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Note: This page contains sample records for the topic "negligible negligible negligible" 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
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1

Optimal Standards of Negligence when One Party is Uninformed  

E-Print Network (OSTI)

and Uncertain Legal Standards, J Law Econ Organ. 2: 279-303.H. , 2007. Optimal Negligence Standards When One PartyIs Ignorant of the Standards, Research in Law and

Lando, Henrik

2008-01-01T23:59:59.000Z

2

Time-critical Underwater Sensor Diffusion with No Proactive Exchanges and Negligible Reactive Floods  

E-Print Network (OSTI)

Time-critical Underwater Sensor Diffusion with No Proactive Exchanges and Negligible Reactive multi-hop ad hoc routing in a scalable Underwater Sensor Network (UWSN), which is a novel network in the challenging new underwater environment. Unlike the terrestrial scenarios, on-demand flooding cannot be both

Park, Joon-Sang

3

Supply disruptions have negligible impact on oil market. (loss ...  

U.S. Energy Information Administration (EIA)

WASHINGTON -- Supply disruptions that normally would bolster oil prices had little impact... | Article from The Oil Daily August 3, 1993

4

(plexiglass) covers (negligible transmittance at 290320 nm). NOx emission decreased  

E-Print Network (OSTI)

that the controlling NOx formation and reduction reactions are insensi- tive to coal rank. This observation has been as the initial NOx level in- creases suggests that the char/NO reduction step(s) is more temperature sensitive concentrations cannot be reduced to levels ap- proaching 0 ppm without the use of downstream NOx reduction

5

A Simple Technique for Islanding Detection with Negligible Nondetection Zone  

E-Print Network (OSTI)

Although active islanding detection techniques have smaller nondetection zones than passive techniques, active methods could degrade the system power quality and are not as simple and easy to implement as passive methods. ...

Kirtley Jr, James L.

6

Accelerated Publication: Drain current enhancement and negligible current collapse in GaN MOSFETs with atomic-layer-deposited HfO2 as a gate dielectric  

Science Conference Proceedings (OSTI)

Accumulation-type GaN metal-oxide-semiconductor field-effect-transistors (MOSFET's) with atomic-layer-deposited HfO"2 gate dielectrics have been fabricated; a 4@mm gate-length device with a gate dielectric of 14.8nm in thickness (an equivalent SiO"2 ... Keywords: Atomic layer deposition (ALD), Current collapse, GaN, HfO2, Metal-oxide-semiconductor field-effect-transistor (MOSFET)

Y. C. Chang; W. H. Chang; Y. H. Chang; J. Kwo; Y. S. Lin; S. H. Hsu; J. M. Hong; C. C. Tsai; M. Hong

2010-11-01T23:59:59.000Z

7

Gurney, L., Bentz, DP, Sato, T., and Weiss, WJ 1 Published in ...  

Science Conference Proceedings (OSTI)

... in cement content and its associated greenhouse gases that ... and Class C) and retardation (Class C) effects. ... ash has a 226 negligible effect on heat ...

2012-12-31T23:59:59.000Z

8

US. DEPARThIl!NT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA...  

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

project management activities for both proposed project initiatives. DOE has determined thai impacts related to these tasks will have negligible or no affects on the human and...

9

APPENDIX C This appendix contains the supplemental forms ...  

Science Conference Proceedings (OSTI)

... Structured at runtime, time negligible. g. total mai1u(~l tilne to build (approximate nuinber of hours) Perhaps 8 person.h()urs. ...

1998-09-02T23:59:59.000Z

10

Finding leading modes of a viscous free surface flow: An asymmetric ...  

Science Conference Proceedings (OSTI)

Viscous free surface flows, as encountered in various extrusion and coating ... boundaries and free surfaces, negligible shear stress by the adjacent air at.

11

Microsoft Word - PSH-12-0130  

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

See Exhibit 10 (contemporaneous reports of security incidentinfraction listing cause as human error and inattention to detail). While even a negligent failure to follow such...

12

Causation and Foreseeability  

E-Print Network (OSTI)

negligently allowed bunker oil to escape from its ship intocase, believed that bunker oil was nonflammable when spreadafter asking whether the oil situation was dangerous and

Grady, Mark

2013-01-01T23:59:59.000Z

13

Numerical experience with solving MPECs as NLPs  

E-Print Network (OSTI)

Aug 20, 2002 ... the additional overhead is negligible, if a sparse matrix storage ... then either be invoked from the ampl prompt or directly from a command line.

14

Microsoft Word - LLNL 2011 CRD_8_1.docx  

National Nuclear Security Administration (NNSA)

it is non- volatile, it is not easily made airborne. The NIF does not have a residual thermal energy source that would mobilize less volatile species. Therefore, negligible...

15

The Extended L-Shaped Method for Mid-Term Planning of ...  

E-Print Network (OSTI)

We assume that the thermal plant has an infinite production capacity. Fixed costs (start-up/shut-down) are assumed to be negligible. The producer can sell its ...

16

A Fast Moving Horizon Estimation Algorithm Based on Nonlinear ...  

E-Print Network (OSTI)

applications with negligible on-line computational costs. .... The cost function ...... Oils. Waxes. Tubular. Reactor. Hyper-Compressor. High-Pressure. Separator.

17

POLY : A new polynomial data structure for Maple - CECM - Simon ...  

E-Print Network (OSTI)

We estimate that Maple takes over 200 clock cycles for each monomial .... In our new Maple, the cost of frontend and indets are now negligible since they no ...

18

Argus Primar Software License  

and expenses arise or are alleged to arise, directly or indirectly, from the participation, whether active or passive, or negligence, whether ordinary or gross, ...

19

GCTOOL COMMERCIAL SOFTWARE LICENSE AGREEMENT  

directly or indirectly, from the participation, whether active or passive, or negligence, whether ordinary or gross, of such parties, their employees, ...

20

NIST Tech Beat for May 15, 2012  

Science Conference Proceedings (OSTI)

... is usually negligible and the oil and gas ... embrittlement, especially for a hydrogen gas line ... technological innovations in domestic production of goods ...

2012-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Closed-Loop Control and FEM-Based Thermal Management on ...  

Science Conference Proceedings (OSTI)

... years as a novel and efficient substitute for oven curing of powder coating, characterized by its high curing speed, negligible heating effects on the substrate

22

NIST X-Ray Form Factor, Atten Scatt. Tables, Sec. 2  

Science Conference Proceedings (OSTI)

... 2. Form Factors and Standard Definitions. ... form factor (f 0 +f?), of magnitude f NT = -Z 2 m/M, with small (negligible) energy and momentum ...

23

Self-Assembly of Gold Nanoparticles at the Surface of Amine- and ...  

showed that there was negligible assembly of the gold nano-particles at the surface of the BNNTs (Figure 10). Both control experiments demonstrate a significant lack of

24

Plasma enhanced chemical vapor deposition vanadium oxide thin ...  

... exhibits a high discharge capacity, a high energy density, and a negligible capacity fade fiom its second cycle to at least 2,900 cycles, ...

25

Low Temperature Direct Growth of Graphene Films on Transparent Substrates by Chemical Vapor Deposition  

E-Print Network (OSTI)

Four-point electrical resistivity measurement…………………………..34with negligible electrical resistivity due to scattering3] . 4.3 Four-point electrical resistivity measurement: For

Antoine, Geoffrey Sandosh Jeffy

2013-01-01T23:59:59.000Z

26

ARPA TRP turboalternator development: Quarterly Report, July--September 1995. Revision 1  

DOE Green Energy (OSTI)

This report presents information on 4 major tasks: under-armor auxiliary power unit (UAAPU) demonstration on an M1A1 tank; low-cost turbogenerator design; negligible emission catalytic combustor development; and turbogenerator demonstration on an electric bus.

NONE

1995-10-01T23:59:59.000Z

27

Design, Construction, and Test Results for Three Different Fiber Optic Tow Cables  

Science Conference Proceedings (OSTI)

The design, manufacture, and testing of three armored fiber optic tow cables is discussed. The motivation for these developments was the technical need to have low-loss high-bandwidth transmission lines, that function with negligible crosstalk and absence ...

E. Althouse

2006-09-01T23:59:59.000Z

28

Evaluation of the K-Gill Propeller Vane  

Science Conference Proceedings (OSTI)

Dynamic properties of the K-Gill propeller vane (k vane) are assessed from perturbation theory, wind tunnel, and field comparison experiments. Measurement errors for average wind speed are negligible. The dynamic response of the k vane can be ...

Job W. Verkaik

1998-08-01T23:59:59.000Z

29

Impact of Atmospheric Moisture Storage on Precipitation Recycling  

Science Conference Proceedings (OSTI)

Computations of precipitation recycling using analytical models are generally performed under the assumption of negligible change in moisture storage in the atmospheric column. Because the moisture storage term is nonnegligible at smaller time ...

Francina Dominguez; Praveen Kumar; Xin-Zhong Liang; Mingfang Ting

2006-04-01T23:59:59.000Z

30

Emotion detection in email customer care  

Science Conference Proceedings (OSTI)

Prompt and knowledgeable responses to customers' emails are critical in maximizing customer satisfaction. Such emails often contain complaints about unfair treatment due to negligence, incompetence, rigid protocols, unfriendly systems, and unresponsive ...

Narendra Gupta; Mazin Gilbert; Giuseppe Di Fabbrizio

2010-06-01T23:59:59.000Z

31

J:\\ARM_19~1\\P367-376.WPD  

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

is similar to that of Deardorff (1978). A single layer of vegetation with negligible heat capacity is assumed to be present and is characterized by its physical height, canopy...

32

Document:  

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

2 I i * V i . (2.6) Since the electric energy density is negligibly small compared to the magnetic energy density in ferromagnetic material, we drop the displacement current term...

33

Slide 1  

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

1,102,098 321,489 22.6% 08121-2902-06 COMPLETE Enumerating Bacteria in Deepwater Pipelines in Real-Time at a Negligible Marginal Cost Per Analysis: A Proof of Concept Study...

34

NIST Realization of the candela  

Science Conference Proceedings (OSTI)

... lm/W, is normally rounded to 683 lm/W with negligible error for all ... quantifies the intensity of a light source as observed by the human visual system. ...

2012-10-02T23:59:59.000Z

35

Discreteness of spectrum and positivity criteria for Schrödinger operators  

E-Print Network (OSTI)

We provide a class of necessary and sufficient conditions for the discreteness of spectrum of Schr\\"odinger operators with scalar potentials which are semibounded below. The classical discreteness of spectrum criterion by A.M.Molchanov (1953) uses a notion of negligible set in a cube as a set whose Wiener's capacity is less than a small constant times the capacity of the cube. We prove that this constant can be taken arbitrarily between 0 and 1. This solves a problem formulated by I.M.Gelfand in 1953. Moreover, we extend the notion of negligibility by allowing the constant to depend on the size of the cube. We give a complete description of all negligibility conditions of this kind. The a priori equivalence of our conditions involving different negligibility classes is a non-trivial property of the capacity. We also establish similar strict positivity criteria for the Schr\\"odinger operators with non-negative potentials.

Vladimir Maz'ya; Mikhail Shubin

2003-05-19T23:59:59.000Z

36

gilbert.docx  

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

Owens S, Caporaso JG, Sperling M, Nissimov, JI, Romac, S, Bittner L, Riebesell U, LaRoche J, Gilbert JA. 2012. Ocean acidification shows negligible impacts on high-latitude...

37

Drop Size Separation in Numerically Simulated Convective Clouds and Its Effect on Warm Rain Formation  

Science Conference Proceedings (OSTI)

It is shown that, as a result of the flow diffluence at the upper levels of the cloud, droplets of different sizes move along different trajectories. The small droplets with negligible fall velocities will have higher probability of being carried ...

Yefim L. Kogan

1993-05-01T23:59:59.000Z

38

661.ps.gz  

E-Print Network (OSTI)

negativity requirement s; > 0 and produces negligible progress toward the ... system (2.3) reveals that if H1 does not depend on z1, then neither does the step.

39

Tax Savings as a Provision of Corporate Welfare is a State-Corporate Crime When it Becomes Socially Injurious  

E-Print Network (OSTI)

Matthews. 2006. ³The Exxon Valdez oil spill´LQMichalowski,recent case-study is the Exxon Oil Spill of 1989. Firstof negligent behavior of the Exxon corporation and the

Nery, Annebelle

2010-01-01T23:59:59.000Z

40

Eclipse Ice Core Accumulation and Stable Isotope Variability as an Indicator of North Pacific Climate  

Science Conference Proceedings (OSTI)

The high accumulation rate and negligible amount of melt at Eclipse Icefield (3017 m) in the Saint Elias Range of Yukon, Canada, allows for the preservation of a high-resolution isotopic and glaciochemical records valuable for reconstruction of ...

Eric P. Kelsey; Cameron P. Wake; Kaplan Yalcin; Karl Kreutz

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Momentum Balance of Gravity Flows  

Science Conference Proceedings (OSTI)

A unified scale analysis of the momentum balance of downslope gravity flows is developed to organize previous theories for the case of negligible ambient flow and fixed temperature deficit scale. The values of several nondimensional parameters ...

L. Mahrt

1982-12-01T23:59:59.000Z

42

CMOS circuits for VCSEL-based optical IO  

E-Print Network (OSTI)

Electrical IO is becoming limited by copper interconnect channel losses that depend on frequency and distance. Package-to-package optical interconnects see negligible frequency-dependent channel losses, but data rates are ...

Kern, Alexandra M., 1979-

2007-01-01T23:59:59.000Z

43

Grid -Based Parallel Data Streaming implemented for the Gyrokinetic Toroidal Code  

Science Conference Proceedings (OSTI)

We have developed a threaded parallel data streaming approach using Globus to transfer multi-terabyte simulation data from a remote supercomputer to the scientistýs home analysis/visualization cluster, as the simulation executes, with negligible ...

S. Klasky; S. Ethier; Z. Lin; K. Martins; D. McCune; R. Samtaney

2003-11-01T23:59:59.000Z

44

Efficient Local Error Parameterizations for Square Root or Ensemble Kalman Filters: Application to a Basin-Scale Ocean Turbulent Flow  

Science Conference Proceedings (OSTI)

In large-sized atmospheric or oceanic applications of square root or ensemble Kalman filters, it is often necessary to introduce the prior assumption that long-range correlations are negligible and force them to zero using a local ...

Jean-Michel Brankart; Emmanuel Cosme; Charles-Emmanuel Testut; Pierre Brasseur; Jacques Verron

2011-02-01T23:59:59.000Z

45

Injection compression modeling of non-linear positive temperature coefficient circuit protection devices  

E-Print Network (OSTI)

Polymeric self-resettable circuit protection devices have been manufactured for many years with an extrusion based process. These devices add negligible resistance to a circuit at normal power operating conditions but ...

Hardy, Joseph T., 1978-

2005-01-01T23:59:59.000Z

46

Dynamics on the Laminar-Turbulent Boundary and the Origin of the Maximum Drag Reduction Asymptote  

E-Print Network (OSTI)

Dynamical trajectories on the boundary in state space between laminar and turbulent plane channel flow—edge states—are computed for Newtonian and viscoelastic fluids. Viscoelasticity has a negligible effect on the properties ...

Graham, Michael D.

47

A Comparison of Key Forecast Variables Derived from Isentropic and Sigma Coordinate Regional Models  

Science Conference Proceedings (OSTI)

When diabatic heating, frictional forces and radiative effects within the atmosphere are negligible then a parcel's entropy will remain nearly constant and its motion will be along isentropic surfaces. Because such conditions may extend over ...

Thomas L. Black

1987-12-01T23:59:59.000Z

48

Instability of a Mixed Layer Model and the Generation of Near-Inertial Motion. Part I: Constant Mixed Layer Depth  

Science Conference Proceedings (OSTI)

The stability of Niiler's model of a deepening mixed layer was investigated assuming the deepening rate was negligible. Two basically different instability mechanisms appeared. One is a mixture of a Kelvin-Helmholtz type and parallel flow viscous ...

John Kroll

1988-07-01T23:59:59.000Z

49

Ionic liquid ion source emitter arrays fabricated on bulk porous substrates for spacecraft propulsion  

E-Print Network (OSTI)

Ionic Liquid Ion Sources (ILIS) are a subset of electrospray capable of producing bipolar beams of pure ions from ionic liquids. Ionic liquids are room temperature molten salts, characterized by negligible vapor pressures, ...

Courtney, Daniel George

2011-01-01T23:59:59.000Z

50

Dynamic Response of CTD Pressure Sensors to Temperature  

Science Conference Proceedings (OSTI)

Pressure sensors used in CTDs (conductivity temperature depth) respond to transients in temperature. It is often assumed that these transients have a negligible effect on pressure. However, in a Sea-Bird CTD used in Hawaiian waters, these ...

S. M. Chiswell

1991-10-01T23:59:59.000Z

51

The Southern Oscillation and Prediction of “Der” Season Rainfall in Somalia  

Science Conference Proceedings (OSTI)

Somalia survives in semiarid to arid conditions, with annual rainfall totals rarely exceeding 700 mm, which are divided between two seasons. Many areas are arid, with negligible precipitation. Seasonal totals are highly variable. Thus, any ...

P. Hutchinson

1992-05-01T23:59:59.000Z

52

Alternative stripper configurations to minimize energy for CO2 capture Babatunde A. Oyenekan and Gary T. Rochelle*  

E-Print Network (OSTI)

. The application method and related issues are demonstrated through a case study on a gas network with compressors in a long horizon- tal pipeline, with negligible kinetic energy change, constant friction coefficient applications [11]. In a centrifugal compressor, work is done on the gas by an impeller. Gas is discharged

Rochelle, Gary T.

53

Method and Tools to Support Stakeholder Engagement in Policy Development: The OCOPOMO Project  

Science Conference Proceedings (OSTI)

Good governance and open government principles require more participative, open, transparent, accountable, and collaborative. However, in public policy development, the negligence of these principles loomed particularly large until recently. In consequence, ... Keywords: Agent-Based Modelling, Good Governance Principles, Open Collaboration, Policy Development, Scenario Building, Stakeholder Involvement

Maria Wimmer; Sabrina Scherer; Scott Moss; Melanie Bicking

2012-07-01T23:59:59.000Z

54

The College of Sciences and Mathematics & The R. W. Yeagy Colloquium present  

E-Print Network (OSTI)

is a system of differential equations that accounts for the belowground biomass, herbivory, and interspecific below ground biomass and the other which emerges from the water, but has negligible below ground biomass (non-negative) equilibria and their stability. If the belowground biomass is assumed constant

Long, Nicholas

55

PROPRIETARY MATERIAL. 2011 The McGraw-Hill Companies, Inc. Limited distribution permitted only to teachers and educators for course preparation. If you are a student using this Manual, you are using it without permission.  

E-Print Network (OSTI)

PROPRIETARY MATERIAL. © 2011 The McGraw-Hill Companies, Inc. Limited distribution permitted only and process heat. The mass flow rate of steam through the boiler for a net power output of 25 MW are negligible. Analysis From the steam tables (Tables A-4, A-5, and A-6), kJ/kg02.86757.844.858 k

Bahrami, Majid

56

TMX-upgrade. X-ray diagnostic: low-energy temperature determination  

Science Conference Proceedings (OSTI)

In order to properly design the x-ray filter set, a reasonable computational model of the plasma emission had to be developed. The radiation continuum computed consisted of two components: bremsstrahlung and recombination radiation. The contribution of line radiation from low Z impurities was estimated to be negligible for x-ray energies above 1 keV.

Jacoby, B.A.

1981-05-01T23:59:59.000Z

57

PROCEEDINGS, Twenty-First Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 22-24, 1996  

E-Print Network (OSTI)

with no spacer. The blocks are sealed in epoxy so that saturation measure- ments can be made throughout air experiment. These results suggest that it is incor- rect to assume negligible capillary continuity in. Tilting the mold re- duced the number of air bubbles which can form along the bottom of the core

58

ResearchMICHIGAN TECHNOLOGICAL UNIVERSITY > 2013 ResearchMICHIGAN TECHNOLOGICAL UNIVERSITY > 2013  

E-Print Network (OSTI)

for the population. Supported by the National Park Service, the National Science Foundation, Michigan Tech to a privileged few. "The public's access to high-powered microscopes is negligible," he says. "With superlenses acrobats in this balancing act as it applies to microgrids. "The word `microgrid' is a little misleading

59

Security principles and management method for secure S/W introduction  

Science Conference Proceedings (OSTI)

An existing S/W development enterprises was negligent in S/W security problem because of imminent development period, insufficient fund and ignorance of security, and weakness problem of S/W almost has solved by beta test and a patch mostly. In addition, ... Keywords: S/W, S/W introduction, secure S/W, security

Jae Hong Han; Ho Seong Kim; Wan S. Yi; Yoo Jae Won

2008-11-01T23:59:59.000Z

60

Low-cost nanosecond electronic coincidence detector  

E-Print Network (OSTI)

We present a simple and low-cost implementation of a fast electronic coincidence detector based on PECL logic with a TTL-compatible interface. The detector has negligible dead time and the coincidence window is adjustable with a minimum width of 1 ns. Coincidence measurements of two independent sources of Bose-Einstein distributed photocounts are presented using different coincidence window widths.

Kim, T; Gorelik, P V; Wong, F N C; Kim, Taehyun; Fiorentino, Marco; Gorelik, Pavel V.; Wong, Franco N. C.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

A comprehensive performance macro-modeling of on-chip RC interconnects considering line shielding effects  

Science Conference Proceedings (OSTI)

The delay of on-chip interconnect wiring is having an important influence on the timing performance of logic path. This is particularly true where drivers are connected through a non-negligible length of wire. If the Elmore resistance-capacitance delay ... Keywords: deep submicron, interconnect, modelling

S. Engels; R. Wilson; N. Azémard; Philippe Maurine

2006-07-01T23:59:59.000Z

62

Hydrodynamical modeling of targets compression to high densities  

E-Print Network (OSTI)

by composite schemes on moving grid. Both models also include heat conductivity. The quotidian equation, E is total energy and heat flux W is given by W = - grad T (2) where T is temperature and is heat note that for most presented computations the heat conductivity is negligible. The above system

Limpouch, Jiri

63

Rotary pneumatic valve  

DOE Patents (OSTI)

A rotary pneumatic valve which is thrust balanced and the pneumatic pressure developed produces only radial loads on the valve cylinder producing negligible resistance and thus minimal torque on the bearings of the valve. The valve is multiplexed such that at least two complete switching cycles occur for each revolution of the cylinder spindle. 4 figs.

Hardee, H.C.

1989-08-02T23:59:59.000Z

64

Surface Waves and Landau Resonant Heating in Unmagnetized Bounded  

E-Print Network (OSTI)

bulk not negligible x V(x,t) x V(x,t) x V(x,t) Instantaneous PotentialInstantaneous Potential x Vrf(x,t) Vrf(x,t)Vrf(x,t) xx RF PotentialRF Potential #12;10/10/2005 K. Bowers 8 Circuit Viewpoint ni = nne

Kaganovich, Igor

65

Under consideration for publication in J. Fluid Mech. 1 Inviscid mean flow through and around  

E-Print Network (OSTI)

velocity is negligible (as the void fraction of the bodies, 0). Within wide and short rectangular arrays of bodies, the average velocity of bubbly flows as a function of void fraction, and the tendency of clouds for void fractions close to 0.1 (Couet, Brown & Hunt 1991). The distinction between different contributions

Reading, University of

66

Progress in Computational Fluid Dynamics, Vol. x, No. x, 200x 1 Copyright 200x Inderscience Enterprises Ltd.  

E-Print Network (OSTI)

, the difference between the Eulerian and Lagrangian mean velocity is negligible (as the void fraction as a function of void fraction, obstacles, and the tendency of clouds of bubbles to be distorted depending in multiphase flows, even for void fractions close to 0.1 (Couet et al. 1991). The distinction between different

Paris-Sud XI, Université de

67

The Author 2011. Published by Oxford University Press on behalf of The British Computer Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com  

E-Print Network (OSTI)

nodes are often equipped with a limited energy source and a processing unit with a small memory capacity-required system-level services on nodes, instead of installing a fixed large system software image for any overhead and a negligible CPU cost compared with the state-of-the-art development models. Keywords

Eliassen, Frank

68

Vilamoura 1 November 2004 The Fast Track to Fusion PowerThe Fast Track to Fusion Power  

E-Print Network (OSTI)

for transport [hydrogen - whence?;...], or introduce large scale conversion of unconventional oil - or coal change + running out (oil first) What must be done? - increased energy R&D (currently negligible [and Geological Survey's estimate of the amount of remaining oil (which is significantly larger than all others

69

SOUTHWEST CATALYSIS 2012 SPRING SYMPOSIUM  

E-Print Network (OSTI)

, and hydrogen are activated with energetic sources such as microwaves to generate plasmas, direct current (DC include the hot filament [2] and many types of microwave plasma [3], which typically have *Corresponding is expected to be negligible since the diamond phase of carbon is very stable and gasification of dia- mond

70

Diamond and Related Materials 6 ( 1997) 1759-I771 Simulation of morphological instabilities during diamond  

E-Print Network (OSTI)

, and hydrogen are activated with energetic sources such as microwaves to generate plasmas, direct current (DC include the hot filament [2] and many types of microwave plasma [3], which typically have *Corresponding is expected to be negligible since the diamond phase of carbon is very stable and gasification of dia- mond

Dandy, David

71

COLLEGE OF ENGINEERING RESEARCH REPORT  

E-Print Network (OSTI)

, and hydrogen are activated with energetic sources such as microwaves to generate plasmas, direct current (DC include the hot filament [2] and many types of microwave plasma [3], which typically have *Corresponding is expected to be negligible since the diamond phase of carbon is very stable and gasification of dia- mond

Saskatchewan, University of

72

National Algal Biofuels Technology Roadmap  

E-Print Network (OSTI)

, and hydrogen are activated with energetic sources such as microwaves to generate plasmas, direct current (DC include the hot filament [2] and many types of microwave plasma [3], which typically have *Corresponding is expected to be negligible since the diamond phase of carbon is very stable and gasification of dia- mond

73

Nonoxidative Activation of Methane Tushar V. Choudhary,#  

E-Print Network (OSTI)

, and hydrogen are activated with energetic sources such as microwaves to generate plasmas, direct current (DC include the hot filament [2] and many types of microwave plasma [3], which typically have *Corresponding is expected to be negligible since the diamond phase of carbon is very stable and gasification of dia- mond

Goodman, Wayne

74

Cycling firing method for bypass operation of bridge converters  

DOE Patents (OSTI)

The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

Zabar, Zivan (99-72 66th Rd., Apt. 9N, Forest Hills, NY 11375)

1982-01-01T23:59:59.000Z

75

Fuzzy hierarchical production planning (with a case study)  

Science Conference Proceedings (OSTI)

Hierarchical production planning (HPP) is a well-known approach to cope with the complexity of multi-level production planning and scheduling problems in real-world industrial cases. However, negligence of some issues such as inherent uncertainty in ... Keywords: Fuzzy mathematical programming, Hierarchical production planning, Make-To-Stock systems

S. A. Torabi; M. Ebadian; R. Tanha

2010-06-01T23:59:59.000Z

76

Chemical Engineering Journal 119 (2006) 4553 Hexavalent chromium ion removal through micellar  

E-Print Network (OSTI)

of surfactant solution Effects of pressure as well as concentration of the surfactant on permeate flux concentration remains constant. 3.4.2. Effect of surfactant concentration Fig. 14 shows negligible influence enhanced ultrafiltration Gargi Ghosh, Prashant K. Bhattacharya Department of Chemical Engineering, Indian

Bandyopadhyaya, Rajdip

77

Atmos. Chem. Phys., 4, 21072117, 2004 www.atmos-chem-phys.org/acp/4/2107/  

E-Print Network (OSTI)

of surfactant solution Effects of pressure as well as concentration of the surfactant on permeate flux concentration remains constant. 3.4.2. Effect of surfactant concentration Fig. 14 shows negligible influence enhanced ultrafiltration Gargi Ghosh, Prashant K. Bhattacharya Department of Chemical Engineering, Indian

Paris-Sud XI, Université de

78

Department of Mechanics KTH, SE-100 44 Stockholm, Sweden  

E-Print Network (OSTI)

of surfactant solution Effects of pressure as well as concentration of the surfactant on permeate flux concentration remains constant. 3.4.2. Effect of surfactant concentration Fig. 14 shows negligible influence enhanced ultrafiltration Gargi Ghosh, Prashant K. Bhattacharya Department of Chemical Engineering, Indian

Haviland, David

79

M E S A + " 0 7 H I G H L I G H T S M E S A + " 0 7  

E-Print Network (OSTI)

of surfactant solution Effects of pressure as well as concentration of the surfactant on permeate flux concentration remains constant. 3.4.2. Effect of surfactant concentration Fig. 14 shows negligible influence enhanced ultrafiltration Gargi Ghosh, Prashant K. Bhattacharya Department of Chemical Engineering, Indian

Twente, Universiteit

80

TheCityCollege Graduate Bulletin  

E-Print Network (OSTI)

of surfactant solution Effects of pressure as well as concentration of the surfactant on permeate flux concentration remains constant. 3.4.2. Effect of surfactant concentration Fig. 14 shows negligible influence enhanced ultrafiltration Gargi Ghosh, Prashant K. Bhattacharya Department of Chemical Engineering, Indian

Brinkmann, Peter

Note: This page contains sample records for the topic "negligible negligible negligible" 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

TTHHEESSEE DDEE DDOOCCTTOORRAATT en vue d`obtenir le grade de  

E-Print Network (OSTI)

of surfactant solution Effects of pressure as well as concentration of the surfactant on permeate flux concentration remains constant. 3.4.2. Effect of surfactant concentration Fig. 14 shows negligible influence enhanced ultrafiltration Gargi Ghosh, Prashant K. Bhattacharya Department of Chemical Engineering, Indian

Paris-Sud XI, Université de

82

NUMA-aware memory manager with dominant-thread-based copying GC  

Science Conference Proceedings (OSTI)

We propose a novel online method of identifying the preferred NUMA nodes for objects with negligible overhead during the garbage collection time as well as object allocation time. Since the number of CPUs (or NUMA nodes) is increasing recently, it is ... Keywords: cc-NUMA, java

Takeshi Ogasawara

2009-10-01T23:59:59.000Z

83

Leveraging Multiple Heterogeneous Radios for Energy-efficient Routing Mehedi Bakht, Riccardo Crepaldi, Albert F. Harris III, and Robin Kravets  

E-Print Network (OSTI)

consumed per unit time in the idle state Low-power/low-rate radios apparently fare better on both counts Low idling cost Low power level in the communication states High-power radios Higher data rate Shorter of using a High-power Radio High idle state overhead Non-negligible state transition costs Our Solution Per

Kravets, Robin

84

Effect of water stress on growth, water consumption and yield of silage maize under flood irrigation in a semiarid climate of Tadla (Morocco)  

E-Print Network (OSTI)

. Capillary rise was considered as negligeable because water table is deep. Author-produced version of irrigation water applied and ETa values were 619.3 and 477.7 mm in 2009 and 535.0 and 463.0 mm in 2010 Author-produced regions. Oktem et al. (2003) showed that Ky value increases with water stress. Author-produced version

85

Solar proton events in cosmogenic isotope data Ilya G. Usoskin,1  

E-Print Network (OSTI)

Solar proton events in cosmogenic isotope data Ilya G. Usoskin,1 Sami K. Solanki,2 Gennady A March 2006; published 27 April 2006. [1] A possible contribution of solar energetic particle events to the production of cosmogenic 10 Be and 14 C in the atmosphere is studied. The solar particle effect is negligible

Usoskin, Ilya G.

86

Development Water, Gas, and Electric Energy Use Projection  

E-Print Network (OSTI)

2. In addition to the sewage flow demand created by the building development, parking drainage and pool backwash may also create additional sanitary sewer flow. These additional flows are assumed to be negligible compared to the rest of the project. B. Sanitary Sewage Discharge 1. The daily sanitary sewer flow will be near the daily building cold water usage as detailed above.

unknown authors

2007-01-01T23:59:59.000Z

87

Control Techniques to Eliminate Voltage Emergencies in High Performance Processors  

E-Print Network (OSTI)

negligible impact on perfor­ mance and energy. With the ITRS roadmap predicting aggres­ sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re­ ferred to as the dI/dt problem, can cause supply voltage fluc­ tuations

Martonosi, Margaret

88

Control Techniques to Eliminate Voltage Emergencies in High Performance Processors  

E-Print Network (OSTI)

negligible impact on perfor- mance and energy. With the ITRS roadmap predicting aggres- sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re- ferred to as the dI/dt problem, can cause supply voltage fluc- tuations

Gupta, Rajiv

89

A brief note on how to unify dark matter, dark energy, and inflation  

E-Print Network (OSTI)

A scenario in which inflation, dark energy and dark matter can be unified into a single scalar field, the inflaton field $\\phi$, is studied. The inflaton is identified with the sneutrino, the scalar partner of the heavy neutrino. We determine the conditions needed for avoiding the gravitino problem and not having negligible plasma effects and we obtain the allowed range for the sneutrino coupling.

Grigoris Panotopoulos

2007-06-15T23:59:59.000Z

90

Energy Harvesting Communications with Hybrid Energy Storage and Processing Cost  

E-Print Network (OSTI)

Energy Harvesting Communications with Hybrid Energy Storage and Processing Cost Omur Ozel Khurram with an energy harvesting transmitter with non-negligible processing circuitry power and a hybrid energy storage for energy storage while the battery has unlimited space. The transmitter stores the harvested energy either

Ulukus, Sennur

91

A new approach to sub-grid surface tension for LES of two-phase flows  

Science Conference Proceedings (OSTI)

In two-phase flow, the presence of inter-phasal surface - the interface - causes additional terms to appear in LES formulation. Those terms were ignored in contemporary works, for the lack of model and because the authors expected them to be of negligible ... Keywords: CLSVOF, Large Eddy Simulation, Surface tension, Two-phase flow

W. Aniszewski; A. Bogus?Awski; M. Marek; A. Tyliszczak

2012-08-01T23:59:59.000Z

92

Position-based cluster routing protocol for mobile ad hoc networks  

Science Conference Proceedings (OSTI)

Some of the proposed mobile ad hoc network routing algorithms require maintaining a global network state at each node. The global state is always an approximation of the current network state due to the non-negligible delay of propagating local state. ... Keywords: GPS, QoS, mobile ad hoc network, multicasting, position-based routing protocol

Chao-Cheng Shih; Tzay-Farn Shih

2006-07-01T23:59:59.000Z

93

Off-shell OPERA neutrinos  

E-Print Network (OSTI)

In the OPERA experiment, superluminal propagation of neutrinos can occur if one of the neutrino masses is extremely small. However the effect only has appreciable amplitude at energies of order this mass and thus has negligible overlap with the multi-GeV scale of the experiment.

Tim R. Morris

2011-10-14T23:59:59.000Z

94

Parameterizations for Water Vapor IR Radiative Transfer in Both the Middle and Lower Atmospheres  

Science Conference Proceedings (OSTI)

Water vapor contributes a maximum of 1°C/day to the middle atmospheric thermal infrared (IR) cooling. This magnitude is small but not negligible. Because of the small amount of mass involved and the extremely narrow molecular absorption lines at ...

Ming-Dah Chou; William L. Ridgway; Michael M-H. Yan

1995-04-01T23:59:59.000Z

95

A Performance Comparison Study of End-to-End Congestion Control Protocols over MIMO Fading Channels  

E-Print Network (OSTI)

Systems The Boeing Company wojtek.furmanski@boeing.com Abstract--We study the performance of end effective packet loss schemes under heavy net- work loads while adhering to a fair bandwidth allocation, negligible packet loss rate, and reasonable fairness. This work was sponsored by the grants from Boeing

Yousefi'zadeh, Homayoun

96

Supporting Information Supplement 1  

E-Print Network (OSTI)

and cooling rates leave negligible time for morphological relaxation mechanisms such as diffusion, oxidation(t) is the time dependent laser fluence (J/m2 ), (z,t) is the absorption coefficient (equation 7) and FWHM is the full width at half maximum of the laser pulse. The absorption coefficient is given as; (7) #12;where

Kondic, Lou

97

JOURNALDE PHYSIQUE IV ColloqueC7, supplkment au Journal de Physique 111,Volume 4,juiIlet 1994  

E-Print Network (OSTI)

and negligible amounts of C14. The wide spread usage of tracer chemistry in biological science brought to grow synthetic diamonds of various isotopic compositions. General Electric Corporate R&D laboratory did the experimental findings with theory did not succeed[2-41,mostly due to the lack of data at lower

Paris-Sud XI, Université de

98

High-temperature seal development for the share receiver  

DOE Green Energy (OSTI)

The development and experimental demonstration of a high-temperature seal for the SHARE ceramic dome cavity receiver is reported. The mechanical contact seal which was tested on one-foot diameter silicon carbide ceramic dome hardware at pressure differentials to four atmospheres and dome temperatures to 2200/sup 0/F (1200/sup 0/C) showed negligible leakage at expected receiver operating conditions.

Jarvinen, P. O.

1979-01-01T23:59:59.000Z

99

Under consideration for publication in J. Fluid Mech. 1 Dam breaking seiches  

E-Print Network (OSTI)

of the dam is m, and g is gravity, the equation of motion for the dam's position can be written #12;Seiches Benjamin (1955), if the dam's edge is relatively sharp, gravity is negligible, and the outflow is similar assembly. As the dam moves up and down, and the assembly rotates, the component of gravity acting

Balmforth, Neil

100

technical program  

Science Conference Proceedings (OSTI)

Aug 2, 1999 ... Steels in Various Types of Nuclear Power Systems: Markus O. Speidel1 ... gen peroxide concentration and the electrochemical corrosion poten- tial (ECP). ...... This paper deals with stress corrosion cracking (SCC) of Russian type ..... wppm exhibited high ductility, low percent TGSCC, and negligible per-.

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Electronic and Geometric Structures of Small Gold Metal Particles: Particles Size Effects and the Relationship to Catalytic Activity  

SciTech Connect

The structure of supported gold nano-particles is affected by the size of the particles. Smaller metal particles have decreased gold - gold bond lengths, a higher d electron count, and have a more reactive d band. The influence of support is negligible compared to that of particle size.

Bokhoven, Jeroen A. van [Institute for chemical and Bioengineering, ETH Zurich (Switzerland); Miller, Jeffrey T. [BP Research Center, Naperville, IL 60565-8406 (United States)

2007-02-02T23:59:59.000Z

102

Search for gravitational waves from binary black hole inspiral, merger and ringdown  

E-Print Network (OSTI)

We present the first modeled search for gravitational waves using the complete binary black hole gravitational waveform from inspiral through the merger and ringdown for binaries with negligible component spin. We searched approximately 2 years of LIGO data taken between November 2005 and September 2007 for systems with component masses of 1-99 solar masses and total masses of 25-100 solar masses. We did not detect any plausible gravitational-wave signals but we do place upper limits on the merger rate of binary black holes as a function of the component masses in this range. We constrain the rate of mergers for binary black hole systems with component masses between 19 and 28 solar masses and negligible spin to be no more than 2.0 per Mpc^3 per Myr at 90% confidence.

The LIGO Scientific Collaboration; the Virgo Collaboration; J. Abadie; B. P. Abbott; R. Abbott; M. Abernathy; T. Accadia; F. Acernese; C. Adams; R. Adhikari; P. Ajith; B. Allen; G. S. Allen; E. Amador Ceron; R. S. Amin; S. B. Anderson; W. G. Anderson; F. Antonucci; M. A. Arain; M. C. Araya; M. Aronsson; Y. Aso; S. M. Aston; P. Astone; D. Atkinson; P. Aufmuth; C. Aulbert; S. Babak; P. Baker; G. Ballardin; T. Ballinger; S. Ballmer; D. Barker; S. Barnum; F. Barone; B. Barr; P. Barriga; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; M. Bastarrika; J. Bauchrowitz; Th. S. Bauer; B. Behnke; M. G. Beker; A. Belletoile; M. Benacquista; A. Bertolini; J. Betzwieser; N. Beveridge; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; S. Birindelli; R. Biswas; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; B. Bland; M. Blom; C. Boccara; O. Bock; T. P. Bodiya; R. Bondarescu; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; B. Bouhou; M. Boyle; S. Braccini; C. Bradaschia; P. R. Brady; V. B. Braginsky; J. E. Brau; J. Breyer; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; R. Budzy?ski; T. Bulik; H. J. Bulten; A. Buonanno; J. Burguet-Castell; O. Burmeister; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Cain; E. Calloni; J. B. Camp; E. Campagna; P. Campsie; J. Cannizzo; K. Cannon; B. Canuel; J. Cao; C. Capano; F. Carbognani; S. Caride; S. Caudill; M. Cavaglia`; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; O. Chaibi; T. Chalermsongsak; E. Chalkley; P. Charlton; E. Chassande-Mottin; S. Chelkowski; Y. Chen; A. Chincarini; N. Christensen; S. S. Y. Chua; C. T. Y. Chung; D. Clark; J. Clark; J. H. Clayton; F. Cleva; E. Coccia; C. N. Colacino; J. Colas; A. Colla; M. Colombini; R. Conte; D. Cook; T. R. Corbitt; N. Cornish; A. Corsi; C. A. Costa; J. -P. Coulon; D. M. Coward; D. C. Coyne; J. D. E. Creighton; T. D. Creighton; A. M. Cruise; R. M. Culter; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; S. L. Danilishin; R. Dannenberg; S. D'Antonio; K. Danzmann; K. Das; V. Dattilo; B. Daudert; M. Davier; G. Davies; A. Davis; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; D. DeBra; G. Debreczeni; J. Degallaix; M. del Prete; V. Dergachev; R. DeRosa; R. DeSalvo; P. Devanka; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; M. Di Paolo Emilio; A. Di Virgilio; M. Díaz; A. Dietz; F. Donovan; K. L. Dooley; E. E. Doomes; S. Dorsher; E. S. D. Douglas; M. Drago; R. W. P. Drever; J. C. Driggers; J. Dueck; J. -C. Dumas; T. Eberle; M. Edgar; M. Edwards; A. Effler; P. Ehrens; G. Ely; R. Engel; T. Etzel; M. Evans; T. Evans; V. Fafone; S. Fairhurst; Y. Fan; B. F. Farr; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Fidecaro; L. S. Finn; I. Fiori; R. Flaminio; M. Flanigan; K. Flasch; S. Foley; C. Forrest; E. Forsi; L. A. Forte; N. Fotopoulos; J. -D. Fournier; J. Franc; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; D. Friedrich; P. Fritschel; V. V. Frolov; P. Fulda; M. Fyffe; M. Galimberti; L. Gammaitoni; J. A. Garofoli; F. Garufi; M. E. Gáspár; G. Gemme; E. Genin; A. Gennai; I. Gholami; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; C. Gill; E. Goetz; L. M. Goggin; G. González; M. L. Gorodetsky; S. Goßler; R. Gouaty; C. Graef; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Greverie; R. Grosso; H. Grote; S. Grunewald; G. M. Guidi; E. K. Gustafson; R. Gustafson; B. Hage; P. Hall; J. M. Hallam; D. Hammer; G. Hammond; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; K. Haughian; K. Hayama; J. -F. Hayau; T. Hayler; J. Heefner; H. Heitmann; P. Hello; I. S. Heng; A. W. Heptonstall; M. Hewitson; S. Hild; E. Hirose; D. Hoak; K. A. Hodge; K. Holt; D. J. Hosken; J. Hough; E. J. Howell; D. Hoyland; D. Huet; B. Hughey; S. Husa; S. H. Huttner; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; P. Jaranowski; W. W. Johnson; D. I. Jones; G. Jones; R. Jones; L. Ju; P. Kalmus; V. Kalogera; S. Kandhasamy; J. B. Kanner; E. Katsavounidis; K. Kawabe; S. Kawamura; F. Kawazoe; W. Kells; D. G. Keppel; A. Khalaidovski; F. Y. Khalili; E. A. Khazanov; H. Kim; P. J. King; D. L. Kinzel; J. S. Kissel; S. Klimenko; V. Kondrashov; R. Kopparapu; S. Koranda; I. Kowalska; D. Kozak; T. Krause; V. Kringel; S. Krishnamurthy; B. Krishnan; A. Królak; G. Kuehn; J. Kullman; R. Kumar; P. Kwee; M. Landry; M. Lang; B. Lantz; N. Lastzka; A. Lazzarini; P. Leaci; J. Leong; I. Leonor; N. Leroy; N. Letendre; J. Li; T. G. F. Li; N. Liguori; H. Lin; P. E. Lindquist; N. A. Lockerbie; D. Lodhia; M. Lorenzini; V. Loriette; M. Lormand; G. Losurdo; P. Lu; J. Luan; M. Lubinski; A. Lucianetti; H. Lück; A. D. Lundgren; B. Machenschalk; M. MacInnis; M. Mageswaran; K. Mailand; E. Majorana

2011-02-18T23:59:59.000Z

103

The Quasi-stationary Structure of Radiating Shock Waves; 2, The Two-temperature Fluid  

E-Print Network (OSTI)

We solve the equations of radiation hydrodynamics in the two-temperature fluid approximation on an adaptive grid. The temperature structure depends upon the electron-ion energy exchange length, $l_{ei}$, and the electron conduction length, $l_{ec}$. Three types of radiating shock structure are observed: subcritical, where preheating of the unshocked gas is negligible; electron supercritical, where radiation preheating raises the temperature of the unshocked electron fluid to be equal to the final electron temperature; supercritical, where preheating and electron-ion energy exchange raise the preshock $T_{e,i}$ to their final post shock values. No supercritical shock develops when $l_{ei}$ is larger than the photospheric depth of the shocked gas because a negligible amount of the ion energy is transferred to the electrons and the shock is weakly radiating. Electron conduction smooths the $T_e$ profile on a length scale $l_{ec}$, reducing the radiation flux.

Sincell, M W; Mihalas, D L

1997-01-01T23:59:59.000Z

104

Structure formation in inhomogeneous Early Dark Energy models  

E-Print Network (OSTI)

We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy component can have the same order of magnitude of dark matter fluctuations. Since two basic approximations usually taken in the standard scenario of quintessence models, that both dark energy density during the matter dominated period and dark energy fluctuations on small scales are negligible, are not valid in such models, we first study approximate analytical solutions for dark matter and dark energy perturbations in the linear regime. This study is helpful to find consistent initial conditions for the system of equations and to analytically understand the effects of Early Dark Energy and its fluctuations, which are also verified numerically. In the linear regime we compute the matter growth and variation of the gravitational potential associated with the Integrated Sach...

Batista, R C

2013-01-01T23:59:59.000Z

105

Production of higher silanes in radio frequency SiH{sub 4} and H{sub 2}-SiH{sub 4} plasmas  

SciTech Connect

Stable gases produced in SiH{sub 4} and H{sub 2}-SiH{sub 4}, capacitively coupled rf discharges operated at typical device-production conditions, were investigated by quadrupole mass spectrometry. The production of disilane and trisilane and the depletion of silane and pressure change were measured during consecutive short discharges. Dissociation rate constants and branching ratios for higher-silane production are obtained from the time-dependent densities. The influence of suspended Si particles on stable-gas production is found to be negligible, by changing the duration of individual discharges and thereby the particle densities and sizes. We have also observed pyrolitic decay of disilane and trisilane at 200 deg. C, although this is negligible under normal reactor conditions.

Horvath, P.; Rozsa, K.; Gallagher, A. [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, Colorado 80309-0440 (United States)

2004-12-15T23:59:59.000Z

106

Primary coolant chemistry of the Peach Bottom and Fort St. Vrain high-temperature gas-cooled reactors  

Science Conference Proceedings (OSTI)

The chemical impurities in the primary coolants of the Peach Bottom and Fort St. Vrain reactors are discussed. The impurity mixtures in the two plants were quite different because the sources of the impurities were different. In the Peach Bottom reactor, the impurities were dominated by H/sub 2/ and CH/sub 4/, which are decomposition products of oil. In the Fort St. Vrain reactor, there were high levels of CO, CO/sub 2/, and H/sub 2/O. Although oil ingress at Peach Bottom created carbon deposits on virtually all surfaces, its effect on reactor operation was negligible. Slow outgassing of water from the thermal insulation at Fort St. Vrain caused delays in reactor startup. The overall graphite oxidation in both plants was negligible.

Burnette, R.D.; Baldwin, N.L.

1980-11-01T23:59:59.000Z

107

Nonproliferation, Nuclear Security, and the Insider Threat  

SciTech Connect

Insider threat concept is evolving and getting more attention: (1) Domestically, internationally and in foreign countries, (2) At the government, academia, and industry levels, and (3) Public awareness and concerns are also growing. Negligence can be an insider's action. Technology advancements provide more opportunities, new tools for the insider. Our understanding of the insider is shaped by our cultural, social and ethnic perceptions and traditions. They also can limit our recognition of the issues and response actions.

Balatsky, Galya I. [Los Alamos National Laboratory; Duggan, Ruth [SNL

2012-07-12T23:59:59.000Z

108

Applicability of the linearly perturbed FRW metric and Newtonian cosmology  

E-Print Network (OSTI)

It has been argued that the effect of cosmological structure formation on the average expansion rate is negligible, because the linear approximation to the metric remains applicable in the regime of non-linear density perturbations. We discuss why the arguments based on the linear theory are not valid. We emphasise the difference between Newtonian gravity and the weak field, small velocity limit of general relativity in the cosmological setting.

Syksy Rasanen

2010-02-25T23:59:59.000Z

109

Widmansta?tten Ferrite and Bainite in Ultra High Strength Steels  

E-Print Network (OSTI)

due to transformation, mm Martensite start temperature, in QC Steady state nucleation rate Negligible partitioning local equilibrium Partitioning local equilibrium Volume fraction of ferrite transformed Austenite Isothermal reaustenitisation... temperature in QC Interfacial energy per unit area Temperature at which stress-free austenite and ferrite of the same composition have identical free energies, QC Same as To except taking stored energy 400 J mol-1 of bainite, QC Radius of spherical nucleus...

Ali, Ashraf

1991-05-07T23:59:59.000Z

110

Relaying an optical wavefront  

DOE Patents (OSTI)

A wavefront rely devices samples an incoming optical wavefront at different locations, optically relays the samples while maintaining the relative position of the samples and the relative phase between the samples. The wavefront is reconstructed due to interference of the samples. Devices can be designed for many different wavelengths, including for example the ultraviolet, visible, infrared and even longer wavelengths such as millimeter waves. In one application, the device function as a telescope but with negligible length.

Sweatt, William C. (Albuquerque, NM); Vawter, G. Allen (Corrales, NM)

2007-03-06T23:59:59.000Z

111

Turbine-meter air calibration proves accurate for gas service  

SciTech Connect

This article presents theory, laboratory verificati*on tests, and field evaluation test data that show that a well-engineered gas-turbine meter (single rotor or tandem rotors) calibrated in air has the same accuracy when operating in natural gas at the same line pressure and flow rate (or the same Reynolds number). The only exception occurs at very low flow rates during which the rotor slip due to mechanical friction is no loner negligible.

Lee, W.F.Z.

1988-04-18T23:59:59.000Z

112

The Effect of Ammonia on Mercury Partitioning in Fly Ash  

Science Conference Proceedings (OSTI)

Management options and environmental assessments for fly ash are driven primarily by their physical and chemical characteristics. This report describes the results of a laboratory study on the leaching of mercury from several paired fly ash samples from facilities employing powdered activated carbon (PAC) injection for mercury control. While previous EPRI research has shown that mercury leaching from ash with PAC is negligible, it has also been found that ammonia complexes can increase the mobility of so...

2008-03-25T23:59:59.000Z

113

Surface instability of binary compounds caused by sputter yield amplification  

Science Conference Proceedings (OSTI)

It is demonstrated that the flat surface of a binary material that is subjected to normal-incidence ion bombardment can be unstable even if the curvature dependence of the sputter yields is negligibly small. This unforeseen instability is brought about by sputter yield amplification, and it results in the formation of a disordered array of nanodots with the lighter of the two atomic species concentrated at the peaks of the dots.

Mark Bradley, R. [Department of Physics, Colorado State University, Fort Collins, Colorado 80523 (United States)

2012-06-01T23:59:59.000Z

114

Comparison of kinetic theory models of laser ablation of carbon  

SciTech Connect

The paper compares the predictions of three-dimensional kinetic theory models of laser ablation of carbon. All the models are based on the moment solution of the Boltzmann equation for arbitrary strong evaporation but use different approximations. Comparison of the model predictions demonstrated that the choice of the particular model has very little influence on the results. The influence of the heat conduction from the gas to the solid phase was also found to be negligible in this problem.

Shusser, Michael [Faculty of Mechanical Engineering, Technion, Haifa 32000 (Israel)

2010-05-15T23:59:59.000Z

115

Self-pumping impurity control  

DOE Patents (OSTI)

Apparatus for removing the helium ash from a fusion reactor having a D-T plasma comprises a helium trapping site within the reactor plasma confinement device, said trapping site being formed of a trapping material having negligible helium solubility and relatively high hydrogen solubility; and means for depositing said trapping material on said site at a rate sufficient to prevent saturation of helium trapping.

Brooks, Jeffrey N. (Darien, IL); Mattas, Richard F. (Downers Grove, IL)

1991-01-01T23:59:59.000Z

116

Recombination Softening and Reheating of the Cosmic Plasma  

E-Print Network (OSTI)

The atomic recombination process leads to a softening of the matter equation of state as reflected by a reduced generalized adiabatic index, with accompanying heat release. We study the effects of this recombination softening and reheating of the cosmic plasma on the ionization history, visibility function, Cold Dark Matter (CDM) transfer function, and the Cosmic Microwave Background (CMB) spectra. The resulting modifications of the CMB spectra are not negligible and should be implemented when data with higher accuracy are analysed.

Leung, P K; Chu, M C; Leung, Po Kin; Chan, Chi-Wang; Chu, Ming-Chung

2004-01-01T23:59:59.000Z

117

NITRIC ACID RECPVERY FROM WASTE COLUTIONS  

DOE Patents (OSTI)

The recovery of nitric acid from aqueous nitrate solutions containing fission products as impurities is described. It is desirable to subject such solutions to concentration by evaporation since nitric acid is regenerated thereby. A difficulty, however, is that the highly radioactive fission product ruthenium is volatilized together with the nitric acid. It has been found that by adding nitrous acids ruthenium volatilization is suppressed and reduced to a negligible degree so that the distillate obtained is practically free of rutheniuim.

Wilson, A.S.

1959-04-14T23:59:59.000Z

118

NITRIC ACID RECOVERY FROM WASTE SOLUTIONS  

DOE Patents (OSTI)

The recovery of nitric acid from aqueous nitrate solutions containing fission products as impurities is described. It is desirable to subject such solutions to concentration by evaporation since nitric acid is regenerated thereby. A difficulty, however, is that the highly radioactive fission product ruthenium is volatilized together with the nitric acid. It has been found that by adding nitrous acid, ruthenium volatilization is suppressed and reduced to a negligible degree so that the distillate obtained is practically free of ruthenium.

Wilson, A.S.

1959-04-14T23:59:59.000Z

119

Calculation of Unbalanced Magnetic Pull in Cage Induction Machines  

E-Print Network (OSTI)

. . . . . . . . . . . . . .. 58 4.4 Rotor Resistance and Leakage Inductance ............... 58 4.5 Carter Factor Correction . . . . . . . . . . . . . . . . . . . . . . . .. 59 9 61 5 Experimental Equipment 5.1 Introduction... only the forces normal to the surface which are considered, the tangential component being assumed negligible. There is also the case of unbalanced magnetic push [24][25], where conductors are pushed towards the bottom of a slot. Again...

Dorrell, David George

1993-10-26T23:59:59.000Z

120

Ceramic dome receiver technology developments  

DOE Green Energy (OSTI)

The development and experimental demonstration of a high-temperature seal for the SHARE ceramic dome cavity receiver is reported. The mechanical contact seal which was tested on one-foot-diameter silicon-carbide ceramic-dome hardware at pressure differentials to four atmospheres and dome temperatures to 2200/sup 0/F (1200/sup 0/C) showed negligible leakage at expected receiver operating conditions. Potential solar receiver applications for the technology are illustrated.

Jarvinen, P. O.

1980-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Laboratory Evaluation of "Formula X-12" Combustion Additive  

Science Conference Proceedings (OSTI)

"Formula X-12," a combustion additive produced by Advanced Petroleum Technologies LLC (APT), has been described as an advanced molecular nanotechnology that reduces pollutants and toxic emissions to negligible levels and contains no metals, with an all-natural nontoxic formulation. When combined with Southridge Enterprises, Inc. branded 85 pure ethanol product, claims were made in a press release that "Formula X-12 would increase energy yield by a minimum of 10." As similar claims regarding potential coa...

2009-05-26T23:59:59.000Z

122

Comparison of CAISO-run Plexos output with LLNL-run Plexos output  

SciTech Connect

In this report we compare the output of the California Independent System Operator (CAISO) 33% RPS Plexos model when run on various computing systems. Specifically, we compare the output resulting from running the model on CAISO's computers (Windows) and LLNL's computers (both Windows and Linux). We conclude that the differences between the three results are negligible in the context of the entire system and likely attributed to minor differences in Plexos version numbers as well as the MIP solver used in each case.

Schmidt, A; Meyers, C; Smith, S

2011-12-20T23:59:59.000Z

123

The benchmark of gutzwiller density functional theory in hydrogen systems  

SciTech Connect

We propose an approximate form of the exchange-correlation energy functional for the Gutzwiller density functional theory. It satisfies certain physical constraints in both weak and strong electron correlation limits. We benchmark the Gutzwiller density functional approximation in the hydrogen systems, where the static correlation error is shown to be negligible. The good transferability is demonstrated by applications to the hydrogen molecule and some crystal structures.

Yao, Y.; Wang, Cai-Zhuang; Ho, Kai-Ming

2012-02-23T23:59:59.000Z

124

Efficient estimation for semiparametric cure models with interval-censored data  

Science Conference Proceedings (OSTI)

This paper is concerned with the analysis of interval-censored survival data in the presence of a non-negligible cure fraction using semiparametric non-mixture cure models. We propose a spline-based sieve estimation method which overcomes numerical difficulties ... Keywords: 62G20, 62N01, 62N02, Constrained optimization, Cure model, Interval censoring, Semiparametric efficiency, Sieve maximum likelihood estimation, Splines

Tao Hu, Liming Xiang

2013-10-01T23:59:59.000Z

125

EAC Recommendations for DOE Action on a Strategic Portable Generation Reserve - October 17, 2012  

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

Richard Cowart, Chair DATE: October 17, 2012 RE: Recommendation on Strategic Portable Generation Reserve _________________________________________________________________________ The purpose of this memorandum is to convey to the U.S. Department of Energy (DOE) the Electricity Advisory Committee (EAC) recommendation that DOE not pursue a Strategic Portable Generation Reserve ("the Reserve") and to summarize the conclusions leading to this recommendation. DOE's establishment of the Reserve would designate it as the national backstop power source for emergencies, with associated fuel delivery responsibility, and position DOE as an owner of critical electric infrastructure. This DOE initiative would require significant effort and provide negligible improvement to electric service reliability.

126

Assessing the risk from the depleted uranium weapons used in Operation Allied Force  

E-Print Network (OSTI)

The conflict in Yugoslavia has been a source of great concern for the neighboring countries, about the radiological and toxic hazard posed by the alleged presence of depleted uranium in NATO weapons. In the present study a worst-case scenario is assumed mainly to assess the risk for Greece and other neighboring countries of Yugoslavia at similar distances . The risk of the weapons currently in use is proved to be negligible at distances greater than 100 Km. For shorter distances classified data of weapons composition are needed to obtain a reliable assessment.

Liolios, T E

1999-01-01T23:59:59.000Z

127

Market response to external events and interventions in spherical minority games  

E-Print Network (OSTI)

We solve the dynamics of large spherical Minority Games (MG) in the presence of non-negligible time dependent external contributions to the overall market bid. The latter represent the actions of market regulators, or other major natural or political events that impact on the market. In contrast to non-spherical MGs, the spherical formulation allows one to derive closed dynamical order parameter equations in explicit form and work out the market's response to such events fully analytically. We focus on a comparison between the response to stationary versus oscillating market interventions, and reveal profound and partially unexpected differences in terms of transition lines and the volatility.

Papadopoulos, P

2008-01-01T23:59:59.000Z

128

Nuclear Interference effects in 8B sub-Coulomb breakup  

E-Print Network (OSTI)

The breakup of $^8$B on $^{58}$Ni below the Coulomb barrier was measured recently with the aim of determining the Coulomb breakup components. We reexamine this reaction, and perform one step quantum-mechanical calculations that include E1, E2 and nuclear contributions. We show that the nuclear contribution is by no means negligible at the intermediate angular range where data was taken. Our results indicate that, for an accurate description of this reaction, Coulomb E1, E2 and nuclear processes all have to be taken into account.

F. M. Nunes; I. J. Thompson

1998-04-30T23:59:59.000Z

129

Extrinsic orbital angular momentum of entangled photon-pairs in spontaneous parametric down-conversion  

E-Print Network (OSTI)

Starting from the standard Hamiltonian describing the optical non-linear process of spontaneous parametric down-conversion, we theoretically show that the generated entangled photon-pairs carry non-negligible orbital angular momentum in the degrees of freedom of relative movement in the type-II cases due to spatial symmetry breaking. We also show that the orbital angular momentum carried by photon-pairs in these degrees of freedom escapes detection in the traditional measurement scheme, which demands development of new techniques for further experimental investigations.

Sheng Feng; Prem Kumar

2008-05-13T23:59:59.000Z

130

Probing the softest region of the nuclear equation of state  

E-Print Network (OSTI)

An attractive, energy-dependent mean-field potential for baryons is introduced in order to generate a soft region in the nuclear equation of state, as suggested by recent lattice QCD calculations of baryon-free matter at finite temperature. Based on a hadronic transport model, we find that although this equation of state has negligible effects on the inclusive hadronic spectra, it leads to a minimum in the energy dependence of the transverse collective flow and a delayed expansion of the compressed matter. In particular, the transverse flow changes its direction as the colliding system passes through the softest region in the equation of state.

Li, Ba; Ko, Che Ming.

1998-01-01T23:59:59.000Z

131

Reducing gain shifts in photomultiplier tubes  

SciTech Connect

A means is provided for reducing gain shifts in multiplier tubes due to varying event count rates. It includes means for limiting the number of cascaded, active dynodes of the multiplier tube to a predetermined number with the last of predetermined number of dynodes being the output terminal of the tube. This output is applied to an amplifier to make up for the gain sacrificed by not totally utilizing all available active stages of the tube. Further reduction is obtained by illuminating the predetermined number of dynodes with a light source of such intensity that noise appearing at the output dynode associated with the illumination is negligible.

Cohn, Charles E. (Clarendon Hills, IL)

1976-01-01T23:59:59.000Z

132

Correlating field and laboratory data for crude oil fouling  

Science Conference Proceedings (OSTI)

Crude oil fouling in a laboratory fouling unit was investigated. The study focused on the preheat-train heat exchangers located just before the crude unit furnace and operating at temperatures in excess of 200 C. A fouling rate model developed using laboratory data from crude blends was used to predict the threshold conditions where negligible fouling was expected under refinery conditions. The results from the model were compared to actual data from a fouling unit located at a refinery. The article discusses factors that may explain the performance of the model and the observed discrepancies between fouling data obtained in the laboratory and the field.

Asomaning, S.; Panchal, C.B.; Liao, C.F.

2000-06-01T23:59:59.000Z

133

Process for forming silicon carbide films and microcomponents  

DOE Patents (OSTI)

Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C{sub 60} precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C{sub 60} with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C{sub 60} on silicon dioxide at surface temperatures less than 1250 K. 5 figs.

Hamza, A.V.; Balooch, M.; Moalem, M.

1999-01-19T23:59:59.000Z

134

Process for forming silicon carbide films and microcomponents  

DOE Patents (OSTI)

Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C.sub.60 precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C.sub.60 with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C.sub.60 on silicon dioxide at surface temperatures less than 1250 K.

Hamza, Alex V. (Livermore, CA); Balooch, Mehdi (Berkeley, CA); Moalem, Mehran (Berkeley, CA)

1999-01-01T23:59:59.000Z

135

Towards the Prediction of Weld Metal Properties  

E-Print Network (OSTI)

assumed to be negligible compared to other contri- 2 Transfer of melted coating to weld pool Metal droplet covered with molten slag Parent metal Figure 1.1: Schematic diagram of the MMA welding process. (After B. Lundqvist (1977), "Sandvik Welding Handbook... ., SVENSSON, L.-E., and GRETOFT, B. (1986), "'Weld- ing and Performance of Pipe Welds", [Proc. Conj.], Welding Institute, Abington, U.K., paper 17. BHADESHIA, H. K. D. H., SVENSSON, L.-E., and GRETOFT, B. (1987), "Weld- ing Metallurgy of Structural Steels...

Sugden, Alastair Allen Brockbank

1989-01-31T23:59:59.000Z

136

Monoenergetic Proton Beams Accelerated by a Radiation Pressure Driven Shock  

DOE Green Energy (OSTI)

We report on the acceleration of impurity-free quasimononenergetic proton beams from an initially gaseous hydrogen target driven by an intense infrared ({lambda} = 10 {micro}m) laser. The front surface of the target was observed by optical probing to be driven forward by the radiation pressure of the laser. A proton beam of MeV energy was simultaneously recorded with narrow energy spread ({sigma}-4%), low normalized emittance (-8 nm), and negligible background. The scaling of proton energy with the ratio of intensity over density (I/n) confirms that the acceleration is due to the radiation pressure driven shock.

Palmer, C.A.; Pogorelsky, I.; Dover, N.P.; Babzien, M.; Dudnikova, G.I.; Ispiriyan, M.; Polyanskiy, M.N.; Schreiber, J.; Shkolnikov, P.; Yakimenko, V.; Najmudin, Z.

2011-11-01T23:59:59.000Z

137

Nonlocal Cosmology  

E-Print Network (OSTI)

We explore nonlocally modified models of gravity, inspired by quantum loop corrections, as a mechanism for explaining current cosmic acceleration. These theories enjoy two major advantages: they allow a delayed response to cosmic events, here the transition from radiation to matter dominance, and they avoid the usual level of fine tuning; instead, emulating Dirac's dictum, the required large numbers come from the large time scales involved. Their solar system effects are safely negligible, and they may even prove useful to the black hole information problem.

S. Deser; R. P. Woodard

2007-06-14T23:59:59.000Z

138

High strength graphite and method for preparing same  

DOE Patents (OSTI)

High strength graphite is manufactured from a mixture of a particulate filler prepared by treating a particulate carbon precursor at a temperature in the range of about 400.degree. to 1000.degree. C., an organic carbonizable binder, and green carbonizable fibers in a concentration of not more than 2 weight per cent of the filler. The use of the relatively small quantity of green fibers provides a substantial increase in the flexural strength of the graphite with only a relatively negligible increase in the modulus of elasticity.

Overholser, Lyle G. (Oak Ridge, TN); Masters, David R. (Knoxville, TN); Napier, John M. (Oak Ridge, TN)

1976-01-01T23:59:59.000Z

139

Measured winter performance of storm windows  

SciTech Connect

Direct comparison measurements were made between various prime/storm window combinations and a well-weatherstripped, single-hung replacement window with a low-E selective glazing. Measurements were made using an accurate outdoor calorimetric facility with the windows facing north. The doublehung prime window was made intentionally leaky. Nevertheless, heat flows due to air infiltration were found to be small, and performance of the prime/storm combinations was approximately what would be expected from calculations that neglect air infiltration. Prime/low-E storm window combinations performed very similarly to the replacement window. Interestingly, solar heat gain was not negligible, even in north-facing orientation.

Klems, Joseph H.

2002-08-23T23:59:59.000Z

140

Integrated Modeling of Building Energy Requirements IncorporatingSolar Assisted Cooling  

DOE Green Energy (OSTI)

This paper expands on prior Berkeley Lab work on integrated simulation of building energy systems by the addition of active solar thermal collecting devices, technology options not previously considered (Siddiqui et al 2005). Collectors can be used as an alternative or additional source of hot water to heat recovery from reciprocating engines or microturbines. An example study is presented that evaluates the operation of solar assisted cooling at a large mail sorting facility in southern California with negligible heat loads and year-round cooling loads. Under current conditions solar thermal energy collection proves an unattractive option, but is a viable carbon emission control strategy.

Firestone, Ryan; Marnay, Chris; Wang, Juan

2005-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Sampling using a 'bank' of clues  

E-Print Network (OSTI)

This is because for a fraction (1 ? ?) of the time the bank sampler is doing standard MHA anyway. Even if no bank-based proposal is ever accepted, the 4 We discuss a realistic example of the cost of overhead of obtaining the bank samples in section 3.5. 5 Fig. 1... that the Bank Sampler was designed to cope with. 5 We note that the preceding statements assume, in line with most realistic sce- narios in particle physics, that the cost of evaluating the “banked” Q-factors in equation (3) is negligible in comparison...

Allanach, B C; Lester, Christopher G

142

Photon pressure induced test mass deformation in gravitational-wave detectors  

E-Print Network (OSTI)

A widely used assumption within the gravitational-wave community has so far been that a test mass acts like a rigid body for frequencies in the detection band, i.e. for frequencies far below the first internal resonance. In this article we demonstrate that localized forces, applied for example by a photon pressure actuator, can result in a non-negligible elastic deformation of the test masses. For a photon pressure actuator setup used in the gravitational wave detector GEO600 we measured that this effect modifies the standard response function by 10% at 1 kHz and about 100% at 2.5 kHz.

S. Hild; M. Brinkmann; K. Danzmann; H. Grote; M. Hewitson; J. Hough; H. Lueck; I. Martin; K. Mossavi; N. Rainer; S. Reid; J. R. Smith; K. Strain; M. Weinert; P. Willems; B. Willke; W. Winkler

2007-10-05T23:59:59.000Z

143

When the Underwriter is the Market Maker: An Examination of Trading in the IPO Aftermarket  

E-Print Network (OSTI)

This paper examines aftermarket trading of underwriters and unaffiliated market makers in the three month period after an IPO. We find that the lead underwriter is always the dominant market maker, he takes substantial inventory positions in the aftermarket trading, and co-managers play a negligible role in aftermarket trading. The lead underwriter engages in stabilization activity for less successful IPOs, and uses the overallotment option to reduce his inventory risk. Compensation to the underwriter arises primarily from fees, but aftermarket trading does generate positive profits, which are positively related to the degree of underpricing.

Katrina Ellis; Roni Michaely; Maureen O' Hara

2000-01-01T23:59:59.000Z

144

On the interplay between allowed Gamow-Teller and Isovector Spin Monopole (IVSM) excitations  

SciTech Connect

The excitation of Gamow-Teller (GT) and Isovector Spin Monopole (IVSM) modes in {sup 116}In by (p,n) and (n,p)) charge-exchange reactions is studied within the framework of the Quasiparticle Random-phase Approximation. It is shown that the admixture of the IVSM and Gamow-Teller (GT) excitations is negligible, and that the contribution to the strength above 20 MeV excitation energy, in {sup 116}In, is, most likely, due to the IVSM ({sigma}r{sup 2}{tau}{sup {+-}}) mode.

Bes, D. R. [Dept of Physics. Lab.Tandar, CAC-CNEA. Avda Gral Paz 1499, 1650 Gral San Martin (Argentina); Civitarese, O. [Dept of Physics, University of La Plata, c.c.67 1900, La Plata (Argentina); Suhonen, J. [Dept of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014, Jyvaeskylae (Finland)

2011-12-16T23:59:59.000Z

145

Li-Ion Batteries from LiFePO4 Cathode and Anatase/Graphene Composite Anode for Stationary Energy Storage  

SciTech Connect

Li-ion batteries based on LiFePO4 cathode and anatase TiO2/graphene anode were investigated for possible stationary energy storage application. Fine-structured LiFePO4 was synthesized by novel molten surfactant approach. Anatase TiO2/graphene nanocomposite was prepared via self assembly method. The full cell that operated at flat 1.6V demonstrated negligible fade after more than 700 cycles. The LiFePO4/TiO2 combination Li-ion battery is inexpensive, environmentally benign, safe and stable. Therefore, it can be practically applied as stationary energy storage for renewable power sources.

Choi, Daiwon; Wang, Donghai; Viswanathan, Vilayanur V.; Bae, In-Tae; Wang, Wei; Nie, Zimin; Zhang, Jiguang; Graff, Gordon L.; Liu, Jun; Yang, Zhenguo; Duong, Tien Q.

2009-11-06T23:59:59.000Z

146

The Echo of the Quantum Bounce  

E-Print Network (OSTI)

We identify a signature of quantum gravitational effects that survives from the early universe to the current era: Fluctuations of quantum fields as seen by comoving observers are significantly influenced by the history of the early universe. In particular we will show how the existence (or not) of a quantum bounce leaves a trace in the background quantum noise that is not damped and would be non-negligible even nowadays. Furthermore, we will estimate an upper bound to the typical energy and length scales where quantum effects are relevant. We will discuss how this signature might be observed and therefore used to build falsifiability tests of quantum gravity theories.

Luis J. Garay; Mercedes Martin-Benito; Eduardo Martin-Martinez

2013-08-20T23:59:59.000Z

147

Method for producing uranium atomic beam source  

DOE Patents (OSTI)

A method for producing a beam of neutral uranium atoms is obtained by vaporizing uranium from a compound UM.sub.x heated to produce U vapor from an M boat or from some other suitable refractory container such as a tungsten boat, where M is a metal whose vapor pressure is negligible compared to that of uranium at the vaporization temperature. The compound, for example, may be the uranium-rhenium compound, URe.sub.2. An evaporation rate in excess of about 10 times that of conventional uranium beam sources is produced.

Krikorian, Oscar H. (Danville, CA)

1976-06-15T23:59:59.000Z

148

Reduction of the Casimir force using aerogels  

E-Print Network (OSTI)

By using silicon oxide based aerogels we show numerically that the Casimir force can be reduced several orders of magnitude, making its effect negligible in nanodevices. This decrease in the Casimir force is also present even when the aerogels are deposited on metallic substrates. To calculate the Casimir force we model the dielectric function of silicon oxide aerogels using an effective medium dielectric function such as the Clausius-Mossotti approximation. The results show that both the porosity of the aerogel and its thickness can be use as control parameters to reduce the magnitude of the Casimir force.

R. Esquivel-Sirvent

2007-08-02T23:59:59.000Z

149

Reduction of the Casimir force using aerogels  

E-Print Network (OSTI)

By using silicon oxide based aerogels we show numerically that the Casimir force can be reduced several orders of magnitude, making its effect negligible in nanodevices. This decrease in the Casimir force is also present even when the aerogels are deposited on metallic substrates. To calculate the Casimir force we model the dielectric function of silicon oxide aerogels using an effective medium dielectric function such as the Clausius-Mossotti approximation. The results show that both the porosity of the aerogel and its thickness can be use as control parameters to reduce the magnitude of the Casimir force.

Esquivel-Sirvent, R

2007-01-01T23:59:59.000Z

150

Gas Analysis of Plutonium Materials Tested in a Bell Jar  

SciTech Connect

Seventy cans containing plutonium bearing materials have been tested for gas generation in bell jars at the Savannah River Site (SRS). Gas samples from five of the tests were taken and analyzed for hydrogen, oxygen, nitrogen, methane, carbon dioxide, carbon monoxide, and nitrous oxide. Gas samples from all five cans showed significant oxygen consumption. Hydrogen and carbon dioxide were found in non-negligible quantities in all gas samples. Hydrogen and carbon dioxide generation rates are presented along with oxygen depletion rates. A description of the plutonium bearing materials is also provided.

Kies, J.

2003-04-15T23:59:59.000Z

151

Computation of ASR Systems  

E-Print Network (OSTI)

This paper proposes a novel technique to reduce the likelihood computation in ASR systems that use continuous density HMMs. Based on the nature of dynamic features and the numerical properties of Gaussian mixture distributions, we approximate the observation likelihood computation to achieve a speedup. Although the technique does not show appreciable benefit in an isolated word task, it yields significant improvements in continuous speech recognition. For example, 50 % of the computation can be saved on the TIMIT database with only a negligible degradation in system performanc 1

Xiao Li; Jeff Bilmes; Xiao Li; Jeff Bilmes

2003-01-01T23:59:59.000Z

152

Analytic formulae for centrifugal effects on turbulent transport of trace impurities in tokamak plasmas  

Science Conference Proceedings (OSTI)

A local gyrokinetic description of the centrifugal effects on impurity transport in tokamak plasmas is presented, which extends previous models with the inclusion of the gradient of the background toroidal angular velocity in the equilibrium distribution. The equations are implemented in a gyrokinetic code. An analytical model is derived and formulae are proposed which allow the calculation of centrifugal effects on impurity transport in the limit where centrifugal effects are large only for heavy impurities in trace concentration, but are negligible for the bulk plasma. The analytic formulae are shown to be in quantitative agreement with the numerical results and are proposed for complementing present transport models.

Angioni, C.; Casson, F. J.; Veth, C. [Max-Planck-Institut fuer Plasmaphysik, IPP-EURATOM Association, D-85748 Garching bei Muenchen (Germany); Peeters, A. G. [Physics Department, University of Bayreuth, 95440 Bayreuth (Germany)

2012-12-15T23:59:59.000Z

153

Development of a gas backup heater for solar domestic hot-water systems. Final report, April 1978-April 1980  

DOE Green Energy (OSTI)

A comprehensive program was undertaken to develop a unique gas fired backup for solar domestic hot water systems. Detailed computer design tools were written. A series of heat transfer experiments were performed to characterize the performance of individual components. A full scale engineering prototype, including the solar preheat tank and solar heat exchanger, was designed, fabricated and subjected to limited testing. Firing efficiency for the backup system was found to be 81.4% at a firing rate of 50,000 Btu/h. Long term standby losses should be negligible.

Morrison, D.J.; Grunes, H.E.; de Winter, F.; Armstrong, P.R.

1980-06-01T23:59:59.000Z

154

Robust Broadcast-Communication Control of Electric Vehicle Charging  

E-Print Network (OSTI)

The anticipated increase in the number of plug-in electric vehicles (EV) will put additional strain on electrical distribution circuits. Many control schemes have been proposed to control EV charging. Here, we develop control algorithms based on randomized EV charging start times and simple one-way broadcast communication allowing for a time delay between communication events. Using arguments from queuing theory and statistical analysis, we seek to maximize the utilization of excess distribution circuit capacity while keeping the probability of a circuit overload negligible.

Turitsyn, Konstantin; Backhaus, Scott; Chertkov, Misha

2010-01-01T23:59:59.000Z

155

Nuclear criticality safety analysis summary report: The S-area defense waste processing facility  

SciTech Connect

The S-Area Defense Waste Processing Facility (DWPF) can process all of the high level radioactive wastes currently stored at the Savannah River Site with negligible risk of nuclear criticality. The characteristics which make the DWPF critically safe are: (1) abundance of neutron absorbers in the waste feeds; (2) and low concentration of fissionable material. This report documents the criticality safety arguments for the S-Area DWPF process as required by DOE orders to characterize and to justify the low potential for criticality. It documents that the nature of the waste feeds and the nature of the DWPF process chemistry preclude criticality.

Ha, B.C.

1994-10-21T23:59:59.000Z

156

On the mirror instability in the presence of electron temperature anisotropy  

Science Conference Proceedings (OSTI)

Computation of the mirror instability growth rate in an ion-electron bi-Maxwellian plasma is revisited, starting from the low-frequency kinetic theory. The role of the electron finite Larmor radius (FLR) effects on the instability quenching is shown to possibly be dominant, even near threshold where the smallest unstable scales significantly exceed the electron gyroscale. Validation of the results by comparison with predictions of the fully kinetic whamp software is also presented. The influence of the electron temperatures on the ion FLR effects very near threshold, where the electron kinetic effects are negligible, is also pointed out.

Kuznetsov, E. A. [P.N. Lebedev Physical Institute RAS, 53 Leninsky Ave., 119991 Moscow, Russia and Space Research Institute, 84/31 Profsoyuznaya St., 117997 Moscow (Russian Federation); Passot, T.; Sulem, P. L. [Universite de Nice Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France)

2012-09-15T23:59:59.000Z

157

Shock waves in a one-dimensional Bose gas: from a Bose-Einstein condensate to a Tonks gas  

E-Print Network (OSTI)

We derive and analyze shock-wave solutions of hydrodynamic equations describing repulsively interacting one dimensional Bose gas. We also use the number-conserving Bogolubov approach to verify accuracy of the Gross-Pitaevskii equation in shock wave problems. We show that quantum corrections to dynamics of shocks (dark-shock-originated solitons) in a Bose-Einstein condensate are negligible (important) for a realistic set of system parameters. We point out possible signatures of a Bose-Einstein condensate -- Tonks crossover in shock dynamics. Our findings can be directly verified in different experimental setups.

Bogdan Damski

2005-06-08T23:59:59.000Z

158

Ultra high energy neutrinos from gamma ray bursts  

E-Print Network (OSTI)

Protons accelerated to high energies in the relativistic shocks that generate gamma ray bursts photoproduce pions, and then neutrinos in situ. I show that ultra high energy neutrinos (> 10^19 eV) are produced during the burst and the afterglow. A larger flux, also from bursts, is generated via photoproduction off CMBR photons in flight but is not correlated with currently observable bursts, appearing as a bright background. Adiabatic/synchrotron losses from protons/pions/muons are negligible. Temporal and directional coincidences with bursts detected by satellites can separate correlated neutrinos from the background.

Mario Vietri

1998-02-18T23:59:59.000Z

159

Robust broadcast-communication control of electric vehicle charging  

SciTech Connect

The anticipated increase in the number of plug-in electric vehicles (EV) will put additional strain on electrical distribution circuits. Many control schemes have been proposed to control EV charging. Here, we develop control algorithms based on randomized EV charging start times and simple one-way broadcast communication allowing for a time delay between communication events. Using arguments from queuing theory and statistical analysis, we seek to maximize the utilization of excess distribution circuit capacity while keeping the probability of a circuit overload negligible.

Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Sulc, Petr [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

160

Monolithic interconnected module with a tunnel junction for enhanced electrical and optical performance  

SciTech Connect

An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMS), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

Murray, Christopher S. (Bethel Park, PA); Wilt, David M. (Bay Village, OH)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Higgs boson decay to mu mubar gamma  

E-Print Network (OSTI)

The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 GeV, the contribution to the radiative width from the one-loop level exceeds the contribution from the tree level, and for Higgs boson masses above 140 GeV, it even exceeds the contribution from the tree level decay H -> mu mubar. We also show that the contributions to the radiative decay width from the interference terms between the tree and one-loop diagrams are negligible.

Ali Abbasabadi; Wayne W. Repko

2000-04-17T23:59:59.000Z

162

Wood substation design beats out steel. [Conversion of 115-kV to 230 kV substations at Carolina Power and Light Co  

SciTech Connect

Construction plans for voltage conversion of substations can lead to new designs that are economical, reduce outage times, and result in minimum impacts on the environment. In fact, these factors prompted Carolina Power and Light Co. to make one such design its construction standard. Cost of converting a 115-kV distribution source substation to 230 kV is 20 percent less than that of replacing it with one of steel design. And because the conversion creates negligible environmental impact, getting government approval for the project is not a major problem. Steel is relegated to special situations.

Thompson, C.M.

1976-09-15T23:59:59.000Z

163

Stationary light in cold atomic gases  

E-Print Network (OSTI)

We discuss stationary light created by a pair of counter-propagating control fields in Lambda-type atomic gases with electromagnetically induced transparency for the case of negligible Doppler broadening. In this case the secular approximation used in the discussion of stationary light in hot vapors is no longer valid. We discuss the quality of the effective light-trapping system and show that in contrast to previous claims it is finite even for vanishing ground-state dephasing. The dynamics of the photon loss is in general non exponential and can be faster or slower than in hot gases.

Gor Nikoghosyan; Michael Fleischhauer

2009-03-10T23:59:59.000Z

164

Heuristics for the  

E-Print Network (OSTI)

Frederic Pelliccia Frederic_P el li ccia s o freten. fr Among the different r/n redundancies, it is necessary to distinguish between the (classic) case of active redundancies (hot standby) and the case of passive redundancies (cold standby) presenting failures at calling instant. This paper deals with passive redundancy including such solicitation failures: redundancy elements only operate in case of the failure of initial elements and have a non negligible probability of failing at the instant of solicitation. In this paper we propose some heuristics in order to integrate their computations in large optimization software using iterative schemes.

For Passive Raymond; Raymond Marie; Emmanuel Arbaretier; Frederic Pelliccia

2002-01-01T23:59:59.000Z

165

Evaluation of differential shim rod worth measurements in the Oak Ridge Research Reactor  

Science Conference Proceedings (OSTI)

Reasonable agreement between calculated and measured differential shim rod worths in the Oak Ridge Research Reactor (ORR) has been achieved by taking into account the combined effects of negative reactivity contributions from changing fuel-moderator temperatures and of delayed photoneutrons. A method has been developed for extracting the asymptotic period from the shape of the initial portion of the measured time-dependent neutron flux profile following a positive reactivity insertion. In this region of the curve temperature-related reactivity feedback effects are negligibly small. Results obtained by applying this technique to differential shim rod worth measurements made in a wide variety of ORR cores are presented.

Bretscher, M.M.

1987-01-01T23:59:59.000Z

166

Pulmonary imaging in pregnancy. Maternal risk and fetal dosimetry  

SciTech Connect

A Tc-99m macroaggregated albumin (MAA) perfusion lung scan and a Tc-99m DTPA aerosol ventilation scan were performed for suspicion of pulmonary embolism (PE) in a patient who was ten weeks pregnant. There was considerable reluctance on the part of the obstetricians to permit this study. Standard MIRD dose estimates to the fetus were performed, which showed a maximum fetal exposure of about 50 mrem. It was concluded that the risk to mother and fetus from undiagnosed and untreated PE is much greater than the negligible risk to the fetus from the radiation exposure; fear of fetal radiation damage should not be a deterrent to performing these scans.

Marcus, C.S.; Mason, G.R.; Kuperus, J.H.; Mena, I.

1985-01-01T23:59:59.000Z

167

Results of First Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)  

DOE Green Energy (OSTI)

The ACP and IRIS are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are unwindowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The first outdoor comparison between the two designs was held from January 28 to February 8, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of IRIS was within 1 W/m2. A difference of 5 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG).

Reda, I.; Grobner, J.; Wacker, S.; Stoffel, T.

2013-03-01T23:59:59.000Z

168

A Monolithic Interconnected module with a tunnel Junction for Enhanced Electrical and Optical Performance  

DOE Patents (OSTI)

An improved thermophotovoltaic (TPV) n/p/n device is provided. Monolithic Interconnected Modules (MIMs), semiconductor devices converting infrared radiation to electricity, have been developed with improved electrical and optical performance. The structure is an n-type emitter on a p-type base with an n-type lateral conduction layer. The incorporation of a tunnel junction and the reduction in the amount of p-type material used results in negligible parasitic absorption, decreased series resistance, increased voltage and increased active area. The novel use of a tunnel junction results in the potential for a TPV device with efficiency greater than 24%.

Murray, Christopher Sean; Wilt, David Morgan

1999-06-30T23:59:59.000Z

169

Experimental performance evaluation of line-focus sun trackers  

DOE Green Energy (OSTI)

Two sun trackers have been tested for tracking accuracy on an sun tracker. Both performed well during the entire test period. Their tracking performance as a function of insolation level was established, and their overall tracking accuracy (rms tracking error) was calculated. Both the flux-line and the shadowband tracker were found to have an effective rms error of about 1 milliradian. This information was used to determine the impact that the two trackers have on the annual energy performance of typical parabolic trough concentrating collectors. One milliradian rms tracking errors were found to result in negligibly small annual performance losses.

Gee, R.C.

1982-05-01T23:59:59.000Z

170

Improved Superconducting Wire for Wind Generators: Superconducting Wires for Direct-Drive Wind Generators  

SciTech Connect

REACT Project: Brookhaven National Laboratory will develop a low-cost superconducting wire that could be used in high-power wind generators. Superconducting wire currently transports 600 times more electric current than a similarly sized copper wire, but is significantly more expensive. Brookhaven National Laboratory will develop a high-performance superconducting wire that can handle significantly more electrical current, and will demonstrate an advanced manufacturing process that has the potential to yield a several-fold reduction in wire costs while using a using negligible amount of rare earth material. This design has the potential to make a wind turbine generator lighter, more powerful, and more efficient, particularly for offshore applications.

2012-01-01T23:59:59.000Z

171

A Materials-Based Mitigation Strategy for SU/SD in PEM Fuel Cells: Properties and Performance-Specific Testing of IrRu OER Catalysts.  

SciTech Connect

Catalysts that enable proton exchange membrane fuel cells to weather the damaging conditions experienced during transient periods of fuel starvation have been developed. The addition of minute amounts of iridium and ruthenium to the cathode enhances the oxygen evolution reaction (OER) during start-up/shutdown events, thus lowering the peak cell voltage closer to the onset of water oxidation. The catalyst loadings ranged from 1 to 10 g/cm2, but showed surprisingly high activity and durability. At such low loadings, it is possible to fully integrate the OER catalysts with negligible interference on fuel cell performance and a marginal increase in catalyst cost.

Atanasoski, Radoslav [3M Industrial Mineral Products; Cullen, David A [ORNL; Vernstrom, George [3M Industrial Mineral Products; Haugen, Gregory [3M Industrial Mineral Products; Atanasoska, Liliana [3M Industrial Mineral Products

2013-01-01T23:59:59.000Z

172

Current Status of the R-Matrix Code SAMMY, with Emphasis on the Relationship to ENDF Formats  

Science Conference Proceedings (OSTI)

During the last decade, advances in evaluations of neutron-induced cross sections in the resolved resonance region have surpassed the ability of the Evaluated Nuclear Data Files (ENDF) to make use of those evaluations. At the higher energies used in new evaluations, effects that in the past were deemed to be negligible are now important. There is also a great demand for including uncertainty information in ENDF files. In this paper, we describe recently approved ENDF formats to accommodate new evaluations and their implementation in SAMMY. Other new features of the SAMMY code, available in the 2006 Revision 7 release, are also described.

Larson, Nancy M [ORNL; Leal, Luiz C [ORNL; Sayer, Royce O [ORNL; Derrien, Herve [ORNL; Wiarda, Dorothea [ORNL; Arbanas, Goran [ORNL

2008-01-01T23:59:59.000Z

173

High sensitive quasi freestanding epitaxial graphene gassensor on 6H-SiC  

E-Print Network (OSTI)

We have measured the electrical response to NO$_2$, N$_2$, NH$_3$ and CO for epitaxial graphene and quasi freestanding epitaxial graphene on 6H-SiC substrates. Quasi freestanding epitaxial graphene shows a 6 fold increase in NO2 sensitivity compared to epitaxial graphene. Both samples show a sensitivity better than the experimentally limited 1 ppb. The strong increase in sensitivity of quasi freestanding epitaxial graphene can be explained by a Fermi-energy close to the Dirac Point leading to a strongly surface doping dependent sample resistance. Both sensors show a negligible sensitivity to N$_2$, NH$_3$ and CO.

Iezhokin, I; Brongersma, S H; Giesbers, A J M; Flipse, C F J

2013-01-01T23:59:59.000Z

174

Fusion rings for quantum groups  

E-Print Network (OSTI)

We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [KS] and give a similar description of the sp(2n)-fusion ring in terms of noncommutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings extending known results in special cases. Finally we also compute the fusion rings for type G2.

Henning Haahr Andersen; Catharina Stroppel

2012-12-22T23:59:59.000Z

175

An application of neutrix calculus to quantum field theory  

E-Print Network (OSTI)

Neutrices are additive groups of negligible functions that do not contain any constants except 0. Their calculus was developed by van der Corput and Hadamard in connection with asymptotic series and divergent integrals. We apply neutrix calculus to quantum field theory, obtaining finite renormalizations in the loop calculations. For renormalizable quantum field theories, we recover all the usual physically observable results. One possible advantage of the neutrix framework is that effective field theories can be accommodated. Quantum gravity theories appear to be more manageable.

Y. Jack Ng; H. van Dam

2005-02-17T23:59:59.000Z

176

Current Renewable Energy Technologies and Future Projections  

SciTech Connect

The generally acknowledged sources of renewable energy are wind, geothermal, biomass, solar, hydropower, and hydrogen. Renewable energy technologies are crucial to the production and utilization of energy from these regenerative and virtually inexhaustible sources. Furthermore, renewable energy technologies provide benefits beyond the establishment of sustainable energy resources. For example, these technologies produce negligible amounts of greenhouse gases and other pollutants in providing energy, and they exploit domestically available energy sources, thereby reducing our dependence on both the importation of fossil fuels and the use of nuclear fuels. The market price of renewable energy technologies does not reflect the economic value of these added benefits.

Allison, Stephen W [ORNL; Lapsa, Melissa Voss [ORNL; Ward, Christina D [ORNL; Smith, Barton [ORNL; Grubb, Kimberly R [ORNL; Lee, Russell [ORNL

2007-05-01T23:59:59.000Z

177

Digital Electronics For The Versatile Array Of Neutron Detectors At Low Energies  

SciTech Connect

A {chi}{sup 2} minimization algorithm has been developed to extract sub-sampling-time information from digitized waveforms, to be used to instrument the future Versatile Array of Neutron Detectors at Low energies. The algorithm performance has been characterized with a fast Arbitrary Function Generator, obtaining time resolution better than 1 ns for signals of amplitudes between 50 mV and 1V, with negligible walk in the whole range. The proof-of-principle measurement of the beta-delayed neutron emission from {sup 89}Br indicates a resolution of 1 ns can be achieved in realistic experimental conditions.

Madurga, M.; Paulauskas, S.; Grzywacz, R.; Padgett, S. W.; Liddick, S. N. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Bardayan, D. W. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Batchelder, J. C.; Matei, C.; Peters, W. A.; Rasco, C. [Oak Ridge Associated Universities, Oak Ridge, TN 37831 (United States); Blackmon, J. C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 708034 (United States); Cizewski, J. A.; O'Malley, P. [Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903, US (Canada); Goans, R. E. [Oak Ridge Associated Universities, Oak Ridge, TN 37831 (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Raiola, F.; Sarazin, F. [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States)

2011-06-01T23:59:59.000Z

178

DC CIRCUIT POWERED BY ORBITAL MOTION: MAGNETIC INTERACTIONS IN COMPACT OBJECT BINARIES AND EXOPLANETARY SYSTEMS  

Science Conference Proceedings (OSTI)

The unipolar induction DC circuit model, originally developed by Goldreich and Lynden-Bell for the Jupiter-Io system, has been applied to different types of binary systems in recent years. We show that there exists an upper limit to the magnetic interaction torque and energy dissipation rate in such a model. This arises because when the resistance of the circuit is too small, the large current flow severely twists the magnetic flux tube connecting the two binary components, leading to the breakdown of the circuit. Applying this limit, we find that in coalescing neutron star binaries, magnetic interactions produce negligible correction to the phase evolution of the gravitational waveform, even for magnetar-like field strengths. However, energy dissipation in the binary magnetosphere may still give rise to electromagnetic radiation prior to the final merger. For ultracompact white dwarf binaries, we find that unipolar induction does not provide adequate energy dissipation to explain the observed X-ray luminosities of several sources. For exoplanetary systems containing close-in Jupiters or super-Earths, the magnetic torque and energy dissipation induced by the orbital motion are negligible, except possibly during the early T Tauri phase, when the stellar magnetic field is stronger than 10{sup 3} G.

Lai Dong [Department of Astronomy, Cornell University, Ithaca, NY 14850 (United States)

2012-09-20T23:59:59.000Z

179

Laser machining of explosives  

DOE Patents (OSTI)

The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

Perry, Michael D. (Livermore, CA); Stuart, Brent C. (Fremont, CA); Banks, Paul S. (Livermore, CA); Myers, Booth R. (Livermore, CA); Sefcik, Joseph A. (Tracy, CA)

2000-01-01T23:59:59.000Z

180

Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference  

DOE Patents (OSTI)

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp.

Simpson, James E. (Gaithersburg, MD)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference  

DOE Patents (OSTI)

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp. 18 figs.

Simpson, J.E.

1999-06-08T23:59:59.000Z

182

Functional requirements for component films in a solar thin-film photovoltaic/thermal panel  

SciTech Connect

The functional requirements of the component films of a solar thin-film photovoltaic/thermal panel were considered. Particular emphasis was placed on the new functions, that each layer is required to perform, in addition to their pre-existing functions. The cut-off wavelength of the window layer, required for solar selectivity, can be achieved with charge carrier concentrations typical of photovoltaic devices, and thus does not compromise electrical efficiency. The upper (semiconductor) absorber layer has a sufficiently high thermal conductivity that there is negligible temperature difference across the film, and thus negligible loss in thermal performance. The lower (cermet) absorber layer can be fabricated with a high ceramic content, to maintain high solar selectivity, without significant increase in electrical resistance. A thin layer of molybdenum-based cermet at the top of this layer can provide an Ohmic contact to the upper absorber layer. A layer of aluminium nitride between the metal substrate and the back metal contact can provide electrical isolation to avoid short-circuiting of series-connected cells, while maintaining a thermal path to the metal substrate and heat extraction systems. Potential problems of differential contraction of heated films and substrates were identified, with a recommendation that fabrication processes, which avoid heating, are preferable. (author)

Johnston, David [Power and Energy Research Group, School of Engineering, Northumbria University, Ellison Place, Newcastle upon Tyne NE1 8ST (United Kingdom)

2010-03-15T23:59:59.000Z

183

Increasing Well Productivity in Gas Condensate Wells in Qatar's North Field  

E-Print Network (OSTI)

Condensate blockage negatively impacts large natural gas condensate reservoirs all over the world; examples include Arun Field in Indonesia, Karachaganak Field in Kazakhstan, Cupiagua Field in Colombia,Shtokmanovskoye Field in Russian Barents Sea, and North Field in Qatar. The main focus of this thesis is to evaluate condensate blockage problems in the North Field, Qatar, and then propose solutions to increase well productivity in these gas condensate wells. The first step of the study involved gathering North Field reservoir data from previously published papers. A commercial simulator was then used to carry out numerical reservoir simulation of fluid flow in the North Field. Once an accurate model was obtained, the following three solutions to increasing productivity in the North Field are presented; namely wettability alteration, horizontal wells, and reduced Non Darcy flow. Results of this study show that wettability alteration can increase well productivity in the North Field by adding significant value to a single well. Horizontal wells can successfully increase well productivity in the North Field because they have a smaller pressure drawdown (compared to vertical wells). Horizontal wells delay condensate formation, and increase the well productivity index by reducing condensate blockage in the near wellbore region. Non Darcy flow effects were found to be negligible in multilateral wells due to a decrease in fluid velocity. Therefore, drilling multilateral wells decreases gas velocity around the wellbore, decreases Non Darcy flow effects to a negligible level, and increases well productivity in the North Field.

Miller, Nathan

2009-12-01T23:59:59.000Z

184

Weak lensing and the Dyer-Roeder approximation  

E-Print Network (OSTI)

The distance-redshift relation plays an important role in cosmology. In the standard approach to cosmology it is assumed that this relation is the same as in the homogeneous universe. As the real universe is not homogeneous there are several methods to calculate the correction. The weak lensing approximation and the Dyer-Roeder relation are one of them. This paper establishes a link between these two approximations. It is shown that if the universe is homogeneous with only small, vanishing after averaging, density fluctuations along the line of sight, then the distance correction is negligible. It is also shown that a vanishing 3D average of density fluctuations does not imply that the mean of density fluctuations along the line of sight is zero. In this case, even within the linear approximation, the distance correction is not negligible. The modified version of the Dyer-Roeder relation is presented and it is shown that this modified relation is consistent with the correction obtained within the weak lensing approximation. The correction to the distance for a source at z ~ 2 is of order of a few percent. Thus, with an increasing precision of cosmological observations an accurate estimation of the distance is essential. Otherwise errors due to miscalculation the distance can become a major source of systematics.

Krzysztof Bolejko

2010-11-17T23:59:59.000Z

185

A multiple-mode three-dimensional model of VLF propagation in the earth-ionosphere waveguide in the presence of localized D region disturbances  

SciTech Connect

Transient localized D region disturbances, such as those associated with lightning discharges, affect the characteristics of VLF waves propagating in the Earth-ionosphere waveguide. In particular, both phase and amplitude changes in the subionospheric signal can be observed at receiving sites as a result of the wave scattering that takes place in the disturbed region. In the present paper we present a multiple-mode three- dimensional model of VLF propagation in the Earth-ionosphere waveguide in the presence of localized D region disturbances. The model takes into account great circle (GC) propagation paths with realistic ground and ionospheric conductivity changes that result in mode conversion along the path. It is assumed that conductivity changes transverse to the GC paths are negligible except in the vicinity of the D region disturbance and that mode coupling is negligible within the distributed region. This new model is applied to experimental observations and is found to be in general agreement. The diagnostics potential of the model for characterizing energetic particle precipitation events is discussed. 33 refs., 14 figs.

Poulsen, W.L.; Inan, U.S.; Bell, T.F. (Stanford Univ., CA (United States))

1993-02-01T23:59:59.000Z

186

A Quantum Approach to Dark Matter  

E-Print Network (OSTI)

This work develops and explores a quantum-based theory which enables the nature and origin of cold dark matter (CDM) to be understood without need to introduce exotic particles. The quantum approach predicts the existence of certain macroscopic quantum structures that are WIMP-like even when occupied by traditional baryonic particles. These structures function as dark matter candidates for CDM theory on large scales where it has been most successful, and retain the potential to yield observationally compliant predictions on galactic cluster and sub-cluster scales. Relatively pure, high angular momentum, eigenstate solutions obtained from Schrodinger's equation in weak gravity form the structural basis. They have no classical analogue, and properties radically different from those of traditional localised matter (whose eigenstate spectra contain negligible quantities of such states). Salient features include radiative lifetimes that can exceed the age of the universe, energies and 'sizes' consistent with galactic halos, and negligible interaction rates with radiation and macroscopic galactic objects. This facilitates the formation of sparsely populated macroscopic quantum structures that are invisible and stable. Viable structure formation scenarios are based on the seed potential wells of primordial black holes formed at the e+/e- phase transition. The structures can potentially produce suitable internal density distributions and have capacity to accommodate the required amount of halo dark matter. The formation scenarios show that it is possible to incorporate structures into universal evolutionary scenarios without significantly compromising the results of WMAP or the measurements of elemental BBN ratios.

A. D. Ernest

2004-06-06T23:59:59.000Z

187

Scaling studies and conceptual experiment designs for NGNP CFD assessment  

SciTech Connect

The objective of this report is to document scaling studies and conceptual designs for flow and heat transfer experiments intended to assess CFD codes and their turbulence models proposed for application to prismatic NGNP concepts. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/systems code calculations for the same geometry. Two aspects of the complex flow in an NGNP are being addressed: (1) flow and thermal mixing in the lower plenum ("hot streaking" issue) and (2) turbulence and resulting temperature distributions in reactor cooling channels ("hot channel" issue). Current prismatic NGNP concepts are being examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses have been applied to determine key non-dimensional parameters and their magnitudes over this operating range. For normal operation, the flow in the coolant channels can be considered to be dominant turbulent forced convection with slight transverse property variation. In a pressurized cooldown (LOFA) simulation, the flow quickly becomes laminar with some possible buoyancy influences. The flow in the lower plenum can locally be considered to be a situation of multiple hot jets into a confined crossflow -- with obstructions. Flow is expected to be turbulent with momentumdominated turbulent jets entering; buoyancy influences are estimated to be negligible in normal full power operation. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments available are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other. Two types of heat transfer experiments are being considered. One addresses the "hot channel" problem, if necessary. The second type will treat heated jets entering a model plenum. Unheated MIR (Matched-Index-of-Refraction) experiments are first steps when the geometry is complicated. One does not want to use a computational technique which will not even handle constant properties properly. The purpose of the fluid dynamics experiments is to develop benchmark databases for the assessment of CFD solutions of the momentum equations, scalar mixing and turbulence models for typical NGNP plenum geometries in the limiting case of negligible buoyancy and constant fluid properties. As indicated by the scaling studies, in normal full power operation of a typical NGNP conceptual design, buoyancy influences should be negligible in the lower plenum. The MIR experiment will simulate flow features of the paths of jets as they mix in flowing through the array of posts in a lower plenum en route to the single exit duct. Conceptual designs for such experiments are described.

D. M. McEligot; G. E. McCreery

2004-11-01T23:59:59.000Z

188

Microsoft PowerPoint - Dose Ranges 24Jan 05.ppt  

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

20 40 60 20 40 60 80 100 rem NRC Dose Limit for Public 100 mrem/yr = 1 mSv/yr (DOE, ICRP, NCRP) ANSI standard N43.17 Personnel scanner, max = 25 mrem/yr Cleanup criteria for site decommissioning/ license termination 25 mrem/yr NCRP "Negligible Dose" Medical Diagnostics (A-J) A C D E G B Temporary "Special Case" annual Public Limit (NRC, DOE) NRC Dose Limit for Workers = 5 rem/yr = 50 mSv/yr Cancer Epidemiology Life Span Study (A-bomb survivors) ( Chart compiled by NF Metting, Office of Science DOE/BER; 24Jan2005,"Orders of Magnitude") Absorbed dose: 100 rad = 1 Gray Dose equivalent: 100 rem = 1 Sievert 100 mrem = 1 mSv (1 rem = 1 rad for x- and gamma- rays) Estimated dose for

189

Instrument Series: Microscopy Ultra-High Vacuum, Low- Temperature Scanning  

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

Low- Low- Temperature Scanning Probe Microscope EMSL's ultra-high vacuum, low-temperature scanning probe microscope instrument, or UHV LT SPM, is the preeminent system dedicated to surface chemistry and physics at low temperatures down to 5 K. Operating at low temperatures provides high mechanical stability, superior vacuum conditions, and negligible drift for long-term experiments. With thermal diffusion being entirely suppressed, stable imaging becomes possible even for weakly bound species. The system is primarily used for probing single-site chemical reactivity, while the combination with a hyperthermal molecular beam allows the study of important chemical processes at energies corresponding to the operational temperatures well beyond typical UHV studies. The LT SPM provides

190

PMC-F F2a  

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

F F2a F F2a 0.0102:o U.S. DER-UITAIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA DETERMINATION RECIPIENT:Pacific Energy Ventures, LLC STATE: CO PROJECT TITLE : Active Acoustic Deterrence of Migratory Whales Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number CID Number DE-FOA-0000069 EE0002660 GFO-10-036 0 Based on my review of the information concerning the proposed action, as NEPA Compliance Officer (authorized under DOE Order 451.1 A), I have made the following determination: CX, EA, EIS APPENDIX AND NUMBER: Descript ion: B3.3 Field and laboratory research, inventory, and information collection activities that are directly related to the conservation of fish or wildlife resources and that involve only negligible habitat destruction or population reduction

191

US DEPARl'lIIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER Nl!PA DETERMINATION  

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

DEPARl'lIIENT OF ENERGY DEPARl'lIIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER Nl!PA DETERMINATION RECIPIENT: Snohomish County PUD PROJECf TITLE: Acoustic Effects of Hydrokinetic Tidal Turbines Page 1 on STATE: WA Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number CID Number DE-FOA-0000069 DE-EEOOO2654 GFQ-0002654-OO2 0 Based on my review orlhe Information concerning the proposed action, as NEPA Compliance Officer (authori1.ed under DOE Order 4S1.1A), I have made the following determination: ex, EA, EIS APPENDIX ANO NUMBER: Description: B3.3 Field and laboratory research, inventory, and information collection activities that are directly related to the conservation of fish or wildlife resources and that involve only negligible habitat destruction or population reduction

192

Static Temperature Survey At Newberry Caldera Area (Combs, Et Al., 1999) |  

Open Energy Info (EERE)

Newberry Caldera Area Newberry Caldera Area (Combs, Et Al., 1999) Exploration Activity Details Location Newberry Caldera Area Exploration Technique Static Temperature Survey Activity Date Usefulness useful DOE-funding Unknown Notes Downhole data collection during this operation was primarily limited to temperature measurements. These temperature logs were taken with Sandia's platinum-resistance-thermometer (PRT) tool which along with a Sandia logging truck remained on-site for the entire project. This instrument uses a simple resistance bridge, with changes in resistance measured from the surface through a four-conductor cable. Since there are no downhole electronics, temperature drift with time is negligible and the PRT temperature measurements are considered a reference standard for this kind

193

PowerPoint Presentation  

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

MetILs: New Ionic Liquids MetILs: New Ionic Liquids for Flow Batteries Travis M. Anderson and David Ingersoll Sandia National Laboratories Sandia National Laboratories is a multiprogram Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04- 94AL85000. Ionic Liquids (ILs) for Flow Batteries Wasserscheid and Keim, Angew. Chem. Int. Ed. 2000, 3772-3789. Nishimura et al, JP Patent 86,935, 2010 * Low symmetry * Weak Intermolecular Forces * Low charge density * Higher energy density * Negligible vapor pressure * Non-corrosive Ionic Liquids with Metal Cations (MetILs) Ferrocenyl-Functionalized Imidazoliums Zinc- and Silver-Amine Complexes Balasubramanian, Wang, and Murray, J. Am. Chem. Soc. 2006, 9994-9995. Huang, Luo,

194

High-Definition Differential Ion Mobility Spectrometry with Resolving Power up to 500  

Science Conference Proceedings (OSTI)

As the resolution of analytical methods improve, further progress tends to be increasingly limited by instrumental parameter instabilities that could be ignored before. This is now the case with differential ion mobility spectrometry (FAIMS), where fluctuations of the voltages and gas pressure have become critical. A new high-definition generator for FAIMS compensation voltage reported here provides a stable and accurate output than can be scanned with negligible steps. This reduces the spectral drift and peak width, thus improving the resolving power (R) and resolution. The gain for multiply-charged peptides that have narrowest peaks is up to ~40%, and R ~ 400 - 500 is achievable using He/N2 or H2/N2 gas mixtures.

Shvartsburg, Alexandre A.; Seim, Thomas A.; Danielson, William F.; Norheim, Randolph V.; Moore, Ronald J.; Anderson, Gordon A.; Smith, Richard D.

2013-01-20T23:59:59.000Z

195

DETERMINATION OF MAXIMUM PERMISSIBLE LEAKAGE FROM THE HRT PROCESS STEAM SYSTEM  

SciTech Connect

Calculations were made to determine the radiation hazard to HRT personnel as a result of leakage to the atmosphere from the process steam system in the event of a heat exchanger tube rupture. These calculations show that with the present four-minute delay before dumping approximately 1020 lb of fuel solution may be transferred to the steam system. The radiation hazard from fission products in the atomosphere will be negligble if the steam killer blower is operating. If this blower is not operatin. a natural convection loop will be set up in the steam killer which will have a condensing capacity of 4 lb/min of steam at atmospheric pressure. In this latter case. the inhalation hazard will be negligible when the leak rate through the steam stop valves is less than 4lb/ min. (auth)

Gift, E.H.

1959-01-30T23:59:59.000Z

196

Is it the boundaries or disorder that dominates electron transport in semiconductor `billiards'?  

E-Print Network (OSTI)

Semiconductor billiards are often considered as ideal systems for studying dynamical chaos in the quantum mechanical limit. In the traditional picture, once the electron's mean free path, as determined by the mobility, becomes larger than the device, disorder is negligible and electron trajectories are shaped by specular reflection from the billiard walls alone. Experimental insight into the electron dynamics is normally obtained by magnetoconductance measurements. A number of recent experimental studies have shown these measurements to be largely independent of the billiards exact shape, and highly dependent on sample-to-sample variations in disorder. In this paper, we discuss these more recent findings within the full historical context of work on semiconductor billiards, and offer strong evidence that small-angle scattering at the sub-100 nm length-scale dominates transport in these devices, with important implications for the role these devices can play for experimental tests of ideas in quantum chaos.

Micolich, A P; Scannell, B C; Marlow, C A; Martin, T P; Pilgrim, I; Hamilton, A R; Linke, H; Taylor, R P

2012-01-01T23:59:59.000Z

197

Protocol assessment issues in low duty cycle sensor networks: The switching energy  

E-Print Network (OSTI)

Energy assessment of MAC protocols for wireless sensor networks is generally based on the times of transmit, receive and sleep modes. The switching energy between two consecutive states is generally considered negligible with respect to them. Although such an assumption is valid for traditional wireless ad hoc networks, is this assumption valid also for low duty cycle wireless sensor networks? The primary objective of this work is to shed some light on relationships between node switching energy and node duty cycle over the total energy consumption. In order to achieve the target, initially, we revisit the energy spent in each state and transitions of three widespread hardware platforms for wireless sensor networks by direct measurements on the EYES node. Successively, we apply the values obtained to the SMAC protocol by using the OmNet++ simulator. The main reason for using SMAC is that it is the protocol normally used as a benchmark against other architectures proposed.

A. G. Ruzzelli; P. Cotan; G. M. P. O’Hare; R. Tynan; P. J. M Havinga

2006-01-01T23:59:59.000Z

198

Assessing the risk from the depleted Uranium weapons used in Operation Allied Force.  

E-Print Network (OSTI)

The conflict in Yugoslavia has been a source of great concern due to the radiological and toxic hazard posed by the alleged presence of depleted uranium in NATO weapons. In the present study some worst-case scenaria are assumed in order to assess the risk for Yugoslavia and its neighboring countries. The risk is proved to be negligible for the neighboring countries while for Yugoslavia itself evidence is given that any increase in total long-term cancer mortality will be so low that it will remain undetected. Local radioactive hotspots such as DU weapons fragments and abandoned battle tanks, fortified or contaminated with DU, constitute a post-war hazard which is not studied in this article.

unknown authors

1999-01-01T23:59:59.000Z

199

Assessing the risk from the depleted uranium weapons used in Operation Allied Force.  

E-Print Network (OSTI)

The conflict in Yugoslavia has been a source of great concern for the neighboring countries, about the radiological and toxic hazard posed by the alleged presence of depleted uranium in NATO weapons. In the present study a worst-case scenario is assumed mainly to assess the risk for Greece and other neighboring countries of Yugoslavia at similar distances. The risk of the weapons currently in use is proved to be negligible at distances greater than 100 Km. For shorter distances classified data of weapons composition are needed to obtain a reliable assessment. Operation Allied Force (OAF) has been going on for weeks in Yugoslavia with grave environmental consequences in the neighboring countries. Unfortunately, the sophisticated weapons that are being used carry the spectrum of radiological contamination. Over the past decades there has been a tremendous effort in weapons laboratories to use depleted uranium

unknown authors

1999-01-01T23:59:59.000Z

200

Impact of Dark Matter Microhalos on Signatures for Direct and Indirect Detection  

E-Print Network (OSTI)

Detecting dark matter as it streams through detectors on Earth relies on knowledge of its phase space density on a scale comparable to the size of our solar system. Numerical simulations predict that our Galactic halo contains an enormous hierarchy of substructures, streams and caustics, the remnants of the merging hierarchy that began with tiny Earth mass microhalos. If these bound or coherent structures persist until the present time, they could dramatically alter signatures for the detection of weakly interacting elementary particle dark matter (WIMP). Using numerical simulations that follow the coarse grained tidal disruption within the Galactic potential and fine grained heating from stellar encounters, we find that microhalos, streams and caustics have a negligible likelihood of impacting direct detection signatures implying that dark matter constraints derived using simple smooth halo models are relatively robust. We also find that many dense central cusps survive, yielding a small enhancement in the signal for indirect detection experiments.

Aurel Schneider; Lawrence M. Krauss; Ben Moore

2010-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Optimal Performance of Quantum Refrigerators  

E-Print Network (OSTI)

A reciprocating quantum refrigerator is studied with the purpose of determining the limitations of cooling to absolute zero. We find that if the energy spectrum of the working medium possesses an uncontrollable gap, then there is a minimum achievable temperature above zero. Such a gap, combined with a negligible amount of noise, prevents adiabatic following during the demagnetization stage which is the necessary condition for reaching $T_c \\to 0$. The refrigerator is based on an Otto cycle where the working medium is an interacting spin system with an energy gap. For this system the external control Hamiltonian does not commute with the internal interaction. As a result during the demagnetization and magnetization segments of the operating cycle the system cannot follow adiabatically the temporal change in the energy levels. We connect the nonadiabatic dynamics to quantum friction. An adiabatic measure is defined characterizing the rate of change of the Hamiltonian. Closed form solutions are found for a const...

Feldmann, Tova

2009-01-01T23:59:59.000Z

202

A Multithreaded Algorithm for Network Alignment Via Approximate Matching  

SciTech Connect

Network alignment is an optimization problem to find the best one-to-one map between the vertices of a pair of graphs that overlaps in as many edges as possible. It is a relaxation of the graph isomorphism problem and is closely related to the subgraph isomorphism problem. The best current approaches are entirely heuristic, and are iterative in nature. They generate real-valued heuristic approximations that must be rounded to find integer solutions. This rounding requires solving a bipartite maximum weight matching problem at each step in order to avoid missing high quality solutions. We investigate substituting a parallel, half-approximation for maximum weight matching instead of an exact computation. Our experiments show that the resulting difference in solution quality is negligible. We demonstrate almost a 20-fold speedup using 40 threads on an 8 processor Intel Xeon E7-8870 system (from 10 minutes to 36 seconds).

Khan, Arif; Gleich, David F.; Pothen, Alex; Halappanavar, Mahantesh

2012-11-16T23:59:59.000Z

203

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

204

HEU age determination  

SciTech Connect

A technique has been developed to determine the Highly Enriched Uranium (HEU) Age which is defined as the time since the HEU was produced in an enrichment process. The HEU age is determined from the ratios of relevant uranium parents and their daughters viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gammas and their daughters by alpha spectroscopy. In some of the samples where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the sample. In this paper we have presented data and methodology of finding the age of two HEU samples.

Moorthy, A.R.; Kato, W.Y.

1995-08-01T23:59:59.000Z

205

Calculation of Radiative Corrections to Hyperfine Splitting in p3/2 States  

DOE Green Energy (OSTI)

A recent calculation of the one-loop radiative correction to hyperfine splitting (hfs) of p{sub 1/2} states that includes binding corrections to all orders is extended to p{sub 3/2} states. Nuclear structure plays an essentially negligible role for such states, which is highly advantageous, as difficulties in controlling the Bohr-Weisskopf effect complicate the isolation of QED contributions for both s{sub 1/2} and p{sub 1/2} states. Three cases are studied. We first treat the hydrogen isoelectronic sequence, which is completely nonperturbative in Z{alpha} for high Z. Secondly the lowest lying p{sub 3/2} states of the neutral alkalis are treated, and finally lithium-like bismuth, where extensive theoretical and experimental studies of the hfs of 2s and 2p{sub 1/2} states have been made, is addressed.

Sapirstein, J; Cheng, K T

2008-07-15T23:59:59.000Z

206

Sand control in horizontal wells in heavy-oil reservoirs  

SciTech Connect

Recent advances in horizontal-well technology has greatly improved the potential for heavy oil recovery. Such recovery may be hampered, however, by sanding problems associated with most heavy-oil reservoirs. These reservoir sands are mostly unconsolidated and may lead to severe productivity-loss problems if produced freely. This paper offers recommendations for sand control in three Canadian heavy-oil reservoirs. Experimental evidence has shown that minimizing the annular space between the casing and the open hole is important, especially in the case of smaller wire space, lower oil viscosity, and thinner pay zone. Several types of wire-wrapped screens and flexible liners were tested for sand control. Only flexible liners reduced sand production to a negligible amount.

Islam, M.R. (Nova Husky Research Corp. (CA)); George, A.E. (Energy, Mines, and Resources (CA))

1991-07-01T23:59:59.000Z

207

Flow and temperature fields in a free discharge inductively coupled plasma  

SciTech Connect

Computations were made of the flow and temperature fields in an inductively coupled argon plasma at atmospheric pressure under confined and free discharge conditions. The model takes into account gravity effects and swirl in the sheath gas. Natural convection was found to have a negligible effect on the flow and temperature fields under confined discharge conditions but a significant effect for the free discharge. The back flow in the discharge was substantially reduced in the presence of swirl for swirl velocities over the range 0-50 m/s. Also with a mode-rate increase in swirl, the conduction heat flux to the wall decreased but increased with the further increase in swirl. From an overall energy balance point of view, conductive heat flux to the wall of the plasma confinement tube was substantially lower for a free plasma discharge compared to that for a confined plasma.

Gagne, R.; Boulos, M.I.; Barnes, R.M.

1979-01-01T23:59:59.000Z

208

Gas permeation carbon capture --- Process modeling and optimization  

SciTech Connect

A multi-staged gas permeation carbon capture process model was developed in Aspen Custom Modeler{reg_sign} (ACM) and optimized in the context of the retrofit of a 550 MW subcritical pulverized coal (PC) power plant. The gas permeation stages in the process are described by a custom multi-component, hollowfiber membrane model. Gas transport across the asymmetric membrane was modeled according to the solution-diffusion model for the selective skin layer and the assumption of negligible flux resistance by the porous support. Counter-current, one-dimensional plug flow was assumed with permeate pressure drop in the fiber lumen side due to capillary constrained flow. A modular optimization framework was used to minimize the levelized cost of electricity (LCOE) by optimizing a set of key process variables. The framework allows the external control of multiple simulation modules from different software packages from a common interface.

Morinelly, Juan; Miller, David

2011-01-01T23:59:59.000Z

209

Evolution of Primordial Black Holes in a radiation and phantom energy environment  

E-Print Network (OSTI)

In this work we extend previous work on the evolution of a Primordial Black Hole (PBH) to address the presence of a dark energy component with a super-negative equation of state as a background, investigating the competition between the radiation accretion, the Hawking evaporation and the phantom accretion, the latter two causing a decrease on black hole mass. It is found that there is an instant during the matter-dominated era after which the radiation accretion becomes negligible compared to the phantom accretion. The Hawking evaporation may become important again depending on a mass threshold. The evaporation of PBHs is quite modified at late times by these effects, but only if the Generalized Second Law of thermodynamics is violated.

Daniel C. Guariento; J. E. Horvath; P. S. Custódio; J. A. de Freitas Pacheco

2007-11-22T23:59:59.000Z

210

Peculiarities of electronic heat capacity of thulium cuprates in pseudogap state  

E-Print Network (OSTI)

Abstract Precise calorimetric measurements have been carried out in the 7- 300 K temperature range on two ceramic samples of thulium 123 cuprates TmBa2Cu3O6.92 and TmBa2Cu3O6.70. The temperature dependence of the heat capacity was analyzed in the region where the pseudogap state (PGS) takes place. The lattice contribution was subtracted from the experimental data. The PGS component has been obtained by comparing electronic heat capacities of two investigated samples because the PGS contribution for the 6.92 sample is negligible. The anomalous behavior of the electronic heat capacity near the temperature boundary of PGS was found. It is supposed that this anomaly is due to peculiarities in N(E) function where N is the density of electronic states and E is the energy of carriers of charge. PACS: 74.25.Bt, 74.72.Jt

E. B. Amitin; K. R. Zhdanov; M. Y. Kameneva; Yu. A. Kovalevskaya; A. G. Blinov

2002-01-01T23:59:59.000Z

211

Research Highlight  

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

Climate Warming Due to Soot and Smoke? Maybe Not. Climate Warming Due to Soot and Smoke? Maybe Not. Submitter: Penner, J. E., University of Michigan Area of Research: Aerosol Properties Working Group(s): Aerosol Journal Reference: Penner, J.E., S.Y. Zhang, and C.C. Chuang, Soot and smoke aerosol may not warm climate, J. Geophys. Res., 108(D21), 4657, doi:10.1029/2003JD003409, 2003. New research results from the Department of Energy's Atmospheric Radiation Measurement (ARM) Program suggest that fossil fuel soot emissions and biomass smoke may actually have a negligible warming effect and, in some cases, may even result in a net cooling effect. Black carbon is the absorbing component of smoke aerosols that result from the incomplete combustion of various fuels, the most significant sources being fossil fuel

212

ARM - Publications: Science Team Meeting Documents  

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

Detection of Thin Cirrus Using MODIS 1.38 Micron Reflection Detection of Thin Cirrus Using MODIS 1.38 Micron Reflection Roskovensky, J.K. and Liou, K.N., University of California, Los Angeles Twelfth Atmospheric Radiation Measurement (ARM) Science Team Meeting The 1.38 µm channel on board MODIS may have significant advantage in detecting thin cirrus over existing methods due to its high sensitivity to upper tropospheric clouds and a nearly negligible sensitivity to low level reflectance. To investigate this potential, three different cloud schemes are employed. One based on the MODIS Cloud Mask Product (MOD35) which utilizes both visible and 1.38 µm reflectance thresholds. The second is a modified version of the cloud phase detection scheme presented in the paper by Ou et al (1996) that incorporates a series of visible, near and far

213

90-day Interim Report on Shale Gas Production - Secretary of Energy  

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

90-day Interim Report on Shale Gas Production - Secretary of Energy 90-day Interim Report on Shale Gas Production - Secretary of Energy Advisory Board 90-day Interim Report on Shale Gas Production - Secretary of Energy Advisory Board The Shale Gas Subcommittee of the Secretary of Energy Advisory Board is charged with identifying measures that can be taken to reduce the environmental impact and improve the safety of shale gas production. Natural gas is a cornerstone of the U.S. economy, providing a quarter of the country's total energy. Owing to breakthroughs in technology, production from shale formations has gone from a negligible amount just a few years ago to being almost 30 percent of total U.S. natural gas production. This has brought lower prices, domestic jobs, and the prospect of enhanced national security due to the potential of substantial

214

ESS 2012 Peer Review - Advanced Materials for Flow Batteries - Travis Anderson, SNL  

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

Advanced Materials for Advanced Materials for Flow Batteries Friday, September 28, 2012 Travis M. Anderson and Harry D. Pratt III Sandia National Laboratories Ionic Liquid Flow Batteries MetIL - + MetIL * 59 mV/n separation (ideally n > 1) * Viscosity < 500 cP * Conductivity > 0.5 mS cm -1 * Open Circuit Potential > 1.5 V Problem: Getting high concentrations of redox active species. MetILs * Transition Metal Cation * Weakly Coordinating Anions * Alkanolamine Ligands * Negligible Vapor Pressure * Non-toxic 2 FY12 Milestones Approach: Design electrolytes with charge storage species as part of their chemical composition. Energy Density/Costs SNL APPROACH: Consider a compound CuL 2 BF 4 (L = methanolamine, MW = 47 g/mol), measured density 1.6 g/mL, formula weight,

215

Enhanced Chemical Cleaning  

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

Chemical Cleaning Chemical Cleaning Renee H. Spires Enhanced Chemical Cleaning Project Manager July 29, 2009 Tank Waste Corporate Board 2 Objective Provide an overview of the ECC process and plan 3 Chemical Cleaning * Oxalic Acid can get tanks clean - Tank 16 set a standard in 1982 - Tanks 5-6 Bulk OA cleaning results under evaluation * However, the downstream flowsheet and financial impacts of handling the spent acid were unacceptable Before After Tank 16 Tank 16 4 Oxalic Acid Flowsheet Impacts Evap Sludge Washing Evap Feed/Drop Tank 8 Wt% Oxalic Acid Neutralization Tank Solids Liquid High oxalate concentration Negligible oxalate concentration * Oxalates from chemical cleaning impact salt processing * A process change was needed Evaporator Saltstone Vaults DWPF Filled Canisters 5 Vision * Eliminate the impacts to the Tank Farm

216

Renewable Energy in South Africa: Issues and Prospects  

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

Renewable Energy in South Africa: Issues and Prospects Renewable Energy in South Africa: Issues and Prospects Speaker(s): Ogunlade Davidson Date: February 1, 2002 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Lynn Price The present contribution of Renewable Energy to the total power supply through grid electricity in South Africa is negligible. However, the government driven by concerns for rural electrification, while realising their overall sustainable objectives and environmental pressures, has set a target of achieving 5% grid supply from renewable technologies by 2010. It is advocated that this target as stated in their strategy paper should be achieved through the development of micro-hydro, biomass, solar and wind systems. Existing renewable energy systems that are operating in South Africa shows that there are major challenges in achieving this target. This

217

NREL: News - NREL Calculates Emissions and Costs of Power Plant Cycling  

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

013 013 NREL Calculates Emissions and Costs of Power Plant Cycling Necessary for Increased Wind and Solar in the West September 24, 2013 New research from the Energy Department's National Renewable Energy Laboratory (NREL) quantifies the potential impacts of increasing wind and solar power generation on the operators of fossil-fueled power plants in the West. To accommodate higher amounts of wind and solar power on the electric grid, utilities must ramp down and ramp up or stop and start conventional generators more frequently to provide reliable power for their customers - a practice called cycling. The study finds that the carbon emissions induced by more frequent cycling are negligible (<0.2%) compared with the carbon reductions achieved through the wind and solar power generation evaluated in the study. Sulfur dioxide

218

1  

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

Sensitivity of Cloud Field Structure to Three Sensitivity of Cloud Field Structure to Three Dimensional Radiative Effects W. O'Hirok and P. Ricchiazzi Institute for Computational Earth System Science University of California Santa Barbara, California C. Gautier Department of Geography and Institute for Computational Earth System Science University of California Santa Barbara, California Introduction During the past decade, research has shown that while 3 dimensional (D) radiative effects are negligible at the horizontal resolution of GCMs, they can be significant at the scale of cloud resolving models. A common thread throughout these studies is the static framework in which they are performed - that is, computations are performed on cloud fields of fixed properties. They ignore the more salient issue of

219

Heat Flow From Four New Research Drill Holes In The Western Cascades,  

Open Energy Info (EERE)

From Four New Research Drill Holes In The Western Cascades, From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Details Activities (1) Areas (1) Regions (0) Abstract: Conceptual models of the thermal structure of the Oregon Cascade Range propose either (1) a narrow zone of magmatic heat sources, flanked by shallow heat-flow anomalies caused by lateral ground-water flow; or (2) a wide zone of magmatic heat sources, with localized, generally negligible ground-water effects. The proposed narrow heat source coincides with the Quaternary volcanic arc, whereas the wider heat source would extend 10-30 km west of the arc. To test the models, four new heat-flow holes were sited

220

Argonne CNM: 2011 Colloquium Series  

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

1 Colloquium Series 1 Colloquium Series 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | Date Title December 21, 2011 "Film Thickness and Elastic Strain Measurements on Silicon-on-Insulator Thin Films," I. Cevdet Noyan, Columbia University, hosted by Jorg Maser Abstract: Silicon-on-insulator (SOI) composites consist of two semiconductor-grade silicon layers bonded to each other via a SiO2 interface. One of these silicon layers is quite thin; it is possible to get thicknesses between 5 and 150 nm. Since this value is much thinner than the extinction distance of X-rays in silicon for commonly used energies, this layer diffracts in the kinematical mode. The second layer is much thicker, around 700 micrometers, and diffracts in the dynamical mode. Both layers can be considered almost perfect, with negligible mosaic structures and no dislocations.

Note: This page contains sample records for the topic "negligible negligible negligible" 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

1  

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

Inversion of Multi-Angle Radiation Measurement Inversion of Multi-Angle Radiation Measurement B. Cairns and M. Alexandrov Columbia University New York, New York A. Lacis and B. Carlson National Aeronautics and Space Administration - Goddard Institute for Space Studies New York, New York Motivation Observations of the polarization and reflectance in bands at 865 nm (negligible liquid water absorption) and 2250 nm (strong liquid water absorption) cannot be fitted by a simple atmospheric model consisting of a homogeneous cloud with a single particle size. If we use the polarization (polarized reflectance) measurements and the reflectance measurements to retrieve cloud particle size independently, we find that it is frequently (although not always) the case that the size retrieved with the polarization measurements is larger than the size retrieved using the

222

ARM - Publications: Science Team Meeting Documents  

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

Detection of Thin Cirrus using a Combinaton of 1.38-um Reflectance and Detection of Thin Cirrus using a Combinaton of 1.38-um Reflectance and Window Brightness Temperature Difference Roskovensky, J.K. and Liou, K.N., Department of Atmospheric Sciences University of California, Los Angeles Thirteenth Atmospheric Radiation Measurement (ARM) Science Team Meeting A new cloud detection scheme has been developed that utilizes 1.38-um reflectance in combination with 8.6-11 um brightness temperature difference to detect cirrus clouds. The 1.38-um channel on board MODIS is useful in detecting thin cirrus due to its high sensitivity to upper tropospheric clouds and a nearly negligible sensitivity to low-level reflectance. Dependent upon neighboring cloud type, water vapor concentration, and the viewing geometry, specific 1.38-um reflectance threshold levels can be

223

Microsoft PowerPoint - NEILS for HTF page 1_ebf.ppt [Compatibility Mode]  

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

A A good HTF must be able to absorb a substantial amount of energy in a given volume, a property known as volumetric heat capacity. Physical properties such as viscosity, thermal stability, and thermal conductivity must also be considered. Ionic liquids (IL) were discovered more than 30 years ago and are organic compounds with negligible vapor pressure. ILs are molten salts with low melting points below 100°C, high liquid range above 400°C, in some cases, freezing points below 0°C. For example, experiments conducted at SRNL examined the ionic liquid known as [C 4 mmim][NTf 2 ] due to commercial availability, good thermal stability, and tolerable viscosity. The studies indicate that the addition of Al 2 O 3 nanoparticles to the ionic liquid can increase density of the liquid by 10%, and increase volumetric heat capacity by 40% compared to neat ILs and 70% compared to traditional volatile

224

A Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene  

Open Energy Info (EERE)

Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Sulfonate as a Liquid-Phase Tracer at the Coso Geothermal Field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: A Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Sulfonate as a Liquid-Phase Tracer at the Coso Geothermal Field Details Activities (1) Areas (1) Regions (0) Abstract: A tracer test was conducted at the Coso geothermal field in order to characterize the flow patterns of fluid injected into well 68-20RD. A conservative liquid phase tracer, 2-naphthalene sulfonate, and a two-phase tracer, ethanol, were injected into well 68-20RD. Surrounding production wells were sampled over the subsequent 125 days and analyzed for the two tracers. The liquid-phase tracer showed negligible returns, whereas the

225

Measurement of top quark polarization in top-antitop events from proton-proton collisions at ?s = 7 TeV using the ATLAS detector  

E-Print Network (OSTI)

This Letter presents measurements of the polarization of the top quark in top–antitop quark pair events, using 4.7 fb$^{¯1}$ of proton–proton collision data recorded with the ATLAS detector at the Large Hadron Collider at ?s = 7 TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of $\\alpha_l P$, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving (CPC) or a CP violating (CPV) production process. The measurements obtained, $\\alpha_l P_{CPC} = ?0.035± 0.014(stat) ± 0.037(syst)$ and $\\alpha_l P_{CPV} = 0.020 ± 0.016(stat)^{+0.013} _{-0.017}(syst)$, are in good agreement with the Standard Model prediction of negligible top quark polarization.

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Aefsky, Scott; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Astbury, Alan; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Bittner, Bernhard

2013-01-01T23:59:59.000Z

226

ADVANCED HEAT EXCHANGERS USING TUNABLE NANOSCALE-MOLECULAR ASSEMBLY  

Science Conference Proceedings (OSTI)

Steam condensation heat transfer on smooth horizontal tubes and enhanced tubes (TURBO-CDI and TURBO-CSL) along with nanoscale hydrophobic coated tubes was studied experimentally. Hydrophobic coatings have been created through self-assembled mono layers (SAMs) on copper alloy (99.9% Cu, 0.1% P) surfaces to enhance steam condensation through dropwise condensation. In general, a SAM system with a long-chain, hydrophobic group is nano-resistant, meaning that such a system forms a protective hydrophobic layer with negligible heat transfer resistance but a much stronger bond. When compared to complete filmwise condensation, the SAM coating on a plain tube increased the condensation heat transfer rate by a factor of 3 for copper alloy surfaces, under vacuum pressure (33.86 kPa) and by a factor of about 8 times when operated at atmospheric pressure (101 kPa). Lifetime of maintaining dropwise condensation is greatly dependent on the processing conditions.

Kwang J. Kim; Thomas W. Bell; Srinivas Vemuri; Sailaja Govindaraju

2004-01-01T23:59:59.000Z

227

Cr/sup 3 +/-doped colquiriite solid state laser material  

DOE Patents (OSTI)

Chromium doped colquiriite, LiCaAlF/sub 6/:Cr/sup 3 +/, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr/sup 3 +/ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slope efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd/sup 3 +/ or Tm/sup 3 +/ for use in a multimegajoule single shot fusion research facility. 4 figs.

Payne, S.A.; Chase, L.L.; Newkirk, H.W.; Krupke, W.F.

1988-03-31T23:59:59.000Z

228

Photorefractive effect at 775 nm in doped lithium niobate crystals  

SciTech Connect

The photorefractive effect induced by 775-nm laser light on doped lithium niobate crystals is investigated by the direct observation in the far field of the transmitted-beam distortion as a function of time. Measurements performed at various Zr-doping concentrations and different light intensities show that the 775-nm light beam induces a steady-state photorefractive effect comparable to that of 532-nm light, but the observed build-up time of the photovoltaic field is longer by three-orders of magnitude. The 775-nm photorefractivity of lithium niobate crystals doped with 3 mol. % ZrO{sub 2} or with 5.5 mol. % MgO is found to be negligible.

Nava, G.; Minzioni, P.; Cristiani, I.; Degiorgio, V. [Department of Electrical, Computer, and Biomedical Engineering, and CNISM, University of Pavia, 27100 Pavia (Italy); Argiolas, N.; Bazzan, M.; Ciampolillo, M. V.; Pozza, G.; Sada, C. [Physics and Astronomy Departement, University of Padova, 35131 Padova (Italy)

2013-07-15T23:59:59.000Z

229

Pressure Drops Due to Silica Scaling  

DOE Green Energy (OSTI)

Experience with reinjection returns in many geothermal fields has prompted a move towards injecting waste fluids at some distance from the production field. This means that often, reinjection pipelines cover very long distances. If the waste water in the pipelines is supersaturated with respect to amorphous silica, then the deposition of silica in these pipelines is almost certain. Although the deposit may be of negligible thickness, the inner surface characteristics of the pipe will be different to those of clean mild steel. During a silica scaling experiment. geothermal brine was passed through a series of pipes of different sizes and over a period of three weeks, silica scale formed on the inner surface. The pressure drop along a distance of approximately 5m was measured by a water manometer in all test pipe sections. Significant pressure drop was observed during this time and can be correlated with the increase in the friction factor of the pipe walls due to silica scaling.

Brown, K.L.; Freeston, D.H.; Dimas, Z.O.; Slatter, A.

1995-01-01T23:59:59.000Z

230

Observation of Synchrotron Radiation from Electrons Accelerated in a Petawatt-Laser-Generated Plasma Cavity  

Science Conference Proceedings (OSTI)

The dynamics of plasma electrons in the focus of a petawatt laser beam are studied via measurements of their x-ray synchrotron radiation. With increasing laser intensity, a forward directed beam of x rays extending to 50 keV is observed. The measured x rays are well described in the synchrotron asymptotic limit of electrons oscillating in a plasma channel. The critical energy of the measured synchrotron spectrum is found to scale as the Maxwellian temperature of the simultaneously measured electron spectra. At low laser intensity transverse oscillations are negligible as the electrons are predominantly accelerated axially by the laser generated wakefield. At high laser intensity, electrons are directly accelerated by the laser and enter a highly radiative regime with up to 5% of their energy converted into x rays.

Kneip, S.; Nagel, S. R.; Bellei, C.; Dangor, A. E.; Mangles, S. P. D.; Nilson, P. M.; Willingale, L.; Najmudin, Z. [Blackett Laboratory, Imperial College London SW7 2AZ (United Kingdom); Bourgeois, N.; Marques, J. R. [Laboratoire pour l'Utilisation des Lasers Intenses, Ecole Polytechnique, 91128 Palaiseau (France); Gopal, A. [Department of Electronics, Technological Educational Institute of Crete, Romanou, 3-GR73133 Chania (Greece); Heathcote, R. [Central Laser Facility, Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom); Maksimchuk, A.; Reed, S. [Center for Ultrafast Optical Science (CUOS) University of Michigan, Ann Arbor, Michigan 48109 (United States); Phuoc, K. Ta; Rousse, A. [Laboratoire d'Optique Applique, ENSTA, Ecole Polytechnique, 91761 Palaiseau (France); Tzoufras, M.; Tsung, F. S.; Mori, W. B. [Department of Physics and Astronomy and Department of Electrical Engineering, UCLA, Los Angeles, California 90095 (United States); Krushelnick, K. [Blackett Laboratory, Imperial College London SW7 2AZ (United Kingdom); Center for Ultrafast Optical Science (CUOS) University of Michigan, Ann Arbor, Michigan 48109 (United States)

2008-03-14T23:59:59.000Z

231

Observed physical processes in mechanical tests of PBX9501 and recomendations for experiments to explore a possible plasticity/damage threshold  

Science Conference Proceedings (OSTI)

This memo discusses observations that have been made in regards to a series of monotonic and cyclic uniaxial experiments performed on PBX9501 by Darla Thompson under Enhanced Surveilance Campaign support. These observations discussed in Section Cyclic compression observations strongly suggest the presence of viscoelastic, plastic, and damage phenomena in the mechanical response of the material. In Secton Uniaxial data analysis and observations methods are discussed for separating out the viscoelastic effects. A crude application of those methods suggests the possibility of a critical stress below which plasticity and damage may be negligible. The threshold should be explored because if it exists it will be an important feature of any constitutive model. Additionally, if the threshold exists then modifications of experimental methods may be feasible which could potentially simplify future experiments or provide higher quality data from those experiments. A set of experiments to explore the threshold stress are proposed in Section Exploratory tests program for identifying threshold stress.

Buechler, Miles A. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

232

Gas lasers with wave-chaotic resonators  

E-Print Network (OSTI)

Semiclassical multimode laser theory is extended to gas lasers with open two-dimensional resonators of arbitrary shape. The Doppler frequency shift of the linear-gain coefficient leads to an additional linear coupling between the modes, which, however, is shown to be negligible. The nonlinear laser equations simplify in the special case of wave-chaotic resonators. In the single-mode regime, the intensity of a chaotic laser, as a function of the mode frequency, displays a local minimum at the frequency of the atomic transition. The width of the minimum scales with the inhomogeneous linewidth, in contrast to the Lamb dip in uniaxial resonators whose width is given by the homogeneous linewidth.

Oleg Zaitsev

2010-10-28T23:59:59.000Z

233

Contribution of HD molecules in cooling of the primordial gas  

E-Print Network (OSTI)

We study the effects of HD molecules on thermochemical evolution of the primordial gas behind shock waves, possibly arised in the process of galaxy formation. We find the critical shock velocity when deuterium transforms efficiently into HD molecules which then dominate gas cooling. Above this velocity the shocked gas is able to cool down to the temperature of the cosmic microwave background. Under these conditions the corresponding Jeans mass depends only on redshift and initial density of baryons $M_J \\propto \\delta_c^{-0.5} (1+z)^{0.5}$. At $z\\simgt 45$ HD molecules heat shocked gas, and at larger redshift their contribution to thermal evolution becomes negligible.

E. O. Vasiliev; Yu. A. Shchekinov

2005-07-26T23:59:59.000Z

234

Transport properties of a meson gas  

E-Print Network (OSTI)

We present recent results on a systematic method to calculate transport coefficients for a meson gas (in particular, we analyze a pion gas) at low temperatures in the context of Chiral Perturbation Theory. Our method is based on the study of Feynman diagrams with a power counting which takes into account collisions in the plasma by means of a non-zero particle width. In this way, we obtain results compatible with analysis of Kinetic Theory with just the leading order diagram. We show the behavior with temperature of electrical and thermal conductivities and shear and bulk viscosities, and we discuss the fundamental role played by unitarity. We obtain that bulk viscosity is negligible against shear viscosity near the chiral phase transition. Relations between the different transport coefficients and bounds on them based on different theoretical approximations are also discussed. We also comment on some applications to heavy-ion collisions.

D. Fernandez-Fraile; A. Gomez Nicola

2007-06-25T23:59:59.000Z

235

Observational Constraints of New Variable Modified Chaplygin Gas Model  

E-Print Network (OSTI)

Assuming the flat FRW universe in Einstein's gravity filled with New Variable Modified Chaplygin gas (NVMCG) dark energy and dark matter having negligible pressure. In this research work we analyze the viability on the basis of recent observation. Hubble parameter $H$ is expressed in terms of the observable parameters $H_0$, $\\Omega_m^0$ and the model parameters $A_0$, $B_0$, $C_0$, $m$, $n$, $\\alpha$ and the red shift parameter $z$. Here we find a best fitted parameter range of $A_0$, $B_0$ keeping $0\\leq \\alpha \\leq 1$ and using Stern data set (12 points) by minimizing the $\\chi^2$ test at 66%, 90% and 99% confidence levels. Next we do the joint analysis with BAO and CMB observations. Again evaluating the distance modulus $\\mu(z)$ vs redshift ($z$) curve obtained in the model NVMCG with dark matter with the best fitted value of the parameters and comparing with that derived from the union2 compilation data.

Jhumpa Bhadra; Ujjal Debnath

2012-11-09T23:59:59.000Z

236

String Gas Cosmology and Non-Gaussianities  

E-Print Network (OSTI)

Recently it has been shown that string gas cosmology, an alternative model of the very early universe which does not involve a period of cosmological inflation, can give rise to an almost scale invariant spectrum of metric perturbations. Here we calculate the non-Gaussianities of the spectrum of cosmological fluctuations in string gas cosmology, and find that these non-Gaussianities depend linearly on the wave number and that their amplitude depends sensitively on the string scale. If the string scale is at the TeV scale, string gas cosmology could lead to observable non-Gaussianities, if it is close to the Planck scale, then the non-Gaussianities on current cosmological scales are negligible.

Bin Chen; Yi Wang; Wei Xue; Robert Brandenberger

2007-12-14T23:59:59.000Z

237

EFFECTS OF SEISMIC VIBRATIONS ON THE EXPERIMENTAL GAS-COOLED REACTOR  

SciTech Connect

The effects of seismic vibrations on the dynamic behavior of a composite system were analyzed. The equations of motion were derived and soIved with special emphasis on determining the resulting stresses. The method of analysis thus developed was applied to the composite structure consisting of the core, pressure vessel, and supporting skirt of the Experimental Gas-Cooled Reactor (EGCR). A system with three degrees of freedom was considered in order to determine the effects of an earthquake of the maximum intensity expected in the area surrounding Oak Ridge, Tennessee. The system of equations of motion was solved both numerically and analytically, and the resonant frequencies were determined. The seismic effect was shown to be small when the frequency of the seismic disturbance coincided with a natural frequency of the system. In particular, the shear stresses in the graphite core were shown to be negligible. (auth)

Witt, F.J.; Carver, D.R.; Maxwell, R.L.

1962-06-22T23:59:59.000Z

238

Generalized Forchheimer Equation for Two-Phase Flow Based on Hybrid Mixture Theory  

E-Print Network (OSTI)

In this paper, we derive a Forchheimer-type equation for two-phase flow through an isotropic porous medium using hybrid mixture theory. Hybrid mixture theory consists of classical mixture theory applied to a multiphase system with volume averaged equations. It applies to media in which the characteristic length of each phase is "small" relative to the extent of the mixture. The derivation of a Forchheimer equation for single phase flow has been obtained elsewhere. These results are extended to include multiphase swelling materials which have non-negligible interfacial thermodynamic properties. Key words. Porous media, swelling porous media, high velocity flow, non-Darcy flow, two-phase flow, multi-phase flow, mixture theory, Forchheimer equation. 1 Introduction Darcy-type equations are used to describe the flow of a single-phase fluid through porous media in a number of situations. The classical Darcy equation, first derived experimentally in 1856, states that the flux is pro...

Lynn Schreyer Bennethum; Tizian Giorgi

1996-01-01T23:59:59.000Z

239

Matter Wave Interferometry of a Levitated Thermal Nano-Oscillator Induced and Probed by a Spin  

E-Print Network (OSTI)

We show how the interference between spatially separated states of the center of mass (COM) of a mesoscopic harmonic oscillator can be evidenced by coupling it to a spin and performing solely spin manipulations and measurements (Ramsey Interferometry). We propose to use an optically levitated diamond bead containing an NV center spin. The nano-scale size of the bead makes the motional decoherence due to levitation negligible. The form of the spin-motion coupling ensures that the scheme works for thermal states so that moderate feedback cooling suffices. No separate control or observation of the COM state is required and thereby one dispenses with cavities, spatially resolved detection and low mass-dispersion ensembles. The controllable relative phase in the Ramsey interferometry stems from a gravitational potential difference so that it uniquely evidences coherence between states which involve the whole nano-crystal being in spatially distinct locations.

M. Scala; M. S. Kim; G. W. Morley; P. F. Barker; S. Bose

2013-06-27T23:59:59.000Z

240

High temperature electrochemical polishing of H{sub 2}S from coal gasification process streams. Quarterly progress report, October 1, 1995--December 31, 1995  

DOE Green Energy (OSTI)

An advanced process for the separation of hydrogen sulfide (H{sub 2}S) from coal gasification product streams through an electrochemical membrane is being developed. H{sub 2}S is removed from the syn-gas stream, split into hydrogen, which enriches the exiting syn-gas, and sulfur, which is condensed from an inert sweep gas stream. The process allows removal of H{sub 2}S without cooling the gas stream and with negligible pressure loss through the separator. The process is made economically attractive by the lack of need for a Claus process for sulfur recovery. Membrane manufacturing coupled with full-cell experimentation was the primary focus this quarter. A tape-casted zirconia membrane was developed and utilized in one full-cell experiment (run 25); run 24 utilized a fabricated membrane purchased from Zircar Corporation. Results are discussed.

Winnick, J.

1995-12-31T23:59:59.000Z

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241

Analysis of core damage frequency due to external events at the DOE (Department of Energy) N-Reactor  

SciTech Connect

A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

Lambright, J.A.; Bohn, M.P.; Daniel, S.L. (Sandia National Labs., Albuquerque, NM (USA)); Baxter, J.T. (Westinghouse Hanford Co., Richland, WA (USA)); Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P. (EQE, Inc., San Francisco, CA (USA)); Brosseau, D.A. (ERCE, Inc., Albuquerque, NM (USA))

1990-11-01T23:59:59.000Z

242

Geothermal Loan Guaranty Program and its impact on geothermal exploration and development  

DOE Green Energy (OSTI)

The study showed that the Geothermal Loan Guaranty Program has had only a negligible effect on geothermal development and the response to the program was far less than expected. The streamlining of environmental regulations and leasing policies, and the granting of intangible drilling cost write-offs and depletion allowances to operators would have had a greater impact on geothermal energy development. The loan guaranty program did not promote the undertaking of any new projects that would not have been undertaken without it. The program only accelerated the pace for some development which might have commenced in the future. Included in the study are recommendations for improving the operation of the program thereby increasing its attractiveness to potential applicants.

Nasr, L.H.

1978-05-01T23:59:59.000Z

243

Examination of Compatibility of Potentially Cavitation-Resistant Modifications of Type 316LN Stainless Steel with Mercury in a Thermal Convection Loop  

Science Conference Proceedings (OSTI)

A 316L stainless steel thermal convection loop (TCL) containing a variety of stainless steel coupons circulated mercury for 2000 h. The TCL conditions included a maximum temperature of 307 C, a maximum temperature gradient of 90 C, and a Hg velocity of about 1.4 m/min. In addition to mill-annealed/surface-ground 316LN coupons serving as the baseline material, other coupons included 316LN that was 50% cold-worked, 316LN that was given a proprietary surface hardening treatment termed ''kolsterizing,'' and Nitronic 60. The purpose of this test was to examine Hg compatibility with these modest variations of annealed 31 6LN stainless steel that are considered potential improvements over annealed 31 6LN for cavitation-erosion resistance in the Spallation Neutron Source (SNS) target containment system. The results indicated negligible weight change for each coupon type, no significant indication of attack or surface roughening, and generally no interaction with Hg.

Pawel, SJ

2002-08-29T23:59:59.000Z

244

Localized saddle-point search and application to temperature-accelerated dynamics  

SciTech Connect

We present a method for speeding up temperature-accelerated dynamics (TAD) simulations by carrying out a localized saddle-point (LSAD) search. In this method, instead of using the entire system to determine the energy barriers of activated processes, the calculation is localized by only including a small chunk of atoms around the atoms directly involved in the transition. Using this method, we have obtained N-independent scaling for the computational cost of the saddle-point search as a function of system size N. The error arising from localization is analyzed using a variety of model systems, including a variety of activated processes on Ag(100) and Cu(100) surfaces, as well as multiatom moves in Cu radiation damage and metal heteroepitaxial growth. Our results show significantly improved performance of TAD with the LSAD method, for the case of Ag/Ag(100) annealing and Cu/Cu(100) growth, while maintaining a negligibly small error in energy barriers.

Shim, Yunsic; Amar, Jacques G. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Callahan, Nathan B. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States)

2013-03-07T23:59:59.000Z

245

X-ray emission from O-type stars : DH Cep and HD 97434  

E-Print Network (OSTI)

We present X-ray emission characteristics of the massive O-type stars DH Cep and HD 97434 using archival XMM-Newton observations. There is no convincing evidence for short term variability in the X-ray intensity during the observations. However, the analysis of their spectra reveals X-ray structure being consistent with two-temperature plasma model. The hydrogen column densities derived from X-ray spectra of DH Cep and HD 97434 are in agreement with the reddening measurements for their corresponding host clusters NGC 7380 and Trumpler 18, indicating that the absorption by stellar wind is negligible. The X-ray emission from these hot stars is interpreted in terms of the standard instability-driven wind shock model.

Bhatt, Himali; Kumar, Brijesh; Sagar, Ram; Singh, K P

2010-01-01T23:59:59.000Z

246

Neutronic design studies for the MIT fission converter beam  

SciTech Connect

Currently available epithermal neutron beams at the Massachusetts Institute of Technology (MIT) are not sufficiently intense to meet the anticipated demand for boron neutron capture therapy (BNCT) treatments if initial, currently in progress clinical trials of BNCT prove successful. Indeed, they are not really adequate for extensive (phase-III) clinical trials. To fulfill this need, a high-intensity, high-quality fission converter-based epithermal neutron beam for BNCT has been designed for the MIT Research Reactor, (MITR-II). This epithermal neutron beam, capable of delivering treatments in a few minutes with negligible beam background contamination, would be installed in the present thermal column and hohlraum of the MITR-II.

Kiger, W.S. III; Harling, O.K. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

1996-12-31T23:59:59.000Z

247

Cell body rocking is a dominant mechanism for flagellar synchronization in a swimming algae  

E-Print Network (OSTI)

The unicellular green algae Chlamydomonas swims with two flagella, which can synchronize their beat. Synchronized beating is required to swim both fast and straight. A long-standing hypothesis proposes that synchronization of flagella results from hydrodynamic coupling, but the details are not understood. Here, we present realistic hydrodynamic computations and high-speed tracking experiments of swimming cells that show how a perturbation from the synchronized state causes rotational motion of the cell body. This rotation feeds back on the flagellar dynamics via hydrodynamic friction forces and rapidly restores the synchronized state in our theory. We calculate that this `cell body rocking' provides the dominant contribution to synchronization in swimming cells, whereas direct hydrodynamic interactions between the flagella contribute negligibly. We experimentally confirmed the coupling between flagellar beating and cell body rocking predicted by our theory. We propose that the interplay of flagellar beating and hydrodynamic forces governs swimming and synchronization in Chlamydomonas.

Veikko Geyer; Frank Jülicher; Jonathon Howard; Benjamin M Friedrich

2013-05-03T23:59:59.000Z

248

An original image slicer designed for Integral Field Spectroscopy with NIRSpec/JSWT  

E-Print Network (OSTI)

Integral Field Spectroscopy (IFS) provides a spectrum simultaneously for each spatial sample of an extended, two-dimensional field. It consists of an Integral Field Unit (IFU) which slices and re-arranges the initial field along the entrance slit of a spectrograph. This article presents an original design of IFU based on the advanced image slicer concept. To reduce optical aberrations, pupil and slit mirrors are disposed in a fan-shaped configuration that means that angles between incident and reflected beams on each elements are minimized. The fan-shaped image slicer improves image quality in terms of wavefront error by a factor 2 comparing with classical image slicer and, furthermore it guaranties a negligible level of differential aberration in the field. As an exemple, we are presenting the design LAM used for its proposal at the NIRSPEC/IFU invitation of tender.

Sébastien Vivès; Eric Prieto

2005-12-01T23:59:59.000Z

249

Short-distance contribution to the spectrum of Hawking radiation  

E-Print Network (OSTI)

The Hawking effect can be rederived in terms of two-point functions and in such a way that it makes it possible to estimate, within the conventional semiclassical theory, the contribution of ultrashort distances to the Planckian spectrum. For Schwarzschild black holes of three solar masses the analysis shows that Hawking radiation is very robust up to frequencies of 96 T_H or 270 T_H for bosons and fermions, respectively. For primordial black holes (with masses around 10^{15} g) these frequencies turn out to be of order 52T_H and 142 T_H. Only at these frequencies and above do we find that the contribution of Planck distances is of order of the total spectrum itself. Below this scale, the contribution of ultrashort distances to the spectrum is negligible. This suggests that only above these frequencies could an underlying quantum theory of gravity potentially predict significant deviations from Hawking's semiclassical result.

I. Agullo; J. Navarro-Salas; Gonzalo J. Olmo; Leonard Parker

2006-11-30T23:59:59.000Z

250

Chameleon effect and the Pioneer anomaly  

E-Print Network (OSTI)

The possibility that the apparent anomalous acceleration of the Pioneer 10 and 11 spacecraft may be due, at least in part, to a chameleon field effect is examined. A small spacecraft, with no thin shell, can have a more pronounced anomalous acceleration than a large compact body, such as a planet, having a thin shell. The chameleon effect seems to present a natural way to explain the differences seen in deviations from pure Newtonian gravity for a spacecraft and for a planet, and appears to be compatible with the basic features of the Pioneer anomaly, including the appearance of a jerk term. However, estimates of the size of the chameleon effect indicate that its contribution to the anomalous acceleration is negligible. We conclude that any inverse-square component in the anomalous acceleration is more likely caused by an unmodelled reaction force from solar-radiation pressure, rather than a chameleon field effect.

John D. Anderson; J. R. Morris

2012-04-12T23:59:59.000Z

251

On the Rate of Spontaneous Magnetic Reconnection  

E-Print Network (OSTI)

Magnetic reconnection is a topological rearrangement of the magnetic field lines, leading to the release of magnetic energy, which is thought to be associated with solar flares, coronal mass ejections and magnetospheric storms. Despite magnetic field lines are supposed to be frozen into the well-conducting plasma, the reconnection observed in nature is, typically, fast, so that the rate of convergence of the magnetic field lines is the fraction of the Alfven speed, v_A. The Sweet-Parker solution predicts reconnection rates which are negligible for the solar or astrophysical conditions, this have prompted research into collisionless reconnection. The stochasticity of magnetic field lines due to ambient turbulence leads to fast reconnection and the rate was predicted to be proportional to kinetic energy density of ambient turbulence. Also, tearing instability of the thin current sheet was proposed as a driver of resistivity-independent reconnection, which was shown to be consistent with two-dimensional simulati...

Beresnyak, Andrey

2013-01-01T23:59:59.000Z

252

Electrochemical Performance and Stability of the Cathode for Solid Oxide Fuel Cells. I. Cross Validation of Polarization Measurements by Impedance Spectroscopy and Current-Potential Sweep  

DOE Green Energy (OSTI)

The aim of this paper is to address three issues in solid oxide fuel cells: (1) cross-validation of the polarization of a single cell measured using both dc and ac approaches, (2) the precise determination of the total areal specific resistance (ASR), and (3) understanding cathode polarization with LSCF cathodes. The ASR of a solid oxide fuel cell is a dynamic property, meaning that it changes with current density. The ASR measured using ac impedance spectroscopy (low frequency interception with real Z´ axis of ac impedance spectrum) matches with that measured from a dc IV sweep (the tangent of dc i-V curve). Due to the dynamic nature of ASR, we found that an ac impedance spectrum measured under open circuit voltage or on a half cell may not represent cathode performance under real operating conditions, particularly at high current density. In this work, the electrode polarization was governed by the cathode activation polarization; the anode contribution was negligible.

Zhou, Xiao Dong; Pederson, Larry R.; Templeton, Jared W.; Stevenson, Jeffry W.

2009-12-09T23:59:59.000Z

253

Preparation of Small Well Characterized Plutonium Oxide Reference Materials and Demonstration of the Usefulness of Such Materials for Nondestructive Analysis  

Science Conference Proceedings (OSTI)

Calibration of neutron coincidence and multiplicity counters for passive nondestructive analysis (NDA) of plutonium requires knowledge of the detector efficiency parameters. These are most often determined empirically. Bias from multiplication and unknown impurities may be incurred even with small plutonium metal samples. Five sets of small, pure plutonium metal standards prepared with well-known geometry and very low levels of impurities now contribute to determining accurate multiplication corrections. Recent measurements of these metal standards, with small but well-defined multiplication and negligible yield of other than fission neutrons, demonstrate an improved characterization and calibration of neutron coincidence/multiplicity counters. The precise knowledge of the mass and isotopic composition of each standard also contributes significantly to verifying the accuracy of the most precise calorimetry and gamma-ray spectroscopy measurements.

B.A. Guillen; S.T. Hsue; J.Y Huang; P.A. Hypes; S.M. Long; C.R. Rudy; P.A. Russo; J.E. Stewart; D.J. Temer

2003-01-01T23:59:59.000Z

254

Approximate mechanism for measuring stability of Internet link in aggregated Internet pipe  

E-Print Network (OSTI)

In this article we propose a method for measuring internet connection stability which is fast and has negligible overhead for the process of its complexity. This method finds a relative value for representing the stability of internet connections and can also be extended for aggregated internet connections. The method is documented with help of a real time implementation and results are shared. This proposed measurement scheme uses HTTP GET method for each connections. The normalized responses to identified sites like gateways of ISPs, google.com etc are used for calculating current link stability. The novelty of the approach is that historic values are used to calculate overall link stability. In this discussion, we also document a method to use the calculated values as a dynamic threshold metric. This is used in routing decisions and for load-balancing each of the connections in an aggregated bandwidth pipe. This scheme is a very popular practice in aggregated internet connections.

M, Vipin

2009-01-01T23:59:59.000Z

255

Matter Wave Interferometry of a Levitated Thermal Nano-Oscillator Induced and Probed by a Spin  

E-Print Network (OSTI)

We show how the interference between spatially separated states of the center of mass of a mesoscopic harmonic oscillator can be evidenced by coupling it to a spin and performing solely spin manipulations and measurements (Ramsey Interferometry). We propose to use an optically levitated diamond bead containing an NV center spin. The nano-scale size of the bead makes the motional decoherence due to levitation negligible. The form of the spin-motion coupling ensures that the scheme works for thermal states so that moderate feedback cooling suffices. No separate control or observation of the center of mass state is required and thereby one also dispenses with cavities, spatially resolved detection and low mass-dispersion ensembles. The controllable relative phase in the Ramsey interferometry stems from a gravitational potential difference so that it uniquely evidences coherence between spatially separated states of the center of mass of a massive object.

M. Scala; M. S. Kim; G. W. Morley; P. F. Barker; S. Bose

2013-06-27T23:59:59.000Z

256

Solar production of industrial process steam for the Lone Star Brewery. Conceptual design report  

DOE Green Energy (OSTI)

The project conceptual design activities are divided into six parts: Industrial Plant, Conceptual System Design, Collector Selection, Heat Transfer Fluid Selection, Site Fabrication, and Engineered Equipment. Included is an overview of the solar steam system and a brief discussion on the environmental impact of the project as well as the safety considerations of the system design. The effect of the solar system on the environment is negligible, and the safety analysis of the system indicates the considerations to be taken to minimize any potential safety hazard due to contamination of the food product or to fire. Both of these potential hazards are discussed in detail. Both the question of product contamination and the question of potential fire hazards will be presented to the industrial partner's safety committee so that the selection of the heat transfer fluid meets with their approval.

Deffenbaugh, D.M.

1978-12-29T23:59:59.000Z

257

Anisotropy in the Interaction of Ultracold Dysprosium  

E-Print Network (OSTI)

The nature of the interaction between ultracold atoms with a large orbital and spin angular momentum has attracted considerable attention. It was suggested that such interactions can lead to the realization of exotic states of highly correlated matter. Here, we report on a theoretical study of the competing anisotropic dispersion, magnetic dipole-dipole, and electric quadrupole-quadrupole forces between two dysprosium atoms. Each dysprosium atom has an orbital angular momentum L=6 and magnetic moment $\\mu=10\\mu_B$. We show that the dispersion coefficients of the ground state adiabatic potentials lie between 1865 a.u. and 1890 a.u., creating a non-negligible anisotropy with a spread of 25 a.u. and that the electric quadrupole-quadrupole interaction is weak compared to the other interactions. We also find that for interatomic separations $Rrates that are the same order of magnitude as the experimental value.

Svetlana Kotochigova; Alexander Petrov

2011-04-28T23:59:59.000Z

258

Electrical conductivity of quark matter at finite T  

E-Print Network (OSTI)

In this talk, I present the recent theoretical results on the electrical conductivity (EC) sigma of quark matter, using the Kubo formula at finite temperature and zero quark density (T>0, mu=0) in the presence of an external strong magnetic field. The dilute instanton-liquid model with the caloron distribution is taken into account. It turns out that sigma=(0.02~0.15)/fm for T=(0~400) MeV with the relaxation time tau=(0.3~0.9) fm. EC is parameterized as sigma/T (0.46,0.77,1.08,1.39)C_EM for tau=(0.3,0.5,0.7,0.9) fm, respectively. These results are well compatible with other theoretical estimations and show almost negligible effects from the magnetic field. The soft photon emission rate from the quark-gluon plasma is discussed as well.

Seung-il Nam

2012-10-30T23:59:59.000Z

259

Municipal Aggregation and Retail Competition in the Ohio Energy Sector  

E-Print Network (OSTI)

Ohio allows communities to vote to aggregate the loads of individual consumers (unless they opt out) in order to seek a competitive energy supplier. Over 200 communities have voted to do this for electricity. By 2004 residential switching reached 69 % in Cleveland territory (95 % from municipal aggregation) but by 2006 had fallen to 8%. Savings are now small, but customer acquisition costs are low and the cost to consumers is negligible. Aggregation and retail competition have been thwarted by Rate Stabilization Plans holding incumbent utility prices below cost since 2006. In the Ohio gas sector, rate regulation has not discouraged aggregation and competition, but market prices falling below municipally negotiated rates can be politically embarrassing. How municipal aggregation would fare against individual choice in a market conducive to retail competition is an open question, but the policy deserves consideration elsewhere.

Stephen Littlechild; Stephen Littlechild

2007-01-01T23:59:59.000Z

260

An Independent Derivation of the Oxford Jet Kinetic Luminosity Formula  

E-Print Network (OSTI)

This letter presents a theoretical derivation of an estimate for a radio source jet kinetic luminosity. The expression yields jet powers that are quantitatively similar to a more sophisticated empirical relation published by the Willott, Blundell and Rawlings at Oxford. The formula allows one to estimate the jet kinetic luminosity from the measurement of the optically thin radio lobe emission in quasars and radio galaxies. Motivated by recent X-ray observation, the derivation assumes that most of the energy in the lobes is in plasma thermal energy with a negligible contribution from magnetic energy (not equipartition). The close agreement of the two independent expressions makes the veracity of these estimates seem very plausible.

Brian Punsly

2005-03-11T23:59:59.000Z

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261

Primary electron transfer in photosynthetic reaction centers  

Science Conference Proceedings (OSTI)

A simple model is presented for the primary step in the photoinduced electron transfer in the photosynthetic reaction centers of Rps. viridis and Rb. sphaeroides. The interaction of the chromophore system (consisting of photoexcited donor P, conduction intermediate B{sub L}, and acceptor H{sub L}) with the environment is assumed to be negligible until vibronic deexcitation takes place resulting in a stochastically perturbed adiabatic electron transfer. This process constitutes a three-level problem. It is shown that this problem, in the present case, can be approximated by a two-level problem which can simple be solved. The unidirectionality of the electron flow is explained by coincidence of energy levels in the L branch due to evolutionary constraint.

Kitzing, E.V.; Kuhn, H. (Max-Planck-Institut fuer Biophysikalische Chemie, Goettingen (Germany, F.R.))

1990-02-22T23:59:59.000Z

262

Energy Saving with Absorption Refrigeration Technologies  

E-Print Network (OSTI)

Absorption refrigeration technology can be an economical and cost effective means of reducing energy cost and/or improving the efficiency and output of your process. We believe the potential benefits of absorption refrigeration technology have generally been overlooked by the process industry. This paper will address the application of the lithium bromide-water cycle in various energy saving modes. A waste heat powered absorption chiller producing chilled water can reduce energy consumption in a process plant by replacing an existing mechanical refrigeration system or replacing cooling tower water with a lower temperature cooling medium at negligible increase in energy cost. A variety of waste heat sources can be used at temperatures as low as 150 F.

Davis, R. C.

1984-01-01T23:59:59.000Z

263

Conjectured explanation for room-temperature superconductivity in narrow channels in oxidized polypropylene  

SciTech Connect

Two groups of scientists have observed conductivity at least five orders of magnitude higher than that of copper at room temperature in narrow channels perpendicular to surfaces of films in oxidized polypropylene. For pulsed currents, this conductivity starts at a minimum value of applied current, and is destroyed at a current of about 30-60 times this value. Because of the existence of an upper critical current and of the observation that electronic thermal conductivity is negligible in the channels, it is thought that the channels are superconducting. A study is made of the hypothesis that these results are due to enhanced pairing, as first suggested by Parameter, when the drift velocity of current carriers becomes close to the velocity of sound or, in work by Hone and by the present author, to an appropriate phase velocity of optical phonons. Such enhancements can be expected to be larger in quasi-one-dimensional systems. 10 refs.

Eagles, D.M. (NASA Marshall Space Flight Center, Huntsville, AL (United States))

1994-06-01T23:59:59.000Z

264

Performance of An Adjustable Strength Permanent Magnet Quadrupole  

SciTech Connect

An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; /STI Optronics, Bellevue; Spencer, C.M.; /SLAC; Volk, J.T.; /Fermilab

2006-03-01T23:59:59.000Z

265

Photoelectron emission from LiF surfaces by ultrashort electromagnetic pulses  

Science Conference Proceedings (OSTI)

Energy- and angle-resolved electron emission spectra produced by incidence of ultrashort electromagnetic pulses on a LiF(001) surface are studied by employing a distorted-wave method named the crystal surface-Volkov (CSV) approximation. The theory makes use of the Volkov phase to describe the action of the external electric field on the emitted electron, while the electron-surface interaction is represented within the tight-binding model. The CSV approach is applied to investigate the effects introduced by the crystal lattice when the electric field is oriented parallel to the surface plane. These effects are essentially governed by the vector potential of the external field, while the influence of the crystal orientation was found to be negligible.

Acuna, M. A. [Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Universidad de Buenos Aires, Buenos Aires (Argentina); Gravielle, M. S. [Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Universidad de Buenos Aires, Buenos Aires (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

2011-03-15T23:59:59.000Z

266

LIMB-DARKENED RADIATION-DRIVEN WINDS FROM MASSIVE STARS  

SciTech Connect

We calculated the influence of the limb-darkened finite-disk correction factor in the theory of radiation-driven winds from massive stars. We solved the one-dimensional m-CAK hydrodynamical equation of rotating radiation-driven winds for all three known solutions, i.e., fast, {Omega}-slow, and {delta}-slow. We found that for the fast solution, the mass-loss rate is increased by a factor of {approx}10%, while the terminal velocity is reduced about 10%, when compared with the solution using a finite-disk correction factor from a uniformly bright star. For the other two slow solutions, the changes are almost negligible. Although we found that the limb darkening has no effects on the wind-momentum-luminosity relationship, it would affect the calculation of synthetic line profiles and the derivation of accurate wind parameters.

Cure, M. [Departamento de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Casilla 5030, Valparaiso (Chile); Cidale, L. [Departamento de Espectroscopia, Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata (UNLP), Paseo del Bosque S/N, 1900 La Plata (Argentina); Rial, D. F., E-mail: michel.cure@uv.cl, E-mail: lydia@fcaglp.unlp.edu.ar, E-mail: drial@dm.uba.ar [Departamento de Matematicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

2012-10-01T23:59:59.000Z

267

Tensile tests of niobium material for SRF cavities  

DOE Green Energy (OSTI)

Mechanical tests of cavity-grade niobium samples were conducted to provide engineering information for the certification of 3rd-harmonic superconducting radio-frequency cavities and cryomodules. Large changes of mechanical properties occur throughout the cavity fabrication process due to the cold work introduced by forming, the heating introduced by electron beam welding, and the recovery of cold work during the anneal used to degas hydrogen after chemical processing. Data is provided here to show the different properties at various stages of fabrication, including both weld regions and samples from the bulk niobium far away from the weld. Measurements of RRR were used to assure that any contamination during annealing was negligible.

Wu, G.; Dhanaraj, N.; Cooley, L.; Hicks, D.; Hahn, E.; Burk, D.; Muranyi, W.; Foley, N.; Edwards, H.; Harms, E.; Champion, M.; /Fermilab /Michigan State U.

2009-06-01T23:59:59.000Z

268

Gas evolution from cathode materials: A pathway to solvent decomposition concomitant to SEI formation.  

SciTech Connect

This work reports a method to explore the catalytic reactivity of electrode surfaces towards the decomposition of carbonate solvents [ethylene carbonate (EC), dimethyl carbonate (DMC), and EC/DMC]. We show that the decomposition of a 1:1 wt% EC/DMC mixture is accelerated over certain commercially available LiCoO2 materials resulting in the formation of CO2 while over pure EC or DMC the reaction is much slower or negligible. The solubility of the produced CO2 in carbonate solvents is high (0.025 grams/mL) which masks the effect of electrolyte decomposition during storage or use. The origin of this decomposition is not clear but it is expected to be present on other cathode materials and may affect the analysis of SEI products as well as the safety of Li-ion batteries.

Browning, Katie L [ORNL; Baggetto, Loic [ORNL; Unocic, Raymond R [ORNL; Dudney, Nancy J [ORNL; Veith, Gabriel M [ORNL

2013-01-01T23:59:59.000Z

269

Optimization of high-temperature superconductor current leads  

SciTech Connect

Methods to improve the performance of high-temperature superconducting current leads are analyzed. Designs are considered that are inherently safe from burnup, even if the lead enters the normal state. The effect of a tapered lead that takes advantage of the increase in critical current density with decreasing temperature will decrease helium boiloff by about a factor of two for an area ratio of four. A new concept, in which Ag powder is distributed in increasing concentration from the cold end to the hot end of the lead in sintered YBCO, is shown to have comparable performance to that of leads made with Ag-alloy sheaths. Performance of the best inherently safe designs is about one order of magnitude better than that of optimized nonsuperconducting leads. BSCCO leads with Ag-alloy sheaths show improved performance for Au fractions up to about 3%, after which increases in Au fraction yield negligible performance improvement.

Seol, S.Y. [Chonnam National Univ., Kwangju (Korea, Democratic People`s Republic of); Hull, J.R. [Argonne National Lab., IL (United States); Chyu, M.C. [Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering

1995-02-01T23:59:59.000Z

270

Attainable entanglement of unitary transformed thermal states in liquid-state nuclear magnetic resonance with the chemical shift  

E-Print Network (OSTI)

Recently, Yu, Brown, and Chuang [Phys. Rev. A {\\bf 71}, 032341 (2005)] investigated the entanglement attainable from unitary transformed thermal states in liquid-state nuclear magnetic resonance (NMR). Their research gave an insight into the role of the entanglement in a liquid-state NMR quantum computer. Moreover, they attempted to reveal the role of mixed-state entanglement in quantum computing. However, they assumed that the Zeeman energy of each nuclear spin which corresponds to a qubit takes a common value for all; there is no chemical shift. In this paper, we research a model with the chemical shifts and analytically derive the physical parameter region where unitary transformed thermal states are entangled, by the positive partial transposition (PPT) criterion with respect to any bipartition. We examine the effect of the chemical shifts on the boundary between the separability and the nonseparability, and find it is negligible.

Yukihiro Ota; Shuji Mikami; Motoyuki Yoshida; Ichiro Ohba

2006-12-19T23:59:59.000Z

271

Hydrogen in titanium alloys  

DOE Green Energy (OSTI)

The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 500/sup 0/C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 150/sup 0/C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement.

Wille, G.W.; Davis, J.W.

1981-04-01T23:59:59.000Z

272

Timescape cosmology with radiation fluid  

E-Print Network (OSTI)

The timescape cosmology represents a potentially viable alternative to the standard homogeneous cosmology, without the need for dark energy. Although average cosmic evolution in the timescape scenario only differs substantially from that of Friedmann-Lemaitre model at relatively late epochs when the contribution from the energy density of radiation is negligible, a full solution of the Buchert equations to incorporate radiation is necessary to smoothly match parameters to the epoch of photon decoupling and to obtain constraints from cosmic microwave background data. Here we extend the matter-dominated solution found in earlier work to include radiation, providing series solutions at early times and an efficient numerical integration strategy for generating the complete solution. The numerical solution is used to directly calculate the scale of the sound horizon at decoupling, and at the baryon drag epoch. The constraints on these scales from the Planck satellite data yield bounds on the timescape cosmological...

Duley, James A G; Wiltshire, David L

2013-01-01T23:59:59.000Z

273

SNG completes deepest underwater pipelay in Gulf of Mexico  

SciTech Connect

This paper reports that gas began flowing this spring in the deepest underwater, large-diameter pipeline in the U.S. Gulf of Mexico. Water depth along the route of the pipeline varies from approximately 460 ft at the Alabaster platform, increasing to the record depth of 1,220 ft in the Mississippi Canyon area, and decreasing to negligible water depth at the landfall site southwest of Venice. The SNG Mississippi Canyon Block 397 pipeline project exemplifies how a pipeline project can encounter an array of conditions which prompt special design considerations and installation techniques. Important considerations for this project were related to pipe properties, anti-corrosion and weight coatings, span and buckle considerations, and installation equipment. A team effort was used to study, research, test, design, and install this pipeline.

Vogt, G.B. (Project Consulting Services Inc., Metairie, LA (US))

1992-08-24T23:59:59.000Z

274

Minimization of investment costs and the effect on economy and availability of coal-fired power plants  

Science Conference Proceedings (OSTI)

Low manufacturing costs and short construction periods are two factors with a major influence on the economy of power plants. This paper identifies, on the basis of a power plant design concept actually developed, potential plant cost savings at the concept design and component design levels and the sometimes contradictory implications to be considered and attempts to assess the impact of these savings on plant economy and availability. By comparison with a conventionally constructed plant, the cost savings that can be achieved over the entire plant, including erection costs, total just on 15 percent. The construction period can be reduced by about 20%. The simplifications implemented in this design concept with a view to minimizing plant costs are expected to entail only a negligible reduction in plant availability, so that this type of power plant retains its overall economic lead.

Hebel, G.; Hauenschild, R. (ABB Kraftwerke AG, Mannheim (DE))

1990-01-01T23:59:59.000Z

275

Dynamics of digging in wet soil  

E-Print Network (OSTI)

Numerous animals live in, and locomote through, subsea soils. To move in a medium dominated by frictional interactions, many of these animals have adopted unique burrowing strategies. This paper presents a burrowing model inspired by the Atlantic razor clam ({\\it Ensis directus}), which uses deformations of its body to cyclically loosen and re-pack the surrounding soil in order to locally manipulate burrowing drag. The model reveals how an anisotropic body -- composed of a cylinder and sphere varying sinusoidally in size and relative displacement -- achieves unidirectional motion through a medium with variable frictional properties. This net displacement is attained even though the body kinematics are reciprocal and inertia of both the model organism and the surrounding medium are negligible. Our results indicate that body aspect ratio has a strong effect on burrowing velocity and efficiency, with a well-defined maximum for given kinematics and soil material properties.

Jung, Sunghwan; Hosoi, A E

2010-01-01T23:59:59.000Z

276

A SUSY GUT of Flavour with S4 x SU(5) to NLO  

E-Print Network (OSTI)

We construct a Supersymmetric (SUSY) Grand Unified Theory (GUT) of Flavour based on S4 x SU(5), together with an additional (global or local) Abelian symmetry, and study it to next-to-leading order (NLO) accuracy. The model includes a successful description of quark and lepton masses and mixing angles at leading order (LO) incorporating the Gatto-Sartori-Tonin (GST) relation and the Georgi-Jarlskog (GJ) relations. We study the vacuum alignment arising from F-terms to NLO and such corrections are shown to have a negligible effect on the results for fermion masses and mixings achieved at LO. Tri-bimaximal (TB) mixing in the neutrino sector is predicted very accurately up to NLO corrections of order 0.1%. Including charged lepton mixing corrections implies small deviations from TB mixing described by a precise sum rule, accurately maximal atmospheric mixing and a reactor mixing angle close to three degrees.

Claudia Hagedorn; Stephen F. King; Christoph Luhn

2010-03-22T23:59:59.000Z

277

A SUSY GUT of Flavour with S4 x SU(5) to NLO  

E-Print Network (OSTI)

We construct a realistic Supersymmetric (SUSY) Grand Unified Theory (GUT) of Flavour based on S4 x SU(5), together with an additional (global or local) Abelian symmetry, and study it to next-to-leading order (NLO) accuracy. The model includes a successful description of quark and lepton masses and mixing angles at leading order (LO) incorporating the Gatto-Sartori-Tonin (GST) relation and the Georgi-Jarlskog (GJ) relations. We study the vacuum alignment arising from F-terms to NLO and such corrections are shown to have a negligible effect on the results for fermion masses and mixings achieved at LO. Tri-bimaximal (TB) mixing in the neutrino sector is predicted very accurately up to NLO corrections of order 0.1%. Including charged lepton mixing corrections implies small deviations from TB mixing described by a precise sum rule, accurately maximal atmospheric mixing and a reactor mixing angle close to three degrees.

Hagedorn, Claudia; Luhn, Christoph

2010-01-01T23:59:59.000Z

278

I; FAST PARALLEL PIPELINED READOUT ARCHITECTURE FOR A COMPLETELY FLASH DIGITIZING SYSTEM WITH MULTI-LEVEL TRIGGER  

E-Print Network (OSTI)

We have built, and used to take physics data, a digitizing and readout system for Brookhaven AGS Experiment 791, a high-rate search for rare kaon decays. All digitization- of charge and time information is “flash ” (performed in less than 200 ns), followed by front-end buffering and a pipelined readout with massive parallelism. A data transfer rate of-- 0.5- Gigabytelsec into dual-port memories in eight 3081-emulating processors has been achieved. A readout-supervising circuit coordinates the three levels of event triggering and the movement of data throughout the system. The host Micro-VAX is interrupted only for the uploading of packets of fully filtered events from the 3081/E’s, Digitizing and data transfer from the front end to the 3081/E’s contribute negligible deadtime to the experiment.

_ Robert D. Cousins; Jacob Konigsberg; Jonathan Kubic; Philip L. Mel; Gregory W. Hart; W& n R. Molzonq; George M. Irwin; Dale A. Ouimette B; Jack L. Ritchiec; Quang H. Trang; Robert J. Whyleyd

1988-01-01T23:59:59.000Z

279

X-ray photoelectron spectroscopy studies on Pd doped SnO{sub 2} liquid petroleum gas sensor  

Science Conference Proceedings (OSTI)

The present investigation deals with the electrical response of palladium doped tin oxide, as a means of improving the selectivity for liquid petroleum gas (LPG) in the presence of CO, CH{sub 4}. The sensor element with the composition of Pd(1.5 wt{percent}) in the base material SnO{sub 2} sintered at 800{degree}C, has shown a high sensitivity towards LPG with a negligible cross interference of CO and CH{sub 4} at an operating temperature of 350{degree}C. This greatly suggests the possibility of utilizing the sensor for the detection of LPG. X-ray photoelectron spectroscopy studies have been carried out to determine the possible chemical species involved in the gas-solid interaction and the enhancing mechanism of the Pd doped SnO{sub 2} sensor element, towards LPG sensitivity. {copyright} {ital 1997 American Institute of Physics.}

Phani, A.R. [Department of Physics, University of LAquila, 67040, LAquila (Italy)

1997-10-01T23:59:59.000Z

280

Electron acceleration by a tightly focused Hermite-Gaussian beam: higher-order corrections  

SciTech Connect

Taking the TEM{sub 1,0}-mode Hermite-Gaussian (H-G) beam as a numerical calculation example, and based on the method of the perturbation series expansion, the higher-order field corrections of H-G beams are derived and used to study the electron acceleration by a tightly focused H-G beam in vacuum. For the case of the off-axis injection the field corrections to the terms of order f{sup 3} (f=1/kw{sub 0}, k and w{sub 0} being the wavenumber and waist width, respectively) are considered, and for the case of the on-axis injection the contributions of the terms of higher orders are negligible. By a suitable optimization of injection parameters the energy gain in the giga-electron-volt regime can be achieved.

Zhao Zhiguo [Department of Physics, Luoyang Normal College, Luoyang 471022 (China); Institute of Laser Physics and Chemistry, Sichuan University, Chengdu 610064 (China); Yang Dangxiao; Lue Baida [Institute of Laser Physics and Chemistry, Sichuan University, Chengdu 610064 (China)

2008-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

String spectra near some null cosmological singularities  

Science Conference Proceedings (OSTI)

We construct cosmological spacetimes with null Kasner-like singularities as purely gravitational solutions with no other background fields turned on. These can be recast as anisotropic plane-wave spacetimes by coordinate transformations. We analyze string quantization to find the spectrum of string modes in these backgrounds. The classical string modes can be solved for exactly in these time-dependent backgrounds, which enables a detailed study of the near-singularity string spectrum, (time-dependent) oscillator masses, and wave functions. We find that for low-lying string modes (finite oscillation number), the classical near-singularity string mode functions are nondivergent for various families of singularities. Furthermore, for any infinitesimal regularization of the vicinity of the singularity, we find a tower of string modes of ultrahigh oscillation number which propagate essentially freely in the background. The resulting picture suggests that string interactions are non-negligible near the singularity.

Madhu, Kallingalthodi [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Narayan, K. [Chennai Mathematical Institute, SIPCOT IT Park, Padur PO, Siruseri 603103 (India)

2009-06-15T23:59:59.000Z

282

Quantum String Seal Is Insecure  

E-Print Network (OSTI)

A quantum string seal encodes the value of a (bit) string as a quantum state in such a way that everyone can extract a non-negligible amount of available information on the string by a suitable measurement. Moreover, such measurement must disturb the quantum state and is likely to be detected by an authorized verifier. In this way, the intactness of the encoded quantum state plays the role of a wax seal in the digital world. Here I analyze the security of quantum string seal by studying the information disturbance tradeoff of a measurement. This information disturbance tradeoff analysis extends the earlier results of Bechmann-Pasquinucci et al. and Chau by concluding that all quantum string seals are insecure. Specifically, I find a way to obtain non-trivial available information on the string that escapes the verifier's detection with at least 50% chance.

H. F. Chau

2006-02-13T23:59:59.000Z

283

Gauge coupling unification in heterotic string models with gauge mediated supersymmetry breaking  

Science Conference Proceedings (OSTI)

We calculate the weak scale minimal supersymmetric standard model spectrum starting from a heterotic string theory compactified on an anisotropic orbifold. Supersymmetry breaking is mediated by vectorlike exotics that arise naturally in heterotic string theories. The messengers that mediate supersymmetry breaking come in incomplete grand unified theory (GUT) multiplets and give rise to nonuniversal gaugino masses at the GUT scale. Models with nonuniversal gaugino masses at the GUT scale have the attractive feature of allowing for precision gauge coupling unification at the GUT scale with negligible contributions from threshold corrections near the unification scale. The unique features of this minimally supersymmetric standard model spectrum are light gluinos and also large mass differences between the lightest and the next-to-lightest neutralinos and charginos which could lead to interesting signatures at the colliders.

Anandakrishnan, Archana; Raby, Stuart [Department of Physics, Ohio State University, 191, W. Woodruff Ave, Columbus, Ohio 43210 (United States)

2011-04-01T23:59:59.000Z

284

Propagation of nonlinear dust magnetoacoustic waves in cylindrical geometry  

SciTech Connect

The cylindrical dust magnetoacoustic shocks in dissipative and solitons in non-dissipative dust-ion plasmas are studied. The dust particles are assumed to be fully negatively charged so that the density of electrons in comparison with dust and ions is negligible. The cylindrical Korteweg-de Vries Burgers and cylindrical Korteweg-de Vries equations are derived for dust magnetosonic waves by employing the reductive perturbation method. It is found that dust plasma parameters such as dust charge number, dust density, and ion temperature have strong influence on the profile of dust magnetoacoustic shocks and solitons. The results are also obtained numerically by using the data from laboratory experiments on dusty plasmas.

Hussain, S.; Mahmood, S. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan) and Department of Physics and Applied Physics (DPAM), PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan)

2011-12-15T23:59:59.000Z

285

Leakage-Aware Reallocation for Periodic Real-Time Tasks on Multicore Processors  

E-Print Network (OSTI)

It is an increasingly important issue to reduce the energy consumption of computing systems. In this paper, we consider partition based energy-aware scheduling of periodic real-time tasks on multicore processors. The scheduling exploits dynamic voltage scaling (DVS) and core sleep scheduling to reduce both dynamic and leakage energy consumption. If the overhead of core state switching is non-negligible, however, the performance of this scheduling strategy in terms of energy efficiency might degrade. To achieve further energy saving, we extend the static task scheduling with run-time task reallocation. The basic idea is to aggregate idle time among cores so that as many cores as possible could be put into sleep in a way that the overall energy consumption is reduced. Simulation results show that the proposed approach results in up to 20% energy saving over traditional leakage-aware DVS.

Huang, Hongtao; Wang, Jijie; Lei, Siyu; Wu, Guowei

2010-01-01T23:59:59.000Z

286

K0 meson physics in the gravitation field: a constraint on the equivalence principle  

E-Print Network (OSTI)

K0-K0bar oscillations are extremely sensitive to the K0 and K0bar energy at rest. Even assuming m_K0=m_K0bar, the energy is not granted to be the same if gravitational effects on K0 and K0bar slightly differ. We consider various gravitation fields present and, in particular, galactic fields, which provide a negligible acceleration, but relatively large gravitational potential energy. A constraint from a possible effect of this potential energy on the kaon oscillations isfound to be |(m_g/m_i)_K0-(m_g/m_i)_K0bar| < 8 x 10^-13 atCL=90%. The derived constraint is competitive with other tests of universality of the free fall. Other applications are also discussed.

Karshenboim, Savely G

2008-01-01T23:59:59.000Z

287

Evaluation of the effects of detonation in a spherical bomb. [PWR; BWR  

DOE Green Energy (OSTI)

An analysis is presented of the time-dependent pressure forces and impulse loadings on the walls of the hemispherical dome of a nuclear reactor pressure vessel arising from a centrally ignited hydrogen-oxygen detonation. Investigated in this context are the effects of richness of the detonable gas mixture as well as those due to the inclusion of water vapor. In the analysis the gas mixture was treated as a perfect gas, and the partial differential equations governing the gasdynamic flow were integrated using the CLOUD CODE - a finite-difference technique set in Lagrangian coordinates and incorporating the smoothing action of artificial viscosity. The most interesting results pertain to the ringing of pressure pulses at the walls. Their frequency is quite uniform, and their pressure peaks, at levels significantly higher than that of combustion at constant volume, decay at a negligible rate.

Kurylo, J.; Oppenheim, A.K.

1979-11-01T23:59:59.000Z

288

EVALUATION OF MILITARY INDIVIDUAL AND COLLECTIVE PROTECTION DEVICES AND CLOTHING  

SciTech Connect

Under conditions resulting from surface and underground detonations of atomic bombs, tests were conducted on Chemical Corps impregnated and unimpregnated protective clothing, Individual Protective Mask M9A1 with M11 Canister, Tank Collective Protector E26 and E22, and Protective Ointment M5. Both impregnated and unimpregnated clothing were capable of preventing contact between the skin and radioactive dusts. Unimpregnated clothing demonstrated better contanmination-decontamination characteristics, but the secondary radiation from all clothing was negligible. The protective cover was effective in preventing contamination of clothing. The M9A1 mask with M11 canister furnished complete protection against inhalation of radioactive dust. The flltering efficiencies of the E26 tank collective protectors were found to be very high, and no deficiencies were found in the unit. The filtering efficiencies of the E22 tank collective protectors were also high. Panels coated with M5 ointment were found to be much more highly contaminated than bare panels. (auth)

Hendrickson, J.R.

1952-07-01T23:59:59.000Z

289

The SuperCDMS Experiment  

SciTech Connect

Modest improvements in the level and/or discrimination of backgrounds are needed to keep backgrounds negligible during the three phases of SuperCDMS. By developing production designs that require only modest testing, detector production rates may be improved sufficiently to allow an exposure of 500 ton d within a reasonable time and budget. Overall, the improvement estimates described above are conservative. Previous development efforts have shown that some areas prove easier and provide larger factors while others prove more difficult. The conservative estimates together with the broad approach reduce the risk and give us confidence that we will succeed, providing the surest way to probe to WIMP-nucleon cross sections of 10{sup -46} cm{sup 2}.

Schnee, Richard W.; Akerib, D.S.; Attisha, M.J.; Bailey, C.N.; Baudis, L.; Bauer, Daniel A.; Brink, P.L.; Brusov, P.P.; Bunker, R.; Cabrera, B.; Caldwell, D.O.; Chang, C.L.; Cooley, J.; Crisler, M.B.; Cushman, P.; Denes, P.; Dragowsky, M.R.; Duong, L.; Filippini, J.; Gaitskell, R.J.; Golwala, S.R.; /Case Western Reserve U. /Brown U. /Florida U. /Fermilab /Stanford U., Phys. Dept. /UC, Santa Barbara /Minnesota U. /LBL, Berkeley /UC, Berkeley /Caltech /Colorado U., Denver /NIST, Boulder /Santa Clara U.

2005-02-01T23:59:59.000Z

290

Water quality impacts from mining in the Black Hills, South Dakota, USA  

Science Conference Proceedings (OSTI)

The focus of this research was to determine if abandoned mines constitute a major environmental hazard in the Black Hills. Many abandoned gold mines in the Black Hills contribute acid and heavy metals to streams. In some areas of sulfide mineralization local impacts are severe, but in most areas the impacts are small because most ore deposits consist of small quartz veins with few sulfides. Pegmatite mines appear to have negligible effects on water due to the insoluble nature of pegmatite minerals. Uranium mines in the southern Black Hills contribute some radioactivity to surface water, but he impact is limited because of the dry climate and lack of runoff in that area. 26 refs.

Rahn, P.H.; Davis, A.D.; Webb, C.J. [South Dakota School of Mines and Technology, Rapid City, SD (United States)] [South Dakota School of Mines and Technology, Rapid City, SD (United States); Nichols, A.D. [Versar, Inc., Eden Prairie, MN (United States)] [Versar, Inc., Eden Prairie, MN (United States)

1996-02-01T23:59:59.000Z

291

Determining foreground contamination in cosmic microwavebackground observations: Diffuse Galactic emission in the MAXIMA-Ifield  

Science Conference Proceedings (OSTI)

Observations of the cosmic microwave background (CMB) can be contaminated by diffuse foreground emission from sources such as Galactic dust and synchrotron radiation. In these cases, the morphology of the contaminating source is known from observations at different frequencies, but not its amplitude at the frequency of interest for the CMB. We develop a technique for accounting for the effects of such emission in this case, and for simultaneously estimating the foreground amplitude in the CMB observations. We apply the technique to CMB data from the MAXIMA-1 experiment, using maps of Galactic dust emission from combinations of IRAS and DIRBE observations, as well as compilations of Galactic synchrotron emission observations. The spectrum of the dust emission over the 150-450 GHz observed by MAXIMA is consistent with preferred models, but the effect on CMB power spectrum observations is negligible.

Jaffe, A.H.; Balbi, A.; Bond, J.R.; Borrill, J.; Ferreira, P.G.; Finkbeiner, D.; Hanany, S.; Lee, A.T.; Rabii, B.; Richards, P.L.; Smoot,G.F.; Stompor, R.; Winant, C.D.; Wu, J.H.P.

2003-01-05T23:59:59.000Z

292

Subcritical Fission Reactor Based on Linear  

E-Print Network (OSTI)

The beams of Linear Collider after main collision can be utilized to build an accelerator–driven sub–critical reactor. ? The project of Linear Collider (LC) contains one essential element that is not present in other colliders. Here each electron (or positron or photon) bunch will be used only once, and physical collision leave two very dense and strongly collimated beams of high energy electrons or/and photons with precisely known time structure. We consider, for definiteness, electron beam parameters of the TESLA project [1] particle energy Ee = 250 GeV, number of electrons per second Ne = 2.7 · 10 14 /s, mean beam power Pb ? 11 MWt, transverse size and angular spread negligible. (1) In the Photon Collider mode the used beams contain photons, electrons and

I. F. Ginzburg

2005-01-01T23:59:59.000Z

293

The Effect of Uncertainty Principle on the Thermodynamics of Early Universe  

E-Print Network (OSTI)

We discuss the concept of measurement in cosmology from the relativistic and quantum mechanical points of view. The uncertainty principle within the particle horizon, excludes the momentum of particles to be less than $\\pi\\hbar H/c$. This effect modifies the standard thermodynamics of early universe for the ultra-relativistic particles such that the equation of state as well as dependence of energy density and pressure to the temperature. We show that this modification to the thermodynamics of early universe is important for energies $E>10^{17} GeV$. During the inflation, the particle horizon inflates to a huge size and makes the uncertainty in the momentum to be negligible.

S. Rahvar; M. Sadegh Movahed; M Saadat

2005-08-15T23:59:59.000Z

294

On Demand Paging Using  

E-Print Network (OSTI)

The power consumption of the network interface plays a major role in determining the total operating lifetime of wireless handheld devices. On demand paging has been proposed earlier to reduce power consumption in cellular networks. In this scheme, a low power secondary radio is used to wake up the higher power radio, allowing the latter to sleep or remain off for longer periods of time. In this paper we present use of Bluetooth radios to serve as a paging channel for the 802.11 wireless LAN. We have implemented an on-demand paging scheme on a WLAN consisting of iPAQ PDAs equipped with Bluetooth radios and Cisco Aironet wireless networking cards. Our results show power saving ranging from 19% to 46% over the present 802.11b standard operating modes with negligible impact on performance.

Bluetooth Radios On; Yuvraj Agarwal; Rajesh K. Gupta

2003-01-01T23:59:59.000Z

295

Use of the WECC WAMS in Wide Area Probing Tests for Validation of System Performance & Modeling  

Science Conference Proceedings (OSTI)

During 2005 and 2006 the Western Electricity Coordinating Council (WECC) performed three major tests of western system dynamics. These tests used a Wide Area Measurement System (WAMS) based primarily on Phasor Measurement Units (PMUs) to determine response to events including the insertion of the 1400-MW Chief Joseph braking resistor, probing signals, and ambient events. Test security was reinforced through real-time analysis of wide area effects, and high-quality data provided dynamic profiles for interarea modes across the entire western interconnection. The tests established that low-level optimized pseudo-random ±20-MW probing with the Pacific DC Intertie (PDCI) roughly doubles the apparent noise that is natural to the power system, providing sharp dynamic information with negligible interference to system operations. Such probing is an effective alternative to use of the 1400-MW Chief Joseph dynamic brake, and it is under consideration as a standard means for assessing dynamic security.

Hauer, John F.; Mittelstadt, William; Martin, Kenneth E.; Burns, J. W.; Lee, Harry; Pierre, John W.; Trudnowski, Daniel

2009-02-01T23:59:59.000Z

296

ACCRETION BY THE SECONDARY IN ETA CARINAE DURING THE SPECTROSCOPIC EVENT: I. FLOW PARAMETERS  

E-Print Network (OSTI)

We examine the influence of the gravity of the companion (the secondary) to the massive primary star ? Carinae on the winds blown by the primary and the secondary. The two winds collide with each other after passing through two respective shock waves, and escape the system while strongly emitting in the X-ray band. While during most of the 5.5 years orbital period, the companion’s gravity has a negligible effect on the winds, we find that near periastron, the companion’s gravity may significantly influence the flow and the companion might accrete from the primary’s wind under certain circumstances. Near periastron passage, the collision region of the two winds may collapse onto the secondary star, a process that could substantially reduce the X-ray luminosity. We suggest that such an accretion process produces the long, almost flat, X-ray minimum in ? Carinae.

Noam Soker

2008-01-01T23:59:59.000Z

297

Complete population transfer in a three-state quantum system by a train of pairs of coincident pulses  

E-Print Network (OSTI)

A technique for complete population transfer between the two end states $\\ket{1}$ and $\\ket{3}$ of a three-state quantum system with a train of $N$ pairs of resonant and coincident pump and Stokes pulses is introduced. A simple analytic formula is derived for the ratios of the pulse amplitudes in each pair for which the maximum transient population $P_2(t)$ of the middle state $\\ket{2}$ is minimized, $P_2^{\\max}=\\sin^2(\\pi/4N)$. It is remarkable that, even though the pulses are on exact resonance, $P_2(t)$ is damped to negligibly small values even for a small number of pulse pairs. The population dynamics resembles generalized $\\pi$-pulses for small $N$ and stimulated Raman adiabatic passage for large $N$ and therefore this technique can be viewed as a bridge between these well-known techniques.

Andon A. Rangelov; Nikolay V. Vitanov

2012-01-04T23:59:59.000Z

298

Rigorous theory of nuclear fusion rates in a plasma  

E-Print Network (OSTI)

Real-time thermal field theory is used to reveal the structure of plasma corrections to nuclear reactions. Previous results are recovered in a fashion that clarifies their nature, and new extensions are made. Brown and Yaffe have introduced the methods of effective quantum field theory into plasma physics. They are used here to treat the interesting limiting case of dilute but very highly charged particles reacting in a dilute, one-component plasma. The highly charged particles are very strongly coupled to this background plasma. The effective field theory proves that this mean field solution plus the one-loop term dominate; higher loop corrections are negligible even though the problem involves strong coupling. Such analytic results for very strong coupling are rarely available, and they can serve as benchmarks for testing computer models.

Lowell S. Brown; David C. Dooling; Dean L. Preston

2005-09-22T23:59:59.000Z

299

Geometry and heterogeneous effects on the neutronic performance of a Yin Yang mirror-reactor blanket  

SciTech Connect

From 5th symposium on engineering problems of fusion research; Princeton, New Jersey, USA (6 Nov 1973). Two-dimensional models and Monte Carlo neutron transport techniques were used to calculate the tritium breeding and energy generation in a mirror-reactor blanket. Results indicate that blanket performance should be quite insensitive to variations in overall geometry as long as there are no large neutron-leakage paths. Injection and leakage penetration can be accommodated as long as the first-wall peneiration area subtends less than 25% of the first wall's spherical area. Heterogeneous and streaming effects in a tubular blanket can be important, but are negligible for closely packed arrays of tubes. The one-dimensional homogeneous spherical-shell model appears to be a useful tool for predicting performance of a tubular blanket conforming to the YinYang mirror geometry. (auth)

Lee, J.D.

1973-10-17T23:59:59.000Z

300

INTERACTION BETWEEN PRISMATIC AND GLISSILE DISLOCATIONS  

SciTech Connect

A theoretical study is made of the interaction between moving dislocations and large point defect clusters in the form of Frank sessile loops and perfect prismatic loops. Long-range interactions are shown to be negligible. The contact interaction depends on the type and orientation of the loops relative to the glide plane and Burgers vector of the gliding dislocation. It is noted that perfect prismatic loops can interact with moving dislocations in four different ways, These cases are analyzed in detail. The interaction with a Frank sessile loop depends on its size. However, even loops possibly too small to be visible by transmission electron microscopy can form strong locking points on a moving dislocation. (auth)

Saada, G.; Washburn, J.

1962-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

International Journal of Engineering & Technology IJET-IJENS Vol: 11 No: 03 7 Co-combustion of Biosolids with Wood Pellets in a  

E-Print Network (OSTI)

Abstract- Co-combustion of biosolids with coal or other biomass fuel can play a significant role in combustion facilities for energy production and waste management policy context. This paper presents the results of an experimental study to investigate the use of biosolids for cocombustion with wood pellets in a wood pellet stove. Fuel property, gas emissions and stove efficiency are compared. In regard to fuel properties, proximate analysis, ultimate analysis and heating values are determined and emissions of carbon monoxide (CO), nitrogen oxides (NOx) and sulphur dioxide (SO2) are measured and compared. Pilot scale combustion tests revealed that cocombustion of 10 % biosolids with 90% wood pellets resulted in successful combustion without any significant degradation of efficiency and emissions. Nitrogen oxides (NOx) emissions were found to be proportional with the N2 content in the fuel. Sulphur dioxide (SO2) emissions were negligible. Index Terms- Biosolids, co-combustion, wood pellet stove, performance and emissions.

Wood Pellet Stove; Murari Mohon Roy; Animesh Dutta; Kenny Corscadden; Peter Havard

2011-01-01T23:59:59.000Z

302

Electrophoretic mobility without charge driven by spontaneous polarization of the nanoparticle/water interface  

E-Print Network (OSTI)

Polarization of the interface, spontaneously occurring when water is in contact with hydrophobic solutes or air, couples with the uniform external field to produce a non-zero force acting on a suspended particle. This force exists even in the absence of a net particle charge, and its direction is affected by the first-order, dipolar and the second-order, qudrupolar orientational order parameters of the interfacial water. The quadrupolar polarization gives rise to an effectively negative charge. The corresponding surface charge density is inversely proportional to the area of the shear surface. As a result, the overall contribution from the quadrupolar polarization to the particle mobility becomes negligible compared to experimentally reported values for particles exceeding a few nanometers in size. The dipolar order of the interface dominates the zero-charge mobility of sub-micron particles. The corresponding electrokinetic charge is determined by the preferential orientation of interfacial dipoles relative to the surface normal.

Dmitry V. Matyushov

2012-12-17T23:59:59.000Z

303

Transient heat and mass transfer in a drop experiencing absorption with internal circulation  

SciTech Connect

Absorption of gas and vapor into moving liquid droplet is frequently encountered in numerous applications in chemical industries and refrigeration technology. Here, transient heat and mass transfer associated with a moving liquid drop during absorption was numerically studied in this work. The roles played by the internal circulation inside the droplet and the exothermic heat effect were demonstrated. The numerical results reveal that the significant absorption enhancement by internal circulation becomes negligible with the increase of exothermic absorption heat. The highly exothermic system of LiBr/H{sub 2}O, which is used as a typical refrigerant/absorbent combination in commercial absorption heat pump (AHP), was selected as an example to illustrate this point.

Lu, H.H.; Wu, T.C.; Yang, Y.M.; Maa, J.R. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering] [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering

1998-11-01T23:59:59.000Z

304

PEAK READING VOLTMETER  

DOE Patents (OSTI)

An improvement in peak reading voltmeters is described, which provides for storing an electrical charge representative of the magnitude of a transient voltage pulse and thereafter measuring the stored charge, drawing oniy negligible energy from the storage element. The incoming voltage is rectified and stored in a condenser. The voltage of the capacitor is applied across a piezoelectric crystal between two parallel plates. Amy change in the voltage of the capacitor is reflected in a change in the dielectric constant of the crystal and the capacitance between a second pair of plates affixed to the crystal is altered. The latter capacitor forms part of the frequency determlning circuit of an oscillator and means is provided for indicating the frequency deviation which is a measure of the peak voltage applied to the voltmeter.

Dyer, A.L.

1958-07-29T23:59:59.000Z

305

Electroslag remelting with used fluxes  

Science Conference Proceedings (OSTI)

The Ukranian Scientific-Research Institute of Specialty Steel collaborated with plants engaged in the production of quality metals to introduce a low-waste electroslag remelting (ESR) technology employing used fluxes. It was established that the fluoride (type ANF-1) and fluoride-oxide (type ANF-6) fluxes which are widely used in ESR still have a high content of calcium fluoride and alumina and a low impurity content after 8-10 h of ESR. In the ESR of steels with used fluxes, the content of monitored components in the final slags changes negligibly, while the content of most impurities decreases. The used flux is also characterized by a low concentration of phosphorus and sulfur. It was found that flux can be used 3-5 times when it makes up 50% of the flux mixture in the charge. The savings realized from the use of spent flux in ESR amounts to 4-9 rubles/ton steel.

Yakovlev, N.F.; Sokha, Yu.S.; Oleinik, Yu.S.; Prokhorov, A.N.; Ol'shanskaya, T.V.

1988-05-01T23:59:59.000Z

306

Atomic Frequency standards Based on Pulsed Coherent Light Storage  

E-Print Network (OSTI)

We propose a new scheme of microwave frequency standards based on pulsed coherent optical information storage. Unlike the usual frequency reference where the Ramsey fringe is printed on the population of a certain state, we print the Ramsey fringe on the coherence. Then the coherence is detected in the form of a retrieval light. The central line of the Ramsey fringe can be used as a frequency reference in an absorption-cell-based atomic frequency standard. This scheme is free of light shifts as the interrogating process is separated from the optical pumping processes, and the cavity pulling effect is negligible due to the low Q requirement. Encoding the Ramsey interference into the retrieval light pulse has the merit of high signal to noise ratio and the estimated frequency stability of shot noise limit is about $2\\times10^{-14}$ in 1 second, this scheme is promising for building small, compact and stable atomic frequency standards.

Yan, Bo; Wang, Yuzhu

2008-01-01T23:59:59.000Z

307

Cr.sup.3+ -doped colquiriite solid state laser material  

DOE Patents (OSTI)

Chromium doped colquiriite, LiCaAlF.sub.6 :Cr.sup.3+, is useful as a tunable laser crystal that has a high intrinsic slope efficiency, comparable to or exceeding that of alexandrite, the current leading performer of vibronic sideband Cr.sup.3+ lasers. The laser output is tunable from at least 720 nm to 840 nm with a measured slop efficiency of about 60% in a Kr laser pumped laser configuration. The intrinsic slope efficiency (in the limit of large output coupling) may approach the quantum defect limited value of 83%. The high slope efficiency implies that excited state absorption (ESA) is negligible. The potential for efficiency and the tuning range of this material satisfy the requirements for a pump laser for a high density storage medium incorporating Nd.sup.3+ or Tm.sup.3+ for use in a multimegajoule single shot fusion research facility.

Payne, Stephen A. (Castro Valley, CA); Chase, Lloyd L. (Livermore, CA); Newkirk, Herbert W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

1989-01-01T23:59:59.000Z

308

The interphase power controller: A new concept for managing power flow within AC networks  

SciTech Connect

The paper presents a new concept for controlling the flow of power within AC networks. The application is based on the series connection of impedances between different phases of the two (synchronous) subnetworks to be interconnected, hence its name: the Interphase Power Controller (IPC). The IPC acts as a current source with the following characteristics: the power flow is nearly constant (within 10%) for a wide range ([+-]25[degree]) of angle between the two subnetworks; there is no significant short-circuit contribution from one network to the other; severe contingencies on one side of the IPC have negligible impact on the voltage of the other side; no harmonics are generated (because there is no control action). Other operating conditions (reduced power, reactive power generation or absorption) are possible by switching impedance components. In all cases, the IPC comprises only conventional elements (transformer, capacitors, reactors, and circuit breakers).

Brochu, J.; Pelletier, P.; Beauregard, F.; Morin, G. (Citeq, Varennes, Quebec (Canada))

1994-04-01T23:59:59.000Z

309

Modulated active charge exchange fast ion diagnostic for the C-2 field-reversed configuration experiment  

Science Conference Proceedings (OSTI)

A diagnostic technique for measuring the fast-ion energy distribution in a field-reversed configuration plasma was developed and tested on the C-2 experiment. A deuterium neutral beam modulated at 22 kHz is injected into the plasma, producing a localized charge-exchange target for the confined fast protons. The escaping fast neutrals are detected by a neutral particle analyzer. The target beam transverse size ({approx}15 cm) defines the spatial resolution of the method. The equivalent current density of the target beam is {density ({approx}6 Multiplication-Sign 10{sup 9} cm{sup -3}) that highly exceeds the background neutral density in the core of C-2. The deuterium fast-ions due to the target beam (E{approx}27 keV), are not confined in C-2 and thus make a negligible contribution to the measured signals.

Korepanov, S.; Smirnov, A.; Clary, R.; Dettrick, S. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Deichuli, P.; Kondakov, A.; Murakhtin, S. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)

2012-10-15T23:59:59.000Z

310

Dark Energy in the Dark Ages  

E-Print Network (OSTI)

Non-negligible dark energy density at high redshifts would indicate dark energy physics distinct from a cosmological constant or ``reasonable'' canonical scalar fields. Such dark energy can be constrained tightly through investigation of the growth of structure, with limits of \\la2% of total energy density at z\\gg1 for many models. Intermediate dark energy can have effects distinct from its energy density; the dark ages acceleration can be constrained to last less than 5% of a Hubble e-fold time, exacerbating the coincidence problem. Both the total linear growth, or equivalently \\sigma_8, and the shape and evolution of the nonlinear mass power spectrum for zenergy behavior over the entire range z=0-1100.

Eric V. Linder

2006-03-21T23:59:59.000Z

311

High electronegativity multi-dipolar electron cyclotron resonance plasma source for etching by negative ions  

SciTech Connect

A large area plasma source based on 12 multi-dipolar ECR plasma cells arranged in a 3 x 4 matrix configuration was built and optimized for silicon etching by negative ions. The density ratio of negative ions to electrons has exceeded 300 in Ar/SF{sub 6} gas mixture when a magnetic filter was used to reduce the electron temperature to about 1.2 eV. Mass spectrometry and electrostatic probe were used for plasma diagnostics. The new source is free of density jumps and instabilities and shows a very good stability for plasma potential, and the dominant negative ion species is F{sup -}. The magnetic field in plasma volume is negligible and there is no contamination by filaments. The etching rate by negative ions measured in Ar/SF{sub 6}/O{sub 2} mixtures was almost similar with that by positive ions reaching 700 nm/min.

Stamate, E. [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, Roskilde 4000 (Denmark); Draghici, M. [Infineon Technologies Austria AG, Siemensstrasse 2, Villach 9500 (Austria)

2012-04-15T23:59:59.000Z

312

Aeroelastic analysis of the troposkien-type wind turbine  

SciTech Connect

The testing of troposkien-type wind turbines has indicated that under certain conditions serious vibrations of the blades can occur, involving flatwise bending, torsion, and chordwise bending. It is the purpose of this report to perform an aeroelastic analysis of the stability of the coupled bending and torsional motion of such blades with a view to determining the cause of these vibrations as a means of suppressing them. The emphasis of the analysis is on obtaining physical understanding rather than exact numerical results. The effect of extreme variation of the chordwise location of the section center of gravity of troposkien-type rotor blades was found to be negligible with regard to blade flutter. This conclusion implies that chordwise mass balancing of the blades is not required, with consequent large reductions in blade design and manufacturing requirements, and therefore in blade cost.

Ham, N.D.

1977-04-01T23:59:59.000Z

313

Reduction of Carbon Monoxide. Past Research Summary  

DOE R&D Accomplishments (OSTI)

Research programs for the year on the preparation, characterization, and reactions of binuclear tantalum complexes are described. All evidence to date suggest the following of these dimeric molecules: (1) the dimer does not break into monomers under mild conditions; (2) intermolecular hydride exchange is not negligible, but it is slow; (3) intermolecular non-ionic halide exchange is fast; (4) the ends of the dimers can rotate partially with respect to one another. The binuclear tantalum hydride complexes were found to react with carbon monoxide to give a molecule which is the only example of reduction of CO by a transition metal hydride to give a complex containing a CHO ligand. Isonitrides also reacted in a similar manner with dimeric tantalum hydride. (ATT)

Schrock, R. R.

1982-00-00T23:59:59.000Z

314

Surrogate Guderley Test Problem Definition  

SciTech Connect

The surrogate Guderley problem (SGP) is a 'spherical shock tube' (or 'spherical driven implosion') designed to ease the notoriously subtle initialization of the true Guderley problem, while still maintaining a high degree of fidelity. In this problem (similar to the Guderley problem), an infinitely strong shock wave forms and converges in one-dimensional (1D) cylindrical or spherical symmetry through a polytropic gas with arbitrary adiabatic index {gamma}, uniform density {rho}{sub 0}, zero velocity, and negligible pre-shock pressure and specific internal energy (SIE). This shock proceeds to focus on the point or axis of symmetry at r = 0 (resulting in ostensibly infinite pressure, velocity, etc.) and reflect back out into the incoming perturbed gas.

Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory

2012-07-06T23:59:59.000Z

315

Towards Understanding the Cesium Cycle of the Persistent H{sup -} Beams at SNS  

Science Conference Proceedings (OSTI)

This paper describes the accomplishments of the SNS H{sup -} ion source, which delivers routinely {approx}50 mA at a 5.4% duty factor with {approx}99% availability, enabling 1 MW beams for neutron production with {approx}90% availability. It discusses the need for increasing reliability and beam current. But mostly it focuses on its unexpected feature: H{sup -} beams that are apparently persistent for up to 5 weeks without adding Cs after an initial dose of less than {approx}5 mg. Thermal emission and sputtering are qualitatively evaluated, and appear consistent with a negligible Cs sputter rate after the initial dose disappears from the Cs plasma. It concludes with a list of future experiments that can shed more light on this apparently unique Cs cycle.

Stockli, Martin P.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Santana, M.; Welton, R. F. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2011-09-26T23:59:59.000Z

316

Wind load design methods for ground-based heliostats and parabolic dish collectors  

DOE Green Energy (OSTI)

The purpose of this design method is to define wind loads on flat heliostat and parabolic dish collectors in a simplified form. Wind loads are defined for both mean and peak loads accounting for the protective influence of upwind collectors, wind protective fences, or other wind-blockage elements. The method used to define wind loads was to generalize wind load data obtained during tests on model collectors, heliostats or parabolic dishes, placed in a modeled atmospheric wind in a boundary-layer wind-tunnel at Colorado State University. For both heliostats and parabolic dishes, loads are reported for solitary collectors and for collectors as elements of a field. All collectors were solid with negligible porosity; thus the effects of porosity in the collectors is not addressed.

Peterka, J.A.; Derickson, R.G. (Colorado State Univ., Fort Collins, CO (United States). Fluid Dynamics and Diffusion Lab.)

1992-09-01T23:59:59.000Z

317

Baryon and lepton number violation in the electroweak theory at TeV energies  

Science Conference Proceedings (OSTI)

In the standard Weinberg-Salam electroweak theory baryon and lepton number (B and L) are NOT exactly conserved. The nonconservation of B and L can be traced to the existence of parity violation in the electroweak theory, together with the chiral current anomaly. This subtle effect gives negligibly small amplitudes for B and L violation at energies and temperatures significantly smaller than M{sub w} sin{sup 2} {theta}{sub w}/{alpha} {approximately} 10 TeV. However, recent theoretical work shows that the rate for B and L nonconservation is unsuppressed at higher energies. The consequences of this for cosmology and the baryon asymmetry of the universe, as well as the prospects for direct verification at the SSC are discussed. 13 refs., 3 figs.

Mottola, E.

1990-01-01T23:59:59.000Z

318

Grid-based Parallel Data Streaming Implemented for the Gyrokinetic Toroidal Code  

Science Conference Proceedings (OSTI)

We have developed a threaded parallel data streaming approach using Globus to transfer multi-terabyte simulation data from a remote supercomputer to the scientist's home analysis/visualization cluster, as the simulation executes, with negligible overhead. Data transfer experiments show that this concurrent data transfer approach is more favorable compared with writing to local disk and then transferring this data to be post-processed. The present approach is conducive to using the grid to pipeline the simulation with post-processing and visualization. We have applied this method to the Gyrokinetic Toroidal Code (GTC), a 3-dimensional particle-in-cell code used to study microturbulence in magnetic confinement fusion from first principles plasma theory.

S. Klasky; S. Ethier; Z. Lin; K. Martins; D. McCune; R. Samtaney

2003-09-15T23:59:59.000Z

319

High performance threaded data streaming for large scale simulations  

E-Print Network (OSTI)

We have developed a threaded parallel data streaming approach using Logistical Networking (LN) to transfer multi-terabyte simulation data from computers at NERSC to our local analysis/visualization cluster, as the simulation executes, with negligible overhead. Data transfer experiments show that this concurrent data transfer approach is more favorable compared with writing to local disk and later transferring this data to be post-processed. Our algorithms are network aware, and can stream data at up to 97Mbs on a 100Mbs link from CA to NJ during a live simulation, using less than 5 % CPU overhead at NERSC. This method is the first step in setting up a pipeline for simulation workflow and data management. 1.

Viraj Bhat; Scott Klasky; Scott Atchley; Micah Beck; Doug Mccune; Manish Parashar

2004-01-01T23:59:59.000Z

320

Wind effects on convective heat loss from a cavity receiver for a parabolic concentrating solar collector  

DOE Green Energy (OSTI)

Tests were performed to determine the convective heat loss characteristics of a cavity receiver for a parabolid dish concentrating solar collector for various tilt angles and wind speeds of 0-24 mph. Natural (no wind) convective heat loss from the receiver is the highest for a horizontal receiver orientation and negligible with the reveler facing straight down. Convection from the receiver is substantially increased by the presence of side-on wind for all receiver tilt angles. For head-on wind, convective heat loss with the receiver facing straight down is approximately the same as that for side-on wind. Overall it was found that for wind speeds of 20--24 mph, convective heat loss from the receiver can be as much as three times that occurring without wind.

Ma, R.Y. [California State Polytechnic Univ., Pomoma, CA (United States). Dept. of Mechanical Engineering

1993-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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
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321

Learning to imitate stochastic time series in a compositional way by chaos  

E-Print Network (OSTI)

This study shows that a mixture of RNN experts model can acquire the ability to generate sequences combining multiple primitive patterns by means of self-organizing chaos. By training of the model, each expert learns a primitive sequence pattern, and a gating network learns to imitate stochastic switching of the multiple primitives via a chaotic dynamics, utilizing a sensitive dependence on initial conditions. As a demonstration, we present a numerical simulation in which the model learns Markov chain switching among some Lissajous curves by a chaotic dynamics. Our analysis shows that by using a sufficient amount of training data, balanced with the network memory capacity, it is possible to satisfy the conditions for embedding the target stochastic sequences into a chaotic dynamical system. It is also shown that reconstruction of a stochastic time series by a chaotic model can be stabilized by adding a negligible amount of noise to the dynamics of the model.

Jun Namikawa; Jun Tani

2008-05-13T23:59:59.000Z

322

Particle Image Velocimetry Measurements and Analysis of Bypass Data for a Scaled 6mm Gap  

SciTech Connect

The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments will use optical techniques, primarily particle image velocimetry (PIV) in the INL Matched Index of Refraction (MIR) flow system.

J.R. Wolf; T.E. Conder; R.R. Schultz

2012-09-01T23:59:59.000Z

323

Low-noise photodiode detector for optical fluctuation diagnostics  

SciTech Connect

The beam emission spectroscopy optical fluctuation diagnostic requires the highest possible quantum efficiency detector at 656 nm to minimize the photon statistical baseline limit to the detectable fluctuation level. A photoconductive photodiode detector with an extremely low-noise preamplifier and a reactive feedback circuit provides quantum efficiencies up to 70%--80% for a useful frequency range of at least 0--150 kHz with incident powers of {similar to}10 nW. The diodes are chosen for negligible leakage current and hence do not require active cooling. These detectors have provided increase in the sensitivity to plasma fluctuation amplitude by a factor of {similar to}14 over photomultipliers and a factor of 4 over large area avalanche photodiodes.

Fonck, R.J.; Ashley, R.; Durst, R. (Department of Nuclear Engineering and Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)); Paul, S.F.; Renda, G. (Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States))

1992-10-01T23:59:59.000Z

324

Li-Ion Battery with LiFePO4 Cathode and Li4Ti5O12 Anode for Stationary Energy Storage  

Science Conference Proceedings (OSTI)

i-ion batteries based on commercially available LiFePO4 cathode and Li4Ti5O12 anode were investigated for potential stationary energy storage applications. The full cell that operated at flat 1.85V demonstrated stable cycling for 200 cycles followed by a rapid fade. A significant improvement in cycling stability was achieved via Ketjen black coating of the cathode. A Li-ion full cell with Ketjen black modified LiFePO4 cathode and an unmodified Li4Ti5O12 anode exhibited negligible fade after more than 1200 cycles with a capacity of ~130mAh/g. The improved stability, along with its cost-effectiveness, environmentally benignity and safety, make the LiFePO4/ Li4Ti5O12 Li-ion battery a promising option of storing renewable energy.

Wang, Wei; Choi, Daiwon; Yang, Zhenguo

2013-01-01T23:59:59.000Z

325

Radiological survey support activities for the decommissioning of the Ames Laboratory Research Reactor Facility, Ames, Iowa  

SciTech Connect

At the request of the Engineering Support Division of the US Department of Energy-Chicago Operations Office and in accordance with the programmatic overview/certification responsibilities of the Department of Energy Environmental and Safety Engineering Division, the Argonne National Laboratory Radiological Survey Group conducted a series of radiological measurements and tests at the Ames Laboratory Research Reactor located in Ames, Iowa. These measurements and tests were conducted during 1980 and 1981 while the reactor building was being decontaminated and decommissioned for the purpose of returning the building to general use. The results of these evaluations are included in this report. Although the surface contamination within the reactor building could presumably be reduced to negligible levels, the potential for airborne contamination from tritiated water vapor remains. This vapor emmanates from contamination within the concrete of the building and should be monitored until such time as it is reduced to background levels. 2 references, 8 figures, 6 tables.

Wynveen, R.A.; Smith, W.H.; Sholeen, C.M.; Justus, A.L.; Flynn, K.F.

1984-09-01T23:59:59.000Z

326

Method for reducing nitrogen oxides in combustion effluents  

DOE Patents (OSTI)

Method for reducing nitrogen oxides (NO.sub.x) in the gas stream from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone, NO.sub.x is converted to nitrogen by reaction with urea or ammonia with negligible remaining ammonia and other reaction pollutants. Specially designed injectors are used to introduce air atomized water droplets containing dissolved urea or ammonia into the gaseous combustion products in a manner that widely disperses the droplets exclusively in the optimum reaction temperature zone. The injector operates in a manner that forms droplet of a size that results in their vaporization exclusively in this optimum NO.sub.x -urea/ammonia reaction temperature zone. Also disclosed is a design of a system to effectively accomplish this injection.

Zauderer, Bert (Merion Station, PA)

2000-01-01T23:59:59.000Z

327

Radiative one- and two-electron transitions into the empty K shell of He-like ions  

Science Conference Proceedings (OSTI)

The branching ratios between the single and double electron radiative transitions to empty K shell in He-like ions with 2s2p configuration are evaluated for 15 ions with 4{electric dipole allowed one-electron radiative transitions is negligible, it substantially changes the spin-forbidden rates and the two-electron one-photon transition probabilities. Also, while the single electron transition rates are gauge independent, the correlated double-electron probabilities are found to be gauge sensitive. The probable uncertainties in the computed transition rates have been evaluated by considering the line strengths and the differences between the calculated and experimental transition energies as accuracy indicators. The present results are compared with other available experimental and theoretical data.

Kadrekar, Riddhi; Natarajan, L. [Department of Physics, University of Mumbai, Mumbai 400 098 (India)

2011-12-15T23:59:59.000Z

328

Fission Barriers of Compound Superheavy Nuclei  

E-Print Network (OSTI)

The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. In this work, we investigate the isentropic fission barriers by means of the self-consistent nuclear density functional theory. The relationship between isothermal and isentropic descriptions is demonstrated. Calculations have been carried out for $^{264}$Fm, $^{272}$Ds, $^{278}$112, $^{292}$114, and $^{312}$124. For nuclei around $^{278}$112 produced in "cold fusion" reactions, we predict a more rapid decrease of fission barriers with excitation energy as compared to the nuclei around $^{292}$114 synthesized in "hot fusion" experiments. This is explained in terms of the difference between the ground-state and saddle-point temperatures. The effect of the particle gas is found to be negligible in the range of temperatures studied.

J. C. Pei; W. Nazarewicz; J. A. Sheikh; A. K. Kerman

2009-01-07T23:59:59.000Z

329

Dissipative Cryogenic Filters with Zero DC Resistance  

SciTech Connect

The authors designed, implemented and tested cryogenic RF filters with zero DC resistance, based on wires with a superconducting core inside a resistive sheath. The superconducting core allows low frequency currents to pass with negligible dissipation. Signals above the cutoff frequency are dissipated in the resistive part due to their small skin depth. The filters consist of twisted wire pairs shielded with copper tape. Above approximately 1 GHz, the attenuation is exponential in {radical}{omega}, as typical for skin depth based RF filters. By using additional capacitors of 10 nF per line, an attenuation of at least 45 dB above 10 MHz can be obtained. Thus, one single filter stage kept at mixing chamber temperature in a dilution refrigerator is sufficient to attenuate room temperature black body radiation to levels corresponding to 10 mK above about 10 MHz.

Bluhm, Hendrik; Moler, Kathryn A.; /Stanford U., Appl. Phys. Dept

2008-04-22T23:59:59.000Z

330

Performance and results of the RICH detector for kaon physics in Hall A at Jefferson Lab  

SciTech Connect

A proximity focusing RICH detector has been constructed for the hadron High Resolution Spectrometer (HRS) of Jefferson Lab Experimental Hall-A. This detector is intended to provide excellent hadron identification up to a momentum of 2.5 GeV/c. The RICH uses a 15 mm thick liquid perfluorohexane radiator in proximity focusing geometry to produce Cherenkov photons traversing a 100 mm thick proximity gap filled with pure methane and converted into electrons by a thin film of CsI deposited on the cathode plane of a MWPC. The detector has been successfully employed in the fixed target, high luminosity and high resolution hypernuclear spectroscopy experiment. With its use as a kaon identifier in the 2 GeV/c region, the very large contribution from pions and protons to the hypernuclear spectrum was reduced to a negligible level. The basic parameters and the resulting performance obtained during the experiment are reported in this paper.

M. Iodice; E. Cisbani; S. Colilli; F. Cusanno; S. Frullani; R. Fratoni; F. Garibaldi; M. Gricia; M. Lucentini; L. Pierangeli; F. Santavenere; G.M. Urciuoli; P. Veneroni; G. De Cataldo; R. De Leo; D. Di Bari; L. Lagamba; E. Nappi; S. Marrone; B. Kross; J.J. LeRose; B. Reitz; J. Segal; C. Zorn and H. Breuer

2005-11-01T23:59:59.000Z

331

On the Requirements for Realistic Modeling of Neutrino Transport in Simulations of Core-collapse Supernovae  

SciTech Connect

We have conducted a series of numerical experiments with the spherically-symmetric, general-relativistic neutrino radiation hydrodynamics code Agile-BOLTZTRAN to examine the effects of several approximations used in multidimensional core-collapse supernova simulations. Our code permits us to examine the effects of these approximations quantitatively by removing, or substituting for, the pieces of supernova physics of interest. These approximations include: (1) using Newtonian versus general-relativistic gravity, hydrodynamics, and transport; (2) using older weak interactions, including the omission of non-isoenergetic neutrino scattering, versus up-to-date weak interactions; and (3) omitting the velocity-dependent terms, or observer corrections, from the neutrino Boltzmann kinetic equation. We demonstrate that each of these changes has non-negligible effects on the outcomes of our simulations. Finally, we discuss the impact these results have for current, and future, multidimensional models.

Lentz, Eric J [ORNL; Mezzacappa, Anthony [ORNL; Messer, Bronson [ORNL; Liebendoerfer, Matthias [Universitat Basel, Switzerland; Hix, William Raphael [ORNL; Bruenn, S. W. [Florida Atlantic University

2012-01-01T23:59:59.000Z

332

Thermalization of secondary electrons under AMSGEMP conditions  

SciTech Connect

A Monte Carlo algorithm is used to determine the time behavior of source secondary electrons for ranges of the electric field to pressure ratio E/p of interest in AMSGEMP. The algorithm contains a very detailed cross section set describing electron interactions with the background gas. The authors show that the delay in the attainment of the peak time independent ionization frequency (or ionization coefficient) may result in negligible ionization over times of interest. In any case the behavior is shown to behave much differently than in examples where limited cross section sets, common in currently employed predictive codes, are employed. In particular, the importance of momentum transfer is indicated. A critique of the scaling implications of the phenomena is made.

Bloomberg, H.W.; Pine, V.W.

1984-12-01T23:59:59.000Z

333

High Temperature Electrochemical Polishing of H(2)S from Coal Gasification Process Streams.  

DOE Green Energy (OSTI)

An advanced process for the separation of hydrogen sulfide from coal gasification streams through an electrochemical membrane is being perfected. H{sub 2}S is removed from a synthetic gas stream, split into hydrogen, which enriches the exiting syngas, and sulfur, which is condensed downstream from an inert sweep gas stream. The process allows for continuous removal of H{sub 2}S without cooling the gas stream while allowing negligible pressure loss through the separator. Moreover, the process is economically attractive due to the elimination of the need for a Claus process for sulfur recovery. To this extent the project presents a novel concept for improving utilization of coal for more efficient power generation.

Winnick, J.

1997-12-31T23:59:59.000Z

334

Velocity characteristics of the flow in motored engines. Final report  

DOE Green Energy (OSTI)

The influence of piston-head geometry, compression and rotational speed has been investigated. Measurements and calculations, without compression have shown the influence of a cylindrical bowl to be negligible; it is expected, and work is in progress to obtain direct evidence, that the influence will be significant with compression. Measurements in a Petter engine have, however, shown that compression has little influence at bottom dead center on the expansion stroke and that a substantial region of solid-body rotation exists in both cases. The influence of rotational speed on the flow patterns and turbulence intensity have been shown to be small except in the immediate vicinity of the inlet port and for rotational speeds (<100 rpm) when the flow is not turbulent. 25 references, 11 figures.

Gosman, A.D.; Whitelaw, J.H.

1980-01-01T23:59:59.000Z

335

Fluid dynamics, particulate segregation, chemical processes, and natural ore analog discussions that relate to the potential for criticality in Hanford tanks  

SciTech Connect

This report presents an in-depth review of the potential for nuclear criticality to occur in Hanford defense waste tanks during past, current and future safe storage and maintenance operations. The report also briefly discusses the potential impacts of proposed retrieval activities, although retrieval was not a main focus of scope. After thorough review of fluid dynamic aspects that focus on particle segregation, chemical aspects that focus on solubility and adsorption processes that might concentrate plutonium and/or separate plutonium from the neutron absorbers in the tank waste, and ore-body formation and mining operations, the interdisciplinary team has come to the conclusion that there is negligible risk of nuclear critically under existing storage conditions in Hanford site underground waste storage tanks. Further, for the accident scenarios considered an accidental criticality is incredible.

Barney, G.S.

1996-09-27T23:59:59.000Z

336

Dosimetric Characteristics for Brachytherapy Sources  

SciTech Connect

Brachytherapy sources are characterized by the dosimetric parameters in a protocol such as the American Association of Physicists in Medicine Task Group 43. The air-kerma strength is measured and traceable to a primary standard. Then the parameters such as dose-rate constant, radial dose function, and anisotropy function are measured and related back to the primary standard. This is normally accomplished with thermoluminescent dosimeters (TLDs). Since radial dose function and anisotropy function are relative parameters, some of the dosimetric corrections are negligible. For the dose-rate constant, parameters such as the energy dependence compared with a calibration beam such as {sup 60}Co need to be accounted for. A description of the primary standard measurements and TLD measurements will be discussed.

DeWerd, Larry A.; Davis, Stephen D. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin (United States)

2011-05-05T23:59:59.000Z

337

Generalizing the Thermodynamics State Relationships in KIVA-3V  

DOE Green Energy (OSTI)

The Peng-Robinson equation of state has been implemented into the KIVA-3V code to better handle high-pressure conditions typical of Diesel engine environments. The implementations modify pressure-volume-temperature relationships, specific heats, and departures in internal energy, among other thermodynamic partial derivatives. Computations show that significant deviations do occur for progressively heavier hydrocarbons. However, when these hydrocarbons exist in a mixture with a non-negligible portion of air, the departures from ideal behavior are mitigated. Internal energy calculations have been extended to allow for pressure effects, but the strongest factor continues to be temperature. Hence departures from ideal behavior in internal energy and related specific heats are minimum.

M.F. Trujillo; P. O'Rourke; D. Torres

2002-10-01T23:59:59.000Z

338

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

339

Accurate calculations of the WIMP halo around the Sun and prospects for gamma ray detection  

E-Print Network (OSTI)

Weakly interacting massive particles (WIMPs) can be captured by heavenly objects, like the Sun. Under the process of being captured by the Sun, they will build up a population of WIMPs around it, that will eventually sink to the core of the Sun. It has been argued with simpler estimates before that this halo of WIMPs around the Sun could be a strong enough gamma ray source to be a detectable signature for WIMP dark matter. We here revisit the problem using detailed Monte Carlo simulations and detailed composition and structure information about the Sun to estimate the size of the gamma ray flux. Compared to earlier estimates, we find that the gamma ray flux from WIMP annihilations in the Sun halo would be negligible and no current or planned detectors would even be able to detect this flux.

Sivertsson, Sofia

2009-01-01T23:59:59.000Z

340

Accurate calculations of the WIMP halo around the Sun and prospects for its gamma ray detection  

E-Print Network (OSTI)

Weakly interacting massive particles (WIMPs) can be captured by heavenly objects, like the Sun. Under the process of being captured by the Sun, they will build up a population of WIMPs around it, which will eventually sink to the core. It has been suggested that this halo of WIMPs around the Sun could be a gamma ray source, possibly distinct enough to have nice detectable signature for WIMP dark matter. We here revisit this problem using detailed Monte Carlo simulations and detailed composition and structure information about the Sun to estimate the size of the gamma ray flux. Compared to earlier simpler estimates, we find that the gamma ray flux from WIMP annihilations in the Sun halo would be negligible; no current or planned detectors would be able to detect this flux.

Sivertsson, Sofia

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "negligible negligible negligible" 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

Two-photon exchange effect studied with neural networks  

SciTech Connect

An approach to the extraction of the two-photon exchange (TPE) correction from elastic ep scattering data is presented. The cross-section, polarization transfer (PT), and charge asymmetry data are considered. It is assumed that the TPE correction to the PT data is negligible. The form factors and TPE correcting term are given by one multidimensional function approximated by the feedforward neural network (NN). To find a model-independent approximation, the Bayesian framework for the NNs is adapted. A large number of different parametrizations is considered. The most optimal model is indicated by the Bayesian algorithm. The obtained fit of the TPE correction behaves linearly in {epsilon} but it has a nontrivial Q{sup 2} dependence. A strong dependence of the TPE fit on the choice of parametrization is observed.

Graczyk, Krzysztof M. [Institute of Theoretical Physics, University of Wroclaw, pl. M. Borna 9, PL-50-204 Wroclaw (Poland)

2011-09-15T23:59:59.000Z

342

Post-processing of polymer foam tissue scaffolds with high power ultrasound: a route to increased pore interconnectivity, pore size and fluid transport  

E-Print Network (OSTI)

We expose thick polymer foam tissue scaffolds to high power ultrasound and study its effect on the openness of the pore architecture and fluid transport through the scaffold. Our analysis is supported by measurements of fluid uptake during insonification and imaging of the scaffold microstructure via x-ray computed tomography, scanning electron microscopy and acoustic microscopy. The ultrasonic treatment is found to increase the mean pore size by over 10%. More striking is the improvement in fluid uptake: for scaffolds with only 40% water uptake via standard immersion techniques, we can routinely achieve full saturation of the scaffold over approximately one hour of exposure. These desirable modifications occur with no loss of scaffold integrity and negligible mass loss, and are optimized when the ultrasound treatment is coupled to a pre-wetting stage with ethanol. Our findings suggest that high power ultrasound is a highly targetted and efficient means to promote pore interconnectivity and fluid transport in...

Watson, N J; Reinwald, Y; White, L J; Ghaemmaghami, A M; Morgan, S P; Rose, F R A J; Povey, M J W; Parker, N G

2013-01-01T23:59:59.000Z

343

Post-processing of polymer foam tissue scaffolds with high power ultrasound: a route to increased pore interconnectivity, pore size and fluid transport  

E-Print Network (OSTI)

We expose thick polymer foam tissue scaffolds to high power ultrasound and study its effect on the openness of the pore architecture and fluid transport through the scaffold. Our analysis is supported by measurements of fluid uptake during insonification and imaging of the scaffold microstructure via x-ray computed tomography, scanning electron microscopy and acoustic microscopy. The ultrasonic treatment is found to increase the mean pore size by over 10%. More striking is the improvement in fluid uptake: for scaffolds with only 40% water uptake via standard immersion techniques, we can routinely achieve full saturation of the scaffold over approximately one hour of exposure. These desirable modifications occur with no loss of scaffold integrity and negligible mass loss, and are optimized when the ultrasound treatment is coupled to a pre-wetting stage with ethanol. Our findings suggest that high power ultrasound is a highly targetted and efficient means to promote pore interconnectivity and fluid transport in thick foam tissue scaffolds.

N J Watson; R K Johal; Y Reinwald; L J White; A M Ghaemmaghami; S P Morgan; F R A J Rose; M J W Povey; N G Parker

2013-02-18T23:59:59.000Z

344

High Temperature Electrochemical Polishing of H(2)S from Coal Gasification. Quarterly progress report, April 1-June 30, 1997  

DOE Green Energy (OSTI)

An advanced process for the separation of hydrogen sulfide from coal gasification streams through an electrochemical membrane is being perfected. H{sub 2}S is removed from a synthetic gas stream, split into hydrogen, which enriches the exiting syngas, and sulfur, which is condensed downstream from an inert sweep gas stream. The process allows for continuous removal of H{sub 2}S without cooling the gas stream while allowing negligible pressure loss through the separator. Moreover, the process is economically attractive due to the elimination of the need for a Claus process for sulfur recovery. To this extent the project presents a novel concept for improving utilization of coal for more efficient power generation.

Winnick, J.

1997-12-31T23:59:59.000Z

345

Writable graphene: Breaking sp2 bonds with soft X-rays  

SciTech Connect

We study the stability of various kinds of graphene samples under soft x-ray irradiation. Our results show that in single-layer exfoliated graphene (a closer analog to two-dimensional material), the in-plane carbon-carbon bonds are unstable under x-ray irradiation, resulting in nanocrystalline structures. As the interaction along the third dimension increases by increasing the number of graphene layers or through the interaction with the substrate (epitaxial graphene), the effect of x-ray irradiation decreases and eventually becomes negligible for graphite and epitaxial graphene. Our results demonstrate the importance of the interaction along the third dimension in stabilizing the long range in-plane carbon-carbon bonding, and suggest the possibility of using x-ray to pattern graphene nanostructures in exfoliated graphene.

Zhou, S.; Girit, C.; Scholl, A.; Jozwiak, C.; Siegel, D.; Yu, P.; Robinson, J.; Wang, F.; Zettl, A.; Lanzara, A.

2010-06-09T23:59:59.000Z

346

Direct Detection of Classically Undetectable Dark Matter through Quantum Decoherence  

E-Print Network (OSTI)

Although various pieces of indirect evidence about the nature of dark matter have been collected, its direct detection has eluded experimental searches despite extensive effort. If the mass of dark matter is below 1 MeV, it is essentially imperceptible to conventional detection methods because negligible energy is transferred to nuclei during collisions. Here I propose directly detecting dark matter through the quantum decoherence it causes rather than its classical effects such as recoil or ionization. I show that quantum spatial superpositions are sensitive to low-mass dark matter which is inaccessible to classical techniques. This provides new independent motivation for matter interferometry with large masses, especially on spaceborne platforms. The apparent dark matter wind we experience as the Sun travels through the Milky Way ensures interferometers and related devices are directional detectors, and so are able to provide unmistakable evidence that decoherence has galactic origins.

C. Jess Riedel

2012-12-13T23:59:59.000Z

347

Graphite Oxidation Thermodynamics/Reactions  

Science Conference Proceedings (OSTI)

The vulnerability of graphite-matrix spent nuclear fuel to oxidation by the ambient atmosphere if the fuel canister is breached was evaluated. Thermochemical and kinetic data over the anticipated range of storage temperatures (200 to 400 C) were used to calculate the times required for a total carbon mass loss of 1 mgcm-2 from a fuel specimen. At 200 C, the time required to produce even this small loss is large, 900,000 yr. However, at 400 C the time required is only 1.9 yr. The rate of oxidation at 200 C is negligible, and the rate even at 400 C is so small as to be of no practical consequence. Therefore, oxidation of the spent nuclear fuel upon a loss of canister integrity is not anticipated to be a concern based upon the results of this study.

Propp, W.A.

1998-09-01T23:59:59.000Z

348

Toward crystal design in organic conductors and superconductors.  

DOE Green Energy (OSTI)

We have seen that many different types of intermolecular interactions in organic conducting cation radical salts. Hydrogen bonding between the donor molecules and the anions is weak but not negligible. The ionic Madelung energy is insufficient to completely intersperse anions and cations, thus the layers favored by the van der Waals interactions remain intact. The search for new conducting and superconducting salts has been mainly by trial-and-error methods, even though simple substitutions have been employed in order to obtain isostructural analogs of successful (e.g., superconducting) salts. However, even seemingly minor substitutions sometimes destroy the packing type, and different crystal structures result. Simulations with the aim at predicting crystal structures have not succeeded, mainly because the different interaction types are of comparable energy, and the delocalized and partial charges render the calculations of the ionic terms extremely unreliable. Clearly, the development of suitable crystal modeling techniques with predictive capabilities is one of the great needs of the field.

Geiser, U.

1999-04-23T23:59:59.000Z

349

141 PATTERNS OF ALKALINE PHOSPHATASE ACTIVI IN THE NUCLEI OF NORMAL AND MALIGNANT CELLS DURING THE PHASES OF GROWTH AND DIFFERENTIATION  

E-Print Network (OSTI)

LoCALIZATION of alkaline phosphatase in the nuclei of normal and malignant stratified epithelia of mammalian cervix is still an open question (Alamanni, 1956; Foraker and Denham, 1957; Gross and Danziger, 1957). It was decided that problems should be attacked with a quantitative technique where risk of error is negligibly small. In the present investigation, alkaline phosphatase activity associated with nuclear heterochromatin of normal and malignant stratified epithelia of human cervix was quantitatively assessed during the phases of growth and differentiation. MATERIALS AND METHODS Normal tissues were collected from the cervices of 5 non-pregnant women who had no positive evidence of any infection, neoplasia and detectable hormonal disturbances. Cancerous tissues were obtained from the epidermoid carcinoma cervix of 6 women. Tissues were fixed in ice-cold 80 per cent ethyl alcohol up to 24 hours in a frigidaire as described before from this laboratory (De, et al., 1961). They were

P. De; R. Chatterjee

1962-01-01T23:59:59.000Z

350

Magic-state distillation with the four-qubit code  

E-Print Network (OSTI)

The distillation of magic states is an often-cited technique for enabling universal quantum computing once the error probability for a special subset of gates has been made negligible by other means. We present a routine for magic-state distillation that reduces the required overhead for a range of parameters of practical interest. Each iteration of the routine uses a four-qubit error-detecting code to distill the +1 eigenstate of the Hadamard gate at a cost of ten input states per two improved output states. Use of this routine in combination with the 15-to-1 distillation routine described by Bravyi and Kitaev allows for further improvements in overhead.

Adam M. Meier; Bryan Eastin; Emanuel Knill

2012-04-18T23:59:59.000Z

351

Small gas turbines exhibit single-digit emissions in service  

Science Conference Proceedings (OSTI)

A 10 MW-class, THM 1304-10D gas turbine from MAN-GHH, equipped with dry low-NO[sub x] combustion chambers, including hybrid burners, entered service last October. The unit was installed on the Stegal long-distance natural gas pipeline from the Olbernhau compression station on the Czech border. The pipeline transmits gas from Russia to the central part of Germany. A similar compression station, featuring three THM 1304-D driven compressor packages, started commercial operation last March in the Rehden station on the Midal pipeline. A test program carried out by MAN-GHH has demonstrated that the THM 1304 gas turbine has a wide operating range with NO[sub x] emission well under TA luft limits and, at the same time, negligible CO emissions. This is accomplished by combined effect of large volume combustion chambers, optimized wall cooling and premix dry low-NO[sub x] burners. 3 figs.

Chellini, R.

1994-06-01T23:59:59.000Z

352

Lifetime of micrometer-sized drops of oil pressed by buoyancy against a planar interface  

E-Print Network (OSTI)

Emulsion Stability Simulations (ESS) are used to estimate the coalescence time of one drop of hexadecane pressed by buoyancy against a planar water/hexadecane interface. In the present simulations the homophase is represented by a big drop of oil at least 500 times larger than the approaching drop ($1\\,\\mu$m to $10\\,\\mu$m). Both deformable and non-deformable drops are considered along with six different diffusion tensors. In each case van der Waals, electrostatic, steric and buoyancy forces are taken into account. The coalescence times are estimated as the average of 1000 random walks. It is found that the repulsive potential barrier has a significant influence in the results. The experimental data can only be reproduced assuming negligible repulsive barriers, as well as non-deformable drops that move with a combination of Stokes and Taylor tensors as they approach the interface.

Clara Rojas; German Urbina-Villalba; Maximo Garcia-Sucre

2010-01-13T23:59:59.000Z

353

Energy loss in high energy heavy ion collisions from the Hydro+Jet model  

E-Print Network (OSTI)

We investigate the effect of energy loss of jets in high energy heavy ion collisions by using a full three-dimensional space-time evolution of a fluid combined with (mini-)jets that are explicitly evolved in space-time. In order to fit the pi^0 data for the Au+Au collisions at sqrt(s_{NN}) = 130 GeV, the space-time averaged energy loss dE/dx(tau energy loss occurs at the very early time less than 2 fm/c in the QGP phase and that energy loss in the mixed phase is negligible within our parameterization for jet energy loss. This is a consequence of strong expansion of the system.

Hirano, T; Hirano, Tetsufumi; Nara, Yasushi

2002-01-01T23:59:59.000Z

354

ONLINE MEASUREMENT OF THE PROGRESS OF DECONTAMINATION  

Science Conference Proceedings (OSTI)

In order to determine if the sensor technology and the decontamination technology will face problems once integrated, a feasibility study (see Appendix B) was produced in which the effect of motion on the efficiency of a radiation sensor was measured. It was found that the effect is not negligible; however, it is not catastrophic, and if the sensors are properly calibrated, this obstacle can be overcome. During the first year of this project, many important tasks have been accomplished. The search for radiation sensors provided knowledge on the technologies commercially available. This, in turn, allowed for a proper assessment of the properties, limitations, different methods of measurement, and requirements of a large number of sensors. The best possible characterization and data collection instrument and decontamination technologies were chosen using the requirement information in Appendix A. There are technical problems with installing sensors within the blasting head, such as steel shot and dust interference. Therefore, the sensor array is placed so that it will measure the radioactivity after the blasting. Sensors are rather sensitive, and therefore it is not feasible to place the sensor windows in such an abrasive environment. Other factors, such as the need for radiation hardening in extreme cases, and the possible interference of gamma rays with the radio frequency modem, have been considered. These factors are expected to be negligible and can be revisited at the time of prototype production. Factors that need to be addressed are the vibrations of the blasting unit and how to isolate the sensor array from these. In addition, an electromagnetic survey must be performed to ensure there will be no interference with the electronic component that will be integrated. The integration design is shown in section 4.0.

M.A. Ebadian, Ph.D.

1999-01-01T23:59:59.000Z

355

Investigation of the MTC noise estimation with a coupled neutronic/thermal-hydraulic dedicated model - 'Closing the loop'  

Science Conference Proceedings (OSTI)

This paper investigates the reliability of different noise estimators aimed at determining the Moderator Temperature Coefficient (MTC) of reactivity in Pressurized Water Reactors. By monitoring the inherent fluctuations in the neutron flux and moderator temperature, an on-line monitoring of the MTC without perturbing reactor operation is possible. In order to get an accurate estimation of the MTC by noise analysis, the point-kinetic component of the neutron noise and the core-averaged moderator temperature noise have to be used. Because of the scarcity of the in-core instrumentation, the determination of these quantities is difficult, and several possibilities thus exist for estimating the MTC by noise analysis. Furthermore, the effect of feedback has to be negligible at the frequency chosen for estimating the MTC in order to get a proper determination of the MTC. By using an integrated neutronic/thermal- hydraulic model specifically developed for estimating the three-dimensional distributions of the fluctuations in neutron flux, moderator properties, and fuel temperature, different approaches for estimating the MTC by noise analysis can be tested individually. It is demonstrated that a reliable MTC estimation can only be provided if the core is equipped with a sufficient number of both neutron detectors and temperature sensors, i.e. if the core contain in-core detectors monitoring both the axial and radial distributions of the fluctuations in neutron flux and moderator temperature. It is further proven that the effect of feedback is negligible for frequencies higher than 0.1 Hz, and thus the MTC noise estimations have to be performed at higher frequencies. (authors)

Demaziere, C.; Larsson, V. [Div. of Nuclear Engineering, Dept. of Applied Physics, Chalmers Univ. of Technology, SE-41296 Gothenburg (Sweden)

2012-07-01T23:59:59.000Z

356

Neutronic design of a fission converter-based epithermal neutron beam for neutron capture therapy  

SciTech Connect

To meet the needs for neutron capture theory (NCT) irradiations, a high-intensity, high-quality fusion converter-based epithermal neutron beam has been designed for the MITR-II research reactor. This epithermal neutron beam, capable of delivering treatments in a few minutes with negligible background contamination from fast neutrons and photons, will be installed in the present thermal column and hohlraum of the 5-MW MITR-II research reactor. Spent or fresh MITR-II fuel elements will be used to fuel the converter. With a fission converter power of {approximately}80 kW using spent fuel, epithermal fluxes (1 eV < E < 10 keV) in excess of 10{sup 10} n/cm{sup 2} {center_dot} s are achievable at the target position with negligible photon and fast neutron contamination, i.e., <2 {times} 10{sup {minus}11}cGy-cm{sup 2}/n. With the currently available {sup 10}B delivery compound boronophenylalanine-fructose, average therapeutic ratios of {approximately}5 can be achieved using this beam for brain irradiations with deep effective penetration ({approximately}9.5 cm) and high dose rates of up to 400 to 600 RBE cGy/min. If NCT becomes an accepted therapy, fission converter-based beams constructed at existing reactors could meet a large fraction of the projected requirements for intense, low-background epithermal neutron beams at a relatively low cost. The results of an extensive set of neutronic design studies investigating all components of the beam are presented. These detailed studies can be useful as guidance for others who may wish to use the fission converter approach to develop epithermal beams for NCT.

Kiger, W.S. III; Sakamoto, S.; Harling, O.K. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1999-01-01T23:59:59.000Z

357

Comparison of iso-octane burning rates between single-phase and two-phase combustion for small droplets  

Science Conference Proceedings (OSTI)

Two-phase combustion is a widespread mechanism of energy conversion that is of practical importance in gas turbines, diesel and spark ignition engines, furnaces, and hazardous environments. However, the exploration of important parameters in combustion systems of practical application is difficult, due to the multiplicity of dependent variables. In the present work, combustion rates of well-defined droplet suspensions of iso-octane have been measured using techniques employed for gaseous combustion. This required a full characterization of the aerosols produced in the combustion apparatus, which determined that the maximum droplet size produced was around 30 {mu}m. Comparisons of two-phase with single-phase laminar mixtures suggest that there were negligible differences in the burning velocity of an aerosol and a gaseous mixture at the same overall equivalence ratio and similar conditions for iso-octane. At high stretch rates, flames remained smooth and droplet enhancement was negligible. However, at lower rates of stretch, both gaseous and aerosol flames became unstable and cellular, and this cellularity, in some cases, increased the burning rate. The values of Markstein length measured for aerosol flames had trends similar to those for gaseous-phase mixtures (Markstein length decreased with equivalence ratio), but were lower than in gaseous combustion. The values of Markstein length in aerosol flames also decreased with liquid equivalence ratio and/or Sauter mean diameter. All this indicates a higher tendency to instabilities in aerosol flames compared to gaseous combustion. A qualitative explanation for the lower values of Markstein length in aerosol combustion is given. It is suggested in the present work that aerosol flames became unstable, and hence had faster burning rates, under conditions that would not result in unstable gaseous flames. Comparisons, qualitative and in terms of dimensionless groups, of two-phase with single-phase turbulent combustion also suggest no enhancement. (author)

Lawes, M.; Lee, Y. [School of Mechanical Engineering, The University of Leeds (United Kingdom); Marquez, N. [Escuela de Ingenieria Mecanica, Universidad del Zulia, Maracaibo 4011 Apto. 526 (Venezuela)

2006-02-01T23:59:59.000Z

358

SHORT VERSUS LONG AND COLLAPSARS VERSUS NON-COLLAPSARS: A QUANTITATIVE CLASSIFICATION OF GAMMA-RAY BURSTS  

SciTech Connect

Gamma-ray bursts (GRBs) are traditionally divided into long and short according to their durations (lg2 s). It was generally believed that this reflects a different physical origin: collapsars (long) and non-collapsars (short). We have recently shown that the duration distribution of collapsars is flat, namely, independent of the duration, at short durations. Using this model for the distribution of Collapsars we determine the duration distribution of non-Collapsars and estimate the probability that a burst with a given duration (and hardness) is a Collapsar or not. We find that this probability depends strongly on the spectral window of the observing detector. While the commonly used limit of 2 s is conservative and suitable for BATSE bursts, 40% of Swift's bursts shorter than 2 s are Collapsars and the division lg0.8 s is more suitable for Swift. We find that the duration overlap of the two populations is very large. On the one hand there is a non-negligible fraction of non-Collapsars longer than 10 s, while on the other hand even bursts shorter than 0.5 s in the Swift sample have a non-negligible probability to be Collapsars. Our results enable the construction of non-Collapsar samples while controlling the Collapsar contamination. They also highlight that no firm conclusions can be drawn based on a single burst and they have numerous implications concerning previous studies of non-Collapsar properties that were based on the current significantly contaminated Swift samples of localized short GRBs. Specifically (1) all known short bursts with z > 1 are most likely Collapsars; (2) the only short burst with a clear jet break is most likely a Collapsar, indicating our lack of knowledge concerning non-Collapsar beaming; and (3) the existence of non-Collapsars with durations up to 10 s imposes new challenges to non-Collapsar models.

Bromberg, Omer; Piran, Tsvi; Sari, Re'em [Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)] [Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel); Nakar, Ehud [The Raymond and Berverly Sackler School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel)] [The Raymond and Berverly Sackler School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel)

2013-02-20T23:59:59.000Z

359

Megavoltage Cone Beam Computed Tomography Dose and the Necessity of Reoptimization for Imaging Dose-Integrated Intensity-Modulated Radiotherapy for Prostate Cancer  

Science Conference Proceedings (OSTI)

Purpose: Megavoltage cone beam computed tomography (MV-CBCT) dose can be integrated with the patient's prescription. Here, we investigated the effects of imaging dose and the necessity for additional optimization when using intensity-modulated radiotherapy (IMRT) to treat prostate cancer. Methods and Materials: An arc beam mimicking MV-CBCT was generated using XiO (version 4.50; Elekta, Stockholm, Sweden). The monitor units (MU) for dose calculation were determined by conforming the calculated dose to the dose measured using an ionization chamber. IMRT treatment plans of 22 patients with prostate cancer were retrospectively analyzed. Arc beams of 3, 5, 8, and 15 MU were added to the IMRT plans, and the dose covering 95% of the planning target volume (PTV) was normalized to the prescribed dose with (reoptimization) or without optimization (compensation). Results: PTV homogeneity and conformality changed negligibly with MV-CBCT integration. For critical organs, an imaging dose-dependent increase was observed for the mean rectal/bladder dose (D{sub mean}), and reoptimization effectively suppressed the D{sub mean} elevations. The bladder generalized equivalent uniform dose (gEUD) increased with imaging dose, and reoptimization suppressed the gEUD elevation when 5- to 15-MU CBCT were added, although rectal gEUD changed negligibly with any imaging dose. Whereas the dose elevation from the simple addition of the imaging dose uniformly increased rectal and bladder dose, the rectal D{sub mean} increase of compensation plans was due mainly to low-dose volumes. In contrast, bladder high-dose volumes were increased by integrating the CBCT dose, and reoptimization reduced them when 5- to 15-MU CBCT were added. Conclusion: Reoptimization is clearly beneficial for reducing dose to critical organs, elevated by addition of high-MU CBCT, especially for the bladder. For low-MU CBCT aimed at bony structure visualization, compensation is sufficient.

Akino, Yuichi [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Koizumi, Masahiko, E-mail: koizumi@radonc.med.osaka-u.ac.jp [Division of Medical Physics, Oncology Center, Osaka University Hospital, Suita, Osaka (Japan); Sumida, Iori; Takahashi, Yutaka; Ogata, Toshiyuki [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Division of Medical Physics, Oncology Center, Osaka University Hospital, Suita, Osaka (Japan); Ota, Seiichi [Division of Radiology, Department of Medical Technology, Osaka University Hospital, Suita, Osaka (Japan); Isohashi, Fumiaki; Konishi, Koji; Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan)

2012-04-01T23:59:59.000Z

360

Radiation Hydrodynamics  

DOE Green Energy (OSTI)

The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is to distinguish hydrogen atoms from helium atoms, for instance. There are all just components of a mixed fluid in this case. So why do we have a special subject called ''radiation hydrodynamics'', when photons are just one of the many kinds of particles that comprise our fluid? The reason is that photons couple rather weakly to the atoms, ions and electrons, much more weakly than those particles couple with each other. Nor is the matter-radiation coupling negligible in many problems, since the star or nebula may be millions of mean free paths in extent. Radiation hydrodynamics exists as a discipline to treat those problems for which the energy and momentum coupling terms between matter and radiation are important, and for which, since the photon mean free path is neither extremely large nor extremely small compared with the size of the system, the radiation field is not very easy to calculate. In the theoretical development of this subject, many of the relations are presented in a form that is described as approximate, and perhaps accurate only to order of {nu}/c. This makes the discussion cumbersome. Why are we required to do this? It is because we are using Newtonian mechanics to treat our fluid, yet its photon component is intrinsically relativistic; the particles travel at the speed of light. There is a perfectly consistent relativistic kinetic theory, and a corresponding relativistic theory of fluid mechanics, which is perfectly suited to describing the photon gas. But it is cumbersome to use this for the fluid in general, and we prefer to avoid it for cases in which the flow velocity satisfies {nu} << c. The price we pay is to spend extra effort making sure that the source-sink terms relating to our relativistic gas component are included in the equations of motion in a form that preserves overall conservation of energy and momentum, something that would be automatic if the relativistic equations were used throughout.

Castor, J I

2003-10-16T23:59:59.000Z

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361

Cardiac Motion During Deep-Inspiration Breath-Hold: Implications for Breast Cancer Radiotherapy  

SciTech Connect

Purpose: Many patients with left-sided breast cancer receive adjuvant radiotherapy during deep-inspiration breath hold (DIBH) to minimize radiation exposure to the heart. We measured the displacement of the left anterior descending artery (LAD) and heart owing to cardiac motion during DIBH, relative to the standard tangential fields for left breast cancer radiotherapy. Methods and Materials: A total of 20 patients who had undergone computed tomography-based coronary angiography with retrospective electrocardiographic gating were randomly selected for the present study. The patients underwent scanning during DIBH to control the influence of respiration on cardiac motion. Standard medial and lateral tangential fields were placed, and the LADs were contoured on the systolic- and diastolic-phase computed tomography data sets by the clinicians. Displacement of the LAD during cardiac contractions was calculated in three directions: toward the posterior edge of the treatment fields, left-right, and anteroposterior. Displacement of the entire heart was measured on the maximal and minimal intensity projection computed tomography images. Results: The mean displacement of the LAD from cardiac contraction without the influence of respiration for 20 patients was 2.3 mm (range, 0.7-3.8) toward the posterior edge of the treatment fields, 2.6 mm (range, 1.0-6.8) in the left-right direction, and 2.3 mm (range, 0.6-6.5) in the anteroposterior direction. At least 30% of the LAD volume was displaced >5 mm in any direction in 2 patients (10%), and <10% of the LAD volume was displaced >5 mm in 10 patients (50%). The extent of displacement of the heart periphery during cardiac motion was negligible near the treatment fields. Conclusions: Displacement of the heart periphery near the treatment fields was negligible during DIBH; however, displacement of the LAD from cardiac contraction varied substantially between and within patients. We recommend maintaining {>=}5 mm of distance between the LAD and the field edge for patients undergoing breast cancer radiotherapy during DIBH.

Wang Xiaochun, E-mail: xiaochunw@mdanderson.org [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Pan Tinsu [Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Pinnix, Chelsea [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Zhang, Sean X.; Salehpour, Mohammad; Sun, Tzouh Liang [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Gladish, Gregory [Department of Diagnostic Radiology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Strom, Eric A.; Perkins, George H.; Tereffe, Welela; Woodward, Wendy; Hoffman, Karen E.; Buchholz, Thomas A.; Yu, T. Kuan [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

2012-02-01T23:59:59.000Z

362

Neutron Interactions in the CUORE Neutrinoless Double Beta Decay Experiment  

SciTech Connect

Neutrinoless double beta decay (0{nu}DBD) is a lepton-number violating process that can occur only for a massive Majorana neutrino. The search for 0{nu}DBD is currently the only practical experimental way to determine whether neutrinos are identical to their own antiparticles (Majorana neutrinos) or have distinct particle and anti-particle states (Dirac neutrinos). In addition, the observation of 0{nu}DBD can provide information about the absolute mass scale of the neutrino. The Cuoricino experiment was a sensitive search for 0{nu}DBD, as well as a proof of principle for the next generation experiment, CUORE. CUORE will search for 0{nu}DBD of {sup 130}Te with a ton-scale array of unenriched TeO{sub 2} bolometers. By increasing mass and decreasing the background for 0{nu}DBD, the half-life sensitivity of CUORE will be a factor of twenty better than that of Cuoricino. The site for both of these experiments is the Laboratori Nazionali del Gran Sasso, an underground laboratory with 3300 meters water equivalent rock overburden and a cosmic ray muon attenuation factor of 10{sup -6}. Because of the extreme low background requirements for CUORE, it is important that all potential sources of background in the 0{nu}DBD peak region at 2530 keV are well understood. One potential source of background for CUORE comes from neutrons, which can be produced underground both by ({alpha},n) reactions and by fast cosmic ray muon interactions. Preliminary simulations by the CUORE collaboration indicate that these backgrounds will be negligible for CUORE. However, in order to accurately simulate the expected neutron background, it is important to understand the cross sections for neutron interactions with detector materials. In order to help refine these simulations, I have measured the gamma-ray production cross sections for interactions of neutrons on the abundant stable isotopes of Te using the GEANIE detector array at the Los Alamos Neutron Science Center. In addition, I have used the GEANIE data to set an upper limit for the production of a 2529 keV gamma-ray from the {sup 126}Te(n,n{prime}{gamma}) reaction. This gamma-ray is a potential source of interference for the 0{nu}DBD peak. Based on this measurement, the contribution of this line to the background is expected to be negligible.

Dolinski, M J

2008-09-24T23:59:59.000Z

363

Investigation of a Novel NDE Method for Monitoring Thermomechanical Damage and Microstructure Evolution in Ferritic-Martensitic Steels for Generation IV Nuclear Energy Systems  

SciTech Connect

The main goal of the proposed project is the development of validated nondestructive evaluation (NDE) techniques for in situ monitoring of ferritic-martensitic steels like Grade 91 9Cr-1Mo, which are candidate materials for Generation IV nuclear energy structural components operating at temperatures up to ~650{degree}C and for steam-generator tubing for sodium-cooled fast reactors. Full assessment of thermomechanical damage requires a clear separation between thermally activated microstructural evolution and creep damage caused by simultaneous mechanical stress. Creep damage can be classified as "negligible" creep without significant plastic strain and "ordinary" creep of the primary, secondary, and tertiary kind that is accompanied by significant plastic deformation and/or cavity nucleation and growth. Under negligible creep conditions of interest in this project, minimal or no plastic strain occurs, and the accumulation of creep damage does not significantly reduce the fatigue life of a structural component so that low-temperature design rules, such as the ASME Section III, Subsection NB, can be applied with confidence. The proposed research project will utilize a multifaceted approach in which the feasibility of electrical conductivity and thermo-electric monitoring methods is researched and coupled with detailed post-thermal/creep exposure characterization of microstructural changes and damage processes using state-of-the-art electron microscopy techniques, with the aim of establishing the most effective nondestructive materials evaluation technique for particular degradation modes in high-temperature alloys that are candidates for use in the Next Generation Nuclear Plant (NGNP) as well as providing the necessary mechanism-based underpinnings for relating the two. Only techniques suitable for practical application in situ will be considered. As the project evolves and results accumulate, we will also study the use of this technique for monitoring other GEN IV materials. Through the results obtained from this integrated materials behavior and NDE study, new insight will be gained into the best nondestructive creep and microstructure monitoring methods for the particular mechanisms identified in these materials. The proposed project includes collaboration with a national laboratory partner and the results will also serve as a foundation to guide the efforts of scientists in the DOE laboratory, university, and industrial communities concerned with the technological challenges of monitoring creep and microstructural evolution in materials planned to be used in Generation IV Nuclear Energy Systems.

Nagy, Peter

2013-09-30T23:59:59.000Z

364

Transport and deposition of functionalized CdTe nanoparticles in saturated porous media  

SciTech Connect

Comprehensive understanding of the transport and deposition of engineered nanoparticles (NPs) in subsurface is required to assess their potential negative impact on the environment. We studied the deposition behavior of functionalized quantum dot (QD) NPs (CdTe) in different types of sands (Accusand, ultrapure quartz, and iron-coated sand) at various solution ionic strengths (IS). The observed transport behavior in ultrapure quartz and iron-coated sand was consistent with conventional colloid deposition theories. However, our results from the Accusand column showed that deposition was minimal at the lowest IS (1 mM) and increased significantly as the IS increased. The effluent breakthrough occurred with a delay, followed by a rapid rise to the maximum normalized concentration of unity. Negligible deposition in the column packed with ultrapure quartz sand (100 mM) and Accusand (1 mM) rules out the effect of straining and suggests the importance of surface charge heterogeneity in QD deposition in Accusand at higher IS. Data analyses further show that only a small fraction of sand surface area contributed in QD deposition even at the highest IS (100 mM) tested. The observed delay in breakthrough curves of QDs was attributed to the fast diffusive mass transfer rate of QDs from bulk solution to the sand surface and QD mass transfer on the solid phase. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis were used to examine the morphology and elemental composition of sand grains. It was observed that there were regions on the sand covered with layers of clay particles. EDX spectra collected from these regions revealed that Si and Al were the major elements suggesting that the clay particles were kaolinite. Additional batch experiments using gold NPs and SEM analysis were performed and it was observed that the gold NPs were only deposited on clay particles originally on the Accusand surface. After removing the clays from the sand surface, we observed negligible QD deposition even at 100 mM IS. We proposed that nanoscale charge heterogeneities on clay particles on Accusand surface played a key role in QD deposition. It was shown that the value of solution IS determined the extent to which the local heterogeneities participated in particle deposition.

Torkzaban, S.; Wan, J.; Kim, Y.; Mulvihill, M.; Tokunaga, T. K.

2010-10-15T23:59:59.000Z

365

Fluidized bed combustion of pelletized biomass and waste-derived fuels  

SciTech Connect

The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away from the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size distribution of primary ash particles liberated upon complete carbon burnoff largely reflected the combustion pattern of each fuel. Primary ash particles of size nearly equal to that of the parent fuel were generated upon complete burnoff of the pelletized sludge. Nonetheless, secondary attrition of primary ash from pelletized sludge is large, to the point where generation of fine ash would be extensive over the typical residence time of bed ash in fluidized bed combustors. Very few and relatively fine primary ash particles were released after complete burnoff of wood pellets. Primary ash particles remaining after complete burnoff of pelletized straw had sizes and shapes that were largely controlled by the occurrence of ash agglomeration phenomena. (author)

Chirone, R.; Scala, F.; Solimene, R. [Istituto di Ricerche sulla Combustione - C.N.R., Piazzale V. Tecchio 80, 80125 Naples (Italy); Salatino, P.; Urciuolo, M. [Dipartimento di Ingegneria Chimica - Universita degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Naples (Italy)

2008-10-15T23:59:59.000Z

366

Enhanced Radiation Tolerance in Sputtered Cu/V Multilayers  

E-Print Network (OSTI)

High energy particle (neutron, proton and He ions) irradiation to materials typically leads to deteriorating properties, including void swelling, blistering, embrittlement, fracture and exfoliation of surfaces. This dissertation examines size dependent radiation damage in nanostructured metallic multilayers synthesized by the magnetron sputtering technique at room temperature. It reveals the roles of interface in achieving enhanced radiation tolerance in metallic materials. The microstructure and mechanical properties of as-deposited Cu/V multilayer films are systemically investigated, providing the basis for studying radiation damage mechanisms. Sputter-deposited Cu/V multilayers are subjected to helium (He) ion irradiation at room temperature with a peak dose of 6 displacements per atom (dpa). The average helium bubble density and lattice expansion induced by radiation decrease significantly with decreasing h, where h is individual layer thickness. The magnitude of radiation hardening decreases with decreasing h, and becomes negligible when h is 2.5 nm or less. The interactions between interfaces and radiation induced point defects and the evolution of microstructurs and mechanical behavior are discussed. This study indicates that nearly immiscible Cu/V interfaces spaced a few nm apart can effectively reduce the concentration of radiation induced point defects. Dose dependent radiation damage at room temperature in these Cu/V multilayers is systematically investigated with a peak dose in the range of 1-12 dpa. Peak bubble density increases with increasing dose, but it is much lower in Cu/V 2.5 nm multilayers than that in Cu/V 50 nm specimens. A similar radiation hardening trend is observed in multilayers irradiated at different fluences. Radiation hardening increases with dose and seems to reach saturation at a peak dose of 6 dpa. Negligible hardening for fine ( h less than/equal to 2.5 nm) multilayers is observed at all dose levels. Thermal stability of Cu/V multilayers is revealed by in situ annealing inside a transmission electron microscope. During isothermal annealing at 600 degrees C grain boundary grooving occurs across layer interfaces in Cu/V 50 nm specimens, whereas Cu/V 5 nm multilayers appear rather stable. Annealing of Cu/V multilayers at 400 degrees C leads to hardening of multilayers, whereas softening occurs in Cu/V multilayers annealed at 600 degrees C. The evolution of mechanical properties during annealing is correlated to the degradation of the layer interface and the consequent reduction of interface resistance to the transmission of single dislocation.

Fu, Engang

2009-08-01T23:59:59.000Z

367

STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS  

DOE Green Energy (OSTI)

Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible hydrocarbons, CO, or NO{sub x} and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at low to intermediate1 temperatures tremendous benefits may be accrued. At low temperatures, in particular, it becomes feasible to use ferritic steel for interconnects instead of expensive and brittle ceramic materials such as those based on LaCrO{sub 3}. In addition, sealing the fuel cell becomes easier and more reliable; rapid start-up is facilitated; thermal stresses (e.g., those caused by thermal expansion mismatches) are reduced; radiative losses ({approx}T{sup 4}) become minimal; electrode sintering becomes negligible and (due to a smaller thermodynamic penalty) the SOFC operating cycle (heating from ambient) would be more efficient. Combined, all these improvements further result in reduced initial and operating costs. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research are to develop a stable high conductivity (> 0.05 S cm{sup -1} at {le} 550 C) electrolyte for lower temperature SOFCs. This objective is specifically directed toward meeting the lowest (and most difficult) temperature criteria for the 21st Century Fuel Cell Program. Meeting this objective provides a potential for future transportation applications of SOFCs, where their ability to directly use hydrocarbon fuels could permit refueling within the existing transportation infrastructure. In order to meet this objective we are developing a functionally gradient bilayer electrolyte comprised of bismuth oxide on the air side and ceria on the fuel side. Bismuth oxide and doped ceria are among the highest ionic conducting electrolytes and in fact bismuth oxide based electrolytes are the only known solid oxide electrolytes to have an ionic conductivity that meets the program conductivity goal.

Eric D. Wachsman; Keith L. Duncan

2001-09-30T23:59:59.000Z

368

Hydrogen diffusion and chemistry during the annealing-induced generation of mobile protons in the oxide layer of Si/SiO{sub 2}/Si capacitors  

DOE Green Energy (OSTI)

In a number of recent studies the generation of mobile protons in the buried oxide of SOI materials and in thermal oxide buried underneath a poly-Si layer has been discussed. The protons are found to be stable and can be easily rearranged by applying an electric field. The details of the hydrogen reactions leading to the generation of the mobile H{sup +} are still under investigation. In a recent work a dynamic equilibrium model was presented. The forward reaction dominates above {approximately} 500 C and the resulting H{sup +} is mobile and entrapped inside the SiO{sub 2}. The electron is donated to the Si. The H{sup 0} is likely to be formed through H{sub 2} + K {Leftrightarrow} HK + H{sup 0}, where K is a cracking site. In the same work it was shown that the reactive hydrogen species enter the oxide from the device edges. Hence, the amount of the reactive species reaching the oxide by diffusion through the Si overlayer is negligible. These results seem to contradict earlier studies where it is shown that hydrogen can easily diffuse through the top Si layer under the given experimental conditions. The authors present here new details on hydrogen diffusion and chemistry during the protonation anneal that may offer an explanation for the hydrogen diffusion paradox. The new findings suggest that reactions at the ambient/SiO{sub 2} interface play a key role.

Vanhuesden, K. [Air Force Research Lab., Kirtland AFB, NM (United States). Space Electronics and Protection Branch; Devine, R.A.B. [France Telecom/CNET, Meylan (France); Fleetwood, D.M.; Warren, W.L. [Sandia National Labs., Albuquerque, NM (United States)

1998-09-01T23:59:59.000Z

369

Quantifying the Effects of Interfacial Electric Fields and Local Crystallinity on Polymer-Fullerene Bulk Heterojunction Solar Cell Performance  

Science Conference Proceedings (OSTI)

The challenges of experimentally probing the physical and electronic structures of the highly intermixed organic semiconductor blends that comprise active layers in high-performance organic photovoltaic (OPV) cells ultimately limit the fundamental understanding of the device performance. We use Fourier-transform IR (FTIR)-absorption spectroscopy to quantitatively determine the interfacial electric field in blended poly(3-hexylthiophene) (P3HT):phenyl- C61-butyric acid methyl ester (PCBM) thin films. The interfacial electric field is {approx}0.2 V nm{sup -1} in the as-spun film and blends annealing at temperatures as high as 150 C, which is the optimal annealing temperature in terms of OPV performance. The field decreases to a negligible value upon further annealing to 170 C, at which temperature PCBM changes from amorphous to crystalline and the open-circuit voltage of the solar cell decreases from 0.62 to 0.4 V. In addition, our measurements also allow determination of the absolute degree of crystallinity within the acceptor material. The roles of interfacial field and local crystallinity in OPV device performance are discussed.

Gearba, R.I.; Black, C.; Mills, T.; Morris, J.; Pindak, R.; Zhu, X.-Y.

2011-05-17T23:59:59.000Z

370

The occurrence and distribution of erionite at Yucca Mountain, Nevada  

SciTech Connect

We have conducted an investigation to determine the occurrence and distribution of erionite, a potential carcinogen, at Yucca Mountain, Nevada. Using x-ray powder diffraction techniques yielding detection limits to below 0.05 wt %, we positively identified erionite in only 3 out of 76 bulk and 12 fracture samples investigated. The three erionite-bearing samples (J12-620/630, UE-25aNo.1-1296.2, and USW G4-1314) all occur above the static water level in clay/zeolite-rich horizons near the top of vitrophyres. Erionite occurs as trace amounts of less than 1 wt % in the whole rock, although it may occur locally in significant amounts as fracture fillings (e.g., UE-25aNo.1-1296.2 where it comprises approximately 45 wt % of the fracture filling material). All three occurrences appear to be extremely isolated cases since erionite was not detected in neighboring samples. Erionite at Yucca Mountain apparently formed only in localized microenvironments, possibly restricted to fractures. Since erionite occurs in trace amounts only in extremely isolated instances, it should pose little or no health hazard to workers in the potential repository at Yucca Mountain or to the public. The amounts of erionite liberated to the biosphere should be negligible, particularly when compared with the amounts of erionite occurring naturally at the surface in Nevada and surrounding states. 24 refs., 7 figs., 2 tabs.

Chipera, S.J.; Bish, D.L.

1989-09-01T23:59:59.000Z

371

Tracking Progress in Reducing Mercury Air Emissions Compiled by the Northeast States for Coordinated Air Use Management (NESCAUM)  

E-Print Network (OSTI)

The Northeast states have taken steps since at least the 1990s to reduce and eliminate mercury emitted to the air from local sources. These steps occurred despite objections often raised against them asserting that they would be ineffective. The objections typically invoke the existence of a global pool of mercury created by mercury emissions from around the world that dominates local and regional mercury deposition. According to this argument, local and regional mercury emission reductions should have negligible benefits for the local and regional environment because the reductions will be overwhelmed by mercury deposition from the global mercury pool. While a global mercury pool does exist, a wealth of real world observations shows that changes in local and regional mercury air emissions are in fact readily seen within fairly short time periods in the local and regional environment. This is indeed borne out by the results seen in the Northeast and elsewhere in the United States. The following sections present the results of scientific studies showing local and regional connections between changes in mercury air emissions and changes in mercury appearing in the environment. These are grouped according to the type of mercury emission source: 1) mercury from coal combustion, 2) mercury from waste incineration, and 3) mercury from smelters. While the main focus is on the Northeast, we include studies from outside the region to further illustrate the connections between changes in local and regional mercury emissions and changes in mercury found in the environment.

unknown authors

2007-01-01T23:59:59.000Z

372

Effects of the Sun's time-retarded gravitational field on the orbital motions of Mercury and Halley's Comet  

E-Print Network (OSTI)

The neoclassical causal version for Newton's acausal gravitational theory explains exactly the anomalous speed-changes observed for six Earth flybys and an anomalous lunar orbital speed-change (arXiv:1105.3857v10). This article estimates the effects of the neoclassical causal theory on the orbital motions of two objects revolving around the Sun, Mercury and Halley's Comet. The change in the period for Mercury is predicted to be about +1.86 ms per year, and the predicted change in the angle for perihelion is -0.032 arc seconds per century, for which the magnitude is negligible compared with the relativistic advance of +43 arc seconds per century. The period for Halley's Comet, 75.3 years, is predicted to decrease by about 10 minutes. Therefore, the neoclassical causal theory does not conflict with general relativity theory, and it is not the cause for a delay of one or two weeks in the return time of Halley's Comet.

J. C. Hafele

2011-11-28T23:59:59.000Z

373

Xe-135 Production from Cf-252  

Science Conference Proceedings (OSTI)

135Xe is a good indicator that fission has occurred and is a valuable isotope that helps enforce the Comprehensive Test Ban Treaty. Due to its rather short half life and minimal commercial interest, there are no known sources where 135Xe can be purchased. Readily available standards of this isotope for calibrating collection and analytical techniques would be very useful. 135Xe can be produced in the fissioning of actinide isotopes, or by neutron capture on 134Xe. Since the neutron capture cross section of 134Xe is 3 mB, neutron capture is a low yield, though potentially useful, production route. 135Xe is also produced by spontaneous fission of 252Cf. 252Cf has a spontaneous fission rate of about 6 x 1011 s-1g-1. The cumulative yield from the spontaneous fission of 252Cf is 4.19%; and the competing neutron capture reaction that depletes 135Xe in thermal reactor systems is negligible because the neutron capture cross-section is low for fast fission neutrons. At the INL, scientists have previously transported fission products from an electroplated 252Cf thin source for the measurement of nuclear data of short-lived fission products using a technique called He-Jet collection. We have applied a similar system to the collection of gaseous 135Xe, in order to produce valuable standards of this isotope.

C. A. McGrath; T. P. Houghton; J. K. Pfeiffer; R. K. Hague

2012-03-01T23:59:59.000Z

374

Improved Characterization of Transmitted Wavefront Error on CADB Epoxy-Free Bonded Solid State Laser Materials  

Science Conference Proceedings (OSTI)

Current state-of-the-art and next generation laser systems - such as those used in the NIF and LIFE experiments at LLNL - depend on ever larger optical elements. The need for wide aperture optics that are tolerant of high power has placed many demands on material growers for such diverse materials as crystalline sapphire, quartz, and laser host materials. For such materials, it is either prohibitively expensive or even physically impossible to fabricate monolithic pieces with the required size. In these cases, it is preferable to optically bond two or more elements together with a technique such as Chemically Activated Direct Bonding (CADB{copyright}). CADB is an epoxy-free bonding method that produces bulk-strength bonded samples with negligible optical loss and excellent environmental robustness. The authors have demonstrated CADB for a variety of different laser glasses and crystals. For this project, they will bond quartz samples together to determine the suitability of the resulting assemblies for large aperture high power laser optics. The assemblies will be evaluated in terms of their transmitted wavefront error, and other optical properties.

Bayramian, A

2010-12-09T23:59:59.000Z

375

Multiplexed single-molecule measurements with magnetic tweezers  

SciTech Connect

We present a method for performing multiple single-molecule manipulation experiments in parallel with magnetic tweezers. We use a microscope with a low magnification, and thus a wide field of view, to visualize multiple DNA-tethered paramagnetic beads and apply an optimized image analysis routine to track the three-dimensional position of each bead simultaneously in real time. Force is applied to each bead using an externally applied magnetic field. Since variations in the field parameters are negligible across the field of view, nearly identical manipulation of all visible beads is possible. However, we find that the error in the position measurement is inversely proportional to the microscope's magnification. To mitigate the increased error caused by demagnification, we have developed a strategy based on tracking multiple fixed beads. Our system is capable of simultaneously manipulating and tracking up to 34 DNA-tethered beads at 60 Hz with {approx}1.5 nm resolution and with {approx}10% variation in applied force.

Ribeck, Noah [Physics Department, University of California, Santa Barbara, Santa Barbara, California 93106 (United States); Saleh, Omar A. [Materials Department and Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93106 (United States)

2008-09-15T23:59:59.000Z

376

Equation of state and phase diagram of FeO  

Science Conference Proceedings (OSTI)

Wuestite, Fe{sub 1-x}O, is an important component in the mineralogy of Earth's lower mantle and may also be a component in the core. Therefore the high pressure, high temperature behavior of FeO, including its phase diagram and equation of state, is essential knowledge for understanding the properties and evolution of Earth's deep interior. We performed X-ray diffraction measurements using a laser-heated diamond anvil cell to achieve simultaneous high pressures and temperatures. Wuestite was mixed with iron metal, which served as our pressure standard, under the assumption that negligible oxygen dissolved into the iron. Our data show a positive slope for the subsolidus phase boundary between the B1 and B8 structures, indicating that the B1 phase is stable at the P-T conditions of the lower mantle and core. We have determined the thermal equation of state of B1 FeO to 156 GPa and 3100 K, finding an isothermal bulk modulus K{sub 0} = 149.4 {+-} 1.0 GPa and its pressure derivative K'{sub 0} = 3.60 {+-} 0.4. This implies that 7.7 {+-} 1.1 wt.% oxygen is required in the outer core to match the seismologically-determined density, under the simplifying assumption of a purely Fe-O outer core.

Fischer, Rebecca A.; Campbell, Andrew J.; Shofner, Gregory A.; Lord, Oliver T.; Dera, Przemyslaw; Prakapenka, Vitali B. (Bristol); (Maryland); (UC)

2012-04-11T23:59:59.000Z

377

Optimal Performance of Quantum Refrigerators  

E-Print Network (OSTI)

A reciprocating quantum refrigerator is studied with the purpose of determining the limitations of cooling to absolute zero. We find that if the energy spectrum of the working medium possesses an uncontrollable gap, then there is a minimum achievable temperature above zero. Such a gap, combined with a negligible amount of noise, prevents adiabatic following during the demagnetization stage which is the necessary condition for reaching $T_c \\to 0$. The refrigerator is based on an Otto cycle where the working medium is an interacting spin system with an energy gap. For this system the external control Hamiltonian does not commute with the internal interaction. As a result during the demagnetization and magnetization segments of the operating cycle the system cannot follow adiabatically the temporal change in the energy levels. We connect the nonadiabatic dynamics to quantum friction. An adiabatic measure is defined characterizing the rate of change of the Hamiltonian. Closed form solutions are found for a constant adiabatic measure for all the cycle segments. We have identified a family of quantized frictionless cycles with increasing cycle times. These cycles minimize the entropy production. Such frictionless cycles are able to cool to $T_c=0$. External noise on the controls eliminates these frictionless cycles. The influence of phase and amplitude noise on the demagnetization and magnetization segments is explicitly derived. An extensive numerical study of optimal cooling cycles was carried out which showed that at sufficiently low temperature the noise always dominates restricting the minimum temperature.

Tova Feldmann; Ronnie Kosloff

2009-06-04T23:59:59.000Z

378

Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet (VUV) synchrotron ionization quadrupole mass spectrometry: Application to low--temperature kinetics and product detection  

SciTech Connect

A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radicalneutralchemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has beendeveloped that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion withexcellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by theairfoil is negligible. The reaction of C2H with C2H2 is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification basedon the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic ratesclose to the collision-determined limit.

Soorkia, Satchin; Liu, Chen-Lin; Savee, John D.; Ferrell, Sarah J.; Leone, Stephen R.; Wilson, Kevin R.

2011-10-12T23:59:59.000Z

379

Kinetic studies of dry sorbents for medium temperature application. Final report, September 1, 1993--August 31, 1994  

SciTech Connect

The purpose of this project is to study the fundamental nature of the sorbent reactivity and reaction kinetics in the medium temperature range from 600{degrees}F to 1200{degrees}F available in the convective pass of a boiler upstream of the economizer, where dry sorbents are injected to remove SO{sub 2} from the flue gas. Research focus is on the fundamental mechanisms of sorbent-flue gas interaction under economizer and hot baghouse conditions utilizing the experimental setup and the results of the first three years of research. During the fourth year, the interference of carbonation reaction to sulfation reaction was studied as well as the concentration dependency of the sulfation reaction. The data to date showed that the carbonation did not interfere the sulfation reaction rate for reactions taking place less than 1 second. However, there was significant decrease in carbonation conversion when the sulfation reaction took place simultaneously. The levels of SO{sub 2} concentration had negligible effects on reaction rates when the concentration was maintained above 3000 ppM. An n-th order deactivation kinetic model was also developed during the fourth year to model the kinetics of various reactions. This model is particularly useful for the dry sorbent reactions, since the apparent rate constants rapidly decrease during the first 1 second of exposure to various gaseous reactants.

Khang, Soon-Jai; Keener, T.C.; Wang, Zhenwei [Cincinnati Univ., OH (United States)

1995-02-01T23:59:59.000Z

380

Activation of Air and Utilities in the National Ignition Facility  

Science Conference Proceedings (OSTI)

Detailed 3-D modeling of the NIF facility is developed to accurately simulate the radiation environment within the NIF. Neutrons streaming outside the NIF Target Chamber will activate the air present inside the Target Bay and the Ar gas inside the laser tubes. Smaller levels of activity are also generated in the Switchyard air and in the Ar portion of the SY laser beam path. The impact of neutron activation of utilities located inside the Target Bay is analyzed for variety of shot types. The impact of activating TB utilities on dose received by maintenance personnel post-shot is analyzed. The current NIF facility model includes all important features of the Target Chamber, shielding system, and building configuration. Flow of activated air from the Target Bay is controlled by the HVAC system. The amount of activated Target Bay air released through the stack is very small and does not pose significant hazard to personnel or the environment. Activation of Switchyard air is negligible. Activation of Target Bay utilities result in a manageable dose rate environment post high yield (20 MJ) shots. The levels of activation generated in air and utilities during D-D and THD shots are small and do not impact work planning post shots.

Khater, H; Pohl, B; Brererton, S

2010-04-08T23:59:59.000Z

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381

Energy Efficiency: Marketing and Service Potential for Energy Utilities' Industrial Markets  

E-Print Network (OSTI)

On paper, the match-up is simple: plant managers need solutions for energy-driven issues such as fuel bills, emissions compliance, process reliability, and workplace safety. Utilities, with their extensive customer account relationships, would be a superb channel for information outreach to the industrial community, especially if that information is value that attracts and retains customers. In practice, this match-up of industry and utility interests is often difficult to achieve. On the part of manufacturers as well as utilities, the failing is often a function of priorities. These differences are not insurmountable, however, as an array of public energy efficiency resources, already developed and freely available, can be tapped by utilities to better serve customers. Energy efficiency conveys benefits to manufacturers in the form of plant reliability and productivity, while also contributing to utilities' objectives regarding load management, growth, and return on assets. The use of trade allies and Internet communication means that this can be accomplished with negligible effort on the part of hard-pressed utility staff.

Russel, C.; Tate, R.; Tubiolo, A.

2002-04-01T23:59:59.000Z

382

Effect of parasitic refrigeration on the efficiency of magnetic liquefiers  

SciTech Connect

Our studies have shown that magnetic refrigerators have the potential to liquefy cryogens very efficiently. High efficiency is especially important for liquid hydrogen and natural gas applications where the liquefaction costs are a significant fraction of the total liquid cost. One of the characteristics of magnetic refrigerators is the requirement for a high-field superconducting magnet. Providing a 4.2-K bath for this magnet will require a small amount of parasitic refrigeration at 4.2 K even though the rest of the liquefier may be at 110 K (liquid natural gas) or higher. For several different refrigeration power levels at 4.2 K, we have calculated the efficiency of the magnetic liquefier as a function of power, temperature and the 4.2-K refrigerator efficiency. The results show that if the ratio of the thermal load at 4.2 K to the main refrigerator power is 0.001 or less, the effect on the efficiency of the liquefier is negligible at all temperatures below room temperature provided the 4.2-K refrigerator efficiency is high.

Barclay, J.A.; Stewart, W.F.

1982-01-01T23:59:59.000Z

383

Bismuth as a modifier of Au Pd catalyst: Enhancing selectivity in alcohol oxidation by suppressing parallel reaction  

SciTech Connect

Bi has been widely employed as a modifier for Pd and Pt based catalyst mainly in order to improve selectivity. We found that when Bi was added to the bimetallic system AuPd, the effect on activity in alcohol oxidation mainly depends on the amount of Bi regardless its position, being negligible when Bi was 0.1 wt% and detectably negative when the amount was increased to 3 wt%. However, the selectivity of the reactions notably varied only when Bi was deposited on the surface of metal nanoparticles suppressing parallel reaction in both benzyl alcohol and glycerol oxidation. After a careful characterization of all the catalysts and additional catalytic tests, we concluded that the Bi influence on the activity of the catalysts could be ascribed to electronic effect whereas the one on selectivity mainly to a geometric modification. Moreover, the Bi-modified AuPd/AC catalyst showed possible application in the production of tartronic acid, a useful intermediate, from glycerol.

Villa, Alberto [Universita di Milano, Italy; Wang, Di [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Veith, Gabriel M [ORNL; Prati, Laura [Universita di Milano, Italy

2012-01-01T23:59:59.000Z

384

Experimental Measurement of Flow Phenomena in a VHTR Lower Plenum Model  

DOE Green Energy (OSTI)

The Very-High-Temperature Reactor (VHTR) is one of six reactor technologies chosen for further development by the Generation IV International Forum. In addition this system is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. In preparation for the thermal-hydraulics and safety analyses that will be required to confirm the performance of the NGNP, work has begun on readying the computational tools that will be needed to predict the thermal-hydraulics conditions and safety margins of the reactor design. Meaningful feasibility studies for VHTR designs will require accurate, reliable predictions of material temperatures which depend upon the thermal convection in the coolant channels of the core and other components. Unfortunately, one-dimensional system codes for gas-cooled reactors typically underpredict these temperatures, particularly for reduced power operations and hypothesized accident scenarios. Likewise, most turbulence models in general-purpose CFD codes also underpredict these temperatures. Matched-Index-of-Refraction (MIR) fluid dynamics experiments have been designed and built to develop benchmark databases for the assessment of CFD solutions of the momentum equations, scalar mixing and turbulence models for typical VHTR plenum geometries in the limiting case of negligible buoyancy and constant fluid properties.

Hugh M. McIlroy Jr.; Keith G. Condie; Glenn E. McCreery; Donald M. McEligot; Robert J. Pink

2006-06-01T23:59:59.000Z

385

Strategies for Energy Efficient Resource Management of Hybrid Programming Models  

Science Conference Proceedings (OSTI)

Many scientific applications are programmed using hybrid programming models that use both message-passing and shared-memory, due to the increasing prevalence of large-scale systems with multicore, multisocket nodes. Previous work has shown that energy efficiency can be improved using software-controlled execution schemes that consider both the programming model and the power-aware execution capabilities of the system. However, such approaches have focused on identifying optimal resource utilization for one programming model, either shared-memory or message-passing, in isolation. The potential solution space, thus the challenge, increases substantially when optimizing hybrid models since the possible resource configurations increase exponentially. Nonetheless, with the accelerating adoption of hybrid programming models, we increasingly need improved energy efficiency in hybrid parallel applications on large-scale systems. In this work, we present new software-controlled execution schemes that consider the effects of dynamic concurrency throttling (DCT) and dynamic voltage and frequency scaling (DVFS) in the context of hybrid programming models. Specifically, we present predictive models and novel algorithms based on statistical analysis that anticipate application power and time requirements under different concurrency and frequency configurations. We apply our models and methods to the NPB MZ benchmarks and selected applications from the ASC Sequoia codes. Overall, we achieve substantial energy savings (8.74% on average and up to 13.8%) with some performance gain (up to 7.5%) or negligible performance loss.

Li, Dong [ORNL; Supinski, Bronis de [Lawrence Livermore National Laboratory (LLNL); Schulz, Martin [Lawrence Livermore National Laboratory (LLNL); Nikolopoulos, Dimitrios S [Virginia Polytechnic Institute and State University; Cameron, Kirk W. [Virginia Polytechnic Institute and State University

2013-01-01T23:59:59.000Z

386

Hiroshima and Nagasaki initial radiations: delayed neutron contributions and comparison of calculated and measured cobalt activations  

SciTech Connect

Calculated estimates of neutron doses received by atomic-bomb survivors at Hiroshima and Nagasaki have not included contributions from delayed neutrons emitted by fission products in the debris cloud, although the possibility of a significant contribution from this source has been suggested. In the present work, an established model accounting for gamma-ray kermas from these fission products is adapted to provide the desired neutron kerma estimates. Adaptations include use of explicit time dependence of neutron emitters, properly folded with the time-dependent phenomenology of the explosion itself, and detailed air-over-ground neutron transport with a source having an energy spectrum characteristic of these delayed neutrons. Results show that delayed neutrons are indeed negligible contributors to atomic-bomb survivor dosimetry, as well as to neutron activations at Hiroshima. About half the activation at Nagasaki, however, is due to the delayed component. Calculated activation of cobalt, a revision of previous estimates, is compared to measured values at Hiroshima and at Nagasaki. The causes of the substantial discrepancies are discussed and compared to previously reported discrepancies for sulfur activation. Additional investigation is recommended.

Loewe, W.E.

1985-03-01T23:59:59.000Z

387

Stray RF Power Estimates From EC Exploitation During ITER Plasma Operations  

SciTech Connect

The EC H and CD system of ITER tokamak is an essential tool for all the phases of ITER operation. Different levels of EC power are required through all the plasma discharge: up to 6.7 MW for assisting the breakdown and burn through, up to 20 MW for current drive and saw-teeth control from the equatorial launcher and up to 20 MW for NTM stabilization from the upper launchers. The assistance to breakdown and burn through is characterized by a very low (if not negligible) RF power absorption by the plasma. A significant level of stray radiation may also arise from partial absorption due to non-optimal plasma parameters and/or wrong injected polarization. The stray power radiated in the vacuum chamber is estimated as a first step toward mitigating potential harmful consequence to in-vessel structures and diagnostics. Power loading of the chamber walls (peek power and average power density for straight beam propagation in the empty chamber) and diffuse stray radiation effects are simulated to infer suitable strategies to avoid damage to first wall and to microwave sensitive components.

Gandini, F.; Henderson, M.; Darbos, C.; Gassmann, T.; Purohit, D.; Omori, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Nazare, C. [Assystem Facilities, 78067 Saint Quentin en Yvelines Cedex (France)

2011-12-23T23:59:59.000Z

388

Iterated and irreducible pion-photon exchange in nuclei  

E-Print Network (OSTI)

We calculate the contribution to the nuclear energy density functional which arises from iterated pion-photon exchange between nucleons. In heavy nuclei, this novel charge symmetry breaking interaction leads to an additional binding of each proton by about 0.2 MeV. Compared to that the analogous effect from irreducible pion-photon exchange is negligibly small. As a possible mechanism to resolve the Nolen-Schiffer anomaly we propose the iteration of one-photon exchange with an attractive short-range NN-interaction. The corresponding energy per proton reads: $\\bar E[\\rho_p]=(2\\alpha/15\\pi^2)(\\pi^2 -3+6 \\ln2) {\\cal A}_{pp} k_p^2$ with $\\rho_p =k_p^3/ 3\\pi^2$ the proton density and ${\\cal A}_{pp}\\approx 2 $fm an effective (in-medium) scattering length. Hints for such a value of ${\\cal A}_{pp}$ come from phenomenological Skyrme forces and from the neutron matter equation of state.

N. Kaiser

2003-12-16T23:59:59.000Z

389

HEU age determination  

SciTech Connect

A new technique has been developed to determine the age of highly enriched uranium (HEU) in solids. Uranium age is defined as the time since the uranium-containing material was last subjected to a process capable of separating uranium from its radioactive-decay daughters. [Most chemical processing, uranium enrichment, volatilization processes, and phase transformations (especially relevant for uranium hexafluoride) can result in separation of the uranium parent material from the decay-product daughters.] Determination of the uranium age, as defined here, may be relevant in verifying arms-control agreements involving uranium-containing nuclear weapons. The HEU age is determined from the ratios of relevant uranium daughter isotopes and their parents, viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gamma rays and their daughters by alpha spectroscopy. In some of the samples, where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the samples. In this report the methodology and the data for determining the age of two HEU samples are presented.

Moorthy, A.R.; Kato, W.Y.

1997-07-01T23:59:59.000Z

390

Design of a Quantum Source of High-Frequency Gravitational Waves (HFGW) and Test Methodology  

E-Print Network (OSTI)

The generation of High-Frequency Gravitational Waves (HFGW) has been identified as the required breakthrough that will lead to new forms of space propulsion. Many techniques have been devised to generate HFGW, but most of them exhibit marginal efficiency, therefore the power emitted in form of gravitational waves (GW) is orders of magnitude lower than the input power. The gravitational wave counterpart of the LASER, termed Gravitational-wave LASER or "GASER" is the quantum approach to the efficient generation of gravitational waves. Electrons, protons, muons, etc, all have charge and mass, if accelerated they usually lose energy through the very fast electric and magnetic channels, this causes a negligible emission through the gravitational channel. Quantum systems can be engineered to forbid electric and magnetic transitions, therefore the gravitational spin-2 transitions can take place. A class of active materials, suitable for making a GASER based on electronic transitions in the solid state, is identified along with their relevant physical properties. Means for creating coherence and population inversion and means to increase the emission probability are described. The expected performances of the device are derived from quantum gravitational theories. Additional properties of the active materials are considered to enforce the theoretical foundation of the device. A proof-of-concept device, operating at about 1 THz, is described. Experiments are proposed as a natural starting point of the research.

Giorgio Fontana

2004-10-04T23:59:59.000Z

391

Three-neutrino model analysis of the world's oscillation data  

E-Print Network (OSTI)

A model of neutrino oscillation experiments is constructed. The experiments incorporated are: solar neutrinos (Chlorine, Gallium, Super-K, and SNO), reactor neutrinos (Bugey and CHOOZ), beam stop neutrinos (LSND decay at rest and decay in flight), and atmospheric neutrinos. Utilizing this model and the standard three-neutrino mixing extension of the standard model, the data are analyzed. Solutions for the mixing angles and mass-squared differences are found to occur in pairs corresponding to the interchange $\\Delta m^2_{12} \\leftrightarrow \\Delta m^2_{23}$. Two pairs of solutions are found that reasonably reproduce the data, including the LSND data. These solutions are $\\theta_{12}\\approx 0.5$, $\\theta_{13}\\approx 0.1$, $\\theta_{23}\\approx 0.7$, $\\Delta m^2_{12} \\approx 5\\times 10^{-5}$ eV$^2$ and $\\Delta m^2_{23} \\approx 0.2$ eV$^2$ or 2.4 eV$^2$. Other statistically significant solutions are also found which produce negligible oscillations for the LSND experiments.

Latimer, D C

2003-01-01T23:59:59.000Z

392

Compressed Baryonic Matter: from Nuclei to Pulsars  

E-Print Network (OSTI)

Our world is wonderful because of the negligible baryonic part although unknown dark matter and dark energy dominate the Universe. Those nuclei in the daily life are forbidden to fuse by compression due to the Coulomb repulse, nevertheless, it is usually unexpected in extraterrestrial extreme-environments: the gravity in a core of massive evolved star is so strong that all the other forces (including the Coulomb one) could be neglected. Compressed baryonic matter is then produced after supernova, manifesting itself as pulsar-like stars observed. The study of this compressed baryonic matter can not only be meaningful in fundamental physics (e.g., the elementary color interaction at low-energy scale, testing gravity theories, detecting nano-Hertz background gravitational waves), but has also profound implications in engineering applications (including time standard and navigation), and additionally, is focused by Chinese advanced telescopes, either terrestrial or in space. Historically, in 1930s, L. Landau speculated that dense matter at supra-nuclear density in stellar cores could be considered as gigantic nuclei (the prototype of standard model of neutron star), however, we address that the residual compact object of supernova could be of condensed matter of quark clusters. The idea that pulsars are quark-cluster stars was not ruled out during the last decade, and we are expecting to test further by future powerful facilities. (in Chinese)

Renxin Xu

2013-10-12T23:59:59.000Z

393

The extraction of nuclear sea quark distribution and energy loss effect in Drell-Yan experiment  

E-Print Network (OSTI)

The next-to-leading order and leading order analysis are performed on the differential cross section ratio from Drell-Yan process. It is found that the effect of next-to-leading order corrections can be negligible on the differential cross section ratios as a function of the quark momentum fraction in the beam proton and the target nuclei for the current Fermilab and future lower beam proton energy. The nuclear Drell-Yan reaction is an ideal tool to study the energy loss of the fast quark moving through cold nuclei. In the leading order analysis, the theoretical results with quark energy loss are in good agreement with the Fermilab E866 experimental data on the Drell-Yan differential cross section ratios as a function of the momentum fraction of the target parton. It is shown that the quark energy loss effect has significant impact on the Drell-Yan differential cross section ratios. The nuclear Drell-Yan experiment at current Fermilab and future lower energy proton beam can not provide us with more information on the nuclear sea quark distribution.

Chun-Gui Duan; Na Liu; Zhan-Yuan Yan

2006-09-06T23:59:59.000Z

394

PROCESSING OF SODIUM--POTASSIUM NIOBATE CERAMICS.  

SciTech Connect

Sintering studies of undoped (Na{sub 0.5}K{sub 0.5})NbO{sub 3} and the same material doped with 1/2, 1, 2, and 4 mole percent BaO and 2 mole % B{sub 2}O{sub 3} were made. The persistence of a second phase after calcining to form the compound led to a study of reactions occurring during calcination. The calcining of sodium-potassium niobates involves the formation of an intermediate compound (the second phase) and its subsequent reaction with sodium oxide and potassium oxide to form (Na{sub 0.5}K{sub 0.5})NbO{sub 3}. Sintering data show that up to 1/2 mole % BaO added to the system increases the initial densification. However, the sintered bodies then exhibit densification and form sharp cubic grains and large voids. Indications are that a liquid phase is the major contributor to densification of this system through the mechanism of particle rearrangement, and that the contribution of any sintering mechanism to densification is negligible.

Powell, B.R. Jr.

1971-01-01T23:59:59.000Z

395

Radiography apparatus using gamma rays emitted by water activated by fusion neutrons  

DOE Patents (OSTI)

Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the {sup 16}O(n,p){sup 16}N reaction using {sup 14}N-MeV neutrons produced at the neutron source via the {sup 3}H(d,n){sup 4}He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second {sup 16}N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.13 seconds of the activated oxygen is sufficient to permit gamma ray generation at a remote location where the activated water is transported, while not presenting a chemical or radioactivity hazard because the radioactivity falls to negligible levels after 1--2 minutes. 15 figs.

Smith, D.L.; Ikeda, Yujiro; Uno, Yoshitomo

1996-11-05T23:59:59.000Z

396

Uptake of nerve growth factor along peripheral and spinal axons of primary sensory neurons  

E-Print Network (OSTI)

To investigate the distribution of nerve growth factor (NGF) receptors on peripheral and central axons, [lZ51]NGF was injected into the sciatic nerve or spinal cord of adult rats. Accumulation of [lZ51]NGF in lumbar dorsal root ganglia was monitored by gamma emission counting and radioautography. [lz51]NGF, injected endoneurially in small quantities, was taken into sensory axons by a saturable process and was transported retrogradely to their cell bodies at a maximal rate of 2.5 to 7.5 mm/hr. Because very little [‘““I]NGF reached peripheral terminals, the results were interpreted to indicate that receptors for NGF are present on nonterminal segments of sensory axons. The specificity and high affinity of NGF uptake were illustrated by observations that negligible amounts of gamma activity accumulated in lumbar dorsal root ganglia after comparable intraneural injection of [l’“I] cytochrome C or [1251]oxidized NGF. Similar techniques were used to demonstrate avid internalization and retrograde transport of [lz51]NGF by intraspinal axons arising from dorsal root ganglia. Following injection of [lZ51]NGF into lumbar or cervical regions of the spinal cord, neuronal perikarya were clearly labeled in

P. M. Richardson; R. J. Riopelle

1984-01-01T23:59:59.000Z

397

Surface detection, meshing and analysis during large molecular dynamics simulations  

SciTech Connect

New techniques are presented for the detection and analysis of surfaces and interfaces in atomistic simulations of solids. Atomistic and other particle-based simulations have no inherent notion of a surface, only atomic positions and interactions. The algorithms we introduce here provide an unambiguous means to determine which atoms constitute the surface, and the list of surface atoms and a tessellation (meshing) of the surface are determined simultaneously. The algorithms have been implemented and demonstrated to run automatically (on the fly) in a large-scale parallel molecular dynamics (MD) code on a supercomputer. We demonstrate the validity of the method in three applications in which the surfaces and interfaces evolve: void surfaces in ductile fracture, the surface morphology due to significant plastic deformation of a nanoscale metal plate, and the interfaces (grain boundaries) and void surfaces in a nanoscale polycrystalline system undergoing ductile failure. The technique is found to be quite robust, even when the topology of the surfaces changes as in the case of void coalescence where two surfaces merge into one. It is found to add negligible computational overhead to an MD code, and is much less expensive than other techniques such as the solvent-accessible surface.

Dupuy, L M; Rudd, R E

2005-08-01T23:59:59.000Z

398

Plasma Lens for Muon and Neutrino Beams  

SciTech Connect

The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-energy lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma for optimum focusing. The plasma lens is immersed in an additional solenoid magnetic field to facilitate the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. Plasma lenses have the additional advantage of negligible pion absorption and scattering by the lens material and reduced neutrino contamination during anti-neutrino running. Results of particle simulations using plasma lens will be presented.

Kahn,S.A.; Korenev, S.; Bishai, M.; Diwan, M.; Gallardo, J.C.; Hershcovitch, A.; Johnson, B.M.

2008-06-23T23:59:59.000Z

399

Magnetic reconnection at the termination shock in a striped pulsar wind  

E-Print Network (OSTI)

Most of the rotational luminosity of a pulsar is carried away by a relativistic magnetised wind in which the matter energy flux is negligible compared to the Poynting flux. Near the equatorial plane of an obliquely rotating pulsar magnetosphere, the magnetic field reverses polarity with the pulsar period, forming a wind with oppositely directed field lines. This structure is called a striped wind; dissipation of alternating fields in the striped wind is the object of our study. The aim of this paper is to study the conditions required for magnetic energy release at the termination shock of the striped pulsar wind. Magnetic reconnection is considered via analytical methods and 1D relativistic PIC simulations. An analytical condition on the upstream parameters for partial and full magnetic reconnection is derived from the conservation laws of energy, momentum and particle number density across the relativistic shock. Furthermore, by using a 1D relativistic PIC code, we study in detail the reconnection process at the termination shock. We found a very simple criterion for dissipation of alternating fields at the termination shock, depending on the upstream parameters of the flow. 1D relativistic PIC simulations are in agreement with our criterion. Thus, alternating magnetic fields annihilate easily at relativistic highly magnetised shocks.

Jerome Petri; Yuri Lyubarsky

2007-07-12T23:59:59.000Z

400

Electrical Power Savings in Pump and Compressor Networks via Load Management  

E-Print Network (OSTI)

Large industrial plants commonly use multiple parallel units in pump and compressor networks for improved reliability. Sometimes, installed equipment capacity can far exceed actual requirements. This excess capacity can be translated into energy cost savings through “optimum load management”. A key decision parameter in determining the operating policy is the Trigger Point at which to switch from N units to N+1, and vice versa. The Trigger Point is defined as the actual flow rate at which the switching is made to the “ideal” (generally maximum) flow rate at which the switching should be made. At the plant under study, the implicit Trigger Point was generally found to be around 85%, probably because this made it easy to have a smooth transition during the switching operation. A number of pumping and compression networks were analyzed to determine what the potential savings would be if this trigger point were increased to 90 or 95%. The savings potential was found to range from 0 to 23%, with an average of 4.4%. Our study demonstrated that by tightening up operating policies to make sure that the minimum number of machines is being run, significant cost savings are possible with zero capital investment, and negligible sacrifice in operating flexibility or reliability. This paper describes the methodology used, as well as representative results from our study.

Kumana, J. D.; Aseeri, A. S.

2005-01-01T23:59:59.000Z

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401

IMPACT OF A REALISTIC DENSITY STRATIFICATION ON A SIMPLE SOLAR DYNAMO CALCULATION  

SciTech Connect

In our Sun, the magnetic cycle is driven by the dynamo action occurring inside the convection zone, beneath the surface. Rotation couples with plasma turbulent motions to produce organized magnetic fields that erupt at the surface and undergo relatively regular cycles of polarity reversal. Among others, the axisymmetric dynamo models have been proved to be a quite useful tool to understand the dynamical processes responsible for the evolution of the solar magnetic cycle and the formation of the sunspots. Here, we discuss the role played by the radial density stratification on the critical layers of the Sun on the solar dynamo. The current view is that a polytropic description of the density stratification from beneath the tachocline region up to the Sun's surface is sufficient for the current precision of axisymmetric dynamo models. In this work, by using an up-to-date density profile obtained from a standard solar model, which is itself consistent with helioseismic data, we show that the detailed peculiarities of the density in critical regions of the Sun's interior, such as the tachocline, the base of the convection zone, the layers of partial ionization of hydrogen and helium, and the super-adiabatic layer, play a non-negligible role on the evolution of the solar magnetic cycle. Furthermore, we found that the chemical composition of the solar model plays a minor role in the formation and evolution of the solar magnetic cycle.

Cardoso, Elisa; Lopes, Ilidio, E-mail: ilidio.lopes@ist.utl.pt [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

2012-09-20T23:59:59.000Z

402

Study of applied magnetic field magnetoplasmadynamic thrusters with particle-in-cell and Monte Carlo collision. II. Investigation of acceleration mechanisms  

Science Conference Proceedings (OSTI)

The particle-in-cell method previously described in paper (I) has been applied to the investigation of acceleration mechanisms in applied-field magnetoplasmadynamic thrusters. This new approach is an alternative to magnetohydrodynamics models and allows nonlocal dynamic effects of particles and improved transport properties. It was used to model a 100 kW, steady-state, applied-field, argon magnetoplasmadynamic thruster to study the physical acceleration processes with discharge currents of 1000-1500 A, mass flow rates of 0.025-0.1 g/s and applied magnetic field strengths of 0.034-0.102 T. The total thrust calculations were used to verify the theoretical approach by comparison with experimental data. Investigations of the acceleration model offer an underlying understanding of applied-field magnetoplasmadynamic thrusters, including the following conclusions: (1) swirl acceleration mechanism is the dominant contributor to the plasma acceleration, and self-magnetic, Hall, gas-dynamic, and swirl acceleration mechanisms are in an approximate ratio of 1:10:10:100; (2) the Hall acceleration produced mainly by electron swirl is insensitive to the change of externally applied magnetic field and shows only slight increases when the current is raised; (3) self-magnetic acceleration is normally negligible for all cases, while the gas-dynamic acceleration contribution increases with increasing applied magnetic field strength, discharge current, and mass flow rate.

Tang Haibin; Cheng Jiao; Liu Chang [School of Astronautics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); York, Thomas M. [Aeronautical and Astronautical Engineering Department, Ohio State University, Columbus, Ohio 43235 (United States)

2012-07-15T23:59:59.000Z

403

The Role of Environment in the Mass-Metallicity Relation  

E-Print Network (OSTI)

Using a sample of 57,377 star-forming galaxies drawn from the Sloan Digital Sky Survey, we study the relationship between gas-phase oxygen abundance and environment in the local Universe. We find that there is a strong relationship between metallicity and environment such that more metal-rich galaxies favor regions of higher overdensity. Furthermore, this metallicity-density relation is comparable in strength to the color-density relation along the blue cloud. After removing the mean dependence of environment on color and luminosity, we find a significant residual trend between metallicity and environment that is largely driven by galaxies in high-density regions, such as groups and clusters. We discuss the potential source of this relationship between metallicity and local galaxy density in the context of feedback models, with special attention paid to quantifying the impact of environment on the scatter in the mass-metallicity relation. We find that environment is a non-negligible source of scatter in this fundamental relation, with > 15% of the measured scatter correlated with environment.

Michael C. Cooper; Christy A. Tremonti; Jeffrey A. Newman; Ann I. Zabludoff

2008-05-02T23:59:59.000Z

404

Constant-pressure measurement of steam-water relative permeability  

DOE Green Energy (OSTI)

A series of steady-state experiments have established relative permeability curves for two-phase flow of water in a porous medium. These experiments have minimized uncertainty in pressure, heat loss, and saturation. By attempting to maintain a constant pressure gradient, the experiments have provided a baseline from which to determine the effect of temperature on relative permeability. The use of a flexible heater with an automatic control system made it possible to assume negligible phase change for the mobile fluid. X-ray computer tomography (CT) aided by measuring in-situ steam saturation more directly. Mobile steam mass fraction was established by separate steam and water inlets or by correlating with previous results. The measured steam-water relative permeability curves assume a shape similar to those obtained by Corey (1954) for the simultaneous flow of nitrogen and water. Close agreement between the curves by Satik (1998), Mahiya (1999), and this study establishes the reliability of the experimental method and instrumentation adopted in these experiments, though some differences may bear further investigation. In particular, the steam phase relative permeability appears to vary much more linearly with saturation than does the water phase relative permeability.

O'Connor, Peter A.

2001-06-01T23:59:59.000Z

405

Hepatic Arterial Embolization with Doxorubicin-Loaded Superabsorbent Polymer Microspheres in a Rabbit Liver Tumor Model  

SciTech Connect

Objectives: The pharmacokinetic profile after hepatic arterial embolization with superabsorbent microspheres (QuadraSpheres) loaded with doxorubicin was studied. Methods: Rabbits with hepatic VX2 tumors were treated with intra-arterial administration of QuadraSpheres loaded with doxorubicin, or transarterial chemoembolization (TACE) using doxorubicin, Lipiodol and Embospheres, or hepatic arterial infusion (HAI) of doxorubicin. Tumor specimens were evaluated by fluorescence microscopy, and plasma and tumor concentrations of doxorubicin were measured. Results: The peak plasma concentration of doxorubicin was lower in the QuadraSphere group (309.9 ng/ml) than in the HAI (673.4 ng/ml) or TACE (360.5 ng/ml) groups, suggesting higher tumor retention in the QuadraSphere group. Intratumoral doxorubicin levels declined to negligible levels at 1 and 3 days after treatment, respectively, in the HAI and TACE groups. In the QuadraSphere groups, intratumoral doxorubicin level declined after day 1, but was still detectable at 14 days after treatment and was higher than that in the other groups at 1, 3, and 7 days. Intratumoral doxorubicin fluorescence was detected at all time points in the QuadraSphere group, but only at 1 day after treatment in the TACE group. Conclusions: Hepatic arterial administration of doxorubicin-loaded QuadraSpheres enables the sustained release of doxorubicin to hepatic tumors.

Gupta, Sanjay, E-mail: sgupta@mdanderson.org; Wright, Kenneth C. [University of Texas M. D. Anderson Cancer Center, Department of Diagnostic Radiology (United States); Ensor, Joe [University of Texas M. D. Anderson Cancer Center, Department of Biostatistics (United States); Van Pelt, Carolyn S. [University of Texas M. D. Anderson Cancer Center, Department of Veterinary Medicine and Surgery (United States); Dixon, Katherine A.; Kundra, Vikas [University of Texas M. D. Anderson Cancer Center, Department of Diagnostic Radiology (United States)

2011-10-15T23:59:59.000Z

406

Colloidal gold nanoparticle probe-based immunochromatographic assay for the rapid detection of chromium ions in water and serum samples  

SciTech Connect

An immunochromatographic assay (ICA) using gold nanoparticles coated with monoclonal antibody (McAb) for the detection of chromium ions (Cr) in water and serum samples was developed, optimized, and validated. Gold nanoparticles coated with affinity- purified monoclonal antibodies against isothiocyanobenzyl-EDTA (iEDTA)-chelated Cr3+ were used as the detecting reagent in this completive immunoassay-based one- step test strip. The ICA was investigated to measure chromium speciation in water samples. Chromium standard samples of 0-80 ng/mL in water were determined by the test strips. The results showed that the visual lowest detection limit (LDL) of the test strip was 50.0 ng/mL. A portable colorimetric lateral flow reader was used for the quantification of Cr. The results indicated that the linear range of the ICA with colorimetric detection was 5-80 ng/mL. The ICA was also validated for the detection of chromium ions in serum samples. The test trips showed high stability in that they could be stored at at 37 C for at least 12 weeks without significant loss of activity. The test strip also showed good selectivity for Cr detection with negligible interference from other heavy metals. Because of its low cost and short testing time (within 5 min), the test strip is especially suitable for on-site large- scale screening of Cr-polluted water samples, biomonitoring of Cr exposure, and many other field applications.

Liu, Xi; Xiang, Jun-Jian; Tang, Yong; Zhang, Xiao-Li; Fu, Qiang-Qiang; Zou, Jun-Hui; Lin, Yuehe

2012-09-01T23:59:59.000Z

407

FAQ 37-What are the potential health risks from transportation of depleted  

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

depleted uranium metal or oxide? depleted uranium metal or oxide? What are the potential health risks from transportation of depleted uranium metal or oxide? In the PEIS, risks associated with transportation of depleted uranium oxide and metal were estimated for transport by either rail or truck. Normal transport of oxide or metal would result in low-level external exposure to radiation for persons in the vicinity of a shipment. Based on estimates in the PEIS, the levels of exposure would result in negligible increased cancer risks. Risks from material released in an accident were also estimated. For a hypothetical railcar accident involving powder U3O8 that was assumed to occur in a highly-populated urban area under stable (nighttime) weather conditions, it was estimated that up to 20 people might experience irreversible adverse effects from chemical toxicity, with no fatalities expected. Approximately 2 potential latent cancer fatalities from radiological hazards are estimated for an accident under the same conditions. The probability of such an accident occurring is very low. The consequences from a truck accident would be lower, because trucks have a smaller shipment capacity. The consequences of transportation accidents involving depleted uranium metal would be much smaller than those involving uranium oxide because uranium metal would be in the form of solid blocks and would not be easily dispersed in an accident.

408

Fermilab Steering Group Report  

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

E: Muon-to-electron conversion in nuclei E: Muon-to-electron conversion in nuclei With the discovery of neutrino masses and mixings we have learned that neutral lepton flavor quantum numbers are violated in nature. An immediate question arises: "Does lepton flavor violation also occur at an appreciable rate with the charged leptons?" While the Standard Model predicts negligible rates for charged lepton flavor violation, many models, including various versions of supersymmetry, predict CLFV at an appreciable and potentially observable rate. Searches for CLFV are the most powerful and promising probes for new physics at and above the TeV scale. illustration The sensitivity to a new physics scale Λ in a μ→e conversion experiment in 48Ti that can probe a normalized capture rate of 10-17 and 10-19, and a μ→eγ search that is sensitive to a branching ratio of 10-13. The sensitivity is plotted as a function of κ, a parameter that interpolates between a fl avor transition magnetic moment-type operator (κ>1). Also depicted is the region already excluded from searches for both μ→eγ and μ→e conversion in 48Ti.

409

FAQ 5-Is uranium radioactive?  

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

Is uranium radioactive? Is uranium radioactive? Is uranium radioactive? All isotopes of uranium are radioactive, with most having extremely long half-lives. Half-life is a measure of the time it takes for one half of the atoms of a particular radionuclide to disintegrate (or decay) into another nuclear form. Each radionuclide has a characteristic half-life. Half-lives vary from millionths of a second to billions of years. Because radioactivity is a measure of the rate at which a radionuclide decays (for example, decays per second), the longer the half-life of a radionuclide, the less radioactive it is for a given mass. The half-life of uranium-238 is about 4.5 billion years, uranium-235 about 700 million years, and uranium-234 about 25 thousand years. Uranium atoms decay into other atoms, or radionuclides, that are also radioactive and commonly called "decay products." Uranium and its decay products primarily emit alpha radiation, however, lower levels of both beta and gamma radiation are also emitted. The total activity level of uranium depends on the isotopic composition and processing history. A sample of natural uranium (as mined) is composed of 99.3% uranium-238, 0.7% uranium-235, and a negligible amount of uranium-234 (by weight), as well as a number of radioactive decay products.

410

bbmix-web.dvi  

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

and and 2013 update for the 2014 edition (URL: http://pdg.lbl.gov) December 18, 2013 11:56 - 2- q b _ t t W + W - q _ b q b _ W W t _ t q _ b Figure 1: Dominant box diagrams for the B 0 q →B 0 q transitions (q = d or s). Similar diagrams exist where one or both t quarks are replaced with c or u quarks. Standard Model predictions and phenomenology In the Standard Model, the transitions B 0 q →B 0 q and B 0 q →B 0 q are due to the weak interaction. They are described, at the lowest order, by box diagrams involving two W bosons and two up-type quarks (see Fig. 1), as is the case for K 0 -K 0 mixing. However, the long range interactions arising from intermediate virtual states are negligible for the neutral B meson systems, because the large B mass is off the region of hadronic resonances. The calculation of the dispersive and absorptive parts of the box diagrams yields the following predictions for the off-diagonal element

411

Making a splash with water repellency  

E-Print Network (OSTI)

A 'splash' is usually heard when a solid body enters water at large velocity. This phenomena originates from the formation of an air cavity resulting from the complex transient dynamics of the free interface during the impact. The classical picture of impacts on free surfaces relies solely on fluid inertia, arguing that surface properties and viscous effects are negligible at sufficiently large velocities. In strong contrast to this large-scale hydrodynamic viewpoint, we demonstrate in this study that the wettability of the impacting body is a key factor in determining the degree of splashing. This unexpected result is illustrated in Fig.1: a large cavity is evident for an impacting hydrophobic sphere (1.b), contrasting with the hydrophilic sphere's impact under the very same conditions (1.a). This unforeseen fact is furthermore embodied in the dependence of the threshold velocity for air entrainment on the contact angle of the impacting body, as well as on the ratio between the surface tension and fluid viscosity, thereby defining a critical capillary velocity. As a paradigm, we show that superhydrophobic impacters make a big 'splash' for any impact velocity. This novel understanding provides a new perspective for impacts on free surfaces, and reveals that modifications of the detailed nature of the surface -- involving physico-chemical aspects at the nanometric scales -- provide an efficient and versatile strategy for controlling the water entry of solid bodies at high velocity.

Cyril Duez; Christophe Ybert; Christophe Clanet; Lyderic Bocquet

2007-01-05T23:59:59.000Z

412

Coulomb and nuclear breakup of $^8$B  

E-Print Network (OSTI)

The cross sections for the ($^8$B,$^7$Be-$p$) breakup reaction on $^{58}$Ni and $^{208}$Pb targets at the beam energies of 25.8 MeV and 415 MeV have been calculated within a one-step prior-form distorted-wave Born approximation. The relative contributions of Coulomb and nuclear breakup of dipole and quadrupole multipolarities as well as their interference have been determined. The nuclear breakup contributions are found to be substantial in the angular distributions of the $^7$Be fragment for angles in the range of 30$^\\circ$ - 80$^\\circ$ at 25.8 MeV beam energy. The Coulomb-nuclear interference terms make the dipole cross section larger than that of quadrupole even at this low beam energy. However, at the incident energy of 415 MeV, these effects are almost negligible in the angular distributions of the ($^7$Be-p) coincidence cross sections at angles below 4$^\\circ$.

R. Shyam; I. J. Thompson

1998-08-27T23:59:59.000Z

413

OTEC performance tests of the Union Carbide enhanced-tube condenser  

DOE Green Energy (OSTI)

Results of performance tests conducted on a Union Carbide enhanced-tube condenser with wire wrapping on the ammonia side and internal axial fins on the water side are reported. This unit performed satisfactorily and was free of operational difficulties. At design operating conditions (a heat duty of 3.2 million Btu/h, an inlet water temperature of 40/sup 0/F, and a water flow rate of 3200 gpm) the steady-state value of the overall heat transfer coefficient was found to be 818 Btu/h.ft/sup 2/./sup 0/F, and the ammonia-side and water-side heat transfer coefficients were 5180 and 1130 Btu/h.ft/sup 2/./sup 0/F, respectively. The water-side pressure drop was 1.8 psi. Varying the heat duty from 2.4 million to 4.0 million Btu/h had a negligible effect on thermal performance. The value obtained for the ammonia-side heat transfer coefficient at nominal conditions is about two times that predicted by the Nusselt expression for condensation on a smooth tube. The water-side coefficient is within 3% of the value predicted by the Noranda correlation for finned tubes.

Yung, D T; Hillis, D L; Lorenz, J J; Sather, N F

1979-05-01T23:59:59.000Z

414

Conceptual design of a 10MW regenerative isobutane geothermal power plant. Technical report No. 18  

DOE Green Energy (OSTI)

At present, there are basically three different systems for converting energy in geothermal fluid into power: vapor-flashing system, total flow system, and binary system. A comparison of the power production processes was made on the basis of work output in Kwh per 1000 pounds of geothermal fluid for self flowing wells with wellhead pressure of 100 psia and for wells with downhole pumps. For simplicity, the assumptions were made that the enthalpy of the geothermal fluid in the reservoir is approximately equal to that at the wellhead, that the thermodynamic properties of geothermal fluid may be approximated by those of water, and that the pressure effects on the properties of fluid are negligible. The results showed that the performance of the two-stage vapor-flashing system is not appreciably improved by using a downhole pump. The total flow system is simple, but its success depends mainly on the development of a reliable machine with sufficiently high thermal efficiency. The regenerative isobutane system is impractical, if the geothermal fluid temperature is below 380/sup 0/F. But, when the brine temperatures range from 485 to 600/sup 0/F, the regenerative isobutane system with downhole pump exhibits superior performance as compared to two-stage vapor-flashing system, basic isobutane system, or total flow system.

Gupta, A.K.; Chou, J.C.S.

1976-10-15T23:59:59.000Z

415

STAR FORMATION HISTORY IN TWO FIELDS OF THE SMALL MAGELLANIC CLOUD BAR  

SciTech Connect

The Bar is the most productive region of the Small Magellanic Cloud in terms of star formation but also the least studied one. In this paper, we investigate the star formation history of two fields located in the SW and in the NE portion of the Bar using two independent and well-tested procedures applied to the color-magnitude diagrams of their stellar populations resolved by means of deep Hubble Space Telescope photometry. We find that the Bar experienced a negligible star formation activity in the first few Gyr, followed by a dramatic enhancement from 6 to 4 Gyr ago and a nearly constant activity since then. The two examined fields differ both in the rate of star formation and in the ratio of recent over past activity, but share the very low level of initial activity and its sudden increase around 5 Gyr ago. The striking similarity between the timing of the enhancement and the timing of the major episode in the Large Magellanic Cloud is suggestive of a close encounter triggering star formation.

Cignoni, M. [Dipartimento di Astronomia, Universita degli Studi di Bologna, via Ranzani, I-40127 Bologna (Italy); Cole, A. A. [School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, Tasmania 7001 (Australia); Tosi, M. [Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Gallagher, J. S. [Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706 (United States); Sabbi, E.; Anderson, J.; Nota, A. [STScI, Baltimore, MD 21218 (United States); Grebel, E. K., E-mail: michele.cignoni@unibo.it [Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstr. 12-14, 69120 Heidelberg (Germany)

2012-08-01T23:59:59.000Z

416

An abstract-device interface for implementing portable parallel-I/O interfaces  

Science Conference Proceedings (OSTI)

Portable parallel programming has been hampered by the lack of a single, standard, portable application-programmer`s interface (API) for parallel I/O. Instead, the programmer must choose from several different APIs, many of which are not portable. To alleviate this problem, the authors have developed an abstract-device interface for parallel I/O, called ADIO. ADIO is not intended as a new API; rather, it is a strategy for implementing other APIs in a simple, portable, and efficient manner. ADIO facilitates the implementation of any existing or new API on any existing or new file system. ADIO thus enables users to experiment with different APIs, a feature that, they think, would help in the definition of a standard API. It also makes existing applications portable across a wide range of platforms. In this paper, they introduce the concept of ADIO. They describe the design of ADIO and its use in implementing APIs. They have currently implemented subsets of the Intel PFS, IBM PIOFS, and MPI-IO APIs on both the PFS and PIOFS file systems. As a result, they are able to run IBM PIOFS applications on the Intel Paragon, Intel PFS applications on the IBM SP, and MPI-IO applications on both systems. They report performance results obtained from two test programs and one real production application on the SP and Paragon. These results indicate that the performance overhead of using ADIO as an implementation strategy is negligible.

Thakur, R.; Gropp, W.; Lusk, E. [Argonne National Lab., IL (United States). Mathematics and Computer Science Div.

1996-12-31T23:59:59.000Z

417

In Summary: Idaho National Engineering and Environmental Laboratory Site Environmental Report for Calendar Year 1997  

SciTech Connect

Scientists from the Environmental Science and Research Foundation, Lockheed Martin Idaho Technologies Company, the US Geological Survey, and other INEEL contractors monitored the environment on and around the INEEL to find contaminants attributable to the INEEL. During 1997, exposures from the INEEL to the public were found to be negligible. Pathways by which INEEL contaminants might reach people were monitored. These included air, precipitation, water, locally grown food (wheat, milk, potatoes, and lettuce), livestock, game animals, and direct radiation. Results from samples collected to monitor these pathways often contain radioactivity from natural sources and nuclear weapons testing carried out in the 1950s and 1960s, termed ''background radioactivity.'' According to the results obtained in 1997, radioactivity from operations at the INEEL could not be distinguished from this background radioactivity in the regions surrounding the INEEL. Because radioactivity from t! he INEEL wa s not detected by offsite environmental surveillance methods, computer models were used to estimate a radiation dose to people. The hypothetical maximum individual dose from the INEEL was calculated to be 0.03 millirem. That is 0.008 percent of an average person's annual dose from background radiation in southeast Idaho.

R. G. Mitchell; D. E. Roush, Jr.; R. B. Evans

1998-10-01T23:59:59.000Z

418

Implant breast reconstruction followed by radiotherapy: Can helical tomotherapy become a standard irradiation treatment?  

SciTech Connect

To evaluate the benefits and limitations of helical tomotherapy (HT) for loco-regional irradiation of patients after a mastectomy and immediate implant-based reconstruction. Ten breast cancer patients with retropectoral implants were randomly selected for this comparative study. Planning target volumes (PTVs) 1 (the volume between the skin and the implant, plus margin) and 2 (supraclavicular, infraclavicular, and internal mammary nodes, plus margin) were 50 Gy in 25 fractions using a standard technique and HT. The extracted dosimetric data were compared using a 2-tailed Wilcoxon matched-pair signed-rank test. Doses for PTV1 and PTV2 were significantly higher with HT (V95 of 98.91 and 97.91%, respectively) compared with the standard technique (77.46 and 72.91%, respectively). Similarly, the indexes of homogeneity were significantly greater with HT (p = 0.002). HT reduced ipsilateral lung volume that received {>=}20 Gy (16.7 vs. 35%), and bilateral lungs (p = 0.01) and neighboring organs received doses that remained well below tolerance levels. The heart volume, which received 25 Gy, was negligible with both techniques. HT can achieve full target coverage while decreasing high doses to the heart and ipsilateral lung. However, the low doses to normal tissue volumes need to be reduced in future studies.

Massabeau, Carole, E-mail: cmassabeau@hotmail.com [Department of Radiation Oncology, Institut Curie, Paris (France); Fournier-Bidoz, Nathalie; Wakil, Georges; Castro Pena, Pablo; Viard, Romain; Zefkili, Sofia; Reyal, Fabien; Campana, Francois; Fourquet, Alain; Kirova, Youlia M. [Department of Radiation Oncology, Institut Curie, Paris (France)

2012-01-01T23:59:59.000Z

419

Primordial helium recombination III: Thomson scattering, isotope shifts, and cumulative results  

E-Print Network (OSTI)

Upcoming precision measurements of the temperature anisotropy of the cosmic microwave background (CMB) at high multipoles will need to be complemented by a more complete understanding of recombination, which determines the damping of anisotropies on these scales. This is the third in a series of papers describing an accurate theory of HeI and HeII recombination. Here we describe the effect of Thomson scattering, the $^3$He isotope shift, the contribution of rare decays, collisional processes, and peculiar motion. These effects are found to be negligible: Thomson and $^3$He scattering modify the free electron fraction $x_e$ at the level of several $\\times 10^{-4}$. The uncertainty in the $2^3P^o-1^1S$ rate is significant, and for conservative estimates gives uncertainties in $x_e$ of order $10^{-3}$. We describe several convergence tests for the atomic level code and its inputs, derive an overall $C_\\ell$ error budget, and relate shifts in $x_e(z)$ to the changes in $C_\\ell$, which are at the level of 0.5% at ...

Switzer, E R; Switzer, Eric R.; Hirata, Christopher M.

2007-01-01T23:59:59.000Z

420

Primordial helium recombination III: Thomson scattering, isotope shifts, and cumulative results  

E-Print Network (OSTI)

Upcoming precision measurements of the temperature anisotropy of the cosmic microwave background (CMB) at high multipoles will need to be complemented by a more complete understanding of recombination, which determines the damping of anisotropies on these scales. This is the third in a series of papers describing an accurate theory of HeI and HeII recombination. Here we describe the effect of Thomson scattering, the $^3$He isotope shift, the contribution of rare decays, collisional processes, and peculiar motion. These effects are found to be negligible: Thomson and $^3$He scattering modify the free electron fraction $x_e$ at the level of several $\\times 10^{-4}$. The uncertainty in the $2^3P^o-1^1S$ rate is significant, and for conservative estimates gives uncertainties in $x_e$ of order $10^{-3}$. We describe several convergence tests for the atomic level code and its inputs, derive an overall $C_\\ell$ error budget, and relate shifts in $x_e(z)$ to the changes in $C_\\ell$, which are at the level of 0.5% at $\\ell =3000$. Finally, we summarize the main corrections developed thus far. The remaining uncertainty from known effects is $\\sim 0.3%$ in $x_e$.

Eric R. Switzer; Christopher M. Hirata

2007-02-06T23:59:59.000Z

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421

An atomic view of surface diffusion on metal surfaces  

SciTech Connect

Investigations of surface diffusion and cluster nucleation by field ion microscopy have provided a considerable amount of physical insight concerning the fundamental interactions that control dynamical processes on surfaces. The investigations rely not only on the FIM`s ability to resolve and track individual atoms on a surface, but also its ability to manipulate the number of adatoms and the size of clusters by the process of field desorption. Results of the investigations are surprising. Whereas metal atom diffusion was once thought to be a simple hopping process, FIM experiments have revealed new mechanisms for atom transport. Whereas cluster nucleation was once thought to be an aggregation process dependent only upon pairwise interactions between atoms, FIM investigations have shown that long-range and many body interactions can make non-negligible contributions to the overall process. By providing a brief overview of the experimental methods used in FIM surface diffusion studies and discussing a few selected applications, I hope to have conveyed some of the rich history as well as the current excitement associated with FIM investigations of dynamical processes on surfaces.

Kellogg, G.L.

1994-08-01T23:59:59.000Z

422

Collisional Particle Disks  

E-Print Network (OSTI)

We present a new, simple, fast algorithm to numerically evolve disks of inelastically colliding particles surrounding a central star. Our algorithm adds negligible computational cost to the fastest existing collisionless N-body codes, and can be used to simulate, for the first time, the interaction of planets with disks over many viscous times. Though the algorithm is implemented in two dimensions-i.e., the motions of bodies need only be tracked in a plane-it captures the behavior of fully three-dimensional disks in which collisions maintain inclinations that are comparable to random eccentricities. We subject the algorithm to a battery of tests for the case of an isolated, narrow, circular ring. Numerical simulations agree with analytic theory with regards to how particles' random velocities equilibrate; how the ring viscously spreads; and how energy dissipation, angular momentum transport, and material transport are connected. We derive and measure the critical value of the coefficient of restitution above which viscous stirring dominates inelastic damping and the particles' velocity dispersion runs away.

Yoram Lithwick; Eugene Chiang

2006-07-11T23:59:59.000Z

423

Mass and temperature limits for blackbody radiation  

E-Print Network (OSTI)

A spherically symmetric distribution of classical blackbody radiation is considered, at conditions in which gravitational self-interaction effects become not negligible. Static solutions to Einstein field equations are searched for, for each choice of the assumed central energy density. Spherical cavities at thermodynamic equilibrium, i.e. filled with blackbody radiation, are then studied, in particular for what concerns the relation among the mass M of the ball of radiation contained in them and their temperature at center and at the boundary. For these cavities it is shown, in particular, that: i) there is no absolute limit to M as well to their central and boundary temperatures; ii) when radius R is fixed, however, limits exist both for mass and for boundary energy density rho_B: M <= K M_S(R) and rho_B <= Q/R^2, with K = 0.493 and Q = 0.02718, dimensionless, and M_S(R) the Schwarzschild mass for that radius. Some implications of the existence and the magnitude of these limits are considered. Finally the radial profiles for entropy for these systems are studied, in their dependence on the mass (or central temperature) of the ball of radiation.

Alessandro Pesci

2006-03-24T23:59:59.000Z

424

Residential space heating cost: geothermal vs conventional systems  

SciTech Connect

The operating characteristics and economies of several representative space heating systems are analyzed. The analysis techniques used may be applied to a larger variety of systems than considered herein, thereby making this document more useful to the residential developer, heating and ventilating contractor, or homeowner considering geothermal space heating. These analyses are based on the use of geothermal water at temperatures as low as 120/sup 0/F in forced air systems and 140/sup 0/F in baseboard convection and radiant floor panel systems. This investigation indicates the baseboard convection system is likely to be the most economical type of geothermal space heating system when geothermal water of at least 140/sup 0/F is available. Heat pumps utilizing water near 70/sup 0/F, with negligible water costs, are economically feasible and they are particularly attractive when space cooling is included in system designs. Generally, procurement and installation costs for similar geothermal and conventional space heating systems are about equal, so geothermal space heating is cost competitive when the unit cost of geothermal energy is less than or equal to the unit cost of conventional energy. Guides are provided for estimating the unit cost of geothermal energy for cases where a geothermal resource is known to exist but has not been developed for use in residential space heating.

Engen, I.A.

1978-02-01T23:59:59.000Z

425

The influence of metal ions on the adsorption of phosphonates onto goethite  

SciTech Connect

Mono- and polyphosphonates, which contain R{sub 3}CP(O)-(OH){sub 2} functional groups, are used in an increasing variety of industrial and household applications including cooling water systems, oil production, textile production, and detergents. The main pathway of phosphonate removal in the environment is via adsorption onto surfaces. This study examines the effect of Ca, Cu, Zn, and Fe{sup III} on the adsorption of six phosphonates onto the iron (hydr)oxide goethite. HEDP, NTMP, EDTMP, and DTPMP are commonly used, while AMP and IDMP have been identified a breakdown products of NTMP. When the molar concentration of Ca, Cu, Zn, and Fe{sup III} is equal to the concentration of the phosphonate, the effects on phosphonate adsorption are either negligible or slight. This can be explained by dissociation of the metal-phosphonate complex and separate adsorption of the metal ion and phosphonate onto different surface sites. When Ca and Zn concentrations are added in excess of the phosphonate concentrations, considerable increases in adsorption are observed, presumably through ternary surface complex formation and adsorption onto precipitated (hydr)oxides of Zn. Excess Ca concentrations can double the maximum surface coverage of NTMP. Phosphonate adsorption at low pH deposits negative charge on (hydr)oxide surfaces and hence increases Cu adsorption through favorable long-range electrostatic interactions.

Nowack, B.; Stone, A.T.

1999-10-15T23:59:59.000Z

426

Renewable Energy for Rural Development in Ethiopia: The Case for New Energy Policies and Institutional Reform. Energy Policy 30  

E-Print Network (OSTI)

This article argues the case for introducing new energy policies in Ethiopia that will ensure energy initiatives for rural development meet the desired expectations. A review of the rural energy sector in Ethiopia is presented. Rural communities have for centuries relied solely on traditional biomass energy sources, human and animal power. In addition, sample findings show that the basic stock of traditional biomass energy resources is dwindling fast for two reasons: one, due to rapid population growth; and two, due to the absence of energy substitutes for traditional energy sources. Renewable energy technologies (RETs) and other modern energy technologies are almost non-existent. In terms of budgetary allocation, rural energy development has not received a fair share of public investment in comparison to education, rural road construction and health. A key policy recommendation made in this article is the need for commitment from concerned authorities to the use of renewables for spurring rural development. This could be through increasing the budget allocation to rural energy, which is currently negligible. Other policy recommendations include the modification of existing institutional frameworks for rural energy delivery, and the design and implementation of appropriate rural energy initiatives suitable for productive activities and sustainable development.

W. Wolde-ghiorgis

2002-01-01T23:59:59.000Z

427

Brownstone and Fang 1 A VEHICLE OWNERSHIP AND UTILIZATION CHOICE MODEL WITH ENDOGENOUS RESIDENTIAL DENSITY  

E-Print Network (OSTI)

This paper explores the impact of residential density on households ’ vehicle type and usage choices using the 2001 National Household Travel Survey (NHTS). Attempts to quantify the effect of urban form on households ’ vehicle choice and utilization often encounter the problem of sample selectivity. Household characteristics that are unobservable to the researchers might determine simultaneously where to live, what vehicles to choose, and how much to drive them. Unless this simultaneity is modeled, any relationship between residential density and vehicle choice may be biased. This paper extends the Bayesian multivariate ordered probit and tobit model developed in Fang (2008) to treat local residential density as endogenous. The model includes equations for vehicle ownership and usage in terms of number of cars, number of trucks (vans, sports utility vehicles, and pickup trucks), miles traveled by cars, and miles traveled by trucks. We carry out policy simulations which show that an increase in residential density has a negligible effect on car choice and utilization, but slightly reduces truck choice and utilization. We also perform an out-of-sample forecast using a holdout sample to test the robustness of the model. * Corresponding author.

David Brownstone; Hao (audrey Fang

2009-01-01T23:59:59.000Z

428

The Calibration and Data Products of the Galaxy Evolution Explorer  

E-Print Network (OSTI)

We describe the calibration status and data products pertaining to the GR2 and GR3 data releases of the Galaxy Evolution Explorer (GALEX). These releases have identical pipeline calibrations that are significantly improved over the GR1 data release. GALEX continues to survey the sky in the Far Ultraviolet (FUV, ~154 nm) and Near Ultraviolet (NUV, ~232 nm) bands, providing simultaneous imaging with a pair of photon counting, microchannel plate, delay line readout detectors. These 1.25 degree field-of-view detectors are well-suited to ultraviolet observations because of their excellent red rejection and negligible background. A dithered mode of observing and photon list output pose complex requirements on the data processing pipeline, entangling detector calibrations and aspect reconstruction algorithms. Recent improvements have achieved photometric repeatability of 0.05 and 0.03 mAB in the FUV and NUV, respectively. We have detected a long term drift of order 1% FUV and 6% NUV over the mission. Astrometric precision is of order 0.5" RMS in both bands. In this paper we provide the GALEX user with a broad overview of the calibration issues likely to be confronted in the current release. Improvements are likely as the GALEX mission continues into an extended phase with a healthy instrument, no consumables, and increased opportunities for guest investigations.

Patrick Morrissey; Tim Conrow; Tom A. Barlow; Todd Small; Mark Seibert; Ted K. Wyder; Tamas Budavari; Stephane Arnouts; Peter G. Friedman; Karl Forster; D. Christopher Martin; Susan G. Neff; David Schiminovich; Luciana Bianchi; Jose Donas; Timothy M. Heckman; Young-Wook Lee; Barry F. Madore; Bruno Milliard; R. Michael Rich; Alex S. Szalay; Barry Y. Welsh; Sukyoung K. Yi

2007-06-06T23:59:59.000Z

429

D0 Decomissioning : Storage of Depleted Uranium Modules Inside D0 Calorimeters after the Termination of D0 Experiment  

Science Conference Proceedings (OSTI)

Dzero liquid Argon calorimeters contain hadronic modules made of depleted uranium plates. After the termination of DO detector's operation, liquid Argon will be transferred back to Argon storage Dewar, and all three calorimeters will be warmed up. At this point, there is no intention to disassemble the calorimeters. The depleted uranium modules will stay inside the cryostats. Depleted uranium is a by-product of the uranium enrichment process. It is slightly radioactive, emits alpha, beta and gamma radiation. External radiation hazards are minimal. Alpha radiation has no external exposure hazards, as dead layers of skin stop it; beta radiation might have effects only when there is a direct contact with skin; and gamma rays are negligible - levels are extremely low. Depleted uranium is a pyrophoric material. Small particles (such as shavings, powder etc.) may ignite with presence of Oxygen (air). Also, in presence of air and moisture it can oxidize. Depleted uranium can absorb moisture and keep oxidizing later, even after air and moisture are excluded. Uranium oxide can powder and flake off. This powder is also pyrographic. Uranium oxide may create health problems if inhaled. Since uranium oxide is water soluble, it may enter the bloodstream and cause toxic effects.

Sarychev, Michael; /Fermilab

2011-09-21T23:59:59.000Z

430

Tomographic imaging system for measuring impurity line emission in a field-reversed configuration  

SciTech Connect

A 16 chord optical tomography system has been developed and implemented in the flux coil generated-field reversed configuration (FRC). The chords are arranged in two fans of eight, which cover {approx}35% of the vessel area at the midplane. Each illuminate separate photomultiplier tubes (PMTs) which are fitted with narrow band-pass filters. In this case, filters are centered at 434.8 nm to measure emission from singly ionized argon. PMT crosstalk is negligible. Background noise due to electron radiation and H{sub {gamma}} line radiation is <10% of argon emission. The spatial resolution of the reconstruction is 1.5 cm. Argon is introduced using a puff valve and tube designed to impart the gas into the system as the FRC is forming. Reconstruction of experimental data results in time-dependent, 2D emissivity profiles of the impurity ions. Analysis of these data show radial, cross-field diffusion to be in the range of 10-10{sup 3} m{sup 2}/s during FRC equilibrium.

Roche, T.; Heidbrink, W. W.; McWilliams, R. [University of California, Irvine, California 92697 (United States); Bolte, N.; Garate, E.; Wessel, F. [University of California, Irvine, California 92697 (United States); Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

2012-10-15T23:59:59.000Z

431

Fundamental studies of fusion plasmas. Final report, May 1, 1993--December 14, 1997  

Science Conference Proceedings (OSTI)

In the course of this grant, Lodestar has collaborated with the TFTR ICRF team to carry out an extensive investigation of rf-edge physics relevant to the understanding and operation of the TFTR fast wave (FW) and ion Bernstein wave (IBW) antennas. Their FW work covered four main areas: rf sheath geometry on TFTR, ICRF convective cells and edge profile modifications, impurity production, and plasma glow and Fermi acceleration. Their IBW work, carried out over the last two years, was in support of the IBW transport barrier and poloidal flow generation experiments. A theoretical survey of rf-edge physics expected to be critical for these antennas was carried out. While the physics that was known to be important for FW systems was considered (especially sheath power dissipation, edge density modifications, and impurities), additional physics enters for IBW waves because of the shorter wavelength, slower group velocity, larger electric fields and the different polarization. In particular, ponderomotive forces, while normally negligible in the FW context, can be substantial for the IBW, but the jitter excursion distance of an electron is too large for validity of the usual theory. A new model for the resulting electron heating and density expulsion was developed. A new model of antenna coupling to the electron plasma wave, mode transformation to the IBW, and the effect of reflected waves at the lower hybrid layer was also developed.

Myra, J.R.

1997-12-15T23:59:59.000Z

432

A Model for Most Luminous and Long Duration Cosmic Gamma Ray Bursts  

E-Print Network (OSTI)

We exploit the fact that General Theory of Relativity (GTR) predicts the existence of compact objects having surface gravitational redshift z_s burst rises dramatically with the value of z_c and can saturate to ~40%. This may explain a gamma ray burst of energy as high as ~5. 10**53 erg. By using the already existing detailed (Newtonian) calculations, it follows that the neutrino heating driven mass loss should be negligible, and the bulk Lorentz factor of the initial fireball could be ~1000. Most of the existing supernova calculations also show that it is extremely difficult to simulate the direct neutrino driven mass loss, and, the shock is not launched if the gravitational field becomes stronger. Since the gravitation potential well of the more compact NS is indded very deep, we do not expect additional baryonic mass ejection. So, without invoking any exotic physics (like strange stars) or overstretching any theory, we may explain most of the luminous GRBs in this simple model.

Abhas Mitra

1998-12-03T23:59:59.000Z

433

Coupled transport processes in semipermeable media  

DOE Green Energy (OSTI)

A numerical simulator has been developed to investigate the effects of coupled processes on heat and mass transport in semipermeable media. The governing equations on which the simulator is based were derived using the thermodynamics of irreversible processes. The equations are nonlinear and have been solved numerically using the n-dimensional Newton's method. As an example of an application, the numerical simulator has been used to investigate heat and solute transport in the vicinity of a heat source buried in a saturated clay-like medium, in part to study solute transport in bentonite packing material surrounding a nuclear waste canister. The coupled processes considered were thermal filtration, thermal osmosis, chemical osmosis and ultrafiltration. In the simulations, heat transport by coupled processes was negligible compared to heat conduction, but pressure and solute migration were affected. Solute migration was retarded relative to the uncoupled case when only chemical osmosis was considered. When both chemical osmosis and thermal osmosis were included, solute migration was enhanced. 18 refs., 20 figs.

Jacobsen, J.S.; Carnahan, C.L.

1990-04-01T23:59:59.000Z

434

Effect of explicit representation of detailed stratigraphy on brine and gas flow at the Waste Isolation Pilot Plant  

Science Conference Proceedings (OSTI)

Stratigraphic units of the Salado Formation at the Waste Isolation Pilot Plant (WIPP) disposal room horizon includes various layers of halite, polyhalitic halite, argillaceous halite, clay, and anhydrite. Current models, including those used in the WIPP Performance Assessment calculations, employ a ``composite stratigraphy`` approach in modeling. This study was initiated to evaluate the impact that an explicit representation of detailed stratigraphy around the repository may have on fluid flow compared to the simplified ``composite stratigraphy`` models currently employed. Sensitivity of model results to intrinsic permeability anisotropy, interbed fracturing, two-phase characteristic curves, and gas-generation rates were studied. The results of this study indicate that explicit representation of the stratigraphy maintains higher pressures and does not allow as much fluid to leave the disposal room as compared to the ``composite stratigraphy`` approach. However, the differences are relatively small. Gas migration distances are also different between the two approaches. However, for the two cases in which explicit layering results were considerably different than the composite model (anisotropic and vapor-limited), the gas-migration distances for both models were negligible. For the cases in which gas migration distances were considerable, van Genuchten/Parker and interbed fracture, the differences between the two models were fairly insignificant. Overall, this study suggests that explicit representation of the stratigraphy in the WIPP PA models is not required for the parameter variations modeled if ``global quantities`` (e.g., disposal room pressures, net brine and gas flux into and out of disposal rooms) are the only concern.

Christian-Frear, T.L.; Webb, S.W. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

1996-04-01T23:59:59.000Z

435

Preliminary results from an advanced lighting controlstestbed  

SciTech Connect

Preliminary results from a large-scale testbed of advanced lighting control technologies at the Phillip Burton Federal Building at 450 Golden Gate Ave. in San Francisco are presented. The first year objective of this project is to determine the sustainable energy savings and cost-effectiveness of different lighting control technologies compared to a portion of the building where only minimal controls are installed. The paper presents the analyzed results from six months of tests focused on accurately characterizing the energy savings potential of one type of daylight-linked lighting controls compared to the lighting in similar open-planned areas without dimming controls. After analyzing a half year;s data, we determined that the annual energy savings for this type of daylight- linked controls was 41% and 30% for the outer rows of lights on the South and North sides of the building, respectively. The annual energy savings dropped to 22% and 16% for the second row of lights for the South and North, respectively, and was negligible for the third rows of lights.

Avery, Douglas; Jennings, Judity; Rubinstein, Francis

1998-03-01T23:59:59.000Z

436

An approach to estimating radiological risk of offsite release from a design basis earthquake for the Process Experimental Pilot Plant (PREPP)  

SciTech Connect

In compliance with Department of Energy (DOE) Order 6430.1A, a seismic analysis was performed on DOE's Process Experimental Pilot Plant (PREPP), a facility for processing low-level and transuranic (TRU) waste. Because no hazard curves were available for the Idaho National Engineering Laboratory (INEL), DOE guidelines were used to estimate the frequency for the specified design-basis earthquake (DBE). A dynamic structural analysis of the building was performed, using the DBE parameters, followed by a probabilistic risk assessment (PRA). For the PRA, a functional organization of the facility equipment was effected so that top events for a representative event tree model could be determined. Building response spectra (calculated from the structural analysis), in conjunction with generic fragility data, were used to generate fragility curves for the PREPP equipment. Using these curves, failure probabilities for each top event were calculated. These probabilities were integrated into the event tree model, and accident sequences and respective probabilities were calculated through quantification. By combining the sequences failure probabilities with a transport analysis of the estimated airborne source term from a DBE, onsite and offsite consequences were calculated. The results of the comprehensive analysis substantiated the ability of the PREPP facility to withstand a DBE with negligible consequence (i.e., estimated release was within personnel and environmental dose guidelines). 57 refs., 19 figs., 20 tabs.

Lucero, V.; Meale, B.M.; Reny, D.A.; Brown, A.N.

1990-09-01T23:59:59.000Z

437

Thermally induced structural changes in coal combustion  

SciTech Connect

Research continued on coal combustion. The project objectives are (1) to measure the effect of devolatilization temperature and time on the properties of the char and (2) characterize and quantify the effect of thermal annealing on char reactivity during char burnout under conditions of pulverized combustion. Work done during this reporting period includes: coal devolatilization/char generation; char oxidation in the thermogravimetric analyzer (TGA). Oxidation was conducted at 500{degree}C in a 5% O{sub 2}-N{sub 2} mixture at 150 cm{sup 3}/min flowrate. Under these conditions external and intraparticle diffusional limitations were negligible. Three chars obtained from the Pittsburgh No. 8 coal were used in the experiments; oxidation of single char particles in the electrodynamic balance. Experiments were carried out with particles from the Pittsburgh No. 8 char and a spherocarb'' synthetic char obtained from a vendor. The spherocarb char was used because the particles are nearly spherical thus avoiding the complications of irregular particle shape. 15 figs., 1 tab.

Gavalas, G.R.; Flagan, R.C.

1990-12-06T23:59:59.000Z

438

Secular Instability and Planetesimal Formation in the Dust Layer  

E-Print Network (OSTI)

Late in the gaseous phase of a protostellar disk, centimeter-sized bodies probably settle into a thin ``dust layer'' at the midplane. A velocity difference between the dust layer and the gas gives rise to turbulence, which prevents further settling and direct gravitational instability of the layer. The associated drag on the surface of the layer causes orbital decay in a few thousand years---as opposed to a few hundred years for an isolated meter-sized body. Within this widely-accepted theoretical framework, we show that the turbulent drag causes radial instabilities even if the selfgravity of the layer is negligible. We formulate axisymmetric, height-integrated dynamical equations for the layer that incorporate turbulent diffusion of mass and momentum in radius and height, vertical settling, selfgravity, and resistance to compression due to gas entrained within the dust layer. In steady-state, the equations describe the inward radial drift of a uniform dust layer. In perturbation, overdense rings form on an orbital timescale with widths comparable to the dust-layer thickness. Selfgravity is almost irrelevant to the linear growth rate but will eventually fragment and collapse the rings into planetesimals larger than a kilometer. We estimate that the drag instability is most efficient at 1 AU when most of the ``dust'' mass lies in the size range 0.1-10 meters.

J. Goodman; B. Pindor

1999-12-28T23:59:59.000Z

439

Generating Cosmological Gaussian Random Fields  

E-Print Network (OSTI)

We present a generic algorithm for generating Gaussian random initial conditions for cosmological simulations on periodic rectangular lattices. We show that imposing periodic boundary conditions on the real-space correlator and choosing initial conditions by convolving a white noise random field results in a significantly smaller error than the traditional procedure of using the power spectrum. This convolution picture produces exact correlation functions out to separations of L/2, where L is the box size, which is the maximum theoretically allowed. This method also produces tophat sphere fluctuations which are exact at radii $ R \\le L/4 $. It is equivalent to windowing the power spectrum with the simulation volume before discretizing, thus bypassing sparse sampling problems. The mean density perturbation in the volume is no longer constrained to be zero, allowing one to assemble a large simulation using a series of smaller ones. This is especially important for simulations of Lyman-$\\alpha$ systems where small boxes with steep power spectra are routinely used. We also present an extension of this procedure which generates exact initial conditions for hierarchical grids at negligible cost.

Ue-Li Pen

1997-09-25T23:59:59.000Z

440

Nuclear Effects in Deep Inelastic Scattering of Charged-Current Neutrino off Nuclear  

E-Print Network (OSTI)

Nuclear effect in the neutrino-nucleus charged-Current inelastic scattering process is studied by analyzing the CCFR and NuTeV data. Structure functions $F_2(x,Q^2)$ and $xF_3(x,Q^2)$ as well as differential cross sections are calculated by using CTEQ parton distribution functions and EKRS and HKN nuclear parton distribution functions, and compared with the CCFR and NuTeV data. It is found that the corrections of nuclear effect to the differential cross section for the charged-current anti-neutrino scattering on nucleus are negligible, the EMC effect exists in the neutrino structure function $F_2(x,Q^2)$ in the large $x$ region, the shadowing and anti-shadowing effect occurs in the distribution functions of valence quarks in the small and medium $x$ region,respectively. It is also found that shadowing effects on $F_2(x,Q^2)$ in the small $x$ region in the neutrino-nucleus and the charged-lepton-nucleus deep inelastic scattering processes are different. It is clear that the neutrino-nucleus deep inelastic scattering data should further be employed in restricting nuclear parton distributions.

Duan ChunGui; Li GuangLie; Shen PengNian

2006-04-18T23:59:59.000Z

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441

Hygrothermal Simulation of Foundations: Part 1 - Soil Material Properties  

SciTech Connect

The hygrothermal performance of soils coupled to buildings is a complicated process. A computational approach for heat transfer through the ground has been well defined (EN ISO 13370:2007, 2007), and simplified methods have been developed (Staszczuk, Radon, and Holm 2010). However, these approaches generally ignore the transfer of soil moisture, which is not negligible (Janssen, Carmeliet, and Hens 2004). This study is divided into several parts. The intention of the first part is to gather, comprehend and adapt soil properties from Soil Science. The obtained information must be applicable to related tasks in Building Science and validated with hygrothermal calculation tools. Future parts of this study will focus on the validation aspect of the soil properties to be implemented. Basic changes in the software code may be requested at this time. Different types of basement construction will be created with a hygrothermal calculation tool, WUFI. Simulations from WUFI will be compared with existing or ongoing measurements. The intentions of the first part of this study have been fulfilled. The soil properties of interest in Building Science have been defined for 12 different soil textures. These properties will serve as input parameters when performing hygrothermal calculations of building constructions coupled to soil materials. The reliability of the soil parameters will be further evaluated with measurements in Part 2.

Kehrer, Manfred [ORNL; Pallin, Simon B [ORNL

2012-10-01T23:59:59.000Z

442

Radiography apparatus using gamma rays emitted by water activated by fusion neutrons  

SciTech Connect

Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the .sup.16 O(n,p).sup.16 N reaction using .sup.14 -MeV neutrons produced at the neutron source via the .sup.3 H(d,n).sup.4 He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second .sup.16 N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.13 seconds of the activated oxygen is sufficient to permit gamma ray generation at a remote location where the activated water is transported, while not presenting a chemical or radioactivity hazard because the radioactivity falls to negligible levels after 1-2 minutes.

Smith, Donald L. (Plainfield, IL); Ikeda, Yujiro (Ibaraki, JP); Uno, Yoshitomo (Ibaraki, JP)

1996-01-01T23:59:59.000Z

443

Office of FreedomCAR and Vehicle Technologies Health Impacts Program (Poster)  

DOE Green Energy (OSTI)

We evaluated day-of-week differences in mean concentrations of ozone precursors [nitric oxide (NO), nitrogen oxides (NOx), volatile organic compounds (VOC) and carbon monoxide (CO)] at monitoring sites in 23 states comprising seven geographic focus areas for the years 1998-2003. We used Wednesdays to represent weekdays and Sundays to represent weekends; we also analyzed Saturdays. Statistical t-tests applied to every monitor showed substantial and statistically significant differences between Wednesday and weekend mean concentrations of ozone precursors in all study areas. At half the sites, nine-hour (6 am through 3 pm) mean concentrations of NO, NOx, and CO declined by at least 65, 49, and 28 percent, respectively, from Wednesdays to Sundays. Large reductions in mean concentrations of ozone precursors on weekends did not reduce mean concentrations of peak ozone significantly, and in many areas, mean peak ozone increased on weekends. Ozone accumulation began earlier on Sundays than on Wednesdays, on average. We also evaluated day-of-week differences in mean concentrations of fine particle and nitrate at available monitoring sites for the same time period and same geographic focus areas. Based on the monitors differences in Wednesday and Sunday means, PM nitrate showed almost negligible weekend decline, despite large NO and NOx declines.

Lawson, D. R.; Eberhardt, J. J.

2006-08-01T23:59:59.000Z

444

Entropy driven multi-photon frequency up-conversion  

E-Print Network (OSTI)

Frequency up-conversion of few low-energy photons into a single high-energy photon, greatly contributes to imaging, light sources, detection and other fields of research. However, it offers negligible efficiency when up-converting many photons. This is because coherent process are fundamentally limited due to momentum conservation requirements, while in incoherent up-conversion the finite intermediate states lifetime requires huge intensities. Thermodynamically, conventional incoherent up-conversion is driven by the internal energy of the incoming photons. However, a system can also drive work through change in its collective properties such as entropy. Here we experimentally demonstrate entropy driven ten-fold up-conversion from 10.6{\\mu} to 1{\\mu}m at internal efficiency above 27% and total efficiency above 10%. In addition, the emitted radiance at 1{\\mu}m exceeds the maximal possible Black-Body radiance of our device, indicating emitter's effective-temperature that is considerably above the bulk-temperatur...

Manor, Assaf; Rotschild, Carmel

2013-01-01T23:59:59.000Z

445

Low Temperature Electrical Performance Characteristics of Li-Ion Cells  

DOE Green Energy (OSTI)

Advanced rechargeable lithium-ion batteries are presently being developed and commercialized worldwide for use in consumer electronics, military and space applications. The motivation behind these efforts involves, among other things, a favorable combination of energy and power density. For some of the applications the power sources may need to perform at a reasonable rate at subambient temperatures. Given the nature of the lithium-ion cell chemistry the low temperature performance of the cells may not be very good. At Sandia National Laboratories, we have used different electrochemical techniques such as impedance and charge/discharge at ambient and subambient temperatures to probe the various electrochemical processes that are occurring in Li-ion cells. The purpose of this study is to identify the component that reduces the cell performance at subambient temperatures. We carried out 3-electrode impedance measurements on the cells which allowed us to measure the anode and cathode impedances separately. Our impedance data suggests that while the variation in the electrolyte resistance between room temperature and -20"C is negligible, the cathode electrolyte interracial resistance increases substantially in the same temperature span. We believe that the slow interracial charge transfer kinetics at the cathode electrolyte may be responsible for the increase in cell impedance and poor cell performance.

Nagasubramanian, Ganesan

1999-04-29T23:59:59.000Z

446

Alteration of gas phase ion polarizabilities upon hydration in high dielectric liquids  

E-Print Network (OSTI)

We investigate the modification of gas phase ion polarizabilities upon solvation in polar solvents and ionic liquids. To this aim, we develop a classical electrostatic theory of charged liquids composed of solvent molecules modeled as finite size dipoles, and embedding polarizable ions that consist of Drude oscillators. In qualitative agreement with ab-initio calculations of polar solvents and ionic liquids, the hydration energy of a polarizable ion in both type of dielectric liquid is shown to favor the expansion of its electronic cloud. Namely, the ion carrying no dipole moment in the gas phase acquires a dipole moment in the liquid environment, but its electron cloud also reaches an enhanced rigidity. We find that the overall effect is an increase of the gas phase polarizability upon hydration. In the specific case of ionic liquids, it is shown that this hydration process is driven by a collective solvation mechanism where the dipole moment of a polarizable ion induced by its interaction with surrounding ions self-consistently adds to the polarization of the liquid, thereby amplifying the dielectric permittivity of the medium in a substantial way. We propose this self-consistent hydration as the underlying mechanism behind the high dielectric permittivities of ionic liquids composed of small charges with negligible gas phase dipole moment. Hydration being a correlation effect, the emerging picture indicates that electrostatic correlations cannot be neglected in polarizable liquids.

Sahin Buyukdagli; Tapio Ala-Nissila

2013-04-23T23:59:59.000Z

447

Startup of the Fission Converter Epithermal Neutron Irradiation Facility at the MIT Reactor  

Science Conference Proceedings (OSTI)

A new epithermal neutron irradiation facility, based on a fission converter assembly placed in the thermal column outside the reactor core, has been put into operation at the Massachusetts Institute of Technology Research Reactor (MITR). This facility was constructed to provide a high-intensity, forward-directed beam for use in neutron capture therapy with an epithermal flux of [approximately equal to]10{sup 10} n/cm{sup 2}.s at the medical room entrance with negligible fast neutron and gamma-ray contamination. The fission converter assembly consists of 10 or 11 MITR fuel elements placed in an aluminum tank and cooled with D{sub 2}O. Thermal-hydraulic criteria were established based on heat deposition calculations. Various startup tests were performed to verify expected neutronic and thermal-hydraulic behavior. Flow testing showed an almost flat flow distribution across the fuel elements with <5% bypass flow. The total reactivity change caused by operation of the facility was measured at 0.014 {+-} 0.002% {delta}K/K. Thermal power produced by the facility was measured to be 83.1 {+-} 4.2 kW. All of these test results satisfied the thermal-hydraulic safety criteria. In addition, radiation shielding design measurements were made that verified design calculations for the neutronic performance.

Newton, Thomas H. Jr.; Riley, Kent J.; Binns, Peter J.; Kohse, Gordon E.; Hu Linwen; Harling, Otto K. [Massachusetts Institute of Technology (United States)

2002-08-15T23:59:59.000Z

448

A Spreadsheet Program for Two-Well Tracer Test Data Analysis  

Science Conference Proceedings (OSTI)

Two-well tracer tests are often conducted to investigate subsurface solute transport in the field. Analyzing breakthrough curves in extraction and monitoring wells using numerical methods is nontrivial due to highly nonuniform flow conditions. We extended approximate analytical solutions for the advection-dispersion equation for an injection-extraction well doublet in a homogeneous confined aquifer under steady-state flow conditions for equal injection and extraction rates with no transverse dispersion and negligible ambient flow, and implemented the solutions in Microsoft Excel using Visual Basic for Application (VBA). Functions were implemented to calculate concentrations in extraction and monitoring wells at any location due to a step or pulse injection. Type curves for a step injection were compared with those calculated by numerically integrating the solution for a pulse injection. The results from the two approaches are similar when the dispersivity is small. As the dispersivity increases, the latter was found to be more accurate but requires more computing time. The code was verified by comparing the results with published-type curves and applied to analyze data from the literature. The method can be used as a first approximation for two-well tracer test design and data analysis, and to check accuracy of numerical solutions. The code and example files are publicly available.

Tang, Guoping [ORNL; Watson, David [ORNL; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Brooks, Scott C [ORNL

2011-01-01T23:59:59.000Z

449

How to Avoid Overestimating Variable Speed Drive Savings  

E-Print Network (OSTI)

This paper addresses eight factors that can cause incorrect and often excessive savings estimates for pump and fan variable speed drive applications. To avoid overestimating savings: 1. Identify system elements that affect head pressure independently of flow rate. 2. Identify system elements that change head pressure in proportion to less than the square of flow rate. 3. Account for dynamic system elements, especially when in systems with minimum static pressure controls. 4. Consider changes in fan efficiency. 5. Account for decreases in motor efficiency at part load, particularly for smaller motors below about 35 percent load. 6. Recognize that existing part load controls may be more efficient than expected. 7. Account for drive losses. 8. Measure full flow power, rather than assuming it is the same as motor nameplate or design power. For many pump and fan systems, none of the eight factors will apply, or their effects will be negligible. However, analysts should consider their applicability when estimating savings for a particular system. This paper provides tools for accounting for the factors.

Maxwell, J. B.

2005-01-01T23:59:59.000Z

450

Calculation of calorific values of coals from ultimate analyses: theoretical basis and geochemical implications. Final report. Part 8  

SciTech Connect

The various formulae for calculating calorific values for coals from ultimate analyses depend essentially on a propositon due to Dulong, that the heat of combustion of an organic compound is nearly equal to the heats of combustion of the elements in it, multiplied by their percentage content in the compound in question. This proposition assumes that the enthalpy of decomposition is negligible compared with the heat of combustion. The various published formulae, such as that due to Mott and Spooner, include empirical adjustments to allow for the fact that the enthalpy of formation or decomposition of no organic compound is zero (except rarely by chance). A new equation is proposed, which excludes empirical correction terms but includes a term explicitly related to the enthalpy of decomposition. As expected from the behavior of known compounds, this enthalpy varies with rank, but it also varies at the same level of rank with the geological history of the sample: rank is not the only source of variance in coal properties. The new equation is at least as effective in predicting calorific values for a set of 992 coals as equivalent equations derived for 6 subsets of the coals. On the whole, the distributions of differences between observed and calculated calorific values are skewed to only a small extent. About 86% of the differences lie between -300 and +300 Btu/lb (+- 700 kJ/kg). 10 references, 7 figures, 4 tables.

Given, P.H.; Weldon, D.; Zoeller, J.H.

1984-03-01T23:59:59.000Z

451

Impact of the number of material measurement categories on measurement error  

DOE Green Energy (OSTI)

There is nearly always some mismatch between the physical properties of items containing nuclear material and standards used to calibrate the assay method. Physical properties include the density and heterogeneity of the item's nonnuclear material and the type of interfering species, such as hydrogen in the case of neutron counting. Some assay techniques are less sensitive to variation in physical properties than others and can be used to generate working standards. Provided that a reference assay method 1 (often calorimetry) is available that is well characterized (having negligible or known dependence on varying physical properties), we can assess the total measurement error of another method 2. In this paper we consider the impact of the number of measurement categories on the measurement error standard deviation of method 2. We assume that working standards (traceable to primary reference standards) are provided by the method 1 assay of actual facility items. Given the same number of working standards, we evaluate the tradeoff between using more working standards for each of a fewer number of categories versus using fewer standards in each of more categories. This leads to a method to determine a good allocation of working standards.

Burr, Tom; Hemphill, G. M. (Geralyn M.); Longmire, V. L. (Victoria L.); Smith, M. K. (Morag K.)

2002-01-01T23:59:59.000Z

452

AMBER on the VLTI: data processing and calibration issues  

E-Print Network (OSTI)

We present here the current performances of the AMBER / VLTI instrument for standard use and compare these with the offered modes of the instrument. We show that the instrument is able to reach its specified precision only for medium and high spectral resolution modes, differential observables and bright objects. For absolute observables, the current achievable accuracy is strongly limited by the vibrations of the Unit Telescopes, and also by the observing procedure which does not take into account the night-long transfer function monitoring. For low-resolution mode, the current limitation is more in the data reduction side, since several effects negligible at medium spectral resolution are not taken into account in the current pipeline. Finally, for faint objects (SNR around 1 per spectral channel), electromagnetic interferences in the VLTI interferometric laboratory with the detector electronics prevents currently to get unbiased measurements. Ideas are under study to correct in the data processing side this effect, but a hardware fix should be investigated seriously since it limits seriously the effective limiting magnitude of the instrument.

Florentin Millour; Romain Petrov; Fabien Malbet; Eric Tatulli; Gilles Duvert; Gérard Zins; Evelyne Altariba; Martin Vannier; Oscar Hernandez; Gianluca Li Causi

2007-05-11T23:59:59.000Z

453

Study on severe accident fuel dispersion behavior in the Advanced Neutron Source reactor at Oak Ridge National Laboratory  

SciTech Connect

Core flow blockage events are a leading contributor to core damage initiation risk in the Advanced Neutron Source (ANS) reactor. During such an accident, insufficient cooling of the fuel could result in core heatup and melting under full coolant flow condition. Coolant inertia forces acting on the melt surface would likely break up the melt into small particles. Under thermal-hydraulic conditions of ANS coolant channel, micro-fine melt particles are expected. Heat transfer between melt particle and coolant, which affects particle breakup, was studied. The study indicates that the thermal effect on melt fragmentation seems to be negligible because the time corresponding to the breakup due to hydrodynamic forces is much shorter than the time for the melt surface to solidify. The study included modeling and analyses to predict transient behavior and transport of debris particles throughout the coolant system. The transient model accounts for the surface forces acting on the particle that results from the pressure variation on the surface, inertia, virtual mass, viscous force due to relative motion of particle in the coolant, gravitation, and resistance due to inhomogenous coolant velocity radially across piping due to possible turbulent coolant motions. Results indicate that debris particles would reside longest in heat exchangers because of lower coolant velocity there. Also core debris tends to move together upon melting and entrainment.

Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V. [Oak Ridge National Lab., TN (United States); Xiang, J.Y. [Wabash Coll., Crawfordsville, IN (United States)

1995-12-31T23:59:59.000Z

454

Study on severe accident fuel dispersion behavior in the Advanced Neutron Source reactor at Oak Ridge National Laboratory  

SciTech Connect

Core flow blockage events have been identified as a leading contributor to core damage initiation risk in the Advanced Neutron Source (ANS) reactor. During such an accident, insufficient cooling of the fuel in a few adjacent blocked coolant channels out of several hundred channels, could also result in core heatup and melting under full coolant flow condition in other coolant channels. Coolant inertia forces acting on the melt surface would likely break up the melt into small particles. Under thermal-hydraulic conditions of ANS coolant channel, micro-fine melt particles are expected. Heat transfer between melt particle and coolant, which affects the particle breakup characteristics, was studied. The study indicates that the thermal effect on melt fragmentation seems to be negligible because the time corresponding to the breakup due to hydrodynamic forces is much shorter than the time for the melt surface to solidify. The study included modeling and analyses to predict transient behavior and transport of debris particles throughout the coolant system. The transient model accounts for the surface forces acting on the particle that result from the pressure variation on the surface, inertia, virtual mass, viscous force due to the relative motion of the particle in the coolant, gravitation, and resistance due to inhomogeneous coolant velocity radially across piping due to expected turbulent coolant motions. The results indicate that debris particles would reside longest in the heat exchangers because of lower coolant velocity there. Also they are entrained and move together in a cloud.

Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

1995-09-01T23:59:59.000Z

455

Parallel TreeSPH: A Tool for Galaxy Formation  

E-Print Network (OSTI)

We describe a new implementation of a parallel Tree-SPH code with the aim to simulate Galaxy Formation and Evolution. The code has been parallelized using SHMEM, a Cray proprietary library to handle communications between the 256 processors of the Silicon Graphics T3E massively parallel supercomputer hosted by the Cineca Super-computing Center (Bologna, Italy). The code combines the Smoothed Particle Hydrodynamics (SPH) method to solve hydro-dynamical equations with the popular Barnes and Hut (1986) tree-code to perform gravity calculation with a $N \\times logN$ scaling, and it is based on the scalar Tree-SPH code developed by Carraro et al (1998)[MNRAS 297, 1021]. Parallelization is achieved distributing particles along processors according to a work-load criterium. Benchmarks, in terms of load-balance and scalability, of the code are analised and critically discussed against the adiabatic collapse of an isothermal gas sphere test using $2 \\times 10^{4}$ particles on 8 processors. The code results balanced at more than 95% level. Increasing the number of processors, the load balance sligthly worsens. The deviation from perfect scalability at increasing number of processors is negligible up to 64 processors. Additionally we have incorporated radiative cooling, star formation, feed-back and an algorithm to follow the chemical enrichment of the interstellar medium.

Cesario Lia; Giovanni Carraro

1999-04-01T23:59:59.000Z

456

Quantitative laser-induced incandescence measurements of soot in turbulent pool fires.  

DOE Green Energy (OSTI)

Laser-induced incandescence measurements have recently been obtained from 10% and 30% toluene in methanol blended fuel pool fires of 2-m diameter. Calibration of the instrument was performed using an ethylene/air laminar diffusion flame produced by a Santoro-type burner which allowed the extraction of absolute soot-volume-fractions from these images. Performance of the optical probe was characterized using the laminar diffusion flame and corrections were implemented for signal dependence upon detector gain, flat field, and location within the probe laser sheet when processing the images. Probability density functions of the soot-volume fraction were constructed for the blended fuels used in this study and the mean values were determined to be 0.0077 and 0.028 ppm for the 10% and 30% blended fuels, respectively. Signal trapping was estimated for the two types of blended fuel and it was determined to be negligible for the 10% toluene/methanol blend and require {approx}10% correction for the 30% toluene/methanol blend.

Frederickson, Kraig; Grasser, Thomas W.; Kearney, Sean Patrick

2009-12-01T23:59:59.000Z

457

Flexible Pillared Graphene-Paper Electrodes for High-Performance Electrochemical Supercapacitors  

SciTech Connect

Flexible graphene paper (GP) pillared by carbon black (CB) nanoparticles using a simple vacuum filtration method is developed as a high-performance electrode material for supercapacitors. Through the introduction of CB nanoparticles as spacers, the self-restacking of graphene sheets during the filtration process is mitigated to a great extent. The pillared GP-based supercapacitors exhibit excellent electrochemical performances and cyclic stabilities compared with GP without the addition of CB nanoparticles. At a scan rate of 10 mV s?1, the specific capacitance of the pillared GP is 138 F g^?1 and 83.2 F g^?1 with negligible 3.85% and 4.35% capacitance degradation after 2000 cycles in aqueous and organic electrolytes, respectively. At an extremely fast scan rate of 500 mV s ^?1, the specific capacitance can reach 80 F g^?1 in aqueous electrolyte. No binder is needed for assembling the supercapacitor cells and the pillared GP itself may serve as a current collector due to its intrinsic high electrical conductivity. The pillared GP has great potential in the development of promising flexible and ultralight-weight supercapacitors for electrochemical energy storage.

Wang, Gongkai; Sun, Xiang; Lu, Fengyuan; Sun, Hongtao; Yu, Mingpeng; Jiang, Weilin; Liu, Changsheng; Lian, Jie

2012-02-09T23:59:59.000Z

458

Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 8: Appendices HYDRO, IRD, LTM, NUTS, PAR, PMR, QAPD, RBP  

SciTech Connect

Geohydrologic data have been collected in the Los Medanos area at the US Department of Energy`s proposed Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico since 1975 as part of a study evaluating the feasibility of storing defense-associated nuclear wastes within the bedded salt of the Salado Formation of Permian age. Drilling and hydrologic testing have identified three principal water-bearing zones above the Salado Formation and one below that could potentially transport wastes to the biosphere if the proposed facility were breached. The zones above the Salado are the contact between the Rustler and Salado Formations and the Culebra and Magenta Dolomite Members of the Rustler Formation of Permian age. The zone below the Salado Formation consists of channel sandstones in the Bell Canyon Formation of the Permian Delaware Mountain Group. Determinations of hydraulic gradients, directions of flow, and hydraulic properties were hindered because of the negligible permeability of the water-bearing zones. Special techniques in drilling, well completion, and hydraulic testing have been developed to determine the hydrologic characteristics of these water-producing zones.

NONE

1995-03-31T23:59:59.000Z

459

Coincident count rates in absorbing dielectric media  

E-Print Network (OSTI)

A study of the effects of absorption on the nonlinear process of parametric down conversion is presented. Absorption within the nonlinear medium is accounted for by employing the framework of macroscopic QED and the Green tensor quantization of the electromagnetic field. An effective interaction Hamiltonian, which describes the nonlinear interaction of the electric field and the linear noise polarization field, is used to derive the quantum state of the light leaving a nonlinear crystal. The signal and idler modes of this quantum state are found to be a superpositions of the electric and noise polarization fields. Using this state, the expression for the coincident count rates for both Type I and Type II conversion are found. The nonlinear interaction with the noise polarization field were shown to cause an increase in the rate on the order of 10^{-12} for absorption of 10% per cm. This astonishingly small effect is found to be negligible compared to the decay caused by linear absorption of the propagating modes. From the expressions for the biphoton amplitude it can be seen the maximally entangled states can still be produced even in the presence of strong absorption.

J. A. Crosse; Stefan Scheel

2010-12-03T23:59:59.000Z

460

Coincident count rates in absorbing dielectric media  

E-Print Network (OSTI)

A study of the effects of absorption on the nonlinear process of parametric down conversion is presented. Absorption within the nonlinear medium is accounted for by employing the framework of macroscopic QED and the Green tensor quantization of the electromagnetic field. An effective interaction Hamiltonian, which describes the nonlinear interaction of the electric field and the linear noise polarization field, is used to derive the quantum state of the light leaving a nonlinear crystal. The signal and idler modes of this quantum state are found to be a superpositions of the electric and noise polarization fields. Using this state, the expression for the coincident count rates for both Type I and Type II conversion are found. The nonlinear interaction with the noise polarization field were shown to cause an increase in the rate on the order of 10^{-12} for absorption of 10% per cm. This astonishingly small effect is found to be negligible compared to the decay caused by linear absorption of the propagating mo...

Crosse, J A

2010-01-01T23:59:59.000Z

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