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1

Direct Kinetic Measurements of a Criegee Intermediate  

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

Direct Kinetic Measurements of a Criegee Intermediate Print Direct Kinetic Measurements of a Criegee Intermediate Print In the earth's troposphere, which blankets the planet surface where we live and breathe, dust particles, gas molecules, water vapor, and sunlight provide the ingredients for a multitude of chemical reactions that can generate effects ranging from clouds and smog to acid rain and climate change. In 1949, chemist Rudolf Criegee proposed a novel chemical pathway for one such reaction, known as ozonolysis: the destruction of alkenes (a type of hydrocarbon), via reaction with ozone, a key pollutant in the troposphere. Although there has been much indirect evidence supporting Criegee's mechanism, breakthrough research done at the ALS by chemists from Sandia National Laboratories, the University of Manchester, and Bristol University has for the first time directly measured reaction rates for so-called "Criegee intermediates," elusive molecules formed at intermediate stages of ozonolysis. The surprising results may have important implications for subjects ranging from advanced engine design to air quality and climate modeling.

2

Direct measurements of the mean flow and eddy kinetic energy structure of the upper ocean circulation in the NE Atlantic  

E-Print Network (OSTI)

Direct measurements of the mean flow and eddy kinetic energy structure of the upper ocean, University of Bergen, Bergen, Norway Tom Rossby Graduate School of Oceanography, University of Rhode Island and variable wind-forcing, and strong and variable deep currents that lead to large uncertainties in the use

3

Direct Observation of Aggregative Nanoparticle Growth: Kinetic...  

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

Aggregative Nanoparticle Growth: Kinetic Modeling of the Size Distribution and Growth Rate. Direct Observation of Aggregative Nanoparticle Growth: Kinetic Modeling of the Size...

4

KINETIC ROUGHENING PHENOMENA, STOCHASTIC GROWTH, DIRECTED  

E-Print Network (OSTI)

KINETIC ROUGHENING PHENOMENA, STOCHASTIC GROWTH, DIRECTED POLYMERS AND ALL THAT Aspects 254 (1995) 215-414 Kinetic roughening phenomena, stochastic growth, directed polymers and all that for the nonlinear term 3.2. Dynamic RG analysis 3.3. A worthy detour: kinetic roughening with conservation law 3

Halpin-Healy, Tim

5

Direct measurement of the kinetics of volume and enthalpy relaxation of an Au-based bulk metallic glass  

SciTech Connect

Structural relaxation of glasses below their glass transition is a well-studied phenomenon that still poses several open issues. With the advent of bulk metallic glasses with exceptionally low glass transition temperatures, new options are available that are based on the experimental assessment of the time dependence of several different thermodynamic quantities by direct measurements with high accuracy. In this contribution the first direct measurement of the isothermal relaxation of the volume and the enthalpy of an Au-based bulk metallic glassformer are reported and discussed with respect of the characteristics describing the underlying processes.

Bünz, J.; Wilde, G. [Institute of Materials Physics, University of Münster, 48149 Münster (Germany)] [Institute of Materials Physics, University of Münster, 48149 Münster (Germany)

2013-12-14T23:59:59.000Z

6

ARTICLES ON SINGLE-MOLECULE PHYSICS AND CHEMISTRY Direct measurements of memory effects in single-molecule kinetics  

E-Print Network (OSTI)

ARTICLES ON SINGLE-MOLECULE PHYSICS AND CHEMISTRY Direct measurements of memory effects in single-molecule and correlations of single-molecule sequences of modulated reactions are explicitly evaluated in the stochastic of the stochastic rate expression, characterizes the correlation in single-molecule rate processes in a formalism

Cao, Jianshu

7

Direct Visualization of Initial SEI Morphology and Growth Kinetics...  

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Initial SEI Morphology and Growth Kinetics During Lithium Deposition by in situ Electrochemical Direct Visualization of Initial SEI Morphology and Growth Kinetics During Lithium...

8

Direct kinetic correlation of carriers and ferromagnetism in...  

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

kinetic correlation of carriers and ferromagnetism in Co2+ : ZnO. Direct kinetic correlation of carriers and ferromagnetism in Co2+ : ZnO. Abstract: We report the use of controlled...

9

Atom probe: a direct technique for kinetic measurements. [Fe-24Cr; Fe-32Cr; Fe-28. 5Cr-10. 6Co  

SciTech Connect

The atom probe has been used to study the phase transformations occurring within the low-temperature miscibility gaps in Fe-Cr and Fe-Cr-Co alloys. The morphology of the two-phase microstructure resulting from phase separation deep within the miscibility gaps was found to be highly interconnected and charactristic of an isotropic spinodal reaction. The characteristic dimensions of the microstructure and the changes in composition were measured as a function of aging. The coarsening of the network structures could be fitted with a power law with time exponents that were significantly less than the classical Lifshitz-Slyozov-Wagner value of one-third.

Miller, M.K.; Brenner, S.S.; Camus, P.P.; Soffa, W.A.

1984-04-04T23:59:59.000Z

10

Time-resolved wavelength modulation spectroscopy measurements of HO2 kinetics  

E-Print Network (OSTI)

of the hydroperoxyl radical HO2 in a laser photolysis and long-path absorption pump-probe kinetics reactor with a near with a 1.5- m diode laser directly modulated at 5 MHz. The measured 2f WMS signal is calibrated by direct ab- sorbance of 1% or less , and the proportionality con- stant is established easily by comparison

11

ARM - Measurement - Shortwave narrowband direct normal irradiance  

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

Measurement : Shortwave narrowband direct normal irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4mum, that comes directly...

12

Corrections to kinetic measurements taken on a disk electrode  

SciTech Connect

Below the limiting current, the rotating disk electrode has a nonuniform current distribution. When the nonuniformities are not explicitly accounted for, errors in values of kinetic parameters determined through measurements on a disk can result. In this analysis, valid for Tafel kinetics, correction factors are obtained as a function of the dimensionless average current density.It is assumed that ohmic corrections are made by the interruption of current. The results indicate that, under certain conditions, the errors are negligible and that the disk geometry, despite its nonuniformities, is adequate for the investigation of systems characterized by Tafel kinetics.

West, A.C.; Newman, J.

1989-01-01T23:59:59.000Z

13

Hydrogen pickup measurements in zirconium alloys: Relation to oxidation kinetics  

E-Print Network (OSTI)

Hydrogen pickup measurements in zirconium alloys: Relation to oxidation kinetics Adrien Couet a to reduce hydrogen pickup during operation, and the associated cladding degradation. The present study focuses on precisely and accurately measuring hydrogen pickup fraction for a set of alloys to specifically

Motta, Arthur T.

14

Compressive direct measurement of the quantum wavefunction  

E-Print Network (OSTI)

The direct measurement of a complex wavefunction has been recently realized by using weak-values. In this paper, we introduce a method that exploits sparsity for compressive measurement of the transverse spatial wavefunction of photons. The procedure involves a weak measurement in random projection operators in the spatial domain followed by a post-selection in the momentum basis. Using this method, we experimentally measure a 192-dimensional state with a fidelity of $90%$ using only $25$ percent of the total required measurements. Furthermore, we demonstrate measurement of a 19200 dimensional state; a task that would require an unfeasibly large acquiring time with the conventional direct measurement technique.

Mohammad Mirhosseini; Omar S. Magaña-Loaiza; Seyed Mohammad Hashemi Rafsanjani; Robert W. Boyd

2014-04-10T23:59:59.000Z

15

Measurement of the Sintering Kinetics of Coal Ash  

Science Journals Connector (OSTI)

Measurement of the Sintering Kinetics of Coal Ash ... A new technique has been developed to determine the sintering rate of coal ash based on the measurement of the pressure-drop across a pellet of ash. ... The technique developed in this study shows a good repeatability of the rate of sintering and confirms that viscous flow is the dominant mechanism for sintering of coal ash. ...

A. Y. Al-Otoom; L. K. Elliott; T. F. Wall; B. Moghtaderi

2000-08-16T23:59:59.000Z

16

A direct search method for determination of DAEM kinetic parameters from nonisothermal TGA data (note)  

Science Journals Connector (OSTI)

In this study, a simple direct search method to be used for the determination of distributed activation energy model (DAEM) kinetic parameters from the nonisothermal thermogravimetric analysis (TGA) data of coals has been introduced. Process steps of ... Keywords: curve fitting, direct search technique, distributed activation energy model (DAEM), thermogravimetric analysis data (TGA)

Mustafa Güne?; Semin Güne?

2002-08-01T23:59:59.000Z

17

ARM - Measurement - Shortwave narrowband direct downwelling irradiance  

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

downwelling irradiance downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband direct downwelling irradiance The direct unscattered radiant energy from the Sun, in a narrow band of wavelengths shorter than approximately 4 {mu}m, passing through a horizontal unit area in a downward direction. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments SOAR : Shipboard Oceanographic and Atmospheric Radiation

18

ARM - Measurement - Shortwave broadband direct normal irradiance  

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

normal irradiance normal irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband direct normal irradiance The rate at which radiant energy in broad bands of wavelengths shorter than approximately 4{mu}m, that comes directly from the Sun without being scattered or absorbed in the atmosphere, passes through a unit area perpendicular to the direction from the Sun. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments

19

Direct Measurement of Neutron?Neutron Scattering  

Science Journals Connector (OSTI)

In order to resolve long?standing discrepancies in indirect measurements of the neutron?neutron scattering length ann and contribute to solving the problem of the charge symmetry of the nuclear force the collaboration DIANNA (Direct Investigation of ann Association) plans to measure the neutron?neutron scattering cross section ? nn . The key issue of our approach is the use of the through?channel in the Russia reactor YAGUAR with a peak neutron flux of 1018 /cm2/s. The proposed experimental setup is described. Results of calculations are presented to connect ? nn with the nn?collision detector count rate and the neutron flux density in the reactor channel. Measurements of the thermal neutron fields inside polyethylene converters show excellent prospects for the realization of the direct nn?experiment.

E. I. Sharapov; C. D. Bowman; B. E. Crawford; W. I. Furman; C. R. Howell; B. G. Levakov; V. I. Litvin; W. I. Lychagin; A. E. Lyzhin; E. P. Magda; G. E. Mitchell; G. V. Muzichka; G. V. Nekhaev; Yu. V. Safronov; V. N. Shvetsov; S. L. Stephenson; A. V. Strelkov; W. Tornow

2003-01-01T23:59:59.000Z

20

Adsorption behavior of direct red 80 and congo red onto activated carbon/surfactant: Process optimization, kinetics and equilibrium  

Science Journals Connector (OSTI)

Abstract Adsorptions of congo red and direct red 80 onto activated carbon/surfactant from aqueous solution were optimized. The Box–Behnken design (BBD) has been employed to analyze the effects of concentration of surfactant, temperature, pH, and initial concentration of the dye in the adsorption capacity. Their corresponding experimental data could be evaluated excellently by second order polynomial regression models and the two models were also examined based on the analysis of variance and t test statistics, respectively. The optimum conditions were obtained as follows: Cs = 34.10 ?M, T = 50 °C, pH = 3.5, and CCR = 160 mg/L for the congo red system, and Cs = 34.10 ?M, T = 50 °C, pH = 6.1, and CDR80 = 110 mg/L for the direct red 80 system. And in these conditions, the measured experimental maximum adsorption capacities for the congo red and direct red 80 removals were 769.48 mg/g and 519.90 mg/g, which were consistent with their corresponding predicted values, with small relative errors of ?2.81% and ?0.67%, respectively. The adsorption equilibrium and kinetics for the two dye adsorptions onto AC/DDAC were also investigated. The experimental data were fitted by four isotherm models, and Langmuir model presented the best fit. The kinetic studies indicated that the kinetic data followed the pseudo-second-order model.

Zhengjun Cheng; Lei Zhang; Xiao Guo; Xiaohui Jiang; Tian Li

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Direct amplitude detuning measurement with ac dipole  

In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of the accelerator. Assessing and understanding these effects in experiments is essential to confirm the accuracy of the magnetic model and improve the machine performance. A direct measurement of the machine nonlinearities can be obtained by characterizing the dependency of the tune as a function of the amplitude of oscillations (usually defined as amplitude detuning). The conventional technique is to excite the beam to large amplitudes with a single kick and derive the tune from turn-by-turn data acquired with beam position monitors. Although this provides a very precise tune measurement it has the significant disadvantage of being destructive. An alternative, nondestructive way of exciting large amplitude oscillations is to use an ac dipole. The perturbation Hamiltonian in the presence of an ac dipole excitation shows a distinct behavior compared to the free oscillations which should be correctly taken into account in the interpretation of experimental data. The use of an ac dipole for direct amplitude detuning measurement requires careful data processing allowing one to observe the natural tune of the machine; the feasibility of such a measurement is demonstrated using experimental data from the Large Hadron Collider. An experimental proof of the theoretical derivations based on measurements performed at injection energy is provided as well as an application of this technique at top energy using a large number of excitations on the same beam.

White, S.; Maclean, E.; Tomás, R.

2013-07-01T23:59:59.000Z

22

A wearable system for multi-segment foot kinetics measurement  

Science Journals Connector (OSTI)

Abstract This study aims to design a wearable system for kinetics measurement of multi-segment foot joints in long-distance walking and to investigate its suitability for clinical evaluations. The wearable system consisted of inertial sensors (3D gyroscopes and 3D accelerometers) on toes, forefoot, hindfoot, and shank, and a plantar pressure insole. After calibration in a laboratory, 10 healthy elderly subjects and 12 patients with ankle osteoarthritis walked 50 m twice wearing this system. Using inverse dynamics, 3D forces, moments, and power were calculated in the joint sections among toes, forefoot, hindfoot, and shank. Compared to those we previously estimated for a one-segment foot model, the sagittal and transverse moments and power in the ankle joint, as measured via multi-segment foot model, showed a normalized RMS difference of less than 11%, 14%, and 13%, respectively, for healthy subjects, and 13%, 15%, and 14%, for patients. Similar to our previous study, the coronal moments were not analyzed. Maxima–minima values of anterior-posterior and vertical force, sagittal moment, and power in shank-hindfoot and hindfoot-forefoot joints were significantly different between patients and healthy subjects. Except for power, the inter-subject repeatability of these parameters was CMC>0.90 for healthy subjects and CMC>0.70 for patients. Repeatability of these parameters was lower for the forefoot-toes joint. The proposed measurement system estimated multi-segment foot joints kinetics with acceptable repeatability but showed difference, compared to those previously estimated for the one-segment foot model. These parameters also could distinguish patients from healthy subjects. Thus, this system is suggested for outcome evaluations of foot treatments.

H. Rouhani; J. Favre; X. Crevoisier; K. Aminian

2014-01-01T23:59:59.000Z

23

Kinetics of Direct Oxidation of H2S in Coal Gas to Elemental Sulfur  

SciTech Connect

Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced Vision 21 plants that produce electric power and clean transportation fuels with coal and natural gas. These Vision 21 plants will require highly clean coal gas with H{sub 2}S below 1 ppm and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation Vision 21 plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The objectives of this research are to measure kinetics of direct oxidation of H{sub 2}S to elemental sulfur in the presence of a simulated coal gas mixture containing SO{sub 2}, H{sub 2}, and moisture, using 160-{micro}m C-500-04 alumina catalyst particles and 400 square cells/inch{sup 2}, {gamma}-Al{sub 2}O{sub 3}-wash-coated monolithic catalyst, and various reactors such as a micro packed-bed reactor, a micro bubble reactor, and a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam.

K.C. Kwon

2005-11-01T23:59:59.000Z

24

On Measuring the Terms of the Turbulent Kinetic Energy Budget from an AUV LOUIS GOODMAN  

E-Print Network (OSTI)

of production of turbulent kinetic energy (TKE). Heat flux is obtained by correlating the vertical velocityOn Measuring the Terms of the Turbulent Kinetic Energy Budget from an AUV LOUIS GOODMAN School of the steady-state, homogeneous turbulent kinetic energy budgets are obtained from mea- surements of turbulence

Goodman, Louis

25

Photo-oxidation of Ge Nanocrystals: Kinetic Measurements by In Situ Raman Spectroscopy  

E-Print Network (OSTI)

Photo-oxidation of Ge Nanocrystals: Kinetic Measurements byrate enhancement is due to a photo-chemical process. Thenanocrystals can be rapidly photo-oxidized. This oxidation

2008-01-01T23:59:59.000Z

26

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

27

On Measuring the Terms of the Turbulent Kinetic Energy Budget from an AUV  

Science Journals Connector (OSTI)

The terms of the steady-state, homogeneous turbulent kinetic energy budgets are obtained from measurements of turbulence and fine structure from the small autonomous underwater vehicle (AUV) Remote Environmental Measuring Units (REMUS). The ...

Louis Goodman; Edward R. Levine; Rolf G. Lueck

2006-07-01T23:59:59.000Z

28

Direct Measurement of Oxygen Incorporation into Thin Film Oxides...  

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

Measurement of Oxygen Incorporation into Thin Film Oxides at Room Temperature Upon Ultraviolet Phton Irradiation. Direct Measurement of Oxygen Incorporation into Thin Film Oxides...

29

Microprocessor Field Impactometer Calibration: Do We Measure Drops’ Momentum or Their Kinetic Energy?  

Science Journals Connector (OSTI)

This study presents the construction and calibration of a low-cost piezoelectric microprocessor impactometer designed for the field measurements of the rainfall kinetic energy (KE) flux. Its precise calibration was performed in laboratory ...

Pawe? Licznar; Janusz ?omotowski; S?awomir B?o?ski; Grzegorz J. Ciach

2008-05-01T23:59:59.000Z

30

WENO-enhanced gas-kinetic scheme for direct simulations of compressible transition and turbulence  

SciTech Connect

The recently developed Gas Kinetic Method (GKM) for computing fluid flow is enhanced with advanced reconstruction (interpolation) schemes to enable direct simulations of highly compressible transition and turbulence fields. Variants of Weighted Essentially Non-Oscillatory (WENO) reconstruction schemes of different orders of accuracy are implemented and examined along with more elementary van Leer method. The competing schemes are evaluated for their accuracy, efficiency and numerical stability. The computed results are compared against the Rapid Distortion Theory for the case of compressible shear turbulence and 'pressure-released' Burgers solution. In the case of decaying isotropic turbulence, the efficacy of the reconstruction schemes is evaluated by comparison against a 'gold standard' high-resolution simulation. The capabilities of the reconstruction schemes to capture linear, non-linear, pressure-released and viscous flow physics as well as solenoidal and dilatational features of the flow fields are established in isolation and combination. The most suitable WENO variant for integration with GKM is identified. Another important outcome of the study is the finding that temperature-interpolation is superior to energy-interpolation in avoiding negative temperatures arising due to the Gibbs phenomenon. Overall, this work advances the applicability of kinetic theory based GKM to a wider range of high Mach number flow physics.

Kumar, G., E-mail: gauravkr@tamu.edu [Department of Aerospace Engineering, Texas A and M University, College Station, TX 77843 (United States); Girimaji, S.S., E-mail: girimaji@tamu.edu [Department of Aerospace Engineering, Texas A and M University, College Station, TX 77843 (United States); Kerimo, J. [Department of Aerospace Engineering, Texas A and M University, College Station, TX 77843 (United States)] [Department of Aerospace Engineering, Texas A and M University, College Station, TX 77843 (United States)

2013-02-01T23:59:59.000Z

31

Direct measurement of antiferromagnetic domain fluctuations  

Science Journals Connector (OSTI)

... those on the nearest neighbour Cr atoms. What actually occurs is sinusoidal modulation of this elementary magnetic structure—called a spin density wave (SDW), with wavelength ?? = ? ... . Even though the measurements were done for mesoscopic samples, the effects on the electrical resistance (R) of the switching dynamics were small (?R/R???10-5) and ...

O. G. Shpyrko; E. D. Isaacs; J. M. Logan; Yejun Feng; G. Aeppli; R. Jaramillo; H. C. Kim; T. F. Rosenbaum; P. Zschack; M. Sprung; S. Narayanan; A. R. Sandy

2007-05-03T23:59:59.000Z

32

Direct kinetic correlation of carriers and ferromagnetism in Co2+ : ZnO  

SciTech Connect

We report the use of controlled introduction and removal of Zni to test the hypothesis that high-Curie-temperature ferromagnetism in cobalt-doped ZnO (Co2+:ZnO) is mediated by carriers. Using oriented epitaxial Co2+:ZnO films grown by chemical vapor deposition, kinetics measurements were used to correlate the oxidative quenching of ferromagnetism with the diffusion and oxidation of interstitial zinc. These results demonstrate controlled systematic variation of a key parameter involved in the ferromagnetism of Co2+:ZnO, namely interstitial zinc, and in the process unambiguously reveal this ferromagnetism to be dependent upon carriers. The distinction between defect-bound and free carriers in Co2+:ZnO is discussed

Kittilstved, Kevin R.; Schwartz, Dana A.; Tuan, Allan C.; Heald, Steve M.; Chambers, Scott A.; Gamelin, Daniel R.

2006-07-21T23:59:59.000Z

33

Kinetic Simulations of Retarding-Field Analyzer Measurements in Tokamak Edge Plasmas  

E-Print Network (OSTI)

Kinetic Simulations of Retarding-Field Analyzer Measurements in Tokamak Edge Plasmas Fabrice of probe measurements in tokamaks, particularly those obtained from Retarding-Field-Analyzers (RFAs) [1]. This type of probe provides an integral of the ion velocity distribution in tokamak edge plasmas, which

34

Direct tests of measurement uncertainty relations: what it takes  

E-Print Network (OSTI)

The uncertainty principle being a cornerstone of quantum mechanics, it is surprising that in nearly 90 years there have been no direct tests of measurement uncertainty relations. This lacuna was due to the absence of two essential ingredients: appropriate measures of measurement error (and disturbance), and precise formulations of such relations that are {\\em universally valid}and {\\em directly testable}. We formulate two distinct forms of direct tests, based on different measures of error. We present a prototype protocol for a direct test of measurement uncertainty relations in terms of {\\em value deviation errors} (hitherto considered nonfeasible), highlighting the lack of universality of these relations. This shows that the formulation of universal, directly testable measurement uncertainty relations for {\\em state-dependent} error measures remains an important open problem. Recent experiments that were claimed to constitute invalidations of Heisenberg's error-disturbance relation are shown to conform with the spirit of Heisenberg's principle if interpreted as direct tests of measurement uncertainty relations for error measures that quantify {\\em distances between observables}.

Paul Busch; Neil Stevens

2015-01-17T23:59:59.000Z

35

Rheology and stability kinetics of bare silicon nanoparticle inks for low-cost direct printing  

SciTech Connect

Highly dispersed and stable silicon nanoparticles ink is formulated for its application in direct printing or printable electronics. These dispersions are prepared from free-standing silicon nanoparticles which are not capped with any organic ligand, making it suitable for electronic applications. Silicon nanoparticles dispersions are prepared by suspending the nanoparticles in benzonitrile or ethanol by using polypropylene glycol (PPG) as a binder. All the samples show typical shear thinning behavior while the dispersion samples show low viscosities signifying good quality dispersion. Such thinning behavior favors in fabrication of dense films with spin-coating or patterns with drop casting. The dispersion stability is monitored by turbiscan measurements showing good stability for one week. A low-cost direct printing method for dispersion samples is also demonstrated to obtain micro-sized patterns. Low electrical resistivity of resulting patterns, adjustable viscosity and good stability makes these silicon nanoparticles dispersions highly applicable for direct printing process.

More, Priyesh V.; Jeong, Sunho; Seo, Yeong-Hui; Ryu, Beyong-Hwan; Choi, Youngmin [Advanced Materials Division, Korea Research Institute of Chemical Technology 141 Gajeong-ro, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Kim, Seong Jip [Advanced Materials Division, Korea Research Institute of Chemical Technology 141 Gajeong-ro, Yuseong-gu, Daejeon 305-600 Korea and Department of Materials Science and Engineering, Korea University 5-1 Anam-Dong, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Nahm, Sahn [Department of Materials Science and Engineering, Korea University 5-1 Anam-Dong, Seongbuk-gu, Seoul 136-701 (Korea, Republic of)

2013-12-16T23:59:59.000Z

36

Gamma Ray Mirrors for Direct Measurement of Spent Nuclear Fuel  

SciTech Connect

Direct measurement of the amount of Pu and U in spent nuclear fuel represents a challenge for the safeguards community. Ideally, the characteristic gamma-ray emission lines from different isotopes provide an observable suitable for this task. However, these lines are generally lost in the fierce flux of radiation emitted by the fuel. The rates are so high that detector dead times limit measurements to only very small solid angles of the fuel. Only through the use of carefully designed view ports and long dwell times are such measurements possible. Recent advances in multilayer grazing-incidence gamma-ray optics provide one possible means of overcoming this difficulty. With a proper optical and coating design, such optics can serve as a notch filter, passing only narrow regions of the overall spectrum to a fully shielded detector that does not view the spent fuel directly. We report on the design of a mirror system and a number of experimental measurements.

Pivovaroff, Dr. Michael J. [Lawrence Livermore National Laboratory (LLNL)] [Lawrence Livermore National Laboratory (LLNL); Ziock, Klaus-Peter [ORNL] [ORNL; Harrison, Mark J [ORNL] [ORNL; Soufli, Regina [Lawrence Livermore National Laboratory (LLNL)] [Lawrence Livermore National Laboratory (LLNL)

2014-01-01T23:59:59.000Z

37

Direct Compressive Measurements of Individual Titanium Dioxide Nanotubes  

E-Print Network (OSTI)

Direct Compressive Measurements of Individual Titanium Dioxide Nanotubes Tolou Shokuhfar the syn- thesis of TiO2 nanotube arrays using an aqueous HF based electrolyte.5 The pH of F ion containing electrolytes was con- trolled to form nanotubes up to a few mi- crometers in length. They reported

Endres. William J.

38

Coalescence kinetics in surfactant stabilized emulsions: Evolution equations from direct numerical simulations  

SciTech Connect

Lattice Boltzmann simulations were used to study the coalescence kinetics in emulsions with amphiphilic surfactant, under neutrally buoyant conditions, and with a significant kinematic viscosity contrast between the phases (emulating water in oil emulsions). The 3D simulation domain was large enough (256 3rd power -- 10 7th power grid points) to obtain good statistics with droplet numbers ranging from a few thousand at early times to a few hundred near equilibrium. Increased surfactant contents slowed down the coalescence rate between droplets due to the Gibbs-Marangoni effect, and the coalescence was driven by a quasi-turbulent velocity field. The kinetic energy decayed at a relatively slow rate at early times, due to conversion of interfacial energy to kinetic energy in the flow during coalescence. Phenomenological, coupled differential equations for the mean droplet diameter D(t) and the number density nd(t) were obtained from the simulation data and from film draining theories. Local (in time) power law exponents for the growth of the mean diameter (and for the concomitant decrease of nd) were established in terms of the instantaneous values of the kinetic energy, coalescence probability, Gibbs elasticity, and interfacial area. The model studies indicated that true power laws for the growth of the droplet size and decrease of the number of droplets with time may not be justified, since the exponents derived using the phenomenological model were time dependent. In contrast to earlier simulation results for symmetric blends with surfactant, we found no evidence for stretched logarithmic scaling of the formD -- [ln (ct)]a for the morphology length, or exponential scalings associated with arrested growth, on the basis of the phenomenological model.

R. Skartlien; E. Sollum; A. Akselsen; P. Meakin; B. Grimes; J. Sjoblom

2012-12-01T23:59:59.000Z

39

NETL: Emissions Characterization - Direct Measurement of Mercury Reactions  

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

Direct Measurement of Mercury Reactions in Coal Power Plant Plumes: Pleasant Prairie Plant Direct Measurement of Mercury Reactions in Coal Power Plant Plumes: Pleasant Prairie Plant Under DOE-NETL Cooperative Agreement DE-FC26-03NT41724, EPRI, in collaboration with Frontier Geosciences and the University of North Dakota Energy and Environmental Research Center (EERC), will perform precise in-stack and in-plume sampling of mercury emitted from the stack of WE Energies' Pleasant Prairie coal-fired power plant near Kenosha, Wisconsin. The overall objective of the project is to clarify the role, rates and end result of chemical transformations that may occur to mercury that has been emitted from elevated stacks of coal-fired electric power plants. This information is critical in determining the role of coal-fired plants in mercury deposition and in developing cost-effective, environmentally sound policies and strategies for reducing the adverse environmental effects of mercury.

40

Low frequency, electrodynamic simulation of kinetic plasmas with the DArwin Direct Implicit Particle-In-Cell (DADIPIC) method  

SciTech Connect

This dissertation describes a new algorithm for simulating low frequency, kinetic phenomena in plasmas. DArwin Direct Implicit Particle-in-Cell (DADIPIC), as its name implies, is a combination of the Darwin and direct implicit methods. One of the difficulties in simulating plasmas lies in the enormous disparity between the fundamental scale lengths of a plasma and the scale lengths of the phenomena of interest. The objective is to create models which can ignore the fundamental constraints without eliminating relevant plasma properties. Over the past twenty years several PIC methods have been investigated for overcoming the constraints on explicit electrodynamic PIC. These models eliminate selected high frequency plasma phenomena while retaining kinetic phenomena at low frequency. This dissertation shows that the combination of Darwin and Direct Implicit allows them to operate better than they have been shown to operate in the past. Through the Darwin method the hyperbolic Maxwell`s equations are reformulated into a set of elliptic equations. Propagating light waves do not exist in the formulation so the Courant constraint on the time step is eliminated. The Direct Implicit method is applied only to the electrostatic field with the result that electrostatic plasma oscillations do not have to be resolved for stability. With the elimination of these constraints spatial and temporal discretization can be much larger than that possible with explicit, electrodynamic PIC. The code functions in a two dimensional Cartesian region and has been implemented with all components of the particle velocities, the E-field, and the B-field. Internal structures, conductors or dielectrics, may be placed in the simulation region, can be set at desired potentials, and driven with specified currents.

Gibbons, M.R.

1995-06-01T23:59:59.000Z

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While these samples are representative of the content of NLEBeta,
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41

Solar Model Parameters and Direct Measurements of Solar Neutrino Fluxes  

E-Print Network (OSTI)

We explore a novel possibility of determining the solar model parameters, which serve as input in the calculations of the solar neutrino fluxes, by exploiting the data from direct measurements of the fluxes. More specifically, we use the rather precise value of the $^8B$ neutrino flux, $\\phi_B$ obtained from the global analysis of the solar neutrino and KamLAND data, to derive constraints on each of the solar model parameters on which $\\phi_B$ depends. We also use more precise values of $^7Be$ and $pp$ fluxes as can be obtained from future prospective data and discuss whether such measurements can help in reducing the uncertainties of one or more input parameters of the Standard Solar Model.

Abhijit Bandyopadhyay; Sandhya Choubey; Srubabati Goswami; S. T. Petcov

2006-08-30T23:59:59.000Z

42

A Direct Measurement of the $W$ Decay Width  

SciTech Connect

A direct measurement of the W boson total decay width is presented in proton-antiproton collisions at {radical}s = 1.96 TeV using data collected by the CDF II detector. The measurement is made by fitting a simulated signal to the tail of the transverse mass distribution in the electron and muon decay channels. An integrated luminosity of 350 pb{sup -1} is used, collected between February 2002 and August 2004. Combining the results from the separate decay channels gives the decay width as 2.038 {+-} 0.072 GeV in agreement with the theoretical prediction of 2.093 {+-} 0.002 GeV. A system is presented for the management of detector calibrations using a relational database schema. A description of the implementation and monitoring of a procedure to provide general users with a simple interface to the complete set of calibrations is also given.

Vine, Troy; /University Coll. London

2008-08-01T23:59:59.000Z

43

Direct Measurements of the Lifetime of Heavy Hypernuclei  

E-Print Network (OSTI)

The lifetime of a Lambda particle embedded in a nucleus (hypernucleus) decreases from that of free Lambda decay due to the opening of the Lambda N to NN weak decay channel. However, it is generally believed that the lifetime of a hypernucleus attains a constant value (saturation) for medium to heavy hypernuclear masses, yet this hypothesis has been difficult to verify. The present paper reports a direct measurement of the lifetime of medium-heavy hypernuclei produced with a photon-beam from Fe, Cu, Ag, and Bi targets. The recoiling hypernuclei were detected by a fission fragment detector using low-pressure multi-wire proportional chambers. The experiment agrees remarkably well with the only previously-measured single-species heavy-hypernucleus lifetime, that of Fe56_Lambda at KEK, and has significantly higher precision. The experiment disagrees with the measured lifetime of an unknown combination of heavy hypernuclei with 180

X. Qiu; L. Tang; A. Margaryan; P. Achenbach; A. Ahmidouch; I. Albayrak; D. Androic; A. Asaturyan; R. Asaturyan; O. Ates; R. Badui; P. Baturin; W. Boeglin; J. Bono; E. Brash; P. Carter; C. Chen; X. Chen; A. Chiba; E. Christy; M. M. Dalton; S. Danagoulian; R. De Leo; D. Doi; M. Elaasar; R. Ent; H. Fenker; Y. Fujii; M. Furic; M. Gabrielyan; L. Gan; F. Garibaldi; D. Gaskell; A. Gasparian; T. Gogami; O. Hashimoto; T. Horn; B. Hu; E. V. Hungerford; M. Jones; H. Kanda; M. Kaneta; M. Kawai; D. Kawama; H. Khanal; M. Kohl; A. Liyanage; W. Luo; K. Maeda; P. Markowitz; T. Maruta; A. Matsumura; V. Maxwell; A. Mkrtchyan; H. Mkrtchyan; S. Nagao; S. N. Nakamura; A. Narayan; C. Neville; G. Niculescu; M. I. Niculescu; A. Nunez; Nuruzzaman; Y. Okayasu; T. Petkovic; J. Pochodzalla; J. Reinhold; V. M. Rodriguez; C. Samanta; B. Sawatzky; T. Seva; A. Shichijo; V. Tadevosyan; N. Taniya; K. Tsukada; M. Veilleux; W. Vulcan; F. R. Wesselmann; S. A. Wood; L. Ya; T. Yamamoto; Z. Ye; K. Yokota; L. Yuan; S. Zhamkochyan; L. Zhu

2013-01-16T23:59:59.000Z

44

Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry  

SciTech Connect

The densities of pore-confined fluids were measured for the first time by means of a vibrating tube method. Isotherms of total adsorption capacity were measured directly making the method complementary to the conventional gravimetric or volumetric/piezometric adsorption techniques, which yield the excess adsorption (the Gibbsian surface excess). A custom-made high-pressure, high-temperature vibrating tube densimeter (VTD) was used to measure the densities of subcritical and supercritical propane (between 35 C and 97 C) and supercritical carbon dioxide (between 32 C and 50 C) saturating hydrophobic silica aerogel (0.2 g/cm3, 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, excess adsorption isotherms for supercritical CO2 and the same porous solid were measured gravimetrically using a precise magnetically-coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum at a subcritical density of the bulk fluid, and then decreased towards zero or negative values at supercritical densities. Compression of the confined fluid significantly beyond the density of the bulk liquid at the same temperature was observed at subcritical temperatures. The features of the isotherms of confined fluid density are interpreted to elucidate the observed behavior of excess adsorption. The maxima of excess adsorption were found to occur below the critical density of the bulk fluid at the conditions corresponding to the beginning of the plateau of total adsorption, marking the end of the transition of pore fluid to a denser, liquid-like pore phase. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. No measurable effect of pore confinement on the liquid-vapor critical point was found. Quantitative agreement was obtained between excess adsorption isotherms determined from VTD total adsorption results and those measured gravimetrically at the same temperature, confirming the validity of the vibrating tube measurements. Vibrating tube densimetry was demonstrated as a novel experimental approach capable of providing the average density of pore-confined fluids.

Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Rother, Gernot [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Wallacher, Dirk [Helmholtz-Zentrum Berlin

2012-01-01T23:59:59.000Z

45

Direct gas chromatography for the study of substrate removal kinetics in multi-component aqueous systems  

E-Print Network (OSTI)

and to provide an indication of the accu- racy and precision of the technique is described in Section III. Chemical oxygen demand. The 'standard APHA procedure is given in reference 2. The chemical oxygen demand test (COD) is a quantitative measure... 2o-3 0 during a test, possibly due to evaporation heat 0 losses. SECTION ZZZ CHEMICAL NOMENCLATURE AND ANALYTICAL HESPONSE Chemical nomenclature. Five organic compounds were investigated in this study. Zn referring to four of these compounds...

Langley, William Douglas

2012-06-07T23:59:59.000Z

46

Determination of the kinetic parameters of the CALIBAN metallic core reactor from stochastic neutron measurements  

SciTech Connect

Several experimental devices are operated by the Criticality and Neutron Science Research Dept. of the CEA Valduc Laboratory. One of these is the Caliban metallic core reactor. The purpose of this study is to develop and perform experiments allowing to determinate some of fundamental kinetic parameters of the reactor. The prompt neutron decay constant and particularly its value at criticality can be measured with reactor noise techniques such as Rossi-{alpha} and Feynman variance-to-mean methods. Subcritical, critical, and even supercritical experiments were performed. Fission chambers detectors were put nearby the core and measurements were analyzed with the Rossi-{alpha} technique. A new value of the prompt neutron decay constant at criticality was determined, which allows, using the Nelson number method, new evaluations of the effective delayed neutron fraction and the in core neutron lifetime. As an introduction of this paper, some motivations of this work are given in part 1. In part 2, principles of the noise measurements experiments performed at the CEA Valduc Laboratory are reminded. The Caliban reactor is described in part 3. Stochastic neutron measurements analysis techniques used in this study are then presented in part 4. Results of fission chamber experiments are summarized in part 5. Part 6 is devoted to the current work, improvement of the experimental device using He 3 neutron detectors and first results obtained with it. Finally, conclusions and perspectives are given in part 7. (authors)

Casoli, P.; Authier, N.; Chapelle, A. [Commissariat a l'Energie Atomique et Aux Energies Alternatives, CEA, DAM, F-21120 Is sur Tille (France)

2012-07-01T23:59:59.000Z

47

Direct Measurement of Mercury Reactions In Coal Power Plant Plumes  

SciTech Connect

Recent field and pilot-scale results indicate that divalent mercury emitted from power plants may rapidly transform to elemental mercury within the power plant plumes. Simulations of mercury chemistry in plumes based on measured rates to date have improved regional model fits to Mercury Deposition Network wet deposition data for particular years, while not degrading model verification fits for remaining years of the ensemble. The years with improved fit are those with simulated deposition in grid cells in the State of Pennsylvania that have matching MDN station data significantly less than the model values. This project seeks to establish a full-scale data basis for whether or not significant reduction or oxidation reactions occur to mercury emitted from coal-fired power plants, and what numerical redox rate should apply for extension to other sources and for modeling of power plant mercury plumes locally, regionally, and nationally. Although in-stack mercury (Hg) speciation measurements are essential to the development of control technologies and to provide data for input into atmospheric fate and transport models, the determination of speciation in a cooling coal combustion plume is more relevant for use in estimating Hg fate and effects through the atmosphere. It is mercury transformations that may occur in the plume that determine the eventual rate and patterns of mercury deposited to the earth's surface. A necessary first step in developing a supportable approach to modeling any such transformations is to directly measure the forms and concentrations of mercury from the stack exit downwind to full dispersion in the atmosphere. As a result, a study was sponsored by EPRI and jointly funded by EPRI, the U.S Department of Energy (DOE), and the Wisconsin Department of Administration. The study was designed to further our understanding of plume chemistry. The study was carried out at the We Energies Pleasant Prairie Power Plant, Pleasant Prairie, Wisconsin, just west of Kenosha. Aircraft and ground measurements support the occurrence of a reduction in the fraction of reactive gaseous mercury (RGM) (with a corresponding increase in elemental mercury) as part of the Total Gaseous Mercury (TGM) emitted from the Pleasant Prairie stack. This occurrence is based on comparison of the RGM concentrations in the plume (at standard conditions) compared to the RGM in the stack. There was found to be a 44% drop in the fraction of RGM between the stack exit and the first sampling arc and a 66% reduction from the stack to the 5-mile sampling arc, with no additional drop between the 5- and 10-mile arcs. Smaller-scale experiments in both test chambers and pilot-scale coal combustor exhaust streams have indicated the presence of rapid and relatively complete reduction reactions converting divalent into elemental mercury within power plant plumes prior to full dispersion in the atmosphere. These measurements, however, have been unable to identify whether the reactions occur during plume rise from physical to virtual stack height (during positive thermal buoyancy). The presence, rate, completeness, ubiquity, and dependence on source characteristics of these reactions, however, must be demonstrated in plume environments associated with fully operational power plants. That requirement, to capture either the reactions or the reaction products of chemistry that may be occurring very close to stack exits in highly turbulent environments, constrains the precision and reproducibility with which such full-scale experiments can be carried out. The work described here is one of several initial steps required to test whether, and in what direction, such rapid mercury redox reactions might be occurring in such plumes.

Leonard Levin

2005-12-31T23:59:59.000Z

48

Weak Values and Direct Measurement of the Quantum Wavefunction  

Science Journals Connector (OSTI)

We review recent work showing that weak values and weak measurements can be used to perform certain measurements with unprecedented accuracy and moreover can be used to perform a...

Boyd, Robert W

49

Measurement of Turbulent Kinetic Energy Dissipation Rate with a Lagrangian Float  

Science Journals Connector (OSTI)

This study tests the ability of a neutrally buoyant float to estimate the dissipation rate of turbulent kinetic energy ? from its vertical acceleration spectrum using an inertial subrange method. A Lagrangian float was equipped with a SonTek ...

Ren-Chieh Lien; Eric A. D'Asaro

2006-07-01T23:59:59.000Z

50

Revealing the surface and bulk regimes of isothermal graphene growth on Ni with in situ kinetic measurements and modeling  

SciTech Connect

In situ optical diagnostics are used to reveal the isothermal nucleation and growth mechanisms of graphene on Ni across a wide temperature range (560 C < T < 840 C) by chemical vapor deposition from single, sub-second pulses of acetylene. An abrupt, two-orders of magnitude change in growth times (~ 100s to 1s) is revealed at T = 680 C. Below and above this temperature, similar sigmoidal kinetics are measured and attributed to autocatalytic growth reactions but by two different mechanisms, surface assembly and dissolution/precipitation, respectively. These data are used to develop a simple and general kinetic model for graphene growth that includes the nucleation phase and includes the effects of carbon solubility in metals, describes delayed nucleation, and allows the interpretation of the competition between surface and bulk growth modes. The sharp transition in growth kinetics at T = 680 C is explained by a change in defect site density required for nucleation due to a transition in the carbon-induced mobility of the Ni surface. The easily-implemented optical reflectivity diagnostics and the simple kinetic model described here allow a pathway to optimize the growth of graphene on metals with arbitrary carbon solubility.

Puretzky, Alexander A [ORNL; Merkulov, Igor A [ORNL; Rouleau, Christopher M [ORNL; Eres, Gyula [ORNL; Geohegan, David B [ORNL

2014-01-01T23:59:59.000Z

51

A TECHNIQUE FOR DIRECTLY MEASURING THE GRAVITATIONAL ACCELERATION OF ANTIHYDROGEN  

E-Print Network (OSTI)

, and the construction of the Low Energy An­ tiproton Ring (LEAR) at CERN has made it possible to trap substantial of antimatter (g) by measuring the deflection of a beam of neutral antihydrogen atoms in the Earth trapping techniques has made it possible to hold and cool particles (charged or neutral) 3

Phillips, Thomas J.

52

Direct Measurements of 22 Mg Resonances and Consequences  

E-Print Network (OSTI)

that depend on the thermonuclear rate of the 22Naðp; �23Mg reaction. We have measured the strengths of low A classical nova is a thermonuclear outburst on the surface of a white-dwarf star that is accreting hydrogen nucleosynthesis because most of the relevant thermonuclear reaction rates are based on experimental information [1

Garcia, Alejandro

53

Direct measurements of neutron capture on radioactive isotopes  

E-Print Network (OSTI)

We simulated the response of a 4p calorimetric g-detector array to decays of radioactive isotopes on the s-process path. The GEANT 3.21 simulation package was used. The main table contains estimates on the maximum sample size and required neutron flux based on the latest available neutron capture cross section at 30 keV. The results are intended to be used to estimate the feasibility of neutron capture measurements with 4p arrays using the time of flight technique.

A. Couture; R. Reifarth

2009-09-30T23:59:59.000Z

54

Direct Measurement of Colloidal Forces in an Anisotropic Solvent  

Science Journals Connector (OSTI)

We present a new method to measure attractive interactions between colloidal particles, and determine the nature of the attraction between particles suspended in a nematic liquid crystal. We confine droplets filled with ferrofluid to a thin layer and apply a magnetic field to induce dipole moments that drive the droplets apart. When the field is removed, the attractive interactions pull the droplets back together. The force is determined from the velocity because the motion is viscously damped. We confirm the dipolar character of the interaction between droplets in a nematic solvent.

P. Poulin; V. Cabuil; D. A. Weitz

1997-12-15T23:59:59.000Z

55

DIRECT MEASUREMENT OF MERCURY REACTIONS IN COAL POWER PLANT PLUMES  

SciTech Connect

This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-02NT41422 and specifically addresses Program Area of Interest: No.5--Environmental and Water Resources. The project team includes the Electric Power Research Institute (EPRI) as the contractor and the University of North Dakota Energy & Environmental Research Center (EERC) and Frontier Geosciences as subcontractors. Wisconsin Energies and its Pleasant Prairie Power Plant acted as host for the field-testing portion of the research. The project is aimed at clarifying the role, rates, and end results of chemical transformations that may occur to mercury that has been emitted from elevated stacks of coal-fired electric power plants. Mercury emitted from power plants emerges in either its elemental, divalent, or particulate-bound form. Deposition of the divalent form is more likely to occur closer to the source than that of the other two forms, due to its solubility in water. Thus, if chemical transformations occur in the stack emissions plume, measurements in the stack may mischaracterize the fate of the material. Initial field and pilot plant measurements have shown significant and rapid chemical reduction of divalent to elemental mercury may occur in these plumes. Mercury models currently assume that the chemical form of mercury occurring in stacks is the same as that which enters the free atmosphere, with no alteration occurring in the emissions plume. Recent data indicate otherwise, but need to be evaluated at full operating scale under field conditions. Prestbo and others have demonstrated the likelihood of significant mercury chemical reactions occurring in power plant plumes (Prestbo et al., 1999; MDNR-PPRP, 2000; EERC, 2001). This experiment will thus increase our understanding of mercury atmospheric chemistry, allowing informed decisions regarding source attribution. The experiment was carried out during the period August 22-September 5, 2003. The experimental site was the Pleasant Prairie Power Plant in Pleasant Prairie, Wisconsin, just west of Kenosha. The experiment involved using an aircraft to capture emissions and document chemistry changes in the plume. While using the airplane for sampling, supplemental fast-response sensors for NOx, connected to data loggers, were used to gauge entry and exit times and transect intervals through plume emissions material. The Frontier Geosciences Static Plume Dilution Chamber (SPDC) was employed simultaneously adjacent to the stack to correlate its findings with the aircraft sampling, as well as providing evaluation of the SPDC as a rapid, less costly sampler for mercury chemistry. A complementary stack plume method, the Dynamic Plume Dilution (DPD) was used in the latter portion of the experiment to measure mercury speciation to observe any mercury reduction reaction with respect to both the reaction time (5 to 30 seconds) and dilution ratio. In addition, stack sampling using the ''Ontario Hydro'' wet chemistry method and continuous mercury monitors (CMM) were used to establish the baseline chemistry in the stack. Comparisons among stack, SPDC, DPD and aircraft measurements allow establishment of whether significant chemical changes to mercury occur in the plume, and of the verisimilitude of the SPDC and DPD methods. This progress report summarizes activities during a period of results review from the stack/aircraft subcontractor, data analysis and synthesis, and preparation and presentation of preliminary results to technical and oversight meetings.

Leonard Levin

2006-06-01T23:59:59.000Z

56

Estimates of rates and errors for measurements of direct-. gamma. and direct-. gamma. + jet production by polarized protons at RHIC  

SciTech Connect

Studies of inclusive direct-{gamma} production by pp interactions at RHIC energies were performed. Rates and the associated uncertainties on spin-spin observables for this process were computed for the planned PHENIX and STAR detectors at energies between {radical}s = 50 and 500 GeV. Also, rates were computed for direct-{gamma} + jet production for the STAR detector. The goal was to study the gluon spin distribution functions with such measurements. Recommendations concerning the electromagnetic calorimeter design and the need for an endcap calorimeter for STAR are made.

Beddo, M.E.; Spinka, H.; Underwood, D.G.

1992-08-14T23:59:59.000Z

57

Direct measurements of ion dynamics in collisional magnetic presheaths  

SciTech Connect

Ion velocities and temperatures are measured in the presheath of a grounded plate downstream from an argon helicon plasma source using laser-induced fluorescence (P{sub rf}?450?750?W, T{sub e}=2.5?5?eV, T{sub i}=0.1?0.6?eV, n{sub 0}?1×10{sup 12}cm{sup ?3},?p{sub n}=1?6.5?mTorr, ?=0.3?2?cm, ?{sub i}??0.5?cm). The plate is held 16°?60° relative to the 1?kG background axial magnetic field. The velocity profiles are compared to a 1D fluid model similar to those presented by Riemann [Phys. Plasmas 1, 552 (1994)] and Ahedo [Phys. Plasmas 4, 4419 (1997)] for the 1 mTorr dataset and are shown to agree well. The model is sensitive to parameters such as collision and ionization frequencies and simplified models, such one presented by Chodura [Phys. Fluids 25, 1628 (1982)], are shown to be inaccurate. E{sup ?}×B{sup ?} flows as large as 40% of c{sub s} at the sheath edge are inferred. Definitions for the term “magnetic presheath” and implications for ion flow to tokamak divertors and Hall thruster walls are discussed.

Siddiqui, M. Umair [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Jackson, Cory D.; Kim, Justin F.; Hershkowitz, Noah [Department of Engineering Physics, The University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States)

2014-10-15T23:59:59.000Z

58

Beam Energy Dependence of Directed and Elliptic Flow Measurement from the STAR Experiment  

E-Print Network (OSTI)

Measurements of anisotropic flow in heavy-ion collisions provide insight into the early stage of the system's evolution. This proceedings presents directed and elliptic flow for Au+Au collisions at 39, 11.5 and 7.7 GeV, and for Cu+Cu at 22.4 GeV, measured in the STAR Experiment at RHIC. Differential measurements of directed and elliptic flow of charged particles as a function of centrality, transverse momentum and pseudorapidity are discussed.

Yadav Pandit

2011-09-13T23:59:59.000Z

59

Direct  

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

interactions, and the pollutant emission is hence directly proportional to the bulk neutral density. Simultaneously monitoring the total emission at 1040 nm and the...

60

On the Results of Measurements of the Direct Sun Radiation Flux...  

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

On the Results of Measurements of the Direct Sun Radiation Flux by Actinometer and of Maximal Polarization of Sky Brightness in the Solar Almucantar A. Kh. Shukurov, K. A....

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


61

A Technique for Deducing Wind Direction from Satellite Microwave Measurements of Wind Speed  

Science Journals Connector (OSTI)

A technique is presented to deduce wind direction from satellite microwave measurements of wind speed information. The technique, based on simple Ekman boundary layer dynamics, makes use of surface pressure fields routinely analyzed at the ...

Tsann-wang Yu

1987-09-01T23:59:59.000Z

62

Can we measure terrestrial photosynthesis from space directly, using spectral reflectance and fluorescence?  

E-Print Network (OSTI)

Can we measure terrestrial photosynthesis from space directly, using spectral reflectance the changes in the xanthophyll cycle, which is closely coupled to photosynthesis. Several studies have shown of fluorescence, which is a directly related to the efficiency of photosynthesis. We discuss the state of the art

Jones, Peter JS

63

A Direct Error Measure for Affine Models of Nonlinear Algebraic Systems  

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

A Direct Error Measure for Affine Models of Nonlinear Algebraic Systems A Direct Error Measure for Affine Models of Nonlinear Algebraic Systems Speaker(s): David Lorenzetti Date: June 2, 1999 - 12:00pm Location: Bldg. 90 The Newton-Raphson solution of a nonlinear system iterately linearizes the equations, then steps to the solution of the resulting affine model. When a step exceeds the predictive range of its model, the method can diverge. The traditional response -- aggregating the equations into a cost function, and applying a minimization method -- suppresses information about how each equation model performs. Direct error measures examine the equations individually, allowing finer control over step lengths. The seminar will develop one such measure through the geometry of simple one- and two-dimensional examples, then present results from a suite of larger

64

PUBLISHED ONLINE: 3 APRIL 2011 | DOI: 10.1038/NPHYS1963 Direct measurement of the energy dissipated by  

E-Print Network (OSTI)

LETTERS PUBLISHED ONLINE: 3 APRIL 2011 | DOI: 10.1038/NPHYS1963 Direct measurement of the energy to make the first direct measurement of the energy released by freely decaying quantum turbulence. Our,5), allowing a determination of . In contrast, a direct measurement of the energy dissipated in quantum

Loss, Daniel

65

Improvement of Tornado Warnings by Doppler Radar Measurement of Mesocyclone Rotational Kinetic Energy  

Science Journals Connector (OSTI)

A significant improvement in the reliability and timeliness of tornado warnings can be achieved through quantitative measurement by Doppler radar of selected mesocyclone features. The mesocyclone, a midsize circulation found in some of the most ...

Ralph J. Donaldson Jr.; Paul R. Desrochers

1990-06-01T23:59:59.000Z

66

Fundamental Kinetics Database Utilizing Shock Tube Measurements (Volumes 1, 2, 3, 4, and Volume 6)  

DOE Data Explorer (OSTI)

The data from shock tube experiments generally takes three forms: ignition delay times, species concentration time-histories and reaction rate measurements. Volume 1 focuses on ignition delay time data measured and published by the Shock Tube Group in the Mechanical Engineering Department of Stanford University. The cut-off date for inclusion into this volume was January 2005. Volume 2 focuses on species concentration time-histories and was cut off December 2005. The two volumes are in PDF format and are accompanied by a zipped file of supporting data. Volume 3 was issued in 2009. Volume 4, Ignition delay times measurements came out in May, 2014, along with Reaction Rates Measurements, Vol 6. Volume 5 is not available at this time.

Davidson, D.F.; Hanson, R.K

67

Small-volume, ultrahigh-vacuum-compatible high-pressure reaction cell for combined kinetic and in situ IR spectroscopic measurements on planar model catalysts  

SciTech Connect

We describe the design and performance of a high-pressure reaction cell for simultaneous kinetic and in situ infrared reflection (IR) spectroscopic measurements on model catalysts at elevated pressures, between 10{sup -3} and 10{sup 3} mbars, which can be operated both as batch reactor and as flow reactor with defined gas flow. The cell is attached to an ultrahigh-vacuum (UHV) system, which is used for sample preparation and also contains facilities for sample characterization. Specific for this design is the combination of a small cell volume, which allows kinetic measurements with high sensitivity under batch or continuous flow conditions, the complete isolation of the cell from the UHV part during UHV measurements, continuous temperature control during both UHV and high-pressure operation, and rapid transfer between UHV and high-pressure stage. Gas dosing is performed by a designed gas-handling system, which allows operation as flow reactor with calibrated gas flows at adjustable pressures. To study the kinetics of reactions on the model catalysts, a quadrupole mass spectrometer is connected to the high-pressure cell. IR measurements are possible in situ by polarization-modulation infrared reflection-absorption spectroscopy, which also allows measurements at elevated pressures. The performance of the setup is demonstrated by test measurements on the kinetics for CO oxidation and the CO adsorption on a Au/TiO{sub 2}/Ru(0001) model catalyst film at 1-50 mbar total pressure.

Zhao, Z.; Diemant, T.; Haering, T.; Rauscher, H.; Behm, R.J. [Department Surface Chemistry and Catalysis, University of Ulm, D-89069 Ulm (Germany)

2005-12-15T23:59:59.000Z

68

Measurement of Condensed-Phase Reaction Kinetics in the Aerosol Phase Using Single Particle Mass Spectrometry  

E-Print Network (OSTI)

thermogravimetric analysis, and a comparison revealed significant differences in measured reaction rates between containing precursors are injected into a thermal reactor, with resulting evaporation of solvent and reaction the reliability of these methods.3 The literature is rife with examples indicating that traditional thermal a

Zachariah, Michael R.

69

1) Title of the paper: Directionality Measurement and Illumination Estimation of  

E-Print Network (OSTI)

International Conference on Pattern Recognition, ICPR.}, year = {2008} } hal-00324244,version1-12Jul2010 Author manuscript, published in "19th International Conference on Pattern Recognition, Tampa : United States (2008 transform projections with different project angles. The measured texture directions are compared with human

Boyer, Edmond

70

GUINEVERE experiment: Kinetic analysis of some reactivity measurement methods by deterministic and Monte Carlo codes  

SciTech Connect

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

71

Direct thrust measurement of a permanent magnet helicon double layer thruster  

SciTech Connect

Direct thrust measurements of a permanent magnet helicon double layer thruster have been made using a pendulum thrust balance and a high sensitivity laser displacement sensor. At the low pressures used (0.08 Pa) an ion beam is detected downstream of the thruster exit, and a maximum thrust force of about 3 mN is measured for argon with an rf input power of about 700 W. The measured thrust is proportional to the upstream plasma density and is in good agreement with the theoretical thrust based on the maximum upstream electron pressure.

Takahashi, K.; Lafleur, T.; Charles, C.; Alexander, P.; Boswell, R. W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Perren, M.; Laine, R. [ASTRIUM-EADS, 6 rue Laurent Pichat, 75016 Paris (France); Pottinger, S.; Lappas, V.; Harle, T.; Lamprou, D. [Surrey Space Centre, University of Surrey, Guildford GU2 7XH (United Kingdom)

2011-04-04T23:59:59.000Z

72

Metal dependent structure, dynamics, and function in RNA measured by site-directed spin labeling and EPR spectroscopy  

E-Print Network (OSTI)

.6 nucleotide, and that in 0.1 M NaCl the docking occurs at submillimolar Mg2+ concentrations ([Mg2+]1/2, docking = ~ 0.7 mM). Kinetics measurements show that the hammerhead ribozyme requires high concentration of Mg2+ for the maximum cleavage activity ([Mg2...

Kim, Nak-Kyoon

2007-04-25T23:59:59.000Z

73

Measurement of the Rates of Production and Dissipation of Turbulent Kinetic Energy in an Energetic Tidal Flow: Red Wharf Bay Revisited  

Science Journals Connector (OSTI)

Simultaneous measurements of the rates of turbulent kinetic energy (TKE) dissipation (?) and production (P) have been made over a period of 24 h at a tidally energetic site in the northern Irish Sea in water of 25-m depth. Some ? profiles from ?5 ...

Tom P. Rippeth; John H. Simpson; Eirwen Williams; Mark E. Inall

2003-09-01T23:59:59.000Z

74

Exploration of jet energy loss via direct $?$-charged particle azimuthal correlation measurements  

E-Print Network (OSTI)

The multiplicities of charged particles azimuthally associated with direct photons and $\\pi^{0}$ have been measured for Au+Au, p+p, and d+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV in the STAR experiment. Charged particles with transverse momentum 0.5 $<$ $p_T^{h^{\\pm}}$ $<$ 16 GeV/c for p+p and d+Au, and 3 $<$ $p_T^{h^{\\pm}}$ $<$ 16 GeV/c for Au+Au and pseudorapidity $\\mid\\eta\\mid$ $\\leq$ 1.5 in coincidence with direct photons and $\\pi^{0}$ of high transverse momentum 8 $<$ $p_T^{\\gamma,\\pi^{0}}$ $<$ 16 GeV/c at $\\mid\\eta\\mid$ $\\leq$ 0.9 have been used for this analysis. Within the considered range of kinematics, the observed suppressions of the associated yields per direct $\\gamma$ in central Au+Au relative to p+p and d+Au are similar and constant with direct photon fractional energy $z_{T}$ ($z_{T}=p_{T}^{h^{\\pm}}/p_{T}^{\\gamma}$). The measured suppressions of the associated yields with direct $\\gamma$ are comparable to those with $\\pi^{0}$. The data are compared to theoretical predictions.

A. M. Hamed

2009-09-25T23:59:59.000Z

75

Separation of Rashba and Dresselhaus spin-orbit interactions using crystal direction dependent transport measurements  

SciTech Connect

The Rashba spin-orbit interaction effective field is always in the plane of the two-dimensional electron gas and perpendicular to the carrier wavevector but the direction of the Dresselhaus field depends on the crystal orientation. These two spin-orbit interaction parameters can be determined separately by measuring and analyzing the Shubnikov-de Haas oscillations for various crystal directions. In the InAs quantum well system investigated, the Dresselhaus term is just 5% of the Rashba term. The gate dependence of the oscillation patterns clearly shows that only the Rashba term is modulated by an external electric field.

Ho Park, Youn [Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of) [Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Hyung-jun; Chang, Joonyeon; Hee Han, Suk [Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of)] [Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Eom, Jonghwa [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)] [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of); Choi, Heon-Jin [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)] [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Cheol Koo, Hyun, E-mail: hckoo@kist.re.kr [Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701 (Korea, Republic of)

2013-12-16T23:59:59.000Z

76

Kinetic measurements of the gas-phase reactions of OH radicals with hydroxy ethers, hydroxy ketones, and keto ethers  

SciTech Connect

Absolute rate constants were determined for the gas-phase reactions of hydroxyl radicals with a series of hydroxy ethers as well as the simplest hydroxy ketone and keto ether with use of the flash photolysis resonance fluorescence technique. At 298 K, the measured rate constants were as follows (in units of 10{sup {minus}12} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}): 2-methoxyethanol, 12.5 {plus minus} 0.7; 2-ethoxyethanol, 18.7 {plus minus} 2.0; 2-butoxyethanol, 23.1 {plus minus} 0.9; 3-ethoxy-1-propanol, 22.0 {plus minus} 1.3; 3-methoxy-l-butanol, 23.6 {plus minus} 1.6; acetol, 3.0 {plus minus} 0.3; and methoxyacetone, 6.8 {plus minus} 0.6. The kinetic data for 2-methoxyethanol obtained between 240 and 440 K were used to derive the following Arrhenius expression: k{sub 1} = (4.5 {plus minus} 1.4) {times} 10{sup {minus}12} exp((325 {plus minus} 100)/T) (cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}). The results for all seven reactants are discussed in terms of the prediction of OH rate constants for oxygenated organic compounds.

Dagaut, P.; Liu, R.; Wallington, T.J.; Kurylo, M.J. (National Institute of Standards and Technology, Gaithersburg, MD (USA))

1989-11-16T23:59:59.000Z

77

Simultaneous measurement of x-ray absorption spectra and kinetics : a fixed-bed, plug-flow operando reactor.  

SciTech Connect

An inexpensive fixed-bed, plug-flow operando reactor is described in which X-ray absorbance and kinetic data can be measured simultaneously. Pt L3 (11.56 keV) XANES and EXAFS data were obtained on a 1.5% Pt/silica catalyst in borosilicate glass reactors of different diameters, 3-6 mm, and thicknesses, 0.3-1.2 mm, some of which are capable of operation at pressures up to about 40 atm. Additionally, polyimide tubular reactors with low absorbance can be used for lower energy edges of the 3d transition metals, or fluorescence detection for low concentration or highly absorbing supports. With the polyimide reactor, however, the pressure is limited to {approx}3.5 atm and the reaction temperature to about 300 C. To validate the reactor, the rate and activation energies for the water-gas shift reaction on 2% Pd, 13.7% Zn on Al2O3 catalyst were within 15% of those obtained in a standard laboratory reactor, which is within laboratory reproducibility. In addition, the Pd K edge (24.35 keV) XANES and EXAFS data on pre-reduced catalyst were identical to that previously determined on a regular cell. The EXAFS data show that the degree of Pd-Zn alloy formation changes with reaction temperature demonstrating the importance of characterizing the catalyst under reaction conditions.

Fingland, B. R.; Ribeiro, F. H.; Miller, J. T.; Purdue Univ.

2009-08-01T23:59:59.000Z

78

Partial discharge measurements on a high voltage direct current mass impregnated paper cable  

SciTech Connect

Partial discharge measurement has been a good tool for the quality assurance of cables under alternating voltage. With the growing interest in High Voltage Direct Current cables it seems therefore logical to extend this technique for use at direct voltage. The paper describes this technique as used on a HVDC cable with mass impregnated paper. The different phases of operation (no load, full load, cooling phase, etc.) are characterized by a different discharge behavior. Special attention is given to the dangerous cooling phase. Models have been developed which can explain the discharge patterns that were measured. This paper gives an insight in the electrical behavior of a HVDC cable with mass impregnated paper insulation.

Jeroense, M.J.P. [NKF KABEL B.V., Delft (Netherlands); Kreuger, F.H. [Delft Univ. of Technology (Netherlands)

1996-12-31T23:59:59.000Z

79

Direct extraction of coherent mode properties from imaging measurements in a linear plasma column  

SciTech Connect

Spectral properties of coherent waves in an argon plasma column are examined using fluctuation data from fast imaging. Visible light from ArII line emission is collected at high frame rates using a high-speed digital camera. A cross-spectral phase technique allows direct visualization of dominant phase structures as a function of frequency, as well as identification of azimuthal asymmetries present in the system. Experimental dispersion estimates are constructed from imaging data alone. Drift-like waves are identified by comparison with theoretical dispersion curves, and a tentative match of a low-frequency spectral feature to Kelvin-Helmholtz-driven waves is presented. Imaging measurements are consistent with previous results, and provide non-invasive, single-shot measurements across the entire plasma cross-section. Implications of the measured spectral properties for imaging measurements of mode dynamics are explored.

Light, A. D.; Sechrest, Y.; Munsat, T. [Center for Momentum Transport and Flow Organization, University of California San Diego, La Jolla, California 92093 (United States) [Center for Momentum Transport and Flow Organization, University of California San Diego, La Jolla, California 92093 (United States); Center for Integrated Plasma Studies, Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309 (United States); Thakur, S. C.; Brandt, C.; Tynan, G. R. [Center for Momentum Transport and Flow Organization, University of California San Diego, La Jolla, California 92093 (United States) [Center for Momentum Transport and Flow Organization, University of California San Diego, La Jolla, California 92093 (United States); Department of Mechanical and Aerospace Engineering and Center for Energy Research, University of California San Diego, La Jolla, California 92093 (United States)

2013-08-15T23:59:59.000Z

80

Nuclear matrix elements from direct lifetime or cross-section measurements  

SciTech Connect

The method of simultaneous lifetime and g factor measurements using a plunger device and the RDDS and TDRIV techniques is introduced. Results on lifetimes and hyperfine-interaction parameters for 2{sup +}{sub 1} states in {sup 104-108}Pd, {sup 96,98,104}Ru, and {sup 92,94}Zr, using a plunger device. Another method to obtain electromagnetic matrix elements is direct cross section measurements using NRF. The method is outlined, and some recent results on {sup 76}Se are shown.

Werner, V.; Cooper, N.; Hinton, M.; Ilie, G.; Radeck, D. [Wright Nuclear Structure Laboratory, Yale University, P.O. Box 208120, New Haven, CT 06520-8120 (United States); Wright Nuclear Structure Laboratory, Yale University, P.O. Box 208120, New Haven, CT 06520-8120 (United States) and Department of Physics, University of Surrey, Guilford, GU27XH (United Kingdom); Wright Nuclear Structure Laboratory, Yale University, P.O. Box 208120, New Haven, CT 06520-8120 (United States) and National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, Bucharest-Magurele (Romania); Wright Nuclear Structure Laboratory, Yale University, P.O. Box 208120, New Haven, CT 06520-8120 (United States) and Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

2012-11-20T23:59:59.000Z

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81

Four-point probe measurements of a direct current potential drop on layered conductive cylinders  

Science Journals Connector (OSTI)

We have determined the steady state electric field due to direct current flowing via point contacts at the cylindrical surface of a uniformly layered conductive rod of finite length. The solution allows one to use four-point probe potential drop measurements to estimate the conductivity or thickness of the layer assuming that the other parameters are known. The electrical potential in the rod has a zero radial derivative at its surface except at the injection and extractions points. This means that the required solution can be expressed in terms of a Green's function satisfying a Neumann boundary condition. Four-point measurements have been made to demonstrate the validity of theoretical results.

Yi Lu; John R Bowler

2012-01-01T23:59:59.000Z

82

Measuring of fissile isotopes partial antineutrino spectra in direct experiment at nuclear reactor  

E-Print Network (OSTI)

The direct measuring method is considered to get nuclear reactor antineutrino spectrum. We suppose to isolate partial spectra of the fissile isotopes by using the method of antineutrino spectrum extraction from the inverse beta decay positron spectrum applied at Rovno experiment. This admits to increase the accuracy of partial antineutrino spectra forming the total nuclear reactor spectrum. It is important for the analysis of the reactor core fuel composition and could be applied for non-proliferation purposes.

V. V. Sinev

2009-02-22T23:59:59.000Z

83

Gamma-gamma directional correlation measurements in 84Kr following thermal neutron capture by natural krypton  

Science Journals Connector (OSTI)

Directional correlations of gamma-ray cascades in 84Kr have been measured following thermal neutron capture by a pressurised natural krypton gas target. Gamma-ray singles spectra were measured up to 5.5 MeV and the correlation data were obtained for the energy range 0.2-2.5 MeV. A decay scheme was developed on the basis of coincidence measurements. The data allow spin-parity assignments to be made to most levels lying below 3.5 MeV and multipole mixing ratios to be evaluated for the more intense transitions. The results are fitted to the SU(5) limit of the IBM-1 and to the IBM-2 and are also compared with the predictions of the dynamic deformation model which indicates that 84Kr is the only krypton isotope with a prolate equilibrium shape. A possible mixed symmetry 2+ state at 2.623 MeV is identified.

S A Hamada; W D Hamilton; F Hoyler

1987-01-01T23:59:59.000Z

84

Direct high-precision measurement of the magnetic moment of the proton  

E-Print Network (OSTI)

The spin-magnetic moment of the proton $\\mu_p$ is a fundamental property of this particle. So far $\\mu_p$ has only been measured indirectly, analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here, we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin-transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in units of the nuclear magneton $\\mu_p=2.792847350(9)\\mu_N$. This measurement outperforms previous Penning trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty year old indirect measurement, in which significant theoretical bound state corrections were required to obtain $\\mu_p$, by a factor of 3. By application of this method to the antiproton magnetic moment $\\mu_{\\bar{p}}$ the fractional precision of the recently reported value can be improved by a factor of at least 1000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons.

A. Mooser; S. Ulmer; K. Blaum; K. Franke; H. Kracke; C. Leiteritz; W. Quint; C. C. Rodegheri; C. Smorra; J. Walz

2014-06-18T23:59:59.000Z

85

Measurement of temperature distributions in large pool fires with the use of directional flame thermometers  

SciTech Connect

Temperatures inside the flame zone of large regulatory pool fires measured during tests of radioactive materials packages vary widely with both time and position. Measurements made with several Directional Flame Thermometers, in which a thermocouple is attached to a thin metal sheet that quickly approaches flame temperatures, have been used to construct fire temperature distributions and cumulative probability distributions. As an aid to computer simulations of these large fires, these distributions are presented. The distributions are constructed by sorting fire temperature data into bins 10 C wide. A typical fire temperature distribution curve has a gradual increase starting at about 600 C, with the number of observations increasing to a peak near 1000 C, followed by an abrupt decrease in frequency, with no temperatures observed above 1200 C.

KOSKI,JORMAN A.

2000-05-09T23:59:59.000Z

86

Direct measurement of onset and offset phonation threshold pressure in normal subjects  

Science Journals Connector (OSTI)

Phonation threshold pressures were directly measured in five normal subjects in a variety of voicing conditions. The effects of fundamental frequency intensity closure speed of the vocal folds and laryngeal airway resistance on phonation threshold pressures were determined. Subglottic air pressures were measured using percutaneous puncture of the cricothyroid membrane. Both onset and offset of phonation were studied to see if a hysteresis effect produced lower offset pressures than onset pressures. Univariate analysis showed that phonation threshold pressure was influenced most strongly by fundamental frequency and intensity. Multiple linear regression showed that these two variables as well as laryngeal airway resistance most strongly predicted phonation threshold pressure. Two of the five subjects demonstrated a significant hysteresis effect but one subject actually had higher offset pressures than onset pressures.

Randall L. Plant; Gary L. Freed; Richard E. Plant

2004-01-01T23:59:59.000Z

87

Qweak: First Direct Measurement of the Weak Charge of the Proton  

SciTech Connect

The Qweak experiment at Hall C of Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton, QWp, through a precision measurement of the parity-violating asymmetry in elastic e-p scattering at low momentum transfer Q2= 0.025 (GeV/c)2 with incident electron beam energy of 1.155 GeV. The Qweak experiment, along with earlier results of parity violating elastic scattering experiments, is expected to determine the most precise value of QWp which is suppressed in the Standard Model. If this result is further combined with the 133Cs atomic parity violation (APV) measurement, significant constraints on the weak charge of the up quark, down quark, and neutron can be extracted. This data will also be used to determine the weak-mixing angle, sin2 ?W, with a relative uncertainty of < 0.5% that will provide a competitive measurement of the running of sin2 ?W to low Q2. An overview of the experiment and its results using the commissioning dataset, constituting approximately 4% of the data collected in the experiment, are reported here.

Nuruzzaman, NFN [Hampton University, JLAB

2014-04-01T23:59:59.000Z

88

Q-weak: First Direct Measurement of the Weak Charge of the Proton  

E-Print Network (OSTI)

The Q-weak experiment at Hall C of Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton, Qweak(p), through a precision measurement of the parity-violating asymmetry in elastic e-p scattering at low momentum transfer Q^2= 0.025 (GeV/c)^2 with incident electron beam energy of 1.155 GeV. The Q-weak experiment, along with earlier results of parity violating elastic scattering experiments, is expected to determine the most precise value of Qweak(p) which is suppressed in the Standard Model. If this result is further combined with the 133Cs atomic parity violation (APV) measurement, significant constraints on the weak charge of the up quark, down quark, and neutron can be extracted. This data will also be used to determine the weak-mixing angle, sin^2 theta_?W, with a relative uncertainty of < 0.5% that will provide a competitive measurement of the running of sin^2 theta_?W to low Q^2. An overview of the experiment and its results using the commissioning dataset, constituting approximately 4% of the data collected in the experiment, are reported here.

Nuruzzaman

2013-12-20T23:59:59.000Z

89

Collision-induced desorption of ammonia chemisorbed on Pt^111: From direct measurement of the threshold energy to determination  

E-Print Network (OSTI)

metal surface by a beam of neutral, energetic Ar atoms. From direct measurement of the threshold energy for NH3 desorption at one-quarter of a monolayer coverage were measured for Ar beam energies up to 3 e surface well depth from a collision-induced desorption experiment is measurement of the threshold energy

Levis, Robert J.

90

Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System  

SciTech Connect

The authors present precision measurements of the direct CP violation parameter, Re({epsilon}{prime}/{epsilon}), the kaon parameters, {Delta}m and {tau}{sub S}, and the CPT tests, {phi}{sub {+-}} and {Delta}{phi}, in neutral kaon decays. These results are based on the full dataset collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This dataset contains {approx} 15 million K {yields} {pi}{sup 0}{pi}{sup 0} decays and {approx} 69 million K {yields} {pi}{sup +}{pi}{sup -} decays. They describe significant improvements to the precision of these measurements relative to previous KTeV analyses. They find Re({epsilon}{prime}/{epsilon}) = [19.2 {+-} 1.1(stat) {+-} 1.8(syst)] x 10{sup -4}, {Delta}m = (5265 {+-} 10) x 10{sup 6} hs{sup -1}, and {tau}{sub S} = (89.62 {+-} 0.05) x 10{sup -12} s. They measure {phi}{sub {+-}} = (44.09 {+-} 1.00){sup o} and {Delta}{phi} = (0.29 {+-} 0.31){sup o}; these results are consistent with CPT symmetry.

Worcester, Elizabeth Turner; /Chicago U.

2007-12-01T23:59:59.000Z

91

Measurements of Direct CP-Violating Asymmetries in Charmless Decays of Bottom Baryons  

E-Print Network (OSTI)

We report final measurements of direct $\\mathit{CP}$--violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using the complete $\\sqrt{s}=1.96$ TeV proton-antiproton collisions data set, corresponding to 9.3 fb$^{-1}$ of integrated luminosity, we measure $\\mathcal{A}(\\Lambda^0_b \\rightarrow p\\pi^{-}) = +0.06 \\pm 0.07\\mathrm{(stat)} \\pm 0.03\\mathrm{(syst)}$ and $\\mathcal{A}(\\Lambda^0_b \\rightarrow pK^{-}) = -0.10 \\pm 0.08\\mathrm{(stat)} \\pm 0.04\\mathrm{(syst)}$, compatible with no asymmetry. In addition we measure the $\\mathit{CP}$--violating asymmetries in $B^0_s \\rightarrow K^{-}\\pi^{+}$ and $B^0 \\rightarrow K^{+}\\pi^{-}$ decays to be $\\mathcal{A}(B^0_s \\rightarrow K^{-}\\pi^{+}) = +0.22 \\pm 0.07\\mathrm{stat)} \\pm 0.02\\mathrm{(syst)}$ and $\\mathcal{A}(B^0 \\rightarrow K^{+}\\pi^{-}) = -0.083\\pm 0.013 \\mathrm{(stat)} \\pm 0.004\\mathrm{(syst)}$, respectively, which are significantly different from zero and consistent with current world averages.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; S. Grinstein; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; M. Martínez; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; N. Ranjan; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu

2014-12-11T23:59:59.000Z

92

Comparison of Direct and Indirect Measures of Critical Bands of the Monaural Chinchilla  

Science Journals Connector (OSTI)

Typically it is found that lower forms (rats cats and chinchillas) require a greater S/N ratio than does man in order to detect the presence of a pure?tone signal in a broad?band noise. Assuming Fletcher's formula to be an adequate means of estimating the operating bandwidth of the auditory system one could come to the conclusion that these lower forms have larger critical ratios larger critical bands and therefore poorer frequency resolving ability than does man. However the behavioral index of auditory sensitivity utilized in these experiments does not permit separation of behavioral criterion and auditory sensitivity. It seems probable that lower forms are trained to maintain a “high” criterion (low false?alarm rate) and thereby produce threshold measures of relatively high S/N ratio. Our efforts have been directed toward measuring both critical ratios and critical bands (band narrowing paradigm) utilizing both traditional threshold measures and criterion free indices of signal detection theory. Data obtained at signal frequencies of 500 Hz 1 2 and 4 kHz will be discussed in terms of (1) the relationship of critical ratios to critical bands as a function of frequency and (2) the effect of criterion contamination on the estimate of the critical ratio and therefore on the estimate of the frequency resolving power of the organism.

W. H. Seaton; C. Trahiotis

1973-01-01T23:59:59.000Z

93

Direct measurement and characterization of active photosynthesis zones inside biofuel producing and wastewater remediating microalgal biofilms  

SciTech Connect

Abstract: Microalgal biofilm based technologies are of keen interest due to their high biomass concentrations and ability to utilize renewable resources, such as light and CO2. While photoautotrophic biofilms have long been used for wastewater remediation applications, biofuel production represents a relatively new and under-represented focus area. However, the direct measurement and characterization of fundamental parameters required for physiological analyses are challenging due to biofilm heterogeneity. This study evaluated oxygenic photosynthesis and biofuel precursor molecule production using a novel rotating algal biofilm reactor (RABR) operated at field- and laboratory-scales for wastewater remediation and biofuel production, respectively. Clear differences in oxygenic-photosynthesis, respiration and biofuel-precursor capacities were observed between the two systems and different conditions based on light and nitrogen availability. Nitrogen depletion was not found to have the same effect on lipid accumulation compared to prior planktonic studies. Physiological characterizations of these microalgal biofilms identify potential areas for future process optimization.

Bernstein, Hans C.; Kesaano, Maureen; Moll, Karen; Smith, Terence; Gerlach, Robin; Carlson, Ross; Miller, Charles D.; Peyton, Brent; Cooksey, Keith; Gardner, Robert D.; Sims, Ronald C.

2014-03-30T23:59:59.000Z

94

Direct measurement of density oscillation induced by a radio-frequency wave  

SciTech Connect

An O-mode reflectometer at a frequency of 25.85 GHz was applied to plasmas heated by the high harmonic fast wave (21 MHz) in the TST-2 spherical tokamak. An oscillation in the phase of the reflected microwave in the rf range was observed directly for the first time. In TST-2, the rf (250 kW) induced density oscillation depends mainly on the poloidal rf electric field, which is estimated to be about 0.2 kV/m rms by the reflectometer measurement. Sideband peaks separated in frequency by ion cyclotron harmonics from 21 MHz, and peaks at ion cyclotron harmonics which are suggested to be quasimodes generated by parametric decay, were detected.

Yamada, T.; Ejiri, A.; Shimada, Y.; Oosako, T.; Tsujimura, J.; Takase, Y.; Kasahara, H. [Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580 (Japan); Graduate School of Frontier Sciences, University of Tokyo, Kashiwa 277-8561 (Japan); National Institute for Fusion Science, Toki 509-5292 (Japan)

2007-08-15T23:59:59.000Z

95

Direct high-resolution characterization of quantum correlations via classical measurements  

E-Print Network (OSTI)

Quantum optics plays a central role in the study of fundamental concepts in quantum mechanics, and in the development of new technological applications. Typical experiments employ non-classical light, such as entangled photons, generated by parametric processes. The standard characterization of the sources by quantum tomography, which relies on detecting the pairs themselves and thus requires single photon detectors, limits both measurement speed and accuracy. Here we show that the spectral characterization of the quantum correlations generated by two-photon sources can be directly performed classically with an unprecedented spectral resolution. This streamlined technique has the potential to speed up design and testing of massively parallel integrated sources by providing a fast and reliable quality control procedure. Adapting our method to explore other degrees of freedom would allow the complete characterization of biphoton states generated by parametric processes.

Andreas Eckstein; Guillaume Boucher; Aristide Lemaître; Pascal Filloux; Ivan Favero; Giuseppe Leo; John E. Sipe; Marco Liscidini; Sara Ducci

2013-12-15T23:59:59.000Z

96

First Direct Measurement of the 17F(p,gamma)18Ne Cross Section  

SciTech Connect

The rate of the {sup 17}F(p,{gamma}){sup 18}Ne reaction is of significant importance in astrophysical events like novae and x-ray bursts. The decay of {sup 17}F is thought to help drive the expansion of the nova envelope, and the {sup 17}F(p,{gamma}){sup 18}Ne reaction affects the production of {sup 18}F, a target of gamma-ray astronomy, as well as being an important link in the ({alpha},p) reaction chain during the ignition phase of x-ray bursts. A 3{sup +} state in {sup 18}Ne predicted to dominate the rate was found at 599.8 keV using the {sup 17}F(p,p){sup 17}F reaction [1], but the resonance strength was unknown. For the first time, the {sup 17}F(p,{gamma}){sup 18}Ne reaction has been measured directly with the Daresbury Recoil Separator, using a mixed beam of radioactive {sup 17}F and stable {sup 17}O from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. A {gamma} width was found for the 599.8 keV resonance in {sup 18}Ne, and an upper limit on the direct capture S factor was determined at an intermediate energy of 800 keV.

Chipps, Kelly A [ORNL; Bardayan, Daniel W [ORNL; Blackmon, Jeff C [ORNL; Chae, K. Y. [University of Tennessee, Knoxville (UTK); Greife, U. [Colorado School of Mines, Golden; Hatarik, Robert [Rutgers University; Kozub, R. L. [Tennessee Technological University; Matei, Catalin [Oak Ridge Associated Universities (ORAU); Moazen, Brian [University of Tennessee, Knoxville (UTK); Nesaraja, Caroline D [ORNL; Pain, Steven D [ORNL; Peters, W. A. [Rutgers University; Pittman, S. T. [University of Tennessee, Knoxville (UTK); ShrinerJr., J. F. [Tennessee Technological University; Smith, Michael Scott [ORNL

2008-01-01T23:59:59.000Z

97

Measuring surface ocean wave height and directional spectra using an Acoustic Doppler Current Profiler from an autonomous underwater vehicle  

E-Print Network (OSTI)

The Acoustic Doppler Current Profiler (ADCP) is a proven technology which is capable of measuring surface wave height and directional information, however it is generally limited to rigid, bottom mounted applications which ...

Haven, Scott

2012-01-01T23:59:59.000Z

98

Microfluidic Technology Platforms for Synthesizing, Labeling and Measuring the Kinetics of Transport and Biochemical Reactions for Developing Molecular Imaging Probes  

SciTech Connect

Radiotracer techniques are used in environmental sciences, geology, biology and medicine. Radiotracers with Positron Emission Tomography (PET) provided biological examinations of ~3 million patients 2008. Despite the success of positron labeled tracers in many sciences, there is limited access in an affordable and convenient manner to develop and use new tracers. Integrated microfluidic chips are a new technology well matched to the concentrations of tracers. Our goal is to develop microfluidic chips and new synthesis approaches to enable wide dissemination of diverse types of tracers at low cost, and to produce new generations of radiochemists for which there are many unfilled jobs. The program objectives are to: 1. Develop an integrated microfluidic platform technology for synthesizing and 18F-labeling diverse arrays of different classes of molecules. 2. Incorporate microfluidic chips into small PC controlled devices (“Synthesizer”) with a platform interfaced to PC for electronic and fluid input/out control. 3. Establish a de-centralized model with Synthesizers for discovering and producing molecular imaging probes, only requiring delivery of inexpensive [18F]fluoride ion from commercial PET radiopharmacies vs the centralized approach of cyclotron facilities synthesizing and shipping a few different types of 18F-probes. 4. Develop a position sensitive avalanche photo diode (PSAPD) camera for beta particles embedded in a microfluidic chip for imaging and measuring transport and biochemical reaction rates to valid new 18F-labeled probes in an array of cell cultures. These objectives are met within a research and educational program integrating radio-chemistry, synthetic chemistry, biochemistry, engineering and biology in the Crump Institute for Molecular Imaging. The Radiochemistry Training Program exposes PhD and post doctoral students to molecular imaging in vitro in cells and microorganisms in microfluidic chips and in vivo with PET, from new technologies for radiochemistry (macro to micro levels), biochemistry and biology to imaging principles, tracer kinetics, pharmacokinetics and biochemical assays. New generations of radiochemists will be immersed in the biochemistry and biology for which their labeled probes are being developed for assays of these processes. In this program engineers and radio-chemists integrate the principles of microfluidics and radiolabeling along with proper system design and chemistry rule sets to yield Synthesizers enabling biological and pharmaceutical scientists to develop diverse arrays of probes to pursue their interests. This progression would allow also radiochemists to focus on the further evolution of rapid, high yield synthetic reactions with new enabling technologies, rather than everyday production of radiotracers that should be done by technologists. The invention of integrated circuits in electronics established a platform technology that allowed an evolution of ideas and applications far beyond what could have been imagined at the beginning. Rather than provide a technology for the solution to a single problem, it is hoped that microfluidic radiochemistry will be an enabling platform technology for others to solve many problems. As part of this objective, another program goal is to commercialize the technologies that come from this work so that they can be provided to others who wish to use it.

Phelps, Michael E.

2009-09-01T23:59:59.000Z

99

Estimates of rates and errors for measurements of direct-{gamma} and direct-{gamma} + jet production by polarized protons at RHIC  

SciTech Connect

Studies of inclusive direct-{gamma} production by pp interactions at RHIC energies were performed. Rates and the associated uncertainties on spin-spin observables for this process were computed for the planned PHENIX and STAR detectors at energies between {radical}s = 50 and 500 GeV. Also, rates were computed for direct-{gamma} + jet production for the STAR detector. The goal was to study the gluon spin distribution functions with such measurements. Recommendations concerning the electromagnetic calorimeter design and the need for an endcap calorimeter for STAR are made.

Beddo, M.E.; Spinka, H.; Underwood, D.G.

1992-08-14T23:59:59.000Z

100

A Direct Measurement of the IGM Opacity to HI Ionizing Photons  

E-Print Network (OSTI)

We present a new method to directly measure the opacity from HI Lyman limit (LL) absorption k_LL along quasar sightlines by the intergalactic medium (IGM). The approach analyzes the average (``stacked'') spectrum of an ensemble of quasars at a common redshift to infer the mean free path (MFP) to ionizing radiation. We apply this technique to 1800 quasars at z=3.50-4.34 drawn from the Sloan Digital Sky Survey (SDSS), giving the most precise measurements on k_LL at any redshift. From z=3.6 to 4.3, the opacity increases steadily as expected and is well parameterized by MFP = (48.4 +/- 2.1) - (38.0 +/- 5.3)*(z-3.6) h^-1 Mpc (proper distance). The relatively high MFP values indicate that the incidence of systems which dominate k_LL evolves less strongly at z>3 than that of the Lya forest. We infer a mean free path three times higher than some previous estimates, a result which has important implications for the photo-ionization rate derived from the emissivity of star forming galaxies and quasars. Finally, our ana...

Prochaska, J Xavier; O'Meara, John M

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" from the National Library of EnergyBeta (NLEBeta).
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101

Direct Measurement of Ion Beam Induced, Nanoscale Roughening of GaN Bentao Cui and P. I. Cohen  

E-Print Network (OSTI)

Direct Measurement of Ion Beam Induced, Nanoscale Roughening of GaN Bentao Cui and P. I. Cohen of a surface roughening term due to curvature-dependent sputtering or asymmetric attachment of vacancies change using atomic force microscopy, we show a method to measure the ion-roughening coefficient. Using

Cohen, Philip I.

102

Direct determination of the adiabatic ionization energy of NO2 as measured by guided ion-beam mass spectrometry  

E-Print Network (OSTI)

Direct determination of the adiabatic ionization energy of NO2 as measured by guided ion-beam mass the past 60 years the value for the ionization energy (IE) of nitrogen dioxide has been measured many times, Utah 84112 (Received 16 April 1992; accepted 4 May 1992) The adiabatic ionization energy (IE) of NOa

Clemmer, David E.

103

Direct measurement of curvature dependent ion etching of GaN Bentao Cui and P.I. Cohen  

E-Print Network (OSTI)

Direct measurement of curvature dependent ion etching of GaN Bentao Cui and P.I. Cohen Department of Electrical and Computer Engineering and Department of Chemical Engineering and Materials Science, University of nanoscale pores or dimples during ion etching of GaN was used to measure the magnitude of the curvature

Cohen, Philip I.

104

Measurements of Wind Speed, Direction, and Vertical Profiles in an Evergreen Forest in Central Cambodia  

Science Journals Connector (OSTI)

The wind characteristics of speed, direction, and vertical profile were studied ... Thom Province, Cambodia. Three seasonal patterns of wind speeds and directions were identified. The first occurred ... , as well...

Koji Tamai; Akira Shimizu…

2007-01-01T23:59:59.000Z

105

Direct measurement of energy barriers on rough and heterogeneous solid surfaces  

SciTech Connect

This paper will deal with the phenomenon of energy barriers to the spread of liquids on solids. These barriers often manifest themselves as a {open_quotes}pinning{close_quotes} of a sessile drop as liquid is added to it. That is, the volume of the drop increases, but the diameter does not. Thus the advancing contact angle ({theta}{sub a}) increases to a maximum. At the point where the hydrostatic pressure in the drop overcomes the {open_quotes}pinning{close_quotes} force the diameter suddenly increases and the drop relaxes to a metastable configuration which has a lower {theta}{sub a}. Energy barriers should be considered in many applications such as the spreading of liquid adhesives where thorough wetting is the goal. The interfacial forces involved are both long-range Lifshitz-van der Waals (LW) forces and short-range acid-base (AB) forces. The authors will describe how they measure the energy barriers on real surfaces directly and resolve them into their LW and AB components.

Lloyd, T.B. [Lehigh Univ., Bethlehem, PA (United States); LaGow, J. [Boeing Commercial Airplane Co., Seattle, WA (United States); Connelly, G.M. [Connelly Applied Research, Nazareth, PA (United States)

1996-12-31T23:59:59.000Z

106

A High Temperature Direct Vehicle Exhaust Flowmeter for Heavy Duty Diesel Emission Measurements.  

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

Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010.

107

Imaging System to Measure Kinetics of Material Cluster Ejection During Exit-Surface Damage Initiation and Growth in Fused Silica  

SciTech Connect

Laser-induced damage on the surface of optical components typically is manifested by the formation of microscopic craters that can ultimately degrade the optics performance characteristics. It is believed that the damage process is the result of the material exposure to high temperatures and pressures within a volume on the order of several cubic microns located just below the surface. The response of the material following initial localized energy deposition by the laser pulse, including the timeline of events and the individual processes involved during this timeline, is still largely unknown. In this work we introduce a time-resolved microscope system designed to enable a detailed investigation of the sequence of dynamic events involved during surface damage. To best capture individual aspects of the damage timeline, this system is employed in multiple imaging configurations (such as multi-view image acquisition at a single time point and multi-image acquisition at different time points of the same event) and offers sensitivity to phenomena at very early delay times. The capabilities of this system are demonstrated with preliminary results from the study of exit-surface damage in fused silica. The time-resolved images provide information on the material response immediately following laser energy deposition, the processes later involved during crater formation or growth, the material ejecta kinetics, and overall material motion and transformation. Such results offer insight into the mechanisms governing damage initiation and growth in the optical components of ICF class laser systems.

Raman, R N; Negres, R A; Demos, S G

2009-10-29T23:59:59.000Z

108

Conductivity measurements of molten metal oxides and their evaluation in a Direct Carbon Fuel Cell (DCFC)  

E-Print Network (OSTI)

ABSTRACT Since Direct Carbon Fuel Cell (DCFC) technology is in a beginning stage, emphasis should be laid on addressing the fundamental aspects. A molten electrolyte is required to facilitate ionic contact between solid ...

Yarlagadda, Venkata Raviteja

2011-09-08T23:59:59.000Z

109

Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb:YAG  

E-Print Network (OSTI)

Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb and heat sink grease respectively). The dynamics of thermal effects is also presented. PACS 42.55.Xi (Diode-pumped in a diode-end-pumped Yb:YAG crystal, using a calibrated infrared camera, with a 60-µm spatial resolution

Paris-Sud XI, Université de

110

Measurement of Vertical Kinetic Energy and Vertical Velocity Skewness in Oceanic Boundary Layers by Imperfectly Lagrangian Floats  

Science Journals Connector (OSTI)

The effects of upward buoyancy on the accuracy with which Lagrangian floats can measure the Eulerian mean variance ?ww?E and skewness SwE of vertical fluid velocity w in the wind-driven upper-ocean boundary layer is investigated using both ...

Ramsey R. Harcourt; Eric A. D’Asaro

2010-11-01T23:59:59.000Z

111

Direct measurement of thin-film thermoelectric figure of merit Rajeev Singh,1,a  

E-Print Network (OSTI)

conductivity of the thermoelectric material. Self-consistent finite-element simulations of the three. © 2009 American Institute of Physics. DOI: 10.1063/1.3094880 Thermoelectric materials are playing application of thermoelectric materials is in direct thermal-to-electrical energy conversion. Because

Bowers, John

112

Spectroscopic Method for Measuring Plasma Magnetic Fields Having Arbitrary Distributions of Direction and Amplitude  

E-Print Network (OSTI)

Spectroscopic Method for Measuring Plasma Magnetic Fields Having Arbitrary Distributions of Science, Rehovot 76100, Israel (Received 21 December 2006; published 31 May 2007) An approach for measurements of magnetic fields, based on the comparison of the magnetic-field- induced contributions

113

Lactose oxidation kinetics with oxygen in catalyst-solution-gas three-phase system with simultaneous electrical potential measurement of supported gold catalyst  

Science Journals Connector (OSTI)

Lactose oxidation kinetics was studied on an supported gold catalyst with simultaneous control of catalyst potential. The experimental data were described well...

D. Yu. Murzin; E. V. Murzina; A. V. Tokarev…

2009-09-01T23:59:59.000Z

114

A Simple Apparatus for the Direct Measurement of Magnetic Forces and Magnetic Properties of Materials  

E-Print Network (OSTI)

In this paper, we describe a simple apparatus consisting of a scale, capable of a one milligram resolution, and a commonly obtainable magnet to measure magnetic forces. This simple apparatus is capable of measuring magnetic properties of materials in either a research or an instructional laboratory. We illustrate the capability of this apparatus by the measurement of the force of iron samples exerted on the magnet, the force of a paramagnetic sample, that by a current carrying wire, and the force of a high temperature superconductor.

Makkinje, Jan A

2014-01-01T23:59:59.000Z

115

Direct measurement of a patient's entrance skin dose during pediatric cardiac catheterization  

Science Journals Connector (OSTI)

......Matsumaru Y, et al. Dose measurement for patients and physicians using a glass dosemeter during endovascular treatment for brain disease. Radiat Prot Dosimetry (2003) 107:247-52. 13 Richardson RB . Past and revised risk estimates for cancer induced......

Lue Sun; Yusuke Mizuno; Mari Iwamoto; Takahisa Goto; Yasuhiro Koguchi; Yuka Miyamoto; Koji Tsuboi; Koichi Chida; Takashi Moritake

2014-11-01T23:59:59.000Z

116

Direct measurement of proton-beam-written polymer optical waveguide sidewall morphorlogy using an atomic force microscope  

SciTech Connect

Proton-beam writing (PBW) is a direct-write micromachining technique capable of fabricating low-loss single-mode polymer waveguides with straight and smooth sidewalls. Recently, the sidewall morphologies of such proton beam written polymer waveguide structures were directly measured using an atomic force microscope (AFM). Statistical information such as the rms roughness and the correlation length of the sidewall profile obtained from the AFM scans allows us to quantify the quality of the sidewalls and optimize the fabrication parameters using PBW. For structures fabricated using a stage scanning speed of {approx}10 {mu}m/s, a rms roughness of 3.8{+-}0.3 nm with a correlation length of 46{+-}6 nm was measured.

Sum, T.C.; Bettiol, A.A.; Seng, H.L.; Kan, J.A. van; Watt, F. [Department of Physics Centre for Ion Beam Applications (CIBA), National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

2004-08-23T23:59:59.000Z

117

Laser-induced fluorescence measurements and kinetic analysis of Si atom formation in a rotating disk chemical vapor deposition reactor  

SciTech Connect

An extensive set of laser-induced fluorescence (LIF) measurements of Si atoms during the chemical vapor deposition (CVD) of silicon from silane and disilane in a research rotating disk reactor are presented. The experimental results are compared in detail with predictions from a numerical model of CVD from silane and disilane that treats the fluid flow coupled to gas-phase and gas-surface chemistry. The comparisons showed that the unimolecular decomposition of SiH[sub 2] could not account for the observed gas-phase Si atom density profiles. The H[sub 3]SiSiH [leftrightarrow] Si + SiH[sub 4] and H[sub 3]SiSiH + SiH[sub 2] [leftrightarrow] Si + Si[sub 2]H[sub 6] reactions are proposed as the primary Si atom production routes. The model is in good agreement with the measured shapes of the Si atom profiles and the trends in Si atom density with susceptor temperature, pressure, and reactant gas mixture. 33 refs., 12 figs., 3 tabs.

Ho, P.; Coltrin, M.E.; Breiland, W.G. (Sandia National Lab., Albuquerque, NM (United States))

1994-10-06T23:59:59.000Z

118

Direct Measurement of EGR Cooler Deposit Thermal Properties for Improved Understanding of Cooler Fouling  

SciTech Connect

Exhaust gas recirculation (EGR) cooler fouling has become a significant issue for compliance with NOX emissions standards. This paper reports results of a study of fundamental aspects of EGR cooler fouling. An apparatus and procedure were developed to allow surrogate EGR cooler tubes to be exposed to diesel engine exhaust under controlled conditions. The resulting fouled tubes were removed and analyzed. Volatile and non-volatile deposit mass was measured for each tube. Thermal diffusivity of the deposited soot cake was measured by milling a window into the tube and using the Xenon flash lamp method. The heat capacity of the deposit was measured at temperatures up to 430 C and was slightly higher than graphite, presumably due to the presence of hydrocarbons. These measurements were combined to allow calculation of the deposit thermal conductivity, which was determined to be 0.041 W/mK, only ~1.5 times that of air and much lower than the 304 stainless steel tube (14.7 W/mK). The main determinant of the deposit thermal conductivity is density, which was measured to be just 2% that of the density of the primary soot particles (or 98% porous). The deposit layer thermal resistance was calculated and compared with estimates of the thermal resistance calculated from gas temperature data during the experiment. The deposit properties were also used to further analyze the temperature data collected during the experiment.

Wang, Hsin [ORNL] [ORNL; Sluder, Scott [ORNL] [ORNL; Storey, John Morse [ORNL] [ORNL

2009-01-01T23:59:59.000Z

119

Verification of isomerism and direct measurement of half-lives in 184Au  

Science Journals Connector (OSTI)

The existence of two decaying isomers in 184Au was confirmed through direct observation of the variation of decay rates with time. The ordering of the low- and high-spin isomers was verified by the decay studies. The isomers are identified as a low-spin (probably 2+) state at an energy of 69 keV with a half-life of 48±1 sec and a high-spin (probably 5+) ground state with a half-life of 21±1 sec.

K. Zaerpoor; Y. Xu; M. Gummin; K. S. Krane; J. L. Wood; N. J. Stone; J. Rikovska

1997-05-01T23:59:59.000Z

120

Controlling combustion noise in direct injection diesel engine through mechanical vibration measurement  

Science Journals Connector (OSTI)

The next generations of direct injection diesel engines have greatly improved their performances compared with petrol engines. However, one of the pending subjects is the noise and vibration levels, due to working cycle itself. The design effort to reduce the emissions of noise and vibration transmitted to the vehicle's driver could be lessened because of the assembly process variation. In this paper, a procedure to control this variation has been suggested in order to maintain noise and vibration performances within the limits of design.

J.A. Calvo; V. Diaz; J.L. San Roman

2005-01-01T23:59:59.000Z

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121

Direct measurement of particle motion in a large-scale FBC boiler model  

SciTech Connect

One of the difficulties of designing fluidized bed combustion boilers is that motion of fluidized particles is uncertain in a large commercial-scale boiler. The authors constructed a large atmospheric fluidized bed model with mock-up tubes and obstacles that were nearly equivalent in size to a commercial-scale bed. The model was used to measure motion and diffusivity of particles from an inserted nozzle. The model had a length of 2.3m, a width of 1.7m and a total height of 8.2m. The bed height was adjusted to about 4m. Motion of particles was measured by a small cantilever on which strain gauges were attached. Before measurement, strain rate of the cantilever was correlated to particle velocity by a certain experimental formula. In order to measure overall motion of particles, a pipe with this cantilever was inserted into the bed and traversed at certain horizontal levels then these data were converted to particle velocity distributions. In the diffusion experiments, tracer particles were injected from the nozzle for a certain period then fluidizing air was terminated immediately. The baffle plate effect on the diffusivity was examined by measuring the mixing rate of tracer particles. Diffusion of particles was compared with unsteady diffusion calculations. Results are summarized as follows: (1) No significant difference was seen in particle velocity distribution when measurement level of the bed was shifted inside a bunch of tubes; (2) Average velocity of particles approximately ranged from {minus}0.02 to 0.02 m/s in the region of the tubes; (3) The vertical diffusion rate of particles was roughly several times higher than their horizontal diffusion rate; and (4) An effect of the baffle plate on particles diffusion was limited. The baffle plate seemed to enhance horizontal diffusion of injected particles only in the vicinity of it.

Ito, Osamu; Kawabe, Ryuhei; Miyamoto, Tomohiko; Orita, Hisayuki; Mizumoto, Mamoru; Miyadera, Hiroshi; Tomuro, Jinichi; Hokari, Nobuyuki; Iwase, Tetsuya

1999-07-01T23:59:59.000Z

122

An Improved Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation  

E-Print Network (OSTI)

array (MPA). The earliest work on an MPA related device for measuring diffuse sky radiation was performed in Finland by M. H2milllien et al. (1985). Further development on the MPA was performed in several countries including the United States where...

Munger, B.; Haberl, J. S.

1994-01-01T23:59:59.000Z

123

Direct mass measurements of neutron-rich zirconium isotopes up to Zr104  

Science Journals Connector (OSTI)

Atomic masses of radioactive zirconium isotopes from Zr96 to Zr104 have been measured with a relative accuracy of ?5×10?7 using a Penning trap coupled to the ion guide isotope separator on-line system. The obtained two-neutron separation energies show strong local correlation in relation to the shape change and shape coexistence between N=58 and 60.

S. Rinta-Antila; S. Kopecky; V. S. Kolhinen; J. Hakala; J. Huikari; A. Jokinen; A. Nieminen; J. Äystö; J. Szerypo

2004-07-14T23:59:59.000Z

124

Determination of Optical-Field Ionization Dynamics in Plasmas through the Direct Measurement of the Optical Phase Change  

SciTech Connect

This is the final report of a three-year Laboratory Directed Research and Development (LDRD) Project at Los Alamos National Laboratory (LANL). The detailed dynamics of an atom in a strong laser field is rich in both interesting physics and potential applications. The goal of this project was to develop a technique for characterizing high-field laser-plasma interactions with femtosecond resolution based on the direct measurement of the phase change of an optical pulse. The authors developed the technique of Multi-pulse Interferometric Frequency Resolved Optical Gating (MI-FROG), which recovers (to all orders) the phase difference between pumped and unpumped probe pulses, enabling the determination of sub-pulsewidth time-resolved phase and frequency shifts impressed by a pump pulse on a weak probe pulse. Using MI-FROG, the authors obtained the first quantitative measurements of high-field ionization rates in noble gases and diatomic molecules. They obtained agreement between the measured ionization rates an d those calculated for the noble gases and diatomic nitrogen and hydrogen using a one-dimensional fluid model and rates derived from tunneling theory. However, much higher rates are measured for diatomic oxygen than predicted by tunneling theory calculations.

Taylor, A.J.; Omenetto, G.; Rodriguez, G.; Siders, C.W.; Siders, J.L.W.; Downer, C.

1999-07-16T23:59:59.000Z

125

Direct Measurement of the Free Energy of Aging Hard-Sphere Colloidal Glasses  

E-Print Network (OSTI)

The nature of the glass transition is one of the most important unsolved problems in condensed matter physics. The difference between glasses and liquids is believed to be caused by very large free energy barriers for particle rearrangements; however so far it has not been possible to confirm this experimentally. We provide the first quantitative determination of the free energy for an aging hard-sphere colloidal glass. The determination of the free energy allows for a number of new insights in the glass transition, notably the quantification of the strong spatial and temporal heterogeneity in the free energy. A study of the local minima of the free energy reveals that the observed variations are directly related to the rearrangements of the particles. Our main finding is that the probability of particle rearrangements shows a power law dependence on the free energy changes associated with the rearrangements, similarly to the Gutenberg-Richter law in seismology.

Rojman Zargar; Bernard Nienhuis; Peter Schall; Daniel Bonn

2013-03-17T23:59:59.000Z

126

Real time cosmology - A direct measure of the expansion rate of the Universe  

E-Print Network (OSTI)

In recent years cosmology has undergone a revolution, with precise measurements of the microwave background radiation, large galaxy redshift surveys, and the discovery of the recent accelerated expansion of the Universe using observations of distant supernovae. In this light, the SKA enables us to do an ultimate test in cosmology by measuring the expansion rate of the Universe in real time. This can be done by a rather simple experiment of observing the neutral hydrogen (HI) signal of galaxies at two different epochs. The signal will encounter a change in frequency imprinted as the Universe expands over time and thus monitoring the drift in frequencies will provide a real time measure of the cosmic acceleration. Over a period of 12 years one would expected a frequency shift of the order of 0.1 Hz assuming a standard Lambda-CDM cosmology. Based on the sensitivity estimates of the SKA and the number counts of the expected HI galaxies, it is shown that the number counts are sufficiently high to compensate for th...

Klöckner, H -R; Martins, C; Raccanelli, A; Champion, D; Roy, A; Lobanov, A; Wagner, J; Keller, R

2015-01-01T23:59:59.000Z

127

Experimental evaluation of actual delivered dose using mega-voltage cone-beam CT and direct point dose measurement  

SciTech Connect

Radiation therapy in patients is planned by using computed tomography (CT) images acquired before start of the treatment course. Here, tumor shrinkage or weight loss or both, which are common during the treatment course for patients with head-and-neck (H and N) cancer, causes unexpected differences from the plan, as well as dose uncertainty with the daily positional error of patients. For accurate clinical evaluation, it is essential to identify these anatomical changes and daily positional errors, as well as consequent dosimetric changes. To evaluate the actual delivered dose, the authors proposed direct dose measurement and dose calculation with mega-voltage cone-beam CT (MVCBCT). The purpose of the present study was to experimentally evaluate dose calculation by MVCBCT. Furthermore, actual delivered dose was evaluated directly with accurate phantom setup. Because MVCBCT has CT-number variation, even when the analyzed object has a uniform density, a specific and simple CT-number correction method was developed and applied for the H and N site of a RANDO phantom. Dose distributions were calculated with the corrected MVCBCT images of a cylindrical polymethyl methacrylate phantom. Treatment processes from planning to beam delivery were performed for the H and N site of the RANDO phantom. The image-guided radiation therapy procedure was utilized for the phantom setup to improve measurement reliability. The calculated dose in the RANDO phantom was compared to the measured dose obtained by metal-oxide-semiconductor field-effect transistor detectors. In the polymethyl methacrylate phantom, the calculated and measured doses agreed within about +3%. In the RANDO phantom, the dose difference was less than +5%. The calculated dose based on simulation-CT agreed with the measured dose within±3%, even in the region with a high dose gradient. The actual delivered dose was successfully determined by dose calculation with MVCBCT, and the point dose measurement with the image-guided radiation therapy procedure.

Matsubara, Kana, E-mail: matsubara-kana@hs.tmu.ac.jp [Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku Tokyo (Japan); Kohno, Ryosuke [National Cancer Center Hospital East, Chiba (Japan); National Cancer Center Research Institute, Chiba (Japan); Nishioka, Shie; Shibuya, Toshiyuki; Ariji, Takaki; Akimoto, Tetsuo [National Cancer Center Hospital East, Chiba (Japan); Saitoh, Hidetoshi [Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku Tokyo (Japan)

2013-07-01T23:59:59.000Z

128

Apparatus for direct measurement of ash fusion and sintering behavior at elevated temperatures and pressures  

Science Journals Connector (OSTI)

Ash fusion sintering and deposition may impose serious operational difficulties in conventional and advanced coal?combustion systems. Conventional ash fusion techniques (e.g. ASTM methods) determine the qualitative behavior of ash samples at atmospheric pressure. Presently there is no known available technique that can measure the behavior of coal ash at elevated temperatures and pressures. In the literature methods based on electrical resistance or shrinkage of coal ash have been reported at atmospheric pressure (elevated temperatures) conditions. A high?pressure microdilatometer (HPMD) has been developed to investigate ash fusion and sintering behavior at elevated pressures and temperatures by the simultaneous measurement of the temperature of initial contraction and electrical resistivity of samples. This novel technique facilitates the measurement of ash properties over a wide range of temperature pressure and gas atmosphere (oxidizing reducing or inert). The operating principle of the HPMD includes measuring the temperature at which there is a significant ‘‘shift’’ in the electrical resistivity (and/or sample volume) that represents ash sintering and fusion. Sintering occurs through the formation of solid?state particle?to?particle ‘‘necks’’ or the appearance of a molten phase which allows a path for electrical conductance. The ability to perform both resistivity and shrinkage measurements simultaneously or independently at e l e v a t e d p r e s s u r e s makes the HPMD truly unique. The HPMD can also be used to investigate the swelling and softening behavior of pyrolyzing coal at elevated pressures and relatively rapid heating rates. The HPMD can provide insights into the sintering/fusion of coal ash or coal swelling at a range of conditions: (a) the influences of various gas atmospheres can be investigated (b) the effects of pressure can be studied (c) different temperature/heating rate schemes can be used (constant rates isothermal holds below or above the sinteringtemperature etc.) and (d) studies can be performed to investigate the influence of increased heating rate at elevated pressures (which were not performed previously) on coal swelling and plasticity.

M. Rashid Khan

1989-01-01T23:59:59.000Z

129

Towards measurement and verification of energy performance under the framework of the European directive for energy performance of buildings  

Science Journals Connector (OSTI)

Abstract Directive 2002/91/EC of the European Parliament and Council on the Energy Performance of Buildings has led to major developments in energy policies followed by the EU Member States. The national energy performance targets for the built environment are mostly rooted in the Building Regulations that are shaped by this Directive. Article 3 of this Directive requires a methodology to calculate energy performance of buildings under standardised operating conditions. Overwhelming evidence suggests that actual energy performance is often significantly higher than this standardised and theoretical performance. The risk is national energy saving targets may not be achieved in practice. The UK evidence for the education and office sectors is presented in this paper. A measurement and verification plan is proposed to compare actual energy performance of a building with its theoretical performance using calibrated thermal modelling. Consequently, the intended vs. actual energy performance can be established under identical operating conditions. This can help identify the shortcomings of construction process and building procurement. Once energy performance gap is determined with reasonable accuracy and root causes identified, effective measures could be adopted to remedy or offset this gap.

Esfand Burman; Dejan Mumovic; Judit Kimpian

2014-01-01T23:59:59.000Z

130

Direct ion flux measurements at high-pressure-depletion conditions for microcrystalline silicon deposition  

SciTech Connect

The contribution of ions to the growth of microcrystalline silicon thin films has been investigated in the well-known high-pressure-depletion (HPD) regime by coupling thin-film analysis with plasma studies. The ion flux, measured by means of a capacitive probe, has been studied in two regimes, i.e., the amorphous-to-microcrystalline transition regime and a low-to-high power regime; the latter regime had been investigated to evaluate the impact of the plasma power on the ion flux in collisional plasmas. The ion flux was found not to change considerably under the conditions where the deposited material undergoes a transition from the amorphous to the microcrystalline silicon phase; for solar-grade material, an ion-to-Si deposition flux of ?0.30 has been determined. As an upper-estimation of the ion energy, a mean ion energy of ?19 eV has been measured under low-pressure conditions (<1 mbar) by means of a retarding field energy analyzer. Combining this upper-estimate with an ion per deposited Si atom ratio of ?0.30, it is concluded that less than 6 eV is available per deposited Si atom. The addition of a small amount of SiH{sub 4} to an H{sub 2} plasma resulted in an increase of the ion flux by about 30% for higher power values, whereas the electron density, deduced from optical emission spectroscopy analysis, decreased. The electron temperature, also deduced from optical emission spectroscopy analysis, reveals a slight decrease with power. Although the dominant ion in the HPD regime is SiH{sub 3}{sup +}, i.e., a change from H{sub 3}{sup +} in pure hydrogen HPD conditions, the measured larger ion loss can be explained by assuming steeper electron density profiles. These results, therefore, confirm the results reported so far: the ion-to-Si deposition flux is relatively large but has neither influence on the microcrystalline silicon film properties nor on the phase transition. Possible explanations are the reported high atomic hydrogen to deposition flux ratio, mitigating the detrimental effects of an excessive ion flux.

Bronneberg, A. C.; Kang, X.; Palmans, J.; Janssen, P. H. J.; Lorne, T. [Applied Physics Department, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven (Netherlands)] [Applied Physics Department, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven (Netherlands); Creatore, M. [Applied Physics Department, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven (Netherlands) [Applied Physics Department, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven (Netherlands); Solliance Solar Research, High Tech Campus 5, 5656AE Eindhoven (Netherlands); Sanden, M. C. M. van de [Applied Physics Department, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven (Netherlands); Dutch Institute for Fundamental Energy Research (DIFFER), P.O. Box 1207, 3430BE Nieuwegein (Netherlands)

2013-08-14T23:59:59.000Z

131

Towards a direct transition energy measurement of the lowest nuclear excitation in 229Th  

E-Print Network (OSTI)

The isomeric first excited state of the isotope 229Th exhibits the lowest nuclear excitation energy in the whole landscape of known atomic nuclei. For a long time this energy was reported in the literature as 3.5(5) eV, however, a new experiment corrected this energy to 7.6(5) eV, corresponding to a UV transition wavelength of 163(11) nm. The expected isomeric lifetime is $\\tau=$ 3-5 hours, leading to an extremely sharp relative linewidth of Delta E/E ~ 10^-20, 5-6 orders of magnitude smaller than typical atomic relative linewidths. For an adequately chosen electronic state the frequency of the nuclear ground-state transition will be independent from influences of external fields in the framework of the linear Zeeman and quadratic Stark effect, rendering 229mTh a candidate for a reference of an optical clock with very high accuracy. Moreover, in the literature speculations about a potentially enhanced sensitivity of the ground-state transition of $^{229m}$Th for eventual time-dependent variations of fundamental constants (e.g. fine structure constant alpha) can be found. We report on our experimental activities that aim at a direct identification of the UV fluorescence of the ground-state transition energy of 229mTh. A further goal is to improve the accuracy of the ground-state transition energy as a prerequisite for a laser-based optical control of this nuclear excited state, allowing to build a bridge between atomic and nuclear physics and open new perspectives for metrological as well as fundamental studies.

L. v. d. Wense; P. G. Thirolf; D. Kalb; M. Laatiaoui

2012-11-04T23:59:59.000Z

132

Potential structure of discharge plasma inside liquid directly measured by an electrostatic probe  

SciTech Connect

Potential structures of a discharge plasma inside a liquid are investigated by an electrostatic probe measurement. The time evolution of radial profiles of the floating potential for the plasma inside liquid reveals that the dominant negative charges in the plasma are the negative ion species such as OH{sup -} and O{sub 2}{sup -} rather than electrons. In addition, a positive potential gradient exists at the plasma-liquid interface due to the presence of an electrical double layer which is caused by the separation of low-mass positive ion of H{sup +} and high-mass negative ions of OH{sup -} and O{sub 2}{sup -} near the plasma-liquid interface.

Chen, Qiang; Hatakeyama, Rikizo [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan)] [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan); Kaneko, Toshiro [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan) [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan); CREST/JST, Tokyo 102-0075 (Japan); Matsuda, Naoki [Measurement Solution Research Center, AIST, Tosu 841-0052 (Japan)] [Measurement Solution Research Center, AIST, Tosu 841-0052 (Japan)

2013-06-17T23:59:59.000Z

133

Reciprocal Relations Between Kinetic Curves  

E-Print Network (OSTI)

We study coupled irreversible processes. For linear or linearized kinetics with microreversibility, $\\dot{x}=Kx$, the kinetic operator $K$ is symmetric in the entropic inner product. This form of Onsager's reciprocal relations implies that the shift in time, $\\exp (Kt)$, is also a symmetric operator. This generates reciprocity relations between kinetic curves. For example, for the Master equation, if we start the process from the $i$th pure state and measure the probability $p_j(t)$ of the $j$th state ($j\

Yablonsky, G S; Constales, D; Galvita, V; Marin, G B

2010-01-01T23:59:59.000Z

134

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems  

SciTech Connect

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 ?m and the velocity error of 1? was about 0.25%, while the grating scale moved 30 mm.

Kang, Dongwoo; Lee, Eonseok; Choi, Young-Man; Lee, Taik-Min [Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of)] [Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Kim, Duk Young [Nano-Opto-Mechatronics Lab., Dept. of Mechanical Eng., KAIST, 335 Gwahangno, Yuseong-Gu, Daejeon 305-701 (Korea, Republic of)] [Nano-Opto-Mechatronics Lab., Dept. of Mechanical Eng., KAIST, 335 Gwahangno, Yuseong-Gu, Daejeon 305-701 (Korea, Republic of); Kim, Dongmin [Korea Research Institute of Standards and Science, 267 Gajeong-Ro, Yuseong-Gu, Daejeon 305-340 (Korea, Republic of)] [Korea Research Institute of Standards and Science, 267 Gajeong-Ro, Yuseong-Gu, Daejeon 305-340 (Korea, Republic of)

2013-12-15T23:59:59.000Z

135

Comparison of BES measurements of ion-scale turbulence with direct, gyrokinetic simulations of MAST L-mode plasmas  

E-Print Network (OSTI)

Observations of ion-scale (k_y*rho_i code NEMORB. This validation exercise highlights the need to include increasingly sophisticated physics, e.g., kinetic treatment of trapped electrons, equilibrium flow shear and collisions, to reprodu...

Field, A R; Ghim, Y-c; Hill, P; McMillan, B; Roach, C M; Saarelma, S; Schekochihin, A A; Zoletnik, S

2013-01-01T23:59:59.000Z

136

Direct, spectroscopic measurement of electric fields in a plasma-RF antenna interaction region in Tore Supra  

SciTech Connect

Balmer-series spectral line profiles of deuterium emission near a lower-hybrid (3.7 GHz) wave, high power (1-4 MW) launcher were measured with high-spectral resolution in the Tore Supra tokamak and fitted to an atomic physics model which includes both Zeeman and dynamic Stark effects. The magnetic field is static and the electric field is assumed to be monochromatic at 3.7 GHz. The determined strength and direction of the high-frequency electric field is found to be in good agreement with the results of a simulation that computes the propagation of these lower hybrid waves into the plasma in the region around the launch antenna and specifically in the region of estimated peak emission contributing to the measurement. This agreement indicates feasibility for the use of dynamic Stark effect spectroscopy to study interaction at the plasma antenna interactions in a fusion plasma environment. (C) 2013 Elsevier B. V. All rights reserved.

Klepper, C Christopher [ORNL] [ORNL; Hillis, Donald Lee [ORNL] [ORNL; Isler, Ralph C [ORNL] [ORNL; Hillairet, J. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Martin, E. H. [North Carolina State University] [North Carolina State University; Colas, L. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance] [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Ekedahl, A. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Goniche, M. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Lotte, Ph. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance] [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Colledani, G. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Martin, V. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Panayotis, Stephanie [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Pegourie, B. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance] [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Harris, Jeffrey H [ORNL] [ORNL

2013-01-01T23:59:59.000Z

137

Direct measurement of anisotropy of interfacial free energy from grain boundary groove morphology in transparent organic metal analong systems  

SciTech Connect

Both academia and industry alike have paid close attention to the mechanisms of microstructural selection during the solidification process. The forces that give rise to and the principles which rule the natural selection of particular morphologies are important to understanding and controlling new microstructures. Interfacial properties play a very crucial role to the selection of such microstructure formation. In the solidification of a metallic alloy, the solid-liquid interface is highly mobile and responds to very minute changes in the local conditions. At this interface, the driving force must be large enough to drive solute diffusion, maintain local curvature, and overcome the kinetic barrier to move the interface. Therefore, the anisotropy of interfacial free energy with respect to crystallographic orientation is has a significant influence on the solidification of metallic systems. Although it is generally accepted that the solid-liquid interfacial free energy and its associated anisotropy are highly important to the overall selection of morphology, the confident measurement of these particular quantities remains a challenge, and reported values are scarce. Methods for measurement of the interfacial free energy include nucleation experiments and grain boundary groove experiments. The predominant method used to determine anisotropy of interfacial energy has been equilibrium shape measurement. There have been numerous investigations involving grain boundaries at a solid-liquid interface. These studies indicated the GBG could be used to describe various interfacial energy values, which affect solidification. Early studies allowed for an estimate of interfacial energy with respect to the GBG energy, and finally absolute interfacial energy in a constant thermal gradient. These studies however, did not account for the anisotropic nature of the material at the GBG. Since interfacial energy is normally dependent on orientation of the crystallographic plane of the solid with respect to the liquid, a better calculation of interfacial energy was needed. Herring described this orientation dependence, which related the interfacial undercooling to the principle interfacial curvatures. The present study pertains to the measurement of the anisotropy of interfacial energy by comparison of experimental and theoretical GBG geometries in pure succinonitrile (SCN) and pivalic acid (PVA). A quantity of SCN and PVA was distilled and zone refined using a process that is defined in the experimental procedure portion of this paper. Very thin (100 {micro}m) slide assemblies were created and filled with these organic materials. For each system, several grooves were photographed and their shapes were compared with theoretical predictions. The correlation between experiment and theory was quantified and plotted as a function of the anisotropy for each of the GBG's examined, and a maximum correlation corresponded to the anisotropy of interfacial energy which describes that particular rotation of the GBG. The results from several rotations were statistically analyzed to ensure confidence in the measurement of the anisotropy of interfacial energy and, finally, compared to reported values obtained with other techniques.

Rustwick, Bryce A.

2005-08-01T23:59:59.000Z

138

Direct measurement of instantaneous source speed for a HDR brachytherapy unit using an optical fiber based detector  

SciTech Connect

Purpose: Several attempts to determine the transit time of a high dose rate (HDR) brachytherapy unit have been reported in the literature with controversial results. The determination of the source speed is necessary to accurately calculate the transient dose in brachytherapy treatments. In these studies, only the average speed of the source was measured as a parameter for transit dose calculation, which does not account for the realistic movement of the source, and is therefore inaccurate for numerical simulations. The purpose of this work is to report the implementation and technical design of an optical fiber based detector to directly measure the instantaneous speed profile of a {sup 192}Ir source in a Nucletron HDR brachytherapy unit. Methods: To accomplish this task, we have developed a setup that uses the Cerenkov light induced in optical fibers as a detection signal for the radiation source moving inside the HDR catheter. As the {sup 192}Ir source travels between two optical fibers with known distance, the threshold of the induced signals are used to extract the transit time and thus the velocity. The high resolution of the detector enables the measurement of the transit time at short separation distance of the fibers, providing the instantaneous speed. Results: Accurate and high resolution speed profiles of the {sup 192}Ir radiation source traveling from the safe to the end of the catheter and between dwell positions are presented. The maximum and minimum velocities of the source were found to be 52.0{+-}1.0 and 17.3{+-}1.2 cm/s. The authors demonstrate that the radiation source follows a uniformly accelerated linear motion with acceleration of |a|=113 cm/s{sup 2}. In addition, the authors compare the average speed measured using the optical fiber detector to those obtained in the literature, showing deviation up to 265%. Conclusions: To the best of the authors' knowledge, the authors directly measured for the first time the instantaneous speed profile of a radiation source in a HDR brachytherapy unit traveling from the unit safe to the end of the catheter and between interdwell distances. The method is feasible and accurate to implement on quality assurance tests and provides a unique database for efficient computational simulations of the transient dose.

Minamisawa, R. A.; Rubo, R. A.; Seraide, R. M.; Rocha, J. R. O.; Almeida, A. [Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, 14040-901, Ribeirao Preto-SP (Brazil); INRAD, Medical School - University of Sao Paulo, Clinical Hospital (HCUSP), 05403-001, Sao Paulo-SP (Brazil); CAISM Radiotherapy Service, CEB, State University of Campinas, 13083-881, Campinas-SP (Brazil); Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, 14040-901, Ribeirao Preto-SP (Brazil)

2010-10-15T23:59:59.000Z

139

Measurement and modeling of muon-induced neutrons in LSM in application for direct dark matter searches  

SciTech Connect

Due to a very low event rate expected in direct dark matter search experiments, a good understanding of every background component is crucial. Muon-induced neutrons constitute a prominent background, since neutrons lead to nuclear recoils and thus can mimic a potential dark matter signal. EDELWEISS is a Ge-bolometer experiment searching for WIMP dark matter. It is located in the Laboratoire Souterrain de Modane (LSM, France). We have measured muon-induced neutrons by means of a neutron counter based on Gd-loaded liquid scintillator. Studies of muon-induced neutrons are presented and include development of the appropriate MC model based on Geant4 and analysis of a 1000-days measurement campaign in LSM. We find a good agreement between measured rates of muon-induced neutrons and those predicted by the developed model with full event topology. The impact of the neutron background on current EDELWEISS data-taking as well as for next generation experiments such as EURECA is briefly discussed.

Kozlov, Valentin [Karlsruhe Institute of Technology, Institut für Kernphysik, Postfach 3640, 76021 Karlsruhe (Germany)] [Karlsruhe Institute of Technology, Institut für Kernphysik, Postfach 3640, 76021 Karlsruhe (Germany); Collaboration: EDELWEISS Collaboration

2013-08-08T23:59:59.000Z

140

Gamma-gamma directional correlation measurements in 130,132Xe following thermal neutron capture by natural xenon  

Science Journals Connector (OSTI)

Directional correlations of gamma-ray cascades in 130,132Xe have been measured following thermal n capture by a pressurised natural xenon gas target. Gamma-ray singles spectra were measured up to 5.5 MeV and the coincidence correlation data were obtained for the energy range 0.2-2.5 MeV. Decay schemes were developed on the basis of the coincidence measurements. The data spin-parity assignments to be made to most levels lying below 3.5 MeV in the 132Xe and the multiple mixing ratios to be evaluated for the more intense transitions. The results are fitted to IBM-1 and IBM-2 and are also compared with the prediction of the dynamic deformation model of Kumar (1983). The 23+ level at 1985 keV in 132Xe is considered to be a mixed-symmetry state with B(M1; 23+ to 21+)=0.29 mu N2.

S A Hamada; W D Hamilton; B More

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)  

SciTech Connect

This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization. Tabs, figs, refs.

Shum, S.

1993-05-01T23:59:59.000Z

142

Measuring the Costs and Economic, Social, and Environmental Benefits of Nationwide Geothermal Heat Pump Deployment and The Potential Employment, Energy, and Environmental Impacts of Direct Use Applications  

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

Project objectives: To measure the costs and economic; social; and environmental benefits of nationwide geothermal heat pump (GHP) deployment; and To survey selected states as to their potential employment; energy use and savings; and environmental impact for direct use applications.

143

Possibility of using active secondary charge-exchange particle diagnostics for measuring the magnetic field direction in the plasma of a magnetic fusion reactor  

Science Journals Connector (OSTI)

An active particle diagnostic method based on the secondary charge exchange of hydrogen atoms of a probing (diagnostic) beam is proposed for local measurements of the magnetic field direction in the plasma of a t...

A. A. Medvedev; V. S. Strelkov

2006-05-01T23:59:59.000Z

144

Quantitative Spreading Kinetics of a Three Molecular Layer Liquid Patch  

Science Journals Connector (OSTI)

Quantitative Spreading Kinetics of a Three Molecular Layer Liquid Patch ... The late stage kinetics of the spreading of a smectic nanodrop on a solid surface was investigated by direct and real time imaging of a three molecular layer patch using the SEEC microscopy. ... (15) At some stage of the spreading kinetics, the structure reduces to a single bilayer patch lying on the surface monolayer. ...

Olivier Noel; Jean-Luc Buraud; Laurent Berger; Dominique Ausserre?

2010-03-19T23:59:59.000Z

145

Characterization of room temperature recrystallization kinetics in electroplated copper thin films with concurrent x-ray diffraction and electrical resistivity measurements  

SciTech Connect

Concurrent in-situ four-point probe resistivity and high resolution synchrotron x-ray diffraction measurements were used to characterize room temperature recrystallization in electroplated Cu thin films. The x-ray data were used to obtain the variation with time of the integrated intensities and the peak-breadth from the Cu 111 and 200 reflections of the transforming grains. The variation of the integrated intensity and resistivity data with time was analyzed using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. For both 111-textured and non-textured electroplated Cu films, four-point probe resistivity measurements yielded shorter transformation times than the values obtained from the integrated intensities of the corresponding Cu 111 reflections. In addition, the JMAK exponents fitted to the resistivity data were significantly smaller. These discrepancies could be explained by considering the different material volumes from which resistivity and diffraction signals originated, and the physical processes which linked these signals to the changes in the evolving microstructure. Based on these issues, calibration of the resistivity analysis with direct structural characterization techniques is recommended.

Treger, Mikhail; Noyan, I. C. [Department of Applied Physics and Applied Mathematics, Columbia University, New York 10027 (United States)] [Department of Applied Physics and Applied Mathematics, Columbia University, New York 10027 (United States); Witt, Christian [GlobalFoundries, T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States)] [GlobalFoundries, T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Cabral, Cyril; Murray, Conal; Jordan-Sweet, Jean [IBM, T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States)] [IBM, T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Rosenberg, Robert [State University of New York, the University at Albany, Albany, NY 12203 (United States)] [State University of New York, the University at Albany, Albany, NY 12203 (United States); Eisenbraun, Eric [College of Nanoscale Science and Engineering, University at Albany, Albany, NY 12203 (United States)] [College of Nanoscale Science and Engineering, University at Albany, Albany, NY 12203 (United States)

2013-06-07T23:59:59.000Z

146

Direct Measurements of Steady-State Kinetics of Cyanobacterial N2 Uptake by Membrane-Leak Mass Spectrometry and Comparisons Between Nitrogen Fixation and Acetylene Reduction  

Science Journals Connector (OSTI)

...from five batches of cyanobacteria The average value of Km for light-induced are shown in Table 2. The conversion factor in etylene reduction at 35 C for five different this case was again greater than the stoichiomet- tches of A. variabilis was 385 50...

Bent Borg Jensen; Raymond P. Cox

1983-04-01T23:59:59.000Z

147

Direct measurement of the spin gap in a quasi-one-dimensional clinopyroxene: NaTiSi2O6  

Science Journals Connector (OSTI)

True inorganic spin-Peierls materials are extremely rare, but NaTiSi2O6 was at one time considered to be an ideal candidate owing to its well separated chains of edge-sharing TiO6 octahedra. At low temperatures, this material undergoes a phase transition from C2/c to P1¯ symmetry, where Ti3+?Ti3+ dimers begin to form within the chains. However, it was quickly realized with magnetic susceptibility that simple spin fluctuations do not progress to the point of enabling such a transition. Since then, considerable experimental and theoretical endeavors have been undertaken to find the true ground state of this system and explain how it manifests. Here, we employ the use of x-ray diffraction, neutron spectroscopy, and magnetic susceptibility to directly and simultaneously measure the symmetry loss, spin singlet-triplet gap, and phonon modes. A gap of 53(3) meV was observed, fit to the magnetic susceptibility, and compared to previous theoretical models to unambiguously assign NaTiSi2O6 as having an orbital-assisted Peierls ground state.

Harlyn J. Silverstein; Alison E. Smith; Cole Mauws; Douglas L. Abernathy; Haidong Zhou; Zhiling Dun; Johan van Lierop; Christopher R. Wiebe

2014-10-13T23:59:59.000Z

148

A NEW METHOD TO DIRECTLY MEASURE THE JEANS SCALE OF THE INTERGALACTIC MEDIUM USING CLOSE QUASAR PAIRS  

SciTech Connect

Although the baryons in the intergalactic medium (IGM) trace dark matter fluctuations on megaparsec scales, on smaller scales ?100 kpc, fluctuations are suppressed because the finite temperature gas is pressure supported against gravity, analogous to the classical Jeans argument. This Jeans filtering scale, which quantifies the small-scale structure of the IGM, has fundamental cosmological implications. First, it provides a thermal record of heat injected by ultraviolet photons during cosmic reionization events, and thus constrains the thermal and reionization history of the universe. Second, the Jeans scale determines the clumpiness of the IGM, a critical ingredient in models of cosmic reionization. Third, it sets the minimum mass scale for gravitational collapse from the IGM, and hence plays a pivotal role in galaxy formation. Unfortunately, it is extremely challenging to measure the Jeans scale via the standard technique of analyzing purely longitudinal Ly? forest spectra, because the thermal Doppler broadening of absorption lines along the line-of-sight, is highly degenerate with Jeans smoothing. In this work, we show that the Jeans filtering scale can be directly measured by characterizing the coherence of correlated Ly? forest absorption in close quasar pairs, with separations small enough ?100 kpc to resolve it. We present a novel technique for this purpose, based on the probability density function (PDF) of phase angle differences of homologous longitudinal Fourier modes in close quasar pair spectra. A Bayesian formalism is introduced based on the phase angle PDF, and Markov Chain Monte Carlo techniques are used to characterize the precision of a hypothetical Jeans scale measurement, and explore degeneracies with other thermal parameters governing the IGM. A semi-analytical model of the Ly? forest is used to generate a large grid (500) of thermal models from a dark matter only simulation. Our full parameter study indicates that a realistic sample of only 20 close quasar pair spectra can pinpoint the Jeans scale to ? 5% precision, independent of the amplitude T{sub 0} and slope ? of the temperature-density relation of the IGM T=T{sub 0}(?/ ?-bar ){sup ?-1}. This exquisite sensitivity arises because even long-wavelength one-dimensional Fourier modes ?10 Mpc, i.e., two orders of magnitude larger than the Jeans scale, are nevertheless dominated by projected small-scale three-dimensional (3D) power. Hence phase angle differences between all modes of quasar pair spectra actually probe the shape of the 3D power spectrum on scales comparable to the pair separation. We show that this new method for measuring the Jeans scale is unbiased and is insensitive to a battery of systematics that typically plague Ly? forest measurements, such as continuum fitting errors, imprecise knowledge of the noise level and/or spectral resolution, and metal-line absorption.

Rorai, Alberto; Hennawi, Joseph F. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); White, Martin [Department of Astronomy, University of California at Berkeley, 601 Campbell Hall, Berkeley, CA 94720-3411 (United States)

2013-10-01T23:59:59.000Z

149

A direct method for air kerma–length product measurement in CT for verification of dose display calibrations  

Science Journals Connector (OSTI)

......kerma-length product measurement in CT for verification of dose display calibrations...kerma-length product measurement in CT for verification of dose display calibrations...practice, this means doing measurements in the standard phantoms......

Katja Merimaa; Hannu Järvinen; Mika Kortesniemi; Juhani Karppinen

2010-08-01T23:59:59.000Z

150

Nonequilibrium quantum kinetics  

SciTech Connect

This paper contains viewgraphs on non-equilibrium quantum kinetics of nuclear reactions at the intermediate and high energy ranges.

Danielewicz, P.

1997-09-22T23:59:59.000Z

151

Apparatus and method for direct measurement of coal ash sintering and fusion properties at elevated temperatures and pressures  

DOE Patents (OSTI)

A high-pressure microdilatometer is provided for measuring the sintering and fusion properties of various coal ashes under the influence of elevated pressures and temperatures in various atmospheres. Electrical resistivity measurements across a sample of coal ash provide a measurement of the onset of the sintering and fusion of the ash particulates while the contraction of the sample during sintering is measured with a linear variable displacement transducer for detecting the initiation of sintering. These measurements of sintering in coal ash at different pressures provide a mechanism by which deleterious problems due to the sintering and fusion of ash in various combustion systems can be minimized or obviated.

Khan, M. Rashid (Morgantown, WV)

1990-01-01T23:59:59.000Z

152

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory  

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

Abreu, P [Lisbon, IST; Aglietta, M [IFSI, Turin; Ahn, E J [Fermilab; Albuquerque, I F.M. [Sao Paulo U.; Allard, D [APC, Paris; Allekotte, I [Centro Atomico Bariloche; Allen, J [New York U.; Allison, P [Ohio State U.; Alvarez Castillo, J [Mexico U., ICN; Alvarez-Muniz, J [Santiago de Compostela U.; Ambrosio, M [Napoli Seconda U.; INFN, Naples; Nijmegen U., IMAPP

2011-06-17T23:59:59.000Z

153

kinetic wave energy  

Science Journals Connector (OSTI)

kinetic wave energy ? kinetische Wellenenergie f [Teil der Wellenlänge, die im Feld der Orbitalgeschwindigkeiten unter der Welle enthalten ist und als Orbitalbewegung am Ort verbleibt

2014-08-01T23:59:59.000Z

154

Chemical Looping Combustion Kinetics  

SciTech Connect

One of the most promising methods of capturing CO{sub 2} emitted by coal-fired power plants for subsequent sequestration is chemical looping combustion (CLC). A powdered metal oxide such as NiO transfers oxygen directly to a fuel in a fuel reactor at high temperatures with no air present. Heat, water, and CO{sub 2} are released, and after H{sub 2}O condensation the CO{sub 2} (undiluted by N{sub 2}) is ready for sequestration, whereas the nickel metal is ready for reoxidation in the air reactor. In principle, these processes can be repeated endlessly with the original nickel metal/nickel oxide participating in a loop that admits fuel and rejects ash, heat, and water. Our project accumulated kinetic rate data at high temperatures and elevated pressures for the metal oxide reduction step and for the metal reoxidation step. These data will be used in computational modeling of CLC on the laboratory scale and presumably later on the plant scale. The oxygen carrier on which the research at Utah is focused is CuO/Cu{sub 2}O rather than nickel oxide because the copper system lends itself to use with solid fuels in an alternative to CLC called 'chemical looping with oxygen uncoupling' (CLOU).

Edward Eyring; Gabor Konya

2009-03-31T23:59:59.000Z

155

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory  

SciTech Connect

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

Abreu, P [Lisbon, IST; Aglietta, M [IFSI, Turin; Ahn, E J [Fermilab; Albuquerque, I F.M. [Sao Paulo U.; Allard, D [APC, Paris; Allekotte, I [Centro Atomico Bariloche; Allen, J [New York U.; Allison, P [Ohio State U.; Alvarez Castillo, J [Mexico U., ICN; Alvarez-Muniz, J [Santiago de Compostela U.; Ambrosio, M [Napoli Seconda U.; INFN, Naples; Nijmegen U., IMAPP

2011-06-17T23:59:59.000Z

156

A Method for Estimating the Turbulent Kinetic Energy Dissipation Rate from a Vertically Pointing Doppler Lidar, and Independent Evaluation from Balloon-Borne In Situ Measurements  

Science Journals Connector (OSTI)

A method of estimating dissipation rates from a vertically pointing Doppler lidar with high temporal and spatial resolution has been evaluated by comparison with independent measurements derived from a balloon-borne sonic anemometer. This method ...

Ewan J. O’Connor; Anthony J. Illingworth; Ian M. Brooks; Christopher D. Westbrook; Robin J. Hogan; Fay Davies; Barbara J. Brooks

2010-10-01T23:59:59.000Z

157

Direct measurement of the W boson decay width in proton-antiproton collisions at s**(1/2) = 1.96-TeV  

SciTech Connect

This dissertation describes a direct measurement of the W boson total decay width, {Lambda}{sub W}, using the D0 detector at the Fermilab Tevatron Collider. The measurement uses an integrated luminosity of 177.3 pb{sup -1} data, collected during the 2002-2003 run. The width is determined from the shape of the transverse mass distribution, M{sub T}, by fitting the data in the tail region 100 < M{sub T} < 200 GeV. The result if {Lambda}{sub W} = 2.011 {+-} 0.093(stat) {+-} 0.107(syst) GeV.

Zhu, Jun-jie; /Maryland U.

2004-10-01T23:59:59.000Z

158

Kinetic Modeling of Microbiological Processes  

SciTech Connect

Kinetic description of microbiological processes is vital for the design and control of microbe-based biotechnologies such as waste water treatment, petroleum oil recovery, and contaminant attenuation and remediation. Various models have been proposed to describe microbiological processes. This editorial article discusses the advantages and limiation of these modeling approaches in cluding tranditional, Monod-type models and derivatives, and recently developed constraint-based approaches. The article also offers the future direction of modeling researches that best suit for petroleum and environmental biotechnologies.

Liu, Chongxuan; Fang, Yilin

2012-09-17T23:59:59.000Z

159

First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches  

E-Print Network (OSTI)

We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs.

S. Burgos; E. Daw; J. Forbes; C. Ghag; M. Gold; C. Hagemann; V. A. Kudryavtsev; T. B. Lawson; D. Loomba; P. Majewski; D. Muna; A. StJ. Murphy; G. G. Nicklin; S. M. Paling; A. Petkov; S. J. S. Plank; M. Robinson; N. Sanghi; D. P. Snowden-Ifft; N. J. C. Spooner; J. Turk; E. Tziaferi

2008-09-10T23:59:59.000Z

160

Technique for Direct eV-Scale Measurements of the Mu and Tau Neutrino Masses Using Supernova Neutrinos  

E-Print Network (OSTI)

Early black hole formation in a core-collapse supernova will abruptly truncate the neutrino fluxes. The sharp cutoff can be used to make model-independent time-of-flight neutrino mass tests. Assuming a neutrino luminosity of $10^{52}$ erg/s per flavor at cutoff and a distance of 10 kpc, SuperKamiokande can detect an electron neutrino mass as small as 1.8 eV, and the proposed OMNIS detector can detect mu and tau neutrino masses as small as 6 eV. This {\\it Letter} presents the first technique with direct sensitivity to eV-scale mu and tau neutrino masses.

J. F. Beacom; R. N. Boyd; A. Mezzacappa

2000-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Direct vs. projective: measures of children's perceptions of the parent-child relationship as predictors of future relationship quality  

E-Print Network (OSTI)

and are a potential mechanism for the observed relation between childhood aggression and the parent-child relationship (Lyons-Ruth, Alpern, dk Repacholi, 1993; Renken, Egeland, Marvinney, Mangelsdorf, & Sroufe, 1989). A subgroup of 71% of a sample... was the quality of a newly formed relationship between the child and a mentor and included measures as reported by the mentor and by the child. The mentor-report measures were the Therapeutic Alliance Scales for Children (TAS-M, Shirk & Saiz, 1992) and mentor...

Collie, Claire Futamase

2012-06-07T23:59:59.000Z

162

Direct measurements of growing amorphous order and non-monotonic dynamic correlations in a colloidal glass-former  

E-Print Network (OSTI)

While the transformation of flowing liquids into rigid glasses is omnipresent, a complete understanding of vitrification remains elusive. Of the numerous approaches aimed at solving the glass transition problem, the Random First-Order Theory (RFOT) is the most prominent. However, the existence of the underlying thermodynamic phase transition envisioned by RFOT remains debatable, since its key microscopic predictions concerning the growth of amorphous order and the nature of dynamic correlations lack experimental verification. Here, by using holographic optical tweezers, we freeze a wall of particles in an equilibrium configuration of a 2D colloidal glass-forming liquid and provide direct evidence for growing amorphous order in the form of a static point-to-set length. Most remarkably, we uncover the non-monotonic dependence of dynamic correlations on area fraction and show that this non-monotonicity follows directly from the change in morphology of cooperatively rearranging regions, as predicted by RFOT. Our findings suggest that the glass transition has a thermodynamic origin.

K. Hima Nagamanasa; Shreyas Gokhale; A. K. Sood; Rajesh Ganapathy

2014-08-23T23:59:59.000Z

163

Measurement of direct CP violation parameters in B±?J/?K± and B±?J/??± decays with 10.4??fb-1 of Tevatron data  

We present a measurement of the direct CP-violating charge asymmetry in B± mesons decaying to J/?K± and J/??± where J/? decays to ?+??, using the full run II data set of 10.4??fb?1 of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B? and B+ mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of AJ/?K=[0.59±0.37]%, which is the most precise measurement to date, and AJ/??=[?4.2±4.5]%. Both measurements are consistent with standard model predictions.

Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Beattie, M.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hart, B.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Holzbauer, J.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Lamont, I.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; Mason, N.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.

2013-06-01T23:59:59.000Z

164

Measurement of Feynman-x Spectra of Photons and Neutrons in the Very Forward Direction in Deep-Inelastic Scattering at HERA  

E-Print Network (OSTI)

Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic $ep$ scattering at HERA are presented as a function of the Feynman variable $x_F$ and of the centre-of-mass energy of the virtual photon-proton system $W$. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $131 \\mathrm{pb}^{-1}$. The measurement is restricted to photons and neutrons in the pseudorapidity range $\\eta>7.9$ and covers the range of negative four momentum transfer squared at the positron vertex $6scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections.

H1 Collaboration

2014-04-01T23:59:59.000Z

165

Direct measurement of {sup 12}C+{sup 4}He?{sup 16}O+? total cross section at E{sub cm}=1.2 MeV  

SciTech Connect

A fusion reaction of {sup 12}C+{sup 4}He?{sup 16}O+? is one of the main reactions in He-burning of stars and important for nucleosynthesis. The fusion cross section at stellar energy of E{sub cm}=0.3 MeV has not been determined precisely yet in spite of efforts for about 40 years. We plan to measure directly the total fusion cross section down to 0.7 MeV at Kyushu University Tandem accelerator Laboratory and to estimate the cross section at 0.3MeV by extrapolation. We have already measured the cross sections at 2.4 MeV and 1.5 MeV. The measurement at E{sub cm}=1.2 MeV is in progress.

Yamaguchi, H.; Sagara, K.; Fujita, K.; Kodama, D.; Narikiyo, Y.; Hamamoto, K.; Ban, T.; Tao, N.; Teranishi, T. [Department of Physics, Kyushu University (Japan)

2014-05-02T23:59:59.000Z

166

Direct measurement results of the time lag of LOS-velocity oscillations between two heights in solar faculae and sunspots  

E-Print Network (OSTI)

We present an investigation of line-of-sight (LOS) velocity oscillations in solar faculae and sunspots. To study the phase relations between chromosphere and photosphere oscillations of the LOS velocity, we measured the time lag of the chromospheric signal relative to the photospheric one for several faculae and sunspots in a set of spectral line pairs. The measured time lags are different for different objects. The mean measured delay between the oscillations in the five-minute band in faculae is 50s for the SiI 10827{\\AA}-HeI 10830{\\AA} pair; for the pair FeI 6569{\\AA}-H-alpha 6563{\\AA} the mean delay is 20s; for the pair FeI 4551{\\AA}-BaII 4554{\\AA} the mean delay is 7s; for the pair SiI 8536{\\AA}-CaII 8542{\\AA} the mean delay is 20s. For the oscillations in the three-minute band in sunspot umbrae the mean delay is 55s for the SiI 10827{\\AA}-HeI 10830{\\AA} pair; for the Fe I 6569{\\AA}-H-alpha 6563{\\AA} pair it was not possible to determine the delay; for the FeI 4551{\\AA}-BaII 4554{\\AA} pair the mean delay...

Kobanov, Nikolai; Kustov, Arseniy; Chupin, Sergey; Chelpanov, Andrey

2013-01-01T23:59:59.000Z

167

Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction  

SciTech Connect

An experimental set-up for accurate measurement of hydrogen generation rate in Lithium-Lead (Li[sub 17]Pb[sub 83]) Steam or water interactions has been designed. The most important features of the design include a pneumatic actuated quick opening and closing high temperature all stainless steel valve used to control the reaction time and the placement of most measuring devices below a water line to minimize leakage of the hydrogen collected. A PC based data acquisition and control system provides remote process sequencing, acquisition and control of all major components of the set-up. Initial tests indicate that the first design objective of maintaining leakproof gas collection chamber has been achieved. Initial pressure tests indicated that the pressure drop over a time span of 30 minutes was within the tolerance of the pressure transducer used to measure the pressure (within 0.690 kPa) at a nominal system pressure of 685 kPa. The experimental system hardware, data acquisition and control programs and data analysis program have been completed, tested and are currently functional.

Biney, P.O.

1993-04-01T23:59:59.000Z

168

Effect of H2/CO ratio and N2/CO2 dilution rate on laminar burning velocity of syngas investigated by direct measurement and simulation  

Science Journals Connector (OSTI)

Abstract Laminar burning velocities of syngas/air premixed flames, varying with H2/CO ratio (from 5/95 to 75/25) and N2 or CO2 dilution rate (from 0% to 60%), were accurately measured using a Teflon coated Heat Flux burner and OH-PLIF based Bunsen flame method. Experiments were carried out at atmospheric pressure and room temperature, with fuel/air equivalence ratios ranging from fuel-lean to fuel-rich. Coupled with experimental data, three chemical kinetic mechanisms, namely GRI-Mech 3.0, USC Mech II and Davis H2–CO mechanism, were validated. The Davis H2–CO and USC Mech II mechanisms appear to provide a better prediction for the laminar burning velocity. The laminar burning velocity variations with H2 and dilution gas contents were systematically investigated. For given dilution gas fraction, the laminar burning velocity reduction rate was enhanced as H2/CO ratio increasing. Effects of the syngas components and equivalence ratio variation on the concentrations of radical H and OH were also studied. It appears that there is a strong linear correlation between the laminar burning velocity and the maximum concentration of the H radical in the reaction zone for syngas. This characteristic is exclusively different from that in methane air premixed flame. These findings indicated that the high thermal diffusivity of the H radical played an important role in the laminar burning velocity enhancement and affected the laminar burning velocity reduction rate under dilution condition.

Z.H. Wang; W.B. Weng; Y. He; Z.S. Li; K.F. Cen

2014-01-01T23:59:59.000Z

169

Kinetic equilibrium reconstruction on EAST tokamak  

Science Journals Connector (OSTI)

Plasma equilibrium is an important basis for tokamak plasma research. The equilibrium reconstructed from experimental diagnostics is a key element for experiments analysis and for theory study. The kinetic equilibrium has the profiles information (current or safety factor profile, kinetic pressure profile), which are key issues for some studies of physics. With the constraints of magnetic measurements, pressure profile and edge current profile, we achieved the first reconstructed kinetic equilibrium on EAST tokamak. The pressure and edge current profiles are based on the diagnostics and theoretical bootstrap current model. The kinetic equilibrium has the pedestal structure for H-mode plasma, which the magnetic reconstruction missed. This improved equilibrium is an important basis for some experimental analysis and theory studies on EAST.

G Q Li; Q L Ren; J P Qian; L L Lao; S Y Ding; Y J Chen; Z X Liu; B Lu; Q Zang

2013-01-01T23:59:59.000Z

170

An experimental verification of the Hall and Eubank method of direct measurement of the interaction of second virial coefficient  

E-Print Network (OSTI)

- olution past the point at which the seal between the valve stem and seat was broken. The lower volume valve was always closed dur;ng pressure measurement. The iipper chamber of the DPI communicated with the pressure mea urement device (dead weight gage...: 1. Mitb Valves l~ 2, and 3 open, UA and V& were purged with C02. The system was then charged to a specified. pressure. 2. Valve 1 was set at a position 1/8 turn past the point at which the stem and. seat broke their seal. Carefully maintaining a...

Bellomy, Marc Thomas

1976-01-01T23:59:59.000Z

171

Measurement of critical energy for direct initiation of spherical detonations in stoichiometric high-pressure H{sub 2}-O{sub 2} mixtures  

SciTech Connect

In this study, the critical energy for direct initiation of spherical detonations in stoichiometric high-pressure hydrogen-oxygen mixtures are measured and investigated to look at the effect of explosion limits on the detonation sensitivity. Results up to an initial pressure of 20 atm are obtained. Experiments are carried out in a spherical bomb and direct initiation is achieved via spark ignition from a high-voltage capacitor discharge. A detailed description of different methods to obtain a good estimate of the correct amount of energy deposited into the mixture used to initiate the detonation, including the calorimeter method and current method, is provided. It is demonstrated that at elevated initial pressure, the second explosion limit effect plays a significant role leading to slow-branching reactions and the detonation sensitivity of hydrogen mixtures is comparable to other common hydrocarbon mixtures at such condition. (author)

Kamenskihs, Vsevolods; Lee, John H.S. [Department of Mechanical Engineering, McGill University, Montreal, Quebec (Canada); Ng, Hoi Dick [Department of Mechanical and Industrial Engineering, Concordia University, Montreal, Quebec (Canada)

2010-09-15T23:59:59.000Z

172

PROBING THE NATURE OF THE HELIOSHEATH WITH THE NEUTRAL ATOM SPECTRA MEASURED BY IBEX IN THE VOYAGER 1 DIRECTION  

SciTech Connect

We are able to show by comparing modeled energetic neutral atoms (ENAs) spectra to those measured by Interstellar Boundary Explorer (IBEX) that the models along the Voyager 1 (V1) trajectory that best agree with the low energy IBEX data include extra heating due to ram and magnetic energy in the quasi-stagnation region or a kappa ion distribution (with ? = 2.0) in the outer heliosheath. The model explored is the multi-ion, multi-fluid (MI-MF) which treats the pick-up ions and the thermal ion fluids with separate Maxwellian distributions. These effects are included ad hoc in the modeled ENA since they are not present in the model. These results indicate that the low energy spectra of ENAs as measured by IBEX is sensitive to the physical nature of the heliosheath and to effects not traditionally present in current global models. Therefore, by comparing the low energy ENA spectra to models, we can potentially probe the heliosheath in locations beyond those probed by V1 and Voyager 2 (V2)

Opher, M.; Prested, C. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA (United States)] [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA (United States); McComas, D. J. [Southwest Research Institute, San Antonio, TX 78238 (United States)] [Southwest Research Institute, San Antonio, TX 78238 (United States); Schwadron, N. A. [Department of Physics and Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)] [Department of Physics and Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Drake, J. F., E-mail: mopher@bu.edu [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742 (United States)

2013-10-20T23:59:59.000Z

173

Measurement of direct CP violation in b -> scc and b -> dcc quark transitions using B+ -> J/psiK+ and B+ -> J/psi pi+ decays  

SciTech Connect

This thesis describes the measurement of the direct CP violation in the b {yields} sc{bar c} transition using the decay B{sup +} {yields} J/{psi}K{sup +}, and in the b {yields} dc{bar c} transition using the decay B{sup +} {yields} J/{psi}{pi}{sup +}. The decays of B{sup +} mesons are reconstructed in approximately 2.8 fb{sup -1} of data recorded by D0 detector in 2002-2007 during Run II of Fermilab Tevatron collider. Using the unbinned likelihood fit, a signal of 40,222 {+-} 242 of B{sup +} {yields} J/{psi}K{sup +} and 1,578 {+-} 119 of B{sup +} {yields} J/{psi}{pi}{sup +} events is obtained. The corresponding direct CP violation asymmetries are measured to be A{sub CP}(B{sup +} {yields} J/{psi}(1S)K{sup +}) = +0.0077 {+-} 0.0061(stat.) {+-} 0.0027(syst.), and A{sub CP}(B{sup +} {yields} J/{psi}(1S){pi}{sup +}) = - 0.089 {+-} 0.081(stat.) {+-} 0.028(syst.). The result on A{sub CP} (B{sup +} {yields} J/{psi}(1S)K{sup +}) is consistent with the 2007 world average and is the most precise measurement of this asymmetry, with uncertainty approaching the level of the Standard Model prediction. The result on A{sub CP} (B{sup +} {yields} J/{psi}(1S){pi}{sup +}) constitutes the first measurement of this asymmetry at the hadron collider, with uncertainty at the level of the 2007 world average. The measurement presented in this thesis has become possible due to the sophisticated online and offline tracking/vertexing implemented at D0, and the regular reversal of the polarities of the D0 detector magnets.

Holubyev, K.; /Lancaster U.

2008-12-01T23:59:59.000Z

174

Measurement  

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

localization that limits the present measurements. The knowledge thus gained will have input not only to fusion research, but to may ques- tions of basic plasma physics....

175

Measurement  

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

in the Department of Physics & Astronomy. Chapel Hill 2005 Approved: A. E. Champagne, Advisor J. C. Blackmon, Reader C. Iliadis, Reader ABSTRACT Ryan P. Fitzgerald: Measurement of...

176

Measurement of the direct $CP$ asymmetry in $\\bar{B}\\rightarrow X_{s+d}\\gamma$ decays with a lepton tag  

E-Print Network (OSTI)

We report the measurement of the direct $CP$ asymmetry in the radiative $\\bar{B}\\rightarrow X_{s+d}\\gamma$ decay using a data sample of $(772 \\pm 11)\\times 10^6$ $B\\bar{B}$ pairs collected at the $\\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The $CP$ asymmetry is measured as a function of the photon energy threshold. For $E^{\\rm{*}}_{\\gamma} \\geq 2.1~{\\rm{GeV}}$, where $E^{\\rm{*}}_{\\gamma}$ is the photon energy in the center-of-mass frame, we obtain $\\mathcal{A}_{CP}(\\bar{B}\\rightarrow X_{s+d}\\gamma)= (2.2 \\pm 3.9 \\pm 0.9) \\%$, consistent with the Standard Model prediction.

Pesántez, L; Dingfelder, J; Abdesselam, A; Adachi, I; Adamczyk, K; Aihara, H; Said, S Al; Arinstein, K; Asner, D M; Aulchenko, V; Aushev, T; Ayad, R; Bahinipati, S; Bakich, A M; Bansal, V; Barberio, E; Bhardwaj, V; Bhuyan, B; Bobrov, A; Bondar, A; Bonvicini, G; Bozek, A; Bra?ko, M; Browder, T E; ?ervenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Chistov, R; Cho, K; Chobanova, V; Choi, Y; Cinabro, D; Dalseno, J; Doležal, Z; Drásal, Z; Drutskoy, A; Dutta, D; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Frost, O; Gaur, V; Gabyshev, N; Ganguly, S; Garmash, A; Getzkow, D; Gillard, R; Goh, Y M; Golob, B; Haba, J; Hasenbusch, J; He, X H; Heller, A; Horiguchi, T; Hou, W -S; Huschle, M; Iijima, T; Inami, K; Ishikawa, A; Itoh, R; Iwasaki, Y; Jaegle, I; Joffe, D; Julius, T; Kang, K H; Kato, E; Kawasaki, T; Kiesling, C; Kim, D Y; Kim, J B; Kim, J H; Kim, K T; Kim, M J; Kim, S H; Kim, Y J; Ko, B R; Kodyš, P; Korpar, S; Križan, P; Krokovny, P; Kronenbitter, B; Kuhr, T; Kumita, T; Kuzmin, A; Kwon, Y -J; Lange, J S; Lee, I S; Li, Y; Gioi, L Li; Libby, J; Liventsev, D; Lukin, P; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Mohanty, G B; Moll, A; Moon, H K; Nakano, E; Nakao, M; Nanut, T; Natkaniec, Z; Nayak, M; Ng, C; Nisar, N K; Nishida, S; Ogawa, S; Okuno, S; Olsen, S L; Oswald, C; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Pedlar, T K; Pestotnik, R; Petri?, M; Piilonen, L E; Ribežl, E; Ritter, M; Rostomyan, A; Rozanska, M; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Sato, Y; Savinov, V; Schneider, O; Schwanda, C; Schwartz, A J; Senyo, K; Seon, O; Sevior, M E; Shebalin, V; Shen, C P; Shibata, T -A; Shiu, J -G; Shwartz, B; Sibidanov, A; Simon, F; Sohn, Y -S; Sokolov, A; Solovieva, E; Stari?, M; Steder, M; Sumiyoshi, T; Tamponi, U; Taniguchi, N; Tatishvili, G; Teramoto, Y; Trabelsi, K; Uchida, M; Uglov, T; Unno, Y; Uno, S; Usov, Y; Van Hulse, C; Vanhoefer, P; Varner, G; Vinokurova, A; Vorobyev, V; Wagner, M N; Wang, B; Wang, C H; Wang, M -Z; Wang, P; Watanabe, Y; Williams, K M; Won, E; Yamaoka, J; Yashchenko, S; Yook, Y; Zhang, Z P; Zhilich, V; Zhulanov, V

2015-01-01T23:59:59.000Z

177

Microfluidic systems for chemical kinetics that rely on chaotic mixing in droplets  

Science Journals Connector (OSTI)

...system is particularly appropriate for chemical kinetics and biochemical assays. The...required. 9. Using the microfluidic platform to measure kinetics This plug-based...Press. Ottino, J. M. 1994 Mixing and chemical-reactions--a tutorial. Chem. Engng...

2004-01-01T23:59:59.000Z

178

Femtosecond kinetics of photoexcited carriers in germanium  

Science Journals Connector (OSTI)

Thermalization, intervalley scattering, and cooling of photoexcited carriers are observed in the indirect-band-gap semiconductor Ge through time-resolved direct-band-gap transmission and luminescence with 100-fs resolution. The transmission experiment, which uses ?=1.53 ?m, 120-fs pulses from a 76-MHz optical parametric oscillator takes advantage of the indirect-band-gap character of Ge to unambiguously determine the ??L intervalley scattering time at 295 K. The measured ??L transfer time for electrons at the ? valley edge is 230±25 fs yielding 4.2±0.2×108 eV/cm for the D?-L intervalley deformation potential. The luminescence experiments were performed at 10 K using a standard time and spectrally gated up-conversion technique employing an 82-MHz, 80-fs pulse width Ti:sapphire laser operating at ?=750 nm. From the luminescence experiments conducted with peak carrier densities of 1018–1019 cm-3, we observe that ??L,X scattering competes with carrier-carrier scattering so that nonthermalized carriers are observed for up to several hundred femtoseconds after an excitation pulse. Because the initial carrier kinetic energy is quite high we find that in addition to phonon-assisted L-L intervalley scattering, X-L and X-X processes must be included to account for a carrier-cooling time. A value of 5×108 eV/cm is obtained for the DX-X deformation potential.

X. Q. Zhou; H. M. van Driel; G. Mak

1994-08-15T23:59:59.000Z

179

Combustion kinetics and reaction pathways  

SciTech Connect

This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.

Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)

1993-12-01T23:59:59.000Z

180

Measurements of the volt-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps  

SciTech Connect

The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1??m and 100??m. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100??m interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted electrons, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.

Klas, M.; Matej?ik, Š. [Department of Experimental Physics, Comenius University, Mlynskadolina F2, 84248 Bratislava (Slovakia); Radjenovi?, B.; Radmilovi?-Radjenovi?, M. [Institute of Physics, University of Belgrade, P.O. Box 57, 11080 Belgrade (Serbia)

2014-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Directed transport in equilibrium  

E-Print Network (OSTI)

We investigate how a microscopic system, which can move only in one direction, comes to equilibrium with a heat-bath. To understand this problem, we investigate a symmetry broken dimer constrained to move in a particular direction when in contact with a uniform heat-bath at a constant temperature. The dimer is not driven by any external force. The system gains kinetic energy from the heat-bath and that the system can only use in directed transport. At the hard core collision limit between the particles of the dimer, we show by exact analytic calculations and complementary numerical results that the dimer undergoes steady directed transport by attaining a stationary distribution for a relevant degree of freedom. Our observation, being perfectly consistent with the {\\it second law of thermodynamics}, leads to a generalization of the existing {\\it Brownian ratchet} paradigm and points out some important limitations of {\\it Fokker-Planck} dynamics.

Bhattacharyay, A

2010-01-01T23:59:59.000Z

182

A Novel Approach to Experimental Studies of Mineral DIsoolution Kinetics  

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

Novel ApproAch to experimeNtAl Novel ApproAch to experimeNtAl StudieS of miNerAl diSSolutioN KiNeticS Background DOE is conducting pilot CO 2 injection tests to evaluate the concept of geologic sequestration. One strategy that has the potential to enhance CO 2 solubility and reduce the risk of CO 2 leaking back to the surface is dissolution of indigenous minerals in the geological formation and formation of secondary carbonate precipitates. This both increases the brine pH and immobilizes the CO 2 . Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this option. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory-measured and field-derived

183

CLEERS Coordination & Joint Development of Benchmark Kinetics...  

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

Kinetic Data CLEERS Coordination & Joint Development of Benchmark Kinetics for LNT & SCR CLEERS Coordination & Development of Catalyst Process Kinetic Data - Pres. 1:...

184

A comprehensive kinetics model for CO oxidation during char combustion  

SciTech Connect

The most important parameter in representing energy feedback to a particle during char combustion concerns the oxidation of CO to CO/sub 2/. If substantial oxidation of CO occurs near a particle, then the greater heat of combustion for the complete oxidation of carbon to CO/sub 2/ (94.1 kcal/mole vs. 26.4 kcal/mole for oxidation to CO) is available for energy feedback mechanisms. ''Energy feedback'' is here defined as any situation in which an individual particle receives a significant fraction of its heat of combustion directly, through the localized oxidation of emitted combustible species, i.e. CO. Conversely, if the oxidation of CO does not occur near a particle, then energy feedback will occur only indirectly, through heating of the bulk gas. The primary reaction product at the particle surface during char combustion is generally considered to be CO, and the location of the subsequent CO oxidation zone plays a very important role in determining the particle temperature. Ayling and Smith performed experimental and modeling work which indicates that CO oxidation is not of major importance under the conditions they investigated, although they noted the need for improved accuracy in measuring char reactivities, as well as for better modeling of the gas phase CO oxidation kinetics. The modeling work presented in this paper attempts to develop an improved understanding of the boundary layer oxidation of CO through the use of a comprehensive set of kinetic expressions.

Haussmann, G.; Kruger, C.

1986-04-01T23:59:59.000Z

185

The conservative cascade of kinetic energy in compressible turbulence  

E-Print Network (OSTI)

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion" scale-range despite not being an invariant of the compressible flow dynamics. We use high-resolution three-dimensional simulations of compressible hydrodynamic turbulence on $512^3$ and $1024^3$ grids. We probe regimes of forced steady-state isothermal flows and of unforced decaying ideal gas flows. The key quantity we measure is pressure dilatation cospectrum, $E^{PD}(k)$, where we provide the first numerical evidence that it decays at a rate faster than $k^{-1}$ as a function of wavenumber. This is sufficient to imply that mean pressure dilatation acts primarily at large-scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale-range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbulence is possible.

Hussein Aluie; Shengtai Li; Hui Li

2011-07-28T23:59:59.000Z

186

The conservative cascade of kinetic energy in compressible turbulence  

E-Print Network (OSTI)

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion" scale-range despite not being an invariant of the compressible flow dynamics. We use high-resolution three-dimensional simulations of compressible hydrodynamic turbulence on $512^3$ and $1024^3$ grids. We probe regimes of forced steady-state isothermal flows and of unforced decaying ideal gas flows. The key quantity we measure is pressure dilatation cospectrum, $E^{PD}(k)$, where we provide the first numerical evidence that it decays at a rate faster than $k^{-1}$ as a function of wavenumber. This is sufficient to imply that mean pressure dilatation acts primarily at large-scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale-range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbu...

Aluie, Hussein; Li, Hui

2011-01-01T23:59:59.000Z

187

Kinetics Of Carbon Gasification  

Science Journals Connector (OSTI)

Kinetics Of Carbon Gasification ... The steam–carbon reaction, which is the essential reaction of the gasification processes of carbon-based feed stocks (e.g., coal and biomass), produces synthesis gas (H2 + CO), a synthetically flexible, environmentally benign energy source. ... Coal Gasification in CO2 and Steam:? Development of a Steam Injection Facility for High-Pressure Wire-Mesh Reactors ...

C. W. Zielke; Everett. Gorin

1957-03-01T23:59:59.000Z

188

First Direct Measurement of the ^{17}O(p,?)^{18}F Reaction Cross-Section at Gamow Energies for Classical Novae  

E-Print Network (OSTI)

Classical novae are important contributors to the abundances of key isotopes, such as the radioactive ^{18}F, whose observation by satellite missions could provide constraints on nucleosynthesis models in novae. The ^{17}O(p,\\gamma)^{18}F reaction plays a critical role in the synthesis of both oxygen and fluorine isotopes but its reaction rate is not well determined because of the lack of experimental data at energies relevant to novae explosions. In this study, the reaction cross section has been measured directly for the first time in a wide energy range Ecm = 200 - 370 keV appropriate to hydrogen burning in classical novae. In addition, the E=183 keV resonance strength, \\omega \\gamma=1.67\\pm0.12 \\mueV, has been measured with the highest precision to date. The uncertainty on the ^{17}O(p,\\gamma)^{18}F reaction rate has been reduced by a factor of 4, thus leading to firmer constraints on accurate models of novae nucleosynthesis.

D. A. Scott; A. Caciolli; A. DiLeva; A. Formicola; M. Aliotta; M. Anders; D. Bemmerer; C. Broggini; M. Campeggio; P. Corvisiero; Z. Elekes; Zs. Fülöp; G. Gervino; A. Guglielmetti; C. Gustavino; Gy. Gyürky; G. Imbriani; M. Junker; M. Laubenstein; R. Menegazzo; M. Marta; E. Napolitani; P. Prati; V. Rigato; V. Roca; E. Somorjai; C. Salvo; O. Straniero; F. Strieder; T. Szücs; F. Terrasi; D. Trezzi

2012-10-24T23:59:59.000Z

189

Turbulent kinetic energy balance as a tool for estimating vertical ...  

Science Journals Connector (OSTI)

Based on microstructure measurements in a simply shaped lake basin, the sources of ... Comparison with turbulent kinetic energy balances, performed in five other lakes, ...... pation (PB) is everywhere the same per unit area of sediment

1910-00-90T23:59:59.000Z

190

LLNL Chemical Kinetics Modeling Group  

SciTech Connect

The LLNL chemical kinetics modeling group has been responsible for much progress in the development of chemical kinetic models for practical fuels. The group began its work in the early 1970s, developing chemical kinetic models for methane, ethane, ethanol and halogenated inhibitors. Most recently, it has been developing chemical kinetic models for large n-alkanes, cycloalkanes, hexenes, and large methyl esters. These component models are needed to represent gasoline, diesel, jet, and oil-sand-derived fuels.

Pitz, W J; Westbrook, C K; Mehl, M; Herbinet, O; Curran, H J; Silke, E J

2008-09-24T23:59:59.000Z

191

Kinetic equilibrium and relativistic thermodynamics  

E-Print Network (OSTI)

Relativistic thermodynamics is treated from the point of view of kinetic theory. It is shown that the generalized J\\"uttner distribution suggested in [1] is compatible with kinetic equilibrium. The requirement of compatibility of kinetic and thermodynamic equilibrium reveals several generalizations of the Gibbs relation where the velocity field is an independent thermodynamic variable.

P. Ván

2011-02-01T23:59:59.000Z

192

Improving alternative fuel utilization: detailed kinetic combustion...  

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

alternative fuel utilization: detailed kinetic combustion modeling & experimental testing Improving alternative fuel utilization: detailed kinetic combustion modeling &...

193

Progress in an oxygen-carrier reaction kinetics experiment for rotary-bed chemical looping combustion .  

E-Print Network (OSTI)

??The design process for an experimental platform measuring reaction kinetics in a chemical looping combustion (CLC) process is documented and justified. To enable an experiment… (more)

Jester-Weinstein, Jack (Jack L.)

2013-01-01T23:59:59.000Z

194

Fully kinetic simulations of megajoule-scale dense plasma focus  

Science Journals Connector (OSTI)

Dense plasma focus (DPF) Z-pinch devices are sources of copious high energy electrons and ions x-rays and neutrons. Megajoule-scale DPFs can generate 1012 neutrons per pulse in deuterium gas through a combination of thermonuclear and beam-target fusion. However the details of the neutron production are not fully understood and past optimization efforts of these devices have been largely empirical. Previously we reported on the first fully kinetic simulations of a kilojoule-scale DPF and demonstrated that both kinetic ions and kinetic electrons are needed to reproduce experimentally observed features such as charged-particle beam formation and anomalous resistivity. Here we present the first fully kinetic simulation of a MegaJoule DPF with predicted ion and neutron spectra neutron anisotropy neutron spot size and time history of neutron production. The total yield predicted by the simulation is in agreement with measured values validating the kinetic model in a second energy regime.

M. May

2014-01-01T23:59:59.000Z

195

Optical measurement of drug concentrations in tissue  

SciTech Connect

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The aim of this project was to develop noninvasive fiber-optic methods for measuring drug concentrations in tissue. Such a system would make possible the study of chemotherapy drug kinetics at specific, targeted locations in the body after the drug is administered. The major result of this project is the development of techniques for measuring changes in absorption of a medium with unknown scattering properties. The developed method was verified by testing on several media with scattering properties in the range typically found for tissue.

Mourant, J.R.; Bigio, I.J.; Jack, D.A.; Johnson, T.M.; Miller, H.D. [Los Alamos National Lab., NM (United States). Chemical Sciences and Technology Div.

1997-10-01T23:59:59.000Z

196

Chemical kinetics modeling  

SciTech Connect

This project emphasizes numerical modeling of chemical kinetics of combustion, including applications in both practical combustion systems and in controlled laboratory experiments. Elementary reaction rate parameters are combined into mechanisms which then describe the overall reaction of the fuels being studied. Detailed sensitivity analyses are used to identify those reaction rates and product species distributions to which the results are most sensitive and therefore warrant the greatest attention from other experimental and theoretical research programs. Experimental data from a variety of environments are combined together to validate the reaction mechanisms, including results from laminar flames, shock tubes, flow systems, detonations, and even internal combustion engines.

Westbrook, C.K.; Pitz, W.J. [Lawrence Livermore National Laboratory, CA (United States)

1993-12-01T23:59:59.000Z

197

INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS  

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

mNAL PERFORMANCE REPORT mNAL PERFORMANCE REPORT for INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS DE-FG05-85ER13439 1-AUG-1985 to 31-JUL-1994 Robert F. Curl and Graham P. Glass Principal Investigators Introduction This research was directed at the detection, monitoring, and study (by infrared absorption spectroscopy) of the chemical kinetic behavior of small free radical species thought to be important intermediates in combustion. The work typically progressed from the detection and analysis of the infrared spectrum of combustion radical to the utilization of the infrared spectrum thus obtained in the investigation of chemical kinetics of the radical species. The methodology employed was infrared kinetic spectroscopy. In this technique the radical is produced by UV flash photolysis using an excimer laser and then

198

Analysis of a kinetic multi-segment foot model part II: Kinetics and clinical implications  

Science Journals Connector (OSTI)

Kinematic multi-segment foot models have seen increased use in clinical and research settings, but the addition of kinetics has been limited and hampered by measurement limitations and modeling assumptions. In this second of two companion papers, we complete the presentation and analysis of a three segment kinetic foot model by incorporating kinetic parameters and calculating joint moments and powers. The model was tested on 17 pediatric subjects (ages 7–18 years) during normal gait. Ground reaction forces were measured using two adjacent force platforms, requiring targeted walking and the creation of two sub-models to analyze ankle, midtarsal, and 1st metatarsophalangeal joints. Targeted walking resulted in only minimal kinematic and kinetic differences compared with walking at self selected speeds. Joint moments and powers were calculated and ensemble averages are presented as a normative database for comparison purposes. Ankle joint powers are shown to be overestimated when using a traditional single-segment foot model, as substantial angular velocities are attributed to the mid-tarsal joint. Power transfer is apparent between the 1st metatarsophalangeal and mid-tarsal joints in terminal stance/pre-swing. While the measurement approach presented here is limited to clinical populations with only minimal impairments, some elements of the model can also be incorporated into routine clinical gait analysis.

Dustin A. Bruening; Kevin M. Cooney; Frank L. Buczek

2012-01-01T23:59:59.000Z

199

Energy efficiency in the European Union: What can be learned from the joint application of directional distance functions and slacks-based measures?  

Science Journals Connector (OSTI)

Abstract Over the last few years concerns have increased about the energy mix in many countries. These concerns have been of greater magnitude for countries with a common energy regulation such as European Union (EU) member states. An important aspect to take into account when choosing a given energy mix is the efficiency involved in its generation. In this context, the present study analyzes the efficiency with which electricity and derived heat was produced in 25 EU member states over the last decade. This analysis considers not only the inputs and outputs involved but, more importantly, which undesirable by-products were generated during the production process, a relevant issue for EU climate policy. To this end, two nonparametric frontier models are applied: first, a Directional Distance Function (DDF), based on Briec’s (1997) [16] proposal and, second, a modified version of Tone’s (2001) [51] Slacks-Based Measure (SBM) model, both of which are especially appropriate in this particular context due to their treatment of undesirable outputs. Results are partly innovative since, with few exceptions, applications on this issue are relatively scarce. From a policy implications’ point of view, our achievements are also interesting because they reveal remarkable efficiency differences among EU countries: those countries from the latest EU enlargements account for the lowest efficiencies, with large opportunities for improvement in CO2 abatement and primary energy saving. Results also show stable efficiencies along the evaluated period and, therefore, highlighting the need to further intensify the initiatives designed to harmonize environmental policies and identifying drivers for efficiency improvement turn out to be still key objectives.

Roberto Gómez-Calvet; David Conesa; Ana Rosa Gómez-Calvet; Emili Tortosa-Ausina

2014-01-01T23:59:59.000Z

200

Kinetics of Diesel Nanoparticle Oxidation  

Science Journals Connector (OSTI)

The oxidation rates in air of diesel nanoparticles sampled directly from the exhaust stream of a medium-duty diesel engine were measured over the temperature range of 800?1140 °C using online aerosol techniques. ... Particulate emission from diesel engines is currently a topic of great concern from both pollution and public health standpoints. ... In addition, the fundamental carbon-to-hydrogen ratio may be different in diesel particles as compared to the commonly used surrogates (15). ...

Kelly J. Higgins; Heejung Jung; David B. Kittelson; Jeffrey T. Roberts; Michael R. Zachariah

2003-03-25T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Interphase transfer kinetics of thorium between nitric acid and tributyl phosphate solutions using the single drop and the Lewis cell techniques  

SciTech Connect

The kinetic rate constants for the interphase transfer of thorium between an aqueous phase and an organic phase of tributyl phosphate-n-paraffin hydrocarbon have been measured using the single drop and the Lewis cell techniques. Results from individual tests performed with the two techniques agree within experimental error. As with uranium, the data are consistent with a model in which the rate-controlling step is the rate of reaction of the components at the phase interface. An organic-soluble complex, represented by Th(NO/sub 3/)/sub 4/.2TBP, forms in the organic phase. The composition of this complex is confirmed by equilibrium, as well as by kinetic, data. The kinetic data include results from tests showing the effects of TBP concentration and nitrate concentration on the values of the forward and the reverse kinetic constants. Other tests show the effect of temperature on the kinetic constant in both the forward and the reverse transfer directions, and the activation energies and enthalpy for the extraction reactions were estimated from these data. Unlike uranium, thorium extraction was shown to have a Marangoni effect under certain conditions. 10 figures, 1 table.

Horner, D.E.; Mailen, J.C.; Coggins, J.R. Jr.; Thiel, S.W.; Scott, T.C.; Pih, N.; Yates, R.G.

1980-01-01T23:59:59.000Z

202

Neutron kinetics in subcritical cores with application to the source modulation method  

E-Print Network (OSTI)

Neutron kinetics in subcritical cores with application to the source modulation method J. Wright for the measurement of reactivity in subcritical, source-driven cores. Methods of measuring reactivity by a single. Hence, first, the conditions of point kinetic behaviour in subcritical source-driven cores are revis

Pázsit, Imre

203

Determination of Depleted Uranium in Urine via Isotope Ratio Measurements Using Large-Bore Direct Injection High Efficiency Nebulizer–Inductively Coupled Plasma Mass Spectrometry  

Science Journals Connector (OSTI)

Inductively coupled plasma mass spectrometry (ICP-MS), coupled with a large-bore direct injection high efficiency nebulizer (LB-DIHEN), was utilized to determine the concentration and...

Westphal, Craig S; McLean, John A; Hakspiel, Shelly J; Jackson, William E; McClain, David E; Montaser, Akbar

2004-01-01T23:59:59.000Z

204

Direct atomic flux measurement of electron-beam evaporated yttrium with a diode-laser-based atomic absorption monitor at 668 nm  

E-Print Network (OSTI)

with a diode-laser-based atomic absorption AA monitor at 668 nm. Atomic number density and velocity were measured through absorption and Doppler shift measurements to provide the atomic flux. The AA previously developed diode-laser-based atomic absorption AA monitors for atomic density measurements

Fejer, Martin M.

205

Femtomole Mixer for Microsecond Kinetic Studies of Protein Folding  

E-Print Network (OSTI)

Femtomole Mixer for Microsecond Kinetic Studies of Protein Folding David E. Hertzog,, Xavier a microfluidic mixer for studying protein folding and other reactions with a mixing time of 8 µs and sample) measurements of single-stranded DNA. We also demon- strate the feasibility of measuring fast protein folding

Michalet, Xavier

206

CLEERS Coordination & Joint Development of Benchmark Kinetics...  

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

CLEERS Coordination & Joint Development of Benchmark Kinetics for LNT & SCR CLEERS Coordination & Joint Development of Benchmark Kinetics for LNT & SCR 2012 DOE Hydrogen and Fuel...

207

CLEERS Coordination & Joint Development of Benchmark Kinetics...  

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

Joint Development of Benchmark Kinetics for LNT & SCR CLEERS Coordination & Joint Development of Benchmark Kinetics for LNT & SCR 2011 DOE Hydrogen and Fuel Cells Program, and...

208

CLEERS Coordination & Development of Catalyst Process Kinetic...  

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

CLEERS Coordination & Development of Catalyst Process Kinetic Data CLEERS Coordination & Development of Catalyst Process Kinetic Data 2009 DOE Hydrogen Program and Vehicle...

209

Multidimensional simulation and chemical kinetics development...  

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

Developing chemical kinetic mechanisms and applying them to simulating engine combustion processes. deer09aceves.pdf More Documents & Publications Chemical Kinetic Research on...

210

NETL: Mercury Emissions Control Technologies - Bench Scale Kinetics of  

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

Bench Scale Kinetics of Mercury Reactions in FGD Liquors Bench Scale Kinetics of Mercury Reactions in FGD Liquors When research into the measurement and control of Hg emissions from coal-fired power plants began in earnest in the early 1990s, it was observed that oxidized mercury can be scrubbed at high efficiency in wet FGD systems, while elemental mercury can not. In many cases, elemental mercury concentrations were observed to increase slightly across wet FGD systems, but this was typically regarded as within the variability of the measurement methods. However, later measurements have shown substantial re-emissions from some FGD systems. The goal of this project is to develop a fundamental understanding of the aqueous chemistry of mercury (Hg) absorbed by wet flue gas desulfurization (FGD) scrubbing liquors. Specifically, the project will determine the chemical reactions that oxidized mercury undergoes once absorbed, the byproducts of those reactions, and reaction kinetics.

211

Infrared absorption spectroscopy and chemical kinetics of free radicals  

SciTech Connect

This research is directed at the detection, monitoring, and study of chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. During the last year, infrared kinetic spectroscopy using excimer laser flash photolysis and color-center laser probing has been employed to study the high resolution spectrum of HCCN, the rate constant of the reaction between ethynyl (C{sub 2}H) radical and H{sub 2} in the temperature region between 295 and 875 K, and the recombination rate of propargyl (CH{sub 2}CCH) at room temperature.

Curl, R.F.; Glass, G.P. [Rice Univ., Houston, TX (United States)

1993-12-01T23:59:59.000Z

212

Interpretation of kinetic rate data taken in a channel flow cell  

SciTech Connect

Nonuniform current distribution can complicate the interpretation of kinetic rate measurements. This paper shows explicitly how nonuniformities affect measurements in the flow-channel cell. Results are given for linear and Tafel kinetics and can be used to relate measurable electrochemical quantities to kinetic parameters. In addition to the appropriate polarization parameter, the interpretation of data requires knowledge of the ratio of the two characteristic lengths and the placement of the reference electrode. The analysis assumes that the ohmic potential drop is subtracted from the measurements by the interruption of current, and that concentration variations are negligible.

West, A.C.; Newman, J. (Materials and Chemical Sciences Div., Lawrence Berkeley Lab., and Dept. of Chemical Engineering, Univ. of California, Berkeley, CA (US))

1989-12-01T23:59:59.000Z

213

Theoretical Studies in Chemical Kinetics  

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

Theoretical Studies in Chemical Kinetics ^ ^ iCi| Theoretical Studies in Chemical Kinetics ^ ^ iCi| under AEC Contract A T (30-1)-3780 " ■ ' Annual Report (1970) Principal In-vestigator: Martin Karpins Institution: Harvard University The research performed under this contract can best be sunmarized under several headings. (a) Alkali-Halideg Alkali-Halide (MX^ M*X*) Exchange Reactions. This project is being continued. A careful study of certain

214

Directives Help  

Directives, Delegations, and Requirements

All DOE directives are available through this site. While it may seem overwhelming, given the number of documents, we have provided a number of ways in which you may get to the information you need.

215

Kinetic analysis of dynamic PET data  

SciTech Connect

Our goal is to quantify regional physiological processes such as blood flow and metabolism by means of tracer kinetic modeling and positron emission tomography (PET). Compartmental models are one way of characterizing the behavior of tracers in physiological systems. This paper describes a general method of estimating compartmental model rate constants from measurements of the concentration of tracers in blood and tissue, taken at multiple time intervals. A computer program which applies the method is described, and examples are shown for simulated and actual data acquired from the Donner 280-Crystal Positron Tomograph.

Knittel, B.

1983-12-01T23:59:59.000Z

216

A Kinetic model of crack fusion  

Science Journals Connector (OSTI)

......Research Note A Kinetic model of crack fusion Zbigniew Czechowski Institute of Geophysics...presents a kinetic approach to the problem of fusion of cracks. A kinetic equation for the...repetitive episodes of seismicity. crack fusion|kinetic model|seismicity| References......

Zbigniew Czechowski

1991-02-01T23:59:59.000Z

217

Kinetic azeotropy and design of reactive distillation columns  

SciTech Connect

The reactive fixed points in the distillation maps of a reactive distillation column (RDC) with kinetically controlled reactions are identified and their role in deciding the design feasibility has been elucidated. The fixed points at which both reaction and distillation vectors have zero magnitudes correspond to the equilibrium fixed point. It is known that the relative positions of these points for the rectifying and stripping sections determine the value of the minimum reflux ratio. However, apart from these fixed points, there are certain fixed points in the distillation map at which, though the reaction and distillation vectors have nonzero magnitudes, they nullify the effects of each other. These points correspond to the kinetic fixed points and have a special significance. Their positions have direct influence on the feasible product composition. A simple example of an ideal ternary system undergoing a reaction 2B {longleftrightarrow} A + c has been illustrated to show the importance of kinetic azeotropy in the design aspects of RDC.

Mahajani, S.M. [Monash Univ., Clayton, Victoria (Australia). Dept. of Chemical Engineering] [Monash Univ., Clayton, Victoria (Australia). Dept. of Chemical Engineering

1999-01-01T23:59:59.000Z

218

First principles Tafel kinetics of methanol oxidation on Pt(111)  

Science Journals Connector (OSTI)

Abstract Electrocatalytic methanol oxidation is of fundamental importance in electrochemistry and also a key reaction in direct methanol fuel cell. To resolve the kinetics at the atomic level, this work investigates the potential-dependent reaction kinetics of methanol oxidation on Pt(111) using the first principles periodic continuum solvation model based on modified-Poisson–Boltzmann equation (CM-MPB), focusing on the initial dehydrogenation elementary steps. A theoretical model to predict Tafel kinetics (current vs potential) is established by considering that the rate-determining step of methanol oxidation (to CO) is the first CH bond breaking (CH3OH(aq) ? CH2OH* + H*) according to the computed free energy profile. The first CH bond breaking reaction needs to overcome a large entropy loss during methanol approaching to the surface and replacing the adsorbed water molecules. While no apparent charge transfer is involved in this elementary step, the charge transfer coefficient of the reaction is calculated to be 0.36, an unconventional value for charge transfer reactions, and the Tafel slope is deduced to be 166 mV. The results show that the metal/adsorbate interaction and the solvation environment play important roles on influencing the Tafel kinetics. The knowledge learned from the potential-dependent kinetics of methanol oxidation can be applied in general for understanding the electrocatalytic reactions of organic molecules at the solid–liquid interface.

Ya-Hui Fang; Zhi-Pan Liu

2014-01-01T23:59:59.000Z

219

Zero electron kinetic energy spectroscopy of the XeCl Thomas Lenzer,a)  

E-Print Network (OSTI)

measurements for the neutral state we construct a Morse­Morse-switching­van der Waals model potential functionZero electron kinetic energy spectroscopy of the XeCl� anion Thomas Lenzer,a) Ivan Yourshaw, Berkeley, California 94720 Received 9 November 2001; accepted 21 December 2001 Zero electron kinetic energy

Neumark, Daniel M.

220

Single molecule analysis of RNA polymerase elongation reveals uniform kinetic behavior  

E-Print Network (OSTI)

Single molecule analysis of RNA polymerase elongation reveals uniform kinetic behavior Karen) By using single-molecule measurements, we demonstrate that the elongation kinetics of individual any variation in the behavior of single RNAP molecules as well as the differences that exist between

La Porta, Arthur

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Elastic anisotropy of core samples from the Taiwan Chelungpu Fault Drilling Project (TCDP): direct 3-D measurements and weak anisotropy approximations  

Science Journals Connector (OSTI)

......samples from the same TCDP borehole. 2 Sampling and method...locations. The vertical drilling of TCDP Hole A in 2004...samples are cored from a large core retrieved at depth...measured velocities is quite large, from 1900 m s-1 at...although the location of the larger low velocity sector remains......

Laurent Louis; Christian David; Petr Špa?ek; Teng-fong Wong; Jérôme Fortin; Sheng Rong Song

2012-01-01T23:59:59.000Z

222

A direct measurement of the Bose-Einstein condensation universality class in NiCl2-4SC(NH2)2  

E-Print Network (OSTI)

)2 at ultra-low temperatures L. Yin1, J.S. Xia1, V.S. Zapf2, N.S. Sullivan1 and A. Paduan-Filho3 1Department with an exponent of 3/2. In this work, AC susceptibility measurements were performed down to 1mK. The Ni S=1 spins

223

Aerial Measuring System  

Directives, Delegations, and Requirements

To establish policy for the Department of Energy's (DOE) Aerial Measuring System (AMS) Program. This directive does not cancel another directive. Canceled by DOE O 153.1.

1991-09-20T23:59:59.000Z

224

Direct measurement of the breakout reaction {sup 11}C({alpha},p){sup 14}N in explosive hydrogen-burning process  

SciTech Connect

We determined the {sup 11}C({alpha},p){sup 14}N reaction rate relevant to the nucleosynthesis in explosive hydrogen-burning stars. The measurement was performed by means of the thick target method in inverse kinematics with {sup 11}C RI beams. We derived the excitation functions for the ground-state transition and excited-state transitions using time-of-flight information for the first time. The present reaction rate is compared to the previous one.

Hayakawa, S.; Kubono, S.; Kahl, D.; Yamaguchi, H.; Binh, Dam N.; Hashimoto, T.; Wakabayashi, Y.; He, J. J.; Iwasa, N.; Kato, S.; Komatsubara, T.; Kwon, Y. K.; Teranishi, T.; Wanajo, S. [Center for Nuclear Study, Graduate of Science, University of Tokyo (Japan) and Institute of Physics (Japan); RCNP, Osaka University (Japan); Japan Atomic Energy Agency (Japan); Institute of Modern Physics (Japan); Department of Physics, Tohoku University (Japan); Department of Physics, Yamagata University (Japan); Department of Physics, University of Tsukuba (Japan); Department of Physics, Chung Ang University (Korea, Republic of); Department of Physics, Kyushu University (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo (Japan)

2012-11-12T23:59:59.000Z

225

A DIRECT MEASUREMENT OF THE LINEAR BIAS OF MID-INFRARED-SELECTED QUASARS AT z ? 1 USING COSMIC MICROWAVE BACKGROUND LENSING  

SciTech Connect

We measure the cross-power spectrum of the projected mass density as traced by the convergence of the cosmic microwave background lensing field from the South Pole Telescope (SPT) and a sample of Type 1 and 2 (unobscured and obscured) quasars at (z) ? 1 selected with the Wide-field Infrared Survey Explorer, over 2500 deg{sup 2}. The cross-power spectrum is detected at ?7?, and we measure a linear bias b = 1.61 ± 0.22, consistent with clustering analyses. Using an independent lensing map, derived from Planck observations, to measure the cross-spectrum, we find excellent agreement with the SPT analysis. The bias of the combined sample of Type 1 and 2 quasars determined in this work is similar to that previously determined for Type 1 quasars alone; we conclude that obscured and unobscured quasars trace the matter field in a similar way. This result has implications for our understanding of quasar unification and evolution schemes.

Geach, J. E. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom)] [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom); Hickox, R. C.; Hainline, K. N. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States)] [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Bleem, L. E.; Benson, B. A.; Bhattacharya, S.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)] [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States)] [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Holder, G. P.; De Haan, T.; Dobbs, M. A.; Dudley, J. [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada)] [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); Aird, K. A. [University of Chicago, Chicago, IL 60637 (United States)] [University of Chicago, Chicago, IL 60637 (United States); Cho, H.-M. [NIST Quantum Devices Group, Boulder, CO 80305 (United States)] [NIST Quantum Devices Group, Boulder, CO 80305 (United States); George, E. M.; Holzapfel, W. L. [Department of Physics, University of California, Berkeley, CA 94720 (United States)] [Department of Physics, University of California, Berkeley, CA 94720 (United States); Halverson, N. W., E-mail: j.geach@herts.ac.uk [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); and others

2013-10-20T23:59:59.000Z

226

Chemical kinetics and combustion modeling  

SciTech Connect

The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

227

Electron kinetics inferred from observations of microwave bursts during edge localised modes in the Mega-Amp Spherical Tokamak  

E-Print Network (OSTI)

Recent measurements of microwave and X-ray emission during edge localised mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should be included in future models for ELMs and the ELM cycle. The observed radiative effects paradoxically imply acceleration of electrons parallel to the magnetic field combined with rapid acquisition of perpendicular momentum. It is shown that this paradox can be resolved by the action of the anomalous Doppler instability which enables fast collective radiative relaxation, in the perpendicular direction, of electrons accelerated in the parallel direction by inductive electric fields generated by the initial ELM instability.

Freethy, S J; Chapman, S C; Dendy, R O; Lai, W N; Pamela, S J P; Shevchenko, V F; Vann, R G L

2014-01-01T23:59:59.000Z

228

First Direct Double-Beta Decay Q-value Measurement of 82Se in Support of Understanding the Nature of the Neutrino  

E-Print Network (OSTI)

In anticipation of results from current and future double-beta decay studies, we report a measurement resulting in a 82Se double-beta decay Q-value of 2997.9(3) keV, an order of magnitude more precise than the currently accepted value. We also present preliminary results of a calculation of the 82Se neutrinoless double-beta decay nuclear matrix element that corrects in part for the small size of the shell model single-particle space. The results of this work are important for designing next generation double-beta decay experiments and for the theoretical interpretations of their observations.

David L. Lincoln; Jason D. Holt; Georg Bollen; Maxime Brodeur; Scott Bustabad; Jonathan Engel; Samuel J. Novario; Matthew Redshaw; Ryan Ringle; Stefan Schwarz

2012-11-24T23:59:59.000Z

229

Spectroscopy and kinetics of combustion gases at high temperatures  

SciTech Connect

This program involves two complementary activities: (1) development and application of cw ring dye laser absorption methods for sensitive detection of radical species and measurement of fundamental spectroscopic parameters at high temperatures; and (2) shock tube studies of reaction kinetics relevant to combustion. Species currently under investigation in the spectroscopic portion of the research include NO and CH{sub 3}; this has necessitated the continued operated at wavelengths in the range 210-230 nm. Shock tube studies of reaction kinetics currently are focussed on reactions involving CH{sub 3} radicals.

Hanson, R.K.; Bowman, C.T. [Stanford Univ., CA (United States)

1993-12-01T23:59:59.000Z

230

Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels  

SciTech Connect

This final report documents the technical results of the 3-year project entitled, “Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels,” funded under the NETL of DOE. The research was conducted under six main tasks: 1) program management and planning; 2) turbulent flame speed measurements of syngas mixtures; 3) laminar flame speed measurements with diluents; 4) NOx mechanism validation experiments; 5) fundamental NOx kinetics; and 6) the effect of impurities on NOx kinetics. Experiments were performed using primary constant-volume vessels for laminar and turbulent flame speeds and shock tubes for ignition delay times and species concentrations. In addition to the existing shock- tube and flame speed facilities, a new capability in measuring turbulent flame speeds was developed under this grant. Other highlights include an improved NOx kinetics mechanism; a database on syngas blends for real fuel mixtures with and without impurities; an improved hydrogen sulfide mechanism; an improved ammonia kintics mechanism; laminar flame speed data at high pressures with water addition; and the development of an inexpensive absorption spectroscopy diagnostic for shock-tube measurements of OH time histories. The Project Results for this work can be divided into 13 major sections, which form the basis of this report. These 13 topics are divided into the five areas: 1) laminar flame speeds; 2) Nitrogen Oxide and Ammonia chemical kinetics; 3) syngas impurities chemical kinetics; 4) turbulent flame speeds; and 5) OH absorption measurements for chemical kinetics.

Peterson, Eric; Krejci, Michael; Mathieu, Olivier; Vissotski, Andrew; Ravi, Sankat; Plichta, Drew; Sikes, Travis; Levacque, Anthony; Camou, Alejandro; Aul, Christopher

2013-09-30T23:59:59.000Z

231

Desorption Kinetics of Methanol, Ethanol, and Water from Graphene...  

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

Desorption Kinetics of Methanol, Ethanol, and Water from Graphene. Desorption Kinetics of Methanol, Ethanol, and Water from Graphene. Abstract: The desorption kinetics of methanol,...

232

Comparison of PM emissions from a gasoline direct injected (GDI) vehicle and a port fuel injected (PFI) vehicle measured by electrical low pressure impactor (ELPI) with two fuels: Gasoline and M15 methanol gasoline  

Science Journals Connector (OSTI)

Two Euro 4 gasoline passenger vehicles (one gasoline direct injected vehicle and one port fuel injected vehicle) were tested over the cold start New European Driving Cycle (NEDC). Each vehicle was respectively fueled with gasoline and M15 methanol gasoline. Particle number concentrations were measured by the electrical low pressure impactor (ELPI). Particle masses were measured by gravimetric method and estimated from the number distributions using two density distributions (one is constant with the particle size and one is power law related with the size). The first 7 stages of ELPI were used for estimation. The results show that for each vehicle, PM masses measured by gravimetric method, the total PM numbers measured by ELPI and estimated PM masses for M15 are lower than those for gasoline. For each kind of fuel, PM masses by two methods and total PM numbers from the GDI vehicle are higher than those from the PFI one. PM number distribution curves of the four vehicle/fuel combinations are similar. All decline gradually and the maximum number of each curve occurs in the first stage. More than 99.9% numbers locate in the first 8 stages of which diameters are less than 1 ?m. PM number emissions correlate well with the acceleration of the two vehicles. The estimated particle masses were much lower than the gravimetric measurements.

Bin Liang; Yunshan Ge; Jianwei Tan; Xiukun Han; Liping Gao; Lijun Hao; Wentao Ye; Peipei Dai

2013-01-01T23:59:59.000Z

233

Direct costing  

E-Print Network (OSTI)

oau 5e reduced. Under the same oonOitions, even ~Me on a bread scale entails not mere1y the conduct of the direct oyeraticns cf yrccessing the materials into finished products, but also the performance of auxiliary functions. these may 'ba power y... purposes have been advanced as folkway le Most of a o03RyaxO' 8 products Grc usual13r sold at prices which oovex' full product costs y plus 861ling a%el administrative expenses, plus normal profit. The inventoi~ valuate. on should be consistent...

Browning, Donald Bullock

2012-06-07T23:59:59.000Z

234

Kinetics of an Inverse Temperature Transition Process and Its Application on Supported Lipid Bilayer  

E-Print Network (OSTI)

the ability to measure the kinetics of the PNIPAM and the ELPs collapse without a heat transfer problem. The conformational change of the ELPs during the phase transition process is utilized as a nanoscale protein filter to modulate ligandreceptor binding...

Chang, Chin-Yuan

2011-10-21T23:59:59.000Z

235

Statistical Prediction of Integrated Kinetic Energy in North Atlantic Tropical Cyclones  

Science Journals Connector (OSTI)

Integrated kinetic energy (IKE) is a useful quantity that measures the size and strength of a tropical cyclone wind field. As a result, it is inherently related to the destructive potential of these powerful storms. In most current operational ...

Michael E. Kozar; Vasubandhu Misra

2014-12-01T23:59:59.000Z

236

Operational Analysis of Multiregional Nuclear Reactor Kinetics  

Science Journals Connector (OSTI)

......Operational Analysis of Multiregional Nuclear Reactor Kinetics NASSAR H. S. HAIDAR...analytically for a multiregional nuclear reactor whose subregions are of arbitrary...Operational Analysis of Multiregional Nuclear Reactor Kinetics NASSAU H. S. HAIDAR......

NASSAR H. S. HAIDAR

1983-05-01T23:59:59.000Z

237

Two-Dimensional Kinetic Turbulence in the Solar Wind  

Science Journals Connector (OSTI)

We present the first 2D hybrid-Vlasov simulations of turbulence in the solar wind that describe the evolution of the energy spectra in a range of two decades of wavelengths around the ion inertial scale. Several previous magnetohydrodynamics and particle-in-cell simulations in the range of large (fluid) wavelengths showed a marked anisotropy of the energy spectra in the direction perpendicular to the mean magnetic field. Here we give evidence that the parallel direction can also be a privileged way for turbulence to develop towards short scales, where kinetic effects govern the plasma dynamics.

F. Valentini; F. Califano; P. Veltri

2010-05-17T23:59:59.000Z

238

Reduced and Validated Kinetic Mechanisms for Hydrogen-CO-sir Combustion in Gas Turbines  

SciTech Connect

Rigorous experimental, theoretical, and numerical investigation of various issues relevant to the development of reduced, validated kinetic mechanisms for synthetic gas combustion in gas turbines was carried out - including the construction of new radiation models for combusting flows, improvement of flame speed measurement techniques, measurements and chemical kinetic analysis of H{sub 2}/CO/CO{sub 2}/O{sub 2}/diluent mixtures, revision of the H{sub 2}/O{sub 2} kinetic model to improve flame speed prediction capabilities, and development of a multi-time scale algorithm to improve computational efficiency in reacting flow simulations.

Yiguang Ju; Frederick Dryer

2009-02-07T23:59:59.000Z

239

Slow Sorption Kinetics of Pentachlorophenol on Soil  

E-Print Network (OSTI)

Slow Sorption Kinetics of Pentachlorophenol on Soil: Concentration Effects J O H N P . D I V I N C of Delaware, Newark, Delaware 19717-1303 We investigated the sorption kinetics of pentachlorophenol (PCP in sorption. The onset of the slow sorption kinetics was also concentration dependent. At higher PCP

Sparks, Donald L.

240

14CME Kinetic Energy and Mass Kinetic energy is the energy that a  

E-Print Network (OSTI)

14CME Kinetic Energy and Mass Kinetic energy is the energy that a body has by virtue of its mass the table by determining the value of the missing entries using the formula for Kinetic Energy. Problem 2: What is the minimum and maximum range for the observed kinetic energies for the 10 CMEs? The largest

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241

Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction. Technical status progress report, October 1, 1991--March 15, 1993  

SciTech Connect

An experimental set-up for accurate measurement of hydrogen generation rate in Lithium-Lead (Li{sub 17}Pb{sub 83}) Steam or water interactions has been designed. The most important features of the design include a pneumatic actuated quick opening and closing high temperature all stainless steel valve used to control the reaction time and the placement of most measuring devices below a water line to minimize leakage of the hydrogen collected. A PC based data acquisition and control system provides remote process sequencing, acquisition and control of all major components of the set-up. Initial tests indicate that the first design objective of maintaining leakproof gas collection chamber has been achieved. Initial pressure tests indicated that the pressure drop over a time span of 30 minutes was within the tolerance of the pressure transducer used to measure the pressure (within 0.690 kPa) at a nominal system pressure of 685 kPa. The experimental system hardware, data acquisition and control programs and data analysis program have been completed, tested and are currently functional.

Biney, P.O.

1993-04-01T23:59:59.000Z

242

Estimating The Thermodynamics And Kinetics Of Chlorinated Hydrocarbon...  

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

Estimating The Thermodynamics And Kinetics Of Chlorinated Hydrocarbon Degradation. Estimating The Thermodynamics And Kinetics Of Chlorinated Hydrocarbon Degradation. Abstract: Many...

243

High-temperature iso-butene absorption diagnostic for shock tube kinetics using a pulsed quantum cascade laser near 11.3 ?m  

Science Journals Connector (OSTI)

Abstract A high-bandwidth absorption sensing technique for iso-butene (iC4H8) was developed to measure transient species concentration behind reflected shock waves for combustion kinetics studies. Direct measurements of iC4H8 were enabled by monitoring absorption in the infrared near 11.3 ?m using a novel pulsed external-cavity quantum cascade laser (ECQCL) with a repetition rate of 600 kHz. Optimal wavelength selection for high-temperature combustion gases was first determined by a spectral survey at 1000 K near the peak of the absorption band (878 cm?1 to 892 cm?1) using the ECQCL. Absorption cross section measurements of iC4H8 at 881.4 cm?1, the selected high-temperature wavelength, were then conducted from 800 K to 1800 K behind reflected shocks to characterize temperature dependence at modest pressures (4–8 atm). The species-specific technique was subsequently demonstrated by time-resolved (100 kHz) measurements of iso-butene decay during thermal decomposition (1280–1480 K). First-ever shock tube measurements of iC4H8 yields from iso-octane pyrolysis (1070–1300 K) were also produced, with a detection limit of ?100 ppm. Experimental results were compared to recent kinetic models to illustrate the potential of this diagnostic for analyzing combustion chemistry.

R.M. Spearrin; S. Li; D.F. Davidson; J.B. Jeffries; R.K. Hanson

2014-01-01T23:59:59.000Z

244

Simulations of Kinetic Events at the Atomic Scale  

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

of kinetic events at the atomic scale of kinetic events at the atomic scale Graeme Henkelman UT Austin Al / Al(100) B 3 I / Si Pd / MgO How can we simulate the dynamics of molecular systems over experimental time scales? Objective: To calculate dynamics of a surface over time scales which are much longer than can be calculated with direct classical dynamics. Problem: time scale gap fs ps ns ms ms s mins atomic dynamics thermally activated experimental vibrations simulations reaction dynamics time scales Most interesting transitions are rare 0.5 eV 1000/s events (much slower than vibrations) Simulating a transition for a typical rare event with classical dynamics can require ~10 12 force evaluations Transition state theory A statistical theory for calculating the rate of slow thermal processes

245

ARM - Measurement - Shortwave broadband direct downwelling irradiance  

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

Experimental) RADFLUXANAL : Radiative Flux Analysis SWFLUXANAL : Shortwave Flux Analysis UAV-ALTUS : UAV Altus UAV-EGRETT : UAV-Egrett UAV-GNAT : UAV-General Atomics GNAT...

246

Direct measurement and analysis of cyclohexadienyl oxidation  

E-Print Network (OSTI)

The oxidation of cyclohexadienyl radical (c-C?H?) and similar resonantly stabilized radicals are important in an astonishing array of processes in nature. Cyclohexadienyl radical has been postulated to be significant in a ...

Taylor, James Wagner

2005-01-01T23:59:59.000Z

247

ESS 2012 Peer Review - Amber Kinetics Flywheel Energy Storage Demo - Ed Chiao, Amber Kinetics  

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

amber_kinetics amber_kinetics DOE Peer Review September 2012 Ed Chiao, CEO amber_kinetics Amber Kinetics: Our Flywheel History Start-up launched in 2009, Stanford University Cleantech Entrepreneurship class Established a technology licensing & flywheel development partnership with LLNL; Amber Kinetics identified new material & lower-cost rotor designs for commercialization Awarded a Smart Grid Energy Storage Demonstration grant award for flywheels Awarded a matching grant for development & demonstration of flywheel technology Stanford University Lawrence Livermore National Laboratory U.S. Department of Energy California Energy Commission World-class institutions | innovative, deep flywheel technology owned by Amber Amber Kinetics, Inc. - Confidential and Proprietary, All Rights Reserved

248

Kinetics of Irreversible Adsorption with Diffusion:? Application to Biomolecule Immobilization  

Science Journals Connector (OSTI)

To demonstrate the utility of the numerical model over the limiting analytical solutions, the kinetics of the adsorption of glucose oxidase (GOD) onto a MPA self-assembled monolayer (SAM) was monitored using a quartz crystal microbalance. ... We have measured the maximum monolayer coverage of GOD as 1 × 10-12 mol cm-2?13 and take the diffusion coefficient as 5 × 10-7 cm2 s-1 for a 10 nm diameter particle. ...

D. Brynn Hibbert; J. Justin Gooding; Paul Erokhin

2002-02-08T23:59:59.000Z

249

Oxidation kinetics of aluminum diboride  

SciTech Connect

The oxidation characteristics of aluminum diboride (AlB{sub 2}) and a physical mixture of its constituent elements (Al+2B) were studied in dry air and pure oxygen using thermal gravimetric analysis to obtain non-mechanistic kinetic parameters. Heating in air at a constant linear heating rate of 10 °C/min showed a marked difference between Al+2B and AlB{sub 2} in the onset of oxidation and final conversion fraction, with AlB{sub 2} beginning to oxidize at higher temperatures but reaching nearly complete conversion by 1500 °C. Kinetic parameters were obtained in both air and oxygen using a model-free isothermal method at temperatures between 500 and 1000 °C. Activation energies were found to decrease, in general, with increasing conversion for AlB{sub 2} and Al+2B in both air and oxygen. AlB{sub 2} exhibited O{sub 2}-pressure-independent oxidation behavior at low conversions, while the activation energies of Al+2B were higher in O{sub 2} than in air. Differences in the composition and morphology between oxidized Al+2B and AlB{sub 2} suggested that Al{sub 2}O{sub 3}–B{sub 2}O{sub 3} interactions slowed Al+2B oxidation by converting Al{sub 2}O{sub 3} on aluminum particles into a Al{sub 4}B{sub 2}O{sub 9} shell, while the same Al{sub 4}B{sub 2}O{sub 9} developed a needle-like morphology in AlB{sub 2} that reduced oxygen diffusion distances and increased conversion. The model-free kinetic analysis was critical for interpreting the complex, multistep oxidation behavior for which a single mechanism could not be assigned. At low temperatures, moisture increased the oxidation rate of Al+2B and AlB{sub 2}, but both appear to be resistant to oxidation in cool, dry environments. - Graphical abstract: Isothermal kinetic data for AlB{sub 2} in air, showing a constantly decreasing activation energy with increasing conversion. Model-free analysis allowed for the calculation of global kinetic parameters despite many simultaneous mechanisms occurring concurrently. (a) Time–temperature plots, (b) conversion as a function of time, (c) Arrhenius plots used to calculate activation energies, and (d) activation energy as a function of conversion. Display Omitted - Highlights: • First reported kinetic parameters for AlB{sub 2} and Al+2B oxidation in air and O{sub 2}. • Possible mechanism of enhanced boron combustion presented. • Moisture sensitivity shown to be problematic for AlB{sub 2}, less for Al+2B.

Whittaker, Michael L., E-mail: michaelwhittaker2016@u.northwestern.edu [Department of Materials Science and Engineering, University of Utah, 122S. Central Campus Drive, Salt Lake City, UT 84112 (United States); Sohn, H.Y. [Department of Metallurgical Engineering, University of Utah, 135S 1460 E, Rm 00412, Salt Lake City, UT 84112 (United States); Cutler, Raymond A. [Ceramatec, Inc., 2425S. 900W., Salt Lake City, UT 84119 (United States)

2013-11-15T23:59:59.000Z

250

Experimental and Kinetic Modeling Study of Extinction and Ignition of Methyl Decanoate in Laminar Nonpremixed Flows  

SciTech Connect

Methyl decanoate is a large methyl ester that can be used as a surrogate for biodiesel. In this experimental and computational study, the combustion of methyl decanoate is investigated in nonpremixed, nonuniform flows. Experiments are performed employing the counterflow configuration with a fuel stream made up of vaporized methyl decanoate and nitrogen, and an oxidizer stream of air. The mass fraction of fuel in the fuel stream is measured as a function of the strain rate at extinction, and critical conditions of ignition are measured in terms of the temperature of the oxidizer stream as a function of the strain rate. It is not possible to use a fully detailed mechanism for methyl decanoate to simulate the counterflow flames because the number of species and reactions is too large to employ with current flame codes and computer resources. Therefore a skeletal mechanism was deduced from a detailed mechanism of 8555 elementary reactions and 3036 species using 'directed relation graph' method. This skeletal mechanism has only 713 elementary reactions and 125 species. Critical conditions of ignition were calculated using this skeletal mechanism and are found to agree well with experimental data. The predicted strain rate at extinction is found to be lower than the measurements. In general, the methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

Seshadri, K; Lu, T; Herbinet, O; Humer, S; Niemann, U; Pitz, W J; Law, C K

2008-01-09T23:59:59.000Z

251

Higher-order desorption kinetics of hydrogen from silane/, disilane/, and D/Si(100)  

Science Journals Connector (OSTI)

Hydrogen desorption kinetics from silane/, disilane/, and D/Si(100)-2×1 surfaces with and without thermal processings have been investigated using temperature-programmed desorption (TPD) measurements. In contrast to previously reported first-order desorption kinetics from H/Si(100) surface, the kinetics became higher-order under certain conditions of hydrogenating gases and thermal processings. Specifically, the hydrogen desorption from a post-annealed, silane-saturated surface showed the highest reaction order of all the combinations. A unified explanation is given to these results using the prepairing of surface hydrogen atoms at a dimer.

Hideki Nakazawa; Maki Suemitsu

1998-01-01T23:59:59.000Z

252

CLEERS Coordination & Development of Catalyst Process Kinetic...  

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

Development of Catalyst Process Kinetic Data - Pres. 1: Coordination of CLEERS Project; Pres. 2: ORNL Research on LNT Sulfation & Desulfation CLEERS Coordination & Development of...

253

CLEERS Coordination & Development of Catalyst Process Kinetic...  

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

& coordinate DOE research efforts (CLEERS Coordination) * Develop detailed technical data required to simulate energy efficient emission controls (LNT & SCR Kinetics, Sulfur &...

254

The Fractional Kinetic Equation and Thermonuclear Functions  

E-Print Network (OSTI)

The paper discusses the solution of a simple kinetic equation of the type used for the computation of the change of the chemical composition in stars like the Sun. Starting from the standard form of the kinetic equation it is generalized to a fractional kinetic equation and its solutions in terms of H-functions are obtained. The role of thermonuclear functions, which are also represented in terms of G- and H-functions, in such a fractional kinetic equation is emphasized. Results contained in this paper are related to recent investigations of possible astrophysical solutions of the solar neutrino problem.

H. J. Haubold; A. M. Mathai

2000-01-16T23:59:59.000Z

255

Kinetics of actinide complexation reactions  

SciTech Connect

Though the literature records extensive compilations of the thermodynamics of actinide complexation reactions, the kinetics of complex formation and dissociation reactions of actinide ions in aqueous solutions have not been extensively investigated. In light of the central role played by such reactions in actinide process and environmental chemistry, this situation is somewhat surprising. The authors report herein a summary of what is known about actinide complexation kinetics. The systems include actinide ions in the four principal oxidation states (III, IV, V, and VI) and complex formation and dissociation rates with both simple and complex ligands. Most of the work reported was conducted in acidic media, but a few address reactions in neutral and alkaline solutions. Complex formation reactions tend in general to be rapid, accessible only to rapid-scan and equilibrium perturbation techniques. Complex dissociation reactions exhibit a wider range of rates and are generally more accessible using standard analytical methods. Literature results are described and correlated with the known properties of the individual ions.

Nash, K.L.; Sullivan, J.C.

1997-09-01T23:59:59.000Z

256

Direct Aerosol Forcing Uncertainty  

DOE Data Explorer (OSTI)

Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

Mccomiskey, Allison

257

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow computations  

E-Print Network (OSTI)

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow. For the non-equilibrium flow computations, i.e., the nozzle flow and hypersonic rarefied flow over flat plate-kinetic method; Hypersonic and rarefied flows 1. Introduction The development of aerospace technology has

Xu, Kun

258

Testing the kinetic energy functional: Kinetic energy density as a density functional  

E-Print Network (OSTI)

is to the exchange-correlation energy as a functional of the density. A large part of the total energy, the kinetic contexts. For finite systems these forms integrate to the same global ki- netic energy, but they differTesting the kinetic energy functional: Kinetic energy density as a density functional Eunji Sim

Burke, Kieron

259

Density measurements Viscosity measurements  

E-Print Network (OSTI)

Density measurements Viscosity measurements Temperature measurements Pressure measurements Flow rate measurements Velocity measurements Sensors How to measure fluid flow properties ? Am´elie Danlos Ravelet Experimental methods for fluid flows: an introduction #12;Density measurements Viscosity

Ravelet, Florent

260

Kinetic roughening on curved interfaces  

E-Print Network (OSTI)

Stochastic growth phenomena on curved interfaces have not been explored in so much detail as their planar counterparts. The independence of the interface macroscopic shape on kinetic roughening has been occasionally assumed, but however, this fact can not be considered as universal. Stochastic partial differential equations on curved interfaces present dynamical and morphological properties that are completely different from their planar equivalents. Herein we will concentrate on equations which planar counterparts are linear. The fundamental differences are the loss of correlation of the interface through time for models showing sub-ballistic propagation of the correlations and the irrelevance of the noise in two and higher dimensional settings. We analyze some of these processes in detail, exploring why these consequences arise, and show that they tend to appear irrespective of the particular metric, provided that it is not Euclidean. Models showing a super-ballistic propagation of correlations present a fl...

Escudero, Carlos

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Decohesion Kinetics in Polymer Organic Solar Cells  

Science Journals Connector (OSTI)

Decohesion Kinetics in Polymer Organic Solar Cells ... We investigate the role of molecular weight (MW) of the photoactive polymer poly(3-hexylthiophene) (P3HT) on the temperature-dependent decohesion kinetics of bulk heterojunction (BHJ) organic solar cells (OSCs). ... fullerenes; solar cells; thin films; fracture; polymer ...

Christopher Bruner; Fernando Novoa; Stephanie Dupont; Reinhold Dauskardt

2014-11-04T23:59:59.000Z

262

Kinetics of Non-Thermal Atmospheric Pressure  

E-Print Network (OSTI)

Kinetics of Non-Thermal Atmospheric Pressure Plasmas Alexander Fridman · Microdischarge Interaction and Structuring in Dielectric Barrier Discharges · Kinetics of Blood Coagulation in Plasma · Surface Wound wire Area of DBD plasma region: ~104cm2 #12;7 Microdischarge Patterning (2D) R22 R23 R24 R26 R27 R28

Kaganovich, Igor

263

Chemical kinetics and oil shale process design  

SciTech Connect

Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.

Burnham, A.K.

1993-07-01T23:59:59.000Z

264

ADVANCES IN ENVIRONMENTAL REACTION KINETICS AND THERMODYNAMICS  

E-Print Network (OSTI)

1262 ADVANCES IN ENVIRONMENTAL REACTION KINETICS AND THERMODYNAMICS: LONG-TERM FATE thermodynamic and kinetic data is available with regard to the formation of these mixed metal precipitate phases to six months from the initial addition of aqueous nickel. Additionally, we have determined thermodynamic

Sparks, Donald L.

265

Velcro Measurement of Turbulence Kinetic Energy Dissipation Rate ?  

Science Journals Connector (OSTI)

Turbulence in the ocean results from many different processes operating over a wide range of space scales and timescales, with spatial and temporal variability particularly extreme in coastal oceans. If the origins and effects of turbulent ...

Ann E. Gargett

1999-12-01T23:59:59.000Z

266

A unified gas kinetic scheme with moving mesh and velocity space adaptation  

Science Journals Connector (OSTI)

There is great difficulty for direct Boltzmann solvers to simulate high Knudsen number flow due to the severe steep slope and high concentration of the gas distribution function in a local particle velocity space. Local mesh adaptation becomes necessary ... Keywords: Adaptive velocity space, Moving mesh, Rarefied gas, Unified gas kinetic scheme

Songze Chen; Kun Xu; Cunbiao Lee; Qingdong Cai

2012-08-01T23:59:59.000Z

267

Conformational Analysis of ET Kinetics across Oligoproline Peptides  

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

Analysis of the Electron-Transfer Kinetics across Analysis of the Electron-Transfer Kinetics across Oligoproline Peptides Using N,N-Dimethyl-1,4-benzenediamine Donors and Pyrene-1-sulfonyl Acceptors Joseph B. Issa, Abdu S. Salameh, Edward W. Castner, Jr., James F. Wishart, and Stephan S. Isied J. Phys. Chem. B 111, 6878-6886 (2007). [Find paper at ACS Publications] or use ACS Articles on Request Abstract: Photoinduced intramolecular charge separation across proline-bridged donor-acceptor complexes of the type Pyr-(Pro)n-DMPD (where Pyr = pyrene-1-sulfonyl and DMPD = N,N-dimethyl-1,4-phenylenediamine) was studied. The steady-state emission spectrum for n = 0, 1, 2, 3 showed an increase in emission intensity with the number of proline residues. Time-dependent emission measured by streak camera showed increasing

268

Systems engineering analysis of kinetic energy weapon concepts  

SciTech Connect

This study examines, from a systems engineering design perspective, the potential of kinetic energy weapons being used in the role of a conventional strategic weapon. Within the Department of Energy (DOE) complex, strategic weapon experience falls predominantly in the nuclear weapons arena. The techniques developed over the years may not be the most suitable methodologies for use in a new design/development arena. For this reason a more fundamental approach was pursued with the objective of developing an information base from which design decisions might be made concerning the conventional strategic weapon system concepts. The study examined (1) a number of generic missions, (2) the effects of a number of damage mechanisms from a physics perspective, (3) measures of effectiveness (MOE`s), and (4) a design envelope for kinetic energy weapon concepts. With the base of information a cut at developing a set of high-level system requirements was made, and a number of concepts were assessed against these requirements.

Senglaub, M.

1996-06-01T23:59:59.000Z

269

Kinetics of surface roughening and smoothing during ion sputtering  

SciTech Connect

We have measured the kinetics of roughness evolution during low energy ion sputtering of SiO{sub 2} surfaces using in situ x-ray reflectivity. Sputtering with heavy ions (Xe) leads to rapid roughening of the surface that can not be explained by a simple random removal process. Subsequent bombardment with light ions (He,H) leads to an exponential decrease in the surface roughness. These kinetics are explained quantitatively by a linear model that contains a balance between smoothing by surface diffusion and viscous flow and roughening by sputter removal of material. A curvature dependent sputter yield leads to amplification of a limited range of spatial frequencies on the surface and the formation of a ripple topography.

Chason, E.; Mayer, T.M.; Howard, A.J.

1993-12-31T23:59:59.000Z

270

Nonequilibrium sensing and its analogy to kinetic proofreading  

E-Print Network (OSTI)

For a paradigmatic model of chemotaxis, we analyze the effect how a nonzero affinity driving receptors out of equilibrium affects sensitivity. This affinity arises whenever changes in receptor activity involve ATP hydrolysis. The sensitivity integrated over a ligand concentration range is shown to be enhanced by the affinity, providing a measure of how much energy consumption improves sensing. With this integrated sensitivity we can establish an intriguing analogy between sensing with nonequilibrium receptors and kinetic proofreading: the increase in integrated sensitivity is equivalent to the decrease of the error in kinetic proofreading. The influence of the occupancy of the receptor on the phosphorylation and dephosphorylation reaction rates is shown to be crucial for the relation between integrated sensitivity and affinity. This influence can even lead to a regime where a nonzero affinity decreases the integrated sensitivity, which corresponds to anti-proofreading.

Hartich, David; Seifert, Udo

2015-01-01T23:59:59.000Z

271

Chemical Kinetic Modeling of Non-Petroleum Based Fuels | Department...  

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

ft010pitz2012o.pdf More Documents & Publications Chemical Kinetic Modeling of Non-Petroleum Based Fuels Chemical Kinetic Modeling of Fuels Chemical Kinetic Research on HCCI &...

272

Recent Advances in Detailed Chemical Kinetic Models for Large Hydrocarbon and Biodiesel Transportation Fuels  

SciTech Connect

n-Hexadecane and 2,2,4,4,6,8,8-heptamethylnonane represent the primary reference fuels for diesel that are used to determine cetane number, a measure of the ignition property of diesel fuel. With the development of chemical kinetics models for these two primary reference fuels for diesel, a new capability is now available to model diesel fuel ignition. Also, we have developed chemical kinetic models for a whole series of large n-alkanes and a large iso-alkane to represent these chemical classes in fuel surrogates for conventional and future fuels. Methyl decanoate and methyl stearate are large methyl esters that are closely related to biodiesel fuels, and kinetic models for these molecules have also been developed. These chemical kinetic models are used to predict the effect of the fuel molecule size and structure on ignition characteristics under conditions found in internal combustion engines.

Westbrook, C K; Pitz, W J; Curran, H J; Herbinet, O; Mehl, M

2009-03-30T23:59:59.000Z

273

Macroscopic Kinetic Effect of Cell-to-Cell Variation in Biochemical Reactions  

Science Journals Connector (OSTI)

Genetically identical cells under the same environmental conditions can show strong variations in protein copy numbers due to inherently stochastic events in individual cells. We here develop a theoretical framework to address how variations in enzyme abundance affect the collective kinetics of metabolic reactions observed within a population of cells. Kinetic parameters measured at the cell population level are shown to be systematically deviated from those of single cells, even within populations of homogeneous parameters. Because of these considerations, Michaelis-Menten kinetics can even be inappropriate to apply at the population level. Our findings elucidate a novel origin of discrepancy between in vivo and in vitro kinetics, and offer potential utility for analysis of single-cell metabolomic data.

Pan-Jun Kim and Nathan D. Price

2010-04-08T23:59:59.000Z

274

Kinetic modelling of krypton fluoride laser systems  

SciTech Connect

A kinetic model has been developed for the KrF* rare gas halide laser system, specifically for electron-beam pumped mixtures of krypton, fluorine, and either helium or argon. The excitation produced in the laser gas by the e-beam was calculated numerically using an algorithm checked by comparing the predicted ionization yields in the pure rare gases with their experimental values. The excitation of the laser media by multi-kilovolt x-rays was also modeled and shown to be similar to that produced by high energy electrons. A system of equations describing the transfer of the initial gas excitation into the laser upper level was assembled using reaction rate constants from both experiment and theory. A one-dimensional treatment of the interaction of the laser radiation with the gas was formulated which considered spontaneous and stimulated emission and absorption. The predictions of this model were in good agreement with the fluorescence signals and gain and absorption measured experimentally.

Jancaitis, K.S.

1983-11-01T23:59:59.000Z

275

Kinetics of methanation on nickel catalysts  

SciTech Connect

Extensive steady-state and transient measurements of the disproportionation of carbon monoxide, the hydrogenation of deposited carbon, and methanation of carbon monoxide were performed over 2 and 10% nickel on silica support. The results indicated that the methanation of carbon monoxide involves competitively adsorbed species; that the reaction is nearly zero order in carbon monoxide at 0.1-0.5 atm CO and 1 atm H/sub 2/, but negative at higher CO partial pressures and that it becomes less negative with increasing temperature or increasing hydrogen pressure; and that the reaction order with respect to hydrogen changes from 0.5 to 1.0 with increasing CO pressure and decreasing H/sub 2/ pressure. A reaction mechanism is proposed which consists of the molecular adsorption of CO, the dissociative adsorption of H/sub 2/, dissociation of the surface CO species, and reaction of two adsorbed hydrogen atoms with the oxygen; and a multistep hydrogenation and desorption process for the adsorbed carbon. The dissociation and reaction of adsorbed CO is probably the rate-limiting step. The kinetic behavior is best represented with the assumption of a heterogeneous catalyst surface, containing three types of sites of widely varying activity.

Ho, S.V.; Harriott, P.

1980-08-01T23:59:59.000Z

276

Transport-controlled kinetics of dissolution and precipitation...  

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

Transport-controlled kinetics of dissolution and precipitation in the sediments under alkaline and saline conditions . Transport-controlled kinetics of dissolution and...

277

Studying The Kinetics Of Crystalline Silicon Nanoparticle Lithiation...  

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

Studying The Kinetics Of Crystalline Silicon Nanoparticle Lithiation With In-Situ Transmission Electron Microscopy. Studying The Kinetics Of Crystalline Silicon Nanoparticle...

278

Global Optimization of Chemical Reactors and Kinetic Optimization  

E-Print Network (OSTI)

Model; 3-D; Monolith; Reactor; Optimization Introduction TheAngeles Global Optimization of Chemical Reactors and KineticGlobal Optimization of Chemical Reactors and Kinetic

ALHUSSEINI, ZAYNA ISHAQ

2013-01-01T23:59:59.000Z

279

Structure, Kinetics, and Thermodynamics of the Aqueous Uranyl...  

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

Kinetics, and Thermodynamics of the Aqueous Uranyl(VI) Cation. Structure, Kinetics, and Thermodynamics of the Aqueous Uranyl(VI) Cation. Abstract: Molecular simulation techniques...

280

Microscale Electrode Design Using Coupled Kinetic, Thermal and...  

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

Microscale Electrode Design Using Coupled Kinetic, Thermal and Mechanical Modeling Microscale Electrode Design Using Coupled Kinetic, Thermal and Mechanical Modeling 2010 DOE...

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Microscale Electrode Design Using Coupled Kinetic, Thermal and...  

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

Microscale Electrode Design Using Coupled Kinetic, Thermal and Mechanical Modeling Microscale Electrode Design Using Coupled Kinetic, Thermal and Mechanical Modeling 2009 DOE...

282

Coupled Kinetic, Thermal, and Mechanical Modeling of FIB Micro...  

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

Coupled Kinetic, Thermal, and Mechanical Modeling of FIB Micro-machined Electrodes Coupled Kinetic, Thermal, and Mechanical Modeling of FIB Micro-machined Electrodes 2010 DOE...

283

Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps...  

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

Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps Development of Chemical Kinetic Models for Lean NOx Traps Modeling the Regeneration Chemistry of Lean NOx Traps...

284

Experimentally determined dissolution kinetics of Na-rich borosilicate...  

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

Experimentally determined dissolution kinetics of Na-rich borosilicate glass at far from equilibrium conditions: Implications Experimentally determined dissolution kinetics of...

285

Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling  

SciTech Connect

The nonlinear evolution of collisionless plasmas is typically a multi-scale process, where the energy is injected at large, fluid scales and dissipated at small, kinetic scales. Accurately modelling the global evolution requires to take into account the main micro-scale physical processes of interest. This is why comparison of different plasma models is today an imperative task aiming at understanding cross-scale processes in plasmas. We report here the first comparative study of the evolution of a magnetized shear flow, through a variety of different plasma models by using magnetohydrodynamic (MHD), Hall-MHD, two-fluid, hybrid kinetic, and full kinetic codes. Kinetic relaxation effects are discussed to emphasize the need for kinetic equilibriums to study the dynamics of collisionless plasmas in non trivial configurations. Discrepancies between models are studied both in the linear and in the nonlinear regime of the magnetized Kelvin-Helmholtz instability, to highlight the effects of small scale processes on the nonlinear evolution of collisionless plasmas. We illustrate how the evolution of a magnetized shear flow depends on the relative orientation of the fluid vorticity with respect to the magnetic field direction during the linear evolution when kinetic effects are taken into account. Even if we found that small scale processes differ between the different models, we show that the feedback from small, kinetic scales to large, fluid scales is negligible in the nonlinear regime. This study shows that the kinetic modeling validates the use of a fluid approach at large scales, which encourages the development and use of fluid codes to study the nonlinear evolution of magnetized fluid flows, even in the collisionless regime.

Henri, P. [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy) [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP 4229 06304, Nice Cedex 4 (France); Cerri, S. S. [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy) [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Califano, F.; Pegoraro, F. [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy)] [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Rossi, C. [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy) [Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); LPP-CNRS, Ecole Polytechnique, UPMC, Université Paris VI, Université Paris XI, route de Saclay, 91128 Palaiseau (France); Faganello, M. [International Institute for Fusion Science/PIIM, UMR 7345 CNRS, Aix-Marseille University, 13397 Marseille (France)] [International Institute for Fusion Science/PIIM, UMR 7345 CNRS, Aix-Marseille University, 13397 Marseille (France); Šebek, O. [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague, Czech Republic and Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, B?ehová 7, 11519 Prague (Czech Republic)] [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague, Czech Republic and Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, B?ehová 7, 11519 Prague (Czech Republic); Trávní?ek, P. M. [Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, California 94720, USA and Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic)] [Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, California 94720, USA and Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); Hellinger, P. [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic)] [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); and others

2013-10-15T23:59:59.000Z

286

Kinetic theory and numerical simulations of two-species coagulation  

E-Print Network (OSTI)

In this work we study the stochastic process of two-species coagulation. This process consists in the aggregation dynamics taking place in a ring. Particles and clusters of particles are set in this ring and they can move either clockwise or counterclockwise. They have a probability to aggregate forming larger clusters when they collide with another particle or cluster. We study the stochastic process both analytically and numerically. Analytically, we derive a kinetic theory which approximately describes the process dynamics. One of our strongest assumptions in this respect is the so called well-stirred limit, that allows neglecting the appearance of spatial coordinates in the theory, so this becomes effectively reduced to a zeroth dimensional model. We determine the long time behavior of such a model, making emphasis in one special case in which it displays self-similar solutions. In particular these calculations answer the question of how the system gets ordered, with all particles and clusters moving in the same direction, in the long time. We compare our analytical results with direct numerical simulations of the stochastic process and both corroborate its predictions and check its limitations. In particular, we numerically confirm the ordering dynamics predicted by the kinetic theory and explore properties of the realizations of the stochastic process which are not accessible to our theoretical approach.

Carlos Escudero; Fabricio Macia; Raul Toral; Juan J. L. Velazquez

2014-04-19T23:59:59.000Z

287

HIGH PRESSURE COAL COMBUSTON KINETICS PROJECT  

SciTech Connect

As part of the U.S. Department of Energy (DoE) initiative to improve the efficiency of coal-fired power plants and reduce the pollution generated by these facilities, DOE has funded the High-Pressure Coal Combustion Kinetics (HPCCK) Projects. A series of laboratory experiments were conducted on selected pulverized coals at elevated pressures with the specific goals to provide new data for pressurized coal combustion that will help extend to high pressure and validate models for burnout, pollutant formation, and generate samples of solid combustion products for analyses to fill crucial gaps in knowledge of char morphology and fly ash formation. Two series of high-pressure coal combustion experiments were performed using SRI's pressurized radiant coal flow reactor. The first series of tests characterized the near burner flame zone (NBFZ). Three coals were tested, two high volatile bituminous (Pittsburgh No.8 and Illinois No.6), and one sub-bituminous (Powder River Basin), at pressures of 1, 2, and 3 MPa (10, 20, and 30 atm). The second series of experiments, which covered high-pressure burnout (HPBO) conditions, utilized a range of substantially longer combustion residence times to produce char burnout levels from 50% to 100%. The same three coals were tested at 1, 2, and 3 MPa, as well as at 0.2 MPa. Tests were also conducted on Pittsburgh No.8 coal in CO2 entrainment gas at 0.2, 1, and 2 MPa to begin establishing a database of experiments relevant to carbon sequestration techniques. The HPBO test series included use of an impactor-type particle sampler to measure the particle size distribution of fly ash produced under complete burnout conditions. The collected data have been interpreted with the help of CFD and detailed kinetics simulation to extend and validate devolatilization, char combustion and pollutant model at elevated pressure. A global NOX production sub-model has been proposed. The submodel reproduces the performance of the detailed chemical reaction mechanism for the NBFZ tests.

Stefano Orsino

2005-03-30T23:59:59.000Z

288

Modeling of Reactor Kinetics and Dynamics  

SciTech Connect

In order to model a full fuel cycle in a nuclear reactor, it is necessary to simulate the short time-scale kinetic behavior of the reactor as well as the long time-scale dynamics that occur with fuel burnup. The former is modeled using the point kinetics equations, while the latter is modeled by coupling fuel burnup equations with the kinetics equations. When the equations are solved simultaneously with a nonlinear equation solver, the end result is a code with the unique capability of modeling transients at any time during a fuel cycle.

Matthew Johnson; Scott Lucas; Pavel Tsvetkov

2010-09-01T23:59:59.000Z

289

Bench-scale Kinetics Study of Mercury Reactions in FGD Liquors  

SciTech Connect

This document is the final report for Cooperative Agreement DE-FC26-04NT42314, 'Kinetics Study of Mercury Reactions in FGD Liquors'. The project was co-funded by the U.S. DOE National Energy Technology Laboratory and EPRI. The objective of the project has been to determine the mechanisms and kinetics of the aqueous reactions of mercury absorbed by wet flue gas desulfurization (FGD) systems, and develop a kinetics model to predict mercury reactions in wet FGD systems. The model may be used to determine optimum wet FGD design and operating conditions to maximize mercury capture in wet FGD systems. Initially, a series of bench-top, liquid-phase reactor tests were conducted and mercury species concentrations were measured by UV/visible light spectroscopy to determine reactant and byproduct concentrations over time. Other measurement methods, such as atomic absorption, were used to measure concentrations of vapor-phase elemental mercury, that cannot be measured by UV/visible light spectroscopy. Next, a series of bench-scale wet FGD simulation tests were conducted. Because of the significant effects of sulfite concentration on mercury re-emission rates, new methods were developed for operating and controlling the bench-scale FGD experiments. Approximately 140 bench-scale wet FGD tests were conducted and several unusual and pertinent effects of process chemistry on mercury re-emissions were identified and characterized. These data have been used to develop an empirically adjusted, theoretically based kinetics model to predict mercury species reactions in wet FGD systems. The model has been verified in tests conducted with the bench-scale wet FGD system, where both gas-phase and liquid-phase mercury concentrations were measured to determine if the model accurately predicts the tendency for mercury re-emissions. This report presents and discusses results from the initial laboratory kinetics measurements, the bench-scale wet FGD tests, and the kinetics modeling efforts.

Gary Blythe; John Currie; David DeBerry

2008-03-31T23:59:59.000Z

290

Kinetics of ethanol dehydrogenation into ethyl acetate  

Science Journals Connector (OSTI)

The kinetics of gas-phase dehydrogenation of ethanol into ethyl acetate over a copper-zinc- ... means to design a reactor for dehydrogenation of ethanol into ethyl acetate in different regimes.

V. A. Men’shchikov; L. Kh. Gol’dshtein; I. P. Semenov

2014-01-01T23:59:59.000Z

291

Kinetics and mechanisms of reactions involving small aromatic reactive intermediates  

SciTech Connect

Small aromatic radicals such as C{sub 6}H{sub 5}, C{sub 6}H{sub 5}O and C{sub 6}H{sub 4} are key prototype species of their homologs. C{sub 6}H{sub 5} and its oxidation product, C{sub 6}H{sub 5}O are believed to be important intermediates which play a pivotal role in hydrocarbon combustion, particularly with regard to soot formation. Despite their fundamental importance, experimental data on the reaction mechanisms and reactivities of these species are very limited. For C{sub 6}H{sub 5}, most kinetic data except its reactions with NO and NO{sub 2}, were obtained by relative rate measurements. For C{sub 6}H{sub 5}O, the authors have earlier measured its fragmentation reaction producing C{sub 5}H{sub 5} + CO in shock waves. For C{sub 6}H{sub 4}, the only rate constant measured in the gas phase is its recombination rate at room temperature. The authors have proposed to investigate systematically the kinetics and mechanisms of this important class of molecules using two parallel laser diagnostic techniques--laser resonance absorption (LRA) and resonance enhanced multiphoton ionization mass spectrometry (REMPI/MS). In the past two years, study has been focused on the development of a new multipass adsorption technique--the {open_quotes}cavity-ring-down{close_quotes} technique for kinetic applications. The preliminary results of this study appear to be quite good and the sensitivity of the technique is at least comparable to that of the laser-induced fluorescence method.

Lin, M.C. [Emory Univ., Atlanta, GA (United States)

1993-12-01T23:59:59.000Z

292

Mechanistic studies using kinetic isotope effects  

E-Print Network (OSTI)

MECHANISTIC STUDIES USING KINETIC ISOTOPE EFFECTS A Thesis by BRIAN E. SCHULMFIER Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requtrements for the degree of MASTER OF SCIENCE December... 1999 Major Subject: Chemistry MECHANISTIC STUDIES USING KINETIC ISOTOPE EFFECTS A Thesis by BRIAN E. SCHULMEIER Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...

Schulmeier, Brian E.

2012-06-07T23:59:59.000Z

293

Kinetic decoupling of WIMPs: analytic expressions  

E-Print Network (OSTI)

We present a general expression for the values of the average kinetic energy and of the temperature of kinetic decoupling of a WIMP, valid for any cosmological model. We show an example of the usage of our solution when the Hubble rate has a power-law dependence on temperature, and we show results for the specific cases of kination cosmology and low- temperature reheating cosmology.

Visinelli, Luca

2015-01-01T23:59:59.000Z

294

Quintom scenario with mixed kinetic terms  

SciTech Connect

We examine an extension of the quintom scenario of dark energy, in which a canonical scalar field and a phantom field are coupled through a kinetic interaction. We perform a phase-space analysis and show that the kinetic coupling gives rise to novel cosmological behavior. In particular, we obtain both quintessence-like and phantomlike late-time solutions, as well as solutions that cross the phantom divide during the evolution of the Universe.

Saridakis, Emmanuel N. [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Weller, Joel M. [Department of Applied Mathematics, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2010-06-15T23:59:59.000Z

295

Directives Quarterly Updates  

Directives, Delegations, and Requirements

Listings of new Justification Memoranda and new or revised Directives that have been posted to the DOE Directives, Delegations, and Requirements Portal. Updated quarterly.

296

Another face of DIRECT  

E-Print Network (OSTI)

authors, see for example, tree-Direct [5]. This paper ..... [4] J.M. Gablonsky, Modifications of the DIRECT Algorithm, Ph.D. Thesis, North Carolina State. University ...

chiter

2007-08-01T23:59:59.000Z

297

Kinetics of light induced defect creation in organic solar cells  

Science Journals Connector (OSTI)

The kinetics of light-induced recombination centers in bulk heterojunction organic solar cells are measured as a function of exposure time intensity and the illumination photon energy. The density of induced centers increases with exposure but stabilizes partially due to self-annealing. UV exposure is roughly 50 times more effective for defect creation than white light or yellow-filtered white light. Light-induced breaking of C-H bonds to create H-related localized states is proposed as the underlying mechanism.

R. A. Street; D. M. Davies

2013-01-01T23:59:59.000Z

298

Single Molecule Acid-Base Kinetics and Thermodynamics  

Science Journals Connector (OSTI)

We report a method in which temperature dependent single-molecule fluorescence measurements are used to study the kinetics and thermodynamics of the acid-base interaction in films of photoresist polymer. We use the two distinct fluorescent prototropic forms of Coumarin 6 (C6?C6+) to indicate the state of the acid-base system. Data are analyzed using a statistical model of the intensity probability distributions, yielding temperature dependent proton exchange rates, which is confirmed through agreement with a simple two-state Monte Carlo model. The temperature dependent rates are used to calculate the activation enthalpy for proton exchange.

Michael D. Mason; Krishanu Ray; Robert D. Grober; Gerd Pohlers; James Cameron

2004-08-13T23:59:59.000Z

299

Mechanism and kinetics of peptide partitioning into membranes  

SciTech Connect

Partitioning properties of transmembrane (TM) polypeptide segments directly determine membrane protein folding, stability, and function, and their understanding is vital for rational design of membrane active peptides. However, direct determination of water-to-bilayer transfer of TM peptides has proved difficult. Experimentally, sufficiently hydrophobic peptides tend to aggregate, while atomistic computer simulations at physiological temperatures cannot yet reach the long time scales required to capture partitioning. Elevating temperatures to accelerate the dynamics has been avoided, as this was thought to lead to rapid denaturing. However, we show here that model TM peptides (WALP) are exceptionally thermostable. Circular dichroism experiments reveal that the peptides remain inserted into the lipid bilayer and are fully helical, even at 90 C. At these temperatures, sampling is 50 500 times faster, sufficient to directly simulate spontaneous partitioning at atomic resolution. A folded insertion pathway is observed, consistent with three-stage partitioning theory. Elevated temperature simulation ensembles further allow the direct calculation of the insertion kinetics, which is found to be first-order for all systems. Insertion barriers are Hin = 15 kcal/mol for a general hydrophobic peptide and 23 kcal/mol for the tryptophan-flanked WALP peptides. The corresponding insertion times at room temperature range from 8.5 s to 163 ms. High-temperature simulations of experimentally validated thermostable systems suggest a new avenue for systematic exploration of peptide partitioning properties.

Ulmschneider, Martin [University of Oxford; Killian, J Antoinette [University of Utrecht; Doux, Jacques P. F. [University of Utrecht; Smith, Jeremy C [ORNL; Ulmschneider, Jakob [University of Heidelberg

2010-02-01T23:59:59.000Z

300

Pseudo-isothermal ice-crystallization kinetics in the gas-diffusion layer  

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

Pseudo-isothermal ice-crystallization kinetics in the gas-diffusion layer Pseudo-isothermal ice-crystallization kinetics in the gas-diffusion layer of a fuel cell from differential scanning calorimetry Title Pseudo-isothermal ice-crystallization kinetics in the gas-diffusion layer of a fuel cell from differential scanning calorimetry Publication Type Journal Article Year of Publication 2013 Authors Dursch, Thomas J., Monica A. Ciontea, Gregory J. Trigub, Clayton J. Radke, and Adam Z. Weber Journal International Journal of Heat and Mass Transfer Volume 60 Pagination 450 - 458 Date Published 5/2013 ISSN 00179310 Keywords crystallization, differential scanning calorimetry, gas-diffusion layer, Heat Transfer, kinetics, melt, nonisothermal crystallization, nucleation, polyesters, polymer crystallization, solidification Abstract Non-isothermal ice-crystallization kinetics in the fibrous gas-diffusion layer (GDL) of a proton-exchange-membrane fuel cell is investigated using differential scanning calorimetry (DSC). Non-isothermal ice-crystallization rates and ice-crystallization temperatures are obtained from heat-flow measurements in a water-saturated commercial GDL at cooling rates of 2.5, 5, 10, and 25 K/min. Our previously developed isothermal ice-crystallization rate expression is extended to non-isothermal crystallization to predict ice-crystallization kinetics in a GDL at various cooling rates. Agreement between DSC experimental results and theory is good. Both show that as the cooling rate increases, ice-crystallization rates increase and crystallization temperatures decrease monotonically. Importantly, we find that the cooling rate during crystallization has a negligible effect on the crystallization rate when crystallization times are much faster than the time to decrease the sample temperature by the subcooling. Based on this finding, we propose a pseudo-isothermal method for obtaining non-isothermal crystallization kinetics using isothermal crystallization kinetics evaluated at the non-isothermal crystallization temperature.

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301

Kinetics of the [beta]-[delta]phase transition in PBX9501.  

SciTech Connect

The initial step in the thermal decomposition of HMX is the solid state phase transition from the centrosymmetric beta form to the noncentrosymmetric delta form. The symmetry change makes the phase transition amenable to the application of second harmonic generation (SHG) as a probe of transition kinetics. We have used SHG to study the temperature dependence of the kinetics for unconfined PBX9501 and HMX. Spatially resolved SHG measurements have shown a nucleation and growth mechanism for the solid state phase transition. We have measured the transition rate as a function of temperature in order to obtain the activation energy and entropy of transition, which determine the phase transition kinetics. Additionally, we have observed temperature dependent reversion of the delta phase to beta phase and have fimd that we can control the reversion rate by controlling the cooling.

Smilowitz, L. B. (Laura B.); Henson, B. F. (Bryan F.); Asay, B. W. (Blaine W.); Dickson, P. M. (Peter M.); Robinson, J. M. (Jeanne M.)

2001-01-01T23:59:59.000Z

302

Microstructure and kinetics of hot corrosion for a nickel alloy in molten salt  

SciTech Connect

Metallography, analytical SEM, and XRD were used to measure kinetics and characterize the microstructure of hot corrosion of the Ni-Cr-Fe alloy INCONEL 600 after 500 h immersion in molten Na{sub 2}CO{sub 3}- NaCl salt at 900-950 C in an oxidizing atmosphere. This was done to assess the alloy as a reaction vessel material for a waste treatment process known as Molten Salt Oxidation. The alloy was found to hot corrode by surface oxidation and intergranular attack. Combined rate for loss of load-bearing cross-section metal was comparable to corrosion rates for analogous salts. About 5% of the oxide scale was a continuous, dense, protective layer of Cr{sub 2}O{sub 3} at the metal/oxide interface. A middle portion comprised about 55% of the scale and was a porous, mixed oxide of NiO>Cr{sub 2}O{sub 3}>Fe{sub 2}O{sub 3}. The outer 40% was nearly all NiO with dense grains and cavitated grain boundaries. Overall, the NiO was dominant and the lesser amounts of Cr{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} were roughly equivalent. No direct invasion of salt through the oxide to the metal was observed.

Stevens, D.W.; Brummond, W.A. [Lawrence Livermore National Lab., CA (United States); Grimmett, D.L.; Newcomb, J.C.; Chiang, K.T.; Gay, R.L. [Boeing North American, Inc., Canoga Park, CA (United States). Rocketdyne Div.

1996-12-01T23:59:59.000Z

303

Alfvenic Turbulence in the Extended Solar Corona: Kinetic Effects and Proton Heating  

E-Print Network (OSTI)

We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Measurements made by UVCS/SOHO have revived interest in the idea that ions are energized by the dissipation of ion cyclotron resonant waves, but such high-frequency (i.e., small wavelength) fluctuations have not been observed. A turbulent cascade is one possible way of generating small-scale fluctuations from a pre-existing population of low-frequency MHD waves. We model this cascade as a combination of advection and diffusion in wavenumber space. The dominant spectral transfer occurs in the direction perpendicular to the background magnetic field. As expected from earlier models, this leads to a highly anisotropic fluctuation spectrum with a rapidly decaying tail in parallel wavenumber. The wave power that decays to high enough frequencies to become ion cyclotron resonant depends on the relative strengths of advection and diffusion in the cascade. For the most realistic values of these parameters, though, there is insufficient power to heat protons and heavy ions. The dominant oblique fluctuations (with dispersion properties of kinetic Alfven waves) undergo Landau damping, which implies strong parallel electron heating. We discuss the probable nonlinear evolution of the electron velocity distributions into parallel beams and discrete phase-space holes (similar to those seen in the terrestrial magnetosphere) which can possibly heat protons via stochastic interactions.

S. R. Cranmer; A. A. van Ballegooijen

2003-05-08T23:59:59.000Z

304

Hydrodenitrogenation: An increasingly important part of catalytic hydroprocessing interlocking of thermodynamics and kinetics  

SciTech Connect

This report outlines a new use of thermodynamic property data. The Gibbs energies of reaction obtained from thermodynamic property measurements are used to estimate, with some success, relative reactivities for aromatic organonitrogen compounds. Calculated relative rates of reaction reproduce literature values within one power of ten. The relative rates of reaction are shown to be directly proportional to the concentration of hydrogenated species formed during hydrodenitrogenation (HDN). The production of completely saturated ring systems (overhydrogenation) in HDN reactions using conventional hydroprocessing is explained solely in terms of the thermodynamics in operation in the system. The results obtained show that the order of relative reactivity obtained is strongly dependence can account for some apparent contradictions when kinetic studies reported in the literature are compared. The results for a study of the hydroprocessing of a straight-run gas oil are reproduced in this report. The formation of anilines and the increase in indole concentration above that in the original gas oil sample are explained via the thermodynamics operating in the system.

Steele, W.V.; Chirico, R.D.

1992-04-01T23:59:59.000Z

305

22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 1 Kinetic theory of Geodesic Acoustic  

E-Print Network (OSTI)

22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 1 Kinetic theory of Geodesic Acoustic Zonca, Liu Chen and Zhiyong Qiu #12;22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 2 Chen and Zhiyong Qiu #12;22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 3 2 Linear

Zonca, Fulvio

306

Heat Transfer Analysis and Assessment of Kinetics Systems for PBX 9501  

SciTech Connect

The study of thermal decomposition in high explosive (HE) charges has been an ongoing process since the early 1900s. This work is specifically directed towards the analysis of PBX 9501. In the early 1970s, Dwight Jaeger of Los Alamos National Laboratory (LANL) developed a single-step, two-species kinetics system that was used in the development of one of the first finite element codes for thermal analyses known as EXPLO. Jaeger's research focused on unconfined spherical samples of HE charges to determine if varied heating ramps would cause detonation or deflagration. Tarver and McGuire of Lawrence Livermore National Laboratory (LLNL) followed soon after with a three-step, four-species kinetics system that was developed for confined spheres under relatively fast heating conditions. Peter Dickson et al. of LANL then introduced a kinetics system with four steps and five species that included bimolecular products to capture the effects of the endothermic phase change that the HE undergoes. The results of four experiments are examined to study the effectiveness of these kinetics systems. The experiments are: (1) The LLNL scaled thermal explosion (STEX) experiments on confined cylindrical charges with long heating ramps in the range of 90 hours. (2) The LLNL one-dimensional time to explosion (ODTX) experiments on spherical charges that include confined, partially confined, and aged HE experiments. (3) The LANL unconfined one-dimensional experiments for small spheres. (4) The Naval Air Warfare Center Weapons Division at China Lake experiments on small confined cylinders. The three kinetics systems are applied to each of the four experiments with the use of the finite element analysis (FEA) heat conduction solver COYOTE. The numerical results using the kinetics systems are compared to each other and to the experimental data to determine which kinetics systems are best suited for analyzing conditions such as time to ignition, containment, heating time, and location of ignition.

Jeffrey W. Jorenby

2006-07-31T23:59:59.000Z

307

7-Gate Kinetic AMPA Model Kinetics to match EPSCs from calyx of Held  

E-Print Network (OSTI)

7-Gate Kinetic AMPA Model · Kinetics to match EPSCs from calyx of Held · Multiple closed, open and EPSC amplitude Bruce Graham Department of Computing Science and Mathematics, University of Stirling, U, including the calyx of Held in the mammalian auditory system. Such depression may be mediated

Graham, Bruce

308

Foreign Direct Investment  

Gasoline and Diesel Fuel Update (EIA)

Investment Investment Foreign Direct Investment Foreign Direct Investment Foreign Direct Investment in U.S. Energy in U.S. Energy in U.S. Energy in U.S. Energy in 1999 in 1999 in 1999 in 1999 June 2001 ii iii Contents Foreign Affiliates' Role in U.S. Energy Industry Operations ..............................................................................1 Foreign Direct Investment: The International Transactions Accounts ..............................................................8 U.S. Companies' Direct Investment Abroad in Energy ......................................................................................14 Conclusion...............................................................................................................................................................19

309

Studies of Reaction Kinetics of Methane Hydrate Dissocation in Porous Media  

SciTech Connect

The objective of this study is the description of the kinetic dissociation of CH4-hydrates in porous media, and the determination of the corresponding kinetic parameters. Knowledge of the kinetic dissociation behavior of hydrates can play a critical role in the evaluation of gas production potential of gas hydrate accumulations in geologic media. We analyzed data from a sequence of tests of CH4-hydrate dissociation by means of thermal stimulation. These tests had been conducted on sand cores partially saturated with water, hydrate and CH4 gas, and contained in an x-ray-transparent aluminum pressure vessel. The pressure, volume of released gas, and temperature (at several locations within the cores) were measured. To avoid misinterpreting local changes as global processes, x-ray computed tomography scans provided accurate images of the location and movement of the reaction interface during the course of the experiments. Analysis of the data by means of inverse modeling (history matching ) provided estimates of the thermal properties and of the kinetic parameters of the hydration reaction in porous media. Comparison of the results from the hydrate-bearing porous media cores to those from pure CH4-hydrate samples provided a measure of the effect of the porous medium on the kinetic reaction. A tentative model of composite thermal conductivity of hydrate-bearing media was also developed.

Moridis, George J.; Seol, Yongkoo; Kneafsey, Timothy J.

2005-03-10T23:59:59.000Z

310

Chemical Kinetic Modeling of Advanced Transportation Fuels  

SciTech Connect

Development of detailed chemical kinetic models for advanced petroleum-based and nonpetroleum based fuels is a difficult challenge because of the hundreds to thousands of different components in these fuels and because some of these fuels contain components that have not been considered in the past. It is important to develop detailed chemical kinetic models for these fuels since the models can be put into engine simulation codes used for optimizing engine design for maximum efficiency and minimal pollutant emissions. For example, these chemistry-enabled engine codes can be used to optimize combustion chamber shape and fuel injection timing. They also allow insight into how the composition of advanced petroleum-based and non-petroleum based fuels affect engine performance characteristics. Additionally, chemical kinetic models can be used separately to interpret important in-cylinder experimental data and gain insight into advanced engine combustion processes such as HCCI and lean burn engines. The objectives are: (1) Develop detailed chemical kinetic reaction models for components of advanced petroleum-based and non-petroleum based fuels. These fuels models include components from vegetable-oil-derived biodiesel, oil-sand derived fuel, alcohol fuels and other advanced bio-based and alternative fuels. (2) Develop detailed chemical kinetic reaction models for mixtures of non-petroleum and petroleum-based components to represent real fuels and lead to efficient reduced combustion models needed for engine modeling codes. (3) Characterize the role of fuel composition on efficiency and pollutant emissions from practical automotive engines.

PItz, W J; Westbrook, C K; Herbinet, O

2009-01-20T23:59:59.000Z

311

Kinetics of Elementary Processes Relevant to Incipient Soot Formation  

SciTech Connect

Soot formation and abatement processes are some of the most important and challenging problems in hydrocarbon combustion. The key reactions involved in the formation of polycyclic aromatic hydrocarbons (PAH�s), the precursors to soot, remain elusive. Small aromatic species such as C5H5, C6H6 and their derivatives are believed to play a pivotal role in incipient soot formation. The goal of this project is to establish a kinetic database for elementary reactions relevant to soot formation in its incipient stages. In the past year, we have completed by CRDS the kinetics for the formation and decomposition of C6H5C2H2O2 in the C6H5C2H2 +O2 reaction and the formation of C10H7O2 in the C10H7 + O2 reaction by directly monitoring C6H5C2H2O2 and C10H7O2 radicals in the visible region; their mechanisms have been elucidated computationally by quantum-chemical calculations. The O + C2H5OH reaction has been studied experimentally and computationally and the OH + HNCN reaction has been investigated by ab initio molecular orbital calculation. In addition, a new pulsed slit molecular beam system has been constructed and tested for spectroscopic studies of aromatic radicals and their derivatives by the cavity ringdown technique (CRDS).

M. C. Lin; M. C. Heaven

2008-04-30T23:59:59.000Z

312

The Kinetics of Analyte Capture on Nanoscale Sensors J. E. Solomon* and M. R. Pauly  

E-Print Network (OSTI)

The Kinetics of Analyte Capture on Nanoscale Sensors J. E. Solomon* and M. R. Pauly *Condensed analyte capture efficiency is a crucial measure of the ultimate sensitivity of such devices years, the potential use of nanoscale electromechanical systems has been considered for high

Paul, Mark

313

Single-Molecule Kinetics of Nanoparticle Catalysis , Hao Shen, Guokun Liu, and Peng Chen  

E-Print Network (OSTI)

#12;Single-Molecule Kinetics of Nanoparticle Catalysis Weilin Xu , Hao Shen, Guokun Liu, and Peng to characterize in ensemble-averaged measurements. The single-molecule approach enables studying the catalysis single-molecule Áuorescence studies of single Au-nanoparticle catalysis, focusing on the theoretical

Chen, Peng

314

Label-free single-molecule detection of DNA-hybridization kinetics with a carbon nanotube  

E-Print Network (OSTI)

Label-free single-molecule detection of DNA- hybridization kinetics with a carbon nanotube field , Colin Nuckolls2 and Kenneth L. Shepard1 * Single-molecule measurements of biomolecules can provide systems with fast dynamics. Here, we report the detection of DNA hybridization at the single-molecule

Hone, James

315

Philips Color Kinetics | Open Energy Information  

Open Energy Info (EERE)

Color Kinetics Color Kinetics Jump to: navigation, search Name Philips Color Kinetics Address 3 Burlington Woods Drive, 4th Floor Place Burlington, Massachusetts Zip 01803 Sector Efficiency Product LED lighting systems Website http://www.colorkinetics.com/ Coordinates 42.5005723°, -71.2042619° 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":42.5005723,"lon":-71.2042619,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

316

Kinetic model for a polymer in one dimension  

Science Journals Connector (OSTI)

We consider a model for a directed polymer on a one-dimensional lattice of width 2, with attractive interactions between monomers that occupy first-neighbor sites on the lattice and are not consecutive along the chain. We show that this model is equivalent to the one-dimensional Ising model with first- and second-neighbor interactions. We study the kinetic behavior of the model in the region of the phase diagram where the ground state is not frustrated, using a Glauber ansatz for the time evolution of the configurations. In order to decouple the dynamical equations, we use the pair approximation. In this approximation, we show that the dynamical exponent of the model is a function of the ratio between second- and first-neighbor interaction strengths. (c) 1995 The American Physical Society

José Arthur Martins and Jürgen F. Stilck

1995-12-01T23:59:59.000Z

317

Kinetics of the heterogeneous photocatalytic oxidation of isopropanol  

SciTech Connect

Intrinsic kinetics for the ambient temperature photocatalytic oxidation (PCO) of dilute isopropanol (IPA) in humid air over near-ultraviolet (UV) irradiated titanium dioxide have been determined using a continuous microreactor flow system. The IPA disappearance rate exhibits a Langmuir-Hinshelwood-Hougen-Watson (LHHW) type dependence on IPA concentration. The rate is nearly first order in UV irradiance at low UV flux. The rate is independent of relative humidity R{sub H} at low R{sub H} levels, but is enhanced by water vapor concentration at higher levels. This relatively unique behavior is likely a direct consequence of the adsorption strength of alcohols on titania, which in general is considerably higher than the corresponding adsorption strengths for other classes of organic compounds. In addition to carbon dioxide, acetone is generated as a product of IPA destruction. This acetone is itself photocatalytically oxidized to carbon dioxide and water vapor at longer residence time. 10 refs., 3 figs.

Ameen, M.; Kalaga, M.; Annapragada, R.; Raupp, G.B. [Arizona State Univ., Tempe, AZ (United States)

1996-12-31T23:59:59.000Z

318

A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics  

SciTech Connect

Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. One strategy that potentially enhances CO{sub 2} solubility and reduces the risk of CO{sub 2} leak back to the surface is dissolution of indigenous minerals in the geological formation and precipitation of secondary carbonate phases, which increases the brine pH and immobilizes CO{sub 2}. Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this strategy. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory-measured and field derived feldspar dissolution rates. To date, there is no real guidance as to how to predict silicate reaction rates for use in quantitative models. Current models for assessment of geological carbon sequestration have generally opted to use laboratory rates, in spite of the dearth of such data for compositionally complex systems, and the persistent disconnect between lab and field applications. Therefore, a firm scientific basis for predicting silicate reaction kinetics in CO{sub 2} injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation to measure silicate dissolution rates and iron carbonate precipitation rates at conditions pertinent to geological carbon sequestration. In the first year of the project, we have successfully developed a sample preparation method and completed three batch feldspar dissolution experiments at 200 C and 300 bars. The changes of solution chemistry as dissolution experiments progressed were monitored with on-line sampling of the aqueous phase at the constant temperature and pressure. These data allow calculating overall apparent feldspar dissolution rates and secondary mineral precipitation rates as a function of saturation states. State-of-the-art atomic resolution transmission electron microscopy (TEM), scanning electron microscopy, and electron microprobe was used to characterize the reactants (feldspars before experiments). We experimented with different sample preparation methods for TEM study, and found excellent images and chemical resolution with reactants, which shows promise of the technology and establishes the baseline for comparison with products (feldspars after the experiments). Preliminary electron microscopic characterization shows that the reacted feldspars have etch pits and are covered with secondary sheet silicate phases. Reaction-path geochemical modeling is used to interpret the experimental results. We have established the software and database, and are making great progress. Also during the first year, our education goal of graduate student training has been achieved. A Ph. D. student at Indiana University is progressing well in the degree program and has taken geochemical modeling, SEM, and TEM courses, which will facilitate research in the second and third year. A Ph. D. student at University of Minnesota is progressing well in conducting the experiments, and is near graduation. With the success of training of graduate students and excellent experimental data in the first year, we anticipate a more fruitful year in the second year.

Chen Zhu; William E. Seyfried

2005-01-01T23:59:59.000Z

319

Kinetic studies of elementary chemical reactions  

SciTech Connect

This program concerning kinetic studies of elementary chemical reactions is presently focussed on understanding reactions of NH{sub x} species. To reach this goal, the author is pursuing experimental studies of reaction rate coefficients and product branching fractions as well as using electronic structure calculations to calculate transition state properties and reaction rate calculations to relate these properties to predicted kinetic behavior. The synergy existing between the experimental and theoretical studies allow one to gain a deeper insight into more complex elementary reactions.

Durant, J.L. Jr. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

320

Direct/Indirect Costs  

Directives, Delegations, and Requirements

This chapter provides recommended categories for direct and indirect elements developed by the Committee for Cost Methods Development (CCMD) and describes various estimating techniques for direct and indirect costs.

1997-03-28T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Argininosuccinate synthetase: steady state kinetics  

E-Print Network (OSTI)

asparate and citrulline was needed to substract any ATPase activity. The rate was observed as a change in absorbance at 340 nm. The protein content was measured at 280 nm assuming an extinction coefficient of 1 AU per mg/mL. The assay mixture... 10 1 I ASP (mM 0 Figure 4. Aspartete versus ATP (citrullinem2. 5 mN) 19 500 450 0. 45mM '&v 350 . 30mM 0. 15m M 200 150 no t 50 1/ ATP (mM ) 10 Figure 5. ATP versus argininosuccinate (citrulline and aspartatem1. 0 mN) 20 340 0. 43...

Seiglie, Jorge Luis

1983-01-01T23:59:59.000Z

322

Directives System Manual  

Directives, Delegations, and Requirements

This Manual provides detailed requirements to supplement DOE O 251.1A, Directives System, dated 1-30-98.

1998-01-30T23:59:59.000Z

323

Studies on the formation of large amplitude kinetic Alfven wave solitons and double layers in plasmas  

SciTech Connect

A two fluid model has been employed to study the oblique propagation of solitary kinetic Alfven waves. Formation of solitary waves and double layers is observed. Amplitude, width (in the case of solitons), and thickness (in the case of double layers) of the nonlinear structures are studied in some detail. Wider solitary structures are found to exist for oblique propagation nearer to the magnetic field direction.

Devi, N.; Gogoi, R.; Das, G. C.; Roychoudhury, R. [Department of Mathematics, Cotton College, Guwahati-781001, Assam (India); Mathematical Sciences Division, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati-781035, Assam (India); Physics and Applied Mathematical Unit, Indian Statistical Institute, Kolkata 700108 (India)

2007-01-15T23:59:59.000Z

324

Kinetic Energy Recovery System for Sailing Yachts: Preliminary Experimental Results  

Science Journals Connector (OSTI)

Abstract SEAKERS (SEA Kinetic Energy Recovery System) is a research project, funded within the 7th EU Framework Program, whose goal is to develop an innovative device consisting in a model of a kinetic energy recovery system for sailing yachts, based on the conversion of wave-induced boat oscillations (heave, pitch and roll) into electric energy by means of a linear generator. The device aims at recovering as much kinetic energy as possible from the natural movements of a sailing yacht on the sea, therefore taking the view of a boat as a moving wave energy converter with energy harvesting capability. The boat's motions can be vertical oscillations due to the buoyancy in the presence of sea waves and rolling and pitching motions originated both by sailing in wavy waters and by the normal boat dynamics due to the sails’ propulsion. This paper presents a brief description of the prototype of linear generator, which has been developed in the SEAKERS project, and reports about the first experimental tests carried out on the prototype. Two kind of tests have been performed on the generator, which can be classified as a linear permanent magnet switched reluctance generator: first, the possibility to use the prototype like an actuator has been investigated, in order to force the cursor to have a motion in phase with the external forcing, so as to recover more energy when the machine acts as generator. The behaviour of the actuator was examined in a static way, measuring the forces between cursor and stator, varying relative position of cursor and current in the coils. The second kind of tests has been performed to analyse the efficiency of the generator, for different external loads and translational velocities. The trend shown in these tests are then explained by an analytical model based on an electromagnetic circuit.

Giuseppe Leo Guizzi; Michele Manno; Guido Manzi; Marco Salvatori; Domenico Serpella

2014-01-01T23:59:59.000Z

325

Pattern Formation and Growth Kinetics in Eutectic Systems  

SciTech Connect

Growth patterns during liquid/solid phase transformation are governed by simultaneous effects of heat and mass transfer mechanisms, creation of new interfaces, jump of the crystallization units from liquid to solid and their rearrangement in the solid matrix. To examine how the above processes influence the scale of microstructure, two eutectic systems are chosen for the study: a polymeric system polyethylene glycol-p-dibromobenzene (PEG-DBBZ) and a simple molecular system succinonitrile (SCN)-camphor. The scaling law for SCN-camphor system is found to follow the classical Jackson-Hunt model of circular rod eutectic, where the diffusion in the liquid and the interface energy are the main physics governing the two-phase pattern. In contrast, a significantly different scaling law is observed for the polymer system. The interface kinetics of PEG phase and its solute concentration dependence thus have been critically investigated for the first time by directional solidification technique. A model is then proposed that shows that the two-phase pattern in polymers is governed by the interface diffusion and the interface kinetics. In SCN-camphor system, a new branch of eutectic, elliptical shape rodl, is found in thin samples where only one layer of camphor rods is present. It is found that the orientation of the ellipse can change from the major axis in the direction of the thickness to the direction of the width as the velocity and/or the sample thickness is decreased. A theoretical model is developed that predicts the spacing and orientation of the elliptical rods in a thin sample. The single phase growth patterns of SCN-camphor system were also examined with emphasis on the three-dimensional single cell and cell/dendrite transition. For the 3D single cell in a capillary tube, the entire cell shape ahead of the eutectic front can be described by the Saffmann-Taylor finger only at extremely low growth rate. A 3D directional solidification model is developed to characterize the cell shape and tip undercooling and the experimental results are compared with the predictions of the model. From the investigation of cell/dendrite transition, a model is proposed, from which the condition for the onset of the transition can be obtained.

Jing Teng

2007-12-01T23:59:59.000Z

326

4A.5 DERIVING TURBULENT KINETIC ENERGY DISSIPATION RATE WITHIN CLOUDS USING GROUND BASED 94 GHZ RADAR  

E-Print Network (OSTI)

distribution of the optical and microphysics properties. Turbulence is also directly linked to the life cycle is to perform spectral analysis on air- craft data (for instance Gultepe and Starr (1995)) or from ground based. The variance 1 #12;v 2 of the mean wind is an indicator of the kinetic energy in turbulent scales

Hogan, Robin

327

Condition on the KohnSham kinetic energy and modern parametrization of the ThomasFermi density  

E-Print Network (OSTI)

; published online 20 January 2009 We study the asymptotic expansion of the neutral-atom energy as the atomic-correlation energy, EXC n , must be approximated. But a direct, orbital-free DFT could be constructed if onlyCondition on the Kohn­Sham kinetic energy and modern parametrization of the Thomas­Fermi density

Burke, Kieron

328

Kinetics of steam gasification of bituminous coals in terms of their use for underground coal gasification  

Science Journals Connector (OSTI)

Abstract The kinetics of steam gasification was examined for bituminous coals of a low coal rank. The examined coals can be the raw material for underground coal gasification. Measurements were carried out under isothermal conditions at a high pressure of 4 MPa and temperatures of 800, 900, 950, and 1000 °C. Yields of gasification products such as carbon monoxide and carbon dioxide, hydrogen and methane were calculated based on the kinetic curves of formation reactions of these products. Also carbon conversion degrees are presented. Moreover, calculations were made of the kinetic parameters of carbon monoxide and hydrogen formation reaction in the coal gasification process. The parameters obtained during the examinations enable a preliminary assessment of coal for the process of underground coal gasification.

Stanis?aw Porada; Grzegorz Czerski; Tadeusz Dziok; Przemys?aw Grzywacz; Dorota Makowska

2015-01-01T23:59:59.000Z

329

CP: AN INVESTIGATION OF COEFFICIENT OF THERMAL EXPANSION, DECOMPOSITION KINETICS, AND REACTION TO VARIOUS STIMULI  

SciTech Connect

The properties of pentaamine (5-cyano-2H-tetrazolato-N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook-off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear heating rates, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 10,000 psi and analyzed over a dynamic temperature range of -20 C to 70 C. Using differential scanning calorimetry, DSC, CP was decomposed at linear heating rates of 1, 3, and 7 C/min and the kinetic triplet calculated using the LLNL code Kinetics05. Values are also reported for spark, friction, and impact sensitivity.

Weese, R K; Burnham, A K; Fontes, A T

2005-03-23T23:59:59.000Z

330

Measurement-Measurement-  

E-Print Network (OSTI)

Internet Measurement- System A Measurement- System B Control System GPS Satellite GPS Satellite GPS Receiver GPS Receiver 2) measurement 3) data1) command Methodology for One-way IP Performance Measurement This paper proposes a methodology for measurement of one-way IP performance metrics such as one-way delay

Jeong, Jaehoon "Paul"

331

Pseudospin formulation of kinetic Ising models  

Science Journals Connector (OSTI)

It is shown that Glauber's kinetic Ising model is equivalent to an Ising model with multispin interactions in a transverse field. In one dimension, certain of Glauber's results are recovered by using the well-known fermion representation for spin-12.

Eric D. Siggia

1977-09-01T23:59:59.000Z

332

ERNSTMORITZARNDTUNIVERSITAT Absolute number density and kinetic analysis  

E-Print Network (OSTI)

and C2F4 molecules in pulsed CF4/H2 rf plasmas I n a u g u r a l d i s s e r t a t i o n zur Erlangung and kinetics of the target species in pulsed CF4/H2 rf plasmas 69 5.1 Plasma process parameters selected

Greifswald, Ernst-Moritz-Arndt-Universität

333

Kinetics of Anionic Surfactant Anoxic Degradation  

E-Print Network (OSTI)

) is the surfactant commonly used in space habitation. The two biofilm models differ in that one assumes a constant biofilm density and the other allows biofilm density changes based on space occupancy theory. Extant kinetic analysis of a mixed microbial culture using...

Camacho, Julianna G.

2010-07-14T23:59:59.000Z

334

STATISTICAL ANALYSIS OF PROTEIN FOLDING KINETICS  

E-Print Network (OSTI)

STATISTICAL ANALYSIS OF PROTEIN FOLDING KINETICS AARON R. DINNER New Chemistry Laboratory for Protein Folding: Advances in Chemical Physics, Volume 120. Edited by Richard A. Friesner. Series Editors Experimental and theoretical studies have led to the emergence of a unified general mechanism for protein

Dinner, Aaron

335

Chemical Kinetic Modeling of Non-Petroleum Based Fuels | Department...  

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

ft010pitz2011o.pdf More Documents & Publications Chemical Kinetic Modeling of Non-Petroleum Based Fuels Chemical Kinetic Modeling of Fuels Simulation of High Efficiency Clean...

336

Ethylbenzene dehydrogenation into styrene: kinetic modeling and reactor simulation  

E-Print Network (OSTI)

detailed kinetic model for coke formation and gasification, which was coupled to the kinetic model for the main reactions. The calculation of the dynamic equilibrium coke content provided a crucial guideline for the selection of the steam to ethylbenzene...

Lee, Won Jae

2007-04-25T23:59:59.000Z

337

Kinetic modelling of the thermal decomposition of ettringite into metaettringite  

E-Print Network (OSTI)

1 Kinetic modelling of the thermal decomposition of ettringite into metaettringite J. Pourchez recent insights into thermal stability and decomposition mechanisms of ettringite, a lack of knowledge isothermal conditions. Keywords: ettringite, metaettringite, thermal decomposition, kinetic modelling. 1

Boyer, Edmond

338

Parameter estimation for models of ligninolytic and cellulolytic enzyme kinetics  

SciTech Connect

While soil enzymes have been explicitly included in the soil organic carbon (SOC) decomposition models, there is a serious lack of suitable data for model parameterization. This study provides well-documented enzymatic parameters for application in enzyme-driven SOC decomposition models from a compilation and analysis of published measurements. In particular, we developed appropriate kinetic parameters for five typical ligninolytic and cellulolytic enzymes ( -glucosidase, cellobiohydrolase, endo-glucanase, peroxidase, and phenol oxidase). The kinetic parameters included the maximum specific enzyme activity (Vmax) and half-saturation constant (Km) in the Michaelis-Menten equation. The activation energy (Ea) and the pH optimum and sensitivity (pHopt and pHsen) were also analyzed. pHsen was estimated by fitting an exponential-quadratic function. The Vmax values, often presented in different units under various measurement conditions, were converted into the same units at a reference temperature (20 C) and pHopt. Major conclusions are: (i) Both Vmax and Km were log-normal distributed, with no significant difference in Vmax exhibited between enzymes originating from bacteria or fungi. (ii) No significant difference in Vmax was found between cellulases and ligninases; however, there was significant difference in Km between them. (iii) Ligninases had higher Ea values and lower pHopt than cellulases; average ratio of pHsen to pHopt ranged 0.3 0.4 for the five enzymes, which means that an increase or decrease of 1.1 1.7 pH units from pHopt would reduce Vmax by 50%. (iv) Our analysis indicated that the Vmax values from lab measurements with purified enzymes were 1 2 orders of magnitude higher than those for use in SOC decomposition models under field conditions.

Wang, Gangsheng [ORNL; Post, Wilfred M [ORNL; Mayes, Melanie [ORNL; Frerichs, Joshua T [ORNL; Jagadamma, Sindhu [ORNL

2012-01-01T23:59:59.000Z

339

Chemical Kinetics Research on HCCI and Diesel Fuels  

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

Discusses detailed chemical kinetics mechanisms for complex hydrocarbon fuels and computationally efficiecnt, accurate methodologies for modeling advanced combustion strategies.

340

Direct measurements of large near-band edge nonlinear index change from 1.48 to 1.55 m in InGaAsInAlGaAs multiquantum wells  

E-Print Network (OSTI)

used to measure di- rectly the nonlinear index change in bulk InGaAsP.10 Com- parison of DFWM results measurements of nonlinear refractive index change and nonlinear absorption in In0.530Al0.141Ga0.329As/In0.530Ga . The index-change-over-absorption figure of merit, F, is greater than unity over much of the spectrum

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


341

Rotational and divergent kinetic energy in the mesoscale model ALADIN  

E-Print Network (OSTI)

Rotational and divergent kinetic energy in the mesoscale model ALADIN By V. BLAZ ICA1 *, N. Z AGAR1 received 7 June 2012; in final form 7 March 2013) ABSTRACT Kinetic energy spectra from the mesoscale. It is shown that about 50% of kinetic energy in the free troposphere in ALADIN is divergent energy

Zagar, Nedjeljka

342

Worldwide Oil Production Michaelis-Menten Kinetics Correlation and Regression  

E-Print Network (OSTI)

Worldwide Oil Production Michaelis-Menten Kinetics Topic 4 Correlation and Regression Transformed Variables 1 / 13 #12;Worldwide Oil Production Michaelis-Menten Kinetics Outline Worldwide Oil Production Michaelis-Menten Kinetics Lineweaver-Burke double reciprocal plot 2 / 13 #12;Worldwide Oil Production

Watkins, Joseph C.

343

Ionization based multi-directional flow sensor  

DOE Patents (OSTI)

A method, system, and apparatus for conducting real-time monitoring of flow (airflow for example) in a system (a hybrid power generation system for example) is disclosed. The method, system and apparatus measure at least flow direction and velocity with minimal pressure drop and fast response. The apparatus comprises an ion source and a multi-directional collection device proximate the ion source. The ion source is configured to generate charged species (electrons and ions for example). The multi-directional collection source is configured to determine the direction and velocity of the flow in real-time.

Chorpening, Benjamin T. (Morgantown, WV); Casleton, Kent H. (Morgantown, WV)

2009-04-28T23:59:59.000Z

344

HTP kinetics studies on isolated elementary combustion reactions over wide temperature ranges  

SciTech Connect

The goals of this project are to provide accurate data on the temperature dependence of the kinetics of elementary combustion reactions, (i) for use by combustion modelers, and (ii) to gain a better fundamental understanding of, and hence predictive ability for, the chemistry involved. Experimental measurements are made mainly by using the pseudo-static HTP (high-temperature photochemistry) technique. While continuing rate coefficient measurements, further aspects of kinetics research are being explored. Thus, starting from the data obtained, a method for predicting the temperature dependence of rate coefficients of oxygen-atom olefin experiment and confirms the underlying mechanistic assumptions. Mechanistic information of another sort, i.e. by product analysis, has recently become accessible with the inauguration of our heated flow tube mass spectrometer facility; early results are reported here. HTP experiments designed to lead to measurements of product channels by resonance fluorescence have started.

Fontijn, A.; Adusei, G.Y.; Hranisavlevic, J.; Bajaj, P.N. [Rensselaer Polytechnic Institute, Troy, NY (United States)

1993-12-01T23:59:59.000Z

345

An experimental and kinetic modelling study of the oxidation of the four isomers of butanol  

E-Print Network (OSTI)

Butanol, an alcohol which can be produced from biomass sources, has received recent interest as an alternative to gasoline for use in spark ignition engines and as a possible blending compound with fossil diesel or biodiesel. Therefore, the autoignition of the four isomers of butanol (1-butanol, 2-butanol, iso-butanol, and tert-butanol) has been experimentally studied at high temperatures in a shock tube and a kinetic mechanism for description of their high-temperature oxidation has been developed. Ignition delay times for butanol/oxygen/argon mixtures have been measured behind reflected shock waves at temperatures and pressures ranging from approximately 1200 to 1800 K and 1 to 4 bar. Electronically excited OH emission and pressure measurements were used to determine ignition delay times. A detailed kinetic mechanism has been developed to describe the oxidation of the butanol isomers and validated by comparison to the shock tube measurements. Reaction flux and sensitivity analysis indicate that the consumpti...

Moss, J T; Oehlschlaeger, M A; Biet, Joffrey; Warth, Valérie; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique; 10.1021/jp806464p

2008-01-01T23:59:59.000Z

346

Departmental Directives Program  

Directives, Delegations, and Requirements

To define requirements and responsibilities for implementing the Department of Energy (DOE) Directives Program in support of the Secretary's memorandum of September 10, 2007, Principles Governing Departmental Directives. See also the current list of Directives Requiring Further Documentation, as required by Appendix D of this Order. Cancels DOE P 251.1A, DOE O 251.1B, DOE M 251.1-1B.

2007-09-10T23:59:59.000Z

347

ERROR ESTIMATIONS FOR INDIRECT MEASUREMENTS  

E-Print Network (OSTI)

Chapter 1 ERROR ESTIMATIONS FOR INDIRECT MEASUREMENTS: RANDOMIZED VS. DETERMINISTIC ALGORITHMS difficult or even impossible to directly measure the quantity in which we are interested: e.g., we cannot directly measure a distance to a distant galaxy or the amount of oil in a given well. Since we cannot

Kreinovich, Vladik

348

Directives System Manual  

Directives, Delegations, and Requirements

This Manual provides detailed requirements to supplement DOE O 251.1, which establishes requirements for the development, coordination, and sunset review of DOE directives.

1995-10-16T23:59:59.000Z

349

Departmental Directives Program  

Directives, Delegations, and Requirements

To establish directives as the primary means to set, communicate, and institutionalize policies, requirements, responsibilities, and procedures for Departmental elements and contractors.

2014-10-16T23:59:59.000Z

350

Ion kinetic effects on the ignition and burn of ICF targets  

E-Print Network (OSTI)

In this Article, we study the hydrodynamics and burn of the thermonuclear fuel in inertial confinement fusion pellets at the ion kinetic level. The analysis is based on a two-velocity-scale Vlasov-Fokker-Planck kinetic model that is specially tailored to treat fusion products (suprathermal {\\alpha}-particles) in a self-consistent manner with the thermal bulk. The model assumes spherical symmetry in configuration space and axial symmetry in velocity space around the mean flow velocity. Compared to fluid simulations where a multi-group diffusion scheme is applied to model {\\alpha} transport, the full ion-kinetic approach reveals significant non-local effects on the transport of energetic $\\alpha$-particles. This has a direct impact on hydrodynamic spatial profiles during combustion: the hot spot reactivity is reduced, while the inner dense fuel layers are preheated by the escaping {\\alpha}-suprathermal particles, which are transported farther out of the hot spot. We show how the kinetic transport enhancement of...

Peigney, Benjamin-Edouard; Tikhonchuk, Vladimir

2014-01-01T23:59:59.000Z

351

Wellbore inertial directional surveying system  

DOE Patents (OSTI)

A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single off-shore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on the electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block aboutthe gimbal axis. Angular rates of the sensor block about axes which are perpendicular to the gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and anular rate information. Kalman estimation techniques are used to compensate for system errors.

Andreas, Ronald D. (Albuquerque, NM); Heck, G. Michael (Albuquerque, NM); Kohler, Stewart M. (Albuquerque, NM); Watts, Alfred C. (Albuquerque, NM)

1991-01-01T23:59:59.000Z

352

Wellbore inertial directional surveying system  

DOE Patents (OSTI)

A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single offshore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on an electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block about the gimbal axis. Angular rates of the sensor block about axes which are perpendicular to te gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and angular rate information. Kalman estimation techniques are used to compensate for system errors. 25 figures.

Andreas, R.D.; Heck, G.M.; Kohler, S.M.; Watts, A.C.

1982-09-08T23:59:59.000Z

353

E-Print Network 3.0 - approximate kinetic equations Sample Search...  

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

equation. Reactor kinetics and Summary: equations, prompt jump approximation; subcritical reactor kinetics, circulating fuel reactor dynamics 5... solution to neutron...

354

Directional detection of dark matter streams  

Science Journals Connector (OSTI)

Directional detection of weakly interacting massive particles, in which the energies and directions of the recoiling nuclei are measured, currently presents the only prospect for probing the local velocity distribution of Galactic dark matter. We investigate the extent to which future directional detectors would be capable of probing dark matter substructure in the form of streams. We analyze the signal expected from a Sagittarius-like stream and also explore the full parameter space of stream speed, direction, dispersion and density. Using a combination of nonparametric directional statistics, a profile likelihood ratio test and Bayesian parameter inference we find that within acceptable exposure times [O(10)??kg?yr for cross sections just below the current exclusion limits] future directional detectors will be sensitive to a wide range of stream velocities and densities. We also examine and discuss the importance of the energy window of the detector.

Ciaran A.?J. O’Hare and Anne M. Green

2014-12-08T23:59:59.000Z

355

Ion mediated crosslink driven mucous swelling kinetics  

E-Print Network (OSTI)

We present an experimentally guided, multi-phasic, multi-species ionic gel model to compare and make qualitative predictions on the rheology of mucus of healthy individuals (Wild Type) versus those infected with Cystic Fibrosis. The mixture theory consists of the mucus (polymer phase) and water (solvent phase) as well as several different ions: H+, Na+ and Ca++. The model is linearized to study the hydration of spherically symmetric mucus gels and calibrated against the experimental data of mucus diffusivities. Near equilibrium, the linearized form of the equation describing the radial size of the gel, reduces to the well-known expression used in the kinetic theory of swelling hydrogels. Numerical studies reveal that the Donnan potential is the dominating mechanism driving the mucus swelling/deswelling transition. However, the altered swelling kinetics of the Cystic Fibrosis infected mucus is not merely governed by the hydroelectric composition of the swelling media, but also due to the altered movement of el...

Sircar, S

2015-01-01T23:59:59.000Z

356

ET Kinetics of Bifunctional Redox Protein Maquettes  

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

Kinetics of Bifunctional Redox Protein Maquettes Kinetics of Bifunctional Redox Protein Maquettes Mitchell W. Mutz, James F. Wishart and George L. McLendon Adv. Chem Ser. 254, Ch. 10, pp. 145-159 Abstract: We prepared three bifunctional redox protein maquettes based on 12-, 16-, and 20-mer three-helix bundles. In each case, the helix was capped with a Co(III) tris-bipyridyl electron acceptor and also functionalized with a C-terminal viologen (1-ethyl-1'-ethyl-4,4'-bipyridinium) donor. Electron transfer (ET) was initiated by pulse radiolysis and flash photolysis and followed spectrometrically to determined average, concentration-independent, first-order rates for the 16-mer and 20-mer maquettes. For the 16-mer bundle, the alpha-helical content was adjusted by the addition of urea or trifluoroethanol to solutions containing the metalloprotein. This

357

Competitive ion kinetics in direct mass spectrometric organic speciation. 1993 Progress report  

SciTech Connect

The following joint projects are either in progress, or have been completed. (1) Southern Illinois University, Prof. S. Scheiner--Combined experimental-theoretical study of the thermochemistry of protonation, complexation, and hydration of di- and polyfunctional ethers. (2) Eastern illinois University, Prof. C. Deakyne--Essentially the same framework as above. The focus here was to determine whether C or N lone pair electrons were more effective in forming ionic hydrogen bonds. (3) Virginia Commonwealth University-Prof. S. El-Shall--The author put the wrap on a joint thermochemical (NIST) and beam expansion study (VCU) which probed structures and stabilities of methanol clusters incorporating either CH{sub 3}CN or (CH{sub 3}){sub 3}N. MeCN and TMA were chosen because of their widely differing proton affinities (PA`s) and the fact that they form single H-bonds (i.e., complex intraclusters involving multiple bonding are unlikely). (4) University of Maryland-Baltimore County-Prof. J. Liebman and the Phillips Laboratory Supercomputer Center, Kirtland Air Force Base, NM-A. Fant--One of the most perplexing problems among physical organic chemists has involved the site of protonation of a class of molecules referred to as quinones and, in particular, the symmetric member, para-benzoquinone, C{sub 6}H{sub 4} (=O{sub 2}), designated below as PBQ. Possible protonation sites either the ring or carbonyl function.

Sieck, L.W.

1993-12-31T23:59:59.000Z

358

Kinetic Ising Model of the Glass Transition  

Science Journals Connector (OSTI)

A graph theory of single-spin-flip kinetic Ising models is developed and applied to a class of spin models with strongly cooperative dynamics. Self-consistent approximations for the spin time correlation function are presented. One of the dynamical models exhibits a glass transition with no underlying thermodynamic singularity. The approximation for the time correlation function predicts a critical temperature, below which small fluctuations from equilibrium in the thermodynamic limit cannot relax in a finite amount of time.

Glenn H. Fredrickson and Hans C. Andersen

1984-09-24T23:59:59.000Z

359

Chemical kinetics models for semiconductor processing  

SciTech Connect

Chemical reactions in the gas-phase and on surfaces are important in the deposition and etching of materials for microelectronic applications. A general software framework for describing homogeneous and heterogeneous reaction kinetics utilizing the Chemkin suite of codes is presented. Experimental, theoretical and modeling approaches to developing chemical reaction mechanisms are discussed. A number of TCAD application modules for simulating the chemically reacting flow in deposition and etching reactors have been developed and are also described.

Coltrin, M.E.; Creighton, J.R. [Sandia National Labs., Albuquerque, NM (United States); Meeks, E.; Grcar, J.F.; Houf, W.G. [Sandia National Labs., Livermore, CA (United States); Kee, R.J. [Colorado School of Mines, Golden, CO (United States)

1997-12-31T23:59:59.000Z

360

Model of the Kinetics of Polymorphous Crystallization  

Science Journals Connector (OSTI)

We propose a phase-field model for the kinetics of isothermal crystallization of an amorphous solid at a concentration nearly equal to the equilibrium crystal stochiometry. The model utilizes two coupled fields: a nonconserved ordering vector field which describes the local lattice structure and a conserved nonordering scalar field describing the local atomic composition. Results of large-scale computer simulations are reported which can be compared with experiments.

B. Morin; K. R. Elder; M. Sutton; Martin Grant

1995-09-11T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Kinetics of atoms in a bichromatic field  

SciTech Connect

The kinetics of atoms in a bichromatic field is considered. Analytic solutions are obtained for the force, friction coefficient, and diffusion coefficient in the model of a two-level atom without limitations imposed on the intensity of light fields. This effect is observed in the domain of global minima and maxima of the optical potential (i.e., at points where the relative phase of two standing waves is Greek-Phi-Symbol = 0, {pi}/2.

Prudnikov, O. N., E-mail: llf@laser.nsc.ru [Novosibirsk State University (Russian Federation); Baklanov, A. S. [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation); Taichenachev, A. V. [Novosibirsk State University (Russian Federation)] [Novosibirsk State University (Russian Federation); Tumaikin, A. M. [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation); Yudin, V. I. [Novosibirsk State University (Russian Federation)] [Novosibirsk State University (Russian Federation)

2013-08-15T23:59:59.000Z

362

Ripping Graphene: Preferred Directions  

Science Journals Connector (OSTI)

Ripping Graphene: Preferred Directions ... Here we present experimental and theoretical studies on cracks or tears in suspended monolayer graphene membranes. ... Edges from mechanically induced ripping exhibit straight lines and are predominantly aligned in the armchair or zigzag directions of the graphene lattice. ...

Kwanpyo Kim; Vasilii I. Artyukhov; William Regan; Yuanyue Liu; M. F. Crommie; Boris I. Yakobson; A. Zettl

2011-12-12T23:59:59.000Z

363

Departmental Directives System  

Directives, Delegations, and Requirements

The order establishes the directives system to be used for publishing permanent and temporary directives issued by DOE Headquarters and addressed to Headquarters and/or field elements. Chg 1 dated 3-14-85. Cancels DOE 1321.1A.

1983-04-07T23:59:59.000Z

364

ARM - Measurement - Cloud fraction  

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

to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud fraction Fraction of sky covered by clouds, observed directly or derived from SW...

365

Isothermal kinetics of new Albany oil shale  

SciTech Connect

From the development of technologies for the utilization of eastern U.S. oil shales, fluidized bed pyrolysis technology is emerging as one of the most promising in terms of oil yield, operating cost, and capital investment. Bench-scale testing of eastern shales has reached a level where scale-up represents the next logical step in the evolution of this technology. A major consideration in this development and an essential part of any fluidized bed reactor scale-up effort--isothermal kinetics-- has largely been ignored for eastern US shale with the exception of a recent study conducted by Richardson et al. with a Cleveland shale. The method of Richardson et al. was used previously by Wallman et al. with western shale and has been used most recently by Forgac, also with western shale. This method, adopted for the present study, entails injecting a charge of shale into a fluidized bed and monitoring the hydrocarbon products with a flame ionization detector (FID). Advantages of this procedure are that fluidized bed heat-up effects are simulated exactly and real-time kinetics are obtained due to the on-line FID. Other isothermal methods have suffered from heat-up and cool-down effects making it impossible to observe the kinetics at realistic operating temperatures. A major drawback of the FID approach, however, is that no differentiation between oil and gas is possible.

Carter, S.D.

1987-04-01T23:59:59.000Z

366

Kinetic regulation of coated vesicle secretion  

E-Print Network (OSTI)

The secretion of vesicles for intracellular transport often rely on the aggregation of specialized membrane-bound proteins into a coat able to curve cell membranes. The nucleation and growth of a protein coat is a kinetic process that competes with the energy-consuming turnover of coat components between the membrane and the cytosol. We propose a generic kinetic description of coat assembly and the formation of coated vesicles, and discuss its implication to the dynamics of COP vesicles that traffic within the Golgi and with the Endoplasmic Reticulum. We show that stationary coats of fixed area emerge from the competition between coat growth and the recycling of coat components, in a fashion resembling the treadmilling of cytoskeletal filaments. We further show that the turnover of coat components allows for a highly sensitive switching mechanism between a quiescent and a vesicle producing membrane, upon a slowing down of the exchange kinetics. We claim that the existence of this switching behaviour, also triggered by factors such as the presence of cargo and variation of the membrane mechanical tension, allows for efficient regulation of vesicle secretion. We propose a model, supported by different experimental observations, in which vesiculation of secretory membranes is impaired by the energy consuming desorption of coat proteins, until the presence of cargo or other factors triggers a dynamical switch into a vesicle producing state.

Lionel Foret; Pierre Sens

2008-07-28T23:59:59.000Z

367

direct_deposit_111609  

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

PROTECT YOUR BANKING INFORMATION: PROTECT YOUR BANKING INFORMATION: DO NOT complete this form until you are ready to submit it to the Payroll Department. DIRECT DEPOSIT REQUEST Directions: 1. Provide required information neatly, legibly; 2. If Checking Account Direct Deposit, include a voided check. a. DO NOT submit a deposit slip! 3. If Savings Account Direct Deposit, include a copy of savings card. 4. Sign this form; 5. Inter-office mail it to Craft Payroll at "P238." DIRECT DEPOSITION AUTHORIZATION I hereby authorize Los Alamos National Laboratory, hereinafter called The Laboratory, to initiate credit entries and, if necessary, debit entries and adjustments for any credit entries in error to my account listed on this form. If deposit is for:

368

Directions and Maps  

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

Directions & Maps Directions & Maps Plan Your Visit Visit About the Museum Museum Hours Directions & Maps When to Visit Arrange for a Visit Around Los Alamos Contact Us invisible utility element Directions and Maps Aerial View of Los Alamos Aerial approach to the Los Alamos airport Where we're located Los Alamos (elevation 7,355 feet) is perched high atop the Pajarito Plateau in the Jemez Mountains, 35 miles northwest of Santa Fe. The Bradbury Science Museum is located in downtown Los Alamos at the corner of Central Avenue and 15th Street. If you're driving here and using GPS navigation, our address is 1350 Central Avenue, Los Alamos, NM 87544. How to get here From Albuquerque take I-25 north to Santa Fe (take NM 599 for most direct route), then US 84/285 north to Pojoaque. At Pojoaque take the NM 502 exit

369

Direct Discharge Permit (Vermont)  

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

A direct discharge permit is required if a project involves the discharge of pollutants to state waters. For generation purposes, this involves the withdrawal of surface water for cooling purposes...

370

Surface Wind Direction Variability  

Science Journals Connector (OSTI)

Common large shifts of wind direction in the weak-wind nocturnal boundary layer are poorly understood and are not adequately captured by numerical models and statistical parameterizations. The current study examines 15 datasets representing a ...

Larry Mahrt

2011-01-01T23:59:59.000Z

371

Art Directable Tornadoes  

E-Print Network (OSTI)

......................................................................... 25 2. Directional Force ........................................................... 26 3. Vortex Force .................................................................. 26 4. Lattice... ................................................................... 7 7 Tornado in its rope stage before disappearing ........................................... 9 8 Fire vortex and Waterspout ........................................................................ 10 9 Landspout and Gustnado...

Dwivedi, Ravindra

2011-08-08T23:59:59.000Z

372

The Excitation Energy Dependence of the Total Kinetic Energy Release in 235U(n,f)  

E-Print Network (OSTI)

The total kinetic energy release in the neutron induced fission of $^{235}$U was measured (using white spectrum neutrons from LANSCE) for neutron energies from E$_{n}$ = 3.2 to 50 MeV. In this energy range the average post-neutron total kinetic energy release drops from 167.4 $\\pm$ 0.7 to 162.1 $\\pm$ 0.8 MeV, exhibiting a local dip near the second chance fission threshold. The values and the slope of the TKE vs. E$_{n}$ agree with previous measurements but do disagree (in magnitude) with systematics. The variances of the TKE distributions are larger than expected and apart from structure near the second chance fission threshold, are invariant for the neutron energy range from 11 to 50 MeV. We also report the dependence of the total excitation energy in fission, TXE, on neutron energy.

R. Yanez; L. Yao; J. King; W. Loveland; F. Tovesson; N. Fotiades

2014-03-18T23:59:59.000Z

373

Phi-values in protein folding kinetics have energetic and structural components  

E-Print Network (OSTI)

Phi-values are experimental measures of how the kinetics of protein folding is changed by single-site mutations. Phi-values measure energetic quantities, but are often interpreted in terms of the structures of the transition state ensemble. Here we describe a simple analytical model of the folding kinetics in terms of the formation of protein substructures. The model shows that Phi-values have both structural and energetic components. In addition, it provides a natural and general interpretation of "nonclassical" Phi-values (i.e., less than zero, or greater than one). The model reproduces the Phi-values for 20 single-residue mutations in the alpha-helix of the protein CI2, including several nonclassical Phi-values, in good agreement with experiments.

Claudia Merlo; Ken A. Dill; Thomas R. Weikl

2005-07-14T23:59:59.000Z

374

Energy Conservation Tests of a Coupled Kinetic-kinetic Plasma-neutral Transport Code  

SciTech Connect

A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.

D.P. Stotler, C.S. Chang, S.H. Ku, J. Lang and G. Park

2012-08-29T23:59:59.000Z

375

Pedestal Fueling Simulations with a Coupled Kinetic-kinetic Plasma-neutral Transport Code  

SciTech Connect

A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.

D.P. Stotler, C.S. Chang, S.H. Ku, J. Lang and G.Y. Park

2012-08-29T23:59:59.000Z

376

Refrigerant directly cooled capacitors  

DOE Patents (OSTI)

The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

Hsu, John S. (Oak Ridge, TN); Seiber, Larry E. (Oak Ridge, TN); Marlino, Laura D. (Oak Ridge, TN); Ayers, Curtis W. (Kingston, TN)

2007-09-11T23:59:59.000Z

377

New Directions in Direct Dark Matter Searches  

E-Print Network (OSTI)

I present the status of direct dark matter detection with specific attention to the experimental results and their phenomenological interpretation in terms of dark matter interactions. In particular I review a new and more general approach to study signals in this field based on non-relativistic operators which parametrize more efficiently the dark matter-nucleus interactions in terms of a very limited number of relevant degrees of freedom. Then I list the major experimental results, pointing out the main uncertainties that affect the theoretical interpretation of the data. Finally, since the underlying theory that describes both the dark matter and the standard model fields is unknown, I address the uncertainties coming from the nature of the interaction. In particular, the phenomenology of a class of models in which the interaction between dark matter particles and target nuclei is of a long-range type is discussed.

Paolo Panci

2014-02-06T23:59:59.000Z

378

Advances and new directions in direct liquefaction  

SciTech Connect

With advance in single stage processes such as H-Coal, EDS and SRC, and refining and upgrading of coal liquids by Chevron and UOP, the direct liquefaction process has continuously evolved to the present two-stage catalytic configuration, which produces the highest liquid yield and product quality of any process worldwide. The Two Stage Liquefaction (TSL) process has been successfully applied to bituminous and subbituminous coals, overcoming problems associated with earlier processes. But, potential for additional improvement is recognized in several areas: cleaning coal prior to liquefaction; low temperature and pressure preconditioning of feed coal; novel catalysts development to arrest regressive reactions and improve hydrotreatment and cracking reactions; improvement in hydrocarbon value recovery and reduced energy rejection by alternate bottoms processing techniques. In this paper, after discussing briefly the history of liquefaction and development of the TSL process, present potential areas for research and development are presented.

Rao, S.N.; Schindler, H.D.; McGurl, G.V.

1988-01-01T23:59:59.000Z

379

Is the directed flow in heavy-ion collisions a puzzle ?  

E-Print Network (OSTI)

Recent STAR data for the directed flow of protons, antiprotons and charged pions obtained within the beam energy scan program are analyzed within the Parton-Hadron-String-Dynamics (PHSD/HSD) transport models and a 3-Fluid hydroDynamics (3FD) approach. Both versions of the kinetic approach, HSD and PHSD, are used to clarify the role of partonic degrees of freedom. The PHSD results, simulating a partonic phase and its coexistence with a hadronic one, are roughly consistent with data. The hydrodynamic results are obtained for two Equation of States (EoS), a pure hadronic EoS and an EoS with a crossover type transition. The latter case is favored by the STAR experimental data. Special attention is paid to the description of antiproton directed flow based on the balance of $p\\bar{p}$ annihilation and the inverse processes for $p\\bar{p}$ pair creation from multi-meson interactions. Generally, the semi-qualitative agreement between the measured data and model results supports the idea of a crossover type of quark-ha...

Konchakovski, V P; Ivanov, Yu B; Toneev, V D

2014-01-01T23:59:59.000Z

380

Initiation Mechanisms and Kinetics of Pyrolysis and Combustion of JP-10 Hydrocarbon Jet Fuel  

Science Journals Connector (OSTI)

Initiation Mechanisms and Kinetics of Pyrolysis and Combustion of JP-10 Hydrocarbon Jet Fuel ... We found that the primary decomposition reactions involve either (1) dissociation of ethylene from JP-10, resulting in the formation of a C8 hydrocarbon intermediate, or (2) the production of two C5 hydrocarbons. ... Heats of combustion (kcal/mole) were measured via O bomb calorimetry; adamantane (I) (c), -1441.95 ...

Kimberly Chenoweth; Adri C. T. van Duin; Siddharth Dasgupta; William A. Goddard III

2009-02-11T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Chemical Kinetic Reaction Mechanisms for Combustion of Hydrocarbon and Other Types of Chemical Fuels  

DOE Data Explorer (OSTI)

Reaction mechanisms have been tested and validated extensively through comparisons between computed results and measured data from laboratory experiments (e.g., shock tubes, laminar flames, rapid compression machines, flow reactors, stirred reactors) and from practical systems (e.g., diesel engines, spark-ignition engines, homogeneous charge, compression ignition (HCCI) engines). These kinetic models are used to examine a wide range of combustion systems.[Taken from https://www-pls.llnl.gov/?url=science_and_technology-chemistry-combustion

382

Kinetic simulation of heterogeneous catalytic processes: Ethane hydrogenolysis over supported group VIII metals  

SciTech Connect

A kinetic model for ethane hydrogenolysis over Pt, Pd, Ir, and Co was formulated in terms of essentially two chemical parameters: the strength of bonding between atomic hydrogen and the metal surface and the strength of carbon-metal bonding between hydrocarbon fragments and the surface. These two surface bond strengths were estimated by calorimetric measurements of the heats of H{sub 2} and CO adsorption, combined with bond order conservation calculations. The results of the kinetic simulations suggest that ethane hydrogenolysis over Pt, Pd, Ir and Co takes place through irreversible C-C rupture of C{sub 2}H{sub 4} and C{sub 2}H{sub 3} surface species. Hydrogenation of monocarbon CH{sub y} fragments is kinetically insignificant. Dissociative adsorption of hydrogen is an equilibrated process, while dissociative adsorption of ethane is slow and reversible. Finally, the role of kinetic modeling in the formulation, interpretation, and generalization of experimental research in heterogeneous catalysis is discussed.

Goddard, S.A.; Amiridis, M.D.; Rekoske, J.E.; Cardona-Martinez, N.; Dumesic, J.A. (Univ. of Wisconsin, Madison (USA))

1989-05-01T23:59:59.000Z

383

ARM - PI Product - Direct Aerosol Forcing Uncertainty  

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

ProductsDirect Aerosol Forcing Uncertainty ProductsDirect Aerosol Forcing Uncertainty Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Direct Aerosol Forcing Uncertainty Site(s) NSA SGP TWP General Description Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in

384

Kinetic equation for the Ising model  

Science Journals Connector (OSTI)

A time-dependent projection-operator formalism is used to derive a kinetic equation for the single-spin density operator in an Ising system of N two-state spins in weak interaction with a heat bath. This equation contains a contribution at the self-consistent-field level and also higher-order contributions due to dynamically generated correlations. A detailed evaluation of the self-consistent-field terms is made. Possibilities for generalizing the method to obtain equations for multispin density operators are discussed.

Michael R. Emptage; Paul Hawrylak; Subir K. Bose

1982-12-01T23:59:59.000Z

385

Hamiltonian approach to kinetic Ising models  

Science Journals Connector (OSTI)

In the framework of the quantum approach to stochastic dynamics, the master equations governing the temporal evolution of the kinetic Ising models (KIM) are cast in the form of imaginary-time Schrödinger equations with second-quantized Hermitian Hamiltonians. On the basis of the quantum formalism a classical evolution equation is derived for an effective time-dependent Ising-type Hamiltonian. The grand ensemble corresponding to the latter describes the statistics of the spin configurations evolving under the dynamics of the KIM. The latter approach was used to qualitatively explain the results of recent Monte Carlo simulations of the Kawasaki KIM. © 1996 The American Physical Society.

V. I. Tokar

1996-02-01T23:59:59.000Z

386

Studies of combustion kinetics and mechanisms  

SciTech Connect

The objective of the current research is to gain new quantitative knowledge of the kinetics and mechanisms of polyatomic free radicals which are important in hydrocarbon combustion processes. The special facility designed and built for these (which includes a heatable tubular reactor coupled to a photoionization mass spectrometer) is continually being improved. Where possible, these experimental studies are coupled with theoretical ones, sometimes conducted in collaboration with others, to obtain an improved understanding of the factors determining reactivity. The decomposition of acetyl radicals, isopropyl radicals, and n-propyl radicals have been studied as well as the oxidation of methylpropargyl radicals.

Gutman, D. [Catholic Univ. of America, Washington, DC (United States)

1993-12-01T23:59:59.000Z

387

Kinetic equilibration from a radiative transport  

E-Print Network (OSTI)

Kinetic equilibration during the early stage of a relativistic heavy ion collision is studied using a radiative transport model. Thermalization is found to dominate over expansion with medium regulated cross sections. Pressure anisotropy shows an approximate alpha_s scaling when radiative processes are included. It approaches an asymptotic time evolution on a time scale of 1 to 2 fm/c. Energy density is also found to approach an asymptotic time evolution that decreases slower than the ideal hydro evolution. These observations indicate that viscosity is important during the early longitudinal expansion phase of a relativistic heavy ion collision.

Bin Zhang

2009-03-11T23:59:59.000Z

388

Approximate von Neumann entropy for directed graphs  

Science Journals Connector (OSTI)

In this paper, we develop an entropy measure for assessing the structural complexity of directed graphs. Although there are many existing alternative measures for quantifying the structural properties of undirected graphs, there are relatively few corresponding measures for directed graphs. To fill this gap in the literature, we explore an alternative technique that is applicable to directed graphs. We commence by using Chung's generalization of the Laplacian of a directed graph to extend the computation of von Neumann entropy from undirected to directed graphs. We provide a simplified form of the entropy which can be expressed in terms of simple node in-degree and out-degree statistics. Moreover, we find approximate forms of the von Neumann entropy that apply to both weakly and strongly directed graphs, and that can be used to characterize network structure. We illustrate the usefulness of these simplified entropy forms defined in this paper on both artificial and real-world data sets, including structures from protein databases and high energy physics theory citation networks.

Cheng Ye; Richard C. Wilson; César H. Comin; Luciano da F. Costa; Edwin R. Hancock

2014-05-12T23:59:59.000Z

389

Adding linear kinetic effects to existing finite-difference simulations  

SciTech Connect

We present the proof-of-principle KINETIC-J module for iterative addition of all-order kinetic effects (parallel and perpendicular) in both the IC and EC frequency ranges, to any existing FD or FE frequency-domain full-wave RF simulation. The module calculates the linear, kinetic plasma current, such that given f 0 (r,v) and the cold plasma solution as an initial guess at the wave electric field, iterating the KINETIC-J module and the existing code (its internal plasma current replaced with the output of the module) converges to the kinetic solution. Since KINETIC-J does not use the k-space representation of the hot plasma dielectric, in favor of data parallel numeric integrals, implementing the module requires minimal code changes.

Green, David L [ORNL; Berry, Lee Alan [XCEL Engineering Inc., Oak Ridge

2013-01-01T23:59:59.000Z

390

Vlasov simulations of Kinetic Alfv\\'en Waves at proton kinetic scales  

E-Print Network (OSTI)

Kinetic Alfv\\'en waves represent an important subject in space plasma physics, since they are thought to play a crucial role in the development of the turbulent energy cascade in the solar wind plasma at short wavelengths (of the order of the proton inertial length $d_p$ and beyond). A full understanding of the physical mechanisms which govern the kinetic plasma dynamics at these scales can provide important clues on the problem of the turbulent dissipation and heating in collisionless systems. In this paper, hybrid Vlasov-Maxwell simulations are employed to analyze in detail the features of the kinetic Alfv\\'en waves at proton kinetic scales, in typical conditions of the solar wind environment. In particular, linear and nonlinear regimes of propagation of these fluctuations have been investigated in a single-wave situation, focusing on the physical processes of collisionless Landau damping and wave-particle resonant interaction. Interestingly, since for wavelengths close to $d_p$ and proton plasma beta $\\bet...

Vasconez, C L; Camporeale, E; Veltri, P

2014-01-01T23:59:59.000Z

391

Direct CP violation in B decays  

E-Print Network (OSTI)

We review recent experimental results on direct CP violation. The hot topic is a measurement in charmless two-body decays of B0, B+. In connection to this the first analogous measurements in Bs0 and Lambda_b0 decays are now available. Furthermore first evidence for direct CP violation in B+ decays is obtained from Dalitz plot analyzes of the K+pi-pi+ final state at B-factories. The last group of discussed results probes the b -> c\\bar{c}d transition in attempt to resolve the discrepancy between Belle and BABAR experiments in CP violation in the B0 -> D+D- decays.

M. Kreps

2008-06-30T23:59:59.000Z

392

3.205 Thermodynamics and Kinetics of Materials, Fall 2003  

E-Print Network (OSTI)

Laws of thermodynamics applied to materials and materials processes. Solution theory. Equilibrium diagrams. Overview of fluid transport processes. Kinetics of processes that occur in materials, including diffusion, phase ...

Allen, Samuel M.

393

Simulations of Kinetic Events at the Atomic Scale  

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

Presentation on the Simulations of Kinetic Events at the Atomic Scale given at the DOE Theory Focus Session on Hydrogen Storage Materials on May 18, 2006.

394

Kinetics, Mechanics and Microstructure Changes in Storage Media  

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

Focus Session on Hydrogen Storage DOE Hydrogen Program Review Crystal Gateway Marriott, Crystal City, VA May 18, 2006 Kinetics, Mechanics and Microstructure Changes in Storage...

395

Extraction of Equilibrium Energy and Kinetic Parameters from...  

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

Investigator for the Extraction of Equilibrium Energy and Kinetic Parameters from Single Molecule Force Spectroscopy Data. LLNL BES Programs Highlight Extraction of...

396

Micro Hydro Kinetic Turbines from Smart Hydro Power | Open Energy...  

Open Energy Info (EERE)

to the MHK database homepage Retrieved from "http:en.openei.orgwindex.php?titleMicroHydroKineticTurbinesfromSmartHydroPower&oldid720939" Category: Marine and...

397

Kinetics, Mechanics and Microstructure Changes in Storage Media  

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

Presentation on the Kinetics, Mechanics and Microstructure Changes in Storage Media given at the DOE Theory Focus Session on Hydrogen Storage Materials on May 18, 2006.

398

Chemical kinetics parameters of nuclear graphite gasification  

Science Journals Connector (OSTI)

This paper provides chemical kinetics parameters for the gasification of nuclear graphite grades of IG-110, IG-430, NBG-18 and NBG-25 and presents empirical correlations for their surface areas of free active sites as a function of mass. The kinetics parameters for the four elementary chemical reactions of gasification of these grades of nuclear graphite include the values and Gaussian distributions of the specific activation energies and the values of the pre-exponential rate coefficients for the adsorption of oxygen and desorption of CO and CO2 gases. The values of these parameters and the surface area of free active sites for IG-110 and NB-25, with fine and medium petroleum coke filler particles, are nearly the same, but slightly different from those of NBG-18 and IG-430, with medium and fine coal tar pitch coke filler particles. Recommended parameters are applicable to future safety analysis of high and very high temperature gas cooled reactors in the unlikely event of a massive air ingress accident.

Mohamed S. El-Genk; Jean-Michel P. Tournier

2013-01-01T23:59:59.000Z

399

Ion mediated crosslink driven mucous swelling kinetics  

E-Print Network (OSTI)

We present an experimentally guided, multi-phasic, multi-species ionic gel model to compare and make qualitative predictions on the rheology of mucus of healthy individuals (Wild Type) versus those infected with Cystic Fibrosis. The mixture theory consists of the mucus (polymer phase) and water (solvent phase) as well as several different ions: H+, Na+ and Ca++. The model is linearized to study the hydration of spherically symmetric mucus gels and calibrated against the experimental data of mucus diffusivities. Near equilibrium, the linearized form of the equation describing the radial size of the gel, reduces to the well-known expression used in the kinetic theory of swelling hydrogels. Numerical studies reveal that the Donnan potential is the dominating mechanism driving the mucus swelling/deswelling transition. However, the altered swelling kinetics of the Cystic Fibrosis infected mucus is not merely governed by the hydroelectric composition of the swelling media, but also due to the altered movement of electrolytes as well as due to the defective properties of the mucin polymer network.

S. Sircar; A. J. Roberts

2015-01-20T23:59:59.000Z

400

Acifluorfen Sorption and Sorption Kinetics in Soil  

Science Journals Connector (OSTI)

The time-dependent increase in sorbed acifluorfen up to 48 h was described by a two-site equilibrium/kinetic model where Si is sorbed concentration (?mol kg-1), C is solution concentration (?M), ke (L kg-1) is the coefficient for sorption at sites 1 exhibiting instantaneous equilibrium, kf (L kg-1 h-1) and kr (h-1) are rate constants for sorption and desorption, respectively, from sites 2, 1/N accounts for sorption nonlinearity, and t (h) is time. ... Alternatively, acifluorfen degradation and time-dependent sorption of metabolites may be qualitatively described by assuming first-order kinetics: where P is the solution concentration of all metabolic products (?M), SP is concentration of sorbed metabolite (?mol kg-1), kd (h-1) and kp (h-1) are first-order rate constants for substrate degradation and metabolite sorption, respectively, v is solution volume (L), and m is sorbent mass (kg). ... All sorption isotherms were nonlinear and exponent (1/N) values less than 1 (Table 1), indicating decreasing fraction sorbed with increasing initial acifluorfen concentration. ...

Martin A. Locke; Lewis A. Gaston; Robert M. Zablotowicz

1997-01-20T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" 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

Electron Paramagnetic Resonance Stopped-Flow Kinetic Study of Manganese(II) Sorption--Desorption on Birnessite  

E-Print Network (OSTI)

Electron Paramagnetic Resonance Stopped-Flow Kinetic Study of Manganese(II) Sorption- nique is demonstrated by investigating the sorption of Mn2+ on S- MnOj. The sorption reaction+ was observed. Measurement of the initial reaction rate al- lowed the forward (sorption) rate constant

Sparks, Donald L.

402

Direct measurements of methoxy removal rate constants for collisions with CH/sub 4/, Ar, N/sub 2/, Xe, and CF/sub 4/ in the temperature range 673--973K  

SciTech Connect

Removal rate constants for CH/sub 3/O by CH/sub 4/, Ar, N/sub 2/, Xe, and CF/sub 4/ were measured over a 400K temperature range using a laser photolysis/laser-induced fluorescence technique. Rapid methoxy removal rates are observed for the non-reactive collision partners (Ar, N/sub 2/, Xe, and CF/sub 4/) at elevated temperatures showing that the dissociation and isomerization channels for CH/sub 3/O are indeed important. The total removal rate constant (reaction /plus/ dissociation and/or isomerization) for CH/sub 4/ exhibits a linear dependence on temperature and has a removal rate constant, k/sub r/ /equals/ (1.2 +- 0.6) /times/ 10/sup /minus/8/exp((/minus/101070 +- 350)/T)cm/sup 3/molecule/sup /minus/1/s/sup /minus/1/. Assuming that the removal rate constant due to dissociation and/or isomerization are similar for CH/sub 4/ and CF/sub 4/, the reaction rate constant for CH/sub 3/O /plus/ CH/sub 4/ is equal to (1.7 +- 1.0) /times/ 10/sup /minus/10/exp((/minus/7480 +- 1100)/T)cm/sup 3/molecule/sup /minus/1/s/sup /minus/1/. 7 refs., 4 figs.

Wantuck, P.J.; Oldenborg, R.C.; Baugchum, S.L.; Winn, K.R.

1988-01-01T23:59:59.000Z

403

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

404

An assessment of chemical kinetics for bio-syngas combustion  

Science Journals Connector (OSTI)

Abstract The present work was devoted to assess the chemical kinetic modelling of bio-syngas combustion. Three reaction mechanisms (the Gas Research Institute-mechanism GRI 3.0, its skeletal version DRM22 and Heghes’ C1–C4 mechanism) were considered for that purpose along with series of ignition delay measurements relevant to the burning of bio-syngas. For experiments involving methane with and without considerably smaller quantities of added hydrogen, the measurements are generally overpredicted by Heghes’ mechanism but underpredicted by the GRI and DRM mechanisms. Experiments involving various blends of the bio-syngas constituents were also simulated. The strong discrepancies present for high pressures and temperatures and low pressures and temperatures could be correlated to five reactions which are only influential under those conditions, four of which involving HO 2 . The effects of variations in the bio-syngas composition on combustion were numerically investigated by using the GRI-mechanism. Globally it was found that an increase in any of the constituents goes hand in hand with higher amount of CO released. The ignition delay is either shortened or left unchanged as the initial concentration is increased except in the case of methane where it is raised. The results were in good agreement with experimental observations made elsewhere.

M. Fischer; X. Jiang

2014-01-01T23:59:59.000Z

405

Direct evidence of plastic events and dynamic heterogeneities in soft-glasses  

E-Print Network (OSTI)

By using fluid-kinetic simulations of confined and concentrated emulsion droplets, we investigate the nature of space non-homogeneity in soft-glassy dynamics and provide quantitative measurements of the statistical features of plastic events in the proximity of the yield-stress threshold. Above the yield stress, our results show the existence of a finite stress correlation scale, which can be mapped directly onto the {\\it cooperativity scale}, recently introduced in the literature to capture non-local effects in the soft-glassy dynamics. In this regime, the emergence of a separate boundary (wall) rheology with higher fluidity than the bulk, is highlighted in terms of near-wall spontaneous segregation of plastic events. Near the yield stress, where the cooperative scale cannot be estimated with sufficient accuracy, the system shows a clear increase of the stress correlation scale, whereas plastic events exhibit intermittent clustering in time, with no preferential spatial location. A quantitative measurement of the space-time correlation associated with the motion of the interface of the droplets is key to spot the long-range amorphous order at the yield stress threshold.

R. Benzi; M. Sbragaglia; P. Perlekar; M. Bernaschi; S. Succi; F. Toschi

2014-02-18T23:59:59.000Z

406

Direct observation of heat dissipation in individual suspended carbon nanotubes using a two-laser technique  

SciTech Connect

A two-laser technique is used to investigate heat spreading along individual single walled carbon nanotube (SWCNT) bundles in vacuum and air environments. A 532 nm laser focused on the center of a suspended SWCNT bundle is used as a local heat source, and a 633 nm laser is used to measure the spatial temperature profile along the SWCNT bundle by monitoring the G band downshifts in the Raman spectra. A constant temperature gradient is observed when the SWCNT bundle is irradiated in vacuum, giving direct evidence of diffusive transport of the phonons probed by the Raman laser. In air, however, we observe an exponentially decaying temperature profile with a decay length of about 7 {mu}m, due to heat dissipation from the SWCNT bundle to the surrounding gas molecules. The thermal conductivity of the suspended carbon nanotube (CNT) is determined from its electrical heating temperature profile as measured in vacuum and the nanotube bundle diameter measured via transmission electron microscopy. Based on the exponential decay curves measured in three different CNTs in air, the heat transfer coefficient between the SWCNTs and the surrounding air molecules is found to range from 1.5 x 10{sup 3} to 7.9 x 10{sup 4} W/m{sup 2} K, which is smaller than the 1 x 10{sup 5} W/m{sup 2} K thermal boundary conductance value calculated using the kinetic theory of gases. This measurement is insensitive to the thermal contact resistance, as no temperature drops occur at the ends of the nanotube. It is also insensitive to errors in the calibration of the G band temperature coefficient. The optical absorption is also obtained from these results and is on the order of 10{sup -5}.

Hsu, I-Kai; Hung, Wei-Hsuan [Department of Materials Science, University of Southern California, Los Angeles, California 90089 (United States); Pettes, Michael T.; Shi Li [Department of Mechanical Engineering and Center for Nano and Molecular Science and Technology, Texas Materials Institute, University of Texas of Austin, Austin, Texas 78712 (United States); Aykol, Mehmet; Theiss, Jesse; Cronin, Stephen B. [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Chang, Chia-Chi [Department of Physics, University of Southern California, Los Angeles, California 90089 (United States)

2011-08-15T23:59:59.000Z

407

Directional gamma detector  

DOE Patents (OSTI)

An improved directional gamma radiation detector has a collector sandwiched etween two layers of insulation of varying thicknesses. The collector and insulation layers are contained within an evacuated casing, or emitter, which releases electrons upon exposure to gamma radiation. Delayed electrons and electrons entering the collector at oblique angles are attenuated as they pass through the insulation layers on route to the collector.

LeVert, Francis E. (Downers Grove, Knoxville, TN); Cox, Samson A. (Downers Grove, IL)

1981-01-01T23:59:59.000Z

408

Extension of DOE Directives  

Directives, Delegations, and Requirements

This Notice extends the following directives until 2/16/04: DOE N 205.2, Foreign National Access to DOE Cyber Systems, and DOE N 205.3, Password Generation, Protection, and Use, dated 11/23/99-7/1/00.

2003-02-24T23:59:59.000Z

409

The windows for kinetically mixed Z'-mediated dark matter and the galactic center gamma ray excess  

E-Print Network (OSTI)

One of the simplest hidden sectors with signatures in the visible sector is fermionic dark matter $\\chi$ coupled to a $Z'$ gauge boson that has purely kinetic mixing with the standard model hypercharge. We consider the combined constraints from relic density, direct detection and collider experiments on such models in which the dark matter is either a Dirac or a Majorana fermion. We point out sensitivity to details of the UV completion for the Majorana model. For kinetic mixing parameter $\\epsilon \\le 0.01$, only relic density and direct detection are relevant, while for larger $\\epsilon$, electroweak precision, LHC dilepton, and missing energy constraints become important. We identify regions of the parameter space of $m_\\chi$, $m_{Z'}$, dark gauge coupling and $\\epsilon$ that are most promising for discovery through these experimental probes. We study the compatibility of the models with the galactic center gamma ray excess, finding compatibility at the 2-3$\\sigma$ level for the Dirac model.

Cline, James M; Liu, Zuowei; Xue, Wei

2014-01-01T23:59:59.000Z

410

Direct Solar Energy Conversion by the Reduction of CO2  

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

Direct Solar Energy Conversion by the Reduction of CO2 Direct Solar Energy Conversion by the Reduction of CO2 Speaker(s): Reed Jensen Date: August 25, 2005 - 12:00pm Location: Bldg. 90 Reed Jensen has successfully demonstrated the direct solar reduction of CO2 to CO and O2 using a solar concentrator dish and ceramic converter that grew out of his work at Los Alamos National Laboratory. He will discuss the thermochemical, kinetic and spectral properties of the CO2 /CO/ O2 system that enable this process and how the CO is subsequently converted to useful fuels by a range of catalytic processes. He will also discuss the technical difficulties associated with the design, construction and operation of a multi-component optical system that must operate at high temperatures. Results from a prototype system will be discussed defining the efficiencies

411

Kinetic model for quartz and spinel dissolution during melting of high-level-waste glass batch  

SciTech Connect

The dissolution of quartz particles and the growth and dissolution of crystalline phases during the conversion of batch to glass potentially affects both the glass melting process and product quality. Crystals of spinel exiting the cold cap to molten glass below can be troublesome during the vitrification of iron-containing high-level wastes. To estimate the distribution of quartz and spinel fractions within the cold cap, we used kinetic models that relate fractions of these phases to temperature and heating rate. Fitting the model equations to data showed that the heating rate, apart from affecting quartz and spinel behavior directly, also affects them indirectly via concurrent processes, such as the formation and motion of bubbles. Because of these indirect effects, it was necessary to allow one kinetic parameter (the pre-exponential factor) to vary with the heating rate. The resulting kinetic equations are sufficiently simple for the detailed modeling of batch-to-glass conversion as it occurs in glass melters. The estimated fractions and sizes of quartz and spinel particles as they leave the cold cap, determined in this study, will provide the source terms needed for modeling the behavior of these solid particles within the flow of molten glass in the melter.

Pokorny, Richard; Rice, Jarrett A.; Crum, Jarrod V.; Schweiger, Michael J.; Hrma, Pavel R.

2013-07-24T23:59:59.000Z

412

Kinetics of Cdc42 Membrane Extraction by Rho-GDI Monitored by Real-Time Fluorescence Resonance Energy Transfer  

Science Journals Connector (OSTI)

Kinetics of Cdc42 Membrane Extraction by Rho-GDI Monitored by Real-Time Fluorescence Resonance Energy Transfer† ... This assay enabled us to directly monitor the (GDI-induced) release of Cdc42 from membranes. ... Specifically, we propose that the GDI first binds rapidly to membrane-associated Cdc42 and then a slower isomerization occurs which represents the rate-limiting step for the dissociation of the Cdc42?RhoGDI complex from membranes. ...

Tyzoon K. Nomanbhoy; Jon W. Erickson; Richard A. Cerione

1999-01-16T23:59:59.000Z

413

Comparison of gasification kinetics parameters of different types of nuclear graphite  

SciTech Connect

A chemical-reaction kinetics model of nuclear graphite gasification has recently been developed and successfully validated with gasification rate measurements for nuclear graphite grades of IG-110, IG-430, NBG-18 and NBG-25. The model employs 4 elementary chemical reactions with applicable parameters, including the values and Gaussian-like distributions of the specific activation energies, the pre-exponential coefficients for adsorption of oxygen and desorption of CO and CO{sub 2} gases, and the surface area of free active sites. These parameters are determined from the reported measurements of the total gasification and transient weight loss using a multi-parameter optimization algorithm. The determined chemical kinetics parameters for IG-100 and NB-25 are nearly the same, but slightly different from those for NBG-18 and IG-430. The initial specific area of free active sites is inversely proportional to the square root of the mass or volume of the graphite specimens used in experiments. The recommended chemical kinetics parameters in this paper for these grades of nuclear graphite should be applicable to future safety analysis of high-temperature gas cooled reactors in the unlikely event of a massive air ingress accident. (authors)

El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Tournier, J. M. P. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

2012-07-01T23:59:59.000Z

414

Kinetic and mechanistic studies of free-radical reactions in combustion  

SciTech Connect

Combustion is driven by energy-releasing chemical reactions. Free radicals that participate in chain reactions carry the combustion process from reactants to products. Research in chemical kinetics enables us to understand the microscopic mechanisms involved in individual chemical reactions as well as to determine the rates at which they proceed. Both types of information are required for an understanding of how flames burn, why engines knock, how to minimize the production of pollutants, and many other important questions in combustion. In this program the authors emphasize accurate measurements over wide temperature ranges of the rates at which ubiquitous free radicals react with stable molecules. The authors investigate a variety of OH, CN, and CH + stable molecule reactions important to fuel conversion, emphasizing application of the extraordinarily precise technique of laser photolysis/continuous-wave laser-induced fluorescence (LP/cwLIF). This precision enables kinetic measurements to serve as mechanistic probes. Since considerable effort is required to study each individual reaction, prudent selection is critical. Two factors encourage selection of a specific reaction: (1) the rates and mechanisms of the subject reaction are required input to a combustion model; and (2) the reaction is a chemical prototype which, upon characterization, will provide fundamental insight into chemical reactivity, facilitate estimation of kinetic parameters for similar reactions, and constrain and test the computational limits of reaction-rate theory. Most studies performed in this project satisfy both conditions.

Tully, F.P. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

415

Letter: Direction and Guidance for Implementing Direct DOE Relationship &  

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

Letter: Direction and Guidance for Implementing Direct DOE Letter: Direction and Guidance for Implementing Direct DOE Relationship & Funding for EMSSABs Letter: Direction and Guidance for Implementing Direct DOE Relationship & Funding for EMSSABs From: Assistant Secretary, Jessie Hill Roberson (EM-11) To: Mr. Monte Wilson, Chair, INEEL Citizens Advisory Board This letter is in response to a November 21, 2003 letter regarding direction and guidance for implementing direct DOE relationship and funding for Environmental Management Site Specific Advisory Boards. Roberson Letter - December 12, 2003 More Documents & Publications Letter: Progress in Implementing a Direct DOE Relationship & Funding for the EMSSABs Letter: Mission, Objectives & Scope of the Site Specific Advisory Board Memorandum: Direction and Guidance for Implementing Direct DOE Relationship

416

Letter: Direction and Guidance for Implementing Direct DOE Relationship &  

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

Letter: Direction and Guidance for Implementing Direct DOE Letter: Direction and Guidance for Implementing Direct DOE Relationship & Funding for EMSSABs Letter: Direction and Guidance for Implementing Direct DOE Relationship & Funding for EMSSABs From: Assistant Secretary, Jessie Hill Roberson (EM-11) To: Mr. Monte Wilson, Chair, INEEL Citizens Advisory Board This letter is in response to a November 21, 2003 letter regarding direction and guidance for implementing direct DOE relationship and funding for Environmental Management Site Specific Advisory Boards. Roberson Letter - December 12, 2003 More Documents & Publications Letter: Progress in Implementing a Direct DOE Relationship & Funding for the EMSSABs Letter: Mission, Objectives & Scope of the Site Specific Advisory Board Memorandum: Direction and Guidance for Implementing Direct DOE Relationship

417

Kinetic Energy Systems | Open Energy Information  

Open Energy Info (EERE)

Systems Systems Jump to: navigation, search Name Kinetic Energy Systems Place Ocala, Florida Zip 34476 Sector Hydro Product Designs and develops tidal generators. Has notably patented the KESC Tidal Generator which is based on free flow hydrodynamics. Coordinates 29.187525°, -82.140394° 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":29.187525,"lon":-82.140394,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

418

Detailed Kinetic Modeling of Gasoline Surrogate Mixtures  

SciTech Connect

Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, a recently revised version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multi-component gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines. Simulation results are discussed focusing attention on the mixing effects of the fuel components.

Mehl, M; Curran, H J; Pitz, W J; Westbrook, C K

2009-03-09T23:59:59.000Z

419

Kinetics of wet sodium vapor complex plasma  

SciTech Connect

In this paper, we have investigated the kinetics of wet (partially condensed) Sodium vapor, which comprises of electrons, ions, neutral atoms, and Sodium droplets (i) in thermal equilibrium and (ii) when irradiated by light. The formulation includes the balance of charge over the droplets, number balance of the plasma constituents, and energy balance of the electrons. In order to evaluate the droplet charge, a phenomenon for de-charging of the droplets, viz., evaporation of positive Sodium ions from the surface has been considered in addition to electron emission and electron/ion accretion. The analysis has been utilized to evaluate the steady state parameters of such complex plasmas (i) in thermal equilibrium and (ii) when irradiated; the results have been graphically illustrated. As a significant outcome irradiated, Sodium droplets are seen to acquire large positive potential, with consequent enhancement in the electron density.

Mishra, S. K., E-mail: nishfeb@rediffmail.com [Institute for Plasma Research (IPR), Gandhinagar 382428 (India); Sodha, M. S. [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)] [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)

2014-04-15T23:59:59.000Z

420

An action with positive kinetic energy term for general relativity  

E-Print Network (OSTI)

At first, we state some results in arXiv: 0707.2639, and then, using a positive kinetic energy coordinate condition given by arXiv: 0707.2639, we present an action with positive kinetic energy term for general relativity. Based on this action, the corresponding theory of canonical quantization is discussed.

T. Mei

2007-11-02T23:59:59.000Z

Note: This page contains sample records for the topic "direct kinetic measurements" from the National Library of EnergyBeta (NLEBeta).
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421

MEANKINETIC ENERGY,EDDY ENERGY,AND KINETIC ENERGYEXCHANGEBETWEENFLUCTUATIONSAND MEAN  

E-Print Network (OSTI)

MEANKINETIC ENERGY,EDDY ENERGY,AND KINETIC ENERGYEXCHANGEBETWEENFLUCTUATIONSAND MEAN FLOWWITHIN by cornputing three quantities suggested by the theory of turbulence: the nean kinetic energy, the eddy energy, and the energy exchange between the nean and fluctuating portions of the flow field (ca11ed dE/dt). Contours

Luther, Douglas S.

422

Kinetics and Modeling of Reductive Dechlorination at High PCE  

E-Print Network (OSTI)

Kinetics and Modeling of Reductive Dechlorination at High PCE and TCE Concentrations Seungho Yu for anaerobic reductive dechlorination of tetrachloroethylene (PCE) and trichloroethylene (TCE) were developed. The models were compared with results from batch kinetic tests conducted over a wide range of PCE and TCE

Semprini, Lewis

423

Drift-/ Kinetic Alfven Eigenmodes in High Performance Tokamak Plasmas  

E-Print Network (OSTI)

Stockholm, Sweden 2) Plasma Science Fusion Centre, MIT, Cambridge MA 02139, USA 3) CRPP-EPFL, 1015 Lausanne to the kinetic Alfv´en wave. This stimulated the development of models such as continuum damping, complex-kinetic description for the bulk plasma. Such a model is required to calculate the power transfer between global fluid

Jaun, André

424

Kinetics of coal pyrolysis and devolatilization  

SciTech Connect

An experimentally based, conceptual model of the devolatilization of a HV bituminous coal is outlined in this report. This model contends that the relative dominance of a process type-chemical kinetic, heat transport, mass transport -- varies with the extent of reaction for a given set of heating conditions and coal type and with experimental conditions for a given coal type and extent of reaction. The rate of devolatilization mass loss process is dominated initially by heat transfer processes, then coupled mass transfer and chemical kinetics, and finally by chemical processes alone. However, the chemical composition of the initial tars are determined primarily by the chemical characteristics of the parent coal. Chemically controlled gas phase reactions of the initial tars and coupled mass transfer and chemically controlled reactions of heavy tars determine the bulk of the light gas yields. For a HV bituminous coal this conceptual model serves to quantify the Two-Component Hypothesis'' of volatiles evolution. The model postulates that the overall rates of coal devolatilization should vary with coal type insofar as the characteristics of the parent coal determine the potential tar yield and the chemical characteristics of the initial tars. Experimental evidence indicates chemical characteristics and yields of primary'' tars vary significantly with coal type. Consequently, the conceptual model would indicate a shift from transport to chemical dominance of rate processes with variation in coal type. Using the conceptual model, United Technologies Research Center has been able to correlate initial mass loss with a heat transfer index for a wide range of conditions for high tar yielding coals. 33 refs., 30 figs., 6 tabs.

Not Available

1987-01-01T23:59:59.000Z

425

A STUDY OF THE PROPERTIES OF CP: COEFFICIENT OF THERMAL EXPANSION, DECOMPOSITION KINETICS AND REACTION TO SPARK, FRICTION AND IMPACT  

SciTech Connect

The properties of pentaamine (5-cyano-2H-tetrazolato-N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook-off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear heating rates, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 10,000 psi and analyzed over a dynamic temperature range of -20 C to 70 C. Using differential scanning calorimetry, DSC, CP was decomposed at linear heating rates of 1, 3, and 7 C/min and the kinetic triplet calculated using the LLNL code Kinetics05. Values are also reported for spark, friction, and impact sensitivity.

Weese, R K; Burnham, A K; Fontes, A T

2005-03-30T23:59:59.000Z

426

A Detailed Chemical Kinetic Reaction Mechanism for Oxidation of Four Small Alkyl Esters in Laminar Premixed Flames  

SciTech Connect

A detailed chemical kinetic reaction mechanism has been developed for a group of four small alkyl ester fuels, consisting of methyl formate, methyl acetate, ethyl formate and ethyl acetate. This mechanism is validated by comparisons between computed results and recently measured intermediate species mole fractions in fuel-rich, low pressure, premixed laminar flames. The model development employs a principle of similarity of functional groups in constraining the H atom abstraction and unimolecular decomposition reactions in each of these fuels. As a result, the reaction mechanism and formalism for mechanism development are suitable for extension to larger oxygenated hydrocarbon fuels, together with an improved kinetic understanding of the structure and chemical kinetics of alkyl ester fuels that can be extended to biodiesel fuels. Variations in concentrations of intermediate species levels in these flames are traced to differences in the molecular structure of the fuel molecules.

Westbrook, C K; Pitz, W J; Westmoreland, P R; Dryer, F L; Chaos, M; Osswald, P; Kohse-Hoinghaus, K; Cool, T A; Wang, J; Yang, B; Hansen, N; Kasper, T

2008-02-08T23:59:59.000Z

427

Non-Equilibrium Superconductivity in Kinetic Inductance Detectors for THz Photon Sensing  

E-Print Network (OSTI)

Low temperature Kinetic Inductance Detectors (KIDs) are attractive candidates for producing quantumsensitive, arrayable sensors for astrophysical and other precision measurement applications. The readout uses a low frequency probe signal with quanta of energy well-below the threshold for pair-breaking in the superconductor. We have calculated the detailed non-equilibrium quasiparticle and phonon energy spectra generated by the probe signal of the KID when operating well-below its superconducting transition temperature Tc within the framework of the coupled kinetic equations described by Chang and Scalapino.[1] At the lowest bath temperature studied Tb/Tc = 0.1 the quasiparticle distributions can be driven far from equilibrium. In addition to the low frequency probe signal we have incorporated a high frequency (~ 1 THz) source signal well-above the pair-breaking threshold of the superconductor. Calculations of source signal detection efficiency are discussed

Goldie, D J

2014-01-01T23:59:59.000Z

428

Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate  

SciTech Connect

New chemical kinetic reaction mechanisms are developed for two of the five major components of biodiesel fuel, methyl stearate and methyl oleate. The mechanisms are produced using existing reaction classes and rules for reaction rates, with additional reaction classes to describe other reactions unique to methyl ester species. Mechanism capabilities were examined by computing fuel/air autoignition delay times and comparing the results with more conventional hydrocarbon fuels for which experimental results are available. Additional comparisons were carried out with measured results taken from jet-stirred reactor experiments for rapeseed methyl ester fuels. In both sets of computational tests, methyl oleate was found to be slightly less reactive than methyl stearate, and an explanation of this observation is made showing that the double bond in methyl oleate inhibits certain low temperature chain branching reaction pathways important in methyl stearate. The resulting detailed chemical kinetic reaction mechanism includes more approximately 3500 chemical species and more than 17,000 chemical reactions.

Naik, C; Westbrook, C K; Herbinet, O; Pitz, W J; Mehl, M

2010-01-22T23:59:59.000Z

429

Influence of the Richtmyer-Meshkov instability on the kinetic energy spectrum.  

SciTech Connect

The fluctuating kinetic energy spectrum in the region near the Richtmyer-Meshkov instability (RMI) is experimentally investigated using particle image velocimetry (PIV). The velocity field is measured at a high spatial resolution in the light gas to observe the effects of turbulence production and dissipation. It is found that the RMI acts as a source of turbulence production near the unstable interface, where energy is transferred from the scales of the perturbation to smaller scales until dissipation. The interface also has an effect on the kinetic energy spectrum farther away by means of the distorted reflected shock wave. The energy spectrum far from the interface initially has a higher energy content than that of similar experiments with a flat interface. These differences are quick to disappear as dissipation dominates the flow far from the interface.

Weber, Christopher R. (University of Wisconsin-Madison, Madison, WI)

2010-09-01T23:59:59.000Z

430

Negative kinetic energy term of general relativity and its removing  

E-Print Network (OSTI)

We first present a new Lagrangian of general relativity, which can be divided into kinetic energy term and potential energy term. Taking advantage of vierbein formalism, we reduce the kinetic energy term to a sum of five positive terms and one negative term. Some gauge conditions removing the negative kinetic energy term are discussed. Finally, we present a Lagrangian that only include positive kinetic energy terms. To remove the negative kinetic energy term leads to a new field equation of general relativity in which there are at least five equations of constraint and at most five dynamical equations, this characteristic is different from the normal Einstein field equation in which there are four equations of constraint and six dynamical equations.

T. Mei

2009-03-30T23:59:59.000Z

431

Formatting paragraph numbering for directives  

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

MEASUREMENT SENSITIVE DOE G 440.1-8 12-27-06 IMPLEMENTATION GUIDE for use with 10 CFR PART 851 WORKER SAFETY AND HEALTH PROGRAM [This Guide describes suggested nonmandatory approaches for meeting requirements. Guides are not requirements documents and are not construed as requirements in any audit or appraisal for compliance with the parent Policy, Order, Notice, or Manual.] U.S. Department of Energy Washington, D.C. 20585 AVAILABLE ONLINE AT: INITIATED BY: www.directives.doe.gov Office of Health, Safety and Security DOE G 440.1-8 i (and ii) 12-27-06 FOREWORD This Department of Energy (DOE) Guide is available for use by all DOE components and their contractors. Beneficial comments (recommendations, additions, and deletions) and pertinent data that may

432

Kinetics of phase transitions in weakly segregated block copolymers: Pseudostable and transient states  

Science Journals Connector (OSTI)

We study the kinetics of order-disorder and order-order transitions in weakly segregated diblock copolymers using a time-dependent Ginzburg-Landau (TDGL) approach. In particular, we investigate the microstructural change as well as the order-parameter evolution after a sudden temperature jump from one phase to another. Direct numerical simulation of the TDGL equations shows that depending on the extent of the temperature jump, these transitions often occur in several stages and can involve nontrivial intermediate states. For example, we find that transition from the lamellar phase to the hexagonal cylinder phase goes through a perforated lamellar state within a certain temperature range. The numerical results are elucidated by a multimode analysis under the single-wave-number approximation. The analysis reveals that the geometric characteristics of the free energy surface, particularly saddle points and ridgelike features, are responsible for the nontrivial intermediate states on the kinetic pathways. On the basis of this analysis, a generalized kinetic ``phase diagram'' is constructed, which is able to account for all the different scenarios observed in the numerical simulation. Our results are discussed in connection with available experimental observations. In particular, we suggest the possibility that the perforated-modulated lamellar structures obtained by Bates and co-workers [I. W. Hamley, K. A. Koppi, J. H. Rosedale, F. S. Bates, K. Almdal, and K. Mortensen, Macromolecules 26, 5959 (1993); S. Förster, A. K. Khandpur, J. Zhao, F. S. Bates, I. W. Hamley, A. J. Ryan, and W. Bras, Macromolecules 27, 6922 (1994)] may be kinetic, intermediate states rather than new equilibrium phases.

Shuyan Qi and Zhen-Gang Wang

1997-02-01T23:59:59.000Z

433

A KINETIC MODEL OF SOLAR WIND GENERATION BY OBLIQUE ION-CYCLOTRON WAVES  

SciTech Connect

The fast solar wind is generated by extended perpendicular ion heating in coronal holes, but the kinetic mechanism responsible for this heating has not been determined. One long-standing possibility is the resonant-cyclotron dissipation of ion-cyclotron waves, replenished from a turbulent cascade of interacting counter-propagating Alfven waves. We present results of a kinetic model for proton heating by the quasilinear resonant-cyclotron wave-particle interaction in a coronal hole. The resonant wave spectrum is taken as a power law in wavenumber, uniformly distributed in propagation direction between 0 deg. and 60 deg. with respect to the large-scale radial magnetic field. We obtain the steady-state solution of the kinetic guiding-center equation for the proton distribution in an expanding coronal hole, including the effects of large-scale forces of gravity, charge-separation electric field, Alfven wave ponderomotive force, and mirror force, along with the small-scale scattering from the wave dissipation. We find that plausible wave intensities can yield reasonable flow speeds and temperatures in the heliocentric radial range between 2 and 6 solar radii. We address the claim in earlier work that dissipation of parallel-propagating ion-cyclotron waves cannot provide enough acceleration and show that claim to be incorrect. We find that the combined action of the large-scale forces and the resonant-cyclotron scattering produces proton distribution functions with a characteristic structure: compressed in the sunward half of velocity space with a high-density shell separate from the origin, and relatively expanded in the anti-sunward half of velocity space. We suggest that qualitatively similar proton distributions would result from the kinetic evolution of any sufficiently effective perpendicular heating mechanism operating in an expanding coronal hole.

Isenberg, Philip A.; Vasquez, Bernard J. [Institute for the Study of Earth, Oceans and Space and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)

2011-04-20T23:59:59.000Z

434

Insulating and sheathing materials of electric and optical cables: common test methods part 4-1: methods specific to polyethylene and polypropylene compounds – resistance to environmental stress cracking – measurement of the melt flow index – carbon black and/or mineral filler content measurement in polyethylene by direct combustion – measurement of carbon black content by thermogravimetric analysis (TGA) – assessment of carbon black dispersion in polyethylene using a microscope  

E-Print Network (OSTI)

Specifies the test methods to be used for testing polymeric insulating and sheathing materials of electric cables for power distribution and telecommunications including cables used on ships. Gives the methods for measurements of the resistance to environmental stress cracking, for wrapping test after thermal ageing in air, for measurement of melt flow index and for measurement of carbon black and/or mineral filler content, which apply to PE and PP coumpounds, including cellular compounds and foam skin for insulation.

International Electrotechnical Commission. Geneva

2004-01-01T23:59:59.000Z

435

A chemical kinetic model of hydrocarbon generation from the Bakken Formation, Williston Basin, North Dakota  

SciTech Connect

This report describes a model of hydrocarbon generation and expulsion in the North Dakota portion of the Williston Basin. The modeling incorporates kinetic methods to simulate chemical reactions and 1-dimensional conductive heat flow models to simulate thermal histories of the Mississippian-Devonian Bakken Formation source rock. We developed thermal histories of the source rock for 53 wells in the basin using stratigraphic and heat flow data obtained by the University of North Dakota. Chemical kinetics for hydrocarbon generation, determined from Pyromat pyrolysis, were, then used with the diennal histories to calculate the present day value of the Rock-Eval T{sub max} for each well. The calculated Rock-Eval T{sub max} values agreed with measured values within amounts attributable to uncertainties in the chemical kinetics and the heat flow. These optimized thermal histories were then used with a more detailed chemical kinetic model of hydrocarbon generation and expulsion, modified from a model developed for the Cretaceous La Luna shale, to simulate pore pressure development and detailed aspects of the hydrocarbon chemistry. When compared to values estimated from sonic logs, the pore pressure calculation underestimates the role of hydrocarbon generation and overestimates the role of compaction disequilibrium, but it matches well the general areal extent of pore pressures of 0.7 times lithostatic and higher. The simulated chemistry agrees very well with measured values of HI, PI, H/C atomic ratio of the kerogen, and Rock-Eval S1. The model is not as successful in simulating the amount of extracted bitumen and its saturate content, suggesting that detailed hydrous pyrolysis experiments will probably be needed to further refine the chemical model.

Sweeney, J.J.; Braun, R.L.; Burnham, A.K. [Lawrence Livermore National Lab., CA (United States); Gosnold, W.D. [North Dakota Univ., Grand Forks, ND (United States)

1992-10-01T23:59:59.000Z

436

PHYSICAL REVIEW B 86, 245427 (2012) Strong anisotropy in surface kinetic roughening: Analysis and experiments  

E-Print Network (OSTI)

PHYSICAL REVIEW B 86, 245427 (2012) Strong anisotropy in surface kinetic roughening: Analysis; published 26 December 2012) We report an experimental assessment of surface kinetic roughening properties systems whose kinetic roughening is strongly anisotropic, as consistently described by this scaling

Cuerno, Rodolfo

437

Kinetics of the 5-Hydroxymethylfurfural Formation Reaction in Chinese Rice Wine  

Science Journals Connector (OSTI)

Kinetics of the 5-Hydroxymethylfurfural Formation Reaction in Chinese Rice Wine ... The kinetics of 5-hydroxymethylfurfural (HMF) formation in Chinese rice wine was investigated under different treatment conditions. ... Chinese rice wine; 5-hydroxymethylfurfural (HMF); kinetics ...

Lei Chen; Huahong Huang; Wenbao Liu; Ning Peng; Xuesong Huang

2010-02-18T23:59:59.000Z

438

Direct and Inverse Cascades in the Wind-Driven Sea  

E-Print Network (OSTI)

We offer a new form for the S(nl) term in the Hasselmann kinetic equation for squared wave amplitudes of wind-driven gravity wave. This form of S(nl) makes possible to rewrite in differential form the conservation laws for energy, momentum, and wave action, and introduce their fluxes by a natural way. We show that the stationary kinetic equation has a family of exact Kolmogorov-type solutions governed by the fluxes of motion constants: wave action, energy, and momentum. The simple "local" model for S(nl) term that is equivalent to the "diffusion approximation" is studied in details. In this case, Kolmogorov spectra are found in the explicit form. We show that a general solution of the stationary kinetic equation behind the spectral peak is described by the Kolmogorov-type solution with frequency-dependent fluxes. The domains of "inverse cascade" and "direct cascade" can be separated by natural way. The spectrum in the universal domain is close to $\\omega^{-4}$.

Zakharov, Vladimir E

2015-01-01T23:59:59.000Z

439

Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression  

DOE Patents (OSTI)

A high-power-density-laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems. 25 figs.

Lasche, G.P.

1987-02-20T23:59:59.000Z

440

Breakout Session -- TEC Direction  

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

III: TEC III: TEC Direction and Priorities Presented to: Transportation External Coordination Working Group Presented by: Alex Thrower Office of Logistics Management February 7, 2008 San Antonio, Texas 2 Topics of Discussion * Transportation External Coordination Working Group (TEC) charter and membership * Topic group functions * Meeting format 3 TEC Charter and Membership * Mission - TEC was formed in 1992 to improve coordination among the Department of Energy (DOE) and external groups interested in the Department's transportation activities The Office of Civilian Radioactive Waste Management (OCRWM) co-chairs TEC with DOE's Environmental Management Program Provides an opportunity for broad based input and information exchange from varied organizations - Members meet semi-annually to participate in

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441

A radially resolved kinetic model for nonlocal electron ripple diffusion losses in tokamaks  

SciTech Connect

A relatively simple radially resolved kinetic model is applied to the ripple diffusion problem for electrons in tokamaks. The distribution function f(r,v) is defined on a two-dimensional grid, where r is the radial coordinate and v is the velocity coordinate. Particle transport in the radial direction is from ripple and banana diffusion and transport in the velocity direction is described by the Fokker-Planck equation. Particles and energy are replaced by source functions that are adjusted to maintain a constant central density and temperature. The relaxed profiles of f(r,v) show that the electron distribution function at the wall contains suprathermal electrons that have diffused from the interior that enhance ripple transport. The transport at the periphery is therefore nonlocal. The energy replacement times from the computational model are near to the experimental replacement times for tokamak discharges in the compilation by Pfeiffer and Waltz [Nucl. Fusion 19, 51 (1979)].

Robertson, Scott [Department of Physics and Center for Integrated Plasma Studies, University of Colorado, Boulder, Colorado 80309-0390 (United States)

2006-09-15T23:59:59.000Z

442

Home: Directives, Delegations, and Requirements  

NLE Websites -- All DOE Office Websites

content. | Skip to navigation content. | Skip to navigation Site Map Contact Us Current Documents Archived Documents Entire Site only in current section Advanced Search... U.S. Department of Energy Office of Management Directives, Delegations, and Requirements Sections Home Directives Current Directives Draft Directives Archives Delegations Current Delegations Current Designations Rescinded Organizations' Assignment of Responsibility Development & Review RevCom Writers' Tools DPC Corner References News and Updates Help Personal tools You are here: Office of Management » Directives, Delegations, and Requirements Info Home Directives are the Department of Energy's primary means of establishing policies, requirements, responsibilities, and procedures for Departmental elements and contractors. Directive

443

Characterization of decommissioned reactor internals: Direct-assay method assessment  

SciTech Connect

This study describes the direct-assay technique for measuring activation levels of irradiated reactor component hardware. It also compares the direct-assay technique with calculational analysis methods that predict activation levels. Direct assay is performed in four steps: (a) planning and component selection, (b) onsite measurements, (c) radiochemical analysis, and (d) data analysis and classification. Uncertainties are estimated for each step of this process, and an overall uncertainty in the classification accuracy is calculated as about {plus_minus}35%. Numerous research ideas are identified to help reduce the uncertainty level; many of these ideas would improve activation determinations performed by either direct assay or by calculational analysis methods.

Cline, J.E.

1993-03-01T23:59:59.000Z

444

Direct measurement of thin-film thermoelectric figure of merit  

E-Print Network (OSTI)

Joule effect- induced and the Peltier effect-induced Seebeckmetal lead due to the Peltier and Joule effects. IndependentJoule heating, and Peltier heating/cooling, respectively. 10

2009-01-01T23:59:59.000Z

445

Direct measurement of the W boson decay width  

E-Print Network (OSTI)

. Greenwood,45 S. Grinstein,1 L. Groer,52 S. Gru¨nendahl,36 A. Gupta,17 S. N. Gurzhiev,26 G. Gutierrez,36 P. Gutierrez,57 N. J. Hadley,46 H. Haggerty,36 S. Hagopian,35 V. Hagopian,35 R. E. Hall,32 S. Hansen,36 J. M. Hauptman,42 C. Hays,52 C. Hebert,43 D. Hedin...,17 H. E. Montgomery,36 R. W. Moore,50 M. Mostafa,1 H. da Motta,2 Y. Mutaf,54 E. Nagy,10 F. Nang,29 M. Narain,47 V. S. Narasimham,17 N. A. Naumann,21 H. A. Neal,49 J. P. Negret,5 A. Nomerotski,36 T. Nunnemann,36 D. O’Neil,50 V. Oguri,3 B. Olivier,12 N...

Baringer, Philip S.; Bean, Alice; Coppage, Don; Hebert, C.

2002-08-29T23:59:59.000Z

446

New imaging tool directly measures liquid surfaces | EMSL  

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

for energy storage, environmental cleanup The schematic of a vacuum compatible aqueous SIMS device. Insert shows the secondary H- and Si- ion images of this aperture. A team of...

447

Detecting Shape Deformation of Soft Objects Using Directional Photoreflectivity Measurement  

E-Print Network (OSTI)

-1-1 Hiyoshi, Kohoku, Yokohama, 223-8526 Japan 2 JST, ERATO, IGARASHI Design Interface Project, 1-28-1-7F, Koishikawa, Bunkyo, Tokyo, 112-0002 Japan 3 Dept of Computer Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033 Japan {y-sugiura | g.kakehi | anusha | calista | inami}@kmd.keio.ac.jp, {sakamoto

Igarashi, Takeo

448

Kinetic cascade beyond magnetohydrodynamics of solar wind turbulence in two-dimensional hybrid simulations  

Science Journals Connector (OSTI)

The nature of solar windturbulence in the dissipation range at scales much smaller than the large magnetohydrodynamic (MHD) scales remains under debate. Here a two-dimensional model based on the hybrid code abbreviated as A.I.K.E.F. is presented which treats massive ions as particles obeying the kinetic Vlasov equation and massless electrons as a neutralizing fluid. Up to a certain wavenumber in the MHD regime the numerical system is initialized by assuming a superposition of isotropic Alfvén waves with amplitudes that follow the empirically confirmed spectral law of Kolmogorov. Then turbulence develops and energy cascades into the dispersive spectral range where also dissipative effects occur. Under typical solar wind conditions weak turbulence develops as a superposition of normal modes in the kinetic regime. Spectral analysis in the direction parallel to the background magnetic field reveals a cascade of left-handed Alfvén/ion-cyclotron waves up to wave vectors where their resonant absorption sets in as well as a continuing cascade of right-handed fast-mode and whistler waves. Perpendicular to the background field a broad turbulent spectrum is found to be built up of fluctuations having a strong compressive component. Ion-Bernstein waves seem to be possible normal modes in this propagation direction for lower driving amplitudes. Also signatures of short-scale pressure-balanced structures (very oblique slow-mode waves) are found.

D. Verscharen; E. Marsch; U. Motschmann; J. Müller

2012-01-01T23:59:59.000Z

449

ARM - Measurement - Horizontal wind  

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

govMeasurementsHorizontal wind govMeasurementsHorizontal wind ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Horizontal wind The horizontal wind in terms of either speed and direction, or the zonal (u) and meridional (v) components. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments SONDE : Balloon-Borne Sounding System CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System DISDROMETER : Impact Disdrometer

450

Measuring oxygen reduction/evolution reactions on the nanoscale  

SciTech Connect

The efficiency of fuel cells and metal-air batteries is significantly limited by the activation of oxygen reduction and evolution reactions (ORR/OER). Despite the well-recognized role of oxygen reaction kinetics on the viability of energy technologies, the governing mechanisms remain elusive and until now addressable only by macroscopic studies. This lack of nanoscale understanding precludes optimization of material architecture. Here we report direct measurements of oxygen reduction/evolution reactions and oxygen vacancy diffusion on oxygen-ion conductive solid surfaces with sub-10 nanometer resolution. In electrochemical strain microscopy (ESM), the biased scanning probe microscopy tip acts as a moving, electrocatalytically active probe exploring local electrochemical activity. The probe concentrates an electric field in a nanometer-scale volume of material, and bias-induced, picometer-level surface displacements provide information on local electrochemical processes. Systematic mapping of oxygen activity on bare and Pt-functionalized yttria-stabilized zirconia (YSZ) surfaces is demonstrated. This approach allows directly visualization of ORR/OER activation process at the triple-phase boundary, and can be extended to broad spectrum of oxygen-conductive and electrocatalytic materials.

Kalinin, Sergei V [ORNL; Jesse, Stephen [ORNL; Kumar, Amit [ORNL; Morozovska, A. N. [National Academy of Science of Ukraine, Kiev, Ukraine; Ciucci, Francesco [Harvard-Smithsonian Center for Astrophysics

2011-01-01T23:59:59.000Z

451

ROLES OF THE KINETIC AND DYNAMIC MECHANISMS IN THE L{sub p} -E{sub p} RELATION  

SciTech Connect

The L{sub p} -E{sub p} relation is a well-known relation in gamma-ray bursts (GRBs). Its implication remains unclear. We propose to investigate the underlying mechanisms of this relation by considering the corresponding kinetic and dynamic mechanisms separately. In this way, one can tell how much the kinetic or dynamic mechanism contributes to the index of the relationship. Our analysis gives rise to several conclusions. (1) The index of the kinetic effect in the L{sub p} -E{sub p} relation can simply be derived from the theory of special relativity, which is generally larger than 2, depending on the situation concerned. (2) The index of the dynamic effect in the relation can be deduced from observation once a model of jets is adopted. According to current GRB data, we find that the dynamic effect alone tends to give rise to an anti-correlation between L{sub p} and E{sub p} ; in terms of statistics, the dynamic effect is obviously smaller than the kinetic effect; in the situation of jets with moving discrete radio clouds that move directly toward the observer, the index of the dynamic effect is currently constrained within (- 1.6, -1), while in other situations of jets, the constraints are different; both internal and external shocks can account for the current data.

Qin, Yi-Ping; Chen, Zhi-Fu, E-mail: ypqin@gzhu.edu.cn [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)] [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)

2013-04-10T23:59:59.000Z

452

Quantum kinetic theory with nonlocal coherence  

E-Print Network (OSTI)

In this thesis we develop a novel approximation scheme (eQPA), where the effects of nonlocal coherence are included in the kinetic approach to nonequilibrium quantum dynamics. The key element in our formalism is the finding of new singular shell solutions, located at $k_{0,z} = 0$ in the phase space of 2-point Wightman function, which describe the nonlocal quantum coherence between the ``opposite'' mass-shell excitations for spatially homogeneous and static planar symmetric problems, respectively. This phase space structure leads to a closed set of transport equations for the corresponding on-shell distribution functions $f$, providing an extension to the standard quantum Boltzmann equation. We have considered a number of applications to demonstrate the use of our formalism, including the Klein problem, quantum reflection from a CP-violating mass wall and coherent production of (fermionic and scalar) particles in an oscillating background. Our formalism should be of relevance for many problems in particle physics and cosmology, including baryogenesis and neutrino flavour oscillations in an inhomogeneous background.

Matti Herranen

2009-06-17T23:59:59.000Z

453

Effects of radiation on NO kinetics in turbulent hydrogen/air diffusion flames  

SciTech Connect

The authors describe a coupled radiation and NO kinetics calculation of turbulent hydrogen/air diffusion flame properties. Transport equations for mass, momentum, mixture fraction, enthalpy (sensible + chemical) including gas band radiation, and NO mass fraction are solved. NO kinetics is described by a one step thermal production mechanism. The local temperature is obtained by solving the enthalpy equation taking radiation loss from H{sub 2}O into consideration. Radiation/turbulence and chemical kinetics/turbulence interactions are treated using a clipped Gaussian probability density function (PDF) for the mixture fraction, and a delta PDF for the enthalpy. The source terms in the enthalpy and mass fraction of NO equations are treated using assumed PDF integration over the mixture fraction space. The results of the simulation are compared with existing measurements of the Emission Indices of NO (EINO) in turbulent H{sub 2}/air diffusion flames. The major conclusion of the paper is that coupled turbulence/radiation interactions should be taken into account while computing the EINO.

Sivathanu, Y.R.; Gore, J.P.; Laurendeau, N.M.

1997-07-01T23:59:59.000Z

454

PROPERTIES OF CP: COEFFICIENT OF THERMAL EXPANSION, DECOMPOSITION KINETICS, AND REACTION TO SPARK, FRICTION AND IMPACT  

SciTech Connect

The properties of pentaamine (5-cyano-2H-tetrazolato-N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook-off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear and isothermal heating, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 10,000 psi and analyzed over a dynamic temperature range of -20 C to 70 C. Differential scanning calorimetry, DSC, was used to monitor CP decomposition at linear heating rates of 1-7 C min{sup -1} in perforated pans and of 0.1-1.0 C min{sup -1} in sealed pans. The kinetic triplet was calculated using the LLNL code Kinetics05, and predictions for 210 and 240 C are compared to isothermal thermogravimetric analysis (TGA) experiments. Values are also reported for spark, friction, and impact sensitivity.

Weese, R K; Burnham, A K

2005-09-28T23:59:59.000Z

455

Foreign Direct Investment in U  

Gasoline and Diesel Fuel Update (EIA)

Foreign Direct Investment in U.S. Energy in 1998 Foreign Direct Investment in U.S. Energy in 1998 Foreign Direct Investment Foreign Direct Investment Foreign Direct Investment Foreign Direct Investment in U.S. Energy in U.S. Energy in U.S. Energy in U.S. Energy in 1998 in 1998 in 1998 in 1998 November 2000 Energy Information Administration/Foreign Direct Investment in U.S. Energy in 1998 Contacts This report was prepared in the Office of Energy Markets and End Use of the Energy Information Administration, U.S. Department of Energy, under the general direction of W. Calvin Kilgore. The project was directed by Mark E. Rodekohr, Director of the Energy Markets and Contingency Information Division (202) 586-1441, and Mary E. Northup, the Team Leader for Financial Analysis (202) 586-1383. Specific technical information concerning this

456

SRNL - Directions and Maps  

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

Map of SRS, with Georgia and South Carolina Map of SRS, with Georgia and South Carolina Directions and Maps The Savannah River National Laboratory is located at the Savannah River Site , a 310 square mile site located in the southeastern coastal area of the United States in the state of South Carolina. It is bordered to the west by the Savannah River and Georgia, and is close to several major cities, including Augusta and Savannah (Ga.), Columbia, Greenville, and Charleston (S.C.). It is in an area residents refer to as the Central Savannah River Area, or CSRA. The Aiken County Technology Laboratory (which houses SRNL's biotechnology laboratories and certain waste treatment technology laboratories) and the Center for Hydrogen Research are located at Aiken County's Savannah River Research Campus, located adjacent to SRS.

457

Memorandum: Direction and Guidance for Implementing Direct DOE Relationship  

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

Direction and Guidance for Implementing Direct DOE Direction and Guidance for Implementing Direct DOE Relationship & Funding for the EMSSAB Memorandum: Direction and Guidance for Implementing Direct DOE Relationship & Funding for the EMSSAB From: Designated Federal Officer, Sandra L. Waisley (EM-11) To: SSAB Members (G. Stegner, J. Reising, G. Bowman, T. Taylor, C. Gertz, B. Murphie, S. McCracken, M. Marvin, J. Rampe, A. Doswell, C. Anderson, B. Wethington, S. Brennan, K. Kozeliski, D. Dollins, P. Halsey, Y. Sherman, L. Bratcher, R. Warther, K. Klein, R. Schepens, F. Lockhart, J. Allison, R. Erickson, E. Sellers, K. Carlson, G. Boyd, R. Butler) The memorandum informs of Assistant Secrectary Roberson's direction and guidance for implementing a DOE direct relationship and funding approach for EM's Site-Specific Advisory Board (EMSSAB).

458

Dependence of Solar-Wind Power Spectra on the Direction of the Local Mean Magnetic Field  

Science Journals Connector (OSTI)

Wavelet analysis can be used to measure the power spectrum of solar-wind fluctuations along a line in any direction (?, ) with respect to the local mean magnetic field B 0. This technique is applied to study solar-wind turbulence in high-speed streams in the ecliptic plane near solar minimum using magnetic field measurements with a cadence of eight vectors per second. The analysis of nine high-speed streams shows that the reduced spectrum of magnetic field fluctuations (trace power) is approximately azimuthally symmetric about B 0 in both the inertial range and dissipation range; in the inertial range the spectra are characterized by a power-law exponent that changes continuously from 1.6 ± 0.1 in the direction perpendicular to the mean field to 2.0 ± 0.1 in the direction parallel to the mean field. The large uncertainties suggest that the perpendicular power-law indices 3/2 and 5/3 are both consistent with the data. The results are similar to those found by Horbury et al. at high heliographic latitudes. Comparisons between solar-wind observations and the theories of strong incompressible MHD turbulence developed by Goldreich & Sridhar and Boldyrev are not rigorously justified because these theories only apply to turbulence with vanishing cross-helicity although the normalized cross-helicity of solar-wind turbulence is not negligible. Assuming these theories can be generalized in such a way that the three-dimensional wavevector spectra have similar functional forms when the cross-helicity is nonzero, then for the interval of Ulysses data analyzed by Horbury et al. the ratio of the spectra perpendicular and parallel to B 0 is more consistent with the Goldreich & Sridhar scaling P ?/P ? ? ?1/3 than with the Boldyrev scaling ?1/2. The analysis of high-speed streams in the ecliptic plane does not yield a reliable measurement of this scaling law. The transition from a turbulent MHD-scale energy cascade to a kinetic Alfvén wave (KAW) cascade occurs when k ?? i 1, which coincides with the spectral break. At slightly higher wavenumbers, in the dissipation range, there is a peak in the power ratio with P ?/P ? 1. The decay of this peak may be caused by the damping of KAWs, which is predicted to occur near k ?? i 4.

J. J. Podesta

2009-01-01T23:59:59.000Z

459

Oxygen reduction at the platinum/Nafion{reg_sign} interface: Electrode kinetics and mass transport  

SciTech Connect

Research in solid polymer electrolyte fuel cells is gaining momentum because of the prospects of attaining high energy efficiencies and power densities, essential for transportation and space applications. The most advanced solid polymer electrolytes for these fuel cells are the perfluorosulfonate ionomers (PFSIs) such as duPont`s Naflon and the Dow PFSIs. The high oxygen solubility, chemical stability, proton conductivity and permselectivity exhibited by Naflon and the Dow PFSI`s make them ideal candidates as electrolytes for fuel cells. Furthermore, the minimal anion adsorption on electrodes from fluorinated acids enhances oxygen reduction kinetics. The primary objectives of this work were to determine the concentration and diffusion coefficient of oxygen in Naflon, and the electrode kinetic parameters for the reduction of oxygen at the Pt/Nafion interface under totally solid-state conditions. Cyclic voltammetric and potentiostatic transient measurements were made at the Pt/Nafion interface. Slow sweep voltammograms yielded Tafel parameters for oxygen reduction. From the two-section Tafel, plot, the calculated exchange current densities were found to be higher than those obtained at any other Pt/acid interface. From an analysis of the transients, the values of oxygen solubility and diffusion coefficient in Naflon were determined. Electrochemical impedance spectroscopic (EIS) investigations were then used to study oxygen reduction under lower humidfication conditions. EIS clearly permits the discrimination of electrode kinetics, mass transport of O{sub 2} and the electrical characteristics of the membrane. A temperature-dependence study in the range of 30{degrees}C to 80{degrees}C yielded the activation energy for oxygen reduction at the Pt/Naflon interface. The diffusion coefficient of oxygen in Nafion increases with temperature while its solubility decreases. the pressure-dependence of oxygen reduction kinetics shows that the reaction order of oxygen is unity.

Parthasarathy, A.

1992-12-31T23:59:59.000Z

460

Rank and directional entropy Rank and directional entropy  

E-Print Network (OSTI)

Rank and directional entropy Rank and directional entropy E. Arthur (Robbie) Robinson (Joint work with Ayse Sahin) The George Washington University Talk at KIAS, Seoul, Korea. September 27, 2010 #12;Rank and directional entropy Outline 1 Introduction 2 Finite rank, Z case 3 The formal definition 4 The Z2 case 5

Robinson Jr., E. Arthur (Robbie)

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


461

An Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions  

Open Energy Info (EERE)

Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions In Variably Saturated Subsurface Flow Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions In Variably Saturated Subsurface Flow Systems Details Activities (0) Areas (0) Regions (0) Abstract: Reactive chemical transport occurs in a variety of geochemical environments, and over a broad range of space and time scales. Efficiency of the chemical speciation and water-rock-gas interaction calculations is important for modeling field-scale multidimensional reactive transport problems. An improved efficient model, REACT, for simulating water-rock-gas interaction under equilibrium and kinetic conditions, has been developed.

462

Mechanistic kinetic modeling of the hydrocracking of complex feedstocks  

E-Print Network (OSTI)

subclasses by distinguishing the isomers of a class according to the number of methyl branches. The kinetic model is plugged into an adiabatic multi-bed trickle flow reactor model. The model contains 33 feedstock and temperature independent parameters which...

Kumar, Hans

2009-05-15T23:59:59.000Z