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1

Separation of heavy water by vapor-phase thermal diffusion coupled with distillation and condensation  

Science Conference Proceedings (OSTI)

A study on the enrichment of heavy water in a vapor-phase thermal-diffusion column has been conducted. With the combination of the effects of distillation, vapor-phase thermal diffusion, and partial condensation, considerable improvement in the degree of enrichment has been achieved in a vapor-phase column rather than in a liquid-phase column. It was also found that even the part of enrichment contributed only by vapor-phase thermal-diffusion effect is much higher than that obtained by liquid-phase thermal diffusion.

Yeh, H.M. [Tamkang Univ., Taiwan (China); Chang, S.M. [Cheng Kung Univ., Taiwan (China)

1994-08-01T23:59:59.000Z

2

Vapor phase heat transport systems  

DOE Green Energy (OSTI)

Vapor phase heat-transport systems are being tested in two of the passive test cells at Los Alamos. The systems consist of an active fin-and-tube solar collector and a condenser inside a water storage tank. The refrigerant, R-11, can be returned to the collector by a pump or by a self-pumping scheme. In one of the test cells the liquid was self-pumped to the roof-mounted collector 17 ft above the condenser. A mechanical valve was designed and tested that showed that the system could operate in a completely passive mode. Performance comparisons have been made with a passive water wall test cell.

Hedstrom, J.C.

1984-01-01T23:59:59.000Z

3

COMBINED THEORETICAL AND EXPERIMENTAL INVESTIGATION OF MECHANISMS AND KINETICS OF VAPOR-PHASE MERCURY UPTAKE BY CARBONACOUES SURFACES  

SciTech Connect

The first part of this study evaluated the application of a versatile optical technique to study the adsorption and desorption of model adsorbates representative of volatile polar (acetone) and non-polar (propane) organic compounds on a model carbonaceous surface under ultra high vacuum (UHV) conditions. The results showed the strong correlation between optical differential reflectance (ODR) and adsorbate coverage determined by temperature programmed desorption (TPD). ODR technique was proved to be a powerful tool to investigate surface adsorption and desorption from UHV to high pressure conditions. The effects of chemical functionality and surface morphology on the adsorption/desorption behavior of acetone, propane and mercury were investigated for two model carbonaceous surfaces, namely air-cleaved highly oriented pyrolytic graphite (HOPG) and plasma-oxidized HOPG. They can be removed by thermal treatment (> 500 K). The presence of these groups almost completely suppresses propane adsorption at 90K and removal of these groups leads to dramatic increase in adsorption capacity. The amount of acetone adsorbed is independent of surface heat treatment and depends only on total exposure. The effects of morphological heterogeneity is evident for plasma-oxidized HOPG as this substrate provides greater surface area, as well as higher energy binding sites. Mercury adsorption at 100 K on HOPG surfaces with and without chemical functionalities and topological heterogeneity created by plasma oxidation occurs through physisorption. The removal of chemical functionalities from HOPG surface enhances mercury physisorption. Plasma oxidation of HOPG provides additional surface area for mercury adsorption. Mercury adsorption by activated carbon at atmospheric pressure occurs through two distinct mechanisms, physisorption below 348 K and chemisorption above 348 K. No significant impact of oxygen functionalities was observed in the chemisorption region. The key findings of this study open the possibility to apply scientific information obtained from the studies with simple surfaces like HOPG under ideal conditions (UHV) to industrial sorbents under realistic process conditions. HOPG surface can be modified chemically and topologically by plasma oxidation to simulate key features of activated carbon adsorbents.

Radisav D. Vidic

2002-05-01T23:59:59.000Z

4

Vapor phase modifiers for oxidative coupling  

DOE Patents (OSTI)

Volatilized metal compounds retard vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

Warren, Barbara K. (Charleston, WV)

1991-01-01T23:59:59.000Z

5

Vapor phase modifiers for oxidative coupling  

DOE Patents (OSTI)

Volatilized metal compounds are described which are capable of retarding vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

Warren, B.K.

1991-12-17T23:59:59.000Z

6

Tidal Diffusivity: A Mechanism for Frontogenesis  

Science Conference Proceedings (OSTI)

It is hypothesized that tidal mixing may provide a “diffusivity” mechanism for frontogenesis. It stems from the fact that tidal diffusivity varies in the opposite sense from the water depth, so the vertically integrated diffusivity may exhibit a ...

Hsien-Wang Ou; Chang-Ming Dong; Dake Chen

2003-04-01T23:59:59.000Z

7

Published on Web 08/16/2003 Vapor Phase Synthesis of Tungsten Nanowires  

E-Print Network (OSTI)

Vapor phase methods for synthesizing metal nanowires directly without the help of templates have not been studied extensively. Even though there have been few reports with one dating back to 1877 on metal whisker synthesis from the vapor phase, the inconclusive growth mechanism did not lead to any serious developments for nanowires. 1 Recently, there are also two reports with one using hydrogen on tungsten oxide for tungsten nanowires, and another using decomposition of tungsten complexed organic precursors for amorphous carbon sheathed, polycrystalline tungsten nanowires. 2 In this context, we report a novel method in which nucleation and growth of metal oxides at temperatures higher than the oxide decomposition temperatures lead to the respective metal nanowires. Specifically, we demonstrate this concept with the bulk synthesis of tungsten nanowires. The chemical vapor transport of tungsten in the presence of oxygen onto substrates kept at temperatures

Sreeram Vaddiraju; Hari Ch; Mahendra K. Sunkara

2003-01-01T23:59:59.000Z

8

Preliminary assessment of halogenated alkanes as vapor-phase tracers  

DOE Green Energy (OSTI)

New tracers are needed to evaluate the efficiency of injection strategies in vapor-dominated environments. One group of compounds that seems to meet the requirements for vapor-phase tracing are the halogenated alkanes (HCFCs). HCFCs are generally nontoxic, and extrapolation of tabulated thermodynamic data indicate that they will be thermally stable and nonreactive in a geothermal environment. The solubilities and stabilities of these compounds, which form several homologous series, vary according to the substituent ratios of fluorine, chlorine, and hydrogen. Laboratory and field tests that will further define the suitability of HCFCs as vapor-phase tracers are under way.

Adams, Michael C.; Moore, Joseph N.; Hirtz, Paul

1991-01-01T23:59:59.000Z

9

Liquid-phase compositions from vapor-phase analyses  

SciTech Connect

Arsenic normally is not considered to be a contaminant. However, because arsenic was found in many cylinders of UF{sub 6}, including in corrosion products, a study was performed of the distribution of the two arsenic fluorides, AsF{sub 3} and AsF{sub 5}, between liquid and vapor phases. The results of the study pertain to condensation or vaporization of liquid UF{sub 6}. This study includes use of various experimental data plus many extrapolations necessitated by the meagerness of the experimental data. The results of this study provide additional support for the vapor-liquid equilibrium model of J.M. Prausnitz and his coworkers as a means of describing the distribution of various impurities between vapor and liquid phases of UF{sub 6}. Thus, it is concluded that AsF{sub 3} will tend to concentrate in the liquid phase but that the concentration of AsF{sub 5} in the vapor phase will exceed its liquid-phase concentration by a factor of about 7.5, which is in agreement with experimental data. Because the weight of the liquid phase in a condensation operation may be in the range of thousands of times that of the vapor phase, most of any AsF{sub 5} will be in the liquid phase in spite of this separation factor of 7.5. It may also be concluded that any arsenic fluorides fed into a uranium isotope separation plant will either travel with other low-molecular-weight gases or react with materials present in the plant. 25 refs., 3 figs., 6 tabs.

Davis, W. Jr. (Oak Ridge Gaseous Diffusion Plant, TN (USA)); Cochran, H.D. (Oak Ridge National Lab., TN (USA))

1990-02-01T23:59:59.000Z

10

AlGaAsSb/GaSb Distributed Bragg Reflectors Grown by Organometallic Vapor Phase Epitaxy  

SciTech Connect

The first AlGaAsSb/GaSb quarter-wave distributed Bragg reflectors grown by metallic vapor phase epitaxy are reported. The peak reflectance is 96% for a 10-period structure.

C.A. Wang; C.J. Vineis; D.R. Calawa

2002-02-13T23:59:59.000Z

11

Mechanisms of Stochastic Diffusion of Energetic Ions in Spherical Tori  

Science Conference Proceedings (OSTI)

Stochastic diffusion of the energetic ions in spherical tori is considered. The following issues are addressed: (I) Goldston-White-Boozer diffusion in a rippled field; (ii) cyclotron-resonance-induced diffusion caused by the ripple; (iii) effects of non-conservation of the magnetic moment in an axisymmetric field. It is found that the stochastic diffusion in spherical tori with a weak magnetic field has a number of peculiarities in comparison with conventional tokamaks; in particular, it is characterized by an increased role of mechanisms associated with non-conservation of the particle magnetic moment. It is concluded that in current experiments on National Spherical Torus eXperiment (NSTX) the stochastic diffusion does not have a considerable influence on the confinement of energetic ions.

Ya.I. Kolesnichenko; R.B. White; Yu.V. Yakovenko

2001-01-18T23:59:59.000Z

12

Microwave-assisted fast vapor-phase transport synthesis of MnAPO-5 molecular sieves  

Science Conference Proceedings (OSTI)

MnAPO-5 was prepared by a microwave-assisted vapor-phase transport method at 180 deg. C in short times. The products were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, UV-vis spectroscopic measurement, NH{sub 3}-temperature-programmed desorption and esterification reaction. It was found that dry gels prepared with aluminum isopropoxide, phosphoric acid and manganese acetate could be transferred to MnAPO-5 in the vapors of triethylamine and water by the microwave-assisted vapor-phase transport method at 180 deg. C for less than 30 min. The crystallization time was greatly reduced by the microwave heating compared with the conventional heating. The resulting MnAPO-5 exhibited much smaller particle sizes, higher surface areas and slightly higher catalytic activity in the esterification of acetic acid and butyl alcohol than those prepared by the conventional vapor-phase transport method and hydrothermal synthesis.

Shao Hui [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China); Department of Chemical Engineering, Jiangsu Polytechnic University, Changzhou 213016 (China); Yao Jianfeng; Ke Xuebin [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zhang Lixiong [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China)], E-mail: lixiongzhang@yahoo.com; Xu Nanping [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China)

2009-04-02T23:59:59.000Z

13

Diffusion-based DNA target colocalization by thermodynamic mechanisms  

E-Print Network (OSTI)

In eukaryotic cell nuclei, a variety of DNA interactions with nuclear elements occur, which, in combination with intra- and inter- chromosomal cross-talks, shape a functional 3D architecture. In some cases they are organized by active, i.e. actin/myosin, motors. More often, however, they have been related to passive diffusion mechanisms. Yet, the crucial questions on how DNA loci recognize their target and are reliably shuttled to their destination by Brownian diffusion are still open. Here, we complement the current experimental scenario by considering a physics model, in which the interaction between distant loci is mediated by diffusing bridging molecules. We show that, in such a system, the mechanism underlying target recognition and colocalization is a thermodynamic switch-like process (a phase transition) that only occurs if the concentration and affinity of binding molecules is above a threshold, or else stable contacts are not possible. We also briefly discuss the kinetics of this "passive-shuttling" process, as produced by random diffusion of DNA loci and their binders, and derive predictions based on the effects of genomic modifications and deletions.

Antonio Scialdone; Mario Nicodemi

2011-05-04T23:59:59.000Z

14

Diffusion based degradation mechanisms in giant magnetoresistive spin valves  

Science Conference Proceedings (OSTI)

Spin valve systems based on the giant magnetoresistive effect as used, for example, in hard disks and automotive applications consist of several functional metallic thin film layers. We have identified by secondary ion mass spectrometry two main degradation mechanisms: one is related to oxygen diffusion through a protective cap layer and the other one is interdiffusion directly at the functional layers of the giant magnetoresistive stack. By choosing a suitable material as cap layer (TaN), the oxidation effect can be suppressed.

Hawraneck, Matthias [Department of Sense and Control, Infineon Technologies AG, 85579 Neubiberg (Germany); Institute for Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany); Zimmer, Juergen; Raberg, Wolfgang; Pruegl, Klemens; Schmitt, Stephan; Bever, Thomas [Department of Sense and Control, Infineon Technologies AG, 85579 Neubiberg (Germany); Flege, Stefan; Alff, Lambert [Institute for Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2008-07-07T23:59:59.000Z

15

Cubic GaN Light Emitting Diode Grown by Metalorganic Vapor-Phase Epitaxy  

E-Print Network (OSTI)

this paper, we report on the doping characteristics of Si and Mg in the growth of cubic GaN by metalorganic vapor-phase epitaxy (MOVPE). We also report the growth of a p-n diode structure made of cubic GaN, and its characterization by electron-beam-induced-current (EBIC) and current injection measurements.

Hidenao Tanaka Member; Vapor-phase Epitaxy; Atsushi Nakadaira

2000-01-01T23:59:59.000Z

16

Inhibition of Pitting and Crevice Corrosion by Filming Amines and Vapor Phase Corrosion Inhibitors  

Science Conference Proceedings (OSTI)

The increase of fossil units that are being removed from service for indeterminate periods due to economic dispatch, seasonal conditions of excess generating capacity, or temporary decommissioning of generating assets necessitates alternative protective measures to prevent and reduce deterioration of the system components during these periods of idle operation. Preservation methods and techniques using vapor phase corrosion inhibitors and film-forming hydrophobic amines may provide an effective alternati...

2012-01-17T23:59:59.000Z

17

Microsoft Word - Vapor Phase Elemental Sulfur Tech Brief DRAFT bbl 08-24.docx  

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

AT A GLANCE AT A GLANCE  eliminates excavation expense  applicable to large or small sites  straightforward deployment  uses heat to distribute sulfur throughout a soil  mercury reacts with sulfur to form immobile and insoluble minerals  patent applied for TechBrief Vapor Phase Elemental Sulfur Amendment for Sequestering Mercury in Contaminated Soil Scientists at the Savannah River National Laboratory (SRNL) have identified a method of targeting mercury in contaminated soil zone by use of sulfur vapor heated gas. Background Mercury contamination in soil is a common problem in the environment. The most common treatment is excavation - a method that works well for small sites where the

18

Compound nuclear decay and the liquid to vapor phase transition: a physical picture  

E-Print Network (OSTI)

Analyses of multifragmentation in terms of the Fisher droplet model (FDM) and the associated construction of a nuclear phase diagram bring forth the problem of the actual existence of the nuclear vapor phase and the meaning of its associated pressure. We present here a physical picture of fragment production from excited nuclei that solves this problem and establishes the relationship between the FDM and the standard compound nucleus decay rate for rare particles emitted in first-chance decay. The compound thermal emission picture is formally equivalent to a FDM-like equilibrium description and avoids the problem of the vapor while also explaining the observation of Boltzmann-like distribution of emission times. In this picture a simple Fermi gas thermometric relation is naturally justified and verified in the fragment yields and time scales. Low energy compound nucleus fragment yields scale according to the FDM and lead to an estimate of the infinite symmetric nuclear matter critical temperature between 18 a...

Moretto, L G; Phair, L

2005-01-01T23:59:59.000Z

19

Growth of vertical-cavity surface emitting lasers by metalorganic vapor phase epitaxy  

SciTech Connect

We present growth and characterization of visible and near-infrared vertical-cavity surface emitting lasers (VCSELs) grown by metalorganic vapor phase epitaxy. Discussions on the growth issue of VCSEL materials include growth rate and composition control using an {ital in}{ital situ} normal-incidence reflectometer, comprehensive p- and n-type doping study in AlGaAs by CCl{sub 4} and Si{sub 2}H{sub 6} over the entire composition range, and optimization of ultra-high material uniformity. We also demonstrate our recent achievements of all-AlGaAs VCSELs which include the first room-temperature continuous- wave demonstration of 700-nm red VCSELs and high-efficiency and low- threshold voltage 850-nm VCSELs.

Hou, H.Q.; Hammons, B.E.; Crawford, M.H.; Lear, K.L.; Choquette, K.D.

1996-10-01T23:59:59.000Z

20

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System  

DOE Green Energy (OSTI)

This report summarizes work of this project from October 2003 through March 2004. The major focus of the research was to further investigate BTEX removal from produced water, to quantify metal ion removal from produced water, and to evaluate a lab-scale vapor phase bioreactor (VPB) for BTEX destruction in off-gases produced during SMZ regeneration. Batch equilibrium sorption studies were conducted to evaluate the effect of semi-volatile organic compounds commonly found in produced water on the sorption of benzene, toluene, ethylbenzene, and xylene (BTEX) onto surfactant-modified zeolite (SMZ) and to examine selected metal ion sorption onto SMZ. The sorption of polar semi-volatile organic compounds and metals commonly found in produced water onto SMZ was also investigated. Batch experiments were performed in a synthetic saline solution that mimicked water from a produced water collection facility in Wyoming. Results indicated that increasing concentrations of semi-volatile organic compounds increased BTEX sorption. The sorption of phenol compounds could be described by linear isotherms, but the linear partitioning coefficients decreased with increasing pH, especially above the pKa's of the compounds. Linear correlations relating partitioning coefficients of phenol compounds with their respective solubilities and octanol-water partitioning coefficients were developed for data collected at pH 7.2. The sorption of chromate, selenate, and barium in synthetic produced water were also described by Langmuir isotherms. Experiments conducted with a lab-scale vapor phase bioreactor (VPB) packed with foam indicated that this system could achieve high BTEX removal efficiencies once the nutrient delivery system was optimized. The xylene isomers and benzene were found to require the greatest biofilter bed depth for removal. This result suggested that these VOCs would ultimately control the size of the biofilter required for the produced water application. The biofilter recovered rapidly from shutdowns showing that the system was resilient to discontinuous feed conditions therefore provided flexibility on the SMZ regeneration process.

Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2004-03-11T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Compound nuclear decay and the liquid to vapor phase transition: a physical picture  

E-Print Network (OSTI)

Analyses of multifragmentation in terms of the Fisher droplet model (FDM) and the associated construction of a nuclear phase diagram bring forth the problem of the actual existence of the nuclear vapor phase and the meaning of its associated pressure. We present here a physical picture of fragment production from excited nuclei that solves this problem and establishes the relationship between the FDM and the standard compound nucleus decay rate for rare particles emitted in first-chance decay. The compound thermal emission picture is formally equivalent to a FDM-like equilibrium description and avoids the problem of the vapor while also explaining the observation of Boltzmann-like distribution of emission times. In this picture a simple Fermi gas thermometric relation is naturally justified and verified in the fragment yields and time scales. Low energy compound nucleus fragment yields scale according to the FDM and lead to an estimate of the infinite symmetric nuclear matter critical temperature between 18 and 27 MeV depending on the choice of the surface energy coefficient of nuclear matter.

L. G. Moretto; J. B. Elliott; L. Phair

2005-07-08T23:59:59.000Z

22

Carbon-Supported bimetallic Pd-Fe catalysts for vapor-phase hydrodeoxygenation of guaiacol  

Science Conference Proceedings (OSTI)

Abstract Carbon supported metal catalysts (Cu/C, Fe/C, Pd/C, Pt/C, PdFe/C and Ru/C) have been prepared, characterized and tested for vapor-phase hydrodeoxygenation (HDO) of guaiacol (GUA) at atmospheric pressure. Phenol was the major intermediate on all catalysts. Over the noble metal catalysts saturation of the aromatic ring was the major pathway observed at low temperature (250 °C), forming predominantly cyclohexanone and cyclohexanol. Substantial ring opening reaction was observed on Pt/C and Ru/C at higher reaction temperatures (e.g., 350 °C). Base metal catalysts, especially Fe/C, were found to exhibit high HDO activity without ring-saturation or ring-opening with the main products being benzene, phenol along with small amounts of cresol, toluene and trimethylbenzene (TMB). A substantial enhancement in HDO activity was observed on the PdFe/C catalysts. Compared with Fe/C, the yield to oxygen-free aromatic products (i.e., benzene/toluene/TMB) on PdFe/C increased by a factor of four at 350 °C, and by approximately a factor of two (83.2% versus 43.3%) at 450 °C. The enhanced activity of PdFe/C is attributed to the formation of PdFe alloy as evidenced by STEM, EDS and TPR.

Sun, Junming; Karim, Ayman M.; Zhang, He; Kovarik, Libor; Li, Xiaohong S.; Hensley, Alyssa; McEwen, Jean-Sabin; Wang, Yong

2013-10-01T23:59:59.000Z

23

Quantization in Classical Mechanics and Diffusion Mechanism of Alpha Decay, Proton and Cluster Radioactivity, Spontaneous Fission  

SciTech Connect

Based on the Chetaev generalized theorem the Schroedinger equation as the stability condition of trajectories in classical dynamics in the presence of dissipative forces is derived. In the framework of this approach the alternative model for unified description of alpha decay, spontaneous fission, cluster and proton radioactivity and is developed. We show the possibility of the classical (without tunneling) description of radioactive decay of heavy nuclei, when the so called noise-induced transition or, in other words, the stochastic channel of radioactive decay conditioned by the Kramers diffusion mechanism is generated under certain conditions.Using the ENSDF nuclear data, we have found the parametrized solutions of the Kramers equation of the Langevin type by the Alexandrov dynamic auto-regularization method (REGN-Dubna program). These solutions describe with high-accuracy the dependences of half-life (the decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products.Verification of the inverse problem solution in the framework of the universal Kramers description of alpha decay, spontaneous fission, cluster and proton radioactivity, which based on the newest experimental data for alpha-decay of even-even superheavy nuclei (Z = 114, 116, 118), shows good coincidence of the experimental and theoretical dependences of half-life on alpha-decay energy.

Rusov, V. D.; Vlasenko, D. S.; Deliyergiyev, M. A. [Department of Theoretical and Experimental Nuclear Physics, Odessa National Polytechnic University, Odessa (Ukraine); Mavrodiev, S. Cht. [Institute for Nuclear Research and Nuclear Energy, BAS, Sofia (Bulgaria)

2010-01-01T23:59:59.000Z

24

Quantization in Classical Mechanics and Diffusion Mechanism of Alpha Decay, Cluster Radioactivity, Spontaneous Fission  

SciTech Connect

Based on the Chetaev generalized theorem the Schredinger equation as the stability condition of trajectories in classical dynamics in the presence of dissipative forces is derived. In the framework of this approach the alternative model for unified description of alpha decay, spontaneous fission, cluster radioactivity and is developed. We show the possibility of the classical (without tunneling) description of radioactive decay of heavy nuclei, when the so called noise-induced transition or, in other words, the stochastic channel of radioactive decay conditioned by the Kramers diffusion mechanism is generated under certain conditions.Using the ENSDF nuclear data, we have found the parametrized solutions of the Kramers equation of the Langevin type by the Alexandrov dynamic auto-regularization method (REGN-Dubna program). These solutions describe with high-accuracy the dependences of half-life (the decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products.Verification of the inverse problem solution in the framework of the universal Kramers description of alpha decay, spontaneous fission, cluster radioactivity, which based on the newest experimental data for alpha-decay of even-even superheavy nuclei (Z = 114, 116, 118), shows good coincidence of the experimental and theoretical dependences of half-life on alpha-decay energy.

Rusov, V. D.; Vlasenko, D. S.; Deliyergiyev, M. A. [Department of Theoretical and Experimental Nuclear Physics, Odessa National Polytechnic University, Odessa (Ukraine); Mavrodiev, S. Cht. [Institute for Nuclear Research and Nuclear Energy, BAS, Sofia (Bulgaria)

2010-05-04T23:59:59.000Z

25

TREATMENT OF PRODUCED WATERS USING A SURFACTANT MODIFIED ZEOLITE/VAPOR PHASE BIOREACTOR SYSTEM  

DOE Green Energy (OSTI)

Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. It is by some estimates the largest single waste stream in the country, aside from nonhazardous industrial wastes. Characteristics of produced water include high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component, and chemicals added during the oil-production process. While most of the produced water is disposed via reinjection, some of them must be treated to remove organic constituents before the water is discharged. Current treatment options are successful in reducing the organic content; however, they cannot always meet the levels of current or proposed regulations for discharged water. Therefore, an efficient, cost-effective treatment technology is needed. Surfactant-modified zeolite (SMZ) has been used successfully to treat contaminated ground water for organic and inorganic constituents. In addition, the low cost of natural zeolites makes their use attractive in water-treatment applications. Our previous DOE research work (DE-AC26-99BC15221) demonstrated that SMZ could successfully remove BTEX compounds from the produced water. In addition, SMZ could be regenerated through a simple air sparging process. The primary goal of this project is to develop a robust SMZ/VPB treatment system to efficiently remove the organic constituents from produced water in a cost-effective manner. This report summarizes work of this project from October 2002 to March 2003. In this starting stage of this study, we have continued our investigation of SMZ regeneration from our previous DOE project. Two saturation/stripping cycles have been completed for SMZ columns saturated with BTEX compounds. Preliminary results suggest that BTEX sorption actually increases with the number of saturation/regeneration cycles. Furthermore, the experimental vapor phase bioreactors for this project have been designed and are currently being assembled to treat the off-gas from the SMZ regeneration process.

Lynn E. Katz; Kerry A. Kinney; R.S. Bowman; E.J. Sullivan

2003-04-01T23:59:59.000Z

26

Treatment of Produced Water Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System  

DOE Green Energy (OSTI)

Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. Produced waters typically contain a high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component as well as chemicals added during the oil-production process. It has been estimated that a total of 14 billion barrels of produced water were generated in 2002 from onshore operations (Veil, 2004). Although much of this produced water is disposed via reinjection, environmental and cost considerations can make surface discharge of this water a more practical means of disposal. In addition, reinjection is not always a feasible option because of geographic, economic, or regulatory considerations. In these situations, it may be desirable, and often necessary from a regulatory viewpoint, to treat produced water before discharge. It may also be feasible to treat waters that slightly exceed regulatory limits for re-use in arid or drought-prone areas, rather than losing them to reinjection. A previous project conducted under DOE Contract DE-AC26-99BC15221 demonstrated that surfactant modified zeolite (SMZ) represents a potential treatment technology for produced water containing BTEX. Laboratory and field experiments suggest that: (1) sorption of benzene, toluene, ethylbenzene and xylenes (BTEX) to SMZ follows linear isotherms in which sorption increases with increasing solute hydrophobicity; (2) the presence of high salt concentrations substantially increases the capacity of the SMZ for BTEX; (3) competitive sorption among the BTEX compounds is negligible; and, (4) complete recovery of the SMZ sorption capacity for BTEX can be achieved by air sparging the SMZ. This report summarizes research for a follow on project to optimize the regeneration process for multiple sorption/regeneration cycles, and to develop and incorporate a vapor phase bioreactor (VPB) system for treatment of the off-gas generated during air sparging. To this end, we conducted batch and column laboratory SMZ and VPB experiments with synthetic and actual produced waters. Based on the results of the laboratory testing, a pilot scale study was designed and conducted to evaluate the combined SMZ/VPB process. An economic and regulatory feasibility analysis was also completed as part of the current study to assess the viability of the process for various water re-use options.

Lynn E. Katz; Kerry A. Kinney; Robert S. Bowman; Enid J. Sullivan; Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Craig R. Altare

2006-01-31T23:59:59.000Z

27

TREATMENT OF PRODUCED WATERS USING A SURFACTANT MODIFIED ZEOLITE/VAPOR PHASE BIOREATOR SYSTEM  

DOE Green Energy (OSTI)

Co-produced water from the oil and gas industry is by some estimates the largest single waste stream in the country, aside from nonhazardous industrial wastes. Characteristics of produced water include high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component, and chemicals added during the oil-production process. While most of the produced water is disposed via reinjection, some of them must be treated to remove organic constituents before the water is discharged. An efficient, cost-effective treatment technology is needed to remove these constituents. Surfactant-modified zeolite (SMZ) has been used successfully to treat contaminated ground water for organic and inorganic constituents. In addition, the low cost of natural zeolites makes their use attractive in water-treatment applications. Our previous DOE research work (DE-AC26-99BC15221) demonstrated that SMZ could successfully remove BTEX compounds from the produced water. In addition, SMZ could be regenerated through a simple air sparging process. The primary goal of this project is to develop a robust SMZ/VPB treatment system to efficiently remove the organic constituents from produced water in a cost-effective manner. This report summarizes work of this project from March 2003 through September 2003. We have continued our investigation of SMZ regeneration from our previous DOE project. Ten saturation/stripping cycles have been completed for SMZ columns saturated with BTEX compounds. The results suggest that BTEX sorption capacity is not lost after ten saturation/regeneration cycles. The composition of produced water from a site operated by Crystal Solutions Ltd. in Wyoming has been characterized and was used to identify key semi-volatile components. Isotherms with selected semi-volatile components have been initiated and preliminary results have been obtained. The experimental vapor phase bioreactors for this project have been designed and assembled to treat the off-gas from the SMZ regeneration process. These columns will be used both in the laboratory and in the proposed field testing to be conducted next year. Innocula for the columns that degrade all of the BTEX columns have been developed.

LYNN E. KATZ; KERRY A. KINNEY; R.S. BOWMAN; E.J. SULLIVAN

2003-10-01T23:59:59.000Z

28

Quantum hologram of macroscopically entangled light via the mechanism of diffuse light storage  

E-Print Network (OSTI)

In the present paper we consider a quantum memory scheme for light diffusely propagating through a spatially disordered atomic gas. The diffuse trapping of the signal light pulse can be naturally integrated with the mechanism of stimulated Raman conversion into a long-lived spin coherence. Then the quantum state of the light can be mapped onto the disordered atomic spin subsystem and can be stored in it for a relatively long time. The proposed memory scheme can be applicable for storage of the macroscopic analog of the $\\Psi^{(-)}$ Bell state and the prepared entangled atomic state performs its quantum hologram, which suggests the possibility of further quantum information processing.

L. V. Gerasimov; I. M. Sokolov; D. V. Kupriyanov; M. D. Havey

2011-11-29T23:59:59.000Z

29

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System  

DOE Green Energy (OSTI)

This report summarizes work performed on this project from October 2004 through March 2005. In previous work, a surfactant modified zeolite (SMZ) was shown to be an effective system for removing BTEX contaminants from produced water. Additional work on this project demonstrated that a compost-based biofilter could biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, it was also determined that the BTEX concentrations in the waste gas stream varied significantly during the regeneration period and the initial BTEX concentrations were too high for the biofilter to handle effectively. A series of experiments were conducted to determine the feasibility of using a passive adsorption column placed upstream of the biofilter to attenuate the peak gas-phase VOC concentrations delivered to the biofilter during the SMZ regeneration process. In preparation for the field test of the SMZ/VPB treatment system in New Mexico, a pilot-scale SMZ system was also designed and constructed during this reporting period. Finally, a cost and feasibility analysis was also completed. To investigate the merits of the passive buffering system during SMZ regeneration, two adsorbents, SMZ and granular activated carbon (GAC) were investigated in flow-through laboratory-scale columns to determine their capacity to handle steady and unsteady VOC feed conditions. When subjected to a toluene-contaminated air stream, the column containing SMZ reduced the peak inlet 1000 ppmv toluene concentration to 630 ppmv at a 10 second contact time. This level of buffering was insufficient to ensure complete removal in the downstream biofilter and the contact time was longer than desired. For this reason, using SMZ as a passive buffering system for the gas phase contaminants was not pursued further. In contrast to the SMZ results, GAC was found to be an effective adsorbent to handle the peak contaminant concentrations that occur early during the SMZ regeneration process. At a one second residence time, the GAC bed reduced peak contaminant concentrations by 97%. After the initial peak, the inlet VOC concentration in the SMZ regeneration gas stream drops exponentially with time. During this period, the contaminants on the GAC subsequently desorbed at a nearly steady rate over the next 45 hours resulting in a relatively steady effluent concentration of approximately 25 ppm{sub v}. This lower concentration is readily degradable by a downstream vapor phase biofilter (VPB) and the steady nature of the feed stream will prevent the biomass in the VPB from enduring starvation conditions between SMZ regeneration cycles. Repetitive sorption and desorption cycles that would be expected in the field were also investigated. It was determined that although the GAC initially lost some VOC sorption capacity, the adsorption and desorption profiles stabilized after approximately 6 cycles indicating that a GAC bed should be suitable for continuous operation. In preparation for the pilot field testing of the SMZ/VPB system, design, ''in-house'' construction and testing of the field system were completed during this project period. The design of the SMZ system for the pilot test was based on previous investigations by the PI's in Wyoming, 2002 and on analyses of the produced water at the field site in New Mexico. The field tests are scheduled for summer, 2005. A cost survey, feasibility of application and cost analyses were completed to investigate the long term effectiveness of the SMZ/VPB system as a method of treating produced water for re-use. Several factors were investigated, including: current costs to treat and dispose of produced water, end-use water quality requirements, and state and federal permitting requirements.

Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2005-03-11T23:59:59.000Z

30

Analysis of the structure and mechanisms of extinction of a counterflow methanol-air diffusion flame  

SciTech Connect

Numerical calculations were performed to determine the structure and to clarify the extinction mechanisms of diffusion flames stabilized between counterflowing streams of methanol and air. The calculations were performed at a value of the thermodynamic pressure equal to 1 atmosphere, with different values for the rate of strain and with two different chemical kinetic mechanisms, mechanism a and mechanism b. Mechanism a and mechanism b have the same set of elementary reactions, but the rate constants for these elementary reactions were obtained from two different references. If mechanism a is used, the authors conclude that at low rates of strain the concentration of CH/sub 2/OH and HCO are in steady state and, if partial equilibrium is assumed for certain reactions, there exist algebraic relations among the concentrations of the radicals OH, H, and O. As the rate of strain is increased, HCO is no longer in steady state and no solution was obtained for a strain rate greater than 521 s/sup -1/. However, if mechanism b is used, the concentration of HCO alone is in steady state, and there also exist algebraic relations among the concentrations of the radicals OH, H, and O. As the rate of strain is increased, no solution was obtained for a strain rate greater than 168 s/sup -1/, and the authors speculate that extinction of the flame is due to a large value of the activation energy for a reaction controlling the pyrolysis of CH/sub 2/OH to CH/sub 2/O.

Seshadri, K.; Trevino, C.; Smooke, M.D.

1989-05-01T23:59:59.000Z

31

The Schrodinger-Chetaev Equation in Bohmian Quantum Mechanics and Diffusion Mechanism for Alpha Decay, Cluster Radioactivity and Spontaneous Fission  

E-Print Network (OSTI)

In the framework of Bohmian quantum mechanics supplemented with the Chetaev theorem on stable trajectories in dynamics in the presence of dissipative forces we have shown the possibility of the classical (without tunneling) universal description of radioactive decay of heavy nuclei, in which under certain conditions so called noise-induced transition is generated or, in other words, the stochastic channel of alpha decay, cluster radioactivity and spontaneous fission conditioned by the Kramers diffusion mechanism. Based on the ENSDF database we have found the parametrized solutions of the Kramers equation of Langevin type by Alexandrov dynamic auto-regularization method (FORTRAN program REGN-Dubna). These solutions describe with high-accuracy the dependence of the half-life (decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products. The verification of inverse problem solution in the framework of the universal Kramers description of the alpha decay, cluster radioactivity and spontaneous fission, which was based on the newest experimental data of alpha-decay of even-even super heavy nuclei (Z=114, 116, 118) have shown the good coincidence of the experimental and theoretical half-life depend upon of alpha-decay energy.

V. D. Rusov; S. Cht. Mavrodiev; M. A. Deliyergiyev

2008-10-16T23:59:59.000Z

32

Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract--In metal organic vapor phase epitaxy we developed  

E-Print Network (OSTI)

Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract-- In metal organic vapor phase epitaxy we developed GaInN/GaN quantum well material suitable for 500 ­ 580 nm light emitting diodes at longer wavelengths. Index Terms-- a-plane GaN, GaInN, Green light emitting diode, m-plane GaN I

Wetzel, Christian M.

33

Vaporization behavior of non-stoichiometric refractory carbide materials and direct observations of the vapor phase using laser diagnostics  

DOE Green Energy (OSTI)

Transition metal and actinide carbides, such as ZrC or NbC and UC or ThC, exhibit a wide range of stoichiometry, and therefore vaporize incongruently. At long times, steady state vaporization can be achieved where relative concentrations of atomic species on solid surface equals that in the gas phase. The surface composition under these steady state conditions is termed the congruently vaporizing composition, (CVC). Modeling the vaporization or corrosion behavior of this dynamic process is complex and requires an understanding of how the surface composition changes with time and a knowledge of CVC, which is both temperature and atmosphere dependent. This paper describes vaporization and corrosion behavior of non-stoichiometric refractory carbide materials and, as an example, describes a thermokinetic model that characterizes the vaporization behavior of the complex carbide U{sub x}Zr{sub 1-x}C{sub y} in hydrogen at 2500 to 3200 K. This model demonstrates that steady state corrosion of U{sub x}Zr{sub l-x}C{sub y} is rate limited by gaseous transport of Zr where partial pressure of Zr is determined by CVC. This paper also briefly describes efforts to image and characterize the vapor phase above the surface of ZrC in static and flowing gas environments using planar laser induced fluorescence. We have developed the method for monitoring and controlling the corrosion behavior of nuclear fuels in nuclear thermal rockets. However, the techniques described can be used, to image boundary layers, and could be used verifying corrosion models.

Butt, D.P.; Wantuck, P.J.; Rehse, S.J.; Wallace, T.C. Sr.

1993-09-01T23:59:59.000Z

34

Erratum: ``Nitrogen diffusion mechanism in the R2Fe17 lattice'' [Appl. Phys. Lett. 67, 208 (1995)  

E-Print Network (OSTI)

Erratum: ``Nitrogen diffusion mechanism in the R2Fe17 lattice'' [Appl. Phys. Lett. 67, 208 (1995 Center for Precision Manufacturing and Institute of Materials Science, University of Connecticut, Storrs concentration distribution in the hollow can be obtained by solving Eq. 8 whose solution is1 cf r,t cf0R r­R0 cf

Yang, De-Ping

35

Determination of the adsorptive capacity and adsorption isotherm of vapor-phase mercury chloride on powdered activated carbon using thermogravimetric analysis  

Science Conference Proceedings (OSTI)

This study investigated the use of thermogravimetric analysis (TGA) to determine the adsorptive capacity and adsorption isotherm of vapor-phase mercury chloride on powdered activated carbon (PAC). The technique is commonly applied to remove mercury-containing air pollutants from gas streams emitted from municipal solid waste incinerators. An alternative form of powdered activated carbon derived from a pyrolyzed tire char was prepared for use herein. The capacity of waste tire-derived PAC to adsorb vapor-phase HgCl{sub 2} was successfully measured using a self-designed TGA adsorption system. Experimental results showed that the maximum adsorptive capacities of HgCl{sub 2} were 1.75, 0.688, and 0.230 mg of HgCl{sub 2} per gram of powdered activated carbon derived from carbon black at 30, 70, and 150{sup o} for 500 {mu}g/m{sup 3} of HgCl{sub 2}, respectively. Four adsorption isotherms obtained using the Langmuir, Freundlich, Redlich-Peterson, and Brunauer-Emmett-eller (BET) models were used to simulate the adsorption of HgCl{sub 2}. The comparison of experimental data associated with the four adsorption isotherms indicated that BET fit the experimental results better than did the other isotherms at 30{sup o}, whereas the Freundlich isotherm fit the experimental results better at 70 and 150{sup o}. Furthermore, the calculations of the parameters associated with Langmuir and Freundlich isotherms revealed that the adsorption of HgCl{sub 2} by PAC-derived carbon black favored adsorption at various HgCl{sub 2} concentrations and temperatures. 35 refs., 7 figs., 3 tabs.

Hsun-Yu Lin; Chung-Shin Yuan; Wei-Ching Chen; Chung-Hsuang Hung [National Sun Yat-Sen University, Taiwan (China). Institute of Environmental Engineering

2006-11-15T23:59:59.000Z

36

Growth and characterization of In{sub 0.2}Ga{sub 0.8}Sb device structures using metalorganic vapor phase epitaxy  

DOE Green Energy (OSTI)

In{sub 0.2}Ga{sub 0.8}Sb epitaxial layers and thermophotovoltaic (TPV) device structures have been grown on GaSb and GaAs substrates by metalorganic vapor phase epitaxy (MOVPE). Control of the n-type doping up to 1 {times} 10{sup 18} cm{sup {minus}3} was achieved using diethyltellurium (DETE) as the dopant source. A Hall mobility of greater than 8,000 cm{sup 2}/Vs at 77 K was obtained for a 3 {times} 10{sup 17} cm{sup {minus}3} doped In{sub 0.2}Ga{sub 0.8}Sb layer grown on high-resistivity GaSb substrate. The In{sub 0.2}Ga{sub 0.8}Sb epilayers directly grown on GaSb substrates were tilted with respect to the substrates, with the amount of tilt increasing with the layer thickness. Transmission electron microscopy (TEM) studies of the layers showed the presence of dislocation networks across the epilayers parallel to the interface at different distances from the interface, but the layers above this dislocation network were virtually free of dislocations. A strong correlation between epilayer tilt and TPV device properties was found, with layers having more tilt providing better devices. The results suggest that the dislocations moving parallel to the interface cause lattice tilt, and control of this layer tilt may enable the fabrication of better quality device structures.

Ehsani, H.; Bhat, I.; Hitchcock, C.; Gutmann, R. [Rensselaer Polytechnic Inst., Troy, NY (United States); Charache, G.; Freeman, M. [Lockheed Martin Inc., Schenectady, NY (United States)

1997-05-01T23:59:59.000Z

37

Transition between the 1 x 1 and ({radical}3 x 2{radical}3)R30{degree} surface structures of GaN in the vapor-phase environment  

SciTech Connect

Out-of-plane structures of the GaN(0001) surface in the metal-organic chemical vapor deposition (MOCVD) environment have been determined using in situ grazing-incidence X-ray scattering. The authors measured 11{bar 2}{ell} crystal truncation rod intensities at a variety of temperatures and ammonia partial pressures on both sides of the 1 x 1 to ({radical}3 x 2{radical}3)R30{degree} surface phase transition. The out-of-plane structure of the ({radical}3 x 2{radical}3)R30{degree} phase appears to be nearly independent of temperature below the transition, while the structure of the 1 x 1 phase changes increase rapidly as the phase transition is approached from above. A model for the structure of the 1 x 1 phase with a partially-occupied top Ga layer agrees well with the data. The observed temperature dependence is consistent with a simple model of the equilibrium between the vapor phase and the surface coverage of Ga and N. In addition, the authors present results on the kinetics of reconstruction domain coarsening following a quench into the ({radical}3 x 2{radical}3)R30{degree} phase field.

Munkholm, A.; Thompson, C.; Stephenson, G. B.; Eastman, J. A.; Auciello, O.; Fini, P.; Speck, J. S.; DenBaars, S. P.

2000-01-12T23:59:59.000Z

38

METAL ORGANIC VAPOR PHASE EPITAXY  

Science Conference Proceedings (OSTI)

Jun 4, 2004 ... used to texture the surface of a Light Emitting Diode (LED) structure, enhancing light extraction by a factor of 2 to 3 times. This paper will.

39

Electromagnetic Nature of Thermo-Mechanical Mass-Energy Transfer Due to Photon Diffusive Re-Emission and  

E-Print Network (OSTI)

mass-transfer trough material systems involved, from a mass-energy source to a sink system. Otherwise- contact" diffusive re-emission and propagation) and commensurate mass-transfer trough material systems conduction theory (parabolic difference equation), allowing infinite speed of thermal energy propagation (i

Kostic, Milivoje M.

40

Differences in the mechanics of information diffusion across topics: idioms, political hashtags, and complex contagion on twitter  

Science Conference Proceedings (OSTI)

There is a widespread intuitive sense that different kinds of information spread differently on-line, but it has been difficult to evaluate this question quantitatively since it requires a setting where many different kinds of information spread in a ... Keywords: information diffusion, social contagion, social media

Daniel M. Romero; Brendan Meeder; Jon Kleinberg

2011-03-01T23:59:59.000Z

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


41

Long Term Field Development of a Surfactant Modified Zeolite/Vapor Phase Bioreactor System for Treatment of Produced Waters for Power Generation  

Science Conference Proceedings (OSTI)

The main goal of this research was to investigate the feasibility of using a combined physicochemical/biological treatment system to remove the organic constituents present in saline produced water. In order to meet this objective, a physical/chemical adsorption process was developed and two separate biological treatment techniques were investigated. Two previous research projects focused on the development of the surfactant modified zeolite adsorption process (DE-AC26-99BC15221) and development of a vapor phase biofilter (VPB) to treat the regeneration off-gas from the surfactant modified zeolite (SMZ) adsorption system (DE-FC26-02NT15461). In this research, the SMZ/VPB was modified to more effectively attenuate peak loads and to maintain stable biodegradation of the BTEX constituents from the produced water. Specifically, a load equalization system was incorporated into the regeneration flow stream. In addition, a membrane bioreactor (MBR) system was tested for its ability to simultaneously remove the aromatic hydrocarbon and carboxylate components from produced water. The specific objectives related to these efforts included the following: (1) Optimize the performance VPBs treating the transient loading expected during SMZ regeneration: (a) Evaluate the impact of biofilter operating parameters on process performance under stable operating conditions. (b) Investigate how transient loads affect biofilter performance, and identify an appropriate technology to improve biological treatment performance during the transient regeneration period of an SMZ adsorption system. (c) Examine the merits of a load equalization technology to attenuate peak VOC loads prior to a VPB system. (d) Evaluate the capability of an SMZ/VPB to remove BTEX from produced water in a field trial. (2) Investigate the feasibility of MBR treatment of produced water: (a) Evaluate the biodegradation of carboxylates and BTEX constituents from synthetic produced water in a laboratory-scale MBR. (b) Evaluate the capability of an SMZ/MBR system to remove carboxylates and BTEX from produced water in a field trial. Laboratory experiments were conducted to provide a better understanding of each component of the SMZ/VPB and SMZ/MBR process. Laboratory VPB studies were designed to address the issue of influent variability and periodic operation (see DE-FC26-02NT15461). These experiments examined multiple influent loading cycles and variable concentration loadings that simulate air sparging as the regeneration option for the SMZ system. Two pilot studies were conducted at a produced water processing facility near Farmington, New Mexico. The first field test evaluated SMZ adsorption, SMZ regeneration, VPB buffering, and VPB performance, and the second test focused on MBR and SMZ/MBR operation. The design of the field studies were based on the results from the previous field tests and laboratory studies. Both of the biological treatment systems were capable of removing the BTEX constituents in the laboratory and in the field over a range of operating conditions. For the VPB, separation of the BTEX constituents from the saline aqueous phase yielded high removal efficiencies. However, carboxylates remained in the aqueous phase and were not removed in the combined VPB/SMZ system. In contrast, the MBR was capable of directly treating the saline produced water and simultaneously removing the BTEX and carboxylate constituents. The major limitation of the MBR system is the potential for membrane fouling, particularly when the system is treating produced water under field conditions. The combined process was able to effectively pretreat water for reverse osmosis treatment and subsequent downstream reuse options including utilization in power generation facilities. The specific conclusions that can be drawn from this study are summarized.

Lynn Katz; Kerry Kinney; Robert Bowman; Enid Sullivan; Soondong Kwon; Elaine Darby; Li-Jung Chen; Craig Altare

2007-12-31T23:59:59.000Z

42

Relativistic diffusion  

E-Print Network (OSTI)

We discuss a relativistic diffusion in the proper time in an approach of Schay and Dudley. We derive (Langevin) stochastic differential equations in various coordinates.We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form.We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution.We discuss drag terms leading to an equilibrium distribution.The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Juettner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

Z. Haba

2008-09-08T23:59:59.000Z

43

Diffusion Coefficients  

Science Conference Proceedings (OSTI)

Mar 13, 2012 ... Challenges in Constructing Diffusion Mobility Databases for Industrial Alloys: ... Implementation of new initiatives such as the Materials Genome ...

44

Organometallic Vapor Phase Epitaxy Technical Program  

Science Conference Proceedings (OSTI)

Mar 12, 2001 ... integrity, Emergency Response, Safety for the ESG products. The pre- ... systems, multi-point gas monitoring, and one or more emergency gas.

45

Sampling Conditioned Hypoelliptic Diffusions  

E-Print Network (OSTI)

A series of recent articles introduced a method to construct stochastic partial differential equations (SPDEs) which are invariant with respect to the distribution of a given conditioned diffusion. These works are restricted to the case of elliptic diffusions where the drift has a gradient structure, and the resulting SPDE is of second order parabolic type. The present article extends this methodology to allow the construction of SPDEs which are invariant with respect to the distribution of a class of hypoelliptic diffusion processes, subject to a bridge conditioning. This allows the treatment of more realistic physical models, for example one can use the resulting SPDE to study transitions between meta-stable states in mechanical systems with friction and noise. In this situation the restriction of the drift being a gradient can also be lifted.

Hairer, Martin; Voss, Jochen

2009-01-01T23:59:59.000Z

46

Diffuse Scattering  

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

Diffuse Scattering Diffuse Scattering * Anticipatory (trick) question: If you have an x-ray or neutron detector looking at a small sample volume, which will scatter more x- rays or neutrons into the detector 1 atom 100 atoms or 1000 atoms? X-ray or neutron beam Answer: Depends! Diffuse Scattering Gene E. Ice Materials Science and Technology Division Oak Ridge National Laboratory, USA National School on Neutron and X-ray Scattering ORNL/SNS June 2011 Presentation concentrates year graduate-level course into 1 hour * Skip mathematical complexities * Expose to range of applications * Develop intuition for length scales * Talk like x-ray/neutron scattering guru - Reciprocal space - Debye Temperature - Laue monotonic - Krivoglaz defects of 1st/2nd kinds! Great for cocktail parties or impressing attractive strangers-

47

Diffusion bonding  

SciTech Connect

1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

Anderson, Robert C. (Oak Ridge, TN)

1976-06-22T23:59:59.000Z

48

BEAM DIFFUSION MEASUREMENTS AT RHIC.  

Science Conference Proceedings (OSTI)

During a store, particles from the beam core continually diffuse outwards into the halo through a variety of mechanisms. Understanding the diffusion rate as a function of particle amplitude can help discover which processes are important to halo growth. A collimator can be used to measure the amplitude growth rate as a function of the particle amplitude. In this paper we present results of diffusion measurements performed at the Relativistic Heavy Ion Collider (RHIC) with fully stripped gold ions, deuterons, and protons. We compare these results with measurements from previous years, and simulations, and discuss any factors that relate to beam growth in RHIC.

FLILLER,R.P.,IIIDREES,A.GASSNER,D.MCINTYRE,G.PEGGS,S.TRBOJEVIC,D.

2003-05-12T23:59:59.000Z

49

Quasichemical Models of Multicomponent Nonlinear Diffusion  

E-Print Network (OSTI)

Diffusion preserves the positivity of concentrations, therefore, multicomponent diffusion should be nonlinear if there exist non-diagonal terms. The vast variety of nonlinear multicomponent diffusion equations should be ordered and special tools are needed to provide the systematic construction of the nonlinear diffusion equations for multicomponent mixtures with significant interaction between components. We develop an approach to nonlinear multicomponent diffusion based on the idea of the reaction mechanism borrowed from chemical kinetics. Chemical kinetics gave rise to very seminal tools for the modeling of processes. This is the stoichiometric algebra supplemented by the simple kinetic law. The results of this invention are now applied in many areas of science, from particle physics to sociology. In our work we extend the area of applications onto nonlinear multicomponent diffusion. We demonstrate, how the mechanism based approach to multicomponent diffusion can be included into the general thermodynamic ...

Gorban, A N; Wahab, H A

2011-01-01T23:59:59.000Z

50

Eddy diffusion  

E-Print Network (OSTI)

Perhaps you have heard that turbulence is the most difficult problem in fluid mechanics and, according to some, the greatest unsolved problem in physics. One indication of the difficulty is that it is impossible to give a satisfactory definition of a “turbulent flow”. But everyone agrees that one

unknown authors

2000-01-01T23:59:59.000Z

51

Study of intradrystalline diffusion in zeolites communication 3. Kinetics of adsorption of trans-2-butene by NaA and NaMgA zeolites  

Science Conference Proceedings (OSTI)

This article studies the kinetics of adsorption of trans-2-butene by NaA zeolite with a varying crystal size, microcrystalline granulated NaA zeolite using granules of different sizes, and microcrystalline powdered Na/sub 8/Mg/sub 2/A zeolite. It is shown that the rate of adsorption is determined by the intracrystalline diffusion and that the effect of transfer in the transport pores and the final rate of dissipation of the heat of adsorption can be neglected. In adsorption of trans-2-butene by Na/sub 8/Mg/sub 2/A zeolite with a stepwise change in the pressure of the adsorbate, the kinetic curves are satisfactorily described by an internal diffusion equation for the kinetics of isothermal adsorption. The kinetics of adsorption were studied at 303 degrees K from the one-component vapor phase on a vacuum adsorption setup using quartz spring balance.

Broddak, R.; Dubinin, M.M.; Falko, L.A.; Gorlov, V.A.; Kuhlmann, B.; Scholner, E.; Voloshchuk, A.M.

1985-09-10T23:59:59.000Z

52

Parallel flow diffusion battery  

DOE Patents (OSTI)

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, Hsu-Chi (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM)

1984-08-07T23:59:59.000Z

53

Parallel flow diffusion battery  

DOE Patents (OSTI)

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, H.C.; Cheng, Y.S.

1984-01-01T23:59:59.000Z

54

2012 Diffusion Workshop Presentation  

Science Conference Proceedings (OSTI)

... Diffusion Studies in Mg-Al-Zn (N. Kulkarni, B. Warmack, J. Mundy, ORNL); Thermodynamics and Correlation Effects on Diffusion in Al-Ni Melts. ...

2012-12-05T23:59:59.000Z

55

Acceleration Mechanisms  

E-Print Network (OSTI)

Glossary I. Background and context of the subject II. Stochastic acceleration III. Resonant scattering IV. Diffusive shock acceleration V. DSA at multiple shocks VI. Applications of DSA VII. Acceleration by parallel electric fields VIII. Other acceleration mechanisms IX. Future directions X. Appendix: Quasilinear equations XI. Bibliography

Melrose, D B

2009-01-01T23:59:59.000Z

56

In vivo facilitated diffusion model  

E-Print Network (OSTI)

Under dilute in vitro conditions transcription factors rapidly locate their target sequence on DNA by using the facilitated diffusion mechanism. However, whether this strategy of alternating between three-dimensional bulk diffusion and one-dimensional sliding along the DNA contour is still beneficial in the crowded interior of cells is highly disputed. Here we use a simple model for the bacterial genome inside the cell and present a semi-analytical model for the in vivo target search of transcription factors within the facilitated diffusion framework. Without having to resort to extensive simulations we determine the mean search time of a lac repressor in a living E. coli cell by including parameters deduced from experimental measurements. The results agree very well with experimental findings, and thus the facilitated diffusion picture emerges as a quantitative approach to gene regulation in living bacteria cells. Furthermore we see that the search time is not very sensitive to the parameters characterizing the DNA configuration and that the cell seems to operate very close to optimal conditions for target localization. Local searches as implied by the colocalization mechanism are only found to mildly accelerate the mean search time within our model.

Max Bauer; Ralf Metzler

2013-01-23T23:59:59.000Z

57

Microfabricated diffusion source  

DOE Patents (OSTI)

A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

Oborny, Michael C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

2008-07-15T23:59:59.000Z

58

DEVELOPMENT OF NIOBIUM DIFFUSION BARRIERS FOR ALUMINUM-CLAD URANIUM ALLOY FUEL ELEMENTS  

DOE Green Energy (OSTI)

S>Nickel was used as a diffusion barrier for Al-clad uranium alloy fuel elements, operating at 650 nif- F in organiccooled reactors. Advanced organic-moderated reactor (AOMR) concepts include operating temperatures up to 850 nif- F. Since the interdiffusion of Al --Ni is 150 times faster at 850 nif- F than at 650 nif- F, an alternate diffusion barrier is required. Subsequent studies resuited in the selection of niobium. Several techniques for bonding niobium to the U--10 Mo fuel were investigated. After considerable development effort, electron beam vacuum deposition yielded adherent, nonporous, ductile coatings. Isostatic bonding, at 1050 nif- C and 12,000 psi for 1 hr, also resulted in metallurgically bonded niobium on the major surfaces of U-10 Mo fuel plates. Roll-bonding achieved metallurgically bonded plates on small test specimens, but was never reproduced on full-size plates. Vapor phase deposition, by H/sub 2/ reduction of NbCl/sub 5/, was also partially successful, but not reproducible. Ultrasonic bonding has shown promise in spot welding tests. Plasma-spray coating and electroplating in a fused salt bath were also considered, but not actively evaluated. (auth)

Briggs, B.N.; Friske, W.H.

1963-10-31T23:59:59.000Z

59

Updating Applied Diffusion Models  

Science Conference Proceedings (OSTI)

Most diffusion models currently used in air quality applications are substantially out of date with understanding of turbulence and diffusion in the planetary boundary layer. Under a Cooperative Agreement with the Environmental Protection Agency, ...

J. C. Weil

1985-11-01T23:59:59.000Z

60

Surveying Diffusion in Complex Geometries. An Essay  

E-Print Network (OSTI)

The surrounding world surprises us by the beauty and variety of complex shapes that emerge from nanometric to macroscopic scales. Natural or manufactured materials (sandstones, sedimentary rocks and cement), colloidal solutions (proteins and DNA), biological cells, tissues and organs (lungs, kidneys and placenta), they all present irregularly shaped "scenes" for a fundamental transport "performance", that is, diffusion. Here, the geometrical complexity, entangled with the stochastic character of diffusive motion, results in numerous fascinating and sometimes unexpected effects like diffusion screening or localization. These effects control many diffusion-mediated processes that play an important role in heterogeneous catalysis, biochemical mechanisms, electrochemistry, growth phenomena, oil recovery, or building industry. In spite of a long and rich history of academic and industrial research in this field, it is striking to see how little we know about diffusion in complex geometries, especially the one whic...

Grebenkov, Denis

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Diffusive Accumulation of Methane Bubbles in Seabed  

E-Print Network (OSTI)

We consider seabed bearing methane bubbles. In the absence of fractures the bubbles are immovably trapped in a porous matrix by surface tension forces; therefore the dominant mechanism of transfer of gas mass becomes the diffusion of gas molecules through the liquid. The adequate description of this process requires accounting "other-than-normal" (non-Fickian) diffusion effects, thermodiffusion and gravity action. We evaluate the diffusive flux of aqueous methane and predict the possibility of existence of bubble mass accumulation zones (which can appear independently from the presence/absence of hydrate stability zone) and effect of non-Fickian drift on the capacity of shallow and deep methane-hydrate deposits.

Goldobin, D S; Levesley, J; Lovell, M A; Rochelle, C A; Jackson, P; Haywood, A; Hunter, S; Rees, J

2010-01-01T23:59:59.000Z

62

Facilitated diffusion of proteins on chromatin  

E-Print Network (OSTI)

We present a theoretical model of facilitated diffusion of proteins in the cell nucleus. This model, which takes into account the successive binding/unbinding events of proteins to DNA, relies on a fractal description of the chromatin which has been recently evidenced experimentally. Facilitated diffusion is shown quantitatively to be favorable for a fast localization of a target locus by a transcription factor, and even to enable the minimization of the search time by tuning the affinity of the transcription factor with DNA. This study shows the robustness of the facilitated diffusion mechanism, invoked so far only for linear conformations of DNA.

O. Benichou; C. Chevalier; B. Meyer; R. Voituriez

2010-06-24T23:59:59.000Z

63

Surveying Diffusion in Complex Geometries. An Essay  

E-Print Network (OSTI)

The surrounding world surprises us by the beauty and variety of complex shapes that emerge from nanometric to macroscopic scales. Natural or manufactured materials (sandstones, sedimentary rocks and cement), colloidal solutions (proteins and DNA), biological cells, tissues and organs (lungs, kidneys and placenta), they all present irregularly shaped "scenes" for a fundamental transport "performance", that is, diffusion. Here, the geometrical complexity, entangled with the stochastic character of diffusive motion, results in numerous fascinating and sometimes unexpected effects like diffusion screening or localization. These effects control many diffusion-mediated processes that play an important role in heterogeneous catalysis, biochemical mechanisms, electrochemistry, growth phenomena, oil recovery, or building industry. In spite of a long and rich history of academic and industrial research in this field, it is striking to see how little we know about diffusion in complex geometries, especially the one which occurs in three dimensions. We present our recent results on restricted diffusion. We look into the role of geometrical complexity at different levels, from boundary microroughness to hierarchical structure and connectivity of the whole diffusion-confining domain. We develop a new approach which consists in combining fast random walk algorithms with spectral tools. The main focus is on studying diffusion in model complex geometries (von Koch boundaries, Kitaoka acinus, etc.), as well as on developing and testing spectral methods. We aim at extending this knowledge and at applying the accomplished arsenal of theoretical and numerical tools to structures found in nature and industry.

Denis Grebenkov

2009-09-08T23:59:59.000Z

64

Thermodynamics and Diffusion  

Science Conference Proceedings (OSTI)

Feb 28, 2011 ... Hume-Rothery Symposium Thermodynamics and Diffusion Coupling ... be quite fundamental and often it cannot be distinguished from “basic” ...

65

Mulitcomponent Multiphase Diffusion  

Science Conference Proceedings (OSTI)

... 54 (2006) p 2431-2439. pdf file; "Hillert, Höglund, and Ågren, "Diffusion in interstitial compounds with thermal and stoichiometric defects," J. Appl. ...

2008-07-22T23:59:59.000Z

66

Tenth Biennial Workshop on Organometallic Vapor Phase Epitaxy  

Science Conference Proceedings (OSTI)

Mar 15, 2001 ... National Renewable Energy Lab. Dr. Simon Watkins. Simon Fraser ..... Payment shall be made in US dollars drawn on a US bank. r Credit Card ...

67

Metal Organic Vapor Phase Epitaxy ICMOVPE-XV  

Science Conference Proceedings (OSTI)

Growth of Energy Technology (solid state lighting, PV, Thermoelectrics, etc) ..... treatment prices when booked in advance for the attendees and guests of.

68

Organic lateral heterojunction devices for vapor-phase chemical detection  

E-Print Network (OSTI)

As the U.S. is engaged in battle overseas, there is an urgent need for the development of sensors for early warning and protection of military forces against potential attacks. On the battlefields, improvised explosive ...

Ho, John C., 1980-

2009-01-01T23:59:59.000Z

69

Ninth International Conference on Metal Organic Vapor Phase ...  

Science Conference Proceedings (OSTI)

Hertz Rent-a-Car System has been selected as the Official Car Rental Company for the ICMOVPE IX. Special rates are being offered and will be honored up to ...

70

Regular Transient Loading Response in a Vapor-Phase  

E-Print Network (OSTI)

from a POTW using a compost bio?lter. ” Water Environ. Res.heat and mass transport within a compost bio?lter: I. ModelM. A. ?1995?. “Operation of compost based bio?lters under

Wright, W F; Schroeder, E D; Chang, Daniel P.Y.

2005-01-01T23:59:59.000Z

71

Ninth International Conference on Metal Organic Vapor Phase ...  

Science Conference Proceedings (OSTI)

Free sample copies of III-Vs Review and information on the Advanced ... on the market an innovative surface contamination analysis with the powerful TOF SIMS ... NIMTEC, located in Chandler, AZ, is a subsidiary of Japan Energy that sells ...

72

Regular Transient Loading Response in a Vapor-Phase  

E-Print Network (OSTI)

JOURNAL OF ENVIRONMENTAL ENGINEERING © ASCE / DECEMBER 2005ENVIRONMENTAL ENGINEERING © ASCE / DECEMBER 2005 / 1657 nol.must be ?led with the ASCE Managing Editor. The manuscript

Wright, W F; Schroeder, E D; Chang, Daniel P.Y.

2005-01-01T23:59:59.000Z

73

Galactic Diffuse Emissions  

DOE Green Energy (OSTI)

Interactions of cosmic rays with interstellar nucleons and photons make the Milky Way a bright, diffuse source of high-energy {gamma}-rays. Observationally, the results from EGRET, COMPTEL, and OSSE have now been extended to higher energies by ground-based experiments, with detections of diffuse emission in the Galactic center reported by H.E.S.S. in the range above 100 GeV and of diffuse emission in Cygnus by MILAGRO in the TeV range. In the range above 100 keV, INTEGRAL SPI has found that diffuse emission remains after point sources are accounted for. I will summarize current knowledge of diffuse {gamma}-ray emission from the Milky Way and review some open issues related to the diffuse emission -- some old, like the distribution of cosmic-ray sources and the origin of the 'excess' of GeV emission observed by EGRET, and some recently recognized, like the amount and distribution of molecular hydrogen not traced by CO emission -- and anticipate some of the advances that will be possible with the Large Area Telescope on GLAST. We plan to develop an accurate physical model for the diffuse emission, which will be useful for detecting and accurately characterizing emission from Galactic point sources as well as any Galactic diffuse emission from exotic processes, and for studying the unresolved extragalactic emission.

Digel, Seth W.; /SLAC

2007-10-25T23:59:59.000Z

74

Eddy Advective and Diffusive Transports of Heat and Salt in the Southern Ocean  

Science Conference Proceedings (OSTI)

There are two distinct mechanisms by which eddies provide systematic transport of tracer on isopycnals: the advective transport, associated with the slumping of isopycnals, and the diffusive transport, associated with down-gradient diffusion. ...

Mei-Man Lee; A. J. George Nurser; A. C. Coward; B. A. de Cuevas

2007-05-01T23:59:59.000Z

75

Nonlinear Horizontal Diffusion for GCMs  

Science Conference Proceedings (OSTI)

The mixing-length-based parameterization of horizontal diffusion, which was originally proposed by Smagorinsky, is revisited. The complete tendencies of horizontal momentum diffusion, the associated frictional heating, and horizontal diffusion of ...

Erich Becker; Ulrike Burkhardt

2007-04-01T23:59:59.000Z

76

VISUALS: Diffusion couple animation - TMS  

Science Conference Proceedings (OSTI)

Sep 25, 2007 ... This Quicktime animation of a diffusion couple shows side-by-side views of two different atomic species - red and green - diffusing across a flat ...

77

Adaptive multigroup radiation diffusion  

E-Print Network (OSTI)

This thesis describes the development and implementation of an algorithm for dramatically increasing the accuracy and reliability of multigroup radiation diffusion simulations at low group counts. This is achieved by ...

Williams, Richard B., Sc. D. Massachusetts Institute of Technology

2005-01-01T23:59:59.000Z

78

Disposal barriers that release contaminants only by molecular diffusion  

Science Conference Proceedings (OSTI)

Engineered barriers can slow the movement of pollutants out of land disposal facilities in several ways. If the advective velocity is low, release will be primarily by molecular diffusion. Attenuation processes also work to slow the transport of many contaminants. Barriers that cause pollutants to be released almost entirely by molecular diffusion represent the best barriers achievable. Use of thick barrier materials will maximize the breakthrough time of contaminants that diffuse through the barrier. Thin barriers with exceedingly low permeabilities will not necessarily outperform thicker, more permeable liners. In fact, if diffusion is the dominant mechanism of release, the thicker, more permeable barrier may actually outperform the thinner barrier with lower permeability.

Daniel, D.E.; Shackelford, C.D.

1988-01-01T23:59:59.000Z

79

FLAMMABLE GAS DIFFUSION THROUGH SINGLE SHELL TANK (SST) DOMES  

DOE Green Energy (OSTI)

This report quantified potential hydrogen diffusion through Hanford Site Single-Shell tank (SST) domes if the SSTs were hypothetically sealed airtight. Results showed that diffusion would keep headspace flammable gas concentrations below the lower flammability limit in the 241-AX and 241-SX SST. The purpose of this document is to quantify the amount of hydrogen that could diffuse through the domes of the SSTs if they were hypothetically sealed airtight. Diffusion is assumed to be the only mechanism available to reduce flammable gas concentrations. The scope of this report is limited to the 149 SSTs.

MEACHAM, J.E.

2003-11-10T23:59:59.000Z

80

Quantum diffusion in the quasiperiodic kicked rotor  

E-Print Network (OSTI)

We study the mechanisms responsible for quantum diffusion in the quasiperiodic kicked rotor. We report experimental measurements of the diffusion constant on the atomic version of the system and develop a theoretical approach (based on the Floquet theorem) explaining the observations, especially the ``sub-Fourier'' character of the resonances observed in the vicinity of exact periodicity, i.e. the ability of the system to distinguish two neighboring driving frequencies in a time shorter than the inverse of the difference of the two frequencies.

Hans Lignier; Jean Claude Garreau; Pascal Szriftgiser; Dominique Delande

2004-12-02T23:59:59.000Z

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


81

Enforcement Documents - Portsmouth Gaseous Diffusion Plant | Department of  

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

Portsmouth Gaseous Diffusion Plant Portsmouth Gaseous Diffusion Plant Enforcement Documents - Portsmouth Gaseous Diffusion Plant March 26, 2010 Enforcement Letter, Intennech, Inc. - March 26, 2010 Enforcement Letter issued to Intermech, Inc. related to Installation and Inspection of Anchor Bolts and Pipe Supports at the DUF6 Conversion Buildings at the Portsmouth and Paducah Gaseous Diffusion Plants March 26, 2010 Enforcement Letter, Geiger Brothers Mechanical Contractors, INC - March 26, 2010 Enforcement Letter issued to Geiger Brothers Mechanical Contractors, Inc. related to Installation and Inspection of Penetration Fire Seals at the DUF6 Conversion Building at the Portsmouth Gaseous Diffusion Plant March 26, 2010 Consent Order, Uranium Disposition Services, LLC - NCO-2010-01 Consent Order issued to Uranium Disposition Services, LLC related to

82

Spherical diffusion of tritium from a point of release in a uniform unsaturated soil. A deterministic model for tritium migration in an arid disposal site  

SciTech Connect

Tritium (Tr), when released as tritiated water at a point in a uniform and relatively dry soil, redistributes in both the liquid and vapor phases. The flux density of Tr in the liquid will exceed that in the vapor phase provided the water content is greater than approximately 15% of the total soil porosity. Thus Tr redistribution must be modeled recognizing transfer ``in parallel`` in both phases. The authors use the diffusion equation cast in spherical coordinates to analyze this problem in order to provide a basis for design of field experiments, and to offer observations on the long term behavior of such systems. The solution of the diffusion equation permits calculation of the evolution of profiles of Tr concentration, within and external to the sphere of released solution, assuming the initial concentration within this sphere to be uniform. The authors also predict the rate of advance of the maximum of Tr as it advances, and attenuates, in the soil. Calculations for the case of 1 million Curies of Tr diluted in 1 liter of water and released at a depth of 20 meters, and 200 meters above the water table, are demonstrated. If the soil has an initial water volume fraction of 0.06 and total porosity of 0.3 they show, for example, that at 5 meters from the point of discharge, the Tr concentration increases to a maximum in 24 years and then slowly declines. That maximum is 1 Curie/liter. The concentration in the gas phase will be 5 orders-of-magnitude less than this. At 60 meters the maximum ever reached in the liquid phase is ca 10{sup {minus}21} Ci/liter; that maximum will be achieved after 408 years. The authors discuss the effects of variation in the volume fractions of water and air originally present in the soil on the effective diffusion coefficient of Tr in soil, consider the effects of a net flux of water in the system, and identify questions to be answered to achieve safe systematic disposal of tritium in the deep unsaturated zone of desert soil.

Smiles, D.E.; Gardner, W.R.; Schulz, R.K. [Univ. of California, Berkeley, CA (United States). Dept. of Environmental Science, Policy and Management

1993-10-01T23:59:59.000Z

83

Diffusion and Numerical Filters  

Science Conference Proceedings (OSTI)

Applications of low-pass filters or implicit diffusion are found to be extremely beneficial in a simple model problem that contains an oven-ordered advection scheme based on a symmetric stencil. In contrast, the effects are negative when either ...

William H. Raymond

1994-04-01T23:59:59.000Z

84

Erbium diffusion in silicon dioxide  

SciTech Connect

Erbium diffusion in silicon dioxide layers prepared by magnetron sputtering, chemical vapor deposition, and thermal growth has been investigated by secondary ion mass spectrometry, and diffusion coefficients have been extracted from simulations based on Fick's second law of diffusion. Erbium diffusion in magnetron sputtered silicon dioxide from buried erbium distributions has in particular been studied, and in this case a simple Arrhenius law can describe the diffusivity with an activation energy of 5.3{+-}0.1 eV. Within a factor of two, the erbium diffusion coefficients at a given temperature are identical for all investigated matrices.

Lu Yingwei; Julsgaard, B.; Petersen, M. Christian [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Jensen, R. V. Skougaard [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg O (Denmark); Pedersen, T. Garm; Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg O (Denmark); Interdisciplinary Nanoscience Center-iNANO, DK-8000 Aarhus C (Denmark); Larsen, A. Nylandsted [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Interdisciplinary Nanoscience Center-iNANO, DK-8000 Aarhus C (Denmark)

2010-10-04T23:59:59.000Z

85

Collective motion in quantum diffusive environment  

E-Print Network (OSTI)

The general problem of dissipation in macroscopic large-amplitude collective motion and its relation to energy diffusion of intrinsic degrees of freedom of a nucleus is studied. By applying the cranking approach to the nuclear many-body system, a set of coupled dynamical equations for the collective classical variable and the quantum mechanical occupancies of the intrinsic nuclear states is derived. Different dynamical regimes of the intrinsic nuclear motion and its consequences on time properties of collective dissipation are discussed.

V. M. Kolomietz; S. Å berg; S. V. Radionov

2007-06-16T23:59:59.000Z

86

Diffusive Transport by Breaking Waves  

Science Conference Proceedings (OSTI)

A simple conceptual model of the relationship between advective transport by breaking waves and diffusive transport is derived. line model postulates that the displacement of fluid parcels by a breaking wave is analogous to molecular diffusion (...

Kenneth P. Bowman

1995-07-01T23:59:59.000Z

87

Diffusion on (110) Surface of Molecular Crystal Pentaerythritol Tetranitrate  

SciTech Connect

Using classical molecular dynamics simulations, we investigate the diffusion mechanisms of admolecules on the (110) surface of molecular crystal pentaerythritol tetranitrate. Our results show that (1) admolecules are stable at off lattice sites, (2) admolecules diffuse along close-packed [1{bar 1}1] and [{bar 1}11] directions, and (3) admolecules detach from the surface at 350K and above. Based on the number of diffusion jumps as a function of temperature, we estimate the jump frequency to be v=1.14 x 10{sup 12} e{sup -0.08eV/kT} per second.

Wang, J; Golfinopoulos, T; Gee, R H; Huang, H

2007-01-25T23:59:59.000Z

88

Effect of pressure on arsenic diffusion in germanium  

SciTech Connect

We report preliminary results of a study of the activation volume for diffusion of arsenic in germanium. High-temperature high-pressure anneals were performed in a liquid argon pressure medium in a diamond anvil cell capable of reaching 5 GPa and 750 C,l which is externally heated for uniform and repeatable temperature profiles. Broadening of an ion-implanted arsenic profile was measured by Secondary Ion Mass Spectrometry. Hydrostatic pressure retards the diffusivity at 575 C, characterized by an activation volume that is +15% of the atomic volume of Ge. Implications for diffusion mechanisms are discussed.

Mitha, S.; Theiss, S.D.; Aziz, M.J. [Harvard Univ., Cambridge, MA (United States); Schiferl, D. [Los Alamos National Lab., NM (United States); Poker, D.B. [Oak Ridge National Lab., TN (United States)

1994-01-01T23:59:59.000Z

89

Sampling diffusive transition paths  

SciTech Connect

We address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with sampling infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with sampling the coarse features of long paths. The fine-features sampling stiffness is eliminated with the use of the fast sampling algorithm (FSA), and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. We use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature.

F. Miller III, Thomas; Predescu, Cristian

2006-10-12T23:59:59.000Z

90

Light diffusing fiber optic chamber  

DOE Patents (OSTI)

A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

Maitland, Duncan J. (Lafayette, CA)

2002-01-01T23:59:59.000Z

91

diffuse radiation | OpenEI  

Open Energy Info (EERE)

Login | Sign Up Wiki Apps Datasets Browse Upload data GDR Community Linked Data Search Share this page on Facebook icon Twitter icon diffuse radiation Dataset Summary...

92

Diffusion Flame Measurements: Notes B  

Science Conference Proceedings (OSTI)

... Profiles in steady and flickering methane/air, ethylene/air, and propane/air diffusion flames at atmospheric pressure using an axisymmetric burner ...

2012-10-17T23:59:59.000Z

93

Tracer Diffusion Databases for ICME  

Science Conference Proceedings (OSTI)

... of a large repository of stable isotopes that can be utilized for tracer diffusion .... Lattice Dynamics and Thermodynamics of Lithium Battery Materials LiMPO4 ...

94

Lithium Diffusion in Graphitic Carbon  

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

Volume 1 Start Page 1176 Issue 8 Pagination 1176-1180 Keywords anode, diffusion, graphene, lithium ion battery, transport Abstract Graphitic carbon is currently considered the...

95

Diffusion of liquid domains in lipid bilayer membranes  

E-Print Network (OSTI)

We report diffusion coeffcients of micron-scale liquid domains in giant unilamellar vesicles of phospholipids and cholesterol. The trajectory of each domain is tracked, and the mean square displacement grows linearly in time as expected for Brownian motion. We study domain dffusion as a function of composition and temperature, and measure how diffusion depends on domain size. We find mechanisms of domain diffusion which are consistent with membrane-dominated drag in viscous Lo phases [P.G. Saffman and M. Delbruck, PNAS 72, 3111 (1975)], and bulk-dominated drag for less viscous L$_\\alpha$ phases [B.D.Hughes et al., J. Fluid Mech. 110, 349 (1981)]. Where applicable, we obtain the membrane viscosity and report activation energies of diffusion.

Pietro Cicuta; Sarah L. Keller; Sarah L. Veatch

2006-11-18T23:59:59.000Z

96

PERFORMANCE ANALYSIS OF MECHANICAL DRAFT COOLING TOWER  

SciTech Connect

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has cross-flow and counter-current MDCT's consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to simulate the cooling tower performance for the counter-current cooling tower and to conduct a parametric study under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model and performed the benchmarking analysis against the integral measurement results to accomplish the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of parametric calculations was performed to investigate the impact of wind speeds and ambient conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was also benchmarked against the literature data and the SRS integral test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be published here.

Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

2009-02-10T23:59:59.000Z

97

Diffuser for augmenting a wind turbine  

DOE Patents (OSTI)

A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

Foreman, Kenneth M. (North Bellmore, NY); Gilbert, Barry L. (Westbury, NY)

1984-01-01T23:59:59.000Z

98

Modeling phosphorus diffusion in three dimensions  

Science Conference Proceedings (OSTI)

A three-dimensional process simulator in which both the standard nonlinear diffusion model and a five-species kinetic model are implemented to model phosphorus diffusion in silicon is described. The reaction-diffusion equations are discretized using ...

W. B. Richardson; G. F. Carey; B. J. Mulvaney

2006-11-01T23:59:59.000Z

99

Diffusion Barrier Characteristic and Breakdown Mechanism of Ni3P ...  

Science Conference Proceedings (OSTI)

... Transformations, and Reactive Phase Formation in Electronic Materials XII ... electrical signal delay and power loss in high-frequency electronic devices.

100

FLAME STRUCTURE MEASUREMENT OF POLYMER DIFFUSION FLAMES  

E-Print Network (OSTI)

of counterflow diffusion flames above condensed fuels:of counterflow diffusion flames in the forward stagnationCA, October 15-16, 1979 FLAME STRUCTURE MEASUREMENT OF

Pitz, W. J.

2011-01-01T23:59:59.000Z

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


101

New frontiers in diffusion modeling  

E-Print Network (OSTI)

Over the last fifty years, diffusion researchers have sought to explain why the rate of adoption of an innovation varies over time. Some innovations are adopted quickly as compared to others, which take decades for adoption. ...

Ranganath, Naveen Chandra

2012-01-01T23:59:59.000Z

102

Diffusion of Hydrogen in Titanium  

Science Conference Proceedings (OSTI)

Sep 1, 1994 ... TMS Member price: 10.00. Non-member price: 25.00. TMS Student Member price : 10.00. Product In Stock. Description The diffusion of ...

103

Programming reaction-diffusion processors  

Science Conference Proceedings (OSTI)

In reaction-diffusion (RD) processors, both the data and the results of the computation are encoded as concentration profiles of the reagents. The computation is performed via the spreading and interaction of wave fronts. Most prototypes of RD computers ...

Andrew Adamatzky

2004-09-01T23:59:59.000Z

104

Patterns of Turbulent and Double-Diffusive Phenomena: Observations from a Rapid-Profiling Microconductivity Probe  

Science Conference Proceedings (OSTI)

Throughout much of the ocean interior, the diapycnal buoyancy flux is maintained by both mechanical and double-diffusive processes. Assessing the relative roles of each is a challenge, particularly in complex coastal environments. During February–...

Matthew Alford; Robert Pinkel

2000-05-01T23:59:59.000Z

105

Minimum Uncertainty, Coherence and Squeezing in Diffusion Processes, and Stochastic Quantization  

E-Print Network (OSTI)

We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states.

Salvatore De Martino; Silvio De Siena; Fabrizio Illuminati; Giuseppe Vitiello

1993-10-18T23:59:59.000Z

106

MINIMUM UNCERTAINTY AND SQUEEZING IN DIFFUSION PROCESSES AND STOCHASTIC QUANTIZATION 1  

E-Print Network (OSTI)

We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states. 1

S. De Martino; S. De Siena; F. Illuminati; G. Vitiello

1993-01-01T23:59:59.000Z

107

LLNL SMP Light Diffuser Fabrication and Preliminary Data  

SciTech Connect

We are developing a cylindrical light diffuser using shape memory polymer (SMP) whose diameter, length, stiffness, and diffusion profile can be tailored to suit a particular application. The cylindrical SMP diffuser is made by casting SMP around the end of a glass optical fiber using a teflon tube as the casting mold, and abrading the cured SMP surface to cause the light to leak radially outward. The inner diameter of the casting tube is slightly larger than the fiber diameter. A smaller teflon tube is positioned over the fiber (between the fiber and the casting tube) to approximately center the fiber tip in the casting tube. As the SMP cures, it bonds with the optical fiber, creating a strong joint without the need for additional adhesives or mechanical fixtures. A close-up of the SMP-fiber joint and the finished SMP diffuser are shown in Fig.1. The SMP formulation (developed in-house) was specifically designed to be optically transparent in the visible and near-infrared regions; the spectral absorption of the SMP is shown in Fig. 2. The low absorption is important because (1) it allows the light to travel the length of the diffuser without suffering excessive loss due to absorption and (2) it permits delivery of up to 7 W (300 {micro}m SMP rod on 100 {micro}m core multimode fiber) of laser power into the diffuser without damaging the diffuser. SMP is a good wave guiding material with a refractive index of approximately 1.5. Also, the SMP stiffness can be tailored from stiff (e.g. acrylic, Ea {approx} 10{sup 9} Pa) to very flexible (e.g. silicon rubber, Ea {approx} 10{sup 6} Pa). Finally, since SMP can self-actuate, the SMP diffuser could be designed to actuate into a shape other than a straight rod (e.g. 2D or 3D coil).

Small IV, W

2006-06-02T23:59:59.000Z

108

Bohmian Mechanics  

E-Print Network (OSTI)

Bohmian mechanics is a theory about point particles moving along trajectories. It has the property that in a world governed by Bohmian mechanics, observers see the same statistics for experimental results as predicted by quantum mechanics. Bohmian mechanics thus provides an explanation of quantum mechanics. Moreover, the Bohmian trajectories are defined in a non-conspiratorial way by a few simple laws.

Detlef Duerr; Sheldon Goldstein; Roderich Tumulka; Nino Zanghi

2009-03-15T23:59:59.000Z

109

Mechanical down jar mechanism  

SciTech Connect

This paper describes a mechanical down jar mechanism for freeing stuck objects within a well bore and for conducting other down hole activities. It comprises: an elongate tubular housing having anvil means; mandrel means adapted for connection to an object to be moved downwardly within the well bore and being disposed in telescoping relation with the anvil means and the elongate tubular housing, the mandrel means adapted to be struck by the anvil means to impart a downwardly directed jarring force to the object; the elongate tubular housing having internal firing and recocking detent groove means located in axially spaced relation and forming a firing lug support land therebetween; a radially expandable and retractable firing lug assembly being disposed within the elongate tubular housing and in absence of force being applied axially thereto being radially restrained by the firing lug support land; load spring means being disposed within the elongate tubular housing and being in downward force transmitting relation with the firing lug assembly; recocking spring means being disposed within the elongate tubular housing and having upward axial force transmitting relation with the firing lug assembly.

Taylor, W.T.

1991-12-03T23:59:59.000Z

110

Fractional reaction-diffusion equations  

E-Print Network (OSTI)

In a series of papers, Saxena, Mathai, and Haubold (2002, 2004a, 2004b) derived solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which provide the extension of the work of Haubold and Mathai (1995, 2000). The subject of the present paper is to investigate the solution of a fractional reaction-diffusion equation. The results derived are of general nature and include the results reported earlier by many authors, notably by Jespersen, Metzler, and Fogedby (1999) for anomalous diffusion and del-Castillo-Negrete, Carreras, and Lynch (2003) for reaction-diffusion systems with L\\'evy flights. The solution has been developed in terms of the H-function in a compact form with the help of Laplace and Fourier transforms. Most of the results obtained are in a form suitable for numerical computation.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2006-04-21T23:59:59.000Z

111

Commercial Building Partnerships Replication and Diffusion  

SciTech Connect

This study presents findings from survey and interview data investigating replication efforts of Commercial Building Partnership (CBP) partners that worked directly with the Pacific Northwest National Laboratory (PNNL). PNNL partnered directly with 12 organizations on new and retrofit construction projects, which represented approximately 28 percent of the entire U.S. Department of Energy (DOE) CBP program. Through a feedback survey mechanism, along with personal interviews, PNNL gathered quantitative and qualitative data relating to replication efforts by each organization. These data were analyzed to provide insight into two primary research areas: 1) CBP partners’ replication efforts of technologies and approaches used in the CBP project to the rest of the organization’s building portfolio (including replication verification), and, 2) the market potential for technology diffusion into the total U.S. commercial building stock, as a direct result of the CBP program. The first area of this research focused specifically on replication efforts underway or planned by each CBP program participant. Factors that impact replication include motivation, organizational structure and objectives firms have for implementation of energy efficient technologies. Comparing these factors between different CBP partners revealed patterns in motivation for constructing energy efficient buildings, along with better insight into market trends for green building practices. The second area of this research develops a diffusion of innovations model to analyze potential broad market impacts of the CBP program on the commercial building industry in the United States.

Antonopoulos, Chrissi A.; Dillon, Heather E.; Baechler, Michael C.

2013-09-16T23:59:59.000Z

112

Ice Formation in Gas-Diffusion Layers  

SciTech Connect

Under sub-freezing conditions, ice forms in the gas-diffusion layer (GDL) of a proton exchange membrane fuel cell (PEMFC) drastically reducing cell performance. Although a number of strategies exist to prevent ice formation, there is little fundamental understanding of the mechanisms of freezing within PEMFC components. Differential scanning calorimetry (DSC) is used to elucidate the effects of hydrophobicity (Teflon® loading) and water saturation on the rate of ice formation within three commercial GDLs. We find that as the Teflon® loading increases, the crystallization temperature decreases due to a change in internal ice/substrate contact angle, as well as the attainable level of water saturation. Classical nucleation theory predicts the correct trend in freezing temperature with Teflon® loading.

Dursch, Thomas; Radke, Clayton J.; Weber, Adam Z.

2010-07-10T23:59:59.000Z

113

Tracer Diffusion Db- NIST09  

Science Conference Proceedings (OSTI)

... DCu Cu-Zn, 780oC Atom Fraction Zinc (X Zn ) 0.0 0.1 0.2 0.3 Tra cer Diffusion Co ... Au-Ni, 900 o C Atom fraction nickel (X Ni ) 0.0 0.2 0.4 0.6 0.8 1.0 ...

2012-10-04T23:59:59.000Z

114

Bohmian mechanics contradicts quantum mechanics  

E-Print Network (OSTI)

Bohmian mechanics contradicts quantum mechanics Arnold Neumaier Institut fur Mathematik, Universit://solon.cma.univie.ac.at/#24;neum/ Abstract. It is shown that, for a harmonic oscillator in the ground state, Bohmian mechanics and quantum mechanics predict values of opposite sign for certain time correlations. The discrepancy can

Neumaier, Arnold

115

Ice Formation in Gas-Diffusion Layers  

E-Print Network (OSTI)

of California. Ice Formation in Gas-Diffusion Layers Thomasconditions, ice forms in the gas-diffusion layer (GDL) of areaction of reactant gases (1). A number of strategies exist

Dursch, Thomas

2013-01-01T23:59:59.000Z

116

Synergistic diffuser/heat-exchanger design  

E-Print Network (OSTI)

The theoretical and numerical evaluation of synergistic diffusing heat-exchanger design is presented. Motivation for this development is based on current diffuser and heat-exchange technologies in cogeneration plants, which ...

Lazzara, David S. (David Sergio), 1980-

2004-01-01T23:59:59.000Z

117

Diffusion Tubes for Ambient NO2 Monitoring  

E-Print Network (OSTI)

in the field of diffusive sampling, and other stakeholders. The following (in alphabetical order) actively or vapour phase pollutant directly from the surrounding air by means of diffusion, without actively drawing

Short, Daniel

118

Hierarchical 3D diffusion wavelet shape priors  

E-Print Network (OSTI)

In this paper, we propose a novel representation of prior knowledge for image segmentation, using diffusion wavelets that can reflect arbitrary continuous interdependencies in shape data. The application of diffusion ...

Langs, Georg

119

Solar diffusion and public incentives  

Science Conference Proceedings (OSTI)

Institutional arrangements for the commercialization of solar technologies cover a variety of incentives. Although this book concentrates on one such incentive, a grant awarded to homeowners purchasing an approved solar hot water heater, the concluding discussion suggests alternative inducements. The empirical work is based on data collected in Connecticut, but attention is given to national- and state-level studies addressing various aspects of the solar-diffusion process. The authors begin by examining public acceptance and various social-science models for diffusion processes. They conclude that the importance of social and behavioral factors in accelerating the energy transition should not be underestimated. Eight appendices include survey and application forms, information releases, and information about the incentive program. 81 references, 4 figures, 33 tables.

Warkov, S.; Meyer, J.W.

1982-01-01T23:59:59.000Z

120

Fluid dynamics of double diffusive systems. Final report  

SciTech Connect

Over the past seven years the authors have conducted an experimental, numerical, and theoretical study of the stability of doubly diffusive systems, and of mixing processes in stratified turbulence. For the study of the stability of doubly diffusive systems continuous gradients of two diffusing components (heat and salinity in this case) were used as the initial condition, and forcing was introduced by lateral heating and surface shear. The goals of this work included (1) quantification of the effects of finite amplitude disturbances on stable, double diffusive systems, particularly with respect to lateral heating, (2) development of an improved understanding of the physical phenomena present in sheardriven flows in doubly diffusive stratified environments, (3) increasing their knowledge-base on turbulent flow in stratified environments and how to represent it, and (4) formulation of a numerical code for such flows. In particular, the overall goals of this aspect of the research were as follows: (1) develop more general stability and scaling criteria for the destabilization of doubly-stratified systems, (2) study the variation of flow structure and scales with Rayleigh ratio and lateral heating ratio, (3) delineate the mechanisms governing convective layer formation and merging, (4) study the mixing processes within the convective layers and across interfaces, and estimate the heat and mass fluxes in such a system, (5) quantify the effects of turbulence and coherent structures (due to a wind-driven surface shear) on a doubly stratified system, and (6) study the interaction between surface shear and side-wall heating destabilization mechanisms. Goals 1 through 4 have been successfully completed and the results are described in this report.

Koseff, J.R.

1995-07-01T23:59:59.000Z

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


121

D-eigenvalues of diffusion kurtosis tensors  

Science Conference Proceedings (OSTI)

Diffusion kurtosis imaging (DKI) is a new model in medical engineering, where a diffusion kurtosis (DK) tensor is involved. A DK tensor is a fourth-order three-dimensional fully symmetric tensor. In this paper, we introduce D-eigenvalues for a DK tensor. ... Keywords: Computation, Diffusion kurtosis, Eigenvalues, Tensors

Liqun Qi; Yiju Wang; Ed X. Wu

2008-11-01T23:59:59.000Z

122

Heat Hyperbolic Diffusion in Planck Gas  

E-Print Network (OSTI)

In this paper we investigate the diffusion of the thermal pulse in Planck Gas. We show that the Fourier diffusion equation gives the speed of diffusion, v > c and breaks the causality of the thermal processes in Planck gas .For hyperbolic heat transport v

Miroslaw Kozlowski; Janina Marciak-Kozlowska

2006-07-06T23:59:59.000Z

123

THE DIFFUSION OF LITHIUM IN ALUMINUM  

SciTech Connect

The diffusion of lithium in aluminum was measured at various temperatures with diffusion couples of aluminum-LiAl. The activation energy, E, is 33.3 kcal/mol, and the diffusion factor, Do, is 4.5 cm{sup2}/sec. (auth)

Costas, L. P.

1963-02-28T23:59:59.000Z

124

Technology Diffusion in Communication Networks  

E-Print Network (OSTI)

In the rich and growing literature on diffusion and cascade effects in social networks, it is assumed that a node's actions are influenced only by its immediate neighbors in the social network. However, there are other contexts in which this highly-local view of influence is not applicable. The diffusion of technologies in communication networks is one important example; here, a node's actions should also be influenced by remote nodes that it can communicate with using the new technology. We propose a new model of technology diffusion inspired by the networking literature on this topic. Given the communication network $G(V,E)$, we assume that node $u$ activates (i.e. deploys the new technology) when it is adjacent to a connected component of active nodes in $G$ of size exceeding node $u$'s threshold $\\theta(u)$. We focus on an algorithmic problem that is well understood in the context of social networks, but thus far has only heuristic solutions in the context of communication networks: determining the smalle...

Goldberg, Sharon

2012-01-01T23:59:59.000Z

125

Independent Oversight Inspection, Portsmouth Gaseous Diffusion Plant -  

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

Portsmouth Gaseous Diffusion Portsmouth Gaseous Diffusion Plant - November 2006 Independent Oversight Inspection, Portsmouth Gaseous Diffusion Plant - November 2006 November 2006 Inspection of Emergency Management at the Portsmouth Gaseous Diffusion Plant The Secretary of Energy's Office of Independent Oversight, within the Office of Security and Safety Performance Assurance, conducted an inspection of the emergency management program at the Portsmouth Gaseous Diffusion Plant (PORTS) in August and September 2006. The coordination of emergency plans and procedures among USEC and DOE contractor organizations has successfully integrated the emergency management programs into a single cohesive program for the PORTS site. Other strengths include accurate hazards surveys that identify applicable

126

H Diffusion for Impurity and Defect Passivation: A Physical Model for Solar Cell Processing; Preprint  

DOE Green Energy (OSTI)

We propose a physical model for diffusion of H in Si containing impurities and defects. The diffusion occurs via several parallel mechanisms, involving complex formation (trapping) and dissociation (detrapping) at impurities and defects, hopping in lattice interstitial sites, and charge-state conversion. The role of bulk and process-induced traps is considered to explain observations from plasma, ion implantation, and PECVD-nitridation processes.

Sopori, B. L.; Zhang, Y.; Reedy, R.

2002-05-01T23:59:59.000Z

127

MODEL OF DIFFUSERS / PERMEATORS FOR HYDROGEN PROCESSING  

DOE Green Energy (OSTI)

Palladium-silver (Pd-Ag) diffusers are mainstays of hydrogen processing. Diffusers separate hydrogen from inert species such as nitrogen, argon or helium. The tubing becomes permeable to hydrogen when heated to more than 250 C and a differential pressure is created across the membrane. The hydrogen diffuses better at higher temperatures. Experimental or experiential results have been the basis for determining or predicting a diffuser's performance. However, the process can be mathematically modeled, and comparison to experimental or other operating data can be utilized to improve the fit of the model. A reliable model-based diffuser system design is the goal which will have impacts on tritium and hydrogen processing. A computer model has been developed to solve the differential equations for diffusion given the operating boundary conditions. The model was compared to operating data for a low pressure diffuser system. The modeling approach and the results are presented in this paper.

Hang, T; William Jacobs, W

2007-08-27T23:59:59.000Z

128

Analysis and calibration of social factors in a consumer acceptance and adoption model for diffusion of diesel vehicle in Europe  

E-Print Network (OSTI)

While large scale diffusion of alternative fuel vehicles (AFVs) is widely anticipated, the mechanisms that determine their success or failure are ill understood. Analysis of an AFV transition model developed at MIT has ...

Zhang, Qi, S.M. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

129

Analysis of mercury diffusion pumps  

SciTech Connect

Several mercury diffusion pump stages in the Tritium Purification process at the Savannah River Site (SRS) have been removed from service for scheduled preventive maintenance. These stages have been examined to determine if failure has occurred. Evidence of fatigue around the flange portion of the pump has been seen. In addition, erosion and cavitation inside the throat of the venturi tube and corrosion on the other surface of the venturi tube has been observed. Several measures are being examined in an attempt to improve the performance of these pumps. These measures, as well as the noted observations, are described. 4 refs.

Dunn, K.A.

1991-12-31T23:59:59.000Z

130

Analysis of mercury diffusion pumps  

SciTech Connect

Several mercury diffusion pump stages in the Tritium Purification process at the Savannah River Site (SRS) have been removed from service for scheduled preventive maintenance. These stages have been examined to determine if failure has occurred. Evidence of fatigue around the flange portion of the pump has been seen. In addition, erosion and cavitation inside the throat of the venturi tube and corrosion on the other surface of the venturi tube has been observed. Several measures are being examined in an attempt to improve the performance of these pumps. These measures, as well as the noted observations, are described. 4 refs.

Dunn, K.A.

1991-01-01T23:59:59.000Z

131

An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples  

SciTech Connect

Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an axisymmetric diffusion experiment coupled with tracer profiling may be a promising approach to estimate of diffusion anisotropy of sedimentary rocks.

Takeda, M.; Hiratsuka, T.; Ito, K.; Finsterle, S.

2011-02-01T23:59:59.000Z

132

“Electrochemical Shock” of Intercalation Electrodes: A Fracture Mechanics Analysis  

E-Print Network (OSTI)

Fracture of electrode particles due to diffusion-induced stress has been implicated as a possible mechanism for capacity fade and impedance growth in lithium-ion batteries. In brittle materials, including many lithium ...

Chiang, Yet-Ming

133

CFD MODELING ANALYSIS OF MECHANICAL DRAFT COOLING TOWER  

Science Conference Proceedings (OSTI)

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was benchmarked against the literature data and the SRS test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be presented here.

Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

2008-03-03T23:59:59.000Z

134

Bulk and surface controlled diffusion of fission gas atoms  

Science Conference Proceedings (OSTI)

Fission gas retention and release impact nuclear fuel performance by, e.g., causing fuel swelling leading to mechanical interaction with the clad, increasing the plenum pressure and reducing the gap thermal conductivity. All of these processes are important to understand in order to optimize operating conditions of nuclear reactors and to simulate accident scenarios. Most fission gases have low solubility in the fuel matrix, which is especially pronounced for large fission gas atoms such as Xe and Kr, and as a result there is a significant driving force for segregation of gas atoms to extended defects such as grain boundaries or dislocations and subsequently for nucleation of gas bubbles at these sinks. Several empirical or semi-empirical models have been developed for fission gas release in nuclear fuels, e.g. [1-6]. One of the most commonly used models in fuel performance codes was published by Massih and Forsberg [3,4,6]. This model is similar to the early Booth model [1] in that it applies an equivalent sphere to separate bulk UO{sub 2} from grain boundaries represented by the sphere circumference. Compared to the Booth model, it also captures trapping at grain boundaries, fission gas resolution and it describes release from the boundary by applying timedependent boundary conditions to the circumference. In this work we focus on the step where fission gas atoms diffuse from the grain interior to the grain boundaries. The original Massih-Forsberg model describes this process by applying an effective diffusivity divided into three temperature regimes. In this report we present results from density functional theory calculations (DFT) that are relevant for the high (D{sub 3}) and intermediate (D{sub 2}) temperature diffusivities of fission gases. The results are validated by making a quantitative comparison to Turnbull's [8-10] and Matzke's data [12]. For the intrinsic or high temperature regime we report activation energies for both Xe and Kr diffusion in UO{sub 2{+-}x}, which compare favorably to available experiments. This is an extension of previous work [13]. In particular, it applies improved chemistry models for the UO{sub 2{+-}x} nonstoichiometry and its impact on the fission gas activation energies. The derivation of these models follows the approach that used in our recent study of uranium vacancy diffusion in UO{sub 2} [14]. Also, based on the calculated DFT data we analyze vacancy enhanced diffusion mechanisms in the intermediate temperature regime. In addition to vacancy enhanced diffusion we investigate species transport on the (111) UO{sub 2} surface. This is motivated by the formation of small voids partially filled with fission gas atoms (bubbles) in UO{sub 2} under irradiation, for which surface diffusion could be the rate-limiting transport step. Diffusion of such bubbles constitutes an alternative mechanism for mass transport in these materials.

Andersson, Anders D. [Los Alamos National Laboratory

2012-08-09T23:59:59.000Z

135

Vacancy Mechanism Davydov I.А.  

National Nuclear Security Administration (NNSA)

9: Computational Physics-MD 9: Computational Physics-MD DFT and MD Simulation of Self-Diffusion in Silicon: Study of Diffusion Vacancy Mechanism Davydov I.А. * , Anisin А.V. † , Eliseev G.М. ‡ , Kopkin S.V. § , and Reese Jones ** *, †, ‡, § Russian Federal Nuclear Center - All-Russia Research Institute of Experimental Physics (RFNC-VNIIEF), 607190 Sarov, Mira-37, Russia ** Sandia National Laboratories, MS 9404, P.O. Box 0969, Livermore, CA 94551, USA Summary: Computations of jump activation energy DH j and diffusion jump frequency n have been carried out using the Density Functional Theory (DFT) and Molecular Dynamics (MD) method for a single crystal of Si. These parameters define the rate of vacancy diffusion transport.

136

Surfactant-Modified Diffusion on Transition-Metal Surfaces  

DOE Green Energy (OSTI)

Wanting to convert surface impurities from a nuisance to a systematically applicable nano-fabrication tool, we have sought to understand how such impurities affect self-diffusion on transition-metal surfaces. Our field-ion microscope experiments reveal that in the presence of surface hydrogen, self-diffusion on Rh(100) is promoted, while on Pt(100), not only is it inhibited, but its mechanism changes. First-principles calculations aimed at learning how oxygen fosters perfect layerwise growth on a growing Pt(111) crystal contradict the idea in the literature that it does so by directly promoting transport over Pt island boundaries. The discovery that its real effect is to burn off adventitious adsorbed carbon monoxide demonstrates the predictive value of state-of-the-art calculation methods.

FEIBELMAN,PETER J.; KELLOGG,GARY LEE

1999-12-01T23:59:59.000Z

137

Fractional diffusion modeling of ion channel gating  

E-Print Network (OSTI)

An anomalous diffusion model for ion channel gating is put forward. This modeling scheme is able to describe the non-exponential, power-law like gating behavior of residence time intervals in several types of ion channels. Our scheme presents a generalization of the discrete diffusion model by Millhauser, Salpeter and Oswald [Proc. Natl. Acad. Sci. USA 85, 1503 (1988)] to the case of a continuous, anomalously slow conformational diffusion. The corresponding generalization is derived from a continuous time random walk composed of nearest neighbor jumps which in the scaling limit results in a fractional diffusion equation. The studied model contains three parameters only: the mean residence time, a characteristic time of conformational diffusion, and the index of subdiffusion. A tractable analytical expression for the characteristic function of the residence time distribution (RTD) is obtained. In the limiting case of normal diffusion a prior result of Goychuk and Hanggi [Proc. Natl. Acad. Sci. USA 99, 3552 (20...

Goychuk, I; Goychuk, Igor; Hanggi, Peter

2004-01-01T23:59:59.000Z

138

Characterizing unsaturated diffusion in porous tuff gravel  

SciTech Connect

Evaluation of solute diffusion in unsaturated porous gravel is very important for investigations of contaminant transport and remediation, risk assessment, and waste disposal (for example, the potential high-level nuclear waste repository at Yucca Mountain, Nevada). For a porous aggregate medium such as granular tuff, the total water content is comprised of surface water and interior water. The surface water component (water film around grains and pendular water between the grain contacts) could serve as a predominant diffusion pathway. To investigate the extent to which surface water films and contact points affect solute diffusion in unsaturated gravel, we examined the configuration of water using x-ray computed tomography in partially saturated gravel, and made quantitative measurements of diffusion at multiple water contents using two different techniques. In the first, diffusion coefficients of potassium chloride in 2-4 mm granular tuff at multiple water contents were calculated from electrical conductivity measurements using the Nernst-Einstein equation. In the second, we used laser ablation with inductively coupled plasma-mass spectrometry to perform micro-scale mapping, allowing the measurement of diffusion coefficients for a mixture of chemical tracers for tuff cubes and tetrahedrons having two contact geometries (cube-cube and cube-tetrahedron). The x-ray computed tomography images show limited contact between grains, and this could hinder the pathways for diffusive transport. Experimental results show the critical role of surface water in controlling transport pathways and hence the magnitude of diffusion. Even with a bulk volumetric water content of 1.5%, the measured solute diffusion coefficient is as low as 1.5 x 10{sup -14} m{sup 2}/s for tuff gravel. Currently used diffusion models relating diffusion coefficients to total volumetric water content inadequately describe unsaturated diffusion behavior in porous gravel at very low water contents.

Hu, Qinhong; Kneafsey, Timothy J.; Roberts, Jeffery J.; Tomutsa, Liviu; Wang, Joseph, S.Y.

2003-11-12T23:59:59.000Z

139

Experience with Palladium Diffusers in Tritium Processing  

DOE Green Energy (OSTI)

Hydrogen isotopes are separated from other gases by permeation through palladium and palladium-silver alloy diffusers in the Tritium Facilities at the US Department of Energy Savannah River Site (SRS). Diffusers have provided effective service for almost forty years. This paper is an overview of the operational experience with the various diffuser types that have been employed at SRS. Alternative technologies being developed at SRS for purifying hydrogen isotopes are also discussed.

Motyka, T.; Clark, E.A.; Dauchess, D.A.; Heung, L.K.; Rabum, R.L.

1995-01-27T23:59:59.000Z

140

Diffusion bonding of Stratapax for drill bits  

DOE Green Energy (OSTI)

A process has been developed for the diffusion bonding of General Electric's Stratapax drill blanks to support studs for cutter assemblies in drill bits. The diffusion bonding process is described and bond strength test data are provided for a variety of materials. The extensive process details, provided in the Appendices, should be sufficient to enable others to successfully build diffusion-bonded drill bit cutter assemblies.

Middleton, J.N.; Finger, J.T.

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Reaction-Diffusion Texture Synthesis - CECM  

E-Print Network (OSTI)

Dec 12, 2000 ... page 9 : Meinhardt's Stripe-Generation System · stripes.png · page 10 : Multiple Reaction-Diffusion Systems · page 11 : Cheetah Spots

142

Portsmouth Gaseous Diffusion Plant, Former Production Workers...  

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

Plant, Former Production Workers Screening Projects Portsmouth Gaseous Diffusion Plant, Former Production Workers Screening Projects Project Name: Worker Health Protection Program...

143

Portsmouth Gaseous Diffusion Plant - Enforcement Documents  

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

Inc. related to Installation and Inspection of Penetration Fire Seals at the DUF6 Conversion Building at the Portsmouth Gaseous Diffusion Plant, March 26, 2010 Consent...

144

Mapping Diffuse Seismicity for Geothermal Reservoir Management...  

Open Energy Info (EERE)

Facebook icon Twitter icon Mapping Diffuse Seismicity for Geothermal Reservoir Management with Matched Field Processing Geothermal Lab Call Project Jump to: navigation,...

145

Laser Extinction in Laminar Inverse Diffusion Flames  

E-Print Network (OSTI)

Diagnostics, Chapter 9: Laser-Induced Incandescence,Laser Extinction in Laminar Inverse Diffusion Flames WesternFoundation, Arlington, VA Laser Extinction in Laminar

Macko, Kevin; Mikofski, Mark A; Fernandez-Pello, Carlos; Blevins, Linda G; Davis, Ronald W.

2005-01-01T23:59:59.000Z

146

Diffusion Flame Measurements: Literature Citations C  

Science Conference Proceedings (OSTI)

... Partial Equilibrium in the Reaction Zone of Methane-Air Diffusion Flames; and Combustion and Flame 37:227-244 (1980). ...

2012-10-17T23:59:59.000Z

147

The Diffusion of GIS in Journalism.  

E-Print Network (OSTI)

??The purposes of this study were to determine the likelihood of reporters to adopt Geographical Information Systems and to predict the future of the diffusion… (more)

Wasike, Ben S.

2005-01-01T23:59:59.000Z

148

Diffusion instability in a thermonuclear burn  

SciTech Connect

Time-dependent, one-dimesional equations are solved to demonstrate the possibility of a superheating-diffusion instability in a steady-state fusion reactor.

Vasil' ev, N.N.; Lukash, V.E.; Nedospasov, A.V.

1979-04-01T23:59:59.000Z

149

FLAME STRUCTURE MEASUREMENT OF POLYMER DIFFUSION FLAMES  

E-Print Network (OSTI)

diffusion flame of gaseous propane and methane provide aCurrent study Tsuji and Yamoaka (propane fuel, -f Oxidizeris air and propane flow rate is constant Nozzle velocity

Pitz, W. J.

2011-01-01T23:59:59.000Z

150

Diffusive separation of noble gases and noble gas abundance patterns in sedimentary rocks  

SciTech Connect

The mechanisms responsible for noble gas concentrations, abundance patterns, and strong retentivity in sedimentary lithologies remain poorly explained. Diffusion-controlled fractionation of noble gases is modeled and examined as an explanation for the absolute and relative abundances of noble gases observed in sediments. Since the physical properties of the noble gases are strong functions of atomic mass, the individual diffusion coefficients, adsorption coefficients and atomic radii combine to impede heavy noble gas (Xe) diffusion relative to light noble gas (Ne) diffusion. Filling of lithic grains/half-spaces by diffusive processes thus produces Ne enrichments in the early and middle stages of the filling process with F(Ne) values similar to that observed in volcanic glasses. Emptying lithic grains/half-spaces produces a Xe-enriched residual in the late (but not final) stages of the process producing F(Xe) values similar to that observed in shales. 'Exotic but unexceptional' shales that exhibit both F(Ne) and F(Xe) enrichments can be produced by incomplete emptying followed by incomplete filling. This mechanism is consistent with literature reported noble gas abundance patterns but may still require a separate mechanism for strong retention. A system of labyrinths-with-constrictions and/or C-, Si-nanotubes when combined with simple adsorption can result in stronger diffusive separation and non-steady-state enrichments that persist for longer times. Enhanced adsorption to multiple C atoms inside C-nanotubes as well as dangling functional groups closing the ends of nanotubes can provide potential mechanisms for 'strong retention'. We need new methods of examining noble gases in rocks to determine the role and function of angstrom-scale structures in both the diffusive enrichment process and the 'strong retention' process for noble gas abundances in terrestrial rocks.

Torgersen, T.; Kennedy, B.M.; van Soest, M.C.

2004-06-14T23:59:59.000Z

151

Diffusion in active magnetic colloids  

E-Print Network (OSTI)

Properties of active colloids of circle swimmers are reviewed. As an particular example of active magnetic colloids the magnetotactic bacteria under the action of a rotating magnetic field is considered. The relation for a diffusion coefficient due to the random switching of the direction of rotation of their rotary motors is derived on the basis of the master equation. The obtained relation is confirmed by the direct numerical simulation of random trajectory of a magnetotactic bacterium under the action of the Poisson type internal noise due to the random switching of rotary motors. The results obtained are in qualitative and quantitative agreement with the available experimental results and allows one to determine the characteristic time between the switching events of a rotary motor of the bacterium.

Reinis Taukulis; Andrejs Cebers

2013-10-04T23:59:59.000Z

152

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System  

DOE Green Energy (OSTI)

This report summarizes work performed on this project from April 2005 through September 2005. In previous work, a series of laboratory scale experiments were conducted to determine the feasibility of using a SMZ system coupled with a VPB to remove and ultimately destroy the organic pollutants found in produced water. Based on the laboratory scale data, a field test of the process was conducted at the McGrath Salt Water Disposal facility in July and August of 2005. The system performed well over repeated feed and regeneration cycles demonstrating the viability of the process for long term operation. Of the BTEX components present in the produced water, benzene had the lowest adsorption affinity for the SMZ and thus controlled the sorption cycle length. Regeneration of the SMZ using air sparging was found to be sufficient in the field to maintain the SMZ adsorption capacity and to allow continuous operation of the system. As expected, the BTEX concentrations in the regeneration off gas stream were initially very high in a given regeneration cycle. However, a granular activated carbon buffering column placed upstream of the VPB reduced the peak BTEX concentrations to acceptable levels for the VPB. In this way, the VPB was able to maintain stable performance over the entire SMZ regeneration period despite the intermittent nature of the feed.

Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2005-09-11T23:59:59.000Z

153

Vapor-Phase-Deposited Organosilane Coatings as "Hardening" Agents for High-Peak-Power Laser Optics  

Science Conference Proceedings (OSTI)

Multilayer-dielectric (MLD) diffraction gratings are used in high-power laser systems to compress laser-energy pulses. The peak power deliverable on target for these short-pulse petawatt class systems is limited by the laser-damage resistance of the optical components in the system, especially the MLD gratings. Recent experiments in our laboratory have shown that vapor treatment of MLD gratings at room temperature with organosilanes such as hexamethyldisilazane (HMDS) produces an increase in their damage threshold as compared to uncoated MLD grating control samples.

Marshall, K.L.; Culakova, Z.; Ashe, B.; Giacofei, C.; Rigatti, A.L.; Kessler, T.J.; Schmid, A.W.; Oliver, J.B.; Kozlov, A.

2008-01-07T23:59:59.000Z

154

Vapor Phase Elemental Sulfur Tech Brief DRAFT bbl 08-24  

saturated heated gas into access wells to distribute the gas throughout the site. Solid ... need to inject liquid/fluids). ...

155

Vapor Phase Catalytic Upgrading of Model Biomass-Derived Oxygenate Compounds  

SciTech Connect

When biomass is converted to a liquid bio-oil through pyrolysis, it has a significantly higher oxygen content compared to petroleum fractions. In order to convert the pyrolysis products into infrastructure-compatible fuels, oxygen removal is required. Oxygen removal can be achieved by both hydrotreating (which requires the addition of hydrogen) and decarboxylation or decarbonylation, whereby oxygen is rejected as CO2 and CO, respectively. In the present contribution, a number of catalysts were tested for their activity and selectivity in deoxygenation of model biomass-derived oxygenated compounds (e.g., acetic acid, phenol). Comparison of catalytic activity of materials for different compounds, as well as material characterization results will be discussed. Materials tested will include modified zeolites and supported transition metal catalysts.

Yung, M. M.; Gomez, E.; Kuhn, J. N.

2012-01-01T23:59:59.000Z

156

Evaluation of Catalysts from Different Origin for Vapor Phase Upgrading in Biomass Pyrolysis  

SciTech Connect

Liquid fuels and chemicals from biomass resources arouse much interests in research and development. Fast pyrolysis of biomass has the potential to effectively change solid biomass materials into liquid products. However, bio-oil from traditional pyrolysis processes is difficult to apply in industry, because of its complicated composition, high oxygen content, low stability, etc. Upgrading or refining of the bio-oil should be performed for industrial application of biomass pyrolysis. Often, the process would be done in a separate reactor downstream of the pyrolysis process. In this paper, a laboratory scale micro test facility was constructed, wherein the pyrolysis of pine and catalytic upgrading of the resulting vapors were closely coupled in one reactor. The composition of vapor effluent was monitored with a molecular beam mass spectrometer (MBMS) for the online evaluation of the catalyst performance. Catalysts from different origin were tested and compared for the effectiveness of pyrolysis vapor upgrading, namely commercial zeolites, Ni based steam reforming catalyst, CaO, MgO, and several laboratory-made catalysts. The reaction temperature for catalytic upgrading varied between 400 and 600 centigrade, and the gaseous residence time ranged from 0.1 second to above 2 second, to simulate the conditions in industrial application. It is revealed that some catalysts are active in transform most of primary biomass pyrolysis vapors into hydrocarbons, resulting in nonoxygenated products, which is beneficial for downstream utilization. Others are not as effective, results in minor improvement compared with blank test results.

Zhang, X.; Mukarakate, C.; Zheng, Z.; Nimlos, M.

2012-01-01T23:59:59.000Z

157

A NOVEL VAPOR-PHASE PROCESS FOR DEEP DESULFURIZATION OF NAPHTHA/DIESEL  

Science Conference Proceedings (OSTI)

Tier 2 regulations issued by the U.S. Environmental Protection Agency (EPA) require a substantial reduction in the sulfur content of gasoline. Similar regulations have been enacted for the sulfur level in on-road diesel and recently off-road diesel. The removal of this sulfur with existing and installed technology faces technical and economic challenges. These challenges created the opportunity for new emerging technologies. Research Triangle Institute (RTI) with subcontract support from Kellogg Brown & Root, Inc., (KBR) used this opportunity to develop RTI's transport reactor naphtha desulfurization (TReND) process. Starting with a simple conceptual process design and some laboratory results that showed promise, RTI initiated an accelerated research program for sorbent development, process development, and marketing and commercialization. Sorbent development has resulted in the identification of an active and attrition resistant sorbent that has been prepared in commercial equipment in 100 lb batches. Process development has demonstrated both the sulfur removal performance and regeneration potential of this sorbent. Process development has scaled up testing from small laboratory to pilot plant transport reactor testing. Testing in the transport reactor pilot plant has demonstrated the attrition resistance, selective sulfur removal activity, and regeneration activity of this sorbent material. Marketing and commercialization activities have shown with the existing information that the process has significant capital and operating cost benefits over existing and other emerging technologies. The market assessment and analysis provided valuable feedback about the testing and performance requirements for the technical development program. This market analysis also provided a list of potential candidates for hosting a demonstration unit. Although the narrow window of opportunity generated by the new sulfur regulations and the conservative nature of the refining industry slowed progress of the demonstration unit, negotiations with potential partners are proceeding for commercialization of this process.

B.S. Turk; R.P. Gupta; S.K. Gangwal

2003-06-30T23:59:59.000Z

158

Metalorganic Vapor-Phase Epitaxial Growth and Characterization of Quaternary AlGaInN  

SciTech Connect

In this letter we report the growth (by MOVPE) and characterization of quaternary AlGaInN. A combination of PL, high-resolution XRD, and RBS characterizations enables us to explore and delineate the contours of equil-emission energy and lattice parameters as functions of the quaternary compositions. The observation of room temperature PL emission as short as 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GdnN MQW heterostructures have also been grown; both x-ray diffraction and PL measurement suggest the possibility of incorporating this quaternary into optoelectronic devices.

BANAS, MICHAEL ANTHONY; CRAWFORD, MARY H.; FIGIEL, JEFFREY J.; HAN, JUNG; LEE, STEPHEN R.; MYERS JR., SAMUEL M.; PETERSON, GARY D.

1999-09-27T23:59:59.000Z

159

Desalination-of water by vapor-phase transport through hydrophobic nanopores  

E-Print Network (OSTI)

We propose a new approach to desalination of water whereby a pressure difference across a vapor-trapping nanopore induces selective transport of water by isothermal evaporation and condensation across the pore. Transport ...

Lee, Jongho

160

Bioremediation of explosives in vadose zone soil using vapor phase carbon source additions.  

E-Print Network (OSTI)

??Explosives contamination in vadose zone soil presents difficulties in remediation. Because vadose zone contamination can extend deep into the subsurface and underneath existing buildings and… (more)

Radtke, Corey William

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Regular transient loading response in a vapor-phase flow-direction-switching biofilter  

E-Print Network (OSTI)

from a POTW using a compost bio?lter. ” Water Environ. Res.heat and mass transport within a compost bio?lter: I. ModelM. A. ?1995?. “Operation of compost based bio?lters under

Wright, W F; Schroeder, E D; Chang, DPY

2005-01-01T23:59:59.000Z

162

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System  

SciTech Connect

This report summarizes work performed on this project from April 2004 through September 2004. Our previous work demonstrated that a polyurethane foam biofilter could successfully biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, establishing the biomass on the polyurethane foam packing was relatively time consuming and daily recirculation of a concentrated nutrient solution was required for efficient operation of the foam biofilter. To simplify the start up and operating requirements of the biofilter system, a simple, compost-based biofilter was investigated for its ability to treat the BTEX contaminants generated during the SMZ regeneration process. The investigation of the compost biofilter was divided into three experimental phases that spanned 180 days of biofilter operation. During Phase 1, the biofilter was continuously supplied a BTEX-contaminated waste gas stream. During Phase 2, a series of periodic shutdown tests were conducted to assess how the biofilter responded when the BTEX feed was discontinued for periods ranging from 1 day to 2.8 days. The Phase 3 experiments focused on determining how the biofilter would handle periodic spikes in inlet BTEX concentration as would be expected when it is coupled with an SMZ column. Results from the continuous feed (Phase 1) experiments demonstrated that the compost biofilter could maintain BTEX removals of greater than 98% within two weeks of startup. Results of the shutdown experiments indicated that benzene removal was the most sensitive to interruptions in the BTEX feed. Nevertheless, the BTEX removal efficiency exceeded 95% within 6 hours of reestablishing the BTEX feed to the biofilter. When the biofilter was subjected to periodic spikes in BTEX concentration (Phase 3), it was found that the total BTEX removal efficiency stabilized at approximately 75% despite the fact that the biofilter was only fed BTEX contaminants 8 hours per day. Finally, the effects of nutrient supply and EBCT on compost biofilter performance were also investigated. The bioreactor maintained greater than 95% removal efficiency for over 40 days without an additional supply of nutrients when a 10X concentrated HCMM was mixed with the compost packing at the beginning of the experiments. Results also suggest that an EBCT greater than 30 seconds is required to maintain high BTEX removal efficiencies in the compost biofilter system.

Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2004-09-11T23:59:59.000Z

163

Transient response of flow-direction-switching vapor-phase biofilters  

E-Print Network (OSTI)

M. A. ?1995?. “Operation of compost-based bio?lters underfrom a POTW using a compost bio?lter. ” Water Environ.heat and mass transport within a compost bio?lter: I. Model

Wright, W F; Schroeder, E D; Chang, Daniel P.Y.

2005-01-01T23:59:59.000Z

164

Transient response of flow-direction-switching vapor-phase biofilters  

E-Print Network (OSTI)

pellet ?Celite R-635? Compost-isolite-limestone Yes Yes Yes Yes Yes UF UF Polyurethane foam Peat-bark-wood

Wright, W F; Schroeder, E D; Chang, Daniel P.Y.

2005-01-01T23:59:59.000Z

165

Vapor-Phase Metalation by Atomic Layer Deposition in a Metal-Organic Framework  

E-Print Network (OSTI)

encompass deposition onto micro- and nanopowders14 and coating of nanoparticle films15 as well as aerogel coating of porous materials that exhibit ultrahigh-aspect ratios.12,13 To date, some striking examples

166

Liquid-phase and vapor-phase dehydration of organic/water solutions  

DOE Patents (OSTI)

Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.

Huang, Yu (Palo Alto, CA); Ly, Jennifer (San Jose, CA); Aldajani, Tiem (San Jose, CA); Baker, Richard W. (Palo Alto, CA)

2011-08-23T23:59:59.000Z

167

Transient response of flow-direction-switching vapor-phase biofilters  

E-Print Network (OSTI)

lter. ” J. Environ. Eng. , ASCE ?accepted?. Wright, W. F. ,OF ENVIRONMENTAL ENGINEERING © ASCE / JULY 2005 / 1009OF ENVIRONMENTAL ENGINEERING © ASCE / JULY 2005 and the

Wright, W F; Schroeder, E D; Chang, Daniel P.Y.

2005-01-01T23:59:59.000Z

168

Regular transient loading response in a vapor-phase flow-direction-switching biofilter  

E-Print Network (OSTI)

JOURNAL OF ENVIRONMENTAL ENGINEERING © ASCE / DECEMBER 2005ENVIRONMENTAL ENGINEERING © ASCE / DECEMBER 2005 / 1657 nol.must be ?led with the ASCE Managing Editor. The manuscript

Wright, W F; Schroeder, E D; Chang, DPY

2005-01-01T23:59:59.000Z

169

Modelling international wind energy diffusion: Are the patterns of induced diffusion `S'  

E-Print Network (OSTI)

Modelling international wind energy diffusion: Are the patterns of induced diffusion `S' shaped datasets, the paper explores the patterns of international wind energy diffusion in OECD countries. The model employed in the paper predicted that wind energy, as a complex and expensive innovation, would

Feigon, Brooke

170

Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by 1H molecular diffusion NMR and 19F spin diffusion NMR  

E-Print Network (OSTI)

of Technology, Pasadena, CA 91125, USA NMR combined withspin diffusion NMR is useful in studying the drug loadingdiffusion . Spin diffusion . NMR Introduction R f -PEGs (

Mathias, Errol V.; Aponte, Julia; Kornfield, Julia A.; Ba, Yong

2010-01-01T23:59:59.000Z

171

Diffusion coefficient of trona in water  

SciTech Connect

Laboratory experiments were conducted to measure the diffusion coefficient of trona in water. The diffusion coefficient of trona from saturated solution in water was measured to be 1.167 *10/sup -5/ cm/sup 2//s with a standard devition of 6.2% at 25/degree/C.30 10/sup 9/ refs.

Mehta, G.D.; Jain, S.C.

1982-07-01T23:59:59.000Z

172

THE MULTIGROUP DIFFUSION EQUATIONS OF REACTOR PHYSICS  

SciTech Connect

The partial differential equations of the multigroup diffusion model of reactor physics are shown to have solutions both in the time-independent and timedependent problems, and the usually assumed behavior of these solutions is shown to be mathematically valid. The method of spectral representation is developed for the multigroup diffusion operator. (auth)

Habetler, G.J.; Martino, M.A.

1958-07-28T23:59:59.000Z

173

Patents and the diffusion of technical information  

E-Print Network (OSTI)

Abstract: Does the disclosure requirement of the patent system encourage the diffusion of inventions? This paper builds a simple model where firms choose between patents and trade secrecy to protect inventions. Diffusion is not necessarily more likely with a patent system nor is the “market for technology ” necessarily greater.

James Bessen; Thanks To Ashish Arora; Robert Barr; Nancy Gallini; Wendy Gordon; Mark Lemley; Mike Meurer

2005-01-01T23:59:59.000Z

174

Geothermal steam muffler diffusers: the Geysers, California. Failure analysis report  

DOE Green Energy (OSTI)

The primary failure mechanism for the T304 diffusers was chloride induced stress corrosion cracking (sec.) Once SCC had progressed to a certain point, high cycle corrosion/fatigue proceeded to the final fracture. Alteration of the environment to prevent SCC is not feasible. The existing environment will also cause sulfide stress cracking (SSC) in susceptible materials; therefore, alternate materials must resist SSC as well as SCC. The very large amplitude operational stresses make heat treatment to relieve residual fabrication stress questionable for the prevention of SCC. (MHR)

McAlpin, R.; Ellis, P.F. II

1980-04-01T23:59:59.000Z

175

Independent Oversight Review, Portsmouth Gaseous Diffusion Plant -  

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

Portsmouth Gaseous Diffusion Plant Portsmouth Gaseous Diffusion Plant - November 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - November 2013 November 5, 2013 Review of Preparedness for Severe Natural Phenomena Events at the Portsmouth Gaseous Diffusion Plant This report documents the results of an independent oversight review of the preparedness of the DOE Portsmouth/Paducah Project Office, contractors at the DOE Portsmouth Gaseous Diffusion Plant, and selected non-leased facilities to respond to a severe natural phenomena event (NPE). The review was conducted in July and August 2013 by the U.S. Department of Energy's (DOE) Office of Safety and Emergency Management Evaluations, which is within the DOE Office of Health, Safety and Security (HSS). The HSS Office of Safety and Emergency Management Evaluations performed this

176

THE DIFFUSION OF HYDROGEN IN BETA ZIRCONIUM  

DOE Green Energy (OSTI)

Diffusion coefficients for hydrogen in beta zirconium were determined from permeation rates in the range 650 to 850 deg C. Both the steady-state method, which is dependent upon the hydrogen concentration, and the time-lag method, which is independent of hydrogen concentration, were employed to obtain diffusion data. Zirconium disks, 0.03 to 0.1 cm thick and varying in hydrogen concentration from 9 to 33 at.%, were used to measure permeation rates. The diffusion coefficients determined by the steady-state and time-lag methods on samples of differing thickness were in agreement. It was concluded that the permeation process was diffusion controlled. The diffusion coefficients were found to be independent of concentration and can be expressed by D = 6.14 x 10/ sup 4/ exp (--45,900/RT). (auth)

Albrecht, W.M.; Goode, W.D. Jr.

1959-08-25T23:59:59.000Z

177

An atomic view of surface diffusion on metal surfaces  

SciTech Connect

Investigations of surface diffusion and cluster nucleation by field ion microscopy have provided a considerable amount of physical insight concerning the fundamental interactions that control dynamical processes on surfaces. The investigations rely not only on the FIM`s ability to resolve and track individual atoms on a surface, but also its ability to manipulate the number of adatoms and the size of clusters by the process of field desorption. Results of the investigations are surprising. Whereas metal atom diffusion was once thought to be a simple hopping process, FIM experiments have revealed new mechanisms for atom transport. Whereas cluster nucleation was once thought to be an aggregation process dependent only upon pairwise interactions between atoms, FIM investigations have shown that long-range and many body interactions can make non-negligible contributions to the overall process. By providing a brief overview of the experimental methods used in FIM surface diffusion studies and discussing a few selected applications, I hope to have conveyed some of the rich history as well as the current excitement associated with FIM investigations of dynamical processes on surfaces.

Kellogg, G.L.

1994-08-01T23:59:59.000Z

178

Information Technology Diffusion with Influentials, Imitators, and Opponents  

Science Conference Proceedings (OSTI)

Information technology (IT) innovations follow a diverse set of diffusion patterns. Early diffusion models explaining technology diffusion patterns assumed that there is a single homogeneous segment of potential adopters. It was later shown that a two-segment ... Keywords: Diffusion Of Innovation, Information Technology Diffusion, Technology Opposition

Hasan Cavusoglu; Nan Hu; Yingjiu Li; Dan Ma

2010-10-01T23:59:59.000Z

179

Evaluation of diffusion coefficients from nonlinear impurity profiles  

Science Conference Proceedings (OSTI)

At high concentrations, impurity diffusion in semiconductors is governed by nonlinear diffusion processes. Using similarity analysis, a general expression for evaluation of the diffusion coefficient from experimental impurity profiles derived for the case of redistributive diffusion of implanted impurities. This expression corresponds to the Boltzmann-Matano analysis for the case of diffusion with constant surface concentration.

Anderson, D.; Jeppson, K.O.

1985-06-01T23:59:59.000Z

180

Progress Report for Diffusion Welding of the NGNP Process Application Heat Exchangers  

DOE Green Energy (OSTI)

The U.S. Department of Energy selected the high temperature gas-cooled reactor as the basis for the Next Generation Nuclear Plant (NGNP). The NGNP will demonstrate the use of nuclear power for electricity, hydrogen production, and process heat applications. The NGNP Project is currently investigating the use of metallic, diffusion welded, compact heat exchangers to transfer heat from the primary (reactor side) heat transport system to the secondary heat transport system. An intermediate heat exchanger will transfer this heat to downstream applications such as hydrogen production, process heat, and electricity generation. The channeled plates that make up the heat transfer surfaces of the intermediate heat exchanger will have to be assembled into an array by diffusion welding. This report describes the preliminary results of a scoping study that evaluated the diffusion welding process parameters and the resultant mechanical properties of diffusion welded joints using Alloy 800H. The long-term goal of the program is to progress towards demonstration of small heat exchanger unit cells fabricated with diffusion welds. Demonstration through mechanical testing of the unit cells will support American Society of Mechanical Engineers rules and standards development, reduce technical risk, and provide proof of concept for heat exchanger fabrication methods needed to deploy heat exchangers in several potential NGNP configurations.1 Researchers also evaluated the usefulness of modern thermodynamic and diffusion computational tools (Thermo-Calc and Dictra) in optimizing the parameters for diffusion welding of Alloy 800H. The modeling efforts suggested a temperature of 1150 C for 1 hour with an applied pressure of 5 MPa using 15 {micro}m nickel foil as joint filler to reduce chromium oxidation on the welded surfaces. Good agreement between modeled and experimentally determined concentration gradients was achieved

R.E. Mizia; D.E. Clark; M.V. Glazoff; T.E. Lister; T.L. Trowbridge

2011-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Compliant mechanisms  

E-Print Network (OSTI)

The motivation for this work has been a variety of motions like navigation of pipelines, insertion operations in assembly, and gripping actions, which require the adaptation of the mechanism to the external constraints, rather than avoid them. To this effect, efforts have been made in building mechanisms that obtain the required degrees of freedom through deformations rather than explicit joints in them. Although the use of many joints provides the required number of degrees of freedom, it does so at the cost of making the system very bulky and complex. With the advent of new polymers, the possibility of building joint-free mechanisms that fulfil the requirements of adaptation has increased. Based on this approach, a Magneto Active Polymer (MAP) material has been developed here at the Texas A\\&M University, in which the actuation is performed by the conversion of electromagnetic energy into mechanical energy. The initial experimentation has proved the vast potential of the use of such a material and a few mechanisms like a magneto active peristaltic pump, have been designed and tested for the first time using this material. In this mechanism, the pumping action is obtained when a moving magnetic field produces peristaltic waves in the magneto active material shaped as a tube. Also for the first time, experiments have been conducted to analyze the response of the MAP material to a pulsating magnetic field with the intent of using the experimental results to develop a model of the MAP. In developing the design for the peristaltic pump and other conceptual models described in this thesis, ideas have been drawn from the different modes of locomotion and actuators present in lower organisms. These have been good sources of inspiration for the work done in this thesis and they have been documented in detail.

Venkataraghavan, Janarthanan T

2001-01-01T23:59:59.000Z

182

Coupled elastic-plastic thermomechanically assisted diffusion: Theory development, numerical implementation, and application  

Science Conference Proceedings (OSTI)

A fully coupled thermomechanical diffusion theory describing the thermal and mechanically assisted mass transport of dilute mobile constituents in an elastic solid is extended to include the effects of elastic-plastic deformation. Using the principles of modern continuum mechanics and classical plasticity theory, balance laws and constitutive equations are derived for a continuum composed of an immobile, but deformable, parent material and a dilute mobile constituent. The resulting equations are cast into a finite element formulation for incorporation into a finite element code. This code serves as a tool for modeling thermomechanically assisted phenomena in elastic-plastic solids. A number of simplified problems for which analytical solutions can be derived are used to benchmark the theory and finite element code. Potential uses of the numerical implementation of the theory are demonstrated using two problems. Specifically, tritium diffusion in a titanium alloy and hydrogen diffusion in a multiphase stainless steel are examined.

Weinacht, D.J.

1995-12-01T23:59:59.000Z

183

Study of lithium diffusion in RF sputtered Nickel/Vanadium mixed oxides thin films  

E-Print Network (OSTI)

Study of lithium diffusion in RF sputtered NickelÁ/Vanadium mixed oxides thin films F. Artuso a lithium insertion inside RF sputtered Ni/V mixed oxides thin films have been investigated employing, showed three steps clearly involved in the intercalation mechanism of lithium in the oxide films: (i

Artuso, Florinda

184

Analysis of an interface stabilised finite element method: The advection-diffusion-reaction equation  

E-Print Network (OSTI)

. Labeur and G. N. Wells. A Galerkin interface stabilisation method for the advection-diffusion and incompressible Navier-Stokes equations. Computer Methods in Applied Mechanics and Engineering, 196(49–52):4985–5000, 2007. [3] B. Cockburn, B. Dong, J. Guzma...

Wells, G N

2009-10-29T23:59:59.000Z

185

Numerical Early Warning Model Research of Landfill Gas Permeation and Diffusion Considering Flow-Temperature Coupling  

Science Conference Proceedings (OSTI)

Based on seepage mechanics in porous medium gas and heat transfer theory, numerical early warning model is established, which is on quantitative description of migration and release of landfill gas and penetration and diffusion of energy, and dynamic ... Keywords: component, landfill gas, flow-temperature coupling, gas pressure and temperature distribution, numerical early warning model

Xue Qiang; Feng Xia-ting; Ma Shi-jin; Zhou Xiao-jun

2009-10-01T23:59:59.000Z

186

Symposium on hydrodynamic diffusion of suspended particles. Final report  

SciTech Connect

The symposium brought together researchers from academic, government, and private laboratories interested in the interactions of particles in fluids and in granular media. There were 68 participants, including 24 students, currently residing In 12 countries. The participants represented a wide variety of fields, including applied mathematics, chemical engineering, computer science, fluid dynamics, materials science, mechanical engineering, physics, and theoretical and applied mechanics. There were 33 talks and 16 posters presented. The focus of the symposium was on multiparticle hydrodynamic interactions which lead to fluctuating motion of the particles and resulting particle migration and dispersion or diffusion. Implications of these phenomena were described for sedimentation, fluidization, suspension flows, granular flows, and fiber suspensions. Computer simulation techniques as well as experimental techniques were described.

1996-05-01T23:59:59.000Z

187

Reaction-diffusion systems and nonlinear waves  

E-Print Network (OSTI)

The authors investigate the solution of a nonlinear reaction-diffusion equation connected with nonlinear waves. The equation discussed is more general than the one discussed recently by Manne, Hurd, and Kenkre (2000). The results are presented in a compact and elegant form in terms of Mittag-Leffler functions and generalized Mittag-Leffler functions, which are suitable for numerical computation. The importance of the derived results lies in the fact that numerous results on fractional reaction, fractional diffusion, anomalous diffusion problems, and fractional telegraph equations scattered in the literature can be derived, as special cases, of the results investigated in this article.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2006-04-21T23:59:59.000Z

188

Chloride Ion Diffusion in Cement-Based Materials ...  

Science Conference Proceedings (OSTI)

... into Hardened Cement Paste , Fly Ash, Silica Fume ... Diffusion Cell: Effects of Material and Test ... LJ, and Yu, SW, Diffusion in Cementitious Materials: II ...

2012-02-23T23:59:59.000Z

189

Non-Destructive Analysis Calibration Standards for Gaseous Diffusion...  

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

Analysis Calibration Standards for Gaseous Diffusion Plant (GDP) Decommissioning The decommissioning of Gaseous Diffusion Plant facilities requires accurate, non-destructive...

190

Production and Handling Slide 25: The Portsmouth Gaseous Diffusion...  

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

Portsmouth Gaseous Diffusion Plant Skip Presentation Navigation First Slide Previous Slide Next Slide Last Presentation Table of Contents The Portsmouth Gaseous Diffusion Plant...

191

Production and Handling Slide 24: The Paducah Gaseous Diffusion...  

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

Paducah Gaseous Diffusion Site Skip Presentation Navigation First Slide Previous Slide Next Slide Last Presentation Table of Contents The Paducah Gaseous Diffusion Site Refer to...

192

ARM - Field Campaign - Diffuse Shortwave IOP  

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

govCampaignsDiffuse Shortwave IOP govCampaignsDiffuse Shortwave IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Diffuse Shortwave IOP 2001.09.24 - 2001.10.22 Lead Scientist : Joseph Michalsky Data Availability Data will not be available for public viewing until April 8, 2002. All data will be archived at the diffuse IOP web site by that date. For data sets, see below. Summary Almost 4 weeks of data were acquired under mostly sunny skies. Ninety-two percent of the daylight hours had measureable direct beam radiation. Much of the sunny data included completely cloud free conditions. The trackers functioned perfectly. Clear-sky data included low to moderate aerosol cases with no high aerosol conditions sampled. Data recovery from the

193

Diffuse solar radiation and associated meteorological  

E-Print Network (OSTI)

Abstract. Solar diffuse radiation data including global radiation, shortwave and longwave balances, net radiation and sunshine hours have been extensively analyzed to study the variation of diffuse radiation with turbidity and cloud discharges appearing in the form of atmospherics over the tropics. Results of surface radiation measurements at Calcutta, Poona, Delhi and Madras are presented together with some meteorological parameters. The monthly values of diffuse radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis in relation to the noise level of atmospherics at Calcutta in the very low frequency band. The results exhibit some definite seasonal changes which appear to be in close agreement with one another. 1

unknown authors

1995-01-01T23:59:59.000Z

194

Wind and Diffusion Modeling for Complex Terrain  

Science Conference Proceedings (OSTI)

Atmospheric transport and dispersion over complex terrain were investigated. Meteorological and sulfur hexafluoride (SF6) concentration data were collected and used to evaluate the performance of a transport and diffusion model coupled with a ...

Robert M. Cox; John Sontowski; Richard N. Fry Jr.; Catherine M. Dougherty; Thomas J. Smith

1998-10-01T23:59:59.000Z

195

Pollutant Transport and Diffusion in Katabatic Flows  

Science Conference Proceedings (OSTI)

The characteristics of pollutant transport and diffusion of a passive contaminant in a two-dimensional katabatic flow over a simple slope are examined using a primitive equation hydrodynamic model. It is shown that pollutants released above the ...

Carmen J. Nappo; K. Shankar Rao; Jerold A. Herwehe

1989-07-01T23:59:59.000Z

196

Turbulence Spectra and Eddy Diffusivity over Forests  

Science Conference Proceedings (OSTI)

The main objectives of this observational study are to examine the stability dependence of velocity and air temperature spectra and to employ the spectral quantities to establish relations for eddy diffusivity over forests. The datasets chosen ...

Xuhui Lee

1996-08-01T23:59:59.000Z

197

Diffuse reflectance imaging with astronomical applications  

E-Print Network (OSTI)

Diffuse objects generally tell us little about the surrounding lighting, since the radiance they reflect blurs together incident lighting from many directions. In this paper we discuss how occlusion geometry can help invert ...

Hasinoff, Samuel W.

198

Electrospray emitters For diffusion vacuum pumps  

E-Print Network (OSTI)

Following similar principles as regular diffusion vacuum pumps, an electrospray emitter is set to produce a jet of charged particles that will drag air molecules out of a volume. To be a feasible concept, the emitted ...

Diaz Gómez Maqueo, Pablo (Pablo Ly)

2011-01-01T23:59:59.000Z

199

Manhattan Project: K-25 Gaseous Diffusion Plant  

Office of Scientific and Technical Information (OSTI)

K-25 Gaseous Diffusion Plant, Oak Ridge Events > The Uranium Path to the Bomb, 1942-1944 Events > The Uranium Path to the Bomb, 1942-1944 > Working K-25 into the Mix, Oak Ridge:...

200

Stochastic approach to diffusion inside the chaotic layer of a resonance  

E-Print Network (OSTI)

We model chaotic diffusion, in a symplectic 4D map by using the result of a theorem that was developed for stochastically perturbed integrable Hamiltonian systems. We explicitly consider a map defined by a free rotator (FR) coupled to a standard map (SM). We focus in the diffusion process in the action, $I$, of the FR, obtaining a semi--numerical method to compute the diffusion coefficient. We study two cases corresponding to a thick and a thin chaotic layer in the SM phase space and we discuss a related conjecture stated in the past. In the first case the numerically computed probability density function for the action $I$ is well interpolated by the solution of a Fokker-Planck (F-P) equation, whereas it presents a non--constant time delay respect to the concomitant F-P solution in the second case suggesting the presence of an anomalous diffusion time scale. The explicit calculation of a diffusion coefficient for a 4D symplectic map can be useful to understand the slow diffusion observed in Celestial Mechanics and Accelerator Physics.

Martín F. Mestre; Armando Bazzani; Pablo M. Cincotta; Claudia M. Giordano

2013-11-11T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Determination of Matrix Diffusion Properties of Granite  

Science Conference Proceedings (OSTI)

Rock-core column experiments were introduced to estimate the diffusion and sorption properties of Kuru Grey granite used in block-scale experiments. The objective was to examine the processes causing retention in solute transport through rock fractures, especially matrix diffusion. The objective was also to estimate the importance of retention processes during transport in different scales and flow conditions. Rock-core columns were constructed from cores drilled into the fracture and were placed inside tubes to form flow channels in the 0.5 mm gap between the cores and the tube walls. Tracer experiments were performed using uranin, HTO, {sup 36}Cl, {sup 131}I, {sup 22}Na and {sup 85}Sr at flow rates of 1-50 {mu}L.min{sup -1}. Rock matrix was characterized using {sup 14}C-PMMA method, scanning electron microscopy (SEM), energy dispersive X-ray micro analysis (EDX) and the B.E.T. method. Solute mass flux through a column was modelled by applying the assumption of a linear velocity profile and molecular diffusion. Coupling of the advection and diffusion processes was based on the model of generalised Taylor dispersion in the linear velocity profile. Experiments could be modelled applying a consistent parameterization and transport processes. The results provide evidence that it is possible to investigate matrix diffusion at the laboratory scale. The effects of matrix diffusion were demonstrated on the slightly-sorbing tracer breakthrough curves. Based on scoping calculations matrix diffusion begins to be clearly observable for non-sorbing tracer when the flow rate is 0.1 {mu}L.min{sup -1}. The experimental results presented here cannot be transferred directly to the spatial and temporal scales that prevail in an underground repository. However, the knowledge and understanding of transport and retention processes gained from this study is transferable to different scales from laboratory to in-situ conditions. (authors)

Holtta, Pirkko; Siitari-Kauppi, Marja; Huittinen, Nina [Laboratory of Radiochemistry, P.O. Box 55, University of Helsinki, FI-00014 (Finland); Poteri, Antti [VTT Processes, P.O. Box 1608, VTT, FI-02044 (Finland)

2007-07-01T23:59:59.000Z

202

Flow and diffusion distributed structures with noise at the inlet  

Science Conference Proceedings (OSTI)

Flow and diffusion distributed structures (FDS) are stationary spatially periodic patterns that can be observed in reaction-diffusion-advection systems. These structures arise when the flow rate exceeds a certain bifurcation point provided that concentrations ... Keywords: 47.54.-r, 82.40.Ck, Flow and diffusion distributed structures, Flow distributed oscillations, Noise, Pattern formation, Reaction-diffusion-advection system

Pavel V. Kuptsov; Razvan A. Satnoianu

2008-11-01T23:59:59.000Z

203

Phase Stability, Diffusion, Kinetics and their Applications (PSDK-VI)  

Science Conference Proceedings (OSTI)

Expedited Processing of CIGS Photovoltaic Absorber Materials · Experimental Uncertainty Propagation in Depth-Profiling Diffusion Experiments.

204

Independent Oversight Review, Portsmouth Gaseous Diffusion Plant- January 2013  

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

Review of the Portsmouth Gaseous Diffusion Plant Work Planning and Control Activities Prior to Work Execution

205

NMR Advanced methodologies to investigate water diffusion in materials  

E-Print Network (OSTI)

NMR Advanced methodologies to investigate water diffusion in materials and biological systems Ph · Introduction: _Water Diffusion _Experimental technique: NMR · Diffusion NMR: applications to the study glasses · Diffusion NMR in the framework of multi-quantum coherences · Project outline #12;Outlook

Roma "La Sapienza", Università di

206

Reaction-diffusion systems with constant diffusivities: conditional symmetries and form-preserving transformations  

E-Print Network (OSTI)

Q-conditional symmetries (nonclassical symmetries) for a general class of two-component reaction-diffusion systems with constant diffusivities are studied. Using the recently introduced notion of Q-conditional symmetries of the first type (R. Cherniha J. Phys. A: Math. Theor., 2010. vol. 43., 405207), an exhaustive list of reaction-diffusion systems admitting such symmetry is derived. The form-preserving transformations for this class of systems are constructed and it is shown that this list contains only non-equivalent systems. The obtained symmetries permit to reduce the reaction-diffusion systems under study to two-dimensional systems of ordinary differential equations and to find exact solutions. As a non-trivial example, multiparameter families of exact solutions are explicitly constructed for two nonlinear reaction-diffusion systems. A possible interpretation to a biologically motivated model is presented.

Roman Cherniha; Vasyl' Davydovych

2013-04-24T23:59:59.000Z

207

Fractal Location and Anomalous Diffusion Dynamics for Oil Wells from the KY Geological Survey  

E-Print Network (OSTI)

Utilizing data available from the Kentucky Geonet (KYGeonet.ky.gov) the fossil fuel mining locations created by the Kentucky Geological Survey geo-locating oil and gas wells are mapped using ESRI ArcGIS in Kentucky single plain 1602 ft projection. This data was then exported into a spreadsheet showing latitude and longitude for each point to be used for modeling at different scales to determine the fractal dimension of the set. Following the porosity and diffusivity studies of Tarafdar and Roy1 we extract fractal dimensions of the fossil fuel mining locations and search for evidence of scaling laws for the set of deposits. The Levy index is used to determine a match to a statistical mechanically motivated generalized probability function for the wells. This probability distribution corresponds to a solution of a dynamical anomalous diffusion equation of fractional order that describes the Levy paths which can be solved in the diffusion limit by the Fox H function ansatz.

Andrew, Keith; Andrew, Kevin A

2009-01-01T23:59:59.000Z

208

Defects and Polytypism in SiC: The Role of Diffuse X-Ray Scattering  

Science Conference Proceedings (OSTI)

Stacking faults (SFs) and the 3C-6H polytypic transition in thick (001)-oriented 3C-SiC crystals are studied by means of diffuse X-ray scattering. The presence of SFs lying in the {l_brace}111{r_brace} planes gives rise to streaked reciprocal lattice points with the streaks being parallel to the directions. In the case of low SF densities the defects are uncorrelated and the simulation of the diffuse intensity distribution allows to derive the SF density. In partially transformed crystals, the SFs are spatially correlated which gives rise to an intense and asymmetric diffuse scattering distribution. Its simulation allows to determine both the transformation mechanism and the transformation level.

Boulle, A.; Dompoint, D. [Science des Procedes Ceramiques et de Traitements de surface (SPCTS-CNRS UMR 6638), ENSCI 47 avenue Albert Thomas 87065 Limoges Cedex (France); Galben-Sandulache, I.; Chaussende, D. [Laboratoires des Materiaux et du Genie Physique (LMGP-CNRS UMR 5628), Grenoble INP, Minatec 3 parvis Louis Neel, BP 257, 38016 Grenoble Cedex 01 (France)

2010-11-01T23:59:59.000Z

209

ARM - Measurement - Shortwave spectral diffuse downwelling irradiance  

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

diffuse downwelling irradiance diffuse 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 spectral diffuse downwelling irradiance The rate at which spectrally resolved radiant energy at wavelengths shorter than approximately 4 {mu}m, that has been scattered in the atmosphere at least once, passes 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. ARM Instruments RSS : Rotating Shadowband Spectroradiometer

210

Diffusion of Radionuclides in Concrete and Soil  

SciTech Connect

One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Such concrete encasement would contain and isolate the waste packages from the hydrologic environment and would act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion and move into the surrounding subsurface environment. Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. The objective of our study was to measure the diffusivity of Re, Tc and I in concrete containment and the surrounding vadose zone soil. Effects of carbonation, presence of metallic iron, and fracturing of concrete and the varying moisture contents in soil on the diffusivities of Tc and I were evaluated.

Mattigod, Shas V.; Wellman, Dawn M.; Bovaird, Chase C.; Parker, Kent E.; Recknagle, Kurtis P.; Clayton, Libby N.; Wood, Marcus I.

2012-04-25T23:59:59.000Z

211

ARM - Measurement - Shortwave broadband diffuse downwelling irradiance  

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

diffuse downwelling irradiance diffuse 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 broadband diffuse downwelling irradiance All of the solar radiation, across the wavelength range of 0.4 and 4 {mu}m, coming directly from the sky except for solar radiation coming directly from the sun and the circumsolar irradiance within approximately three degrees of 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

212

INDEXING MECHANISM  

DOE Patents (OSTI)

A device is presented for loading and unloading fuel elements containing material fissionable by neutrons of thermal energy. The device comprises a combination of mechanical features Including a base, a lever pivotally attached to the base, an Indexing plate on the base parallel to the plane of lever rotation and having a plurality of apertures, the apertures being disposed In rows, each aperture having a keyway, an Index pin movably disposed to the plane of lever rotation and having a plurality of apertures, the apertures being disposed in rows, each aperture having a keyway, an index pin movably disposed on the lever normal to the plane rotation, a key on the pin, a sleeve on the lever spaced from and parallel to the index pin, a pair of pulleys and a cable disposed between them, an open collar rotatably attached to the sleeve and linked to one of the pulleys, a pin extending from the collar, and a bearing movably mounted in the sleeve and having at least two longitudinal grooves in the outside surface.

Kock, L.J.

1959-09-22T23:59:59.000Z

213

Comparison of Diffuse Shortwave Irradiance Measurements  

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

Diffuse Shortwave Diffuse Shortwave Irradiance Measurements J. J. Michalsky and J. Schlemmer Atmospheric Sciences Research Center State University of New York Albany, New York B. C. Bush, S. Leitner, D. Marsden, and F. P. J. Valero Scripps Institution of Oceanography University of California, San Diego La Jolla, California R. Dolce and A. Los Kipp & Zonen, Inc. Bohemia, New York and Delft The Netherlands E. G. Dutton Climate Monitoring and Diagnostics Laboratory National Oceanic and Atmospheric Administration Boulder, Colorado M. P. Haeffelin Virginia Polytechnic Institute and State University Blackburg, Virginia G. Major Budapest University of Economic Sciences and Public Administration Budapest, Hungry J. Hickey The Eppley Laboratory, Inc. Newport, Rhode Island

214

Calculating the Diffuse Responsivity of Solar Pyranometers  

DOE Green Energy (OSTI)

Pyranometers are used to measure the global and diffuse components of solar irradiance. One of the methods to calculate the unshade (global) responsivity of a pyranometer is the standard shading method, described in the Annual Book of ASTM Standards, section 14, volume 14.02. In this paper, the standard method is used to calculate the shade (diffuse) responsivity of a pyranometer by accounting for the zenith and azimuth response of the pyranometer. A discussion of the effect of pyranometer offset on the calculated responsivity is also presented.

Reda, I.; Myers, D.

1999-08-16T23:59:59.000Z

215

Separation of Hydrogen Isotopes by Thermal Diffusion  

SciTech Connect

At high hot wall temperatures the gas phase thermal diffusion column acts as an atomic rather than a molecular separator. A modified theory was developed to describe the process. Equivalent transport equations were derived for the two nuclides in a binary atomic mixture. The equations are identical in form to those normally encountered in thermal diffusion column theory. Experiments to test the theory were carried out with two 3-meter columns. Experimental results with deuterium-tritium mixtures were found to be in satisfactory agreement with theory, and it was concluded that the theory was sufficiently accurate for design purposes.

Rutherford, W. M.; Lindsay, C. N.

1985-09-01T23:59:59.000Z

216

Hydrogen spillover: Its "diffusion" from catalysis to hydrogen storage community  

DOE Green Energy (OSTI)

Dissociative adsorption of hydrogen on catalyst sites followed by surface diffusion (spillover) to a carbon support was first reported for Pt-carbon catalysts (Robell, 1964) and was soon accepted as a valid step of numerous catalytic reactions. However, the concept of metal-assisted hydrogen storage (Schwarz, 1988) based on spillover entered much later the hydrogen community (Lueking and Yang, 2002) and is gaining recognition slowly as an alternate approach for enhancing hydrogen storage capacity of microporous materials for fuel-cell powered vehicles. This talk will analyze the significance and limits of the spillover mechanism for adsorptive storage of hydrogen, with examples of enhanced hydrogen uptake on Pd-containing activated carbon fibers. Evidence of the atomic nature of spilt-over hydrogen will be presented based on experimental results from inelastic neutron spectroscopy studies. Research sponsored by the Division of Materials Sciences and Engineering, U.S. Department of Energy under contract with UT-Battelle, LLC.

Contescu, Cristian I [ORNL; Bhat, Vinay V [ORNL; Gallego, Nidia C [ORNL

2009-01-01T23:59:59.000Z

217

Mechanical Design  

SciTech Connect

The particle beam of the SXR (soft x-ray) beam line in the LCLS (Linac Coherent Light Source) has a high intensity in order to penetrate through samples at the atomic level. However, the intensity is so high that many experiments fail because of severe damage. To correct this issue, attenuators are put into the beam line to reduce this intensity to a level suitable for experimentation. Attenuation is defined as 'the gradual loss in intensity of any flux through a medium' by [1]. It is found that Beryllium and Boron Carbide can survive the intensity of the beam. At very thin films, both of these materials work very well as filters for reducing the beam intensity. Using a total of 12 filters, the first 9 being made of Beryllium and the rest made of Boron Carbide, the beam's energy range of photons can be attenuated between 800 eV and 9000 eV. The design of the filters allows attenuation for different beam intensities so that experiments can obtain different intensities from the beam if desired. The step of attenuation varies, but is relative to the thickness of the filter as a power function of 2. A relationship for this is f(n) = x{sub 0}2{sup n} where n is the step of attenuation desired and x{sub 0} is the initial thickness of the material. To allow for this desired variation, a mechanism must be designed within the test chamber. This is visualized using a 3D computer aided design modeling tool known as Solid Edge.

2010-08-25T23:59:59.000Z

218

Zero-flux planes, flux reversals and diffusion paths in ternary and quaternary diffusion  

SciTech Connect

During isothermal multicomponent diffusion, interdiffusion fluxes of individual components can go to zero at zero-flux planes (ZFP) and exhibit flux reversals from one side to the other of such planes. Interdiffusion fluxes as well as the locations and compositions of ZFPs for components are determined directly from the concentration profiles of diffusion couples without the need for prior knowledge of interdiffusion coefficients. The development and identification of ZFPs is reviewed with the aid of single phase and two-phase diffusion couples investigated in the Cu-Ni-Zn system at 775/sup 0/C. ZFP locations in the diffusion zone nearly correspond to sections where the activity of a component is the same as its activity in either of the terminal alloys of a couple. Path slopes at ZFPs are uniquely dictated by the atomic mobility and thermodynamic data for the components. Discontinuous flux reversals for the components can also occur at interfaces in multiphase couples. Identification of ZFPs is also presented for diffusion in the Cu-Ni-Zn-Mn quaternary system. Analytical representation of diffusion paths for both ternary and quaternary diffusion couples is presented with the aid of characteristic path parameters.

Dayananda, M.A.

1986-05-23T23:59:59.000Z

219

Enforcement Letter, Geiger Brothers Mechanical Contractors, INC - March 26,  

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

Geiger Brothers Mechanical Contractors, INC - Geiger Brothers Mechanical Contractors, INC - March 26, 2010 Enforcement Letter, Geiger Brothers Mechanical Contractors, INC - March 26, 2010 March 26, 2010 Enforcement Letter issued to Geiger Brothers Mechanical Contractors, Inc. related to Installation and Inspection of Penetration Fire Seals at the DUF6 Conversion Building at the Portsmouth Gaseous Diffusion Plant This letter refers to the Office of Health, Safety and Security's Office of Enforcement investigation into the facts and circumstances associated with deficiencies in the installation and inspection of penetration fire seals at the DUF6 Conversion Building, located at the Portsmouth Gaseous Diffusion Plant. DOE's investigation report, dated January 22, 2009, was provided to Geiger Brothers Mechanical Contractors, Inc. (Geiger) under

220

ICT diffusion in the Republic of Armenia  

Science Conference Proceedings (OSTI)

The Republic of Armenia, a high literacy and high poverty country, allows for a test of digital divide beliefs about the role of economic wellbeing in ownership of and skills in using information communication technology. While socioeconomic status was ... Keywords: Armenia, ICT, ICTD, adoption, diffusion, digital divide

Katy E. Pearce

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Information and attitude diffusion in networks  

Science Conference Proceedings (OSTI)

The availability of diverse information does not guarantee that a person's views will be equally diverse. Research has consistently shown that attitudinal positions on an issue will lead to selective reception and dissemination of information, which ... Keywords: active dissemination of information, attitude diffusion, information cascades, selective exposure of information

Wai-Tat Fu; Q. Vera Liao

2012-04-01T23:59:59.000Z

222

A Two?Stage Oil Diffusion Pump  

Science Conference Proceedings (OSTI)

A two?stage oil diffusion pump built of glass is described which makes possible the utilization of the advantages of oil without requiring the use of an unusually good coarse vacuum. The novelty of the pump resides in the first stage which is so designed that it cannot clog even with the small clearances needed to work against high pressures.

Joseph E. Henderson

1935-01-01T23:59:59.000Z

223

Some Recent Long-Range Diffusion Observations  

Science Conference Proceedings (OSTI)

Recent atmospheric cloud-spreading (relative diffusion) data from a variety of sources are combined to show that the horizontal spreading rate is approximately linear over a time range from 1 to 10 or more hours (20?200 or more km) of downwind ...

F. A. Gifford

1995-07-01T23:59:59.000Z

224

Diffusion Processes in Turbulent Magnetic Fields  

E-Print Network (OSTI)

We study of the effect of turbulence on diffusion processes within magnetized medium. While we exemplify our treatment with heat transfer processes, our results are quite general and are applicable to different processes, e.g. diffusion of heavy elements. Our treatment is also applicable to describing the diffusion of cosmic rays arising from magnetic field wandering. In particular, we find that when the energy injection velocity is smaller than the Alfven speed the heat transfer is partially suppressed, while in the opposite regime the effects of turbulence depend on the intensity of driving. In fact, the scale $l_A$ at which the turbulent velocity is equal the Alfven velocity is a new important parameter. When the electron mean free path $\\lambda$ is larger than $l_A$, the stronger the the turbulence, the lower thermal conductivity by electrons is. The turbulent motions, however, induces their own advective transport, that can provide effective diffusivity. For clusters of galaxies, we find that the turbulence is the most important agent for heat transfer. We also show that the domain of applicability of the subdiffusion concept is rather limited.

Alex Lazarian

2007-07-04T23:59:59.000Z

225

Diffusion Processes in Turbulent Magnetic Fields  

E-Print Network (OSTI)

We study of the effect of turbulence on diffusion processes within magnetized medium. While we exemplify our treatment with heat transfer processes, our results are quite general and are applicable to different processes, e.g. diffusion of heavy elements. Our treatment is also applicable to describing the diffusion of cosmic rays arising from magnetic field wandering. In particular, we find that when the energy injection velocity is smaller than the Alfven speed the heat transfer is partially suppressed, while in the opposite regime the effects of turbulence depend on the intensity of driving. In fact, the scale $l_A$ at which the turbulent velocity is equal the Alfven velocity is a new important parameter. When the electron mean free path $\\lambda$ is larger than $l_A$, the stronger the the turbulence, the lower thermal conductivity by electrons is. The turbulent motions, however, induces their own advective transport, that can provide effective diffusivity. For clusters of galaxies, we find that the turbule...

Lazarian, Alex

2007-01-01T23:59:59.000Z

226

The diffusion of mobile phones in India  

Science Conference Proceedings (OSTI)

Mobile phones, which were introduced around a decade ago in 1995-1996 in India, are becoming the dominant means of accessing communication. At the end of 2005-2006, there were 90 million mobile subscribers in India in comparison to 50 million subscribers ... Keywords: Mobile telecommunications, Technology diffusion

Sanjay Kumar Singh

2008-10-01T23:59:59.000Z

227

Independent Activity Report, Portsmouth Gaseous Diffusion Plant - July 2011  

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

Activity Report, Portsmouth Gaseous Diffusion Plant - Activity Report, Portsmouth Gaseous Diffusion Plant - July 2011 Independent Activity Report, Portsmouth Gaseous Diffusion Plant - July 2011 July 2011 Orientation Visit to the Portsmouth Gaseous Diffusion Plant [HIAR-PAD-2011-07-27] The purpose of the visit was to discuss the nuclear safety oversight strategy, describe the site lead program, increase HSS personnel's operational awareness of the site's activities, and to determine how HSS can carry out its independent oversight and mission support responsibilities. Independent Activity Report, Portsmouth Gaseous Diffusion Plant - July 2011 More Documents & Publications Independent Activity Report, Portsmouth Gaseous Diffusion Plant - August 2011 Independent Activity Report, Argonne National Laboratory - August 2011

228

An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples  

E-Print Network (OSTI)

Nuclear Waste Management, Shackelford, C.D. , Daniel, D.E. ,ASCE 117(3), 467-484. Shackelford, C.D. , Daniel, D.E. ,diffusion” effects (Shackelford and Daniel, 1991a) may

Takeda, M.

2011-01-01T23:59:59.000Z

229

Physicalism versus quantum mechanics  

E-Print Network (OSTI)

Foundations of Quantum Mechanics. (Princeton UniversityMind, Matter, and Quantum Mechanics, (Springer, Berlin & NewMindful Universe: Quantum Mechanics and the Participating

Stapp, Henry P; Theoretical Physics Group; Physics Division

2009-01-01T23:59:59.000Z

230

Diffusion Multilayer Sampling of Ground Water in Five Wells at...  

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

Diffusion Multilayer Sampling of Ground Water in Five Wells at the Tuba City, Arizona, Site Diffusion Multilayer Sampling of Ground Water in Five Wells at the Tuba City, Arizona,...

231

Does rotation influence double-diffusive fluxes in polar oceans?  

Science Conference Proceedings (OSTI)

The diffusive (or semi-convection) regime of double-diffusive convection (DDC) is wide-spread in the polar oceans, generating “staircases” consisting of high-gradient interfaces of temperature and salinity separated by convectively mixed layers. ...

J. R. Carpenter; M.-L. Timmermans

232

Modeling of Spectralon diffusers for radiometric calibration in remote sensing  

E-Print Network (OSTI)

Modeling of Spectralon diffusers for radiometric calibration in remote sensing G. Bazalgette Courre Abstract. Onboard calibration of radiometric measurements in remote sensing is often achieved for publication May 28, 2003. 1 Introduction Light diffusers are used in remote sensing applications

Sprik, Rudolf

233

Stable Schemes for Nonlinear Vertical Diffusion in Atmospheric Circulation Models  

Science Conference Proceedings (OSTI)

The intensity of vertical mixing in atmospheric models generally depends on wind shear and static stability, making the diffusion process nonlinear. Traditional implicit numerical schemes, which treat the variables to be diffused implicitly but ...

Claude Girard; Yves Delage

1990-03-01T23:59:59.000Z

234

SunShot Initiative: Solar Energy Evolution and Diffusion Studies  

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

Solar Energy Evolution and Diffusion Studies to someone by E-mail Share SunShot Initiative: Solar Energy Evolution and Diffusion Studies on Facebook Tweet about SunShot Initiative:...

235

Isothermal Ice Crystallization Kinetics in the Gas-Diffusion...  

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

Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer of a Proton-Exchange-Membrane Fuel Cell Title Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer...

236

Fundamental Studies of Diffusion and Reactions in Hydrogen Storage Materials  

E-Print Network (OSTI)

energy production and use [1,2], but adequate hydrogen storageEnergy Fundamental studies of diffusion and reactions in hydrogen storageEnergy 010 "Fundamental studies of diffusion and reactions in hydrogen storage

Van de Walle, Chris G; Peles, Amra; Janotti, Anderson; Wilson-Short, Gareth

2008-01-01T23:59:59.000Z

237

A Simulation Study of Diffusion in Microporous Materials  

E-Print Network (OSTI)

dynamics simulation of the diffusion of n- butane andi-butane in silicalite. J. Chem. Phys. 108, 2170–2172 (Stefan diffusivity of iso-butane in MFI zeolite. Chem. Phys.

Abouelnasr, Mahmoud Kamal Forrest

2013-01-01T23:59:59.000Z

238

Oceanographic implications of Laboratory Experiments on Diffusive Interfaces  

Science Conference Proceedings (OSTI)

This paper contains a summary of the results from some laboratory and theoretical studies on the diffusive interface in double diffusive convection, paying particular attention to the recent work of Fernando. A simple model is developed which ...

Harindra J. S. Fernando

1989-11-01T23:59:59.000Z

239

Modeling Vertical and Horizontal Diffusivities with the Sigma Coordinate System  

Science Conference Proceedings (OSTI)

The use of diffusive terms in numerical ocean models is examined relative to different coordinate systems. The conventional model for horizontal diffusion is found to be incorrect when bottom topographical slopes are large. A new formulation is ...

George L. Mellor; Alan F. Blumberg

1985-08-01T23:59:59.000Z

240

Tritium diffusion in lithium oxide solid breeder materials  

DOE Green Energy (OSTI)

A review of data of tritium diffusion in Li/sub 2/O is presented. Also diffusion coefficients in Li/sub 2/O of tritium, lithium, oxygen, hydrogen, and deuterium are given. (MOW)

Shearer, J.A.; Tam, S.W.; Johnson, C.E.

1983-01-01T23:59:59.000Z

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


241

Development of a micro-FID using a diffusion flame.  

E-Print Network (OSTI)

??A micro-flame ionization detector (micro-FID) was developed operating with a diffusion flame with a folded flame structure. Unlike conventional FIDs, an air-hydrogen diffusion flame was… (more)

Kim, Jihyung

2011-01-01T23:59:59.000Z

242

Gas Diffusion Electrodes for Fuel Cells - Energy Innovation Portal  

A unique gas diffusion electrode technique resulting in little to no leftover methanol, therefore increasing the overall effectiveness and performance ...

243

Independent Oversight Review, Portsmouth Gaseous Diffusion Plant- April 2013  

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

Review of the Integrated Safety Management System Phase I Verification Review at the Portsmouth Gaseous Diffusion Plant

244

Fundamental Studies of Diffusion and Reactions in Hydrogen Storage Materials  

E-Print Network (OSTI)

Fundamental Science ofEnergy 010 "Fundamental studies of diffusion and reactionsInstitute's (UCEI) Fundamental Science of Energy Working

Van de Walle, Chris G; Peles, Amra; Janotti, Anderson; Wilson-Short, Gareth

2008-01-01T23:59:59.000Z

245

Fukushima's decomposition for diffusions associated with semi-Dirichlet forms  

E-Print Network (OSTI)

In this paper, we give Fukushima's decomposition for diffusions associated with semi-Dirichlet forms and discuss some related topics.

Ma, Li; Sun, Wei

2011-01-01T23:59:59.000Z

246

Gaseous Diffusion Plant Production Workers Needs Assessment  

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

Department of Energy Gaseous Diffusion Plants Department of Energy Gaseous Diffusion Plants Phase I: Needs Assessment Robert Wages Oil, Chemical and Atomic Inte national Union Steven Markowitz Mount Sinai School of Medicine Sylvia Kieding Oil, Chemical and Atomic International Union Mark Griffon University of Massachusetts Lowell Elizabeth Averill Samaras Alice Hamilton College October 1, 1997 TABLE OF CONTENTS Page Number Executive Summary 1 J: OVERVIEW 1. Introduction 2-3 2. Methods 3-8 3. Principal Findings 9-16 4. Need for Medical Surveillance and Risk Communication 16-17 PART II: METHODOLOGY AND RESULTS 4. Exposure Assessment Appendix A Appendix B Appendix C 5. Focus Group Results Appendix A Appendix B Appendix C 6. Epidemiology and Other Health Studies EXECUTIVE SUMMARY Purpose We report the results and analysis of a one year needs assessment study evaluating

247

Pumping Fluid Condensation in Oil Diffusion Pumps  

Science Conference Proceedings (OSTI)

Condensation conditions of the motive fluid in an oil diffusion pump are considered with particular attention to the backstreaming problem. The backstreaming rate is correlated with the temperature of the “cold caps” surrounding the pump nozzle and it is demonstrated that an upper temperature limit exists near 200?°F where such devices cease to function effectively. The effect of “oleophobic” surfaces on cold caps and baffles is discussed. Conditions existing at the inlet of diffusion pumps and in baffles do not warrant attempts to introduce dropwise condensation. The condensation coefficient of pumping vapor at the temperature of the water cooled wall and with the flow rates used at the top nozzle appears to be very close to unity. The usefulness of creep barriers with modern pumping fluids and trap designs is judged to be questionable.

M. H. Hablanian

1972-01-01T23:59:59.000Z

248

Diffusion barriers in modified air brazes  

DOE Patents (OSTI)

A method for joining two ceramic parts, or a ceramic part and a metal part, and the joint formed thereby. The method provides two or more parts, a braze consisting of a mixture of copper oxide and silver, a diffusion barrier, and then heats the braze for a time and at a temperature sufficient to form the braze into a bond holding the two or more parts together. The diffusion barrier is an oxidizable metal that forms either a homogeneous component of the braze, a heterogeneous component of the braze, a separate layer bordering the braze, or combinations thereof. The oxidizable metal is selected from the group Al, Mg, Cr, Si, Ni, Co, Mn, Ti, Zr, Hf, Pt, Pd, Au, lanthanides, and combinations thereof.

Weil, Kenneth Scott; Hardy, John S; Kim, Jin Yong; Choi, Jung-Pyung

2013-04-23T23:59:59.000Z

249

Methodology and apparatus for diffuse photon mimaging  

DOE Patents (OSTI)

Non-invasive near infrared optical medical imaging devices for both hematoma detection in the brain and early tumor detection in the breast is achieved using image reconstruction which allows a mapping of the position dependent contrast diffusive propagation constants, which are related to the optical absorption coefficient and scattering coefficient in the tissue, at near infrared wavelengths. Spatial resolutions in the range of 5 mm for adult brain sizes and breast sizes can be achieved. The image reconstruction utilizes WKB approximation on most probable diffusion paths which has as lowest order approximation the straight line-of-sight between the plurality of sources and the plurality of detectors. The WKB approximation yields a set of linear equations in which the contrast optical absorption coefficients are the unknowns and for which signals can be generated to produce a pixel map of the contrast optical resolution of the scanned tissue.

Feng, Shechao C. (Los Angeles, CA); Zeng, Fanan (Los Angeles, CA); Zhao, Hui-Lin (Los Angeles, CA)

1997-12-09T23:59:59.000Z

250

Methodology and apparatus for diffuse photon imaging  

DOE Patents (OSTI)

Non-invasive near infrared optical medical imaging devices for both hematoma detection in the brain and early tumor detection in the breast is achieved using image reconstruction which allows a mapping of the position dependent contrast diffusive propagation constants, which are related to the optical absorption coefficient and scattering coefficient in the tissue, at near infrared wavelengths. Spatial resolutions in the range of 5 mm for adult brain sizes and breast sizes can be achieved. The image reconstruction utilizes WKB approximation on most probable diffusion paths which has as lowest order approximation the straight line-of-sight between the plurality of sources and the plurality of detectors. The WKB approximation yields a set of linear equations in which the contrast optical absorption coefficients are the unknowns and for which signals can be generated to produce a pixel map of the contrast optical resolution of the scanned tissue. 58 figs.

Feng, S.C.; Zeng, F.; Zhao, H.L.

1997-12-09T23:59:59.000Z

251

Distributed Energy Resources Market Diffusion Model  

SciTech Connect

Distributed generation (DG) technologies, such as gas-fired reciprocating engines and microturbines, have been found to be economically beneficial in meeting commercial-sector electrical, heating, and cooling loads. Even though the electric-only efficiency of DG is lower than that offered by traditional central stations, combined heat and power (CHP) applications using recovered heat can make the overall system energy efficiency of distributed energy resources (DER) greater. From a policy perspective, however, it would be useful to have good estimates of penetration rates of DER under various economic and regulatory scenarios. In order to examine the extent to which DER systems may be adopted at a national level, we model the diffusion of DER in the US commercial building sector under different technical research and technology outreach scenarios. In this context, technology market diffusion is assumed to depend on the system's economic attractiveness and the developer's knowledge about the technology. The latter can be spread both by word-of-mouth and by public outreach programs. To account for regional differences in energy markets and climates, as well as the economic potential for different building types, optimal DER systems are found for several building types and regions. Technology diffusion is then predicted via two scenarios: a baseline scenario and a program scenario, in which more research improves DER performance and stronger technology outreach programs increase DER knowledge. The results depict a large and diverse market where both optimal installed capacity and profitability vary significantly across regions and building types. According to the technology diffusion model, the West region will take the lead in DER installations mainly due to high electricity prices, followed by a later adoption in the Northeast and Midwest regions. Since the DER market is in an early stage, both technology research and outreach programs have the potential to increase DER adoption, and thus, shift building energy consumption to a more efficient alternative.

Maribu, Karl Magnus; Firestone, Ryan; Marnay, Chris; Siddiqui,Afzal S.

2006-06-16T23:59:59.000Z

252

Distributed Energy Resources Market Diffusion Model  

SciTech Connect

Distributed generation (DG) technologies, such as gas-fired reciprocating engines and microturbines, have been found to be economically beneficial in meeting commercial-sector electrical, heating, and cooling loads. Even though the electric-only efficiency of DG is lower than that offered by traditional central stations, combined heat and power (CHP) applications using recovered heat can make the overall system energy efficiency of distributed energy resources (DER) greater. From a policy perspective, however, it would be useful to have good estimates of penetration rates of DER under various economic and regulatory scenarios. In order to examine the extent to which DER systems may be adopted at a national level, we model the diffusion of DER in the US commercial building sector under different technical research and technology outreach scenarios. In this context, technology market diffusion is assumed to depend on the system's economic attractiveness and the developer's knowledge about the technology. The latter can be spread both by word-of-mouth and by public outreach programs. To account for regional differences in energy markets and climates, as well as the economic potential for different building types, optimal DER systems are found for several building types and regions. Technology diffusion is then predicted via two scenarios: a baseline scenario and a program scenario, in which more research improves DER performance and stronger technology outreach programs increase DER knowledge. The results depict a large and diverse market where both optimal installed capacity and profitability vary significantly across regions and building types. According to the technology diffusion model, the West region will take the lead in DER installations mainly due to high electricity prices, followed by a later adoption in the Northeast and Midwest regions. Since the DER market is in an early stage, both technology research and outreach programs have the potential to increase DER adoption, and thus, shift building energy consumption to a more efficient alternative.

Maribu, Karl Magnus; Firestone, Ryan; Marnay, Chris; Siddiqui,Afzal S.

2006-06-16T23:59:59.000Z

253

A stochastic mechanism of electron heating  

Science Conference Proceedings (OSTI)

Due to Landau resonant interaction with lower hybrid waves in the lower hybrid current drive scheme part of electrons are accelerated and, as a result of this, a tail of energetic electrons is formed on the electron distribution function. The same situation takes place in the problem of type III radio bursts when the suprathermal burst electrons acquire a plateau distribution due to excitation of plasma waves in the solar wind plasma. These distributions are unstable with respect to the cyclotron excitation of waves at anomalous Doppler resonance ('fan' instability). In this case, the tail electrons interact simultaneously with both (i) waves that accelerate or decelerate them (Cerenkov resonance) and (ii) waves excited in the process of the fan instability that led to their pitch angle diffusion. Because velocity diffusion lines of electrons formed due to heir interaction with each type of waves intersect, this interaction can lead not only to pitch angle diffusion but also to heating of electrons mainly in perpendicular direction. We investigated this mechanism of electron heating and studied the temporal evolution of the electron temperature and the energy of excited waves. Our results show significant enhancement of the electron perpendicular temperature T{sub Up-Tack} due to this stochastic heating mechanism.

Galinsky, V. L.; Shevchenko, V. I. [University of California, San Diego, ECE Department, La Jolla, California 92093-0407 (United States)

2012-08-15T23:59:59.000Z

254

Single Cell Mechanics BIOMATERIALS  

E-Print Network (OSTI)

Single Cell Mechanics BIOMATERIALS Our goal is to develop fundamental tools to measure the response of live cells to mechanical stimulation. The mechanisms by which cells convert mechanical forces evaluate the underlying mechanisms of cell mechanics. Objective Impact and Customers · Cancer, heart

255

Diffusion bonding of commercially pure Ni using Cu interlayer  

Science Conference Proceedings (OSTI)

The concentration dependence of diffusivity in a multi-component diffusion system makes it complicated to predict the concentration profiles of diffusing species. This so called chemical diffusivity can be expressed as a function of thermodynamic and kinetic data. DICTRA software can calculate the concentration profiles using appropriate mobility and thermodynamic data. It can also optimize the diffusivity data using experimental diffusivity data. Then the optimized diffusivity data is stored as mobility data which is a linear function of temperature. In this work, diffusion bonding of commercially pure Ni using Cu interlayers is reported. The mobility parameters of Ni-Cu alloy binary systems were optimized using DICTRA/Thermocalc software from the available self-, tracer and chemical diffusion coefficients. The optimized mobility parameters were used to simulate concentration profiles of Ni-Cu diffusion joints using DICTRA/Thermocalc software. The calculated and experimental concentration profiles agreed well at 1100 Degree-Sign C. Agreement between the simulated and experimental profiles was less good at 1050 Degree-Sign C due to the grain boundary contribution to the overall diffusion. - Highlights: Black-Right-Pointing-Pointer The concentration profiles of Cu in Ni-Cu diffusion joints are modeled. Black-Right-Pointing-Pointer Interdiffusion coefficients in Ni-Cu system are optimized. Black-Right-Pointing-Pointer Optimized interdiffusion coefficients are expressed as mobility parameters. Black-Right-Pointing-Pointer Simulated profiles are comparable with experimental profiles.

Rahman, A.H.M.E., E-mail: a.rahman@my.und.edu; Cavalli, M.N.

2012-07-15T23:59:59.000Z

256

Nonlinear analysis of a reaction-diffusion system: Amplitude equations  

Science Conference Proceedings (OSTI)

A reaction-diffusion system with a nonlinear diffusion term is considered. Based on nonlinear analysis, the amplitude equations are obtained in the cases of the Hopf and Turing instabilities in the system. Turing pattern-forming regions in the parameter space are determined for supercritical and subcritical instabilities in a two-component reaction-diffusion system.

Zemskov, E. P., E-mail: zemskov@ccas.ru [Russian Academy of Sciences, Dorodnicyn Computing Center (Russian Federation)

2012-10-15T23:59:59.000Z

257

The diffusion of the Internet: A cross-country analysis  

Science Conference Proceedings (OSTI)

This paper analyzes the process of Internet diffusion across the world using a panel of 214 countries during the period 1990-2004. Countries are classified as low- or high-income and it is shown that the diffusion process is characterized by a different ... Keywords: Digital divide, Internet, Network externalities, O14, O33, O57, S-shape curve, Technological diffusion

Luis Andrés; David Cuberes; Mame Diouf; Tomás Serebrisky

2010-06-01T23:59:59.000Z

258

Does the photon-diffusion coefficient depend on absorption?  

E-Print Network (OSTI)

and M. C. Edlund, The Elements of Nuclear Reactor Theory (Van Nostrand, New York, 1952), Chaps. 5 and 14 diffusion coefficient gives better agreement with theory than the traditionally accepted photon diffusion diffusion theory by using the two different diffu- sion coefficients, we quantitatively demonstrate

Boas, David

259

Vacancy Mechanism Davydov I.?.  

National Nuclear Security Administration (NNSA)

9404, P.O. Box 0969, Livermore, CA 94551, USA Summary: Computations of jump activation energy DH j and diffusion jump frequency n have been carried out using the Density Functional...

260

A mechanistic study of Soret diffusion in hydrogen-air flames  

Science Conference Proceedings (OSTI)

The separate and combined effects of Soret diffusion of the hydrogen molecule (H{sub 2}) and radical (H) on the structure and propagation speed of the freely-propagating planar premixed flames, and the strain-induced extinction response of premixed and nonpremixed counterflow flames, were computationally studied for hydrogen-air mixtures using a detailed reaction mechanism and transport properties. Results show that, except for the conservative freely-propagating planar flame, Soret diffusion of H{sub 2} increases the fuel concentration entering the flame structure and as such modifies the mixture stoichiometry and flame temperature, which could lead to substantial increase (decrease) of the flame speed for the lean (rich) mixtures respectively. On the other hand, Soret diffusion of H actively modifies its concentration and distribution in the reaction zone, which in turn affects the individual reaction rates. In particular, the reaction rates of the symmetric, twin, counterflow premixed flames, especially at near-extinction states, can be increased for lean flames but decreased for rich flames, whose active reaction regions are respectively located at, and away from, the stagnation surface. However, such a difference is eliminated for the single counterflow flame stabilized by an opposing cold nitrogen stream, as the active reaction zone up to the state of extinction is always located away from the stagnation surface. Finally, the reaction rate is increased in general for diffusion flames because the bell-shaped temperature distribution localizes the H concentration to the reaction region which has the maximum temperature. (author)

Yang, F. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Department of Engineering Mechanics, Tsinghua University, Beijing (China); Law, C.K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Sung, C.J. [Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269 (United States); Zhang, H.Q. [Department of Engineering Mechanics, Tsinghua University, Beijing (China)

2010-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Gaseous Diffusion Plant Production Workers Needs Assessment  

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

been identified at Oak Ridge. The risk mapping sessions highlighted the instrument mechanics as a job classification with significant mercury exposure. Solvents Solvent...

262

Adaptive Implicit Non-Equilibrium Radiation Diffusion  

SciTech Connect

We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

Philip, Bobby [ORNL; Wang, Zhen [ORNL; Berrill, Mark A [ORNL; Rodriguez Rodriguez, Manuel [ORNL; Pernice, Michael [Idaho National Laboratory (INL)

2013-01-01T23:59:59.000Z

263

Band Formation during Gaseous Diffusion in Aerogels  

E-Print Network (OSTI)

We study experimentally how gaseous HCl and NH_3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The reaction leads to solid NH_4Cl, which is deposited in thin sheet-like structures. We present a numerical study of the phenomenon. Due to the difference in boundary conditions between this system and those usually studied, we find the sheet-like structures in the aerogel to differ significantly from older studies. The influence of random nucleation centers and inhomogeneities in the aerogel is studied numerically.

M. A. Einarsrud; F. A. Maao; A. Hansen; M. Kirkedelen; J. Samseth

1997-06-18T23:59:59.000Z

264

Solar mechanics thermal response capabilities.  

DOE Green Energy (OSTI)

In many applications, the thermal response of structures exposed to solar heat loads is of interest. Solar mechanics governing equations were developed and integrated with the Calore thermal response code via user subroutines to provide this computational simulation capability. Solar heat loads are estimated based on the latitude and day of the year. Vector algebra is used to determine the solar loading on each face of a finite element model based on its orientation relative to the sun as the earth rotates. Atmospheric attenuation is accounted for as the optical path length varies from sunrise to sunset. Both direct and diffuse components of solar flux are calculated. In addition, shadowing of structures by other structures can be accounted for. User subroutines were also developed to provide convective and radiative boundary conditions for the diurnal variations in air temperature and effective sky temperature. These temperature boundary conditions are based on available local weather data and depend on latitude and day of the year, consistent with the solar mechanics formulation. These user subroutines, coupled with the Calore three-dimensional thermal response code, provide a complete package for addressing complex thermal problems involving solar heating. The governing equations are documented in sufficient detail to facilitate implementation into other heat transfer codes. Suggestions for improvements to the approach are offered.

Dobranich, Dean D.

2009-07-01T23:59:59.000Z

265

Effects of molecular transport on turbulence-chemistry interactions in a hydrogen-argon-air jet diffusion flame  

DOE Green Energy (OSTI)

A numerical simulation of entrainment, turbulent advection, molecular import and chemical kinetics in a turbulent diffusion flame is used to investigate effects of molecular transport on turbulence-chemistry interactions. A fun finite-rate chemical mechanism is used to represent the combustion of a hydrogen-argon mixture issuing into air. Results based on incorporation of differential diffusion and variable Lewis number are compared to cases with the former effect, or both-effects, suppressed. Significant impact on radical species production and on NO emission index (based on a reduced mechanism for thermal NO) is found. A reduced mechanism for hydrogen-air combustion, omitting both effects and incorporating other simplifications, performs comparably except that its NO predictions agree well with the case of full chemistry and molecular transport, possibly due to cancellation of errors.

Menon, S.; Calhoon, W.H. Jr.; Goldin, G. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Aerospace Engineering; Kerstein, A.R. [Sandia National Labs., Livermore, CA (United States)

1994-01-01T23:59:59.000Z

266

Measurement of Solute Diffusion Behavior in Fractured Waste Glass Media  

SciTech Connect

Determination of aqueous phase diffusion coefficients of solutes through fractured media is essential for understanding and modeling contaminants transport at many hazardous waste disposal sites. No methods for earlier measurements are available for the characterization of diffusion in fractured glass blocks. We report here the use of time-lag diffusion experimental method to assess the diffusion behavior of three different solutes (Cs, Sr and Pentafluoro Benzoic Acid or PFBA) in fractured, immobilized low activity waste (ILAW) glass forms. A fractured media time-lag diffusion experimental apparatus that allows the measurement of diffusion coefficients has been designed and built for this purpose. Use of time-lag diffusion method, a considerably easier experimental method than the other available methods, was not previously demonstrated for measuring diffusion in any fractured media. Hydraulic conductivity, porosity and diffusion coefficients of a solute were experimentally measured in fractured glass blocks using this method for the first time. Results agree with the range of properties reported for similar rock media earlier, indicating that the time-lag experimental method can effectively characterize the diffusion coefficients of fractured ILAW glass media.

Saripalli, Kanaka P.; Lindberg, Michael J.; Meyer, Philip D.

2008-10-01T23:59:59.000Z

267

Ratcheted diffusion transport through crowded nanochannels  

E-Print Network (OSTI)

The problem of transport through nanochannels is one of the major questions in cell biology, with a wide range of applications. Brownian ratchets are fundamental in various biochemical processes, and are roughly divided into two categories: active (usually ATP-powered) molecular motors and passive constructions with a directional bias, where the transport is driven by thermal motion. In this paper we discuss the latter process, of spontaneous translocation of molecules (Brownian particles) by ratcheted diffusion with no external energy input: a problem relevant for protein translocation along bacterial flagella or injectosome complex, or DNA translocation by bacteriophages. We use molecular dynamics simulations and statistical theory to identify two regimes of transport: at low rate of particles injection into the channel the process is controlled by the individual diffusion towards the open end (the first passage problem), while at a higher rate of injection the crowded regime sets in. In this regime the particle density in the channel reaches a constant saturation level and the resistance force increases substantially, due to the osmotic pressure build-up. To achieve a steady-state transport, the apparatus that injects new particles into a crowded channel has to operate with an increasing power consumption, proportional to the length of the channel and the required rate of transport. The analysis of resistance force, and accordingly -- the power required to inject the particles into a crowded channel to oversome its clogging, is also relevant for many microfluidics applications.

Anna Lappala; Alessio Zaccone; Eugene M. Terentjev

2013-07-23T23:59:59.000Z

268

LHC Beam Diffusion Effects: Models and Measurements  

Science Conference Proceedings (OSTI)

Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

Mastorides, T.; /SLAC; Rivetta, C.; /SLAC; Fox, J.D.; /SLAC; Van Winkle, D.; /SLAC; Baudrenghien, P.; /CERN; Butterworth, A.; /CERN; Molendijk, J.; /CERN

2010-09-14T23:59:59.000Z

269

MechanicalTesting  

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

structures, validation of encapsulant cure stress models, development of frac- ture mechanics tests for use in adhesion studies and understanding the failure mechanism of...

270

Diffusion of hydrogen isotopes in palladium hydride and deuteride in the presence of lithium  

Science Conference Proceedings (OSTI)

The effect of Li incorporation into Pd on the hydrogen flow through a membrane Pd-electrode was found. It was of interest to determine the mechanism of this effect by a direct measurement of the diffusion coefficient of hydrogen in the Pd-H{sub x} phase and in the ternary Li-PdH{sub x} phase that was formed by the cathodic polarization of Pd in the solutions of lithium salts. A study of the effect of lithium on the diffusion of deuterium in the Li-PdD{sub x} phase might also be useful in solving this problem. In this work, a method of electrochemical extraction of absorbed hydrogen is used for these measurements; this method has been developed for nonsteady-state conditions, in particular. The X-ray examination of the formed phases was performed by a DRON-3M set-up with the use of CoK{sub {alpha}} radiation.

Astakhov, I.I.; Kazarinov, V.E.; Reznikova, L.A.; Teplitskaya, G.L. [Frumkin Institute of Electrochemistry, Moscow (Russian Federation)

1994-12-01T23:59:59.000Z

271

Surfactant-modified diffusion on transition-metal surfaces (reprinted with the addition of the appendices)  

DOE Green Energy (OSTI)

Wanting to convert surface impurities from a nuisance to a systematically applicable nano-fabrication tool, the authors have sought to understand how such impurities affect self-diffusion on transition-metal surfaces. Their field-ion microscope experiments reveal that in the presence of surface hydrogen, self-diffusion on Rh(100) is promoted, while on Pt(100), not only is it inhibited, but its mechanism changes. First-principles calculations aimed at learning how oxygen fosters perfect layerwise growth on a growing Pt(111) crystal contradict the idea in the literature that it does so by directly promoting transport over Pt island boundaries. The discovery that its real effect is to burn off adventitious adsorbed carbon monoxide demonstrates the predictive value of state-of-the-art calculation methods.

FEIBELMAN,PETER J.; KELLOGG,GARY LEE

2000-03-01T23:59:59.000Z

272

Electrophoretic Migration and Axial Diffusion of Individual Nanoparticles in Cylindrical Nanopores  

SciTech Connect

Membranes with straight, vertical nanopores have found widespread applications in chemical and biological sciences, including separation, detection, catalysis, and drug delivery. They can also serve as a model system to understand molecular behavior and fundamental mechanisms of separation, bridging the gap between conventional model systems such as flat surfaces and real chromatographic stationary phases such as micrometer-sized porous particles. We recently found that the axial motion of individual biomolecules inside nanopores can be significantly slower than in bulk solution. This suggests that either chromatographic adsorption was present and/or the viscosity inside the nanopores was unusually high. In this study, we measured the electrophoretic motion as well as the axial diffusion of individual nanoparticles in cylindrical alumina nanopores. We found that the electrophoretic mobilities and the diffusion coefficients of polystyrene nanoparticles were both substantially smaller compared to bulk solution independent of particle size or pore diameter. The results imply that the apparent solution viscosity in nanodomains is anomalous.

Han, Rui; Wang, Gufeng; Qi, Shengda; Ma, Changbei; Yeung, Edward S.

2012-08-01T23:59:59.000Z

273

K-25 Gaseous Diffusion Process Building | Department of Energy  

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

Operational Management » History » Manhattan Project » Signature Operational Management » History » Manhattan Project » Signature Facilities » K-25 Gaseous Diffusion Process Building K-25 Gaseous Diffusion Process Building K-25 Gaseous Diffusion Process Building The K-25 plant, located on the southwestern end of the Oak Ridge reservation, used the gaseous diffusion method to separate uranium-235 from uranium-238. Based on the well-known principle that molecules of a lighter isotope would pass through a porous barrier more readily than molecules of a heavier one, gaseous diffusion produced through myriads of repetitions a gas increasingly rich in uranium-235 as the heavier uranium-238 was separated out in a system of cascades. Although producing minute amounts of final product measured in grams, gaseous diffusion required a massive

274

Narrow groove welding gas diffuser assembly and welding torch  

DOE Patents (OSTI)

A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

Rooney, Stephen J.

2000-02-04T23:59:59.000Z

275

Narrow groove welding gas diffuser assembly and welding torch  

DOE Patents (OSTI)

A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

Rooney, Stephen J. (East Berne, NY)

2001-01-01T23:59:59.000Z

276

Thermodynamic Stability and Al Diffusion Mechanism in Al5Fe2  

Science Conference Proceedings (OSTI)

External Energy Pulse Accelerated Anomalous Mass Transfer (AMT) · Extraction of ... Relations of High Temperature Materials for Fossil Energy Applications.

277

Prediction of Soot Formation in Laminar Opposed Diffusion Flame with Detailed and Reduced Reaction Mechanisms .  

E-Print Network (OSTI)

??The present work focuses on a computational study of a simplified soot model to predict soot production and destruction in methane/oxidizer (O2 and N2) and… (more)

Chang, Hojoon

2004-01-01T23:59:59.000Z

278

Results of tritium experiments on ceramic electrolysis cells and palladium diffusers for application to fusion reactor fuel cleanup systems  

Science Conference Proceedings (OSTI)

Tritium tests at the Tritium Systems Test Assembly have demonstrated that ceramic electrolysis cells and palladium alloy diffuser developed in Japan are possible components for a fusion reactor fuel cleanup system. Both components have been successfully operated with tritium for over a year. A failure of the first electrolysis cell was most likely the result of an over voltage on the ceramic. A simple circuit was developed to eliminate this mode of failure. The palladium diffusers tubes exhibited some degradation of mechanical properties as a result of the build up of helium from the tritium decay, after 450 days of operation with tritium, however the effects were not significant enough to affect the performance. New models of the diffuser and electrolysis cell, providing higher flow rates and more tritium compatible designs are currently being tested with tritium. 8 refs., 5 figs.

Carlson, R.V.; Binning, K.E.; Konishi, S.; Yoshida, H.; Naruse, Y.

1987-01-01T23:59:59.000Z

279

Hydrogen trapping, diffusion, and recombination in austenitic stainless steels  

DOE Green Energy (OSTI)

Trapping, diffusion, and recombination of hydrogen in austenitic stainless steels are reviewed. It is suggested that since all of these processes are strongly interdependent and since the measured recombination rates are found to vary four orders of magnitude at any temperature, the data analysis techniques used to date are insufficient. A two-region diffusion model with surface recombination is proposed in which the surface layer is characterized by a smaller diffusion coefficient than the bulk.

Langley, R.A.

1984-01-01T23:59:59.000Z

280

"Diffuse Scattering and the Fundamental Properties of materials"  

Science Conference Proceedings (OSTI)

This book highlights emerging research areas that exploit the ability of diffuse scattering to characterize local structures in materials. An emphasis is placed on the coming renaissance in diffuse scattering driven by new sources, better instrumentation, novel new materials, and advanced theories and methods. This book will provide an overview of some of the most exciting recent advances in diffuse scattering and provides guidance for students and researchers interested in new methods to characterize their samples.

Barabash, Rozaliya [ORNL; Ice, Gene E [ORNL; Turchi, Dr. Patrice E.A. [Lawrence Livermore National Laboratory (LLNL)

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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281

Measurement of Thermal Diffusity and Flow Resistance for TCAP Materials  

DOE Green Energy (OSTI)

SRS uses the Thermal Cycling Absorption Process (TCAP) to separate isotopes of hydrogen. The frequency of thermal cycles is a limit of the productivity of the process and that frequency is largely determined by the thermal diffusivity of the absorbent material. For a given tube diameter, a larger thermal diffusivity decreases the time required for each cycle. In 1998, the Engineering Development Laboratory measured thermal diffusivity and thermal conductivity for three TCAP materials in helium.

STEIMKE, JOHN

2004-11-11T23:59:59.000Z

282

Gas fixation solar cell using gas diffusion semiconductor electrode  

SciTech Connect

A gas diffusion semiconductor electrode and solar cell and a process for gaseous fixation, such as nitrogen photoreduction, CO/sub 2/ photoreduction and fuel gas photo-oxidation are described. The gas diffusion photosensitive electrode has a central electrolyte porous matrix with an activated semiconductor material on one side adapted to be in contact with an electrolyte and a hydrophobic gas diffusion region on the opposite side adapted to be in contact with a supply of molecular gas.

Ang, P.G.; Sammells, A.F.

1980-12-23T23:59:59.000Z

283

Low cost fuel cell diffusion layer configured for optimized anode water management  

DOE Patents (OSTI)

A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel is higher than the diffusion resistance of the cathode gas diffusion layer. The anode gas diffusion layer may comprise filler particles having in-plane platelet geometries and be made of lower cost materials and manufacturing processes than currently available commercial carbon fiber substrates. The diffusion resistance difference between the anode gas diffusion layer and the cathode gas diffusion layer may allow for passive water balance control.

Owejan, Jon P; Nicotera, Paul D; Mench, Matthew M; Evans, Robert E

2013-08-27T23:59:59.000Z

284

Quantitative Vapor-phase IR Intensities and DFT Computations to Predict Absolute IR Spectra based on Molecular Structure: I. Alkanes  

SciTech Connect

Recently recorded quantitative IR spectra of a variety of gas-phase alkanes are shown to have integrated intensities in both the C-H stretching and C-H bending regions that depend linearly on the molecular size, i.e. the number of C-H bonds. This result is well predicted from CH4 to C15H32 by DFT computations of IR spectra at the B3LYP/6-31+G(d,p) level of DFT theory. A simple model predicting the absolute IR band intensities of alkanes based only on structural formula is proposed: For the C-H stretching band near 2930 cm-1 this is given by (in km/mol): CH¬_str = (34±3)*CH – (41±60) where CH is number of C-H bonds in the alkane. The linearity is explained in terms of coordinated motion of methylene groups rather than the summed intensities of autonomous -CH2- units. The effect of alkyl chain length on the intensity of a C-H bending mode is explored and interpreted in terms of conformer distribution. The relative intensity contribution of a methyl mode compared to the total C-H stretch intensity is shown to be linear in the number of terminal methyl groups in the alkane, and can be used to predict quantitative spectra a priori based on structure alone.

Williams, Stephen D.; Johnson, Timothy J.; Sharpe, Steven W.; Yavelak, Veronica; Oats, R. P.; Brauer, Carolyn S.

2013-11-13T23:59:59.000Z

285

Characterizing organometallic-vapor-phase-epitaxy-grown indium gallium nitride islands on gallium nitride for light emitting diode applications.  

E-Print Network (OSTI)

??The indium-gallium-nitride on gallium-nitride (InGaN/GaN) materials system is a promising candidate for providing a high intensity, high efficiency solution to the yet unsolved problem of… (more)

Anderson, Kathy Perkins Jenkins

2011-01-01T23:59:59.000Z

286

Enhanced quality thin film Cu(In,Ga)Se.sub.2 for semiconductor device applications by vapor-phase recrystallization  

DOE Patents (OSTI)

Enhanced quality thin films of Cu.sub.w (In,Ga.sub.y)Se.sub.z for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In,Ga):Cu.sub.x Se on a substrate to form a large-grain precursor and then converting the excess Cu.sub.x Se to Cu(In,Ga)Se.sub.2 by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In,Ga).sub.y Se.sub.z. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300.degree.-600.degree. C., where the Cu(In,Ga)Se.sub.2 remains solid, while the excess Cu.sub.x Se is in a liquid flux. The characteristic of the resulting Cu.sub.w (In,Ga).sub.y Se.sub.z can be controlled by the temperature. Higher temperatures, such as 500.degree.-600.degree. C., result in a nearly stoichiometric Cu(In,Ga)Se.sub.2, whereas lower temperatures, such as 300.degree.-400.degree. C., result in a more Cu-poor compound, such as the Cu.sub.z (In,Ga).sub.4 Se.sub.7 phase.

Tuttle, John R. (Denver, CO); Contreras, Miguel A. (Golden, CO); Noufi, Rommel (Golden, CO); Albin, David S. (Denver, CO)

1994-01-01T23:59:59.000Z

287

Mechanism of pressure welding  

SciTech Connect

Thesis. The mechanism in polycrystalline aluminum, copper, silver, and gold was investigated. (19 figures) (DLC)

Mohamed, H.A.E.F.

1973-12-01T23:59:59.000Z

288

CARTESIAN MECHANICS* Sophie Roux  

E-Print Network (OSTI)

1 CARTESIAN MECHANICS* Sophie Roux (Centre Alexandre Koyré, EHESS, Paris) Introduction For many the search for a mathematical treatment of phenomena, on the other hand the demand for mechanical as the typical mechanical philosopher, and contrasted as such to the founder of mechanics as a science, namely

Paris-Sud XI, Université de

289

INTRODUCTION TO THE MECHANICS  

E-Print Network (OSTI)

INTRODUCTION TO THE MECHANICS OF A CONTINUOUS MEDIUM Lawrence E. Malvern Professor of Mechanics princi- ples common to all branches of solid and fluid mechanics, designed to appeal to the intuition science. The book arose from the need to provide a general preparation in contin- uum mechanics

Kaminski, Edouard

290

Graduate quantum mechanics reform  

Science Conference Proceedings (OSTI)

We address four main areas in which graduatequantum mechanics education can be improved: course content

L. D. Carr; S. B. McKagan

2009-01-01T23:59:59.000Z

291

Non-Destructive Analysis Calibration Standards for Gaseous Diffusion Plant  

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

Non-Destructive Analysis Calibration Standards for Gaseous Non-Destructive Analysis Calibration Standards for Gaseous Diffusion Plant (GDP) Decommissioning Non-Destructive Analysis Calibration Standards for Gaseous Diffusion Plant (GDP) Decommissioning The decommissioning of Gaseous Diffusion Plant facilities requires accurate, non-destructive assay (NDA) of residual enriched uranium in facility components for safeguards and nuclear criticality safety purposes. Current practices used to perform NDA measurements frequently have poorly defined uncertainties due to multiple factors. Working reference material (WRM) standards and container-specific surrogates are required to verify and validate NDA methods used to support characterization of gaseous diffusion equipment within the D&D project. Because working reference

292

Reference Self Diffusion Mobility Data for CALPHAD and Beyond  

Science Conference Proceedings (OSTI)

Presentation Title, Reference Self Diffusion Mobility Data for CALPHAD and Beyond. Author(s) ... Development of New Ferrous Alloys with High Al Content.

293

Development of a Reference Self-Diffusion Mobility Database  

Science Conference Proceedings (OSTI)

Register as a New User ... Scope, Twenty years ago, John Ågren initiated the development of a CALPHAD-based approach to diffusion mobility databases.

294

Orientation Visit to the Paducah Gaseous Diffusion Plant  

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

PAD-2011-07-27 Site: Paducah Gaseous Diffusion Plant Subject: Office of Enforcement and Oversight's Office of Safety and Emergency Management Evaluations Activity Report for the...

295

Effect of Additives on Diffusion Processes in UO2  

Science Conference Proceedings (OSTI)

The oxygen and uranium Frenkel pairs and the uranium-oxygen Schottky defects regulate the O/U ratio, which in turn influence diffusion processes in UO2.

296

Lithium Diffusion in Graphitic Carbon and Implications for the...  

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

Carbon and Implications for the Rate Capability of Anodes Title Lithium Diffusion in Graphitic Carbon and Implications for the Rate Capability of Anodes Publication Type Journal...

297

Optical processing furnace with quartz muffle and diffuser plate  

SciTech Connect

An optical furnace for annealing a process wafer comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the door or wall of the muffle is also provided for controlling the source of optical energy. The quartz for the diffuser plate is surface etched (to give the quartz diffusive qualities) in the furnace during a high intensity burn-in process.

Sopori, Bhushan L. (Denver, CO)

1995-01-01T23:59:59.000Z

298

Phase Stability, Diffusion, Kinetics and their Applications (PSDK-VIII)  

Science Conference Proceedings (OSTI)

Mar 31, 2013 ... Michael Gao, National Energy Technology Lab. Scope, Phase stability and diffusion are central themes of materials science and engineering, ...

299

On Correction of Diffuse Radiation Measured by MFRSR  

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

an angular correction is needed. Such a correction of MFRSR data is performed for direct solar radiation, whereas uncertainty exists concerning the diffuse irradiance, whose...

300

Former Worker Medical Screening Program - Paducah Gaseous Diffusion...  

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

Paducah Gaseous Diffusion Plant Construction Workers Former Worker Medical Screening Program (FWP) Project Name: Building Trades National Medical Screening Program Covered DOE...

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


301

A Metallography-Based Examination of Inadvertent Diffusion ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Inadvertent diffusion bonding of workpieces during heat treatment is a ... Characterization of Breaks in Creep Resistant Feeding Grid Links in the ...

302

HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid Architectures  

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

HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid Architectures The Boltzmann transport equation provides high fidelity simulation of a diverse range of kinetic systems....

303

High-Temperature Reactor for Diffuse Reflectance Infrared ...  

High-Temperature Reactor for Diffuse Reflectance Infrared Fourier-Transform Spectroscopy Note: The technology described above is an early stage ...

304

Diffusion and Segregation of Hydrogen in Martensitic AISI 5140  

Science Conference Proceedings (OSTI)

Presentation Title, Diffusion and Segregation of Hydrogen in Martensitic AISI 5140: Influence of Baking Time at 20°C on the Hydrogen Distribution and ...

305

ARM - Measurement - Shortwave narrowband diffuse upwelling irradiance  

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

upwelling irradiance upwelling 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 diffuse upwelling irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4 {mu}m, that has been scattered in the atmosphere at least once, passes through a horizontal unit area in an upward 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. ARM Instruments MFR : Multifilter Radiometer

306

Diffusion effects on a superconductive model  

E-Print Network (OSTI)

A superconductive model characterized by a third order parabolic operator L" is analysed. When the viscous terms, represented by higher - order deriva- tives, tend to zero, a hyperbolic operator L0 appears. Furthermore, if P" is the Dirichlet initial boundary - value problem for L", when L" turns into L0; P" turns into a problem P0 with the same initial - boundary conditions as P". The solution of the nonlinear problem related to the remainder term r is achieved, as long as the higher-order derivatives of the solution of P0 are bounded. More- over, some classes of explicit solutions related to P0 are determined, proving the existence of at least one motion whose derivatives are bounded. The estimate shows that the diffusion effects are bounded even when time tends to infinity.

M. de Angelis; G. Fiore

2012-11-06T23:59:59.000Z

307

Random walk computations of diffusive fields  

E-Print Network (OSTI)

A numerical study of three problems is carried out using the gradient random walk method. These problems include the heat equation, Fitzhugh-Nagumo equation, and Burgers' equation. Each problem illustrates various aspects of the operation of the numerical method. The heat equation with no reaction term illustrates the numerical algorithm, the Fitzhugh-Nagumo equation is a system with an explicit reaction term, Burgers' equation has an advection term. The gradient random walk numerical method is well suited for the diffusion problem due to the connection between Gaussian distributions and the kernel of the heat equation. The numerical results compare well with known analytical solutions. Burgers' equation is studied to examine any effects the advection term has on the results of the numerical method.

Lindstrom, Gregory Scot

1993-01-01T23:59:59.000Z

308

Diffuse gamma-rays from galactic halos  

E-Print Network (OSTI)

Here we review our current knowledge on diffuse gamma-rays from galactic halos. Estimates of the relative contribution of the various emission processes at low and high latitudes are compared to the data over 6 decades in energy. The observed spectral shape differs from what was expected, especially at ver low and very high energies. In the latter case, above 1 GeV, the sky emission related to gas exceeds the expected pi^0 decay spectrum. At energies below 1 MeV the relatively high gamma-ray intensity indicates at high density of nearly relativistic electrons which would have a strong influence on the energy and ionisation balance of the interstellar medium. Given the EGRET results for the Magellanic Clouds the gamma-ray emissivity in the outer halo is probably small, so that a substantial amount of baryonic dark matter may be hidden at 20-50 kpc radius without inducing observable gamma-ray emission.

M. Pohl

1996-03-12T23:59:59.000Z

309

A Simplified HTTR Diffusion Theory Benchmark  

SciTech Connect

The Georgia Institute of Technology (GA-Tech) recently developed a transport theory benchmark based closely on the geometry and the features of the HTTR reactor that is operational in Japan. Though simplified, the benchmark retains all the principal physical features of the reactor and thus provides a realistic and challenging test for the codes. The purpose of this paper is twofold. The first goal is an extension of the benchmark to diffusion theory applications by generating the additional data not provided in the GA-Tech prior work. The second goal is to use the benchmark on the HEXPEDITE code available to the INL. The HEXPEDITE code is a Green’s function-based neutron diffusion code in 3D hexagonal-z geometry. The results showed that the HEXPEDITE code accurately reproduces the effective multiplication factor of the reference HELIOS solution. A secondary, but no less important, conclusion is that in the testing against actual HTTR data of a full sequence of codes that would include HEXPEDITE, in the apportioning of inevitable discrepancies between experiment and models, the portion of error attributable to HEXPEDITE would be expected to be modest. If large discrepancies are observed, they would have to be explained by errors in the data fed into HEXPEDITE. Results based on a fully realistic model of the HTTR reactor are presented in a companion paper. The suite of codes used in that paper also includes HEXPEDITE. The results shown here should help that effort in the decision making process for refining the modeling steps in the full sequence of codes.

Rodolfo M. Ferrer; Abderrafi M. Ougouag; Farzad Rahnema

2010-10-01T23:59:59.000Z

310

NSLS Mechanical Tech  

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

Mechanical Tech Mechanical Tech The Mechanical Technician group is supervised by Robert Scheuerer and consists of Mechanical Technicians with fabrication/machining, assembly, installation, and alignment/surveying skills. This group also serves as an interface to Central Fabrication Services when more complex or larger fabrication efforts are needed. The Mechanical Tech group is responsible for fabricating, installing, aligning, and troubleshooting the mechanical hardware used on NSLS and SDL accelerators, front ends, and User beamlines, often starting solely from Mechanical Design group drawings or CAD files. The Mechanical Tech Group is responsible for the fabrication, assembly and installation of components at the NSLS. These components include all mechanical assemblies and RF cavities. Another part of their job is to

311

Internal pipe attachment mechanism  

DOE Patents (OSTI)

An attachment mechanism is described for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection. 6 figures.

Bast, R.M.; Chesnut, D.A.; Henning, C.D.; Lennon, J.P.; Pastrnak, J.W.; Smith, J.A.

1994-12-13T23:59:59.000Z

312

Peer Effects in the Diffusion of Solar Photovoltaic Panels  

Science Conference Proceedings (OSTI)

Social interaction (peer) effects are recognized as a potentially important factor in the diffusion of new products. In the case of environmentally friendly goods or technologies, both marketers and policy makers are interested in the presence of causal ... Keywords: diffusion models, empirical IO methods, endogeneity, probability models, social contagion, word of mouth

Bryan Bollinger; Kenneth Gillingham

2012-11-01T23:59:59.000Z

313

Diffusion of a plasma subject to neutral beam injection  

SciTech Connect

Two-dimensional numerical plasma simulations have been carried out in a uniform magnetic field to study the effects of neutral beam injection on plasma diffusion. Neutral beams injected across a magnetic field are assumed to be ionized by various ionization processes in a plasma. It is found that the suprathermal convective motion of a plasma generated by the injection of neutral beams is dissipated via anomalous viscosity, leading to enhanced cross-field diffusion. The diffusion coefficient depends weakly on the magnetic field and plasma density, similar to the diffusion due to thermally excited convective cells. The magnitude of the diffusion increases with the injection energy and is much larger than the thermal diffusion because of the presence of suprathermal plasma convection. It is shown that a similar anomalous plasma diffusion may occur in a plasma subject to radio frequency (RF) wave heating where only a localized region of plasma across a magnetic field is heated to a temperature much higher than the surrounding temperature. Theoretical investigations are given on the scaling of enhanced plasma diffusion.

Okuda, H.; Hiroe, S.

1986-10-01T23:59:59.000Z

314

Diffusion and semi-convexity of fuzzy set multifunctions  

Science Conference Proceedings (OSTI)

We present some properties regarding diffusion and semi-convexity for fuzzy set multifunctions defined on a ring of subsets of an abstract nonvoid space and taking values in the family of all nonvoid closed subsets of a real normed space. Keywords: Darboux property, diffused, fuzzy set multifunction, multimeasure, non-atomicity, null-additive, regular, semi-convex

Alina Gavrilu?; Anca Croitoru; Nikos E. Mastorakis

2010-07-01T23:59:59.000Z

315

Studying Diffusion of Viral Content at Dyadic Level  

Science Conference Proceedings (OSTI)

Diffusion of information and viral content, social contagion and influence are still topics of broad evaluation. As theory explaining the role of influentials moves slightly to reduce their importance in the propagation of viral content, authors of the ... Keywords: diffusion of information, viral content, dyads, motif analysis, influentials, influence factors, social networks, virtual worlds

Anita Zbieg; Blazej Zak; Jaroslaw Jankowski; Radoslaw Michalski; Sylwia Ciuberek

2012-08-01T23:59:59.000Z

316

Studying paths of participation in viral diffusion process  

Science Conference Proceedings (OSTI)

Authors propose a conceptual model of participation in viral diffusion process composed of four stages: awareness, infection, engagement and action. To verify the model it has been applied and studied in the virtual social chat environment settings. ... Keywords: information diffusion, multistage analysis, online social networks, participation model

Jaros?aw Jankowski; Sylwia Ciuberek; Anita Zbieg; Rados?aw Michalski

2012-12-01T23:59:59.000Z

317

Accelerating large-scale data exploration through data diffusion  

Science Conference Proceedings (OSTI)

Data-intensive applications often require exploratory analysis of large datasets. If analysis is performed on distributed resources, data locality can be crucial to high throughput and performance. We propose a "data diffusion" approach that acquires ... Keywords: Falkon, Swift, data caching, data diffusion, data management, data-aware scheduling, data-intensive applications, grid

Ioan Raicu; Yong Zhao; Ian T. Foster; Alex Szalay

2008-06-01T23:59:59.000Z

318

Numerical Discretization of Rotated Diffusion Operators in Ocean Models  

Science Conference Proceedings (OSTI)

A method to improve the behavior of the numerical discretization of a rotated diffusion operator such as, for example, the isopycnal diffusion parameterization used in large-scale ocean models based on the so-called z-coordinate system is ...

J-M. Beckers; H. Burchard; E. Deleersnijder; P. P. Mathieu

2000-08-01T23:59:59.000Z

319

A Novel Image Denoising Algorithm Based on Anisotropic Diffusion Equation  

Science Conference Proceedings (OSTI)

This article first give the concept of the scale space, and construct the relationship between the heat conduction equation and the Gaussian scale space, which lead to the partial differential equations. Then the article introduces linear diffusion equation, ... Keywords: Anisotropic diffusion equation, image denoising, partial differential equation

Haozheng Ren Hongbo, Hongbo Yu, Yihua Lan

2013-08-01T23:59:59.000Z

320

ENERGY DIFFUSION IN HARMONIC SYSTEM WITH CONSERVATIVE NOISE  

E-Print Network (OSTI)

ENERGY DIFFUSION IN HARMONIC SYSTEM WITH CONSERVATIVE NOISE GIADA BASILE AND STEFANO OLLA Abstract. We prove diffusive behaviour of the energy fluctua- tions in a system of harmonic oscillators with a stochastic pertur- bation of the dynamics that conserves energy and momentum. The results concern pinned

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Projecting diffusion along the normal bundle of a plane curve  

E-Print Network (OSTI)

The purpose of this paper is to provide new formulas for the estimation of the effective diffusion coefficient of an equation of Fick-Jacob's type obtained by projecting the two-dimensional diffusion equation along the normal direction of an arbitrary plane curve.

Carlos Valero Valdes; Rafael Herrera Guzman

2013-08-21T23:59:59.000Z

322

Predicting information diffusion on social networks with partial knowledge  

Science Conference Proceedings (OSTI)

Models of information diffusion and propagation over large social media usually rely on a Close World Assumption: information can only propagate onto the network relational structure, it cannot come from external sources, the network structure ... Keywords: diffusion, machine learning, social networks

Anis Najar; Ludovic Denoyer; Patrick Gallinari

2012-04-01T23:59:59.000Z

323

The Department of Mechanical Engineering --Engineering Mechanics  

E-Print Network (OSTI)

, Missile, Research, Development and Engineering Directorate's Propulsion Iaborato'. Ills primaly areas of research are in numerical combustion, and the thermal and mechanical aging ofnitrate esterpropellants decomposition and combustion. Stabilizers are added to the propellants to neutralize the decomposition products

Endres. William J.

324

DOE - Office of Legacy Management -- Portsmouth Gaseous Diffusion Plant -  

Office of Legacy Management (LM)

Portsmouth Gaseous Diffusion Plant Portsmouth Gaseous Diffusion Plant - 026 FUSRAP Considered Sites Site: Portsmouth Gaseous Diffusion Plant (026 ) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition: Radioactive Materials Handled: Primary Radioactive Materials Handled: Radiological Survey(s): Site Status: The Portsmouth Gaseous Diffusion Plant (PGDP) is located in south central Ohio, approximately 20 miles north of Portsmouth, Ohio and 70 miles south of Columbus, Ohio. Construction of the PGDP began in late 1952 to expand the Federal Government¿s gaseous diffusion program already in place at Oak Ridge, Tennessee and Paducah, Kentucky. The facility was built to increase the production of enriched uranium at rates substantially above the other

325

Relativistic diffusion with friction on a pseudoriemannian manifold  

E-Print Network (OSTI)

We study a relativistic diffusion equation on the Riemannian phase space defined by Franchi and Le Jan. We discuss stochastic Ito (Langevin) differential equations (defining the diffusion) as a perturbation by noise of the geodesic equation. We show that the expectation value of the angular momentum and the energy grow exponentially fast. We discuss drifts leading to an equilibrium. It is shown that the diffusion process corresponding to the Juettner or quantum equilibrium distributions has a bounded expectation value of angular momentum and energy. The energy and the angular momentum tend exponentially fast to their equilibrium values. As examples we discuss a particle in a plane fronted gravitational wave and a particle in de Sitter universe. It is shown that the relativistic diffusion of momentum in de Sitter space is the same as the relativistic diffusion on the Minkowski mass-shell with the temperature proportional to the de Sitter radius.

Z. Haba

2009-09-15T23:59:59.000Z

326

Relativistic diffusion with friction on a pseudoriemannian manifold  

E-Print Network (OSTI)

We study a relativistic diffusion equation on the Riemannian phase space defined by Franchi and Le Jan. We discuss stochastic Ito (Langevin) differential equations (defining the diffusion) as a perturbation by noise of the geodesic equation. We show that the expectation value of the angular momentum and the energy grow exponentially fast. We discuss drifts leading to an equilibrium. It is shown that the diffusion process corresponding to the Juettner or quantum equilibrium distributions has a bounded expectation value of angular momentum and energy. The energy and the angular momentum tend exponentially fast to their equilibrium values. As examples we discuss a particle in a plane fronted gravitational wave and a particle in de Sitter universe. It is shown that the relativistic diffusion of momentum in de Sitter space is the same as the relativistic diffusion on the Minkowski mass-shell with the temperature proportional to the de Sitter radius.

Haba, Z

2009-01-01T23:59:59.000Z

327

On anomalous diffusion in a plasma in velocity space  

E-Print Network (OSTI)

The problem of anomalous diffusion in momentum space is considered for plasma-like systems on the basis of a new collision integral, which is appropriate for consideration of the probability transition function (PTF) with long tails in momentum space. The generalized Fokker-Planck equation for description of diffusion (in momentum space) of particles (ions, grains etc.) in a stochastic system of light particles (electrons, or electrons and ions, respectively) is applied to the evolution of the momentum particle distribution in a plasma. In a plasma the developed approach is also applicable to the diffusion of particles with an arbitrary mass relation, due to the small characteristic momentum transfer. The cases of an exponentially decreasing in momentum space (including the Boltzmann-like) kernel in the PT-function, as well as the more general kernels, which create the anomalous diffusion in velocity space due to the long tail in the PT-function, are considered. Effective friction and diffusion coefficients f...

Trigger, S A; van Heijst, G J F; Schram, P P J M; Sokolov, I M

2010-01-01T23:59:59.000Z

328

Overcoming Barriers to the Transfer and Diffusion of Climate Technologies |  

Open Energy Info (EERE)

Overcoming Barriers to the Transfer and Diffusion of Climate Technologies Overcoming Barriers to the Transfer and Diffusion of Climate Technologies Jump to: navigation, search Tool Summary Name: Overcoming Barriers to the Transfer and Diffusion of Climate Technologies Agency/Company /Organization: UNEP-Risoe Centre Sector: Energy, Climate Focus Area: Greenhouse Gas Topics: Technology characterizations Resource Type: Publications, Guide/manual, Training materials Website: uneprisoe.org/ Cost: Free Overcoming Barriers to the Transfer and Diffusion of Climate Technologies Screenshot References: UNEP-Risoe[1] Logo: Overcoming Barriers to the Transfer and Diffusion of Climate Technologies This guidebook deals with the transfer of proven technologies both between countries and within them. "The purpose of the TNA project is to assist participant developing country

329

Orientation Visit to the Paducah Gaseous Diffusion Plant, July 2011 |  

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

Orientation Visit to the Paducah Gaseous Diffusion Plant, July 2011 Orientation Visit to the Paducah Gaseous Diffusion Plant, July 2011 Orientation Visit to the Paducah Gaseous Diffusion Plant, July 2011 The U.S. Department of Energy (DOE) Office of Enforcement and Oversight, within the Office of Health, Safety and Security (HSS), conducted an orientation visit to the DOE Paducah Site Office (PAD) from July 25-27, 2011. The purpose of the visit was to discuss the nuclear safety oversight strategy, describe the site lead program, increase HSS personnel's operational awareness of the site's activities, and to determine how HSS can carry out its independent oversight and mission support responsibilities. Orientation Visit to the Paducah Gaseous Diffusion Plant, July 2011 More Documents & Publications Independent Activity Report, Portsmouth Gaseous Diffusion Plant - August

330

Radon diffusion through multilayer earthen covers: models and simulations  

SciTech Connect

A capability to model and analyze the fundamental interactions that influence the diffusion of radon gas through uranium mill tailings and cover systems has been investigated. The purpose of this study is to develop the theoretical basis for modeling radon diffusion and to develop an understanding of the fundamental interactions that influence radon diffusion. This study develops the theoretical basis for modeling radon diffusion in one, two and three dimensions. The theory has been incorporated into three computer models that are used to analyze several tailings and cover configurations. This report contains a discussion of the theoretical basis for modeling radon diffusion, a discussion of the computer models used to analyze uranium mill tailings and multilayered cover systems, and presents the results that have been obtained.

Mayer, D.W.; Oster, C.A.; Nelson, R.W.; Gee, G.W.

1981-09-01T23:59:59.000Z

331

Evolutionary Dynamics of Information Diffusion over Social Networks  

E-Print Network (OSTI)

Current social networks are of extremely large-scale generating tremendous information flows at every moment. How information diffuse over social networks has attracted much attention from both industry and academics. Most of the existing works on information diffusion analysis are based on machine learning methods focusing on social network structure analysis and empirical data mining. However, the dynamics of information diffusion, which are heavily influenced by network users' decisions, actions and their socio-economic interactions, is generally ignored by most of existing works. In this paper, we propose an evolutionary game theoretic framework to model the dynamic information diffusion process in social networks. Specifically, we derive the information diffusion dynamics in complete networks, uniform degree and non-uniform degree networks, with the highlight of two special networks, Erd\\H{o}s-R\\'enyi random network and the Barab\\'asi-Albert scale-free network. We find that the dynamics of information di...

Jiang, Chunxiao; Liu, K J Ray

2013-01-01T23:59:59.000Z

332

Effect of superbanana diffusion on fusion reactivity in stellarators  

Science Conference Proceedings (OSTI)

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

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

2012-08-15T23:59:59.000Z

333

Evaluations of nutrient diffusing substrates and the primary importance of light in controlling periphyton  

E-Print Network (OSTI)

Eutrophication is an increasingly recognized threat to the health of streams and rivers in the United States. This thesis presents two studies aimed at increasing the utility of periphyton analysis as a tool for water resource managers to address eutrophication. In the first study, artificial channels were used to investigate the response of periphyton to different nutrient delivery mechanisms. In two channels, nutrients were delivered via diffusion to periphyton growth surfaces using modified Matlock Periphytometers. In two additional channels, nutrients were delivered by dosing water in the channel. The data showed that nutrient delivery via diffusion elicits a significantly greater periphyton response. The use of diffusing substrates for periphyton studies remains a viable tool for some objectives, but results should be extrapolated to natural conditions with caution. In the second study, modified Matlock Periphytometers and inexpensive light meters were used to investigate the relationship between periphyton growth and light availability in two fourth-order Texas streams. The data indicate that light availability explains 91.9 percent of the variability of observed periphyton growth under control conditions, and 99.7 percent under nutrient-enriched conditions. The strong correlation suggests that efforts to address eutrophication should recognize the importance of riparian shade. Equations to predict chlorophyll-a as a function of relative light intensity are also presented.

Murawski, Matthew Thomas

2001-01-01T23:59:59.000Z

334

Compliant mechanism learning toolkit  

E-Print Network (OSTI)

This thesis concerns a toolkit designed to assist in learning the behavior of complaint mechanisms. In the design of complaint mechanisms, increasingly complicated designs behave in ways that are harder to intuitively ...

Allard, Nicholas (Nicholas A.)

2006-01-01T23:59:59.000Z

335

Emergence of Quantum Mechanics from a Sub-Quantum Statistical Mechanics  

E-Print Network (OSTI)

A research program within the scope of theories on "Emergent Quantum Mechanics" is presented, which has gained some momentum in recent years. Via the modeling of a quantum system as a non-equilibrium steady-state maintained by a permanent throughput of energy from the zero-point vacuum, the quantum is considered as an emergent system. We implement a specific "bouncer-walker" model in the context of an assumed sub-quantum statistical physics, in analogy to the results of experiments by Couder's group on a classical wave-particle duality. We can thus give an explanation of various quantum mechanical features and results on the basis of a "21st century classical physics", such as the appearance of Planck's constant, the Schr\\"odinger equation, etc. An essential result is given by the proof that averaged particle trajectories' behaviors correspond to a specific type of anomalous diffusion termed "ballistic" diffusion on a sub-quantum level. It is further demonstrated both analytically and with the aid of computer simulations that our model provides explanations for various quantum effects such as double-slit or n-slit interference. We show the averaged trajectories emerging from our model to be identical to Bohmian trajectories, albeit without the need to invoke complex wave functions or any other quantum mechanical tool. Finally, the model provides new insights into the origins of entanglement, and, in particular, into the phenomenon of a "systemic" nonlocality.

Gerhard Groessing

2013-04-12T23:59:59.000Z

336

QUICK QUANTUM MECHANICS ---Introduction ---  

E-Print Network (OSTI)

QUICK QUANTUM MECHANICS --- Introduction --- The following notes are intended to be a supplement to your study of Liboff's ``Introductory Quantum Mechanics.'' They are not an alternative! My purpose here of Classical Mechanics After Newton found his equations of motion, physicists knew they would have to wait

Jackson, Andrew D.

337

Surface Properties of PEMFC Gas Diffusion Layers  

Science Conference Proceedings (OSTI)

The wetting properties of PEMFC Gas Diffusion Layers (GDLs) were quantified by surface characterization measurements and modeling of material properties. Single-fiber contact-angle and surface energy (both Zisman and Owens-Wendt) data of a wide spectrum of GDL types is presented to delineate the effects of hydrophobic post-processing treatments. Modeling of the basic sessile-drop contact angle demonstrates that this value only gives a fraction of the total picture of interfacial wetting physics. Polar forces are shown to contribute 10-20 less than dispersive forces to the composite wetting of GDLs. Internal water contact angles obtained from Owens-Wendt analysis were measured at 13-19 higher than their single-fiber counterparts. An inverse relationship was found between internal contact angle and both Owens-Wendt surface energy and % polarity of the GDL. The most sophisticated PEMFC mathematical models use either experimentally measured capillary pressures or the standard Young-Laplace capillary-pressure equation. Based on the results of the Owens-Wendt analysis, an advancement to the Young-Laplace equation is proposed for use in these mathematical models, which utilizes only solid surface energies and fractional surface coverage of fluoropolymer. Capillary constants for the spectrum of analyzed GDLs are presented for the same purpose.

WoodIII, David L [Los Alamos National Laboratory (LANL); Rulison, Christopher [Augustine Scientific; Borup, Rodney [Los Alamos National Laboratory (LANL)

2010-01-01T23:59:59.000Z

338

Spectral Components Analysis of Diffuse Emission Processes  

Science Conference Proceedings (OSTI)

We develop a novel method to separate the components of a diffuse emission process based on an association with the energy spectra. Most of the existing methods use some information about the spatial distribution of components, e.g., closeness to an external template, independence of components etc., in order to separate them. In this paper we propose a method where one puts conditions on the spectra only. The advantages of our method are: 1) it is internal: the maps of the components are constructed as combinations of data in different energy bins, 2) the components may be correlated among each other, 3) the method is semi-blind: in many cases, it is sufficient to assume a functional form of the spectra and determine the parameters from a maximization of a likelihood function. As an example, we derive the CMB map and the foreground maps for seven yeas of WMAP data. In an Appendix, we present a generalization of the method, where one can also add a number of external templates.

Malyshev, Dmitry; /KIPAC, Menlo Park

2012-09-14T23:59:59.000Z

339

Linear diffusion into a Faraday cage.  

SciTech Connect

Linear lightning diffusion into a Faraday cage is studied. An early-time integral valid for large ratios of enclosure size to enclosure thickness and small relative permeability ({mu}/{mu}{sub 0} {le} 10) is used for this study. Existing solutions for nearby lightning impulse responses of electrically thick-wall enclosures are refined and extended to calculate the nearby lightning magnetic field (H) and time-derivative magnetic field (HDOT) inside enclosures of varying thickness caused by a decaying exponential excitation. For a direct strike scenario, the early-time integral for a worst-case line source outside the enclosure caused by an impulse is simplified and numerically integrated to give the interior H and HDOT at the location closest to the source as well as a function of distance from the source. H and HDOT enclosure response functions for decaying exponentials are considered for an enclosure wall of any thickness. Simple formulas are derived to provide a description of enclosure interior H and HDOT as well. Direct strike voltage and current bounds for a single-turn optimally-coupled loop for all three waveforms are also given.

Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.

2011-11-01T23:59:59.000Z

340

DIFFUSIVE SHOCK ACCELERATION SIMULATIONS OF RADIO RELICS  

Science Conference Proceedings (OSTI)

Recent radio observations have identified a class of structures, so-called radio relics, in clusters of galaxies. The radio emission from these sources is interpreted as synchrotron radiation from GeV electrons gyrating in {mu}G-level magnetic fields. Radio relics, located mostly in the outskirts of clusters, seem to associate with shock waves, especially those developed during mergers. In fact, they seem to be good structures to identify and probe such shocks in intracluster media (ICMs), provided we understand the electron acceleration and re-acceleration at those shocks. In this paper, we describe time-dependent simulations for diffusive shock acceleration at weak shocks that are expected to be found in ICMs. Freshly injected as well as pre-existing populations of cosmic-ray (CR) electrons are considered, and energy losses via synchrotron and inverse Compton are included. We then compare the synchrotron flux and spectral distributions estimated from the simulations with those in two well-observed radio relics in CIZA J2242.8+5301 and ZwCl0008.8+5215. Considering that CR electron injection is expected to be rather inefficient at weak shocks with Mach number M {approx}< a few, the existence of radio relics could indicate the pre-existing population of low-energy CR electrons in ICMs. The implication of our results on the merger shock scenario of radio relics is discussed.

Kang, Hyesung [Department of Earth Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of); Ryu, Dongsu [Department of Astronomy and Space Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Jones, T. W., E-mail: kang@uju.es.pusan.ac.kr, E-mail: ryu@canopus.cnu.ac.kr, E-mail: twj@msi.umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" from the National Library of EnergyBeta (NLEBeta).
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341

Molecular cooling in the diffuse interstellar medium  

E-Print Network (OSTI)

We use a simple one-zone model of the thermal and chemical evolution of interstellar gas to study whether molecular hydrogen (H2) is ever an important coolant of the warm, diffuse interstellar medium (ISM). We demonstrate that at solar metallicity, H2 cooling is unimportant and the thermal evolution of the ISM is dominated by metal line cooling. At metallicities below 0.1 Z_solar, however, metal line cooling of low density gas quickly becomes unimportant and H2 can become the dominant coolant, even though its abundance in the gas remains small. We investigate the conditions required in order for H2 to dominate, and show that it provides significant cooling only when the ratio of the interstellar radiation field strength to the gas density is small. Finally, we demonstrate that our results are insensitive to changes in the initial fractional ionization of the gas or to uncertainties in the nature of the dust present in the low-metallicity ISM.

Glover, S C O

2013-01-01T23:59:59.000Z

342

Complementarity and Classical Limit of Quantum Mechanics: Energy Measurement aspects  

E-Print Network (OSTI)

In the present contribution we discuss the role of experimental limitations in the classical limit problem. We studied some simple models and found that Quantum Mechanics does not re-produce classical mechanical predictions, unless we consider the experimental limitations ruled by uncertainty principle. We have shown that the discrete nature of energy levels of integrable systems can be accessed by classical measurements. We have defined a precise limit for this procedure. It may be used as a tool to define the classical limit as far as the discrete spectra of integrable systems are concerned. If a diffusive environment is considered, we conclude that the "lifetime" of discreteness is approximately $1/\\kappa$ ($\\kappa$ is the diffusion constant), thus it was possible to relate the classical limit of a spectra with the action of an environment and experimental resolution.

Adélcio C. Oliveira; Zolacir T. Oliveira Junior; Nestor S. Correia

2013-07-01T23:59:59.000Z

343

Fabrication and Design Aspects of High-Temperature Compact Diffusion Bonded Heat Exchangers  

SciTech Connect

The very high temperature reactor (VHTR), using gas-cooled reactor technology, is one of the six reactor concepts selected by the Generation IV International Forum and is anticipated to be the reactor type for the next generation nuclear plant (NGNP). In this type of reactor with an indirect power cycle system, a high-temperature and high integrity intermediate heat exchanger (IHX) with high effectiveness is required to efficiently transfer the core thermal output to secondary fluid for electricity production, process heat, or hydrogen cogeneration. The current Technology Readiness Level status issued by NGNP to all components associated with the IHX for reactor core outlet temperatures of 750-800oC is 3 on a scale of 1 to 10 with 10 being the most ready. At present, there is no proven high-temperature IHX concept for VHTRs. Amongst the various potential IHX concepts available, diffusion bonded heat exchangers (henceforth called printed circuit heat exchangers, or PCHEs) appear promising for NGNP applications. The design and fabrication of this key component of NGNP is the primary focus of this paper. In the current study, two PCHEs were fabricated using Alloy 617 plates and will be experimentally investigated for their thermal-hydraulic performance in a high-temperature helium test facility (HTHF). The HTHF was primarily designed and constructed to test the thermal-hydraulic performance of PCHEs The test facility is primarily of Alloy 800H construction and is designed to facilitate experiments at temperatures and pressures up to 800oC and 3 MPa, respectively. The PCHE fabrication related processes, i.e., photochemical machining and diffusion bonding are briefly discussed for Alloy 617 plates. Diffusion bonding of Alloy 617 plates with and without a Ni interlayer is discussed. Furthermore, preliminary microstructural and mechanical characterization studies of representative diffusion bonded Alloy 617 specimens are presented.

Mylavarapu, Sai K. [Ohio State University; Sun, Xiaodong [Ohio State University; Christensen, Richard N. [Ohio State University; Glosup, Richard E. [Ohio State University; Unocic, Raymond R [ORNL

2012-01-01T23:59:59.000Z

344

HYDRAULIC SERVO CONTROL MECHANISM  

DOE Patents (OSTI)

A hydraulic servo control mechanism of compact construction and low fluid requirements is described. The mechanism consists of a main hydraulic piston, comprising the drive output, which is connected mechanically for feedback purposes to a servo control piston. A control sleeve having control slots for the system encloses the servo piston, which acts to cover or uncover the slots as a means of controlling the operation of the system. This operation permits only a small amount of fluid to regulate the operation of the mechanism, which, as a result, is compact and relatively light. This mechanism is particuiarly adaptable to the drive and control of control rods in nuclear reactors. (auth)

Hussey, R.B.; Gottsche, M.J. Jr.

1963-09-17T23:59:59.000Z

345

Mechanical Seal Assembly  

DOE Patents (OSTI)

An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

Kotlyar, Oleg M.

1999-06-18T23:59:59.000Z

346

Mechanical seal assembly  

DOE Patents (OSTI)

An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

Kotlyar, Oleg M. (Salt Lake City, UT)

2001-01-01T23:59:59.000Z

347

Manhattan Project: The Navy and Thermal Diffusion, 1944  

Office of Scientific and Technical Information (OSTI)

Diffusion columns, S-50 Thermal Diffusion Plant, Oak Ridge, 1945. THE NAVY AND THERMAL DIFFUSION Diffusion columns, S-50 Thermal Diffusion Plant, Oak Ridge, 1945. THE NAVY AND THERMAL DIFFUSION (Oak Ridge: Clinton, 1944) Events > The Uranium Path to the Bomb, 1942-1944 Y-12: Design, 1942-1943 Y-12: Construction, 1943 Y-12: Operation, 1943-1944 Working K-25 into the Mix, 1943-1944 The Navy and Thermal Diffusion, 1944 As problems with both Y-12 and K-25 reached crisis proportions in spring and summer 1944, the Manhattan Project received help from an unexpected source: the United States Navy. President Roosevelt had instructed that the atomic bomb effort be an Army program and that the Navy be excluded from deliberations. Navy research on atomic power, conducted primarily for submarines, received no direct aid from Leslie Groves, who, in fact, was not up-to-date on the state of Navy efforts when he received a letter on the subject from Robert Oppenheimer late in April 1944.

348

Application of diffusion research to solar energy policy issues  

DOE Green Energy (OSTI)

This paper examines two types of information requirements that appear to be basic to DOE solar-energy-policy decisions: (1) how can the future market success of solar energy technologies be estimated, and (2) what factors influence the adoption of solar energy technologies, and what specific programs could promote solar energy adoption most effectively. This paper assesses the ability of a body of research, referred to here as diffusion research, to supply information that could partially satisfy these requirements. This assessment proceeds, first, by defining in greater detail a series of policy issues that face DOE. These are divided into cost reduction and performance improvement issues which include issues confronting the technology development component of the solar energy program, and barriers and incentives issues which are most relevant to problems of solar energy application. Second, these issues are translated into a series of questions that the diffusion approach can help resolve. Third, various elements within diffusion research are assessed in terms of their abilities to answer policy questions. Finally, the strengths and limitations of current knowledge about the diffusion of innovations are summarized, the applicability of both existing knowledge and the diffusion approach to the identified solar-energy-policy issues are discussed, and ways are suggested in which diffusion approaches can be modified and existing knowledge employed to meet short- and long-term goals of DOE. The inquiry covers the field of classical diffusion research, market research and consumer behavior, communication research, and solar-energy market-penetration modeling.

Roessner, J. D.; Posner, D.; Shoemaker, F.; Shama, A.

1979-03-01T23:59:59.000Z

349

Instability and Diapycnal Momentum Transport in a Double-Diffusive, Stratified Shear Layer  

Science Conference Proceedings (OSTI)

The linear stability of a double-diffusively stratified, inflectional shear flow is investigated. Double-diffusive stratification has little effect on shear instability except when the density ratio R? is close to unity. Double-diffusive ...

William D. Smyth; Satoshi Kimura

2007-06-01T23:59:59.000Z

350

Understanding the Regional Variability of Eddy Diffusivity in the Pacific Sector of the Southern Ocean  

E-Print Network (OSTI)

A diagnostic framework is presented, based on the Nakamura effective diffusivity, to investigate the regional variation in eddy diffusivity. Comparison of three different diffusivity calculations enables the effects of ...

Shuckburgh, Emily

351

THE COMBUSTION OF SOLVENT REPINED COAL IN AN OPPOSED FLOW DIFFUSION FLAME  

E-Print Network (OSTI)

of counterflow diffusion flames above condensed fuels.IN AN OPPOSED FLOW DIFFUSION FLAME* W.K. Chin R.F. Sawyeropposed flow diffusion flame burner. An earlier experimental

Chin, W.K.

2011-01-01T23:59:59.000Z

352

Enhanced production of HD and D_2 molecules on small dust grains in diffuse clouds  

E-Print Network (OSTI)

Motivated by recent observations of deuterated molecules in the interstellar medium, we examine the production of HD and D$_2$ molecules on dust grain surfaces. A mechanism for the enhanced production of these deuterated molecules is studied. This mechanism applies on grain surfaces on which D atoms stick more strongly than H atoms, under conditions of low flux and within a suitable range of temperatures. It is shown that under these conditions the production rates of HD and D$_2$ are greatly enhanced (vs. the H$_2$ production rate) compared with the expected rates based on the adsorption of gas-phase atomic abundances of D and H. The enhancement in the formation rate of HD is comparable with the enhancement due to gas-phase ion-molecule reactions in diffuse clouds.

Azi Lipshtat; Ofer Biham; Eric Herbst

2003-11-23T23:59:59.000Z

353

Hydrogen Diffusion through Multiple Packaging Layers  

DOE Green Energy (OSTI)

For this scenario, hydrogen is generated in a container that is eventually stored within a drum or some type of long range storage container. When preparing for long-term storage, the hydrogen container (HC) is placed in a plastic bag (PB1). The PB1 is then placed inside an inner drum (ID). The ID is placed inside a plastic bag (PB2) which is then placed within an outer drum (OD). One or more ODs are then storage is a large container (LC). Filtered vents or vent holes are located on all the container barriers to prevent pressurization and allow gases to flow in and out of the HC. The LC is vented to the atmosphere with four vent paths for this example. The source of hydrogen generation for this study is not important. Any source that generates hydrogen in elemental form (i.e., H{sub 2}) is a candidate for the purposes of this generic evaluation. The released hydrogen accumulates inside the waste packaging. Depending on the permeability of the packaging layers, some of the accumulated hydrogen may diffuse out of the packaging layers and into the space surrounding the drums. Since the drums are confined in the LC, the hydrogen accumulates in the LC as it did inside the drums if venting of the LC does not occur. If accumulation in the LC is allowed without venting, the confinement is eventually breached or the hydrogen is consumed by reaction with other chemical species. One possible reaction is combustion with oxygen. Such a reaction can be explosive, and from this possibility arises the safety concern.

McAllister, J.; Mohiuddin, A.

2010-05-05T23:59:59.000Z

354

Non-Brownian molecular self-diffusion in bulk water  

E-Print Network (OSTI)

The paper presents the velocity autocorrelation spectrum of bulk water measured by a new technique of NMR modulated gradient spin echo method. This technique is unprecedented for the spectrum measurement in the frequency interval between a few Hz to about 100 kHz with respect to directness and clarity of results and shows that a simple model of Brownian self-diffusion is not applicable to describe the diffusion dynamics of water molecules. The observed temperature dependant spectra of water show the existence of a slow chain-like dynamics in water, which we explain by coupling of diffusing molecule to broken bonds in the hydrogen bond network.

Janez Stepišnik; Aleš Mohori?; Igor Serša

2010-10-06T23:59:59.000Z

355

Energy diffusion in strongly driven quantum chaotic systems  

E-Print Network (OSTI)

The energy evolution of a quantum chaotic system under the perturbation that harmonically depends on time is studied for the case of large perturbation, in which the rate of transition calculated from the Fermi golden rule exceeds the frequency of perturbation. It is shown that the energy evolution retains its diffusive character, with the diffusion coefficient that is asymptotically proportional to the magnitude of perturbation and to the square root of the density of states. The results are supported by numerical calculation. They imply the absence of the quantum-classical correspondence for the energy diffusion and the energy absorption in the classical limit $\\hbar \\to 0$.

P. V. Elyutin

2005-04-14T23:59:59.000Z

356

Kinetic Isotopic Fractionation During Diffusion of Ionic Speciesin Water  

Science Conference Proceedings (OSTI)

Experiments specifically designed to measure the ratio of the diffusivities of ions dissolved in water were used to determine D{sub Li}/D{sub K}, D{sub 7{sub Li}}/D{sub 6{sub Li}}, D{sub 25{sub Mg}}/D{sub 24{sub Mg}}, D{sub 26{sub Mg}}/D{sub 25{sub Mg}}, and D{sub 37{sub Cl}}/D{sub 35{sub Cl}}. The measured ratio of the diffusion coefficients for Li and K in water (D{sub Li}/D{sub K} = 0.6) is in good agreement with published data, providing evidence that the experimental design being used resolves the relative mobility of ions with adequate precision to also be used for determining the fractionation of isotopes by diffusion in water. In the case of Li we found measurable isotopic fractionation associated with the diffusion of dissolved LiCl (D{sub 7{sub Li}}/D{sub 6{sub Li}} = 0.99772 {+-} 0.00026). This difference in the diffusion coefficient of {sup 7}Li compared to {sup 6}Li is significantly less than reported in an earlier study, a difference we attribute to the fact that in the earlier study Li diffused through a membrane separating the water reservoirs. Our experiments involving Mg diffusing in water found no measurable isotopic fractionation (D{sub 25{sub Mg}}/D{sub 24{sub Mg}} = 1.00003 {+-} 0.00006). Cl isotopes were fractionated during diffusion in water (D{sub 37{sub Cl}}/D{sub 35{sub Cl}} = 0.99857 {+-} 0.00080) whether or not the co-diffuser (Li or Mg) was isotopically fractionated. The isotopic fractionation associated with the diffusion of ions in water is much smaller than values we found previously for the isotopic fractionation of Li and Ca isotopes by diffusion in molten silicate liquids. A major distinction between water and silicate liquids is that water, being a polar liquid, surrounds dissolved ions with hydration shells, which very likely play an important but still poorly understood role in reducing isotopic fractionation associated with diffusion.

Richter, Frank M.; Mendybaev, Ruslan A.; Christensen, John; Hutcheon, Ian D.; Williams, Ross W.; Sturchio, Neil C.; Beloso Jr.,Abelardo D.

2005-06-09T23:59:59.000Z

357

A local view of bonding and diffusion at metal surfaces  

SciTech Connect

First-principles density functional calculations and corresponding experimental results underline the importance of basic chemical concepts, such as coordination, valence saturation and promotion-hybridization energetics, in understanding bonding and diffusion of atoms at and on metal surfaces. Several examples are reviewed, including outer-layer relaxations of clean hcp(0001) surfaces, liquid-metal-embrittlement energetics, separation energies of metal-adatom dimers, concerted substitutional self-diffusion on fcc(001) surfaces, and adsorption and diffusion barrier sites for adatoms near steps.

Feibelman, P.J.

1996-09-01T23:59:59.000Z

358

Oxygen diffusion in UO2+x and (U,Pu)O2+-x  

SciTech Connect

In the first part of this report we revisit an earlier study of oxygen diffusion in UO{sub 2+x}, in which we used density functional theory (DFT) calculations to parameterize a kinetic Monte Carlo (kMC) model. The results from these earlier kMC simulations are reproduced in Fig. 1 and they indicate fairly good agreement with available experiments. This work was later expanded to include a larger temperature range. However, since the publication of this study there have been a number of advancements in DFT methodology for UO{sub 2} and UO{sub 2+x} providing increased accuracy. We have also gained better understanding of the oxygen clustering phenomena occurring in UO{sub 2+x}. For these two reasons, the DFT calculations of the migration barriers of single oxygen interstitials and di-interstitial clusters have been repeated using the LDA+U and GGA+U methodologies. The earlier study used regular GGA and, even though this method captures similar trends as the more advanced LDA+U and GGA+U techniques, it does not fulfill the quantitative requirements set by some applications. Additionally, we have identified a mechanism for the most stable quad-interstitial clusters to migrate and here we calculate the corresponding barriers within both the LDA+U and GGA+U methodologies. The new LDA+U and GGA+U data sets are analyzed in terms of available experiments. In the second part of this report we present initial results for the impact of Pu on oxygen diffusion in UO{sub 2}. The first step in understanding this process is to calculate the binding energies of oxygen vacancies and interstitials to a Pu ion in the UO{sub 2} matrix. Possible diffusion mechanisms are discussed for (U,Pu)O{sub 2-x}, (U,Pu)O{sub 2} and (U,Pu)O{sub 2+x}.

Andersson, Anders D. [Los Alamos National Laboratory; Liu, Xiang-Yang [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

359

3D-Printerens Udbredelse; The Diffusion of the 3D-Printer.  

E-Print Network (OSTI)

??This Paper investigates the 3D Printers curent state of diffusion and impact on modernity with use of Rogers theory of diffusion of innovation in relation… (more)

Lindhardt, Tobias

2013-01-01T23:59:59.000Z

360

3D-skrivebordsprinteren Udbredelse Gennem Diffusion Og Netværk Som Innovation.  

E-Print Network (OSTI)

??This project surrounds the complexity of working with diffusion of the innovation, the desktop-3DPrinter. With offset in theorist Everet Rogers Diffusion of Innovations Theory and… (more)

Madsen, Martin Jacob

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Effects of Nanoparticle Geometry and Size Distribution on Diffusion Impedance of Battery Electrodes  

E-Print Network (OSTI)

The short diffusion lengths in insertion battery nanoparticles render the capacitive behavior of bounded diffusion, which is rarely observable with conventional larger particles, now accessible to impedance measurements. ...

Song, Juhyun

362

Exploiting breakdown of the similarity relation for diffuse light transport: simultaneous retrieval of scattering anisotropy and diffusion constant  

E-Print Network (OSTI)

As manifested in the similarity relation of diffuse light transport, it is difficult to assess single scattering characteristics from multiply scattered light. We take advantage of the limited validity of the diffusion approximation of light transport and demonstrate, experimentally and numerically, that even deep into the multiple scattering regime, time-resolved detection of transmitted light allows simultaneous assessment of both single scattering anisotropy and scattering mean free path, and therefore also macroscopic parameters like the diffusion constant and the transport mean free path. This is achieved via careful assessment of early light and matching against Monte Carlo simulations of radiative transfer.

Svensson, Tomas; Alerstam, Erik; Vynck, Kevin; Burresi, Matteo; Wiersma, Diederik S

2012-01-01T23:59:59.000Z

363

An Instrument Design Concept for Measuring Solar Diffuse Irradiance  

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

An Instrument Design Concept for Measuring Solar Diffuse Irradiance An Instrument Design Concept for Measuring Solar Diffuse Irradiance Rutledge, Charles NASA Langley Research Center Schuster, Greg NASA Langley Research Center Category: Instruments Recent effort towards the development of a diffuse horizontal solar irradiance standard group [Michalsky et.al. 2005] using well calibrated pyranometers suggested that inter-instrument differences in cosine response characteristics may be problematic. They showed a calibration method using overcast skies (an approximately uniform radiance distribution) produced superior diffuse radiometer performance when compared to a calibration method using clear skies (which have a radiance distribution systematically varying from horizon to the near vicinity of the sun). The proposed instrument offers a significantly different basic design compared to

364

The Diffusion Kernel Filter Applied to Lagrangian Data Assimilation  

Science Conference Proceedings (OSTI)

The diffusion kernel filter is a sequential particle-method approach to data assimilation of time series data and evolutionary models. The method is applicable to nonlinear/non-Gaussian problems. Within branches of prediction it parameterizes ...

Paul Krause; Juan M. Restrepo

2009-12-01T23:59:59.000Z

365

Diffusion Follows Structure ¾ A Network Model of the Software  

Science Conference Proceedings (OSTI)

By conducting simulations, we show that the structure of the personal networks significantly influences the diffusion processes in network effect markets like the software market. Varying connectivity (number of links to other participants), the heterogeneity ...

Falk v. Westarp; Oliver Wendt

2000-01-01T23:59:59.000Z

366

Diffusivity and Mobility Data: Building Blocks for ICME  

Science Conference Proceedings (OSTI)

Presentation Title, Diffusivity and Mobility Data: Building Blocks for ICME ... Elastic Strain Energy Effects on Grain Boundary Segregation and Solute Drag in ... Solidification Microstructure Characteristics: Benchmark Data Generated by In Situ ...

367

Global Patterns of Mesoscale Eddy Properties and Diffusivities  

Science Conference Proceedings (OSTI)

Mesoscale eddies play a major role in the transport of tracers in the ocean. Focusing on a sector in the East Pacific, we present estimates of eddy diffusivities derived from kinematic tracer simulations using satellite-observed velocity fields. ...

Andreas Klocker; Ryan Abernathey

368

A combinatorial model of malware diffusion via Bluetooth connections  

E-Print Network (OSTI)

We outline here the mathematical expression of a diffusion model for cellphones malware transmitted through Bluetooth channels. In particular, we provide both the recursive and the explicit formula underlying the proposed model.

Merler, Stefano

2012-01-01T23:59:59.000Z

369

Transportation cost inequalities for diffusions under uniform distance  

E-Print Network (OSTI)

We prove the transportation inequality with the uniform norm for the laws of diffusion processes with Lipschitz and/or dissipative coefficients and apply them to some singular stochastic differential equations of interest.

Ali Suleyman Ustunel

2010-09-27T23:59:59.000Z

370

High accuracy diffuse horizontal irradiance measurements without a shadowband  

DOE Green Energy (OSTI)

The standard method for measuring diffuse horizontal irradiance uses a fixed shadowband to block direct solar radiation. This method requires a correction for the excess skylight blocked by the band, and this correction varies with sky conditions. Alternately, diffuse horizontal irradiance may be calculated from total horizontal and direct normal irradiance. This method is in error because of angular (cosine) response of the total horizontal pyranometer to direct beam irradiance. This paper describes an improved calculation of diffuse horizontal irradiance from total horizontal and direct normal irradiance using a predetermination of the angular response of the total horizontal pyranometer. We compare these diffuse horizontal irradiance calculations with measurements made with a shading-disk pyranometer that shields direct irradiance using a tracking disk. Results indicate significant improvement in most cases. Remaining disagreement most likely arises from undetected tracking errors and instrument leveling.

Schlemmer, J.A; Michalsky, J.J.

1995-12-31T23:59:59.000Z

371

Climatology of Diffusion Potential Classes for Minneapolis–St. Paul  

Science Conference Proceedings (OSTI)

This climatological study reports on the potential for atmospheric diffusion at Minneapolis–St. Paul, Minnesota, cities located in the heart of the North American continent. As such, the results can be considered typical of an urban setting ...

Allen B. Johnson; Donald G. Baker

1997-12-01T23:59:59.000Z

372

Effect of Reduced Diffusion on Surface Wind and Wave Fields  

Science Conference Proceedings (OSTI)

Horizontal diffusion is used in meteorological models to reduce noise in the shorter spatial scales and to increase numerical stability. In turn, this affects the surface wind distribution. A series of tests on real situations in the ...

Luigi Cavaleri; Luciana Bertotti; Mariano Hortal; Martin Miller

1997-11-01T23:59:59.000Z

373

Three essays on the development and diffusion of pharmaceutical innovations  

E-Print Network (OSTI)

The thesis comprises three essays on various aspects of the development and diffusion of pharmaceutical innovations, woven together by the idea that the production of clinical knowl- edge influences organizational design, ...

Azoulay, Pierre

2001-01-01T23:59:59.000Z

374

Diffusion driven object propulsion in density stratified fluids  

E-Print Network (OSTI)

An experimental study was conducted in order to verify the appropriateness of a two dimensional model of the flow creating diffusion driven object propulsion in density stratified fluids. Initial flow field experiments ...

Lenahan, Conor (Conor P.)

2009-01-01T23:59:59.000Z

375

Horizontal Momentum Diffusion in GCMs Using the Dynamic Smagorinsky Model  

Science Conference Proceedings (OSTI)

A dynamic version of Smagorinsky’s diffusion scheme is presented that is applicable for large-eddy simulations (LES) of the atmospheric dynamics. The approach is motivated (i) by the incompatibility of conventional hyperdiffusion schemes with the ...

Urs Schaefer-Rolffs; Erich Becker

2013-03-01T23:59:59.000Z

376

Diffuse gamm-ray Emission: Lessons and Perspectives  

SciTech Connect

The Galactic diffuse emission is potentially able to reveal much about the sources and propagation of cosmic rays (CR), their spectra and intensities in distant locations. It can possibly unveil WIMP dark matter (DM) through its annihilation signatures. The extragalactic background may provide vital information about the early stages of the universe, neutralino annihilation, and unresolved sources (blazars) and their cosmological evolution. The g-ray instrument EGRET on the CGRO contributed much to the exploration of the Galactic diffuse emission. The new NASA Gamma-ray Large Area Space Telescope (GLAST) is scheduled for launch in 2007; study of the diffuse g-ray emission is one of the priority goals. We describe current understanding of the diffuse emission and its potential for future discoveries.

Moskalenko, Igor V.; /NASA, Goddard; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

2007-04-25T23:59:59.000Z

377

Analytical Parameterizations of Diffusion: The Convective Boundary Layer  

Science Conference Proceedings (OSTI)

A brief review is made of data bases which have been used for developing diffusion parameterizations for the convective boundary layer (CBL). A variety of parameterizations for lateral and vertical dispersion, ?y and ?z, are surveyed; some of ...

Gary A. Briggs

1985-11-01T23:59:59.000Z

378

A New Horizontal Gradient, Continuous Flow, Ice Thermal Diffusion Chamber  

Science Conference Proceedings (OSTI)

A continuous-flow, horizontal gradient, ice thermal diffusion chamber has been developed and tested for heterogeneous ice nucleation of aerosol particles under accurately controlled supersaturations and supercooling in the absence of a substrate. ...

E. M. Tomlinson; N. Fukuta

1985-12-01T23:59:59.000Z

379

Equilibration of Two-Dimensional Double-Diffusive Intrusions  

Science Conference Proceedings (OSTI)

This paper considers the equilibration of lateral intrusions in a doubly diffusive fluid with uniform unbounded basic-state gradients in temperature and salinity. These are density compensated in the horizontal direction and finger favorable in ...

Julian Simeonov; Melvin E. Stern

2007-03-01T23:59:59.000Z

380

Validation of Parameterization Scheme for Eddy Diffusion from Satellite Data  

Science Conference Proceedings (OSTI)

The eddy diffusion coefficient Kyy has been calculated using LIMS data for the months of December 1978 and January and February 1979. Two methods have been used. The first implements the suggestion made by Tung (1987) to parameterize the eddy ...

F. Sassi; G. Visconti; J. C. Gille

1990-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

A Review of Relative Diffusion Analysis and Results  

Science Conference Proceedings (OSTI)

Some confusion in the nature and difference between absolute and relative diffusion is found in the work of Kao and Al-Gain (1968) and Kirwan et al. (1978).

John F. Middleton

1980-06-01T23:59:59.000Z

382

Metallic diffusion process and improved article produced thereby  

DOE Patents (OSTI)

A uniquely surface-modified metallic part is provided by the utilization of microwave energy to promote diffusion of desired metals into the surface of the formed metallic part.

Morrow, M. Stanley (Kingston, TN); Schechter, Donald E. (Ten Mile, TN); Grant, Harley A. (Harrison, TN)

2003-04-29T23:59:59.000Z

383

Pre-plated reactive diffusion-bonded battery electrode plaques  

SciTech Connect

A high strength, metallic fiber battery plaque is made using reactive diffusion bonding techniques, where a substantial amount of the fibers are bonded together by an iron-nickel alloy.

Maskalick, Nicholas J. (Pittsburgh, PA)

1984-01-01T23:59:59.000Z

384

Addition of Diffusion Model to MELCOR and Comparison with Data  

Science Conference Proceedings (OSTI)

A chemical diffusion model was incorporated into the thermal-hydraulics package of the MELCOR Severe Accident code (Reference 1) for analyzing air ingress events for a very high temperature gas-cooled reactor.

Brad Merrill; Richard Moore; Chang Oh

2004-06-01T23:59:59.000Z

385

Two-Zone Convective Scaling of Diffusion in Complex Terrain  

Science Conference Proceedings (OSTI)

A “two-zone” convective scaling equation is developed that allows for a step change in scaling parameters. The results of the Lompoc Valley Diffusion Experiment, conducted at coastal site in California under variable cloud cover, are compared to ...

C. E. Skupniewicz

1994-05-01T23:59:59.000Z

386

The Permeation And Diffusion Of Hydrogen In Molybdenum  

DOE Green Energy (OSTI)

Permeation and diffusion constants have been determined for hydrogen in molybdenum and the solubility constant calculated. The solution of hydrogen in molybdenum is more endothermic than other systems for which the heat of solution is known.

Jones, P.M.S.; Gibson, R.; Evans, J.A.

1966-02-01T23:59:59.000Z

387

International diffusion practice : lessons from South Korea's New Village Movement  

E-Print Network (OSTI)

This research focuses on how South Korea's development model-namely, the Saemaul Undong, or the New Village Movement-is diffused internationally, in particular, to the developing country of Vietnam. South Korea's successful ...

Kim, Jung Hwa, M.C.P. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

388

The Growth of Ice Crystals by Molecular Diffusion  

Science Conference Proceedings (OSTI)

The mass transfer of water molecules by diffusion onto ice particles is best described by their Sherwood number (Sh), a dimensionless quantity, which combines molecular and convective effects and depends on the airflow as represented by the ...

Hyun Youk; Roland List; Theophilus Ola

2006-06-01T23:59:59.000Z

389

Finescale Instabilities of the Double-Diffusive Shear Flow  

Science Conference Proceedings (OSTI)

This study examines dynamics of finescale instabilities in thermohaline–shear flows. It is shown that the presence of the background diapycnal temperature and salinity fluxes due to double diffusion has a destabilizing effect on the basic ...

Timour Radko; Melvin E. Stern

2011-03-01T23:59:59.000Z

390

DOE Seeks Deactivation Contractor for Paducah Gaseous Diffusion Plant  

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

Cincinnati – The U.S. Department of Energy (DOE) today issued a Request for Task Proposal (RTP) for deactivation activities at the Paducah Gaseous Diffusion Plant (GDP) in Paducah, Kentucky.

391

CORELLI: the Elastic Diffuse Scattering Spectrometer at SNS | ORNL Neutron  

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

The Elastic Diffuse Scattering Spectrometer The Elastic Diffuse Scattering Spectrometer CORELLI The CORELLI instrument. CORELLI is a statistical chopper spectrometer with energy discrimination. It's designed and optimized to probe complex disorder in crystalline materials through diffuse scattering of single-crystal samples. The momentum transfer ranges from 0.5 to 12 Å-1, and the energy of incident neutrons ranges from 10 to 200 meV. This instrument combines the high efficiency of white-beam Laue diffraction with energy discrimination by modulating the beam with a statistical chopper. A cross-correlation method is used to reconstruct the elastic signal from the modulated data. Accurate modeling of the short-range order associated with the diffuse scattering requires measurements over large volumes of three-dimensional reciprocal space, with sufficient momentum

392

Energy Department Completes K-25 Gaseous Diffusion Building Demolition |  

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

Energy Department Completes K-25 Gaseous Diffusion Building Energy Department Completes K-25 Gaseous Diffusion Building Demolition Energy Department Completes K-25 Gaseous Diffusion Building Demolition December 19, 2013 - 12:00pm Addthis K-25 Demolition - Oak Ridge 2013 K-25 Demolition - Oak Ridge 2013 Media Contacts Ben Williams, DOE, (865) 574-4912 Wayne McKinney, UCOR, (865) 576-6284 Oak Ridge, Tenn. - Today, the Department of Energy announced that its contractor URS|CH2M Oak Ridge, LLC, or UCOR, has completed demolition of the K-25 gaseous diffusion building, the largest facility in the DOE complex. UCOR took over the project in 2011 and has maintained a strong safety record while completing the demolition over one year ahead of its current schedule and approximately $300 million under the current budget. All debris removal is expected to be completed in spring 2014.

393

Mechanics of Funding matrix  

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

FUNDING MECHANISMS FUNDING MECHANISMS Funding Mechanism Advantages Disadvantages Comments 1. From Doe to regional organizations * * Facilitates a broad, regional approach to planning and implementation that enhances consistency and uniformity * * Especially beneficial for new programs where early planning is needed * * Simplifies communication for DOE to have only one point of contact for information and discussion * * Cooperative agreement mechanism has proven relatively simple to administer * * Approach would require modification for Tribes * * Would also require that funding be provided to individual States to enable them to participate in the process, since planning authority and responsibility rests with the individual State * * Differs from OCRWM approach to 180(c) funding * * Introduces another layer of

394

Mechanical Behavior II  

Science Conference Proceedings (OSTI)

Mar 5, 2013 ... Impact of Cooling Rate on Low Silver Sn-Ag-Cu Solder Interconnect Board Level Mechanical Shock and Thermal Cycling Performance: ...

395

Structures and Mechanical Properties  

Science Conference Proceedings (OSTI)

Mar 7, 2013... Refractory High-entropy Alloy: Chien-Chang Juan1; Jien-Wei Yeh1; ... The main wear mechanism was adhesive wear in deionized water, ...

396

Mechanical Behavior I  

Science Conference Proceedings (OSTI)

Mar 5, 2013... (IMC) is essential for understandingthe mechanical behavior of the ... Reliability and by the SHaRE User Facility, Scientific User Facilities ...

397

Measure of Diffusion Model Error for Thermal Radiation Transport  

E-Print Network (OSTI)

The diffusion approximation to the equation of transfer (Boltzmann transport equation) is usually applied to media where scattering dominates the interactions. Diffusion approximation helps in significant savings in terms of code complexity and computational time. However, this approximation often has significant error. Error due to the inherent nature of a physics model is called model error. Information about the model error associated with the diffusion approximation is clearly desirable. An indirect measure of model error is a quantity that is related in some way to the error but not equal to the error. In general, indirect measures of error are expected to be less costly than direct measures. Perhaps the most well-known indirect measure of the diffusion model error is the variable-Eddington tensor. This tensor provides a great deal of information about the angular dependence of the angular intensity solution, but it is not always simple to interpret. We define a new indirect measure of the diffusion model error called the diffusion model error source (DME source). When this DME source is added to the diffusion equation, the transport solution for the angular-integrated intensity is obtained. In contrast to the variable-Eddington tensor, our DME source is a scalar that is conceptually easy to interpret. In addition to defining the DME source analytically, we show how to generate this source numerically relative to the Sn radiative transfer equations with linear-discontinuous spatial discretization. This numerical source is computationally tested and shown to reproduce the Sn solution for a number of problems. Our radiative transfer model solves a coupled, time dependent, multi-frequency, 1-D slab equation and material heat transfer equation. We then use diffusion approximation to solve the same problem. The difference due to this approximation can be modelled by a “diffusion source”. The diffusion source is defined as an amount of inhomogeneous source that, when added to a diffusion calculation, gives a solution for the angle-integrated intensity that is equal to the transport solution.

Kumar, Akansha

2013-05-01T23:59:59.000Z

398

Anisotropic Diffusion of Polyelectrolyte Chains within Multi-layer Films  

SciTech Connect

We found diffusion of polyelectrolyte chains within multilayer films to be highly anisotropic, with the preferential chain motion parallel to the substrate. The degree of anisotropy was quantified by a combination of fluorescence recovery after photobleaching and neutron reflectometry, probing chain diffusion in directions parallel and perpendicular to the substrate, respectively. Chain mobility was controlled by ionic strength of annealing solutions and steric hindrance to ionic pairing of interacting polyelectrolytes.

Xu, Li [Stevens Institute of Technology, Hoboken, New Jersey; Kozlovskaya, Veronika [University of Alabama, Birmingham; Kharlampieva, Eugenia [University of Alabama, Birmingham; Ankner, John Francis [ORNL; Sukhishvili, Prof. Svetlana A. [Stevens Institute of Technology, Hoboken, New Jersey

2012-01-01T23:59:59.000Z

399

Optical processing furnace with quartz muffle and diffuser plate  

DOE Patents (OSTI)

An optical furnace for annealing a process wafer is disclosed comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the wall of the muffle is also provided for controlling the source of optical energy. 5 figs.

Sopori, B.L.

1996-11-19T23:59:59.000Z

400

Discrete diffusion Monte Carlo for frequency-dependent radiative transfer  

SciTech Connect

Discrete Diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Implicit Monte Carlo radiative-transfer simulations. In this paper, we develop an extension of DDMC for frequency-dependent radiative transfer. We base our new DDMC method on a frequency-integrated diffusion equation for frequencies below a specified threshold. Above this threshold we employ standard Monte Carlo. With a frequency-dependent test problem, we confirm the increased efficiency of our new DDMC technique.

Densmore, Jeffrey D [Los Alamos National Laboratory; Kelly, Thompson G [Los Alamos National Laboratory; Urbatish, Todd J [Los Alamos National Laboratory

2010-11-17T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

Analysis of price diffusion in financial markets using PUCK model  

E-Print Network (OSTI)

Based on the new type of random walk process called the Potentials of Unbalanced Complex Kinetics (PUCK) model, we theoretically show that the price diffusion in large scales is amplified 2/(2 + b) times, where b is the coefficient of quadratic term of the potential. In short time scales the price diffusion depends on the size M of the super moving average. Both numerical simulations and real data analysis of Yen-Dollar rates are consistent with theoretical analysis.

Mizuno, T; Takayasu, M; Mizuno, Takayuki; Takayasu, Hideki; Takayasu, Misako

2006-01-01T23:59:59.000Z

402

Anomalous diffusion and scaling in coupled stochastic processes  

SciTech Connect

Inspired by problems in biochemical kinetics, we study statistical properties of an overdamped Langevin processes with the friction coefficient depending on the state of a similar, unobserved, process. Integrating out the latter, we derive the Pocker-Planck the friction coefficient of the first depends on the state of the second. Integrating out the latter, we derive the Focker-Planck equation for the probability distribution of the former. This has the fonn of diffusion equation with time-dependent diffusion coefficient, resulting in an anomalous diffusion. The diffusion exponent can not be predicted using a simple scaling argument, and anomalous scaling appears as well. The diffusion exponent of the Weiss-Havlin comb model is derived as a special case, and the same exponent holds even for weakly coupled processes. We compare our theoretical predictions with numerical simulations and find an excellent agreement. The findings caution against treating biochemical systems with unobserved dynamical degrees of freedom by means of standandard, diffusive Langevin descritpion.

Bel, Golan [Los Alamos National Laboratory; Nemenman, Ilya [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

403

Diffusion coefficients in trimethyleneoxide containing comb branch polymer  

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

Diffusion coefficients in trimethyleneoxide containing comb branch polymer Diffusion coefficients in trimethyleneoxide containing comb branch polymer electrolytes Title Diffusion coefficients in trimethyleneoxide containing comb branch polymer electrolytes Publication Type Journal Article Year of Publication 2004 Authors Liu, Gao, Craig L. Reeder, Xiaoguang Sun, and John B. Kerr Journal Solid State Ionics Volume 175 Pagination 781-783 Keywords comb branch polyethers, conductivity, lithium battery, polymer electrolytes, salt diffusion coefficient, trimethylene oxide Abstract This paper reports on a new comb branch polymer based on trimethylene oxide (TMO) side chains as a polymer electrolyte for potential application in lithium metal rechargeable batteries. The trimethylene oxide (TMO) units are attached to the side chains of a polyepoxide ether to maximize the segmental motion. Lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) salt was used to formulate the polymer electrolyte with the new TMO containing polymers. The new polymer electrolytes show improved salt diffusion coefficients (Ds) and conductivity at ambient and subambient temperature compare to the ethylene oxide (EO) counterpart, whereas performance at high temperature (85 °C) remains the same or is actually worse for salt diffusivity.

404

Binding Preferences, Surface Attachment, Diffusivity, and Orientation of a Family 1 Carbohydrate-Binding Module on Cellulose  

DOE Green Energy (OSTI)

Cellulase enzymes often contain carbohydrate-binding modules (CBMs) for binding to cellulose. The mechanisms by which CBMs recognize specific surfaces of cellulose and aid in deconstruction are essential to understand cellulase action. The Family 1 CBM from the Trichoderma reesei Family 7 cellobiohydrolase, Cel7A, is known to selectively bind to hydrophobic surfaces of native cellulose. It is most commonly suggested that three aromatic residues identify the planar binding face of this CBM, but several recent studies have challenged this hypothesis. Here, we use molecular simulation to study the CBM binding orientation and affinity on hydrophilic and hydrophobic cellulose surfaces. Roughly 43 {mu}s of molecular dynamics simulations were conducted, which enables statistically significant observations. We quantify the fractions of the CBMs that detach from crystal surfaces or diffuse to other surfaces, the diffusivity along the hydrophobic surface, and the overall orientation of the CBM on both hydrophobic and hydrophilic faces. The simulations demonstrate that there is a thermodynamic driving force for the Cel7A CBM to bind preferentially to the hydrophobic surface of cellulose relative to hydrophilic surfaces. In addition, the simulations demonstrate that the CBM can diffuse from hydrophilic surfaces to the hydrophobic surface, whereas the reverse transition is not observed. Lastly, our simulations suggest that the flat faces of Family 1 CBMs are the preferred binding surfaces. These results enhance our understanding of how Family 1 CBMs interact with and recognize specific cellulose surfaces and provide insights into the initial events of cellulase adsorption and diffusion on cellulose.

Nimlos, M. R.; Beckham, G. T.; Matthews, J. F.; Bu, L.; Himmel, M. E.; Crowley, M. F.

2012-06-08T23:59:59.000Z

405

Fabrication and Design Aspects of High-Temperature Compact Diffusion Bonded Heat Exchangers  

Science Conference Proceedings (OSTI)

The Very High Temperature Reactor (VHTR) using gas-cooled reactor technology is anticipated to be the reactor type for the Next Generation Nuclear Plant (NGNP). In this reactor concept with an indirect power cycle system, a high-temperature and high integrity Intermediate Heat Exchanger (IHX) with high effectiveness is required to efficiently transfer the core thermal output to a secondary fluid for electricity generation, hydrogen production, and/or industrial process heat applications. At present, there is no proven IHX concept for VHTRs. The current Technology Readiness Level (TRL) status issued by NGNP to all components associated with the IHX for reduced nominal reactor outlet temperatures of 750–800 degrees C is 3 on a 1–10 scale, with 10 indicating omplete technological maturity. Among the various potential IHX concepts available, diffusion bonded heat exchangers (henceforth called printed circuit heat exchangers, or PCHEs) appear promising for NGNP applications. The design and fabrication of this key component of NGNP with Alloy 617, a candidate high-temperature structural material for NGNP applications, are the primary focus of this paper. In the current study, diffusion bonding of Alloy 617 has been demonstrated, although the optimum diffusion bonding process parameters to engineer a quasi interface-free joint are yet to be determined. The PCHE fabrication related processes, i.e., photochemical etching and diffusion bonding are discussed for Alloy 617 plates. In addition, the authors’ experiences with these non-conventional machining and joining techniques are discussed. Two PCHEs are fabricated using Alloy 617 plates and are being experimentally investigated for their thermal-hydraulic performance in a High-Temperature Helium Facility (HTHF). The HTHF is primarily of Alloy 800H construction and is designed to facilitate experiments at temperatures and pressures up to 800 degrees C and 3 MPa, respectively. Furthermore, some preliminary microstructural and mechanical property characterization studies of representative diffusion bonded Alloy 617 specimens are presented. The characterization studies are restricted and less severe from an NGNP perspective but provide sufficient confidence to ensure safe operation of the heat exchangers in the HTHF. The test results are used to determine the design operating conditions for the PCHEs fabricated.

Sai K. Mylavarapu; Richard N. Christensen; Raymond R. Unocic; Richard E. Glosup; Mike W. Patterson

2012-08-01T23:59:59.000Z

406

Mecanica Clasica (Classical Mechanics)  

E-Print Network (OSTI)

First Internet undergraduate course on Classical Mechanics in Spanish (Castellano). This is about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. English and Romanian versions are in (slow) progress and hopefully will be arXived. For a similar course on Quantum Mechanics, see physics/9808031

Rosu, H C

1999-01-01T23:59:59.000Z

407

Quantum Mechanics Measurements, Mutually  

E-Print Network (OSTI)

Quantum Mechanics Measurements, Mutually Unbiased Bases and Finite Geometry Or why six is the first) #12;Quantum Mechanics for Dummies Finite dimensional quantum states are represented by trace one,1 -icS1,1[ ] #12;Quantum systems evolve and are measured. The evolution of a quantum system using

Gruner, Daniel S.

408

Mechanical code comparator  

DOE Patents (OSTI)

A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

Peter, Frank J. (Albuquerque, NM); Dalton, Larry J. (Bernalillo, NM); Plummer, David W. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

409

Structural Mechanics & Solid Mechanics A finite element toolbox to MATLAB  

E-Print Network (OSTI)

Structural Mechanics & Solid Mechanics Department of Mechanics and Materials CALFEM A finite.3 Copyright © 1999 by Structural Mechanics, LTH, Sweden. Printed by JABE Offset, Lund, Sweden. ISRN LUTVDG/TVSM--99/9001--SE (1-265) ISSN 0281-6679 Department of Mechanics and Materials Structural Mechanics #12;The

Ehrhardt, Matthias

410

Rotary mechanical latch  

Science Conference Proceedings (OSTI)

A rotary mechanical latch for positive latching and unlatching of a rotary device with a latchable rotating assembly having a latching gear that can be driven to latched and unlatched states by a drive mechanism such as an electric motor. A cam arm affixed to the latching gear interfaces with leading and trailing latch cams affixed to a flange within the drive mechanism. The interaction of the cam arm with leading and trailing latch cams prevents rotation of the rotating assembly by external forces such as those due to vibration or tampering.

Spletzer, Barry L.; Martinez, Michael A.; Marron, Lisa C.

2012-11-13T23:59:59.000Z

411

Quantum Mechanics Without Observers  

E-Print Network (OSTI)

The measurement problem and the role of observers have plagued quantum mechanics since its conception. Attempts to resolve these have introduced anthropomorphic or non-realist notions into physics. A shift of perspective based upon process theory and utilizing methods from combinatorial games, interpolation theory and complex systems theory results in a novel realist version of quantum mechanics incorporating quasi-local, nondeterministic hidden variables that are compatible with the no-hidden variable theorems and relativistic invariance, and reproduce the standard results of quantum mechanics to a high degree of accuracy without invoking observers.

W. H. Sulis

2013-02-18T23:59:59.000Z

412

Electronic door locking mechanism  

DOE Patents (OSTI)

The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch. 6 figs.

Williams, G.L.; Kirby, P.G.

1997-10-21T23:59:59.000Z

413

Electronic door locking mechanism  

SciTech Connect

The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch.

Williams, Gary Lin (428 E. Third Ave., Kennewick, WA 99336); Kirby, Patrick Gerald (1010 W. Fifteenth Pl., Kennewick, WA 99337)

1997-01-01T23:59:59.000Z

414

Is quantum mechanics exact?  

SciTech Connect

We formulate physically motivated axioms for a physical theory which for systems with a finite number of degrees of freedom uniquely lead to quantum mechanics as the only nontrivial consistent theory. Complex numbers and the existence of the Planck constant common to all systems arise naturally in this approach. The axioms are divided into two groups covering kinematics and basic measurement theory, respectively. We show that even if the second group of axioms is dropped, there are no deformations of quantum mechanics which preserve the kinematic axioms. Thus, any theory going beyond quantum mechanics must represent a radical departure from the usual a priori assumptions about the laws of nature.

Kapustin, Anton [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States)

2013-06-15T23:59:59.000Z

415

Migration Mechanisms of Oxygen Interstitial Clusters in UO2  

Science Conference Proceedings (OSTI)

Understanding the migration kinetics of radiation-induced point defects and defect clusters is a key to predicting the microstructural evolution and mass transport in nuclear fuels. Although the diffusion kinetics of point defects in UO2 is well explored both experimentally and theoretically, the kinetics of defect clusters is not well understood. In this work the migration mechanisms of oxygen interstitial clusters of size one to five atoms (1Oi – 5Oi) in UO2 are investigated by temperature-accelerated dynamics simulations without any a priori assumptions of migration mechanisms. It is found that the migration paths of oxygen interstitial clusters are complex and non-intuitive and that multiple migration paths and barriers exist for some clusters. It is also found that the cluster migration barrier does not increase with increasing cluster size and its magnitude has the following order: 2Oi < 3Oi < 1Oi < 5Oi < 4Oi. Possible finite-size effects are checked with three different sized systems. The results show good agreement with other available experimental and theoretical data. In particular, the relatively large migration barriers of cuboctahedral clusters (4Oi and 5Oi) are in good agreement with the experimentally measured oxygen diffusion activation energy in U4O9, which is thought to contain many such clusters. The cluster migration sequence may explain the interesting relationship between the oxygen diffusivity and stoichiometry in UO2+x.

Xian-Ming Bai; Anter El-Azab; Jianguo Yu; Todd R. Allen

2013-01-01T23:59:59.000Z

416

Refraining from Imitation: Professional Resistance and Limited Diffusion in a Financial Market  

Science Conference Proceedings (OSTI)

Why do some practices not spread? Although this is an important question for both diffusion theorists and those interested in institutional change, we know surprisingly little about the limitations on diffusion because most diffusion studies sample on ... Keywords: diffusion, institutional change, institutional theory

Stefan Jonsson

2009-01-01T23:59:59.000Z

417

Interdiffusion between Zr Diffusion Barrier and U-Mo Alloy  

Science Conference Proceedings (OSTI)

U-Mo alloys are being developed as low enrichment uranium fuels under the Reduced Enrichment for Research and Test Reactor (RERTR) program. Significant reactions have been observed between U-Mo fuels and Al or Al alloy matrix. Refractory metal Zr has been proposed as barrier material to reduce the interactions. In order to investigate the compatibility and barrier effects between U-Mo alloy and Zr, solid-to-solid U-10wt.%Mo vs. Zr diffusion couples were assembled and annealed at 600, 700, 800, 900 and 1000 °C for various times. The microstructures and concentration profiles due to interdiffusion and reactions were examined via scanning electron microscopy and electron probe microanalysis, respectively. Intermetallic phase Mo2Zr was found at the interface and its population increased when annealing temperature decreased. Diffusion paths were also plotted on the U-Mo-Zr ternary phase diagrams with good consistency. The growth rate of interdiffusion zone between U-10wt.%Mo and Zr was also calculated under the assumption of parabolic diffusion, and was determined to be about 103 times lower than the growth rate of diffusional interaction layer found in diffusion couples U-10wt.%Mo vs. Al or Al-Si alloy. Other desirable physical properties of Zr as barrier material, such as neutron adsorption rate, melting point and thermal conductivity are presented as supplementary information to demonstrate the great potential of Zr as the diffusion barrier for U-Mo fuel systems in RERTR.

K. Huang; Y. Park; Y. H. Sohn

2012-12-01T23:59:59.000Z

418

Transverse spin diffusion in strongly interacting Fermi gases  

E-Print Network (OSTI)

We compute spin diffusion in a dilute Fermi gas at arbitrary temperature, polarization and strong interaction in the normal phase using kinetic theory. While the longitudinal spin diffusivity depends weakly on polarization and diverges for small temperatures, the transverse spin diffusivity D_\\perp has a strong polarization dependence and approaches a finite value for T->0 in the Fermi liquid phase. For a 3D unitary Fermi gas at infinite scattering length the diffusivities reach a minimum near the quantum limit of diffusion \\hbar/m in the quantum degenerate regime and are strongly suppressed by medium scattering, and we discuss the importance of the spin-rotation effect. In two dimensions, D_\\perp attains a minimum at strong coupling -1 < ln(kFa2D) < 1 and reaches D_\\perp~0.2...0.3\\hbar/m at large polarization. These values are consistent with recent measurements of two-dimensional ultracold atomic gases in the strong coupling regime.

Tilman Enss

2013-07-19T23:59:59.000Z

419

Test Program for High Efficiency Gas Turbine Exhaust Diffuser  

DOE Green Energy (OSTI)

This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust geometry. Importantly, low frequency diffuser noise was reduced by 5 dB or more, compared to the baseline. Appolicability to other diffuser geometries is yet to be demonstrated.

Norris, Thomas R.

2009-12-31T23:59:59.000Z

420

Counter Current Multiplier Mechanism  

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

Counter Current Multiplier Mechanism Counter Current Multiplier Mechanism Name: Stephen Location: N/A Country: N/A Date: N/A Question: Can you please explain to me the counter-current multiplier mechanism. I understand that cholride and sodium ions are filtered out of the ascending loop of Henle into the interstial fluid, however, I'm not sure exactly what happens from there and how this effects osmotic pressure gradients in the nephron. Any help would be greatly appriciated. Replies: This mechanism is very complex when it comes to writing a response. You have to have a strong background in osmotic pressure understanding and the anatomy of the kidney. It involves the cortex, outer and inner medula in relationship to the vasa recta, interstitial fluids at two points, the loop of Henle and the collecting duct. The size of the tubes and the position in relations to the cortex and medulla is an essential part. I can suggest some references.

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421

Mechanical Testing of Plastics  

Science Conference Proceedings (OSTI)

Table 7   ASTM and ISO mechanical test standards for plastics...by pendulum method D 1938 6383-1 Tear propagation resistance of plastic film and thin

422

Conservative-Bayesian Mechanisms  

E-Print Network (OSTI)

We put forward a new class of mechanisms. In this extended abstract, we exemplify our approach only for single-good auctions in what we call a conservative-Bayesian setting. (Essentially, no common-knowledge about the ...

Azar, Pablo

2010-09-08T23:59:59.000Z

423

REACTOR CONTROL MECHANISM  

DOE Patents (OSTI)

A quick-releasing mechanism is described which may be used to rapidiy drop a device supported from beneath during normal use, such as a safety rod in a nuclear reactor. In accordance with this invention an electrical control signal, such as may be provided by radiation detection or other alarm condition sensing devices, is delivered to an electromagnetic solenoid, the armature of which is coupled to an actuating mechanism. The solenoid is energized when the mechanism is in its upper or cocked position. In such position, the mechanism engages a plurality of retaining balls, forcing them outward into engagement with a shoulder or recess in a corresponding section of a tubular extension on the upheld device. When the control signal to the solenoid suddenly ceases, the armature drops out, allowing the actuating mechanism to move slightly but rapidly under the force of a compressed spring. The weight of the device will urge the balls inward against a beveled portion of the actuating mechanism and away from the engaging section on the tubular extension, thus allowing the upheld device to fall freely under the influence of gravity.

Lane, J.A.; Engberg, R.E.; Welch, J.M.

1959-05-12T23:59:59.000Z

424

Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - April  

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

April 2013 April 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - April 2013 April 2013 Review of the Integrated Safety Management System Phase I Verification Review at the Portsmouth Gaseous Diffusion Plant The Office of Enforcement and Oversight (Independent Oversight), within the Office of Health, Safety and Security (HSS), conducted an independent review of the U.S. Department of Energy (DOE) Portsmouth/Paducah Project Office (PPPO). The objective of the Independent Oversight review was to evaluate PPPO's conduct of the Integrated Safety Management System (ISMS) Phase I verification review at the Portsmouth Gaseous Diffusion Plant (PORTS). The contractor at PORTS is Fluor-Babcock & Wilcox Portsmouth (FBP). The HSS Office of Safety and Emergency Management Evaluations

425

Paducah Gaseous Diffusion Plant, Construction Worker Screening Project |  

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

Paducah Gaseous Diffusion Plant, Construction Worker Screening Paducah Gaseous Diffusion Plant, Construction Worker Screening Project Paducah Gaseous Diffusion Plant, Construction Worker Screening Project Project Name: Building Trades National Medical Screening Program Covered DOE Site: Paducah Worker Population Served: Construction Workers Principal Investigator: Knut Ringen, DrPH, MHA, MPH Toll-free Telephone: (888) 464-0009 Local Outreach Office: Joe Hudson 1930 North 13th Street Paducah, KY 42001 Website: http://www.btmed.org This project is intended to provide free medical screening to former workers in the building trades (construction workers). The screening targets health problems resulting from exposures, including asbestos, beryllium, cadmium, chromium, lead, mercury, noise, radiation, silica and/or solvents. The project is being carried out by a large group led by

426

Molecular dynamics simulation of hydrogen diffusion in titanium  

National Nuclear Security Administration (NNSA)

9: Computation Physics 9: Computation Physics Atomistic Simulation of Hydrogen Diffusion in Titanium. Alexandr S. Rokhmanenkov, Alexey Yu. Kuksin, and Vladimir V. Stegailov All-Russia Research Institute of Automatics, Moscow 125412, Russia rohmanenkov@gmail.com Summary Study of the behavior of hydrogen in metals and alloys. The study is based on classical molecular dynamics (MD) and density functional theory (DFT) calculations. Study of the behavior of hydrogen in metals and alloys is of great importance due to the practical uses of hydrogen-metal systems for absorption of nuclear radiation, in neutron sources, for storage of hydrogen, or as catalyzers. This work is devoted to atomistic simulation of hydrogen diffusion in titanium hydrides and the effect of stresses and lattice defects on diffusivity.

427

Portsmouth Gaseous Diffusion Plant, Former Production Workers Screening  

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

Portsmouth Gaseous Diffusion Plant, Former Production Workers Portsmouth Gaseous Diffusion Plant, Former Production Workers Screening Projects Portsmouth Gaseous Diffusion Plant, Former Production Workers Screening Projects Project Name: Worker Health Protection Program Covered DOE Site: Portsmouth Worker Population Served: Production Workers Principal Investigator: Jim Frederick Co-Principal Investigator: Steven Markowitz, MD Toll-free Telephone: (888) 241-1199 Local Outreach Office: Jeanne Cisco 2288 Wakefield Mound Road Piketon, OH 45661 Website: http://www.worker-health.org/ This project is conducted by the Unitedsteel Workers in conjunction with Queens College of the City University of New York. The program is being offered as a service to both former and current workers. Free of charge, eligible workers can receive a medical exam, including chest X-ray and

428

Long slit spectroscopy of diffuse ionized gas in NGC 55  

E-Print Network (OSTI)

Spectroscopic measurements of emission line ratios and velocities are presented for ionized gas across the central plane of NGC 55, a late-type galaxy in the Sculptor group. The low metallicity in NGC 55 leads to relatively low line ratios of [S II]/H$\\alpha$ and [N II]/H$\\alpha$ for H II regions as well as the diffuse ionized gas. These are the first spectroscopical measurements of line ratios in ionized gas exterior to the stellar disc of NGC 55. Analysis of the line ratios and the relative velocities of different features suggests that photoionization is a plausible explanation for the ionization of this diffuse gas. The observed shell structures and the corresponding velocities support the idea of diffuse gas being pushed into the halo by supernova explosions and stellar winds.

B. Otte; R. -J. Dettmar

1999-01-21T23:59:59.000Z

429

Detailed stress tensor measurements in a centrifugal compressor vaneless diffuser  

Science Conference Proceedings (OSTI)

Detailed flow measurements have been made in the vaneless diffuser of a large low-speed centrifugal compressor using hot-wire anemometry. The three time mean velocity components and full stress tensor distributions have been determined on eight measurement plans within the diffuser. High levels of Reynolds stress result in the rapid mixing out of the blade wake. Although high levels of turbulent kinetic energy are found in the passage wake, they are not associated with strong Reynolds stresses and hence the passage wake mixes out only slowly. Low-frequency meandering of the wake position is therefore likely to be responsible for the high kinetic energy levels. The anisotropic nature of the turbulence suggests that Reynolds stress turbulence models are required for CFD modeling of diffuser flows.

Pinarbasi, A.; Johnson, M.W. [Univ. of Liverpool (United Kingdom). Dept. of Mechanical Engineering

1996-04-01T23:59:59.000Z

430

ELEVATED TEMPERATURE DIFFUSION BONDING OF TUNGSTEN TO TUNGSTEN UNDER PRESSURE  

DOE Green Energy (OSTI)

Solid-state diffusion bonding of tungsten to tungsten was investigated at temperatures ranging from 1700 to 2600 nif- C, under surface contact pressures up to 3000 psi, while under high vacuum or hydrogen atmosphere. Various interface coatings were employed to promote diffusion, including graphite, oxide, metal slurries, electroplates, direct surface oxidation, and Mo - -W deposits from carbonyl decompositions. Thorough metallurgical bonding was achieved, particularly with the latter two surface coatings, after 2 hours at 2350 nif- C in H/sub 2/ under 1400 psi. Corresponding tensile strengths of 30,000 psi were obtained. Powder-compacted tungsten sheet containing 50 vo1% UO/sub 2/, spray-coated with an outer layer of tungsten, was effectively bonded to itself and to tungsten metal under 2 hour diffusion treatments at 2000 nif- C and moderate pressures of the order of 1000 psi. (auth)

Batista, R.I.; Hanks, G.S.; Murphy, D.J.

1962-08-01T23:59:59.000Z

431

Diffusion bonding resistant valve development for sodium service  

SciTech Connect

Unanticipated functional failures occurred in valves undergoing containment integrity testing for liquid sodium service. The failures resulted from diffusion bonding of the Stellite 6B valve plug to the Type 316 stainless steel (SS) seat. As a result of these failures, a valve development program was undertaken. A modified valve incorporating a Tribaloy 800 plug showed significant improvement in resistance to diffusion bonding but still failed after long term exposure in a closed position. A second modified valve using Tribaloy 800 in both the valve plug and seat successfully resisted diffusion bonding failure. This paper reports the details of the testing and posttest valve examinations. The results of scanning electron microscopy, dispersive x-ray spectrometry, and metallography provide the characteristics of the valve failures. Limitations of the various valve designs are also discussed.

Crandall, D.L.; Low, J.O.; Chung, D.T.; Loop, R.B.

1984-04-16T23:59:59.000Z

432

Feasibility of gas-phase decontamination of gaseous diffusion equipment  

SciTech Connect

The five buildings at the K-25 Site formerly involved in the gaseous diffusion process contain 5000 gaseous diffusion stages as well as support facilities that are internally contaminated with uranium deposits. The gaseous diffusion facilities located at the Portsmouth Gaseous Diffusion Plant and the Paducah Gaseous Diffusion Plant also contain similar equipment and will eventually close. The decontamination of these facilities will require the most cost-effective technology consistent with the criticality, health physics, industrial hygiene, and environmental concerns; the technology must keep exposures to hazardous substances to levels as low as reasonably achievable (ALARA). This report documents recent laboratory experiments that were conducted to determine the feasibility of gas-phase decontamination of the internal surfaces of the gaseous diffusion equipment that is contaminated with uranium deposits. A gaseous fluorinating agent is used to fluorinate the solid uranium deposits to gaseous uranium hexafluoride (UF{sub 6}), which can be recovered by chemical trapping or freezing. The lab results regarding the feasibility of the gas-phase process are encouraging. These results especially showed promise for a novel decontamination approach called the long-term, low-temperature (LTLT) process. In the LTLT process: The equipment is rendered leak tight, evacuated, leak tested, and pretreated, charged with chlorine trifluoride (ClF{sub 3}) to subatmospheric pressure, left for an extended period, possibly > 4 months, while processing other items. Then the UF{sub 6} and other gases are evacuated. The UF{sub 6} is recovered by chemical trapping. The lab results demonstrated that ClF{sub 3} gas at subatmospheric pressure and at {approx} 75{degree}F is capable of volatilizing heavy deposits of uranyl fluoride from copper metal surfaces sufficiently that the remaining radioactive emissions are below limits.

Munday, E.B.; Simmons, D.W.

1993-02-01T23:59:59.000Z

433

Diffusive transport without detailed balance in motile bacteria: Does microbiology need statistical physics?  

E-Print Network (OSTI)

Microbiology is the science of microbes, particularly bacteria. Many bacteria are motile: they are capable of self-propulsion. Among these, a significant class execute so-called run-and-tumble motion: they follow a fairly straight path for a certain distance, then abruptly change direction before repeating the process. This dynamics has something in common with Brownian motion (it is diffusive at large scales), and also something in contrast. Specifically, motility parameters such as the run speed and tumble rate depend on the local environment and hence can vary in space. When they do so, even if a steady state is reached, this is not generally invariant under time-reversal: the principle of detailed balance, which restores the microscopic time-reversal symmetry of systems in thermal equilibrium, is mesoscopically absent in motile bacteria. This lack of detailed balance (allowed by the flux of chemical energy that drives motility) creates pitfalls for the unwary modeller. Here I review some statistical mechanical models for bacterial motility, presenting them as a paradigm for exploring diffusion without detailed balance. I also discuss the extent to which statistical physics is useful in understanding real or potential microbiological experiments.

M. E. Cates

2012-08-20T23:59:59.000Z

434

Lévy Fluctuations and Tracer Diffusion in Dilute Suspensions of Algae and Bacteria  

E-Print Network (OSTI)

Swimming microorganisms rely on effective mixing strategies to achieve efficient nutrient influx. Recent experiments, probing the mixing capability of unicellular biflagellates, revealed that passive tracer particles exhibit anomalous non-Gaussian diffusion when immersed in a dilute suspension of self-motile Chlamydomonas reinhardtii algae. Qualitatively, this observation can be explained by the fact that the algae induce a fluid flow that may occasionally accelerate the colloidal tracers to relatively large velocities. A satisfactory quantitative theory of enhanced mixing in dilute active suspensions, however, is lacking at present. In particular, it is unclear how non-Gaussian signatures in the tracers' position distribution are linked to the self-propulsion mechanism of a microorganism. Here, we develop a systematic theoretical description of anomalous tracer diffusion in active suspensions, based on a simplified tracer-swimmer interaction model that captures the typical distance scaling of a microswimmer's flow field. We show that the experimentally observed non-Gaussian tails are generic and arise due to a combination of truncated L\\'evy statistics for the velocity field and algebraically decaying time correlations in the fluid. Our analytical considerations are illustrated through extensive simulations, implemented on graphics processing units to achieve the large sample sizes required for analyzing the tails of the tracer distributions.

Irwin M. Zaid; Jörn Dunkel; Julia M. Yeomans

2010-09-20T23:59:59.000Z

435

Multiscale framework for predicting the coupling between deformation and fluid diffusion in porous rocks  

SciTech Connect

In this project, a predictive multiscale framework will be developed to simulate the strong coupling between solid deformations and fluid diffusion in porous rocks. We intend to improve macroscale modeling by incorporating fundamental physical modeling at the microscale in a computationally efficient way. This is an essential step toward further developments in multiphysics modeling, linking hydraulic, thermal, chemical, and geomechanical processes. This research will focus on areas where severe deformations are observed, such as deformation bands, where classical phenomenology breaks down. Multiscale geometric complexities and key geomechanical and hydraulic attributes of deformation bands (e.g., grain sliding and crushing, and pore collapse, causing interstitial fluid expulsion under saturated conditions), can significantly affect the constitutive response of the skeleton and the intrinsic permeability. Discrete mechanics (DEM) and the lattice Boltzmann method (LBM) will be used to probe the microstructure---under the current state---to extract the evolution of macroscopic constitutive parameters and the permeability tensor. These evolving macroscopic constitutive parameters are then directly used in continuum scale predictions using the finite element method (FEM) accounting for the coupled solid deformation and fluid diffusion. A particularly valuable aspect of this research is the thorough quantitative verification and validation program at different scales. The multiscale homogenization framework will be validated using X-ray computed tomography and 3D digital image correlation in situ at the Advanced Photon Source in Argonne National Laboratories. Also, the hierarchical computations at the specimen level will be validated using the aforementioned techniques in samples of sandstone undergoing deformation bands.

Josà © E. Andrade; John W. Rudnicki

2012-12-14T23:59:59.000Z

436

Retention/Diffusivity Studies in Free-Surface Flowing Liquid Lithium  

DOE Green Energy (OSTI)

FLIRE was designed to measure the hydrogen and helium retention and diffusivity in a flowing stream of liquid lithium, and it has accomplished these goals. Retention coefficients for helium in the flowing liquid stream were 0.1-2% for flow speeds of 44 cm/s and implantation energies between 500 and 2000 eV. The energy dependence of retention is linear for the energy range considered, as expected, and the dependence of retention on flow velocity fits the expected square-root of flow speed dependence. Estimates of the helium diffusion coefficient in the flowing lithium stream were {approx} 4 x 10{sup -7} cm{sup 2}/s, and are independent of implantation energy. This value is much lower than expected, which could be due to several factors, such as mixing, bubble formation or surface film formation. In the case of hydrogen, long term retention and release mechanisms are of greatest importance, since this relates to tritium inventory in flowing lithium PFCs for fusion applications. The amount of hydride formation was measured for flowing lithium exposed to neutral deuterium gas. Thermal desorption spectroscopy (TDS) measurements indicate that the hydride concentration was between 0.1 and 0.2% over a wide range of pressures (6.5 x 10{sup -5} to 1 Torr). This result implies that the deuterium absorption rate is limited by the surface dissociation rate, since deuterium (hydrogen/tritium) is absorbed in its atomic form, not its molecular form.

R.A. Stubbers; G.H. Miley; M. Nieto; W. Olczak; D.N. Ruzic; A. Hassanein

2004-12-14T23:59:59.000Z

437

THE INFLUENCE OF DEUTERATION AND TURBULENT DIFFUSION ON THE OBSERVED D/H RATIO  

Science Conference Proceedings (OSTI)

The influence of turbulent mixing on the chemistry of the interstellar medium (ISM) has so far received little attention. Previous studies of this effect have suggested that it might play an important role in mixing the various phases of the ISM. In this paper, we examine the potential effects of turbulent diffusion on the deuterium chemistry within molecular clouds. We find that such mixing acts to reduce the efficiency of deuteration in these clouds by increasing the ionization fraction and reducing freeze-out of heavy molecules. This leads to lower abundances for many deuterated species. We also examine the influence of turbulent mixing on the transition from atomic hydrogen to H{sub 2} and from atomic deuterium to HD near the cloud edge. We find that including turbulent diffusion in our models serves to push these transitions deeper into the cloud and helps maintain a higher atomic fraction throughout the cloud envelope. Based on these findings, we propose a new process to account for the significant scatter in the observed atomic D/H ratio for galactic sightlines extending beyond the Local Bubble. Although several mechanisms have been put forward to explain this scatter, they are unable to fully account for the range in D/H values. We suggest a scenario in which turbulent mixing of atomic and molecular gas at the edges of molecular clouds causes the observed atomic D/H ratio to vary by a factor of {approx}2.

Bell, T. A.; Phillips, T. G.; Lis, D. C. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Willacy, K.; Allen, M., E-mail: tab@caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

2011-04-10T23:59:59.000Z

438

ELEVATED TEMPERATURE DIFFUSION BONDING OF TUNGSTEN TO TUNGSTEN UNDER PRESSURE  

DOE Green Energy (OSTI)

Solid state diffusion bonding of tungsten to tungsten was investigated at temperatures ranging from 1700 to 2600 nif- C, under surface contact pressures up to 3000 psi, while under high vacuum or hydrogen atmosphere. Various interface coatings were employed to promote diffusion, including graphite, oxide, and metai slurries, electro-plates, direct surface oxidation, and Mo-W deposits from carbonyl decompositions. Thorough metallurgical bonding was achieved, particularly with the latter two surface coatings, after 2 hours at 2350 nif- C in H/sub 2/ under 1400 psi. Corresponding tensile strengths of 30000 psi were obtained. (auth)

Batista, R.I.; Hanks, G.S.; Murphy, D.J.

1962-01-01T23:59:59.000Z

439

Classical diffusive dynamics for the quasiperiodic kicked rotor  

E-Print Network (OSTI)

We study the classical dynamics of a quasiperiodic kicked rotor, whose quantum counterpart is known to be an equivalent of the 3D Anderson model. Using this correspondence allowed for a recent experimental observation of the Anderson transition with atomic matter waves. In such a context, it is particularly important to assert the chaotic character of the classical dynamics of this system. We show here that it is a 3D anisotropic diffusion. Our simple analytical predictions for the associated diffusion tensor are found in good agreement with the results of numerical simulations.

Gabriel Lemarié; Dominique Delande; Jean Claude Garreau; Pascal Szriftgiser

2010-03-23T23:59:59.000Z

440

Anomalous diffusion in the resonant quantum kicked rotor  

E-Print Network (OSTI)

We study the resonances of the quantum kicked rotor subjected to an excitation that follows a deterministic time-dependent prescription. For the primary resonances we find an analytical relation between the long-time behavior of the standard deviation and the external kick strength. For the secondary resonances we obtain essentially the same result numerically. Selecting the time sequence of the kick allows to obtain a variety of asymptotic wave-function spreadings: super-ballistic, ballistic, sub-ballistic, diffusive, sub-diffusive and localized.

A. Romanelli; Guzmán Hernández

2009-08-31T23:59:59.000Z

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


441

Diffusion Bonding Aluminium Alloys and Composites: New Approaches and Modelling  

E-Print Network (OSTI)

certain materials. Some oxide films either dissolve in the bulk of the metal or decompose at the bonding temperature (e.g. those of many steels, copper, titanium, tantalum and zirconium), and so metal-to-metal contact can be readily established... to the diffusion bonding of all materials. Diffusion bonding of most metals is conducted under a vacuum of 10-3-10-5 mbar or in an inert atmosphere (normally dry nitrogen, argon or helium) in order to reduce detrimental oxidation of the faying surfaces. Bonding...

Shirzadi Ghoshouni, Amir Abbas

1998-07-10T23:59:59.000Z

442

Discrepancies in Shortwave Diffuse Measured and Modeled Irradiances in Antarctica  

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

Discrepancies in Shortwave Diffuse Measured and Discrepancies in Shortwave Diffuse Measured and Modeled Irradiances in Antarctica A. Payton, P. Ricchiazzi, and C. Gautier University of California Santa Barbara, California D. Lubin Scripps Scripps Institution of Oceanography La Jolla, California Introduction Measurements of clear-sky shortwave (SW) radiation at the surface show discrepancies between measurements and model simulations, but only for certain measurements across time and space. Most of the observations entail broadband measurements. A spectral and spatial analysis of the occurrence of this discrepancy may lend insight into the responsible processes. Langley calibrated multi-filter rotating shadowband radiometer (MFRSR) measurements collected at the Antarctic coastline reveal significant

443

Conservation Laws of Multidimensional Diffusion-Convection Equations  

E-Print Network (OSTI)

All possible linearly independent local conservation laws for $n$-dimensional diffusion--convection equations $u_t=(A(u))_{ii}+(B^i(u))_i$ were constructed using the direct method and the composite variational principle. Application of the method of classification of conservation laws with respect to the group of point transformations [R.O. Popovych, N.M. Ivanova, J. Math. Phys., 2005, V.46, 043502 (math-ph/0407008)] allows us to formulate the result in explicit closed form. Action of the symmetry groups on the conservation laws of diffusion equations is investigated and generating sets of conservation laws are constructed.

Nataliya M. Ivanova

2006-04-24T23:59:59.000Z

444

Jar mechanism energizer  

Science Conference Proceedings (OSTI)

An energizer for use with a jar mechanism incorporated on inner and outer bodies in a well string to assist the jar mechanism in delivering an upward jar to the well string includes longitudinally spaced seal means between the inner and outer bodies forming a chamber for receiving a compressible medium therein. A differential area formed on one of the bodies within the compressible medium chamber compresses a compressible medium in the chamber as the well string is lowered to position the inner and outer bodies so that the jar mechanism is actuated to restrain relative longitudinal movement between the inner and outer bodies to an extended position whereby a pull force may be developed in the well string in one of the bodies. The differential area is responsive to the compressed gas in the chamber to assist the jar mechanism in applying an upward jarring force when the jar mechanism, in response to a predetermined pull force in the well string, releases the bodies for contact to apply an upward force to the well string.

Webb, D. D.; Anderson, E. A.

1985-10-08T23:59:59.000Z

445

Jar mechanism accelerator  

SciTech Connect

This patent describes an accelerator for use with a jar mechanism in a well pipe string to enhance the jarring impact delivered to a stuck object wherein the jar mechanism includes inner and outer members for connection, respectively, between the well pipe string the stuck object. The jar mechanism members are constructed to (1) restrict relative longitudinal movement therebetween to build up energy in the well pipe string and accelerator and then (2) to release the jar mechanism members for unrestrained, free relative longitudinal movement therebetween to engage jarring surfaces on the jar mechanism members for delivering a jarring impact to the stuck object. The accelerator includes: inner and outer telescopically connected members relatively movable longitudinally to accumulate energy in the accelerator; the inner and outer accelerator members each having means for connecting the accelerator in the well pipe string; means associated with the inner and outer members for initially accomodating a predetermined minimum length of unrestrained, free relative longitudinal movement between the inner and outer accelerator members.

Anderson, E.A.; Webb, D.D.

1989-07-11T23:59:59.000Z

446

High Co2 Emissions Through Porous Media- Transport Mechanisms And  

Open Energy Info (EERE)

Co2 Emissions Through Porous Media- Transport Mechanisms And Co2 Emissions Through Porous Media- Transport Mechanisms And Implications For Flux Measurement And Fractionation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: High Co2 Emissions Through Porous Media- Transport Mechanisms And Implications For Flux Measurement And Fractionation Details Activities (1) Areas (1) Regions (0) Abstract: Diffuse emissions of CO2 are known to be large around some volcanoes and hydrothermal areas. Accumulation-chamber measurements of CO2 flux are increasingly used to estimate the total magmatic or metamorphic CO2 released from such areas. To assess the performance of accumulation chamber systems at fluxes one to three orders of magnitude higher than normally encountered in soil respiration studies, a test system was

447

A UNIFIED PARTICLE DIFFUSION THEORY FOR CROSS-FIELD SCATTERING: SUBDIFFUSION, RECOVERY OF DIFFUSION, AND DIFFUSION IN THREE-DIMENSIONAL TURBULENCE  

Science Conference Proceedings (OSTI)

A new nonlinear theory for cosmic-ray scattering across the mean magnetic field is derived. This theory can be applied for arbitrary turbulence geometry. Previous theories such as the extended nonlinear guiding center theory are deduced as special limits. Furthermore, the new theory can explain subdiffusive transport for slab turbulence and the recovery of diffusion for slab/two-dimensional and three-dimensional turbulence. The nonlinear standard theory for field line wandering can be obtained as a special limit.

Shalchi, A., E-mail: andreasm4@yahoo.co [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada)

2010-09-10T23:59:59.000Z

448

In situ bioremediation: A network model of diffusion and flow in granular porous media  

SciTech Connect

In situ bioremediation is a potentially expedient, permanent and cost- effective means of waste site decontamination. However, permeability reductions due to the transport and deposition of native fines or due to excessive microorganism populations may severely inhibit the injection of supplemental oxygen in the contamination zone. To help understand this phenomenon, we have developed a micro-mechanical network model of flow, diffusion and particle transport in granular porous materials. The model differs from most similar models in that the network is defined by particle positions in a numerically-generated particle array. The model is thus widely applicable to computing effective transport properties for both ordered and realistic random porous media. A laboratory-scale apparatus to measure permeability reductions has also been designed, built and tested.

Griffiths, S.K.; Nilson, R.H.; Bradshaw, R.W.

1997-04-01T23:59:59.000Z

449

Investigation of the Gas-Diffusion-Electrode Used as Lithium/Air Cathode in Non-aqueous Electrolyte and the Importance of Carbon Material Porosity  

SciTech Connect

The gas-diffusion-electrode used in a Li-air cell has been studied in a unique homemade electrochemical cell. Three major obstacles for the development of a feasible Li-air system were discussed with a focus on the development of a functional gas-diffusion-electrode in non-aqueous electrolytes and the way of avoiding the passivation of gas-diffusion-electrodes caused by the deposition of the reduction products. It is the first time that the importance of establishing the 3-phase electrochemical interface in non-aqueous electrolyte is demonstrated by creating air-diffusion paths and an air saturated portion for an air cathode. A model mechanism of electrode passivation by the reaction products was also proposed. Lithium oxides formed during O{sub 2} reduction tend to block small pores, preventing them from further utilization in the electrochemical reaction. On the other hand, lithium oxides would accumulate inside the large pores during the reduction until the density of oxides becomes high enough to choke-off the mass transfer. Carbon materials with a high surface area associated with larger pores should be selected to make the gas-diffusion-electrode for Li-air battery. For the first time, a near linear relationship between the capacity of GDE in a non-aqueous electrolyte and the average pore diameter was demonstrated, which could be used to estimate the capacity of the GDE quantitatively.

Qu, D.; Yang, X.; Tran, C.

2010-04-02T23:59:59.000Z

450

Experimental unsaturated soil mechanics  

E-Print Network (OSTI)

In this general report, experimental systems and procedures of investigating the hydro-mechanical behaviour of unsaturated soils are presented. The water retention properties of unsaturated soils are commented and linked to various physical parameters and properties of the soils. Techniques of controlling suction are described together with their adaptation in various laboratory testing devices. Some typical features of the mechanical behaviour of unsaturated soils are presented within an elasto-plastic framework. An attempt to describe the numerous and significant recent advances in the investigation of the behaviour of unsaturated soils, including the contributions to this Conference, is proposed.

Delage, Pierre

2008-01-01T23:59:59.000Z

451

Breakthrough in fracture mechanics  

SciTech Connect

Fracture mechanics, the science of calculating material characteristics, stress, and flaws in plant equipment to evaluate structural integrity, usually spares the owners of nuclear power plants unnecessary expense. Instead of replacing equipment prematurely or waiting for costly, unscheduled materials failures that can take months to repair and cost thousands of dollars a day for replacement power, utilities use fracture mechanics techniques to carefully consider their options. If analyses show repair is unnecessary, plant operation can confidently be resumed. If repair is required, it can either be done immediately or, if deferrable, be scheduled for a later, more convenient outage.

Lihach, N.

1981-05-01T23:59:59.000Z

452

Cesium incorporation and diffusion in cancrinite, sodalite, zeolite, and allophane  

E-Print Network (OSTI)

Department of EnergyÃ?s Hanford site, high level nuclear waste has leaked from underground storage tanks; Allophane; Intraparticle diffusion 1. Introduction At the Hanford site, a former plutonium production and channels to balance the charge of the structural frame- works. Cancrinite contains small e-cages made

Flury, Markus

453

Low Mach Number Fluctuating Hydrodynamics of Diffusively Mixing Fluids  

E-Print Network (OSTI)

We formulate low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different density and transport coefficients. These equations eliminate the fast isentropic fluctuations in pressure associated with the propagation of sound waves by replacing the equation of state with a local thermodynamic constraint. We demonstrate that the low Mach number model preserves the spatio-temporal spectrum of the slower diffusive fluctuations. We develop a strictly conservative finite-volume spatial discretization of the low Mach number fluctuating equations in both two and three dimensions. We construct several explicit Runge-Kutta temporal integrators that strictly maintain the equation of state constraint. The resulting spatio-temporal discretization is second-order accurate deterministically and maintains fluctuation-dissipation balance in the linearized stochastic equations. We apply our algorithms to model the development of giant concentration fluctuations in the presence of concentration gradients, and investigate the validity of common simplifications neglecting the spatial non-homogeneity of density and transport properties. We perform simulations of diffusive mixing of two fluids of different densities in two dimensions and compare the results of low Mach number continuum simulations to hard-disk molecular dynamics simulations. Excellent agreement is observed between the particle and continuum simulations of giant fluctuations during time-dependent diffusive mixing.

A. Donev; A. J. Nonaka; Y. Sun; T. G. Fai; A. L. Garcia; J. B. Bell

2012-12-11T23:59:59.000Z

454

A New Look at Eddy Diffusivity as a Mixing Diagnostic  

Science Conference Proceedings (OSTI)

It is shown that the Eulerian-mean advection–diffusion equation for a passive tracer, q, can be cast, uniquely and exactly into where the bar denotes an arbitrary Eulerian average (spatial, temporal, or both), v* is a nondivergent effective ...

Noboru Nakamura

2001-12-01T23:59:59.000Z

455

Determination of Isopycnal Diffusivity in the Sargasso Sea  

Science Conference Proceedings (OSTI)

Using observed space and time derivatives of the distribution of 3He, tritium and tritium–helium age in the Sargasso Sea, and the tritium–helium age equation, the isopycnal eddy diffusivity is estimated to be 1840 ± SW 440 m2s?1 within the main ...

W. J. Jenkins

1991-07-01T23:59:59.000Z

456

From transport to diffusion through a space asymptotic approach  

Science Conference Proceedings (OSTI)

The spatially asymptotic theory is a useful approach to the neutron transport model for nuclear reactor physics applications. For steady-state problems the transport equation is taken in an infinite medium and it is treated by the Fourier transform. ... Keywords: Neutron diffusion, Neutron transport, Space asymptotic theory

S. Dulla; S. Canepa; P. Ravetto

2010-07-01T23:59:59.000Z

457

Collisional diffusion in toroidal plasmas with elongation and triangularity  

Science Conference Proceedings (OSTI)

Collisional diffusion is analyzed for plasma tokamaks with different ellipticities and triangularities. Improved nonlinear equations for the families of magnetic surfaces are used here. Dimensionless average velocities are calculated as a function of the inductive electric field, elongation, triangularity, and Shafranov shift. Confinement has been found to depend significantly on triangularity.

Martin, P.; Castro, E.; Haines, M. G. [Departamento de Fisica, Universidad Simon Bolivar, Apartado. 89000, Caracas 1080A (Venezuela); Blackett Laboratory, Imperial College, London SW7 2BZ, England (United Kingdom)

2007-05-15T23:59:59.000Z

458

Microstructural Evolution and interfacial motion in systems with diffusion barriers  

SciTech Connect

This research program was designed to model and simulate phase transformations in systems containing diffusion barriers. The modeling work included mass flow, phase formation, and microstructural evolution in interdiffusing systems. Simulation work was done by developing Cahn-Hilliard and phase field equations governing both the temporal and spatial evolution of the composition and deformation fields and other important phase variables.

Perry H. Leo

2009-03-05T23:59:59.000Z

459

Diffuse gamma-ray emission: Galactic and extragalactic  

E-Print Network (OSTI)

Here is reviewed our current understanding of Galactic and extragalactic diffuse gamma-ray emission. The spectrum of the extragalactic gamma-ray background above 30 MeV can be well described by a power law with photon index s=2.1. In the 2-10 MeV range a preliminary analysis of COMPTEL data indicates a lower intensity than previously found, with no evidence for an MeV bump. Most of the models of a truly diffuse background seem to be in conflict with the observed spectrum. Though AGN are the most likely input from discrete sources, two independent attempts to model the high energy background as the superposition of unresolved AGN indicate that AGN underproduce the observed intensity. Therefore the origin of the extragalactic gamma-ray background is still unknown. The Galactic diffuse gamma-ray continuum is more intense than expected both at very low energies (energies (> 1 GeV). The published models for these excesses all involve cosmic ray electron interactions. While the low energy excess may have something to do with in-situ acceleration of electrons, the excess at high energies may be understood if the sources of cosmic ray electrons are discrete. The measured energy spectrum of the diffuse Galactic gamma-ray continuum radiation thus may provide new insights into the acceleration of cosmic rays.

Martin Pohl

1998-07-27T23:59:59.000Z

460

Multiple copy distillation and purification of phase diffused squeezed states  

E-Print Network (OSTI)

We provide a detailed theoretical analysis of multiple copy purification and distillation protocols for phase diffused squeezed states of light. The standard iterative distillation protocol is generalized to a collective purification of an arbitrary number of N copies. We also derive a semi-analytical expression for the asymptotic limit of the iterative distillation and purification protocol and discuss its properties.

Petr Marek; Jaromir Fiurasek; Boris Hage; Alexander Franzen; James DiGugliemo; Roman Schnabel

2007-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "vapor-phase diffusion mechanisms" 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

E-Commerce Readiness and Diffusion: The Case of Brazil  

Science Conference Proceedings (OSTI)

In Brazil, a poor telecommunication infrastructure was considered an important barrier for e-business diffusion. However, from 1998, when the telecom system was privatized, to 2000, telecom investments boosted to an average of 1.36% of GNP a year, a ...

Paulo Bastos Tigre

2003-12-01T23:59:59.000Z

462

STATISTICAL MECHANICS AND FIELD THEORY  

E-Print Network (OSTI)

1. L. 1. Schiff, Quantum Mechanics, third edition (McGraw-two-dimensional quantum mechanics problem vith a potential,Theory Methods to Statistical Mechanics Chapter I The Use of

Samuel, S.A.

2010-01-01T23:59:59.000Z

463

DEPARTMENT OF MECHANICAL ENGINEERING  

E-Print Network (OSTI)

the Chair Advanced Power Systems Research Group Engineering Education Innovation Research Group Mechanics of MultiScale Materials Research Group MultiScale Systems and Sensors Research Group Space Systems Research Group Sustainable Manufacturing and Design Research Group Faculty Profiles Michigan

Endres. William J.

464

MECHANICAL TEST LAB CAPABILITIES  

E-Print Network (OSTI)

MECHANICAL TEST LAB CAPABILITIES · Static and cyclic testing (ASTM and non-standard) · Impact drop testing · Slow-cycle fatigue testing · High temperature testing to 2500°F · ASTM/ Boeing/ SACMA standard testing · Ability to design and fabricate non-standard test fixtures and perform non-standard tests

465

SAFETY-MECHANICAL STANDARDS  

SciTech Connect

Hanford Atomic Production Operation specification guides and standards for plumbing, chemical ngineering, mechanical engineering, sanitary engineering, exhaust systems, steam engineering, stainless steel, dry boxes, thermal insulation, filtration, and materials testing are presented. Details of this manual are given in TID-4100 (Suppl.). (N.W.R.)

1964-10-31T23:59:59.000Z

466

Higgs Mechanism for Gravitons  

E-Print Network (OSTI)

Just like the vector gauge bosons in the gauge theories, it is now known that gravitons acquire mass in the process of spontaneous symmetry breaking of diffeomorphisms through the condensation of scalar fields. The point is that we should find the gravitational Higgs mechanism such that it results in massive gravity in a flat Minkowski space-time without non-unitary propagating modes. This is usually achieved by including higher-derivative terms in scalars and tuning the cosmological constant to be a negative value in a proper way. Recently, a similar but different gravitational Higgs mechanism has been advocated by Chamseddine and Mukhanov where one can relax the negative cosmological constant to zero or positive one. In this work, we investigate why the non-unitary ghost mode decouples from physical Hilbert space in a general space-time dimension. Moreover, we generalize the model to possess an arbitrary potential and clarify under what conditions the general model exhibits the gravitational Higgs mechanism. By searching for solutions to the conditions, we arrive at two classes of potentials exhibiting gravitational Higgs mechanism. One class includes the model by Chamseddine and Mukhanov in a specific case while the other is completely a new model.

Ichiro Oda

2010-03-07T23:59:59.000Z

467

Fractals and quantum mechanics  

Science Conference Proceedings (OSTI)

A new application of a fractal concept to quantum physics has been developed. The fractional path integrals over the paths of the Lévy flights are defined. It is shown that if fractality of the Brownian trajectories leads to standard quantum mechanics

Nick Laskin

2000-01-01T23:59:59.000Z

468

Quantum Mechanics and Black Holes  

E-Print Network (OSTI)

This paper discusses the existence of black holes from the foundations of quantum mechanics. It is found that quantum mechanics rule out a possible gravitational collapse.

Jose N. Pecina-Cruz

2005-11-11T23:59:59.000Z

469

Scaling dependence on time and distance in nonlinear fractional diffusion equations and possible applications to the water transport in soils  

E-Print Network (OSTI)

Recently, fractional derivatives have been employed to analyze various systems in engineering, physics, finance and hidrology. For instance, they have been used to investigate anomalous diffusion processes which are present in different physical systems like: amorphous semicondutors, polymers, composite heterogeneous films and porous media. They have also been used to calculate the heat load intensity change in blast furnace walls, to solve problems of control theory \\ and dynamic problems of linear and nonlinear hereditary mechanics of solids. In this work, we investigate the scaling properties related to the nonlinear fractional diffusion equations and indicate the possibilities to the applications of these equations to simulate the water transport in unsaturated soils. Usually, the water transport in soils with anomalous diffusion, the dependence of concentration on time and distance may be expressed in term of a single variable given by $\\lambda _{q}=x/t^{q}.$ In particular, for $q=1/2$ the systems obey Fick's law and Richards' equation for water transport. We show that a generalization of Richards' equation via fractional approach can incorporate the above property.

Kwok Sau Fa; E. K. Lenzi

2004-04-15T23:59:59.000Z

470

Mechanisms in the size segregation of a binary granular mixture  

E-Print Network (OSTI)

A granular mixture of particles of two sizes that is shaken vertically will in most cases segregate. If the larger particles accumulate at the top of the sample, this is called the Brazil-nut effect (BNE); if they accumulate at the bottom, the reverse Brazil-nut effect (RBNE). While this process is of great industrial importance in the handling of bulk solids, it is not well understood. In recent years ten different mechanisms have been suggested to explain when each type of segregation is observed. However, the dependence of the mechanisms on driving conditions and material parameters and hence their relative importance is largely unknown. In this paper we present experiments and simulations where both types of particles are made from the same material and shaken under low air pressure, which reduces the number of mechanisms to be considered to seven. We observe both BNE and RBNE by varying systematically the driving frequency and amplitude, diameter ratio, ratio of total volume of small to large particles, and overall sample volume. All our results can be explained by a combination of three mechanisms: a geometrical mechanism called void filling, transport of particles in sidewall-driven convection rolls, and thermal diffusion, a mechanism predicted by kinetic theory.

M. Schröter; S. Ulrich; J. Kreft; J. B. Swift; H. L. Swinney

2006-01-10T23:59:59.000Z

471

Mechanical Operations and Maintenance  

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

Holiday Work Status Holiday Work Status Mechanical Operations & Maintenance Group APS Storage Ring Magnets The Advanced Photon Source (APS) at the Argonne National Laboratory is a national synchrotron-radiation research facility funded by the U.S. Department of Energy. Using high-brilliance x-ray beams from the APS, an international community of scientists conducts forefront basic and applied research in the fields of material science, biological science, physics, chemistry, environmental, geophysical and planetary science. The 1.1-km circumference APS facility consists of several major subsystems including magnets, vacuum chambers, radio-frequency cavities, diagnostics instrumentation, x-ray absorbers and apertures, and cooling water subsystems. Each of these subsystems contains hundreds of mechanical

472

NUT SCREW MECHANISMS  

DOE Patents (OSTI)

A reactor control mechanism is described wherein the control is achieved by the partial or total withdrawal of the fissile material which is in the form of a fuel rod. The fuel rod is designed to be raised and lowered from the reactor core area by means of two concentric ball nut and screw assemblies that may telescope one within the other. These screw mechanisms are connected through a magnetic clutch to a speed reduction gear and an accurately controllable prime motive source. With the clutch energized, the fuel rod may be moved into the reactor core area, and fine adjustments may be made through the reduction gearing. However, in the event of a power failure or an emergency signal, the magnetic clutch will become deenergized, and the fuel rod will drop out of the core area by the force of gravity, thus shutting down the operation of the reactor.

Glass, J.A.F.

1958-07-01T23:59:59.000Z

473

Testing quantum mechanics  

E-Print Network (OSTI)

As experiments continue to push the quantum-classical boundary to include increasingly complex dynamical systems, the interpretation of experimental data becomes more and more challenging: when the observations are noisy, indirect, and limited, how can we be sure that we are observing quantum behavior? This tutorial highlights some of the difficulties in such experimental tests of quantum mechanics, using optomechanics as the central example, and discusses how the issues can be resolved using techniques from statistics and insights from quantum information theory.

Mankei Tsang

2013-06-12T23:59:59.000Z

474

TRANSIENT QUANTUM MECHANICAL PROCESSES  

SciTech Connect

Our principal objective has centered on the development of sophisticated computational techniques to solve the time-dependent Schroedinger equation that governs the evolution of quantum mechanical systems. We have perfected two complementary methods, discrete variable representation and real space product formula, that show great promise in solving these complicated temporal problems. We have applied these methods to the interaction of laser light with molecules with the intent of not only investigating the basic mechanisms but also devising schemes for actually controlling the outcome of microscopic processes. Lasers now exist that produce pulses of such short duration as to probe a molecular process many times within its characteristic period--allowing the actual observation of an evolving quantum mechanical system. We have studied the potassium dimer as an example and found agreement with experimental changes in the intermediate state populations as a function of laser frequency--a simple control prescription. We have also employed elaborate quantum chemistry programs to improve the accuracy of basic input such as bound-bound and bound-free coupling moments. These techniques have far-ranging applicability; for example, to trapped quantum systems at very low temperatures such as Bose-Einstein condensates.

L. COLLINS; J. KRESS; R. WALKER

1999-07-01T23:59:59.000Z

475

Mechanical Compression Heat Pumps  

E-Print Network (OSTI)

Mechanical compression heat pumping is not new in industrial applications. In fact, industry history suggests that the theoretical concept was developed before 1825. Heat pump manufacturers gained the support of consultants and end-users when the energy crisis hit this country in 1973. That interest, today, has been dampened because there is a current abundance of the basic sources of industrial energy (namely oil and natural gas). Meanwhile, Mycom used the window of the current opportunities to develop, design and test compressors built to meet the needs of the mechanically demanding industrial heat pump applications which often require high compression ratios and temperatures in excess of 200 degrees F. This paper will review the theoretical foundation for heat pumps and present the mechanical and thermal requirements of the compressors which constitute the heart and soul of the system. It will also provide a quick survey of the available types of compressors for heat pumping and some of the industrial processes where simultaneous heating and cooling proceed along parallel demand paths. The case history will examine the system flexibility and the economic advantages realized in a barley malting process.

Apaloo, T. L.; Kawamura, K.; Matsuda, J.

1986-06-01T23:59:59.000Z

476

Measurement of Mechanical and Electrical  

Science Conference Proceedings (OSTI)

Measurement of Mechanical and Electrical Properties of Ultra-thin Insulating Films. NIST Nanomechanical Properties Group ...

2012-10-01T23:59:59.000Z

477

Fundamental Interaction Mechanisms of Engineered ...  

Science Conference Proceedings (OSTI)

Fundamental Interaction Mechanisms of Engineered Nanomaterials with DNA. Summary: We utilized isotope-dilution liquid ...

2012-10-01T23:59:59.000Z

478

Understanding Bohmian mechanics: A dialogue  

E-Print Network (OSTI)

This paper is an introduction to the ideas of Bohmian mechanics, an interpretation of quantum mechanics in which the observer plays no fundamental role. Bohmian mechanics describes, instead of probabilities of measurement results, objective microscopic events. In recent years, Bohmian mechanics has attracted increasing attention by researchers. The form of a dialogue allows me to address questions about the Bohmian view that often arise.

Roderich Tumulka

2004-08-18T23:59:59.000Z

479

Bohmian Mechanics Detlef Durr1  

E-Print Network (OSTI)

Bohmian Mechanics Detlef D¨urr1 , Sheldon Goldstein2 , Roderich Tumulka3 , and Nino Zangh`i4, Via Dodecaneso 33, 16146 Genova, Italy. E-mail: zanghi@ge.infn.it #12;Bohmian mechanics is a theory mechanics, observers see the same statistics for experimental results as predicted by quantum mechanics

Goldstein, Sheldon

480

The diffusion of H{sub 2} in hexagonal ice at low temperature  

DOE Green Energy (OSTI)

We have studied the diffusive motion of hydrogen in D{sub 2}O ice by measuring the quasielastic scattering and estimating the single particle diffusion coefficient of hydrogen.

Strauss, H.L.; Chen, Z. [Univ. of California, Berkeley, CA (United States); Loong, C.K. [Argonne National Lab., IL (United States)

1996-02-01T23:59:59.000Z

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


481

SEX DIFFERENCES IN THE HUMAN CONNECTOME: 4-TESLA HIGH ANGULAR RESOLUTION DIFFUSION IMAGING (HARDI)  

E-Print Network (OSTI)

SEX DIFFERENCES IN THE HUMAN CONNECTOME: 4-TESLA HIGH ANGULAR RESOLUTION DIFFUSION IMAGING (HARDI diffusion imaging at 4 Tesla, we scanned 234 young adult twins and siblings (mean age: 23.4 ± 2.0 SD years

Thompson, Paul

482

Ab initio screening of lithium diffusion rates in transition metal oxide cathodes for lithium ion batteries  

E-Print Network (OSTI)

A screening metric for diffusion limitations in lithium ion battery cathodes is derived using transition state theory and common materials properties. The metric relies on net activation barrier for lithium diffusion. ...

Moore, Charles J. (Charles Jacob)

2012-01-01T23:59:59.000Z

483

A Technique for Mapping the Distribution of Diffuse Solar Radiation over the Sky Hemisphere  

Science Conference Proceedings (OSTI)

A technique to map the distribution of diffuse solar radiation over the sky hemisphere is described. The method is based on an analysis of all-sky, visible photographs and concurrent actinometric measurements of diffuse solar radiance. The ...

L. J. Bruce McArthur; John E. Hay

1981-04-01T23:59:59.000Z

484

Signatures of Doubly Diffusive Convection and Turbulence in an Intrusive Regime  

Science Conference Proceedings (OSTI)

Doubly diffusive convection and turbulence were measured from a submarine in a region where the mean gradients do not support doubly diffusive processes but intrusions provide favorable sites. The stability of the submarine-mounted CTD system ...

Thomas R. Osborn

1988-01-01T23:59:59.000Z

485

Effect of helium injection on diffusion dominated air ingress accidents in pebble bed reactors  

E-Print Network (OSTI)

The primary objective of this thesis was to validate the sustained counter air diffusion (SCAD) method at preventing natural circulation onset in diffusion dominated air ingress accidents. The analysis presented in this ...

Yurko, Joseph Paul

2010-01-01T23:59:59.000Z

486

Diffusion versus Nonlocal Models of Stratospheric Mixing, in Theory and Practice  

Science Conference Proceedings (OSTI)

In zonally averaged chemical transport models of the stratosphere, quasi-isentropic mixing is represented by diffusion in latitude. However, it is fairly certain that the real mixing is to some extent nonlocal, so that the diffusive ...

Adam H. Sobel

1999-08-01T23:59:59.000Z