratio of $\\dot M_{\\rm w} / \\dot M_{\\rm a}$ and a dimensionless magnetization parameter, $\\Psi \\equiv B_*^2 R_*^2 (\\dot M_{\\rm a} v_{\\rm esc})^{-1}$, where $\\dot M_{\\rm w}$ is the stellar wind mass outflow rate, $\\dot M_{\\rm a}$ the accretion rate, $B_*$ the stellar surface magnetic field strength, $R_*$ the stellar radius, and $v_{\\rm esc}$ the surface escape speed. For parameters typical of accreting pre-main-sequence stars, this explains spin rates of $\\sim 10$% of breakup speed for $\\dot M_{\\rm w} / \\dot M_{\\rm a} \\sim 0.1$. Finally, the assumption that the stellar wind is driven by a fraction of the accretion power leads to an upper limit to the mass flow ratio of $\\dot M_{\\rm w} / \\dot M_{\\rm a} \\la 0.6$.

Sean Matt; Ralph E. Pudritz

2008-01-02T23:59:59.000Z

209

Accretion-powered Stellar Winds as a Solution to the Stellar Angular Momentum Problem  

E-Print Network (OSTI)

We compare the angular momentum extracted by a wind from a pre-main-sequence star to the torques arising from the interaction between the star and its Keplerian accretion disk. We find that the wind alone can counteract the spin-up torque from mass accretion, solving the mystery of why accreting pre-main-sequence stars are observed to spin at less than 10% of break-up speed, provided that the mass outflow rate in the stellar winds is ~10% of the accretion rate. We suggest that such massive winds will be driven by some fraction $\\epsilon$ of the accretion power. For observationally constrained typical parameters of classical T-Tauri stars, $\\epsilon$ needs to be between a few and a few tens of percent. In this scenario, efficient braking of the star will terminate simultaneously with accretion, as is usually assumed to explain the rotation velocities of stars in young clusters.

Sean Matt; Ralph E. Pudritz

2005-10-03T23:59:59.000Z

210

Stellar pollution and [Fe/H] in the Hyades  

E-Print Network (OSTI)

The Hyades open cluster presents a unique laboratory for planet formation and stellar pollution studies because all of the stars have essentially the same age and were born from the same cloud of gas. Furthermore, with an age of roughly 650 Myr most of the intermediate and low mass stars are on the main sequence. Given these assumptions, the accretion of metal rich material onto the surface of a star during and shortly after the formation of planetary systems should be evident via the enhanced metallicity of the star. Building on previous work, stellar evolution models which include the effects of stellar pollution are applied to the Hyades. The results of several Monte Carlo simulations, in which the amount of accreted material is drawn at random from a Gaussian distribution with standard deviation equal to half the mean, are presented. An effective temperature-[Fe/H] relation is produced and compared to recent observations. The theoretical predictions presented in this letter will be useful in future searches for evidence of stellar pollution due to planet formation. It is concluded that stellar pollution effects at the mean level of >=2 Earth masses of iron are ruled out by current observational data.

Aaron Dotter; Brian Chaboyer

2003-08-15T23:59:59.000Z

211

Thermonuclear inverse magnetic pumping power cycle for stellarator reactor  

DOE Patents (OSTI)

The plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energy is obtained from this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure. The cycle can be made self-sustaining by operating a system of two stellarator reactors in tandem. Part of the energy derived from the expansion phase of a first stellarator reactor is used to compress the plasma in a second stellarator reactor. 9 figs., 4 tabs.

Ho, D.D.M.; Kulsrud, R.M.

1986-09-25T23:59:59.000Z

212

Heat capacity and compactness of denatured proteins  

E-Print Network (OSTI)

One of the striking results of protein thermodynamics is that the heat capacity change upon denaturation is large and positive. This change is generally ascribed to the exposure of non-polar groups to water on denaturation, in analogy to the large heat capacity change for the transfer of small non-polar molecules from hydrocarbons to water. Calculations of the heat capacity based on the exposed surface area of the completely unfolded denatured state give good agreement with experimental data. This result is difficult to reconcile with evidence that the heat denatured state in the absence of denaturants is reasonably compact. In this work, sample conformations for the denatured state of truncated CI2 are obtained by use of an effective energy function for proteins in solution. The energy function gives denatured conformations that are compact with radii of gyration that are slightly larger than that of the native state. The model is used to estimate the heat capacity, as well as that of the native state, at 300 and 350 K via finite enthalpy differences. The calculations show that the heat capacity of denaturation can have large positive contributions from non-covalent intraprotein interactions because these interactions change more with temperature in non-native conformations than in the native state. Including this contribution, which has been neglected in empirical surface area models, leads to heat capacities of unfolding for compact denatured states that are consistent with the experimental heat capacity data. Estimates of the stability curve of CI2 made with the effective energy function support the present model. # 1999 Elsevier Science B.V. All rights reserved.

Themis Lazaridis; Martin Karplus

1999-01-01T23:59:59.000Z

213

Proposal to produce large compact toroids  

SciTech Connect

Relatively large, hot compact toroids might be produced in the annular space between two concentric one-turn coils. With currents in the two coils flowing in the same direction, the magnetic fields on each side of the plasma are in opposite directions. As the fields are raised, the plasma ring is heated and compressed radially towards the center of the annular space. By the addition of two sets of auxiliary coils, the plasma ring can be ejected out one end of the two-coil system into a long axial magnetic field.

Phillips, J.A.

1981-03-01T23:59:59.000Z

214

Survivability of Electronic Compact Fluorescent Lamps  

Science Conference Proceedings (OSTI)

This EPRI Technical Report addresses the fastest growing energy efficient light source8212the electronic compact fluorescent lamp (CFL). Because some of the failure modes for screw-in CFLs are different than those for plug-in CFLs, a cursory review of the difference between the two types of CFLs is provided in the first part of Chapter 2. A broad definition of shortened-life CFLs is also provided in Chapter 2 with an emphasis on revisiting mortality curves, the 10-minute lamp start, other relevant defini...

2008-03-31T23:59:59.000Z

215

Galactic Coronae in the Intracluster Environment: Semi-confined Stellar-feedback-driven Outflows  

E-Print Network (OSTI)

Recently X-ray observations have shown the common presence of compact galactic coronae around intermediate-mass spheroid galaxies embedded in the intracluster/intragroup medium (ICM). We conduct 2-D hydrodynamic simulations to study the quasi-steady-state properties of such coronae as the natural products of the ongoing distributed stellar feedback semi-confined by the thermal and ram pressures of the ICM. We find that the temperature of a simulated corona depends primarily on the specific energy of the feedback, consistent with the lack of the correlation between the observed hot gas temperature and K-band luminosity of galaxies. The simulated coronae typically represent subsonic outflows, chiefly because of the semi-confinement. As a result, the hot gas density increases with the ICM thermal pressure. The ram pressure, on the other hand, chiefly affects the size and lopsidedness of the coronae. The density increase could lead to the compression of cool gas clouds, if present, and hence the formation of star...

Lu, Zhankui

2010-01-01T23:59:59.000Z

216

Dynamical properties of nuclear and stellar matter and the symmetry energy  

Science Conference Proceedings (OSTI)

The effects of density dependence of the symmetry energy on the collective modes and dynamical instabilities of cold and warm nuclear and stellar matter are studied in the framework of relativistic mean-field hadron models. The existence of the collective isovector and possibly an isoscalar collective mode above saturation density is discussed. It is shown that soft equations of state do not allow for a high-density isoscalar collective mode; however, if the symmetry energy is hard enough, an isovector mode will not disappear at high densities. The crust-core transition density and pressure are obtained as a function of temperature for {beta}-equilibrium matter with and without neutrino trapping. Estimations of the size of the clusters formed in the nonhomogeneous phase, as well as the corresponding growth rates and distillation effect, are made. It is shown that cluster sizes increase with temperature, that the distillation effect close to the inner edge of the crust-core transition is very sensitive to the symmetry energy, and that, within a dynamical instability calculation, the pasta phase exists in warm compact stars up to 10-12 MeV.

Pais, Helena; Santos, Alexandre; Brito, Lucilia; Providencia, Constanca [Centro de Fisica Computacional, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

2010-08-15T23:59:59.000Z

217

A HIGH STELLAR OBLIQUITY IN THE WASP-7 EXOPLANETARY SYSTEM  

Science Conference Proceedings (OSTI)

We measure a tilt of 86 Degree-Sign {+-} 6 Degree-Sign between the sky projections of the rotation axis of the WASP-7 star and the orbital axis of its close-in giant planet. This measurement is based on observations of the Rossiter-McLaughlin (RM) effect with the Planet Finder Spectrograph on the Magellan II telescope. The result conforms with the previously noted pattern among hot-Jupiter hosts, namely, that the hosts lacking thick convective envelopes have high obliquities. Because the planet's trajectory crosses a wide range of stellar latitudes, observations of the RM effect can in principle reveal the stellar differential rotation profile; however, with the present data the signal of differential rotation could not be detected. The host star is found to exhibit radial-velocity noise ({sup s}tellar jitter{sup )} with an amplitude of Almost-Equal-To 30 m s{sup -1} over a timescale of days.

Albrecht, Simon; Winn, Joshua N.; Hirano, Teruyuki [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Butler, R. Paul [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B. [The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Wittenmyer, Robert A. [Department of Astrophysics, School of Physics, University of NSW, 2052 (Australia)

2012-01-10T23:59:59.000Z

218

Thermodynamics of magnetized binary compact objects  

Science Conference Proceedings (OSTI)

Binary systems of compact objects with electromagnetic field are modeled by helically symmetric Einstein-Maxwell spacetimes with charged and magnetized perfect fluids. Previously derived thermodynamic laws for helically symmetric perfect-fluid spacetimes are extended to include the electromagnetic fields, and electric currents and charges; the first law is written as a relation between the change in the asymptotic Noether charge {delta}Q and the changes in the area and electric charge of black holes, and in the vorticity, baryon rest mass, entropy, charge and magnetic flux of the magnetized fluid. Using the conservation laws of the circulation of magnetized flow found by Bekenstein and Oron for the ideal magnetohydrodynamic fluid, and also for the flow with zero conducting current, we show that, for nearby equilibria that conserve the quantities mentioned above, the relation {delta}Q=0 is satisfied. We also discuss a formulation for computing numerical solutions of magnetized binary compact objects in equilibrium with emphasis on a first integral of the ideal magnetohydrodynamic-Euler equation.

Uryu, Koji [Department of Physics, University of the Ryukyus, Senbaru, Nishihara, Okinawa 903-0213 (Japan); Gourgoulhon, Eric [Laboratoire Univers et Theories, UMR 8102 du CNRS, Observatoire de Paris, Universite Paris Diderot, F-92190 Meudon (France); Markakis, Charalampos [Department of Physics, University of Wisconsin-Milwaukee, Post Office Box 413, Milwaukee, Wisconsin 53201 (United States)

2010-11-15T23:59:59.000Z

219

Magnetic Fields in High-Density Stellar Matter  

E-Print Network (OSTI)

I briefly review some aspects of the effect of magnetic fields in the high density regime relevant to neutron stars, focusing mainly on compact star structure and composition, superconductivity, combustion processes, and gamma ray bursts.

German Lugones

2005-04-20T23:59:59.000Z

220

Northwest Interstate Compact on Low-Level Radioactive Waste Management  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Northwest Interstate Compact on Low-Level Radioactive Waste Northwest Interstate Compact on Low-Level Radioactive Waste Management (Multiple States) Northwest Interstate Compact on Low-Level Radioactive Waste Management (Multiple States) < Back Eligibility Utility Fed. Government Commercial Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Rural Electric Cooperative Tribal Government Institutional Nonprofit Program Info Start Date 1981 State Alaska Program Type Siting and Permitting Provider Northwest Interstate Compact The Northwest Interstate Compact on Low-Level Radioactive Waste Management, enacted in 1981, was ratified by Congress in 1985. The Compact is a cooperative effort of the party states to protect their citizens, and maintain and enhance economic viability, while sharing the responsibilities

Note: This page contains sample records for the topic "national compact stellarator" 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

Atlantic Interstate Low-Level Radioactive Waste Management Compact (South  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Atlantic Interstate Low-Level Radioactive Waste Management Compact Atlantic Interstate Low-Level Radioactive Waste Management Compact (South Carolina) Atlantic Interstate Low-Level Radioactive Waste Management Compact (South Carolina) < Back Eligibility Utility Commercial Agricultural Investor-Owned Utility Industrial Construction Municipal/Public Utility Local Government Installer/Contractor Rural Electric Cooperative Tribal Government Program Info Start Date 1986 State South Carolina Program Type Environmental Regulations Siting and Permitting Provider Atlantic Compact Commission The Atlantic (Northeast) Interstate Low-Level Radioactive Waste Management Compact is a cooperative effort to plan, regulate, and administer the disposal of low-level radioactive waste in the region. The states of Connecticut, New Jersey, and South Carolina are party to this compact

222

Sabine River Compact (Multiple States) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Sabine River Compact (Multiple States) Sabine River Compact (Multiple States) Sabine River Compact (Multiple States) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Residential Installer/Contractor Rural Electric Cooperative Tribal Government Low-Income Residential Schools Retail Supplier Institutional Multi-Family Residential Systems Integrator Fuel Distributor Nonprofit General Public/Consumer Transportation Savings Category Water Buying & Making Electricity Home Weatherization Program Info State Texas Program Type Siting and Permitting Provider Sabine River Compact Commission The Sabine River Compact Commission administers the Sabine River Compact to ensure that Texas receives its equitable share of quality water from the

223

Bounce-averaged Fokker-Planck code for stellarator transport  

Science Conference Proceedings (OSTI)

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

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

1985-07-01T23:59:59.000Z

224

DOUBLE COMPACT OBJECTS. I. THE SIGNIFICANCE OF THE COMMON ENVELOPE ON MERGER RATES  

Science Conference Proceedings (OSTI)

The last decade of observational and theoretical developments in stellar and binary evolution provides an opportunity to incorporate major improvements to the predictions from population synthesis models. We compute the Galactic merger rates for NS-NS, BH-NS, and BH-BH mergers with the StarTrack code. The most important revisions include updated wind mass-loss rates (allowing for stellar-mass black holes up to 80 M {sub Sun }), a realistic treatment of the common envelope phase (a process that can affect merger rates by 2-3 orders of magnitude), and a qualitatively new neutron star/black hole mass distribution (consistent with the observed {sup m}ass gap{sup )}. Our findings include the following. (1) The binding energy of the envelope plays a pivotal role in determining whether a binary merges within a Hubble time. (2) Our description of natal kicks from supernovae plays an important role, especially for the formation of BH-BH systems. (3) The masses of BH-BH systems can be substantially increased in the case of low metallicities or weak winds. (4) Certain combinations of parameters underpredict the Galactic NS-NS merger rate and can be ruled out. (5) Models incorporating delayed supernovae do not agree with the observed NS/BH 'mass gap', in accordance with our previous work. This is the first in a series of three papers. The second paper will study the merger rates of double compact objects as a function of redshift, star formation rate, and metallicity. In the third paper, we will present the detection rates for gravitational-wave observatories, using up-to-date signal waveforms and sensitivity curves.

Dominik, Michal; Belczynski, Krzysztof; Bulik, Tomasz [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Fryer, Christopher [CCS-2, MSD409, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Holz, Daniel E. [Enrico Fermi Institute, Department of Physics, and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Berti, Emanuele [Department of Physics and Astronomy, University of Mississippi, University, MS 38677 (United States); Mandel, Ilya [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); O'Shaughnessy, Richard [Center for Gravitation and Cosmology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States)

2012-11-01T23:59:59.000Z

225

Western Interstate Nuclear Compact State Nuclear Policy (Multiple States) |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Western Interstate Nuclear Compact State Nuclear Policy (Multiple Western Interstate Nuclear Compact State Nuclear Policy (Multiple States) Western Interstate Nuclear Compact State Nuclear Policy (Multiple States) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor Industrial Institutional Investor-Owned Utility Local Government Municipal/Public Utility Nonprofit Retail Supplier Rural Electric Cooperative State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Arizona Program Type Siting and Permitting Provider Western Interstate Energy Board Legislation authorizes states' entrance into the Western Interstate Nuclear Compact, which aims to undertake the cooperation of participating states in

226

Modeling Metal Powder Compaction Using Combined Finite and ...  

Science Conference Proceedings (OSTI)

Presentation Title, Modeling Metal Powder Compaction Using Combined Finite ... Optimization of Thermal Cycle for Rails with Respect to the Wear Resistance.

227

Nanograting-based compact vacuum ultraviolet spectrometer and ...  

Nanograting-based compact vacuum ultraviolet spectrometer and beam pro?ler for in situ characterization of high-order harmonic generation light sources

228

NIST Shows How to Make a Compact Frequency Comb in ...  

Science Conference Proceedings (OSTI)

NIST Shows How to Make a Compact Frequency Comb in Minutes Video Transcript. ... These resonators actually have a pretty wide range of uses. ...

2013-07-11T23:59:59.000Z

229

Interstate Oil and Gas Conservation Compact (Montana) | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Montana) Interstate Oil and Gas Conservation Compact (Montana) Eligibility Utility Commercial Investor-Owned Utility Industrial Construction MunicipalPublic Utility Rural Electric...

230

The ALCAN Compact Degasser: A through-Based Aluminum ...  

Science Conference Proceedings (OSTI)

Sep 1, 1996 ... The ALCAN Compact Degasser: A through-Based Aluminum Treatment Process. Part I: Metallurgical Principles and Performance by P. Waite ...

231

Effect of Powder Compact Holding Time on the Microstructure and ...  

Science Conference Proceedings (OSTI)

The microstructure and mechanical properties of Ti-6Al-4V alloy and the effects of powder compact holding time on them were investigated. The results showed ...

232

Dense Deposition of Nanocomposites by a Compact YAG Laser  

Science Conference Proceedings (OSTI)

Feb 1, 2002 ... Dense Deposition of Nanocomposites by a Compact YAG Laser by M. Senna and K. Hamada. Publisher: TMS. Product Format: PDF. Pages ...

233

Appalachian States Low-Level Radioactive Waste Compact (Maryland)  

Energy.gov (U.S. Department of Energy (DOE))

This legislation authorizes Maryland's entrance into the Appalachian States Low-Level Radioactive Waste Compact, which seeks to promote interstate cooperation for the proper management and disposal...

234

PF Coil System Comparisons for a Compact Ignition Device  

Science Conference Proceedings (OSTI)

The Compact Ignition Tokamak Program / Proceedings of the Seveth Topical Meeting on the Technology of Fusion Energy (Reno, Nevada, June 15–19, 1986)

R.D. Pillsbury; Jr.; J.H. Schultz; R.J. Thome

235

An Innovative Compact Heat Exchanger Solution for Aluminium Off ...  

Science Conference Proceedings (OSTI)

Presentation Title, An Innovative Compact Heat Exchanger Solution for Aluminium Off-Gas Cooling and Heat Recovery. Author(s), El Hani Bouhabila, Erling ...

236

Conservation potential of compact fluorescent lamps in India and Brazil  

SciTech Connect

We evaluate the conservation potential of compact fluorescent lamps (CFLs) for managing the rapidly increasing electrical energy and peak demand in India and Brazil. Using very conservative assumptions, we find that the cost of conserved energy using 16 W CFLs is 4 and 6 times less than the long range marginal cost of electricity for the two countries. The cost of avoided peak installed capacity is 6 and 9.5 times less than the cost of new installed capacity for India and Brazil. The analysis is undertaken from the three separate perspectives of the national economies, the consumers, and the utilities. We find that because residential electricity is subsidized, the consumers have little or no incentive to purchase and install the CFLs, unless they too are subsidized. However, the benefits of CFL installation to the utility are so large that subsidizing them is a paying proposition for the utility are so large that subsidizing them is a paying proposition for the utility in almost all cases. As an illustration of a gradual introduction strategy for CFLs, we calculate a scenario where national savings of the order of US $1.2 million per day for India and US $2.5 million per day for Brazil are reached in 10 years by a small and gradual transfer of subsidy from residential electricity to CFLs. We then explore the barriers to immediate large scale introduction of these lamps in the two countries. Specific technical and marketing problems are identified and discussed, which would require solution before such an introduction can be attempted. Lastly, we discuss the range of policy instruments, in addition to a subsidy scheme, that can be used for promoting the diffusion of these lamps in the domestic and commercial sector. 47 refs., 15 figs., 2 tabs.

Gadgil, A.; Martino Jannuzzi, G. de (Lawrence Berkeley Lab., CA (USA); Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia)

1989-07-01T23:59:59.000Z

237

Investigating spatial variation in the surface and atmosphere of Pluto through stellar occultations and PSF photometry  

E-Print Network (OSTI)

Stellar occultations provide a high-resolution view of a single chord through Pluto's atmosphere. This thesis presents three projects related to stellar occultation observations of Pluto. The first project concerns the ...

Zangari, Amanda Marie

2013-01-01T23:59:59.000Z

238

AN ASTROMETRIC SEARCH FOR A STELLAR COM COMPANION TO THE SUN  

E-Print Network (OSTI)

come- tary impacts and the Sun's motion perpendicular to theA STELLAR COMPANION TO THE SUN S. Perlmutter (PhD. Thesis)for a Stellar Companion to the Sun Saul Perlmutter Lawrence

Perlmutter, S.

2008-01-01T23:59:59.000Z

239

Buoyancy waves in Pluto's high atmosphere: Implications for stellar occultations  

E-Print Network (OSTI)

We apply scintillation theory to stellar signal fluctuations in the high-resolution, high signal/noise, dual-wavelength data from the MMT observation of the 2007 March 18 occultation of P445.3 by Pluto. A well-defined high ...

Person, Michael J.

240

KEPLER INPUT CATALOG: PHOTOMETRIC CALIBRATION AND STELLAR CLASSIFICATION  

Science Conference Proceedings (OSTI)

We describe the photometric calibration and stellar classification methods used by the Stellar Classification Project to produce the Kepler Input Catalog (KIC). The KIC is a catalog containing photometric and physical data for sources in the Kepler mission field of view; it is used by the mission to select optimal targets. Four of the visible-light (g, r, i, z) magnitudes used in the KIC are tied to Sloan Digital Sky Survey magnitudes; the fifth (D51) is an AB magnitude calibrated to be consistent with Castelli and Kurucz (CK) model atmosphere fluxes. We derived atmospheric extinction corrections from hourly observations of secondary standard fields within the Kepler field of view. For these filters and extinction estimates, repeatability of absolute photometry for stars brighter than magnitude 15 is typically 2%. We estimated stellar parameters {l_brace}T{sub eff}, log (g), log (Z), E{sub B-V}{r_brace} using Bayesian posterior probability maximization to match observed colors to CK stellar atmosphere models. We applied Bayesian priors describing the distribution of solar-neighborhood stars in the color-magnitude diagram, in log (Z), and in height above the galactic plane. Several comparisons with samples of stars classified by other means indicate that for 4500 K {data archive.

Brown, Timothy M. [Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States); Latham, David W.; Esquerdo, Gilbert A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Everett, Mark E., E-mail: tbrown@lcogt.net, E-mail: latham@cfa.harvard.edu, E-mail: gesquerd@cfa.harvard.edu, E-mail: everett@noao.edu [National Optical Astronomy Observatories, Tucson, AZ 85721 (United States)

2011-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

The Stellar IMF as a Property of Turbulence  

E-Print Network (OSTI)

We propose to interpret the stellar IMF as a property of the turbulence in the star--forming gas. Gravitationally unstable density enhancements in the turbulent flow collapse and form stars. Their mass distribution can be derived analytically from the power spectrum of the turbulent flow and the isothermal shock jump conditions in the magnetized gas. For a power spectrum index \\beta=1.74, consistent with Larson's velocity dispersion--size relation as well as with new numerical and analytic results on supersonic turbulence, we obtain a power law mass distribution of dense cores with a slope equal to 3/(4-\\beta)=1.33, consistent with the slope of Salpeter's stellar IMF. Below one solar mass, the mass distribution flattens and turns around at a fraction of a solar mass, as observed for the stellar IMF in a number of stellar clusters, because only the densest cores are gravitationally unstable. The mass distribution at low masses is determined by the Log--Normal distribution of the gas density. The intermittent nature of this distribution is responsible for the generation of a significant number of collapsing cores of brown dwarf mass.

Paolo Padoan; Ake Nordlund

2004-11-16T23:59:59.000Z

242

Simulations of stellar convection with CO5BOLD  

Science Conference Proceedings (OSTI)

High-resolution images of the solar surface show a granulation pattern of hot rising and cooler downward-sinking material - the top of the deep-reaching solar convection zone. Convection plays a role for the thermal structure of the solar interior and ... Keywords: Numerical simulations, Radiation (magneto)hydrodynamics, Stellar surface convection

B. Freytag; M. Steffen; H. -G. Ludwig; S. Wedemeyer-Böhm; W. Schaffenberger; O. Steiner

2012-02-01T23:59:59.000Z

243

Life Cycles of Magnetic Fields in Stellar Evolution  

E-Print Network (OSTI)

This is a white paper submitted to the Stars and Stellar Evolution (SSE) Science Frontier Panel (SFP) of the NRC's Astronomy and Astrophysics 2010 Decadal Survey. The white paper is endorsed by the American Physical Society's (APS) Topical Group on Plasma Astrophysics (GPAP).

Uzdensky, D; Balbus, S; Blackman, E; Goodman, J; Medvedev, M; Spitkovsky, A; Stone, J

2009-01-01T23:59:59.000Z

244

Molecular Lines as Diagnostics of Solar and Stellar Magnetic Fields  

E-Print Network (OSTI)

Molecular Lines as Diagnostics of Solar and Stellar Magnetic Fields S.V. Berdyugina1, S.K. Solanki2 (Berdyugina et al. 2000; Berdyugina & Solanki 2001a). The synthetic Stokes profiles of various molecular and sunspot temperature. Introducing molecular lines into the inversion of sunspot spectra leads

Berdyugina, Svetlana

245

Compact reversed-field pinch reactors (CRFPR)  

Science Conference Proceedings (OSTI)

The unique confinement properties of the Reversed-Field Pinch (RFP) are exploited to examine physics and technical issues related to a compact, high-power-density fusion reactor. This resistive-coil, steady-state, toroidal device would use a dual-media power cycle driven by a fusion power core (FPC, i.e., plasma chamber, first wall, blanket, shield, and coils) with a power density and mass approaching values characteristic of pressurized-water fission rectors. A 1000-MWe(net) base case is selected from a comprehensive trade-off study to examine technological issues related to operating a high-power-density FPC. After describing the main physics and technology issues for this base-case reactor, directions for future study are suggested.

Krakowski, R.A.; Miller, R.L.; Bathke, C.G.; Hagenson, R.L.; Copenhaver, C.; Werley, K.A.

1986-01-01T23:59:59.000Z

246

Compact microwave ion source for industrial applications  

SciTech Connect

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

2012-02-15T23:59:59.000Z

247

Compact shell solitons in K field theories  

Science Conference Proceedings (OSTI)

Some models providing shell-shaped static solutions with compact support (compactons) in 3+1 and 4+1 dimensions are introduced, and the corresponding exact solutions are calculated analytically. These solutions turn out to be topological solitons and may be classified as maps S{sup 3}{yields}S{sup 3} and suspended Hopf maps, respectively. The Lagrangian of these models is given by a scalar field with a nonstandard kinetic term (K field) coupled to a pure Skyrme term restricted to S{sup 2}, rised to the appropriate power to avoid the Derrick scaling argument. Further, the existence of infinitely many exact shell solitons is explained using the generalized integrability approach. Finally, similar models allowing for nontopological compactons of the ball type in 3+1 dimensions are briefly discussed.

Adam, C.; Klimas, P.; Sanchez-Guillen, J. [Departamento de Fisica de Particulas, Universidad de Santiago and Instituto Galego de Fisica de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Wereszczynski, A. [Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark and Institute of Physics, Jagiellonian University, Reymonta 4, Krakow, 30-059 (Poland)

2009-10-15T23:59:59.000Z

248

A compact multichannel spectrometer for Thomson scattering  

Science Conference Proceedings (OSTI)

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15T23:59:59.000Z

249

Stirling Air Conditioner for Compact Cooling  

Science Conference Proceedings (OSTI)

BEETIT Project: Infinia is developing a compact air conditioner that uses an unconventional high efficient Stirling cycle system (vs. conventional vapor compression systems) to produce cool air that is energy efficient and does not rely on polluting refrigerants. The Stirling cycle system is a type of air conditioning system that uses a motor with a piston to remove heat to the outside atmosphere using a gas refrigerant. To date, Stirling systems have been expensive and have not had the right kind of heat exchanger to help cool air efficiently. Infinia is using chip cooling technology from the computer industry to make improvements to the heat exchanger and improve system performance. Infinia’s air conditioner uses helium gas as refrigerant, an environmentally benign gas that does not react with other chemicals and does not burn. Infinia’s improvements to the Stirling cycle system will enable the cost-effective mass production of high-efficiency air conditioners that use no polluting refrigerants.

None

2010-09-01T23:59:59.000Z

250

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents (OSTI)

The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

1996-01-01T23:59:59.000Z

251

Compact imaging spectrometer utilizing immersed gratings  

DOE Patents (OSTI)

A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

2007-07-03T23:59:59.000Z

252

Compact and highly efficient laser pump cavity  

SciTech Connect

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, Jim J. (Dublin, CA); Bass, Isaac L. (Castro Valley, CA); Zapata, Luis E. (Livermore, CA)

1999-01-01T23:59:59.000Z

253

Compact and highly efficient laser pump cavity  

SciTech Connect

A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

Chang, J.J.; Bass, I.L.; Zapata, L.E.

1999-11-02T23:59:59.000Z

254

A STELLAR MASS THRESHOLD FOR QUENCHING OF FIELD GALAXIES  

SciTech Connect

We demonstrate that dwarf galaxies (10{sup 7} < M{sub stellar} < 10{sup 9} M{sub Sun }, -12 > M{sub r} > -18) with no active star formation are extremely rare (<0.06%) in the field. Our sample is based on the NASA-Sloan Atlas which is a reanalysis of the Sloan Digital Sky Survey Data Release 8. We examine the relative number of quenched versus star-forming dwarf galaxies, defining quenched galaxies as having no H{alpha} emission (EW{sub H{alpha}} < 2 A) and a strong 4000 A break. The fraction of quenched dwarf galaxies decreases rapidly with increasing distance from a massive host, leveling off for distances beyond 1.5 Mpc. We define galaxies beyond 1.5 Mpc of a massive host galaxy to be in the field. We demonstrate that there is a stellar mass threshold of M{sub stellar} < 1.0 Multiplication-Sign 10{sup 9} M{sub Sun} below which quenched galaxies do not exist in the field. Below this threshold, we find that none of the 2951 field dwarf galaxies are quenched; all field dwarf galaxies show evidence for recent star formation. Correcting for volume effects, this corresponds to a 1{sigma} upper limit on the quenched fraction of 0.06%. In more dense environments, quenched galaxies account for 23% of the dwarf population over the same stellar mass range. The majority of quenched dwarf galaxies (often classified as dwarf elliptical galaxies) are within 2 virial radii of a massive galaxy, and only a few percent of quenched dwarf galaxies exist beyond 4 virial radii. Thus, for galaxies with stellar mass less than 1.0 Multiplication-Sign 10{sup 9} M{sub Sun }, ending star formation requires the presence of a more massive neighbor, providing a stringent constraint on models of star formation feedback.

Geha, M. [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Blanton, M. R.; Yan, R.; Tinker, J. L., E-mail: marla.geha@yale.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

2012-09-20T23:59:59.000Z

255

Long-Term Performance of Screwbase Compact Fluorescent Lamps  

Science Conference Proceedings (OSTI)

The packaging material for compact fluorescent lamps normally includes some claim regarding expected lamp lifetime. This claimed lifetime is generally not obtained through rigorous testing. This study shows how different operating cycles, components, and lamp and ballast designs affect screwbase compact fluorescent lamp (SCFL) life.

2000-04-11T23:59:59.000Z

256

PREPARATION OF COMPACTS MADE FROM URANIUM AND BERYLLIUM BY SINTERING  

DOE Patents (OSTI)

A powder metallurgical method for making high-density compacts of uranium and beryllium is reported. Powdered UBe/sub 9/ and powdered Be are blended, compacted, and then sintered by rapidly heating to a temperature of approximately 1220 to 1280 deg C in an inert atmosphere.

Angier, R.P.

1961-04-11T23:59:59.000Z

257

compactness in transport theory Mustapha Mokhtar-Kharroubi  

E-Print Network (OSTI)

A main feature of spectra of transport operators in nuclear reactor theory relies on the compactness (orOn L1 compactness in transport theory Mustapha Mokhtar-Kharroubi Département de Mathématiques spectral theory of neutron transport equations on both n-dimensional torus and spatial domains with ...nite

Paris-Sud XI, Université de

258

National Laboratories  

NLE Websites -- All DOE Office Websites (Extended Search)

Laboratories Los Alamos National Laboratory (the Laboratory) is one of 17 National Laboratories in the United States and is one of the two located in New Mexico. The Laboratory has...

259

NATIONAL CONFERENCE  

Science Conference Proceedings (OSTI)

... Oak Room ... of the Secretariats, the US National Work Groups ... the continued cooperation with the International Laboratory Accreditation Cooperation ...

2010-12-17T23:59:59.000Z

260

Compact Fluorescent Lighting in America: Lessons Learned on the Way to Market  

SciTech Connect

This report describes the history of compact fluorescent lamps (CFLs) in America. CFLs were introduced in the 1970s; however, it has taken more than 20 years for them to gain widespread recognition in the U.S. residential lighting market. This report reviews the development of CFLs, efforts to increase market acceptance of them, and barriers to that acceptance. Lessons to be learned from this study of CFLs are identified in hopes of assisting future market introduction efforts for other promising energy-efficient technologies. This report was prepared by the Pacific Northwest National Laboratory for the U.S. Department of Energy’s Office of Building Technologies, Emerging Technologies Program.

Sandahl, Linda J.; Gilbride, Theresa L.; Ledbetter, Marc R.; Steward, Heidi E.; Calwell, Chris

2006-05-22T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Southwestern Low-Level Radioactive Waste Disposal Compact (South Dakota) |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Southwestern Low-Level Radioactive Waste Disposal Compact (South Southwestern Low-Level Radioactive Waste Disposal Compact (South Dakota) Southwestern Low-Level Radioactive Waste Disposal Compact (South Dakota) < Back Eligibility Utility Investor-Owned Utility Industrial Construction Municipal/Public Utility Rural Electric Cooperative Fuel Distributor Program Info State South Dakota Program Type Siting and Permitting Provider Southwestern Low-Level Radioactive Waste Commission This legislation authorizes the state's entrance into the Southwestern Low-Level Radioactive Waste Disposal Compact, which provides for the cooperative management of low-level radioactive waste. The Compact is administered by a commission, which can regulate and impose fees on in-state radioactive waste generators. The states of Arizona, California,

262

The Evolution of Stellar Mass Density and its Implied Star Formation History  

E-Print Network (OSTI)

Using a compilation of measurements of the stellar mass density as a function of redshift we can infer the cosmic star formation history. For z histories. At higher redshifts the instantaneous indicators suggest star formation rates larger than that implied by the evolution of the stellar mass density. This discrepancy peaks at z = 3 where instantaneous indicators suggest a star formation rate around 0.6 dex higher than those of the best fit to the stellar mass history. We discuss a variety of explanations for this inconsistency, such as inaccurate dust extinction corrections, incorrect measurements of stellar masses and a possible evolution of the stellar initial mass function.

S. M. Wilkins; N. Trentham; A. M. Hopkins

2008-03-27T23:59:59.000Z

263

The pressure confined wind of the massive and compact superstar cluster M82-A1  

E-Print Network (OSTI)

The observed parameters of the young superstar cluster M82-A1 and its associated compact HII region are here shown to indicate a low heating efficiency or immediate loss, through radiative cooling, of a large fraction of the energy inserted by stellar winds and supernovae during the early evolution of the cluster. This implies a bimodal hydrodynamic solution which leads to a reduced mass deposition rate into the ISM, with a much reduced outflow velocity. Furthermore, to match the observed parameters of the HII region associated to M82-A1, the resultant star cluster wind is here shown to ought to be confined by a high pressure interstellar medium. The cluster wind parameters, as well as the location of the reverse shock, its cooling length and the radius of the standing outer HII region are derived analytically. All of these properties are then confirmed with a semi-analytical integration of the flow equations, which provides us also with the run of the hydrodynamic variables as a function of radius. The impac...

Silich, Sergiy; Munoz-Tunon, Casiana

2007-01-01T23:59:59.000Z

264

GLOBAL MODELING OF RADIATIVELY DRIVEN ACCRETION OF METALS FROM COMPACT DEBRIS DISKS ONTO WHITE DWARFS  

Science Conference Proceedings (OSTI)

Recent infrared observations have revealed the presence of compact (radii {approx}rate M-dot{sub PR}{approx}10{sup 8} g s{sup -1}. Here we extend this local analysis by exploring the global evolution of the debris disk under the action of the PR drag for a variety of assumptions about the disk properties. We find that massive disks (mass {approx}> 10{sup 20} g), which are optically thick to incident stellar radiation, inevitably give rise to metal accretion at rates M-dot {approx}>0.2 M-dot{sub PR}. The magnitude of M-dot and its time evolution are determined predominantly by the initial pattern of the radial distribution of the debris (i.e., ring-like versus disk-like) but not by the total mass of the disk. The latter determines only the disk lifetime, which can be several Myr or longer. The evolution of an optically thick disk generically results in the development of a sharp outer edge of the disk. We also find that the low-mass ({approx}< 10{sup 20} g), optically thin disks exhibit M-dot << M-dot{sub PR} and evolve on a characteristic timescale {approx}10{sup 5}-10{sup 6} yr, independent of their total mass.

Bochkarev, Konstantin V. [Department of General and Applied Physics, Moscow Institute of Physics and Technology, Dolgoprudny, 141700 (Russian Federation); Rafikov, Roman R., E-mail: bochkarevkv@gmail.com, E-mail: rrr@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08540 (United States)

2011-11-01T23:59:59.000Z

265

INNER EDGES OF COMPACT DEBRIS DISKS AROUND METAL-RICH WHITE DWARFS  

SciTech Connect

A number of metal-rich white dwarfs (WDs) are known to host compact, dense particle disks, which are thought to be responsible for metal pollution of these stars. In many such systems, the inner radii of disks inferred from their spectra are so close to the WD that particles directly exposed to starlight must be heated above 1500 K and are expected to be unstable against sublimation. To reconcile this expectation with observations, we explore particle sublimation in H-poor debris disks around WDs. We show that because of the high metal vapor pressure the characteristic sublimation temperature in these disks is 300-400 K higher than in their protoplanetary analogs, allowing particles to survive at higher temperatures. We then look at the structure of the inner edges of debris disks and show that they should generically feature superheated inner rims directly exposed to starlight with temperatures reaching 2500-3500 K. Particles migrating through the rim toward the WD (and rapidly sublimating) shield the disk behind them from strong stellar heating, making the survival of solids possible close to the WD. Our model agrees well with observations of WD+disk systems provided that disk particles are composed of Si-rich material such as olivine, and have sizes in the range {approx}0.03-30 cm.

Rafikov, Roman R.; Garmilla, Jose A., E-mail: rrr@astro.princeton.edu, E-mail: garmilla@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States)

2012-12-01T23:59:59.000Z

266

Difficulties for Compact Composite Object Dark Matter  

E-Print Network (OSTI)

It has been suggested ``that DM particles are strongly interacting composite macroscopically large objects ... made of well known light quarks (or ... antiquarks)." In doing so it is argued that these compact composite objects (CCOs) are ``natural explanations of many observed data, such as [the] 511 keV line from the bulge of our galaxy" observed by INTEGRAL and the excess of diffuse gamma-rays in the 1-20 MeV band observed by COMPTEL. Here we argue that the atmospheres of positrons that surround CCOs composed of di-antiquark pairs in the favoured Colour-Flavour-Locked superconducting state are sufficiently dense as to stringently limit the penetration of interstellar electrons incident upon them, resulting in an extreme suppression of previously estimated rates of positronium, and hence the flux of 511 keV photons resulting from their decays, and also in the rate of direct electron-positron annihilations, which yield the MeV photons proposed to explain the 1-20 MeV excess. We also demonstrate that even if a fraction of positrons somehow penetrated to the surface of the CCOs, the extremely strong electric fields generated from the bulk antiquark matter would result in the destruction of positronium atoms long before they decay.

Daniel T. Cumberbatch; Glenn D. Starkman; Joseph Silk

2006-06-18T23:59:59.000Z

267

QUARK MATTER IN MASSIVE COMPACT STARS  

SciTech Connect

The recent observation of the pulsar PSR J1614-2230 with a mass of 1.97 {+-} 0.04 M{sub sun} gives a strong constraint on the quark and nuclear matter equations of state (EoS). We explore the parameter ranges for a parameterized EoS for quark stars. We find that strange stars, made of absolutely stable strange quark matter, comply with the new constraint only if effects from the strong coupling constant and color-superconductivity are taken into account. Hybrid stars, compact stars with a quark matter core and a hadronic outer layer, can be as massive as 2 M{sub sun}, but only for a significantly limited range of parameters. We demonstrate that the appearance of quark matter in massive stars crucially depends on the stiffness of the nuclear matter EoS. We show that the masses of hybrid stars stay below the ones of hadronic and pure quark stars, due to the softening of the EoS at the quark-hadron phase transition.

Weissenborn, Simon; Pagliara, Giuseppe; Schaffner-Bielich, Juergen [Institute for Theoretical Physics, Ruprecht-Karls University, 69120 Heidelberg (Germany); Sagert, Irina [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Hempel, Matthias [Department of Physics, University of Basel, 4056 Basel (Switzerland)

2011-10-10T23:59:59.000Z

268

Absolute Spectrophotometry of Northern Compact Planetary Nebulae  

E-Print Network (OSTI)

We present medium-dispersion spectra and narrowband images of six northern compact planetary nebulae (PNe): BoBn 1, DdDm 1, IC 5117, M 1-5, M 1-71, and NGC 6833. From broad-slit spectra, total absolute fluxes and equivalent widths were measured for all observable emission lines. High signal-to noise emission line fluxes of H-alpha, H-beta, [OIII], [NII], and HeI may serve as emission line flux standards for northern hemisphere observers. From narrow-slit spectra, we derive systemic radial velocities. For four PNe, available emission line fluxes were measured with sufficient signal-to-noise to probe the physical properties of their electron densities, temperatures, and chemical abundances. BoBn 1 and DdDm 1, both type IV PNe, have an H-beta flux over three sigma away from previous measurements. We report the first abundance measurements of M 1-71. NGC 6833 measured radial velocity and galactic coordinates suggest that it is associated with the outer arm or possibly the galactic halo, and its low abundance ([O/H]=1.3x10E-4) may be indicative of low metallicity within that region.

S. A. Wright; R. L. M. Corradi; M. Perinotto

2005-05-12T23:59:59.000Z

269

Process for forming coal compacts and product thereof  

DOE Patents (OSTI)

A process for forming durable, mechanically strong compacts from coal particulates without use of a binder is disclosed. The process involves applying a compressive stress to a particulate feed comprising substantially water-saturated coal particles while the feed is heated to a final compaction temperature in excess of about 100.degree. C. The water present in the feed remains substantially in the liquid phase throughout the compact forming process. This is achieved by heating and compressing the particulate feed and cooling the formed compact at a pressure sufficient to prevent water present in the feed from boiling. The compacts produced by the process have a moisture content near their water saturation point. As a result, these compacts absorb little water and retain exceptional mechanical strength when immersed in high pressure water. The process can be used to form large, cylindrically-shaped compacts from coal particles (i.e., "coal logs") so that the coal can be transported in a hydraulic coal log pipeline.

Gunnink, Brett (Columbia, MO); Kanunar, Jayanth (Arlington, MA); Liang, Zhuoxiong (San Francisco, CA)

2002-01-01T23:59:59.000Z

270

The Milky Way's stellar halo - lumpy or triaxial?  

E-Print Network (OSTI)

We present minimum chi-squared fits of power law and Hernquist density profiles to F-turnoff stars in eight 2.5 deg wide stripes of SDSS data: five in the North Galactic Cap and three in the South Galactic cap. Portions of the stellar Galactic halo that are known to contain large streams of tidal debris or other lumpy structure, or that may include significant contamination from the thick disk, are avoided. The data strongly favor a model that is not symmetric about the Galaxy's axis of rotation. If included as a free parameter, the best fit to the center of the spheroid is surprisingly approx 3 kpc from the Galactic center in the direction of the Sun's motion. The model fits favor a low value of the density of halo stars at the solar position. The alternative to a non-axisymmetric stellar distribution is that our fits are contaminated by previously unidentified lumpy substructure.

Heidi Jo Newberg; Brian Yanny

2005-07-28T23:59:59.000Z

271

Numerical Solution of the Expanding Stellar Atmosphere Problem  

E-Print Network (OSTI)

In this paper we discuss numerical methods and algorithms for the solution of NLTE stellar atmosphere problems involving expanding atmospheres, e.g., found in novae, supernovae and stellar winds. We show how a scheme of nested iterations can be used to reduce the high dimension of the problem to a number of problems with smaller dimensions. As examples of these sub-problems, we discuss the numerical solution of the radiative transfer equation for relativistically expanding media with spherical symmetry, the solution of the multi-level non-LTE statistical equilibrium problem for extremely large model atoms, and our temperature correction procedure. Although modern iteration schemes are very efficient, parallel algorithms are essential in making large scale calculations feasible, therefore we discuss some parallelization schemes that we have developed.

Hauschildt, P H

1998-01-01T23:59:59.000Z

272

Numerical Solution of the Expanding Stellar Atmosphere Problem  

E-Print Network (OSTI)

In this paper we discuss numerical methods and algorithms for the solution of NLTE stellar atmosphere problems involving expanding atmospheres, e.g., found in novae, supernovae and stellar winds. We show how a scheme of nested iterations can be used to reduce the high dimension of the problem to a number of problems with smaller dimensions. As examples of these sub-problems, we discuss the numerical solution of the radiative transfer equation for relativistically expanding media with spherical symmetry, the solution of the multi-level non-LTE statistical equilibrium problem for extremely large model atoms, and our temperature correction procedure. Although modern iteration schemes are very efficient, parallel algorithms are essential in making large scale calculations feasible, therefore we discuss some parallelization schemes that we have developed.

P. H. Hauschildt; E. Baron

1998-08-18T23:59:59.000Z

273

Buoyancy waves in Pluto's high atmosphere: Implications for stellar occultations  

E-Print Network (OSTI)

We apply scintillation theory to stellar signal fluctuations in the high-resolution, high signal/noise, dual-wavelength data from the MMT observation of the 2007 March 18 occultation of P445.3 by Pluto. A well-defined high wavenumber cutoff in the fluctuations is consistent with viscous-thermal dissipation of buoyancy waves (internal gravity waves) in Pluto's high atmosphere, and provides strong evidence that the underlying density fluctuations are governed by the gravity-wave dispersion relation.

Hubbard, W B; Kulesa, C A; Benecchi, S D; Person, M J; Elliot, J L; Gulbis, A A S

2009-01-01T23:59:59.000Z

274

BARS REJUVENATING BULGES? EVIDENCE FROM STELLAR POPULATION ANALYSIS  

SciTech Connect

We obtained stellar ages and metallicities via spectrum fitting for a sample of 575 bulges with spectra available from the Sloan Digital Sky Survey. The structural properties of the galaxies have been studied in detail in 2009 by Gadotti and the sample contains 251 bulges in galaxies with bars. Using the whole sample, where galaxy stellar mass distributions for barred and unbarred galaxies are similar, we find that bulges in barred and unbarred galaxies occupy similar loci in the age versus metallicity plane. However, the distribution of bulge ages in barred galaxies shows an excess of populations younger than {approx}4 Gyr, when compared to bulges in unbarred galaxies. Kolmogorov-Smirnov statistics confirm that the age distributions are different with a significance of 99.94%. If we select sub-samples for which the bulge stellar mass distributions are similar for barred and unbarred galaxies, this excess vanishes for galaxies with bulge mass log M < 10.1 M{sub Sun }, while for more massive galaxies we find a bimodal bulge age distribution for barred galaxies only, corresponding to two normal distributions with mean ages of 10.4 and 4.7 Gyr. We also find twice as much active galactic nuclei among barred galaxies, as compared to unbarred galaxies, for low-mass bulges. By combining a large sample of high-quality data with sophisticated image and spectral analysis, we are able to find evidence that the presence of bars affects the mean stellar ages of bulges. This lends strong support to models in which bars trigger star formation activity in the centers of galaxies.

Coelho, P. [Nucleo de Astrofisica Teorica, Universidade Cruzeiro do Sul, R. Galvao Bueno 868, Liberdade 01506-000, Sao Paulo (Brazil); Gadotti, D. A., E-mail: paula.coelho@cruzeirodosul.edu.br, E-mail: dgadotti@eso.org [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

2011-12-10T23:59:59.000Z

275

Thermal distributions in stellar plasmas, nuclear reactions and solar neutrinos  

E-Print Network (OSTI)

The physics of nuclear reactions in stellar plasma is reviewed with special emphasis on the importance of the velocity distribution of ions. Then the properties (density and temperature) of the weak-coupled solar plasma are analysed, showing that the ion velocities should deviate from the Maxwellian distribution and could be better described by a weakly-nonexstensive (|q-1|solar neutrino fluxes, and on the pp neutrino energy spectrum, and analyse the consequences for the solar neutrino problem.

M. Coraddu; G. Kaniadakis; A. Lavagno; M. Lissia; G. Mezzorani; P. Quarati

1998-11-24T23:59:59.000Z

276

Technique for inferring sizes of stellar-active regions  

Science Conference Proceedings (OSTI)

Inspection of spectroheliograms showing large, well-developed active regions generally show the sunspots to lead the associated plage, in the sense of the solar rotation. Measurements have been made from spectroheliograms of spot-plage offsets and compared with nearly contemporaneous integrated disk observations. Larger active regions generally show larger spot leads; however, information regarding active-region sizes and spot-plage offsets is not readily obtainable form stellar-type observations of the Sun.

Dobson-Hockey, A.K.; Radick, R.R.

1986-01-01T23:59:59.000Z

277

Southern States Energy Compact (Multiple States) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Southern States Energy Compact (Multiple States) Southern States Energy Compact (Multiple States) Southern States Energy Compact (Multiple States) < Back Eligibility Agricultural Commercial Construction Developer Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Alabama Program Type Environmental Regulations Industry Recruitment/Support Provider Southern States Energy Board

278

Iron-carbon compacts and process for making them  

DOE Patents (OSTI)

The present invention includes iron-carbon compacts and a process for making them. The process includes preparing a slurry comprising iron powder, furfuryl alcohol, and a polymerization catalyst for initiating the polymerization of the furfuryl alcohol into a resin, and heating the slurry to convert the alcohol into the resin. The resulting mixture is pressed into a green body and heated to form the iron-carbon compact. The compact can be used as, or machined into, a magnetic flux concentrator for an induction heating apparatus.

Sheinberg, Haskell (Santa Fe, NM)

2000-01-01T23:59:59.000Z

279

Development of a Compact Rotating-Wave Electron Beam Accelerator  

Science Conference Proceedings (OSTI)

We present the successful prototype development results of a novel compact rotating-wave electron beam accelerator (RWA). The RWA uses a single cylindrical cavity holding a transverse-magnetic resonant mode in combination with an axial static magnetic field to accelerate electrons to higher energies. With approximately 80 kilowatts of microwave power fed into a C-band cavity, we have been able to successfully accelerate a 3 keV electron beam to {approx}760 keV. The compact RWA accelerator could be the basis for a new class of compact and affordable 1-10 MeV microwave accelerators for military, medical and industrial applications.

Velazco, Jose E.; Ceperley, Peter H. [Microwave Technologies Incorporated, Fairfax, Virginia 22030 (United States); Departments of Physics and Electrical Engineering, George Mason University, Fairfax, Virginia 22030 (United States)

2003-08-26T23:59:59.000Z

280

METHOD AND APPARATUS FOR MAKING URANIUM-HYDRIDE COMPACTS  

DOE Patents (OSTI)

A method and apparatus are presented for making compacts of pyrophoric hydrides in a continuous operation out of contact with air. It is particularly useful for the preparation of a canned compact of uranium hydride possessing high density and purity. The metallic uranium is enclosed in a container, positioned in a die body evacuated and nvert the uranium to the hydride is admitted and the container sealed. Heat is applied to bring about the formation of the hydride, following which compression is used to form the compact sealed in a container ready for use.

Wellborn, W.; Armstrong, J.R.

1959-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

National Report  

Science Conference Proceedings (OSTI)

... A methodology for grade calculation and a glossary of terms can be found at the back, along with the 2013 National Scorecard. ... Category Glossary ...

2013-07-29T23:59:59.000Z

282

Compact harsh environment energy conversion systems  

E-Print Network (OSTI)

The quest for energy is leading the industry into drilling deeper wells. Typically, a temperature gradient of 1°C/150 ft can be expected, with bottom hole temperatures reaching beyond 200°C in many areas of the world. Moreover, the increased recovery benefits and cost reductions possible with the use of horizontal and multilateral wells has triggered a need for higher power energy conversion systems in bottom hole assemblies, such as rotary steerable tools and downhole tractors. The concepts developed throughout this work address some of these new needs. This research investigated improvements, novel solutions and considerations that will lead to significant advantages in terms of reliability, extended temperature operation, increased power capability and reduced size and cost of compact harsh environment energy conversion systems. Improvements to both the electromechanical subsystem and the power electronic subsystem are introduced. Air gap viscous losses were shown to a have a significant effect on the optimal design of submersible PM (permanent magnet) machines, and a design procedure to account for this loss component in the design was developed. The application of a dual winding exterior rotor PM machine in a downhole environment enabled a significant increase in the application’s torque capability, provided protection against generator winding over voltage, and reduced parts count. Comprehensive switching device qualification, testing, and simulation lead to a simple failure mitigation technique for the operation of the most suitable devices at elevated temperature. A flying capacitor multilevel inverter was then successfully constructed and temperature tested. A novel motor drive concept suited for elevated temperature oil filled environment applications concluded the research.

Ahmed, Shehab

2007-05-01T23:59:59.000Z

283

Yellowstone River Compact (North Dakota) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Yellowstone River Compact (North Dakota) Yellowstone River Compact (North Dakota) Yellowstone River Compact (North Dakota) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Residential Installer/Contractor Rural Electric Cooperative Tribal Government Low-Income Residential Schools Retail Supplier Institutional Multi-Family Residential Systems Integrator Fuel Distributor Nonprofit General Public/Consumer Transportation Savings Category Water Buying & Making Electricity Program Info State North Dakota Program Type Siting and Permitting The Yellowstone River Compact, agreed to by the States of Montana, North Dakota, and Wyoming, provides for an equitable division and apportionment of the waters of the Yellowstone River, as well as for the conservation,

284

Lighting the Way with Compact Fluorescent Lighting | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting April 28, 2009 - 5:00am Addthis John Lippert There is a major push today to get homeowners to adopt compact fluorescent lamp (CFL) light bulbs. They have been on the market for nearly three decades, and many homeowners still do not use them widely. But the tide is definitely turning. Their availability and the percentage of homeowners familiar with the technology and purchasing them for their homes have been steadily rising. The products have improved considerably compared to early products, and their prices have plummeted. The ENERGY STAR® Change a Light, Change the World Campaign has been running now for more than half a dozen years. This campaign is designed to

285

Covered Product Category: Compact Fluorescent Lamps | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Covered Product Category: Compact Fluorescent Lamps Covered Product Category: Compact Fluorescent Lamps Covered Product Category: Compact Fluorescent Lamps October 7, 2013 - 10:48am Addthis ENERGY STAR Qualified Products Federal Energy Management Program (FEMP) provides acquisition guidance across a variety of product categories, including compact fluorescent lamps (CFLs), which are an ENERGY STAR-qualified product category. Federal laws and executive orders mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law. Most manufacturers display the ENERGY STAR label on complying models. For a model not displaying this label, check the manufacturer's literature to determine if it meets the efficiency requirements outlined by ENERGY STAR.

286

Lighting the Way with Compact Fluorescent Lighting | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting April 28, 2009 - 5:00am Addthis John Lippert There is a major push today to get homeowners to adopt compact fluorescent lamp (CFL) light bulbs. They have been on the market for nearly three decades, and many homeowners still do not use them widely. But the tide is definitely turning. Their availability and the percentage of homeowners familiar with the technology and purchasing them for their homes have been steadily rising. The products have improved considerably compared to early products, and their prices have plummeted. The ENERGY STAR® Change a Light, Change the World Campaign has been running now for more than half a dozen years. This campaign is designed to

287

Future 'Comb on a Chip': NIST's Compact Frequency Comb ...  

Science Conference Proceedings (OSTI)

... A full-size frequency comb uses a high-power, ultrafast laser.** By contrast, the new compact version relies on a low-power laser and the cavity's ...

2011-10-25T23:59:59.000Z

288

Compact high resolution isobar separator for study of exotic...  

NLE Websites -- All DOE Office Websites (Extended Search)

Compact high resolution isobar separator for study of exotic decays A. Piechaczek 1 , V. Shchepunov 1 , H. K. Carter 1 J. C. Batchelder 1 , E. F. Zganjar 2 1 UNIRIB, Oak Ridge...

289

Compact Ignition Tokamak Program: issues to be resolved by January  

SciTech Connect

This Compact Ignition Tokamak Program report addresses unresolved issues concerning: concept configuration; design space characterization; facility/device layouts; auxiliary system development; cost; R and D; and alternate sites. (JDB)

Flanagan, C.A.

1985-01-01T23:59:59.000Z

290

High Energy Gamma Rays from Protons Hitting Compact Objects  

E-Print Network (OSTI)

In a previous paper the spectrum of positrons produced by matter initially at rest falling onto a massive compact object was calculated. In this paper this calculation is generalized to obtain both the spectrum of in-flight positron annihilation and pi0 decay gamma rays produced when protons with a cosmic ray-like spectrum hit the surface. The resulting pi0 decay gamma ray spectrum reflects the high energy proton energy spectrum, and is largely independent of the mass of the compact object. One notable prediction for all compact objects is a dip in the spectrum below 70 MeV. As applied to the 10^6 solar mass massive compact object near to the center of our galaxy, our theory shows promise for explaining the gamma rays coming from the galactic center as observed by both the Compton satellite and HESS ground based array.

J. Barbieri; G. Chapline

2008-06-09T23:59:59.000Z

291

A compact setup to study homogeneous nucleation and condensation  

Science Conference Proceedings (OSTI)

An experiment is presented to study homogeneous nucleation and the subsequent droplet growth at high temperatures and high pressures in a compact setup that does not use moving parts. Nucleation and condensation are induced in an adiabatic

Mattias Karlsson; Ivo Alxneit; Frederik Rütten; Daniel Wuillemin; Hans Rudolf Tschudi

2007-01-01T23:59:59.000Z

292

Preparation of bulk superhard B-C-N nanocomposite compact  

DOE Patents (OSTI)

Bulk, superhard, B--C--N nanocomposite compacts were prepared by ball milling a mixture of graphite and hexagonal boron nitride, encapsulating the ball-milled mixture at a pressure in a range of from about 15 GPa to about 25 GPa, and sintering the pressurized encapsulated ball-milled mixture at a temperature in a range of from about 1800-2500 K. The product bulk, superhard, nanocomposite compacts were well sintered compacts with nanocrystalline grains of at least one high-pressure phase of B--C--N surrounded by amorphous diamond-like carbon grain boundaries. The bulk compacts had a measured Vicker's hardness in a range of from about 41 GPa to about 68 GPa.

Zhao, Yusheng (Los Alamos, NM); He, Duanwei (Sichuan, CN)

2011-05-10T23:59:59.000Z

293

Lighting the Way with Compact Fluorescent Lighting | Department...  

NLE Websites -- All DOE Office Websites (Extended Search)

and compact fluorescent lights. And I've already purchased a few of the new light emitting diode (LED) solid-state lighting lights-but that's the topic of a future blog. Stay...

294

The Effects of Table Lamp Shade Shape and Compact Fluorescent...  

NLE Websites -- All DOE Office Websites (Extended Search)

The Effects of Table Lamp Shade Shape and Compact Fluorescent Lamp Burning Position on Visual Comfort Speaker(s): Zaidi Abdullah Date: March 15, 2001 - 12:00pm Location: Bldg. 90...

295

The Compact RCS / Antenna Range at MIT Lincoln Laboratory  

E-Print Network (OSTI)

A new compact range with a state-of-the-art instrumentation system was installed at Lincoln Laboratory and is currently in use. This paper describes the chamber with varied-height absorber, the rolled-edge reflector and ...

Shields, Michael W.

296

Light Flicker in Compact Fluorescent Lamps Caused by Voltage Fluctuations  

Science Conference Proceedings (OSTI)

This power quality (PQ) case study presents tests performed at the EPRI Power Electronics Applications Center (PEAC) Power Quality Test Facility to characterize the light output of an incandescent lamp and compact fluorescent lamps during voltage fluctuations.

2003-12-31T23:59:59.000Z

297

Belle Fourche River Compact (South Dakota) | Open Energy Information  

Open Energy Info (EERE)

History Share this page on Facebook icon Twitter icon Belle Fourche River Compact (South Dakota) This is the approved revision of this page, as well as being the most...

298

Plasma Frequency Shift Due to a Slowly Rotating Compact Star  

E-Print Network (OSTI)

We investigate the effects of a slowly rotating compact gravitational source on plasma oscillations using the gravitoelectromagnetic approximation to General Relativity. It is shown that there is a shift in the plasma frequency and hence in the refractive index of the plasma due to the gravitomagnetic force. Estimates for the difference in frequency of radially transmitted electromagnetic signals are given for typical compact star candidates. 1

Babur M. Mirza; Hamid Saleem

2005-01-01T23:59:59.000Z

299

New Terms for the Compact Form of Electroweak Chiral Lagrangian  

E-Print Network (OSTI)

The compact form of the electroweak chiral Lagrangian is a reformulation of its original form and is expressed in terms of chiral rotated electroweak gauge fields, which is crucial for relating the information of underlying theories to the coefficients of the low-energy effective Lagrangian. However the compact form obtained in previous works is not complete. In this letter we add several new chiral invariant terms to it and discuss the contributions of these terms to the original electroweak chiral Lagrangian.

Hong-Hao Zhang; Wen-Bin Yan; J. K. Parry; Xue-Song Li

2007-04-09T23:59:59.000Z

300

The Evolution of Stellar Mass and the Implied Star Formation History  

E-Print Network (OSTI)

We present a compilation of measurements of the stellar mass density as a function of redshift. Using this stellar mass history we obtain a star formation history and compare it to the instantaneous star formation history. For zhistories. At higher redshifts the instantaneous indicators suggest star formation rates larger than that implied by the evolution of the stellar mass density. This discrepancy peaks at z=3 where instantaneous indicators suggest a star formation rate around 0.6 dex higher than those of the best fit to the stellar mass history. We discuss a variety of explanations for this inconsistency, such as inaccurate dust extinction corrections, incorrect measurements of stellar masses and a possible evolution of the stellar initial mass function.

Stephen M. Wilkins; Neil Trentham; Andrew M. Hopkins

2008-01-10T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Modeling the Stellar Spectral Energy Distributions of Star-Forming Galaxies  

E-Print Network (OSTI)

I will review recent progress in the modeling of the stellar spectral energy distributions of star-forming galaxies. I will cover the full relevant wavelength range from the near-infrared to the extreme ultraviolet, with an emphasis on the ultraviolet long- and shortward of the Lyman break where most of the stellar luminosity is emitted. Uncertainties in stellar atmosphere and evolution models will be critically examined, and the impact on the total panchromatic luminosity will be highlighted.

Claus Leitherer

2004-11-12T23:59:59.000Z

302

OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY  

E-Print Network (OSTI)

RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Advanced Gas Reactor Fuel Compact Development Team in the ASTM nuclear grade graphite standards & ASME Code development. · Funded by DOE -10.0 -5.0 0.0 5.0 10 Technology Group Dr. Tim Burchell Leader, Carbon Materials Technology Group Materials Science & Technology

303

Estimation of stellar atmospheric parameters from SDSS/SEGUE spectra  

E-Print Network (OSTI)

We present techniques for the estimation of stellar atmospheric parameters (Teff,logg,[Fe/H]) for stars from the SDSS/SEGUE survey. The atmospheric parameters are derived from the observed medium-resolution (R=2000) stellar spectra using non-linear regression models trained either on (1) pre-classified observed data or (2) synthetic stellar spectra. In the first case we use our models to automate and generalize parametrization produced by a preliminary version of the SDSS/SEGUE Spectroscopic Parameter Pipeline (SSPP). In the second case we directly model the mapping between synthetic spectra (derived from Kurucz model atmospheres) and the atmospheric parameters, independently of any intermediate estimates. After training, we apply our models to various samples of SDSS spectra to derive atmospheric parameters, and compare our results with those obtained previously by the SSPP for the same samples. We obtain consistency between the two approaches, with RMS deviations of 150K in Teff, 0.35dex in logg, and 0.22dex in [Fe/H]. The models are applied to pre-processed spectra, either via Principal Components Analysis or a Wavelength Range Selection method, which employs a subset of the full 3850-9000A spectral range. This is both for computational reasons, and because it delivers higher accuracy. From an analysis of cluster candidates with available SDSS spectroscopy (M15, M13, M2, and NGC2420), we find evidence for small systematic offsets in Teff and/or logg for the atmospheric parameter estimates from the model trained on real data with the SSPP. Thus, this model turns out to derive more precise, but less accurate, atmospheric parameters than the model trained on synthetic data.

P. Re Fiorentin; C. A. L. Bailer-Jones; Y. S. Lee; T. C. Beers; T. Sivarani; R. Wilhelm; C. Allende Prieto; J. E. Norris

2007-03-13T23:59:59.000Z

304

On the formation of dwarf galaxies and stellar halos  

E-Print Network (OSTI)

Using analytic arguments and a suite of very high resolution (10^3 Msun per particle) cosmological hydro-dynamical simulations, we argue that high redshift, z ~ 10, M ~ 10^8 Msun halos, form the smallest `baryonic building block' (BBB) for galaxy formation. These halos are just massive enough to efficiently form stars through atomic line cooling and to hold onto their gas in the presence of supernovae winds and reionisation. These combined effects, in particular that of the supernovae feedback, create a sharp transition: over the mass range 3-10x10^7 Msun, the BBBs drop two orders ofmagnitude in stellar mass. Below ~2x10^7 Msun, galaxies will be dark with almost no stars and no gas. Above this scale is the smallest unit of galaxy formation: the BBB. A small fraction (~100) of these gas rich BBBs fall in to a galaxy the size of the Milky Way. Ten percent of these survive to become the observed LG dwarf galaxies at the present epoch. Those in-falling halos on benign orbits which keep them far away from the Milky Way or Andromeda manage to retain their gas and slowly form stars - these become the smallest dwarf irregular galax ies; those on more severe orbits lose their gas faster than they can form stars and become the dwarf spheroidals. The remaining 90% of the BBBs will be accreted. We show that this gives a metallicity and total stellar mass consistent with the Milky Way old stellar halo (abridged).

J. I. Read; A. P. Pontzen; M. Viel

2006-06-16T23:59:59.000Z

305

Ionized gas and stellar kinematics of seventeen nearby spiral galaxies  

E-Print Network (OSTI)

Ionized gas and stellar kinematics have been measured along the major axes of seventeen nearby spiral galaxies of intermediate to late morphological type. We discuss the properties of each sample galaxy distinguishing between those characterized by regular or peculiar kinematics. In most of the observed galaxies ionized gas rotates more rapidly than stars and have a lower velocity dispersion, as is to be expected if the gas is confined in the disc and supported by rotation while the stars are mostly supported by dynamical pressure. In a few objects, gas and stars show almost the same rotational velocity and low velocity dispersion, suggesting that their motion is dominated by rotation. Incorporating the spiral galaxies studied by Bertola et al. (1996), Corsini et al. (1999, 2003) and Vega Beltran et al. (2001) we have compiled a sample of 50 S0/a-Scd galaxies, for which the major-axis kinematics of the ionized gas and stars have been obtained with the same spatial (~1'') and spectral (~50km/s) resolution, and measured with the same analysis techniques. This allowed us to address the frequency of counterrotation in spiral galaxies. It turns out that less than 12% and less than 8% (at the 95% confidence level) of the sample galaxies host a counterrotating gaseous and stellar disc, respectively. The comparison with S0 galaxies suggests that the retrograde acquisition of small amounts of external gas gives rise to counterrotating gaseous discs only in gas-poor S0s, while in gas-rich spirals the newly acquired gas is swept away by the pre-existing gas. Counterrotating gaseous and stellar discs in spirals are formed only from the retrograde acquisition of large amounts of gas exceeding that of pre-existing gas, and subsequent star formation, respectively.

A. Pizzella; E. M. Corsini; J. C. Vega-Beltran; F. Bertola

2004-04-28T23:59:59.000Z

306

QUANTUM SUBGROUPS OF THE COMPACT QUANTUM GROUP SU-1(3) JULIEN BICHON AND ROBERT YUNCKEN  

E-Print Network (OSTI)

QUANTUM SUBGROUPS OF THE COMPACT QUANTUM GROUP SU-1(3) JULIEN BICHON AND ROBERT YUNCKEN Abstract. We study the (compact) quantum subgroups of the compact quantum group SU-1(3): we show that any non-classical such quantum subgroup is a twist of a compact subgroup of SU(3) or is isomorphic to a quantum subgroup of U-1

307

QUANTUM SUBGROUPS OF THE COMPACT QUANTUM GROUP SU-1(3) JULIEN BICHON AND ROBERT YUNCKEN  

E-Print Network (OSTI)

QUANTUM SUBGROUPS OF THE COMPACT QUANTUM GROUP SU-1(3) JULIEN BICHON AND ROBERT YUNCKEN Abstract. We study the (compact) quantum subgroups of the compact quantum group SU-1(3): we show that any such non-classical quantum subgroup is a twist of a compact subgroup of SU(3) or is isomorphic to a quantum

Sart, Remi

308

AGN ACTIVITY AND THE MISALIGNED HOT ISM IN THE COMPACT RADIO ELLIPTICAL NGC 4278  

SciTech Connect

The analysis of a deep (579 ks) Chandra ACIS pointing of the elliptical galaxy NGC 4278, which hosts a low-luminosity active galactic nucleus (AGN) and compact radio emission, allowed us to detect extended emission from hot gas out to a radius of {approx}5 kpc, with 0.5-8 keV luminosity of 2.4 Multiplication-Sign 10{sup 39} erg s{sup -1}. The emission is elongated in the NE-SW direction, misaligned with respect to the stellar body, and aligned with the ionized gas and with the Spitzer IRAC 8 {mu}m non-stellar emission. The nuclear X-ray luminosity decreased by a factor of {approx}18 since the first Chandra observation in 2005, a dimming that enabled the detection of hot gas even at the position of the nucleus. The gas shows a significantly larger temperature (kT = 0.75 keV) in both the projected and deprojected profiles in the inner {approx}300 pc than in the surrounding region, where it stays at {approx}0.3 keV, a value lower than expected from standard gas heating assumptions. The nuclear X-ray emission is consistent with that of a low radiative efficiency accretion flow, accreting mass at a rate close to the Bondi rate; estimates of the power of the nuclear jets require that the accretion rate is not largely reduced with respect to the Bondi rate. Among possible origins for the central large hot gas temperature, such as gravitational heating from the central massive black hole and a recent AGN outburst, interaction with the nuclear jets seems more likely, especially if the latter remain confined, and heat the nuclear region frequently. The unusual hot gas distribution on the galactic scale could be due to the accreting cold gas triggering the cooling of the hot phase, a process also contributing to the observed line emission from ionized gas, and to the hot gas temperature being lower than expected; alternatively, the latter could be due to the efficiency of the Type Ia supernova heating that is lower than usually adopted.

Pellegrini, Silvia [Department of Astronomy, University of Bologna, via Ranzani 1, I-40127 Bologna (Italy); Wang Junfeng; Fabbiano, Giuseppina; Kim, Dong-Woo [Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Brassington, Nicola J. [School of Physics, Astronomy, and Mathematics, University of Hertfordshire, Hatfield (United Kingdom); Gallagher, John S. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Trinchieri, Ginevra [INAF-Osservatorio Astronomico di Brera, Via Brera 28, I-20121 Milano (Italy); Zezas, Andreas [Physics Department, University of Crete, Heraklion (Greece)

2012-10-20T23:59:59.000Z

309

WHAT ARE THE PROGENITORS OF COMPACT, MASSIVE, QUIESCENT GALAXIES AT z = 2.3? THE POPULATION OF MASSIVE GALAXIES AT z > 3 FROM NMBS AND CANDELS  

SciTech Connect

Using public data from the NEWFIRM Medium-Band Survey (NMBS) and the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS), we investigate the population of massive galaxies at z > 3. The main aim of this work is to identify the potential progenitors of z {approx} 2 compact, massive, quiescent galaxies (CMQGs), furthering our understanding of the onset and evolution of massive galaxies. Our work is enabled by high-resolution images from CANDELS data and accurate photometric redshifts, stellar masses, and star formation rates (SFRs) from 37-band NMBS photometry. The total number of massive galaxies at z > 3 is consistent with the number of massive, quiescent galaxies (MQGs) at z {approx} 2, implying that the SFRs for all of these galaxies must be much lower by z {approx} 2. We discover four CMQGs at z > 3, pushing back the time for which such galaxies have been observed. However, the volume density for these galaxies is significantly less than that of galaxies at z < 2 with similar masses, SFRs, and sizes, implying that additional CMQGs must be created in the intervening {approx}1 Gyr between z = 3 and z = 2. We find five star-forming galaxies at z {approx} 3 that are compact (R{sub e} < 1.4 kpc) and have stellar mass M{sub *} > 10{sup 10.6} M{sub Sun }; these galaxies are likely to become members of the massive, quiescent, compact galaxy population at z {approx} 2. We evolve the stellar masses and SFRs of each individual z > 3 galaxy adopting five different star formation histories (SFHs) and studying the resulting population of massive galaxies at z = 2.3. We find that declining or truncated SFHs are necessary to match the observed number density of MQGs at z {approx} 2, whereas a constant delayed-exponential SFH would result in a number density significantly smaller than observed. All of our assumed SFHs imply number densities of CMQGs at z {approx} 2 that are consistent with the observed number density. Better agreement with the observed number density of CMQGs at z {approx} 2 is obtained if merging is included in the analysis and better still if star formation quenching is assumed to shortly follow the merging event, as implied by recent models of the formation of MQGs.

Stefanon, Mauro; Rudnick, Gregory H. [Department of Physics and Astronomy, University of Kansas, Malott Room 1082, 1251 Wescoe Hall Drive, Lawrence, KS 66045 (United States); Marchesini, Danilo [Physics and Astronomy Department, Tufts University, Robinson Hall, Room 257, Medford, MA 02155 (United States); Brammer, Gabriel B. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Whitaker, Katherine E., E-mail: stefanonm@missouri.edu [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)

2013-05-01T23:59:59.000Z

310

Peering through the stellar wind of IGR J19140+0951 with simultaneous INTEGRAL/RXTE observations  

E-Print Network (OSTI)

We have used the RXTE and INTEGRAL satellites simultaneously to observe the High Mass X-ray binary IGR J19140+0951. The spectra obtained in the 3--80 keV range have allowed us to perform a precise spectral analysis of the system along its binary orbit. The spectral evolution confirms the supergiant nature of the companion star and the neutron star nature of the compact object. Using a simple stellar wind model to describe the evolution of the photoelectric absorption, we were able to restrict the orbital inclination angle in the range 38--75 degrees. This analysis leads to a wind mass-loss rate from the companion star of ~5x 10e-8 Msun/year, consistent with an OB I spectral type. We have detected a soft excess in at least four observations, for the first time for this source. Such soft excesses have been reported in several HMXBs in the past. We discuss the possible origin of this excess, and suggest, based on its spectral properties and occurrences around the superior conjunction, that it may be explained as...

Prat, L; Hannikainen, D C; Shaw, S E

2008-01-01T23:59:59.000Z

311

Peering through the stellar wind of IGR J19140+0951 with simultaneous INTEGRAL/RXTE observations  

E-Print Network (OSTI)

We have used the RXTE and INTEGRAL satellites simultaneously to observe the High Mass X-ray binary IGR J19140+0951. The spectra obtained in the 3--80 keV range have allowed us to perform a precise spectral analysis of the system along its binary orbit. The spectral evolution confirms the supergiant nature of the companion star and the neutron star nature of the compact object. Using a simple stellar wind model to describe the evolution of the photoelectric absorption, we were able to restrict the orbital inclination angle in the range 38--75 degrees. This analysis leads to a wind mass-loss rate from the companion star of ~5x 10e-8 Msun/year, consistent with an OB I spectral type. We have detected a soft excess in at least four observations, for the first time for this source. Such soft excesses have been reported in several HMXBs in the past. We discuss the possible origin of this excess, and suggest, based on its spectral properties and occurrences around the superior conjunction, that it may be explained as the reprocessing of the X-ray emission originating from the neutron star by the surrounding ionised gas.

L. Prat; J. Rodriguez; D. C. Hannikainen; S. E. Shaw

2008-06-11T23:59:59.000Z

312

THE LOW-MASS STELLAR POPULATION IN L1641: EVIDENCE FOR ENVIRONMENTAL DEPENDENCE OF THE STELLAR INITIAL MASS FUNCTION  

Science Conference Proceedings (OSTI)

We present results from an optical photometric and spectroscopic survey of the young stellar population in L1641, the low-density star-forming region of the Orion A cloud south of the Orion Nebula Cluster (ONC). Our goal is to determine whether L1641 has a large enough low-mass population to make the known lack of high-mass stars a statistically significant demonstration of environmental dependence of the upper mass stellar initial mass function (IMF). Our spectroscopic sample consists of IR-excess objects selected from the Spitzer/IRAC survey and non-excess objects selected from optical photometry. We have spectral confirmation of 864 members, with another 98 probable members; of the confirmed members, 406 have infrared excesses and 458 do not. Assuming the same ratio of stars with and without IR excesses in the highly extincted regions, L1641 may contain as many as {approx}1600 stars down to {approx}0.1 M{sub Sun }, comparable within a factor of two to the ONC. Compared to the standard models of the IMF, L1641 is deficient in O and early B stars to a 3{sigma}-4{sigma} significance level, assuming that we know of all the massive stars in L1641. With a forthcoming survey of the intermediate-mass stars, we will be in a better position to make a direct comparison with the neighboring, dense ONC, which should yield a stronger test of the dependence of the high-mass end of the stellar IMF on environment.

Hsu, Wen-Hsin; Hartmann, Lee [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Allen, Lori [National Optical Astronomy Observatory, 950 North Cherry Ave., Tucson, AZ 85719 (United States); Hernandez, Jesus [Centro de Investigaciones de Astronomia, Apdo. Postal 264, Merida 5101-A (Venezuela, Bolivarian Republic of); Megeath, S. T. [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Mosby, Gregory [Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter Street, Madison, WI 53706 (United States); Tobin, John J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Espaillat, Catherine [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States)

2012-06-10T23:59:59.000Z

313

Compact Reversed-Field Pinch Reactors (CRFPR): preliminary engineering considerations  

SciTech Connect

The unique confinement physics of the Reversed-Field Pinch (RFP) projects to a compact, high-power-density fusion reactor that promises a significant reduction in the cost of electricity. The compact reactor also promises a factor-of-two reduction in the fraction of total cost devoted to the reactor plant equipment (i.e., fusion power core (FPC) plus support systems). In addition to operational and developmental benefits, these physically smaller systems can operate economically over a range of total power output. After giving an extended background and rationale for the compact fusion approaches, key FPC subsystems for the Compact RFP Reactor (CRFPR) are developed, designed, and integrated for a minimum-cost, 1000-MWe(net) system. Both the problems and promise of the compact, high-power-density fusion reactor are quantitatively evaluated on the basis of this conceptual design. The material presented in this report both forms a framework for a broader, more expanded conceptual design as well as suggests directions and emphases for related research and development.

Hagenson, R.L.; Krakowski, R.A.; Bathke, C.G.; Miller, R.L.; Embrechts, M.J.; Schnurr, N.M.; Battat, M.E.; LaBauve, R.J.; Davidson, J.W.

1984-08-01T23:59:59.000Z

314

Detection of Small Kuiper Belt Objects by Stellar Occultations  

E-Print Network (OSTI)

Knowledge of the Kuiper Belt is currently limited to those objects that can be detected directly. Objects with diameters less than $\\sim$10km reflect too little light to be detected. These smaller bodies could contain most of the mass in the Kuiper Belt while the abundance of these bodies may constrain the distribution of mass. The overall size distribution of bodies within the Kuiper Belt can also be inferred from the relative abundances of sub-km and larger bodies. Stellar occultations are already used to study dark objects in the Solar System, such as asteroids or planetary rings. Occultation by a KBO of a size comparable to, or larger than, that of the Fresnel Scale will result in Fresnel diffraction. Detection of diffraction effects requires fast multiple-star photometry, which will be conducted in July 2007 using the Orthogonal Parallel Transfer Imaging Camera (OPTIC) mounted on the University of Hawaii 2.2m telescope on Mauna Kea. This paper details how knowledge of the mass and structure of the outer Solar System may be obtained through the detection of serendipitous stellar occultations.

R. Stevenson

2007-12-10T23:59:59.000Z

315

Stellar Evolution Constraints on the Triple-Alpha Reaction Rate  

E-Print Network (OSTI)

We investigate the quantitative constraint on the triple-alpha reaction rate based on stellar evolution theory, motivated by the recent significant revision of the rate proposed by nuclear physics calculations. Targeted stellar models were computed in order to investigate the impact of that rate in the mass range of 0.8 rate has a significant impact on the evolution of low- and intermediate-mass stars, while its influence on the evolution of massive stars (M >~ 10 Msun) is minimal. We find that employing the revised rate suppresses helium shell flashes on AGB phase for stars in the initial mass range 0.8 10 at T = 1 - 1.2 x 10^8 K where the cross section is proportional to T^{nu}. We also derive the helium ignition curve to estimate the maximum cross section to retain the low-mass first red giants. The semi-analytically derived ignition curves suggest that the reaction rate should be less than ~ 10^{-29} cm^6 s^{-1} mole^{-2} at ~ 10^{7.8} K, which corresponds to about three orders of magnitude larger than that of the NACRE compilation. In an effort to compromise with the revised rates, we calculate and analyze models with enhanced CNO cycle reaction rates to increase the maximum luminosity of the first giant branch. However, it is impossible to reach the typical RGB tip luminosity even if all the reaction rates related to CNO cycles are enhanced by more than ten orders of magnitude.

Takuma Suda; Raphael Hirschi; Masayuki Y. Fujimoto

2011-07-25T23:59:59.000Z

316

Nucleosynthesis: Stellar and Solar Abundances and Atomic Data  

E-Print Network (OSTI)

Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy -- the progenitors of the halo stars -- responsible for neutron-capture synthesis. Comparisons of abundance trends can be used to understand the chemical evolution of the Galaxy and the nature of heavy element nucleosynthesis. In addition age determinations, based upon long-lived radioactive nuclei abundances, can now be obtained. These stellar abundance determinations depend critically upon atomic data. Improved laboratory transition probabilities have been recently obtained for a number of elements. These new gf values have been used to greatly refine the abundances of neutron-capture elemental abundances in the solar photosphere and in very metal-poor Galactic halo stars. The newly determined stellar abundances are surprisingly consistent with a (relative) Solar System r-process pattern, and are also consistent with abundance predictions expected from such neutron-capture nucleosynthesis.

John J. Cowan; James E. Lawler; Christopher Sneden; E. A. Den Hartog; Jason Collier

2006-05-04T23:59:59.000Z

317

ON THE FORMATION OF HOT JUPITERS IN STELLAR BINARIES  

Science Conference Proceedings (OSTI)

We study the production of hot Jupiters (HJs) in stellar binaries. We show that the 'eccentric Kozai-Lidov' (EKL) mechanism can play a key role in the dynamical evolution of a star-planet-star triple system. We run a large set of Monte Carlo simulations including the secular evolution of the orbits, general relativistic precession, and tides, and we determine the semimajor axis, eccentricity, inclination, and spin-orbit angle distributions of the HJs that are produced. We explore the effect of different tidal friction parameters on the results. We find that the efficiency of forming HJs when taking the EKL mechanism into account is higher then previously estimated. Accounting for the frequency of stellar binaries, we find that this production mechanism can account for about 30% of the observed HJ population. Current observations of spin-orbit angles are consistent with this mechanism producing {approx}30% of all HJs, and up to 100% of the misaligned systems. Based on the properties of binaries without an HJ in our simulations, we predict the existence of many Jupiter-like planets with moderately eccentric and inclined orbits and semimajor axes of several AU.

Naoz, Smadar [Harvard Smithsonian Center for Astrophysics, Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States); Farr, Will M.; Rasio, Frederic A. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, Evanston, IL 60208 (United States)

2012-08-01T23:59:59.000Z

318

ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE  

SciTech Connect

The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman-Doppler imaging. When the magnetic field is sufficiently weak, the circular and linear polarization profiles locally in each point of the star are proportional to the first and second derivatives of the unperturbed intensity profile, respectively. We show that the weak-field approximation (for weak lines in the case of linear polarization) can be generalized to the case of a rotating star including the Doppler effect and taking into account the integration on the stellar surface. The Stokes profiles are written as a linear combination of wavelength-dependent terms expressed as series expansions in terms of Hermite polynomials. These terms contain the surface-integrated magnetic field and velocity components. The direct numerical evaluation of these quantities is limited to rotation velocities not larger than eight times the Doppler width of the local absorption profiles. Additionally, we demonstrate that in a rotating star, the circular polarization flux depends on the derivative of the intensity flux with respect to the wavelength and also on the profile itself. Likewise, the linear polarization depends on the profile and on its first and second derivatives with respect to the wavelength. We particularize the general expressions to a rotating dipole.

Martinez Gonzalez, M. J. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Asensio Ramos, A. [Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife (Spain)

2012-08-20T23:59:59.000Z

319

Stellar Population in LLAGN.I: Ground-based observations  

E-Print Network (OSTI)

(Abridge): We present a spectroscopic study of the stellar populations of Low Luminosity AGN (LLAGN). Our main goal is to determine whether the stars who live in the innermost (100 pc-scale) regions of these galaxies are in some way related to the emission line properties, which would imply a link between the stellar population and the ionization mechanism. High signal to noise, ground based long-slit spectra in the 3500--5500 A interval were collected for 60 galaxies.Our main findings are: (1) Few LLAGN have a detectable young (weak [OI] emission, but rare (10 %) in LLAGN with stronger [OI]. This is intriguing since LLAGN with weak [OI] have been previously hypothesized to be ``transition objects'' in which both an AGN and young stars contribute to the emission-line excitation. Massive stars, if present, are completely outshone by intermediate age and old stars in the optical. This happens in at least a couple of objects where independent UV spectroscopy detects young starbursts not seen in the optical. (4) Objects with predominantly old stars span the whole range of [OI]/Halpha values, but (5) sources with significant young and/or intermediate age populations are nearly all (90%) weak [OI] emitters.

Roberto Cid Fernandes; Rosa M. Gonzalez Delgado; Henrique Schmitt; Thaisa Storchi-Bergmann; Lucimara P. Martins; Enrique Perez; Timothy Heckman; Claus Leitherer; Daniel Schaerer

2004-01-21T23:59:59.000Z

320

STELLAR ELEMENTAL ABUNDANCE PATTERNS: IMPLICATIONS FOR PLANET FORMATION  

SciTech Connect

The solar photosphere is depleted in refractory elements compared to most solar twins, with the degree of depletion increasing with an element's condensation temperature. Here, I show that adding 4 Earth masses of Earth-like and carbonaceous-chondrite-like material to the solar convection zone brings the Sun's composition into line with the mean value for the solar twins. The observed solar composition could have arisen if the Sun's convection zone accreted material from the solar nebula that was depleted in refractory elements due to the formation of the terrestrial planets and ejection of rocky protoplanets from the asteroid belt. Most solar analogs are missing 0-10 Earth masses of rocky material compared to the most refractory-rich stars, providing an upper limit to the mass of rocky terrestrial planets that they possess. The missing mass is correlated with stellar metallicity. This suggests that the efficiency of planetesimal formation increases with stellar metallicity. Stars with and without known giant planets show a similar distribution of abundance trends. If refractory depletion is a signature of the presence of terrestrial planets, this suggests that there is not a strong correlation between the presence of terrestrial and giant planets in the same system.

Chambers, J. E., E-mail: chambers@dtm.ciw.ed [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States)

2010-11-20T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

FESAC White Paper Path to Market for Compact Systems July 2012 The Path to Market for Compact Modular Fusion Power Cores1  

E-Print Network (OSTI)

FESAC White Paper Path to Market for Compact Systems July 2012 The Path to Market for Compact of Representatives (2010) #12;FESAC White Paper Path to Market for Compact Systems July 2012 (TRL) of a technology) distributed power generation. These units can be added to existing facilities when and where needed, or phased

322

National System Templates: Building Sustainable National Inventory...  

Open Energy Info (EERE)

National System Templates: Building Sustainable National Inventory Management Systems Jump to: navigation, search Tool Summary Name: National System Templates: Building Sustainable...

323

National Security Initiatives | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Bioinformatics Facilities Events and Conferences Supporting Organizations National Security Home | Science & Discovery | National Security | Initiatives SHARE National...

324

National Preparedness Goal  

Science Conference Proceedings (OSTI)

... impact on security, national economic security, national public health or ... technology; national monuments and icons; nuclear reactors, material, and ...

2011-10-20T23:59:59.000Z

325

Cape Light Compact - Commercial, Industrial and Municipal Buildings Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Cape Light Compact - Commercial, Industrial and Municipal Buildings Cape Light Compact - Commercial, Industrial and Municipal Buildings Energy Efficiency Rebate Program Cape Light Compact - Commercial, Industrial and Municipal Buildings Energy Efficiency Rebate Program < Back Eligibility Commercial Industrial Local Government Savings Category Heating & Cooling Commercial Heating & Cooling Heating Cooling Manufacturing Other Construction Heat Pumps Appliances & Electronics Commercial Lighting Lighting Commercial Weatherization Water Heating Maximum Rebate Retrofit: 50% of cost of upgraded equipment, or an amount that buys down the cost of the project to a 1.5 year simple payback. New Construction: 70% of incremental cost of higher efficiency equipment, or an amount that buys down the incremental investment to a 1.5 year simple

326

Cape Light Compact - Residential Energy Efficiency Rebate Program |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Cape Light Compact - Residential Energy Efficiency Rebate Program Cape Light Compact - Residential Energy Efficiency Rebate Program Cape Light Compact - Residential Energy Efficiency Rebate Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Home Weatherization Commercial Weatherization Cooling Construction Design & Remodeling Sealing Your Home Ventilation Heat Pumps Windows, Doors, & Skylights Solar Water Heating Maximum Rebate Home Energy Assessment/Weatherization: $2,000 Income Eligible Weatherization Measures: $2,000 - $3,000 Program Info State Massachusetts Program Type Local Rebate Program Rebate Amount Home Energy Assessment/Weatherization: 75% Single Family Energy Star Home: $750 - $8,000 Multi-Family Energy Star Home: $350 - $4,000/unit Income Eligible Weatherization Measures: 100% of cost

327

Compact multiwavelength transmitter module for multimode fiber optic ribbon cable  

DOE Patents (OSTI)

A compact multiwavelength transmitter module for multimode fiber optic ribbon cable, which couples light from an M.times.N array of emitters onto N fibers, where the M wavelength may be distributed across two or more vertical-cavity surface-emitting laser (VCSEL) chips, and combining emitters and multiplexer into a compact package that is compatible with placement on a printed circuit board. A key feature is bringing together two emitter arrays fabricated on different substrates--each array designed for a different wavelength--into close physical proximity. Another key feature is to compactly and efficiently combine the light from two or more clusters of optical emitters, each in a different wavelength band, into a fiber ribbon.

Deri, Robert J. (Pleasanton, CA); Pocha, Michael D. (Livermore, CA); Larson, Michael C. (Goleta, CA); Garrett, Henry E. (Livermore, CA)

2002-01-01T23:59:59.000Z

328

Micromechanics of compaction in an analogue reservoir sandstone  

SciTech Connect

Energy production, deformation, and fluid transport in reservoirs are linked closely. Recent field, laboratory, and theoretical studies suggest that, under certain stress conditions, compaction of porous rocks may be accommodated by narrow zones of localized compressive deformation oriented perpendicular to the maximum compressive stress. Triaxial compression experiments were performed on Castlegate, an analogue reservoir sandstone, that included acoustic emission detection and location. Initially, acoustic emissions were focused in horizontal bands that initiated at the sample ends (perpendicular to the maximum compressive stress), but with continued loading progressed axially towards the center. This paper describes microscopy studies that were performed to elucidate the micromechanics of compaction during the experiments. The microscopy revealed that compaction of this weakly-cemented sandstone proceeded in two phases: an initial stage of porosity decrease accomplished by breakage of grain contacts and grain rotation, and a second stage of further reduction accommodated by intense grain breakage and rotation.

DIGIOVANNI,ANTHONY A.; FREDRICH,JOANNE T.; HOLCOMB,DAVID J.; OLSSON,WILLIAM A.

2000-02-28T23:59:59.000Z

329

Energy Cost Calculator for Compact Fluorescent Lamps | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Compact Fluorescent Lamps Compact Fluorescent Lamps Energy Cost Calculator for Compact Fluorescent Lamps October 8, 2013 - 2:18pm Addthis This tool calculates the payback period for your calc retrofit project. Modify the default values to suit your project requirements. Existing incandescent lamp wattage Watts Incandescent lamp cost dollars Incandescent lamp life 1000 hours calc wattage Watts calc cost dollars calc life (6000 hours for moderate use, 10000 hours for high use) 8000 hours Number of lamps in retrofit project Hours operating per week hours Average cost of electricity 0.06 $/kWh Relamper labor costs $/hr Time taken to retrofit all lamps in this project min Time taken to relamp one lamp min Type of Relamping Practiced: Group Relamping: Calculate Simple Payback Period months

330

Dartmouth Stellar Evolution Database and the ACS Survey of Galactic Globular Clusters II. Stellar Evolution Tracks, Isochrones, Luminosity Functions, and Synthetic Horizontal-Branch Models  

DOE Data Explorer (OSTI)

Web tools are also available at the home page (http://stellar.dartmouth.edu/~models/index.html). These tools allow users to create isochrones and convert them to luminosity functions or create synthetic horizontal branch models.

Dotter, A; Chaboyer, B; Jevremovic, D; Kostov, V; Baron, E; Ferguson, J; Sarajedini, A; Anderson, J

331

Compile-Time Compaction Of Traces For Memory Simulation  

E-Print Network (OSTI)

This thesis examines compile-time compaction of program execution traces. It presents a new method for compacting traces for memory simulation. Further, it describes a tool prototype that implements the method. Experiments with the tool prototype show that the new method reduces the time needed in simulating the operation of memories. Memory simulation is needed in the performance analysis and in the design of programs. In high performance applications, the data transfer between different layers of memory is one of the main bottlenecks. A program execution trace is a list of memory references. Using traces as simulation inputs is a flexible way of analyzing the memory perfor...

Vesa Hirvisalo; Vesa Hirvisalo; Dr. Tech Esko Nuutila

1998-01-01T23:59:59.000Z

332

Compact two-beam push-pull free electron laser  

DOE Patents (OSTI)

An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

Hutton, Andrew (Yorktown, VA)

2009-03-03T23:59:59.000Z

333

Plasma Frequency Shift Due to a Slowly Rotating Compact Star  

E-Print Network (OSTI)

We investigate the effects of a slowly rotating compact gravitational source on electron oscillations in a homogeneous electrically neutral plasma in the absence of an external electric or magnetic field. Neglecting the random thermal motion of the electrons we assume the gravitoelectromagnetic approximation to the general theory of relativity for the gravitational field. It is shown that there is a shift in the plasma frequency and hence in the dielectric constant of the plasma due to the gravitomagnetic force. We also give estimates for the difference in the frequency of radially transmitted electromagnetic signals for typical compact star candidates.

Babur M. Mirza; Hamid Saleem

2005-01-01T23:59:59.000Z

334

Compaction and mobility in randomly agitated granular assemblies  

E-Print Network (OSTI)

We study the compaction and mobility properties of a dense granular material under weak random vibration. By putting in direct contact millimetric glass beads with piezoelectric transducers we manage to inject energy to the system in a disordered manner with accelerations much smaller than gravity, resulting in a slow compaction dynamics and no convection. We characterize the mobility inside the medium by pulling through it an intruder grain at constant velocity. We present an extensive study of the relation between drag force and velocity for different vibration conditions and sizes of the intruder.

G. Caballero; J. Lanuza; E. Clement

2005-04-25T23:59:59.000Z

335

On the string topology category of compact Lie groups.  

E-Print Network (OSTI)

This paper examines the string topology category of a manifold, defined by Blumberg, Cohen and Teleman. Since the string topology category is a subcategory of a compactly generated triangulated category, the machinery of stratification, constructed by Benson, Krause and Iyengar, can be applied in order to gain an understanding of the string topology category. It is shown that an appropriate stratification holds when the manifold in question is a simply connected compact Lie group. This last result is used to derive some properties of the relevant string topology categories.

Shoham Shamir

336

SPATIALLY RESOLVED SPECTROSCOPIC STAR FORMATION HISTORIES OF NEARBY DISKS: HINTS OF STELLAR MIGRATION  

SciTech Connect

We use the Mitchell Spectrograph (formerly VIRUS-P) to observe 12 nearby disk galaxies. We successfully measure ages in the outer disk in six systems. In three cases (NGC 2684, NGC 6155, and NGC 7437), we find that a downward break in the disk surface brightness profile corresponds with a change in the dominant stellar population with the interior being dominated by active star formation and the exterior having older stellar populations that are best fit with star formation histories that decline with time. The observed increase in average stellar ages beyond a profile break is similar to theoretical models that predict surface brightness breaks are caused by stellar migration, with the outer disk being populated from scattered old interior stars. In three more cases (IC 1132, NGC 4904, and NGC 6691), we find no significant change in the stellar population as one crosses the break radius. In these galaxies, both the inner and outer disks are dominated by active star formation and younger stellar populations. While radial migration can contribute to the stellar populations beyond the break, it appears that more than one mechanism is required to explain all of our observed stellar profile breaks.

Yoachim, Peter [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Roskar, Rok [Institute for Theoretical Physics, University of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland); Debattista, Victor P., E-mail: yoachim@u.washington.edu [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

2012-06-20T23:59:59.000Z

337

Lithium in cool stellar atmospheres: Big bang nucleosynthesis and extrasolar planets  

E-Print Network (OSTI)

Lithium in cool stellar atmospheres: Big bang nucleosynthesis and extrasolar planets Matthias Steffen and Elisabetta Caffau Sternphysik In metal-poor stellar atmospheres, the Lithium line at 6707 Ã?-NLTE, respectively. The accurate spectroscopic determination of the Lithium abundance and in particular the 6Li/7Li

338

STELLAR PULSATIONS AND PERIOD CHANGES IN THE SX PHOENICIS STAR XX CYGNI  

SciTech Connect

Time-series photometric observations were made for the SX Phoenicis star XX Cyg between 2007 and 2011 at the Xinglong Station of National Astronomical Observatories of China. With the light curves derived from the new observations, we do not detect any secondary maximum in the descending portion of the light curves of XX Cyg, as reported in some previous work. Frequency analysis of the light curves confirms a fundamental frequency f{sub 0} = 7.4148 cycles day{sup -1} and up to 19 harmonics, 11 of which are newly detected. However, no secondary mode of pulsation is detected from the light curves. The O-C diagram, produced from 46 newly determined times of maximum light combined with those derived from the literature, reveals a continuous period increase with the rate of (1/P)(dP/dt) = 1.19(13) Multiplication-Sign 10{sup -8} yr{sup -1}. Theoretical rates of period change due to the stellar evolution were calculated with a modeling code. The result shows that the observed rate of period change is fully consistent with period change caused by evolutionary behavior predicted by standard theoretical models.

Yang, X. H.; Fu, J. N.; Zha, Q., E-mail: jnfu@bnu.edu.cn [Astronomy Department, Beijing Normal University, Beijing 100875 (China)

2012-10-01T23:59:59.000Z

339

A tandem-based compact dual-energy gamma generator  

E-Print Network (OSTI)

DE-AC02-05CH11231 and by Sandia National Laboratories underT. Raber, and P. Rossi, Sandia National Laboratories Reportand Paula Provencio at Sandia National Laboratories for

Persaud, A.

2010-01-01T23:59:59.000Z

340

Manager, Sandia National Laboratories | National Nuclear Security...  

National Nuclear Security Administration (NNSA)

Sandia National Laboratories | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response...

Note: This page contains sample records for the topic "national compact stellarator" 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

The 1998 November 14 Occultation of GSC 0622-00345 by Saturn. I. Techniques for Ground-Based Stellar Occultations  

E-Print Network (OSTI)

On 1998 November 14, Saturn and its rings occulted the star GSC 0622-00345. We observed atmospheric immersion with NSFCAM at the National Aeronautics and Space Administration's Infrared Telescope Facility on Mauna Kea, Hawaii. Immersion occurred at 55.5\\circ S planetocentric latitude. A 2.3 {\\mu}m, methane-band filter suppressed reflected sunlight. Atmospheric emersion and ring data were not successfully obtained. We describe our observation, light-curve production, and timing techniques, including improvements in aperture positioning, removal of telluric scintillation effects, and timing. Many of these techniques are known within the occultation community, but have not been described in the reviewed literature. We present a light curve whose signal-to-noise ratio per scale height is 267, among the best ground-based signals yet achieved, despite a disadvantage of up to 8 mag in the stellar flux compared to prior work.

Harrington, Joseph; 10.1088/0004-637X/716/1/398

2010-01-01T23:59:59.000Z

342

Stability of the toroidal magnetic field in stellar radiation zones  

E-Print Network (OSTI)

Understanding the stability of the magnetic field in radiation zones is of crucial importance for various processes in stellar interior like mixing, circulation and angular momentum transport. The stability properties of a star containing a prominent toroidal field in a radiation zone is investigated by means of a linear stability analysis in the Boussinesq approximation taking into account the effect of thermal conductivity. The growth rate of the instability is explicitly calculated and the effects of stable stratification and heat transport are discussed in detail. It is argued that the stabilizing influence of gravity can never entirely suppress the instability caused by electric currents in radiation zones although the stable stratification can significantly decrease the growth rate of instability

Bonanno, Alfio

2011-01-01T23:59:59.000Z

343

Rotational suppression of the Tayler instability in stellar radiation zones  

E-Print Network (OSTI)

The study of the magnetic field in stellar radiation zones is an important topic in modern astrophysics because the magnetic field can play an important role in several transport phenomena such as mixing and angular momentum transport. We consider the influence of rotation on stability of a predominantly toroidal magnetic field in the radiation zone. We find that the effect of rotation on the stability depends on the magnetic configuration of the basic state. If the toroidal field increases sufficiently rapidly with the spherical radius, the instability cannot be suppressed entirely even by a very fast rotation although the strength of the instability can be significantly reduced. On the other hand, if the field increases slowly enough with the radius or decreases, the instability has a threshold and can be completely suppressed in rapidly rotating stars. We find that in the regions where the instability is entirely suppressed a particular type of magnetohydrodynamic waves may exist which are marginally stabl...

Bonanno, Alfio

2013-01-01T23:59:59.000Z

344

CESAM: a free code for stellar evolution calculations  

E-Print Network (OSTI)

The Cesam code is a consistent set of programs and routines which perform calculations of 1D quasi-hydrostatic stellar evolution including microscopic diffusion of chemical species and diffusion of angular momentum. The solution of the quasi-static equilibrium is performed by a collocation method based on piecewise polynomials approximations projected on a B-spline basis; that allows stable and robust calculations, and the exact restitution of the solution, not only at grid points, even for the discontinuous variables. Other advantages are the monitoring by only one parameter of the accuracy and its improvement by super-convergence. An automatic mesh refinement has been designed for adjusting the localisations of grid points according to the changes of unknowns. For standard models, the evolution of the chemical composition is solved by stiffly stable schemes of orders up to four; in the convection zones mixing and evolution of chemical are simultaneous. The solution of the diffusion equation employs the Gale...

Morel, Pierre

2008-01-01T23:59:59.000Z

345

Carbon-poor stellar cores as supernova progenitors  

E-Print Network (OSTI)

Exploring stellar models which ignite carbon off-center (in the mass range of about 1.05 - 1.25 Msun, depending on the carbon mass fraction) we find that they may present an interesting SN I progenitor scenario, since whereas in the standard scenario runaway always takes place at the same density of about 2 X 10^9 gr/cm^3, in our case, due to the small amount of carbon ignited, we get a whole range of densities from 1 X 10^9 up to 6 X 10^9 gr/cm^3. These results could contribute in resolving the emerging recognition that at least some diversity among SNe I exists, since runaway at various central densities is expected to yield various outcomes in terms of the velocities and composition of the ejecta, which should be modeled and compared to observations.

Roni Waldman; Zalman Barkat

2007-01-31T23:59:59.000Z

346

Effect of superbanana diffusion on fusion reactivity in stellarators  

Science Conference Proceedings (OSTI)

Fusion reactivity is usually obtained using a Maxwellian distribution. However, energy-dependent radial diffusion can modify the energy distribution. Superbanana diffusion is energy-dependent and occurs in nonaxisymmetric magnetic confinement devices, such as stellarators, because of ripple-trapped particles which can take large steps between collisions. In this paper, the D-T fusion reactivity is calculated using a non-Maxwellian energy distribution obtained by solving the Fokker-Planck equation numerically, including radial superbanana diffusion as well as energy scattering. The ions in the tail of the distribution, with energies larger than thermal, which are most needed for fusion, are depleted by superbanana diffusion. In this paper, it is shown that the D-T fusion reactivity is reduced by tail ion depletion due to superbanana diffusion, by roughly a factor of 0.5 for the parameters used in the calculation.

Hinton, Fred L. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, California 92093-0424 (United States)

2012-08-15T23:59:59.000Z

347

Compact Einstein-Weyl Manifolds With Large Symmetry Group  

E-Print Network (OSTI)

A geometric classification of the compact four-dimensional Einstein-Weyl manifolds with at least four-dimensional symmetry group is given. Our results also sharpen previous results on four-dimensional Einstein metrics and correct Parker's topological classification of cohomogeneity-one four-manifolds.

Anders Bisbjerg Madsen; Henrik Pedersen; Yat Sun Poon; Andrew Swann

1995-01-01T23:59:59.000Z

348

Identification of transparent, compact, accurate and reliable linguistic fuzzy models  

Science Conference Proceedings (OSTI)

Transparency, accuracy, compactness and reliability all appear to be vital (even though somewhat contradictory) requirements when it comes down to linguistic fuzzy modeling. This paper presents a methodology for simultaneous optimization of these criteria ... Keywords: Complexity reduction, Fuzzy modeling, Interpretability of fuzzy systems

Andri Riid; Ennu Rüstern

2011-10-01T23:59:59.000Z

349

A Compact Wireless Charging System for Electric Vehicles  

Science Conference Proceedings (OSTI)

In this paper, a compact high efficiency wireless power transfer system has been designed and developed. The detailed gate drive design, cooling system design, power stage development, and system assembling are presented. The successful tests verified the feasibility of wireless power transfer system to achieve over-all 90% efficiency.

Ning, Puqi [ORNL; Miller, John M [ORNL; Onar, Omer C [ORNL; White, Cliff P [ORNL

2013-01-01T23:59:59.000Z

350

The Hot Working Behaviour of Mar M200 Superalloy Compacts  

Science Conference Proceedings (OSTI)

testing in the range 105O'C to 12OO'C at constant true strain rates between 10m4 s-l and 1 s,-l. The compacts were pressed either below or above the y' solvus.

351

Compact X-ray Light Source Workshop Report  

SciTech Connect

This report, produced jointly by EMSL and FCSD, is the result of a workshop held in September 2011 that examined the utility of a compact x-ray light source (CXLS) in addressing many scientific challenges critical to advancing energy science and technology.

Thevuthasan, Suntharampillai; Evans, James E.; Terminello, Louis J.; Koppenaal, David W.; Manke, Kristin L.; Plata, Charity

2012-12-01T23:59:59.000Z

352

Ultra-compact Marx-type high-voltage generator  

DOE Patents (OSTI)

An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

Goerz, David A. (Brentwood, CA); Wilson, Michael J. (Modesto, CA)

2000-01-01T23:59:59.000Z

353

Compact data format for advertising and discovery in ubiquitous networks  

Science Conference Proceedings (OSTI)

In this paper, we describe a packet data size minimization method designed specifically for advertising and discovery in ubiquitous networks. The minimization is effective for achieving superior discovery performance characteristics such as discovery ... Keywords: compact data format, discovery system, service discovery

Pavel Poupyrev; Yoshihiro Kawahara; Peter Davis; Hiroyuki Morikawa

2007-11-01T23:59:59.000Z

354

Compact anhydrous HCl to aqueous HCl conversion system  

DOE Patents (OSTI)

The present invention is directed to an inexpensive and compact apparatus adapted for use with a [sup 196]Hg isotope separation process and the conversion of anhydrous HCl to aqueous HCl without the use of air flow to carry the HCl vapor into the converter system.

Grossman, M.W.; Speer, R.

1993-06-01T23:59:59.000Z

355

Fouling characteristics of compact heat exchangers and enhanced tubes.  

Science Conference Proceedings (OSTI)

Fouling is a complex phenomenon that (1) encompasses formation and transportation of precursors, and (2) attachment and possible removal of foulants. A basic understanding of fouling mechanisms should guide the development of effective mitigation techniques. The literature on fouling in complex flow passages of compact heat exchangers is limited; however, significant progress has been made with enhanced tubes.

Panchal, C. B.; Rabas, T. J.

1999-07-15T23:59:59.000Z

356

Compact anhydrous HCl to aqueous HCl conversion system  

DOE Patents (OSTI)

The present invention is directed to an inexpensive and compact apparatus adapted for use with a .sup.196 Hg isotope separation process and the conversion of anhydrous HCl to aqueous HCl without the use of air flow to carry the HCl vapor into the converter system.

Grossman, Mark W. (Belmont, MA); Speer, Richard (S. Hamilton, MA)

1993-01-01T23:59:59.000Z

357

Direct construction of compact context-dependency transducers from data  

Science Conference Proceedings (OSTI)

This paper describes a new method for building compact context-dependency transducers for finite-state transducer-based ASR decoders. Instead of the conventional phonetic decision tree growing followed by FST compilation, this approach incorporates the ... Keywords: LVCSR, WFST

David Rybach, Michael Riley, Chris Alberti

2014-01-01T23:59:59.000Z

358

On-Line Construction of Compact Directed Acyclic Word Graphs  

Science Conference Proceedings (OSTI)

A Compact Directed Acyclic Word Graph (CDAWG) is a space-efficient text indexing structure, that can be used in several different string algorithms, especially in the analysis of biological sequences. In this paper, we present a new on-line algorithm ...

Shunsuke Inenaga; Hiromasa Hoshino; Ayumi Shinohara; Masayuki Takeda; Setsuo Arikawa; Giancarlo Mauri; Giulio Pavesi

2001-07-01T23:59:59.000Z

359

A compact FPGA-based montgomery multiplier over prime fields  

Science Conference Proceedings (OSTI)

This work describes a compact FPGA hardware architecture for computing modular multiplications over GF(p) using the Montgomery method, suitable for public key cryptography for embedded or mobile systems. The multiplier is parameterizable, allowing ... Keywords: coprocessor, finite field arithmetic, fpga, montgomery multiplication, prime fields

Miguel Morales-Sandoval; Arturo Diaz-Perez

2013-05-01T23:59:59.000Z

360

ULTRA-COMPACT ACCELERATOR TECHNOLOGIES FOR APPLICATION IN NUCLEAR TECHNIQUES  

Science Conference Proceedings (OSTI)

We report on compact accelerator technology development for potential use as a pulsed neutron source quantitative post verifier. The technology is derived from our on-going compact accelerator technology development program for radiography under the US Department of Energy and for a clinic sized compact proton therapy systems under an industry sponsored Cooperative Research and Development Agreement. The accelerator technique relies on the synchronous discharge of a prompt pulse generating stacked transmission line structure with the beam transit. The goal of this technology is to achieve {approx}10 MV/m gradients for 10s of nanoseconds pulses and to {approx}100 MV/m gradients for {approx}1 ns systems. As a post verifier for supplementing existing x-ray equipment, this system can remain in a charged, stand-by state with little or no energy consumption. We detail the progress of our overall component development effort with the multilayer dielectric wall insulators (i.e., the accelerator wall), compact power supply technology, kHz repetition-rate surface flashover ion sources, and the prompt pulse generation system consisting of wide-bandgap switches and high performance dielectric materials.

Sampayan, S; Caporaso, G; Chen, Y; Carazo, V; Falabella, S; Guethlein, G; Guse, S; Harris, J R; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Paul, A C; Pearson, D; Poole, B; Schmidt, R; Sanders, D; Selenes, K; Sitaraman, S; Sullivan, J; Wang, L; Watson, J

2009-06-11T23:59:59.000Z

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


361

National System Templates: Building Sustainable National Inventory  

Open Energy Info (EERE)

National System Templates: Building Sustainable National Inventory National System Templates: Building Sustainable National Inventory Management Systems Jump to: navigation, search Tool Summary LAUNCH TOOL Name: National System Templates: Building Sustainable National Inventory Management Systems Agency/Company /Organization: United States Environmental Protection Agency, United States Agency for International Development Sector: Energy, Land Focus Area: Non-renewable Energy, Forestry, Agriculture Topics: GHG inventory Resource Type: Guide/manual, Training materials Website: www.epa.gov/climatechange/emissions/ghginventorycapacitybuilding/templ National System Templates: Building Sustainable National Inventory Management Systems Screenshot References: National System Templates: Building Sustainable National Inventory Management Systems[1]

362

National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Homesteading on the Pajarito Plateau Homesteading on the Pajarito Plateau topic of inaugural lecture at Los Alamos National Laboratory January 4, 2013 Lecture series begins yearlong commemoration of 70th anniversary LOS ALAMOS, NEW MEXICO, Jan. 3, 2013-In commemoration of its 70th anniversary, Los Alamos National Laboratory kicks off a yearlong lecture series on Wednesday, Jan. 9, at 5:30 p.m. with a presentation about homesteading on the Pajarito Plateau at the Bradbury Science Museum, 1350 Central Avenue, Los Alamos. - 2 - The inaugural lecture is based on a book by local writers Dorothy Hoard, Judy Machen and Ellen McGehee about the area's settlement between 1887 and 1942. On hikes across the Pajarito Plateau, Hoard envisioned the Los Alamos area before modern roads and bridges made transportation much easier. The trails she walked

363

NATIONAL NEWS  

NLE Websites -- All DOE Office Websites (Extended Search)

March 5, 2010 National News......................................................................3 Schumer Proposal to Halt ARRA Funds for Renewable Projects Would Cause Immediate Job Loss in U.S., DOE Officials Tell Congress .................................................................................................................................. 3 Geothermal Energy Holds Strong Presence at Renewable Energy World Conference; Applications with Oil and Gas Coproduction Gain Attention .......................................................................................................................... 4 House Subcommittee on Energy and Mineral Resources Hold Legislative Hearing on the Geothermal Production and Expansion Act, HR 3709 ..............................................................................................................

364

Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts  

SciTech Connect

The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Five irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These five compacts also included all four TRISO coating variations irradiated in the AGR experiment. The five compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. Approximately 40 to 80 particles within each cross section were exposed near enough to mid-plane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 830 classified particles allowed other relationships among morphological types to be established.

Paul Demkowicz; Scott Ploger; John Hunn

2012-05-01T23:59:59.000Z

365

Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts  

SciTech Connect

The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Six irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These six compacts also included all four TRISO coating variations irradiated in the AGR experiment. The six compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. From 36 to 79 particles within each cross section were exposed near enough to midplane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 931 classified particles allowed other relationships among morphological types to be established.

Paul Demkowicz; Scott Ploger; John Hunn; Jay S. Kehn

2012-09-01T23:59:59.000Z

366

Diffusion of inorganic chemical wastes in compacted clay  

SciTech Connect

The factors that were investigated included the water content/dry unit weight, the method of compaction, the mineralogy of the soil, and the concentration of the ions. The effective diffusion coefficients (D{asterisk}) of three anions (Cl{sup {minus}}, Br{sup {minus}}, and I{sup {minus}}) and three cations (K{sup +}, Cd{sup 2+}, and Zn{sup 2+}) in a simulated waste leachate were measured. Two clay soils (kaolinite and Lufkin clay) and a sand were used in the study. The clay samples were compacted and pre-soaked to minimize hydraulic gradients due to negative pore pressures. Mass balance calculations were performed to indicate possible sinks/sources in the diffusion system. The results of the diffusion tests were analyzed using two analytical solutions to Fick's second law and a commercially available semi-analytical solution. The D{asterisk} values for tests using high-concentration (0.04 N) leachate generally fell in the narrow range of about 4.0 {times} 10{sup {minus}6} to 2.0 {times} 10{sup {minus}5} cm{sup 2}/s, and were relatively insensitive to compaction water content/dry unit weight and to compaction method. The variability in the results from the tests with low-concentration (0.013 N) leachate precluded any definite conclusions from these tests. The values of D{asterisk} measured in this study were compared to values from previous studies, and the D{asterisk} values from this study were found to be slightly conservative (i.e., high). However, the results of the tests may be affected by several chemical and physical factors, and care should be taken to ensure that the soils used in the tests are representative of those used in the application of the test results. Recommendations are made for estimating D{asterisk} values for use in the design of compacted clay barriers for the containment of inorganic chemical wastes.

Shackelford, C.D.

1988-01-01T23:59:59.000Z

367

A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.  

SciTech Connect

The University of Michigan and Sandia National Laboratories collaborated on the initial development of a compact single-camera approach for simultaneously measuring 3-D gasphase velocity and temperature fields at high frame rates. A compact diagnostic tool is desired to enable investigations of flows with limited optical access, such as near-wall flows in an internal combustion engine. These in-cylinder flows play a crucial role in improving engine performance. Thermographic phosphors were proposed as flow and temperature tracers to extend the capabilities of a novel, compact 3D velocimetry diagnostic to include high-speed thermometry. Ratiometric measurements were performed using two spectral bands of laser-induced phosphorescence emission from BaMg2Al10O17:Eu (BAM) phosphors in a heated air flow to determine the optimal optical configuration for accurate temperature measurements. The originally planned multi-year research project ended prematurely after the first year due to the Sandia-sponsored student leaving the research group at the University of Michigan.

Lu, Louise [University of Michigan, Ann Arbor, MI; Sick, Volker [University of Michigan, Ann Arbor, MI; Frank, Jonathan H.

2013-09-01T23:59:59.000Z

368

Development and Deployment of a Compact Eye-safe Scanning Differential Absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for MVA at Geologic Carbon Sequestration Sites  

NLE Websites -- All DOE Office Websites (Extended Search)

Deployment of a Deployment of a Compact Eye-safe Scanning Differential Absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for MVA at Geologic Carbon Sequestration Sites Description Through its core research and development program administered by the National Energy Technology Laboratory (NETL), the U.S. Department of Energy (DOE) emphasizes monitoring, verification, and accounting (MVA), as well as computer simulation, of possible carbon dioxide (CO 2 ) leakage at CO 2

369

Casimir potential of a compact object enclosed by a spherical cavity  

E-Print Network (OSTI)

We study the electromagnetic Casimir interaction of a compact object contained inside a closed cavity of another compact object. We express the interaction energy in terms of the objects’ scattering matrices and translation ...

Zaheer, Saad

370

Have You Switched to Compact Fluorescent Lights? Why or Why Not...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Switched to Compact Fluorescent Lights? Why or Why Not? Have You Switched to Compact Fluorescent Lights? Why or Why Not? May 1, 2009 - 1:52pm Addthis On Tuesday, John wrote about...

371

Heat transfer and condensation of water vapour from humid air in compact heat exchangers.  

E-Print Network (OSTI)

??In this thesis, an experimental and simulation study of heat transfer in water-to-air compact-plate heat exchanger is presented. A compact-plate heat exchanger made of polypropylene,… (more)

Saraireh, Mohammad

2012-01-01T23:59:59.000Z

372

A Four Cell Lattice for the UCLA Compact Light Source Synchrotron  

E-Print Network (OSTI)

SCMAG-659 A Four Cell Lattice for the UCLA Compact Lightof California A Four Cell Lattice for the UCLA Compact LightT m-2) SF SO Table 2: Lattice Parameters for the Six Cell

Garren, A.A.

2011-01-01T23:59:59.000Z

373

Design and Development of Integrated Compact Multiphase Separation System (CMSS)  

SciTech Connect

The petroleum industry has relied in the past mainly on conventional vessel-type separators, which are bulky, heavy and expensive, to process wellhead production of oil-water-gas flow. Economic and operational pressures continue to force the petroleum industry to seek less expensive and more efficient separation alternatives in the form of compact separators. The compact dimensions, smaller footprint and lower weight of compact separators have a potential for cost savings to the industry, especially in offshore and subsea applications. Also, compact separators reduce the inventory of hydrocarbons significantly, which is critical for environmental This report presents a brief overview of the activities and tasks accomplished during the Budget Period II (October 09, 2004-April 30, 2006) of the DOE project titled ''Design and Development of Integrated Compact Multiphase Separation System (CMSS{copyright})''. An executive summary is presented initially followed by the tasks of the current budget period. Then, detailed description of the experimental and modeling investigations are presented. Subsequently, the technical and scientific results of the activities of this project period are presented with discussions. The findings of this investigation are summarized in the ''Conclusions'' section In this investigation, the concept of CMSS{copyright} has been developed and is proven through simulation studies and validated by experimental data. As part of the second phase of the project (Budget Period II--10/09/2004-04/30/2006) experimental investigation of the integrated CMSS{copyright} for different configurations has been conducted in order to evaluate the performance of the individual separation components, and determine how they will affect the performance of each other when integrated in the CMSS{copyright}. An intelligent control system is also developed to improve the total system efficiency of Compact Multiphase Separation System (CMSS{copyright}). In mature oil fields, water handling poses a huge problem. Thus water knock out at the earliest stage helps in significant cost savings during handling, separation and transportation of oil. One of the objectives of the CMSS{copyright} configuration is to knock out free water from the upstream fluids. The results from theoretical and experimental studies show that Free Water Knock Out (FWKO) CMSS{copyright} system can be readily deployed in the field using the control system strategies designed, implemented and tested in this study.

Ram S. Mohan; Ovadia Shoham

2006-04-30T23:59:59.000Z

374

STELLAR POPULATIONS AND RADIAL MIGRATIONS IN VIRGO DISK GALAXIES  

SciTech Connect

We present new stellar age profiles, derived from well-resolved optical and near-infrared images of 64 Virgo cluster disk galaxies, whose analysis poses a challenge for current disk galaxy formation models. Our ability to break the age-metallicity degeneracy and the significant size of our sample represent key improvements over complementary studies of field disk galaxies. Our results can be summarized as follows: first, and contrary to observations of disk galaxies in the field, these cluster galaxies are distributed almost equally amongst the three main types of disk galaxy luminosity profiles (I/II/III), indicating that the formation and/or survival of Type II breaks is suppressed within the cluster environment. Second, we find examples of statistically significant inversions ({sup U}-shapes{sup )} in the age profiles of all three disk galaxy types, reminiscent of predictions from high-resolution simulations of classically truncated Type II disks in the field. These features characterize the age profiles for only about a third ({<=}36%) of each disk galaxy type in our sample. An even smaller fraction of cluster disks ({approx}11% of the total sample) exhibit age profiles that decrease outward (i.e., negative age gradients). Instead, flat and/or positive age gradients prevail ({>=}50%) within our Type I, II, and III subsamples. These observations thus suggest that while stellar migrations and inside-out growth can play a significant role in the evolution of all disk galaxy types, other factors contributing to the evolution of galaxies can overwhelm the predicted signatures of these processes. We interpret our observations through a scenario whereby Virgo cluster disk galaxies formed initially like their brethren in the field but which, upon falling into the cluster, were transformed into their present state through external processes linked to the environment (e.g., ram-pressure stripping and harassment). Current disk galaxy formation models, which have largely focused on field galaxies, fail to reproduce these results, thus calling for adequate hydrodynamical simulations of dense galaxy environments if we are to understand cluster disks. The current paper highlights numerous constraints for such simulations. In the Appendix, we confirm the claim by Erwin et al. that Type II breaks are absent in Virgo cluster S0s and discuss the detection of Type III breaks in such galaxies.

Roediger, Joel C.; Courteau, Stephane [Department of Physics, Engineering Physics and Astronomy, Queen's University, Kingston, Ontario (Canada); Sanchez-Blazquez, Patricia [Deptartamento de Fisica Teorica, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); McDonald, Michael, E-mail: jroediger@astro.queensu.ca, E-mail: courteau@astro.queensu.ca, E-mail: p.sanchezblazquez@uam.es, E-mail: mcdonald@space.mit.edu [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology Cambridge, MA (United States)

2012-10-10T23:59:59.000Z

375

Compact-designed supercapacitors using free-standing single-walled carbon nanotube films  

E-Print Network (OSTI)

Compact-designed supercapacitors using free-standing single-walled carbon nanotube films Zhiqiang0ee00261e We reported the realization of assembling compact-designed supercapacitors using large) were achieved from the prepared SWCNT film-based compact-designed supercapacitors with small equivalent

Wang, Wei Hua

376

Compact and mobile high resolution PET brain imager  

DOE Patents (OSTI)

A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

Majewski, Stanislaw (Yorktown, VA); Proffitt, James (Newport News, VA)

2011-02-08T23:59:59.000Z

377

Compact and mobile high resolution PET brain imager  

Science Conference Proceedings (OSTI)

A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

Majewski, Stanislaw (Yorktown, VA); Proffitt, James (Newport News, VA)

2011-02-08T23:59:59.000Z

378

Compact toroid experiments: spheromaks and field-reversed configurations  

SciTech Connect

Compact toroids (CT) containing both poloidal and toroidal magnetic field spheromaks, are generated in the CTX experiment using a magnetized coaxial plasma gun, and are trapped and stably confined in an oblate flux conserver. Total configuration lifetimes are observed up to approx. 0.8 ms, consistent with classical resistive decay. The field reversed configuration (FRC) is a high beta, axisymmetric, highly prolate compact toroid, containing only poloidal magnetic field, formed in a field-reversed theta pinch. A quiescent confinement period of 30 to 90 ..mu..s with T/sub i/ approx. 200 to 500 eV and n approx. 5 x 10/sup 15/ cm/sup -3/ is terminated by an n = 2 rotational instability. The FRC is stable to MHD modes including the tilting instability.

Quinn, W.E.

1982-01-01T23:59:59.000Z

379

NERSC and CRD Help Decipher Science from Compact Accelerator Simulations -  

NLE Websites -- All DOE Office Websites (Extended Search)

and CRD Help and CRD Help Decipher Science from Compact Accelerator Simulations NERSC and CRD Help Decipher Science from Compact Accelerator Simulations May 26, 2009 3D Particle Surfing : Electrons are moving from left to right in this LOASIS experiment. The blue shells show the plasma wake, while bunches of surfing electrons are shown as green and yellow. Green reveals low-energy particles, and yellow shows high-energy. The simulation was conducted in the VORPAL framework, and visualized with VisIt and VizSchema. Scientists use many different tools to understand the universe. While telescopes offer valuable insights about interactions between stars, planets and galaxies; particle accelerators give researchers a better understanding of the basic particles that make up these structures, as well

380

Solar System Signatures of Impacts by Compact Ultra Dense Objects  

E-Print Network (OSTI)

As a means of detecting compact ultra dense objects (CUDOs) with nuclear density or greater, and a mass $10^{-10}solar system bodies. We find that a heavy enough CUDO pulverizes, heats and entrains material in a small cylinder around its trajectory through the target body. Because the resulting impact features endure for geologic timescales, data is accumulated over the history of the solar system. Exclusion of all CUDO impact signatures would set a strong limit on their local abundance.

Labun, Lance; Rafelski, Johann

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Modeling of reservoir compaction and surface subsidence at South Belridge  

SciTech Connect

Finite-element models of depletion-induced reservoir compaction and surface subsidence have been calibrated with observed subsidence, locations of surface fissures, and regions of subsurface casing damage at South Belridge and used predictively for the evaluation of alternative reservoir-development plans. Pressure maintenance through diatomite waterflooding appears to be a beneficial means of minimizing additional subsidence and fissuring as well as reducing axial-compressive-type casing damage.

Hansen, K.S. [Shell Western E and P Inc., Houston, TX (United States); Chan, C.K. [Shell Oil Co., Houston, TX (United States); Prats, M.

1995-08-01T23:59:59.000Z

382

Compact nuclear power systems based on particle bed reactors  

SciTech Connect

Compact, low cost nuclear power systems with an extremely low radioactive inventory are described. These systems use the Particle Bed Reactor (PBR), in which HTGR particle fuel is contained in packed beds that are changed daily. The small diameter particle fuel (500 ..mu..m) is directly cooled utilizing the large heat transfer area available (7.8 m/sup 2//liter), thus allowing high bed power densities (MW/liter).

Horn, F.L.; Powell, J.R.; Steinberg, M.; Takahashi, H.

1986-01-01T23:59:59.000Z

383

Sensitivity in X-ray grating interferometry on compact systems  

SciTech Connect

The optimization of compact X-ray grating interferometry systems is crucial for the progress of this technique in industrial devices. Here, an analytical formulation for the sensitivity of the phase contrast image acquisition is derived using previous results from noise analyses. Furthermore, experimental measurements of the sensitivity for different configurations are compared, providing further insight into the dependence on polychromatic radiation. Finally, strategies for the geometrical optimization are given.

Thuering, Thomas; Modregger, Peter; Haemmerle, Stefan; Weiss, Stephan; Nueesch, Joachim; Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, Villigen PSI (Switzerland) and Institute for Biomedical Engineering, Swiss Federal Institute of Technology, Zurich (Switzerland); School of Biology and Medicine, University of Lausanne, Lausanne (Switzerland); SCANCO Medical AG, Bruettisellen (Switzerland)

2012-07-31T23:59:59.000Z

384

PREPARATION OF METAL POWDER COMPACTS PRIOR TO PRESSING  

DOE Patents (OSTI)

A method of fabricating uranium by a powder metallurgical technique is described. It consists in introducing powdered uranium hydride into a receptacle shaped to coincide with the coatour of the die cavity and heating the hydride so that it decomposes to uranium metal. The metal particles cohere in the shapw of the receptacle and thereafter the prefurmed metal powder is pressed and sintered to obtain a dense compact.

Mansfield, H.

1958-08-26T23:59:59.000Z

385

Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings  

DOE Patents (OSTI)

A compact imaging spectrometer comprising an entrance slit for directing light, a first means for receiving the light and focusing the light, an immersed diffraction grating that receives the light from the first means and defracts the light, a second means for receiving the light from the immersed diffraction grating and focusing the light, and an image plane that receives the light from the second means

Lerner, Scott A. (Livermore, CA); Bennett, Charles L. (Livermore, CA); Bixler, Jay V. (Oakland, CA); Kuzmenko, Paul J. (Livermore, CA); Lewis, Isabella T. (San Jose, CA)

2005-07-26T23:59:59.000Z

386

Stein's Method and Characters of Compact Lie Groups  

E-Print Network (OSTI)

Stein's method is used to study the trace of a random element from a compact Lie group or symmetric space. Central limit theorems are proved using very little information: character values on a single element and the decomposition of the square of the trace into irreducible components. This is illustrated for Lie groups of classical type and Dyson's circular ensembles. The approach in this paper will be useful for the study of higher dimensional characters, where normal approximations need not hold.

Jason Fulman

2008-06-13T23:59:59.000Z

387

Compact-range coordinate system established using a laser tracker.  

DOE Green Energy (OSTI)

Establishing a Cartesian coordinate reference system for an existing Compact Antenna Range using the parabolic reflector is presented. A SMX (Spatial Metrix Corporation) M/N 4000 laser-based coordinate measuring system established absolute coordinates for the facility. Electric field characteristics with positional movement correction are evaluated. Feed Horn relocation for alignment with the reflector axis is also described. Reference points are established for follow-on non-laser alignments utilizing a theodolite.

Gallegos, Floyd H.; Bryce, Edwin Anthony

2006-12-01T23:59:59.000Z

388

Lawrence Livermore National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Lawrence Livermore National Laboratory Lawrence Livermore National Laboratorys (LLNL) primary mission is research and development in support of national security. As a...

389

National Hydrogen Energy Roadmap  

NLE Websites -- All DOE Office Websites (Extended Search)

NATIONAL HYDROGEN ENERGY ROADMAP NATIONAL HYDROGEN ENERGY ROADMAP . . Toward a More Secure and Cleaner Energy Future for America Based on the results of the National Hydrogen...

390

Lawrence Livermore National Laboratory Lawrence Livermore National...  

National Nuclear Security Administration (NNSA)

racks "Green" supercomputer reduces energy footprint by 75% "Green" supercomputer reduces energy footprint by 75% Lawrence Livermore National Laboratory Lawrence Livermore National...

391

Sandia National Laboratories | National Nuclear Security Administratio...  

NLE Websites -- All DOE Office Websites (Extended Search)

Allison Davis Sandia National Laboratories Allison Davis Allison Davis Role: Sandia National Laboratories Award: NNSA Defense Programs Award of Excellence Profile: Two individuals...

392

Sandia National Laboratories Albuquerque | National Nuclear Security...  

NLE Websites -- All DOE Office Websites (Extended Search)

Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our Locations > Sandia National Laboratories Albuquerque Sandia National Laboratories Albuquerque http:...

393

Sandia National Laboratories | National Nuclear Security Administratio...  

NLE Websites -- All DOE Office Websites (Extended Search)

Kevin Eklund Sandia National Laboratories Kevin Eklund Kevin Eklund Role: Sandia National Laboratories Profile: Two individuals and nine teams received the NNSA Defense Programs...

394

National National Strategy for Pandemic Influenza, Implementation...  

NLE Websites -- All DOE Office Websites (Extended Search)

to renew a declaration of national emergency to prevent its automatic expiration. The Presidential declaration of a national emergency under the act is a prerequisite to...

395

National Supplemental Screening Program | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

National Supplemental Screening Program The National Supplemental Screening Program (NSSP) offers medical screenings at no charge for former U.S. Department of Energy (DOE) site...

396

Researcher, Sandia National Laboratories | National Nuclear Security...  

National Nuclear Security Administration (NNSA)

Paul Dodd Researcher, Sandia National Laboratories Paul Dodd Paul Dodd Role: Researcher, Sandia National Laboratories Award: Fellow of the Institute of Electrical & Electronics...

397

Engineer, Sandia National Laboratories | National Nuclear Security...  

National Nuclear Security Administration (NNSA)

Clifford Ho Engineer, Sandia National Laboratories Clifford Ho Clifford Ho Role: Engineer, Sandia National Laboratories Award: Asian American Engineer of the Year Profile: Clifford...

398

Detection of Small Kuiper Belt Objects by Stellar Occultations  

E-Print Network (OSTI)

Knowledge of the Kuiper Belt is currently limited to those objects that can be detected directly. Objects with diameters less than $\\sim$10km reflect too little light to be detected. These smaller bodies could contain most of the mass in the Kuiper Belt while the abundance of these bodies may constrain the distribution of mass. The overall size distribution of bodies within the Kuiper Belt can also be inferred from the relative abundances of sub-km and larger bodies. Stellar occultations are already used to study dark objects in the Solar System, such as asteroids or planetary rings. Occultation by a KBO of a size comparable to, or larger than, that of the Fresnel Scale will result in Fresnel diffraction. Detection of diffraction effects requires fast multiple-star photometry, which will be conducted in July 2007 using the Orthogonal Parallel Transfer Imaging Camera (OPTIC) mounted on the University of Hawaii 2.2m telescope on Mauna Kea. This paper details how knowledge of the mass and structure of the outer ...

Stevenson, R

2007-01-01T23:59:59.000Z

399

CESAM: a free code for stellar evolution calculations  

E-Print Network (OSTI)

The Cesam code is a consistent set of programs and routines which perform calculations of 1D quasi-hydrostatic stellar evolution including microscopic diffusion of chemical species and diffusion of angular momentum. The solution of the quasi-static equilibrium is performed by a collocation method based on piecewise polynomials approximations projected on a B-spline basis; that allows stable and robust calculations, and the exact restitution of the solution, not only at grid points, even for the discontinuous variables. Other advantages are the monitoring by only one parameter of the accuracy and its improvement by super-convergence. An automatic mesh refinement has been designed for adjusting the localisations of grid points according to the changes of unknowns. For standard models, the evolution of the chemical composition is solved by stiffly stable schemes of orders up to four; in the convection zones mixing and evolution of chemical are simultaneous. The solution of the diffusion equation employs the Galerkin finite elements scheme; the mixing of chemicals is then performed by a strong turbulent diffusion. A precise restoration of the atmosphere is allowed for.

Pierre Morel; Yveline Lebreton

2008-01-14T23:59:59.000Z

400

On the formation of dwarf galaxies and stellar halos  

E-Print Network (OSTI)

Using analytic arguments and a suite of very high resolution (10^3Msun per particle) cosmological hydro-dynamical simulations, we argue that high redshift, z ~ 10, M ~ 10^8Msun halos, form the smallest `baryonic building block' (BBB) for galaxy formation. These halos are just massive enough to efficiently form stars through atomic line cooling and to hold onto their gas in the presence of supernovae winds and reionisation. These combined effects, in particular that of the supernovae feedback, create a sharp transition: over the mass range 3-10x10^7Msun, the BBBs drop two orders ofmagnitude in stellar mass. Below ~2x10^7Msun, galaxies will be dark with almost no stars and no gas. Above this scale is the smallest unit of galaxy formation: the BBB. A small fraction (~100) of these gas rich BBBs fall in to a galaxy the size of the Milky Way. Ten percent of these survive to become the observed LG dwarf galaxies at the present epoch. Those in-falling halos on benign orbits which keep them far away from the Milky Wa...

Read, J I; Viel, M

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Why Buckling Stellar Bars Weaken in Disk Galaxies  

E-Print Network (OSTI)

Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks embedded in live halos, we have analyzed the bar structure throughout this instability and found that the outer third of the bar dissolves completely while the inner part (within the vertical inner Lindblad resonance) becomes less oval. The bar acquires the frequently observed peanut/boxy-shaped isophotes. We also find that the bar buckling is responsible for a mass injection above the plane, which is subsequently trapped by specific 3-D families of periodic orbits of particular shapes explaining the observed isophotes, in line with previous work. Using a 3-D orbit analysis and surfaces of sections, we infer that the outer part of the bar is dissolved by a rapidly widening stochastic region around its corotation radius -- a process related to the bar growth. This leads to a...

Martinez-Valpuesta, I

2004-01-01T23:59:59.000Z

402

Observational studies of stellar black hole binaries and ULXs  

E-Print Network (OSTI)

We outline a framework for understanding the X-ray spectra of high mass accretion rate stellar black holes based on X-ray data from RXTE and ASCA. Three spectral regimes can be separated out by the behaviour of the observed disk luminosity and temperature. The well established "standard regime" is seen when the disk dominates the spectrum, where only a small fraction of the luminosity is emitted in the power law tail. These spectra generally satisfy the standard relation expected for thermal emission from a constant area, namely that the disk bolometric luminosity, Ldisk, is proportional to its maximum temperature, Tin^4. However, at higher luminosities this starts to change to Tin^2. This "apparently standard regime" is still dominated by the disk emission, but this difference luminosity-temperature relation and subtle changes in spectral shape may show that another cooling process is required in addition to radiative cooling. At intermediate luminosities there is an anomalous regime (or weak very high state...

Kubota, A; Kubota, Aya; Makishima, Kazuo

2005-01-01T23:59:59.000Z

403

PROBING THE ROSETTE NEBULA STELLAR BUBBLE WITH FARADAY ROTATION  

SciTech Connect

We report the results of Faraday rotation measurements of 23 background radio sources whose lines of sight pass through or close to the Rosette Nebula. We made linear polarization measurements with the Karl G. Jansky Very Large Array (VLA) at frequencies of 4.4 GHz, 4.9 GHz, and 7.6 GHz. We find the background Galactic contribution to the rotation measure in this part of the sky to be +147 rad m{sup -2}. Sources whose lines of sight pass through the nebula have an excess rotation measure of 50-750 rad m{sup -2}, which we attribute to the plasma shell of the Rosette Nebula. We consider two simple plasma shell models and how they reproduce the magnitude and sign of the rotation measure, and its dependence on distance from the center of the nebula. These two models represent different modes of interaction of the Rosette Nebula star cluster with the surrounding interstellar medium. Both can reproduce the magnitude and spatial extent of the rotation measure enhancement, given plausible free parameters. We contend that the model based on a stellar bubble more closely reproduces the observed dependence of rotation measure on distance from the center of the nebula.

Savage, Allison H.; Spangler, Steven R.; Fischer, Patrick D. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)] [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)

2013-03-01T23:59:59.000Z

404

Compact high resolution isobar separator for study of exotic decays  

NLE Websites -- All DOE Office Websites (Extended Search)

Compact high resolution isobar separator for study of Compact high resolution isobar separator for study of exotic decays A. Piechaczek 1 , V. Shchepunov 1 , H. K. Carter 1 J. C. Batchelder 1 , E. F. Zganjar 2 1 UNIRIB, Oak Ridge Associated Universities, Oak Ridge, TN 37830 2 Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803 A compact isobar separator, based on the Multi-Pass-Time-of-Flight (MTOF) principle, is developed [1]. A mass resolving power (MRP) as spectrometer of 110,000 (FWHM) is achieved in Time-of-Flight spectra of N 2 molecules (no physical ion separation) after 300 laps or ToF = 9.7 ms. Operated as a separator [2], molecules of N 2 and CO with ∆M/M = 1/2500 or 10.433 MeV are separated with a Bradbury Nielsen electrostatic ion gate, and the MRP (FWHM) is about 40,000 after 120 laps. In the separator as well as in

405

VALIDATION OF A THERMAL CONDUCTIVITY MEASUREMENT SYSTEM FOR FUEL COMPACTS  

SciTech Connect

A high temperature guarded-comparative-longitudinal heat flow measurement system has been built to measure the thermal conductivity of a composite nuclear fuel compact. It is a steady-state measurement device designed to operate over a temperature range of 300 K to 1200 K. No existing apparatus is currently available for obtaining the thermal conductivity of the composite fuel in a non-destructive manner due to the compact’s unique geometry and composite nature. The current system design has been adapted from ASTM E 1225. As a way to simplify the design and operation of the system, it uses a unique radiative heat sink to conduct heat away from the sample column. A finite element analysis was performed on the measurement system to analyze the associated error for various operating conditions. Optimal operational conditions have been discovered through this analysis and results are presented. Several materials have been measured by the system and results are presented for stainless steel 304, inconel 625, and 99.95% pure iron covering a range of thermal conductivities of 10 W/m*K to 70 W/m*K. A comparison of the results has been made to data from existing literature.

Jeff Phillips; Colby Jensen; Changhu Xing; Heng Ban

2011-03-01T23:59:59.000Z

406

Ultra-Compact High-Efficiency Luminaire for General Illumination  

SciTech Connect

Cree has developed a new ultra-compact light emitting diode (LED) luminaire capable of providing high efficacy with excellent color quality that can lead to significant energy savings in todayâ??s commercial and retail applications. This success was based on an integrated development effort tailoring the LED component characteristics, optics, thermal management and driver design for the small footprint to achieve an overall system efficiency of â?¥ 70%. A new LED component was designed to provide high brightness and efficacy in a form factor that allowed for a small directional beam with a luminaire housing design able to dissipate the heat effectively using a small physical envelope. A very compact, 90% efficient driver was developed to meet the system performance while not taking away any thermal mass from the heat sink. A 91% efficient secondary optics was designed to maximize efficiency while providing a smooth beam. The reliability of the new LED component was robust under accelerated testing conditions. Luminaires were assembled integrating the novel LED component, secondary optics, heat sink and driver technology to demonstrate the system improvement. Cree has successfully completed this project by developing an ultra-compact LED luminaire that provided 380 lumens at a correlated color temperature (CCT) of 2822 K and color rendering index (CRI) of 94 with an efficacy of 94 lumens per watt (LPW) when operating at 4 W input power (steady state) with an overall system efficiency of 81%. At a higher input power of 9 Watts, the lamp provided 658 lumens at 71 LPW.

Ted Lowes

2012-04-08T23:59:59.000Z

407

THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY. III. MEASURING AGES AND MASSES OF PARTIALLY RESOLVED STELLAR CLUSTERS  

Science Conference Proceedings (OSTI)

The apparent age and mass of a stellar cluster can be strongly affected by stochastic sampling of the stellar initial mass function (IMF), when inferred from the integrated color of low-mass clusters ({approx}light of the fainter, more numerous unresolved stars can be analyzed separately. When comparing the light from the less luminous cluster members to models of unresolved light, more accurate age estimates can be obtained than when analyzing the integrated light from the entire cluster under the assumption that the IMF is fully populated. We show the success of this technique first using simulated clusters, and then with a stellar cluster in M31. This method represents one way of accounting for the discrete, stochastic sampling of the stellar IMF in less massive clusters and can be leveraged in studies of clusters throughout the Local Group and other nearby galaxies.

Beerman, Lori C.; Johnson, L. Clifton; Fouesneau, Morgan; Dalcanton, Julianne J.; Weisz, Daniel R.; Williams, Ben F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Seth, Anil C. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Bianchi, Luciana C. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Gouliermis, Dimitrios A. [Zentrum fuer Astronomie, Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Kalirai, Jason S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Larsen, Soren S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Melbourne, Jason L. [Caltech Optical Observatories, Division of Physics, Mathematics and Astronomy, Mail Stop 301-17, California Institute of Technology, Pasadena, CA 91125 (United States); Rix, Hans-Walter [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Skillman, Evan D., E-mail: beermalc@astro.washington.edu [Department of Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2012-12-01T23:59:59.000Z

408

Molecular and Stellar Disks Galaxies Lisa Young (New Mexico Tech) and Martin Bureau (Oxford)  

E-Print Network (OSTI)

Molecular and Stellar Disks Galaxies Lisa Young (New Mexico Tech) and Martin Bureau (Oxford galaxies contain molecular disks. These internal structures evolution galaxies. to place observational constraints on the formation in early galaxies studying the relationships between embedded disks, molecular

Bureau, Martin

409

DETECTING TRIAXIALITY IN THE GALACTIC DARK MATTER HALO THROUGH STELLAR KINEMATICS  

Science Conference Proceedings (OSTI)

Assuming the dark matter halo of the Milky Way to be a non-spherical potential (i.e., triaxial, prolate, oblate), we show how the assembling process of the Milky Way halo may have left long-lasting stellar halo kinematic fossils due to the shape of the dark matter halo. In contrast with tidal streams, which are associated with recent satellite accretion events, these stellar kinematic groups will typically show inhomogeneous chemical and stellar population properties. However, they may be dominated by a single accretion event for certain mass assembling histories. If the detection of these peculiar kinematic stellar groups were confirmed, they would be the smoking gun for the predicted triaxiality of dark halos in cosmological galaxy formation scenarios.

Rojas-Nino, Armando; Valenzuela, Octavio; Pichardo, Barbara [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, A.P. 70-264, 04510, Mexico, D.F., Universitaria, D.F. (Mexico); Aguilar, Luis A., E-mail: octavio@astro.unam.mx, E-mail: barbara@astro.unam.mx [Observatorio Astronomico Nacional, Universidad Nacional Autonoma de Mexico, Apdo. postal 877, 22800 Ensenada (Mexico)

2012-10-01T23:59:59.000Z

410

Nuclear | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

ARG-US RFID System for Managing High-Risk Materials More Rapid Detection of Strontium in Urine Samples RadTrac: Portable and Compact Tracking of Radioactive Materials Tracking...

411

Multimedia Resources, including the CMS Eye, from the Compact Muon Solenoid (CMS) Experiment at CERN  

DOE Data Explorer (OSTI)

The Compact Muon Solenoid (CMS) experiment is one of two large general-purpose particle physics detectors built on the proton-proton Large Hadron Collider (LHC) at CERN in Switzerland and France. The CMS detector is located in an underground cavern at Cessy in France. The CMS detector will study many aspects of proton collisions at 14 TeV, the center-of-mass energy of the LHC particle accelerator. [from http://en.wikipedia.org/wiki/Compact_Muon_Solenoid]

The US CMS collaboration, with 48 institutions, 420 Ph.D. physicists, over 100 graduate students, and nearly 200 engineers, technicians, and computer scientists is the largest national group in the CMS collaboration. US groups have made significant contributions to nearly every aspect of the detector throughout all phases including construction, installation and preparation for data-taking. The US collaboration also made major contributions to the construction and operation of the computing facilities needed to analyze the unprecedented amount of data to be generated by CMS. This work includes the software that allows physicists to operate the CMS detector, reconstruct the data, analyze it and extract new physics.

The CMS media website from CERN provides images, videos, presentations, and the CMS Eye, a system of webcams looking into the underground cavern at Cessy, into the control room, and even out of the window of the control room at the village of Cessy and the Jura Mountains. Many event displays are available in the image collections, as well as the CMS Photo Book covering 1998 û 2008 when CMS was being assembled, installed, and commissioned.

US-LHC and the International CMS Collaboration

412

Department of Energy National Laboratories  

Idaho National Laboratory SLAC National Accelerator Laboratory Department of Energy National Laboratories. Laboratory or Facility Website ...

413

Implications for National Policy  

Science Conference Proceedings (OSTI)

The World Is Flat: Making Materials Matter. National Policy Implications. Toni Marechaux. Board on Manufacturing and Engineering Design. National Research ...

414

Pangue hydro: Responding to the needs of a nation  

SciTech Connect

An overview of technical, financial, and regulatory issues affecting the 450-MW Pangue Hydroelectric Project in Chile is provided. The role of the project in the overall national electricity expansion plan is described. Unusual aspects of the project that are highlighted include the roller-compacted concrete construction of the dam, seismic design criteria for electromechanical turbines, and the water management control system. The influence of environmental, financial, and scheduling considerations on the project also receive emphasis.

Maturana, C. [Empresa Electrica Pangue S.A., Santiago (Chile)

1997-05-01T23:59:59.000Z

415

The Milky Way Tomography with SDSS. 2. Stellar Metallicity  

Science Conference Proceedings (OSTI)

In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra. Using effective temperature and metallicity derived from SDSS spectra for {approx}60,000 F and G type main sequence stars (0.2 < g-r < 0.6), we develop polynomial models, reminiscent of traditional methods based on the UBV photometry, for estimating these parameters from the SDSS u-g and g-r colors. These estimators reproduce SDSS spectroscopic parameters with a root-mean-square scatter of 100 K for effective temperature, and 0.2 dex for metallicity (limited by photometric errors), which are similar to random and systematic uncertainties in spectroscopic determinations. We apply this method to a photometric catalog of coadded SDSS observations and study the photometric metallicity distribution of {approx}200,000 F and G type stars observed in 300 deg{sup 2} of high Galactic latitude sky. These deeper (g < 20.5) and photometrically precise ({approx}0.01 mag) coadded data enable an accurate measurement of the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, that correspond to disk and halo. The best-fit number ratio of the two components is consistent with that implied by the decomposition of stellar counts profiles into exponential disk and power-law halo components by Juric et al. (2008). The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component can be modeled as a spatially invariant Gaussian distribution with a mean of [Fe/H] = -1.46 and a standard deviation of {approx}0.3 dex. The disk metallicity distribution is non-Gaussian, with a remarkably small scatter (rms {approx}0.16 dex) and the median smoothly decreasing with distance from the plane from -0.6 at 500 pc to -0.8 beyond several kpc. Similarly, we find using proper motion measurements that a non-Gaussian rotational velocity distribution of disk stars shifts by {approx}50 km/s as the distance from the plane increases from 500 pc to several kpc. Despite this similarity, the metallicity and rotational velocity distributions of disk stars are not correlated (Kendall's {tau} = 0.017 {+-} 0.018). This absence of a correlation between metallicity and kinematics for disk stars is in a conflict with the traditional decomposition in terms of thin and thick disks, which predicts a strong correlation ({tau} = ?0.30 {+-} 0.04) at {approx}1 kpc from the mid-plane. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non-Gaussian functions that retain their shapes and only shift as the distance from the mid-plane increases. We also study the metallicity distribution using a shallower (g < 19.5) but much larger sample of close to three million stars in 8500 sq. deg. of sky included in SDSS Data Release 6. The large sky coverage enables the detection of coherent substructures in the kinematics-metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of [Fe/H] = ?0.95, with an rms scatter of only {approx}0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that the LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper motion measurements accurate to {approx}0.2-0.5 mas/yr, for about 200 million F/G dwarf stars within a distance limit of {approx}100 kpc (g < 23.5).

Ivezic, Zeljko; /Washington U., Seattle; Sesar, Branimir; /Washington U., Seattle; Juric, Mario; /Princeton, Inst. Advanced Study; Bond, Nicholas; /Princeton U.; Dalcanton, Julianne; /Washington U., Seattle; Rockosi, Constance M.; /UC, Santa Cruz; Yanny, Brian; /Fermilab; Newberg, Heidi J.; /Rensselaer Poly.; Beers, Timothy C.; /Michigan State U.; Prieto, Carlos Allende; /Texas U.; Wilhelm, Ron; /Texas Tech. /Michigan State U.

2008-04-01T23:59:59.000Z

416

Why Buckling Stellar Bars Weaken in Disk Galaxies  

E-Print Network (OSTI)

Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks embedded in live halos, we have analyzed the bar structure throughout this instability and found that the outer third of the bar dissolves completely while the inner part (within the vertical inner Lindblad resonance) becomes less oval. The bar acquires the frequently observed peanut/boxy-shaped isophotes. We also find that the bar buckling is responsible for a mass injection above the plane, which is subsequently trapped by specific 3-D families of periodic orbits of particular shapes explaining the observed isophotes, in line with previous work. Using a 3-D orbit analysis and surfaces of sections, we infer that the outer part of the bar is dissolved by a rapidly widening stochastic region around its corotation radius -- a process related to the bar growth. This leads to a dramatic decrease in the bar size, decrease in the overall bar strength and a mild increase in its pattern speed, but is not expected to lead to a complete bar dissolution. The buckling instability appears primarily responsible for shortening the secular diffusion timescale to a dynamical one when building the boxy isophotes. The sufficiently long timescale of described evolution, ~1 Gyr, can affect the observed bar fraction in local universe and at higher redshifts, both through reduced bar strength and the absence of dust offset lanes in the bar.

Inma Martinez-Valpuesta; Isaac Shlosman

2004-08-13T23:59:59.000Z

417

X-ray chemistry in envelopes around young stellar objects  

E-Print Network (OSTI)

We present chemical models of the envelope of a young stellar object (YSO) exposed to a central X-ray source. The models are applied to the massive star-forming region AFGL 2591 for different X-ray fluxes. The total X-ray ionization rate is dominated by the `secondary' ionization rate of H2 resulting from fast electrons. The carbon, sulphur and nitrogen chemistries are discussed. It is found that He+ and H3+ are enhanced and trigger a peculiar chemistry. Several molecular X-ray tracers are found and compared to tracers of the far ultraviolet (FUV) field. Like ultraviolet radiation fields, X-rays enhance simple hydrides, ions and radicals. In contrast to ultraviolet photons, X-rays can penetrate deep into the envelope and affect the chemistry even at large distances from the source. Whereas the FUV enhanced species cover a region of 200-300 AU, the region enhanced by X-rays is >1000 AU. Best-fit models for AFGL 2591 predict an X-ray luminosity LX > 1e+31 ergs/s with a hard X-ray spectrum TX > 3e+07 K. Furthermore, we find LX/Lbol ~ 1e-6. The chemistry of the bulk of the envelope mass is dominated by cosmic-ray induced reactions rather than by X-ray induced ionization for X-ray luminosities LX < 1e+33 ergs/s. The calculated line intensities of HCO+ and HCS+ show that high-J lines are more affected than lower J lines by the presence of X-rays due to their higher critical densities, and that such differences are detectable even with large aperture single-dish telescopes. Future instruments such as Herschel-HIFI or SOFIA will be able to observe X-ray enhanced hydrides whereas the sensitivity and spatial resolution of ALMA is well-suited to measure the size and geometry of the region affected by X-rays.

P. Staeuber; S. D. Doty; E. F. van Dishoeck; A. O. Benz

2005-06-14T23:59:59.000Z

418

Water destruction by X-rays in young stellar objects  

E-Print Network (OSTI)

We study the H2O chemistry in star-forming environments under the influence of a central X-ray source and a central far ultraviolet (FUV) radiation field. The gas-phase water chemistry is modeled as a function of time, hydrogen density and X-ray flux. To cover a wide range of physical environments, densities between n_H = 10^4-10^9 cm^-3 and temperatures between T = 10-1000 K are studied. Three different regimes are found: For T water abundance is of order 10^-7-10^-6 and can be somewhat enhanced or reduced due to X-rays, depending on time and density. For 100 K 10^-3 ergs s-1 cm^-2 (t = 10^4 yrs) and for F_X > 10^-4 ergs s^-1 cm^-2 (t = 10^5 yrs). At higher temperatures (T > 250 K) and hydrogen densities, water can persist with x(H2O) ~ 10^-4 even for high X-ray fluxes. The X-ray and FUV models are applied to envelopes around low-mass Class 0 and I young stellar objects (YSOs). Water is destroyed in both Class 0 and I envelopes on relatively short timescales (t ~ 5000 yrs) for realistic X-ray fluxes, although the effect is less prominent in Class 0 envelopes due to the higher X-ray absorbing densities there. FUV photons from the central source are not effective in destroying water. The average water abundance in Class I sources for L_X > 10^27 ergs s^-1 is predicted to be x(H2O) < 10^-6.

P. Stauber; J. K. Jorgensen; E. F. van Dishoeck; S. D. Doty; A. O. Benz

2006-02-06T23:59:59.000Z

419

Observational studies of stellar black hole binaries and ULXs  

E-Print Network (OSTI)

We outline a framework for understanding the X-ray spectra of high mass accretion rate stellar black holes based on X-ray data from RXTE and ASCA. Three spectral regimes can be separated out by the behaviour of the observed disk luminosity and temperature. The well established "standard regime" is seen when the disk dominates the spectrum, where only a small fraction of the luminosity is emitted in the power law tail. These spectra generally satisfy the standard relation expected for thermal emission from a constant area, namely that the disk bolometric luminosity, Ldisk, is proportional to its maximum temperature, Tin^4. However, at higher luminosities this starts to change to Tin^2. This "apparently standard regime" is still dominated by the disk emission, but this difference luminosity-temperature relation and subtle changes in spectral shape may show that another cooling process is required in addition to radiative cooling. At intermediate luminosities there is an anomalous regime (or weak very high state) where the disk temperature and luminosity are less clearly related. These spectra are characterized by the presence of a much stronger comptonized tail indicating high energy electrons. When observed disk emission is corrected for the the effects of comptonisation then these points lie back on the standard relation. The growth of this comptonising corona is also clearly linked to the quasi-periodic oscillations, as these are observed preferentially in the anomalous regime. This presented picture was found to explain the spectral behavior of both black hole binaries in our Galaxy and LMC. Spectral evolution of several bright ULXs observed with ASCA were also successfully explained in the same picture.

Aya Kubota; Kazuo Makishima

2005-07-12T23:59:59.000Z

420

Categorical Exclusion Determinations: National Energy Technology Laboratory  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

29, 2011 29, 2011 CX-005666: Categorical Exclusion Determination DeKalb County/Metropolitan Atlanta Alternative Fuel and Advanced Technology Vehicle Project CX(s) Applied: A1, B5.1 Date: 04/29/2011 Location(s): Marrow, Georgia Office(s): Energy Efficiency and Renewable Energy, National Energy Technology Laboratory April 29, 2011 CX-005664: Categorical Exclusion Determination Development and Testing of Compact Heat Exchange Reactors (CHER) for Synthesis of Liquid Fuels CX(s) Applied: B3.6 Date: 04/29/2011 Location(s): Laramie, Wyoming Office(s): Fossil Energy, National Energy Technology Laboratory April 29, 2011 CX-005663: Categorical Exclusion Determination Vortex Tube Project Decommissioning Project CX(s) Applied: B3.6 Date: 04/29/2011 Location(s): Morgantown, West Virginia

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421

Microscopic analysis of irradiated AGR-1 coated particle fuel compacts  

SciTech Connect

The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak burnup of 19.5% FIMA with no in-pile failures observed out of 3×105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Five compacts have been examined so far, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose between approximately 40-80 individual particles on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer-IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, over 800 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in approximately 23% of the particles, and these fractures often resulted in unconstrained kernel swelling into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer-IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only three particles, all in conjunction with IPyC-SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures, IPyC-SiC debonds, and SiC fractures.

Scott Ploger; Paul Demkowicz; John Hunn; Robert Morris

2012-10-01T23:59:59.000Z

422

COMPACT BINARY PROGENITORS OF SHORT GAMMA-RAY BURSTS  

SciTech Connect

In recent years, detailed observations and accurate numerical simulations have provided support to the idea that mergers of compact binaries containing either two neutron stars (NSs) or an NS and a black hole (BH) may constitute the central engine of short gamma-ray bursts (SGRBs). The merger of such compact binaries is expected to lead to the production of a spinning BH surrounded by an accreting torus. Several mechanisms can extract energy from this system and power the SGRBs. Here we connect observations and numerical simulations of compact binary mergers, and use the current sample of SGRBs with measured energies to constrain the mass of their powering tori. By comparing the masses of the tori with the results of fully general-relativistic simulations, we are able to infer the properties of the binary progenitors that yield SGRBs. By assuming a constant efficiency in converting torus mass into jet energy, {epsilon}{sub jet} = 10%, we find that most of the tori have masses smaller than 0.01 M{sub Sun }, favoring 'high-mass' binary NSs mergers, i.e., binaries with total masses {approx}> 1.5 the maximum mass of an isolated NS. This has important consequences for the gravitational wave signals that may be detected in association with SGRBs, since 'high-mass' systems do not form a long-lived hypermassive NS after the merger. While NS-BH systems cannot be excluded to be the engine of at least some of the SGRBs, the BH would need to have an initial spin of {approx}0.9 or higher.

Giacomazzo, Bruno [JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309 (United States); Perna, Rosalba [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Rezzolla, Luciano [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Potsdam D-14476 (Germany); Troja, Eleonora [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lazzati, Davide [Department of Physics, NC State University, 2401 Stinson Drive, Raleigh, NC 27695-8202 (United States)

2013-01-10T23:59:59.000Z

423

ON THE LAST 10 BILLION YEARS OF STELLAR MASS GROWTH IN STAR-FORMING GALAXIES  

SciTech Connect

The star formation rate-stellar mass relation (SFR-M{sub *}) and its evolution (i.e., the SFR main sequence) describe the growth rate of galaxies of a given stellar mass and at a given redshift. Assuming that present-day star-forming galaxies (SFGs) were always star forming in the past, these growth rate observations can be integrated to calculate average star formation histories (SFHs). Using this Main Sequence Integration (MSI) approach, we trace present-day massive SFGs back to when they were 10%-20% of their current stellar mass. The integration is robust throughout those epochs: the SFR data underpinning our calculations are consistent with the evolution of stellar mass density in this regime. Analytic approximations to these SFHs are provided. Integration-based results reaffirm previous suggestions that current SFGs formed virtually all of their stellar mass at z < 2. It follows that massive galaxies observed at z > 2 are not the typical progenitors of SFGs today. We also check MSI-based SFHs against those inferred from analysis of the fossil record-from spectral energy distributions (SEDs) of SFGs in the Sloan Digital Sky Survey and color-magnitude diagrams (CMDs) of resolved stars in dwarf irregular galaxies. Once stellar population age uncertainties are accounted for, the main sequence is in excellent agreement with SED-based SFHs (from VESPA). Extrapolating SFR main sequence observations to dwarf galaxies, we find differences between MSI results and SFHs from CMD analysis of Advanced Camera for Surveys Nearby Galaxy Survey Treasury and Local Group galaxies. Resolved dwarfs appear to grow much slower than main sequence trends imply, and also slower than slightly higher mass SED-analyzed galaxies. This difference may signal problems with SFH determinations, but it may also signal a shift in star formation trends at the lowest stellar masses.

Leitner, Samuel N. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

2012-02-01T23:59:59.000Z

424

A GRID OF THREE-DIMENSIONAL STELLAR ATMOSPHERE MODELS OF SOLAR METALLICITY. I. GENERAL PROPERTIES, GRANULATION, AND ATMOSPHERIC EXPANSION  

SciTech Connect

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive power to such models of late-type stars. We present a grid of improved and more reliable stellar atmosphere models of late-type stars, based on deep, three-dimensional (3D), convective, stellar atmosphere simulations. This grid is to be used in general for interpreting observations and improving stellar and asteroseismic modeling. We solve the Navier Stokes equations in 3D and concurrent with the radiative transfer equation, for a range of atmospheric parameters, covering most of stellar evolution with convection at the surface. We emphasize the use of the best available atomic physics for quantitative predictions and comparisons with observations. We present granulation size, convective expansion of the acoustic cavity, and asymptotic adiabat as functions of atmospheric parameters.

Trampedach, Regner [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309 (United States); Asplund, Martin; Collet, Remo [Research School of Astronomy and Astrophysics, Mt. Stromlo Observatory, Cotter Road, Weston ACT 2611 (Australia); Nordlund, Ake [Astronomical Observatory/Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Stein, Robert F. [Department of Physics and Astronomy, Michigan State University East Lansing, MI 48824 (United States)

2013-05-20T23:59:59.000Z

425

Structural Reliability: Assessing the Condition and Reliability of Casing in Compacting Reservoirs  

E-Print Network (OSTI)

Casing has a higher risk of failure in a compacting reservoir than in a typical reservoir. Casing fails when reservoir compaction induces compression and shear stresses onto it. They compact as reservoir pressure depletes during production. High compaction reservoirs typically are composed of unconsolidated, overpressured rocks such as chalk, diatomite, and sandstone. Pore pressure depletion increases effective stress, which is the rock matrix stress pushing upward against overburden pressure. Effective stress may exceed rock compressive strength, inducing compaction. Wells in compacting reservoirs risk high failure and deformation rates. This project introduces the concept of structural reliability to quantify casing failure risks in compacting reservoirs. This research developed probabilistic models for casing capacities using current design methods and a reservoir compaction load using finite-element model simulations. Probabilistic models were used in creating two limit-states functions to predict casing failure: axial yielding and buckling failures. A limit-state function describes the casing condition as the casing experiences a reservoir compaction load. The limit state function is the input in component and system analyses for casing fragility and conditional probability of casing failure. Fragilities can predict casing probability of failure as reservoir pressure is depleting. Sensitivity and importance analyses are also performed to determine the importance of parameters affecting the casing reliability. Applying the knowledge produced from this research to casing design methods can improve design reliabilities and forecast the risk of casing failure in compacting reservoirs.

Chantose, Prasongsit

2011-12-01T23:59:59.000Z

426

Preliminary results of post-irradiation examination of the AGR-1 TRISO fuel compacts  

Science Conference Proceedings (OSTI)

Five irradiated fuel compacts from the AGR-1 experiment have been examined in detail in order to assess in-pile fission product release behavior. Compacts were electrolytically deconsolidated and analyzed using the leach-burn-leach technique to measure fission product inventory in the compact matrix and identify any particles with a defective SiC layer. Loose particles were then gamma counted to measure the fission product inventory. One particle with a defective SiC layer was found in the five compacts examined. The fractional release of Ag 110m from the particles was significant. The total fraction of silver released from all the particles within a compact ranged from 0-0.63 and individual particles within a single compact often exhibited a very wide range of silver release. The average fractional release of Eu-154 from all particles in a compact was 2.4×10-4—1.3×10-2, which is indicative of release through intact coatings. The fractional Cs-134 inventory in the compact matrix was inventory was found in the compact matrix for two of the compacts, indicating significant release through intact coatings.

Paul Demkowicz; John Hunn; Robert Morris; Jason Harp; Philip Winston; Charles Baldwin; Fred Montgomery; Scott Ploger; Isabella van Rooyen

2012-10-01T23:59:59.000Z

427

Preliminary results of post-irradiation examination of the AGR-1 TRISO fuel compacts  

SciTech Connect

Five irradiated fuel compacts from the AGR-1 experiment have been examined in detail in order to assess in-pile fission product release behavior. Compacts were electrolytically deconsolidated and analyzed using the leach-burn-leach technique to measure fission product inventory in the compact matrix and identify any particles with a defective SiC layer. Loose particles were then gamma counted to measure the fission product inventory. One particle with a defective SiC layer was found in the five compacts examined. The fractional release of Ag 110m from the particles was significant. The total fraction of silver released from all the particles within a compact ranged from 0-0.63 and individual particles within a single compact often exhibited a very wide range of silver release. The average fractional release of Eu-154 from all particles in a compact was 2.4×10-4—1.3×10-2, which is indicative of release through intact coatings. The fractional Cs-134 inventory in the compact matrix was <2×10-5 when all coatings remained intact, indicating good cesium retention. Approximately 1% of the palladium inventory was found in the compact matrix for two of the compacts, indicating significant release through intact coatings.

Paul Demkowicz; John Hunn; Robert Morris; Jason Harp; Philip Winston; Charles Baldwin; Fred Montgomery; Scott Ploger; Isabella van Rooyen

2012-10-01T23:59:59.000Z

428

Radiation field modeling and optimization of a compact and modular  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiation field modeling and optimization of a compact and modular Radiation field modeling and optimization of a compact and modular multi-plate photocatalytic reactor (MPPR) for air/water purification by Monte Carlo method Title Radiation field modeling and optimization of a compact and modular multi-plate photocatalytic reactor (MPPR) for air/water purification by Monte Carlo method Publication Type Journal Article Year of Publication 2013 Authors Zazueta, Ana Luisa Loo, Hugo Destaillats, and Gianluca Li Puma Journal Chemical Engineering Journal Volume 217 Pagination 475-485 Date Published 02/01/2013 Abstract The radiation field in a multi-plate photocatalytic reactor (MPPR) for air or water purification was modeled and optimized using a Monte Carlo stochastic method. The MPPR consists of parallel photocatalytic plates irradiated by cylindrical UV lamps orthogonal to the plates. The photocatalyst titanium dioxide (TiO2) is supported on the plates as a thin film. The photoreactor design is compact and offers a large irradiated photocatalytic surface area, a high degree of photon utilization, low pressure drop and a modular design which can facilitate scale-up. These features are desirable for the decontamination of indoor air in ventilation ducts or for water detoxification. The Monte Carlo method was applied to determine three dimensionless reactor performance parameters: the photon absorption efficiency (Φ), the uniformity of the distribution of the dimensionless radiation intensity (η) and the overall photonic efficiency (Φ). The emission of photons from the light sources was simulated by the extensive source with superficial emission (ESSE) model. Simulations were performed by varying the catalyst reflectivity albedo, the number and the diameter of lamps, and the dimensions and spacing of the photocatalytic plates. Optimal design for a basic reactor module with one lamp was accomplished for lamp-diameter-to-plate-height ratio (β) of 0.7, while the plate-spacing-to-plate-height ratio (α) was correlated by [αoptimum = 0.191 β2 - 0.5597 β + 0.3854]. A multilamp arrangement leads to a feasible increase in the size and number of the plates and the irradiated photocatalytic surface area. The optimum design was validated by measuring the apparent quantum yield of the oxidation of toluene (7 ppmv) in a humidified air stream using immobilized TiO2 (Degussa P25). Experiments performed varying the geometrical parameter α correlated well with the model calculations, with maximum apparent quantum yield for α = 0.137. The results are directly transferable to the treatment of water by photocatalysis.

429

Compact cyclone filter train for radiological and hazardous environments  

DOE Patents (OSTI)

A compact cyclone filter train for the removal of hazardous and radiologi particles from a gaseous fluid medium which permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired.

Bench, Thomas R. (Pittsburgh, PA)

1998-01-01T23:59:59.000Z

430

Compact cyclone filter train for radiological and hazardous environments  

DOE Patents (OSTI)

A compact cyclone filter train is disclosed for the removal of hazardous and radiological particles from a gaseous fluid medium. This filter train permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separator and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired. 3 figs.

Bench, T.R.

1998-04-28T23:59:59.000Z

431

Numerical simulation of reservoir compaction in liquid dominated geothermal systems  

DOE Green Energy (OSTI)

A numerical model is introduced which simulates the effects of fluid production as well as reinjection on the vertical deformation of water dominated geothermal reservoirs. This program, based on an Integrated Finite Difference technique and Terzaghi's one-dimensional consolidation model, computes the transport of heat and water through porous media, and resulting pore volume changes. Examples are presented to show the effects of reservoir heterogeneities on the compaction of these hot water systems, as well as the effects of different production-injection schemes. The use of isothermal models to simulate the deformation of non-isothermal systems was also investigated.

Lippmann, M.J.; Narasimhan, T.N.; Witherspoon, P.A.

1976-12-01T23:59:59.000Z

432

Diffusion Welding of Compact Heat Exchangers for Nuclear Applications  

Science Conference Proceedings (OSTI)

The next-­-generation nuclear plant (NGNP) is designed to be a flexible source of energy, producing various mixes of electrical energy and process heat (for example, for hydrogen generation) on demand. Compact heat exchangers provide an attractive way to move energy from the helium primary reactor coolant to process heat uses. For process heat efficiency, reactor outlet temperatures of 750-­-900°C are desirable. There are minor but deleterious components in the primary coolant; the number of alloys that can handle this environment is small. The present work concentrates on Alloys 800H and 617.

Denis Clark; Ron Mizia; Dr. Michael V. Glazoff; Mr. Michael W. Patterson

2012-06-01T23:59:59.000Z

433

Compact Ceramic Heat Exchangers for Corrosive Waste Gas Applications  

E-Print Network (OSTI)

The development of large ceramic heat exchangers is described and performance data given for units installed on steel industry soaking pits in the U.K. Operational experience since 1973 confirms that ceramic heat exchangers capable of operating with high airside pressures have long lives and low maintenance even when operating with dirty gases at 1350 deg. C and preheating combustion air to 800 deg. C. The design of compact units suitable for factory assembly is also described. Units have been developed for low temperature corrosive gas situations and have been applied to the pottery industry and are being developed for coal fired air heaters for the food industry.

Laws, W. R.; Reed, G. R.

1982-01-01T23:59:59.000Z

434

A compact neutron generator using a field ionization source  

Science Conference Proceedings (OSTI)

Field ionization as a means to create ions for compact and rugged neutron sources is pursued. Arrays of carbon nano-#12;bers promise the high #12;eld-enhancement factors required for efficient field ionization. We report on the fabrication of arrays of #12;field emitters with a density up to 10{sup 6} tips/cm{sup 2} and measure their performance characteristics using electron field emission. The critical issue of uniformity is discussed, as are efforts towards coating the nano-fibers to enhance their lifetime and surface properties.

Persaud, Arun; Waldmann, Ole; Kapadia, Rehan; Takei, Kuniharu; Javey, Ali; Schenkel, Thomas

2011-10-31T23:59:59.000Z

435

PREPARATION OF HIGH-DENSITY, COMPACTIBLE THORIUM OXIDE PARTICLES  

DOE Patents (OSTI)

A method is given for preparing millimeter-size, highdensity thorium oxide particles suitable for fabrication into nuclear reactor feel elements by means of vibratory compaction. A thorium oxide gel containing 3.7 to 7 weight per cent residual volatile nitrate and water is prepared by drying a thorium oxide sol. The gel is then slowly heated to a temperature of about 450DEC, and the resulting gel fragments are calcined. The starting sol is prepared by repeated dispersion of oxalate-source thorium oxide in a nitrate system or by dispersion of steam-denitrated thorium oxide in water. (AEC)

McCorkle, K.H.; Kleinsteuber, A.T.; Schilling, C.E.; Dean, O.C.

1962-05-22T23:59:59.000Z

436

Compact cyclone filter train for radiological and hazardous environments  

DOE Patents (OSTI)

A compact cyclone filter train is described for the removal of hazardous and radiological particles from a gaseous fluid medium which permits a small cyclone separator to be used in a very small space envelope due to the arrangement of the filter housing adjacent to the separator with the cyclone separators and the filters mounted on a plate. The entire unit will have a hoist connection at the center of gravity so that the entire unit including the separator, the filters, and the base can be lifted and repositioned as desired.

Bench, T.R.

1996-12-31T23:59:59.000Z

437

Electron and positron pair production of compact stars  

E-Print Network (OSTI)

Neutral stellar core at or over nuclear densities is described by a positive charged baryon core and negative charged electron fluid since they possess different masses and interactions. Based on a simplified model of a gravitationally collapsing or pulsating baryon core, we approximately integrate the Einstein-Maxwell equations and the equations for the number and energy-momentum conservation of complete degenerate electron fluid. We show possible electric processes that lead to the production of electron-positron pairs in the boundary of a baryon core and calculate the number and energy of electron-positron pairs. This can be relevant for understanding the energetic sources of supernovae and gamma-ray bursts.

Wen-Biao Han; Remo Ruffini; She-Sheng Xue

2011-10-04T23:59:59.000Z

438

Previous Sandia National Laboratories | National Nuclear Security  

National Nuclear Security Administration (NNSA)

Previous Sandia National Laboratories | National Nuclear Security Previous Sandia National Laboratories | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Previous Sandia National Laboratories Home > About Us > Our Operations > Acquisition and Project Management > M & O Support Department > Sandia National Laboratories > Previous Sandia

439

THE SOLAR HEAVY ELEMENT ABUNDANCES. II. CONSTRAINTS FROM STELLAR ATMOSPHERES  

Science Conference Proceedings (OSTI)

Estimates of the bulk metal abundance of the Sun derived from the latest generation of model atmospheres are significantly lower than the earlier standard values. In Paper I, we demonstrated that helioseismic data combined with stellar interiors theory set strong bounds on the solar metal abundance. The seismically derived abundances are inconsistent with the low photospheric abundances if the quoted errors in the atmospheric models (of order 0.05 dex) are correct. In this paper, we undertake a critical analysis of the solar metallicity and its uncertainty from a model atmospheric perspective, focusing on CNO. We argue that the non-LTE (NLTE) corrections for abundances derived from atomic features are overestimated in the recent abundance studies, while systematic errors in the absolute abundances are underestimated. In general, abundances derived from molecular features are lower than those derived from atomic features for the three-dimensional hydro models, while a weaker trend in the opposite direction tends to hold for abundances derived from one-dimensional models. If we adopt the internal consistency between different indicators as a measure of goodness of fit, we obtain intermediate abundances [C/H] = 8.44 +- 0.06, [N/H] = 7.96 +- 0.10 and [O/H] = 8.75 +- 0.08. The errors reflect the fact that both the high and low scales are internally consistent within the errors, and they are too large to conclude that there is a solar abundance problem. However, the center-to-limb continuum flux variations predicted in the simulations appear to be inconsistent with solar data based on recently published work. This would favor the traditional thermal structure and lead to high CNO abundances of (8.52, 7.96, 8.80) close to the seismic scale. We argue that further empirical tests of NLTE corrections and the thermal structure are required for precise absolute abundances. The sensitivity of the simulations to spatial resolution and systematic errors in the underlying atmospheric physics should also be examined, and these effects may lead to an overestimate of the impact of convective overshooting on the thermal structure of the outer layers of the solar atmosphere. The uncertainties in the solar oxygen also imply that strong conclusions about the absence of solar beryllium depletion cannot be made.

Pinsonneault, M. H. [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States); Delahaye, Franck [CEA, IRFU, Serv. Astrophys., F-91191 Gif-sur-Yvette (France)

2009-10-20T23:59:59.000Z

440

Nuclear Stellar Populations in the Infrared Space Observatory Atlas of Bright Spiral Galaxies  

E-Print Network (OSTI)

To understand the nuclear stellar populations and star formation histories of the nuclei of spiral galaxies, we have obtained K-band nuclear spectra for 41 galaxies and H-band spectra for 20 galaxies in the ISO Atlas of Bright Spiral Galaxies. In the vast majority of the subsample (80%), the near-infrared spectra suggest that evolved red stars completely dominate the nuclear stellar populations and that hot young stars are virtually non-existent. The signatures of recent star formation activity are only found in 20% of the subsample, even though older red stars still dominate the stellar populations in these galaxies. Given the dominance of evolved stars in most galaxy nuclei and the nature of the emission lines in the galaxies where they were detected, we suggest that nuclear star formation proceeds in the form of instantaneous bursts. The stars produced by these bursts comprise only ~2% of the total nuclear stellar mass in these galaxies, but we demonstrate how the nuclear stellar populations of normal spiral galaxies can be built up through a series of these bursts. The bursts were detected only in Sbc galaxies and later, and both bars and interactions appeared to be sufficient but not necessary triggers for the nuclear star formation activity. The vast majority of galaxies with nuclear star formation were classified as HII galaxies. With one exception, LINERs and transition objects were dominated by older red stars, which suggested that star formation was not responsible for generating these galaxies' optical line emission.

George J. Bendo; Robert D. Joseph

2004-03-04T23:59:59.000Z

Note: This page contains sample records for the topic "national compact stellarator" 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

Microchannel Process Technology for Compact Methane Steam Reforming  

Science Conference Proceedings (OSTI)

The study of microchannel reaction engineering and applications to compact chemical reactors has expanded rapidly both academically and industrially in recent years. Velocys{reg_sign}, a spin-out company from Battelle Memorial Institute, is commercializing microchannel process technology for large-scale chemical processing. Hydrogen production at industrial rates in compact Velocys hardware is made possible through increases in both heat and mass transfer rates for highly active and novel catalysts. In one example, a microchannel methane steam reforming reactor is presented with integrated catalytic partial oxidation of methane prior to catalytic combustion with low excess air (25%) to generate the required energy for undothermic methane steam reforming in adjacent channels. Heat transfer rates from the exothermic reactions exceed 18 W/cm{sup 2} of interplanar heat transfer surface area and exceed 65 W/cm{sup 3} of total reaction volume for a methane steam reforming contact time near 4 milliseconds. The process intensity of the Velocys methane steam reformer well exceeds that of conventional steam reformers, which have a typical volumetric heat flux below 1 W/cm{sup 3}. The integration of multiple unit operations and improvements in process intensification result in significant capital and operating cost savings for commercial applications.

Tonkovich, A L.; Perry, Steve; Wang, Yong; Qiu, Dongming; LaPlante, Timothy J.; Rogers, William A.

2004-12-01T23:59:59.000Z

442

The Compact Muon Solenoid (CMS) Experiment on YouTube  

DOE Data Explorer (OSTI)

The Compact Muon Solenoid (CMS) experiment is one of two large general-purpose particle physics detectors built on the proton-proton Large Hadron Collider (LHC) at CERN in Switzerland and France. The CMS detector is located in an underground cavern at Cessy in France and studies many aspects of proton collisions at 14 TeV, the center-of-mass energy of the LHC particle accelerator. [http://en.wikipedia.org/wiki/Compact_Muon_Solenoid]. US groups have made significant contributions to nearly every aspect of the detector throughout all phases including construction, installation and now in the data-taking stage. The US collaboration also made major contributions to the construction and operation of the computing facilities needed to analyze the unprecedented amount of data to be generated by CMS. This work includes the software that allows physicists to operate the CMS detector, reconstruct the data, analyze it and extract new physics. The CMS channel on YouTube was established in 2009.

443

Compact multiple-valued multiplexers using negative differential resistance devices  

E-Print Network (OSTI)

Abstract-Quantum electronic devices with negative differen-tial resistance (NDR) characteristics have been used to design compact multiplexers. These multiplexers may be used either as analog multiplexers where the signal on a single select line selects one out of four analog inputs, or as four-valued logic multiplexers where the select line and the input lines represent one of four quantized signal values and the output line corre-sponds to the selected input. Any four-valued logic function can be implemented using only four-valued multiplexers (also known as T-gates), and this T-gate uses just 13 devices (transistors) as compared to 44 devices in CMOS. The design of the T-gate was done using a combination of resonant tunneling diodes (RTD’s) and heterojunction bipolar transistors (HBT’s) with the folded I-V characteristic (NDR characteristic) of the RTD’s providing the compact logic implementation and the HBT’s providing the gain and isolation. The application of the same design principles to the design of T-gates using other NDR devices such as reso-nant tunneling hot electron transistors (RHET’s) and resonant tunneling bipolar transistors (RTBT’s) is also demonstrated. I.

H. L. Chan; S. Mohan; Pinaki Mazumder; Senior Member; George I. Haddad

1996-01-01T23:59:59.000Z

444

Institut National Polytechnique de Toulouse (INP Toulouse) Mathmatiques Informatique Tlcommunications (MITT)  

E-Print Network (OSTI)

], meteorological investigations [3, 4], wetland monitoring [5], estimation of forest parameters [6], oil spill study of vessel detection and oil-spill recog- nition, based on linear and hybrid/compact dual-pol DoP, using recent data from the Deepwater Horizon oil-spill, acquired by the National Aeronautics and Space

Mailhes, Corinne

445

National Energy Technology Laboratory National Energy Technology...  

NLE Websites -- All DOE Office Websites (Extended Search)

4U.S. Department of Energy U.S. Department of Energy National Energy Technology Laboratory National Energy Technology Laboratory Office of Public Affairs Office of Public Affairs...

446

Sandia National Laboratories: National Security Missions: Defense...  

NLE Websites -- All DOE Office Websites (Extended Search)

Cybersecurity Delivering experience & expertise Training the next generation of cyber defenders Cybersecurity computing Defending national security Applying science and engineering...

447

Office of National Infrastructure & Sustainability | National...  

National Nuclear Security Administration (NNSA)

of National Infrastructure & Sustainability Home > About Us > Our Programs > Nonproliferation > Nuclear Nonproliferation Program Offices > Office of International Material...

448

Sandia National Laboratories Albuquerque | National Nuclear Security...  

National Nuclear Security Administration (NNSA)

Laboratories, the laboratories responsible for the development, testing, and production of specialized nonnuclear components. Laboratories: The NNSA Sandia National...

449

Origin of Compact Triangular Islands in Metal-on-Metal Growth  

Science Conference Proceedings (OSTI)

The microscopic origin of compact triangular islands on close-packed surfaces is identified using kinetic Monte Carlo simulations with energy barriers obtained from density-functional calculations. In contrast to earlier accounts, corner diffusion anisotropy is found to control the shape of compact islands at intermediate temperatures. We rationalize the correlation between the orientation of dendrites grown at low temperatures and triangular islands grown at higher temperatures, and explain why in some systems dendrites grow fat before turning compact.

Bogicevic, Alexander; Lundqvist, Bengt I.; Ovesson, Staffan

1999-07-12T23:59:59.000Z

450

Probing the origin of the iron K_alpha line around stellar and supermassive black holes using X-ray polarimetry  

E-Print Network (OSTI)

Asymmetric, broad iron lines are a common feature in the X-ray spectra of both X-ray binaries (XRBs) and type-1 Active Galactic Nuclei (AGN). It was suggested that the distortion of the Fe K_alpha emission results from Doppler and relativistic effects affecting the radiative transfer close to the strong gravitational well of the central compact object: a stellar mass black hole (BH) or neutron star (NS) in the case of XRBs, or a super massive black hole (SMBH) in the case of AGN. However, alternative approaches based on reprocessing and transmission of radiation through surrounding media also attempt to explain the line broadening. So far, spectroscopic and timing analyzes have not yet convinced the whole community to discriminate between the two scenarios. Here we study to which extent X-ray polarimetric measurements of black hole X-ray binaries (BHXRBs) and type-1 AGN could help to identify the possible origin of the line distortion. To do so, we report on recent simulations obtained for the two BH flavors and show that the proposed scenarios are found to behave differently in polarization degree and polarization angle. A relativistic origin for the distortion is found to be more probable in the context of BHXRBs, supporting the idea that the same mechanism should lead the way also for AGN. We show that the discriminating polarization signal could have been detectable by several X-ray polarimetry missions proposed in the past.

Frederic Marin; Francesco Tamborra

2013-09-06T23:59:59.000Z

451

BSA 07-22: Compact Room-Temperature Radiation Detector for Oil ...  

BSA 07-22: Compact Room-Temperature Radiation Detector for Oil & Gas Exploration. BNL Reference Number: BSA 07-22. Patent Status: U.S. Patent ...

452

Dimming of Compact Fluorescent Lamps Caused By Cold-Air Drafts  

Science Conference Proceedings (OSTI)

This Case Study documents the investigation performed by the New York Port Authority (PA) of the dimming of compact fluorescent lamps (CFLs) in the World Trade Center.

2003-12-31T23:59:59.000Z

453

EAC Recommendations for DOE Action Regarding the CSG Interstate Transmission Siting Compact- June 6, 2013  

Energy.gov (U.S. Department of Energy (DOE))

EAC Recommendations for DOE Action Regarding the CSG Interstate Transmission Siting Compact, approved at the June 5-6, 2013 EAC Meeting.

454

Abart CDS - a New Compact Multi-pollutant Pot Gas and Alumina ...  

Science Conference Proceedings (OSTI)

Abstract Scope, A new modular Abart CDS is developed that integrates silos, alumina handling, heat exchangers, fans, SO2 scrubber and stack into a compact

455

Nuclear fuel particles and method of making nuclear fuel compacts therefrom  

DOE Patents (OSTI)

Methods for making nuclear fuel compacts exhibiting low heavy metal contamination and fewer defective coatings following compact fabrication from a mixture of hardenable binder, such as petroleum pitch, and nuclear fuel particles having multiple layer fission-product-retentive coatings, with the dense outermost layer of the fission-product-retentive coating being surrounded by a protective overcoating, e.g., pyrocarbon having a density between about 1 and 1.3 g/cm.sup.3. Such particles can be pre-compacted in molds under relatively high pressures and then combined with a fluid binder which is ultimately carbonized to produce carbonaceous nuclear fuel compacts having relatively high fuel loadings.

DeVelasco, Rubin I. (Encinitas, CA); Adams, Charles C. (San Diego, CA)

1991-01-01T23:59:59.000Z

456

Method of using in situ porosity measurements to place an upper bound on geothermal reservoir compaction  

DOE Green Energy (OSTI)

Placing an upper bound on reservoir compaction requires placing a lower bound on the reservoir effective compaction modulus. Porosity-depth data can be used to find that lower-bound modulus in a young sedimentary basin. Well-log and sample porosity data from a geothermal field in the Imperial Valley, CA, give a lower-bound modulus of 7.7 x 10{sup 3} psi. This modulus is used with pressure drops calculated for a reservoir to determine an upper bound on reservoir compaction. The effects of partial reinjection and aquifer leakage on upper-bound subsidence estimated from the compaction are illustrated for a hypothetical reservoir and well array.

Schatz, J.F.; Kasameyer, P.W.; Cheney, J.A.

1979-01-03T23:59:59.000Z

457

The Influence of Chemi-ionization and Recombination Processes on Spectral Line Shapes in Stellar Atmospheres  

E-Print Network (OSTI)

In this work, the chemi-ionization processes in atom- Rydberg atom collisions, as well as the corresponding chemi-recombination processes are considered as factors of influence on the atom exited-state populations in weakly ionized layers of stellar atmospheres. The presented results are related to the photospheres of the Sun and some M red dwarfs as well as weakly ionized layers of DB white dwarfs atmospheres. It has been found that the mentioned chemi ionization/recombination processes dominate over the relevant concurrent electron-atom and electron-ion ionization and recombination process in all parts of considered stellar atmospheres. The obtained results demonstrate the fact that the considered chemi ionization/recombination processes must have a very significant influence on the optical properties of the stellar atmospheres. Thus, it is shown that these processes and their importance for non-local thermodynamic equilibrium (non-LTE) modeling of the solar atmospheres should be investigated further.

Mihajlov, Anatolij A; Sreckovic, Vladimir A; Dimitrijevic, Milan S

2011-01-01T23:59:59.000Z

458

Deviation of Stellar Orbits from Test Particle Trajectories Around Sgr A* Due to Tides and Winds  

E-Print Network (OSTI)

Monitoring the orbits of stars around Sgr A* offers the possibility of detecting the precession of their orbital planes due to frame dragging, of measuring the spin and quadrupole moment of the black hole, and of testing the no-hair theorem. Here we investigate whether the deviations of stellar orbits from test-particle trajectories due to wind mass loss and tidal dissipation of the orbital energy compromise such measurements. We find that the effects of stellar winds are, in general, negligible. On the other hand, for the most eccentric orbits (e>0.96) for which an optical interferometer, such as GRAVITY, will detect orbital plane precession due to frame dragging, the tidal dissipation of orbital energy occurs at timescales comparable to the timescale of precession due to the quadrupole moment of the black hole. As a result, this non-conservative effect is a potential source of systematic uncertainty in testing the no-hair theorem with stellar orbits.

Dimitrios Psaltis; Gongjie Li; Abraham Loeb

2012-12-13T23:59:59.000Z

459

ARGONNE NATIONAL LABORATORY is....  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering June 12-18, 2010 - Argonne National Laboratory June 19-26, 2010 - Oak Ridge National Laboratory Argonne National Laboratory is a U.S. Department of Energy laboratory...

460

Argonne's National Security Information Systems National  

NLE Websites -- All DOE Office Websites (Extended Search)

National Security National Security Information Systems National Security The NSIS team has worked with various government agencies and programs over the past 15 years to create customized technological solutions that meet specific needs, while also fulfilling national security objectives, improving efficiency and reducing costs. Applying a broad range of expertise and experience, the Argonne team develops both unclassified and classified information technology (IT) systems for national security and nonproliferation programs, with a focus on security operations, international treaty implementation, export control and law enforcement support. Some examples of NSIS-developed systems include:  Electronic Facility Clearance (e-FCL) System for the U.S. Department of Defense (DOD)

Note: This page contains sample records for the topic "national compact stellarator" 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

Advanced Alloys for Compact, High-Efficiency, High-Temperature Heat-Exchangers  

Science Conference Proceedings (OSTI)

Oak Ridge National Laboratory (ORNL) has conducted research and development for several years which has been focused on the behavior and performance improvements of sheets and foils of various alloys for compact heat-exchangers (recuperators) for advanced microturbines. The performance and reliability of such thin sections are challenged at 650-750 C by fine grain size causing excessive creep, and by moisture effects greatly enhancing oxidation attack in exhaust gas environments. Standard 347 stainless steel has been used successfully at or below 600 C, but has suffered from both of these kinds of degradation at 650 C and above. Alloys have been identified which can have very good properties for such heat-exchangers, especially with careful control of microstructure during processing, including alloy 625, HR120 and the new AL20-25+Nb. These alloys, and the mechanistic understanding behind their behavior, are also applicable to achieving the better heat-exchanger technology needed for fuel cells or other high-temperature, clean-energy applications.

Maziasz, Philip J [ORNL; Pint, Bruce A [ORNL; Shingledecker, John P [ORNL; Evans, Neal D [ORNL; Yamamoto, Yukinori [ORNL; More, Karren Leslie [ORNL; Lara-Curzio, Edgar [ORNL

2006-01-01T23:59:59.000Z

462

Chemist, Sandia National Laboratories | National Nuclear Security  

National Nuclear Security Administration (NNSA)

Chemist, Sandia National Laboratories | National Nuclear Security Chemist, Sandia National Laboratories | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Who We Are > In The Spotlight > Jerilyn Timlin Chemist, Sandia National Laboratories Jerilyn Timlin Jerilyn Timlin Role: Chemist, Sandia National Laboratories Award: National Institutes of Health (NIH) New Innovator Award

463

Debojyoti Ghosh | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

for hyperbolic conservations laws Scientific computing Computational fluid dynamics Compact schemes ENO and Weighted ENO schemes Telephone (630) 252-4548 E-mail...

464

Lawrence Livermore National Laboratory  

LLNL Home. Latest News Headlines. ... Operated by Lawrence Livermore National Security, LLC, for the Department of Energy's National Nuclear Security Administration

465

Documents for Foreign Nationals  

NLE Websites -- All DOE Office Websites (Extended Search)

Turkmenistan, Ukraine, and Uzbekistan. **Terrorist-sponsoring countries include: Cuba, Iran, Sudan, and Syria. Requirements for Foreign Nationals (excluding nationals of sensitive...

466

2012 National Electricity Forum  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1 U.S. Department of Energy U.S. Department of Energy National Electric Transmission Congestion Study Workshop - December 8, 2011 National Electric Transmission Congestion Study...

467

Procurement | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Procurement "Doing business with Argonne and Fermi national labs" - Aug. 21, 2013 Read more about "Doing business with Argonne and Fermi national labs" - Aug. 21, 2013 Argonne and...

468

National Hydrogen Energy Roadmap  

NLE Websites -- All DOE Office Websites (Extended Search)

HYDROGEN ENERGY ROADMAP NATIONAL HYDROGEN ENERGY ROADMAP . . Toward a More Secure and Cleaner Energy Future for America Based on the results of the National Hydrogen Energy Roadmap...

469

Nationalism in Modern Greece.  

E-Print Network (OSTI)

??The focus of this project is the nature of nationalism viewed from different approaches and Greek nationalism in particular manifested in the support for the… (more)

Flethøj, Marie

2013-01-01T23:59:59.000Z

470

National Research Council Homepage  

Science Conference Proceedings (OSTI)

... with permission from the National Academy of Sciences, courtesy of the National Academies Press, Washington, DC This report is presented in .pdf ...

2013-06-27T23:59:59.000Z

471

First National Technology Center  

NLE Websites -- All DOE Office Websites (Extended Search)

9 10 First National Technology First National Technology Center Center The Nature of the Grid - Industrial Age Power - Normal Course Voltage Interruptions: 2-3 seconds Lights and...

472

GSH Group Inc. and Stellar Management: SPP Success Story | ENERGY STAR  

NLE Websites -- All DOE Office Websites (Extended Search)

GSH Group Inc. and Stellar Management: SPP Success Story GSH Group Inc. and Stellar Management: SPP Success Story Secondary menu About us Press room Contact Us Portfolio Manager Login Facility owners and managers Existing buildings Commercial new construction Industrial energy management Small business Service providers Service and product providers Verify applications for ENERGY STAR certification Design commercial buildings Energy efficiency program administrators Commercial and industrial program sponsors Associations State and local governments Federal agencies Tools and resources Training In This Section Campaigns Commercial building design Communications resources Energy management guidance Financial resources Portfolio Manager Products and purchasing Recognition Research and reports Service and product provider (SPP) resources

473

Combined Stellar Structure and Atmosphere Models: Exploratory Results for Wolf-Rayet Stars  

E-Print Network (OSTI)

In this paper we present Complete Stellar models (CoStar) for massive stars, which treat the stellar interior and atmosphere, including its wind. Particular emphasis is given to Wolf-Rayet stars. We address the question of the effective temperatures of WNE and WC stars. Our first results show a satisfactory agreement between the CoStar models and the simple temperature correction method applied by Schaller et al. (1992). An analyses of the subphotospheric structure of the WR star models shows the importance of metal opacity. This may be essential for understanding the driving mechanism of Wolf-Rayet winds.

D. Schaerer; A. de Koter; W. Schmutz

1994-10-14T23:59:59.000Z

474

Stellar abundances and ages for metal-rich Milky Way globular clusters - Stellar parameters and elemental abundances for 9 HB stars in NGC6352  

E-Print Network (OSTI)

[ABRIDGED] Metal-rich globular clusters provide important tracers of the formation of our Galaxy. Moreover, and not less important, they are very important calibrators for the derivation of properties of extra-galactic metal-rich stellar populations. Nonetheless, only a few of the metal-rich globular clusters in the Milky Way have been studied using high-resolution stellar spectra to derive elemental abundances. In this paper we present elemental abundances for nine HB stars in the metal-rich globular cluster NGC6352. The elemental abundances are based on high-resolution, high signal-to-noise spectra obtained with VLT/UVES. The elemental abundances have been derived using standard LTE calculations. We find that NGC6352 has [Fe/H]= -0.55, is enhanced in the alpha-elements to about +0.2 dex for Ca, Si, and Ti relative to Fe. For the iron-peak elements we find solar values. Based on the spectroscopically derived stellar parameters we find that an E(B-V)=0.24 and (m-M) roughly equal to 14.05 better fits the data ...

Feltzing, S; Johnson, R A

2008-01-01T23:59:59.000Z

475

Specification Test Compaction for Analog Circuits and MEMS  

E-Print Network (OSTI)

Testing a non-digital integrated system against all of its specifications can be quite expensive due to the elaborate test application and measurement setup required. We propose to eliminate redundant tests by employing e-SVM based statistical learning. Application of the proposed methodology to an operational amplifier and a MEMS accelerometer reveal that redundant tests can be statistically identified from a complete set of specification-based tests with negligible error. Specifically, after eliminating five of eleven specification-based tests for an operational amplifier, the defect escape and yield loss is small at 0.6% and 0.9%, respectively. For the accelerometer, defect escape of 0.2% and yield loss of 0.1% occurs when the hot and colt tests are eliminated. For the accelerometer, this level of Compaction would reduce test cost by more than half.

Biswas, Sounil; D., R; Blanton,; Pileggi, Larry T

2011-01-01T23:59:59.000Z