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Note: This page contains sample records for the topic "mont belvieu spot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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1

An exposure assessment survey of the Mont Belvieu polyethylene plant  

E-Print Network [OSTI]

exposure health risks based on quantitative and qualitative data; ~ Provide a quality tool for standardizing the measurement of workplace exposure health risk; and ~ Provide a means for an immediate and out-of-cycle exposure assessment following... with indicator substances in corres ondin RAC Worker Group HCW Kl K3 K5 Ll Lg L9 Number of RACs with Rankin of I Number of RACs Number of RACs with Rankin of 2 with Rankin of 3 The results from the exposure assessment of individual job tasks, based...

Tucker, Thomas Franklin

2012-06-07T23:59:59.000Z

2

Canopy hot-spot as crop identifier  

SciTech Connect (OSTI)

Illuminating any reflective rough or structured surface by a directional light source results in an angular reflectance distribution that shows a narrow peak in the direction of retro-reflection. This is called the Heiligenschein or hot-spot of vegetation canopies and is caused by mutual shading of leaves. The angular intensity distribution of the hot-spot, its brightness and slope, are therefore indicators of the plant's geometry. We propose the use of hot-spot characteristics as crop identifiers in satellite remote sensing because the canopy hot-spot carries information about plant stand architecture that is more distinctive for different plant species than, for instance, their spectral reflectance characteristics. A simple three-dimensional Monte Carlo/ray tracing model and an analytic two-dimensional model are developed to estimate the angular distribution of the hot-spot as a function of the size of the plant leaves. The results show that the brightness-distribution and slope of the hot-spot change distinctively for different leaf sizes indicating a much more peaked maximum for the smaller leaves.

Gerstl, S.A.W.; Simmer, C.; Powers, B.J.

1986-05-01T23:59:59.000Z

3

Utility spot pricing, California  

E-Print Network [OSTI]

The objective of the present spot pricing study carried out for SCE and PG&E is to develop the concepts which wculd lead to an experimental design for spot pricing in the two utilities. The report suggests a set of experiments ...

Schweppe, Fred C.

1982-01-01T23:59:59.000Z

4

Natural Gas Spot Prices:  

Gasoline and Diesel Fuel Update (EIA)

4 of 26 4 of 26 Notes: Spot wellhead prices last summer averaged well over $4.00 per thousand cubic feet during a normally low-price season. During the fall, these prices stayed above $5.00 per thousand cubic feet, more than double the year-ago average price. In January, the spot wellhead price averaged a record $8.98 per thousand cubic feet. Spot prices at the wellhead have never been this high for such a prolonged period. The chief reason for these sustained high gas prices was, and still is, uneasiness about the supply situation. Concern about the adequacy of winter supplies loomed throughout most of the summer and fall as storage levels remained significantly depressed. Last December, the most severe assumptions about low storage levels became real, when the spot price

5

Reactor hot spot analysis  

SciTech Connect (OSTI)

The principle methods for performing reactor hot spot analysis are reviewed and examined for potential use in the Applied Physics Division. The semistatistical horizontal method is recommended for future work and is now available as an option in the SE2-ANL core thermal hydraulic code. The semistatistical horizontal method is applied to a small LMR to illustrate the calculation of cladding midwall and fuel centerline hot spot temperatures. The example includes a listing of uncertainties, estimates for their magnitudes, computation of hot spot subfactor values and calculation of two sigma temperatures. A review of the uncertainties that affect liquid metal fast reactors is also presented. It was found that hot spot subfactor magnitudes are strongly dependent on the reactor design and therefore reactor specific details must be carefully studied. 13 refs., 1 fig., 5 tabs.

Vilim, R.B.

1985-08-01T23:59:59.000Z

6

Wholesale/Spot Henry Hub Spot Price ........  

Gasoline and Diesel Fuel Update (EIA)

Wholesale/Spot Wholesale/Spot Henry Hub Spot Price ........ 2.52 2.35 2.97 3.50 3.59 4.13 3.66 3.83 3.92 3.67 3.92 4.08 2.83 3.81 3.90 Residential New England ...................... 13.08 14.05 16.86 13.62 13.05 13.88 17.27 14.17 14.04 15.15 18.40 15.22 13.73 13.84 14.91 Middle Atlantic .................... 11.34 13.46 16.92 11.76 10.98 13.32 17.88 13.58 12.80 14.60 18.94 14.39 12.20 12.56 13.95 E. N. Central ...................... 8.30 10.68 15.52 8.57 7.74 10.79 15.82 9.37 8.80 11.38 17.13 10.31 9.20 9.15 10.13 W. N. Central ..................... 8.45 11.99 16.39 9.08 8.10 10.47 17.24 9.38 8.79 11.27 17.99 10.23 9.60 9.35 10.11 S. Atlantic ........................... 12.37 17.68 22.08 12.24 11.10 15.05 22.27 13.49 12.56 18.03 24.66 14.95 13.71 13.12 14.77 E. S. Central ....................... 10.26 14.69 17.56 10.41 9.25 12.36 18.26 11.50

7

MAIN APPLICATIONS Spot welding  

E-Print Network [OSTI]

IRB 6400 MAIN APPLICATIONS Spot welding Press tending Material handling Machine tending Palletizing with high material strength. The arms are mechanically balanced and equipped with double bearings. Advanced DATA, IRB 6400 INDUSTRIAL ROBOT WORKING RANGE AND LOAD DIAGRAM IRB 6400PE IRB 6400R IRB 6400S PR10036EN

De Luca, Alessandro

8

Hot Spot | Open Energy Information  

Open Energy Info (EERE)

Spot Dictionary.png Hot Spot: Anomalous volcanic regions that can occur within a tectonic plate and are thought to be caused by mantle plumes Other definitions:Wikipedia Reegle...

9

Small Spot, Brighter Beam  

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

Small Spot, Brighter Beam Small Spot, Brighter Beam Small Spot, Brighter Beam Print Do you notice the brighter beam? During the most recent shutdown, all of the corrector magnets were replaced with sextupoles, reducing the horizontal emittance and increasing beam brightness. "This is part of ongoing improvement to keep the ALS on the cutting edge," says Alastair MacDowell, a beamline scientist on Beamline 12.2.2. The brightness has increased by a factor of about three in the storage ring. Beamlines on superbend or center-bend magnets will see the most noticeable increase in brightness, but the horizontal beam size and divergence have been substantially reduced at all beamlines. "We are starting to approach the resolution of many beamlines. Therefore, not every beamline will be able to resolve the full improvement," says Christoph Steier, project leader of the brightness upgrade. Though superbend and center-bend magnet source sizes are reduced by roughly a factor of three, "measured improvements so far range from a factor of 2-2.5," Steier says. He and MacDowell agree that the beamline optics are likely the limiting factor in resolving the full improvement at the beamlines.

10

Spot-spraying Johnsongrass.  

E-Print Network [OSTI]

of naphtha and diesel fuel oil is the oil spray most generally used. Various other oil mixtures may be used for economy, for increased contact toxicity, or for a combination of contact toxicity and residual effectiveness. Oil sprays kill on contact... mixture of 40 pounds of sodium TCA and 20 pounds of sodium dalapon can be used for spot-treating sparsely infested cotton fields. It is a knock-out spray under some conditions. Maleic hydrazide (MH-30) is a translocated growth inhibitor with no residual...

Rea, H. E.

1958-01-01T23:59:59.000Z

11

Spot-Oiling Johnsongrass.  

E-Print Network [OSTI]

I TEXAS AGRICULTURAL EXTENSIO-N SERVICE G. G. Gibson, Director, College Station, Texas [Blank Page in Original Bulletin] I the bast I ir used the low I . .. 1 the fol or mort , needed SPOT-OILING JOHNSONGRASS H. E. Rea, M. J. Norris..., and Fred C. Elliott* Texas A. & M. College System ~HNSONGRASS CAN BE killed to the i ground by the application of 1 / 3 teaspoonful of a herbicidal oil to the crown of each stem. Eradication of established Johnsongrass can be obtained in a single...

Elliott, Fred C.; Norris, M. J.; Rea, H. E.

1955-01-01T23:59:59.000Z

12

U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

units greater than their levels last year. The Mont Belvieu natural gas plant liquids composite price fell 0.3% to 9.37MMBtu for the week covering August 18 - August 22. The...

13

U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

year ago, while gas rigs were down by 48. The Mont Belvieu natural gas plant liquids composite price fell 1.5%, or 0.14MMBtu, to 9.44MMBtu for the week covering September 28 -...

14

U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

units greater than their levels last year. The Mont Belvieu natural gas plant liquids composite price rose 0.5% to 9.41MMBtu for the week covering August 25 " August 29. The...

15

U.S. Energy Information Administration (EIA)  

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

203 units greater than last year's level. The Mont Belvieu natural gas plant liquids composite price decreased for the sixth consecutive week, averaging 9.38MMBtu for the week...

16

U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

units greater than their levels last year. The Mont Belvieu natural gas plant liquids composite price decreased by 2.9% to 9.58MMBtu for the week of September 22-26. All other...

17

U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

328 active units from the previous week. The Mont Belvieu natural gas plant liquids composite price declined again this week, dropping 7.8%, or 72 cents, to 8.42MMBtu for the...

18

U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

rig count increased by 18 units to 1,609. The Mont Belvieu natural gas plant liquids composite price declined 3.5%, or 33 cent, to 9.14MMBtu for the week covering October 6 -...

19

U.S. Energy Information Administration (EIA)  

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

and is 219 units greater than last year. The Mont Belvieu natural gas plant liquids composite price rose 1.3% to 9.53MMBtu for the week covering September 1 - September 5. The...

20

How to spot a nuke  

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

How to spot a nuke How to spot a nuke 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues » submit How to spot a nuke Neutrons set loose by a high-power laser can identify illicit nuclear materials inside closed containers. November 25, 2013 How to spot a nuke Could you identify dangerous nuclear materials inside this box if it weren't labeled? We can. Laser-driven blast of neutrons reveals concealed nuclear bomb materials Los Alamos scientists recently demonstrated a new laser-based technique for producing a burst of neutrons capable of revealing the presence of illicit nuclear materials, such as plutonium. "No one knew it could actually be done," said Andrea Favalli, one of the team leaders, "until we worked out the details, fabricated the parts, and performed the test." The

Note: This page contains sample records for the topic "mont belvieu spot" 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

Utility spot pricing study : Wisconsin  

E-Print Network [OSTI]

Spot pricing covers a range of electric utility pricing structures which relate the marginal costs of electric generation to the prices seen by utility customers. At the shortest time frames prices change every five ...

Caramanis, Michael C.

1982-01-01T23:59:59.000Z

22

Monte Carlo fundamentals  

SciTech Connect (OSTI)

This report is composed of the lecture notes from the first half of a 32-hour graduate-level course on Monte Carlo methods offered at KAPL. These notes, prepared by two of the principle developers of KAPL`s RACER Monte Carlo code, cover the fundamental theory, concepts, and practices for Monte Carlo analysis. In particular, a thorough grounding in the basic fundamentals of Monte Carlo methods is presented, including random number generation, random sampling, the Monte Carlo approach to solving transport problems, computational geometry, collision physics, tallies, and eigenvalue calculations. Furthermore, modern computational algorithms for vector and parallel approaches to Monte Carlo calculations are covered in detail, including fundamental parallel and vector concepts, the event-based algorithm, master/slave schemes, parallel scaling laws, and portability issues.

Brown, F.B.; Sutton, T.M.

1996-02-01T23:59:59.000Z

23

Natural Gas Spot Price Outlook  

Gasoline and Diesel Fuel Update (EIA)

7 of 17 7 of 17 Notes: Despite signs that domestic natural gas production has begun to turn around (the Texas Railroad Commission now reports year-to-date (through Sep.) gains in Texas gas production of 1.2 percent, compared to a 4.7-percent decline for the same months in 1999 versus 1998) the reality of the U.S. gas market is that supply responses have been too little, too late to prevent record-high spot prices and prospects for very high average prices this winter. We now expect to see peak monthly spot wellhead prices this winter of over $6.00 per thousand cubic feet (mcf) (December). Last month we maintained confidence that conditions would improve enough to keep the $5.10 per mcf recorded in October as the peak for this heating season. With partial data available, a monthly average value of about $5.60 per mcf looks likely for

24

HotSpot | Department of Energy  

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

HotSpot HotSpot HotSpot Current Central Registry Toolbox Version(s): 2.07.1 Code Owner: Department of Energy, Office of Emergency Operations and Lawrence Livermore National Laboratory (LLNL) Description: The HotSpot Health Physics Code is used for safety-analysis of DOE facilities handling nuclear material. Additionally, HotSpot provides emergency response personnel and emergency planners with a fast, field-portable set of software tools for evaluating incidents involving radioactive material. HotSpot provides a fast and usually conservative means for estimation of the radiation effects associated with atmospheric release of radioactive materials. The HotSpot atmospheric dispersion models are designed for near-surface releases, short-range (less than 10 km) dispersion, and short-term (less than 24 hours) release durations in

25

West Texas Intermediate Spot Average ............................  

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

Crude Oil (dollars per barrel) Crude Oil (dollars per barrel) West Texas Intermediate Spot Average ............................ 102.88 93.42 92.24 87.96 94.34 94.10 105.84 96.30 95.67 95.33 95.67 93.33 94.12 97.64 95.00 Brent Spot Average ........................................................... 118.49 108.42 109.61 110.09 112.49 102.58 110.27 108.29 106.33 105.00 103.00 102.00 111.65 108.41 104.08 Imported Average .............................................................. 108.14 101.18 97.18 97.64 98.71 97.39 103.07 100.03 99.64 99.33 99.69 97.35 101.09 99.85 99.04 Refiner Average Acquisition Cost ...................................... 107.61 101.44 97.38 97.27 101.14 99.45 105.24 100.44 100.15 99.82 100.18 97.83 100.83 101.61 99.50 Liquid Fuels (cents per gallon) Refiner Prices for Resale Gasoline .........................................................................

26

Table Definitions, Sources, and Explanatory Notes  

Gasoline and Diesel Fuel Update (EIA)

Futures Prices Futures Prices Definitions Key Terms Definition Contract 1 A futures contract specifying the earliest delivery date. Natural gas contracts expire three business days prior to the first calendar day of the delivery month. Thus, the delivery month for Contract 1 is the calendar month following the trade date. Contract 2-4 Represent the successive delivery months following Contract 1. Futures Price The price quoted for delivering a specified quantity of a commodity at a specified time and place in the future. Natural Gas A gaseous mixture of hydrocarbon compounds, the primary one being methane. NGL Composite Price The natural gas liquids (NGL) composite price is derived from daily Bloomberg spot price data for natural gas liquids at Mont Belvieu, Texas, weighted by gas processing plant production volumes of each product as reported on Form EIA-816, "Monthly Natural Gas Liquids Report."

27

Resistance Spot Welding of Galvanized Steel: Part II. Mechanisms of Spot Weld Nugget Formation  

E-Print Network [OSTI]

of material variations and weld process parameter modifications on resistance spot welding of coated( l Resistance Spot Welding of Galvanized Steel: Part II. Mechanisms of Spot Weld Nugget Formation S. A. GEDEON and T. W. EAGAR Dynamic inspection monitoring of the weld current, voltage, resistance

Eagar, Thomas W.

28

Spot Distillate & Crude Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

5 5 Notes: Retail distillate prices follow the spot distillate markets, and crude oil prices have been the main driver behind distillate spot price increases until recently. Crude oil rose about 36 cents per gallon from its low point in mid February 1999 to the middle of January 2000. Over this same time period, New York Harbor spot heating oil had risen about 42 cents per gallon, reflecting both the crude price rise and a return to a more usual seasonal spread over the price of crude oil. The week ending January 21, heating oil spot prices in the Northeast spiked dramatically to record levels, closing on Friday at $1.26 per gallon -- up 50 cents from the prior week. Gulf Coast prices were not spiking, but were probably pulled slightly higher as the New York Harbor market began to

29

Retail Price Changes Lag Spot Prices  

Gasoline and Diesel Fuel Update (EIA)

1 1 Notes: While EIA cannot claim to explain all of the factors that drive retail gasoline prices, we have had a fair amount of success in exploring the relationship between wholesale and retail prices. In particular, we have looked closely at the "pass-through" of changes in spot prices to the retail market. This graph shows a weighted national average of spot prices for regular gasoline -both conventional and reformulated (shown in red), and EIA's weekly survey price for retail regular (again both conventional and reformulated). As you can see, spot prices tend to be more volatile (and would be even more so on a daily basis), while these changes are smoother by the time they reach the retail pump. Furthermore, by looking at the peaks, you can see the retail prices seem to lag the spot price changes

30

Building Energy Software Tools Directory: SPOT  

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

SPOT SPOT SPOT screen image Quantifies existing or intended electric lighting performance, evaluate annual daylighting characteristics and help establish the optimal photosensor placement in a given space relative to annual performance and annual energy savings. The Sensor Placement and Optimization Tool, or SPOT, was developed with classroom daylighting in mind, but can be used for all types of spaces. Screen Shots Keywords daylighting, electric lighting, photosensor, energy savings Validation/Testing Various individuals have tested the software. Testing and validation continues. Documentation of the test and validation results are available on the web site. Expertise Required Energy engineering or lighting design background is helpful for analysis of results. A working familiarity with Excel may be helpful, but it is not

31

Short-lived spots in solar-like stars as observed by CoRoT  

E-Print Network [OSTI]

Context. CoRoT light curves have an unprecedented photometric quality, having simultaneously a high signal-to-noise ratio, a long time span and a nearly continuous duty-cycle. Aims. We analyse the light-curves of four bright targets observed in the seismology field and study short-lived small spots in solar-like stars. Methods. We present a simple spot modeling by iterative analysis. Its ability to extract relevant parameters is ensured by implementing relaxation steps to avoid convergence to local minima of the sum of the residuals between observations and modeling. The use of Monte-Carlo simulations allows us to estimate the performance of the fits. Results. Our starspot modeling gives a representation of the spots on these stars in agreement with other well tested methods. Within this framework, parameters such as rigid-body rotation and spot lifetimes seem to be precisely determined. Then, the lifetime/rotation period ratios are in the range 0.5 - 2, and there is clear evidence for differential rotation.

Mosser, B; Lanza, A F; Hulot, J C; Catala, C; Baglin, A; Auvergne, M

2009-01-01T23:59:59.000Z

32

The robustness of dynamic vehicle performance to spot weld failures  

Science Journals Connector (OSTI)

Spot welds are the dominant joining method in the vehicle assembly process. As the automated assembly process is not perfect, some spot welds may be absent when the vehicle leaves the assembly line. Furthermore, spot welds are highly susceptible to fatigue, ... Keywords: Failure, Fatigue, Finite element analysis, Robustness, Spot welds, Structural dynamics

S. Donders; M. Brughmans; L. Hermans; C. Liefooghe; H. Van der Auweraer; W. Desmet

2006-05-01T23:59:59.000Z

33

POWER '99 Conference 1 Stochastic Models of Electricity Spot Price  

E-Print Network [OSTI]

spread call options. power spot price delivery at PV gas spot price SoCal system 8000 heat rate When power. When the spot market implied heat rate is below the unit operating heat rate, generator should1 POWER '99 Conference 1 Stochastic Models of Electricity Spot Price and their Applications Shijie

California at Berkeley. University of

34

Relationship between Hot Spot Residues and Ligand Binding Hot Spots in Protein-Protein Interfaces  

E-Print Network [OSTI]

, while identification of a hot spot by alanine scanning establishes the potential to generate substantial, termed "hot spots", that comprise the subset of residues that contribute the bulk of the binding free proposed as prime targets for drug binding.1,4 The established approach to the identification of such hot

Vajda, Sandor

35

Discriminative Keyword Spotting David Grangier1  

E-Print Network [OSTI]

Laboratories America, Princeton, NJ, USA 2 IDIAP Research Institute, Martigny, Switzerland 3 Google Inc., Mountain View, CA, USA This chapter introduces a discriminative method for detecting and spotting keywords and transition models, or the Expectation-Maximization (EM) training procedure, which is prone to convergence

Tomkins, Andrew

36

Training Program EHS ~ 244: Resistance Spot Welding Safety Training  

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

4: Resistance Spot Welding Safety Training 4: Resistance Spot Welding Safety Training Course Syllabus Subject Category: Resistance Spot Welding Course Prerequisite: None Course Length: 25 minutes Medical Approval: No Delivery Mode: Web-Based Course Goal: Participants will be introduced to resistance spot welding processes, hazards, and safe work practices. Course Objectives: By the end of this course, you will be able to: * Identify resistance spot welding processes * Identify hazards, safe work practices, and personal protective equipment associated with resistance spot welding * Recognize the purpose of resistance spot welding schedules * Locate resistance spot welding schedule Subject Matter Expert: Joe Dionne x 7586 Training Compliance: 29 CFR 1910 Subparts O & Z, 29 CFR 1926 Subparts J & Z

37

Sourcing Flexibility, Spot Trading, and Procurement Contract Structure  

E-Print Network [OSTI]

We analyze the structure and pricing of option contracts for an industrial good in the presence of spot trading. We combine the analysis of spot trading and buyers' disparate private valuations for different suppliers' ...

Pei, Pamela Pen-Erh

38

EECBG Success Story: Bright Green Spot: Fort Worth Library |...  

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

Bright Green Spot: Fort Worth Library EECBG Success Story: Bright Green Spot: Fort Worth Library September 30, 2010 - 9:53am Addthis Fort Worth's Central Library is seeing...

39

Dealing in practice with hot-spots  

E-Print Network [OSTI]

The hot-spot phenomenon is a relatively frequent problem occurring in current photovoltaic generators. It entails both a risk for the photovoltaic module's lifetime and a decrease in its operational efficiency. Nevertheless, there is still a lack of widely accepted procedures for dealing with them in practice. This paper presents the IES-UPM observations on 200 affected modules. Visual and infrared inspection, electroluminescence, peak power and operating voltage tests have been accomplished. Hot-spot observation procedures and well defined acceptance and rejection criteria are proposed, addressing both the lifetime and the operational efficiency of the modules. The operating voltage has come out as the best parameter to control effective efficiency losses for the affected modules. This procedure is oriented to its possible application in contractual frameworks.

Moretón, Rodrigo; Leloux, Jonathan; Carrillo, José Manuel

2014-01-01T23:59:59.000Z

40

The fractal nature of vacuum arc cathode spots  

SciTech Connect (OSTI)

Cathode spot phenomena show many features of fractals, for example self-similar patterns in the emitted light and arc erosion traces. Although there have been hints on the fractal nature of cathode spots in the literature, the fractal approach to spot interpretation is underutilized. In this work, a brief review of spot properties is given, touching the differences between spot type 1 (on cathodes surfaces with dielectric layers) and spot type 2 (on metallic, clean surfaces) as well as the known spot fragment or cell structure. The basic properties of self-similarity, power laws, random colored noise, and fractals are introduced. Several points of evidence for the fractal nature of spots are provided. Specifically power laws are identified as signature of fractal properties, such as spectral power of noisy arc parameters (ion current, arc voltage, etc) obtained by fast Fourier transform. It is shown that fractal properties can be observed down to the cutoff by measurement resolution or occurrence of elementary steps in physical processes. Random walk models of cathode spot motion are well established: they go asymptotically to Brownian motion for infinitesimal step width. The power spectrum of the arc voltage noise falls as 1/f {sup 2}, where f is frequency, supporting a fractal spot model associated with Brownian motion.

Anders, Andre

2005-05-27T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Sensor Placement + Optimization Software (SPOT) | Open Energy Information  

Open Energy Info (EERE)

Sensor Placement + Optimization Software (SPOT) Sensor Placement + Optimization Software (SPOT) Jump to: navigation, search Tool Summary Name: SPOT Agency/Company /Organization: Architectural Energy Corporation Sector: Energy Focus Area: Buildings, Energy Efficiency Topics: Technology characterizations Resource Type: Software/modeling tools User Interface: Spreadsheet Website: www.archenergy.com/SPOT/ Cost: Free Language: English References: http://www.archenergy.com/SPOT/ SPOT(tm) is intended to assist a designer in quantifying the existing or intended electric lighting and annual daylighting characteristics of a given space and to help establish the optimal photosensor placement for the space relative to annual performance and annual energy savings. The software was developed with classroom daylighting in mind, but can be used

42

Spot Distillate & Crude Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

mid-January, 2000. WTI crude oil price rose about $17 per mid-January, 2000. WTI crude oil price rose about $17 per barrel or 40 cents per gallon from its low point in mid February 1999 to January 17, 2000. Over this same time period, New York Harbor spot heating oil had risen about 42 cents per gallon, reflecting both the crude price rise and the beginning of a return to a more usual seasonal spread over the price of crude oil. The week ending January 21, distillate spot prices in the Northeast spiked dramatically to record levels, closing on Friday at $1.26 per gallon -- up 50 cents from the prior week. Gulf Coast prices were not spiking, but were probably pulled higher as the New York Harbor market began to draw on product from other areas. They closed at 83 cents per gallon, an increase of 11 cents from the prior Friday. Crude oil had risen about 4 cents from

43

Friction Stir Spot Welding of Advanced High Strength Steels II...  

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

II Friction Stir Spot Welding of Advanced High Strength Steels II 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

44

Monte Carlo for the LHC  

E-Print Network [OSTI]

I review the status of the general-purpose Monte Carlo event generators for the LHC, with emphasis on areas of recent physics developments. There has been great progress, especially in multi-jet simulation, but I mention some question marks that have recently arisen.

Michael H. Seymour

2010-08-17T23:59:59.000Z

45

Pinch spot formation in high atomic number z discharges  

Science Journals Connector (OSTI)

A nonlinear, quasi-two-dimensional model for pinch spot formation in radiation-dominated, high atomic number z pinches is presented that reproduces the experimental electrical and radiation characteristics. The high line-radiation rates of such discharges produce localized, high-density pinch spots in contrast to the spindle pinches predicted for hydrogenic discharges.

D. Mosher and D. Colombant

1992-04-27T23:59:59.000Z

46

A NONGAUSSIAN ORNSTEINUHLENBECK PROCESS FOR ELECTRICITY SPOT PRICE MODELING AND  

E-Print Network [OSTI]

A NON­GAUSSIAN ORNSTEIN­UHLENBECK PROCESS FOR ELECTRICITY SPOT PRICE MODELING AND DERIVATIVES for analytical pricing of electricity forward and futures contracts. Electricity forward and futures contracts to capture the observed dynamics of electricity spot prices. We also discuss the pricing of European call

Kallsen, Jan

47

Modelling spot and forward prices for energy companies  

E-Print Network [OSTI]

Modelling spot and forward prices for energy companies Dafydd Steele MSc Stochastics and Financial forward and spot prices for energy com- panies. The two main ways of modelling power prices are stochastic markets (coal, gas and power). The fundamental model is a mixed-integer programming stack model

Bhulai, Sandjai

48

Dark spot formation relative to ITO surface roughness for polyfluorene  

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

Dark spot formation relative to ITO surface roughness for polyfluorene Dark spot formation relative to ITO surface roughness for polyfluorene devices Title Dark spot formation relative to ITO surface roughness for polyfluorene devices Publication Type Journal Article Year of Publication 2004 Authors Liu, Gao, John B. Kerr, and Stephen G. Johnson Journal Synthetic Metals Volume 144 Pagination 1-6 Keywords dark spot, failure mechanism, interface, ito surface, oled Abstract The failure behaviors of ITO/PEDOT;PSS/polyfluorene/Al devices are different depending on the surface roughness of the sputtered ITO anode film. The spikes on ITO surface are responsible for the initial local shorts of the device, which develop into dark spots very quickly. Indium adsorption is observed on the polymer and Al cathode interface. A chemical etching procedure is used to smoothen the ITO surface without changing the ITO thickness and the sheet resistance. Devices made out of smooth ITO show minimum changes at polymer-cathode interface during operation.

49

The formation of a single-pulse electrospark deposition spot  

Science Journals Connector (OSTI)

The investigation of the formation mechanism of the rotating-type electrospark deposition (ESD) was presented, based on studying the single-pulse electrospark deposition spot. Four different substrate/electrode couples were selected to produce single-pulse deposition spots. The similar morphology of the spots and element migration tendency were detected. A heuristic physical model was established to interpret this deposition process. The concept of “gush and splash effect” was originally proposed and proved as the dominant factor in the formation mechanism of the single-pulse electrospark deposition spot. In addition, the rotation behavior of the electrode was identified to impact on the formation of the single-pulse deposition spot.

Jun Liu; Ruijun Wang; Yiyu Qian

2005-01-01T23:59:59.000Z

50

Mont Vista Capital LLC | Open Energy Information  

Open Energy Info (EERE)

Vista Capital LLC Vista Capital LLC Jump to: navigation, search Name Mont Vista Capital LLC Place New York, New York Zip 10167 Sector Services Product Mont Vista Capital is a leading global provider of services to clients in the alternative energy industry. Mont Vista also seeks proprietary trading and growth equity opportunities in alternative energy markets which add value for our stakeholders. References Mont Vista Capital LLC[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Mont Vista Capital LLC is a company located in New York, New York . References ↑ "Mont Vista Capital LLC" Retrieved from "http://en.openei.org/w/index.php?title=Mont_Vista_Capital_LLC&oldid=348916"

51

Monte Carlo methods in ICF  

SciTech Connect (OSTI)

Monte Carlo methods appropriate to simulate the transport of x-rays, neutrons, ion and electrons in Inertial Confinement Fusion targets are described and analyzed. The Implicit Monte Carlo method of x-ray transport handles symmetry within indirect drive ICF hohlraums well, but can be improved 50X in efficiency by angular biasing the x-rays towards the fuel capsule. Accurate simulation of thermonuclear burns nd burn diagnostics involves detailed particle source spectra, charged particle ranges, inflight reaction kinematics, corrections for bulk and thermal Doppler effects and variance reduction to obtain adequate statistics for rare events. It is found that the effects of angular Coulomb scattering must be included in models of charged particle transport through heterogeneous materials.

Zimmerman, G.B.

1997-06-24T23:59:59.000Z

52

Parallel Monte Carlo reactor neutronics  

SciTech Connect (OSTI)

The issues affecting implementation of parallel algorithms for large-scale engineering Monte Carlo neutron transport simulations are discussed. For nuclear reactor calculations, these include load balancing, recoding effort, reproducibility, domain decomposition techniques, I/O minimization, and strategies for different parallel architectures. Two codes were parallelized and tested for performance. The architectures employed include SIMD, MIMD-distributed memory, and workstation network with uneven interactive load. Speedups linear with the number of nodes were achieved.

Blomquist, R.N.; Brown, F.B.

1994-03-01T23:59:59.000Z

53

Monte Carlo charged-particle tracking and energy deposition on a Lagrangian mesh  

Science Journals Connector (OSTI)

A Monte Carlo algorithm for alpha particle tracking and energy deposition on a RZ cylindrical computational mesh in a Lagrangian hydrodynamics code used for inertial confinement fusion (ICF) simulations is presented. The straight line approximation is used to follow propagation of “Monte Carlo particles” which represent collections of alpha particles generated from thermonuclear deuterium-tritium (DT) reactions. Energy deposition in the plasma is modeled by the continuous slowing down approximation. The scheme addresses various aspects arising in the coupling of Monte Carlo tracking with Lagrangian hydrodynamics; such as non-orthogonal severely distorted mesh cells, particle relocation on the moving mesh and particle relocation after rezoning. A comparison with the flux-limited multi-group diffusion transport method is presented for a polar direct drive target design for the National Ignition Facility. Simulations show the Monte Carlo transport method predicts about 30picosecond earlier ignition than predicted by the diffusion method, and generates higher hot spot temperature. Nearly linear speed-up is achieved for multi-processor parallel simulations.

J. Yuan; G. A. Moses; P. W. McKenty

2005-10-10T23:59:59.000Z

54

E-Print Network 3.0 - angular leaf spot Sample Search Results  

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

Gray Snow Mold Pink Snow Mold Leaf SpotMelting Out Red Thread Dollar Spot Brown Patch Gray Leaf... Spot Anthracnose Pythium Blight Leaf Rust Powdery Mildew Slime Mold Fairy...

55

This Week In Petroleum Summary Printer-Friendly Version  

Gasoline and Diesel Fuel Update (EIA)

- Summary Printer-Friendly Version - Summary Printer-Friendly Version Released: January 15, 2014 Next Release: January 23, 2014 Midwest propane markets tighten further on cold weather The Upper Midwest is facing a tight market for propane this winter, as evidenced by a 1.5-million-barrel inventory draw in the region for the week ending last Friday, January 10. At the beginning of November, the corn harvest in the Upper Midwest (Minnesota, Iowa, Wisconsin, Nebraska) pulled large quantities of propane from distribution terminals for corn drying. Between late-November and December, supply disruptions prevented these terminals from replenishing their supplies of propane. With the onset of severely cold weather this past week, propane supplies are extremely tight, forcing emergency measures to ensure supply and increasing the Midwest spot price of propane at Conway, Kansas compared with the spot price on the Gulf Coast at Mont Belvieu, Texas. Propane prices in the Midwest will likely need to rise to keep propane in the region rather than flowing south to the Gulf Coast.

56

Hottest spot temperatures in ventilated dry type transformers  

SciTech Connect (OSTI)

The hottest spot temperature allowance to be used for the different insulation system temperature classes is a major unknown facing IEEE Working Groups developing standards and loading guides for ventilated dry type transformers. In 1944, the hottest spot temperature allowance for ventilated dry type transformers was established as 30 C for 80 C average winding temperature rise. Since 1944, insulation temperature classes have increased to 220 C but IEEE standards continue to use a constant 30 C hottest spot temperature allowance. IEC standards use a variable hottest spot temperature allowance from 5 to 30 C. Six full size test windings were manufactured with imbedded thermocouples and 133 test runs performed to obtain temperature rise data. The test data indicated that the hottest spot temperature allowance used in IEEE standards for ventilated dry type transformers above 500 kVA is too low. This is due to the large thermal gradient from the bottom to the top of the windings caused by natural convection air flow through the cooling ducts. A constant ratio of hottest spot winding temperature rise to average winding temperature rise should be used in product standards for all insulation temperature classes. A ratio of 1.5 is suggested for ventilated dry type transformers above 500 kVA. This would increase the hottest spot temperature allowance from 30 C to 60 C and decrease the permissible average winding temperature rise from 150 C to 120 C for the 220 C insulation temperature class.

Pierce, L.W. (General Electric Co., Rome, GA (United States))

1994-01-01T23:59:59.000Z

57

Wall and laser spot motion in cylindrical hohlraums  

SciTech Connect (OSTI)

Wall and laser spot motion measurements in empty, propane-filled and plastic (CH)-lined gold coated cylindrical hohlraums were performed on the Omega laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Wall motion was measured using axial two-dimensional (2D) x-ray imaging and laser spot motion was perpendicularly observed through a thinned wall using streaked hard x-ray imaging. Experimental results and 2D hydrodynamic simulations show that while empty targets exhibit on-axis plasma collision, CH-lined and propane-filled targets inhibit wall expansion, corroborated with perpendicular streaked imaging showing a slower motion of laser spots.

Huser, G.; Courtois, C.; Monteil, M.-C. [CEA, DAM, DIF, F-91297 Arpajon (France)

2009-03-15T23:59:59.000Z

58

Llanto al pie del Monte Carmelo  

E-Print Network [OSTI]

llantos feroces, llorando al pie de aquella fuente te estoySpring, 1988) Monte Carmelo al pie del Hay tiempo que no por

Ferrer, Juan José Prat

1988-01-01T23:59:59.000Z

59

Friction Stir Spot Welding of Advanced High Strength Steels ...  

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

Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. lm14grant.pdf More Documents & Publications Friction Stir Spot Welding of Advanced High...

60

LED Lighting Freeform Lens for achieving Octagon Spot  

Science Journals Connector (OSTI)

To decreasing the design error caused by the point source model, a method combining freeform and aspherical surface is presented. A LED spotlight lens for realizing octagon spot is...

Shaoyun, Yin; Sun, Xiuhui; Xia, Liangping; Du, Chunlei

Note: This page contains sample records for the topic "mont belvieu spot" 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

Techniques for spot microsampling and analysis of corrosion site fluid  

SciTech Connect (OSTI)

This paper presents techniques for the extraction and analysis of crevice fluid microsamples. Results are presented from ambient temperature benchtop proof-of-principle testing with the spot microsample extraction technique and from the high temperature test method.

Lynch, Garry J.; Niehaus, William C.

1999-02-01T23:59:59.000Z

62

Friction Stir Spot Welding of Advanced High Strength Steels ...  

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

Steels (AHSS) Friction Stir Spot Welding of Advanced High Strength Steels (AHSS) Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February...

63

The Information Role of Spot Prices and Inventories  

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

Information Role of Spot Prices and Inventories James L. Smith, Rex Thompson, and Thomas Lee June 24, 2014 Independent Statistics & Analysis www.eia.gov U.S. Energy Information...

64

A Monte Carlo algorithm for degenerate plasmas  

Science Journals Connector (OSTI)

A procedure for performing Monte Carlo calculations of plasmas with an arbitrary level of degeneracy is outlined. It has possible applications in inertial confinement fusion and astrophysics. Degenerate particles are initialised according to the Fermi-Dirac ... Keywords: Degenerate plasma, Monte Carlo

A. E. Turrell; M. Sherlock; S. J. Rose

2013-09-01T23:59:59.000Z

65

Monte Carlo Simulation of Isopentane Glass  

Science Journals Connector (OSTI)

...research-article Monte Carlo Simulation of Isopentane Glass S. Yashonath C. N. R. Rao Monte Carlo...quenching the liquid, we have obtained the glass-transition temperature from the temperature...distribution functions suggest a structure of the glass primarily influenced by geometrical factors...

1985-01-01T23:59:59.000Z

66

The MC21 Monte Carlo Transport Code  

SciTech Connect (OSTI)

MC21 is a new Monte Carlo neutron and photon transport code currently under joint development at the Knolls Atomic Power Laboratory and the Bettis Atomic Power Laboratory. MC21 is the Monte Carlo transport kernel of the broader Common Monte Carlo Design Tool (CMCDT), which is also currently under development. The vision for CMCDT is to provide an automated, computer-aided modeling and post-processing environment integrated with a Monte Carlo solver that is optimized for reactor analysis. CMCDT represents a strategy to push the Monte Carlo method beyond its traditional role as a benchmarking tool or ''tool of last resort'' and into a dominant design role. This paper describes various aspects of the code, including the neutron physics and nuclear data treatments, the geometry representation, and the tally and depletion capabilities.

Sutton TM, Donovan TJ, Trumbull TH, Dobreff PS, Caro E, Griesheimer DP, Tyburski LJ, Carpenter DC, Joo H

2007-01-09T23:59:59.000Z

67

HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid Architectures  

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

HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid Architectures HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid Architectures The Boltzmann transport equation...

68

Predicting hottest spot temperatures in ventilated dry type transformer windings  

SciTech Connect (OSTI)

Test data indicates that hottest spot allowances used in IEEE standards for ventilated dry type transformers above 500 kVA are too low. A mathematical model to predict hottest spot temperature rises in ventilated dry type transformers was developed. Data from six layer type test windings and a 2500 kva prototype was used to refine the model. A correlation for the local heat transfer coefficient in the cooling ducts was developed. The model was used to study the effect of various parameters on the ratio of hottest spot to average winding temperature rise. The number of conductor layers, insulation thickness, and conductor strand size were found to have only a minor effect on the ratio. Winding height was found to be the main parameter influencing the ratio of hottest spot to average winding temperature rise. The study based on the mathematical model confirmed previous conclusions based on test data that the hottest spot allowances used in IEEE standards for ventilated dry type transformers above 500 kVA should be revised.

Pierce, L.W. (General Electric Co., Rome, GA (United States))

1994-04-01T23:59:59.000Z

69

Bright Green Spot: Fort Worth Library | Department of Energy  

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

Bright Green Spot: Fort Worth Library Bright Green Spot: Fort Worth Library Bright Green Spot: Fort Worth Library September 30, 2010 - 4:07pm Addthis Lindsay Gsell Fort Worth's Central Library is seeing tremendous energy savings by cutting down consumption. Using an Energy Efficiency and Conservation Block Grant from the Recovery Act, the city was able to have the building retrofitted and install a building management system. The system allows library staff to control the indoor climate of the library from one location to reduce operating costs of the facility. Addthis Related Articles Captured data from the monitoring system at the public library shows that energy usage was highest at 10:30a.m., a time when a number of patrons in the library would be using computers and lighting. | Photo courtesy of Texas Institute for Sustainable Technology Research

70

Io hot spots - infrared photometry of satellite occultations  

SciTech Connect (OSTI)

Io's active hot spots, which are presently mapped on the basis of IR photometry of this moon's occultation by other Gallilean satellites, are obtained with greatest spatial resolution near the sub-earth point. A model is developed for the occultation lightcurves, and its fitting to the data defines the apparent path of the occulting satellite relative to Io; the mean error in apparent relative position of occulting satellites is of the order of 178 km. A heretofore unknown, 20-km diameter hot spot is noted on Io's leading hemisphere. 31 references.

Goguen, J.D.; Matson, D.L.; Sinton, W.M.; Howell, R.R.; Dyck, H.M.

1988-12-01T23:59:59.000Z

71

THE BEGINNING of the MONTE CARLO METHOD  

E-Print Network [OSTI]

. For a whole host of 125 #12;Monte Carlo reasons, he had become seriously inter- ested in the thermonuclear a preliminary computational model of a thermonuclear reaction for the ENIAC. He felt he could convince

72

Monte Carlo, Colloids, and Public Health  

Science Journals Connector (OSTI)

Here we see in a snapshot the importance of the Monte Carlo algorithm which is used in recent work to simulate data on women's mortality in a specific health-screening program.

Charles Day

2013-01-01T23:59:59.000Z

73

An evaluation of spot tests for boron and the development of a superior spot test for boron  

E-Print Network [OSTI]

three factors are well defined this 1;. st need not be faulty. A satisfactory spot test could then be defined as one that is: I) easy to perform, 2) has a well defined sensitivity, $) is detailed. as to procedure and inter- fering substances, and. 4... of hese involve the use of turmeric paper to . vhioh the test solu', i~n is ad ed ancL then dried. , and most involve '-he prolonged drying of the paper in air or in a des-icator. '2his is a rather lengthy procedure for a spot test. Peigl L...

Van Tuyl, Dixon Peacock

2012-06-07T23:59:59.000Z

74

Minimum-Hot-Spot Query Trees for Wireless Sensor Networks  

E-Print Network [OSTI]

an energy- efficient query routing tree. (a) Energy harvesting for battery- less nodes for the (b) Voltree to the querying node. Energy-efficient query routing trees are needed in a plethora of systems such as PeopleMinimum-Hot-Spot Query Trees for Wireless Sensor Networks Georgios Chatzimilioudis Dept

Zeinalipour, Demetris

75

Bipolar magnetic spots from dynamos in stratified spherical shell turbulence  

E-Print Network [OSTI]

Recent work by Mitra et al. (2014) has shown that in strongly stratified forced two-layer turbulence with helicity and corresponding large-scale dynamo action in the lower layer, a magnetic field occurs in the upper layer in the form of sharply bounded bipolar magnetic spots. Here we extend this model to spherical wedge geometry covering the northern hemisphere up to 75{\\deg} latitude and an azimuthal extent of 180{\\deg}. The kinetic helicity and therefore also the large-scale magnetic field are strongest at low latitudes. For moderately strong stratification, several bipolar spots form that fill eventually the full longitudinal extent. At early times, the polarity of spots reflects the orientation of the underlying azimuthal field, as expected from {\\Omega}-shaped flux loops. At late times their tilt changes such that there is a radial field of opposite orientation at different latitudes separated by about 10{\\deg}. Our model demonstrates for the first time the spontaneous formation of spots of sizes much la...

Jabbari, Sarah; Kleeorin, Nathan; Mitra, Dhrubaditya; Rogachevskii, Igor

2014-01-01T23:59:59.000Z

76

Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation  

E-Print Network [OSTI]

Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Aljoscha Rheinwalt 14. Januar 2009 Betreuender Professor: Prof. M. M¨uller-Preu�ker #12;Das Ising-Modell und Monte-Carlo-Simulation Gliederung Gliederung Ising-Modell Definition Anwendungen Numerische Analyse Statistische Beschreibung Monte

77

Spot welding of steel and aluminum using insert sheet  

SciTech Connect (OSTI)

Automobile industries have been increasingly interested in the use of aluminum and thus joining of steel and aluminum becomes of importance. The joining of the two types of metal raises a problem of brittle welds caused by the formation of intermetallic compounds. The authors solved the problem by using an insert sheet. This paper deals with the resistance spot welding of steel and aluminum sheets using insert sheets. The insert sheet used in the present development was a steel/aluminum clad sheet of the 0.8 mm thickness with 50% steel and 50% aluminum. The clad sheet was produced by warm rolling of steel and aluminum with a direct resistance heating process. Steel to be warm rolled was of EDDQ of the 0.4 mm thickness and aluminum was of JIS A1050 of 0.6 mm thickness. The mechanical properties of the insert clad sheets were in between those of the steel sheets and the aluminum sheets, while the clad sheets showed much better formability than the aluminum sheets. Resistance spot welding was conducted for 0.8 mm thick EDDQ steel sheets and 1.0 mm thick aluminum alloy (AL-5.5%Mg) sheets under the welding force of 1.96 kN, welding current ranging between 4.2 and 20.1 kA, and welding time from 0.5 to 10 cycles. The steel was spot welded to the steel side of the insert sheet while the aluminum was welded to the aluminum side. What the authors investigated were the applicable welding current range, nugget diameter, tensile shear strength, U-tension strength, and macro- and microstructures. In conclusion, steel sheets can be spot welded to aluminum sheets without difficulty by using clad sheets as insert materials while the strength level of the dissimilar metal spot welds is close to that of aluminum joints.

Oikawa, H.; Saito, T.; Yoshimura, T. [and others

1994-12-31T23:59:59.000Z

78

A New Species of Rhytisma Causes Tar Spot on Comarostaphylis arbutoides (Ericaceae) in Panama  

Science Journals Connector (OSTI)

A fungus causing tar spots on leaves of Comarostaphylis arbutoides (Ericaceae) in Panama is described as a new species, Rhytisma panamense. The fungus forms gregarious black stromata on pale yellow spots on the a...

Cheng-Lin Hou; Tanja Trampe; Meike Piepenbring

2010-03-01T23:59:59.000Z

79

E-Print Network 3.0 - anti-white spot syndrome Sample Search...  

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

white spot syndrome Search Powered by Explorit Topic List Advanced Search Sample search results for: anti-white spot syndrome Page: << < 1 2 3 4 5 > >> 1 JOURNAL OF VIROLOGY, June...

80

Development of New Ultrasonic Inspection Technique for Spot Welds with Matrix Arrayed Probe and SAFT  

Science Journals Connector (OSTI)

A portable type of 3D ultrasonic inspection system, named “Matrixeye”, was applied to the spot welds, in which a matrix-arrayed probe was used as a sensing unit, and the welding zone in the spot welds was visuali...

T. Ikeda; H. Karasawa; S. Matsumoto; S. Satonaka; C. Iwamoto

2006-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Delivery and Hedging Delivery ties the futures price to the spot price.  

E-Print Network [OSTI]

Delivery and Hedging · Delivery ties the futures price to the spot price. · On the delivery date, the settlement price of the futures contract is determined by the spot price. · Hence, when the delivery period is reached, the futures price should be very close to the spot price. · Changes in futures prices usually

Lyuu, Yuh-Dauh

82

QPO emission from moving hot spots on the surface of neutron stars: a model  

Science Journals Connector (OSTI)

......measurable from the spot-omega diagram described below and thus, as...P 0. 3.2 The spot-omega diagram We need a tool to describe the...2009). Figure 11 Spot-omega diagram for the case ), . In this case...misaligned dipole magnetic field. 3D MHD simulations have shown that......

Matteo Bachetti; Marina M. Romanova; Akshay Kulkarni; Luciano Burderi; Tiziana di Salvo

2010-04-11T23:59:59.000Z

83

The NordPool Market The spot and electricity forward relation  

E-Print Network [OSTI]

The NordPool Market The spot and electricity forward relation Spot price modelling HJM approach to forwards Conclusions Modelling and pricing in electricity markets Fred Espen Benth Work in collaboration and electricity forward relation Spot price modelling HJM approach to forwards Conclusions Overview

Pfeifer, Holger

84

A k-factor GIGARCH process: Estimation and Application on electricity market spot prices.  

E-Print Network [OSTI]

A k-factor GIGARCH process: Estimation and Application on electricity market spot prices. Abdou Kâ time series of market data, such as electricity spot price, exhibit long-memory, in the sense of slowly this approach to electricity prices (spot prices) from the German energy market (European Energy e

Paris-Sud XI, Université de

85

IMPROVING MULTI-LATTICE ALIGNMENT BASED SPOKEN KEYWORD SPOTTING Hui Lin, Alex Stupakov and Jeff Bilmes  

E-Print Network [OSTI]

, such as when- ever it is inconvenient, unsafe, or impossible for the user to enter a search query using and the utterance being searched is beneficial for spoken keyword spotting. In this paper, we introduce several im- prove the performance of spoken keyword spotting. Index Terms-- Spoken keyword spotting, lattice

Noble, William Stafford

86

Tight Product Balance Pushes Up Product Spread (Spot Product - Crude  

Gasoline and Diesel Fuel Update (EIA)

5 5 Notes: Gasoline inventories indicate how tight the gasoline product market is in any one region. When the gasoline market is tight, it affects the portion of gasoline price is the spread between spot product price and crude oil price. Note that in late 1998-and early 1999 spreads were very small when inventories were quite high. Contrast summers of 1998 or 1999 with summer 2000. Last summer's tight markets, resulting low stocks and transition to Phase 2 RFG added price pressure over and above the already high crude price pressure on gasoline -- particularly in the Midwest. As we ended last winter, gasoline inventories were low, and the spread between spot prices and crude oil were higher than typical as a result. Inventories stayed well below average and the spread during the

87

Forecasting Crude Oil Spot Price Using OECD Petroleum Inventory  

Gasoline and Diesel Fuel Update (EIA)

Forecasting Forecasting Crude Oil Spot Price Using OECD Petroleum Inventory Levels MICHAEL YE, ∗ JOHN ZYREN, ∗∗ AND JOANNE SHORE ∗∗ Abstract This paper presents a short-term monthly forecasting model of West Texas Intermedi- ate crude oil spot price using OECD petroleum inventory levels. Theoretically, petroleum inventory levels are a measure of the balance, or imbalance, between petroleum production and demand, and thus provide a good market barometer of crude oil price change. Based on an understanding of petroleum market fundamentals and observed market behavior during the post-Gulf War period, the model was developed with the objectives of being both simple and practical, with required data readily available. As a result, the model is useful to industry and government decision-makers in forecasting price and investigat- ing the impacts of changes on price, should inventories,

88

X-ray focal spot locating apparatus and method  

DOE Patents [OSTI]

An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

Gilbert, Hubert W. (Cedar Crest, NM)

1985-07-30T23:59:59.000Z

89

Evidence of randomness in United States spot oil prices  

SciTech Connect (OSTI)

This study investigates U.S. crude oil spot-market prices to determine if they were cyclical, autoregressive, or random in nature. The fact that oil-price volatility emerged only with the rise of spot markets meant that data for this type of an analysis were not previously available. The hypothesis tested was that U.S. crude oil price changes are neither cyclical nor autocorrelated, and are, therefore, random. Daily data on U.S. crude oil spot market prices (for the period of December 3, 1984 to November 4, 1988) were analyzed using spectral analysis; this converts time-series data into a frequency series, where it can be analyzed using more-powerful statistical methods. The spectral results of the price series gave a maximum power spectrum of 0.026, which is considerably smaller than the significance level of 0.052, considered acceptable using a 99% confidence level. The conclusion reached was that there was no significant cyclicality or autocorrelation in the data. This indicated that the U.S. crude oil prices are efficient, and that it would not be possible to predict crude oil price changes by using historical price data, seasonality, or business cycles.

Howard, B.W.

1989-01-01T23:59:59.000Z

90

Understanding plastic deformation in thermal glasses from single-soft-spot dynamics  

E-Print Network [OSTI]

By considering the low-frequency vibrational modes of amorphous solids, Manning and Liu [Phys. Rev. Lett. 107, 108302 (2011)] showed that a population of "soft spots" can be identified that are intimately related to plasticity at zero temperature under quasistatic shear. In this work we track individual soft spots with time in a two-dimensional sheared thermal Lennard Jones glass at temperatures ranging from deep in the glassy regime to above the glass transition temperature. We show that the lifetimes of individual soft spots are correlated with the timescale for structural relaxation. We additionally calculate the number of rearrangements required to destroy soft spots, and show that most soft spots can survive many rearrangements. Finally, we show that soft spots are robust predictors of rearrangements at temperatures well into the super-cooled regime. Altogether, these results pave the way for mesoscopic theories of plasticity of amorphous solids based on dynamical behavior of individual soft spots.

Samuel S. Schoenholz; Andrea J. Liu; Robert A. Riggleman; Joerg Rottler

2014-04-04T23:59:59.000Z

91

Monte Carlo event reconstruction implemented with artificial neural networks  

E-Print Network [OSTI]

I implemented event reconstruction of a Monte Carlo simulation using neural networks. The OLYMPUS Collaboration is using a Monte Carlo simulation of the OLYMPUS particle detector to evaluate systematics and reconstruct ...

Tolley, Emma Elizabeth

2011-01-01T23:59:59.000Z

92

A survey of Monte Carlo methods Jonathan Weare  

E-Print Network [OSTI]

A survey of Monte Carlo methods Jonathan Weare University of Chicago April 5, 2011 Jonathan Weare?) problems are high dimensional so we need MC. Jonathan Weare A survey of Monte Carlo methods #12;Some high in the initial conditions for an evolutionary PDE propagate? and many more · · · Jonathan Weare A survey of Monte

Anisimov, Mikhail

93

Module 2: Monte Carlo Methods Prof. Mike Giles  

E-Print Network [OSTI]

, Bermudan options, optimal trading given transaction costs) MC Lecture 1 ­ p. 7 #12;Monte Carlo vs. finite 1 ­ p. 5 #12;Monte Carlo vs. finite differences Hard to get reliable figures, but my "guesstimate most heavily? . . . and will it stay that way in the future? MC Lecture 1 ­ p. 6 #12;Monte Carlo vs

Giles, Mike

94

John von Neumann Institute for Computing Monte Carlo Protein Folding  

E-Print Network [OSTI]

John von Neumann Institute for Computing Monte Carlo Protein Folding: Simulations of Met://www.fz-juelich.de/nic-series/volume20 #12;#12;Monte Carlo Protein Folding: Simulations of Met-Enkephalin with Solvent-Accessible Area difficulties in applying Monte Carlo methods to protein folding. The solvent-accessible area method, a popular

Hsu, Hsiao-Ping

95

Mont Alto Borough | Open Energy Information  

Open Energy Info (EERE)

Alto Borough Alto Borough Jump to: navigation, search Name Mont Alto Borough Place Pennsylvania Utility Id 12817 Utility Location Yes Ownership M NERC Location RFC NERC RFC Yes Activity Buying Transmission Yes Activity Distribution Yes References EIA Form EIA-861 Final Data File for 2010 - File1_a[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Utility Rate Schedules Grid-background.png Commercial Commercial Residential Residential Average Rates Residential: $0.1460/kWh Commercial: $0.0899/kWh Industrial: $0.1480/kWh References ↑ "EIA Form EIA-861 Final Data File for 2010 - File1_a" Retrieved from "http://en.openei.org/w/index.php?title=Mont_Alto_Borough&oldid=411118"

96

Asymptotic Scaling and Monte Carlo Data  

E-Print Network [OSTI]

It is a generally known problem that the behaviour predicted from perturbation theory for asymptotically free theories like QCD, i.e. asymptotic scaling, has not been observed in Monte Carlo simulations when the series is expressed in terms of the bare coupling g_0. This discrepancy has been explained in the past with the poor convergence properties of the perturbative series in the g_0. An alternative point of view, called Lattice-Distorted Perturbation Theory proposes that lattice artifacts due to the finiteness of the lattice spacing, a, cause the disagreement between Monte Carlo data and perturbative scaling. Following this alternative scenario, we fit recent quenched data from different observables to fitting functions that include these cut-off effects, confirming that the lattice data are well reproduced by g_0-PT with the simple addition of terms O(a^n).

A. Trivini; C. R. Allton

2005-11-02T23:59:59.000Z

97

Single-shot and single-spot measurement of laser ablation threshold for carbon nanotubes  

E-Print Network [OSTI]

A simple and convenient procedure for single-shot, single-spot ablation threshold measurement has been developed. It is based on the employment of cylindrical lens to obtain elliptical Gaussian laser spot. The ablated spot chords which are parallel to the minor axis were measured across the spot major axis which is proportional to the fluence cross-section thus providing wide range dependence of damaged spot size versus fluence in one spot measurement. For both conventional and new-developed procedures the ablation threshold for typical Nd:YAG laser parameters (1064 nm, 10 ns) has been measured as 50 mJ/cm2 which is one order of magnitude lower than that for a bulk graphite.

Lednev, Vasily N; Obraztsova, Elena D; Kudryashov, Sergey I; Bunkin, Alexey F

2013-01-01T23:59:59.000Z

98

Spot Prices for Crude Oil and Petroleum Products  

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

Spot Prices Spot Prices (Crude Oil in Dollars per Barrel, Products in Dollars per Gallon) Period: Daily Weekly Monthly Annual Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes Product by Area 12/09/13 12/10/13 12/11/13 12/12/13 12/13/13 12/16/13 View History Crude Oil WTI - Cushing, Oklahoma 97.1 98.32 97.25 97.21 96.27 97.18 1986-2013 Brent - Europe 110.07 108.91 109.47 108.99 108.08 110.3 1987-2013 Conventional Gasoline New York Harbor, Regular 2.677 2.698 2.670 2.643 2.639 2.650 1986-2013 U.S. Gulf Coast, Regular 2.459 2.481 2.429 2.398 2.377 2.422 1986-2013 RBOB Regular Gasoline Los Angeles 2.639 2.661 2.569 2.543 2.514 2.527 2003-2013 No. 2 Heating Oil New York Harbor

99

Overview of Monte Carlo radiation transport codes  

SciTech Connect (OSTI)

The Radiation Safety Information Computational Center (RSICC) is the designated central repository of the United States Department of Energy (DOE) for nuclear software in radiation transport, safety, and shielding. Since the center was established in the early 60's, there have been several Monte Carlo particle transport (MC) computer codes contributed by scientists from various countries. An overview of the neutron transport computer codes in the RSICC collection is presented.

Kirk, Bernadette Lugue [ORNL] [ORNL

2010-01-01T23:59:59.000Z

100

New Monte Carlo Algorithm for Protein Folding  

Science Journals Connector (OSTI)

We demonstrate that the recently introduced pruned-enriched Rosenbluth method leads to extremely efficient algorithms for the folding of simple model proteins. We test them on several models for lattice heteropolymers, and compare the results to published Monte Carlo studies. In all cases our algorithms are faster than previous ones, and in several cases we find new minimal energy states. In addition, our algorithms give estimates for the partition sum at finite temperatures.

Helge Frauenkron; Ugo Bastolla; Erwin Gerstner; Peter Grassberger; Walter Nadler

1998-04-06T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Monte Carlo event generators at nonleading order  

Science Journals Connector (OSTI)

A method to construct Monte Carlo event generators at arbitrarily nonleading order is explained for the case of a nongauge theory. A precise and correct treatment of parton kinematics is provided. Modifications of the conventional formalism are required: parton showering is not exactly the same as Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution, and the external line prescription for the hard scattering differs from the Lehmann-Symanzik-Zimmermann prescription. The prospects for extending the results to QCD are discussed.

John Collins

2002-05-06T23:59:59.000Z

102

Transformation from spots to waves in a model of actin pattern formation  

E-Print Network [OSTI]

Actin networks in certain single-celled organisms exhibit a complex pattern-forming dynamics that starts with the appearance of static spots of actin on the cell cortex. Spots soon become mobile, executing persistent random walks, and eventually give rise to traveling waves of actin. Here we describe a possible physical mechanism for this distinctive set of dynamic transformations, by equipping an excitable reaction-diffusion model with a field describing the spatial orientation of its chief constituent (which we consider to be actin). The interplay of anisotropic actin growth and spatial inhibition drives a transformation at fixed parameter values from static spots to moving spots to waves.

Stephen Whitelam; Till Bretschneider; Nigel J. Burroughs

2009-05-18T23:59:59.000Z

103

Unit root properties of crude oil spot and futures prices  

Science Journals Connector (OSTI)

In this article, we examine whether WTI and Brent crude oil spot and futures prices (at 1, 3 and 6 months to maturity) contain a unit root with one and two structural breaks, employing weekly data over the period 1991–2004. To realise this objective we employ Lagrange multiplier (LM) unit root tests with one and two endogenous structural breaks proposed by Lee and Strazicich [2003. Minimum Lagrange multiplier unit root test with two structural breaks. Review of Economics and Statistics, 85, 1082–1089; 2004. Minimum LM unit root test with one structural break. Working Paper no. 04–17, Department of Economics, Appalachian State University]. We find that each of the oil price series can be characterised as a random walk process and that the endogenous structural breaks are significant and meaningful in terms of events that have impacted on world oil markets.

Svetlana Maslyuk; Russell Smyth

2008-01-01T23:59:59.000Z

104

Doppler-free Yb spectroscopy with the fluorescence spot technique  

SciTech Connect (OSTI)

We demonstrate a simple technique to measure the resonant frequency of the 398.9-nm {sup 1}S{sub 0}{leftrightarrow}{sup 1}P{sub 1} transition for the different Yb isotopes. The technique, which works by observing and aligning fluorescence spots, has enabled us to measure transition frequencies and isotope shifts with an accuracy of 60 MHz. We provide wavelength measurements for the transition that differ from previously published work. Our technique also allows for the determination of Doppler-shifted transition frequencies for photoionization experiments when the atomic beam and the laser beam are not perpendicular and furthermore allows us to determine the average velocity of the atoms along the direction of the atomic beam.

Nizamani, Altaf H.; McLoughlin, James J.; Hensinger, Winfried K. [Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, East-Sussex, BN1 9QH (United Kingdom)

2010-10-15T23:59:59.000Z

105

Monte Carlo Particle Transport: Algorithm and Performance Overview  

National Nuclear Security Administration (NNSA)

Monte Carlo Particle Transport: Monte Carlo Particle Transport: Algorithm and Performance Overview N. A. Gentile, R. J. Procassini and H. A. Scott Lawrence Livermore National Laboratory, Livermore, California, 94551 Monte Carlo methods are frequently used for neutron and radiation trans- port. These methods have several advantages, such as relative ease of programming and dealing with complex meshes. Disadvantages include long run times and statistical noise. Monte Carlo photon transport calcu- lations also often suffer from inaccuracies in matter temperature due to the lack of implicitness. In this paper we discuss the Monte Carlo algo- rithm as it is applied to neutron and photon transport, detail the differ- ences between neutron and photon Monte Carlo, and give an overview of the ways the numerical method has been modified to deal with issues that

106

Highly Shocked Polymer Bonded Explosives at a Nonplanar Interface: Hot-Spot Formation Leading to Detonation  

E-Print Network [OSTI]

to Detonation Qi An, William A. Goddard III,* Sergey V. Zybin, Andres Jaramillo-Botero, and Tingting Zhou the ReaxFF reactive force field to examine shock-induced hot-spot formation followed by detonation and pressure in the hot-spot region, until detonation. By contrast, the first step for PETN is NO2 release

Goddard III, William A.

107

Creation of Onset Voltage Hash by Anode Spots in a Magnetoplasmadynamic Thruster  

E-Print Network [OSTI]

Creation of Onset Voltage Hash by Anode Spots in a Magnetoplasmadynamic Thruster Luke Uribarri flow rate) of onset voltage fluctuations in a magnetoplasmadynamic thruster operating with three anode materials, and an anode spot model is presented which provides a physical explanation for the properties

Choueiri, Edgar

108

Creation of Onset Voltage Hash by Anode Spots in Magnetoplasmadynamic Thrusters  

E-Print Network [OSTI]

Creation of Onset Voltage Hash by Anode Spots in Magnetoplasmadynamic Thrusters Luke Uribarri and E (MPDTs) operating with three anode materials, and an anode spot model is presented which provides below and above onset with anodes of cop- per, graphite, and lead are analyzed using the statistical

Choueiri, Edgar

109

A NON-GAUSSIAN ORNSTEIN-UHLENBECK PROCESS FOR ELECTRICITY SPOT PRICE MODELING AND  

E-Print Network [OSTI]

A NON-GAUSSIAN ORNSTEIN-UHLENBECK PROCESS FOR ELECTRICITY SPOT PRICE MODELING AND DERIVATIVES for analytical pricing of electricity forward and futures contracts. Electricity forward and futures contracts to capture the observed dynamics of electricity spot prices. We also discuss the pricing of European call

Kallsen, Jan

110

Spot Convenience Yield Models for the Energy Markets Rene Carmona and Michael Ludkovski  

E-Print Network [OSTI]

Spot Convenience Yield Models for the Energy Markets Ren´e Carmona and Michael Ludkovski Abstract of convenience yield recently proposed as a viable alternative. 1. Introduction As the energy markets continue and phrases. Spot price, convenience yield, energy markets. 1 #12;2 REN´E CARMONA AND MICHAEL LUDKOVSKI

Carmona, Rene

111

Onset Voltage Hash and Anode Spots in Quasi-Steady Magnetoplasmadynamic  

E-Print Network [OSTI]

Onset Voltage Hash and Anode Spots in Quasi-Steady Magnetoplasmadynamic Thrusters Luke Uribarri: Edgar Y. Choueiri November 2008 #12;ONSET VOLTAGE HASH AND ANODE SPOTS IN QUASI noise ("hash") and anode damage in a self-field, quasi-steady magnetoplasmadynamic thruster (MPDT

Choueiri, Edgar

112

Relationship Between Anode Spots and Onset Voltage Hash in Magnetoplasmadynamic Thrusters  

E-Print Network [OSTI]

Relationship Between Anode Spots and Onset Voltage Hash in Magnetoplasmadynamic Thrusters Luke in magnetoplasmadynamic thrusters operating above onset and the time-resolved appearance of destructively released anode material in the thruster plume. Such a relationship gives support to previously discussed anode spotting

Choueiri, Edgar

113

SpotSigs: robust and efficient near duplicate detection in large web collections  

Science Journals Connector (OSTI)

Motivated by our work with political scientists who need to manually analyze large Web archives of news sites, we present SpotSigs, a new algorithm for extracting and matching signatures for near duplicate detection in large Web crawls. Our spot ... Keywords: high-dimensional similarity search, inverted index pruning, optimal partitioning, stopword signatures

Martin Theobald; Jonathan Siddharth; Andreas Paepcke

2008-07-01T23:59:59.000Z

114

Coherent Control of Nanoscale Light Localization in Metamaterial: Creating and Positioning Isolated Subwavelength Energy Hot Spots  

E-Print Network [OSTI]

in a subwavelength local- ization of optical energy. A desired nanoscale light hot spot can be engineered simplyCoherent Control of Nanoscale Light Localization in Metamaterial: Creating and Positioning Isolated Subwavelength Energy Hot Spots T. S. Kao,1 S. D. Jenkins,2 J. Ruostekoski,2 and N. I. Zheludev1,* 1

Zheludev, Nikolay

115

Ecological assessment of Phragmites australis wetlands using multi-season2 SPOT-5 scenes3  

E-Print Network [OSTI]

1 Ecological assessment of Phragmites australis wetlands using multi-season2 SPOT-5 scenes3 4 5 indices; multitemporal46 imagery; Phragmites australis; vegetation structure, SPOT-5 satellite; state).59 Common reed Phragmites australis (Cav. Trin. ex Steudel) is the most widely distributed60 flowering plant

Boyer, Edmond

116

A Monte Carlo algorithm for degenerate plasmas  

SciTech Connect (OSTI)

A procedure for performing Monte Carlo calculations of plasmas with an arbitrary level of degeneracy is outlined. It has possible applications in inertial confinement fusion and astrophysics. Degenerate particles are initialised according to the Fermi–Dirac distribution function, and scattering is via a Pauli blocked binary collision approximation. The algorithm is tested against degenerate electron–ion equilibration, and the degenerate resistivity transport coefficient from unmagnetised first order transport theory. The code is applied to the cold fuel shell and alpha particle equilibration problem of inertial confinement fusion.

Turrell, A.E., E-mail: a.turrell09@imperial.ac.uk; Sherlock, M.; Rose, S.J.

2013-09-15T23:59:59.000Z

117

Hybrid Monte Carlo and topological modes of full QCD  

E-Print Network [OSTI]

We investigate the performance of the hybrid Monte Carlo algorithm, the standard algorithm used for lattice QCD simulations involving fermions, in updating non-trivial global topological structures. We find that the hybrid Monte Carlo algorithm has serious problems decorrelating the global topological charge at the values of $\\beta$ and $m$ currently simulated, where continuum physics should be approximately realized. This represents a warning which must be seriously considered when simulating full QCD by hybrid Monte Carlo.

B. Allés; G. Boyd; M. D'Elia; A. Di Giacomo; E. Vicari

1996-07-22T23:59:59.000Z

118

Monte Carlo Simulations of the Corrosion of Aluminoborosilicate...  

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

Simulations of the Corrosion of Aluminoborosilicate Glasses. Monte Carlo Simulations of the Corrosion of Aluminoborosilicate Glasses. Abstract: Aluminum is one of the most common...

119

Posters Monte Carlo Simulation of Longwave Fluxes Through Broken...  

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

5 Posters Monte Carlo Simulation of Longwave Fluxes Through Broken Scattering Cloud Fields E. E. Takara and R. G. Ellingson University of Maryland College Park, Maryland To...

120

Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo...  

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

Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo Benchmarks and Validation of van der Waals Density Functional Methods P. Ganesh,* , Jeongnim Kim, Changwon...

Note: This page contains sample records for the topic "mont belvieu spot" 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

Evaluation of HotSpot, Lawerence Livermore National Laboratory - June 11,  

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

Evaluation of HotSpot, Lawerence Livermore National Laboratory - Evaluation of HotSpot, Lawerence Livermore National Laboratory - June 11, 2010 Evaluation of HotSpot, Lawerence Livermore National Laboratory - June 11, 2010 June 11, 2010 Letter from Andy Lawrence to John Nasstrom accepting the revised Hotspot In your letter dated April 16, 2010, you summarized the work done by the Lawerence Livermore National Laboratory (LLNL) to meet the Department of Energy's (DOE) recommendations from the 2007, Software Evaluation of HotSpot, and DOE, Safety Software Toolbox Recommendation, for inclusion of V2.07 in the DOE Safety Software Central Registry. Based on this work, you futher requested that HotSpot be included in the DOE Central Registry. Letter from Andy Lawrence to John Nasstrom accepting the revised Hotspot More Documents & Publications

122

Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses  

SciTech Connect (OSTI)

We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Zoology); Rose, K.A. (Oak Ridge National Lab., TN (United States))

1992-01-01T23:59:59.000Z

123

Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses  

SciTech Connect (OSTI)

We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Zoology; Rose, K.A. [Oak Ridge National Lab., TN (United States)

1992-12-31T23:59:59.000Z

124

THE MCNPX MONTE CARLO RADIATION TRANSPORT CODE  

SciTech Connect (OSTI)

MCNPX (Monte Carlo N-Particle eXtended) is a general-purpose Monte Carlo radiation transport code with three-dimensional geometry and continuous-energy transport of 34 particles and light ions. It contains flexible source and tally options, interactive graphics, and support for both sequential and multi-processing computer platforms. MCNPX is based on MCNP4B, and has been upgraded to most MCNP5 capabilities. MCNP is a highly stable code tracking neutrons, photons and electrons, and using evaluated nuclear data libraries for low-energy interaction probabilities. MCNPX has extended this base to a comprehensive set of particles and light ions, with heavy ion transport in development. Models have been included to calculate interaction probabilities when libraries are not available. Recent additions focus on the time evolution of residual nuclei decay, allowing calculation of transmutation and delayed particle emission. MCNPX is now a code of great dynamic range, and the excellent neutronics capabilities allow new opportunities to simulate devices of interest to experimental particle physics; particularly calorimetry. This paper describes the capabilities of the current MCNPX version 2.6.C, and also discusses ongoing code development.

WATERS, LAURIE S. [Los Alamos National Laboratory; MCKINNEY, GREGG W. [Los Alamos National Laboratory; DURKEE, JOE W. [Los Alamos National Laboratory; FENSIN, MICHAEL L. [Los Alamos National Laboratory; JAMES, MICHAEL R. [Los Alamos National Laboratory; JOHNS, RUSSELL C. [Los Alamos National Laboratory; PELOWITZ, DENISE B. [Los Alamos National Laboratory

2007-01-10T23:59:59.000Z

125

Calculating Pi Using the Monte Carlo Method  

Science Journals Connector (OSTI)

During the summer of 2012 I had the opportunity to participate in a research experience for teachers at the center for sustainable energy at Notre Dame University (RET @ cSEND) working with Professor John LoSecco on the problem of using antineutrino detection to accurately determine the fuel makeup and operating power of nuclear reactors. During full power operation a reactor may produce 1021 antineutrinos per second with approximately 100 per day being detected. While becoming familiar with the design and operation of the detectors and how total antineutrino flux could be obtained from such a small sample I read about a simulation program called Monte Carlo. 1 Further investigation led me to the Monte Carlo method page of Wikipedia 2 where I saw an example of approximating pi using this simulation. Other examples where this method was applied were typically done with computer simulations 2 or purely mathematical. 3 It is my belief that this method may be easily related to the students by performing the simple activity of sprinkling rice on an arc drawn in a square. The activity that follows was inspired by those simulations and was used by my AP Physics class last year with very good results.

Timothy Williamson

2013-01-01T23:59:59.000Z

126

Quantum Monte Carlo methods for nuclear physics  

E-Print Network [OSTI]

Quantum Monte Carlo methods have proved very valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states and transition moments in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. We review the nuclear interactions and currents, and describe the continuum Quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit, and three-body interactions. We present a variety of results including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. We also describe low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars. A coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.

J. Carlson; S. Gandolfi; F. Pederiva; Steven C. Pieper; R. Schiavilla; K. E. Schmidt; R. B. Wiringa

2014-12-09T23:59:59.000Z

127

Energy Monte Carlo (EMCEE) | Open Energy Information  

Open Energy Info (EERE)

Energy Monte Carlo (EMCEE) Energy Monte Carlo (EMCEE) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: EMCEE and Emc2 Agency/Company /Organization: United States Geological Survey Sector: Energy Focus Area: Non-renewable Energy Topics: Resource assessment Resource Type: Software/modeling tools User Interface: Spreadsheet Website: pubs.usgs.gov/pp/pp1713/26/ Country: United States Cost: Free Northern America Coordinates: 37.09024°, -95.712891° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.09024,"lon":-95.712891,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

128

Forecasting the conditional volatility of oil spot and futures prices with structural breaks and long memory models  

E-Print Network [OSTI]

downturns as a result of the September 11, 2001 terrorist attack, the West Texas Intermediate (WTI) spot

Paris-Sud XI, Université de

129

RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS  

E-Print Network [OSTI]

RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS A. Kersch1 W. Moroko2 A. Schuster1 1Siemens of Quasi-Monte Carlo to this problem. 1.1 Radiative Heat Transfer Reactors In the manufacturing of the problems which can be solved by such a simulation is high accuracy modeling of the radiative heat transfer

130

Sequential Monte Carlo EM for multivariate probit models  

Science Journals Connector (OSTI)

Multivariate probit models have the appealing feature of capturing some of the dependence structure between the components of multidimensional binary responses. The key for the dependence modelling is the covariance matrix of an underlying latent multivariate ... Keywords: Adaptive sequential Monte Carlo, Maximum likelihood, Monte Carlo EM, Multivariate probit

Giusi Moffa; Jack Kuipers

2014-04-01T23:59:59.000Z

131

CERN-TH.6275/91 Monte Carlo Event Generation  

E-Print Network [OSTI]

CERN-TH.6275/91 Monte Carlo Event Generation for LHC T. Sj¨ostrand CERN -- Geneva Abstract The necessity of event generators for LHC physics studies is illustrated, and the Monte Carlo approach is outlined. A survey is presented of existing event generators, followed by a more detailed study

Sjöstrand, Torbjörn

132

Top Spot is an intelligent advertising product that targets your most suitable listings to the right people  

E-Print Network [OSTI]

Top Spot is an intelligent advertising product that targets your most suitable listings estate agency both before and after signing up to Top Spot. 72% MORE VIEWS^ Advertising with Top Spot Premium design ­ bold colour and larger "Hero Shot" photo Smarter, efficient and targeted advertising

Peters, Richard

133

Monte Carlo stratified source-sampling  

SciTech Connect (OSTI)

In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo {open_quotes}eigenvalue of the world{close_quotes} problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. The original test-problem was treated by a special code designed specifically for that purpose. Recently ANL started work on a method for dealing with more realistic eigenvalue of the world configurations, and has been incorporating this method into VIM. The original method has been modified to take into account real-world statistical noise sources not included in the model problem. This paper constitutes a status report on work still in progress.

Blomquist, R.N.; Gelbard, E.M.

1997-09-01T23:59:59.000Z

134

Monte Carlo Simulation of Joint Transport of Neutrons Monte Carlo Simulation of Joint Transport of Neutrons  

National Nuclear Security Administration (NNSA)

Monte Carlo Simulation of Joint Transport of Neutrons Monte Carlo Simulation of Joint Transport of Neutrons Monte Carlo Simulation of Joint Transport of Neutrons and Photons and Photons Zhitnik Zhitnik A A . . K K . . , , Artemeva Artemeva E.V., E.V., Bakanov Bakanov V.V., V.V., Donskoy Donskoy E.N., E.N., Zalyalov Zalyalov A.N., A.N., Ivanov Ivanov N.V., N.V., Ognev Ognev S.P., S.P., Ronzhin Ronzhin A.B., A.B., Roslov Roslov V.I., V.I., Semenova Semenova T.V. T.V. RFNC-VNIIEF, 607190, Sarov, RFNC-VNIIEF, 607190, Sarov, Nizhni Nizhni Novgorod region Novgorod region The approaches used at VNIIEF to simulate transport of neutrons and photons in standard (with The approaches used at VNIIEF to simulate transport of neutrons and photons in standard (with surface description of region interfaces) and grid geometries are considered in the paper.

135

E-Print Network 3.0 - all-atom monte carlo Sample Search Results  

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

Source: Collection: Engineering ; Computer Technologies and Information Sciences 17 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

136

E-Print Network 3.0 - accurate monte carlo Sample Search Results  

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

Tilburg University Collection: Computer Technologies and Information Sciences 59 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

137

E-Print Network 3.0 - adjoint monte carlo Sample Search Results  

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

Oxford Collection: Engineering ; Computer Technologies and Information Sciences 37 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

138

Accelerated rescaling of single Monte Carlo simulation runs with the Graphics Processing Unit (GPU)  

E-Print Network [OSTI]

and S. Andersson-Engels, “Accelerated Monte Carlo models toAccelerated rescaling of single Monte Carlo simulation runsreported on online, GPU- accelerated MC simulations. Along

Yang, Owen; Choi, Bernard

2013-01-01T23:59:59.000Z

139

Photovoltaic ground fault and blind spot electrical simulations.  

SciTech Connect (OSTI)

Ground faults in photovoltaic (PV) systems pose a fire and shock hazard. To mitigate these risks, AC-isolated, DC grounded PV systems in the United States use Ground Fault Protection Devices (GFPDs), e.g., fuses, to de-energize the PV system when there is a ground fault. Recently the effectiveness of these protection devices has come under question because multiple fires have started when ground faults went undetected. In order to understand the limitations of fuse-based ground fault protection in PV systems, analytical and numerical simulations of different ground faults were performed. The numerical simulations were conducted with Simulation Program with Integrated Circuit Emphasis (SPICE) using a circuit model of the PV system which included the modules, wiring, switchgear, grounded or ungrounded components, and the inverter. The derivation of the SPICE model and the results of parametric fault current studies are provided with varying array topologies, fuse sizes, and fault impedances. Closed-form analytical approximations for GFPD currents from faults to the grounded current carrying conductor-known as %E2%80%9Cblind spot%E2%80%9D ground faults-are derived to provide greater understanding of the influence of array impedances on fault currents. The behavior of the array during various ground faults is studied for a range of ground fault fuse sizes to determine if reducing the size of the fuse improves ground fault detection sensitivity. The results of the simulations show that reducing the amperage rating of the protective fuse does increase fault current detection sensitivity without increasing the likelihood of nuisance trips to a degree. Unfortunately, this benefit reaches a limit as fuses become smaller and their internal resistance increases to the point of becoming a major element in the fault current circuit.

Flicker, Jack David; Johnson, Jay

2013-06-01T23:59:59.000Z

140

Calculation of the fast ion tail distribution for a spherically symmetric hot spot  

SciTech Connect (OSTI)

The fast ion tail for a spherically symmetric hot spot is computed via the solution of a simplified Fokker-Planck collision operator. Emphasis is placed on describing the energy scaling of the fast ion distribution function in the hot spot as well as the surrounding cold plasma throughout a broad range of collisionalities and temperatures. It is found that while the fast ion tail inside the hot spot is significantly depleted, leading to a reduction of the fusion yield in this region, a surplus of fast ions is observed in the neighboring cold plasma region. The presence of this surplus of fast ions in the neighboring cold region is shown to result in a partial recovery of the fusion yield lost in the hot spot.

McDevitt, C. J.; Tang, X.-Z.; Guo, Z. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Berk, H. L. [Department of Physics, University of Texas, Austin, Texas 78712 (United States)

2014-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

E-Print Network 3.0 - automatic robotic spotting Sample Search...  

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

spotting Page: << < 1 2 3 4 5 > >> 1 Dynamic Networks for Motion Planning in Multi-Robot Space Systems Summary: on a simple example involving 3 robots, with no obstacles. A...

142

Computing electricity spot price prediction intervals using quantile regression and forecast averaging  

Science Journals Connector (OSTI)

We examine possible accuracy gains from forecast averaging in the context of interval forecasts of electricity spot prices. First, we test whether constructing empirical prediction intervals (PI) from combined electricity

Jakub Nowotarski; Rafa? Weron

2014-08-01T23:59:59.000Z

143

Hot-spot measurements on the US-LCT coils in the IFSMTF  

SciTech Connect (OSTI)

Hot-spot temperature during a quench is a major concern for superconducting coil protection. If the allowable temperature can be increased, then the dump time constant can be made longer and the dump voltage correspondingly reduced. Thus, the insulation requirement can be less stringent and the dump operation can be safer. The US-made Large Coil Task (LCT) coils are all instrumented with heaters, resistive or inductive. The hot-spot temperatures of these coils were found by repeatedly driving the conductor normal with the heaters at increasing coil currents until the normal zone propagated. The resulting hot-spot temperature was measured by the resistance of the conductor over a fixed length. The effect of dump time delay on the hot-spot temperature was also investigated. The results are compared with calculations based on various assumptions. 4 refs., 7 figs.

Lue, J.W.; Dresner, L.; Fehling, D.T.; Lubell, M.S.; Luton, J.N.; McManamy, T.J.; Shen, S.S.; Wilson, C.T.; Wintenberg, R.E.

1987-01-01T23:59:59.000Z

144

E-Print Network 3.0 - availability hot spot Sample Search Results  

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

20.00 2006 IEEE 22nd IEEE SEMI-THERM Symposium Hot Spot Cooling using Embedded Thermoelectric Coolers Summary: 0-7803-XXXX-X0620.00 2006 IEEE 22nd IEEE SEMI-THERM...

145

The influence of purification protocol and pH on tomato spotted wilt virions  

E-Print Network [OSTI]

Two purification protocols were tested for their influence on yield of tomato spotted wilt virions. Protocol "A" was developed by Black et al (2), modified by Mohammed et al (34), and described by Gonsalves and Trujillo (16). Protocol "B...

Shimek, Christina Marie

1993-01-01T23:59:59.000Z

146

Wetland monitoring using classification trees and SPOT-5 seasonal time series. Aurlie Davranche1  

E-Print Network [OSTI]

to estimate the area of4 marshes covered with common reeds (Phragmites australis) and submerged macrophytes5 Phragmites australis, remote sensing, SPOT-5, submerged macrophytes, wetland monitoring.29 30 1. Introduction

Paris-Sud XI, Université de

147

Reedbed monitoring using classification trees and SPOT-5 seasonal time series  

E-Print Network [OSTI]

, Phragmites australis, Remote sensing, SPOT-5. Abstract The Camargue, the Rhône river delta in south of France to model the presence of common reed (Phragmite australis) stands in Camargue. The development

Paris-Sud XI, Université de

148

Iterative acceleration methods for Monte Carlo and deterministic criticality calculations  

SciTech Connect (OSTI)

If you have ever given up on a nuclear criticality calculation and terminated it because it took so long to converge, you might find this thesis of interest. The author develops three methods for improving the fission source convergence in nuclear criticality calculations for physical systems with high dominance ratios for which convergence is slow. The Fission Matrix Acceleration Method and the Fission Diffusion Synthetic Acceleration (FDSA) Method are acceleration methods that speed fission source convergence for both Monte Carlo and deterministic methods. The third method is a hybrid Monte Carlo method that also converges for difficult problems where the unaccelerated Monte Carlo method fails. The author tested the feasibility of all three methods in a test bed consisting of idealized problems. He has successfully accelerated fission source convergence in both deterministic and Monte Carlo criticality calculations. By filtering statistical noise, he has incorporated deterministic attributes into the Monte Carlo calculations in order to speed their source convergence. He has used both the fission matrix and a diffusion approximation to perform unbiased accelerations. The Fission Matrix Acceleration method has been implemented in the production code MCNP and successfully applied to a real problem. When the unaccelerated calculations are unable to converge to the correct solution, they cannot be accelerated in an unbiased fashion. A Hybrid Monte Carlo method weds Monte Carlo and a modified diffusion calculation to overcome these deficiencies. The Hybrid method additionally possesses reduced statistical errors.

Urbatsch, T.J.

1995-11-01T23:59:59.000Z

149

Recent advances and future prospects for Monte Carlo  

SciTech Connect (OSTI)

The history of Monte Carlo methods is closely linked to that of computers: The first known Monte Carlo program was written in 1947 for the ENIAC; a pre-release of the first Fortran compiler was used for Monte Carlo In 1957; Monte Carlo codes were adapted to vector computers in the 1980s, clusters and parallel computers in the 1990s, and teraflop systems in the 2000s. Recent advances include hierarchical parallelism, combining threaded calculations on multicore processors with message-passing among different nodes. With the advances In computmg, Monte Carlo codes have evolved with new capabilities and new ways of use. Production codes such as MCNP, MVP, MONK, TRIPOLI and SCALE are now 20-30 years old (or more) and are very rich in advanced featUres. The former 'method of last resort' has now become the first choice for many applications. Calculations are now routinely performed on office computers, not just on supercomputers. Current research and development efforts are investigating the use of Monte Carlo methods on FPGAs. GPUs, and many-core processors. Other far-reaching research is exploring ways to adapt Monte Carlo methods to future exaflop systems that may have 1M or more concurrent computational processes.

Brown, Forrest B [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

150

Testing a class of non-Kerr metrics with hot spots orbiting SgrA$^*$  

E-Print Network [OSTI]

SgrA$^*$, the supermassive black hole candidate at the Galactic Center, exhibits flares in the X-ray, NIR, and sub-mm bands that may be interpreted within a hot spot model. Light curves and images of hot spots orbiting a black hole are affected by a number of special and general relativistic effects, and they can be potentially used to check whether the object is a Kerr black hole of general relativity. However, in a previous study we have shown that the relativistic features are usually subdominant with respect to the background noise and the model-dependent properties of the hot spot, and eventually it is at most possible to estimate the frequency of the innermost stable circular orbit. In this case, tests of the Kerr metric are only possible in combination with other measurements. In the present work, we consider a class of non-Kerr spacetimes in which the hot spot orbit may be outside the equatorial plane. If the hot spot is sufficiently close to the massive object, the image affected by Doppler blueshift is brighter than the other one and this provides a specific observational signature in the hot spot's centroid track. We conclude that accurate astrometric observations of SgrA$^*$ with an instrument like GRAVITY should be able to test this class of metrics, except in the more unlikely case of a small viewing angle.

Dan Liu; Zilong Li; Cosimo Bambi

2014-11-10T23:59:59.000Z

151

Monte Carlo methods for the nuclear shell model  

E-Print Network [OSTI]

We present novel Monte Carlo methods for treating the interacting shell model that allow exact calculations much larger than those heretofore possible. The two-body interaction is linearized by an auxiliary field; Monte Carlo evaluation of the resulting functional integral gives ground-state or thermal expectation values of few-body operators. The ``sign problem'' generic to quantum Monte Carlo calculations is absent in a number of cases. We discuss the favorable scaling of these methods with nucleon numb er and basis size and their suitability to parallel computation.

C. W. Johnson; S. E. Koonin; G. H. Lang; W. E. Ormand

1992-10-20T23:59:59.000Z

152

Sequential Monte Carlo Methods for Protein Folding  

E-Print Network [OSTI]

We describe a class of growth algorithms for finding low energy states of heteropolymers. These polymers form toy models for proteins, and the hope is that similar methods will ultimately be useful for finding native states of real proteins from heuristic or a priori determined force fields. These algorithms share with standard Markov chain Monte Carlo methods that they generate Gibbs-Boltzmann distributions, but they are not based on the strategy that this distribution is obtained as stationary state of a suitably constructed Markov chain. Rather, they are based on growing the polymer by successively adding individual particles, guiding the growth towards configurations with lower energies, and using "population control" to eliminate bad configurations and increase the number of "good ones". This is not done via a breadth-first implementation as in genetic algorithms, but depth-first via recursive backtracking. As seen from various benchmark tests, the resulting algorithms are extremely efficient for lattice models, and are still competitive with other methods for simple off-lattice models.

Peter Grassberger

2004-08-26T23:59:59.000Z

153

Weekly Petroleum Status Report  

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

5 5 Table 12. Spot Prices of Ultra-Low Sulfur Diesel Fuel, Kerosene-Type Jet Fuel, and Propane, 2012 to Present (Dollars per Gallon) Year / Product Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2012 No. 2 Distillate Ultra-Low Sulfur Diesel Fuel New York Harbor ................ 3.080 3.223 3.302 3.242 2.987 2.710 2.921 3.179 3.229 3.236 3.180 3.070 U.S. Gulf Coast ................... 3.034 3.178 3.270 3.217 2.947 2.667 2.879 3.143 3.186 3.157 2.997 2.960 Los Angeles ........................ 3.088 3.242 3.384 3.252 3.007 2.654 2.854 3.225 3.299 3.226 3.071 2.971 Kerosene-Type Jet Fuel U.S. Gulf Coast ..................... 3.087 3.207 3.256 3.226 2.974 2.678 2.892 3.156 3.191 3.111 2.960 2.940 Propane Mont Belvieu ......................... 1.294 1.220 1.261 1.196 0.954 0.788 0.874 0.901 0.910 0.962 0.890 0.797 2013 No. 2 Distillate

154

Use of treatment log files in spot scanning proton therapy as part of patient-specific quality assurance  

SciTech Connect (OSTI)

Purpose: The purpose of this work was to assess the monitor unit (MU) values and position accuracy of spot scanning proton beams as recorded by the daily treatment logs of the treatment control system, and furthermore establish the feasibility of using the delivered spot positions and MU values to calculate and evaluate delivered doses to patients. Methods: To validate the accuracy of the recorded spot positions, the authors generated and executed a test treatment plan containing nine spot positions, to which the authors delivered ten MU each. The spot positions were measured with radiographic films and Matrixx 2D ion-chambers array placed at the isocenter plane and compared for displacements from the planned and recorded positions. Treatment logs for 14 patients were then used to determine the spot MU values and position accuracy of the scanning proton beam delivery system. Univariate analysis was used to detect any systematic error or large variation between patients, treatment dates, proton energies, gantry angles, and planned spot positions. The recorded patient spot positions and MU values were then used to replace the spot positions and MU values in the plan, and the treatment planning system was used to calculate the delivered doses to patients. The results were compared with the treatment plan. Results: Within a treatment session, spot positions were reproducible within {+-}0.2 mm. The spot positions measured by film agreed with the planned positions within {+-}1 mm and with the recorded positions within {+-}0.5 mm. The maximum day-to-day variation for any given spot position was within {+-}1 mm. For all 14 patients, with {approx}1 500 000 spots recorded, the total MU accuracy was within 0.1% of the planned MU values, the mean (x, y) spot displacement from the planned value was (-0.03 mm, -0.01 mm), the maximum (x, y) displacement was (1.68 mm, 2.27 mm), and the (x, y) standard deviation was (0.26 mm, 0.42 mm). The maximum dose difference between calculated dose to the patient based on the plan and recorded data was within 2%. Conclusions: The authors have shown that the treatment log file in a spot scanning proton beam delivery system is precise enough to serve as a quality assurance tool to monitor variation in spot position and MU value, as well as the delivered dose uncertainty from the treatment delivery system. The analysis tool developed here could be useful for assessing spot position uncertainty and thus dose uncertainty for any patient receiving spot scanning proton beam therapy.

Li Heng; Sahoo, Narayan; Poenisch, Falk; Suzuki, Kazumichi; Li Yupeng; Li Xiaoqiang; Zhang Xiaodong; Gillin, Michael T.; Zhu, X. Ronald [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Lee, Andrew K. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2013-02-15T23:59:59.000Z

155

Report of the Monte Rosa Expedition of 1911  

Science Journals Connector (OSTI)

1 January 1915 research-article Report of the Monte Rosa Expedition of 1911 J. Barcroft M. Camis C. G. Mathison Ff. Roberts J. H. Ryffel The Royal Society is collaborating...

1915-01-01T23:59:59.000Z

156

A Monte Carlo tool for multi-node reliability evaluation  

E-Print Network [OSTI]

-Area Reliability Program(NARP) is based on the random sampling of generator and transmission line status for each hour. Monte Carlo Approach for Estimating Contingency Statistics along with the Evaluation Subroutine(MACS-ES) advances the generation...

Thalasila, Chander Pravin

2012-06-07T23:59:59.000Z

157

An Analysis Tool for Flight Dynamics Monte Carlo Simulations  

E-Print Network [OSTI]

and analysis work to understand vehicle operating limits and identify circumstances that lead to mission failure. A Monte Carlo simulation approach that varies a wide range of physical parameters is typically used to generate thousands of test cases...

Restrepo, Carolina 1982-

2011-05-20T23:59:59.000Z

158

Variance Reduction Techniques for Implicit Monte Carlo Simulations  

E-Print Network [OSTI]

The Implicit Monte Carlo (IMC) method is widely used for simulating thermal radiative transfer and solving the radiation transport equation. During an IMC run a grid network is constructed and particles are sourced into the problem to simulate...

Landman, Jacob Taylor

2013-09-19T23:59:59.000Z

159

Implications of Monte Carlo Statistical Errors in Criticality Safety Assessments  

SciTech Connect (OSTI)

Most criticality safety calculations are performed using Monte Carlo techniques because of Monte Carlo's ability to handle complex three-dimensional geometries. For Monte Carlo calculations, the more histories sampled, the lower the standard deviation of the resulting estimates. The common intuition is, therefore, that the more histories, the better; as a result, analysts tend to run Monte Carlo analyses as long as possible (or at least to a minimum acceptable uncertainty). For Monte Carlo criticality safety analyses, however, the optimization situation is complicated by the fact that procedures usually require that an extra margin of safety be added because of the statistical uncertainty of the Monte Carlo calculations. This additional safety margin affects the impact of the choice of the calculational standard deviation, both on production and on safety. This paper shows that, under the assumptions of normally distributed benchmarking calculational errors and exact compliance with the upper subcritical limit (USL), the standard deviation that optimizes production is zero, but there is a non-zero value of the calculational standard deviation that minimizes the risk of inadvertently labeling a supercritical configuration as subcritical. Furthermore, this value is shown to be a simple function of the typical benchmarking step outcomes--the bias, the standard deviation of the bias, the upper subcritical limit, and the number of standard deviations added to calculated k-effectives before comparison to the USL.

Pevey, Ronald E.

2005-09-15T23:59:59.000Z

160

Magnetic dipole discharges. II. Cathode and anode spot discharges and probe diagnostics  

SciTech Connect (OSTI)

The high current regime of a magnetron-type discharge has been investigated. The discharge uses a permanent magnet as a cold cathode which emits secondary electrons while the chamber wall or a grounded electrode serves as the anode. As the discharge voltage is increased, the magnet develops cathode spots, which are short duration arcs that provide copious electrons to increase the discharge current dramatically. Short (1 ?s), high current (200 A) and high voltage (750 V) discharge pulses are produced in a relaxation instability between the plasma and a charging capacitor. Spots are also observed on a negatively biased plane Langmuir probe. The probe current pulses are as large as those on the magnet, implying that the high discharge current does not depend on the cathode surface area but on the properties of the spots. The fast current pulses produce large inductive voltages, which can reverse the electrical polarity of the magnet and temporarily operate it as an anode. The discharge current may also oscillate at the frequency determined by the charging capacitor and the discharge circuit inductance. Each half cycle of high-current current pulses exhibits a fast (?10 ns) current rise when a spot is formed. It induces high frequency (10–100 MHz) transients and ringing oscillations in probes and current circuits. Most probes behave like unmatched antennas for the electromagnetic pulses of spot discharges. Examples are shown to distinguish the source of oscillations and some rf characteristics of Langmuir probes.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)] [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

2013-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Testing a class of non-Kerr metrics with hot spots orbiting SgrA$^*$  

E-Print Network [OSTI]

SgrA$^*$, the supermassive black hole candidate at the Galactic Center, exhibits flares in the X-ray, NIR, and sub-mm bands that may be interpreted within a hot spot model. Light curves and images of hot spots orbiting a black hole are affected by a number of special and general relativistic effects, and they can be potentially used to check whether the object is a Kerr black hole of general relativity. However, in a previous study we have shown that the relativistic features are usually subdominant with respect to the background noise and the model-dependent properties of the hot spot, and eventually it is at most possible to estimate the frequency of the innermost stable circular orbit. In this case, tests of the Kerr metric are only possible in combination with other measurements. In the present work, we consider a class of non-Kerr spacetimes in which the hot spot orbit may be outside the equatorial plane. If the hot spot is sufficiently close to the massive object, the image affected by Doppler blueshift...

Liu, Dan; Bambi, Cosimo

2014-01-01T23:59:59.000Z

162

The Observer March 2003 page 3 CSU Fresno 16" SCT at f/38 & Jupiter's Great Red Spot  

E-Print Network [OSTI]

The Observer March 2003 page 3 CSU Fresno 16" SCT at f/38 & Jupiter's Great Red Spot By Greg Morgan in March that the Great Red Spot will be making a central meridian crossing along with the shadow of one in the region of the Great Red Spot. Similarly, on Tuesday evening April 1st , from 10:24 PM to 1:48 AM PDT, Io

Ringwald, Frederick A.

163

New EM Technology: Spray Lights up Contamination Hot Spots | Department of  

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

EM Technology: Spray Lights up Contamination Hot Spots EM Technology: Spray Lights up Contamination Hot Spots New EM Technology: Spray Lights up Contamination Hot Spots July 24, 2013 - 12:00pm Addthis The ORNL researchers conducted a test in which they sprayed the scintillating phosphor on simulated debris material marked with technetium-99. The ORNL researchers conducted a test in which they sprayed the scintillating phosphor on simulated debris material marked with technetium-99. An image intensified camera system captured an image of the simulated debris material in dark conditions. An image intensified camera system captured an image of the simulated debris material in dark conditions. The ORNL researchers conducted a test in which they sprayed the scintillating phosphor on simulated debris material marked with technetium-99.

164

,"Weekly Henry Hub Natural Gas Spot Price (Dollars per Million Btu)"  

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

Henry Hub Natural Gas Spot Price (Dollars per Million Btu)" Henry Hub Natural Gas Spot Price (Dollars per Million Btu)" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Weekly Henry Hub Natural Gas Spot Price (Dollars per Million Btu)",1,"Weekly","12/13/2013" ,"Release Date:","12/18/2013" ,"Next Release Date:","12/27/2013" ,"Excel File Name:","rngwhhdw.xls" ,"Available from Web Page:","http://tonto.eia.gov/dnav/ng/hist/rngwhhdw.htm" ,"Source:" ,"For Help, Contact:","infoctr@eia.doe.gov" ,,"(202) 586-8800",,,"12/18/2013 12:22:22 PM"

165

New EM Technology: Spray Lights up Contamination Hot Spots | Department of  

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

New EM Technology: Spray Lights up Contamination Hot Spots New EM Technology: Spray Lights up Contamination Hot Spots New EM Technology: Spray Lights up Contamination Hot Spots July 24, 2013 - 12:00pm Addthis The ORNL researchers conducted a test in which they sprayed the scintillating phosphor on simulated debris material marked with technetium-99. The ORNL researchers conducted a test in which they sprayed the scintillating phosphor on simulated debris material marked with technetium-99. An image intensified camera system captured an image of the simulated debris material in dark conditions. An image intensified camera system captured an image of the simulated debris material in dark conditions. The ORNL researchers conducted a test in which they sprayed the scintillating phosphor on simulated debris material marked with technetium-99.

166

Roosting Spot for These Nocturnal Mammals is Just Batty | Department of  

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

Roosting Spot for These Nocturnal Mammals is Just Batty Roosting Spot for These Nocturnal Mammals is Just Batty Roosting Spot for These Nocturnal Mammals is Just Batty November 7, 2012 - 3:05pm Addthis A Yuma bat flying inside the clearwell at 100-F Area. | Photo courtesy of the Office of Environmental Management. A Yuma bat flying inside the clearwell at 100-F Area. | Photo courtesy of the Office of Environmental Management. David Sheeley Editor/Writer for Environmental Management's Office of External Affairs What are the key facts? Yuma bats reside in a clearwell, a concrete structure formerly used to filter water from the Columbia River for cooling a reactor. Yuma bats have buff-colored bodies that are about 1.5 to 2 inches long with a wingspan of up to 9 inches. Think about the places where bats roost, and abandoned cab-ins, attics,

167

Powerful Radio Galaxies with Simbol-X: Lobes and Hot Spots  

SciTech Connect (OSTI)

We present here the first Simbol-X simulations of the extended components, lobes and hot spots, of the radio galaxies. We use the paradigmatic case of Pictor A to test the capabilities of Simbol-X in this field of studies. Simulations demonstrate that Simbol-X will be able not only to perform spatially resolved studies on the lobes of radio galaxies below 10 keV but also to observe, for the first time, hard X-ray emission from the hot spots. These extremely promising results show the considerable potentiality of Simbol-X in studying interaction phenomena between relativistic plasma and surrounding environment.

Migliori, G. [SISSA/ISAS, via Beirut 2-4, I-34014 Trieste (Italy); Grandi, P.; Raimondi, L.; Torresi, E. [INAF/IASF Bologna, viale Gobetti 101, I-40129 Bologna (Italy); Angelini, L. [NASA/Goddard Space Flight Center (United States); Palumbo, G. G. C. [Dipartimento di Astronomia, Universita di Bologna, via Ranzani 1, I-40127 Bologna (Italy)

2009-05-11T23:59:59.000Z

168

DOE Science Showcase - Monte Carlo Methods | OSTI, US Dept of Energy,  

Office of Scientific and Technical Information (OSTI)

Monte Carlo Methods Monte Carlo Methods Monte Carlo calculation methods are algorithms for solving various kinds of computational problems by using (pseudo)random numbers. Developed in the 1940s during the Manhattan Project, the Monte Carlo method signified a radical change in how scientists solved problems. Learn about the ways these methods are used in DOE's research endeavors today in "Monte Carlo Methods" by Dr. William Watson, Physicist, OSTI staff. Effects of static particle dispersions on grain growth are studied using SPPARKS simulations Image credit: Sandia National Laboratory Monte Carlo Results in DOE Databases Lab biophysicist invents improvement to Monte Carlo technique, LLNL News Monte Carlo Benchmark software, ESTSC Improved Monte Carlo Renormalization Group Method, DOE R&D

169

El Monte, California: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Monte, California: Energy Resources Monte, California: Energy Resources (Redirected from El Monte, CA) Jump to: navigation, search Equivalent URI DBpedia Coordinates 34.0686206°, -118.0275667° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":34.0686206,"lon":-118.0275667,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

170

An Overview of Geometry Representation in Monte Carlo Codes  

National Nuclear Security Administration (NNSA)

Geometry Representation Geometry Representation in Monte Carlo Codes R.P. Kensek, * B.C. Franke, * T.W. Laub * , L.J. Lorence, * M. R. Martin, * S. Warren † * Sandia National Laboratories, P.O. Box 5800, MS 1179, Albuquerque, NM 87185 † Kansas State University, Manhattan, KS 66506 Geometry representations in production Monte Carlo radiation transport codes used for linear-transport simulations are traditionally limited to combinatorial geometry (CG) topologies. While CG representations of input geometries are efficient to query, they are difficult to construct. In the Integrated-TIGER-Series (ITS) Monte Carlo code suite, a new approach for radiation transport geometry engines has been implemented that allows for Computer Aided Design (CAD), facetted approximations, and other geometry types to simultaneously define an input geometry.

171

The Monte Carlo Independent Column Approximation Model Intercomparison  

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

The Monte Carlo Independent Column Approximation Model Intercomparison The Monte Carlo Independent Column Approximation Model Intercomparison Project (McMIP) Barker, Howard Meteorological Service of Canada Cole, Jason Meteorological Service of Canada Raisanen, Petri Finnish Meteorological Institute Pincus, Robert NOAA-CIRES Climate Diagnostics Center Morcrette, Jean-Jacques European Centre for Medium-Range Weather Forecasts Li, Jiangnan Canadian Center for Climate Modelling Stephens, Graeme Colorado State University Vaillancourt, Paul Environment Canada Oreopoulos, Lazaros JCET/UMBC and NASA/GSFC Siebesma, Pier KNMI Los, Alexander KNMI Clothiaux, Eugene The Pennsylvania State University Randall, David Colorado State University Iacono, Michael Atmospheric & Environmental Research, Inc. Category: Radiation The Monte Carlo Independent Column Approximation (McICA) method for

172

Fast neutron fluxes in pressure vessels using Monte Carlo methods  

SciTech Connect (OSTI)

The objective of this project is to determine the feasibility of calculating the fast neutron flux in the pressure vessel of a pressurized water reactor by Monte Carlo methods. Neutron reactions reduce the ductility of the steel and thus limit the useful life of this important reactor component. This work was performed for Virginia Power (VEPCO). VIM is a continuous-energy Monte Carlo code which provides a versatile geometrical capability and a neutron physics data base closely representing the EDNF/B-IV data from which it was derived.

Edlund, M.C.; Thomas, J.R.

1986-01-01T23:59:59.000Z

173

Detection, tracking and analysis of turbulent spots and other coherent structures  

E-Print Network [OSTI]

transition. 1 Jacques Lewalle2 and David E. Ashpis3 Abstract Transition on turbine blades is an important of this preliminary study was to evaluate which spot properties can be quanti ed based on hot lm data, and which seem station, which provides smooth data to measure the phase relative to the rst stage blade passing

Lewalle, Jacques

174

Energy Spot Price Models and Spread Options Pricing Samuel Hikspoors and Sebastian Jaimungal a  

E-Print Network [OSTI]

). The world wide energy commodities markets have created a need for a deeper quan- titative understandingEnergy Spot Price Models and Spread Options Pricing Samuel Hikspoors and Sebastian Jaimungal a a Department of Statistics and Mathematical Finance Program, University of Toronto, 100 St. George Street

Jaimungal, Sebastian

175

The Onset of Voltage Hash and its Relationship to Anode Spots in Magnetoplasmadynamic Thrusters  

E-Print Network [OSTI]

The Onset of Voltage Hash and its Relationship to Anode Spots in Magnetoplasmadynamic Thrusters, 08544 A phenomenological model is developed to elucidate the relationship between voltage hash and anode electromagnetic force density leads to a mass depletion in the anode region which, in turn, leads to a disparity

Choueiri, Edgar

176

A Scalable Soft Spot Analysis Methodology for Compound Noise Effects in Nano-meter Circuits  

E-Print Network [OSTI]

A Scalable Soft Spot Analysis Methodology for Compound Noise Effects in Nano-meter Circuits Chong@ece.ucsd.edu ABSTRACT Circuits using nano-meter technologies are becoming increasingly vulnerable to signal interference methodology to study the vulnerability of digital ICs exposed to nano-meter noise and transient soft errors

California at San Diego, University of

177

Joint Modelling of Gas and Electricity spot prices N. Frikha1 , V. Lemaire2  

E-Print Network [OSTI]

Joint Modelling of Gas and Electricity spot prices N. Frikha1 , V. Lemaire2 October 13, 2010 for developing a risk management framework as well as pricing of options. Many derivatives on both electricity and electricity prices is a relevant issue. Numerous diffusion-type and econometric models have been proposed

Boyer, Edmond

178

Forecasting electricity spot market prices with a k-factor GIGARCH process.  

E-Print Network [OSTI]

Forecasting electricity spot market prices with a k-factor GIGARCH process. Abdou Kâ Diongue this method to the German electricity price market for the period August 15, 2000 - De- cember 31, 2002 and we; Electricity prices; Forecast; GIGARCH process. Corresponding author: Universite Gaston Berger de Saint

Paris-Sud XI, Université de

179

Joint Modelling of Gas and Electricity spot prices N. Frikha1 , V. Lemaire2  

E-Print Network [OSTI]

Joint Modelling of Gas and Electricity spot prices N. Frikha1 , V. Lemaire2 October 9, 2009 for developing a risk management framework as well as pricing of options. Many derivatives on both electricity and electricity prices is a relevant issue. Numerous diffusion-type and econometric models have been proposed

180

Fusion of SPOT5 multispectral and Ikonos panchromatic images R. ALONSO REYES  

E-Print Network [OSTI]

Fusion of SPOT5 multispectral and Ikonos panchromatic images R. ALONSO REYES Atmosphere, Remote & Modélisation, Centre Energétique, Ecole des Mines de Paris, Sophia Antipolis, France Keywords: Fusion methods spatial and spec- tral resolutions. The field of data fusion of remotely sensed data grown also very fast

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "mont belvieu spot" 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

Exploiting Regular Hot-Spots for Drive-thru Internet Jorg Ott and Dirk Kutscher  

E-Print Network [OSTI]

-spot installations is ever-increasing: besides hotels, caf´es and the like particularly airports, train stations, gas]. While 1 Examples include Agip gas stations and MAXI service areas in Germany, Neste A24 gas stations stations, and service areas are covered, i.e., places serving commuters and travellers on the road. 1

Ott, Jörg

182

SPIRIT-IPY: List of Publications SPOT 5 stereoscopic survey of Polar Ice: Reference Images &  

E-Print Network [OSTI]

, A. and Gallee, H.: Modeling the mass and surface heat budgets in a coastal blue ice area of AdelieSPIRIT-IPY: List of Publications SPOT 5 stereoscopic survey of Polar Ice: Reference Images stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year

Berthier, Etienne

183

Integrated thermal-microstructure model to predict the property gradients in resistance spot steel welds  

SciTech Connect (OSTI)

An integrated model approach was proposed for relating resistance welding parameters to weldment properties. An existing microstructure model was used to determine the microstructural and property gradients in resistance spot welds of plain carbon steel. The effect of these gradients on the weld integrity was evaluated with finite element analysis. Further modifications to this integrated thermal-microstructure model are discussed.

Babu, S.S.; Riemer, B.W.; Santella, M.L. [Oak Ridge National Lab., TN (United States); Feng, Z. [Edison Welding Inst., Columbus, OH (United States)

1998-11-01T23:59:59.000Z

184

Variable rate spreader for real-time spot-application of granular fertilizer in wild blueberry  

Science Journals Connector (OSTI)

The commercial variable rate (VR) fertilizer spreader can change fertilizer rates in different management zones using global positioning system (GPS) guided prescription maps. The VR fertilizer spreader allows the independent control only on half of ... Keywords: Controller, Digital photography, Fertilizer, Sensing and control system, Spot-application, Wild blueberry

Hassan S. Chattha; Qamar U. Zaman; Young K. Chang; Scott Read; Arnold W. Schumann; Gordon R. Brewster; Aitazaz A. Farooque

2014-01-01T23:59:59.000Z

185

Reduced form electricity spot price modeling with a view towards spike risk  

E-Print Network [OSTI]

Reduced form electricity spot price modeling with a view towards spike risk Prof. Dr. Meyer. Februar 2010, 16:15 Uhr Seminarraum, LudwigstraÃ?e 33 I The recent deregulation of electricity markets has led to the creation of energy exchanges, where the electricity is freely traded. We study the most

Gerkmann, Ralf

186

Futures pricing in electricity markets based on stable CARMA spot models  

E-Print Network [OSTI]

Futures pricing in electricity markets based on stable CARMA spot models Gernot M¨uller Vortrag im years, electricity markets throughout the world have undergone massive changes due to deregulations risk but also against price movements. Consequently, statistical modeling and estimation of electricity

Gerkmann, Ralf

187

DROPLET-BASED HOT SPOT COOLING USING TOPLESS DIGITAL MICROFLUIDICS ON A PRINTED CIRCUIT BOARD  

E-Print Network [OSTI]

DROPLET-BASED HOT SPOT COOLING USING TOPLESS DIGITAL MICROFLUIDICS ON A PRINTED CIRCUIT BOARD Phil demonstrated a cooling method on a "digital microfluidics" platform whereby discrete droplets are manipulated and the effective flow rate of the droplets. The results presented here suggest that digital microfluidics

Paris-Sud XI, Université de

188

Mapping the Energy Distribution of SERRS Hot Spots from Anti-Stokes to Stokes Intensity Ratios  

E-Print Network [OSTI]

Mapping the Energy Distribution of SERRS Hot Spots from Anti- Stokes to Stokes Intensity Ratios in the anti-Stokes to Stokes intensity ratios in single-molecule surface-enhanced resonance Raman scattering-enhanced Raman scattering. Moreover, a methodology to estimate the distribution of resonance energies

Brolo, Alexandre G.

189

Experimental Observation of Hot Spots in a Filippov-Type Plasma Focus Device  

Science Journals Connector (OSTI)

In this paper we have presented the experimental results of hot spots observation in different working conditions in Filippov-type Plasma Focus Device “Dena” (90 kJ, 25...2, Ar, Kr and Ne the formation of hot spo...

S. Goudarzi; A. Raeisdana

2010-04-01T23:59:59.000Z

190

Third harmonic order imaging as a focal spot diagnostic for high intensity laser-solid interactions  

E-Print Network [OSTI]

intensity inter- actions, i.e., fast ignition fusion, laser based ion acceleration etc., where fluctuationsThird harmonic order imaging as a focal spot diagnostic for high intensity laser-solid interactions, Glasgow, UK 4 Central Laser Facility, STFC Rutherford Appleton Laboratory. Chilton, Didcot, Didcot, UK 5

Strathclyde, University of

191

Experimental investigation of bright spots in broadband, gated x-ray images of ignition-scale implosions on the National Ignition Facility  

SciTech Connect (OSTI)

Bright spots in the hot spot intensity profile of gated x-ray images of ignition-scale implosions at the National Ignition Facility [G. H. Miller et al., Opt. Eng. 443, (2004)] are observed. X-ray images of cryogenically layered deuterium-tritium (DT) and tritium-hydrogen-deuterium (THD) ice capsules, and gas filled plastic shell capsules (Symcap) were recorded along the hohlraum symmetry axis. Heterogeneous mixing of ablator material and fuel into the hot spot (i.e., hot-spot mix) by hydrodynamic instabilities causes the bright spots. Hot-spot mix increases the radiative cooling of the hot spot. Fourier analysis of the x-ray images is used to quantify the evolution of bright spots in both x- and k-space. Bright spot images were azimuthally binned to characterize bright spot location relative to known isolated defects on the capsule surface. A strong correlation is observed between bright spot location and the fill tube for both Symcap and cryogenically layered DT and THD ice targets, indicating the fill tube is a significant seed for the ablation front instability causing hot-spot mix. The fill tube is the predominant seed for Symcaps, while other capsule non-uniformities are dominant seeds for the cryogenically layered DT and THD ice targets. A comparison of the bright spot power observed for Si- and Ge-doped ablator targets shows heterogeneous mix in Symcap targets is mostly material from the doped ablator layer.

Barrios, M. A.; Suter, L. J.; Glenn, S.; Benedetti, L. R.; Bradley, D. K.; Collins, G. W.; Hammel, B. A.; Izumi, N.; Ma, T.; Scott, H.; Smalyuk, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Regan, S. P.; Epstein, R. [Laboratory for Laser Energetics, University of Rochester 250 East River Road, Rochester, New York 14623-199 (United States)] [Laboratory for Laser Energetics, University of Rochester 250 East River Road, Rochester, New York 14623-199 (United States); Kyrala, G. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-07-15T23:59:59.000Z

192

E-Print Network 3.0 - atlas monte carlo Sample Search Results  

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

di - Dipartimento di Fisica, Quantum Optics Group Collection: Physics 50 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

193

E-Print Network 3.0 - accelerated monte carlo Sample Search Results  

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

Nuclear Technologies ; Environmental Sciences and Ecology ; Biology and Medicine 36 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

194

E-Print Network 3.0 - applicator monte carlo Sample Search Results  

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

of Electrical and Computer Engineering, Virginia Tech Collection: Engineering 85 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

195

E-Print Network 3.0 - adaptive monte carlo Sample Search Results  

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

and Statistics, University of New South Wales Collection: Mathematics 47 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

196

E-Print Network 3.0 - accelerating monte carlo Sample Search...  

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

Nuclear Technologies ; Environmental Sciences and Ecology ; Biology and Medicine 36 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

197

E-Print Network 3.0 - anatomy monte carlo Sample Search Results  

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

de Lige Collection: Power Transmission, Distribution and Plants ; Engineering 19 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

198

E-Print Network 3.0 - absolute monte carlo Sample Search Results  

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

Engineering, University of California at San Diego Collection: Engineering 37 Das Ising-Modell und Monte-Carlo-Simulation Das Ising-Modell und Monte-Carlo-Simulation Summary:...

199

Bone Penetration of Amoxicillin and Clavulanic Acid Evaluated by Population Pharmacokinetics and Monte Carlo Simulation  

Science Journals Connector (OSTI)

...infusion. Simulations with our...equilibration by modeling and to derive...Monte Carlo simulations. Drusano...bone was rapid for both...using a fully automated extraction...pharmacokinetic modeling and Monte Carlo simulation. Antimicrob...

Cornelia B. Landersdorfer; Martina Kinzig; Jürgen B. Bulitta; Friedrich F. Hennig; Ulrike Holzgrabe; Fritz Sörgel; Johannes Gusinde

2009-03-23T23:59:59.000Z

200

The theoretical development of a new high speed solution for Monte Carlo radiation transport computations  

E-Print Network [OSTI]

Advancements in parallel and cluster computing have made many complex Monte Carlo simulations possible in the past several years. Unfortunately, cluster computers are large, expensive, and still not fast enough to make the Monte Carlo technique...

Pasciak, Alexander Samuel

2007-04-25T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes  

E-Print Network [OSTI]

candidates for thermoelectric materials as they can provide extremely low thermal conductivity , relatively of boundary scattering on the thermal conductivity. We show that the material porosity strongly affects1 Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes Stefanie Wolf1

202

Impact of random numbers on parallel Monte Carlo application  

SciTech Connect (OSTI)

A number of graduate students are involved at various level of research in this project. We investigate the basic issues in materials using Monte Carlo simulations with specific interest in heterogeneous materials. Attempts have been made to seek collaborations with the DOE laboratories. Specific details are given.

Pandey, Ras B.

2002-10-22T23:59:59.000Z

203

Observations of Comet b 1881 made at Monte Video  

Science Journals Connector (OSTI)

... 1881 Royal Astronomical Society. Provided by the NASA Astrophysics Data System 14 July 1881 research-article Articles Observations of Comet b 1881 made at Monte Video Lieut. B. E. W. Gwynne R.A. 1881MNRAS..41..438G...

B. E. W. Gwynne

1881-07-14T23:59:59.000Z

204

Monte Carlo calibration of avalanches described as Coulomb fluid flows  

Science Journals Connector (OSTI)

...different mathematical issues to invert a relationship in the form...crude current knowledge of snow rheology and avalanche physics as well...positioned on each side of 0 and a flat asymmetric tail extending over...Theoretical Monte Carlo Method Motion Rheology methods Snow chemistry Static...

2005-01-01T23:59:59.000Z

205

Difficulties in vector-parallel processing of Monte Carlo codes  

SciTech Connect (OSTI)

Experiences with vectorization of production-level Monte Carlo codes such as KENO-IV, MCNP, VIM, and MORSE have shown that it is difficult to attain high speedup ratios on vector processors because of indirect addressing, nests of conditional branches, short vector length, cache misses, and operations for realization of robustness and generality. A previous work has already shown that the first, second, and third difficulties can be resolved by using special computer hardware for vector processing of Monte Carlo codes. Here, the fourth and fifth difficulties are discussed in detail using the results for a vectorized version of the MORSE code. As for the fourth difficulty, it is shown that the cache miss-hit ratio affects execution times of the vectorized Monte Carlo codes and the ratio strongly depends on the number of the particles simultaneously tracked. As for the fifth difficulty, it is shown that remarkable speedup ratios are obtained by removing operations that are not essential to the specific problem being solved. These experiences have shown that if a production-level Monte Carlo code system had a capability to selectively construct source coding that complements the input data, then the resulting code could achieve much higher performance.

Higuchi, Kenji; Asai, Kiyoshi [Japan Atomic Energy Research Inst., Tokyo (Japan). Center for Promotion of Computational Science and Engineering; Hasegawa, Yukihiro [Research Organization for Information Science and Technology, Tokai, Ibaraki (Japan)

1997-09-01T23:59:59.000Z

206

Using random number generators in Monte Carlo simulations  

Science Journals Connector (OSTI)

One of the standard tests for Monte Carlo algorithms and for testing random number generators is the two-dimensional Ising model. We show that at least in the present case, where we study the two-state clock model, good random number generators can give inconsistent values for the critical temperature.

F. J. Resende and B. V. Costa

1998-10-01T23:59:59.000Z

207

Evolutionary Monte Carlo for protein folding simulations Faming Lianga)  

E-Print Network [OSTI]

Evolutionary Monte Carlo for protein folding simulations Faming Lianga) Department of Statistics to simulations of protein folding on simple lattice models, and to finding the ground state of a protein. In all structures in protein folding. The numerical results show that it is drastically superior to other methods

Liang, Faming

208

ccsd00003115, Coupled Electron Ion Monte Carlo Calculations of Atomic  

E-Print Network [OSTI]

ccsd­00003115, version 1 ­ 21 Oct 2004 Coupled Electron Ion Monte Carlo Calculations of Atomic state calculations where both electronic and protonic degrees of freedom are treated quantum­zero temperature with a QMC calculation for the electronic energies where the Born­Oppenheimer approximation helps

209

ENVIRONMENTAL MODELING: 1 APPLICATIONS: MONTE CARLO SENSITIVITY SIMULATIONS  

E-Print Network [OSTI]

SIMULATIONS TO THE PROBLEM OF AIR POLLUTION TRANSPORT 3 1.1 The Danish Eulerian Model #12;Chapter 1 APPLICATIONS: MONTE CARLO SENSITIVITY SIMULATIONS TO THE PROBLEM OF AIR POLLUTION of pollutants in a real-live scenario of air-pollution transport over Europe. First, the developed technique

Dimov, Ivan

210

Faster Fermions in the Tempered Hybrid Monte Carlo Algorithm  

E-Print Network [OSTI]

Tempering is used to change the quark mass while remaining in equilibrium between the trajectories of a standard hybrid Monte Carlo simulation of four flavours of staggered fermions. The algorithm is faster for small enough quark masses, and particularly so when more than one mass is required.

G. Boyd

1997-01-20T23:59:59.000Z

211

Monte Carlo sampling from the quantum state space. II  

E-Print Network [OSTI]

High-quality random samples of quantum states are needed for a variety of tasks in quantum information and quantum computation. Searching the high-dimensional quantum state space for a global maximum of an objective function with many local maxima or evaluating an integral over a region in the quantum state space are but two exemplary applications of many. These tasks can only be performed reliably and efficiently with Monte Carlo methods, which involve good samplings of the parameter space in accordance with the relevant target distribution. We show how the Markov-chain Monte Carlo method known as Hamiltonian Monte Carlo, or Hybrid Monte Carlo, can be adapted to this context. It is applicable when an efficient parameterization of the state space is available. The resulting random walk is entirely inside the physical parameter space, and the Hamiltonian dynamics enable us to take big steps, thereby avoiding strong correlations between successive sample points while enjoying a high acceptance rate. We use examples of single and double qubit measurements for illustration.

Yi-Lin Seah; Jiangwei Shang; Hui Khoon Ng; David John Nott; Berthold-Georg Englert

2014-07-29T23:59:59.000Z

212

SciTech Connect: Fast Monte Carlo for radiation therapy: the...  

Office of Scientific and Technical Information (OSTI)

MEDICINE, BASIC STUDIES; RADIOTHERAPY; PLANNING; COMPUTER CALCULATIONS; RADIATION DOSE DISTRIBUTIONS; MONTE CARLO METHOD; THREE-DIMENSIONAL CALCULATIONS; COMPUTERIZED TOMOGRAPHY...

213

Operating conditions for the generation of stable anode spot plasma in front of a positively biased electrode  

SciTech Connect (OSTI)

Stability of an anode spot plasma, which is an additional high density plasma generated in front of a positively biased electrode immersed in ambient plasma, is a critical issue for its utilization to various types of ion sources. In this study, operating conditions for the generation of stable anode spot plasmas are experimentally investigated. Diagnostics of the bias current flowing into the positively biased electrode and the properties of ambient plasma reveal that unstable nature of the anode spot is deeply associated with the reduction of double layer potential between the anode spot plasma and the ambient plasma. It is found that stability of the anode spot plasma can be improved with increasing the ionization rate in ambient plasma so as to compensate the loss of electrons across the double layer or with enlarging the area of the biased electrode to prevent electron accumulation inside the anode spot. The results obtained from the present study give the guideline for operating conditions of anode spot plasmas as an ion source with high brightness.

Park, Yeong-Shin; Lee, Yuna; Dang, Jeong-Jeung [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of) [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2014-02-15T23:59:59.000Z

214

Linear and non-linear Granger causality between oil spot and futures prices: A wavelet based test  

Science Journals Connector (OSTI)

Abstract This study is the first attempt to investigate both the linear and non-linear Granger causality between wavelet transformed spot and futures oil prices. Our findings consistently indicate bidirectional causality between the spot and futures oil markets at different time scales, under linear and non-linear causality assumptions, and also during the recent financial crisis. Our results tend to shed further light on the ongoing controversy over the relative price discovery role played by spot market as opposed to futures market in oil price fluctuations, especially during periods of high uncertainty.

Mohammed Alzahrani; Mansur Masih; Omar Al-Titi

2014-01-01T23:59:59.000Z

215

,"Henry Hub Natural Gas Spot Price (Dollars per Million Btu)"  

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

Annual",2012 Annual",2012 ,"Release Date:","12/18/2013" ,"Next Release Date:","12/27/2013" ,"Excel File Name:","rngwhhda.xls" ,"Available from Web Page:","http://tonto.eia.gov/dnav/ng/hist/rngwhhda.htm" ,"Source:" ,"For Help, Contact:","infoctr@eia.doe.gov" ,,"(202) 586-8800",,,"12/18/2013 12:22:19 PM" "Back to Contents","Data 1: Henry Hub Natural Gas Spot Price (Dollars per Million Btu)" "Sourcekey","RNGWHHD" "Date","Henry Hub Natural Gas Spot Price (Dollars per Million Btu)" 35611,2.49 35976,2.09 36341,2.27 36707,4.31 37072,3.96 37437,3.38 37802,5.47 38168,5.89 38533,8.69 38898,6.73

216

,"Henry Hub Natural Gas Spot Price (Dollars per Million Btu)"  

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

Daily","12/16/2013" Daily","12/16/2013" ,"Release Date:","12/18/2013" ,"Next Release Date:","12/27/2013" ,"Excel File Name:","rngwhhdd.xls" ,"Available from Web Page:","http://tonto.eia.gov/dnav/ng/hist/rngwhhdd.htm" ,"Source:" ,"For Help, Contact:","infoctr@eia.doe.gov" ,,"(202) 586-8800",,,"12/18/2013 12:22:24 PM" "Back to Contents","Data 1: Henry Hub Natural Gas Spot Price (Dollars per Million Btu)" "Sourcekey","RNGWHHD" "Date","Henry Hub Natural Gas Spot Price (Dollars per Million Btu)" 35437,3.82 35438,3.8 35439,3.61 35440,3.92 35443,4 35444,4.01 35445,4.34 35446,4.71 35447,3.91

217

Essays on price dynamics, discovery, and dynamic threshold effects among energy spot markets in North America  

E-Print Network [OSTI]

stylized facts concerning electricity prices: high volatility, mean-reversion, seasonality, and frequent extreme jumps in prices (Huisman and Mahieu, 2003). See Bunn (2004) for more studies concerning modeling electricity prices. De Vany and Walls (1999... or five trading days) convergence with respect to external shocks. Jerko, Mjelde, and Bessler (2004) using directed graphs to examine the contemporaneous causal flows 9 among spot markets suggested electricity price information flows...

Park, Haesun

2005-11-01T23:59:59.000Z

218

Spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB  

DOE Patents [OSTI]

A simple, sensitive and specific spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB, is described. Upon the application of the composition of matter of the subject invention to samples containing in excess of 0.1 mg of this explosive, a bright orange color results. Interfering species such as TNT and Tetryl can be removed by first treating the sample with a solvent which does not dissolve the TATB, but readily dissolves these interfering explosives.

Harris, B.W.

1984-11-29T23:59:59.000Z

219

Eutectic structures in friction spot welding joint of aluminum alloy to copper  

SciTech Connect (OSTI)

A dissimilar joint of AA5083 Al alloy and copper was produced by friction spot welding. The Al-MgCuAl{sub 2} eutectic in both coupled and divorced manners were found in the weld. At a relatively high temperature, mass transport of Cu due to plastic deformation, material flow, and atomic diffusion, combined with the alloy system of AA5083 are responsible for the ternary eutectic melting.

Shen, Junjun, E-mail: junjun.shen@hzg.de; Suhuddin, Uceu F. H.; Cardillo, Maria E. B.; Santos, Jorge F. dos [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Materials Mechanics, Solid-State Joining Processes, Max-Planck-Str. 1, 21502 Geesthacht (Germany)

2014-05-12T23:59:59.000Z

220

The role of trader positions in spot and futures prices for WTI  

Science Journals Connector (OSTI)

Abstract We extend the analysis of causal relations between trader positions and oil prices and the process of price discovery by estimating a cointegrating vector autoregression (CVAR) model that expands the cash-and-carry relation between spot and futures prices to quantify long- and short-run relations among oil prices, trader positions, interest rates, and oil inventories. Results indicate that oil inventories and trader positions are needed to generate cointegration between spot and futures prices. The presence of trader positions and oil inventories suggest that both play a role in price discovery. Furthermore, the cointegrating relation for price loads into the equation for both oil prices and trader positions. This suggests a bi-directional simultaneous adjustment process between oil prices and trader positions. This expands the unidirectional causal relation from oil prices to trader positions that is generated by previous studies. Additional results suggest that price discovery occurs in the market for heavily traded near-month futures contracts, but discovery for thin far-month futures markets occurs in the spot market. Together, these results suggest mechanisms by which speculation could affect oil prices but the results presented here are moot regarding their effects.

Marek Kolodziej; Robert K. Kaufmann

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Friction Stir Spot Welding (FSSW) of Advanced High Strength Steel (AHSS)  

SciTech Connect (OSTI)

Friction stir spot welding (FSSW) is applied to join advanced high strength steels (AHSS): galvannealed dual phase 780 MPa steel (DP780GA), transformation induced plasticity 780 MPa steel (TRIP780), and hot-stamped boron steel (HSBS). A low-cost Si3N4 ceramic tool was developed and used for making welds in this study instead of polycrystalline cubic boron nitride (PCBN) material used in earlier studies. FSSW has the advantages of solid-state, low-temperature process, and the ability of joining dissimilar grade of steels and thicknesses. Two different tool shoulder geometries, concave with smooth surface and convex with spiral pattern, were used in the study. Welds were made by a 2-step displacement control process with weld time of 4, 6, and 10 seconds. Static tensile lap-shear strength achieved 16.4 kN for DP780GA-HSBS and 13.2kN for TRIP780-HSBS, above the spot weld strength requirements by AWS. Nugget pull-out was the failure mode of the joint. The joining mechanism was illustrated from the cross-section micrographs. Microhardness measurement showed hardening in the upper sheet steel (DP780GA or TRIP780) in the weld, but softening of HSBS in the heat-affect zone (HAZ). The study demonstrated the feasibility of making high-strength AHSS spot welds with low-cost tools.

Santella, M. L.; Hovanski, Yuri; Pan, Tsung-Yu

2012-04-16T23:59:59.000Z

222

Load Balancing Of Parallel Monte Carlo Transport Calculations  

National Nuclear Security Administration (NNSA)

Load Balancing Of Parallel Load Balancing Of Parallel Monte Carlo Transport Calculations R.J. Procassini, M. J. O'Brien and J.M. Taylor Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, CA 94551 The performance of parallel Monte Carlo transport calculations which use both spatial and particle parallelism is increased by dynamically assigning processors to the most worked domains. Since the particle work load varies over the course of the simulation, each cycle this algorithm determines if dynamic load balancing would speed up the calculation. If load balancing is required, a small number of particle communications are initiated in order to achieve load balance. This method has decreased the parallel run time by more than a factor of three for certain criticality

223

Beyond the Born-Oppenheimer approximation with quantum Monte Carlo  

E-Print Network [OSTI]

In this work we develop tools that enable the study of non-adiabatic effects with variational and diffusion Monte Carlo methods. We introduce a highly accurate wave function ansatz for electron-ion systems that can involve a combination of both fixed and quantum ions. We explicitly calculate the ground state energies of H$_{2}$, LiH, H$_{2}$O and FHF$^{-}$ using fixed-node quantum Monte Carlo with wave function nodes that explicitly depend on the ion positions. The obtained energies implicitly include the effects arising from quantum nuclei and electron-nucleus coupling. We compare our results to the best theoretical and experimental results available and find excellent agreement.

Tubman, Norm M; Hammes-Schiffer, Sharon; Ceperley, David M

2014-01-01T23:59:59.000Z

224

Monte Carlo simulation of gamma ray scanning gauge  

SciTech Connect (OSTI)

A gamma ray scanning gauge was simulated with Monte Carlo to study the properties of gamma scanning gauges and to resolve the counts coming from a {sup 235}U source from those coming from a contaminant ({sup 232}U) whose daughters emit high energy gamma rays. The simulation has been used to infer the amount of the {sup 232}U contaminant in a {sup 235}U source to select the best size for the NaI(Tl) detector crystal to minimize the effect of the contaminant. The results demonstrate that Monte Carlo simulation provides a systematic tool for designing a gauge with desired properties and for estimating properties of the gamma source from measured count rates.

Hartfield, G.L.; Freeman, L.B.; Dei, D.E.; Emert, C.J.; Glickstein, S.S.; Kahler, A.C.; Niedzwecki, P.F.

1990-12-31T23:59:59.000Z

225

The hybrid Monte Carlo Algorithm and the chiral transition  

SciTech Connect (OSTI)

In this talk the author describes tests of the Hybrid Monte Carlo Algorithm for QCD done in collaboration with Greg Kilcup and Stephen Sharpe. We find that the acceptance in the glubal Metropolis step for Staggered fermions can be tuned and kept large without having to make the step-size prohibitively small. We present results for the finite temperature transition on 4/sup 4/ and 4 x 6/sup 3/ lattices using this algorithm.

Gupta, R.

1987-01-01T23:59:59.000Z

226

Improved diffusion coefficients generated from Monte Carlo codes  

SciTech Connect (OSTI)

Monte Carlo codes are becoming more widely used for reactor analysis. Some of these applications involve the generation of diffusion theory parameters including macroscopic cross sections and diffusion coefficients. Two approximations used to generate diffusion coefficients are assessed using the Monte Carlo code MC21. The first is the method of homogenization; whether to weight either fine-group transport cross sections or fine-group diffusion coefficients when collapsing to few-group diffusion coefficients. The second is a fundamental approximation made to the energy-dependent P1 equations to derive the energy-dependent diffusion equations. Standard Monte Carlo codes usually generate a flux-weighted transport cross section with no correction to the diffusion approximation. Results indicate that this causes noticeable tilting in reconstructed pin powers in simple test lattices with L2 norm error of 3.6%. This error is reduced significantly to 0.27% when weighting fine-group diffusion coefficients by the flux and applying a correction to the diffusion approximation. Noticeable tilting in reconstructed fluxes and pin powers was reduced when applying these corrections. (authors)

Herman, B. R.; Forget, B.; Smith, K. [Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Aviles, B. N. [Knolls Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P.O. Box 1072, Schenectady, NY 12301-1072 (United States)

2013-07-01T23:59:59.000Z

227

Post-Harvest Control of Two-Spotted Spider Mites in Nikki Rothwell, District Fruit IPM Educator  

E-Print Network [OSTI]

with two distinct black spots; irregular dark splotches may appear after feeding. Male TSSM are more as both species can have greenish colored stages. TSSM infestations are often accompanied by silk webbing

228

Effect of Acidulated Phosphate Fluoride Gel on the Prevention of White Spot Lesions in Patients Undergoing Active Orthodontic Treatment  

E-Print Network [OSTI]

Introduction: The purpose of this study was to evaluate the effect of 1.23% acidulated phosphate fluoride (APF) gel on white spot lesion (WSL) formation utilizing a typical orthodontic treatment interval for the applications. Methods...

Hutto Fretty, Corneil Kimberly

2014-05-06T23:59:59.000Z

229

Managing Two-Spotted Spider Mites on Soybeans Ken Ostlie, Extension Entomologist, and Bruce Potter, IPM Specialist  

E-Print Network [OSTI]

Managing Two-Spotted Spider Mites on Soybeans Ken Ostlie, Extension Entomologist, and Bruce Potter? Spider mite populations are held in balance by natural enemies, weather and host quality. Drought

Minnesota, University of

230

DEVELOPMENT AND EVALUATION OF A PROTOTYPE VARIABLE RATE SPRAYER FOR SPOT-APPLICATION OF AGROCHEMICALS IN WILD BLUEBERRY FIELDS.  

E-Print Network [OSTI]

??An automated prototype variable rate (VR) sprayer was developed for control of eight individual nozzles on a 6.1 m sprayer boom for spot-application (SA) of… (more)

Esau, Travis

2012-01-01T23:59:59.000Z

231

Coherent control of nanoscale light localization: creating and positioning isolated sub-wavelength energy hot-spots  

Science Journals Connector (OSTI)

A new paradigm was suggested for achieving prescribed light localization with nanoscale accuracy. Well isolated energy hot-spots as small as ?/10 can be created and positioned at...

Kao, Tsung Sheng; Jenkins, Stewart; Ruostekoski, Janne; Zheludev, Nikolay

232

Decision making in coastal fisheries conflict: the case of red drum and spotted seatrout legislation in Texas  

E-Print Network [OSTI]

Stricter Measures Called For The TPWD Increases Regulations on Red and Spotted Seatrout Illegal Netting 61 65 66 Drum TABLE OF CONTENTS (continued) IV CASE FINDINGS (continued) The Opposition Increases The Legislative Process Economic Impact... of the controversial House B i 1 1 1000 in the Texas Legislature. H B. 1000 was signed into law in May, 1981 and prohibits the possession or transportation for the purpose of sale red drum or spotted seatrout taken from waters under the jurisdiction of the state...

Christian, Richard Travis

1986-01-01T23:59:59.000Z

233

Characteristics of elliptical sources in BEAMnrc Monte Carlo system: Implementation and application  

SciTech Connect (OSTI)

Recently, several papers noticed that the electron focal spot of a linear accelerator (linac) could be elliptical which would cause dosimetric discrepancies between measurements and Monte Carlo simulations. To resolve the mismatch, two elliptical source models were developed in BEAMnrc code. The first was a parallel beam elliptical source with uniform distribution where the shape of the source was primarily considered. The other was a parallel beam elliptical source with Gaussian distribution whose source distribution follows the normal distribution. To validate the elliptical source models, uniform and Gaussian electron beams were impinged on a thin air target. Both models successfully reproduced the elliptical shapes and source distributions. Then, this study investigated the characteristics of the elliptical Gaussian source for a 6 MV photon beam in a Varian 21EX linac. The linac head model was implemented in the BEAMnrc/EGSnrc system and commissioned by comparing the lateral and depth dose profiles to the ion chamber measurements acquired from the annual quality assurance (QA). It was found that the circular Gaussian beam with 6 MeV/0.2 cm full width half maximum (FWHM) produces the best matches to the QA data. To explore the characteristics of the elliptical Gaussian source, this study employed an elliptical Gaussian electron source with 0.1 cm FWHM in the x axis and 0.2 cm FWHM in the y axis which was incident on the target of the linac head. Two circular Gaussian beams with 0.1 and 0.2 cm FWHM were employed to compare the differences between circular and elliptical sources. For all the sources, planar and energy fluences were acquired and analyzed. This study also compared the lateral and depth dose profiles in a water phantom by using a DOSXYZnrc user code. In results, a constricted shoulder effect was observed in both planar and energy fluence plots when the FWHM value was increased and the field size is larger than 30x30 cm{sup 2}. The same effect was also noticed in the lateral dose profiles, while the depth dose profile did not vary much.

Kim, Sangroh [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States)

2009-04-15T23:59:59.000Z

234

Control of Black Spot of Roses with Sulphur-Copper Dust.  

E-Print Network [OSTI]

TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, Director College Station, Texas BULLETIN NO. 648 APRIL, 1944 CONTROL OF BLACK SPOT OF ROSES WITH SULPHUR-COPPER DUST E. W. LYLE Division of Plant Pathology and Physiology l ,i- ' 7, r... - . /.~ric[~i L~jj c,, J: . i, , . t : :V~S @ollogs Stat hn, ieias AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS F. C. BOLTON, Acting President D-16-444-4M Fig. 1. Rose plants from commercial fields. On left, plant dusted with sulphur-copper mix- ture...

Lyle, E. W. (Eldon W.)

1944-01-01T23:59:59.000Z

235

Resistance Spot Welding of Aluminum Alloy to Steel with Transition Material - From Process to Performance  

SciTech Connect (OSTI)

This paper summarizes work to date on resistance spot welding (RSW) of aluminum alloy to mild steel from process development to performance evaluation. A cold-rolled strip material is introduced as a transition material to aid the resistance welding process. The optimal welding parameters and electrode selections were established using a combination of experimental and analytical approaches. The mechanical behaviors of welded samples was evaluated using static and dynamic strength tests and cyclic fatigue tests. A statistical analysis was also performed to analyze the effect of different failure modes on the sample's peak load and energy absorption.

Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.; Shao, H; Kimchi, Menachem; Menachem Kimchi and Wanda Newman

2004-05-11T23:59:59.000Z

236

Properties of Reactive Oxygen Species by Quantum Monte Carlo  

E-Print Network [OSTI]

The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of Chemistry, Biology and Atmospheric Science. Nevertheless, the electronic structure of such species is a challenge for ab-initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal Power (JAGP) wave function ansatz, which has been recently shown to effectively describe the statical and dynamical correlation of different molecular systems. In particular we have studied the oxygen molecule, the superoxide anion, the nitric oxide radical and anion, the hydroxyl and hydroperoxyl radicals and their corresponding anions, and the hydrotrioxyl radical. Overall, the methodology was able to correctly describe the geometrical and electronic properties of these systems, through compact but fully-optimised basis sets and with a computational cost which scales as $N^3-N^4$, where $N$ is the number of electrons. This work is therefore opening the way to the accurate study of the energetics and of the reactivity of large and complex oxygen species by first principles.

Andrea Zen; Bernhardt L. Trout; Leonardo Guidoni

2014-03-11T23:59:59.000Z

237

Monte Carlo Tools for charged Higgs boson production  

E-Print Network [OSTI]

In this short review we discuss two implementations of the charged Higgs boson production process in association with a top quark in Monte Carlo event generators at next-to-leading order in QCD. We introduce the MC@NLO and the POWHEG method of matching next-to-leading order matrix elements with parton showers and compare both methods analyzing the charged Higgs boson production process in association with a top quark. We shortly discuss the case of a light charged Higgs boson where the associated charged Higgs production interferes with the charged Higgs production via t tbar-production and subsequent decay of the top quark.

Kovarik, K

2014-01-01T23:59:59.000Z

238

Protein folding bottlenecks: A lattice Monte Carlo simulation  

Science Journals Connector (OSTI)

Results of Monte Carlo simulations of folding of a model ‘‘protein,’’ which is a freely joined 27-monomer chain on a simple cubic lattice with nearest-neighbor interactions, are reported. All compact self-avoiding conformations on this chain have been enumerated, and the conformation (‘‘native’’) corresponding to the global minimum of energy is known for each sequence. Only one out of thirty sequences folds and finds the global minimum. For this sequence, the folding process has a two-stage character, with a rapid noncooperative compactization followed by a slower transition over a free-energy barrier to the global minimum. The evolutionary implications of the results are discussed.

E. Shakhnovich; G. Farztdinov; A. M. Gutin; M. Karplus

1991-09-16T23:59:59.000Z

239

Monte Carlo Tools for charged Higgs boson production  

E-Print Network [OSTI]

In this short review we discuss two implementations of the charged Higgs boson production process in association with a top quark in Monte Carlo event generators at next-to-leading order in QCD. We introduce the MC@NLO and the POWHEG method of matching next-to-leading order matrix elements with parton showers and compare both methods analyzing the charged Higgs boson production process in association with a top quark. We shortly discuss the case of a light charged Higgs boson where the associated charged Higgs production interferes with the charged Higgs production via t tbar-production and subsequent decay of the top quark.

K. Kovarik

2014-12-18T23:59:59.000Z

240

Multijet and single diffraction dissociation Monte Carlo generator  

Science Journals Connector (OSTI)

We have built a Monte Carlo generator for simulating propagation of cosmic ray particles in the atmosphere. The core of the generator is a p-air nuclear interaction model in which SD and NSD processes are included in the inelastic collisions. Based on QCD partonic theory, multiple minijet production is described in detail in the NSD process. A phase-space model is used for the SD process in our work. This generator reproduces cosmic ray experimental data well at very high energies.

J. C. Chen; Q. Q. Zhu; A. X. Huo

1997-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" from the National Library of EnergyBeta (NLEBeta).
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241

GPU accelerated Monte Carlo simulations of lattice spin models  

E-Print Network [OSTI]

We consider Monte Carlo simulations of classical spin models of statistical mechanics using the massively parallel architecture provided by graphics processing units (GPUs). We discuss simulations of models with discrete and continuous variables, and using an array of algorithms ranging from single-spin flip Metropolis updates over cluster algorithms to multicanonical and Wang-Landau techniques to judge the scope and limitations of GPU accelerated computation in this field. For most simulations discussed, we find significant speed-ups by two to three orders of magnitude as compared to single-threaded CPU implementations.

Martin Weigel; Taras Yavors'kii

2011-07-27T23:59:59.000Z

242

Temperature and density extrapolations in canonical ensemble Monte Carlo simulations  

E-Print Network [OSTI]

We show how to use the multiple histogram method to combine canonical ensemble Monte Carlo simulations made at different temperatures and densities. The method can be applied to study systems of particles with arbitrary interaction potential and to compute the thermodynamic properties over a range of temperatures and densities. The calculation of the Helmholtz free energy relative to some thermodynamic reference state enables us to study phase coexistence properties. We test the method on the Lennard-Jones fluids for which many results are available.

A. L. Ferreira; M. A. Barroso

1999-06-14T23:59:59.000Z

243

Monte Carlo Fundamentals E B. BROWN and T M. S N  

Office of Scientific and Technical Information (OSTI)

e 32-64 X - Parallel & vector processing are now "routine" & necessary for high-performance computing I661 Vector & Parallel Monte Carlo - Introduction .. .. Characterize...

244

Investigation of Protein Folding by Using Combined Method of Molecular Dynamics and Monte Carlo Simulations.  

E-Print Network [OSTI]

??We used the combination of molecular dynamics and Monte Carlo method to investigate protein folding problems. The environments of proteins are very big, and often… (more)

Liao, Jun-min

2006-01-01T23:59:59.000Z

245

Protein folding and phylogenetic tree reconstruction using stochastic approximation Monte Carlo.  

E-Print Network [OSTI]

??Recently, the stochastic approximation Monte Carlo algorithm has been proposed by Liang et al. (2005) as a general-purpose stochastic optimization and simulation algorithm. An annealing… (more)

Cheon, Sooyoung

2007-01-01T23:59:59.000Z

246

Doppler effect's contribution to ultrasonic modulation of multiply scattered coherent light: Monte Carlo modeling  

Science Journals Connector (OSTI)

Modulation of light by ultrasound in turbid media is investigated by modified public domain software based on the Monte Carlo algorithm. Apart from the recognized modulation...

Elazar, Jovan M; Steshenko, Oleg

2008-01-01T23:59:59.000Z

247

Pulse shaping effects on weld porosity in laser beam spot welds : contrast of long- & short- pulse welds.  

SciTech Connect (OSTI)

Weld porosity is being investigated for long-pulse spot welds produced by high power continuous output lasers. Short-pulse spot welds (made with a pulsed laser system) are also being studied but to a much small extent. Given that weld area of a spot weld is commensurate with weld strength, the loss of weld area due to an undefined or unexpected pore results in undefined or unexpected loss in strength. For this reason, a better understanding of spot weld porosity is sought. Long-pulse spot welds are defined and limited by the slow shutter speed of most high output power continuous lasers. Continuous lasers typically ramp up to a simmer power before reaching the high power needed to produce the desired weld. A post-pulse ramp down time is usually present as well. The result is a pulse length tenths of a second long as oppose to the typical millisecond regime of the short-pulse pulsed laser. This study will employ a Lumonics JK802 Nd:YAG laser with Super Modulation pulse shaping capability and a Lasag SLS C16 40 W pulsed Nd:YAG laser. Pulse shaping will include square wave modulation of various peak powers for long-pulse welds and square (or top hat) and constant ramp down pulses for short-pulse welds. Characterization of weld porosity will be performed for both pulse welding methods.

Ellison, Chad M. (Honeywell FM& T, Kansas City, MO); Perricone, Matthew J. (R.J. Lee Group, Inc., Monroeville, PA); Faraone, Kevin M. (BWX Technologies, Inc., Lynchburg, VA); Norris, Jerome T.

2007-10-01T23:59:59.000Z

248

The Influence of spot size on the expansion dynamics of nanosecond-laser-produced copper plasmas in atmosphere  

SciTech Connect (OSTI)

Laser produced copper plasmas of different spot sizes in air were investigated using fast photography and optical emission spectroscopy (OES). The laser energy was 33 mJ. There were dramatic changes in the plasma plume expansion into the ambient air when spot sizes changed from {approx}0.1 mm to {approx}0.6 mm. A stream-like structure and a hemispherical structure were, respectively, observed. It appeared that the same spot size resulted in similar expansion dynamics no matter whether the target was located in the front of or behind the focal point, although laser-induced air breakdown sometimes occurred in the latter case. Plasma plume front positions agree well with the classic blast wave model for the large spot-size cases, while an unexpected stagnation of {approx}80 ns occurred after the laser pulse ends for the small spot size cases. This stagnation can be understood in terms of the evolution of enhanced plasma shielding effects near the plasma front. Axial distributions of plasma components by OES revealed a good confinement effect. Electron number densities were estimated and interpreted using the recorded Intensified Charge Coupled Device (ICCD) images.

Li, Xingwen; Wei, Wenfu; Wu, Jian; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)

2013-06-28T23:59:59.000Z

249

DEFINING THE 'BLIND SPOT' OF HINODE EIS AND XRT TEMPERATURE MEASUREMENTS  

SciTech Connect (OSTI)

Observing high-temperature, low emission measure plasma is key to unlocking the coronal heating problem. With current instrumentation, a combination of EUV spectral data from Hinode Extreme-ultraviolet Imaging Spectrometer (EIS; sensitive to temperatures up to 4 MK) and broadband filter data from Hinode X-ray Telescope (XRT; sensitive to higher temperatures) is typically used to diagnose the temperature structure of the observed plasma. In this Letter, we demonstrate that a 'blind spot' exists in temperature-emission measure space for combined Hinode EIS and XRT observations. For a typical active region core with significant emission at 3-4 MK, Hinode EIS and XRT are insensitive to plasma with temperatures greater than {approx}6 MK and emission measures less than {approx}10{sup 27} cm{sup -5}. We then demonstrate that the temperature and emission measure limits of this blind spot depend upon the temperature distribution of the plasma along the line of sight by considering a hypothetical emission measure distribution sharply peaked at 1 MK. For this emission measure distribution, we find that EIS and XRT are insensitive to plasma with emission measures less than {approx}10{sup 26} cm{sup -5}. We suggest that a spatially and spectrally resolved 6-24 Angstrom-Sign spectrum would improve the sensitivity to these high-temperature, low emission measure plasma.

Winebarger, Amy R.; Cirtain, Jonathan; Mulu-Moore, Fana [NASA Marshall Space Flight Center, VP 62, Huntsville, AL 35812 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Schmelz, Joan T. [Physics Department, University of Memphis, Memphis, TN 38152 (United States); Golub, Leon [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Kobayashi, Ken, E-mail: amy.r.winebarger@nasa.gov [Center for Space Plasma and Aeronomic Research, 320 Sparkman Dr, Huntsville, AL 35805 (United States)

2012-02-20T23:59:59.000Z

250

Joint strength in high speed friction stir spot welded DP 980 steel  

SciTech Connect (OSTI)

High speed friction stir spot welding was applied to 1.2 mm thick DP 980 steel sheets under different welding conditions, using PCBN tools. The range of vertical feed rates used during welding was 2.5 mm – 102 mm per minute, while the range of spindle speeds was 2500 – 6000 rpm. Extended testing was carried out for five different sets of welding conditions, until tool failure. These welding conditions resulted in vertical welding loads of 3.6 – 8.2 kN and lap shear tension failure loads of 8.9 – 11.1 kN. PCBN tools were shown, in the best case, to provide lap shear tension fracture loads at or above 9 kN for 900 spot welds, after which tool failure caused a rapid drop in joint strength. Joint strength was shown to be strongly correlated to bond area, which was measured from weld cross sections. Failure modes of the tested joints were a function of bond area and softening that occurred in the heat-affected zone.

Saunders, Nathan; Miles, Michael; Hartman, Trent; Hovanski, Yuri; Hong, Sung Tae; Steel, Russell

2014-05-01T23:59:59.000Z

251

Wear testing of friction stir spot welding tools for joining of DP 980 Steel  

SciTech Connect (OSTI)

Friction stir spot welding has been shown to be a viable method of joining ultra high strength steel (UHSS), both in terms of joint strength and process cycle time. However, the cost of tooling must be reasonable in order for this method to be adopted as an industrial process. Several tooling materials have been evaluated in prior studies, including silicon nitride and polycrystalline cubic boron nitride (PCBN). Recently a new tool alloy has been developed, where a blend of PCBN and tungsten rhenium (W-Re) was used in order to improve the toughness of the tool. Wear testing results are presented for two of these alloys: one with a composition of 60% PCBN and 40% W-Re (designated as Q60), and one with 70% PCBN and 30% W-Re (designated at Q70). The sheet material used for all wear testing was DP 980. Tool profiles were measured periodically during the testing process in order to show the progression of wear as a function of the number of spots produced. Lap shear testing was done each time a tool profile was taken in order to show the relationship between tool wear and joint strength. For the welding parameters chosen for this study the Q70 tool provided the best combination of wear resistance and joint strength.

Ridges, Chris; Miles, Michael; Hovanski, Yuri; Peterson, Jeremy; Steel, Russell

2011-06-06T23:59:59.000Z

252

Monitoring seasonal and annual wetland changes in a freshwater marsh with SPOT HRV data  

SciTech Connect (OSTI)

Eleven dates of SPOT HRV data along with near-concurrent vertical aerial photographic and phenological data for 1987, 1988, and 1989 were evaluated to determine seasonal and annual changes in a 400-hectare, southeastern freshwater marsh. Early April through mid-May was the best time to discriminate among the cypress (Taxodium distichum)/water tupelo (Nyssa acquatica) swamp forest and the non-persistent (Ludwigia spp.) and persistent (Typha spp.) stands in this wetlands. Furthermore, a ten-fold decrease in flow rate from 11 cubic meters per sec (cms) in 1987 to one cms in 1988 was recorded in the marsh followed by a shift to drier wetland communities. The Savannah River Site (SRS), maintained by the US Department of Energy, is a 777 km{sup 2} area located in south central South Carolina. Five tributaries of the Savannah River run southwest through the SRS and into the floodplain swamp of the Savannah River. This paper describes the use of SPOT HRV data to monitor seasonal and annual trends in one of these swamp deltas, Pen Branch Delta, during a three-year period, 1987--1989.

Mackey, H.E. Jr.

1989-01-01T23:59:59.000Z

253

Monitoring seasonal and annual wetland changes in a freshwater marsh with SPOT HRV data  

SciTech Connect (OSTI)

Eleven dates of SPOT HRV data along with near-concurrent vertical aerial photographic and phenological data for 1987, 1988, and 1989 were evaluated to determine seasonal and annual changes in a 400-hectare, southeastern freshwater marsh. Early April through mid-May was the best time to discriminate among the cypress (Taxodium distichum)/water tupelo (Nyssa acquatica) swamp forest and the non-persistent (Ludwigia spp.) and persistent (Typha spp.) stands in this wetlands. Furthermore, a ten-fold decrease in flow rate from 11 cubic meters per sec (cms) in 1987 to one cms in 1988 was recorded in the marsh followed by a shift to drier wetland communities. The Savannah River Site (SRS), maintained by the US Department of Energy, is a 777 km{sup 2} area located in south central South Carolina. Five tributaries of the Savannah River run southwest through the SRS and into the floodplain swamp of the Savannah River. This paper describes the use of SPOT HRV data to monitor seasonal and annual trends in one of these swamp deltas, Pen Branch Delta, during a three-year period, 1987--1989.

Mackey, H.E. Jr.

1989-12-31T23:59:59.000Z

254

Monte Carlo Domain Decomposition for Robust Nuclear Reactor Analyses  

Science Journals Connector (OSTI)

Abstract Monte Carlo (MC) neutral particle transport codes are considered the gold-standard for nuclear simulations, but they cannot be robustly applied to high-fidelity nuclear reactor analysis without accommodating several terabytes of materials and tally data. While this is not a large amount of aggregate data for a typical high performance computer, MC methods are only embarrassingly parallel when the key data structures are replicated for each processing element, an approach which is likely infeasible on future machines. The present work explores the use of spatial domain decomposition to make full-scale nuclear reactor simulations tractable with Monte Carlo methods, presenting a simple implementation in a production-scale code. Good performance is achieved for mesh-tallies of up to 2.39TB distributed across 512 compute nodes while running a full-core reactor benchmark on the Mira Blue Gene/Q supercomputer at the Argonne National Laboratory. In addition, the effects of load imbalances are explored with an updated performance model that is empirically validated against observed timing results. Several load balancing techniques are also implemented to demonstrate that imbalances can be largely mitigated, including a new and efficient way to distribute extra compute resources across coarse domain meshes.

Nicholas Horelik; Andrew Siegel; Benoit Forget; Kord Smith

2014-01-01T23:59:59.000Z

255

Improved criticality convergence via a modified Monte Carlo iteration method  

SciTech Connect (OSTI)

Nuclear criticality calculations with Monte Carlo codes are normally done using a power iteration method to obtain the dominant eigenfunction and eigenvalue. In the last few years it has been shown that the power iteration method can be modified to obtain the first two eigenfunctions. This modified power iteration method directly subtracts out the second eigenfunction and thus only powers out the third and higher eigenfunctions. The result is a convergence rate to the dominant eigenfunction being |k{sub 3}|/k{sub 1} instead of |k{sub 2}|/k{sub 1}. One difficulty is that the second eigenfunction contains particles of both positive and negative weights that must sum somehow to maintain the second eigenfunction. Summing negative and positive weights can be done using point detector mechanics, but this sometimes can be quite slow. We show that an approximate cancellation scheme is sufficient to accelerate the convergence to the dominant eigenfunction. A second difficulty is that for some problems the Monte Carlo implementation of the modified power method has some stability problems. We also show that a simple method deals with this in an effective, but ad hoc manner.

Booth, Thomas E [Los Alamos National Laboratory; Gubernatis, James E [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

256

Monte Carlo simulation of quantum Zeno effect in the brain  

E-Print Network [OSTI]

Environmental decoherence appears to be the biggest obstacle for successful construction of quantum mind theories. Nevertheless, the quantum physicist Henry Stapp promoted the view that the mind could utilize quantum Zeno effect to influence brain dynamics and that the efficacy of such mental efforts would not be undermined by environmental decoherence of the brain. To address the physical plausibility of Stapp's claim, we modeled the brain using quantum tunneling of an electron in a multiple-well structure such as the voltage sensor in neuronal ion channels and performed Monte Carlo simulations of quantum Zeno effect exerted by the mind upon the brain in the presence or absence of environmental decoherence. The simulations unambiguously showed that the quantum Zeno effect breaks down for timescales greater than the brain decoherence time. To generalize the Monte Carlo simulation results for any n-level quantum system, we further analyzed the change of brain entropy due to the mind probing actions and proved a theorem according to which local projections cannot decrease the von Neumann entropy of the unconditional brain density matrix. The latter theorem establishes that Stapp's model is physically implausible but leaves a door open for future development of quantum mind theories provided the brain has a decoherence-free subspace.

Danko Georgiev

2014-12-11T23:59:59.000Z

257

Monte Carlo Simulation of Massive Absorbers for Cryogenic Calorimeters  

SciTech Connect (OSTI)

There is a growing interest in cryogenic calorimeters with macroscopic absorbers for applications such as dark matter direct detection and rare event search experiments. The physics of energy transport in calorimeters with absorber masses exceeding several grams is made complex by the anisotropic nature of the absorber crystals as well as the changing mean free paths as phonons decay to progressively lower energies. We present a Monte Carlo model capable of simulating anisotropic phonon transport in cryogenic crystals. We have initiated the validation process and discuss the level of agreement between our simulation and experimental results reported in the literature, focusing on heat pulse propagation in germanium. The simulation framework is implemented using Geant4, a toolkit originally developed for high-energy physics Monte Carlo simulations. Geant4 has also been used for nuclear and accelerator physics, and applications in medical and space sciences. We believe that our current work may open up new avenues for applications in material science and condensed matter physics.

Brandt, D.; Asai, M.; Brink, P.L.; /SLAC; Cabrera, B.; /Stanford U.; Silva, E.do Couto e; Kelsey, M.; /SLAC; Leman, S.W.; McArthy, K.; /MIT; Resch, R.; Wright, D.; /SLAC; Figueroa-Feliciano, E.; /MIT

2012-06-12T23:59:59.000Z

258

Monte Carlo source convergence and the Whitesides problem  

SciTech Connect (OSTI)

The issue of fission source convergence in Monte Carlo eigenvalue calculations is of interest because of the potential consequences of erroneous criticality safety calculations. In this work, the authors compare two different techniques to improve the source convergence behavior of standard Monte Carlo calculations applied to challenging source convergence problems. The first method, super-history powering, attempts to avoid discarding important fission sites between generations by delaying stochastic sampling of the fission site bank until after several generations of multiplication. The second method, stratified sampling of the fission site bank, explicitly keeps the important sites even if conventional sampling would have eliminated them. The test problems are variants of Whitesides' Criticality of the World problem in which the fission site phase space was intentionally undersampled in order to induce marginally intolerable variability in local fission site populations. Three variants of the problem were studied, each with a different degree of coupling between fissionable pieces. Both the superhistory powering method and the stratified sampling method were shown to improve convergence behavior, although stratified sampling is more robust for the extreme case of no coupling. Neither algorithm completely eliminates the loss of the most important fissionable piece, and if coupling is absent, the lost piece cannot be recovered unless its sites from earlier generations have been retained. Finally, criteria for measuring source convergence reliability are proposed and applied to the test problems.

Blomquist, R. N.

2000-02-25T23:59:59.000Z

259

Stratified source-sampling techniques for Monte Carlo eigenvalue analysis.  

SciTech Connect (OSTI)

In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo ''Eigenvalue of the World'' problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. In this paper, stratified source-sampling techniques are generalized and applied to three different Eigenvalue of the World configurations which take into account real-world statistical noise sources not included in the model problem, but which differ in the amount of neutronic coupling among the constituents of each configuration. It is concluded that, in Monte Carlo eigenvalue analysis of loosely-coupled arrays, the use of stratified source-sampling reduces the probability of encountering an anomalous result over that if conventional source-sampling methods are used. However, this gain in reliability is substantially less than that observed in the model-problem results.

Mohamed, A.

1998-07-10T23:59:59.000Z

260

Gyrocenter Shift of Low-Temperature Plasmas and the Retrograde Motion of Cathode Spots in Arc Discharges  

SciTech Connect (OSTI)

The gyrocenter shift phenomenon explained the mechanism of radial electric field formation at the high confinement mode transition in fusion devices. This Letter reports that the theory of gyrocenter shift is also applicable to low temperature high collisional plasmas such as arc discharges by the generalization of the theory resulting from a short mean free path compared with the gyroradius. The retrograde motion of cathode spots in the arc discharge is investigated through a model with the expanded formula of gyrocenter shift. It is found that a reversed electric field is formed in front of the cathode spots when they are under a magnetic field, and this reversed electric field generates a rotation of cathode spots opposite to the Amperian direction. The ion drift velocity profiles calculated from the model are in agreement with the experimental results as functions of magnetic flux density and gas pressure.

Lee, K. C. [Department of Applied Science, University of California, Davis, California 95616 (United States)

2007-08-10T23:59:59.000Z

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


261

Monte Carlo simulations of free chains in end-linked polymer networks Nisha Gilra  

E-Print Network [OSTI]

be significantly altered.1­3 This occurs because the micro- scopic structure including network defectsMonte Carlo simulations of free chains in end-linked polymer networks Nisha Gilra School networks prepared in the presence of inert linear chain solvent were investigated with Monte Carlo

262

Self-assembly of surfactants in a supercritical solvent from lattice Monte Carlo simulations  

E-Print Network [OSTI]

Self-assembly of surfactants in a supercritical solvent from lattice Monte Carlo simulations Martin self-assembly of surfactants in a supercritical solvent by large-scale Monte Carlo simulations. CarbonCO2.3 Surfactant molecules used in scCO2 have two mutually incompatible components: a CO2-philic tail

Lisal, Martin

263

Effect of different genotypes of Phytophthora infestans (Mont. de Bary) and temperature on tuber disease development  

E-Print Network [OSTI]

Effect of different genotypes of Phytophthora infestans (Mont. de Bary) and temperature on tuber Lines (ABL) of potato with different genotypes of the potato late blight pathogen (Phytophthora Phytophthora infestans (Mont. de Bary) is the greatest threat to the potato crop, accounting for significant

Douches, David S.

264

Quantum Monte Carlo study of a disordered 2D Josephson junction array  

E-Print Network [OSTI]

Quantum Monte Carlo study of a disordered 2D Josephson junction array W.A. Al-Saidi *, D. Stroud reserved. PACS: 74.25.Dw; 05.30.Jp; 85.25.Cp Keywords: Josephson junctions; Quantum Monte Carlo; Disorder 1. Introduction A Josephson junction array (JJA) consists of a collection of superconducting islands connected

Stroud, David

265

Optimization of quantum Monte Carlo wave functions using analytical energy derivatives  

E-Print Network [OSTI]

Optimization of quantum Monte Carlo wave functions using analytical energy derivatives Xi Lin of the local energy, H^ / .5 If the wave function were the exact ground eigenstate, the local energy would November 1999 An algorithm is proposed to optimize quantum Monte Carlo QMC wave functions based on Newton

Lin, Xi

266

Status of the VIM Monte Carlo neutron/photon transport code.  

SciTech Connect (OSTI)

Recent work on the VIM Monte Carlo code has aimed at advanced data libraries, ease of use, availability to users outside of Argonne, and fission source convergence algorithms in eigenvalue calculations. VIM is one of three US Monte Carlo codes in the USDOE Nuclear Criticality Safety Program, and is available through RSICC and the NEA Data Bank.

Blomquist, R.N.

2002-01-22T23:59:59.000Z

267

Overview of Bayesian sequential Monte Carlo methods for group and extended object tracking  

Science Journals Connector (OSTI)

This work presents the current state-of-the-art in techniques for tracking a number of objects moving in a coordinated and interacting fashion. Groups are structured objects characterized with particular motion patterns. The group can be comprised of ... Keywords: Group and extended object tracking, Markov chain Monte Carlo methods, Metropolis Hastings, Nonlinear filtering, Reasoning over time, Sequential Monte Carlo methods

Lyudmila Mihaylova; Avishy Y. Carmi; François Septier; Amadou Gning; Sze Kim Pang; Simon Godsill

2014-02-01T23:59:59.000Z

268

Melting of Iron under Earth's Core Conditions from Diffusion Monte Carlo Free Energy Calculations  

E-Print Network [OSTI]

Melting of Iron under Earth's Core Conditions from Diffusion Monte Carlo Free Energy Calculations Ester Sola1 and Dario Alfe`1,2 1 Thomas Young Centre@UCL, and Department of Earth Sciences, UCL, Gower. Here we used quantum Monte Carlo techniques to compute the free energies of solid and liquid iron

Alfè, Dario

269

Fluid simulations with localized boltzmann upscaling by direct simulation Monte-Carlo  

Science Journals Connector (OSTI)

In the present work, we present a novel numerical algorithm to couple the Direct Simulation Monte Carlo method (DSMC) for the solution of the Boltzmann equation with a finite volume like method for the solution of the Euler equations. Recently we presented ... Keywords: Boltzmann equation, Kinetic-fluid coupling, Monte Carlo methods, Multiscale problems

Pierre Degond; Giacomo Dimarco

2012-03-01T23:59:59.000Z

270

Using Monte-Carlo simulation for risk assessment: application to occupational exposure during remediation works  

Science Journals Connector (OSTI)

The aim of this study was to apply the Monte-Carlo techniques to develop a probabilistic risk assessment. The risk resulting from the occupational exposure during the remediation activities of a uranium tailings disposal, in an abandoned uranium mining ... Keywords: Monte Carlo simulation, occupational exposure, risk and dose assessment, uranium tailings disposal

M. L. Dinis; A. Fiúza

2010-08-01T23:59:59.000Z

271

Aspects of the life history and population dynamics of the spot, Leiostomus xanthurus, in the Northwestern Gulf of Mexico  

E-Print Network [OSTI]

. Spot are distributed from &5 to 73 m but are most abundant at 5-9 m. Spot of one cohort recruit to the Gulf primarily in two periods, May- July (Spring), at 3-7 mo, and January-March (winter), at 13-18 mo of age. Recruitment occurs in waters &5-16 m... at any one time and only one of either normally predominates. Spring recruits are not abundant after about 9-10 mo of age but may reach 18 mo, whereas winter recruits are not abundant after 19-21 mo but may reach 36 mo. Mean size of Spring recruits...

Hata, David Noboru

2012-06-07T23:59:59.000Z

272

Hot spots and transition from d-wave to another pairing symmetry in the electron-doped cuprate superconductors  

Science Journals Connector (OSTI)

We present a simple theoretical explanation for a transition from d-wave to another superconducting pairing observed in the electron-doped cuprates. The dx2-y2 pairing potential ?, which has the maximal magnitude and opposite signs at the hot spots on the Fermi surface, becomes suppressed with the increase of electron doping, because the hot spots approach the Brillouin zone diagonals, where ? vanishes. Then, dx2-y2 pairing is replaced by either singlet s-wave or triplet p-wave pairing. We argue in favor of the latter and propose experiments to uncover it.

V. A. Khodel; Victor M. Yakovenko; M. V. Zverev; Haeyong Kang

2004-04-02T23:59:59.000Z

273

Markov-Chain Monte Carlo Methods for Simulations of Biomolecules  

E-Print Network [OSTI]

The computer revolution has been driven by a sustained increase of computational speed of approximately one order of magnitude (a factor of ten) every five years since about 1950. In natural sciences this has led to a continuous increase of the importance of computer simulations. Major enabling techniques are Markov Chain Monte Carlo (MCMC) and Molecular Dynamics (MD) simulations. This article deals with the MCMC approach. First basic simulation techniques, as well as methods for their statistical analysis are reviewed. Afterwards the focus is on generalized ensembles and biased updating, two advanced techniques, which are of relevance for simulations of biomolecules, or are expected to become relevant with that respect. In particular we consider the multicanonical ensemble and the replica exchange method (also known as parallel tempering or method of multiple Markov chains).

Bernd A. Berg

2007-09-04T23:59:59.000Z

274

Shell model Monte Carlo investigation of rare earth nuclei  

Science Journals Connector (OSTI)

We utilize the shell model Monte Carlo method to study the structure of rare earth nuclei. This work demonstrates the first systematic full oscillator shell with intruder calculations in such heavy nuclei. Exact solutions of a pairing plus quadrupole Hamiltonian are compared with the static path approximation in several dysprosium isotopes from A=152 to 162, including the odd mass A=153. Some comparisons are also made with Hartree-Fock-Bogoliubov results from Baranger and Kumar. Basic properties of these nuclei at various temperatures and spin are explored. These include energy, deformation, moments of inertia, pairing channel strengths, band crossing, and evolution of shell model occupation numbers. Exact level densities are also calculated and, in the case of 162Dy, compared with experimental data.

J. A. White; S. E. Koonin; D. J. Dean

2000-02-14T23:59:59.000Z

275

Hydrogen molecule ion: Path-integral Monte Carlo approach  

SciTech Connect (OSTI)

The path-integral Monte Carlo approach is used to study the coupled quantum dynamics of the electron and nuclei in hydrogen molecule ion. The coupling effects are demonstrated by comparing differences in adiabatic Born-Oppenheimer and nonadiabatic simulations, and inspecting projections of the full three-body dynamics onto the adiabatic Born-Oppenheimer approximation. Coupling of the electron and nuclear quantum dynamics is clearly seen. The nuclear pair correlation function is found to broaden by 0.040a{sub 0}, and the average bond length is larger by 0.056a{sub 0}. Also, a nonadiabatic correction to the binding energy is found. The electronic distribution is affected less than the nuclear one upon inclusion of nonadiabatic effects.

Kylaenpaeae, I.; Leino, M.; Rantala, T. T. [Institute of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland)

2007-11-15T23:59:59.000Z

276

Monte Carlo sampling of negative-temperature plasma states  

Science Journals Connector (OSTI)

A Monte Carlo procedure is used to generate N-particle configurations compatible with two-temperature canonical equilibria in two dimensions, with particular attention to nonlinear plasma gyrokinetics. An unusual feature of the problem is the importance of a nontrivial probability density function P0(?), the probability of realizing a set ? of Fourier amplitudes associated with an ensemble of uniformly distributed, independent particles. This quantity arises because the equilibrium distribution is specified in terms of ?, whereas the sampling procedure naturally produces particle states ?; ? and ? are related via a gyrokinetic Poisson equation, highly nonlinear in its dependence on ?. Expansion and asymptotic methods are used to calculate P0(?) analytically; excellent agreement is found between the large-N asymptotic result and a direct numerical calculation. The algorithm is tested by successfully generating a variety of states of both positive and negative temperature, including ones in which either the longest- or shortest-wavelength modes are excited to relatively large amplitudes.

John A. Krommes and Sharadini Rath

2003-06-09T23:59:59.000Z

277

Velocity renormalization in graphene from lattice Monte Carlo  

E-Print Network [OSTI]

We compute the Fermi velocity of the Dirac quasiparticles in clean graphene at the charge neutrality point for strong Coulomb coupling alpha_g. We perform a Lattice Monte Carlo calculation within the low-energy Dirac theory, which includes an instantaneous, long-range Coulomb interaction. We find a renormalized Fermi velocity v_FR > v_F, where v_F = c/300. Our results are consistent with a momentum-independent v_FR which increases approximately linearly with alpha_g, although a logarithmic running with momentum cannot be excluded at present. At the predicted critical coupling alpha_gc for the semimetal-insulator transition due to excitonic pair formation, we find v_FR/v_F = 3.3, which we discuss in light of experimental findings for v_FR/v_F at the charge neutrality point in ultra-clean suspended graphene.

Joaquín E. Drut; Timo A. Lähde

2014-03-26T23:59:59.000Z

278

Monte Carlo modeling of spallation targets containing uranium and americium  

E-Print Network [OSTI]

Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on $^{241}$Am and $^{243}$Am nuclei allows to use this model for simulations with extended Am targets. Several geometry options and material compositions (U, U+Am, Am, Am$_2$O$_3$) are considered for spallation targets to be used in Accelerator Driven Systems. It was demonstrated that MCADS model can be reliably used for calculating critical masses of fissile materials. All considered options operate as deep subcritical targets having neutron multiplication factor of $k \\sim 0.5$. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

Malyshkin, Yury; Mishustin, Igor; Greiner, Walter

2013-01-01T23:59:59.000Z

279

Monte Carlo modeling of spallation targets containing uranium and americium  

E-Print Network [OSTI]

Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on $^{241}$Am and $^{243}$Am nuclei allows to use this model for simulations with extended Am targets. It was demonstrated that MCADS model can be used for calculating the values of critical mass for $^{233,235}$U, $^{237}$Np, $^{239}$Pu and $^{241}$Am. Several geometry options and material compositions (U, U+Am, Am, Am$_2$O$_3$) are considered for spallation targets to be used in Accelerator Driven Systems. All considered options operate as deep subcritical targets having neutron multiplication factor of $k \\sim 0.5$. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

Yury Malyshkin; Igor Pshenichnov; Igor Mishustin; Walter Greiner

2014-05-02T23:59:59.000Z

280

Lifting -- A Nonreversible Markov Chain Monte Carlo Algorithm  

E-Print Network [OSTI]

Markov Chain Monte Carlo algorithms are invaluable numerical tools for exploring stationary properties of physical systems -- in particular when direct sampling is not feasible. They are widely used in many areas of physics and other sciences. Most common implementations are done with reversible Markov chains -- Markov chains that obey detailed balance. Reversible Markov chains are sufficient in order for the physical system to relax to equilibrium, but it is not necessary. Here we review several works that use "lifted" or nonreversible Markov chains, which violate detailed balance, yet still converge to the correct stationary distribution (they obey the global balance condition). In certain cases, the acceleration is a square root improvement at most, to the conventional reversible Markov chains. We introduce the problem in a way that makes it accessible to non-specialists. We illustrate the method on several representative examples (sampling on a ring, sampling on a torus, an Ising model on a complete graph...

Vucelja, Marija

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

MONTE-CARLO BURNUP CALCULATION UNCERTAINTY QUANTIFICATION AND PROPAGATION DETERMINATION  

SciTech Connect (OSTI)

MONTEBURNS is a Monte-Carlo depletion routine utilizing MCNP and ORIGEN 2.2. Uncertainties exist in the MCNP transport calculation, but this information is not passed to the depletion calculation in ORIGEN or saved. To quantify this transport uncertainty and determine how it propagates between burnup steps, a statistical analysis of a multiple repeated depletion runs is performed. The reactor model chosen is the Oak Ridge Research Reactor (ORR) in a single assembly, infinite lattice configuration. This model was burned for a 25.5 day cycle broken down into three steps. The output isotopics as well as effective multiplication factor (k-effective) were tabulated and histograms were created at each burnup step using the Scott Method to determine the bin width. It was expected that the gram quantities and k-effective histograms would produce normally distributed results since they were produced from a Monte-Carlo routine, but some of results do not. The standard deviation at each burnup step was consistent between fission product isotopes as expected, while the uranium isotopes created some unique results. The variation in the quantity of uranium was small enough that, from the reaction rate MCNP tally, round off error occurred producing a set of repeated results with slight variation. Statistical analyses were performed using the {chi}{sup 2} test against a normal distribution for several isotopes and the k-effective results. While the isotopes failed to reject the null hypothesis of being normally distributed, the {chi}{sup 2} statistic grew through the steps in the k-effective test. The null hypothesis was rejected in the later steps. These results suggest, for a high accuracy solution, MCNP cell material quantities less than 100 grams and greater kcode parameters are needed to minimize uncertainty propagation and minimize round off effects.

Nichols, T.; Sternat, M.; Charlton, W.

2011-05-08T23:59:59.000Z

282

Polarized light propagation in highly scattering turbid media with a distribution of the particle size: a Monte Carlo study  

E-Print Network [OSTI]

The light propagation in highly scattering turbid media composed of the particles with different size distribution is studied using a Monte Carlo simulation model implemented in Standard C. Monte Carlo method has been widely utilized to study...

Koh, Wonshill

2013-02-22T23:59:59.000Z

283

In R&D, Super X-rays Mark Many Spots  

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

A New Gas Loading System for Diamond Anvil Cells at GSECARS A New Gas Loading System for Diamond Anvil Cells at GSECARS Sidorowicz Named "Supervisor of the Year" SESS 2007: The School for Environmental Sciences with Synchrotrons Art and Science A Breakthrough in Interface Science APS News Archives: 2012 | 2011 | 2010 | 2009 2008 | 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed In R&D, Super X-rays Mark Many Spots MARCH 11, 2008 Bookmark and Share Research and Design Magazine "The Advanced Photon Source (APS) at the U.S. Dept. of Energy's Argonne National Laboratory has been kept busy of late." That's the first sentence of R&D Magazine's recent overview of research results from the APS. The article highlights "a new ultrafast synchrotron x-ray full-field phase contrast imaging technique and used it to reveal

284

Spot Size Limited Carbon Propellant Characterization for Efficient High Isp Laser Propulsion  

SciTech Connect (OSTI)

Laser propulsion has very unique advantage of producing exhausting gas (ions) of very high velocity. Specific impulse from laser plasma could easily exceed 10,000 seconds that reduce the current propellant consumption rate on space born thrusters significantly. For efficient propellant usage, it is desirable that the exhaust plasma has rather narrow velocity distribution of fast ions. In order to accomplish the requirements, thermal conduction and neutral particle losses at and vicinity of the laser heated region have to be eliminated. A concept of spot size limited propellant shape has been proposed and tested in terms of the effects of the loss reduction. Ion and neutral particle measurements from laser plasmas produced on the above mentioned carbon targets are used to characterize the performance of the propellant.

Uchida, Shigeaki; Shimada, Yoshinori; Hashimoto, Kazuhisa; Yamaura, Michiteru [Institute for Laser Technology, Osaka (Japan); Birou, Tomoya; Yoshida, Minoru [Kinki University, Osaka (Japan)

2005-04-27T23:59:59.000Z

285

Modelling power spot prices in deregulated European energy markets: a dual long memory approach  

Science Journals Connector (OSTI)

In the last decade, with deregulation and introduction of competition in power markets, prices forecasting have become a real challenge for all market participants. However, forecasting is a rather complex task since electricity prices involve many features comparably with financial ones. Electricity markets have a highly volatile nature. They are indeed a more unpredictable than that of other commodities referred to as extreme volatile. In this paper, the two most emerging European electricity markets are considered. A preliminary analysis of the time series attests to the presence of a long range dependance behaviour. Therefore, prices processes are modelled using ARFIMA-FIGARCH under Gaussian and non-Gaussian distributions. Such models are sufficiently flexible to handle the long memory phenomena often encountered in both conditional mean and conditional variance in electricity spot prices. Forecasting is subsequently performed on the basis of adequate models.

Najeh Chaâbane; Foued Saâdaoui; Saloua Benammou

2012-01-01T23:59:59.000Z

286

The Romanian Energy System Structure and its Impact on the Electricity Spot Market  

Science Journals Connector (OSTI)

Abstract The international economic literature offers a significant number of publications approaching the European energy markets functioning, including comparative studies. The development and performances of the Romanian electricity spot market were less investigated, mainly because of the relatively short period of its functioning. The paper quantifies the impact of the electricity generation utilities’ structure by primary energy resources, on bidding prices resulted after the closure of the day ahead market. The multidimensional regression method was utilized for the models development. As a result, three distinct econometric models were obtained for different hourly periods of the day (off peak hours, peak hours, daily average) for working days and other three models for the weekend days. Based on these models, negative and positive correlations were established between the electricity prices and the seasonal contribution of the different categories of energy facilities to the demand curve coverage.

Mateescu Mihaela; Marina B?dileanu

2014-01-01T23:59:59.000Z

287

Impact of tool wear on joint strength in friction stir spot welding of DP 980 steel  

SciTech Connect (OSTI)

Friction stir spot welding has been shown to be a viable method of joining ultra high strength steel (UHSS), both in terms of joint strength and process cycle time. However, the cost of tooling must be reasonable in order for this method to be adopted as an industrial process. Recently a new tool alloy has been developed, using a blend of PCBN and tungsten rhenium (W-Re) in order to improve the toughness of the tool. Wear testing results are presented for two of these alloys: one with a composition of 60% PCBN and 40% W-Re, and one with 70% PCBN and 30% W-Re. The sheet material used for all wear testing was 1.4 mm DP 980. Lap shear testing was used to show the relationship between tool wear and joint strength. The Q70 tool provided the best combination of wear resistance and joint strength.

Miles, Michael; Ridges, Chris; Hovanski, Yuri; Peterson, Jeremy; Santella, M. L.; Steel, Russel

2011-09-14T23:59:59.000Z

288

Ion flux from vacuum arc cathode spots in the absence and presence of a magnetic field  

SciTech Connect (OSTI)

Because plasma production at vacuum cathode spots is approximately proportional to the arc current, arc current modulation can be used to generate ion current modulation that can be detected far from the spot using a negatively biased ion collector. The drift time to the ion detector can used to determine kinetic ion energies. A very wide range of cathode materials have been used. It has been found that the kinetic ion energy is higher at the beginning of each discharge and approximately constant after 150 {micro}s. The kinetic energy is correlated with the arc voltage and the cohesive energy of the cathode material. The ion erosion rate has in inverse relation to the cohesive energy, enhancing the effect that the power input per plasma particle correlates with the cohesive energy of the cathode material. The influence of three magnetic field configurations on the kinetic energy has been investigated. Generally, a magnetic field increases the plasma impedance, arc burning voltage, and kinetic ion energy. However, if the plasma is produced in a region of low field strength and streaming into a region of higher field strength, the velocity may decrease due to the mirror effect. A magnetic field can increase the plasma temperature but may reduce the density gradients by preventing free expansion into vacuum. Therefore, depending on the configuration, a magnetic field may increase or decrease the kinetic energy of ions. Additionally, the angular distribution of the ion flux and ion kinetic energy has been investigated in the absence of an external magnetic field. The result can be fitted by a superposition of an isotropic and a cosine distribution.

Anders, Andre; Yushkov, George Yu.

2001-10-02T23:59:59.000Z

289

Benchmarking and validation of a Geant4-SHADOW Monte Carlo simulation for dose calculations in microbeam radiation therapy  

Science Journals Connector (OSTI)

Benchmarking and validation of a new Monte Carlo code for dose calculations in microbeam radiation therapy are described.

Cornelius, I.

2014-04-03T23:59:59.000Z

290

Instabilities of a three-dimensional localized spot Marcin Leda, Vladimir K. Vanag, and Irving R. Epstein  

E-Print Network [OSTI]

-Zhabotinsky reaction in water-in-oil microemulsion. We find three types of instabili- ties: splitting of a single spot be classified as either supercritical or subcritical. In reaction-diffusion systems, supercritical instabilities of a ho- mogeneous steady state SS can give rise to small-amplitude patterns, while subcritical

Epstein, Irving R.

291

23. Gray{Scott equations Patterns are everywhere in nature. Examples include spots on butter ies, stripes on zebras, tri-  

E-Print Network [OSTI]

23. Gray{Scott equations Patterns are everywhere in nature. Examples include spots on butter ies variety. The Gray{Scott equations were formulated originally by Gray and Scott in 1983; we shall advantage of this principle. References P. Gray and S. K. Scott, papers in Chem. Eng. Sci. 38 (1983), 29

Trefethen, Nick

292

P~!ETRIC STUDY OF HEAT FLOW DURING RESISTANCE SPOT WELDING Euiwhan Kim and Thomas W. Eagar  

E-Print Network [OSTI]

pieces , electrical contact resistance, material properties, phase changes and heat dissipationi ...) P~!ETRIC STUDY OF HEAT FLOW DURING RESISTANCE SPOT WELDING Euiwhan Kim and Thomas W. Eagar Department of Materials Science and Engineering Hassachusetts Institute of Technology Cambridge, MA 02139

Eagar, Thomas W.

293

Relative phase interactions of two copropagating laser beams in underdense plasmas at different intensities and spot sizes  

SciTech Connect (OSTI)

The mutual interactions of two copropagating laser beams at a relative phase are studied using a two-dimensional fluid code. The interactions are investigated in underdense plasma at selected beam configurations and beam parameters for two separate nonlinearities, i.e., the ponderomotive and the relativistic nonlinearity. The selected beam configurations are introduced by different initial transverse spot size perturbations (finite and infinite) and different initial transversal intensity distributions (nonuniform and uniform) over those spot sizes and the selected beam parameters are given by different initial beam intensities relevant to each nonlinearity. In the ponderomotive nonlinearity, simulation results show that no mutual interactions are demonstrated between the copropagating beams regardless of the initial beam configurations and parameters. In nonlinear relativistic simulations, the mutual interactions between the beams are clearly observed, a mutual repulsion is formed in the presence of initial intensities that are nonuniformly distributed over finite spot sizes, and an effective strongly modulated mutual attraction takes places in the presence of initial intensities that are uniformly distributed over infinite spot sizes. Moreover, it is found in these simulations that increasing the initial beam intensities improves the attraction properties between the copropagationg beams.

Mahdy, A. I. [Department of Plasma and Nuclear Fusion, Nuclear Research Centre, Atomic Energy Authority, 13759 Cairo (Egypt)

2010-06-15T23:59:59.000Z

294

Soci t d exploitation du parc olien de Mont d H z cques SARL | Open Energy  

Open Energy Info (EERE)

Soci t d exploitation du parc olien de Mont d H z cques SARL Soci t d exploitation du parc olien de Mont d H z cques SARL Jump to: navigation, search Name Société d'exploitation du parc éolien de Mont d'Hézècques SARL Place Madrid, Spain Sector Wind energy Product Special purpose vehicle for French wind farm project development. References Société d'exploitation du parc éolien de Mont d'Hézècques SARL[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Société d'exploitation du parc éolien de Mont d'Hézècques SARL is a company located in Madrid, Spain . References ↑ "[ Société d'exploitation du parc éolien de Mont d'Hézècques SARL]" Retrieved from "http://en.openei.org/w/index.php?title=Soci_t_d_exploitation_du_parc_olien_de_Mont_d_H_z_cques_SARL&oldid=351211

295

Generation of SFR few-group constants using the Monte Carlo code Serpent  

SciTech Connect (OSTI)

In this study, the Serpent Monte Carlo code was used as a tool for preparation of homogenized few-group cross sections for the nodal diffusion analysis of Sodium cooled Fast Reactor (SFR) cores. Few-group constants for two reference SFR cores were generated by Serpent and then employed by nodal diffusion code DYN3D in 2D full core calculations. The DYN3D results were verified against the references full core Serpent Monte Carlo solutions. A good agreement between the reference Monte Carlo and nodal diffusion results was observed demonstrating the feasibility of using Serpent for generation of few-group constants for the deterministic SFR analysis. (authors)

Fridman, E.; Rachamin, R. [Helmholz-Zentrum Dresden-Rossendorf, POB 510119, Dresden, 01314 (Germany); Shwageraus, E. [Ben-Gurion University, POB 653, 84105 Beer-Sheva (Israel)

2013-07-01T23:59:59.000Z

296

Coupled Electron-Ion Monte Carlo Calculations of Dense Metallic Hydrogen  

Science Journals Connector (OSTI)

We present an efficient new Monte Carlo method which couples path integrals for finite temperature protons with quantum Monte Carlo calculations for ground state electrons, and we apply it to metallic hydrogen for pressures beyond molecular dissociation. We report data for the equation of state for temperatures across the melting of the proton crystal. Our data exhibit more structure and higher melting temperatures of the proton crystal than do Car-Parrinello molecular dynamics results. This method fills the gap between high temperature electron-proton path integral and ground state diffusion Monte Carlo methods and should have wide applicability.

Carlo Pierleoni; David M. Ceperley; Markus Holzmann

2004-09-27T23:59:59.000Z

297

Quantum Monte Carlo for electronic structure: Recent developments and applications  

SciTech Connect (OSTI)

Quantum Monte Carlo (QMC) methods have been found to give excellent results when applied to chemical systems. The main goal of the present work is to use QMC to perform electronic structure calculations. In QMC, a Monte Carlo simulation is used to solve the Schroedinger equation, taking advantage of its analogy to a classical diffusion process with branching. In the present work the author focuses on how to extend the usefulness of QMC to more meaningful molecular systems. This study is aimed at questions concerning polyatomic and large atomic number systems. The accuracy of the solution obtained is determined by the accuracy of the trial wave function`s nodal structure. Efforts in the group have given great emphasis to finding optimized wave functions for the QMC calculations. Little work had been done by systematically looking at a family of systems to see how the best wave functions evolve with system size. In this work the author presents a study of trial wave functions for C, CH, C{sub 2}H and C{sub 2}H{sub 2}. The goal is to study how to build wave functions for larger systems by accumulating knowledge from the wave functions of its fragments as well as gaining some knowledge on the usefulness of multi-reference wave functions. In a MC calculation of a heavy atom, for reasonable time steps most moves for core electrons are rejected. For this reason true equilibration is rarely achieved. A method proposed by Batrouni and Reynolds modifies the way the simulation is performed without altering the final steady-state solution. It introduces an acceleration matrix chosen so that all coordinates (i.e., of core and valence electrons) propagate at comparable speeds. A study of the results obtained using their proposed matrix suggests that it may not be the optimum choice. In this work the author has found that the desired mixing of coordinates between core and valence electrons is not achieved when using this matrix. A bibliography of 175 references is included.

Rodriguez, M.M.S. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.

1995-04-01T23:59:59.000Z

298

Complete Monte Carlo Simulation of Neutron Scattering Experiments  

SciTech Connect (OSTI)

In the far past, it was not possible to accurately correct for the finite geometry and the finite sample size of a neutron scattering set-up. The limited calculation power of the ancient computers as well as the lack of powerful Monte Carlo codes and the limitation in the data base available then prevented a complete simulation of the actual experiment. Using e.g. the Monte Carlo neutron transport code MCNPX [1], neutron scattering experiments can be simulated almost completely with a high degree of precision using a modern PC, which has a computing power that is ten thousand times that of a super computer of the early 1970s. Thus, (better) corrections can also be obtained easily for previous published data provided that these experiments are sufficiently well documented. Better knowledge of reference data (e.g. atomic mass, relativistic correction, and monitor cross sections) further contributes to data improvement. Elastic neutron scattering experiments from liquid samples of the helium isotopes performed around 1970 at LANL happen to be very well documented. Considering that the cryogenic targets are expensive and complicated, it is certainly worthwhile to improve these data by correcting them using this comparatively straightforward method. As two thirds of all differential scattering cross section data of {sup 3}He(n,n){sup 3}He are connected to the LANL data, it became necessary to correct the dependent data measured in Karlsruhe, Germany, as well. A thorough simulation of both the LANL experiments and the Karlsruhe experiment is presented, starting from the neutron production, followed by the interaction in the air, the interaction with the cryostat structure, and finally the scattering medium itself. In addition, scattering from the hydrogen reference sample was simulated. For the LANL data, the multiple scattering corrections are smaller by a factor of five at least, making this work relevant. Even more important are the corrections to the Karlsruhe data due to the inclusion of the missing outgoing self-attenuation that amounts to up to 15%.

Drosg, M. [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Wien (Austria)

2011-12-13T23:59:59.000Z

299

An efficient approach to ab initio Monte Carlo simulation  

SciTech Connect (OSTI)

We present a Nested Markov chain Monte Carlo (NMC) scheme for building equilibrium averages based on accurate potentials such as density functional theory. Metropolis sampling of a reference system, defined by an inexpensive but approximate potential, was used to substantially decorrelate configurations at which the potential of interest was evaluated, thereby dramatically reducing the number needed to build ensemble averages at a given level of precision. The efficiency of this procedure was maximized on-the-fly through variation of the reference system thermodynamic state (characterized here by its inverse temperature ?{sup 0}), which was otherwise unconstrained. Local density approximation results are presented for shocked states of argon at pressures from 4 to 60 GPa, where—depending on the quality of the reference system potential—acceptance probabilities were enhanced by factors of 1.2–28 relative to unoptimized NMC. The optimization procedure compensated strongly for reference potential shortcomings, as evidenced by significantly higher speedups when using a reference potential of lower quality. The efficiency of optimized NMC is shown to be competitive with that of standard ab initio molecular dynamics in the canonical ensemble.

Leiding, Jeff; Coe, Joshua D., E-mail: jcoe@lanl.gov [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-01-21T23:59:59.000Z

300

Ensemble bayesian model averaging using markov chain Monte Carlo sampling  

SciTech Connect (OSTI)

Bayesian model averaging (BMA) has recently been proposed as a statistical method to calibrate forecast ensembles from numerical weather models. Successful implementation of BMA however, requires accurate estimates of the weights and variances of the individual competing models in the ensemble. In their seminal paper (Raftery etal. Mon Weather Rev 133: 1155-1174, 2(05)) has recommended the Expectation-Maximization (EM) algorithm for BMA model training, even though global convergence of this algorithm cannot be guaranteed. In this paper, we compare the performance of the EM algorithm and the recently developed Differential Evolution Adaptive Metropolis (DREAM) Markov Chain Monte Carlo (MCMC) algorithm for estimating the BMA weights and variances. Simulation experiments using 48-hour ensemble data of surface temperature and multi-model stream-flow forecasts show that both methods produce similar results, and that their performance is unaffected by the length of the training data set. However, MCMC simulation with DREAM is capable of efficiently handling a wide variety of BMA predictive distributions, and provides useful information about the uncertainty associated with the estimated BMA weights and variances.

Vrugt, Jasper A [Los Alamos National Laboratory; Diks, Cees G H [NON LANL; Clark, Martyn P [NON LANL

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" 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

Cohesion Energetics of Carbon Allotropes: Quantum Monte Carlo Study  

SciTech Connect (OSTI)

We have performed quantum Monte Carlo calculations to study the cohesion energetics of carbon allotropes, including sp3-bonded diamond, sp2-bonded graphene, sp-sp2 hybridized graphynes, and sp-bonded carbyne. The comput- ed cohesive energies of diamond and graphene are found to be in excellent agreement with the corresponding values de- termined experimentally for diamond and graphite, respectively, when the zero-point energies, along with the interlayer binding in the case of graphite, are included. We have also found that the cohesive energy of graphyne decreases system- atically as the ratio of sp-bonded carbon atoms increases. The cohesive energy of -graphyne, the most energetically- stable graphyne, turns out to be 6.766(6) eV/atom, which is smaller than that of graphene by 0.698(12) eV/atom. Experi- mental difficulty in synthesizing graphynes could be explained by their significantly smaller cohesive energies. Finally we conclude that the cohesive energy of a newly-proposed two-dimensional carbon network can be accurately estimated with the carbon-carbon bond energies determined from the cohesive energies of graphene and three different graphynes.

Shin, Hyeondeok [Konkuk University, South Korea] [Konkuk University, South Korea; Kang, Sinabro [Konkuk University, South Korea] [Konkuk University, South Korea; Koo, Jahyun [Konkuk University, South Korea] [Konkuk University, South Korea; Lee, Hoonkyung [Konkuk University, South Korea] [Konkuk University, South Korea; Kim, Jeongnim [ORNL] [ORNL; Kwon, Yongkyung [Konkuk University, South Korea] [Konkuk University, South Korea

2014-01-01T23:59:59.000Z

302

Random Number Generation for Petascale Quantum Monte Carlo  

SciTech Connect (OSTI)

The quality of random number generators can affect the results of Monte Carlo computations, especially when a large number of random numbers are consumed. Furthermore, correlations present between different random number streams in a parallel computation can further affect the results. The SPRNG software, which the author had developed earlier, has pseudo-random number generators (PRNGs) capable of producing large numbers of streams with large periods. However, they had been empirically tested on only thousand streams earlier. In the work summarized here, we tested the SPRNG generators with over a hundred thousand streams, involving over 10^14 random numbers per test, on some tests. We also tested the popular Mersenne Twister. We believe that these are the largest tests of PRNGs, both in terms of the numbers of streams tested and the number of random numbers tested. We observed defects in some of these generators, including the Mersenne Twister, while a few generators appeared to perform well. We also corrected an error in the implementation of one of the SPRNG generators.

Ashok Srinivasan

2010-03-16T23:59:59.000Z

303

Improving computational efficiency of Monte Carlo simulations with variance reduction  

SciTech Connect (OSTI)

CCFE perform Monte-Carlo transport simulations on large and complex tokamak models such as ITER. Such simulations are challenging since streaming and deep penetration effects are equally important. In order to make such simulations tractable, both variance reduction (VR) techniques and parallel computing are used. It has been found that the application of VR techniques in such models significantly reduces the efficiency of parallel computation due to 'long histories'. VR in MCNP can be accomplished using energy-dependent weight windows. The weight window represents an 'average behaviour' of particles, and large deviations in the arriving weight of a particle give rise to extreme amounts of splitting being performed and a long history. When running on parallel clusters, a long history can have a detrimental effect on the parallel efficiency - if one process is computing the long history, the other CPUs complete their batch of histories and wait idle. Furthermore some long histories have been found to be effectively intractable. To combat this effect, CCFE has developed an adaptation of MCNP which dynamically adjusts the WW where a large weight deviation is encountered. The method effectively 'de-optimises' the WW, reducing the VR performance but this is offset by a significant increase in parallel efficiency. Testing with a simple geometry has shown the method does not bias the result. This 'long history method' has enabled CCFE to significantly improve the performance of MCNP calculations for ITER on parallel clusters, and will be beneficial for any geometry combining streaming and deep penetration effects. (authors)

Turner, A. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon, 0X14 3DB (United Kingdom); Davis, A. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon, 0X14 3DB (United Kingdom); University of Wisconsin-Madison, Madison, WI 53706 (United States)

2013-07-01T23:59:59.000Z

304

Monte Carlo sampling from the quantum state space. I  

E-Print Network [OSTI]

High-quality random samples of quantum states are needed for a variety of tasks in quantum information and quantum computation. Searching the high-dimensional quantum state space for a global maximum of an objective function with many local maxima or evaluating an integral over a region in the quantum state space are but two exemplary applications of many. These tasks can only be performed reliably and efficiently with Monte Carlo methods, which involve good samplings of the parameter space in accordance with the relevant target distribution. We show how the standard strategies of rejection sampling, importance sampling, and Markov-chain sampling can be adapted to this context, where the samples must obey the constraints imposed by the positivity of the statistical operator. For a comparison of these sampling methods, we generate sample points in the probability space for two-qubit states probed with a tomographically incomplete measurement, and then use the sample for the calculation of the size and credibility of the recently-introduced optimal error regions [see New J. Phys. 15 (2013) 123026]. Another illustration is the computation of the fractional volume of separable two-qubit states.

Jiangwei Shang; Yi-Lin Seah; Hui Khoon Ng; David John Nott; Berthold-Georg Englert

2014-07-29T23:59:59.000Z

305

A Monte Carlo code describing the neutral gas transport in pipe configurations with attenuating media  

Science Journals Connector (OSTI)

A three-dimensional Monte Carlo description of the neutral gas transport in pipe configurations with almost arbitrary torsion and curvature is presented. To avoid quadratic or even transcendental expressions describing the pipe surfaces confining and ...

A. Nicolai

1993-06-01T23:59:59.000Z

306

Vectorization on Monte Carlo particle transport: an architectural study using the LANL benchmark “GAMTEB”  

Science Journals Connector (OSTI)

Fully vectorized versions of the Los Alamos National Laboratory benchmark code Gamteb, a Monte Carlo photon transport algorithm, were developed for the Cyber 205/ETA-10 and Cray X-MP/Y-MP architectures. Single-processor performance measurements ...

P. J. Burns; M. Christon; R. Schweitzer; O. M. Lubeck; H. J. Wasserman

1989-08-01T23:59:59.000Z

307

A semi Monte Carlo calculation of the flux of high-energy muons in air showers  

Science Journals Connector (OSTI)

A semi Monte Carlo method has been used to calculate the flux of muons of energy ?180 GeV associated with air showers at ... of nucleon and pion interactions at ultra-high energies. Various aspects of these muons

Siddheshwar Lal

1967-03-21T23:59:59.000Z

308

E-Print Network 3.0 - au code monte Sample Search Results  

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

ON APPLIED SUPERCONDUCTIVITY, VOL. 13, NO. 2, JUNE 2003 889 High Quality YBa2Cu3O7 Josephson Junctions Summary: been studied by Monte Carlo simulation using a mod- ified...

309

APR1400 LBLOCA uncertainty quantification by Monte Carlo method and comparison with Wilks' formula  

SciTech Connect (OSTI)

An analysis of the uncertainty quantification for the PWR LBLOCA by the Monte Carlo calculation has been performed and compared with the tolerance level determined by Wilks' formula. The uncertainty range and distribution of each input parameter associated with the LBLOCA accident were determined by the PIRT results from the BEMUSE project. The Monte-Carlo method shows that the 95. percentile PCT value can be obtained reliably with a 95% confidence level using the Wilks' formula. The extra margin by the Wilks' formula over the true 95. percentile PCT by the Monte-Carlo method was rather large. Even using the 3 rd order formula, the calculated value using the Wilks' formula is nearly 100 K over the true value. It is shown that, with the ever increasing computational capability, the Monte-Carlo method is accessible for the nuclear power plant safety analysis within a realistic time frame. (authors)

Hwang, M.; Bae, S.; Chung, B. D. [Korea Atomic Energy Research Inst., 150 Dukjin-dong, Yuseong-gu, Daejeon (Korea, Republic of)

2012-07-01T23:59:59.000Z

310

Observations of the Great Southern Comet 1880, I. made at Monte Video  

Science Journals Connector (OSTI)

... 1880 Royal Astronomical Society. Provided by the NASA Astrophysics Data System 12 March 1880 research-article Articles Observations of the Great Southern Comet 1880, I. made at Monte Video Lieut. B. Gwynne 1880MNRAS..40..295G...

B. Gwynne

1880-03-12T23:59:59.000Z

311

Sextant Observations of Comet Pons-Brooks made at Monte Video  

Science Journals Connector (OSTI)

... 1884 Royal Astronomical Society. Provided by the NASA Astrophysics Data System 14 March 1884 research-article Articles Sextant Observations of Comet Pons-Brooks made at Monte Video Rev. S. S. O. Morris 1884MNRAS..44..256M...

S. S. O. Morris

1884-03-14T23:59:59.000Z

312

Modeling of Asymmetry between Gasoline and Crude Oil Prices: A Monte Carlo Comparison  

Science Journals Connector (OSTI)

An Engle–Granger two-step procedure is commonly used to estimate cointegrating vectors and consequently asymmetric error-correction models. This study uses Monte Carlo methods and demonstrates that the Engle–G...

Afshin Honarvar

2010-10-01T23:59:59.000Z

313

Monte Carlo Simulations of Microchannel Plate Based, Fast-Gated X-Ray Imagers  

SciTech Connect (OSTI)

This is a chapter in a book titled Applications of Monte Carlo Method in Science and Engineering Edited by: Shaul Mordechai ISBN 978-953-307-691-1, Hard cover, 950 pages Publisher: InTech Publication date: February 2011

Wu., M., Kruschwitz, C.

2011-02-01T23:59:59.000Z

314

Protein folding and phylogenetic tree reconstruction using stochastic approximation Monte Carlo  

E-Print Network [OSTI]

folding problems. The numerical results indicate that it outperforms simulated annealing and conventional Monte Carlo algorithms as a stochastic optimization algorithm. We also propose one method for the use of secondary structures in protein folding...

Cheon, Sooyoung

2007-09-17T23:59:59.000Z

315

Probability Distributions and Threshold Selection for Monte Carlo–Type Tropical Cyclone Wind Speed Forecasts  

Science Journals Connector (OSTI)

Probabilistic wind speed forecasts for tropical cyclones from Monte Carlo–type simulations are assessed within a theoretical framework for a simple unbiased Gaussian system that is based on feature size and location error that mimic tropical ...

Michael E. Splitt; Steven M. Lazarus; Sarah Collins; Denis N. Botambekov; William P. Roeder

2014-10-01T23:59:59.000Z

316

MonteCarlo and Analytical Methods for Forced Outage Rate Calculations of Peaking Units  

E-Print Network [OSTI]

(unavailability) of such units. This thesis examines the representation of peaking units using a four-state model and performs the analytical calculations and Monte Carlo simulations to examine whether such a model does indeed represent the peaking units...

Rondla, Preethi 1988-

2012-10-26T23:59:59.000Z

317

A Monte Carlo Approach To Generator Portfolio Planning And Carbon Emissions  

Open Energy Info (EERE)

Monte Carlo Approach To Generator Portfolio Planning And Carbon Emissions Monte Carlo Approach To Generator Portfolio Planning And Carbon Emissions Assessments Of Systems With Large Penetrations Of Variable Renewables Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Monte Carlo Approach To Generator Portfolio Planning And Carbon Emissions Assessments Of Systems With Large Penetrations Of Variable Renewables Details Activities (0) Areas (0) Regions (0) Abstract: A new generator portfolio planning model is described that is capable of quantifying the carbon emissions associated with systems that include very high penetrations of variable renewables. The model combines a deterministic renewable portfolio planning module with a Monte Carlo simulation of system operation that determines the expected least-cost

318

Monte Carlo simulation model for electromagnetic scattering from vegetation and inversion of vegetation parameters  

E-Print Network [OSTI]

In this thesis research, a coherent scattering model for microwave remote sensing of vegetation canopy is developed on the basis of Monte Carlo simulations. An accurate model of vegetation structure is essential for the ...

Wang, Li-Fang, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

319

The Monte Carlo Independent Column Approximation’s Conditional Random Noise: Impact on Simulated Climate  

Science Journals Connector (OSTI)

The Monte Carlo Independent Column Approximation (McICA) method for computing domain-average radiative fluxes is unbiased with respect to the full ICA, but its flux estimates contain conditional random noise. Results for five experiments are used ...

P. Räisänen; H. W. Barker; J. N. S. Cole

2005-11-01T23:59:59.000Z

320

High explosive spot test analyses of samples from Operable Unit (OU) 1111  

SciTech Connect (OSTI)

A preliminary evaluation has been completed of environmental contaminants at selected sites within the Group DX-10 (formally Group M-7) area. Soil samples taken from specific locations at this detonator facility were analyzed for harmful metals and screened for explosives. A sanitary outflow, a burn pit, a pentaerythritol tetranitrate (PETN) production outflow field, an active firing chamber, an inactive firing chamber, and a leach field were sampled. Energy dispersive x-ray fluorescence (EDXRF) was used to obtain semi-quantitative concentrations of metals in the soil. Two field spot-test kits for explosives were used to assess the presence of energetic materials in the soil and in items found at the areas tested. PETN is the major explosive in detonators manufactured and destroyed at Los Alamos. No measurable amounts of PETN or other explosives were detected in the soil, but items taken from the burn area and a high-energy explosive (HE)/chemical sump were contaminated. The concentrations of lead, mercury, and uranium are given.

McRae, D.; Haywood, W.; Powell, J.; Harris, B.

1995-01-01T23:59:59.000Z

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


321

The effect of load imbalances on the performance of Monte Carlo algorithms in LWR analysis  

SciTech Connect (OSTI)

A model is developed to predict the impact of particle load imbalances on the performance of domain-decomposed Monte Carlo neutron transport algorithms. Expressions for upper bound performance “penalties” are derived in terms of simple machine characteristics, material characterizations and initial particle distributions. The hope is that these relations can be used to evaluate tradeoffs among different memory decomposition strategies in next generation Monte Carlo codes, and perhaps as a metric for triggering particle redistribution in production codes.

Siegel, A.R., E-mail: siegela@mcs.anl.gov [Argonne National Laboratory, Nuclear Engineering Division (United States); Argonne National Laboratory, Mathematics and Computer Science Division (United States); Smith, K., E-mail: kord@mit.edu [Massachusetts Institute of Technology, Department of Nuclear Science and Engineering (United States); Romano, P.K., E-mail: romano7@mit.edu [Massachusetts Institute of Technology, Department of Nuclear Science and Engineering (United States); Forget, B., E-mail: bforget@mit.edu [Massachusetts Institute of Technology, Department of Nuclear Science and Engineering (United States); Felker, K., E-mail: felker@mcs.anl.gov [Argonne National Laboratory, Mathematics and Computer Science Division (United States)

2013-02-15T23:59:59.000Z

322

Monte Carlo techniques of simulation applied to a single item inventory system  

E-Print Network [OSTI]

MONTE CARI, O TECHNIQUES OF SIMULATION APPLIED TO A SINGLE ITEM INVENTORY SYSTEM A Thesis By WILLIAM MURRAY ALDRED, JR. Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1965 Major SubJect: Computer Science MONTE CARLO TECHNIQUES OF SIMULATION APPLIED TO A SINGLE ITEM INVENTORY SYSTEM A Thesis By WILLIAM MURRAY ALDRED, JR. Approved as to style and content by: (Chairman of Committee (Head...

Aldred, William Murray

2012-06-07T23:59:59.000Z

323

Preventing xenon oscillations in Monte Carlo burnup calculations by enforcing equilibrium xenon distribution  

Science Journals Connector (OSTI)

Abstract Existing Monte Carlo burnup codes suffer from instabilities caused by spatial xenon oscillations. These oscillations can be prevented by forcing equilibrium between the neutron flux and saturated xenon distribution. The equilibrium calculation can be integrated to Monte Carlo neutronics, which provides a simple and lightweight solution that can be used with any of the existing burnup calculation algorithms. The stabilizing effect of this approach, as well as its limitations are demonstrated using the reactor physics code Serpent.

A.E. Isotalo; J. Leppänen; J. Dufek

2013-01-01T23:59:59.000Z

324

Comparison of value-added models for school ranking and classification: a Monte Carlo study  

E-Print Network [OSTI]

COMPARISON OF VALUE-ADDED MODELS FOR SCHOOL RANKING AND CLASSIFICATION: A MONTE CARLO STUDY A Dissertation by ZHONGMIAO WANG Submitted to the Office of Graduate Studies of Texas A&M University... AND CLASSIFICATION: A MONTE CARLO STUDY A Dissertation by ZHONGMIAO WANG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Co...

Wang, Zhongmiao

2009-05-15T23:59:59.000Z

325

PyMercury: Interactive Python for the Mercury Monte Carlo Particle Transport Code  

SciTech Connect (OSTI)

Monte Carlo particle transport applications are often written in low-level languages (C/C++) for optimal performance on clusters and supercomputers. However, this development approach often sacrifices straightforward usability and testing in the interest of fast application performance. To improve usability, some high-performance computing applications employ mixed-language programming with high-level and low-level languages. In this study, we consider the benefits of incorporating an interactive Python interface into a Monte Carlo application. With PyMercury, a new Python extension to the Mercury general-purpose Monte Carlo particle transport code, we improve application usability without diminishing performance. In two case studies, we illustrate how PyMercury improves usability and simplifies testing and validation in a Monte Carlo application. In short, PyMercury demonstrates the value of interactive Python for Monte Carlo particle transport applications. In the future, we expect interactive Python to play an increasingly significant role in Monte Carlo usage and testing.

Iandola, F N; O'Brien, M J; Procassini, R J

2010-11-29T23:59:59.000Z

326

Analysis of testing the single-fluxon dynamics in a long Josephson junction by a dissipative spot  

SciTech Connect (OSTI)

A change of the [ital I]-[ital V] characteristics of a long Josephson junction, operating in the zero-field single-fluxon regime, under the action of a hot spot'' (e.g., created by a focused electron beam) is calculated analytically by means of the perturbation theory, and also investigated numerically. The change of the average voltage at a given value of the bias current is calculated as a function of the hot spot-position. The overlap Josephson junction geometry is considered in detail, while the inline one is briefly discussed. A good accord between analytical and numerical results is found. The results are relevant for the interpretation of the low-temperature scanning electron microscopy experiments on imaging the fluxon dynamic states in a long Josephson junction.

Malomed, B.A. (Dipartimento di Fisica, Universita di Salerno, I-84801 Baronissi (Saudi Arabia) (Italy)); Ustinov, A.V. (Institute for Thin Films and Ion Technology, Research Centre (KFA), D-52425 Juelich (Germany))

1994-05-01T23:59:59.000Z

327

Estimating VaR and ES of the spot price of oil using futures-varying centiles  

Science Journals Connector (OSTI)

This paper illustrates the power of modern statistical modelling in estimating measures of market risk, here applied to the Brent and WTI spot price of oil. Both Value-at-Risk (VaR) and Expected Shortfall (ES) are cast in terms of conditional centiles based upon semi-parametric regression models. Using the GAMLSS statistical framework, we stress the important aspects of selecting a highly flexible parametric distribution (skewed Student's t-distribution) and of modelling both skewness and kurtosis as non-parametric functions of the price of oil futures. Furthermore, an empirical application characterises the relationship between spot oil prices and oil futures - exploiting the futures market to explain the dynamics of the physical market. Our results suggest that NYMEX WTI has heavier tails compared with the ICE Brent. Contrary to the common platitude of the industry, we argue that 'somebody knows something' in the oil business.

Giacomo Scandroglio; Andrea Gori; Emiliano Vaccaro; Vlasios Voudouris

2013-01-01T23:59:59.000Z

328

A new class of accelerated kinetic Monte Carlo algorithms  

SciTech Connect (OSTI)

Kinetic (aka dynamic) Monte Carlo (KMC) is a powerful method for numerical simulations of time dependent evolution applied in a wide range of contexts including biology, chemistry, physics, nuclear sciences, financial engineering, etc. Generally, in a KMC the time evolution takes place one event at a time, where the sequence of events and the time intervals between them are selected (or sampled) using random numbers. While details of the method implementation vary depending on the model and context, there exist certain common issues that limit KMC applicability in almost all applications. Among such is the notorious 'flicker problem' where the same states of the systems are repeatedly visited but otherwise no essential evolution is observed. In its simplest form the flicker problem arises when two states are connected to each other by transitions whose rates far exceed the rates of all other transitions out of the same two states. In such cases, the model will endlessly hop between the two states otherwise producing no meaningful evolution. In most situation of practical interest, the trapping cluster includes more than two states making the flicker somewhat more difficult to detect and to deal with. Several methods have been proposed to overcome or mitigate the flicker problem, exactly [1-3] or approximately [4,5]. Of the exact methods, the one proposed by Novotny [1] is perhaps most relevant to our research. Novotny formulates the problem of escaping from a trapping cluster as a Markov system with absorbing states. Given an initial state inside the cluster, it is in principle possible to solve the Master Equation for the time dependent probabilities to find the walker in a given state (transient or absorbing) of the cluster at any time in the future. Novotny then proceeds to demonstrate implementation of his general method to trapping clusters containing the initial state plus one or two transient states and all of their absorbing states. Similar methods have been subsequently proposed in [refs] but applied in a different context. The most serious deficiency of the earlier methods is that size of the trapping cluster size is fixed and often too small to bring substantial simulation speedup. Furthermore, the overhead associated with solving for the probability distribution on the trapping cluster sometimes makes such simulations less efficient than the standard KMC. Here we report on a general and exact accelerated kinetic Monte Carlo algorithm generally applicable to arbitrary Markov models1. Two different implementations are attempted both based on incremental expansion of trapping sub-set of Markov states: (1) numerical solution of the Master Equation with absorbing states and (2) incremental graph reduction followed by randomization. Of the two implementations, the 2nd one performs better allowing, for the first time, to overcome trapping basins spanning several million Markov states. The new method is used for simulations of anomalous diffusion on a 2D substrate and of the kinetics of diffusive 1st order phase transformations in binary alloys. Depending on temperature and (alloy) super-saturation conditions, speedups of 3 to 7 orders of magnitude are demonstrated, with no compromise of simulation accuracy.

Bulatov, V V; Oppelstrup, T; Athenes, M

2011-11-30T23:59:59.000Z

329

Quantum Monte Carlo methods and lithium cluster properties  

SciTech Connect (OSTI)

Properties of small lithium clusters with sizes ranging from n = 1 to 5 atoms were investigated using quantum Monte Carlo (QMC) methods. Cluster geometries were found from complete active space self consistent field (CASSCF) calculations. A detailed development of the QMC method leading to the variational QMC (V-QMC) and diffusion QMC (D-QMC) methods is shown. The many-body aspect of electron correlation is introduced into the QMC importance sampling electron-electron correlation functions by using density dependent parameters, and are shown to increase the amount of correlation energy obtained in V-QMC calculations. A detailed analysis of D-QMC time-step bias is made and is found to be at least linear with respect to the time-step. The D-QMC calculations determined the lithium cluster ionization potentials to be 0.1982(14) [0.1981], 0.1895(9) [0.1874(4)], 0.1530(34) [0.1599(73)], 0.1664(37) [0.1724(110)], 0.1613(43) [0.1675(110)] Hartrees for lithium clusters n = 1 through 5, respectively; in good agreement with experimental results shown in the brackets. Also, the binding energies per atom was computed to be 0.0177(8) [0.0203(12)], 0.0188(10) [0.0220(21)], 0.0247(8) [0.0310(12)], 0.0253(8) [0.0351(8)] Hartrees for lithium clusters n = 2 through 5, respectively. The lithium cluster one-electron density is shown to have charge concentrations corresponding to nonnuclear attractors. The overall shape of the electronic charge density also bears a remarkable similarity with the anisotropic harmonic oscillator model shape for the given number of valence electrons.

Owen, R.K.

1990-12-01T23:59:59.000Z

330

Quantitative structure–activity relationships for toxicity and genotoxicity of halogenated aliphatic compounds: Wing spot test of Drosophila melanogaster  

Science Journals Connector (OSTI)

Halogenated aliphatic compounds were evaluated for toxic and genotoxic effects in the somatic mutation and recombination test employing Drosophila melanogaster. The tested chemicals included chlorinated, brominated and iodinated; mono-, di- and tri-substituted; saturated and unsaturated alkanes: 1,2-dibromoethane, 1-bromo-2-chloroethane, 1-iodopropane, 2,3-dichloropropene, 3-bromo-1-propene, epibromohydrin, 2-iodobutane, 3-chloro-2-methylpropene, 1,2,3-trichloropropane, 1,2-dichloroethane, 1,2-dichlorobutane, 1-chloro-2-methylpropane, 1,3-dichloropropane, 1,2-dichloropropane, 2-chloroethymethylether, 1-bromo-2-methylpropane and 1-chloropentane. N-methyl-N-nitrosourea served as the positive and distilled water as the negative control. The set of chemicals for the toxicological testing was selected by the use of statistical experiment design. Group of unsaturated aliphatic hydrocarbons were generally more toxic than saturated analogues. The genotoxic effect was observed with 14 compounds in the wing spot test, while 3 substances did not show any genotoxicity by using the wing spot test at 50% lethal concentration. The highest number of wing spots was observed in genotoxicity assay with 1-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromoethane and 1-iodopropane. Nucleophilic superdelocalizability calculated by quantum mechanics appears to be a good parameter for prediction of both toxicity and genotoxicity effects of halogenated aliphatic compounds.

Karel Chroust; Martina Pavlová; Zbyn?k Prokop; Jan Mendel; Kate?ina Božková; Zden?k Kubát; Veronika Zaj?´?ková; Ji??´ Damborský

2007-01-01T23:59:59.000Z

331

Detection of surface carbon and hydrocarbons in hot spot regions of niobium superconducting rf cavities by Raman spectroscopy  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Raman microscopy/spectroscopy measurements are presented on high purity niobium (Nb) samples, including pieces from hot spot regions of a tested superconducting rf cavity that exhibit a high density of etch pits. Measured spectra are compared with density functional theory calculations of Raman-active, vibrational modes of possible surface Nb-O and Nb-H complexes. The Raman spectra inside particularly rough pits in all Nb samples show clear differences from surrounding areas, exhibiting enhanced intensity and sharp peaks. While some of the sharp peaks are consistent with calculated NbH and NbH2 modes, there is better overall agreement with C-H modes in chain-type hydrocarbons. Other spectra reveal two broader peaks attributed to amorphous carbon. Niobium foils annealed to >2000°C in high vacuum develop identical Raman peaks when subjected to cold working. Regions with enhanced C and O have also been found by SEM/EDX spectroscopy in the hot spot samples and cold-worked foils, corroborating the Raman results. Such regions with high concentrations of impurities are expected to suppress the local superconductivity and this may explain the correlation between hot spots in superconducting rf (SRF) cavities and the observation of a high density of surface pits. The origin of localized high carbon and hydrocarbon regions is unclear at present but it is suggested that particular processing steps in SRF cavity fabrication may be responsible.

Cao, C.; Ford, D.; Bishnoi, S.; Proslier, T.; Albee, B.; Hommerding, E.; Korczakowski, A.; Cooley, L.; Ciovati, G.; Zasadzinski, J. F.

2013-06-01T23:59:59.000Z

332

Dynamics of plasma jets and electrode spots in the pulsed source of a high-purity plasma obtained from a dielectric material at atmospheric pressure  

Science Journals Connector (OSTI)

The results of investigation of the distinctive features of the dynamics of outflow of plasma jets and of formation of electrode spots in the source of a high-purity plasma obtained from a dielectric material at

V. B. Avramenko; A. M. Kuz’mitski…

2011-05-01T23:59:59.000Z

333

Sequence diversity of the nucleoprotein gene of iris yellow spot virus (genus Tospovirus, family Bunyaviridae) isolates from the western region of the United States  

Science Journals Connector (OSTI)

Iris yellow spot virus (IYSV), a tentative virus species in the genus Tospovirus and family Bunyaviridae, is considered a rapidly emerging threat to onion production in the western United States (US). The present...

H. R. Pappu; L. J. du Toit; H. F. Schwartz; S. K. Mohan

2006-05-01T23:59:59.000Z

334

Identification and characterization of biologically distinct isolates of Iris yellow spot virus (genus Tospovirus, family Bunyaviridae), a serious pathogen of onion  

Science Journals Connector (OSTI)

Iris yellow spot virus (IYSV) causes an economically important disease in onion bulb and seed crops. While considerable information on the genetic diversity of the virus is available, little is k...

Sudeep Bag; H. F. Schwartz; H. R. Pappu

2012-09-01T23:59:59.000Z

335

Monte Carlo Simulations of the Corrosion of Aluminoborosilicate Glasses  

SciTech Connect (OSTI)

Aluminum is one of the most common components included in nuclear waste glasses. Therefore, Monte Carlo (MC) simulations were carried out to investigate the influence of aluminum on the rate and mechanism of dissolution of sodium borosilicate glasses in static conditions. The glasses studied were in the compositional range (70 2x)% SiO2x% Al2O3 15% B2O3 (15 + x)% Na2O, where 0 x 15%. The simulation results show that increasing amounts of aluminum in the pristine glasses slow down the initial rate of dissolution as determined from the rate of boron release. However, the extent of corrosion as measured by the total amount of boron release initially increases with addition of Al2O3, up to 5 mol% Al2O3, but subsequently decreases with further Al2O3 addition. The MC simulations reveal that this behavior is due to the interplay between two opposing mechanisms: (1) aluminum slows down the kinetics of hydrolysis/condensation reactions that drive the reorganization of the glass surface and eventual formation of a blocking layer; and (2) aluminum strengthens the glass thereby increasing the lifetime of the upper part of its surface and allowing for more rapid formation of a blocking layer. Additional MC simulations were performed whereby a process representing the formation of a secondary aluminosilicate phase was included. Secondary phase formation draws dissolved glass components out of the aqueous solution, thereby diminishing the rate of condensation and delaying the formation of a blocking layer. As a result, the extent of corrosion is found to increase continuously with increasing Al2O3 content, as observed experimentally. For Al2O3 < 10 mol%, the MC simulations also indicate that, because the secondary phase solubility eventually controls the aluminum content in the part of the altered layer in contact with the bulk aqueous solution, the dissolved aluminum and silicon concentrations at steady state are not dependent on the Al2O3 content of the pristine aluminoborosilicate glass.

Kerisit, Sebastien [Pacific Northwest National Laboratory (PNNL); Ryan, Joseph V [Pacific Northwest National Laboratory (PNNL); Pierce, Eric M [ORNL

2013-01-01T23:59:59.000Z

336

Monte Carlo Simulations of the Corrosion of Aluminoborosilicate Glasses  

SciTech Connect (OSTI)

Aluminum is one of the most common components included in nuclear waste glasses. Therefore, Monte Carlo (MC) simulations were carried out to investigate the influence of aluminum on the rate and mechanism of dissolution of sodium borosilicate glasses in static conditions. The glasses studied were in the compositional range (70-2x)% SiO2 x% Al2O3 15% B2O3 (15+x)% Na2O, where 0 ? x ? 15%. The simulation results show that increasing amounts of aluminum in the pristine glasses slow down the initial rate of dissolution as determined from the rate of boron release. However, the extent of corrosion - as measured by the total amount of boron release - initially increases with addition of Al2O3, up to 5 Al2O3 mol%, but subsequently decreases with further Al2O3 addition. The MC simulations reveal that this behavior is due to the interplay between two opposing mechanisms: (1) aluminum slows down the kinetics of hydrolysis/condensation reactions that drive the reorganization of the glass surface and eventual formation of a blocking layer; and (2) aluminum strengthens the glass thereby increasing the lifetime of the upper part of its surface and allowing for more rapid formation of a blocking layer. Additional MC simulations were performed whereby a process representing the formation of a secondary aluminosilicate phase was included. Secondary phase formation draws dissolved glass components out of the aqueous solution, thereby diminishing the rate of condensation and delaying the formation of a blocking layer. As a result, the extent of corrosion is found to increase continuously with increasing Al2O3 content, as observed experimentally. For Al2O3 < 10 mol%, the MC simulations also indicate that, because the secondary phase solubility eventually controls the aluminum content in the part of the altered layer in contact with the bulk aqueous solution, the dissolved aluminum and silicon concentrations at steady state are not dependent on the Al2O3 content of the pristine aluminoborosilicate glass.

Kerisit, Sebastien N.; Ryan, Joseph V.; Pierce, Eric M.

2013-10-15T23:59:59.000Z

337

A midway forward-adjoint coupling method for neutron and photon Monte Carlo transport  

SciTech Connect (OSTI)

The midway Monte Carlo method for calculating detector responses combines a forward and an adjoint Monte Carlo calculation. In both calculations, particle scores are registered at a surface to be chosen by the user somewhere between the source and detector domains. The theory of the midway response determination is developed within the framework of transport theory for external sources and for criticality theory. The theory is also developed for photons, which are generated at inelastic scattering or capture of neutrons. In either the forward or the adjoint calculation a so-called black absorber technique can be applied; i.e., particles need not be followed after passing the midway surface. The midway Monte Carlo method is implemented in the general-purpose MCNP Monte Carlo code. The midway Monte Carlo method is demonstrated to be very efficient in problems with deep penetration, small source and detector domains, and complicated streaming paths. All the problems considered pose difficult variance reduction challenges. Calculations were performed using existing variance reduction methods of normal MCNP runs and using the midway method. The performed comparative analyses show that the midway method appears to be much more efficient than the standard techniques in an overwhelming majority of cases and can be recommended for use in many difficult variance reduction problems of neutral particle transport.

Serov, I.V.; John, T.M.; Hoogenboom, J.E. [Delft Univ. of Technology (Netherlands). Interfaculty Reactor Inst.

1999-09-01T23:59:59.000Z

338

Coupled forward-adjoint monte carlo simulations of radiative transport for the study of optical probe design in heterogeneous tissues  

E-Print Network [OSTI]

A new e?ective Monte Carlo midway coupling method in MCNPand J. E. Hoogenboom, A midway forward-adjoint couplingand described the “midway” forward- adjoint coupling method

Hayakawa, Carole K.; Spanier, Jerome; Venugopalan, Vasan

2007-01-01T23:59:59.000Z

339

Tests of Monte Carlo Independent Column Approximation With a Mixed-Layer Ocean Model  

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

Tests of Monte Carlo Independent Column Tests of Monte Carlo Independent Column Approximation With a Mixed-Layer Ocean Model Petri Simo Järvenoja Heikki Järvinen Räisänen Finnish Meteorological Institute Figure 1. Root-mean-square sampling errors in local instant- aneous total (LW+SW) net flux at the surface and total radiative heating rate for the 1COL, CLDS, and REF approaches. Global rms values are given at the upper right hand corner of the plots. 1. Introduction The Monte Carlo Independent Column Approximation (McICA) separates the description of unresolved cloud structure from the radiative transfer solver very flexible ! unbiased with respect to ICA ! However, the radiative fluxes and heating rates contain conditional random errors ("McICA noise"). ? The topic of this poster: All previous tests of McICA

340

Tests of Monte Carlo Independent Column Approximation in the ECHAM5  

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

Tests of Monte Carlo Independent Column Approximation in the ECHAM5 Tests of Monte Carlo Independent Column Approximation in the ECHAM5 Atmospheric GCM Raisanen, Petri Finnish Meteoroligical Institute Jarvenoja, Simo Finnish Meteorological Institute Jarvinen, Heikki Finnish Meteorological Institute Category: Modeling The Monte Carlo Independent Column Approximation (McICA) was recently introduced as a new approach for parametrizing broadband radiative fluxes in global climate models (GCMs). The McICA allows a flexible description of unresolved cloud structure, and it is unbiased with respect to the full ICA, but its results contain conditional random errors (i.e., noise). In this work, McICA and a stochastic cloud generator have been implemented to the Max Planck Institute for Meteorology's ECHAM5 atmospheric GCM. The

Note: This page contains sample records for the topic "mont belvieu spot" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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341

A Proposal for a Standard Interface Between Monte Carlo Tools And One-Loop Programs  

SciTech Connect (OSTI)

Many highly developed Monte Carlo tools for the evaluation of cross sections based on tree matrix elements exist and are used by experimental collaborations in high energy physics. As the evaluation of one-loop matrix elements has recently been undergoing enormous progress, the combination of one-loop matrix elements with existing Monte Carlo tools is on the horizon. This would lead to phenomenological predictions at the next-to-leading order level. This note summarises the discussion of the next-to-leading order multi-leg (NLM) working group on this issue which has been taking place during the workshop on Physics at TeV Colliders at Les Houches, France, in June 2009. The result is a proposal for a standard interface between Monte Carlo tools and one-loop matrix element programs.

Binoth, T.; /Edinburgh U.; Boudjema, F.; /Annecy, LAPP; Dissertori, G.; Lazopoulos, A.; /Zurich, ETH; Denner, A.; /PSI, Villigen; Dittmaier, S.; /Freiburg U.; Frederix, R.; Greiner, N.; Hoeche, Stefan; /Zurich U.; Giele, W.; Skands, P.; Winter, J.; /Fermilab; Gleisberg, T.; /SLAC; Archibald, J.; Heinrich, G.; Krauss, F.; Maitre, D.; /Durham U., IPPP; Huber, M.; /Munich, Max Planck Inst.; Huston, J.; /Michigan State U.; Kauer, N.; /Royal Holloway, U. of London; Maltoni, F.; /Louvain U., CP3 /Milan Bicocca U. /INFN, Turin /Turin U. /Granada U., Theor. Phys. Astrophys. /CERN /NIKHEF, Amsterdam /Heidelberg U. /Oxford U., Theor. Phys.

2011-11-11T23:59:59.000Z

342

A proposal for a standard interface between Monte Carlo tools and one-loop programs  

SciTech Connect (OSTI)

Many highly developed Monte Carlo tools for the evaluation of cross sections based on tree matrix elements exist and are used by experimental collaborations in high energy physics. As the evaluation of one-loop matrix elements has recently been undergoing enormous progress, the combination of one-loop matrix elements with existing Monte Carlo tools is on the horizon. This would lead to phenomenological predictions at the next-to-leading order level. This note summarizes the discussion of the next-to-leading order multi-leg (NLM) working group on this issue which has been taking place during the workshop on Physics at TeV colliders at Les Houches, France, in June 2009. The result is a proposal for a standard interface between Monte Carlo tools and one-loop matrix element programs.

Binoth, T.; Boudjema, F.; Dissertori, G.; Lazopoulos, A.; Denner, A.; Dittmaier, S.; Frederix, R.; Greiner, N.; Hoche, S.; Giele, W.; Skands, P.

2010-01-01T23:59:59.000Z

343

Adjoint and forward Monte Carlo coupled weight window generator for variance reduction  

SciTech Connect (OSTI)

Among the various variance-reduction methods in Monte Carlo calculations, one of the most widely used techniques is the weight window method. The MCNP code provides a weight window generator (WWG) option. In WWG of MCNP, the importance of a cell is estimated by the virtual sampling method during normal Monte Carlo calculation. But, the performance of WWG tends to deteriorate in deep penetration problems. To enhance the performance of the weight window method, importance estimation by the deterministic adjoint calculation has been proposed. However, this approach is possible only when the related deterministic code and interface program are available. The midway coupling method is a surface tally technique that calculates detector response based on the reciprocity theorem, but it does not provide an importance generator. In this paper, a new weight window generation method, called adjoint and forward Monte Carlo coupled WWG, is proposed to overcome the drawbacks of the current WWG in MCNP and the deterministic adjoint calculation method.

Ahn, J.G.; Cho, N.Z.

2000-07-01T23:59:59.000Z

344

Calculation of radiation therapy dose using all particle Monte Carlo transport  

DOE Patents [OSTI]

The actual radiation dose absorbed in the body is calculated using three-dimensional Monte Carlo transport. Neutrons, protons, deuterons, tritons, helium-3, alpha particles, photons, electrons, and positrons are transported in a completely coupled manner, using this Monte Carlo All-Particle Method (MCAPM). The major elements of the invention include: computer hardware, user description of the patient, description of the radiation source, physical databases, Monte Carlo transport, and output of dose distributions. This facilitated the estimation of dose distributions on a Cartesian grid for neutrons, photons, electrons, positrons, and heavy charged-particles incident on any biological target, with resolutions ranging from microns to centimeters. Calculations can be extended to estimate dose distributions on general-geometry (non-Cartesian) grids for biological and/or non-biological media.

Chandler, William P. (Tracy, CA); Hartmann-Siantar, Christine L. (San Ramon, CA); Rathkopf, James A. (Livermore, CA)

1999-01-01T23:59:59.000Z

345

Magnetic properties of carbon doped CdS: A first-principles and Monte Carlo study  

Science Journals Connector (OSTI)

Carbon doping of CdS is studied using first-principles calculations and Monte Carlo simulation. Our calculations predict ferromagnetism in C doped CdS, resulting from carbon substitution of sulfur. A single carbon substitution of sulfur favors a spin-polarized state with a magnetic moment of 1.22?B. Ferromagnetic coupling is generally observed between these magnetic moments. A transition temperature of 270K is predicted through Monte Carlo simulation. The ferromagnetism of C doped CdS can be explained by the hole-mediated double exchange mechanism.

Hui Pan; Yuan Ping Feng; Qin Yun Wu; Zhi Gao Huang; Jianyi Lin

2008-03-13T23:59:59.000Z

346

Pseudo-random number generators for Monte Carlo simulations on Graphics Processing Units  

E-Print Network [OSTI]

Basic uniform pseudo-random number generators are implemented on ATI Graphics Processing Units (GPU). The performance results of the realized generators (multiplicative linear congruential (GGL), XOR-shift (XOR128), RANECU, RANMAR, RANLUX and Mersenne Twister (MT19937)) on CPU and GPU are discussed. The obtained speed-up factor is hundreds of times in comparison with CPU. RANLUX generator is found to be the most appropriate for using on GPU in Monte Carlo simulations. The brief review of the pseudo-random number generators used in modern software packages for Monte Carlo simulations in high-energy physics is present.

Demchik, Vadim

2010-01-01T23:59:59.000Z

347

Pseudo-random number generators for Monte Carlo simulations on Graphics Processing Units  

E-Print Network [OSTI]

Basic uniform pseudo-random number generators are implemented on ATI Graphics Processing Units (GPU). The performance results of the realized generators (multiplicative linear congruential (GGL), XOR-shift (XOR128), RANECU, RANMAR, RANLUX and Mersenne Twister (MT19937)) on CPU and GPU are discussed. The obtained speed-up factor is hundreds of times in comparison with CPU. RANLUX generator is found to be the most appropriate for using on GPU in Monte Carlo simulations. The brief review of the pseudo-random number generators used in modern software packages for Monte Carlo simulations in high-energy physics is present.

Vadim Demchik

2010-03-09T23:59:59.000Z

348

Improved convergence of Monte Carlo generated multi-group scattering moments  

SciTech Connect (OSTI)

This paper introduces an improved method of obtaining multi-group scattering moments from a Monte Carlo neutron transport code for use in deterministic transport solvers. The new method increases the information obtained from scattering events and therefore has more useful convergence characteristics than the currently used analog techniques. A prototype of the improved method was implemented in the OpenMC Monte Carlo transport code to compare the accuracy and convergence characteristics of the new method. The prototype showed that accuracy was retained (or improved) while increasing the figure-of-merit for the generation of multi-group scattering moments. (authors)

Nelson, A. G.; Martin, W. R. [University of Michigan, Department of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48104 (United States)

2013-07-01T23:59:59.000Z

349

Milagro Version 2 An Implicit Monte Carlo Code for Thermal Radiative Transfer: Capabilities, Development, and Usage  

SciTech Connect (OSTI)

We have released Version 2 of Milagro, an object-oriented, C++ code that performs radiative transfer using Fleck and Cummings' Implicit Monte Carlo method. Milagro, a part of the Jayenne program, is a stand-alone driver code used as a methods research vehicle and to verify its underlying classes. These underlying classes are used to construct Implicit Monte Carlo packages for external customers. Milagro-2 represents a design overhaul that allows better parallelism and extensibility. New features in Milagro-2 include verified momentum deposition, restart capability, graphics capability, exact energy conservation, and improved load balancing and parallel efficiency. A users' guide also describes how to configure, make, and run Milagro2.

T.J. Urbatsch; T.M. Evans

2006-02-15T23:59:59.000Z

350

A Monte Carlo synthetic-acceleration method for solving the thermal radiation diffusion equation  

SciTech Connect (OSTI)

We present a novel synthetic-acceleration-based Monte Carlo method for solving the equilibrium thermal radiation diffusion equation in three spatial dimensions. The algorithm performance is compared against traditional solution techniques using a Marshak benchmark problem and a more complex multiple material problem. Our results show that our Monte Carlo method is an effective solver for sparse matrix systems. For solutions converged to the same tolerance, it performs competitively with deterministic methods including preconditioned conjugate gradient and GMRES. We also discuss various aspects of preconditioning the method and its general applicability to broader classes of problems.

Evans, Thomas M., E-mail: evanstm@ornl.gov [Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States); Mosher, Scott W., E-mail: moshersw@ornl.gov [Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States); Slattery, Stuart R., E-mail: sslattery@wisc.edu [University of Wisconsin–Madison, 1500 Engineering Dr., Madison, WI 53716 (United States); Hamilton, Steven P., E-mail: hamiltonsp@ornl.gov [Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States)

2014-02-01T23:59:59.000Z

351

Monte Carlo study of a compressible Ising antiferromagnet on a triangular lattice Lei Gu and Bulbul Chakraborty  

E-Print Network [OSTI]

ARTICLES Monte Carlo study of a compressible Ising antiferromagnet on a triangular lattice Lei Gu the compressible antiferromagnetic Ising Model on a triangular lattice using Monte Carlo simulations. It is found broken symmetries: the Ising symmetry and a three-state Potts symmetry characteristic of the triangular

Garrido, Pedro L.

352

Inverted List Kinetic Monte Carlo with Rejection ap-plied to Directed Self-Assembly of Epitaxial Growth  

E-Print Network [OSTI]

Inverted List Kinetic Monte Carlo with Rejection ap- plied to Directed Self-Assembly of Epitaxial of subsequently deposited material using a kinetic Monte Carlo algorithm that combines the use of inverted lists finding is that the relative performance of the inverted list algorithm improves with increasing system

Schulze, Tim

353

Quasi-Monte Carlo simulation of the light environment of plants Mikolaj CieslakA,E,F  

E-Print Network [OSTI]

Quasi-Monte Carlo simulation of the light environment of plants Mikolaj CieslakA,E,F , Christiane-based CARIBU software (Chelle et al. 2004),and we showthat thesetwo programs produceconsistent results. Wealso assessed theperformance oftheRQMCpath tracing algorithm by comparing it with Monte Carlo path tracing

Prusinkiewicz, Przemyslaw

354

Large-scale simulations on multiple Graphics Processing Units (GPUs) for the direct simulation Monte Carlo method  

Science Journals Connector (OSTI)

In this study, the application of the two-dimensional direct simulation Monte Carlo (DSMC) method using an MPI-CUDA parallelization paradigm on Graphics Processing Units (GPUs) clusters is presented. An all-device (i.e. GPU) computational approach is ... Keywords: Graphics Processing Unit (GPU), MPI-CUDA, Parallel direct simulation Monte Carlo, Rarefied gas dynamics, Very large-scale simulation

C. -C. Su; M. R. Smith; F. -A. Kuo; J. -S. Wu; C. -W. Hsieh; K. -C. Tseng

2012-10-01T23:59:59.000Z

355

Energetics of carbon clusters C8 and C10 from all-electron quantum Monte Carlo calculations  

E-Print Network [OSTI]

Energetics of carbon clusters C8 and C10 from all-electron quantum Monte Carlo calculations Yuri calculations. The total electronic energies obtained are 0.4­1.2 hartrees lower than those of the lowest of the scaling of computational effort with the number of electrons Ne for these quantum Monte Carlo calculations

Anderson, James B.

356

Application of collision-based two dimensional Monte Carlo method in a simulated microscale ground water model  

E-Print Network [OSTI]

While the use of Monte Carlo method has been prevalent in nuclear engineering, it has yet to fully blossom in the study of solute transport in porous media. By using an etched-glass micromodel, an attempt is made to apply Monte Carlo method...

Chung, Kiwhan

2012-06-07T23:59:59.000Z

357

Monte-Carlo simulation of Ising droplets in correlated site-bond percolation  

E-Print Network [OSTI]

L-99 Monte-Carlo simulation of Ising droplets in correlated site-bond percolation D. Stauffer ordinateur la définition de Coniglio et Klein pour les gouttes du modèle Ising, sur les réseaux carré et doublé. Abstract. 2014 The definition of droplets in the Ising model by Coniglio and Klein

Paris-Sud XI, Université de

358

Ising nematic phase in ultrathin magnetic films: A Monte Carlo study Sergio A. Cannas,1,  

E-Print Network [OSTI]

Ising nematic phase in ultrathin magnetic films: A Monte Carlo study Sergio A. Cannas,1, * Mateus F-dimensional Ising model with competing ferromagnetic exchange and dipolar interactions, which models an ultrathin at different temperatures with an intermediate Ising nematic phase between the stripe and the tetragonal ones

Stariolo, Daniel Adrián

359

Simulating and Visualising Phase Transitions: Small-World Effects on the Monte Carlo Ising Model  

E-Print Network [OSTI]

Simulating and Visualising Phase Transitions: Small-World Effects on the Monte Carlo Ising Model K Science, Institute of Information & Mathematical Sciences, Massey University, Albany The Ising Model Many temperature and the material becomes magnetic. A simulation model such as the Ising model has been widely used

Hawick, Ken

360

Monte-Carlo Simulations of Linear Polarization in Clumpy OB-Star Winds  

E-Print Network [OSTI]

Monte-Carlo Simulations of Linear Polarization in Clumpy OB-Star Winds Rich Townsend & Nick Mast Department of Astronomy, University of Wisconsin-Madison Observations of linear polarization in OB-star winds can in principle be used to constrain the characteristics of wind clumping. However, models exploring

Townsend, Richard

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


361

MONT 109N Mathematics Across Cultures Discussion/Problem Set 5 Indian Mathematics  

E-Print Network [OSTI]

MONT 109N ­ Mathematics Across Cultures Discussion/Problem Set 5 ­ Indian Mathematics April 8, 2011 Background and Assignment In this assignment, we want to look at a sample of Indian mathematics from. Use the formula above to express 17 + 240 as a sum of two square roots. C. Probably the high point

Little, John B.

362

Path-Integral Monte Carlo And The Squeezed Trapped Bose-Einstein Gas  

E-Print Network [OSTI]

Path-Integral Monte Carlo And The Squeezed Trapped Bose-Einstein Gas Juan Pablo Fernández1 the gas becomes effectively two-dimensional (2D). We confirm the plausibility of this result by performing different estimates for the condensate fraction. For the ideal gas, we find that the PIMC column density

Mullin, William J.

363

Quantum Monte Carlo for large chemical systems: Implementing efficient strategies for petascale platforms and beyond  

E-Print Network [OSTI]

Quantum Monte Carlo for large chemical systems: Implementing efficient strategies for petascale platforms and beyond Anthony Scemama, Michel Caffarel Laboratoire de Chimie et Physique Quantiques, CNRS efficiently QMC simulations for large chemical systems are pre- sented. These include: i.) the introduction

Paris-Sud XI, Université de

364

Passive revolution in the green economy: activism and the Belo Monte dam  

Science Journals Connector (OSTI)

Belo Monte is slated to be the world’s third largest dam, and it is Brazil’s largest infrastructure project, at a cost of at least USD 13 billion. It is forecast to produce around 11,000 GW of energy

Eve Bratman

2014-11-01T23:59:59.000Z

365

Multi-level Monte-Carlo Wiener-Hopf simulation for Lvy processes.  

E-Print Network [OSTI]

Multi-level Monte-Carlo Wiener-Hopf simulation for Lévy processes. Andreas Kyprianou University of Bath Friday May 23, 2014 15:00-16:00 Salle/Room PK-5115, Pavillon Président-Kennedy Building UQAM for a large family of Lévy processes that is based on the Wiener-Hopf decomposition. We pursue this idea

Leclercq, Remi

366

Monte Carlo Electromagnetic Cross Section Production Method for Low Energy Charged Particle Transport Through Single Molecules  

E-Print Network [OSTI]

to the many-body Schrödinger equation and proceeds to use Monte Carlo methods to calculate the perturbations in the internal electron field to determine the aforementioned processes. Results are computed for molecular water in the form of linear energy loss...

Madsen, Jonathan R

2013-08-13T23:59:59.000Z

367

A Java-Based Direct Monte Carlo Simulation of a Nano-Scale Pulse Detonation Engine  

E-Print Network [OSTI]

A Java-Based Direct Monte Carlo Simulation of a Nano- Scale Pulse Detonation Engine Darryl J. Here, the pulse detonation engine is proposed as a means of propulsion for micro-air vehicles and nano attempting to implement the pulse detonation engine at such small length scales is the dominance of the wall

368

Composition of Fish Communities in a European Macrotidal Salt Marsh (the Mont Saint-Michel Bay,  

E-Print Network [OSTI]

Composition of Fish Communities in a European Macrotidal Salt Marsh (the Mont Saint-Michel Bay At least 100 fish species are known to be present in the intertidal areas (estuaries, mudflats and salt, such as estuaries and lagoons, play a nursery role for many fish species. However, in Europe little attention has

Boyer, Edmond

369

Dose point kernel simulation for monoenergetic electrons and radionuclides using Monte Carlo techniques  

Science Journals Connector (OSTI)

......Figure-1. Scaled DPKs in water calculated using MCNP5...Figure-2. Scaled DPKs in water calculated using MCNP5...from LHC to ICARUS and atmospheric showers. (1997) Proceedings...dose point kernels in water generated by the Monte...database, random number generator and statistical error......

J. Wu; Y. L. Liu; S. J. Chang; M. M. Chao; S. Y. Tsai; D. E. Huang

2012-11-01T23:59:59.000Z

370

Monte-Carlo simulations of light propagation in luminescent solar concentrators based on semiconductor nanoparticles  

E-Print Network [OSTI]

wavelengths, which can be more efficiently converted to electricity by a PV cell. To achieve this, most-remission events. This is also a big advantage over conventional single material semiconductor nanopar- ticles of semiconductor-based LSCs in detail we employ Monte Carlo simulations (see Sec. II) using the measured data

Ilan, Boaz

371

Monte Carlo simulation methodology of the ghost interface theory for the planar surface tension  

E-Print Network [OSTI]

Monte Carlo simulation methodology of the ghost interface theory for the planar surface tension October 2003 A novel ``ghost interface'' expression for the surface tension of a planar liquid coexisting phases. Results generated from the ghost interface theory for the surface tension are presented

Attard, Phil

372

Monte Carlo Estimation of Time Mismatch Effect in an OFDM EER Architecture  

E-Print Network [OSTI]

Monte Carlo Estimation of Time Mismatch Effect in an OFDM EER Architecture J-F.Bercher, A.Diet, C technique due to non-linearities of the power amplification operation. EER architecture can be used to solve-linearities in the radio- frequency transmitter. Linearization methods are necessary. EER (Envelope Elimination

Baudoin, Geneviève

373

Quasi-Monte Carlo Simulation of the Light Environment of Plants Mikolaj Cieslak1,5  

E-Print Network [OSTI]

Quasi-Monte Carlo Simulation of the Light Environment of Plants Mikolaj Cieslak1,5 , Christiane and Food Research Institute of New Zealand Limited Running Title: QMC Simulation of the Light Environment. In this paper, we will outline the RQMC path tracing algorithm that we use in our light environment program

Lemieux, Christiane

374

Uncertainty of Oil Field GHG Emissions Resulting from Information Gaps: A Monte Carlo Approach  

Science Journals Connector (OSTI)

Uncertainty of Oil Field GHG Emissions Resulting from Information Gaps: A Monte Carlo Approach ... Regulations on greenhouse gas (GHG) emissions from liquid fuel production generally work with incomplete data about oil production operations. ... We study the effect of incomplete information on estimates of GHG emissions from oil production operations. ...

Kourosh Vafi; Adam R. Brandt

2014-08-10T23:59:59.000Z

375

Use of single scatter electron monte carlo transport for medical radiation sciences  

DOE Patents [OSTI]

The single scatter Monte Carlo code CREEP models precise microscopic interactions of electrons with matter to enhance physical understanding of radiation sciences. It is designed to simulate electrons in any medium, including materials important for biological studies. It simulates each interaction individually by sampling from a library which contains accurate information over a broad range of energies.

Svatos, Michelle M. (Oakland, CA)

2001-01-01T23:59:59.000Z

376

Monte Carlo Study of the Spin Transport in Magnetic Materials , K. Akablia,b  

E-Print Network [OSTI]

Monte Carlo Study of the Spin Transport in Magnetic Materials Y. Magnina , K. Akablia,b , H. T of Natural Science and Technology, Okayama University 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.. Abstract The resistivity in magnetic materials has been theoretically shown to depend on the spin

377

VIM Monte Carlo versus CASMO comparisons for BWR advanced fuel designs  

SciTech Connect (OSTI)

Eigenvalues and two-dimensional fission rate distributions computed with the CASMO-3G lattice physics code and the VIM Monte Carlo Code are compared. The cases assessed are two advanced commercial BWR pin bundle designs. Generally, the two codes show good agreement in K{sub inf}, fission rate distributions, and control rod worths.

Pallotta, A.S. [Commonwealth Edison Co., Chicago, IL (United States); Blomquist, R.N. [Argonne National Lab., IL (United States)

1994-03-01T23:59:59.000Z

378

Quantum Monte Carlo calculations of electronic excitation energies: the case of the singlet n  

E-Print Network [OSTI]

) transition in acrolein Julien Toulouse1 , Michel Caffarel2 , Peter Reinhardt1 , Philip E. Hoggan3 , and C. J-of-the-art quantum Monte Carlo calculations of the singlet n (CO) vertical excitation energy in the acrolein in the acrolein molecule without reoptimization of the determinantal part of the wave function. The acrolein

Paris-Sud XI, Université de

379

Monte Carlo Simulation of Electromagnetic Interactions of Radiation with Liquid Water in  

E-Print Network [OSTI]

; nevertheless the concept of dose is not adequate to estimate the radiation effects when microscopic entitiesMonte Carlo Simulation of Electromagnetic Interactions of Radiation with Liquid Water. They address a physics domain relevant to the simulation of radiation effects in biological systems, where

Paris-Sud XI, Université de

380

Monte Carlo calculations of pair production in high-intensity laser-plasma interactions  

E-Print Network [OSTI]

Gamma-ray and electron-positron pair production will figure prominently in laser-plasma experiments with next generation lasers. Using a Monte Carlo approach we show that straggling effects arising from the finite recoil an electron experiences when it emits a high energy photon, increase the number of pairs produced on further interaction with the laser fields.

Roland Duclous; John Kirk; Anthony Bell

2010-10-21T23:59:59.000Z

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


381

Monte Carlo Characterization of a Pulsed Laser-Wakefield Driven Monochromatic  

E-Print Network [OSTI]

Monte Carlo Characterization of a Pulsed Laser-Wakefield Driven Monochromatic X-Ray Source S. D determination of the incident X-ray energy by using unfolding techniques. I. INTRODUCTION HE Diocles laser light from the same laser system, producing monochromatic X-rays with energy and spectral width

Umstadter, Donald

382

Direct Simulation Monte Carlo of Inductively Coupled Plasma and Comparison with Experiments  

E-Print Network [OSTI]

Direct Simulation Monte Carlo of Inductively Coupled Plasma and Comparison with Experiments Justine of Chemical Engineering, University of Houston, Houston, Texas 77204-4 792, USA ABSTRACT Direct simulation-density inductively coupled reactor with chlorine (electronegative) chemistry. Electron density and temperature were

Economou, Demetre J.

383

Optimisation of masked ion irradiation damage profiles in YBCO thin films by Monte Carlo simulation  

E-Print Network [OSTI]

Optimisation of masked ion irradiation damage profiles in YBCO thin films by Monte Carlo simulation production with a given mask structure. The results suggest that minimum ion scattering broadening tails with beam energy up to a few hundred keV, though the throughput is intrinsically low [1]. A combination

Webb, Roger P.

384

Interactive design of neutron beam collimators using the Monte Carlo technique in APL  

Science Journals Connector (OSTI)

The scattering and absorption of a neutron beam in a system of collimation rings is simulated step by step under user's control. In the APL notation, the expression of a parallel Monte Carlo simulation scheme is straightforward. Coupled with a fullscreen ...

C. Bastian

1982-07-01T23:59:59.000Z

385

Collective enhancement of nuclear state densities by the shell model Monte Carlo approach  

E-Print Network [OSTI]

The shell model Monte Carlo (SMMC) approach allows for the microscopic calculation of statistical and collective properties of heavy nuclei using the framework of the configuration-interaction shell model in very large model spaces. We present recent applications of the SMMC method to the calculation of state densities and their collective enhancement factors in rare-earth nuclei.

Özen, C; Nakada, H

2015-01-01T23:59:59.000Z

386

The effects of mapping CT images to Monte Carlo materials on GEANT4 proton simulation accuracy  

SciTech Connect (OSTI)

Purpose: Monte Carlo simulations of radiation therapy require conversion from Hounsfield units (HU) in CT images to an exact tissue composition and density. The number of discrete densities (or density bins) used in this mapping affects the simulation accuracy, execution time, and memory usage in GEANT4 and other Monte Carlo code. The relationship between the number of density bins and CT noise was examined in general for all simulations that use HU conversion to density. Additionally, the effect of this on simulation accuracy was examined for proton radiation. Methods: Relative uncertainty from CT noise was compared with uncertainty from density binning to determine an upper limit on the number of density bins required in the presence of CT noise. Error propagation analysis was also performed on continuously slowing down approximation range calculations to determine the proton range uncertainty caused by density binning. These results were verified with Monte Carlo simulations. Results: In the presence of even modest CT noise (5 HU or 0.5%) 450 density bins were found to only cause a 5% increase in the density uncertainty (i.e., 95% of density uncertainty from CT noise, 5% from binning). Larger numbers of density bins are not required as CT noise will prevent increased density accuracy; this applies across all types of Monte Carlo simulations. Examining uncertainty in proton range, only 127 density bins are required for a proton range error of <0.1 mm in most tissue and <0.5 mm in low density tissue (e.g., lung). Conclusions: By considering CT noise and actual range uncertainty, the number of required density bins can be restricted to a very modest 127 depending on the application. Reducing the number of density bins provides large memory and execution time savings in GEANT4 and other Monte Carlo packages.

Barnes, Samuel; McAuley, Grant; Slater, James [Department of Radiation Medicine, Loma Linda University, Loma Linda, California 92350 (United States); Wroe, Andrew [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92350 (United States)

2013-04-15T23:59:59.000Z

387

Operational Experiences Tuning the ATF2 Final Focus Optics Towards Obtaining a 37nm Electron Beam IP Spot Size  

SciTech Connect (OSTI)

The primary aim of the ATF2 research accelerator is to test a scaled version of the final focus optics planned for use in next-generation linear lepton colliders. ATF2 consists of a 1.3 GeV linac, damping ring providing low-emittance electron beams (< 12pm in the vertical plane), extraction line and final focus optics. The design details of the final focus optics and implementation at ATF2 are presented elsewhere. The ATF2 accelerator is currently being commissioned, with a staged approach to achieving the design IP spot size. It is expected that as we implement more demanding optics and reduce the vertical beta function at the IP, the tuning becomes more difficult and takes longer. We present here a description of the implementation of the tuning procedures and describe operational experiences and performances.

White, Glen; /SLAC; Seryi, Andrei; /SLAC; Woodley, Mark; /SLAC; Bai, Sha; /Beijing, Inst. High Energy Phys.; Bambade, Philip; /Orsay, LAL; Renier, Yves; /Orsay, LAL; Bolzon, Benoit; /Annecy, LAPP; Kamiya, Yoshio; /Tokyo U., ICEPP; Komamiya, Sachio; /Tokyo U.; Oroku, Masahiro; /Tokyo U.; Yamaguchi, Yohei; /Tokyo U.; Yamanaka, Takashi; /Tokyo U.; Kubo, Kiyoshi; /KEK, Tsukuba; Kuroda, Shigeru; /KEK, Tsukuba; Okugi, Toshiyuki; /KEK, Tsukuba; Tauchi, Toshiaki; /KEK, Tsukuba; Marin, Eduardo; /CERN

2012-07-06T23:59:59.000Z

388

Contamination by chlorinated pesticides, \\{PCBs\\} and \\{PBDEs\\} in Atlantic spotted dolphin (Stenella frontalis) in western South Atlantic  

Science Journals Connector (OSTI)

Chlorinated pesticides, \\{PCBs\\} and \\{PBDEs\\} were analysed in nine blubber samples of Atlantic spotted dolphins, Stenella frontalis, incidentally captured during fishing operations in southern and southeastern Brazil between 2005 and 2007. The majority of compounds analysed were detected, suggesting widespread contamination over the region. Although the samples came from a location far from main coastal industrial areas, the results revealed an influence from such sources. Therefore, levels of \\{PCBs\\} (774–23 659 ng g?1 lipid wt.) and \\{PBDEs\\} (23–1326 ng g?1 lipid wt.) detected seem to be related to the movement of individuals throughout near-shore and offshore waters. The sample from a lactating female exhibited a lower level of contamination and a distinct pattern, indicating selective transfer favouring less lipophilic compounds.

Juliana Leonel; Satie Taniguchi; Dalton K. Sasaki; Mauro J. Cascaes; Patrick S. Dias; Silvina Botta; Marcos C. de O. Santos; Rosalinda C. Montone

2012-01-01T23:59:59.000Z

389

A predictive model of yellow spotted river turtle (Podocnemis unifilis) encounter rates at basking sites in lowland eastern Bolivia  

Science Journals Connector (OSTI)

Abstract This paper develops a model predicting encounter rates of the yellow-spotted river turtle (Podocnemis unifilis) based on human hunting pressure and an ecological classification of potential basking sites. We estimate Poisson regression models for turtles observed in basking surveys. Field surveys were conducted in eastern lowland Bolivia in 2000 and 2011. Our model predicts a significant correlation between turtle encounter rates and two ecological classifications – steep cliff with vegetation and muddy flats that we believe are important habitat types for these turtles. Additionally, our model supports the hypothesis that human population has a significant but less negative impact on observed turtle encounter rates. Analyses of turtle encounter rates and factors that influence it are critical for the conservation of P. unifilis turtles and the broader Amazonian ecological system.

Kristen Conway-Gómez; Michael Reibel; Christopher Mihiar

2014-01-01T23:59:59.000Z

390

Mechanical strength evaluation for Nd-YAG laser and electric resistance spot weld (ERSW) joint under multiaxial loading  

Science Journals Connector (OSTI)

This work presents a comparison between laser weld (LBW) and electric resistance spot weld (ERSW) processes used for assemblies of components in a body-in-white (BIW) at a world class automotive industry. It is carried out by evaluating the mechanical strength modeled both by experimental and numerical methods. An “Arcan” multiaxial test was designed and manufactured in order to enable 0°, 45° and 90° directional loadings. The welded specimens were uncoated low carbon steel sheets (Sy = 170 MPa) used currently at the automotive industry, with two different thicknesses: 0.80 and 1.20 mm. A numerical analysis was carried out using the finite element method (FEM) through LS-DYNA code.

Haroldo Akira Kavamura; Gilmar Ferreira Batalha

2008-01-01T23:59:59.000Z

391

In the OSTI Collections: Monte Carlo Methods | OSTI, US Dept of Energy,  

Office of Scientific and Technical Information (OSTI)

Monte Carlo Methods Monte Carlo Methods "The first thoughts and attempts I made ... were suggested by a question which occurred to me in 1946 as I was convalescing from an illness and playing solitaires. The question was what are the chances that a Canfield solitaire laid out with 52 cards will come out successfully? After spending a lot of time trying to estimate them by pure combinatorial calculations, I wondered whether a more practical method than 'abstract thinking' might not be to lay it out say one hundred times and simply observe and count the number of successful plays. This was already possible to envisage with the beginning of the new era of fast computers, and I immediately thought of problems of neutron diffusion and other questions of mathematical physics,

392

Monte-Carlo Simulations for the optimisation of a TOF-MIEZE Instrument  

E-Print Network [OSTI]

The MIEZE (Modulation of Intensity with Zero Effort) technique is a variant of neutron resonance spin echo (NRSE), which has proven to be a unique neutron scattering technique for measuring with high energy resolution in magnetic fields. Its limitations in terms of flight path differences have already been investigated analytically for neutron beams with vanishing divergence. In the present work Monte-Carlo simulations for quasi-elastic MIEZE experiments taking into account beam divergence as well as the sample dimensions are presented. One application of the MIEZE technique could be a dedicated NRSE-MIEZE instrument at the European Spallation Source (ESS) in Sweden. The optimisation of a particular design based on Montel mirror optics with the help of Monte Carlo simulations will be discussed here in detail.

Weber, T; Georgii, R; Häußler, W; Weichselbaumer, S; Böni, P; 10.1016/j.nima.2013.03.010

2013-01-01T23:59:59.000Z

393

Calculating alpha Eigenvalues in a Continuous-Energy Infinite Medium with Monte Carlo  

SciTech Connect (OSTI)

The {alpha} eigenvalue has implications for time-dependent problems where the system is sub- or supercritical. We present methods and results from calculating the {alpha}-eigenvalue spectrum for a continuous-energy infinite medium with a simplified Monte Carlo transport code. We formulate the {alpha}-eigenvalue problem, detail the Monte Carlo code physics, and provide verification and results. We have a method for calculating the {alpha}-eigenvalue spectrum in a continuous-energy infinite-medium. The continuous-time Markov process described by the transition rate matrix provides a way of obtaining the {alpha}-eigenvalue spectrum and kinetic modes. These are useful for the approximation of the time dependence of the system.

Betzler, Benjamin R. [Los Alamos National Laboratory; Kiedrowski, Brian C. [Los Alamos National Laboratory; Brown, Forrest B. [Los Alamos National Laboratory; Martin, William R. [Los Alamos National Laboratory

2012-09-04T23:59:59.000Z

394

Monte Carlo study of the performance of a time-of-flight multichopper spectrometer  

SciTech Connect (OSTI)

The Monte Carlo method is a powerful technique for neutron transport studies. While it has been applied for many years to the study of nuclear systems, there are few codes available for neutron transport in the optical regime. The recent surge of interest in so-called next generation spallation neutron sources and the desire to design new and optimized instruments for these facilities has led us to develop a Monte Carlo code geared toward the simulation of neutron scattering instruments. The time-of-flight multichopper spectrometer, of which IN5 at the ILL is the prototypical example, is the first spectrometer studied with the code. Some of the results of a comparison between the IN5 performance at a reactor and at a Long Pulse Spallation Source (LPSS) are summarized here.

Daemen, L.L.; Eckert, J.; Pynn, R. [and others

1995-12-01T23:59:59.000Z

395

A new effective Monte Carlo Midway coupling method in MCNP applied to a well logging problem  

Science Journals Connector (OSTI)

The background of the Midway forward–adjoint coupling method including the black absorber technique for efficient Monte Carlo determination of radiation detector responses is described. The method is implemented in the general purpose MCNP Monte Carlo code. The utilization of the method is fairly straightforward and does not require any substantial extra expertise. The method was applied to a standard neutron well logging porosity tool problem. The results exhibit reliability and high efficiency of the Midway method. For the studied problem the efficiency gain is considerably higher than for a normal forward calculation, which is already strongly optimized by weight-windows. No additional effort is required to adjust the Midway model if the position of the detector or the porosity of the formation is changed. Additionally, the Midway method can be used with other variance reduction techniques if extra gain in efficiency is desired.

I.V. Serov; T.M. John; J.E. Hoogenboom

1998-01-01T23:59:59.000Z

396

Study of Monte Carlo approach to experimental uncertainty propagation with MSTW 2008 PDFs  

E-Print Network [OSTI]

We investigate the Monte Carlo approach to propagation of experimental uncertainties within the context of the established "MSTW 2008" global analysis of parton distribution functions (PDFs) of the proton at next-to-leading order in the strong coupling. We show that the Monte Carlo approach using replicas of the original data gives PDF uncertainties in good agreement with the usual Hessian approach using the standard Delta(chi^2) = 1 criterion, then we explore potential parameterisation bias by increasing the number of free parameters, concluding that any parameterisation bias is likely to be small, with the exception of the valence-quark distributions at low momentum fractions x. We motivate the need for a larger tolerance, Delta(chi^2) > 1, by making fits to restricted data sets and idealised consistent or inconsistent pseudodata. Instead of using data replicas, we alternatively produce PDF sets randomly distributed according to the covariance matrix of fit parameters including appropriate tolerance values,...

Watt, G

2012-01-01T23:59:59.000Z

397

MCAMC: An Advanced Algorithm for Kinetic Monte Carlo Simulations: from Magnetization Switching to Protein Folding  

E-Print Network [OSTI]

We present the Monte Carlo with Absorbing Markov Chains (MCAMC) method for extremely long kinetic Monte Carlo simulations. The MCAMC algorithm does not modify the system dynamics. It is extremely useful for models with discrete state spaces when low-temperature simulations are desired. To illustrate the strengths and limitations of this algorithm we introduce a simple model involving random walkers on an energy landscape. This simple model has some of the characteristics of protein folding and could also be experimentally realizable in domain motion in nanoscale magnets. We find that even the simplest MCAMC algorithm can speed up calculations by many orders of magnitude. More complicated MCAMC simulations can gain further increases in speed by orders of magnitude.

M. A. Novotny; Shannon M. Wheeler

2002-11-02T23:59:59.000Z

398

Adaptive kinetic Monte Carlo simulation of methanol decomposition on Cu(100)  

SciTech Connect (OSTI)

The adaptive kinetic Monte Carlo method was used to calculate the dynamics of methanol decomposition on Cu(100) at room temperature over a time scale of minutes. Mechanisms of reaction were found using min-mode following saddle point searches based upon forces and energies from density functional theory. Rates of reaction were calculated with harmonic transition state theory. The dynamics followed a pathway from CH3-OH, CH3-O, CH2-O, CH-O and finally C-O. Our calculations confirm that methanol decomposition starts with breaking the O-H bond followed by breaking C-H bonds in the dehydrogenated intermediates until CO is produced. The bridge site on the Cu(100) surface is the active site for scissoring chemical bonds. Reaction intermediates are mobile on the surface which allows them to find this active reaction site. This study illustrates how the adaptive kinetic Monte Carlo method can model the dynamics of surface chemistry from first principles.

Xu, Lijun; Mei, Donghai; Henkelman, Graeme A.

2009-12-31T23:59:59.000Z

399

A comparison of maximum likelihood and other estimators of eigenvalues from several correlated Monte Carlo samples  

SciTech Connect (OSTI)

The maximum likelihood method for the multivariate normal distribution is applied to the case of several individual eigenvalues. Correlated Monte Carlo estimates of the eigenvalue are assumed to follow this prescription and aspects of the assumption are examined. Monte Carlo cell calculations using the SAM-CE and VIM codes for the TRX-1 and TRX-2 benchmark reactors, and SAM-CE full core results are analyzed with this method. Variance reductions of a few percent to a factor of 2 are obtained from maximum likelihood estimation as compared with the simple average and the minimum variance individual eigenvalue. The numerical results verify that the use of sample variances and correlation coefficients in place of the corresponding population statistics still leads to nearly minimum variance estimation for a sufficient number of histories and aggregates.

Beer, M.

1980-12-01T23:59:59.000Z

400

Photon energy absorption coefficients for nuclear track detectors using Geant4 Monte Carlo simulation  

Science Journals Connector (OSTI)

Abstract Geant4 Monte Carlo code simulations were used to solve experimental and theoretical complications for calculation of mass energy-absorption coefficients of elements, air, and compounds. The mass energy-absorption coefficients for nuclear track detectors were computed first time using Geant4 Monte Carlo code for energy 1 keV–20 MeV. Very good agreements for simulated results of mass energy-absorption coefficients for carbon, nitrogen, silicon, sodium iodide and nuclear track detectors were observed on comparison with the values reported in the literatures. Kerma relative to air for energy 1 keV–20 MeV and energy absorption buildup factors for energy 50 keV–10 MeV up to 10 mfp penetration depths of the selected nuclear track detectors were also calculated to evaluate the absorption of the gamma photons. Geant4 simulation can be utilized for estimation of mass energy-absorption coefficients in elements and composite materials.

Vishwanath P. Singh; M.E. Medhat; N.M. Badiger

2015-01-01T23:59:59.000Z

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


401

Geometric representations in the developmental Monte Carlo transport code MC21  

SciTech Connect (OSTI)

The geometry kernel of the developmental Monte Carlo transport code MC21 is designed as a combination of the geometry capabilities of several existing Monte Carlo codes. This combination of capabilities is intended to meet efficiently the general requirements associated with in-core design products and, at the same time, be flexible enough to support highly general geometric models. This paper provides a description of the different geometry representations of MC21 and outlines how the geometric data is stored internally through the use of Fortran-90 data structures. Finally, two alternative geometric representations of a published BWR unit assembly model are discussed. Results for the two representations are contrasted, including k-effective results, relative memory footprints, and relative computational speeds. While total memory footprint is not noticeably reduced, results show significant speed advantages of one representation. (authors)

Donovan, T. [KAPL, Inc. - A Lockheed Martin Company, Schenectady, NY (United States); Tyburski, L. [Bechtel Bettis, Inc., West Mifflin, PA (United States)

2006-07-01T23:59:59.000Z

402

Unbiased Reduced Density Matrices and Electronic Properties from Full Configuration Interaction Quantum Monte Carlo  

E-Print Network [OSTI]

Properties that are necessarily formulated within pure (symmetric) expectation values are difficult to calculate for projector quantum Monte Carlo approaches, but are critical in order to compute many of the important observable properties of electronic systems. Here, we investigate an approach for the sampling of unbiased reduced density matrices within the Full Configuration Interaction Quantum Monte Carlo dynamic, which requires only small computational overheads. This is achieved via an independent replica population of walkers in the dynamic, sampled alongside the original population. The resulting reduced density matrices are free from systematic error (beyond those present via constraints on the dynamic itself), and can be used to compute a variety of expectation values and properties, with rapid convergence to an exact limit. A quasi-variational energy estimate derived from these density matrices is proposed as an accurate alternative to the projected estimator for multiconfigurational wavefunctions, ...

Overy, Catherine; Blunt, N S; Shepherd, James; Cleland, Deidre; Alavi, Ali

2014-01-01T23:59:59.000Z

403

09-07-13 07:53More snapping turtles spotted in Ottawa: residents Page 1 sur 5http://www.cbc.ca/canada/ottawa/story/2009/07/10/ottawa-turtle-eggs-rideau.html#socialcomments  

E-Print Network [OSTI]

09-07-13 07:53More snapping turtles spotted in Ottawa: residents Page 1 sur 5http://www.cbc.ca/canada/ottawa/story/2009/07/10/ottawa-turtle-eggs-rideau.html#socialcomments More snapping turtles spotted in Ottawa the Rideau River say they've seen more snapping turtles since construction on the city's sewers began

Blouin-Demers, Gabriel

404

IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 38, NO. 6, JUNE 2002 665 Facet Reflectivity of a Spot-Size-Converter Integrated  

E-Print Network [OSTI]

of 7 dBm are observed at the fabricated SOA, which consists of a window length of 20 m, facet angle reflectivity, semiconductor op- tical amplifier, spot-size-converter, window. I. INTRODUCTION SEMICONDUCTOR) coating requires a quarter-wave film with a refractive index equal to the square root of the refractive

405

Research on patterns in the fluctuation of the co-movement between crude oil futures and spot prices: A complex network approach  

Science Journals Connector (OSTI)

Abstract The price of crude oil is fluctuating. Researchers focus on the fluctuation of crude oil prices or relationship between crude oil futures and spot prices. However, the relationship also presents fluctuation which draws our attention. This paper designed a complex network approach for examining the dynamics of the co-movement between crude oil futures and spot prices. We defined the co-movement modes by a coarse-graining procedure and analyzed the transformation characteristics between the modes by weighted complex network models and evolutionary models. We analyzed the parameters of these models by using the West Texas Intermediate crude oil future prices and the Daqing (China) crude oil spot prices from November 25, 2002 to March 22, 2011 as sample data. The results indicate that the co-movement modes of the crude oil futures and spot prices are clustered around a few critical modes during the evolution. The co-movement of the crude oil prices has the characteristic of grouping, and the conversion of the co-movement modes requires an average of 5–7 days. There are some important transitional phases in the evolution of prices, and the results validate the current trend of rising oil prices. This research may provide information for the oil price decision-making process, and more importantly, provides a new approach for examining the co-movement between variables.

Haizhong An; Xiangyun Gao; Wei Fang; Yinghui Ding; Weiqiong Zhong

2014-01-01T23:59:59.000Z

406

Original papers: Development of prototype automated variable rate sprayer for real-time spot-application of agrochemicals in wild blueberry fields  

Science Journals Connector (OSTI)

An automated prototype variable rate (VR) sprayer was developed for control of 8 individual nozzles on a 6.1m sprayer boom for in-season, site-specific application of agrochemicals on weeds. The sprayer boom was divided into 8 sections and mounted behind ... Keywords: Controllers, Herbicides, Precision agriculture, Sensors, Spot-application, Weeds

Qamar Uz Zaman; Travis J. Esau; Arnold W. Schumann; David C. Percival; Young Ki Chang; Scott M. Read; Aitazaz A. Farooque

2011-05-01T23:59:59.000Z

407

A comparison of automated land cover/use classification methods for a Texas bottomland hardwood system using lidar, spot-5, and ancillary data  

E-Print Network [OSTI]

decisions affecting these disappearing systems. SPOT-5 imagery from 2005 was combined with Light Detection and Ranging (LiDAR) data from 2006 and several ancillary datasets to map a portion of the bottomland hardwood system found in the Sulphur River Basin...

Vernon, Zachary Isaac

2009-05-15T23:59:59.000Z

408

Validation of a Monte Carlo Based Depletion Methodology Using HFIR Post-Irradiation Measurements  

SciTech Connect (OSTI)

Post-irradiation uranium isotopic atomic densities within the core of the High Flux Isotope Reactor (HFIR) were calculated and compared to uranium mass spectrographic data measured in the late 1960s and early 70s [1]. This study was performed in order to validate a Monte Carlo based depletion methodology for calculating the burn-up dependent nuclide inventory, specifically the post-irradiation uranium

Chandler, David [ORNL; Maldonado, G Ivan [ORNL; Primm, Trent [ORNL

2009-11-01T23:59:59.000Z

409

Hybrid Monte Carlo with Wilson Dirac operator on the Fermi GPU  

E-Print Network [OSTI]

In this article we present our implementation of a Hybrid Monte Carlo algorithm for Lattice Gauge Theory using two degenerate flavours of Wilson-Dirac fermions on a Fermi GPU. We find that using registers instead of global memory speeds up the code by almost an order of magnitude. To map the array variables to scalars, so that the compiler puts them in the registers, we use code generators. Our final program is more than 10 times faster than a generic single CPU.

Abhijit Chakrabarty; Pushan Majumdar

2012-07-10T23:59:59.000Z

410

SU?FF?T?109: Automation of Monte Carlo Simulations For A Proton Therapy System  

Science Journals Connector (OSTI)

Purpose: To develop a code system to automate the processes associated with Monte Carlo simulations of a clinical proton therapy system. Method and Materials: A software system was developed that accepts a clinical prescription (beam range range modulation and field size) and generates a complete Monte Carlo simulation input file that includes all major components in the M. D. Anderson passively scattered treatment head plus one of several user?selectable phantoms. The simulations are automatically submitted to a 130 dual?CPU cluster. Post processing scripts were also developed to analyze the simulation results and generate required configuration data for the Varian Eclipse treatment planning system. Quality assurance procedures such as design inspection unit test incremental integration test regression test and integration test were performed to ensure the code system produces correct results. The code system was written in mainly C language with some shell scripts and it runs on the LINUX operating system. Results: A code system has been developed to automatically generate MCNPX input files run simulations and perform post?processing of simulation results for a proton therapy system. The code system has been used to simulate dose profiles and generate required data for commissioning the M. D. Anderson proton therapy system. Over one thousand dose profiles were generated for different beam configurations by the code system in two months. Example beam data will be presented. Conclusion: The automated Monte Carlo code system has proved to be a useful tool for simulations of clinical applications in proton therapy. It allows for rapid modeling of proton therapy systems and the results of this study suggest that data from Monte Carlo simulations will play an increasingly prominent role in proton therapy projects i.e. pre?clinical design commissioning studies and routine clinical tasks.

Y Zheng; J Fontenot; N Koch

2006-01-01T23:59:59.000Z

411

The Metropolis Monte Carlo method with CUDA enabled Graphic Processing Units  

SciTech Connect (OSTI)

We present a CPU–GPU system for runtime acceleration of large molecular simulations using GPU computation and memory swaps. The memory architecture of the GPU can be used both as container for simulation data stored on the graphics card and as floating-point code target, providing an effective means for the manipulation of atomistic or molecular data on the GPU. To fully take advantage of this mechanism, efficient GPU realizations of algorithms used to perform atomistic and molecular simulations are essential. Our system implements a versatile molecular engine, including inter-molecule interactions and orientational variables for performing the Metropolis Monte Carlo (MMC) algorithm, which is one type of Markov chain Monte Carlo. By combining memory objects with floating-point code fragments we have implemented an MMC parallel engine that entirely avoids the communication time of molecular data at runtime. Our runtime acceleration system is a forerunner of a new class of CPU–GPU algorithms exploiting memory concepts combined with threading for avoiding bus bandwidth and communication. The testbed molecular system used here is a condensed phase system of oligopyrrole chains. A benchmark shows a size scaling speedup of 60 for systems with 210,000 pyrrole monomers. Our implementation can easily be combined with MPI to connect in parallel several CPU–GPU duets. -- Highlights: •We parallelize the Metropolis Monte Carlo (MMC) algorithm on one CPU—GPU duet. •The Adaptive Tempering Monte Carlo employs MMC and profits from this CPU—GPU implementation. •Our benchmark shows a size scaling-up speedup of 62 for systems with 225,000 particles. •The testbed involves a polymeric system of oligopyrroles in the condensed phase. •The CPU—GPU parallelization includes dipole—dipole and Mie—Jones classic potentials.

Hall, Clifford [Computational Materials Science Center, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States) [Computational Materials Science Center, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States); School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States); Ji, Weixiao [Computational Materials Science Center, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States)] [Computational Materials Science Center, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States); Blaisten-Barojas, Estela, E-mail: blaisten@gmu.edu [Computational Materials Science Center, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States) [Computational Materials Science Center, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States); School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States)

2014-02-01T23:59:59.000Z

412

Radiative transfer in the earth's atmosphere-ocean system using Monte Carlo techniques  

E-Print Network [OSTI]

are described in the next chapter. The books by Morgan and Hammersley and Handscomb describe the theory and some methods of variance reduction for general applications. One item that is required of any Monte Carlo simulation is a supply of randoni numbers... be checked through modification of the model since the same sequeiice of random numbers may be generated repeatedly. Discussions on the properties ot' random nuinbers and their generation may be found in the books by Morgan' and Hammersley and Handscomb...

Bradley, Paul Andrew

2012-06-07T23:59:59.000Z

413

Path-integral Monte Carlo calculation of the kinetic energy of condensed lithium  

Science Journals Connector (OSTI)

We report path-integral Monte Carlo calculations of the kinetic energy of condensed lithium for several temperatures in both the solid and liquid phases. The excess kinetic energy of lithium decreases from about 10.4% of the classical value at 300 K to 3.2% at 520 K indicating a very slow decay with temperature. A Wigner-Kirkwood perturbation treatment of quantum effects to order ?2 gives a satisfactory agreement with the path-integral results.

Claudia Filippi and David M. Ceperley

1998-01-01T23:59:59.000Z

414

Modular, object-oriented redesign of a large-scale Monte Carlo neutron transport program  

SciTech Connect (OSTI)

This paper describes the modular, object-oriented redesign of a large-scale Monte Carlo neutron transport program. This effort represents a complete 'white sheet of paper' rewrite of the code. In this paper, the motivation driving this project, the design objectives for the new version of the program, and the design choices and their consequences will be discussed. The design itself will also be described, including the important subsystems as well as the key classes within those subsystems.

Moskowitz, B.S.

2000-02-01T23:59:59.000Z

415

A unified Monte Carlo approach to fast neutron cross section data evaluation.  

SciTech Connect (OSTI)

A unified Monte Carlo (UMC) approach to fast neutron cross section data evaluation that incorporates both model-calculated and experimental information is described. The method is based on applications of Bayes Theorem and the Principle of Maximum Entropy as well as on fundamental definitions from probability theory. This report describes the formalism, discusses various practical considerations, and examines a few numerical examples in some detail.

Smith, D.; Nuclear Engineering Division

2008-03-03T23:59:59.000Z

416

Using exploratory data analysis modified Box Plots to enhance Monte Carlo simulated Range Estimating Decision Technology  

E-Print Network [OSTI]

of the thesis is written with the intent of reviewing some of the significant pieces of literature relating to Monte Carlo simulated REDT and exploratory data analysis Box Plots. In 1964 David Hertz published an article in the Harvard Business Review... entitled, "Risk Analysis in Capital Investment" (Hertz 1964). While this article does not directly discuss range estimating, it is the foundation for the current REDT theory. In his atticle, Hertz discussed the problems associated with estimating...

Clutter, David John

1992-01-01T23:59:59.000Z

417

Experimental validation and evaluation of uncertainty in the monte carlo modeling of electron irradiation of complex objects  

E-Print Network [OSTI]

Monte Carlo method is an invaluable tool in the field of radiation protection, used to calculate shielding effectiveness, as well as dose for medical applications. With few exceptions, most of the objects currently simulated have been homogeneous...

Tutt, Teresa Elizabeth

2009-05-15T23:59:59.000Z

418

Monte Carlo Simulation of Solid-State Thermionic Energy Conversion Devices Based on Non-Planar Heterostructure Interfaces  

Science Journals Connector (OSTI)

In this paper, electron emission from non-planar potential barrier structures is analyzed using a Monte Carlo electron transport model. Compared to the planar structures, about twice bigger emission current ca...

Z. Bian; A. Shakouri

2006-01-01T23:59:59.000Z

419

Monte Carlo Study of Patchy Nanostructures Self-Assembled from a Single Multiblock Chain  

E-Print Network [OSTI]

We present a lattice Monte Carlo simulation for a multiblock copolymer chain of length N=240 and microarchitecture $(10-10)_{12}$.The simulation was performed using the Monte Carlo method with the Metropolis algorithm. We measured average energy, heat capacity, the mean squared radius of gyration, and the histogram of cluster count distribution. Those quantities were investigated as a function of temperature and incompatibility between segments, quantified by parameter {\\omega}. We determined the temperature of the coil-globule transition and constructed the phase diagram exhibiting a variety of patchy nanostructures. The presented results yield a qualitative agreement with those of the off-lattice Monte Carlo method reported earlier, with a significant exception for small incompatibilities,{\\omega}, and low temperatures, where 3-cluster patchy nanostructures are observed in contrast to the 2-cluster structures observed for the off-lattice $(10-10)_{12}$ chain. We attribute this difference to a considerable stiffness of lattice chains in comparison to that of the off-lattice chains.

Jakub Krajniak; Michal Banaszak

2014-10-15T23:59:59.000Z

420

MC21 analysis of the nuclear energy agency Monte Carlo performance benchmark problem  

SciTech Connect (OSTI)

Due to the steadily decreasing cost and wider availability of large scale computing platforms, there is growing interest in the prospects for the use of Monte Carlo for reactor design calculations that are currently performed using few-group diffusion theory or other low-order methods. To facilitate the monitoring of the progress being made toward the goal of practical full-core reactor design calculations using Monte Carlo, a performance benchmark has been developed and made available through the Nuclear Energy Agency. A first analysis of this benchmark using the MC21 Monte Carlo code was reported on in 2010, and several practical difficulties were highlighted. In this paper, a newer version of MC21 that addresses some of these difficulties has been applied to the benchmark. In particular, the confidence-interval-determination method has been improved to eliminate source correlation bias, and a fission-source-weighting method has been implemented to provide a more uniform distribution of statistical uncertainties. In addition, the Forward-Weighted, Consistent-Adjoint-Driven Importance Sampling methodology has been applied to the benchmark problem. Results of several analyses using these methods are presented, as well as results from a very large calculation with statistical uncertainties that approach what is needed for design applications. (authors)

Kelly, D. J.; Sutton, T. M. [Knolls Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P. O. Box 1072, Schenectady, NY 12301-1072 (United States); Wilson, S. C. [Bertis Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P. O. Box 79, West Mifflin, PA 15122-0079 (United States)

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" from the National Library of EnergyBeta (NLEBeta).
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421

Spatial homogenization of thermal feedback regions in Monte Carlo reactor calculations  

SciTech Connect (OSTI)

An integrated thermal-hydraulic feedback module has previously been developed for the Monte Carlo transport solver, MC21. The module incorporates a flexible input format that allows the user to describe heat transfer and coolant flow paths within the geometric model at any level of spatial detail desired. The effect that the varying levels of spatial homogenization of thermal regions has on the accuracy of the Monte Carlo simulations is examined in this study. Six thermal feedback mappings are constructed from the same geometric model of the Calvert Cliffs core. The spatial homogenization of the thermal regions is varied, giving each scheme a different level of detail, and the adequacy of the spatial homogenization is determined based on the eigenvalue produced by each Monte Carlo calculation. The purpose of these numerical experiments is to determine the level of detail necessarily to accurately capture the thermal feedback effect on reactivity. Several different core models are considered: axial-flow only, axial and lateral flow, asymmetry due to control rod insertion, and fuel heating (temperature -dependent cross sections). The thermal results generated by the MC21 thermal feedback module are consistent with expectations. Based upon the numerical experiments conducted it is concluded that the amount of spatial detail necessary to accurately capture the feedback effect on reactivity is relatively small. Homogenization at the assembly level for the Calvert Cliffs PWR model results in a similar power defect to that calculated with individual pin-cells modeled as explicit thermal regions. (authors)

Hanna, B. R.; Gill, D. F.; Griesheimer, D. P. [Bertis Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P.O. Box 79, West Mifflin, PA 15122 (United States)

2012-07-01T23:59:59.000Z

422

Movable geometry and eigenvalue search capability in the MC21 Monte Carlo code  

SciTech Connect (OSTI)

A description of a robust and flexible movable geometry implementation in the Monte Carlo code MC21 is described along with a search algorithm that can be used in conjunction with the movable geometry capability to perform eigenvalue searches based on the position of some geometric component. The natural use of the combined movement and search capability is searching to critical through variation of control rod (or control drum) position. The movable geometry discussion provides the mathematical framework for moving surfaces in the MC21 combinatorial solid geometry description. A discussion of the interface between the movable geometry system and the user is also described, particularly the ability to create a hierarchy of movable groups. Combined with the hierarchical geometry description in MC21 the movable group framework provides a very powerful system for inline geometry modification. The eigenvalue search algorithm implemented in MC21 is also described. The foundations of this algorithm are a regula falsi search though several considerations are made in an effort to increase the efficiency of the algorithm for use with Monte Carlo. Specifically, criteria are developed to determine after each batch whether the Monte Carlo calculation should be continued, the search iteration can be rejected, or the search iteration has converged. These criteria seek to minimize the amount of time spent per iteration. Results for the regula falsi method are shown, illustrating that the method as implemented is indeed convergent and that the optimizations made ultimately reduce the total computational expense. (authors)

Gill, D. F.; Nease, B. R.; Griesheimer, D. P. [Bettis Atomic Power Laboratory, PO Box 79, West Mifflin, PA 15122 (United States)

2013-07-01T23:59:59.000Z

423

Multiphoton Monte Carlo event generator for Bhabha scattering at small angles  

Science Journals Connector (OSTI)

We describe in this paper the application of the theory of Yennie, Frautschi, and Suura (YFS) to construct a Monte Carlo (MC) event generator with multiple-photon production for Bhabha scattering at low angles. The respective generator provides the four-momenta of the electron and positron and of all soft and hard photons with a proper treatment of the phase space and conservation of the total four-momentum. The final-state electron and positron are assumed to be visible above some minimum angle with respect to the beams (double tag). The QED matrix element in the algorithm is taken according to the YFS exponentiation scheme. The Monte Carlo program will be helpful in luminosity determination at experiments at the SLAC Linear Collider and the CERN collider LEP; it takes into account QED O(?) and the leading higher-order corrections. The important difference with the existing MC procedures is that the minimum energy above which photons are generated may be set arbitrarily low. Sample Monte Carlo data are illustrated in our discussion.

Stanislaw Jadach and B. F. L. Ward

1989-12-01T23:59:59.000Z

424

MCNPX Monte Carlo burnup simulations of the isotope correlation experiments in the NPP obrigheim.  

SciTech Connect (OSTI)

This paper describes the simulation work of the Isotope Correlation Experiment (ICE) using the MCNPX Monte Carlo computer code package. The Monte Carlo simulation results are compared with the ICE-Experimental measurements for burnup up to 30 GWD/t. The comparison shows the good capabilities of the MCNPX computer code package for predicting the depletion of the uranium fuel and the buildup of the plutonium isotopes in a PWR thermal reactor. The Monte Carlo simulation results show also good agreements with the experimental data for calculating several long-lived and stable fission products. However, for the americium and curium actinides, it is difficult to judge the predication capabilities for these actinides due to the large uncertainties in the ICE-Experimental data. In the MCNPX numerical simulations, a pin cell model is utilized to simulate the fuel lattice of the nuclear power reactor. Temperature dependent libraries based on JEFF3.1 nuclear data files are utilized for the calculations. In addition, temperature dependent libraries based ENDF/B-VII nuclear data files are utilized and the obtained results are very close to the JEFF3.1 results, except for {approx}10% differences in the prediction of the minor actinide isotopes buildup.

Cao, Y.; Gohar, Y.; Broeders, C. (Nuclear Engineering Division); (Inst. for Neutron Physics and Reactor Technology)

2010-10-01T23:59:59.000Z

425

Monte Carlo depletion calculations using VESTA 2.1 new features and perspectives  

SciTech Connect (OSTI)

VESTA is a Monte Carlo depletion interface code that is currently under development at IRSN. With VESTA, the emphasis lies on both accuracy and performance, so that the code will be capable of providing accurate and complete answers in an acceptable amount of time compared to other Monte Carlo depletion codes. From its inception, VESTA is intended to be a generic interface code so that it will ultimately be capable of using any Monte-Carlo code or depletion module and that can be tailored to the users needs. A new version of the code (version 2.1.x) will be released in 2012. The most important additions to the code are a burn up dependent isomeric branching ratio treatment to improve the prediction of metastable nuclides such as {sup 242m}Am and the integration of the PHOENIX point depletion module (also developed at IRSN) to overcome some of the limitations of the ORIGEN 2.2 module. The task of extracting and visualising the basic results and also the calculation of physical quantities or other data that can be derived from the basic output provided by VESTA will be the task of the AURORA depletion analysis tool which will be released at the same time as VESTA 2.1.x. The experimental validation database was also extended for this new version and it now contains a total of 35 samples with chemical assay data and 34 assembly decay heat measurements. (authors)

Haeck, W.; Cochet, B.; Aguiar, L. [Institut de Radioprotection et de Surete Nucleaire IRSN, BP 17, 92262 Fontenay-aux-Roses Cedex (France)

2012-07-01T23:59:59.000Z

426

Characterization of plasma ion source utilizing anode spot with positively biased electrode for stable and high-current ion beam extraction  

SciTech Connect (OSTI)

The operating conditions of a rf plasma ion source utilizing a positively biased electrode have been investigated to develop a stably operating, high-current ion source. Ion beam characteristics such as currents and energies are measured and compared with bias currents by varying the bias voltages on the electrode immersed in the ambient rf plasma. Current-voltage curves of the bias electrode and photographs confirm that a small and dense plasma, so-called anode spot, is formed near an extraction aperture and plays a key role to enhance the performance of the plasma ion source. The ion beam currents from the anode spot are observed to be maximized at the optimum bias voltage near the knee of the characteristic current-voltage curve of the anode spot. Increased potential barrier to obstruct beam extraction is the reason for the reduction of the ion beam current in spite of the increased bias current indicating the density of the anode spot. The optimum bias voltage is measured to be lower at higher operating pressure, which is favorable for stable operation without severe sputtering damage on the electrode. The ion beam current can be further enhanced by increasing the power for the ambient plasma without increasing the bias voltage. In the same manner, noble gases with higher atomic number as a feedstock gas are preferable for extracting higher beam current more stably. Therefore, performance of the plasma ion source with a positively biased electrode can be enhanced by controlling the operating conditions of the anode spot in various manners.

Park, Yeong-Shin; Lee, Yuna; Chung, Kyoung-Jae; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2011-12-15T23:59:59.000Z

427

Measured and Monte Carlo calculated k{sub Q} factors: Accuracy and comparison  

SciTech Connect (OSTI)

Purpose: The journal Medical Physics recently published two papers that determine beam quality conversion factors, k{sub Q}, for large sets of ion chambers. In the first paper [McEwen Med. Phys. 37, 2179-2193 (2010)], k{sub Q} was determined experimentally, while the second paper [Muir and Rogers Med. Phys. 37, 5939-5950 (2010)] provides k{sub Q} factors calculated using Monte Carlo simulations. This work investigates a variety of additional consistency checks to verify the accuracy of the k{sub Q} factors determined in each publication and a comparison of the two data sets. Uncertainty introduced in calculated k{sub Q} factors by possible variation of W/e with beam energy is investigated further. Methods: The validity of the experimental set of k{sub Q} factors relies on the accuracy of the NE2571 reference chamber measurements to which k{sub Q} factors for all other ion chambers are correlated. The stability of NE2571 absorbed dose to water calibration coefficients is determined and comparison to other experimental k{sub Q} factors is analyzed. Reliability of Monte Carlo calculated k{sub Q} factors is assessed through comparison to other publications that provide Monte Carlo calculations of k{sub Q} as well as an analysis of the sleeve effect, the effect of cavity length and self-consistencies between graphite-walled Farmer-chambers. Comparison between the two data sets is given in terms of the percent difference between the k{sub Q} factors presented in both publications. Results: Monitoring of the absorbed dose calibration coefficients for the NE2571 chambers over a period of more than 15 yrs exhibit consistency at a level better than 0.1%. Agreement of the NE2571 k{sub Q} factors with a quadratic fit to all other experimental data from standards labs for the same chamber is observed within 0.3%. Monte Carlo calculated k{sub Q} factors are in good agreement with most other Monte Carlo calculated k{sub Q} factors. Expected results are observed for the sleeve effect and the effect of cavity length on k{sub Q}. The mean percent differences between experimental and Monte Carlo calculated k{sub Q} factors are -0.08, -0.07, and -0.23% for the Elekta 6, 10, and 25 MV nominal beam energies, respectively. An upper limit on the variation of W/e in photon beams from cobalt-60 to 25 MV is determined as 0.4% with 95% confidence. The combined uncertainty on Monte Carlo calculated k{sub Q} factors is reassessed and amounts to between 0.40 and 0.49% depending on the wall material of the chamber. Conclusions: Excellent agreement (mean percent difference of only 0.13% for the entire data set) between experimental and calculated k{sub Q} factors is observed. For some chambers, k{sub Q} is measured for only one chamber of each type--the level of agreement observed in this study would suggest that for those chambers the measured k{sub Q} values are generally representative of the chamber type.

Muir, B. R.; McEwen, M. R.; Rogers, D. W. O. [Ottawa Medical Physics Institute (OMPI), Ottawa Carleton Institute for Physics, Carleton University Campus, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada); Institute for National Measurement Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada); Ottawa Medical Physics Institute (OMPI), Ottawa Carleton Institute for Physics, Carleton University Campus, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada)

2011-08-15T23:59:59.000Z

428

Uranium Bioreduction Rates across Scales: Biogeochemical Hot Moments and Hot Spots during a Biostimulation Experiment at Rifle, Colorado  

SciTech Connect (OSTI)

We aim to understand the scale-dependent evolution of uranium bioreduction during a field experiment at a former uranium mill site near Rifle, Colorado. Acetate was injected to stimulate Fe-reducing bacteria (FeRB) and to immobilize aqueous U(VI) to insoluble U(IV). Bicarbonate was coinjected in half of the domain to mobilize sorbed U(VI). We used reactive transport modeling to integrate hydraulic and geochemical data and to quantify rates at the grid block (0.25 m) and experimental field scale (tens of meters). Although local rates varied by orders of magnitude in conjunction with biostimulation fronts propagating downstream, field-scale rates were dominated by those orders of magnitude higher rates at a few selected hot spots where Fe(III), U(VI), and FeRB were at their maxima in the vicinity of the injection wells. At particular locations, the hot moments with maximum rates negatively corresponded to their distance from the injection wells. Although bicarbonate injection enhanced local rates near the injection wells by a maximum of 39.4%, its effect at the field scale was limited to a maximum of 10.0%. We propose a rate-versus-measurement-length relationship (log R' = -0.63

Bao, Chen; Wu, Hongfei; Li, Li; Newcomer, Darrell R.; Long, Philip E.; Williams, Kenneth H.

2014-09-02T23:59:59.000Z

429

Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium–tritium implosions on OMEGA  

SciTech Connect (OSTI)

Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of ? ? 4, an implosion velocity of 3.8?×?10{sup 7}?cm/s, and a laser intensity of ?10{sup 15}?W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); and others

2014-05-15T23:59:59.000Z

430

The applicability of certain Monte Carlo methods to the analysis of interacting polymers  

SciTech Connect (OSTI)

The authors consider polymers, modeled as self-avoiding walks with interactions on a hexagonal lattice, and examine the applicability of certain Monte Carlo methods for estimating their mean properties at equilibrium. Specifically, the authors use the pivoting algorithm of Madras and Sokal and Metroplis rejection to locate the phase transition, which is known to occur at {beta}{sub crit} {approx} 0.99, and to recalculate the known value of the critical exponent {nu} {approx} 0.58 of the system for {beta} = {beta}{sub crit}. Although the pivoting-Metropolis algorithm works well for short walks (N < 300), for larger N the Metropolis criterion combined with the self-avoidance constraint lead to an unacceptably small acceptance fraction. In addition, the algorithm becomes effectively non-ergodic, getting trapped in valleys whose centers are local energy minima in phase space, leading to convergence towards different values of {nu}. The authors use a variety of tools, e.g. entropy estimation and histograms, to improve the results for large N, but they are only of limited effectiveness. Their estimate of {beta}{sub crit} using smaller values of N is 1.01 {+-} 0.01, and the estimate for {nu} at this value of {beta} is 0.59 {+-} 0.005. They conclude that even a seemingly simple system and a Monte Carlo algorithm which satisfies, in principle, ergodicity and detailed balance conditions, can in practice fail to sample phase space accurately and thus not allow accurate estimations of thermal averages. This should serve as a warning to people who use Monte Carlo methods in complicated polymer folding calculations. The structure of the phase space combined with the algorithm itself can lead to surprising behavior, and simply increasing the number of samples in the calculation does not necessarily lead to more accurate results.

Krapp, D.M. Jr. [Univ. of California, Berkeley, CA (United States)

1998-05-01T23:59:59.000Z

431

Charged-Particle Thermonuclear Reaction Rates: I. Monte Carlo Method and Statistical Distributions  

E-Print Network [OSTI]

A method based on Monte Carlo techniques is presented for evaluating thermonuclear reaction rates. We begin by reviewing commonly applied procedures and point out that reaction rates that have been reported up to now in the literature have no rigorous statistical meaning. Subsequently, we associate each nuclear physics quantity entering in the calculation of reaction rates with a specific probability density function, including Gaussian, lognormal and chi-squared distributions. Based on these probability density functions the total reaction rate is randomly sampled many times until the required statistical precision is achieved. This procedure results in a median (Monte Carlo) rate which agrees under certain conditions with the commonly reported recommended "classical" rate. In addition, we present at each temperature a low rate and a high rate, corresponding to the 0.16 and 0.84 quantiles of the cumulative reaction rate distribution. These quantities are in general different from the statistically meaningless "minimum" (or "lower limit") and "maximum" (or "upper limit") reaction rates which are commonly reported. Furthermore, we approximate the output reaction rate probability density function by a lognormal distribution and present, at each temperature, the lognormal parameters miu and sigma. The values of these quantities will be crucial for future Monte Carlo nucleosynthesis studies. Our new reaction rates, appropriate for bare nuclei in the laboratory, are tabulated in the second paper of this series (Paper II). The nuclear physics input used to derive our reaction rates is presented in the third paper of this series (Paper III). In the fourth paper of this series (Paper IV) we compare our new reaction rates to previous results.

Richard Longland; Christian Iliadis; Art Champagne; Joe Newton; Claudio Ugalde; Alain Coc; Ryan Fitzgerald

2010-04-23T23:59:59.000Z

432

SIM-RIBRAS: A Monte-Carlo simulation package for RIBRAS system  

SciTech Connect (OSTI)

SIM-RIBRAS is a Root-based Monte-Carlo simulation tool designed to help RIBRAS users on experience planning and experimental setup enhancing and caracterization. It is divided into two main programs: CineRIBRAS, aiming beam kinematics, and SolFocus, aiming beam optics. SIM-RIBRAS replaces other methods and programs used in the past, providing more complete and accurate results and requiring much less manual labour. Moreover, the user can easily make modifications in the codes, adequating it for specific requirements of an experiment.

Leistenschneider, E.; Lepine-Szily, A.; Lichtenthaeler, R. [Departamento de Fisica Nuclear, Instituto de Fisica, Universidade de Sao Paulo (Brazil)

2013-05-06T23:59:59.000Z

433

Introduction to the Latest Version of the Test-Particle Monte Carlo Code Molflow+  

E-Print Network [OSTI]

The Test-Particle Monte Carlo code Molflow+ is getting more and more attention from the scientific community needing detailed 3D calculations of vacuum in the molecular flow regime mainly, but not limited to, the particle accelerator field. Substantial changes, bug fixes, geometry-editing and modelling features, and computational speed improvements have been made to the code in the last couple of years. This paper will outline some of these new features, and show examples of applications to the design and analysis of vacuum systems at CERN and elsewhere.

Ady, M

2014-01-01T23:59:59.000Z

434

Determination of the interaction potential from the pair distribution function: An inverse Monte Carlo technique  

Science Journals Connector (OSTI)

In this work we present an efficient procedure to evaluate effective pair potentials compatible with “experimental” distribution functions using a Monte Carlo simulation scheme. Using computer simulation results for the pair distribution functions, we have applied the method to a Lennard-Jones fluid and to a model of liquid aluminum. In both cases the procedure was able to recover with high accuracy the actual interaction potential of the systems. Moreover, the procedure can easily incorporate additional information, for instance, thermodynamic properties, in order to improve the reliability of the results.

N. G. Almarza and E. Lomba

2003-07-03T23:59:59.000Z

435

Tomographic image of prompt gamma ray from boron neutron capture therapy: A Monte Carlo simulation study  

SciTech Connect (OSTI)

Purpose of paper is to confirm the feasibility of acquisition of three dimensional single photon emission computed tomography image from boron neutron capture therapy using Monte Carlo simulation. Prompt gamma ray (478?keV) was used to reconstruct image with ordered subsets expectation maximization method. From analysis of receiver operating characteristic curve, area under curve values of three boron regions were 0.738, 0.623, and 0.817. The differences between length of centers of two boron regions and distance of maximum count points were 0.3?cm, 1.6?cm, and 1.4?cm.

Yoon, Do-Kun; Jung, Joo-Young; Suk Suh, Tae, E-mail: suhsanta@catholic.ac.kr [Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul 505 (Korea, Republic of); Jo Hong, Key [Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, 300 Pasteur Drive, Stanford, California 94305 (United States)

2014-02-24T23:59:59.000Z

436

Monte-Carlo study of the phase transition in the AA-stacked bilayer graphene  

E-Print Network [OSTI]

Tight-binding model of the AA-stacked bilayer graphene with screened electron-electron interactions has been studied using the Hybrid Monte Carlo simulations on the original double-layer hexagonal lattice. Instantaneous screened Coulomb potential is taken into account using Hubbard-Stratonovich transformation. G-type antiferromagnetic ordering has been studied and the phase transition with spontaneous generation of the mass gap has been observed. Dependence of the antiferromagnetic condensate on the on-site electron-electron interaction is examined.

Nikolaev, A A

2014-01-01T23:59:59.000Z

437

Monte-Carlo study of the phase transition in the AA-stacked bilayer graphene  

E-Print Network [OSTI]

Tight-binding model of the AA-stacked bilayer graphene with screened electron-electron interactions has been studied using the Hybrid Monte Carlo simulations on the original double-layer hexagonal lattice. Instantaneous screened Coulomb potential is taken into account using Hubbard-Stratonovich transformation. G-type antiferromagnetic ordering has been studied and the phase transition with spontaneous generation of the mass gap has been observed. Dependence of the antiferromagnetic condensate on the on-site electron-electron interaction is examined.

A. A. Nikolaev; M. V. Ulybyshev

2014-12-03T23:59:59.000Z

438

3D Monte Carlo Modeling of the EEDF in Negative Hydrogen Ion Sources  

SciTech Connect (OSTI)

For optimization and accurate prediction of the amount of H{sup -} ion production in negative ion sources, analysis of electron energy distribution function (EEDF) is necessary. We are developing a numerical code which analyzes EEDF in tandem-type arc-discharge sources. It is a three-dimensional Monte Carlo simulation code with the realistic geometry and magnetic configuration. Coulomb collision between electrons is treated with 'Binary Collision' model and collisions with hydrogen species are treated with 'Null-collision (NC)' method. We have applied this code to the analysis of the JAEA 10 ampere negative ion source. The numerical result shows that the obtained EEDFs reasonably agree with experimental results.

Terasaki, R.; Hatayama, A.; Shibata, T. [Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Inoue, T. [Japan Atomic Energy Agency, 801-1 Mukouyama, Naka 311-0193 (Japan)

2011-09-26T23:59:59.000Z

439

A Monte Carlo implementation of the predictor-corrector Quasi-Static method  

SciTech Connect (OSTI)

The Quasi-Static method (QS) is a useful tool for solving reactor transients since it allows for larger time steps when updating neutron distributions. Because of the beneficial attributes of Monte Carlo (MC) methods (exact geometries and continuous energy treatment), it is desirable to develop a MC implementation for the QS method. In this work, the latest version of the QS method known as the Predictor-Corrector Quasi-Static method is implemented. Experiments utilizing two energy-groups provide results that show good agreement with analytical and reference solutions. The method as presented can easily be implemented in any continuous energy, arbitrary geometry, MC code. (authors)

Hackemack, M. W.; Ragusa, J. C. [Department of Nuclear Engineering, Texas A and M University, 337 Zachry Engineering Building, College Station, TX 77843 (United States); Griesheimer, D. P.; Pounders, J. M. [Bettis Atomic Laboratory, Bechtel Marine Propulsion Corporation, P.O. Box 79, West Mifflin, PA 15122 (United States)

2013-07-01T23:59:59.000Z

440

Role of collisional broadening in Monte Carlo simulations of terahertz quantum cascade lasers  

SciTech Connect (OSTI)

Using a generalized version of Fermi's golden rule, collisional broadening is self-consistently implemented into ensemble Monte Carlo carrier transport simulations, and its effect on the transport and optical properties of terahertz quantum cascade lasers is investigated. The inclusion of broadening yields improved agreement with the experiment, without a significant increase of the numerical load. Specifically, this effect is crucial for a correct modeling at low biases. In the lasing regime, broadening can lead to significantly reduced optical gain and output power, affecting the obtained current-voltage characteristics.

Matyas, Alpar; Lugli, Paolo; Jirauschek, Christian [Institute for Nanoelectronics, Technische Universitaet Muenchen, D-80333 Munich (Germany)] [Institute for Nanoelectronics, Technische Universitaet Muenchen, D-80333 Munich (Germany)

2013-01-07T23:59:59.000Z

Note: This page contains sample records for the topic "mont belvieu spot" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology  

SciTech Connect (OSTI)

Purpose: Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Methods: Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 {mu}m at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Results: Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy/min/A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 {mu}m. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 {mu}m. Conclusions: Monte Carlo simulations demonstrate that the proposed compact MRT system design is capable of delivering a sufficient dose rate and peak-to-valley ratio for small animal MRT studies.

Schreiber, Eric C.; Chang, Sha X. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

2012-08-15T23:59:59.000Z

442

Anisotropic transverse flow introduction in Monte Carlo generators for heavy ion collisions  

Science Journals Connector (OSTI)

Anisotropic transverse flow patterns that are observed in relativistic heavy ion collisions can be added to the available microscopic Monte Carlo event generators as a final state modification to the azimuthal angles of the particles, which are generated isotropically. The method proposed for this purpose by A. M. Poskanzer and S. A. Voloshin [Phys. Rev. C 58, 1671 (1998)] is valid only for small values of the Fourier coefficients vn and therefore it is not suitable for simulations with large values of anisotropy such as the ones predicted for Pb-Pb collisions at the LHC. We present here a possible solution to treat the cases of large anisotropies.

M. Masera; G. Ortona; M. G. Poghosyan; F. Prino

2009-06-26T23:59:59.000Z

443

Thermonuclear reaction rate of $^{18}$Ne($?$,$p$)$^{21}$Na from Monte-Carlo calculations  

E-Print Network [OSTI]

The $^{18}$Ne($\\alpha$,$p$)$^{21}$Na reaction impacts the break-out from the hot CNO-cycles to the $rp$-process in type I X-ray bursts. We present a revised thermonuclear reaction rate, which is based on the latest experimental data. The new rate is derived from Monte-Carlo calculations, taking into account the uncertainties of all nuclear physics input quantities. In addition, we present the reaction rate uncertainty and probability density versus temperature. Our results are also consistent with estimates obtained using different indirect approaches.

P. Mohr; R. Longland; C. Iliadis

2014-12-09T23:59:59.000Z

444

Thermonuclear reaction rate of $^{18}$Ne($?$,$p$)$^{21}$Na from Monte-Carlo calculations  

E-Print Network [OSTI]

The $^{18}$Ne($\\alpha$,$p$)$^{21}$Na reaction impacts the break-out from the hot CNO-cycles to the $rp$-process in type I X-ray bursts. We present a revised thermonuclear reaction rate, which is based on the latest experimental data. The new rate is derived from Monte-Carlo calculations, taking into account the uncertainties of all nuclear physics input quantities. In addition, we present the reaction rate uncertainty and probability density versus temperature. Our results are also consistent with estimates obtained using different indirect approaches.

P. Mohr; R. Longland; C. Iliadis

2014-12-14T23:59:59.000Z

445

Thermonuclear reaction rate of $^{18}$Ne($\\alpha$,$p$)$^{21}$Na from Monte-Carlo calculations  

E-Print Network [OSTI]

The $^{18}$Ne($\\alpha$,$p$)$^{21}$Na reaction impacts the break-out from the hot CNO-cycles to the $rp$-process in type I X-ray bursts. We present a revised thermonuclear reaction rate, which is based on the latest experimental data. The new rate is derived from Monte-Carlo calculations, taking into account the uncertainties of all nuclear physics input quantities. In addition, we present the reaction rate uncertainty and probability density versus temperature. Our results are also consistent with estimates obtained using different indirect approaches.

Mohr, P; Iliadis, C

2014-01-01T23:59:59.000Z

446

Transport anisotropy of the pnictides studied via Monte Carlo simulations of the Spin-Fermion model  

SciTech Connect (OSTI)

An undoped three-orbital spin-fermion model for the Fe-based superconductors is studied via Monte Carlo techniques in two-dimensional clusters. At low temperatures, the magnetic and one-particle spectral properties are in agreement with neutron and photoemission experiments. Our main results are the resistance versus temperature curves that display the same features observed in BaFe{sub 2}As{sub 2} detwinned single crystals (under uniaxial stress), including a low-temperature anisotropy between the two directions followed by a peak at the magnetic ordering temperature, that qualitatively appears related to short-range spin order and concomitant Fermi surface orbital order.

Liang, Shuhua [ORNL; Alvarez, Gonzalo [ORNL; Sen, Cengiz [ORNL; Moreo, Adriana [ORNL; Dagotto, Elbio R [ORNL

2012-01-01T23:59:59.000Z

447

Bayesian Modeling of Time Trends in Component Reliability Data via Markov Chain Monte Carlo Simulation  

SciTech Connect (OSTI)

Markov chain Monte Carlo (MCMC) techniques represent an extremely flexible and powerful approach to Bayesian modeling. This work illustrates the application of such techniques to time-dependent reliability of components with repair. The WinBUGS package is used to illustrate, via examples, how Bayesian techniques can be used for parametric statistical modeling of time-dependent component reliability. Additionally, the crucial, but often overlooked subject of model validation is discussed, and summary statistics for judging the model’s ability to replicate the observed data are developed, based on the posterior predictive distribution for the parameters of interest.

D. L. Kelly

2007-06-01T23:59:59.000Z

448

CoRoT's view on variable B8/9 stars: spots versus pulsations: Evidence for differential rotation in HD 174648  

E-Print Network [OSTI]

Context. There exist few variability studies of stars in the region in the Hertzsprung-Russell diagram between the A and B-star pulsational instability strips. With the aid of the high precision continuous measurements of the CoRoT space satellite, low amplitudes are more easily detected, making a study of this neglected region worthwhile. Aims. We collected a small sample of B stars observed by CoRoT to determine the origin of the different types of variability observed. Methods. We combine literature photometry and spectroscopy to measure the fundamental parameters of the stars in the sample, and compare asteroseismic modelling of the light curves with (differentially rotating) spotted star models. Results. We found strong evidence for the existence of spots and differential rotation in HD 174648, and formulated hypotheses for their origin. We show that the distinction between pulsations and rotational modulation is difficult to make solely based on the light curve, especially in slowly rotating stars.

Degroote, P; Samadi, R; Aerts, C; Kurtz, D W; Noels, A; Miglio, A; Montalban, J; Bloemen, S; Baglin, A; Baudin, F; Catala, C; Michel, E; Auvergne, M

2011-01-01T23:59:59.000Z

449

Plasmon Mapping in Metallic Nanostructures and its Application to Single Molecule Surface Enhanced Raman Scattering: Imaging Electromagnetic Hot-Spots and Analyte Location  

SciTech Connect (OSTI)

A major component of this proposal is to elucidate the connection between optical and electron excitation of plasmon modes in metallic nanostructures. These accomplishments are reported: developed a routine protocol for obtaining spatially resolved, low energy EELS spectra, and resonance Rayleigh scattering spectra from the same nanostructures.; correlated optical scattering spectra and plasmon maps obtained using STEM/EELS.; and imaged electromagnetic hot spots responsible for single-molecule surface-enhanced Raman scattering (SMSERS).

Camden, Jon P

2013-07-16T23:59:59.000Z

450

Estimation of organs doses and radiation-induced secondary cancer risk from scattered photons for conventional radiation therapy of nasopharynx: a Monte Carlo study  

Science Journals Connector (OSTI)

We used Monte Carlo modeling to calculate the organs doses due to out-of field photons during radiation therapy of the nasopharynx.

Asghar Mesbahi; Farshad Seyednejad; Amir Gasemi-Jangjoo

2010-06-01T23:59:59.000Z

451

Building A Simulation Model For The Prediction Of Temperature Distribution In Pulsed Laser Spot Welding Of Dissimilar Low Carbon Steel 1020 To Aluminum Alloy 6061  

SciTech Connect (OSTI)

This paper describes the development of a computer model used to analyze the heat flow during pulsed Nd: YAG laser spot welding of dissimilar metal; low carbon steel (1020) to aluminum alloy (6061). The model is built using ANSYS FLUENT 3.6 software where almost all the environments simulated to be similar to the experimental environments. A simulation analysis was implemented based on conduction heat transfer out of the key hole where no melting occurs. The effect of laser power and pulse duration was studied.Three peak powers 1, 1.66 and 2.5 kW were varied during pulsed laser spot welding (keeping the energy constant), also the effect of two pulse durations 4 and 8 ms (with constant peak power), on the transient temperature distribution and weld pool dimension were predicated using the present simulation. It was found that the present simulation model can give an indication for choosing the suitable laser parameters (i.e. pulse durations, peak power and interaction time required) during pulsed laser spot welding of dissimilar metals.

Yousef, Adel K. M. [Faculty of Engineering , University of Diyala, Diyala-Baqouba (Iraq); Taha, Ziad A.; Shehab, Abeer A. [Institute of laser for postgraduate studies, Baghdad University, Baghdad (Iraq)

2011-01-17T23:59:59.000Z

452

GUINEVERE experiment: Kinetic analysis of some reactivity measurement methods by deterministic and Monte Carlo codes  

SciTech Connect (OSTI)

The GUINEVERE experiment (Generation of Uninterrupted Intense Neutrons at the lead Venus Reactor) is an experimental program in support of the ADS technology presently carried out at SCK-CEN in Mol (Belgium). In the experiment a modified lay-out of the original thermal VENUS critical facility is coupled to an accelerator, built by the French body CNRS in Grenoble, working in both continuous and pulsed mode and delivering 14 MeV neutrons by bombardment of deuterons on a tritium-target. The modified lay-out of the facility consists of a fast subcritical core made of 30% U-235 enriched metallic Uranium in a lead matrix. Several off-line and on-line reactivity measurement techniques will be investigated during the experimental campaign. This report is focused on the simulation by deterministic (ERANOS French code) and Monte Carlo (MCNPX US code) calculations of three reactivity measurement techniques, Slope ({alpha}-fitting), Area-ratio and Source-jerk, applied to a GUINEVERE subcritical configuration (namely SC1). The inferred reactivity, in dollar units, by the Area-ratio method shows an overall agreement between the two deterministic and Monte Carlo computational approaches, whereas the MCNPX Source-jerk results are affected by large uncertainties and allow only partial conclusions about the comparison. Finally, no particular spatial dependence of the results is observed in the case of the GUINEVERE SC1 subcritical configuration. (authors)

Bianchini, G.; Burgio, N.; Carta, M. [ENEA C.R. CASACCIA, via Anguillarese, 301, 00123 S. Maria di Galeria Roma (Italy); Peluso, V. [ENEA C.R. BOLOGNA, Via Martiri di Monte Sole, 4, 40129 Bologna (Italy); Fabrizio, V.; Ricci, L. [Univ. of Rome La Sapienza, C/o ENEA C.R. CASACCIA, via Anguillarese, 301, 00123 S. Maria di Galeria Roma (Italy)

2012-07-01T23:59:59.000Z

453

Applications of FLUKA Monte Carlo Code for Nuclear and Accelerator Physics  

SciTech Connect (OSTI)

FLUKA is a general purpose Monte Carlo code capable of handling all radiation components from thermal energies (for neutrons) or 1 keV (for all other particles) to cosmic ray energies and can be applied in many different fields. Presently the code is maintained on Linux. The validity of the physical models implemented in FLUKA has been benchmarked against a variety of experimental data over a wide energy range, from accelerator data to cosmic ray showers in the Earth atmosphere. FLUKA is widely used for studies related both to basic research and to applications in particle accelerators, radiation protection and dosimetry, including the specific issue of radiation damage in space missions, radiobiology (including radiotherapy) and cosmic ray calculations. After a short description of the main features that make FLUKA valuable for these topics, the present paper summarizes some of the recent applications of the FLUKA Monte Carlo code in the nuclear as well high energy physics. In particular it addresses such topics as accelerator related applications.

Battistoni, Giuseppe; /INFN, Milan /Milan U.; Broggi, Francesco; /INFN, Milan /Milan U.; Brugger, Markus; /CERN; Campanella, Mauro; /INFN, Milan /Milan U.; Carboni, Massimo; /INFN, Legnaro; Empl, Anton; /Houston U.; Fasso, Alberto; /SLAC; Gadioli, Ettore; /INFN, Milan /Milan U.; Cerutti, Francesco; /CERN; Ferrari, Alfredo; /CERN; Ferrari, Anna; /Frascati; Lantz, Matthias; /Nishina Ctr., RIKEN; Mairani, Andrea; /INFN, Milan /Milan U.; Margiotta, M.; /INFN, Bologna /Bologna U.; Morone, Christina; /Rome U.,Tor Vergata /INFN, Rome2; Muraro, Silvia; /INFN, Milan /Milan U.; Parodi, Katerina; /HITS, Heidelberg; Patera, Vincenzo; /Frascati; Pelliccioni, Maurizio; /Frascati; Pinsky, Lawrence; /Houston U.; Ranft, Johannes; /Siegen U. /CERN /Seibersdorf, Reaktorzentrum /INFN, Milan /Milan U. /SLAC /INFN, Legnaro /INFN, Bologna /Bologna U. /CERN /HITS, Heidelberg /CERN /CERN /Frascati /CERN /CERN /CERN /CERN /NASA, Houston

2012-04-17T23:59:59.000Z

454

A Monte Carlo Study of Multiplicity Fluctuations in Pb-Pb Collisions at LHC Energies  

E-Print Network [OSTI]

With large volumes of data available from LHC, it has become possible to study the multiplicity distributions for the various possible behaviours of the multiparticle production in collisions of relativistic heavy ion collisions, where a system of dense and hot partons has been created. In this context it is important and interesting as well to check how well the Monte Carlo generators can describe the properties or the behaviour of multiparticle production processes. One such possible behaviour is the self-similarity in the particle production, which can be studied with the intermittency studies and further with chaoticity/erraticity, in the heavy ion collisions. We analyse the behaviour of erraticity index in central Pb-Pb collisions at centre of mass energy of 2.76 TeV per nucleon using the AMPT monte carlo event generator, following the recent proposal by R.C. Hwa and C.B. Yang, concerning the local multiplicity fluctuation study as a signature of critical hadronization in heavy-ion collisions. We report ...

Gupta, Ramni

2015-01-01T23:59:59.000Z

455

Nuclear data processing for energy release and deposition calculations in the MC21 Monte Carlo code  

SciTech Connect (OSTI)

With the recent emphasis in performing multiphysics calculations using Monte Carlo transport codes such as MC21, the need for accurate estimates of the energy deposition-and the subsequent heating - has increased. However, the availability and quality of data necessary to enable accurate neutron and photon energy deposition calculations can be an issue. A comprehensive method for handling the nuclear data required for energy deposition calculations in MC21 has been developed using the NDEX nuclear data processing system and leveraging the capabilities of NJOY. The method provides a collection of data to the MC21 Monte Carlo code supporting the computation of a wide variety of energy release and deposition tallies while also allowing calculations with different levels of fidelity to be performed. Detailed discussions on the usage of the various components of the energy release data are provided to demonstrate novel methods in borrowing photon production data, correcting for negative energy release quantities, and adjusting Q values when necessary to preserve energy balance. Since energy deposition within a reactor is a result of both neutron and photon interactions with materials, a discussion on the photon energy deposition data processing is also provided. (authors)

Trumbull, T. H. [Knolls Atomic Power Laboratory, PO Box 1072, Schenectady, NY 12301 (United States)

2013-07-01T23:59:59.000Z

456

Massively parallel Monte Carlo for many-particle simulations on GPUs  

SciTech Connect (OSTI)

Current trends in parallel processors call for the design of efficient massively parallel algorithms for scientific computing. Parallel algorithms for Monte Carlo simulations of thermodynamic ensembles of particles have received little attention because of the inherent serial nature of the statistical sampling. In this paper, we present a massively parallel method that obeys detailed balance and implement it for a system of hard disks on the GPU. We reproduce results of serial high-precision Monte Carlo runs to verify the method. This is a good test case because the hard disk equation of state over the range where the liquid transforms into the solid is particularly sensitive to small deviations away from the balance conditions. On a Tesla K20, our GPU implementation executes over one billion trial moves per second, which is 148 times faster than on a single Intel Xeon E5540 CPU core, enables 27 times better performance per dollar, and cuts energy usage by a factor of 13. With this improved performance we are able to calculate the equation of state for systems of up to one million hard disks. These large system sizes are required in order to probe the nature of the melting transition, which has been debated for the last forty years. In this paper we present the details of our computational method, and discuss the thermodynamics of hard disks separately in a companion paper.

Anderson, Joshua A.; Jankowski, Eric [Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Grubb, Thomas L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Engel, Michael [Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Glotzer, Sharon C., E-mail: sglotzer@umich.edu [Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

2013-12-01T23:59:59.000Z

457

Conformal field theories at non-zero temperature: operator product expansions, Monte Carlo, and holography  

E-Print Network [OSTI]

We compute the non-zero temperature conductivity of conserved flavor currents in conformal field theories (CFTs) in 2+1 spacetime dimensions. At frequencies much greater than the temperature, $\\hbar\\omega>> k_B T$, the $\\omega$ dependence can be computed from the operator product expansion (OPE) between the currents and operators which acquire a non-zero expectation value at T > 0. Such results are found to be in excellent agreement with quantum Monte Carlo studies of the O(2) Wilson-Fisher CFT. Results for the conductivity and other observables are also obtained in vector 1/N expansions. We match these large $\\omega$ results to the corresponding correlators of holographic representations of the CFT: the holographic approach then allows us to extrapolate to small $\\hbar \\omega/(k_B T)$. Other holographic studies implicitly only used the OPE between the currents and the energy-momentum tensor, and this yields the correct leading large $\\omega$ behavior for a large class of CFTs. However, for the Wilson-Fisher CFT a relevant "thermal" operator must also be considered, and then consistency with the Monte Carlo results is obtained without a previously needed ad hoc rescaling of the T value. We also establish sum rules obeyed by the conductivity of a wide class of CFTs.

Emanuel Katz; Subir Sachdev; Erik S. Sorensen; William Witczak-Krempa

2014-09-12T23:59:59.000Z

458

Study of Monte Carlo approach to experimental uncertainty propagation with MSTW 2008 PDFs  

E-Print Network [OSTI]

We investigate the Monte Carlo approach to propagation of experimental uncertainties within the context of the established "MSTW 2008" global analysis of parton distribution functions (PDFs) of the proton at next-to-leading order in the strong coupling. We show that the Monte Carlo approach using replicas of the original data gives PDF uncertainties in good agreement with the usual Hessian approach using the standard Delta(chi^2) = 1 criterion, then we explore potential parameterisation bias by increasing the number of free parameters, concluding that any parameterisation bias is likely to be small, with the exception of the valence-quark distributions at low momentum fractions x. We motivate the need for a larger tolerance, Delta(chi^2) > 1, by making fits to restricted data sets and idealised consistent or inconsistent pseudodata. Instead of using data replicas, we alternatively produce PDF sets randomly distributed according to the covariance matrix of fit parameters including appropriate tolerance values, then we demonstrate a simpler method to produce an arbitrary number of random predictions on-the-fly from the existing eigenvector PDF sets. Finally, as a simple example application, we use Bayesian reweighting to study the effect of recent LHC data on the lepton charge asymmetry from W boson decays.

G. Watt; R. S. Thorne

2012-05-17T23:59:59.000Z

459

Monte Carlo wave packet approach to dissociative multiple ionization in diatomic molecules  

SciTech Connect (OSTI)

A detailed description of the Monte Carlo wave packet technique applied to dissociative multiple ionization of diatomic molecules in short intense laser pulses is presented. The Monte Carlo wave packet technique relies on the Born-Oppenheimer separation of electronic and nuclear dynamics and provides a consistent theoretical framework for treating simultaneously both ionization and dissociation. By simulating the detection of continuum electrons and collapsing the system onto either the neutral, singly ionized or doubly ionized states in every time step the nuclear dynamics can be solved separately for each molecular charge state. Our model circumvents the solution of a multiparticle Schroedinger equation and makes it possible to extract the kinetic energy release spectrum via the Coulomb explosion channel as well as the physical origin of the different structures in the spectrum. The computational effort is restricted and the model is applicable to any molecular system where electronic Born-Oppenheimer curves, dipole moment functions, and ionization rates as a function of nuclear coordinates can be determined.

Leth, Henriette Astrup; Madsen, Lars Bojer; Moelmer, Klaus [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)

2010-05-15T23:59:59.000Z

460

Monte Carlo approach for hadron azimuthal correlations in high energy proton and nuclear collisions  

E-Print Network [OSTI]

We use a Monte Carlo approach to study hadron azimuthal angular correlations in high energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider (RHIC) energies at mid-rapidity. We build a hadron event generator that incorporates the production of $2\\to 2$ and $2\\to 3$ parton processes and their evolution into hadron states. For nucleus-nucleus collisions we include the effect of parton energy loss in the Quark-Gluon Plasma using a modified fragmentation function approach. In the presence of the medium, for the case when three partons are produced in the hard scattering, we analyze the Monte Carlo sample in parton and hadron momentum bins to reconstruct the angular correlations. We characterize this sample by the number of partons that are able to hadronize by fragmentation within the selected bins. In the nuclear environment the model allows hadronization by fragmentation only for partons with momentum above a threshold $p_T^{{\\tiny{thresh}}}=2.4$ GeV. We argue that...

Ayala, Alejandro; Jalilian-Marian, Jamal; Magnin, J; Tejeda-Yeomans, Maria Elena

2012-01-01T23:59:59.000Z

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461

Monte Carlo approach for hadron azimuthal correlations in high energy proton and nuclear collisions  

E-Print Network [OSTI]

We use a Monte Carlo approach to study hadron azimuthal angular correlations in high energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider (RHIC) energies at mid-rapidity. We build a hadron event generator that incorporates the production of $2\\to 2$ and $2\\to 3$ parton processes and their evolution into hadron states. For nucleus-nucleus collisions we include the effect of parton energy loss in the Quark-Gluon Plasma using a modified fragmentation function approach. In the presence of the medium, for the case when three partons are produced in the hard scattering, we analyze the Monte Carlo sample in parton and hadron momentum bins to reconstruct the angular correlations. We characterize this sample by the number of partons that are able to hadronize by fragmentation within the selected bins. In the nuclear environment the model allows hadronization by fragmentation only for partons with momentum above a threshold $p_T^{{\\tiny{thresh}}}=2.4$ GeV. We argue that one should treat properly the effect of those partons with momentum below the threshold, since their interaction with the medium may lead to showers of low momentum hadrons along the direction of motion of the original partons as the medium becomes diluted.

Alejandro Ayala; Isabel Dominguez; Jamal Jalilian-Marian; J. Magnin; Maria Elena Tejeda-Yeomans

2012-07-31T23:59:59.000Z

462

Energy density matrix formalism for interacting quantum systems: a quantum Monte Carlo study  

SciTech Connect (OSTI)

We develop an energy density matrix that parallels the one-body reduced density matrix (1RDM) for many-body quantum systems. Just as the density matrix gives access to the number density and occupation numbers, the energy density matrix yields the energy density and orbital occupation energies. The eigenvectors of the matrix provide a natural orbital partitioning of the energy density while the eigenvalues comprise a single particle energy spectrum obeying a total energy sum rule. For mean-field systems the energy density matrix recovers the exact spectrum. When correlation becomes important, the occupation energies resemble quasiparticle energies in some respects. We explore the occupation energy spectrum for the finite 3D homogeneous electron gas in the metallic regime and an isolated oxygen atom with ground state quantum Monte Carlo techniques imple- mented in the QMCPACK simulation code. The occupation energy spectrum for the homogeneous electron gas can be described by an effective mass below the Fermi level. Above the Fermi level evanescent behavior in the occupation energies is observed in similar fashion to the occupation numbers of the 1RDM. A direct comparison with total energy differences demonstrates a quantita- tive connection between the occupation energies and electron addition and removal energies for the electron gas. For the oxygen atom, the association between the ground state occupation energies and particle addition and removal energies becomes only qualitative. The energy density matrix provides a new avenue for describing energetics with quantum Monte Carlo methods which have traditionally been limited to total energies.

Krogel, Jaron T [ORNL] [ORNL; Kim, Jeongnim [ORNL] [ORNL; Reboredo, Fernando A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

463

Physics and Algorithm Enhancements for a Validated MCNP/X Monte Carlo Simulation Tool, Phase VII  

SciTech Connect (OSTI)

Currently the US lacks an end-to-end (i.e., source-to-detector) radiation transport simulation code with predictive capability for the broad range of DHS nuclear material detection applications. For example, gaps in the physics, along with inadequate analysis algorithms, make it difficult for Monte Carlo simulations to provide a comprehensive evaluation, design, and optimization of proposed interrogation systems. With the development and implementation of several key physics and algorithm enhancements, along with needed improvements in evaluated data and benchmark measurements, the MCNP/X Monte Carlo codes will provide designers, operators, and systems analysts with a validated tool for developing state-of-the-art active and passive detection systems. This project is currently in its seventh year (Phase VII). This presentation will review thirty enhancements that have been implemented in MCNPX over the last 3 years and were included in the 2011 release of version 2.7.0. These improvements include 12 physics enhancements, 4 source enhancements, 8 tally enhancements, and 6 other enhancements. Examples and results will be provided for each of these features. The presentation will also discuss the eight enhancements that will be migrated into MCNP6 over the upcoming year.

McKinney, Gregg W [Los Alamos National Laboratory

2012-07-17T23:59:59.000Z

464

Basic physical and chemical information needed for development of Monte Carlo codes  

SciTech Connect (OSTI)

It is important to view track structure analysis as an application of a branch of theoretical physics (i.e., statistical physics and physical kinetics in the language of the Landau school). Monte Carlo methods and transport equation methods represent two major approaches. In either approach, it is of paramount importance to use as input the cross section data that best represent the elementary microscopic processes. Transport analysis based on unrealistic input data must be viewed with caution, because results can be misleading. Work toward establishing the cross section data, which demands a wide scope of knowledge and expertise, is being carried out through extensive international collaborations. In track structure analysis for radiation biology, the need for cross sections for the interactions of electrons with DNA and neighboring protein molecules seems to be especially urgent. Finally, it is important to interpret results of Monte Carlo calculations fully and adequately. To this end, workers should document input data as thoroughly as possible and report their results in detail in many ways. Workers in analytic transport theory are then likely to contribute to the interpretation of the results.

Inokuti, M.

1993-08-01T23:59:59.000Z

465

MONTE CARLO SIMULATION MODEL OF ENERGETIC PROTON TRANSPORT THROUGH SELF-GENERATED ALFVEN WAVES  

SciTech Connect (OSTI)

A new Monte Carlo simulation model for the transport of energetic protons through self-generated Alfven waves is presented. The key point of the model is that, unlike the previous ones, it employs the full form (i.e., includes the dependence on the pitch-angle cosine) of the resonance condition governing the scattering of particles off Alfven waves-the process that approximates the wave-particle interactions in the framework of quasilinear theory. This allows us to model the wave-particle interactions in weak turbulence more adequately, in particular, to implement anisotropic particle scattering instead of isotropic scattering, which the previous Monte Carlo models were based on. The developed model is applied to study the transport of flare-accelerated protons in an open magnetic flux tube. Simulation results for the transport of monoenergetic protons through the spectrum of Alfven waves reveal that the anisotropic scattering leads to spatially more distributed wave growth than isotropic scattering. This result can have important implications for diffusive shock acceleration, e.g., affect the scattering mean free path of the accelerated particles in and the size of the foreshock region.

Afanasiev, A.; Vainio, R., E-mail: alexandr.afanasiev@helsinki.fi [Department of Physics, University of Helsinki (Finland)

2013-08-15T23:59:59.000Z

466

Explicit temperature treatment in Monte Carlo neutron tracking routines - First results  

SciTech Connect (OSTI)

This article discusses the preliminary implementation of the new explicit temperature treatment method to the development version Monte Carlo reactor physics code Serpent 2 and presents the first practical results calculated using the method. The explicit temperature treatment method, as introduced in [1], is a stochastic method for taking the effect of thermal motion into account on-the-fly in a Monte Carlo neutron transport calculation. The method is based on explicit treatment of the motion of target nuclei at collision sites and requires cross sections at 0 K temperature only, regardless of the number of temperatures in the problem geometry. The method includes a novel capability of modelling continuous temperature distributions. Test calculations are performed for two test cases, a PWR pin-cell and a HTGR system. The resulting k{sub eff} and flux spectra are compared to a reference solution calculated using Serpent 1.1.16 with Doppler-broadening rejection correction [2]. The results are in very good agreement with the reference and also the increase in calculation time due to the new method is on acceptable level although not fully insignificant. On the basis of the current study, the explicit treatment method can be considered feasible for practical calculations. (authors)

Tuomas, V.; Jaakko, L. [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT (Finland)

2012-07-01T23:59:59.000Z

467

Patient-Specific Quality Assurance for Prostate Cancer Patients Receiving Spot Scanning Proton Therapy Using Single-Field Uniform Dose  

SciTech Connect (OSTI)

Purpose: To describe our experiences with patient-specific quality assurance (QA) for patients with prostate cancer receiving spot scanning proton therapy (SSPT) using single-field uniform dose (SFUD). Methods and Materials: The first group of 249 patients with prostate cancer treated with SSPT using SFUD was included in this work. The scanning-beam planning target volume and number of monitor units were recorded and checked for consistency. Patient-specific dosimetric measurements were performed, including the point dose for each plan, depth doses, and two-dimensional (2D) dose distribution in the planes perpendicular to the incident beam direction for each field at multiple depths. The {gamma}-index with 3% dose or 3-mm distance agreement criteria was used to evaluate the 2D dose distributions. Results: We observed a linear relationship between the number of monitor units and scanning-beam planning target volume. The difference between the measured and calculated point doses (mean {+-} SD) was 0.0% {+-} 0.7% (range, -2.9% to 1.8%). In general, the depth doses exhibited good agreement except at the distal end of the spread-out Bragg peak. The pass rate of {gamma}-index (mean {+-} SD) for 2D dose comparison was 96.2% {+-} 2.6% (range, 90-100%). Discrepancies between the measured and calculated dose distributions primarily resulted from the limitation of the model used by the treatment planning system. Conclusions: We have established a patient-specific QA program for prostate cancer patients receiving SSPT using SFUD.

Zhu, X. Ronald, E-mail: xrzhu@mdanderson.org [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Poenisch, Falk; Song, Xiaofei; Johnson, Jennifer L.; Ciangaru, George; Taylor, M. Brad; Lii, Ming Fwu; Martin, Craig; Arjomandy, Bijan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Lee, Andrew K.; Choi, Seungtaek; Nguyen, Quynh nhu [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Gillin, Michael T.; Sahoo, Narayan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2011-10-01T23:59:59.000Z

468

Quality of Life and Toxicity From Passively Scattered and Spot-Scanning Proton Beam Therapy for Localized Prostate Cancer  

SciTech Connect (OSTI)

Purpose: To report quality of life (QOL)/toxicity in men treated with proton beam therapy for localized prostate cancer and to compare outcomes between passively scattered proton therapy (PSPT) and spot-scanning proton therapy (SSPT). Methods and Materials: Men with localized prostate cancer enrolled on a prospective QOL protocol with a minimum of 2 years' follow-up were reviewed. Comparative groups were defined by technique (PSPT vs SSPT). Patients completed Expanded Prostate Cancer Index Composite questionnaires at baseline and every 3-6 months after proton beam therapy. Clinically meaningful differences in QOL were defined as ?0.5 × baseline standard deviation. The cumulative incidence of modified Radiation Therapy Oncology Group grade ?2 gastrointestinal (GI) or genitourinary (GU) toxicity and argon plasma coagulation were determined by the Kaplan-Meier method. Results: A total of 226 men received PSPT, and 65 received SSPT. Both PSPT and SSPT resulted in statistically significant changes in sexual, urinary, and bowel Expanded Prostate Cancer Index Composite summary scores. Only bowel summary, function, and bother resulted in clinically meaningful decrements beyond treatment completion. The decrement in bowel QOL persisted through 24-month follow-up. Cumulative grade ?2 GU and GI toxicity at 24 months were 13.4% and 9.6%, respectively. There was 1 grade 3 GI toxicity (PSPT group) and no other grade ?3 GI or GU toxicity. Argon plasma coagulation application was infrequent (PSPT 4.4% vs SSPT 1.5%; P=.21). No statistically significant differences were appreciated between PSPT and SSPT regarding toxicity or QOL. Conclusion: Both PSPT and SSPT confer low rates of grade ?2 GI or GU toxicity, with preservation of meaningful sexual and urinary QOL at 24 months. A modest, yet clinically meaningful, decrement in bowel QOL was seen throughout follow-up. No toxicity or QOL differences between PSPT and SSPT were identified. Long-term comparative results in a larger patient cohort are warranted.

Pugh, Thomas J. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Choi, Seungtaek; Nguyen, Quyhn Nhu; Mathai, Benson [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhu, X. Ron; Sahoo, Narayan; Gillin, Michael; Johnson, Jennifer L.; Amos, Richard A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Dong, Lei [Scripps Proton Therapy Center, San Diego, California (United States); Mahmood, Usama; Kuban, Deborah A.; Frank, Steven J.; Hoffman, Karen E.; McGuire, Sean E. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lee, Andrew K., E-mail: aklee@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2013-12-01T23:59:59.000Z

469

CPMC-Lab: A Matlab package for Constrained Path Monte Carlo calculations  

Science Journals Connector (OSTI)

Abstract We describe CPMC-Lab, a Matlab program for the constrained-path and phaseless auxiliary-field Monte Carlo methods. These methods have allowed applications ranging from the study of strongly correlated models, such as the Hubbard model, to ab initio calculations in molecules and solids. The present package implements the full ground-state constrained-path Monte Carlo (CPMC) method in Matlab with a graphical interface, using the Hubbard model as an example. The package can perform calculations in finite supercells in any dimensions, under periodic or twist boundary conditions. Importance sampling and all other algorithmic details of a total energy calculation are included and illustrated. This open-source tool allows users to experiment with various model and run parameters and visualize the results. It provides a direct and interactive environment to learn the method and study the code with minimal overhead for setup. Furthermore, the package can be easily generalized for auxiliary-field quantum Monte Carlo (AFQMC) calculations in many other models for correlated electron systems, and can serve as a template for developing a production code for AFQMC total energy calculations in real materials. Several illustrative studies are carried out in one- and two-dimensional lattices on total energy, kinetic energy, potential energy, and charge- and spin-gaps. Program summary Program title: CPMC-Lab Catalogue identifier: AEUD_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEUD_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 2850 No. of bytes in distributed program, including test data, etc.: 24 838 Distribution format: tar.gz Programming language:Matlab. Computer: The non-interactive scripts can be executed on any computer capable of running Matlab with all Matlab versions. The GUI requires Matlab \\{R2010b\\} (version 7.11) and above. Operating system: Windows, Mac OS X, Linux. RAM: Variable. Classification: 7.3. External routines:Matlab Nature of problem: Obtaining ground state energy of a repulsive Hubbard model in a supercell in any number of dimensions. Solution method: In the Constrained Path Monte Carlo (CPMC) method, the ground state of a many-fermion system is projected from an initial trial wave function by a branching random walk in an overcomplete basis of Slater determinants. Constraining the determinants according to a trial wave function | ? T ? removes the exponential decay of the signal-to-noise ratio characteristic of the sign problem. The method is exact if | ? T ? is exact. Unusual features: Direct and interactive environment with a Graphical User Interface for beginners to learn and study the Constrained Path Monte Carlo method with minimal overhead for setup. Running time: The sample provided takes a few seconds to run, the batch sample a few minutes.

Huy Nguyen; Hao Shi; Jie Xu; Shiwei Zhang

2014-01-01T23:59:59.000Z

470

Moment approach to the bootstrap current in nonaxisymmetric toroidal plasmas using {delta}f Monte Carlo methods  

SciTech Connect (OSTI)

To evaluate the bootstrap current in nonaxisymmetric toroidal plasmas quantitatively, a {delta}f Monte Carlo method is incorporated into the moment approach. From the drift-kinetic equation with the pitch-angle scattering collision operator, the bootstrap current and neoclassical conductivity coefficients are calculated. The neoclassical viscosity is evaluated from these two monoenergetic transport coefficients. Numerical results obtained by the {delta}f Monte Carlo method for a model heliotron are in reasonable agreement with asymptotic formulae and with the results obtained by the variational principle.

Matsuyama, A. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Isaev, M. Yu. [Nuclear Fusion Institute, RRC Kurchatov Institute, 123182 Moscow (Russian Federation); Watanabe, K. Y.; Suzuki, Y.; Nakajima, N. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Hanatani, K. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Cooper, W. A.; Tran, T. M. [Centre de Recherches en Physique des Plasmas, Association Euratom-Suisse, Ecole Polytechnique Federale de Lausanne, CH1015 Lausanne (Switzerland)

2009-05-15T23:59:59.000Z

471

Monte carlo Techniques for the Comprehensive Modeling of Isotopic Inventories in Future Nuclear Systems and Fuel Cycles  

SciTech Connect (OSTI)

The development of Monte Carlo techniques for isotopic inventory analysis has been explored in order to facilitate the modeling of systems with flowing streams of material through varying neutron irradiation environments. This represents a novel application of Monte Carlo methods to a field that has traditionally relied on deterministic solutions to systems of first-order differential equations. The Monte Carlo techniques were based largely on the known modeling techniques of Monte Carlo radiation transport, but with important differences, particularly in the area of variance reduction and efficiency measurement. The software that was developed to implement and test these methods now provides a basis for validating approximate modeling techniques that are available to deterministic methodologies. The Monte Carlo methods have been shown to be effective in reproducing the solutions of simple problems that are possible using both stochastic and deterministic methods. The Monte Carlo methods are also effective for tracking flows of materials through complex systems including the ability to model removal of individual elements or isotopes in the system. Computational performance is best for flows that have characteristic times that are large fractions of the system lifetime. As the characteristic times become short, leading to thousands or millions of passes through the system, the computational performance drops significantly. Further research is underway to determine modeling techniques to improve performance within this range of problems. This report describes the technical development of Monte Carlo techniques for isotopic inventory analysis. The primary motivation for this solution methodology is the ability to model systems of flowing material being exposed to varying and stochastically varying radiation environments. The methodology was developed in three stages: analog methods which model each atom with true reaction probabilities (Section 2), non-analog methods which bias the probability distributions while adjusting atom weights to preserve a fair game (Section 3), and efficiency measures to provide local and global measures of the effectiveness of the non-analog methods (Section 4). Following this development, the MCise (Monte Carlo isotope simulation engine) software was used to explore the efficiency of different modeling techniques (Section 5).

Paul P.H. Wilson

2005-07-30T23:59:59.000Z

472

Quantum Monte Carlo Simulation of the High-Pressure Molecular-Atomic Crossover in Fluid Hydrogen  

Science Journals Connector (OSTI)

A first-order liquid-liquid phase transition in high-pressure hydrogen between molecular and atomic fluid phases has been predicted in computer simulations using ab initio molecular dynamics approaches. However, experiments indicate that molecular dissociation may occur through a continuous crossover rather than a first-order transition. Here we study the nature of molecular dissociation in fluid hydrogen using an alternative simulation technique in which electronic correlation is computed within quantum Monte Carlo methods, the so-called coupled electron-ion Monte Carlo method. We find no evidence for a first-order liquid-liquid phase transition.

Kris T. Delaney; Carlo Pierleoni; D. M. Ceperley

2006-12-06T23:59:59.000Z

473

Spot the number plates  

Science Journals Connector (OSTI)

......which forms part of the ROMANSE project in Southampton, and has also...potential for infringing civil liberties. Also, in the costcutting...this direction. The ROMANSE project in Southampton seeks to control...which forms part of the ROMANSE project in Southampton, and has also......

Chris Gillham

1996-09-01T23:59:59.000Z

474

Surface tension of an electrolyteair interface: a Monte Carlo study This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network [OSTI]

Surface tension of an electrolyte­air interface: a Monte Carlo study This article has been 24 (2012) 284115 (5pp) doi:10.1088/0953-8984/24/28/284115 Surface tension of an electrolyte for calculating the surface tension of an electrolyte­air interface using Monte Carlo (MC) simulations

Levin, Yan

475

Overview of Geometry Representation in Monte Carlo Codes Ronald P. Kensek  

National Nuclear Security Administration (NNSA)

Overview of Geometry Representation Overview of Geometry Representation in Monte Carlo Codes Ronald P. Kensek Brian C. Franke Thomas W. Laub Leonard J. Lorence Matthew R. Martin Sandia National Laboratories Steve Warren Kansas State University Joint Russian-American Five-Laboratory Conference on Computational Mathematics / Physics Vienna, Austria June 19-23, 2005 Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States National Nuclear Security Administration and the Department of Energy under contract DE-AC04-94AL85000. 2 Problem Setup: Engineering designs CG vs. CAD Combinatorial Geometry (CG) * Engineering designs are not typically created in this format * No general automatic translation from CAD to CG yet exists * Problem setup is difficult: Creation

476

Coil-bridge transition and Monte Carlo simulation of a stretched polymer  

Science Journals Connector (OSTI)

The structure of the system consisting of a grafted self-avoiding polymer chain attracted to the surface layer of a flat wall at a distance away by a short-ranged force is investigated. A first-order transition is determined between the coil state at a low attraction energy and the bridge state at a high attraction energy. The transition properties of the system are obtained by a Monte Carlo simulation, which uses the inverse density of states as the transition weight and is reweighted back to a canonical ensemble. The determination of the density of states follows a revised Wang-Landau procedure in which the center-of-mass distance from the grafted site is used as the variable. Scaling arguments are also given for the observed numerical results.

Jeff Z. Y. Chen

2011-10-25T23:59:59.000Z

477

Kinetics of electron-positron pair plasmas using an adaptive Monte Carlo method  

E-Print Network [OSTI]

A new algorithm for implementing the adaptive Monte Carlo method is given. It is used to solve the relativistic Boltzmann equations that describe the time evolution of a nonequilibrium electron-positron pair plasma containing high-energy photons and pairs. The collision kernels for the photons as well as pairs are constructed for Compton scattering, pair annihilation and creation, bremsstrahlung, and Bhabha & Moller scattering. For a homogeneous and isotropic plasma, analytical equilibrium solutions are obtained in terms of the initial conditions. For two non-equilibrium models, the time evolution of the photon and pair spectra is determined using the new method. The asymptotic numerical solutions are found to be in a good agreement with the analytical equilibrium states. Astrophysical applications of this scheme are discussed.

Ravi P. Pilla; Jacob Shaham

1997-02-21T23:59:59.000Z

478

Reversible jump Markov chain Monte Carlo computation and Bayesian model determination  

E-Print Network [OSTI]

Markov chain Monte Carlo methods for Bayesian computation have until recently been restricted to problems where the joint distribution of all variables has a density with respect to some xed standard underlying measure. They have therefore not been available for application to Bayesian model determination, where the dimensionality of the parameter vector is typically not xed. This article proposes a new framework for the construction of reversible Markov chain samplers that jump between parameter subspaces of di ering dimensionality, which is exible and entirely constructive. It should therefore have wide applicability in model determination problems. The methodology is illustrated with applications to multiple change-point analysis in one and two dimensions, and toaBayesian comparison of binomial experiments.

Peter J. Green

1995-01-01T23:59:59.000Z

479

Monte Carlo simulation of the electrical properties of electrolytes adsorbed in charged slit-systems  

E-Print Network [OSTI]

We study the adsorption of primitive model electrolytes into a layered slit system using grand canonical Monte Carlo simulations. The slit system contains a series of charged membranes. The ions are forbidden from the membranes, while they are allowed to be adsorbed into the slits between the membranes. We focus on the electrical properties of the slit system. We show concentration, charge, electric field, and electrical potential profiles. We show that the potential difference between the slit system and the bulk phase is mainly due to the double layers formed at the boundaries of the slit system, but polarization of external slits also contributes to the potential drop. We demonstrate that the electrical work necessary to bring an ion into the slit system can be studied only if we simulate the slit together with the bulk phases in one single simulation cell.

R. Kovács; M. Valiskó; D. Boda

2012-07-13T23:59:59.000Z

480

Monte Carlo Modeling of Photon Interrogation Methods for Characterization of Special Nuclear Material  

SciTech Connect (OSTI)

This work illustrates a methodology based on photon interrogation and coincidence counting for determining the characteristics of fissile material. The feasibility of the proposed methods was demonstrated using a Monte Carlo code system to simulate the full statistics of the neutron and photon field generated by the photon interrogation of fissile and non-fissile materials. Time correlation functions between detectors were simulated for photon beam-on and photon beam-off operation. In the latter case, the correlation signal is obtained via delayed neutrons from photofission, which induce further fission chains in the nuclear material. An analysis methodology was demonstrated based on features selected from the simulated correlation functions and on the use of artificial neural networks. We show that the methodology can reliably differentiate between highly enriched uranium and plutonium. Furthermore, the mass of the material can be determined with a relative error of about 12%. Keywords: MCNP, MCNP-PoliMi, Artificial neural network, Correlation measurement, Photofission

Pozzi, Sara A [ORNL; Downar, Thomas J [ORNL; Padovani, Enrico [Nuclear Engineering Department Politecnico di Milano, Milan, Italy; Clarke, Shaun D [ORNL

2006-01-01T23:59:59.000Z

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


481

Validation of GEANT4 Monte Carlo Models with a Highly Granular Scintillator-Steel Hadron Calorimeter  

E-Print Network [OSTI]

Calorimeters with a high granularity are a fundamental requirement of the Particle Flow paradigm. This paper focuses on the prototype of a hadron calorimeter with analog readout, consisting of thirty-eight scintillator layers alternating with steel absorber planes. The scintillator plates are finely segmented into tiles individually read out via Silicon Photomultipliers. The presented results are based on data collected with pion beams in the energy range from 8GeV to 100GeV. The fine segmentation of the sensitive layers and the high sampling frequency allow for an excellent reconstruction of the spatial development of hadronic showers. A comparison between data and Monte Carlo simulations is presented, concerning both the longitudinal and lateral development of hadronic showers and the global response of the calorimeter. The performance of several GEANT4 physics lists with respect to these observables is evaluated.

C. Adloff; J. Blaha; J. -J. Blaising; C. Drancourt; A. Espargilière; R. Gaglione; N. Geffroy; Y. Karyotakis; J. Prast; G. Vouters; K. Francis; J. Repond; J. Schlereth; J. Smith; L. Xia; E. Baldolemar; J. Li; S. T. Park; M. Sosebee; A. P. White; J. Yu; T. Buanes; G. Eigen; Y. Mikami; N. K. Watson; G. Mavromanolakis; M. A. Thomson; D. R. Ward; W. Yan; D. Benchekroun; A. Hoummada; Y. Khoulaki; J. Apostolakis; A. Dotti; G. Folger; V. Ivantchenko; V. Uzhinskiy; M. Benyamna; C. Cârloganu; F. Fehr; P. Gay; S. Manen; L. Royer; G. C. Blazey; A. Dyshkant; J. G. R. Lima; V. Zutshi; J. -Y. Hostachy; L. Morin; U. Cornett; D. David; G. Falley; K. Gadow; P. Göttlicher; C. Günter; B. Hermberg; S. Karstensen; F. Krivan; A. -I. Lucaci-Timoce; S. Lu; B. Lutz; S. Morozov; V. Morgunov; M. Reinecke; F. Sefkow; P. Smirnov; M. Terwort; A. Vargas-Trevino; N. Feege; E. Garutti; I. Marchesinik; M. Ramilli; P. Eckert; T. Harion; A. Kaplan; H. -Ch. Schultz-Coulon; W. Shen; R. Stamen; B. Bilki; E. Norbeck; Y. Onel; G. W. Wilson; K. Kawagoe; P. D. Dauncey; A. -M. Magnan; V. Bartsch; M. Wing; F. Salvatore; E. Calvo Alamillo; M. -C. Fouz; J. Puerta-Pelayo; B. Bobchenko; M. Chadeeva; M. Danilov; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Popov; V. Rusinov; E. Tarkovsky; N. Kirikova; V. Kozlov; P. Smirnov; Y. Soloviev; P. Buzhan; A. Ilyin; V. Kantserov; V. Kaplin; A. Karakash; E. Popova; V. Tikhomirov; C. Kiesling; K. Seidel; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; M. S. Amjad; J. Bonis; S. Callier; S. Conforti di Lorenzo; P. Cornebise; Ph. Doublet; F. Dulucq; J. Fleury; T. Frisson; N. van der Kolk; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Pöschl; L. Raux; J. Rouëné; N. Seguin-Moreau; M. Anduze; V. Boudry; J-C. Brient; D. Jeans; P. Mora de Freitas; G. Musat; M. Reinhard; M. Ruan; H. Videau; B. Bulanek; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; J. Kvasnicka; D. Lednicky; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; B. Belhorma; H. Ghazlane; T. Takeshita; S. Uozumi; M. Götze; O. Hartbrich; J. Sauer; S. Weber; C. Zeitnitz

2014-06-15T23:59:59.000Z

482

Uncertainties associated with the use of the KENO Monte Carlo criticality codes  

SciTech Connect (OSTI)

The KENO multi-group Monte Carlo criticality codes have earned the reputation of being efficient, user friendly tools especially suited for the analysis of situations commonly encountered in the storage and transportation of fissile materials. Throughout their twenty years of service, a continuing effort has been made to maintain and improve these codes to meet the needs of the nuclear criticality safety community. Foremost among these needs is the knowledge of how to utilize the results safely and effectively. Therefore it is important that code users be aware of uncertainties that may affect their results. These uncertainties originate from approximations in the problem data, methods used to process cross sections, and assumptions, limitations and approximations within the criticality computer code itself. 6 refs., 8 figs., 1 tab.

Landers, N.F.; Petrie, L.M. (Oak Ridge National Lab., TN (USA))

1989-01-01T23:59:59.000Z

483

Monte-Carlo study of quasiparticle dispersion relation in monolayer graphene  

E-Print Network [OSTI]

The density of electronic one-particle states in monolayer graphene is studied by performing the Hybrid Monte-Carlo simulations of the tight-binding model for electrons on the pi orbitals of carbon atoms which make up the graphene lattice. Density of states is approximated as a derivative of the number of particles over the chemical potential at sufficiently small temperature. Simulations are performed in the partially quenched approximation, in which virtual particles and holes have zero chemical potential. It is found that the Van Hove singularity becomes much sharper than in the free tight-binding model. Simulation results also suggest that the Fermi velocity increases with interaction strength up to the transition to the phase with spontaneously broken chiral symmetry.

P. V. Buividovich

2013-01-07T23:59:59.000Z

484

Monte Carlo Study on Distortion of the Space-Dimension in COBE Monopole Data  

E-Print Network [OSTI]

A concise explanation of studies on distortion of space-time dimension is briefly introduced. Second we obtain the limits (i.e., bounded values) of the dimensionless chemical potential $\\mu$, the Sunyaev--Zeldovich (SZ) effect y and distortion of the space-dimension $\\varepsilon$ by Monte Carlo (MC) analysis of the parameter set (T, $d=3+\\varepsilon$, $\\mu$, and $y$) in cosmic microwave data assuming that the SZ effect is positive (y>0). In this analysis, the magnitude of the space-dimension d with distortion of the space-dimension $\\varepsilon$ is defined by $d=3+\\varepsilon$. The limits of $\\mu$ and $y$ are determined as $|\\mu| |y|$. The estimated limit of $|y| < 5\\times 10^{-6}$ appears to be related to re-ionization processes occurring at redshift $z_{ri}\\sim 10$. We also present data analysis assuming a relativistic SZ effect.

Minoru Biyajima; Takuya Mizoguchi

2013-05-31T23:59:59.000Z

485

Report on International Collaboration Involving the FE Heater and HG-A Tests at Mont Terri  

SciTech Connect (OSTI)

Nuclear waste programs outside of the US have focused on different host rock types for geological disposal of high-level radioactive waste. Several countries, including France, Switzerland, Belgium, and Japan are exploring the possibility of waste disposal in shale and other clay-rich rock that fall within the general classification of argillaceous rock. This rock type is also of interest for the US program because the US has extensive sedimentary basins containing large deposits of argillaceous rock. LBNL, as part of the DOE-NE Used Fuel Disposition Campaign, is collaborating on some of the underground research laboratory (URL) activities at the Mont Terri URL near Saint-Ursanne, Switzerland. The Mont Terri project, which began in 1995, has developed a URL at a depth of about 300 m in a stiff clay formation called the Opalinus Clay. Our current collaboration efforts include two test modeling activities for the FE heater test and the HG-A leak-off test. This report documents results concerning our current modeling of these field tests. The overall objectives of these activities include an improved understanding of and advanced relevant modeling capabilities for EDZ evolution in clay repositories and the associated coupled processes, and to develop a technical basis for the maximum allowable temperature for a clay repository. The R&D activities documented in this report are part of the work package of natural system evaluation and tool development that directly supports the following Used Fuel Disposition Campaign (UFDC) objectives: ? Develop a fundamental understanding of disposal-system performance in a range of environments for potential wastes that could arise from future nuclear-fuel-cycle alternatives through theory, simulation, testing, and experimentation. ? Develop a computational modeling capability for the performance of storage and disposal options for a range of fuel-cycle alternatives, evolving from generic models to more robust models of performance assessment. For the purpose of validating modeling capabilities for thermal-hydro-mechanical (THM) processes, we developed a suite of simulation models for the planned full-scale FE Experiment to be conducted in the Mont Terri URL, including a full three-dimensional model that will be used for direct comparison to experimental data once available. We performed for the first time a THM analysis involving the Barcelona Basic Model (BBM) in a full three-dimensional field setting for modeling the geomechanical behavior of the buffer material and its interaction with the argillaceous host rock. We have simulated a well defined benchmark that will be used for codeto- code verification against modeling results from other international modeling teams. The analysis highlights the complex coupled geomechanical behavior in the buffer and its interaction with the surrounding rock and the importance of a well characterized buffer material in terms of THM properties. A new geomechanical fracture-damage model, TOUGH-RBSN, was applied to investigate damage behavior in the ongoing HG-A test at Mont Terri URL. Two model modifications have been implemented so that the Rigid-Body-Spring-Network (RBSN) model can be used for analysis of fracturing around the HG-A microtunnel. These modifications are (1) a methodology to compute fracture generation under compressive stress conditions and (2) a method to represent anisotropic elastic and strength properties. The method for computing fracture generation under compressive load produces results that roughly follow trends expected for homogeneous and layered systems. Anisotropic properties for the bulk rock were represented in the RBSN model using layered heterogeneity and gave bulk material responses in line with expectations. These model improvements were implemented for an initial model of fracture damage at the HG-A test. While the HG-A test model results show some similarities with the test observations, differences between the model results and observations remain.

Houseworth, Jim; Rutqvist, Jonny; Asahina, Daisuke; Chen, Fei; Vilarrasa, Victor; Liu, Hui-Hai; Birkholzer, Jens

2013-11-06T23:59:59.000Z

486

2 × 2 commensurate-incommensurate transition in Ising models: Monte Carlo simulation  

Science Journals Connector (OSTI)

Phase diagrams of Ising models with antiferromagnetic nearest-(NN) and next-nearest-neighbor (NNN) interactions are obtained by Monte Carlo simulations. For the triangular lattice a paramagnetic (P)-2×2 commensurate (C) phase transition is found, which is second order when the NN interaction is small. The exponents are consistent with the ones of the four-state Potts model. For large NNN interactions the transition becomes first order. For three-dimensional stacking of triangular layers an incommensurate (I) phase is found in addition. The P-C and I-C transitions are of first order whereas the P-I transition seems to be of second order. The model is used to interpret the P-I-C transitions in ?-eucryptite.

Y. Saito

1981-12-01T23:59:59.000Z

487

Monte Carlo study of living polymers with the bond-fluctuation method  

Science Journals Connector (OSTI)

The highly efficient bond-fluctuation method for Monte Carlo simulations of both static and dynamic properties of polymers is applied to a system of living polymers. Parallel to stochastic movements of monomers, which result in Rouse dynamics of the macromolecules, the polymer chains break, or associate at chain ends with other chains and single monomers, in the process of equilibrium polymerization. We study the changes in equilibrium properties, such as molecular-weight distribution, average chain length, and radius of gyration, and specific heat with varying density and temperature of the system. The results of our numeric experiments indicate a very good agreement with the recently suggested description in terms of the mean-field approximation. The coincidence of the specific heat maximum position at kBT=V/4 in both theory and simulation suggests the use of calorimetric measurements for the determination of the scission-recombination energy V in real experiments.

Yannick Rouault and Andrey Milchev

1995-06-01T23:59:59.000Z

488

Dynamical Monte Carlo study of equilibrium polymers: Effects of high density and ring formation  

Science Journals Connector (OSTI)

An off-lattice Monte Carlo algorithm for solutions of equilibrium polymers (EPs) is proposed. At low and moderate densities this is shown to reproduce faithfully the (static) properties found recently for flexible linear EPs using a lattice model. The molecular weight distribution (MWD) is well described in the dilute limit by a Schultz-Zimm distribution and becomes purely exponential in the semidilute limit. Additionally, very concentrated molten systems are studied. The MWD remains a pure exponential in contrast to recent claims. The mean chain mass is found to increase faster with density than in the semidilute regime due to additional entropic interactions generated by the dense packing of spheres. We also consider systems in which the formation of rings is allowed so that both the linear chains and the rings compete for the monomers. In agreement with earlier predictions the MWD of the rings reveals a strong singularity whereas the MWD of the coexisting linear chains remains essentially unaffected.

A. Milchev; J. P. Wittmer; D. P. Landau

2000-03-01T23:59:59.000Z

489

Simulation of Cone Beam CT System Based on Monte Carlo Method  

E-Print Network [OSTI]

Adaptive Radiation Therapy (ART) was developed based on Image-guided Radiation Therapy (IGRT) and it is the trend of photon radiation therapy. To get a better use of Cone Beam CT (CBCT) images for ART, the CBCT system model was established based on Monte Carlo program and validated against the measurement. The BEAMnrc program was adopted to the KV x-ray tube. Both IOURCE-13 and ISOURCE-24 were chosen to simulate the path of beam particles. The measured Percentage Depth Dose (PDD) and lateral dose profiles under 1cm water were compared with the dose calculated by DOSXYZnrc program. The calculated PDD was better than 1% within the depth of 10cm. More than 85% points of calculated lateral dose profiles was within 2%. The correct CBCT system model helps to improve CBCT image quality for dose verification in ART and assess the CBCT image concomitant dose risk.

Wang, Yu; Cao, Ruifen; Hu, Liqin; Li, Bingbing

2014-01-01T23:59:59.000Z

490

A Monte Carlo approach to forecasting the demand for offshore supply vessels  

Science Journals Connector (OSTI)

In the near future, the demand for offshore supply vessels in Brazil will be driven by the activities induced by the bids carried out by the regulatory agency, ANP. The likely tendency is to increase the number of bids and consequently, the demand for vessels in the coming years. The proposed model consists of a Monte Carlo simulation of the offshore oil exploration and production projects. The model considers some parameters that aim at capturing the effect of the operators patterns, water depth, duration of seismic research and exploration and drilling work, number of wells, geographic location and geological risk. An estimate is obtained for the additional offshore supply vessels demand, for the period of 2006-2008.

Jr">Floriano C.M. Pires Jr; Augusto R. Antoun

2012-01-01T23:59:59.000Z

491

Monte Carlo procedure for protein folding in lattice model. Conformational rigidity  

E-Print Network [OSTI]

A rigourous Monte Carlo method for protein folding simulation on lattice model is introduced. We show that a parameter which can be seen as the rigidity of the conformations has to be introduced in order to satisfy the detailed balance condition. Its properties are discussed and its role during the folding process is elucidated. This method is applied on small chains on two-dimensional lattice. A Bortz-Kalos-Lebowitz type algorithm which allows to study the kinetic of the chains at very low temperature is implemented in the presented method. We show that the coefficients of the Arrhenius law are in good agreement with the value of the main potential barrier of the system.

Olivier Collet

1999-07-19T23:59:59.000Z

492

Interfaces in partly compatible polymer mixtures: A Monte Carlo simulation approach  

E-Print Network [OSTI]

The structure of polymer coils near interfaces between coexisting phases of symmetrical polymer mixtures (AB) is discussed, as well as the structure of symmetric diblock copolymers of the same chain length N adsorbed at the interface. The problem is studied by Monte Carlo simulations of the bond fluctuation model on the simple cubic lattice, using massively parallel computers (CRAY T3D). While homopolymer coils in the strong segregation limit are oriented parallel to the interface, the diblocks form ``dumbbells'' oriented perpendicular to the interface. However, in the dilute case (``mushroom regime'' rather than ``brush regime''), the diblocks are only weakly stretched. Distribution functions for monomers at the chain ends and in the center of the polymer are obtained, and a comparison to the self consistent field theory is made.

K. Binder; M. Mueller; F. Schmid; A. Werner

1997-06-27T23:59:59.000Z

493

Quantum Monte Carlo for Noncovalent Interactions: Analysis of Protocols and Simplified Scheme Attaining Benchmark Accuracy  

E-Print Network [OSTI]

Reliable theoretical predictions of noncovalent interaction energies, which are important e.g. in drug-design and hydrogen-storage applications, belong to longstanding challenges of contemporary quantum chemistry. In this respect, the fixed-node diffusion Monte Carlo (FN-DMC) is a promising alternative to the commonly used ``gold standard'' coupled-cluster CCSD(T)/CBS method for its benchmark accuracy and favourable scaling, in contrast to other correlated wave function approaches. This work is focused on the analysis of protocols and possible tradeoffs for FN-DMC estimations of noncovalent interaction energies and proposes a significantly more efficient yet accurate computational protocol using simplified explicit correlation terms. Its performance is illustrated on a number of weakly bound complexes, including water dimer, benzene/hydrogen, T-shape benzene dimer and stacked adenine-thymine DNA base pair complex. The proposed protocol achieves excellent agreement ($\\sim$0.2 kcal/mol) with respect to the reli...

Dubecký, Matúš; Jure?ka, Petr; Mitas, Lubos; Hobza, Pavel; Otyepka, Michal

2014-01-01T23:59:59.000Z

494

Shell-model Monte Carlo studies of fp-shell nuclei  

Science Journals Connector (OSTI)

We study the gross properties of even-even and N=Z nuclei with A=48–64 using shell-model Monte Carlo methods. Our calculations account for all 0?? configurations in the fp shell and employ the modified Kuo-Brown interaction KB3. We find good agreement with data for masses and total B(E2) strengths, the latter employing effective charges ep=1.35e and en=0.35e. The calculated total Gamow-Teller strengths agree consistently with the B(GT+) values deduced from (n,p) data if the shell-model results are renormalized by 0.64, as has already been established for sd-shell nuclei. The present calculations therefore suggest that this renormalization (i.e., gA=1 in the nuclear medium) is universal.

K. Langanke; D. J. Dean; P. B. Radha; Y. Alhassid; S. E. Koonin

1995-08-01T23:59:59.000Z

495

An Auxiliary-Field Quantum Monte Carlo Study of the Chromium Dimer  

E-Print Network [OSTI]

The chromium dimer (Cr2) presents an outstanding challenge for many-body electronic structure methods. Its complicated nature of binding, with a formal sextuple bond and an unusual potential energy curve, is emblematic of the competing tendencies and delicate balance found in many strongly correlated materials. We present a near-exact calculation of the potential energy curve (PEC) and ground state properties of Cr2, using the auxiliary-field quantum Monte Carlo (AFQMC) method. Unconstrained, exact AFQMC calculations are first carried out for a medium-sized but realistic basis set. Elimination of the remaining finite-basis errors and extrapolation to the complete basis set (CBS) limit is then achieved with a combination of phaseless and exact AFQMC calculations. Final results for the PEC and spectroscopic constants are in excellent agreement with experiment.

Purwanto, Wirawan; Krakauer, Henry

2014-01-01T23:59:59.000Z

496

MaGe - a Geant4-based Monte Carlo framework for low-background experiments  

E-Print Network [OSTI]

A Monte Carlo framework, MaGe, has been developed based on the Geant4 simulation toolkit. Its purpose is to simulate physics processes in low-energy and low-background radiation detectors, specifically for the Majorana and Gerda $^{76}$Ge neutrinoless double-beta decay experiments. This jointly-developed tool is also used to verify the simulation of physics processes relevant to other low-background experiments in Geant4. The MaGe framework contains simulations of prototype experiments and test stands, and is easily extended to incorporate new geometries and configurations while still using the same verified physics processes, tunings, and code framework. This reduces duplication of efforts and improves the robustness of and confidence in the simulation output.

Yuen-Dat Chan; Jason A. Detwiler; Reyco Henning; Victor M. Gehman; Rob A. Johnson; David V. Jordan; Kareem Kazkaz; Markus Knapp; Kevin Kroninger; Daniel Lenz; Jing Liu; Xiang Liu; Michael G. Marino; Akbar Mokhtarani; Luciano Pandola; Alexis G. Schubert; Claudia Tomei

2008-02-06T23:59:59.000Z

497

Monte Carlo simulation on the resistivity and magnetization in anisotropic layered structure  

Science Journals Connector (OSTI)

An anisotropic layered mode structure composed of line groups as an approach to anisotropic bilayered manganites is constructed based on the elementary interactions existing in the bilayered manganites. The anisotropic electronic transport and magnetic behaviors of the mode structure are investigated using Monte Carlo simulation and the microscopic resistor network scheme in Ising model. The simulation reproduces qualitatively the main characteristictransport behaviors of bilayered manganites. The significant anisotropy in resistivity and ferromagnetic orderings along different orientations is observed and the underlying physics is discussed in the framework of spatial correlation of the microscopic metallic resistor network. The simulated results are believed to cast some light on the understanding of the anomaly in the transport behaviors of bilayered manganites which are gaining more and more importance.

X. Y. Yao; Sh. Dong; H. Zhu; H. Yu; J.-M. Liu

2005-01-01T23:59:59.000Z

498

Seabed shear stresses under irregular waves plus current from Monte Carlo simulations of parameterized models  

Science Journals Connector (OSTI)

Shear stresses on a rough seabed under irregular waves plus current are calculated. Parameterized models valid for regular waves plus current have been used in Monte Carlo simulations, assuming the wave amplitudes to be Rayleigh-distributed. Numerical estimates of the probability distribution functions are presented. For waves only, the shear stress maxima follow a Weibull distribution, while for waves plus current, both the maximum and time-averaged shear stresses are well represented by a three-parameter Weibull distribution. The behaviour of the maximum shear stresses under a wide range of wave-current conditions has been investigated, and it appears that under certain conditions, the current has a significant influence on the maximum shear stresses. Results of comparison between predictions and measurements of the maximum bottom shear stresses from laboratory and field experiments are presented.

Lars Erik Holmedal; Dag Myrhaug; Håvard Rue

2000-01-01T23:59:59.000Z

499

Ab-initio molecular dynamics simulation of liquid water by Quantum Monte Carlo  

E-Print Network [OSTI]

Despite liquid water is ubiquitous in chemical reactions at roots of life and climate on earth, the prediction of its properties by high-level ab initio molecular dynamics simulations still represents a formidable task for quantum chemistry. In this article we present a room temperature simulation of liquid water based on the potential energy surface obtained by a many-body wave function through quantum Monte Carlo (QMC) methods. The simulated properties are in excellent agreement with recent neutron scattering and X-ray experiments, particularly concerning the position of the oxygen-oxygen peak in the radial distr