Sample records for lng vapor dispersion

  1. Control of Vapor Dispersion and Pool Fire of Liquefied Natural Gas (LNG) with Expansion Foam 

    E-print Network

    Yun, Geun Woong

    2011-10-21

    in outdoor field tests. Thus, this research focused on experimental determination of the effect of expansion foam application on LNG vapor dispersion and pool fire. Specifically, for evaluating the use of foam to control the vapor hazard from spilled LNG...

  2. Study of the Effects of Obstacles in Liquefied Natural Gas (LNG) Vapor Dispersion using CFD Modeling

    E-print Network

    Ruiz Vasquez, Roberto

    2012-10-19

    The evaluation of the potential hazards related with the operation of an LNG terminal includes possible release scenarios with the consequent flammable vapor dispersion within the facility; therefore, it is important to know the behavior...

  3. Liquefied Natural Gas (LNG) Vapor Dispersion Modeling with Computational Fluid Dynamics Codes

    E-print Network

    Qi, Ruifeng

    2012-10-19

    Federal regulation 49 CFR 193 and standard NFPA 59A require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. For modeling purposes, the physical...

  4. Computational fluid dynamics for LNG vapor dispersion modeling: a key parameters study 

    E-print Network

    Cormier, Benjamin Rodolphe

    2009-05-15

    COMPUTATIONAL?FLUID?DYNAMICS?FOR?LNG?VAPOR?DISPERSION?MODELING:?A?KEY? PARAMETERS?STUDY? ? ? A?Dissertation? by? BENJAMIN?R.?CORMIER? ? ? Submitted?to?the?Office?of?Graduate?Studies?of? Texas?A&M?University? in...?partial?fulfillment?of?the?requirements?for?the?degree?of?? ? DOCTOR?OF?PHILOSOPHY? ? ? August?2008? ? ? Major?Subject:?Chemical?Engineering? ? ? COMPUTATIONAL?FLUID?DYNAMICS?FOR?LNG?VAPOR?DISPERSION?MODELING:?A?KEY? PARAMETERS?STUDY? ? ? A?Dissertation? by? BENJAMIN?R.?CORMIER? ? ? Submitted?to...

  5. Numerical simulations of LNG vapor dispersion in Brayton Fire Training Field tests with ANSYS CFX.

    PubMed

    Qi, Ruifeng; Ng, Dedy; Cormier, Benjamin R; Mannan, M Sam

    2010-11-15

    Federal safety regulations require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. One tool that is being developed in industry for exclusion zone determination and LNG vapor dispersion modeling is computational fluid dynamics (CFD). This paper uses the ANSYS CFX CFD code to model LNG vapor dispersion in the atmosphere. Discussed are important parameters that are essential inputs to the ANSYS CFX simulations, including the atmospheric conditions, LNG evaporation rate and pool area, turbulence in the source term, ground surface temperature and roughness height, and effects of obstacles. A sensitivity analysis was conducted to illustrate uncertainties in the simulation results arising from the mesh size and source term turbulence intensity. In addition, a set of medium-scale LNG spill tests were performed at the Brayton Fire Training Field to collect data for validating the ANSYS CFX prediction results. A comparison of test data with simulation results demonstrated that CFX was able to describe the dense gas behavior of LNG vapor cloud, and its prediction results of downwind gas concentrations close to ground level were in approximate agreement with the test data. PMID:20692092

  6. Application of Computational Fluid Dynamics in the Forced Dispersion Modeling of LNG Vapor Clouds

    E-print Network

    Kim, Byung-Kyu

    2013-05-31

    to investigate the forced dispersion of LNG vapor using upward-oriented full-cone spray nozzles. A Eulerian-Lagrangian approach was applied to simulate the energy and momentum exchange between the continuous (gas flow) and discrete (droplets) phases. Discussed...

  7. Application of Computational Fluid Dynamics in the Forced Dispersion Modeling of LNG Vapor Clouds 

    E-print Network

    Kim, Byung-Kyu

    2013-05-31

    of instruments and spray nozzle sites ..................................................... 31 Fig. 17. Crosswind vapor concentrations near ground at x = 90 m .................................. 32 Fig. 18. Experimental setup of Nov 2007 MKOPSC LNG spill test...

  8. Phenomenology and modeling of liquefied natural gas vapor dispersion

    Microsoft Academic Search

    D. L. Jr. Morgan; L. K. Morris; S. T. Chan; D. L. Ermak; T. G. McRae; R. T. Cederwall; R. P. Koopman; H. C. Jr. Goldwire; J. W. McClure; W. J. Hogan

    1984-01-01

    The purpose of the Burro series of spill experiments, in 1980, and one of the purposes of the Coyote series, in 1981, was to investigate the atmospheric dispersion of cold, dense LNG vapor resulting from an LNG spill onto water. The atmospheric dispersion of LNG vapor differs from that of passive pollutants. Analysis of the LNG vapor concentration data obtained

  9. Computational fluid dynamics for LNG vapor dispersion modeling: a key parameters study

    E-print Network

    Cormier, Benjamin Rodolphe

    2009-05-15

    The increased demand for liquefied natural gas (LNG) has led to the construction of several new LNG terminals in the United States (US) and around the world. To ensure the safety of the public, consequence modeling is used to estimate the exclusion...

  10. Liquefied Natural Gas (LNG) Vapor Dispersion Modeling with Computational Fluid Dynamics Codes 

    E-print Network

    Qi, Ruifeng

    2012-10-19

    .......................................... 12 1.3 LNG Hazards ................................................................................................... 12 1.3.1 Cryogenic Hazards .............................................................................. 13 ix Page 1... ....................................................................................... 18 1.5 LNG Hazard Consequence Modeling ............................................................. 19 1.5.1 Source Term Modeling ........................................................................ 19 1.5.1.1 Release Rate...

  11. LNG fire and vapor control system technologies

    SciTech Connect

    Konzek, G.J.; Yasutake, K.M.; Franklin, A.L.

    1982-06-01

    This report provides a review of fire and vapor control practices used in the liquefied natural gas (LNG) industry. Specific objectives of this effort were to summarize the state-of-the-art of LNG fire and vapor control; define representative LNG facilities and their associated fire and vapor control systems; and develop an approach for a quantitative effectiveness evaluation of LNG fire and vapor control systems. In this report a brief summary of LNG physical properties is given. This is followed by a discussion of basic fire and vapor control design philosophy and detailed reviews of fire and vapor control practices. The operating characteristics and typical applications and application limitations of leak detectors, fire detectors, dikes, coatings, closed circuit television, communication systems, dry chemicals, water, high expansion foam, carbon dioxide and halogenated hydrocarbons are described. Summary descriptions of a representative LNG peakshaving facility and import terminal are included in this report together with typical fire and vapor control systems and their locations in these types of facilities. This state-of-the-art review identifies large differences in the application of fire and vapor control systems throughout the LNG industry.

  12. Modeling of LNG Pool Spreading and Vaporization 

    E-print Network

    Basha, Omar 1988-

    2012-11-20

    In this work, a source term model for estimating the rate of spreading and vaporization of LNG on land and sea is introduced. The model takes into account the composition changes of the boiling mixture, the varying thermodynamic properties due...

  13. Regulatory application of wind tunnel models and complex mathematical models for simulating atmospheric dispersion of LNG vapor

    SciTech Connect

    Havens, J.; Spicer, T.; Walker, H. [Univ. of Arkansas, Fayettesville, AR (United States); Williams, T.

    1995-12-31

    An ultra-low-speed boundary layer wind tunnel has been constructed to provide experimental data sets for evaluating physical modeling methods for dense gas dispersion as well as FEM3A model predictions thereof. A low exit-momentum argon release into a nominal 20 cm/s wind flow over a smooth floor was designed to evaluate flow laminarization and provide measurements for comparison with FEM3A simulations of the release. Model-field similarity was also studied by using FEM3A to simulate a 100-to-1 scaled release. FEM3A predictions showed good agreement with previously reported wind tunnel concentration measurements and with measurements reported herein. Numerical simulation comparisons with wind tunnel scale measurements indicate vertical diffusion of the cloud to LFL (level) concentrations are dominated by molecular diffusion. Based on a field-scale prototype (100 to 1 of wind tunnel scale), FEM3A simulations of the experiments and the prototype release indicated that the vertical density stratification of the prototype cloud decreased vertical (turbulent) mixing below that which would be represented by the (wind tunnel) scaled molecular diffusivity; under such conditions, scaled-up wind tunnel predictions of the downwind extent to flammability-level gas concentrations would be underpredicted.

  14. Thermoelectric Power Conversion System Combined with LNG Vaporizer

    NASA Astrophysics Data System (ADS)

    Kambe, Mitsuru; Morita, Ryo; Omoto, Kazuyuki; Koji, Yasuhiro; Yoshida, Tatsuo; Noishiki, Koji

    A conceptual design of the thermoelectric power conversion system combined with open rack type LNG (liquefied natural gas) vaporizer to make use of cold heat of LNG is presented. The system performance analysis has been made based on the thermoelectric module performance data obtained at the cryogenic thermoelectric (CTE) test rig which could realize temperature and fluid dynamic condition of the open rack type LNG vaporizer. Conventional bismuth-telluride thermoelectric modules were tested, however, each module is encapsulated in the stainless steel container to achieve water proof. Electricity production cost evaluation of the system is also discussed.

  15. Phenomenology and modeling of liquefied natural gas vapor dispersion

    SciTech Connect

    Morgan, D.L. Jr.; Morris, L.K.; Chan, S.T.; Ermak, D.L.; McRae, T.G.; Cederwall, R.T.; Koopman, R.P.; Goldwire, H.C. Jr.; McClure, J.W.; Hogan, W.J.

    1984-04-01

    The purpose of the Burro series of spill experiments, in 1980, and one of the purposes of the Coyote series, in 1981, was to investigate the atmospheric dispersion of cold, dense LNG vapor resulting from an LNG spill onto water. The atmospheric dispersion of LNG vapor differs from that of passive pollutants. Analysis of the LNG vapor concentration data obtained in these spill experiments shows the effects of three physical phenomena that are particularly important in the dispersion of a dense cryogenic gas: (1) reduction in the turbulent mixing rate with air due to stable density stratification, (2) gravity flow of the cloud, and (3) ground heating of the cloud. These phenomena affect the maximum distance to the lower flammability limit (LFL), an important quantity which indicates the potential extent of an accidental combustion. The LFL distance also depends on the spill parameters and meteorological conditions. Our analysis indicates two additional phenomena, rapid-phase-transition (RPT) explosions and differential boiloff (producing increased ethane-to-methane ratio), that can lead to significant increases in the LFL distance. Both the SLAB and FEM3 computer codes incorporate mathematical models of the physics that governs the dispersion phenomena. SLAB is a one-dimensional, crosswind-averaged, conservation-equation model that calculates cloud height and width, and then uses these values to determine the crosswind distribution of LNG vapor concentration. FEM3 is a fully three-dimensional, conservation-equation model that can include variable terrain. Both models are time-dependent. In spill simulations, both give results that are in agreement with the experimental data for downwind extent and duration of the flammable region and other cloud features. In addition, FEM3 can simulate the complicated three-dimensional structure of a cloud where heavy-gas dispersion and terrain effects predominate. 24 refs., 48 figs., 6 tabs.

  16. The application of expansion foam on liquefied natural gas (LNG) to suppress LNG vapor and LNG pool fire thermal radiation 

    E-print Network

    Suardin, Jaffee Arizon

    2009-05-15

    effectiveness heavily depends on application rate, generator location, and LNG containment pit design. Complicated phenomena involved and previous studies have not completely filled the gaps increases the needs for LNG field experiments involving expansion foam...

  17. Modeling of LNG spills into trenches.

    PubMed

    Gavelli, Filippo; Chernovsky, Melissa K; Bullister, Edward; Kytomaa, Harri K

    2010-08-15

    A new method for the analysis of LNG spills into trenches has been developed to quantify vapor dispersion hazard distances. The model uses three steps to capture the behavior of an LNG spill into a trench. The first is to analytically calculate the evolving LNG flow, the second to calculate the vaporization rate along the trench, and the third is to calculate the dispersion of the vapors using a CFD model that has been validated for this application in the presence of complex geometries. This paper presents case studies that show the effect of wind perpendicular and parallel to the large aspect ratio trenches on vapor dispersion. The case studies also demonstrate the effect of complex terrain and obstacles such as vapor fences on vapor dispersion. The simulations show that wind direction relative to the trench has a significant effect on cloud shape, height, and maximum downwind distance. The addition of vapor fences to mitigate vapor dispersion hazards from an LNG spill into the LNG containment trench is shown to be effective. PMID:20447763

  18. Available power generation cycles to be coupled with the liquid natural gas (LNG) vaporization process in a Spanish LNG terminal

    Microsoft Academic Search

    E. Querol; B. Gonzalez-Regueral; J. García-Torrent; Alberto Ramos

    2011-01-01

    The boil off gas in Spanish LNG terminals is managed using recondensers. The electricity consumed by these terminals is bought in the Spanish wholesale market. Several power generating options using current available equipment and assuring the availability of the current terminal process have been analyzed thermoeconomically. A new combined cycle using a gas turbine and a pure NH3 Rankine cycle

  19. LNG measurement at Hopkinton plant

    Microsoft Academic Search

    R. C. Farmer; E. J. Cooney

    1974-01-01

    The Hopkinton LNG Corp. effectively uses turbine meters to measure the LNG vaporized from its LNG facility at Hopkinton, Mass., for peakshaving to serve customers of its parent companies, the New England Gas and Electric Association and Air Products and Chemicals, Inc., as well as NEGEA subsidiary Commonwealth Gas Co. The joint venture also includes the 500 million cf LNG

  20. Vaporization, dispersion, and radiant fluxes from LPG spills. Final report

    SciTech Connect

    Welker, J.R.; Cavin, W.D.

    1981-12-01

    Both burning and non-burning spills of LPG (primarily propane) were studied. Vaporization rates for propane spills on soil, concrete, insulating concrete, asphalt, sod, wood, and polymer foams were measured. Thermal conductivity, heat transfer coefficients, and steady state vaporization rates were determined. Vapor concentrations were measured downwind of open propane pools 25, 100, 400, and 1600 ft/sup 2/ in area. A Gaussian dispersion model modified for area sources provided a good correlation of measured concentrations. Emitted and incident radiant fluxes from propane fires were measured. Simplified flame radiation models were adequate for predicting radiant fluxes; the maximum effective flux emitted at the flame surface was about 50,000 Btu/h-ft/sup 2/. A few tests in which propane was sprayed into the air showed that at moderately high spray rates all the propane flashed to vapor or atomized; no liquid collected on the ground.

  1. 49 CFR 193.2059 - Flammable vapor-gas dispersion protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Flammable vapor-gas dispersion protection. 193.2059...CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS... § 193.2059 Flammable vapor-gas dispersion protection....

  2. 49 CFR 193.2059 - Flammable vapor-gas dispersion protection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Flammable vapor-gas dispersion protection. 193.2059...CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS... § 193.2059 Flammable vapor-gas dispersion protection....

  3. 49 CFR 193.2059 - Flammable vapor-gas dispersion protection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Flammable vapor-gas dispersion protection. 193.2059...CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS... § 193.2059 Flammable vapor-gas dispersion protection....

  4. 49 CFR 193.2059 - Flammable vapor-gas dispersion protection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Flammable vapor-gas dispersion protection. 193.2059...CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS... § 193.2059 Flammable vapor-gas dispersion protection....

  5. LNG SAFETY RESEARCH: FEM3A MODEL DEVELOPMENT

    SciTech Connect

    Jerry Havens; Iraj A. Salehi

    2005-05-10

    The objective of this report is to develop the FEM3A model for application to general scenarios involving dispersion problems with obstacles and terrain features of realistic complexity, and for very low wind speed, stable weather conditions as required for LNG vapor dispersion application specified in 49 CFR 193. The dispersion model DEGADIS specified in 49 CFR 193 is limited to application for dispersion over smooth, level terrain free of obstacles (such as buildings, tanks, or dikes). There is a need for a dispersion model that allows consideration of the effects of terrain features and obstacles on the dispersion of LNG vapor clouds. Project milestones are: (1) Simulation of Low-Wind-Speed Stable Atmospheric Milestones Conditions; (2) Verification for Dispersion over Rough Surfaces, With And Without Obstacles; and (3) Adapting the FEM3A Model for General Application. Results for this quarter are work continues to underway to address numerical problems during simulation of low-wind-speed, stable, atmospheric conditions with FEM3A. Steps 1 and 2 in the plan outlined in the first Quarterly report are complete and steps 3 and 4 are in progress. During this quarter, we have been investigating the effect upon numerical stability of the heat transfer model used to predict the surface-to-cloud heat transfer, which can be important for LNG vapor dispersion. Previously, no consideration has been given to ground cooling as a result of heat transfer to the colder gas cloud in FEM3A. The present effort is directed to describing the ground surface temperature decrease as a function of time.

  6. Study of the Effects of Obstacles in Liquefied Natural Gas (LNG) Vapor Dispersion using CFD Modeling 

    E-print Network

    Ruiz Vasquez, Roberto

    2012-10-19

    . Some of these configurations include crosswind canyons, sloping terrain, semicircular fence placed upwind or downwind from a release, and a fence completely surrounding a release (Coldrick et al., 2010). The fences were located downwind from...

  7. Study of gelled LNG

    SciTech Connect

    Rudnicki, M.I.; Cabeal, J.A.; Hoffman, L.C.; Newton, R.A.; Schaplowsky, R.K.; Vander Wall, E.M.

    1981-05-01

    This research included (1) further characterization of gelled LNG (GELNG) rheological properties, (2) assessment of the relative leakage of GELNG vs LNG through a perforated wall, (3) relative spread and vaporization rates of unconfined spills on water, and (4) relative spread and vaporization rates of unconfined spills on land. Shear stress vs strain rate was determined for a range of gelant concentrations. The shear diagram was extended to cover shear rates in the range of 13 to 14,800 inverse seconds, expanding previous results at both low and high shear rates. Leakage tests of GELNG through a known geometry perforation were conducted along with comparative testing with LNG. Rapid cessation of flow through the perforated plate was observed for all tested concentrations of GELNG and at all driving pressures. This cessation of leakage was observed for both moist ambient air and dry helium isothermal environments. LNG showed no flow cessation tendencies under any of the test conditions. Land spills were found to give inconclusive results due to difficulties in measuring transient weight changes during the spill. Water spills were conducted in such a way that spread areas could be photographically recorded. Gelation increases total vaporization time significantly in water spills.

  8. Lessons learned from LNG safety research.

    PubMed

    Koopman, Ronald P; Ermak, Donald L

    2007-02-20

    During the period from 1977 to 1989, the Lawrence Livermore National Laboratory (LLNL) conducted a liquefied gaseous fuels spill effects program under the sponsorship of the US Department of Energy, Department of Transportation, Gas Research Institute and others. The goal of this program was to develop and validate tools that could be used to predict the effects of a large liquefied gas spill through the execution of large scale field experiments and the development of computer models to make predictions for conditions under which tests could not be performed. Over the course of the program, three series of LNG spill experiments were performed to study cloud formation, dispersion, combustion and rapid phase transition (RPT) explosions. The purpose of this paper is to provide an overview of this program, the lessons learned from 12 years of research as well as some recommendations for the future. The general conclusion from this program is that cold, dense gas related phenomena can dominate the dispersion of a large volume, high release rate spill of LNG especially under low ambient wind speed and stable atmospheric conditions, and therefore, it is necessary to include a detailed and validated description of these phenomena in computer models to adequately predict the consequences of a release. Specific conclusions include: * LNG vapor clouds are lower and wider than trace gas clouds and tend to follow the downhill slope of terrain due to dampened vertical turbulence and gravity flow within the cloud. Under low wind speed, stable atmospheric conditions, a bifurcated, two lobed structure develops. * Navier-Stokes models provide the most complete description of LNG dispersion, while more highly parameterized Lagrangian models were found to be well suited to emergency response applications. * The measured heat flux from LNG vapor cloud burns exceeded levels necessary for third degree burns and were large enough to ignite most flammable materials. * RPTs are of two types, source generated and enrichment generated, and were observed to increase the burn area by a factor of two and to extend the downwind burn distance by 65%. Additional large scale experiments and model development are recommended. PMID:17126482

  9. 46 CFR 154.1854 - Methane (LNG) as fuel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Methane (LNG) as fuel. 154.1854 Section 154.1854 ...LIQUEFIED GASES Operations § 154.1854 Methane (LNG) as fuel. (a) If methane (LNG) vapors are used as fuel in the main...

  10. Means for maintaining the substitutability of LNG

    Microsoft Academic Search

    R. C. Proctor; R. W. Parrish

    1967-01-01

    Substitutability as applied to liquid natural gas (LNG) is a method of reducing vaporization of the more volatile components and thus maintaining the heating value at a desirable level. A continuous process is described for cooling LNG below the boiling point of its most volatile component. A large-scale storage tank is provided with adequate space in the top for a

  11. Application of CFD (Fluent) to LNG spills into geometrically complex environments.

    PubMed

    Gavelli, Filippo; Bullister, Edward; Kytomaa, Harri

    2008-11-15

    Recent discussions on the fate of LNG spills into impoundments have suggested that the commonly used combination of SOURCE5 and DEGADIS to predict the flammable vapor dispersion distances is not accurate, as it does not account for vapor entrainment by wind. SOURCE5 assumes the vapor layer to grow upward uniformly in the form of a quiescent saturated gas cloud that ultimately spills over impoundment walls. The rate of spillage is then used as the source term for DEGADIS. A more rigorous approach to predict the flammable vapor dispersion distance is to use a computational fluid dynamics (CFD) model. CFD codes can take into account the physical phenomena that govern the fate of LNG spills into impoundments, such as the mixing between air and the evaporated gas. Before a CFD code can be proposed as an alternate method for the prediction of flammable vapor cloud distances, it has to be validated with proper experimental data. This paper describes the use of Fluent, a widely-used commercial CFD code, to simulate one of the tests in the "Falcon" series of LNG spill tests. The "Falcon" test series was the only series that specifically addressed the effects of impoundment walls and construction obstructions on the behavior and dispersion of the vapor cloud. Most other tests, such as the Coyote and the Burro series, involved spills onto water and relatively flat ground. The paper discusses the critical parameters necessary for a CFD model to accurately predict the behavior of a cryogenic spill in a geometrically complex domain, and presents comparisons between the gas concentrations measured during the Falcon-1 test and those predicted using Fluent. Finally, the paper discusses the effect vapor barriers have in containing part of the spill thereby shortening the ignitable vapor cloud and therefore the required hazard area. This issue was addressed by comparing the Falcon-1 simulation (spill into the impoundment) with the simulation of an identical spill without any impoundment walls, or obstacles within the impoundment area. PMID:18359557

  12. 75 FR 53371 - Liquefied Natural Gas Facilities: Obtaining Approval of Alternative Vapor-Gas Dispersion Models

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ...dispersion model that accounts for additional cloud dilution which may be caused by the complex...to influence the flow field of the vapor cloud) and/or through a sensitivity analysis...arc wise concentration relative to the cloud centerline. The centerline...

  13. Dispersion of flammable vapor clouds resulting from large spills of liquid hydrogen

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1981-01-01

    The purpose of this paper is to report the preliminary findings of hydrogen vapor cloud dispersion experiments conducted by NASA. The experiments were performed to obtain basic information regarding the physical phenomena governing the dispersion of flammable clouds formed as the result of spills of large quantities of liquid hydrogen. The experiments consisted of ground spills of up to 5.7 cubic meters (1500 gal) of liquid hydrogen, with spill durations of approximately 35 seconds. Instrumented towers, located downwind of the spill site, gather data on the temperature, hydrogen concentration, and turbulence levels as the hydrogen vapor cloud drifted downwind. Visual phenomena were recorded by motion picture and still cameras. Preliminary results of the experiments indicate that, for rapid spills, thermal and momentum induced turbulences cause the cloud to disperse to safe concentration levels and become positively buoyant long before mixing due to normal atmospheric turbulence becomes a major factor.

  14. United states regulations for siting LNG terminals: problems and potential.

    PubMed

    Havens, Jerry; Spicer, Tom

    2007-02-20

    The regulations being applied to liquefied natural gas (LNG) import terminal siting in the United States are reviewed. There are no requirements for exclusion zones to protect the public from LNG spills onto water. Serious problems with current practices used to determine exclusion zones on the land-based part of the facility are identified. Many of the questions that are considered relate to the use of computational fluid dynamic (CFD) models, which appear to offer the best potential for realistic modeling to determine vapor cloud exclusion zones that result from LNG spills into impounded areas with or without dispersion in the presence of other obstacles to the wind flow. Failure to use CFD models, which are already approved by the regulation, and continued use of practices which have been demonstrated to be in error, raises important questions of credibility as well as denies the applicant full use of scientific tools that are available to optimize the design of such facilities so as to best provide for safety of the public. PMID:17110028

  15. Curves to determine the relative importance of advection and dispersion for solute and vapor transport

    USGS Publications Warehouse

    Garges, J.A.; Baehr, A.L.

    1998-01-01

    The relative importance of advection and dispersion for both solute and vapor transport can be determined from type curves or concentration, flux, or cumulative flux. The dimensionless form of the type curves provides a means to directly evaluate the importance of mass transport by advection relative to that of mass transport by diffusion and dispersion. Type curves based on an analytical solution to the advection-dispersion equation are plotted in terms of dimensionless time and Peclet number. Flux and cumulative flux type curves provide additional rationale for transport regime determination in addition to the traditional concentration type curves. The extension of type curves to include vapor transport with phase partitioning in the unsaturated zone is a new development. Type curves for negative Peclet numbers also are presented. A negative Peclet number characterizes a problem in which one direction of flow is toward the contamination source, and thereby diffusion and advection can act in opposite directions. Examples are the diffusion of solutes away from the downgradient edge of a pump-and-treat capture zone, the upward diffusion of vapors through the unsaturated zone with recharge, and the diffusion of solutes through a low hydraulic conductivity cutoff wall with an inward advective gradient.

  16. Exergy of LNG regasification - possible utilization method. Case study of LNG - ANG coupling

    NASA Astrophysics Data System (ADS)

    Roszak, E. A.; Chorowski, M.

    2014-01-01

    This article gives an overview on new exergy recovery methods for LNG. The concept is based on coupling the LNG regasification unit with the filling process of Adsorbed Natural Gas (ANG) tanks. The latent heat of the LNG vaporization is directly used for precooling the ANG adsorption bed. This reduces the back pressure from filling ANG tanks due to strong adsorption temperature dependency. This improves the economic attractiveness of ANG storage (no need for compressors, longer lifetime cycle of adsorbent). This case study presents the concept of LNG - ANG coupling. Presented results are based on experimental adsorption data. A brief exergy analysis of the process shows an advantage of this method over others. This LNG-ANG method is worth consideration as a cost optimizing solution, especially for periodically working regasification stations.

  17. Kinetics of the oxidation of iron carbide dispersed in a carbon matrix with water vapor.

    PubMed

    Arabczyk, Walerian; Ekiert, Ewa; Jedrzejewski, Roman

    2009-04-30

    The reaction of iron carbide embedded in a carbon matrix with water vapor was studied in the temperature range 300-500 degrees C and the partial pressure of water vapor p(H(2)O) = 0.63-3.26 kPa. At these conditions the superfine magnetite and hematite are the products of this reaction. High oxidation temperature and low partial pressure of water vapor are favorable conditions to obtain only magnetite phase dispersed in a carbon matrix. The oxidation rate of iron and iron carbide is the same for both of them in the initial, kinetic stage of the reaction. It was observed that carbon deposit caused an increase in the reaction rate as a result of spillover effect. The oxidation rate of iron carbide distributed in a carbon matrix increases linearly with the carburization degree of the sample. The reaction rate is also linearly dependent on the partial pressure of water vapor. The apparent activation energy was determined as 110 kJ/mol. PMID:19338325

  18. Water Vapor Sorption and Diffusion in Secondary Dispersion Barrier Coatings: A Critical Comparison with Emulsion Polymers.

    PubMed

    Liu, Yang; Soer, Willem-Jan; Scheerder, Jürgen; Satgurunathan, Guru; Keddie, Joseph L

    2015-06-10

    The conventional method for synthesizing waterborne polymer colloids is emulsion polymerization using surfactants. An emerging method is the use of secondary dispersions (SD) of polymers in water, which avoids the addition of any surfactant. Although there are numerous studies of the water barrier properties (sorption, diffusion, and permeability) of waterborne emulsion (Em) polymer coatings, the properties of SD coatings, in comparison, have not been thoroughly investigated. Here, dynamic water vapor sorption analysis is used to compare the equilibrium sorption isotherms of the two forms of styrene-acrylate copolymers (Em and SD) with the same monomer composition. From an analysis of the kinetics of vapor sorption, the diffusion coefficient of water in the polymer coatings is determined. The combined effects of particle boundaries and surfactant addition were investigated through a comparison of the properties of SD and Em coatings to those of (1) solvent-cast polymer coatings (of the same monomer composition), (2) Em polymers that underwent dialysis to partially remove the water-soluble species, and (3) SD polymers with added surfactants. The results reveal that both the particle boundaries and the surfactants increase vapor sorption. The diffusion coefficients of water are comparable in magnitude in all of the polymer systems but are inversely related to water activity because of molecular clustering. Compared to all of the other waterborne polymer systems, the SD barrier coatings show the lowest equilibrium vapor sorption and permeability coefficients at high relative humidities as well as the lowest water diffusion coefficient at low humidities. These barrier properties make SD coatings an attractive alternative to conventional emulsion polymer coatings. PMID:25985183

  19. Dispersion of seed vapor and gas ionization in an MHD second stage combustor and channel

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.

    1992-01-01

    An approach is introduced for the simulation of a magnetohydrodynamic system consisting of a second stage combustor, a convergent nozzle, and a channel. The simulation uses an Argonne integral combustion flow computer code and another Argonne channel computer code to predict flow, thermal and electric properties in the seed particle laden reacting flow in the system. The combustion code is a general hydrodynamics computer code for two-phase, two-dimensional, turbulent, and reacting flows, based on mass, momentum, and energy conservation laws for gaseous and condensed phases. The channel code is a multigrid three-dimensional computer code for compressible flow subject to magnetic and electric interactions. Results of this study suggests that (1) the processes of seed particle evaporation, seed vapor dispersion, and gas ionization in the reacting flow are critical to the evaluation of the downstream channel performance and (2) particle size, loading, and inlet profile have strong effects on wall deposition and plasma temperature development.

  20. Dispersion of seed vapor and gas ionization in an MHD second stage combustor and channel

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.

    1992-07-01

    An approach is introduced for the simulation of a magnetohydrodynamic system consisting of a second stage combustor, a convergent nozzle, and a channel. The simulation uses an Argonne integral combustion flow computer code and another Argonne channel computer code to predict flow, thermal and electric properties in the seed particle laden reacting flow in the system. The combustion code is a general hydrodynamics computer code for two-phase, two-dimensional, turbulent, and reacting flows, based on mass, momentum, and energy conservation laws for gaseous and condensed phases. The channel code is a multigrid three-dimensional computer code for compressible flow subject to magnetic and electric interactions. Results of this study suggests that (1) the processes of seed particle evaporation, seed vapor dispersion, and gas ionization in the reacting flow are critical to the evaluation of the downstream channel performance and (2) particle size, loading, and inlet profile have strong effects on wall deposition and plasma temperature development.

  1. Vapor-liquid Coexistence Curves for Methanol and Methane using Dispersion-Corrected Density Functional Theory

    SciTech Connect

    McGrath, Matthew J.; Kuo, I-F W.; Ghogomu, Julius N.; Mundy, Christopher J.; Siepmann, Joern I.

    2011-10-13

    First principles Monte Carlo simulations in the Gibbs and isobaric-isothermal ensembles were performed to map the vapor-liquid coexistence curves (VLCC) of methanol and methane described by Kohn-Sham density functional theory using the Becke-Lee-Yang-Parr (BLYP) exchange and correlation functionals with the Grimme correction term for dispersive (D2) interactions. The simulations indicate that the BLYP-D2 description underpredicts the saturated vapor densities and overpredicts the saturated liquid densities and critical and boiling temperatures for both compounds. Although the deviations are quite large, these results present a significant improvement over the BLYP functional without the correction term which misses the experimental results by a larger extent in the opposite direction. With the D2 correction, an increase in the basis set does not lead to significant changes in the VLCC properties. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  2. Caribbean LNG project marks progress; LNG tanker launched

    SciTech Connect

    NONE

    1997-10-20

    World LNG trade continues to expand as construction of a major LNG project in the Caribbean hits full stride this fall and another LNG carrier was launched earlier this year. Engineering is nearly complete and construction is nearing midway on Trinidad`s Atlantic LNG. In Japan, NKK Corp. launched another LNG tanker that employs the membrane-storage system. The 50-mile pipeline to move natural gas to the Atlantic LNG facility is also on track for completion by October 1998.

  3. Comparative safety analysis of LNG storage tanks

    SciTech Connect

    Fecht, B.A.; Gates, T.E.; Nelson, K.O.; Marr, G.D.

    1982-07-01

    LNG storage tank design and response to selected release scenarios were reviewed. The selection of the scenarios was based on an investigation of potential hazards as cited in the literature. A review of the structure of specific LNG storage facilities is given. Scenarios initially addressed included those that most likely emerge from the tank facility itself: conditions of overfill and overflow as related to liquid LNG content levels; over/underpressurization at respective tank vapor pressure boundaries; subsidence of bearing soil below tank foundations; and crack propagation in tank walls due to possible exposure of structural material to cryogenic temperatures. Additional scenarios addressed include those that result from external events: tornado induced winds and pressure drops; exterior tank missile impact with tornado winds and rotating machinery being the investigated mode of generation; thermal response due to adjacent fire conditions; and tank response due to intense seismic activity. Applicability of each scenario depended heavily on the specific tank configurations and material types selected. (PSB)

  4. High efficiency Brayton cycles using LNG

    DOEpatents

    Morrow, Charles W. (Albuquerque, NM)

    2006-04-18

    A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.

  5. Vapor spill pipe monitor

    DOEpatents

    Bianchini, G.M.; McRae, T.G.

    1983-06-23

    The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

  6. Vapor spill pipe monitor

    NASA Astrophysics Data System (ADS)

    Bianchini, G. M.; McRae, T. G.

    1983-06-01

    The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote IR gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote IR sensor which measures the gas composition.

  7. A review of large-scale LNG spills: experiments and modeling.

    PubMed

    Luketa-Hanlin, Anay

    2006-05-20

    The prediction of the possible hazards associated with the storage and transportation of liquefied natural gas (LNG) by ship has motivated a substantial number of experimental and analytical studies. This paper reviews the experimental and analytical work performed to date on large-scale spills of LNG. Specifically, experiments on the dispersion of LNG, as well as experiments of LNG fires from spills on water and land are reviewed. Explosion, pool boiling, and rapid phase transition (RPT) explosion studies are described and discussed, as well as models used to predict dispersion and thermal hazard distances. Although there have been significant advances in understanding the behavior of LNG spills, technical knowledge gaps to improve hazard prediction are identified. Some of these gaps can be addressed with current modeling and testing capabilities. A discussion of the state of knowledge and recommendations to further improve the understanding of the behavior of LNG spills on water is provided. PMID:16271829

  8. 49 CFR 193.2059 - Flammable vapor-gas dispersion protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Alternatively, in order to account for additional cloud dilution which may be caused by the complex...terrain both upwind and downwind of the vapor cloud has dense vegetation and that the vapor cloud height is more than ten times the height...

  9. Forced Dispersion of Liquefied Natural Gas Vapor Clouds with Water Spray Curtain Application

    E-print Network

    Rana, Morshed A.

    2011-02-22

    during forced dispersion CM momentum coefficient (nozzle) CND gas concentration during natural dispersion gpC heat capacity of the gas mixture J/kgK 12txC concentration at x2 at any time t1 25txC concentration at x5 at time t2... Cfree_dispersion open field dispersion concentration Cforced_dispersion concentration in presence of the water spray D base diameter (eqn 6 and 7) m D droplet diameter (eqn 17) m DF dilution factor Dn diameter of nozzle m...

  10. An LNG release, transport, and fate model system for marine spills.

    PubMed

    Spaulding, Malcolm L; Swanson, J Craig; Jayko, Kathy; Whittier, Nicole

    2007-02-20

    LNGMAP, a fully integrated, geographic information based modular system, has been developed to predict the fate and transport of marine spills of LNG. The model is organized as a discrete set of linked algorithms that represent the processes (time dependent release rate, spreading, transport on the water surface, evaporation from the water surface, transport and dispersion in the atmosphere, and, if ignited, burning and associated radiated heat fields) affecting LNG once it is released into the environment. A particle-based approach is employed in which discrete masses of LNG released from the source are modeled as individual masses of LNG or spillets. The model is designed to predict the gas mass balance as a function of time and to display the spatial and temporal evolution of the gas (and radiated energy field). LNGMAP has been validated by comparisons to predictions of models developed by ABS Consulting and Sandia for time dependent point releases from a draining tank, with and without burning. Simulations were in excellent agreement with those performed by ABS Consulting and consistent with Sandia's steady state results. To illustrate the model predictive capability for realistic emergency scenarios, simulations were performed for a tanker entering Block Island Sound. Three hypothetical cases were studied: the first assumes the vessel continues on course after the spill starts, the second that the vessel stops as soon as practical after the release begins (3 min), and the third that the vessel grounds at the closest site practical. The model shows that the areas of the surface pool and the incident thermal radiation field (with burning) are minimized and dispersed vapor cloud area (without burning) maximized if the vessel continues on course. For this case the surface pool area, with burning, is substantially smaller than for the without burning case because of the higher mass loss rate from the surface pool due to burning. Since the vessel speed substantially exceeds the spill spreading rate, both the thermal radiation fields and surface pool trail the vessel. The relative directions and speeds of the wind and vessel movement govern the orientation of the dispersed plume. If the vessel stops, the areas of the surface pool and incident radiation field (with burning) are maximized and the dispersed cloud area (without burning) minimized. The longer the delay in stopping the vessel, the smaller the peak values are for the pool area and the size of the thermal radiation field. Once the vessel stops, the spill pool is adjacent to the vessel and moving down current. The thermal radiation field is oriented similarly. These results may be particularly useful in contingency planning for underway vessels. PMID:17110025

  11. Introduction to LNG vehicle safety

    NASA Astrophysics Data System (ADS)

    Bratvold, Delma; Friedman, David; Chernoff, Harry; Farkhondehpay, Dariush; Comay, Claudia

    1994-03-01

    Basic information on the characteristics of liquefied natural gas (LNG) is assembled to provide an overview of safety issues and practices for the use of LNG vehicles. This document is intended for those planning or considering the use of LNG vehicles, including vehicle fleet owners and operators, public transit officials and boards, local fire and safety officials, manufacturers and distributors, and gas industry officials. Safety issues and mitigation measures that should be considered for candidate LNG vehicle projects are addressed.

  12. Thermodynamic analysis of an LNG fuelled combined cycle power plant with waste heat recovery and utilization system

    Microsoft Academic Search

    Xiaojun Shi; Defu Che

    2007-01-01

    SUMMARY This paper has proposed an improved liquefied natural gas (LNG) fuelled combined cycle power plant with a waste heat recovery and utilization system. The proposed combined cycle, which provides power outputs and thermal energy, consists of the gas\\/steam combined cycle, the subsystem utilizing the latent heat of spent steam from the steam turbine to vaporize LNG, the subsystem that

  13. June 15, 1993 / Vol. 18, No. 12 / OPTICS LETTERS Sodium-vapor dispersive Faraday filter

    E-print Network

    transition near 422.7 nm. These experimen- tal studies were carried out under relatively weak magnetic fields experimentally with a thin Na cell in an axial magnetic field of 1750 G. A peak vapor transmission of 85%, a FWHM-band filters are necessary in free-space optical communication to extract narrow-band signal in the presence

  14. Forced Dispersion of Liquefied Natural Gas Vapor Clouds with Water Spray Curtain Application 

    E-print Network

    Rana, Morshed A.

    2011-02-22

    11.3 m vx and sx mass fraction of water vapor and pollutant z vertical direction (z is positive in the upward direction) m z* dimensionless vertical distance ? thermal diffusivity of the ground m2/s ? gravity parameter.... .................................................... 92 Fig. 40. Rate of momentum calculated at the nozzle tip ................................................. 93 Fig. 41. Upward water spray from a conical nozzle. ..................................................... 101 Fig. 42...

  15. LNG annotated bibliography

    SciTech Connect

    Bomelburg, H.J.; Counts, C.A.; Cowan, C.E.; Davis, W.E.; DeSteese, J.G.; Pelto, P.J.

    1982-09-01

    This document updates the bibliography published in Liquefied Gaseous Fuels Safety and Environmental Control Assessment Program: third status report (PNL-4172) and is a complete listing of literature reviewed and reported under the LNG Technical Surveillance Task. The bibliography is organized alphabetically by author.

  16. Chemical vapor deposition of highly dispersed Pt nanoparticles on multi-walled carbon nanotubes for use as fuel-cell electrodes

    Microsoft Academic Search

    Heeyeon Kim; Sang Heup Moon

    2011-01-01

    Fuel-cell electrode catalysts with improved electrochemical properties have been prepared by dispersing Pt nanoparticles onto carbon nanotubes (CNT) using a chemical vapor deposition (CVD) method. (Trimethyl)methylcyclopentadienyl platinum (MeCpPtMe3) has been used as a Pt precursor in the CVD process and the CVD conditions have been optimized to disperse small Pt particles onto the CNT. Pt particles synthesized by CVD have

  17. 33 CFR 127.319 - LNG transfer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Waters 2 2010-07-01 2010-07-01 false LNG transfer. 127.319 Section 127.319 Navigation...Liquefied Natural Gas Operations § 127.319 LNG transfer. During LNG transfer operations, the following must be...

  18. Blanketing effect of expansion foam on liquefied natural gas (LNG) spillage pool.

    PubMed

    Zhang, Bin; Liu, Yi; Olewski, Tomasz; Vechot, Luc; Mannan, M Sam

    2014-09-15

    With increasing consumption of natural gas, the safety of liquefied natural gas (LNG) utilization has become an issue that requires a comprehensive study on the risk of LNG spillage in facilities with mitigation measures. The immediate hazard associated with an LNG spill is the vapor hazard, i.e., a flammable vapor cloud at the ground level, due to rapid vaporization and dense gas behavior. It was believed that high expansion foam mitigated LNG vapor hazard through warming effect (raising vapor buoyancy), but the boil-off effect increased vaporization rate due to the heat from water drainage of foam. This work reveals the existence of blocking effect (blocking convection and radiation to the pool) to reduce vaporization rate. The blanketing effect on source term (vaporization rate) is a combination of boil-off and blocking effect, which was quantitatively studied through seven tests conducted in a wind tunnel with liquid nitrogen. Since the blocking effect reduces more heat to the pool than the boil-off effect adds, the blanketing effect contributes to the net reduction of heat convection and radiation to the pool by 70%. Water drainage rate of high expansion foam is essential to determine the effectiveness of blanketing effect, since water provides the boil-off effect. PMID:25194555

  19. Modeling of LNG Pool Spreading and Vaporization

    E-print Network

    Basha, Omar 1988-

    2012-11-20

    sensitivity analysis was conducted to determine the effect of boiling heat transfer regimes, friction, thermal contact/roughness correction parameter and VLE/mixture thermodynamics on the pool spreading behavior. The aim was to provide a better understanding...

  20. Liquefied Natural Gas (LNG) dispenser verification device

    NASA Astrophysics Data System (ADS)

    Xiong, Maotao; Yang, Jie-bin; Zhao, Pu-jun; Yu, Bo; Deng, Wan-quan

    2013-01-01

    The composition of working principle and calibration status of LNG (Liquefied Natural Gas) dispenser in China are introduced. According to the defect of weighing method in the calibration of LNG dispenser, LNG dispenser verification device has been researched. The verification device bases on the master meter method to verify LNG dispenser in the field. The experimental results of the device indicate it has steady performance, high accuracy level and flexible construction, and it reaches the international advanced level. Then LNG dispenser verification device will promote the development of LNG dispenser industry in China and to improve the technical level of LNG dispenser manufacture.

  1. Modeling the release, spreading, and burning of LNG, LPG, and gasoline on water.

    PubMed

    Johnson, David W; Cornwell, John B

    2007-02-20

    Current interest in the shipment of liquefied natural gas (LNG) has renewed the debate about the safety of shipping large volumes of flammable fuels. The size of a spreading pool following a release of LNG from an LNG tank ship has been the subject of numerous papers and studies dating back to the mid-1970s. Several papers have presented idealized views of how the LNG would be released and spread across a quiescent water surface. There is a considerable amount of publicly available material describing these idealized releases, but little discussion of how other flammable fuels would behave if released from similar sized ships. The purpose of this paper is to determine whether the models currently available from the United States Federal Energy Regulatory Commission (FERC) can be used to simulate the release, spreading, vaporization, and pool fire impacts for materials other than LNG, and if so, identify which material-specific parameters are required. The review of the basic equations and principles in FERC's LNG release, spreading, and burning models did not reveal a critical fault that would prevent their use in evaluating the consequences of other flammable fluid releases. With the correct physical data, the models can be used with the same level of confidence for materials such as LPG and gasoline as they are for LNG. PMID:17112658

  2. Vaporizing Vapor

    NSDL National Science Digital Library

    2012-08-03

    In this demonstration, relative humidity is modeled using a sponge and a pan of water, and the concept of saturation is depicted. Students answer questions examining the relationship between temperature and the capacity of air to hold water vapor. The resource is part of the teacher's guide accompanying the video, NASA Sci Files: The Case of the Phenomenal Weather. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

  3. 76 FR 2677 - Southern LNG Company, LLC; Notice of Public Scoping Meeting for the Proposed LNG Truck Loading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ...Docket No. CP10-477-000] Southern LNG Company, LLC; Notice of Public Scoping Meeting for the Proposed LNG Truck Loading Project January 7, 2011...to the environmental analysis of Southern LNG Company, LLC's (Southern) LNG...

  4. Study of heavy gas effects on the atmospheric dispersion of dense gases. Revision 1

    SciTech Connect

    Ermak, D.L.; Chan, S.T.

    1985-04-01

    In this paper, four different types of dispersion simulations are compared with the results from three heavy gas dispersion experiments. The experiments include two different release gases (LNG vapor, a cold dense gas and NO/sub 2/, an isothermal dense gas) and three different wind speeds and atmospheric stabilities. The four types of dispersion simulations are a heavy gas simulations, a neutrally buoyant gas simulation, and two types of trace gas simulations. We use two models (FEM3 and Steady-State SLAB) to make the predictions. FEM3 simulates the dispersion of a heavy gas by solving the time-dependent, three-dimensional conservation equations and uses similarity profiles to determine the crosswind dependence. The purpose of this paper is to demonstrate how the inclusion of heavy gas phenomena and the choice in concentration averaging time affect the concentration prediction from a heavy gas release. 13 refs., 9 figs., 1 tab.

  5. Investigation of low-cost LNG vehicle fuel tank concepts. Final report

    SciTech Connect

    O`Brien, J.E.; Siahpush, A. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.

    1998-02-01

    The objective of this study was to investigate development of a low-cost liquid natural gas (LNG) vehicle fuel storage tank with low fuel boil-off, low tank pressure, and high safety margin. One of the largest contributors to the cost of converting a vehicle to LNG is the cost of the LNG fuel tank. To minimize heat leak from the surroundings into the low-temperature fuel, these tanks are designed as cryogenic dewars with double walls separated by an evacuated insulation space containing multi-layer insulation. The cost of these fuel tanks is driven by this double-walled construction, both in terms of materials and labor. The primary focus of the analysis was to try to devise a fuel tank concept that would allow for the elimination of the double-wall requirement. Results of this study have validated the benefit of vacuum/MLI insulation for LNG fuel tanks and the difficulty in identifying viable alternatives. The thickness of a non-vacuum insulation layer would have to be unreasonably large to achieve an acceptable non-venting hold time. Reasonable hold times could be achieved by using an auxiliary tank to accept boil-off vapor from a non-vacuum insulated primary tank, if the vapor in the auxiliary tank can be stored at high pressure. The primary focus of the analysis was to try to devise a fuel tank concept that allowed for the elimination of the double-wall requirement. Thermodynamic relations were developed for analyzing the fuel tank transient response to heat transfer, venting of vapor, and out-flow of either vapor or liquid. One of the major costs associated with conversion of a vehicle to LNG fuel is the cost of the LNG fuel tank. The cost of these tanks is driven by the cryogenic nature of the fuel and by the fundamental design requirements of long non-venting hold times and low storage pressure.

  6. 46 CFR 154.703 - Methane (LNG).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Methane (LNG). 154.703 Section 154...Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG) can withstand the pressure build up due to boil-off for 21 days, the pressure...

  7. Concrete LNG GBS Terminal Ship Collision Study

    Microsoft Academic Search

    Fuqiang Wu; Frank Puskar

    2008-01-01

    A Concrete Gravity Based Structure (GBS) provides an opportunity for the storage of Liquefied Natural Gas (LNG) and represents one of the key elements of an LNG receiving and regasification terminal. The impact resistance of an offshore LNG GBS against accidental ship collision needs to be evaluated. Nonlinear elasto-plastic Finite Element Analysis (FEA) provides a useful numerical tool to assess

  8. Optimization of Compressor Networks in LNG Operations

    Microsoft Academic Search

    M. M. Faruque Hasan; I. A. Karimi

    2009-01-01

    Liquefied natural gas (LNG) is the most economic way of transporting natural gas (NG) over long distances. Although LNG is an attractive source of clean fossil fuel, it involves energy intensive liquefaction of NG using refrigeration. Often the compressors that run the refrigerant cycles in an LNG plant operate in suboptimal fashion, which results in higher fuel and energy consumption.

  9. Growth of carbon nanotubes via chemical vapor deposition on Co catalyst nanoparticles dispersed in CaO

    Microsoft Academic Search

    E. V. Shlyakhova; N. F. Yudanov; A. V. Okotrub; Yu. V. Shubin; L. I. Yudanova; L. G. Bulusheva

    2008-01-01

    Multiwalled carbon nanotubes (CNTs) have been synthesized by chemical vapor deposition (CVD) from methane and carbon monoxide.\\u000a The process was catalyzed by cobalt nanoparticles produced via pyrolysis of a solid solution between cobalt and calcium tartrates.\\u000a The solid solution was characterized by x-ray diffraction, thermogravimetry, and chemical analysis. As shown by transmission\\u000a electron microscopy, the introduction of water vapor during

  10. On the application of computational fluid dynamics codes for liquefied natural gas dispersion.

    PubMed

    Luketa-Hanlin, Anay; Koopman, Ronald P; Ermak, Donald L

    2007-02-20

    Computational fluid dynamics (CFD) codes are increasingly being used in the liquefied natural gas (LNG) industry to predict natural gas dispersion distances. This paper addresses several issues regarding the use of CFD for LNG dispersion such as specification of the domain, grid, boundary and initial conditions. A description of the k-epsilon model is presented, along with modifications required for atmospheric flows. Validation issues pertaining to the experimental data from the Burro, Coyote, and Falcon series of LNG dispersion experiments are also discussed. A description of the atmosphere is provided as well as discussion on the inclusion of the Coriolis force to model very large LNG spills. PMID:17113710

  11. Mobile LNG (liquified natural gas) gelator. Final report, July 1980-September 1981

    SciTech Connect

    Rudnicki, M.I.; Hoffman, L.C.; Newton, R.A.

    1981-12-01

    Gelled liquified natural gas (GELNG) offers potential safety advantages over LNG in the case of an accidental spill. GELNG has shown reduced spread area, lower vaporization rate, and crack sealing capability relative to the ungelled material. The purpose of this contract was to develop a mobile, continuous gelator which would produce a minimum of one cubic meter per hour of GELNG; previously, GELNG had been produced in small quantities by batch processes. Major achievements under the contract were the design and construction of the mobile gelator, checkout of the system with liquid nitrogen, and testing of the system on LNG. GELNG was not produced in the test series.

  12. 49 CFR 193.2019 - Mobile and temporary LNG facilities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Mobile and temporary LNG facilities...STANDARDS General § 193.2019 Mobile and temporary LNG facilities. (a) Mobile and temporary LNG facilities for peakshaving application, for service maintenance...

  13. Simulation and integration of liquefied natural gas (lng) processes

    E-print Network

    Al-Sobhi, Saad Ali

    2009-05-15

    gas (LNG). When there is a considerable distance involved in transporting natural gas, LNG is becoming the preferred method of supply because of technical, economic, and political reasons. Thus, LNG is expected to play a major role in meeting...

  14. 76 FR 53425 - Pivotal LNG, Inc.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ...Docket No. CP11-532-000] Pivotal LNG, Inc.; Notice of Application Take notice that on August 8, 2011, Pivotal LNG, Inc. (Pivotal), Ten Peachtree Place...non-jurisdictional liquefied natural gas (LNG) liquefaction and storage facility in...

  15. 49 CFR 193.2181 - Impoundment capacity: LNG storage tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Impoundment capacity: LNG storage tanks. 193.2181 Section 193...Capacity § 193.2181 Impoundment capacity: LNG storage tanks. Each impounding system serving an LNG storage tank must have a minimum...

  16. 49 CFR 193.2623 - Inspecting LNG storage tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Inspecting LNG storage tanks. 193.2623 Section 193.2623...STANDARDS Maintenance § 193.2623 Inspecting LNG storage tanks. Each LNG storage tank must be inspected or tested to...

  17. Environmental and Economical Evaluation of Integrating NGL Extraction and LNG Liquefaction Technology in Iran LNG Project 

    E-print Network

    Manesh, M. H. K.; Mazhari, V.

    2009-01-01

    The combination of changing global markets for natural gas liquids (NGL) with the simultaneous increase in global demand for liquefied natural gas (LNG) has stimulated an interest in the integration of NGL recovery technology with LNG liquefaction...

  18. Floating LNG terminal and LNG carrier interaction analysis for side-by-side offloading operation 

    E-print Network

    Kuriakose, Vinu P.

    2005-11-01

    Floating LNG terminals are a relatively new concept with the first such terminal in the world installed this year. The hydrodynamic interaction effects between the terminal and a LNG carrier in a side-by-side offloading ...

  19. On the application of computational fluid dynamics codes for liquefied natural gas dispersion

    Microsoft Academic Search

    Anay Luketa-Hanlin; Ronald P. Koopman; Donald L. Ermak

    2007-01-01

    Computational fluid dynamics (CFD) codes are increasingly being used in the liquefied natural gas (LNG) industry to predict natural gas dispersion distances. This paper addresses several issues regarding the use of CFD for LNG dispersion such as specification of the domain, grid, boundary and initial conditions. A description of the k–? model is presented, along with modifications required for atmospheric

  20. Characterization of the Near-Field Transport and Dispersion of Vapors Released from the Headspaces of Hanford Site Underground Storage Tanks

    SciTech Connect

    Droppo, James G.

    2004-07-30

    A parametric air dispersion analysis has been conducted to define the range of tank vapor concentrations from the Hanford Site underground tanks that can potentially occur in the worker breathing zones from active and passive releases from the waste tanks. The potential influences of tank farm specific release characteristics, ambient meteorological conditions, local farm surface roughness, and topographical influences are considered. The parametric approach allows consideration of the full range venting configurations and potential vapor concentration over the range of meteorological conditions at the Hanford Site. The results indicate that occasional short duration exposures of up to several seconds to relatively undiluted headspace air can be expected in the immediate vicinity of the tank vents. Average concentrations which represent diffusion, as well as spatial averaging, fall off rapidly with distance for the passive vents and to a lesser extent for the forced-air stacks. The addition of the influence of the surface roughness elements on the tank farms will result in a faster decrease of concentrations with downwind distance.

  1. COGAS propulsion for LNG ships

    NASA Astrophysics Data System (ADS)

    Wiggins, Edwin G.

    2011-06-01

    Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service, and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers significant advantages over steam and diesel propulsion. This paper presents the case for the COGAS cycle.

  2. Re-Examining the Properties of the Aqueous Vapor-Liquid Interface Using Dispersion Corrected Density Functional Theory

    SciTech Connect

    Baer, Marcel D.; Mundy, Christopher J.; McGrath, Matthew J.; Kuo, I-F W.; Siepmann, Joern I.; Tobias, Douglas J.

    2011-09-28

    First-principles molecular dynamics simulations, in which the forces are computed from electronic structure calculations, have great potential to provide unique insight into structure, dynamics, electronic properties, and chemistry at aqueous interfaces that is not available from empirical force fields. The majority of current first-principles simulations are driven by forces derived from density functional theory with generalized gradient approximations to the exchange-correlation energy, which do not capture dispersion interactions. We have carried out first-principles molecular dynamics simulations of air-water interfaces employing a particular generalized gradient approximation to the exchange-correlation functional (BLYP), with and without empirical dispersion corrections. We assess the utility of the dispersion corrections by comparison of a variety of structural, dynamic, and thermodynamic properties of bulk and interfacial water with experimental data, as well as other first-principles and force field-based simulations. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  3. Salt-assisted dispersive liquid-liquid microextraction coupled with programmed temperature vaporization gas chromatography-mass spectrometry for the determination of haloacetonitriles in drinking water.

    PubMed

    Ma, Huilian; Li, Yun; Zhang, Haijun; Shah, Syed Mazhar; Chen, Jiping

    2014-09-01

    We report here a new analytical method for the simultaneous determination of seven haloacetonitriles (HANs) in drinking water by coupling salt-assisted dispersive liquid-liquid microextraction (SADLLME) with programmed temperature vaporizer-gas chromatography-mass spectrometry (PTV-GC-MS). The newly developed method involves the dispersion of the extractant in aqueous sample by addition of a few grams of salt and no dispersion liquid was required as compared to the traditional DLLME methods. The extractant (CH2Cl2, 50?L) and the salt (Na2SO4, 2.4g) were successively added to water (8mL) in a conical centrifuge tube that was shaken for 1min and centrifuged (3500rpm, 3min). The aliquot of sedimented phase (4?L) was then directly injected into the PTV-GC-MS system. The limits of detection and quantification for the HANs were 0.4-13.2ngL(-1) and 1.2-43.9ngL(-1), respectively. The calibration curves showed good linearity (r(2)?0.9904) over 3 orders of magnitude. The repeatability of the method was investigated by evaluating the intra- and inter-day precisions. The relative standard deviations (RSDs) obtained were lower than 10.2% and 7.8% at low and high concentration levels. The relative recoveries ranged from 79.3% to 105.1%. The developed methodology was applied for the analysis of seven HANs in several drinking water samples in coastal and inland cities of China. It was demonstrated to be a simple, sensible, reproducible and environment friendly method for the determination of trace HANs in drinking water samples. PMID:24997512

  4. SIGNIFICANT EVENTS IN THE HISTORY OF LNG 1914 First (U.S.) patent awarded for LNG handling/shipping.

    E-print Network

    SIGNIFICANT EVENTS IN THE HISTORY OF LNG 1914 First (U.S.) patent awarded for LNG handling/shipping commercial LNG shipping. 1960 Conch International Methane conducts pioneering series of experiments involving Utilities Commission to approve one terminal. Indonesia begins shipping LNG to Japan. 1978 Cove Point, MD

  5. LNG Safety Research: FEM3A Model Development

    SciTech Connect

    Liese Dallbauman

    2004-06-30

    During this reporting period, kickoff and planning meetings were held. Subcontracted experimental and modeling tasks were defined. Efforts to address the numerical stability problems that hamper FEM3A's applicability to low wind speed, stable atmospheric conditions were initiated. A detailed review of FEM3A code and its execution, required for development of an accessible user interface, was also begun. A one-day workshop on LNG safety models has been scheduled for September 2004. The goals of this project are to develop a national focal point for LNG safety research and technical dissemination and to develop the FEM3A dispersion model for application to general scenarios involving dispersion problems with obstacle and terrain features of realistic complexity. During this reporting period, the objectives and scope of the project and its constituent tasks were discussed at a project kickoff meeting in Morgantown. Details of the subcontracted experimental and modeling tasks were further defined at a separate meeting at the University of Arkansas. Researchers at the university have begun to modify the turbulence closure model used in FEM3A to insure numerical stability during simulation of low-wind-speed, stable atmospheric conditions. The university's wind tunnel is being prepared for upcoming experimental studies. GTI has begun a detailed review of the FEM3A code and its execution that will provide guidance during development of an accessible user interface. Plans were made for a one day workshop on LNG safety models that will be held at the end of September and will provide an introduction to currently available and pending software tools.

  6. Simultaneous speciation of inorganic arsenic, selenium and tellurium in environmental water samples by dispersive liquid liquid microextraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry.

    PubMed

    Liu, Ying; He, Man; Chen, Beibei; Hu, Bin

    2015-09-01

    A new method based on dispersive liquid liquid microextraction (DLLME) combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was developed for the simultaneous speciation of inorganic arsenic (As), selenium (Se) and tellurium (Te) with sodium diethyldithiocarbamate (DDTC) as both chelating reagent and chemical modifier. As(III), Se(IV) and Te(IV) were transformed into DDTC-chelates at pH 7 and extracted into the fine droplets formed by injecting the binary solution of bromobenzene (extraction solvent) and methanol (dispersive solvent) into the sample solution. After phase separation by centrifugation, As(III), Se(IV) and Te(IV) preconcentrated in the organic phase were determined by ETV-ICP-MS. Total inorganic As, Se and Te were obtained by reducing As(V), Se(VI) and Te(VI) to As(III), Se(IV) and Te(IV) with l-cysteine, which were then subjected to the same DLLME-ETV-ICP-MS process. The concentration of As(V), Se(VI), Te(VI) were calculated by subtracting the concentration of As(III), Se(IV) and Te(IV) from the total inorganic As, Se and Te, respectively. The main factors affecting the microextraction efficiency and the vaporization behavior of target species were investigated in detail. Under the optimal conditions, the limits of detection were 2.5, 8.6 and 0.56ngL(-1) for As(III), Se(IV) and Te(IV), respectively, with the relative standard deviations (n=7) of 8.5-9.7%. The developed method was applied to the speciation of inorganic As, Se and Te in Certified Reference Materials of GSBZ50004-88, GBW(E)080395 and GBW(E)080548 environmental waters, and the determined values are in good agreement with the certified values. The method was also successfully applied to the simultaneous speciation of inorganic As, Se and Te in different environmental water samples with the recoveries in the range of 86.3-107% for the spiked samples. PMID:26003714

  7. Controlling size dispersity, morphology and spatial orientation of nanostructures by electrodeposition and chemical vapor deposition on highly oriented pyrolytic graphite

    NASA Astrophysics Data System (ADS)

    Zach, Michael Paul

    With current manufacturing methods for electronics running into serious limitations of size, structures that self assemble from small, perfect building blocks---individual atoms, molecules, and ions---are one possibility for making smaller structures. The criticism most often expressed concerning self-assembly is lack of uniformity in fabricated structures and poor control over making patterns needed for making complex devices. The research presented here addresses some of these issues. Properties of materials are often size dependent---especially in the size range below 100 nm. Early attempts to electrochemically grow uniform particles failed due to problems that can be attributed with overlapping diffusion layers. Hydrogen Coevolution Electrodeposition Technique (HCET) is a new method for depositing materials using high overpotentials to rapidly evolve hydrogen bubbles for mixing the electrolyte solution right at the interface of developing particles thereby minimizing problems associated with the depletion layer. Wires ranging from a few nanometers to nearly a micron in diameter with lengths of up to hundreds of microns can now be made millions at a time by the simple benchtop techniques of Electrochemical Step Edge Decoration (ESED). Differences between basal plane surfaces and reactive step edges can also be exploited to grow dielectric coatings on steps by Chemical Vapor Deposition of Step Edge Decoration (CVD-SED) by highly water reactive precursors that react with water adhering to edges. In addition to parallel arrays of wires used for sensors, other potentially useful structures can be made. Wires can be structured by controlling the step edges. Methods for cleaving the graphite, thermal etching, chemical modification the step edges, and masking steps with dielectric coatings can all be used as tools to modify the final structure of metals, metal oxides, semiconductors and dielectrics which can now be deposited.

  8. Bayesian-lopa methodology for risk assessment of an LNG importation terminal

    E-print Network

    Yun, Geun-Woong

    2009-05-15

    LNG (Liquefied Natural Gas) is one of the fastest growing energy sources in the U.S. to fulfill the increasing energy demands. In order to meet the LNG demand, many LNG facilities including LNG importation terminals are operating currently...

  9. Study of gelled LNG. Final technical report

    SciTech Connect

    Rudnicki, M I; Cabeal, J A; Hoffman, L C; Newton, R A; Schaplowsky, R K; Vander Wall, E M

    1980-01-01

    Research involved the characterization of gelled LNG (GELNG) with respect to process, flow, and use properties and an examination of the degree of safety enhancement attainable by gelation. The investigation included (1) an experimental examination of gel properties and gel safety characteristics as well as (2) an analytical study involving the economics and preliminary design of an industrial scale gelation system. The safety-related criterion for successful application of gelled LNG is the substantial reduction of the Maximum Distance to the Lower Flammability Limit, MDLFL. This will be achieved by first, gel-inhibition of the hydrodynamic pooling and spreading of the spill, and second, the suppressed thermal transport properties of the GELNG relative to those of LNG. The industrial scale gelation study evaluated a design capable of producing 11,000 gallons (LNG tank truck) of gel in two hours. The increased cost of gelation using this equipment was estimated at $0.23/10/sup 6/ Btu for plants with liquefaction facilities. The technical results of this study are supportive of the conclusion that gelation of LNG will reduce, relative to ungelled LNG, the hazard associated with a given size spill. Parameters of interest to the LNG facility operator (such as pumpability) are not significantly affected by gelation, and the impact on LNG delivery cost appears to be small, about 5%. Thus, the initial assumption that gelation would provide a practical means to enhance safety is supported by the results of this study. Larger scale, comparative spill tests of LNG and GELNG are now required to confirm the safety aspects of use of the gelled material.

  10. Recent progress in modeling the atmospheric dispersion of heavy gases over variable terrain using the three-dimensional conservation equations

    SciTech Connect

    Chan, S. T.; Ermak, D. L.

    1983-08-01

    In this paper, a three-dimensional, conservation equation model for simulating the atmospheric dispersion of heavy gases has been briefly described; the model was successfully applied and assessed via simulating three distinctly different LNG spill experiments. These experiments involve approximately 30 m/sup 3/ LNG spills, with atmospheric conditions ranging from slightly stable to slightly unstable (ambient wind speed from about 2 m/s to 10 m/s). In general, good agreement between model predictions and field measurements was observed in all cases based on comparing, among others, the maximum concentrations as a function of downwind distance, the maximum downwind distances to the LFL, time histories of concentration at specific locations, and concentration contours on certain horizontal and crosswind surfaces. In particular, the overall results obtained in the model calculations with the simulated actual topography were shown to correlate much better with the field data in that many important features of the vapor cloud observed under the light wind conditions of Burro 8 were successfully reproduced. These include the spreading of vapor cloud in all directions (in upwind direction as well), the vortex-induced high concentration regions, the bifurcation of the NG cloud, and the deflection of the NG cloud due to sloping terrain. Through the present numerical simulations, the effects of variable terrain on the dispersion of heavy gases have been clearly demonstrated. Even with the relatively mild terrain at the test site and under a moderately high wind speed of approx. 6 m/s (Burro 9), the resulting vapor cloud dispersion was seen to differ noticeably from that using a flat terrain assumption. The combined effects of large gravity-flow (relative to the mean wind) over variable terrain and under light wind conditions (Burro 8) were shown to be even more profound. In such gravity-flow dominated regimes, proper treatment of the terrain, if present, is obviously necessary.

  11. LNG fires: a review of experimental results, models and hazard prediction challenges.

    PubMed

    Raj, Phani K

    2007-02-20

    A number of experimental investigations of LNG fires (of sizes 35 m diameter and smaller) were undertaken, world wide, during the 1970s and 1980s to study their physical and radiative characteristics. This paper reviews the published data from several of these tests including from the largest test to date, the 35 m, Montoir tests. Also reviewed in this paper is the state of the art in modeling LNG pool and vapor fires, including thermal radiation hazard modeling. The review is limited to considering the integral and semi-empirical models (solid flame and point source); CFD models are not reviewed. Several aspects of modeling LNG fires are reviewed including, the physical characteristics, such as the (visible) fire size and shape, tilt and drag in windy conditions, smoke production, radiant thermal output, etc., and the consideration of experimental data in the models. Comparisons of model results with experimental data are indicated and current deficiencies in modeling are discussed. The requirements in the US and European regulations related to LNG fire hazard assessment are reviewed, in brief, in the light of model inaccuracies, criteria for hazards to people and structures, and the effects of mitigating circumstances. The paper identifies: (i) critical parameters for which there exist no data, (ii) uncertainties and unknowns in modeling and (iii) deficiencies and gaps in current regulatory recipes for predicting hazards. PMID:17156916

  12. Research of design challenges and new technologies for floating LNG

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Hyun; Ha, Mun-Keun; Kim, Soo-Young; Shin, Sung-Chul

    2014-06-01

    With the rate of worldwide LNG demand expected to grow faster than that of gas demand, most major oil companies are currently investing their resources to develop floating LNG-FLNG (i.e. LNG FSRU and LNG FPSO). The global Floating LNG (FLNG) market trend will be reviewed based on demand and supply chain relationships. Typical technical issues associated with FLNG design are categorized in terms of global performance evaluation. Although many proven technologies developed through LNG carrier and oil FPSO projects are available for FLNG design, we are still faced with several technical challenges to clear for successful FLNG projects. In this study, some of the challenges encountered during development of the floating LNG facility (i.e. LNG FPSO and FSRU) will be reviewed together with their investigated solution. At the same time, research of new LNG-related technologies such as combined containment system will be presented.

  13. Damage-detection system for LNG carriers

    NASA Technical Reports Server (NTRS)

    Mastandrea, J. R.; Scherb, M. V.

    1978-01-01

    System utilizes array of acoustical transducers to detect cracks and leaks in liquefied natural gas (LNG) containers onboard ships. In addition to detecting leaks, device indicates location and leak rate.

  14. Assessment of the effects of release variables on the consequences of LNG spillage onto water using FERC models.

    PubMed

    Qiao, Yuanhua; West, Harry H; Mannan, M Sam; Johnson, David W; Cornwell, John B

    2006-03-17

    Liquefied natural gas (LNG) release, spread, evaporation, and dispersion processes are illustrated using the Federal Energy Regulatory Commission models in this paper. The spillage consequences are dependent upon the tank conditions, release scenarios, and the environmental conditions. The effects of the contributing variables, including the tank configuration, breach hole size, ullage pressure, wind speed and stability class, and surface roughness, on the consequence of LNG spillage onto water are evaluated using the models. The sensitivities of the consequences to those variables are discussed. PMID:16310951

  15. International Trade in Natural Gas: Golden Age of LNG?

    E-print Network

    Gabrieli, John

    International Trade in Natural Gas: Golden Age of LNG? Yichen Du and Sergey Paltsev Report No. 271;1 International Trade in Natural Gas: Golden Age of LNG? Yichen Du* and Sergey Paltsev* Abstract The introduction of liquefied natural gas (LNG) as an option for international trade has created a market for natural gas where

  16. 78 FR 41047 - UGI LNG, Inc.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-09

    ...DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-504-000] UGI LNG, Inc.; Notice of Application On June 17, 2013, UGI LNG, Inc. (UGI LNG) filed a request pursuant to section 7(c) of the Natural Gas Act, and...

  17. 33 CFR 127.321 - Release of LNG.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Release of LNG. 127.321 Section 127.321 Navigation...Gas Operations § 127.321 Release of LNG. (a) The operator of the waterfront facility handling LNG shall ensure that— (1) No person...

  18. 75 FR 26744 - Cameron LNG, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ...Docket No. CP10-165-000] Cameron LNG, LLC; Notice of Application May 5, 2010. On April 22, 2010, Cameron LNG, LLC filed with the Federal Energy Regulatory...Senior Regulatory Counsel at Cameron LNG, LLC, 101 Ash Street, HQ-12,...

  19. 75 FR 11000 - Security Zone; Freeport LNG Basin, Freeport, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ...RIN 1625-AA87 Security Zone; Freeport LNG Basin, Freeport, TX AGENCY: Coast Guard...permanent security zone in the Freeport LNG Basin. This security zone is needed to...NPRM) entitled Security Zone; Freeport LNG Basin, Freeport, TX in the Federal...

  20. 78 FR 38703 - LNG Development Company (d/b/a Oregon LNG); Oregon Pipeline Company, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-27

    ...PF12-7-000; Docket No. CP09-7-001] LNG Development Company (d/b/a Oregon LNG); Oregon Pipeline Company, LLC; Notice of Application Take notice that on June 7, 2013, LNG Development Company, LLC (d/ b/a Oregon...

  1. Seismic design criteria for LNG tanks

    SciTech Connect

    Devanna, L.R.; Blackman, J.

    1980-01-01

    According to this review of the various factors considered in revising the seismic design criteria in the National Fire Protection Association's LNG standards (NFPA 59A), the new criteria reflect the state-of-the-art and represent a rational, straightforward approach that will provide the same level of safety for LNG tanks across the country without restricting the exercise of good judgment and the incorporation of new developments. When properly applied, the approach evaluates all factors that could be relevant to seismic design, then specifies the safe-shut-down and operating-basis earthquake levels (SSE and OBE); the use of two sets of specifications avoids the need for an LNG-tank safety system designed for extremely high earthquake levels while assuring a tank's structural integrity during the worst earthquake that could reasonably be expected to occur over the facility's operating life.

  2. Status report on GELNG (gelled LNG)

    SciTech Connect

    Rudnicki, M.; Hoffman, L.C.; Vander Wall, E.M.

    1980-01-01

    Over the past 2 years, Aerojet's research on characterizing the process, flow, and use properties of gelled LNG has covered (1) its safety-enhancement potential, (2) the economics and preliminary design of an industrial-scale gelation system, and (3) the design of a portable gelator for larger scale (40 m/sup 3/) spill tests. The technical results thus far continue to support the conclusion that GELNG would substantially reduce spill hazards. Operating parameters would not be significantly changed by gelation, and the cost impact on delivered LNG appears to be small (about 5%).

  3. The effects of LNG-sloshing on the global responses of LNG-carriers

    E-print Network

    Lee, Seung Jae

    2008-10-10

    are coupled in frequency and time domain, similar to the method in the MARIN-FPSO case. Sloshing effect on LNG-carrier motion is investigated with respect to different tank filling levels including various conditions such as gap distance between two bodies... of roll restoring coefficient. ....................................................... 67  Fig. 5.1 General sketch of MARIN-FPSO and LNG tanks arrangement. .................... 70  Fig. 5.2 Grid generation of hull for 3D panel method (Number of panels=2300...

  4. Dispersed flow film boiling

    E-print Network

    Yoder, Graydon L.

    1980-01-01

    Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...

  5. 77 FR 10732 - Cameron LNG, LLC; Application for Long-Term Authorization To Export Domestically Produced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-23

    ...seeks authorization to export LNG from the Cameron LNG Terminal, owned by Cameron, in Cameron Parish, Louisiana...corporation. Cameron owns and operates the Cameron LNG Terminal (Terminal) in Cameron Parish Louisiana. In 2003, the...

  6. 78 FR 933 - Cameron LNG, LLC; Cameron Interstate Pipeline, LLC; Notice of Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ...27-000 and Docket No. PF12-12-000] Cameron LNG, LLC; Cameron Interstate Pipeline, LLC; Notice of...Applications Take notice that on December 7, 2012, Cameron LNG, LLC (Cameron LNG), 101 Ash Street, San Diego, California...

  7. 76 FR 81925 - Freeport LNG Development, L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ...Commission [Docket No. CP12-29-000] Freeport LNG Development, L.P.; Notice of Application Take notice that on December 9, 2011, Freeport LNG Development, L.P. (Freeport LNG), filed an application pursuant to Section...

  8. 75 FR 2126 - Calais Pipeline Company, LLC; Calais LNG Project Company, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ...PF08-24-000] Calais Pipeline Company, LLC; Calais LNG Project Company, LLC; Notice of Application January...Take notice that on December 18, 2009, Calais LNG Project Company, LLC (Calais LNG) and Calais Pipeline Company, LLC (Calais...

  9. Beauty of Simplicity: Phillips Optimized Cascade LNG Liquefaction Process

    NASA Astrophysics Data System (ADS)

    Andress, D. L.; Watkins, R. J.

    2004-06-01

    Paper describes how use of single component refrigerants yields an LNG liquefaction process that is safe, simple to operate, easy to understand, and robust in reliability. The 34-year operating history of Kenai LNG has proven the inherent advantages of the Phillips Optimized Cascade LNG Process. The paper is written from an operational point of view, and describes basic design parameters and operation of the processes.

  10. LNG safety, safety regulations and public perception

    SciTech Connect

    Lewis, J.P.; Outtrim, P.A. [Project Technical Liaison Associates, Inc., Spring, TX (United States)

    1995-12-31

    Although the subjects of safety, safety regulations and public perception are relatively separate, they should be discussed within the context of their total impact on the owner`s operation. The safety of LNG is a major issue both on an absolute safety basis and perceived safety basis. Public and regulatory perception are the dominant factors in the development of regulations and issue of permits. A safe operation includes protection of the public, plant personnel, investment in facilities and continued operation. In addition, protection of the company from litigation and regulatory restraint are also considerations. The paper discusses general safety considerations, safety regulation considerations, storage and impoundment, transport, odorization, personnel training, recent OSHA and EPA rule making activities, and recent research and progress in LNG safety.

  11. LNG ship tank inert gas generation system

    Microsoft Academic Search

    1974-01-01

    Chicago Bridge and Iron Co.'s new inert-gas system, designed for safely emptying LNG from storage tanks and avoiding potentially explosive gas\\/air mixtures in case of catastrophic ship collision, does not require the usual additional machinery such as an internal-combustion engine and a compressor. The inert-gas system consists of a supply tank for a liquefied inert gas such as nitrogen, an

  12. Liquefied Gaseous Fuels Safety and Environmental Control Assessment Program: second status report

    SciTech Connect

    None

    1980-10-01

    Volume 2 consists of 19 reports describing technical effort performed by Government Contractors in the area of LNG Safety and Environmental Control. Report topics are: simulation of LNG vapor spread and dispersion by finite element methods; modeling of negatively buoyant vapor cloud dispersion; effect of humidity on the energy budget of a liquefied natural gas (LNG) vapor cloud; LNG fire and explosion phenomena research evaluation; modeling of laminar flames in mixtures of vaporized liquefied natural gas (LNG) and air; chemical kinetics in LNG detonations; effects of cellular structure on the behavior of gaseous detonation waves under transient conditions; computer simulation of combustion and fluid dynamics in two and three dimensions; LNG release prevention and control; the feasibility of methods and systems for reducing LNG tanker fire hazards; safety assessment of gelled LNG; and a four band differential radiometer for monitoring LNG vapors.

  13. Visual Simulation of Offshore Liquefied Natural Gas (LNG) Terminals

    E-print Network

    Standiford, Richard B.

    Visual Simulation of Offshore Liquefied Natural Gas (LNG) Terminals in a Decision-Making Context1, Berkeley. 3/ Liquified Natural Gas Act Stats, 1977, Chap. 855, Page 2506 (effective Sept. 17, 1977 potential offshore Liquified Natural Gas (LNG) sites and the types of terminals that might occupy those

  14. 76 FR 73609 - Cameron LNG, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ...NGA) for authority to construct and operate a boil-off gas (BOG) liquefaction system at its LNG import terminal in Cameron Parish...a closed loop refrigeration system at the terminal to liquefy BOG and return such gas in the form of LNG to its storage...

  15. A critique of offshore liquefied natural gas (LNG) terminal policy

    Microsoft Academic Search

    William D. Whitmore; Vern K. Baxter; Shirley L. Laska

    2009-01-01

    The Maritime Transportation Security Act of 2002 amended the Deepwater Port Act of 1974 to permit the construction of offshore liquefied natural gas (LNG) terminals. Terminals with environmentally destructive open-loop regasification systems were quickly approved in the Gulf of Mexico. This study analyzed the political methods of the George W. Bush administration to determine how it developed offshore LNG. Findings

  16. Performance of cryogenic thermoelectric generators in LNG cold energy utilization

    Microsoft Academic Search

    Wei Sun; Peng Hu; Zeshao Chen; Lei Jia

    2005-01-01

    The cold energy of liquefied natural gas (LNG) is generally wasted when the LNG is extracted for utilization. This paper proposes cryogenic thermoelectric generators to recover this cold energy. The theoretical performance of the generator has been analyzed. An analytical method and numerical method of calculation of the optimum parameters of the generator have been demonstrated.

  17. 78 FR 20312 - Downeast LNG, Inc., Downeast Pipeline, LLC.; Notice of Availability of the Supplemental Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-04

    ...CP07-53-000; CP07-53-001] Downeast LNG, Inc., Downeast Pipeline, LLC.; Notice...Impact Statement for the Proposed Downeast LNG Project The staff of the Federal Energy...Impact Statement (EIS) for the Downeast LNG Project, proposed by Downeast LNG,...

  18. 77 FR 66830 - LNG Development Company, LLC and Oregon Pipeline Company; Northwest Pipeline GP; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ...PF12-18-000; Docket No. PF12-20-000] LNG Development Company, LLC and Oregon Pipeline...Extension of Comment Period for the Oregon LNG Export and Washington Expansion Projects...process and comment period for the Oregon LNG Export Project proposed by LNG...

  19. New energy saving system for future LNG carriers

    SciTech Connect

    Kahara, Susumu; Suetake, Yoshihiro [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Ishimaru, Junshiro; Hiraoka, Kazuyoshi [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan)

    1994-12-31

    Steam turbine plant, which burns BOG (Boil-Off Gas) as fuel, has bene installed for LNG carriers with the necessity of disposing BOG safely. Are other plants unpractical for LNG carriers? To answer to this question, this paper evaluates (1) dual fuel diesel, (2) diesel with reliquefaction plant, (3) diesel with auxiliary boiler and power assist motor, (4) gas turbine/steam turbine and (5) steam turbine with CRP (Contra Rotating Propeller) from several aspects, such as safety and reliability, maintainability and operability, economy and effect on environment. Based on the above studies, this paper proposes Steam turbine with CRP plant as a new energy saving system for future LNG carriers.

  20. 75 FR 11169 - AES Sparrows Point LNG, LLC; Mid-Atlantic Express, LLC; Notice of Availability of the Revised...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ...Pennsylvania for the Proposed Sparrows Point LNG Terminal and Pipeline Project March 1, 2010...liquefied natural gas (LNG) import terminal and natural gas pipeline proposed by...construction and operation of the following LNG terminal and natural gas pipeline...

  1. 76 FR 76698 - Dominion Cove Point LNG, LP; Application To Export Domestic Liquefied Natural Gas to Non-Free...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ...authorization to export LNG from the Cove Point LNG Terminal, owned by DCP, in Calvert County, Maryland, to...Richmond, Virginia. DCP owns the Cove Point LNG Terminal (Terminal), as well as the 88- mile Cove Point Pipeline...

  2. 75 FR 20591 - AES Sparrows Point LNG, LLC and Mid-Atlantic Express, LLC; Notice of Final General Conformity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-20

    ...Pennsylvania for the Proposed Sparrows Point LNG Terminal and Pipeline Project April 13, 2010...liquefied natural gas (LNG) import terminal and natural gas pipeline proposed by...construction and operation of the following LNG terminal and natural gas pipeline...

  3. 75 FR 353 - AES Sparrows Point LNG, LLC and Mid-Atlantic Express, LLC; Notice of Availability of the Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ...Maryland for the Proposed Sparrows Point LNG Terminal and Pipeline Project December 29, 2009...liquefied natural gas (LNG) import terminal and natural gas pipeline proposed by...construction and operation of the following LNG terminal and natural gas pipeline...

  4. 40 CFR Table W - 5 of Subpart W-Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Methane Emission Factors for Liquefied Natural Gas (LNG) Storage W Table W...GREENHOUSE GAS REPORTING Petroleum and Natural Gas Systems Definitions. Pt...Methane Emission Factors for Liquefied Natural Gas (LNG) Storage LNG...

  5. 78 FR 42587 - Deepwater Port License: Amendment of the Neptune LNG LLC Deepwater Port License and Temporary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-16

    ...Deepwater Port License: Amendment of the Neptune LNG LLC Deepwater Port License and...Temporary Suspension of Operations at the Neptune LNG Deepwater Port AGENCY: Maritime...decision to approve the request of Neptune LNG LLC (Neptune) for a...

  6. Numerical Simulation and Optimazation of Small Scale LNG Plant

    NASA Astrophysics Data System (ADS)

    Li, H. Y.; Jia, L. X.; Fan, Q. H.; Yin, Q. S.

    2006-04-01

    The LNG20 is a small-scale natural gas liquefier. Its capacity is 20 cube meters LNG per day. This liquefier could be used for the pipeline gas, coalbed gas, oil field gas liquefaction and peakshaving plant for town gas gate station and natural gas power plant. Two processing cycles are applied to LNG20, nitrogen expander cycle and mixed refrigerant cycle. In this report, two feed gases are the target sources; one is the pipeline gas in "West-to-east pipeline gas" in a gate station in Zhejiang province and coalbed gas in Northeast China. The numerical simulation and optimization for the LNG20 were carried out to obtain the design parameters.

  7. Conceptual Liquefied Natural Gas (LNG) terminal design for Kuwait

    E-print Network

    Aljeeran, Fares

    2006-08-16

    This research study investigated a new conceptual design for a modular structural configuration incorporating storage for Liquefied Natural Gas (LNG) within the base of the platform structure. The structure, referred to as a modified gravity base...

  8. The Phoenix series large scale LNG pool fire experiments.

    SciTech Connect

    Simpson, Richard B.; Jensen, Richard Pearson; Demosthenous, Byron; Luketa, Anay Josephine; Ricks, Allen Joseph; Hightower, Marion Michael; Blanchat, Thomas K.; Helmick, Paul H.; Tieszen, Sheldon Robert; Deola, Regina Anne; Mercier, Jeffrey Alan; Suo-Anttila, Jill Marie; Miller, Timothy J.

    2010-12-01

    The increasing demand for natural gas could increase the number and frequency of Liquefied Natural Gas (LNG) tanker deliveries to ports across the United States. Because of the increasing number of shipments and the number of possible new facilities, concerns about the potential safety of the public and property from an accidental, and even more importantly intentional spills, have increased. While improvements have been made over the past decade in assessing hazards from LNG spills, the existing experimental data is much smaller in size and scale than many postulated large accidental and intentional spills. Since the physics and hazards from a fire change with fire size, there are concerns about the adequacy of current hazard prediction techniques for large LNG spills and fires. To address these concerns, Congress funded the Department of Energy (DOE) in 2008 to conduct a series of laboratory and large-scale LNG pool fire experiments at Sandia National Laboratories (Sandia) in Albuquerque, New Mexico. This report presents the test data and results of both sets of fire experiments. A series of five reduced-scale (gas burner) tests (yielding 27 sets of data) were conducted in 2007 and 2008 at Sandia's Thermal Test Complex (TTC) to assess flame height to fire diameter ratios as a function of nondimensional heat release rates for extrapolation to large-scale LNG fires. The large-scale LNG pool fire experiments were conducted in a 120 m diameter pond specially designed and constructed in Sandia's Area III large-scale test complex. Two fire tests of LNG spills of 21 and 81 m in diameter were conducted in 2009 to improve the understanding of flame height, smoke production, and burn rate and therefore the physics and hazards of large LNG spills and fires.

  9. Fitness for service applications in LNG plants

    SciTech Connect

    Bagnoli, D.L.; Polk, C.J.; Yin, H. [Mobil Research and Development Corp., Princeton, NJ (United States); Gordon, J.R. [Edison Welding Inst., Columbus, OH (United States)

    1995-12-31

    Fitness-for-service assessments can provide information regarding operational reliability of equipment. However, to be meaningful, such assessments require an analytical procedure to determine the ability of engineering structures to tolerate the presence of weld flaws. In recent years, there has been a significant interest in this technology by the refining and petrochemical industries for predicting and avoiding fracture in pressurized components. Most applications have covered pressure vessel and piping where carbon and low alloy steels are the traditional materials of construction. More recently, fitness for service questions have developed for equipment with highly ductile materials such as aluminum alloys. In order to handle these questions ductile tearing resistance must be considered and R curve methods are required. In this paper examples are cited where fitness for service assessments were required for an aluminum heat exchanger in LNG service. Suitable R curve data were developed in order to establish flaw tolerance following UT inspections of this equipment.

  10. Liquid dynamic loads in LNG cargo tanks

    SciTech Connect

    Bass, R.L. III; Bowles, E.B.; Cox, P.A.

    1980-01-01

    To evaluate the dynamic sloshing loads in LNG cargo tanks, marine engineers comprehensively reviewed the worldwide scale-model sloshing data and, for the purposes of defining the design load coefficients, reduced the data to a common format. Additional scale-model laboratory experiments established the pressure-time histories needed to perform a structural response analysis. The analytical methods presented provide techniques for determining the wall's structural response to the dynamic slosh loads. Applicable to membrane, semimembrane, gravity, and pressure tanks, the design methodology sequence consists of (1) comparing ship periods with resonant sloshing periods, (2) establishing loads based on the load coefficients, and (3) designing the tank structures by specifically delineated methods that vary with tank type.

  11. Prediction of sloshing loads in LNG ships

    SciTech Connect

    Peck, J.C.; Jean, P.

    1981-01-01

    To improve LNG-sloshing prediction methodology, researchers studied high-fill-ratio sloshing phenomena via computer models and developed the MDC 2D slosh code, which accounts for large-amplitude sloshing, interaction with tank ceiling and chamfers, and liquid compressibility. Application of the MDC code showed that computer programs based on the marker-and-cell technique can serve as practical design and research tools. The analytical results demonstrated that (1) for realistic random ship motions, increasing the chamfer size is beneficial and (2) under pure vacuum ullage conditions, the inability to properly scale liquid compressibility in model tests requires the use of compressible pressure scaling laws. The good correlation between liquid surface motion and code predictions verified the accuracy of both the code and Froude scaling for liquid motions.

  12. LNG Safety Research: FEM3A Model Development

    SciTech Connect

    None

    2006-09-30

    The initial scope of work for this project included: 1) Improving the FEM3A advanced turbulence closure module, 2) Adaptation of FEM3A for more general applications, and 3) Verification of dispersion over rough surfaces, with and without obstacle using the advanced turbulence closure module. These work elements were to be performed by Chemical Hazards Research Center (CHRC), Department of Chemical Engineering, University of Arkansas as a subcontractor to Gas Technology Institute (GTI). The tasks for GTI included establishment of the scientific support base for standardization of the FEM3A model, project management, technology transfer, and project administration. Later in the course of the project, the scope of work was modified by the National Energy Technology Laboratories (NETL) to remove the emphasis on FEM3A model and instead, develop data in support of NETL’s FLUENT modeling. With this change, GTI was also instructed to cease activities relative to FEM3A model. GTI’s technical activities through this project included the initial verification of FEM3A model, provision of technical inputs to CHRC researchers regarding the structure of the final product, and participation in technical discussion sessions with CHRC and NETL technical staff. GTI also began the development of a Windows-based front end for the model but the work was stopped due to the change in scope of work. In the meantime, GTI organized a workshop on LNG safety in Houston, Texas. The workshop was very successful and 75 people from various industries participated. All technical objectives were met satisfactorily by Dr. Jerry Havens and Dr. Tom Spicer of CHRC and results are presented in a stand-alone report included as Appendix A to this report.

  13. LNG Safety Research: FEM3A Model Development

    SciTech Connect

    Iraj A. Salehi; Jerry Havens; Tom Spicer

    2006-09-30

    The initial scope of work for this project included: (1) Improving the FEM3A advanced turbulence closure module, (2) Adaptation of FEM3A for more general applications, and (3) Verification of dispersion over rough surfaces, with and without obstacle using the advanced turbulence closure module. These work elements were to be performed by Chemical Hazards Research Center (CHRC), Department of Chemical Engineering, University of Arkansas as a subcontractor to Gas Technology Institute (GTI). The tasks for GTI included establishment of the scientific support base for standardization of the FEM3A model, project management, technology transfer, and project administration. Later in the course of the project, the scope of work was modified by the National Energy Technology Laboratories (NETL) to remove the emphasis on FEM3A model and instead, develop data in support of NETL's FLUENT modeling. With this change, GTI was also instructed to cease activities relative to FEM3A model. GTI's technical activities through this project included the initial verification of FEM3A model, provision of technical inputs to CHRC researchers regarding the structure of the final product, and participation in technical discussion sessions with CHRC and NETL technical staff. GTI also began the development of a Windows-based front end for the model but the work was stopped due to the change in scope of work. In the meantime, GTI organized a workshop on LNG safety in Houston, Texas. The workshop was very successful and 75 people from various industries participated. All technical objectives were met satisfactorily by Dr. Jerry Havens and Dr. Tom Spicer of CHRC and results are presented in a stand-alone report included as Appendix A to this report.

  14. Fuel vapor canister

    SciTech Connect

    Moskaitis, R.J.; Ciuffetelli, L.A.

    1991-03-26

    This paper discusses an improved fuel vapor storage canister for use in a vehicle emission system of the type utilizing an enclosure with an interior communicated with a source of fuel vapor. The improved canister comprises: the enclosure having a mixture including particles of activated charcoal and many pieces of foam rubber, the pieces of foam rubber in the mixture being randomly and substantially evenly dispersed whereby substantially all the charcoal particles are spaced relatively closely to at least one foam rubber piece; the mixture being packed into the enclosure under pressure so that the pieces of foam rubber are compressed enough to tightly secure the charcoal particles one against another to prevent a griding action therebetween.

  15. LNG cascading damage study. Volume I, fracture testing report.

    SciTech Connect

    Petti, Jason P.; Kalan, Robert J.

    2011-12-01

    As part of the liquefied natural gas (LNG) Cascading Damage Study, a series of structural tests were conducted to investigate the thermal induced fracture of steel plate structures. The thermal stresses were achieved by applying liquid nitrogen (LN{sub 2}) onto sections of each steel plate. In addition to inducing large thermal stresses, the lowering of the steel temperature simultaneously reduced the fracture toughness. Liquid nitrogen was used as a surrogate for LNG due to safety concerns and since the temperature of LN{sub 2} is similar (-190 C) to LNG (-161 C). The use of LN{sub 2} ensured that the tests could achieve cryogenic temperatures in the range an actual vessel would encounter during a LNG spill. There were four phases to this test series. Phase I was the initial exploratory stage, which was used to develop the testing process. In the Phase II series of tests, larger plates were used and tested until fracture. The plate sizes ranged from 4 ft square pieces to 6 ft square sections with thicknesses from 1/4 inches to 3/4 inches. This phase investigated the cooling rates on larger plates and the effect of different notch geometries (stress concentrations used to initiate brittle fracture). Phase II was divided into two sections, Phase II-A and Phase II-B. Phase II-A used standard A36 steel, while Phase II-B used marine grade steels. In Phase III, the test structures were significantly larger, in the range of 12 ft by 12 ft by 3 ft high. These structures were designed with more complex geometries to include features similar to those on LNG vessels. The final test phase, Phase IV, investigated differences in the heat transfer (cooling rates) between LNG and LN{sub 2}. All of the tests conducted in this study are used in subsequent parts of the LNG Cascading Damage Study, specifically the computational analyses.

  16. 75 FR 74029 - Sabine Pass LNG, L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ...CP11-32-000] Sabine Pass LNG, L.P.; Notice of Application...November 12, 2010, Sabine Pass LNG, L.P. (Sabine Pass...operate a redundant high pressure boil off gas compressor at its existing Sabine Pass LNG Terminal, located in...

  17. 77 FR 788 - Southern LNG Company, L.L.C.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ...December 15, 2011, Southern LNG Company, L.L.C. (SLNG...its liquefied natural gas (LNG) terminal located at Elba...adequate compression to allow boil-off gas generated naturally within...need to regasify additional LNG as is required with the...

  18. Development of an FBG-based low temperature measurement system for cargo containment of LNG tankers

    Microsoft Academic Search

    D. G. Kim; W. Yoo; P. Swinehart; B. Jiang; T. Haber; A. Mendez

    2007-01-01

    Given the growing demand for oil and natural gas to meet the world's energy needs, there is nowadays renewed interest in the use of liquefied natural gas (LNG) systems. For LNG to remain in its liquid phase, the gas has to be kept at cryogenic temperatures (< 160°C). And, as part of the LNG supply process, it becomes necessary to

  19. 78 FR 23552 - Dominion Cove Point LNG, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-19

    ...PF12-16-000] Dominion Cove Point LNG, LP; Notice of Application Take notice that on April 1, 2013, Dominion Cove Point LNG, LP (Dominion Cove Point), 120 Tredegar...for the export at its existing Cove Point LNG terminal in Calvert County,...

  20. 76 FR 78188 - Reconsideration of Letters of Recommendation for Waterfront Facilities Handling LNG and LHG

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-16

    ...Recommendation for Waterfront Facilities Handling LNG and LHG AGENCY: Coast Guard, DHS. ACTION...of a waterway for liquefied natural gas (LNG) or liquefied hazardous gas (LHG) marine...Federal Register LHG Liquefied hazardous gas LNG Liquefied natural gas LOR Letter of...

  1. 75 FR 51989 - Southern LNG Company, L.L.C.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-24

    ...Commission [Docket No. CP10-477-000] Southern LNG Company, L.L.C.; Notice of Application August...Take notice that on August 4, 2010, Southern LNG Company, L.L.C. (Southern LNG), Post Office Box 2563, Birmingham,...

  2. 75 FR 53688 - Southern LNG Company, L.L.C.; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ...Commission [Docket No. RP10-829-000] Southern LNG Company, L.L.C.; Notice of Technical Conference...Washington, DC 20426. On June 7, 2010, Southern LNG Company, L.L.C. (Southern LNG) filed a tariff sheet to revise its tariff...

  3. 76 FR 31326 - Gulf LNG Pipeline, LLC; Notice of Request Under Blanket Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ...Commission [Docket No. CP11-486-000 ] Gulf LNG Pipeline, LLC; Notice of Request Under...Take notice that on May 18, 2011, Gulf LNG Pipeline, LLC (GLNG Pipeline), Colonial...to Margaret G. Coffman, Counsel, Gulf LNG Pipeline Company, LLC, Colonial...

  4. 33 CFR 127.703 - Access to the marine transfer area for LNG.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Access to the marine transfer area for LNG. 127.703 Section 127.703 Navigation... Access to the marine transfer area for LNG. The operator shall ensure that— (a) Access to the marine transfer area for LNG from the shoreside and the waterside is...

  5. The diseconomics of long-haul LNG trading

    SciTech Connect

    Stauffer, T.R.

    1995-12-31

    Long-haul liquefied natural gas (LNG) exports yield little or no economic rent. Trades, such as Borneo to Japan, are economical, but government takes otherwise are minimal. Today, the price of LNG is capped by the technical option of modifying gas turbines to bum liquid fuels. The maximum premium for LNG is less than 50 cents per thousand cubic feet (/Mcf), and buyers are resisting any price above oil parity. Costs of LNG are high and increase with distance. The netback value is zero or even negative for the longer-distance trades. The value of extracted co-products (natural gas liquids) is 50 cents to $1/Mcf. These credits are the principal source of profit, especially for foreign partners because natural gas liquids are taxed at low {open_quotes}industrial{close_quotes} rates. Returns are even less when the gas supply is nonassociated so that the project must {open_quotes}pay{close_quotes} the production costs as well. Some exporting countries profit; but the Organization of the Petroleum Exporting Countries as a whole looses because low-revenue LNG energy displaces at the margin fully taxed oil.

  6. Overview study of LNG release prevention and control systems

    SciTech Connect

    Pelto, P.J.; Baker, E.G.; Holter, G.M.; Powers, T.B.

    1982-03-01

    The liquefied natural gas (LNG) industry employs a variety of release prevention and control techniques to reduce the likelihood and the consequences of accidental LNG releases. A study of the effectiveness of these release prevention and control systems is being performed. Reference descriptions for the basic types of LNG facilities were developed. Then an overview study was performed to identify areas that merit subsequent and more detailed analyses. The specific objectives were to characterize the LNG facilities of interest and their release prevention and control systems, identify possible weak links and research needs, and provide an analytical framework for subsequent detailed analyses. The LNG facilities analyzed include a reference export terminal, marine vessel, import terminal, peakshaving facility, truck tanker, and satellite facility. A reference description for these facilities, a preliminary hazards analysis (PHA), and a list of representative release scenarios are included. The reference facility descriptions outline basic process flows, plant layouts, and safety features. The PHA identifies the important release prevention operations. Representative release scenarios provide a format for discussing potential initiating events, effects of the release prevention and control systems, information needs, and potential design changes. These scenarios range from relatively frequent but low consequence releases to unlikely but large releases and are the principal basis for the next stage of analysis.

  7. Floating LNG plant will stress reliability and safety

    SciTech Connect

    Kinney, C.D.; Schulz, H.R.; Spring, W.

    1997-07-01

    Mobil has developed a unique floating LNG plant design after extensive studies that set safety as the highest priority. The result is a production, storage and offloading platform designed to produce 6 million tons per year of LNG and up to 55,000 bpd of condensate from 1 Bcfd of feed gas. All production and off-loading equipment is supported by a square donut-shaped concrete hull, which is spread-moored. The hull contains storage tanks for 250,000 m{sup 3} of LNG, 6540,000 bbl of condensate and ballast water. Both LNG and condensate can be directly offloaded to shuttle tankers. Since the plant may be moved to produce from several different gas fields during its life, the plant and barge were designed to be generic. It can be used at any location in the Pacific Rim, with up to 15% CO{sub 2}, 100 ppm H{sub 2}S, 55 bbl/MMcf condensate and 650 ft water depth. It can be modified to handle other water depths, depending upon the environment. In addition, it is much more economical than an onshore grassroots LNG plant, with potential capital savings of 25% or more. The paper describes the machinery, meteorology and oceanography, and safety engineering.

  8. Vapor fragrancer

    NASA Astrophysics Data System (ADS)

    Sang, Q. Tran; Bryant, Timothy D.

    1987-05-01

    This invention relates to a vapor fragrancer for continuously, uniformly, and economically odorizing or deodorizing an environment. Homes, offices, automobiles, and space stations require either odorizing or deodorizing of the atmosphere to create pleasant conditions for work or leisure. A vapor fragrancer is provided to accomplish these goals. A supplier continuously supplies a predetermined amount of desired liquid fragrance from a container to a retaining material, which is positioned in the circulation path of the atmosphere. The supplier is either a low powered pump or a gravity dispenser. The atmosphere flowing in a circulation path passes over the retaining material containing the liquid fragrance and lifts a fragrant vapor from the retaining material. The atmosphere is thereby continuously and uniformly fragranced.

  9. Non-contraceptive uses of levonorgestrel-releasing hormone system (LNG-IUS)—A systematic enquiry and overview

    Microsoft Academic Search

    Rajesh Varma; Deepali Sinha; Janesh K. Gupta

    2006-01-01

    Levonorgestrel releasing-intrauterine systems (LNG-IUS) were originally developed as a method of contraception in the mid 1970s. The only LNG-IUS approved for general public use is the Mirena® LNG-IUS, which releases 20mcg of levonorgestrel per day directly in to the uterine cavity. However, new lower dose (10 and 14mcg per day) and smaller sized LNG-IUS (MLS, FibroPlant-LNG) are currently under clinical

  10. Monitoring, safety systems for LNG and LPG operators

    SciTech Connect

    True, W.R.

    1998-11-16

    Operators in Korea and Australia have chosen monitoring and control systems in recent contracts for LNG and LPG storage. Korea Gas Corp. (Kogas) has hired Whessoe Varec, Calais, to provide monitoring systems for four LNG storage tanks being built at Kogas` Inchon terminal. For Elgas Ltd., Port Botany, Australia, Whessoe Varec has already shipped a safety valve-shutdown system to a new LPG cavern-storage facility under construction. The paper describes the systems, terminal monitoring, dynamic approach to tank management, and meeting the growing demand for LPG.

  11. Thermal boundary layer development in dispersed flow film boiling

    E-print Network

    Hull, Lawrence M.

    1982-01-01

    Dispersed flow film boiling consists of a dispersion of droplets which are carried over a very hot surface by their vapor. This process occurs in cryogenic equipment and wet steam turbines. It is also of interest in the ...

  12. Pressure Build-Up in LNG and LH2 Vehicular Cryogenic Storage Tanks

    NASA Astrophysics Data System (ADS)

    Barclay, J. A.; Rowe, A. M.; Barclay, M. A.

    2004-06-01

    The use of LNG and LH2 as fuels in heavy duty vehicles is increasing steadily because cryogenic liquids provides superior volumetric and gravimetric energy densities compared to other means of on-board storage. Although several sizes and types of tanks exist, a typical vehicular storage tank has a volume of ˜400 liters (˜100 gallons). The pressure in the ullage space of a tank freshly filled is usually ˜0.25 MPa but may vary during use from ˜0.25 MPa (˜20 psig) to ˜0.92 MPa (˜120 psig). Cryogenic vehicular tanks are typically dual-walled, stainless steel vessels with vacuum and superinsulation isolation between the inner and outer vessel walls. The heat leaks into such tanks are measured as a percentage boil-off per day. For a storage tank of vehicular size range, the boil-off may be ˜ 1 % day, depending upon the cryogen and the quality of the tank. The corresponding heat leak into the cryogenic liquid vaporizes a certain amount of liquid that in turn increases the pressure in the tank which in turn significantly influences the properties of the cryogens. We have used a novel approach to calculate the increase in pressure of LNG and LH2 in a closed cryogenic vessel with a fixed heat leak as a function of time using real equations of state for the properties of the cryogens. The method and results for the time it takes for a freshly filled tank to increase in pressure from the filling pressure of ˜0.25 MPa to a venting pressure of ˜1.73 MPa are presented.

  13. Fire performance of LNG carriers insulated with polystyrene foam.

    PubMed

    Havens, Jerry; Venart, James

    2008-10-30

    Analysis of the response of a liquid-full Moss Sphere LNG tank insulated with polystyrene foam to an engulfing LNG fire indicates that current regulatory requirements for pressure relief capacity sufficient to prevent tank rupture are inadequate. The inadequacy of the current requirements stems primarily from two factors. Firstly, the area of the Moss Sphere protruding above what would be the nominal deck on a conventional carrier, which is protected only by a steel weather cover from exposure to heat from a tank-engulfing fire, is being underestimated. Secondly, aluminum foil-covered polystyrene foam insulation applied to the exterior of the LNG tank is protected above the deck only by the steel weather cover under which the insulation could begin to melt in as little as 1-3 min, and could completely liquefy in as few as 10 min. U.S. and International Regulations require that the insulations on the above-deck portion of tanks have approved fire proofing and stability under fire exposure. Polystyrene foam, as currently installed on LNG carriers, does not appear to meet these criteria. As a result of these findings, but giving no consideration to the significant potential for further damage if the polystyrene should burn, the boil-off rate is predicted to be an order-of-magnitude higher than provided for by current PRV sizing requirements. PMID:18372107

  14. Comparison of hypothetical LNG and fuel oil fires on water

    Microsoft Academic Search

    William Lehr; Debra Simecek-Beatty

    2004-01-01

    Large spills of refined petroleum products have been an occasional occurrence over the past few decades. This has not been true for large spills of liquefied natural gas (LNG). This paper compares the likely similarities and differences between accidental releases from a ship of sizable quantities of these different hydrocarbon fuels, their subsequent spreading, and possible pool-fire behavior. Quantitative estimates

  15. Evaluation of liquid dynamic loads in slack LNG cargo tanks

    SciTech Connect

    Cox, P.A.; Bowles, E.B.; Bass, R.L.

    1980-05-01

    This report provides an evaluation of dynamic sloshing loads in slack LNG cargo tanks. A comprehensive review of worldwide scale model sloshing data is presented. The design methodology presented in this article is based on a thorough review of the literature supplemented by additional experiments and analytical studies. 101 refs.

  16. Soot-Free Combustion Of Methane And LNG

    NASA Technical Reports Server (NTRS)

    Bossard, John

    1992-01-01

    Neither methane nor liquefied natural gas (LNG) produces soot when burned in turbine simulator with liquid oxygen under conditions like those in gas-generator section of rocket engine. Experiments conducted to determine if these fuels behave similarly to other hydrocarbon fuels, which give off soot coating turbomachinery and reducing performance.

  17. 40 CFR Table W - 5 of Subpart W of Part 98-Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Methane Emission Factors for Liquefied Natural Gas (LNG) Storage W Table W...GREENHOUSE GAS REPORTING Petroleum and Natural Gas Systems Definitions. Pt...Methane Emission Factors for Liquefied Natural Gas (LNG) Storage LNG...

  18. 40 CFR Table W - 5 of Subpart W of Part 98-Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Methane Emission Factors for Liquefied Natural Gas (LNG) Storage W Table W...GREENHOUSE GAS REPORTING Petroleum and Natural Gas Systems Definitions. Pt...Methane Emission Factors for Liquefied Natural Gas (LNG) Storage LNG...

  19. Investigation of propulsion system for large LNG ships

    NASA Astrophysics Data System (ADS)

    Sinha, R. P.; Nik, Wan Mohd Norsani Wan

    2012-09-01

    Requirements to move away from coal for power generation has made LNG as the most sought after fuel source, raising steep demands on its supply and production. Added to this scenario is the gradual depletion of the offshore oil and gas fields which is pushing future explorations and production activities far away into the hostile environment of deep sea. Production of gas in such environment has great technical and commercial impacts on gas business. For instance, laying gas pipes from deep sea to distant receiving terminals will be technically and economically challenging. Alternative to laying gas pipes will require installing re-liquefaction unit on board FPSOs to convert gas into liquid for transportation by sea. But, then because of increased distance between gas source and receiving terminals the current medium size LNG ships will no longer remain economical to operate. Recognizing this business scenario shipowners are making huge investments in the acquisition of large LNG ships. As power need of large LNG ships is very different from the current small ones, a variety of propulsion derivatives such as UST, DFDE, 2-Stroke DRL and Combined cycle GT have been proposed by leading engine manufacturers. Since, propulsion system constitutes major element of the ship's capital and life cycle cost, which of these options is most suited for large LNG ships is currently a major concern of the shipping industry and must be thoroughly assessed. In this paper the authors investigate relative merits of these propulsion options against the benchmark performance criteria of BOG disposal, fuel consumption, gas emissions, plant availability and overall life cycle cost.

  20. Two-phase heat transfer and pressure drop of LNG during saturated flow boiling in a horizontal tube

    NASA Astrophysics Data System (ADS)

    Chen, Dongsheng; Shi, Yumei

    2013-12-01

    Two-phase heat transfer and pressure drop of LNG (liquefied natural gas) have been measured in a horizontal smooth tube with an inner diameter of 8 mm. The experiments were conducted at inlet pressures from 0.3 to 0.7 MPa with a heat flux of 8-36 kW m-2, and mass flux of 49.2-201.8 kg m-2 s-1. The effect of vapor quality, inlet pressure, heat flux and mass flux on the heat transfer characteristic are discussed. The comparisons of the experimental data with the predicted value by existing correlations are analyzed. Zou et al. (2010) correlation shows the best accuracy with 24.1% RMS deviation among them. Moreover four frictional pressure drop methods are also chosen to compare with the experimental database.

  1. Qualitative Risk Assessment for an LNG Refueling Station and Review of Relevant Safety Issues

    SciTech Connect

    Siu, N.; Herring, J.S.; Cadwallader, L.; Reece, W.; Byers, J.

    1998-02-01

    This report is a qualitative assessment of the public and worker risk involved with the operation of a liquefied natural gas (LNG) vehicle refueling facility. This study includes facility maintenance and operations, tank truck deliveries, and end-use vehicle fueling; it does not treat the risks of LNG vehicles on roadways. Accident initiating events are identified by using a Master Logic Diagram, a Failure Modes and Effects Analysis, and historical operating experiences. The event trees were drawn to depict possible sequences of mitigating events following the initiating events. The phenomenology of LNG and other vehicle fuels is discussed to characterize the hazard posed by LNG usage. Based on the risk modeling and analysis, recommendations are given to improve the safety of LNG refueling stations in the areas of procedures and training, station design, and the dissemination of ``best practice`` information throughout the LNG community.

  2. Kalimantan field development hikes gas supply for LNG export

    SciTech Connect

    Suharmoko, G.R. (Total Indonesie, Balikpapan (ID))

    1991-10-14

    This paper reports on the development of Tambora and Tunu gas fields in Kalimantan that have increased available gas supply for the export of liquefied natural gas (LNG) from Indonesia. The demand for LNG is increasing in the energy thirsty Far East market. And Indonesia, the world's largest exporter, is keeping pace by expanding the Bontang liquefaction plant in East Kalimantan. A fifth train, with a capacity of around 2.5 million tons/year, began operating in January 1990. Start-up of a sixth train, of identical capacity, is planned for January 1994. The Bontang plant is operated by PT Badak on behalf of Pertamina, the Indonesian state oil and gas mining company. The feed to the fifth train comes primarily from the first-phase development of Total Indonesie's two gas fields, Tambora and Tunu. The sixth train will be fed by a second-phase development of the Tunu field.

  3. Using LNG as a Fuel in Heavy-Duty Tractors

    SciTech Connect

    Liquid Carbonic, Inc. and Trucking Research Institute

    1999-08-09

    Recognizing the lack of operational data on alternative fuel heavy-truck trucks, NREL contracted with the Trucking Research Institute (TRI) in 1994 to obtain a cooperative agreement with Liquid Carbonic. The purpose of this agreement was to (1) purchase and operate liquid natural gas- (LNG-) powered heavy-duty tractor-trailers with prototype Detroit Diesel Corporation (DDC) Series 60 natural gas (S60G) engines in over-the-road commercial service applications; and (2) collect and provide operational data to DDC to facilitate the on-road prototype development of the engine and to NREL for the Alternative Fuels Data Center. The vehicles operated from August 1994 through April of 1997 and led to a commercially available, emissions-certified S60G in 1998. This report briefly documents the engine development, the operational characteristics of LNG, and the lessons learned during the project.

  4. 78 FR 17189 - Trunkline LNG Export, LLC; Application for Long-Term Authorization to Export Liquefied Natural...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ...Bcf/day of natural gas), from the LNG terminal in Lake Charles, Louisiana (Lake Charles Terminal). TLNG Export requests this authorization...owns and operates the Lake Charles LNG Terminal. TLNG Export will own the proposed...

  5. Analysis of temperature and pressure changes in liquefied natural gas (LNG) cryogenic tanks

    NASA Astrophysics Data System (ADS)

    Chen, Q.-S.; Wegrzyn, J.; Prasad, V.

    2004-10-01

    Liquefied natural gas (LNG) is being developed as a transportation fuel for heavy vehicles such as trucks and transit buses, to lessen the dependency on oil and to reduce greenhouse gas emissions. The LNG stations are properly designed to prevent the venting of natural gas (NG) from LNG tanks, which can cause evaporative greenhouse gas emissions and result in fluctuations of fuel flow and changes of fuel composition. Boil-off is caused by the heat added into the LNG fuel during the storage and fueling. Heat can leak into the LNG fuel through the shell of tank during the storage and through hoses and dispensers during the fueling. Gas from tanks onboard vehicles, when returned to LNG tanks, can add additional heat into the LNG fuel. A thermodynamic and heat transfer model has been developed to analyze different mechanisms of heat leak into the LNG fuel. The evolving of properties and compositions of LNG fuel inside LNG tanks is simulated. The effect of a number of buses fueled each day on the possible total fuel loss rate has been analyzed. It is found that by increasing the number of buses, fueled each day, the total fuel loss rate can be reduced significantly. It is proposed that an electric generator be used to consume the boil-off gas or a liquefier be used to re-liquefy the boil-off gas to reduce the tank pressure and eliminate fuel losses. These approaches can prevent boil-off of natural gas emissions, and reduce the costs of LNG as transportation fuel.

  6. 75 FR 57766 - Notice of Petition To Amend Authorizations Under Section 3 of the Natural Gas Act; Cameron LNG, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ...Section 3 of the Natural Gas Act; Cameron LNG, LLC September 15, 2010. Take notice that on September 3, 2010, Cameron LNG, LLC (Cameron), 101 Ash Street, San...operate its existing liquefied natural gas (LNG) terminal facility located in Cameron...

  7. 77 FR 58118 - Freeport LNG Development, L.P., FLNG Liquefaction, LLC, FLNG Liquefaction 2, LLC, FLNG...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-19

    ...CP12-509-000; PF11-2-000] Freeport LNG Development, L.P., FLNG Liquefaction...notice that on August 31, 2012, Freeport LNG Development, L.P., FLNG Liquefaction...constructed adjacent to the existing Freeport LNG Development, L.P.'s liquefied...

  8. 78 FR 66909 - Sabine Pass Liquefaction, LLC; Sabine Pass LNG, L.P.; Notice of Application to Amend...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ...Sabine Pass Liquefaction, LLC; Sabine Pass LNG, L.P.; Notice of Application to Amend...Pass Liquefaction, LLC and Sabine Pass LNG, L.P. (collectively, Sabine Pass...2013, in order to increase the total LNG production capacity of the...

  9. 77 FR 65546 - Sabine Pass Liquefaction, LLC; Sabine Pass LNG, L.P.; Notice of Petition To Amend Authorizations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ...Sabine Pass Liquefaction, LLC; Sabine Pass LNG, L.P.; Notice of Petition To Amend...Pass Liquefaction, LLC and Sabine Pass LNG, L.P. (collectively, Sabine Pass...Modification Project) at the existing Sabine Pass LNG Terminal, located in Cameron Parish,...

  10. 76 FR 9573 - Sabine Pass Liquefaction, LLC and Sabine Pass LNG, L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ...Pass Liquefaction, LLC and Sabine Pass LNG, L.P.; Notice of Application Take notice...Pass Liquefaction, LLC and Sabine Pass LNG, L.P. (collectively, Sabine Pass...Liquefaction Project) at the existing Sabine Pass LNG Terminal, located in Cameron Parish,...

  11. 78 FR 62344 - Sabine Pass Liquefaction Expansion, LLC, Sabine Pass Liquefaction, LLC, and Sabine Pass LNG, L.P...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-18

    ...Pass Liquefaction, LLC, and Sabine Pass LNG, L.P., Cheniere Creole Trail Pipeline...Pass Liquefaction, LLC, and Sabine Pass LNG, L.P. (collectively referred to as...operate additional liquefied natural gas (LNG) export facilities at the Sabine Pass...

  12. 75 FR 61475 - Cameron LNG, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ...Docket No. CP10-496-000] Cameron LNG, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed Cameron LNG Export Project and Request for Comments...the environmental impacts of the Cameron LNG Export Project involving the export of...

  13. Numerical Simulation of Sloshing in LNG Tanks with a Compressible Two-Phase Model

    Microsoft Academic Search

    Rik Wemmenhove; Roel Luppes; Arthur E. P. Veldman; Tim Bunnik

    2007-01-01

    The study of liquid dynamics in LNG tanks is getting more and more important with the actual trend of LNG tankers sailing with partially filled tanks. The effect of sloshing liquid in the tanks on pressure levels at the tank walls and on the overall ship motion indicates the relevance of an accurate simulation of the fluid behaviour. This paper

  14. Sloshing in the LNG shipping industry: risk modelling through multivariate heavy-tail analysis

    E-print Network

    Sloshing in the LNG shipping industry: risk modelling through multivariate heavy-tail analysis In the liquefied natural gas (LNG) shipping industry, the phenomenon of slosh- ing can lead to the occurrence and corresponding to a worst-case risk analysis, is applied to the study of sloshing. Multivariate heavy

  15. Risk-based siting considerations for LNG terminals – Comparative perspectives of United States & Europe

    Microsoft Academic Search

    Frank A. Licari; C. David Weimer

    2011-01-01

    Siting regulations and industrial standards for liquefied natural gas (LNG) terminals are evolving along different paths within Europe and the United States (U.S.). The 49 Code of Federal Regulations (CFR), Part 190 continues to delineate the United States process to adopt and revise safety regulations pertaining to LNG terminals and peak shaving plant sitting.11Title 49, Code of Federal Regulations, Part

  16. 76 FR 40723 - Dominion Cove Point LNG, LP; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ...RP11-2136-000; RP11-2137-000] Dominion Cove Point LNG, LP; Notice of Technical Conference On May 27, 2011, pursuant...section 4 of the Natural Gas Act (NGA), Dominion Cove Point LNG, LP (Cove Point) filed revised tariff records in Docket...

  17. FERC (U. S. Federal Energy Regulatory Commission) judge approves West Coast LNG project

    Microsoft Academic Search

    1979-01-01

    In mid-Aug. 1979, FERC Judge S. Gordon approved Western LNG Terminal Associate's proposed southern California LNG terminal subject to final approval by FERC and by the U.S. Economic Regulatory Administration. The terminal would be located at Little Cojo, near Point Conception. Gordon noted that the California Public Utilities Commission decided in favor of the Point Conception site, and dismissed two

  18. 33 CFR 127.105 - Layout and spacing of marine transfer area for LNG.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Navigable Waters 2 2014-07-01 2014-07-01 false Layout and spacing of marine transfer area for LNG. 127.105 ...Waterfront Facilities Handling Liquefied Natural Gas § 127.105 Layout and spacing of marine transfer area for LNG. (a)...

  19. 78 FR 53750 - EcoEléctrica, L.P.; Notice of Intent To Prepare an Environmental Assessment for the Proposed LNG...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ...LNG to a proposed adjacent LNG truck loading facility that...long, 4-inch-diameter LNG transfer pipeline; an approximately...foot-long, 6-inch-diameter boil-off gas return pipeline; an...1.5-inch-diameter LNG recirculation...

  20. Calibrated vapor generator source

    SciTech Connect

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  1. Fundamental Study on Coking Inhibition for Regenerative Cooled LNG Rocket Engines

    NASA Astrophysics Data System (ADS)

    ??, ??; ??, ??; ??, ??; ??, ??; ??, ??; ??, ??

    Liquefied Natural Gas (LNG) is lower cost, higher density and easier handling than Liquefied hydrogen (LH2), therefore, is expected as the most promising candidate for the next generation rocket propellant. For LNG propellant, a full expander or an expander cycle rocket engine with regenerative cooling system is expected because its molecular weight is middle value between LH2 and Kerosene. Temperature of turbopump driven LNG gas should be higher to improve the specific impulse or combustion pressure for these rocket engine. In this case, coking of LNG in heat exchanger or regenerative cooling system becomes a significant problem. In the present study, two coking inhibition methods, n-C6H14 coating and graphite coating, are presented and their effects are evaluated. Contrary to our expectation, the former method is accelerated the LNG pyrolysis, resulting of coking promotion. On the other hand graphite coating can successfully inhibit coking up to 973K.

  2. Thermodynamic Processes Involving Liquefied Natural Gas at the LNG Receiving Terminals / Procesy termodynamiczne z wykorzystaniem skroplonego gazu ziemnego w terminalach odbiorczych LNG

    NASA Astrophysics Data System (ADS)

    ?aciak, Mariusz

    2013-06-01

    The increase in demand for natural gas in the world, cause that the production of liquefied natural gas (LNG) and in consequences its regasification becoming more common process related to its transportation. Liquefied gas is transported in the tanks at a temperature of about 111K at atmospheric pressure. The process required to convert LNG from a liquid to a gas phase for further pipeline transport, allows the use of exergy of LNG to various applications, including for electricity generation. Exergy analysis is a well known technique for analyzing irreversible losses in a separate process. It allows to specify the distribution, the source and size of the irreversible losses in energy systems, and thus provide guidelines for energy efficiency. Because both the LNG regasification and liquefaction of natural gas are energy intensive, exergy analysis process is essential for designing highly efficient cryogenic installations. Wzrost zapotrzebowania na gaz ziemny na ?wiecie powoduje, ?e produkcja skroplonego gazu ziemnego (LNG), a w konsekwencji jego regazyfikacja, staje si? coraz bardziej powszechnym procesem zwi?zanym z jego transportem. Skroplony gaz transportowany jest w zbiornikach w temperaturze oko?o 111K pod ci?nieniem atmosferycznym. Przebieg procesu regazyfikacji niezb?dny do zamiany LNG z fazy ciek?ej w gazow? dla dalszego transportu w sieci, umo?liwia wykorzystanie egzergii LNG do ró?nych zastosowa?, mi?dzy innymi do produkcji energii elektrycznej. Analiza egzergii jest znan? technik? analizowania nieodwracalnych strat w wydzielonym procesie. Pozwala na okre?lenie dystrybucji, ?ród?a i wielko?ci nieodwracalnych strat w systemach energetycznych, a wi?c ustali? wytyczne dotycz?ce efektywnego zu?ycia energii. Poniewa? zarówno regazyfikacja LNG jak i skraplanie gazu ziemnego s? energoch?onne, proces analizy egzergii jest niezb?dny do projektowania wysoce wydajnych instalacji kriogenicznych.

  3. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    SciTech Connect

    ANDERSON, T.J.

    2006-12-20

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  4. Liquefied Noble Gas (LNG) detectors for detection of nuclear materials

    NASA Astrophysics Data System (ADS)

    Nikkel, J. A.; Gozani, T.; Brown, C.; Kwong, J.; McKinsey, D. N.; Shin, Y.; Kane, S.; Gary, C.; Firestone, M.

    2012-03-01

    Liquefied-noble-gas (LNG) detectors offer, in principle, very good energy resolution for both neutrons and gamma rays, fast response time (hence high-count-rate capabilities), excellent discrimination between neutrons and gamma rays, and scalability to large volumes. They do, however, need cryogenics. LNG detectors in sizes of interest for fissionable material detection in cargo are reaching a certain level of maturity because of the ongoing extensive R&}D effort in high-energy physics regarding their use in the search for dark matter and neutrinoless double beta decay. The unique properties of LNG detectors, especially those using Liquid Argon (LAr) and Liquid Xenon (LXe), call for a study to determine their suitability for Non-Intrusive Inspection (NII) for Special Nuclear Materials (SNM) and possibly for other threats in cargo. Rapiscan Systems Laboratory, Yale University Physics Department, and Adelphi Technology are collaborating in the investigation of the suitability of LAr as a scintillation material for large size inspection systems for air and maritime containers and trucks. This program studies their suitability for NII, determines their potential uses, determines what improvements in performance they offer and recommends changes to their design to further enhance their suitability. An existing 3.1 liter LAr detector (microCLEAN) at Yale University, developed for R&}D on the detection of weakly interacting massive particles (WIMPs) was employed for testing. A larger version of this detector (15 liters), more suitable for the detection of higher energy gamma rays and neutrons is being built for experimental evaluation. Results of measurements and simulations of gamma ray and neutron detection in microCLEAN and a larger detector (326 liter CL38) are presented.

  5. Chrysler to race hybrid electric-LNG car

    SciTech Connect

    NONE

    1994-03-07

    Chrysler Corp. hopes to race a hybrid electric-liquefied natural gas car in the Le Mans in 1995. Preparing for a racing program will speed technological advances that could take years under a regular development program. The car converts LNG to electricity with a two-turbine alternator that powers an electric traction motor. Power not used immediately is placed in reserve in an ultra-high-speed carbon-fiber flywheel, which also captures kinetic energy at braking. Even with the accelerated race program, Chrysler says it will likely be the next century before hybrid technology will make it into production cars.

  6. Seed Dispersal

    NSDL National Science Digital Library

    2012-06-26

    In this outdoor activity and bingo-like game, learners explore why and how seeds spread far from the plants that produce them. To understand natural adaptions that let seeds and fruit be dispersed, learners make modifications to dried beans and peas so they could be dispersed by natural forces like water, air, or an animal moving from one place to another. In the "Seed-Go" Game, learners match ways that seeds are dispersed, to fill rows on the game board.

  7. Biofilm Dispersal

    PubMed Central

    2010-01-01

    Like all sessile organisms, surface-attached communities of bacteria known as biofilms must release and disperse cells into the environment to colonize new sites. For many pathogenic bacteria, biofilm dispersal plays an important role in the transmission of bacteria from environmental reservoirs to human hosts, in horizontal and vertical cross-host transmission, and in the exacerbation and spread of infection within a host. The molecular mechanisms of bacterial biofilm dispersal are only beginning to be elucidated. Biofilm dispersal is a promising area of research that may lead to the development of novel agents that inhibit biofilm formation or promote biofilm cell detachment. Such agents may be useful for the prevention and treatment of biofilms in a variety of industrial and clinical settings. This review describes the current status of research on biofilm dispersal, with an emphasis on studies aimed to characterize dispersal mechanisms, and to identify environmental cues and inter- and intracellular signals that regulate the dispersal process. The clinical implications of biofilm dispersal and the potential therapeutic applications of some of the most recent findings will also be discussed. PMID:20139339

  8. Ocular dispersion

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Noojin, Gary D.; Thomas, Robert J.; Stolarski, David J.; Rockwell, Benjamin A.; Welch, Ashley J.

    1999-06-01

    Spectrally resolved white-light interferometry (SRWLI) was used to measure the wavelength dependence of refractive index (i.e., dispersion) for various ocular components. The accuracy of the technique was assessed by measurement of fused silica and water, the refractive indices of which have been measured at several different wavelengths. The dispersion of bovine and rabbit aqueous and vitreous humor was measured from 400 to 1100 nm. Also, the dispersion was measured from 400 to 700 nm for aqueous and vitreous humor extracted from goat and rhesus monkey eyes. For the humors, the dispersion did not deviate significantly from water. In an additional experiment, the dispersion of aqueous and vitreous humor that had aged up to a month was compared to freshly harvested material. No difference was found between the fresh and aged media. An unsuccessful attempt was also made to use the technique for dispersion measurement of bovine cornea and lens. Future refinement may allow measurement of the dispersion of cornea and lens across the entire visible and near-infrared wavelength band. The principles of white- light interferometry including image analysis, measurement accuracy, and limitations of the technique, are discussed. In addition, alternate techniques and previous measurements of ocular dispersion are reviewed.

  9. Disperse Systems

    Microsoft Academic Search

    Makoto Takeo

    1999-01-01

    Interesting applications for disperse systems exist in many areas of modern technology. Weight and cost savings achieved in engineered foams for complex designs and computer-modeled optical pigments for creating astounding effects in coating are but two examples of such diverse applications. In addition to the cost and material reductions already achieved in existing applications, future applications of disperse systems are

  10. 49 CFR 191.22 - National Registry of Pipeline and LNG operators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false National Registry of Pipeline and LNG operators. 191.22 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL...

  11. 49 CFR 195.64 - National Registry of Pipeline and LNG Operators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false National Registry of Pipeline and LNG Operators. 195.64 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

  12. 49 CFR 191.22 - National Registry of Pipeline and LNG operators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false National Registry of Pipeline and LNG operators. 191.22 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL...

  13. 49 CFR 195.64 - National Registry of Pipeline and LNG Operators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false National Registry of Pipeline and LNG Operators. 195.64 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

  14. 49 CFR 191.22 - National Registry of Pipeline and LNG operators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false National Registry of Pipeline and LNG operators. 191.22 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL...

  15. 49 CFR 195.64 - National Registry of Pipeline and LNG Operators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false National Registry of Pipeline and LNG Operators. 195.64 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

  16. 77 FR 38128 - Withdrawal of TORP Terminal LP, Bienville Offshore Energy Terminal Liquefied Natural Gas (LNG...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ...USCG-2006-24644] Withdrawal of TORP Terminal LP, Bienville Offshore Energy Terminal Liquefied Natural Gas (LNG) Deepwater Port...Maritime Administration (MARAD) announces TORP Terminal LP's (TORP) withdrawal of the...

  17. 75 FR 70350 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ...Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY...received an application for the licensing of a natural gas deepwater port and the application...

  18. 49 CFR 195.64 - National Registry of Pipeline and LNG Operators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false National Registry of Pipeline and LNG Operators. 195.64 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

  19. 49 CFR 191.22 - National Registry of Pipeline and LNG operators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false National Registry of Pipeline and LNG operators. 191.22 Section...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL...

  20. Mesoporous Nickel–Alumina Catalysts for Hydrogen Production by Steam Reforming of Liquefied Natural Gas (LNG)

    Microsoft Academic Search

    Jeong Gil Seo; Min Hye Youn; In Kyu Song

    2010-01-01

    Recent progress on the mesoporous nickel–alumina catalysts for hydrogen production by steam reforming of liquefied natural\\u000a gas (LNG) was reported in this review. A number of mesoporous nickel–alumina composite catalysts were prepared by a single-step\\u000a surfactant-templating method using cationic, anionic, and non-ionic surfactant as structure-directing agents for use in hydrogen\\u000a production by steam reforming of LNG. For comparison, nickel catalysts

  1. Analysis of the sloshing flows of a LNG cargo tank

    NASA Astrophysics Data System (ADS)

    Doh, Deog Hee; Jo, Hyo Je; Shin, Byeong Rog; Ryu, Min Cheol; Hwang, Yoon Sik

    2011-10-01

    The sloshing flows in a LNG cargo tank model (1/50 scale) of a ship are measured by an embedded panoramicPIV system. The measurement system consists of a Nd-Yag laser(120mJ, 15Hz), two cameras(1k x 1k) and a host computer. Four experimental cases were tested for the tank model, in which swaying motions are made by a 6 DOF-motion platform. The amplitudes of swaying are 9.76mm and 29.29mm, and the swaying frequencies are 0.633Hz and 0.828Hz. The measurement regions are the vertical plane 50mm away from the front wall of the tank where a pump tower is installed. It was verified that the flow patterns of the sloshing are similar to each other when the swaying amplitudes are similar.

  2. Energy Transfer by Collision in Benzene Vapor

    Microsoft Academic Search

    Laura M. Cheng

    1951-01-01

    The velocity and absorption of ultrasonic waves in benzene vapor were measured by means of the sonic interferometer, at frequencies of 251.44 kc, 497.44 kc, and 1008.06 kc, within the pressure range 2 to 9.5 cm Hg, between the temperature limits 30.2°C to 37.6°C. Dispersion of the velocity, after being reduced to 30°C, ranged from 190.4 m\\/sec to 207.31 m\\/sec.

  3. D-optimal experimental design coupled with parallel factor analysis 2 decomposition a useful tool in the determination of triazines in oranges by programmed temperature vaporization-gas chromatography-mass spectrometry when using dispersive-solid phase extraction.

    PubMed

    Herrero, A; Ortiz, M C; Sarabia, L A

    2013-05-01

    The determination of triazines in oranges using a GC-MS system coupled to a programmed temperature vaporizer (PTV) inlet in the context of legislation is performed. Both pretreatment (using a Quick Easy Cheap Effective Rugged and Safe (QuEChERS) procedure) and injection steps are optimized using D-optimal experimental designs for reducing the experimental effort. The relative dirty extracts obtained and the elution time shifts make it necessary to use a PARAFAC2 decomposition to solve these two usual problems in the chromatographic determinations. The "second-order advantage" of the PARAFAC2 decomposition allows unequivocal identification according to document SANCO/12495/2011 (taking into account the tolerances for relative retention time and the relative abundance for the diagnostic ions), avoiding false negatives even in the presence of unknown co-eluents. The detection limits (CC?) found, from 0.51 to 1.05?gkg(-1), are far below the maximum residue levels (MRLs) established by the European Union for simazine, atrazine, terbuthylazine, ametryn, simetryn, prometryn and terbutryn in oranges. No MRL violations were found in the commercial oranges analyzed. PMID:23522618

  4. VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA

    E-print Network

    Rudnyi, Evgenii B.

    1 VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA Rudnyi E in the vapors above alkali halides at high temperature introduces special problems in the assessment of thermodynamic properties of the vapor and the vaporization process, coupling pressure measurements

  5. Vapor spill monitoring method

    DOEpatents

    Bianchini, Gregory M. (Livermore, CA); McRae, Thomas G. (Livermore, CA)

    1985-01-01

    Method for continuous sampling of liquified natural gas effluent from a spill pipe, vaporizing the cold liquified natural gas, and feeding the vaporized gas into an infrared detector to measure the gas composition. The apparatus utilizes a probe having an inner channel for receiving samples of liquified natural gas and a surrounding water jacket through which warm water is flowed to flash vaporize the liquified natural gas.

  6. Experiments for the Measurement of LNG Mass Burning Rates

    E-print Network

    Herrera Gomez, Lady Carolina

    2012-07-16

    on the radiometers used inside the pit area after the tests ...................................................... 56#1; Figure 27. Comparison of the measured and calculated radiative heat flux received at the pool surface... of this cryogenic fluid. ? Flash fire: occurs when flammable vapors are not ignited immediately after the release, but instead, a vapor cloud forms, ignites, and burns back to the leak source. This type of combustion does not create significant overpressure...

  7. Optimization and testing of the Beck Engineering free-piston cryogenic pump for LNG systems on heavy vehicles. Final technical report

    SciTech Connect

    Beck, Douglas S.

    2003-01-10

    Task 7 was completed by reaching Milestone 7: Test free piston cryogenic pump (FPCP) in Integrated LNG System. Task 4: Alternative Pump Design was also completed. The type of performance of the prototype LNG system is consistent with requirements of fuel systems for heavy vehicles; however, the maximum flow capacity of the prototype LNG system is significantly less than the total flow requirement. The flow capacity of the prototype LNG system is determined by a cavitation limit for the FPCP.

  8. Three-dimensional model for simulating atmospheric dispersion of heavy-gases over complex terrain

    SciTech Connect

    Chan, S.T.

    1997-09-01

    To help understand heavy gas releases and simulate the resultant dispersion, we have developed a three-dimensional finite element model called FEM3 and an improved version names FEM3A for solving the time dependent conservation equations based on generalized anelastic approximation. Recent enhancements to the model to include the treatment of dispersion scenarios involving density variations much larger than the liquefied natural gas range and an advanced turbulence submodel based on the buoyancy-extended transport equations. This paper presents the main features of the present model FEM3C and numerical results from the simulations of a field-scale LNG spill experiment.

  9. Process simulation for a new conceptual design of LNG terminal coupling NGL recovery and LNG re-gasification for maximum energy savings

    NASA Astrophysics Data System (ADS)

    Muqeet, Mohammed A.

    With the high demands of shale gas and promising development of LNG terminals, a lot of research has focused towards the process development for effective recovery of C2+ hydrocarbons (NGL). Shale gas requires a large amount of cold energy to cool down and recover the NGL; and the LNG re-gasification process requires a lot of heat energy to evaporate for NGL recovery. Thus, coupling the shale gas NGL recovery process and LNG re-gasification process, for utilizing the cold energy from LNG re-gasification process to assist NGL recovery from shale gas has significant economic benefits on both energy saving and high value product recovery. Wang et al. developed new conceptual design of such coupled process in 2013 and later Wang and Xu developed an optimal design considering uncertainties in 2014. This work deals with process simulation of both these designs and the feasibility of the process is verified. A steady state model is developed based on the plant design proposed by Wang et al. using Aspen plusRTM and then a dynamic model of the process is developed using Aspen dynamicsRTM. An effective control strategy is developed and the flexibility of the dynamic model is examined by giving disturbances in the shale gas feed. A comparison is made between the two proposed design and the prospects of the design for real plant scenario is discussed.

  10. Petroleum Vapor - Field Technical

    EPA Science Inventory

    The screening approach being developed by EPA OUST to evaluate petroleum vapor intrusion (PVI) requires information that has not be routinely collected in the past at vapor intrusion sites. What is the best way to collect this data? What are the relevant data quality issues and ...

  11. Vapor Pressure Data

    NSDL National Science Digital Library

    Ohe, Shuzo.

    Created by Professor Shuzo Ohe of the Graduate School of Chemical Engineering and the Science University or Tokyo, this site offers vapor pressure data. Available in graph form, data represent vapor pressure (mmHg) as a function of temperature (C, or F). Substances are listed alphabetically and include acetaldehyde, acetic acid, benzene, butane, carbon dioxide, and water, to name a few.

  12. Physical model for vaporization

    E-print Network

    Jozsef Garai

    2009-07-30

    Based on two assumptions, the surface layer is flexible, and the internal energy of the latent heat of vaporization is completely utilized by the atoms for overcoming on the surface resistance of the liquid, the enthalpy of vaporization was calculated for 45 elements. The theoretical values were tested against experiments with positive result.

  13. Disperse Systems

    NASA Astrophysics Data System (ADS)

    Takeo, Makoto

    1999-03-01

    Interesting applications for disperse systems exist in many areas of modern technology. Weight and cost savings achieved in engineered foams for complex designs and computer-modeled optical pigments for creating astounding effects in coating are but two examples of such diverse applications. In addition to the cost and material reductions already achieved in existing applications, future applications of disperse systems are ripe with many heretofore-undeveloped products possessing unprecedented properties. A thorough understanding of the relationship between microscopic composition and the measurable macroscopic behaviour of disperse systems is necessary for technologists to exploit the unique properties of these systems. With such an understanding, the reader will be equipped to develop new products efficiently and to effectively achieve required material properties. Professor Makoto Takeo, the renowned expert from Portland State University, addresses this need for an understanding of disperse systems in a remarkable new text. The current knowledge base is presented and the underlying principles of these systems are revealed in a straightforward and easily accessible manner. It is an indispensable work for those who want to competently enter this fascinating field, and an absolute must for tomorrow's physicists and materials scientists.

  14. Dispersion Modeling.

    ERIC Educational Resources Information Center

    Budiansky, Stephen

    1980-01-01

    This article discusses the need for more accurate and complete input data and field verification of the various models of air pollutant dispension. Consideration should be given to changing the form of air quality standards based on enhanced dispersion modeling techniques. (Author/RE)

  15. Mechanisms of L-NG nitroarginine/indomethacin-resistant relaxation in bovine and porcine coronary arteries.

    PubMed Central

    Graier, W. F.; Holzmann, S.; Hoebel, B. G.; Kukovetz, W. R.; Kostner, G. M.

    1996-01-01

    1. Coronary arteries from bovines (BCA) and pigs (PCA) were used for measuring endothelium-dependent relaxation in the presence of L-NG nitroarginine and indomethacin. As some compounds tested have been found to have an inhibitory effect on autacoid-activated endothelial Ca2+ signalling, endothelium-dependent relaxation was initiated with the Ca2+ ionophore A23187. 2. The common compounds for modulating arachidonic acid release/pathway, mepacrine and econazole only inhibited L-NG nitroarginine-resistant relaxation in BCA not in PCA. In contrast, proadifen (SKF 525A) diminished relaxation in BCA and PCA. Mepacrine and proadifen inhibited Hoe-234-initiated relaxation in BCA and PCA, while econazole only inhibited Hoe 234-induced relaxation in PCA. Due to the multiple effects of these compounds, caution is necessary in the interpretation of results obtained with these compounds. 3. The inhibitor of Ca(2+)-activated K+ channels, apamin, strongly attenuated A23187-induced L-NG nitroarginine-resistant relaxation in BCA while apamin did not affect L-NG nitroarginine-resistant relaxation in PCA. 4. Pertussis toxin blunted L-NG nitroarginine-resistant relaxation in BCA, while relaxation of PCA was not affected by pertussis toxin. 5. Thiopentone sodium inhibited endothelial cytochrome P450 epoxygenase (EPO) in PCA but not in BCA, while L-NG nitroarginine-resistant relaxation of BCA and PCA were unchanged. Protoporphyrine IX inhibited EPO in BCA and PCA and abolished L-NG nitroarginine-resistant relaxation of BCA not PCA. 6. An EPO-derived compound, 11,12-epoxy-eicosatrienoic acid (11,12-EET) yielded significant relaxation in BCA and PCA in three out of six experiments. 7. These findings suggest that L-NG nitroarginine-resistant relaxation in BCA and PCA constitutes two distinct pathways. In BCA, activation of Ca(2+)-activated K+ channels via a pertussis-toxin-sensitive G protein and EPO-derived compounds might be involved. In PCA, no selective inhibition of L-NG nitroarginine-resistant relaxation was found. PMID:8937721

  16. Flexible LNG supply, storage and price formation in a global natural gas market

    NASA Astrophysics Data System (ADS)

    Hayes, Mark Hanley

    The body of work included in this dissertation explores the interaction of the growing, flexible liquefied natural gas (LNG) trade with the fundamentals of pipeline gas supply, gas storage, and gas consumption. By nature of its uses---largely for residential heating and electric power generation---the consumption of natural gas is highly variable both seasonally and on less predictable daily and weekly timescales. Flexible LNG trade will interconnect previously isolated regional gas markets, each with non-correlated variability in gas demand, differing gas storage costs, and heterogeneous institutional structures. The dissertation employs a series of analytical models to address key issues that will affect the expansion of the LNG trade and the implications for gas prices, investment and energy policy. First, I employ an optimization model to evaluate the fundamentals of seasonal LNG swing between markets with non-correlated gas demand (the U.S. and Europe). The model provides insights about the interaction of LNG trade with gas storage and price formation in interconnected regional markets. I then explore how random (stochastic) variability in gas demand will drive spot cargo movements and covariation in regional gas prices. Finally, I analyze the different institutional structures of the gas markets in the U.S. and Europe and consider how managed gas markets in Europe---without a competitive wholesale gas market---may effectively "export" supply and price volatility to countries with more competitive gas markets, such as the U.S.

  17. Seismic analysis of a LNG storage tank isolated by a multiple friction pendulum system

    NASA Astrophysics Data System (ADS)

    Zhang, Ruifu; Weng, Dagen; Ren, Xiaosong

    2011-06-01

    The seismic response of an isolated vertical, cylindrical, extra-large liquefied natural gas (LNG) tank by a multiple friction pendulum system (MFPS) is analyzed. Most of the extra-large LNG tanks have a fundamental frequency which involves a range of resonance of most earthquake ground motions. It is an effective way to decrease the response of an isolation system used for extra-large LNG storage tanks under a strong earthquake. However, it is difficult to implement in practice with common isolation bearings due to issues such as low temperature, soft site and other severe environment factors. The extra-large LNG tank isolated by a MFPS is presented in this study to address these problems. A MFPS is appropriate for large displacements induced by earthquakes with long predominant periods. A simplified finite element model by Malhotra and Dunkerley is used to determine the usefulness of the isolation system. Data reported and statistically sorted include pile shear, wave height, impulsive acceleration, convective acceleration and outer tank acceleration. The results show that the isolation system has excellent adaptability for different liquid levels and is very effective in controlling the seismic response of extra-large LNG tanks.

  18. Strategic petroleum reserve and liquefied natural gas supplies. Final report. [Impact of LNG and\\/or oil embargo

    Microsoft Academic Search

    R. J. Fink; B. A. Bancroft; T. M. Palmieri

    1977-01-01

    The United States is planning to import liquefied natural gas (LNG) to offset the effects of our apparent dwindling natural gas supply. These imports would begin by the 1980s and would come from Algeria, Indonesia, Pakistan, Iran, Nigeria, and possibly the Soviet Union. If a disruption in LNG supplies were to occur, the impact to the nation could be eased

  19. Corporate Strategies along the LNG Value Added Chain An Empirical Analysis of the Determinants of Vertical Integration

    Microsoft Academic Search

    Sophia Ruester; Anne Neumann

    This study analyzes corporate strategies in the emerging global LNG market. In particular, we provide an empirical analysis of the determinants driving companies towards increasing vertical integration. Our hypothesis is that high transaction costs along the LNG value added chain induce a higher degree of vertical integration. This hypothesis is tested by implementing ordered response models. To explain determinants of

  20. Economics of the LNG Value Chain and Corporate Strategies An Empirical Analysis of the Determinants of Vertical Integration

    Microsoft Academic Search

    Sophia Ruester; Anne Neumann

    This paper analyzes corporate strategies in the emerging global market for liquefied natural gas (LNG). In particular, we provide an empirical analysis of the determinants driving companies towards increasing vertical integration leading to an industry in which a small number of large and powerful players are active. Our hypothesis of high transaction costs along the LNG value chain inducing a

  1. DYNAMIC SIMULATION FOR IMPROVING THE PERFORMANCE OF BOIL-OFF GAS RECONDENSATION SYSTEM AT LNG RECEIVING TERMINALS

    Microsoft Academic Search

    Yajun Li; Xingshui Chen

    2012-01-01

    The boil-off gas (BOG) recondensation system is one of the most important facilities at liquefied natural gas (LNG) storing and receiving terminals, whose failure may cause BOG loss and\\/or severe accidents. Operation of a BOG recondensation system requires sufficient care under various situations, especially when LNG load and BOG load fluctuate. This study improves the control algorithm for a BOG

  2. Natural gas and CO2 price variation: impact on the relative cost-efficiency of LNG and pipelines.

    PubMed

    Ulvestad, Marte; Overland, Indra

    2012-06-01

    THIS ARTICLE DEVELOPS A FORMAL MODEL FOR COMPARING THE COST STRUCTURE OF THE TWO MAIN TRANSPORT OPTIONS FOR NATURAL GAS: liquefied natural gas (LNG) and pipelines. In particular, it evaluates how variations in the prices of natural gas and greenhouse gas emissions affect the relative cost-efficiency of these two options. Natural gas is often promoted as the most environmentally friendly of all fossil fuels, and LNG as a modern and efficient way of transporting it. Some research has been carried out into the local environmental impact of LNG facilities, but almost none into aspects related to climate change. This paper concludes that at current price levels for natural gas and CO2 emissions the distance from field to consumer and the volume of natural gas transported are the main determinants of transport costs. The pricing of natural gas and greenhouse emissions influence the relative cost-efficiency of LNG and pipeline transport, but only to a limited degree at current price levels. Because more energy is required for the LNG process (especially for fuelling the liquefaction process) than for pipelines at distances below 9100 km, LNG is more exposed to variability in the price of natural gas and greenhouse gas emissions up to this distance. If the prices of natural gas and/or greenhouse gas emission rise dramatically in the future, this will affect the choice between pipelines and LNG. Such a price increase will be favourable for pipelines relative to LNG. PMID:24683269

  3. Natural gas and CO2 price variation: impact on the relative cost-efficiency of LNG and pipelines

    PubMed Central

    Ulvestad, Marte; Overland, Indra

    2012-01-01

    This article develops a formal model for comparing the cost structure of the two main transport options for natural gas: liquefied natural gas (LNG) and pipelines. In particular, it evaluates how variations in the prices of natural gas and greenhouse gas emissions affect the relative cost-efficiency of these two options. Natural gas is often promoted as the most environmentally friendly of all fossil fuels, and LNG as a modern and efficient way of transporting it. Some research has been carried out into the local environmental impact of LNG facilities, but almost none into aspects related to climate change. This paper concludes that at current price levels for natural gas and CO2 emissions the distance from field to consumer and the volume of natural gas transported are the main determinants of transport costs. The pricing of natural gas and greenhouse emissions influence the relative cost-efficiency of LNG and pipeline transport, but only to a limited degree at current price levels. Because more energy is required for the LNG process (especially for fuelling the liquefaction process) than for pipelines at distances below 9100 km, LNG is more exposed to variability in the price of natural gas and greenhouse gas emissions up to this distance. If the prices of natural gas and/or greenhouse gas emission rise dramatically in the future, this will affect the choice between pipelines and LNG. Such a price increase will be favourable for pipelines relative to LNG. PMID:24683269

  4. Vacuum vapor deposition

    NASA Technical Reports Server (NTRS)

    Poorman, Richard M. (inventor); Weeks, Jack L. (inventor)

    1995-01-01

    A method and apparatus is described for vapor deposition of a thin metallic film utilizing an ionized gas arc directed onto a source material spaced from a substrate to be coated in a substantial vacuum while providing a pressure differential between the source and the substrate so that, as a portion of the source is vaporized, the vapors are carried to the substrate. The apparatus includes a modified tungsten arc welding torch having a hollow electrode through which a gas, preferably inert, flows and an arc is struck between the electrode and the source. The torch, source, and substrate are confined within a chamber within which a vacuum is drawn. When the arc is struck, a portion of the source is vaporized and the vapors flow rapidly toward the substrate. A reflecting shield is positioned about the torch above the electrode and the source to ensure that the arc is struck between the electrode and the source at startup. The electrode and the source may be confined within a vapor guide housing having a duct opening toward the substrate for directing the vapors onto the substrate.

  5. Motion analysis of parallelly connected FPSO unit and LNG carrier

    SciTech Connect

    Inoue, Yoshiyuki; Self, M.S. [Yokohama National Univ. (Japan); Asada, Hiroshi; Yamashita, Seiya [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan)

    1996-12-31

    Nowadays, the floating production, storage, and offloading (FPSO) units are used to marginal oil fields and deep seas, because of mobility and reduced lead time from discovery to first production. One of the methods for offloading is to moor a tanker alongside the FPSO unit. In this case motion response of the system becomes highly complex, and will be affected by many factors such as hydrodynamic interaction and mechanical connections between the vessels. In this study, a quite general method is developed which has taken into account the hydrodynamic interaction as well as the effects of connectors and mooring lines, in motion response analysis of a multi-body floating system. For this purpose, 3-D source distribution method is applied for hydrodynamic analysis, and linear stiffness matrices are introduced to represent the effect of connectors and mooring lines on the motion equations. The method has been used for motion analysis of a practical problem in which an LNG carrier is connected alongside of an FPSO unit. The results of simulation are wave exciting forces, absolute motions and relative motions in frequency domain. Furthermore, some nonlinear behavior of connecting systems are discussed on the basis of the numerical results.

  6. Vapor resistant arteries

    NASA Technical Reports Server (NTRS)

    Shaubach, Robert M. (Inventor); Dussinger, Peter M. (Inventor); Buchko, Matthew T. (Inventor)

    1989-01-01

    A vapor block resistant liquid artery structure for heat pipes. A solid tube artery with openings is encased in the sintered material of a heat pipe wick. The openings are limited to that side of the artery which is most remote from the heat source. The liquid in the artery can thus exit the artery through the openings and wet the sintered sheath, but vapor generated at the heat source is unlikely to move around the solid wall of the artery and reverse its direction in order to penetrate the artery through the openings. An alternate embodiment uses finer pore size wick material to resist vapor entry.

  7. AMTEC vapor-vapor series connected cells

    NASA Technical Reports Server (NTRS)

    Underwood, Mark L. (inventor); Williams, Roger M. (inventor); Ryan, Margaret A. (inventor); Nakamura, Barbara J. (inventor); Oconnor, Dennis E. (inventor)

    1995-01-01

    An alkali metal thermoelectric converter (AMTEC) having a plurality of cells structurally connected in series to form a septum dividing a plenum into two chambers, and electrically connected in series, is provided with porous metal anodes and porous metal cathodes in the cells. The cells may be planar or annular, and in either case a metal alkali vapor at a high temperature is provided to the plenum through one chamber on one side of the wall and returned to a vapor boiler after condensation at a chamber on the other side of the wall in the plenum. If the cells are annular, a heating core may be placed along the axis of the stacked cells. This arrangement of series-connected cells allows efficient generation of power at high voltage and low current.

  8. AMTEC vapor-vapor series connected cells

    NASA Astrophysics Data System (ADS)

    Underwood, Mark L.; Williams, Robert M.; Ryan, Margaret A.; Jeffries-Nakamura, Barbara; Oconnor, Dennis

    1993-01-01

    An alkali metal thermoelectric converter (AMTEC) having a plurality of cells structurally connected in series to form a septum dividing a plenum into two chambers, and electrically connected in series, is provided with porous metal anodes and porous metal cathodes in the cells. The cells may be planar or annular, and in either case a metal alkali vapor at a high temperature is provided to the plenum through one chamber on one side of the wall and returned to a vapor boiler after condensation at a chamber on the other side of the wall in the plenum. If the cells are annular, a heating core may be placed along the axis of the stacked cells. This arrangement of series-connected cells allows efficient generation of power at high voltage and low current.

  9. AMTEC vapor-vapor series connected cells

    NASA Astrophysics Data System (ADS)

    Underwood, Mark L.; Williams, Roger M.; Ryan, Margaret A.; Nakamura, Barbara J.; Oconnor, Dennis E.

    1995-08-01

    An alkali metal thermoelectric converter (AMTEC) having a plurality of cells structurally connected in series to form a septum dividing a plenum into two chambers, and electrically connected in series, is provided with porous metal anodes and porous metal cathodes in the cells. The cells may be planar or annular, and in either case a metal alkali vapor at a high temperature is provided to the plenum through one chamber on one side of the wall and returned to a vapor boiler after condensation at a chamber on the other side of the wall in the plenum. If the cells are annular, a heating core may be placed along the axis of the stacked cells. This arrangement of series-connected cells allows efficient generation of power at high voltage and low current.

  10. Biofiltration of methanol vapor

    Microsoft Academic Search

    Zarook Shareefdeen; Basil C. Baltzis; Young-Sook Oh; Richard Bartha

    1993-01-01

    Biofiltration of solvent and fuel vapors may offer a cost-effective way to comply with increasingly strict air emission standards. An important step in the development of this technology is to derive and validate mathematical models of the biofiltration process for predictive and scaleup calculations. For the study of methanol vapor biofiltration, an 8-membered bacterial consortium was obtained from methanol-exposed soil.

  11. Worker Protection from Chemical Vapors: Hanford Tank Farms

    SciTech Connect

    Anderson, T.J. [CH2M HILL Hanford Group, Inc. / Environmental Health, Richland, WA (United States)

    2007-07-01

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank head-spaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns, risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits (OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors. (authors)

  12. Aligning vapor-grown carbon fibers in polydimethylsiloxane using dc electric or magnetic field

    Microsoft Academic Search

    Tatsuhiro Takahashi; Taichi Murayama; Ayumu Higuchi; Hiroshi Awano; Koichiro Yonetake

    2006-01-01

    A trace amount of vapor-grown carbon fibers (VGCFs), which, as received, had an aggregated lump form, was completely dispersed in polydimethylsiloxane, a nonpolar viscous liquid, at room temperature by mechanical stirring. Using this uniformly dispersed sample as a starting material, a dc electric or magnetic field was applied to induce the formation of an aligned structure. In situ transmission optical

  13. Training Protocols for the Detection of Explosive Vapors in Interior Spaces.

    SciTech Connect

    Phelan, James M.; Webb, Stephen W.

    2007-07-01

    Computational fluid dynamics simulations for dispersal of explosive vapors in interior spaces have been performed including details of typical ventilation systems. The interior spaces investigated include an office area, a single-family house, and a warehouse store. Explosive vapor sources are defined in the various interior spaces, and contours of the vapor concentration in the interior spaces relative to the source concentration are presented for relative concentrations down to 10-5. Training protocols for detection of explosive vapors in interior spaces should include an awareness of the time to equilibrium evident in these simulations as well as the significance of ventilation zones.3

  14. Implications of the US-Algerian liquefied natural gas price dispute and LNG imports

    SciTech Connect

    Staats, E.B.

    1980-12-16

    In early 1980 Algeria demanded a 200% increase in the price of its liquefied natural gas. When the US company involved refused to pay this price, Algeria stopped LNG deliveries. The Energy Department, which is now the primary US negotiator with Algeria, says it will not agree to the price demand. If it did Canada and Mexico, at least in the long run, would probably request equivalent prices for their gas. If their price requests were met, US natural gas import bills, at present import levels, would increase by about 79%, or $3.5 billion. However, as the prices increased, demand for imported gas would probably drop substantially. GAO does not believe importing large amounts of LNG from OPEC countries is in the national interest. LNG imports generally trade oil dependence for gas dependence. It makes little sense to increase US dependence on gas at a time when extraordinary steps are being taken to reduce dependence on oil. Current indications are, however, that not many more proposals for LNG from OPEC countries will be forthcoming in the next few years.

  15. Fundamental Study on Sulfur Attack and Coking of LNG Rocket Engines

    NASA Astrophysics Data System (ADS)

    Higashino, Kazuyuki; Sugioka, Masatoshi; Kobayashi, Takao; Sakai, Masahiro; Minato, Ryojiro; Sasayama, Yousuke; Otsuka, Masaya; Okita, Koichi; Aoki, Kenji; Kawashima, Hideto; Azuma, Nobuyuki

    Liquified Natural Gas (LNG) is one of the most promising propellant for near future space transportation rocket engine because of its low cost and fewer handling concerns. However, for LNG propellant, erosion of engine material by sulfur (sulfur attack) and coking by LNG pyrolysis are significant problems in a regenerative cooling passage. In this study, the effects of sulfur attack and coking are experimentally evaluated for material candidates such as Inconel600, SUS316, Hastelloy-X, and some copper alloys. In the sulfur attack tests, EPMA and Raman analysis indicate that metallic sulfide can be observed only on the surface and XRD analysis indicates that sulfur attack are hardly recognized for all of material in the test conditions. In coking tests, it is clear that coking of methane with 5% propane can proceed more than those of pure methane. The thermal decomposition temperature is significantly decreased by catalytic effects of Ni in engine material. The results of coking tests will be included in the design criteria of combustion chamber, nozzle of the LNG rocket engines.

  16. Structural health monitoring for insulation panels of LNG carriers using fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Kim, Myung Hyun; Son, Young Joo; Kang, Sung Won; Lee, Jae Myung; Na, Sung Soo

    2006-03-01

    The aim of this study is to investigate dynamic failure initiation and failure modes of insulation panels of LNG carriers. Insulation panels of LNG cargo tanks may include mechanical failures such as cracks as well as delaminations within the layers due to impact sloshing loads and fatigue loadings, and these failures cause a significant decrease of structural integrity. In this study, a structural health monitoring system, employing fiber optic sensors is developed for monitoring various failures that can occur in LNG insulation panels. Fiber optic sensors have the advantage of being embedded inside of insulation panels. The signal of embedded fiber optic sensors is used to calculate the strain of insulation panels and is processed by digital filtering to identify damage initiations. It has been observed that the presence of defects and delaminations produce noticeable changes in the strain measurement in a predictable manner. In addition, fiber optic sensors are used to measure static and dynamic strain variations of insulation panels with and without damage. It is expected that this study will be used as a fundamental study for the safety assessment of the LNG insulation panels.

  17. In-situ strain monitoring in liquid containers of LNG transporting carriers

    NASA Astrophysics Data System (ADS)

    Oh, Min-Cheol; Seo, Jun-Kyu; Kim, Kyung-Jo; Lee, Sang-Min; Kim, Myung-Hyun

    2008-08-01

    Liquefied natural gas (LNG) transport carriers are exposed to a risk by the repeated bump in the LNG container during the vessel traveling over the wave in ocean. The liquid inside the container, especially when it was not fully contained, make a strong bump onto the insulation panel of the tank wall. The insulation panel consists of several layers of thick polyurethane foam (PUF) to maintain the LNG below the cryogenic temperature, -162°C. Due to the repeated shock on the PUF, a crack could be developed on the tank wall causing a tremendous disaster for LNG carriers. To prevent the accidental crack on the tank, a continuous monitoring of the strain imposed on the PUF is recommended. In this work, a fiber-optic Bragg grating was imbedded inside the PUF for monitoring the strain parallel to the impact direction. The optical fiber sensor with a small diameter of 125 ?m was suitable to be inserted in the PUF through a small hole drilled after the PUF was cured. In-situ monitoring of the strain producing the change of Bragg reflection wavelength, a high speed wavelength interrogation method was employed by using an arrayed waveguide grating. By dropping a heavy mass on the PUF, we measured the strain imposed on the insulation panel.

  18. LIQUID NATURAL GAS (LNG): AN ALTERNATIVE FUEL FROM LANDFILL GAS (LFG) AND WASTEWATER DIGESTER GAS

    SciTech Connect

    VANDOR,D.

    1999-03-01

    This Research and Development Subcontract sought to find economic, technical and policy links between methane recovery at landfill and wastewater treatment sites in New York and Maryland, and ways to use that methane as an alternative fuel--compressed natural gas (CNG) or liquid natural gas (LNG) -- in centrally fueled Alternative Fueled Vehicles (AFVs).

  19. A parametric sensitivity study on LNG tank sloshing loads by numerical simulations

    Microsoft Academic Search

    D. H. Lee; M. H. Kim; S. H. Kwon; J. W. Kim; Y. B. Lee

    2007-01-01

    A series of parametric sensitivity studies on unmatched dimensionless scale parameters is carried out on the liquified natural gas (LNG) tank sloshing loads by using a computational fluid dynamics (CFD) program. First, a brief dimensional analysis is conducted to identify the governing and non-matched non-dimensional parameters, assuming that Froude scaling law is adopted. Then the sensitivity of impact pressure is

  20. Department of Mechanical Engineering Dresser-Rand 1: LNG Test Rig Movable LSD Vanes

    E-print Network

    Demirel, Melik C.

    PENNSTATE Department of Mechanical Engineering Fall 2011 Dresser-Rand 1: LNG Test Rig Movable LSD (LSD) vanes which can easily be incorporated into current test rigs for centrifugal gas compressors of the system Approach Our team started the project by doing an extensive study on LSD vanes and current

  1. Department of Mechanical Engineering Spring 2012 LNG Test Rig Movable LSD Vanes

    E-print Network

    Demirel, Melik C.

    PENNSTATE Department of Mechanical Engineering Spring 2012 LNG Test Rig Movable LSD Vanes Overview (LSD) vanes are used to smoothly align the flow and minimize the losses. These vanes are fixed a diffuser with movable LSD vanes that can be incorporated into test rigs for centrifugal gas compressors

  2. 77 FR 70886 - Reconsideration of Letters of Recommendation for Waterfront Facilities Handling LNG and LHG

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ...hazardous gas LNG Liquefied natural gas LOI Letter of Intent LOR Letter of Recommendation...facility, must submit a Letter of Intent (LOI) to the Captain of the Port (COTP) of...Coast Guard issues an LOR in response to an LOI received from an owner or operator...

  3. Development of an FBG-based low temperature measurement system for cargo containment of LNG tankers

    NASA Astrophysics Data System (ADS)

    Kim, D. G.; Yoo, W.; Swinehart, P.; Jiang, B.; Haber, T.; Mendez, A.

    2007-09-01

    Given the growing demand for oil and natural gas to meet the world's energy needs, there is nowadays renewed interest in the use of liquefied natural gas (LNG) systems. For LNG to remain in its liquid phase, the gas has to be kept at cryogenic temperatures (< 160°C). And, as part of the LNG supply process, it becomes necessary to transport it using massive carrier tankers with cargo hulls operating at low temperatures and using special insulating double-wall construction. The safe and reliable storage and transportation of LNG products calls for low temperature monitoring of said containers to detect the onset of any potential leaks and possible thermal insulation degradation. Because of the hazardous nature of this cargo, only intrinsically-safe, explosion proof devices can be used. Optical fiber sensors-- such as fiber Bragg gratings-- are ideal for this application given their dielectric nature and multi-point sensing telemetry capability. In this paper, we describe the development of an on-line, multi-point FBG-based low temperature monitoring system based on a network of specially packaged FBG temperature and strain sensors mounted at critical locations within the inner hull, cofferdam and secondary barriers of a LNG carrier tanker. Given the stringent cryogenic operating temperature conditions, pertinent FBG designs, coatings and packaging approaches were formulated along with adequate installation techniques and integration of the interrogating FBG electronics into the tanker's overall SCADA monitoring system. FBG temperature sensors were demonstrated to be stable and sensitive over the 80-480K range. Stability is +/- 0.25K or better with repeated calibrations, and long term stability at 480K is ~0.2mK/hour.

  4. Electrolyte vapor condenser

    DOEpatents

    Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

    1983-02-08

    A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

  5. Thermal non-equilibrium in dispersed flow film boiling in a vertical tube

    E-print Network

    Forslund, Robert Paul

    1966-01-01

    The departure from thermal equilibrium between a dispersed liquid phase and its vapor at high quality during film boiling is investigated, The departure from equilibruim is manifested by the high resistance to heat transfer ...

  6. Guidance on risk analysis and safety implications of a large liquefied natural gas (LNG) spill over water.

    SciTech Connect

    Wellman, Gerald William; Melof, Brian Matthew; Luketa-Hanlin, Anay Josephine; Hightower, Marion Michael; Covan, John Morgan; Gritzo, Louis Alan; Irwin, Michael James; Kaneshige, Michael Jiro; Morrow, Charles W.

    2004-12-01

    While recognized standards exist for the systematic safety analysis of potential spills or releases from LNG (Liquefied Natural Gas) storage terminals and facilities on land, no equivalent set of standards or guidance exists for the evaluation of the safety or consequences from LNG spills over water. Heightened security awareness and energy surety issues have increased industry's and the public's attention to these activities. The report reviews several existing studies of LNG spills with respect to their assumptions, inputs, models, and experimental data. Based on this review and further analysis, the report provides guidance on the appropriateness of models, assumptions, and risk management to address public safety and property relative to a potential LNG spill over water.

  7. 78 FR 47691 - UGI, Inc.; Notice of Intent to Prepare an Environmental Assessment for the Proposed Temple LNG...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ...Regulatory Commission [Docket No. CP13-504-000] UGI, Inc.; Notice of Intent to Prepare an Environmental...involving construction and operation of facilities by UGI, Inc. (UGI) at its Temple liquefied natural gas (LNG)...

  8. 18 CFR 157.21 - Pre-filing procedures and review process for LNG terminal facilities and other natural gas...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...LNG terminal facilities and other natural gas facilities prior to filing of applications...DEPARTMENT OF ENERGY REGULATIONS UNDER NATURAL GAS ACT APPLICATIONS FOR CERTIFICATES...ABANDONMENT UNDER SECTION 7 OF THE NATURAL GAS ACT Applications for...

  9. 33 CFR 165.1709 - Security Zones: Liquefied Natural Gas Tanker Transits and Operations at Phillips Petroleum LNG...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1709 Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1000-yard radius of the Liquefied Natural Gas (LNG) tankers during their inbound and...

  10. 33 CFR 165.1709 - Security Zones: Liquefied Natural Gas Tanker Transits and Operations at Phillips Petroleum LNG...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1709 Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1000-yard radius of the Liquefied Natural Gas (LNG) tankers during their inbound and...

  11. 18 CFR 157.21 - Pre-filing procedures and review process for LNG terminal facilities and other natural gas...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...LNG terminal facilities and other natural gas facilities prior to filing of applications...DEPARTMENT OF ENERGY REGULATIONS UNDER NATURAL GAS ACT APPLICATIONS FOR CERTIFICATES...ABANDONMENT UNDER SECTION 7 OF THE NATURAL GAS ACT Applications for...

  12. 18 CFR 157.21 - Pre-filing procedures and review process for LNG terminal facilities and other natural gas...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...LNG terminal facilities and other natural gas facilities prior to filing of applications...DEPARTMENT OF ENERGY REGULATIONS UNDER NATURAL GAS ACT APPLICATIONS FOR CERTIFICATES...ABANDONMENT UNDER SECTION 7 OF THE NATURAL GAS ACT Applications for...

  13. 33 CFR 165.1709 - Security Zones: Liquefied Natural Gas Tanker Transits and Operations at Phillips Petroleum LNG...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1709 Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1000-yard radius of the Liquefied Natural Gas (LNG) tankers during their inbound and...

  14. 33 CFR 165.1709 - Security Zones: Liquefied Natural Gas Tanker Transits and Operations at Phillips Petroleum LNG...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1709 Security Zones: Liquefied Natural Gas Tanker Transits and Operations...1000-yard radius of the Liquefied Natural Gas (LNG) tankers during their inbound and...

  15. 77 FR 7568 - Freeport LNG Expansion, L.P. and FLNG Liquefaction, LLC; Application for Long-Term Authorization...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ...Domestically Produced Liquefied Natural Gas to Non Free Trade Agreement Countries...domestically produced liquefied natural gas (LNG) in an amount up to the...511 Billion cubic feet (Bcf) of natural gas per year, which averages to...

  16. 18 CFR 157.21 - Pre-filing procedures and review process for LNG terminal facilities and other natural gas...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...LNG terminal facilities and other natural gas facilities prior to filing of applications...DEPARTMENT OF ENERGY REGULATIONS UNDER NATURAL GAS ACT APPLICATIONS FOR CERTIFICATES...ABANDONMENT UNDER SECTION 7 OF THE NATURAL GAS ACT Applications for...

  17. 78 FR 13330 - Pangea LNG (North America) Holdings, LLC; Application for Long-Term Authorization To Export...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ...Long- Term Authorization To Export Liquefied Natural Gas Produced From Domestic Natural Gas Resources to Non-Free Trade Agreement Countries...authorization to export domestically produced liquefied natural gas (LNG) in an amount up to the equivalent...

  18. BioVapor Model Evaluation

    EPA Science Inventory

    General background on modeling and specifics of modeling vapor intrusion are given. Three classical model applications are described and related to the problem of petroleum vapor intrusion. These indicate the need for model calibration and uncertainty analysis. Evaluation of Bi...

  19. Propandiol vapor nucleation rates

    NASA Astrophysics Data System (ADS)

    Anisimov, M. P.; Nasibulin, A. G.; Timoshina, L. V.; Koropchak, J. A.

    2000-08-01

    Consideration of vapor-gas nucleation as binary vapor nucleation (instead widely used the one component approximation for nucleation of this system now) may lead the progress in the development of nucleation theory. Observations of phase transitions initiated by the carrier gas in the critical embryos of condensate can be a sufficiently convincing argument in this discussion. In order to confirm the role of the carrier gases received in the recent research1, in present study 1,2-propanediol and 1,3-propanediol vapor nucleation rates were measured. Carbon dioxide (Tc=304.2 K,Pc=7.39 MPa) and sulfur hexafluoride (Tc=318.7 K,Pc=3.75 MPa) were chosen as the carrier gases, because of their low and convenient critical temperatures, Tc, and critical pressures, Pc. Analysis of the experimental data shows that gas-carrier molecules are involved in new phase embryo formation. Vapor nucleation of investigated substances in a carrier gas atmosphere can be considered as nucleation of binary system.

  20. Explosive vaporization in microenclosures

    Microsoft Academic Search

    G. Romera-Guereca; J. Lichtenberg; A. Hierlemann; D. Poulikakos; B. Kang

    2006-01-01

    The explosive vaporization of a liquid above planar microheaters induces a fast increase of pressure that is exploited in many thermally driven actuators in MEMS components such as ink jet printer cartridges, pumps, valves and optical switches. Some of these components need to enclose the working fluid as it is the case of valves in which the heated liquid is

  1. Chemical vapor deposition growth

    Microsoft Academic Search

    R. P. Ruth; H. M. Manasevit; A. G. Campbell; R. E. Johnson; J. L. Kenty; L. A. Moudy; G. L. Shaw; W. I. Simpson; J. J. Yang

    1978-01-01

    The objective was to investigate and develop chemical vapor deposition (CVD) techniques for the growth of large areas of Si sheet on inexpensive substrate materials, with resulting sheet properties suitable for fabricating solar cells that would meet the technical goals of the Low Cost Silicon Solar Array Project. The program involved six main technical tasks: (1) modification and test of

  2. Passive Vaporizing Heat Sink

    NASA Technical Reports Server (NTRS)

    Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

    2011-01-01

    A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

  3. LNG imports to U. S. have been approved by FERC (U. S. Federal Energy Regulatory Commission) Judge W. T. Southworth

    Microsoft Academic Search

    Southworth

    1978-01-01

    The Algeria II Project involves importing 926 million cu ft\\/day LNG for 20 yr starting in 1983. Southworth stated that the U.S. oil companies would invest more than $1.5 billion for six tankers. Sonatrach's investment of $3 billion or more would include the other six tankers needed to deliver the LNG. The case involves applications by El Paso Natural Gas

  4. MESOSCOPIC SCALE MODELING FOR CHEMICAL VAPOR DEPOSITION

    E-print Network

    Ringhofer, Christian

    MESOSCOPIC SCALE MODELING FOR CHEMICAL VAPOR DEPOSITION IN SEMICONDUCTOR MANUFACTURING MATTHIAS K. GOBBERT \\Lambda AND CHRISTIAN RINGHOFER y Abstract. Low pressure chemical vapor deposition is a process, homogenization, multiscale modeling, chemical vapor deposition. 1. Introduction. Chemical vapor deposition (CVD

  5. On speed of a photon in a dispersing medium

    E-print Network

    Ogluzdin, Valeriy E

    2011-01-01

    On speed of a photon in a dispersing medium Ogluzdin Valeriy E. Abstract Based on the author of the experimental results and their treatment, a model that demonstrates that the real dispersive medium in spectral regions where the refractive index greater than unity, the velocity of propagation of photons in this environment corresponds to the phase velocity of light. These portions of the spectrum (for example, atomic potassium vapor or other alkali metal) are from low-frequency side of the main lines of the doublet and are available for research using tunable lasers. In the calculations took into account the fact that the atomic vapor of alkali metal used as a dispersing medium, in accordance with the theory of dispersion in the above sections of the spectrum, on the periphery of the cross section of laser beam with Gaussian intensity distribution across the beam - in the shadows refractive index n ({\

  6. Hydrogen Cars and Water Vapor

    E-print Network

    Colorado at Boulder, University of

    of complexities in the water vapor life cycle. How- ever, our pre- liminary calcula- tions indicate early in its development cycle. We are skeptical, however, that water vapor produced by combustion canHydrogen Cars and Water Vapor D.W.KEITHANDA.E.FARRELL'S POLICY FORUM "Rethinking hydrogen cars" (18

  7. Evaluation of sloshing resistance performance for LNG carrier insulation system based on fluid-structure interaction analysis

    NASA Astrophysics Data System (ADS)

    Lee, Chi-Seung; Cho, Jin-Rae; Kim, Wha-Soo; Noh, Byeong-Jae; Kim, Myung-Hyun; Lee, Jae-Myung

    2013-03-01

    In the present paper, the sloshing resistance performance of a huge-size LNG carrier's insulation system is evaluated by the fluid-structure interaction (FSI) analysis. To do this, the global-local analysis which is based on the arbitrary Lagrangian-Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG sloshing of a KC-1 type LNG carrier insulation system. During the global analysis, the sloshing flow and hydrodynamic pressure of internal LNG are analyzed by postulating the flexible insulation system as a rigid body. In addition, during the local analysis, the local hydroelastic response of the LNG carrier insulation system is computed by solving the local hydroelastic model where the entire and flexible insulation system is adopted and the numerical analysis results of the global analysis such as initial and boundary conditions are implemented into the local finite element model. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

  8. Comparative life-cycle air emissions of coal, domestic natural gas, LNG, and SNG for electricity generation

    SciTech Connect

    Paulina Jaramillo; W. Michael Griffin; H. Scott Matthews [Carnegie Mellon University, Pittsburgh, PA (United States). Civil and Environmental Engineering Department

    2007-09-15

    The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of this study is to compare greenhouse gas (GHG), SOx, and NOx life-cycle emissions of electricity generated with NG/LNG/SNG and coal. This life-cycle comparison of air emissions from different fuels can help us better understand the advantages and disadvantages of using coal versus globally sourced NG for electricity generation. Our estimates suggest that with the current fleet of power plants, a mix of domestic NG, LNG, and SNG would have lower GHG emissions than coal. If advanced technologies with carbon capture and sequestration (CCS) are used, however, coal and a mix of domestic NG, LNG, and SNG would have very similar life-cycle GHG emissions. For SOx and NOx we find there are significant emissions in the upstream stages of the NG/LNG life-cycles, which contribute to a larger range in SOx and NOx emissions for NG/LNG than for coal and SNG. 38 refs., 3 figs., 2 tabs.

  9. The control of mercury vapor using biotrickling filters.

    PubMed

    Philip, Ligy; Deshusses, Marc A

    2008-01-01

    The feasibility of using biotrickling filters for the removal of mercury vapor from simulated flue gases was evaluated. The experiments were carried out in laboratory-scale biotrickling filters with various mixed cultures naturally attached on a polyurethane foam packing. Sulfur oxidizing bacteria, toluene degraders and denitrifiers were used and compared for their ability to remove Hg 0 vapor. In particular, the biotrickling filters with sulfur oxidizing bacteria were able to remove 100% of mercury vapor, with an inlet concentration of 300-650 microg m(-3), at a gas contact time as low as six seconds. 87-92% of the removed mercury was fixed in or onto the microbial cells while the remaining left the system with the trickling liquid. The removal of mercury vapors in a biotrickling filter with dead cells was almost equivalent to this in biotrickling filters with live cells, indicating that significant abiotic removal mechanisms existed. Sulfur oxidizing bacteria biotrickling filters were the most effective in controlling mercury vapors, suggesting that sulfur played a key role. Identification of the location of metal deposition and of the form of metal was conducted using TEM, energy dispersive X-ray analysis (EDAX) and mercury elution analyses. The results suggested that mercury removal was through a series of complex mechanisms, probably both biotic and abiotic, including sorption in and onto cellular material and possible biotransformations. Overall, the study demonstrates that biotrickling filters appear to be a promising alternative for mercury vapor removal from flue gases. PMID:17692357

  10. The vapor pressures of explosives

    SciTech Connect

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  11. Stratified vapor generator

    DOEpatents

    Bharathan, Desikan (Lakewood, CO); Hassani, Vahab (Golden, CO)

    2008-05-20

    A stratified vapor generator (110) comprises a first heating section (H.sub.1) and a second heating section (H.sub.2). The first and second heating sections (H.sub.1, H.sub.2) are arranged so that the inlet of the second heating section (H.sub.2) is operatively associated with the outlet of the first heating section (H.sub.1). A moisture separator (126) having a vapor outlet (164) and a liquid outlet (144) is operatively associated with the outlet (124) of the second heating section (H.sub.2). A cooling section (C.sub.1) is operatively associated with the liquid outlet (144) of the moisture separator (126) and includes an outlet that is operatively associated with the inlet of the second heating section (H.sub.2).

  12. Role of Co-Vapors in Vapor Deposition Polymerization

    NASA Astrophysics Data System (ADS)

    Lee, Ji Eun; Lee, Younghee; Ahn, Ki-Jin; Huh, Jinyoung; Shim, Hyeon Woo; Sampath, Gayathri; Im, Won Bin; Huh, Yang–Il; Yoon, Hyeonseok

    2015-02-01

    Polypyrrole (PPy)/cellulose (PPCL) composite papers were fabricated by vapor phase polymerization. Importantly, the vapor-phase deposition of PPy onto cellulose was assisted by employing different co-vapors namely methanol, ethanol, benzene, water, toluene and hexane, in addition to pyrrole. The resulting PPCL papers possessed high mechanical flexibility, large surface-to-volume ratio, and good redox properties. Their main properties were highly influenced by the nature of the co-vaporized solvent. The morphology and oxidation level of deposited PPy were tuned by employing co-vapors during the polymerization, which in turn led to change in the electrochemical properties of the PPCL papers. When methanol and ethanol were used as co-vapors, the conductivities of PPCL papers were found to have improved five times, which was likely due to the enhanced orientation of PPy chain by the polar co-vapors with high dipole moment. The specific capacitance of PPCL papers obtained using benzene, toluene, water and hexane co-vapors was higher than those of the others, which is attributed to the enlarged effective surface area of the electrode material. The results indicate that the judicious choice and combination of co-vapors in vapor-deposition polymerization (VDP) offers the possibility of tuning the morphological, electrical, and electrochemical properties of deposited conducting polymers.

  13. Mechanical Characteristics of 9% Ni Steel Welded Joint for Lng Storage Tank at Cryogenic

    NASA Astrophysics Data System (ADS)

    Yoon, Yong-Keun; Kim, Jae-Hoon; Shim, Kyu-Taek; Kim, Young-Kyun

    To confirm the safety performance of LNG storage tank, the change in fatigue crack growth rate and fracture toughness within X-grooved weld heat-affected zone (HAZ) of newly developed 9% Ni steel, which was SMAW welded, was investigated. These materials were produced by QT (quenching, tempering) heat treatment. The weld metal specimens were prepared by taking the same weld procedure applied in actual inner shell of LNG storage tank. All tests were performed in the temperature ranging from R.T. and -162°C. The fatigue crack growth behavior was carried out using CT specimen. Investigation has been carried out to study the influence of temperature and weld effect on fatigue crack growth behavior. Also, Fracture surfaces after tests were observe by scanning electron microscope (SEM).

  14. Thermodynamic analysis of liquefied natural gas (LNG) production cycle in APCI process

    NASA Astrophysics Data System (ADS)

    Nezhad, Shahrooz Abbasi; Shabani, Bezhan; Soleimani, Majid

    2012-12-01

    The appropriate production of liquefied natural gas (LNG) with least consuming energy and maximum efficiency is quite important. In this paper, LNG production cycle by means of APCI Process has been studied. Energy equilibrium equations and exergy equilibrium equations of each equipment in the APCI cycle were established. The equipments are described using rigorous thermodynamics and no significant simplification is assumed. Taken some operating parameters as key parameters, influences of these parameters on coefficient of performance (COP) and exergy efficiency of the cascading cycle were analyzed. The results indicate that COP and exergy efficiency will be improved with the increasing of the inlet pressure of MR (mixed refrigerant) compressors, the decreasing of the NG and MR after precooling process, outlet pressure of turbine, inlet temperature of MR compressor and NG temperature after cooling in main cryogenic heat exchanger (MCHE). The COP and exergy efficiency of the APCI cycle will be above 2% and 40%, respectively, after optimizing the key parameters.

  15. Enceladus' water vapor plume.

    PubMed

    Hansen, Candice J; Esposito, L; Stewart, A I F; Colwell, J; Hendrix, A; Pryor, W; Shemansky, D; West, R

    2006-03-10

    The Cassini spacecraft flew close to Saturn's small moon Enceladus three times in 2005. Cassini's UltraViolet Imaging Spectrograph observed stellar occultations on two flybys and confirmed the existence, composition, and regionally confined nature of a water vapor plume in the south polar region of Enceladus. This plume provides an adequate amount of water to resupply losses from Saturn's E ring and to be the dominant source of the neutral OH and atomic oxygen that fill the Saturnian system. PMID:16527971

  16. Hydrodynamic optimization of twin-skeg LNG ships by CFD and model testing

    NASA Astrophysics Data System (ADS)

    Kim, Keunjae; Tillig, Fabian; Bathfield, Nicolas; Liljenberg, Hans

    2014-06-01

    SSPA experiences a growing interest in twin skeg ships as one attractive green ship solution. The twin skeg concept is well proven with obvious advantages for the design of ships with full hull forms, restricted draft or highly loaded propellers. SSPA has conducted extensive hull optimizations studies of LNG ships of different size based on an extensive hull data base with over 7,000 models tested, including over 400 twin skeg hull forms. Main hull dimensions and different hull concepts such as twin skeg and single screw were of main interest in the studies. In the present paper, one twin skeg and one single screw 170 K LNG ship were designed for optimally selected main dimension parameters. The twin skeg hull was further optimized and evaluated using SHIPFLOW FRIENDSHIP design package by performing parameter variation in order to modify the shape and positions of the skegs. The finally optimized models were then built and tested in order to confirm the lower power demand of twin skeg designed compaed with the signle screw design. This paper is a full description of one of the design developments of a LNG twin skeg hull, from early dimensional parameter study, through design optimization phase towards the confirmation by model tests.

  17. Process study and exergy analysis of a novel air separation process cooled by LNG cold energy

    NASA Astrophysics Data System (ADS)

    Xu, Wendong; Duan, Jiao; Mao, Wenjun

    2014-02-01

    In order to resolve the problems of the current air separation process such as the complex process, cumbersome operation and high operating costs, a novel air separation process cooled by LNG cold energy is proposed in this paper, which is based on high-efficiency heat exchanger network and chemical packing separation technology. The operating temperature range of LNG cold energy is widened from 133K-203K to 113K-283K by high-efficiency heat exchanger network and air separation pressure is declined from 0.5MPa to about 0.35MPa due to packing separation technology, thereby greatly improve the energy efficiency. Both the traditional and novel air separation processes are simulated with air handling capacity of 20t·h-1. Comparing with the traditional process, the LNG consumption is reduced by 44.2%, power consumption decrease is 211.5 kWh per hour, which means the annual benefit will be up to 1.218 million CNY. And the exergy efficiency is also improved by 42.5%.

  18. Kinetic theory for condensation of multicomponent vapor under dynamic conditions

    NASA Astrophysics Data System (ADS)

    Kurasov, V.

    1994-06-01

    The kinetics of the multicomponent condesation under dynamic external conditions is described analytically. The multidimensional problem is reduced to the one-dimensional case. Concrete expressions for all main characteristics of the process are obtained with the help of an iteration procedure. As a result an analytical theory for the whole process of transformation of a metastable multicomponent mixture of vapors into a state of liquid disperse phase is completely constructed.

  19. Electrode testing in simple vapor-vapor AMTEC cells

    SciTech Connect

    Hunt, T.K.; Borkowski, C.A.; Childs, K.F.; Sievers, R.K. [Advanced Modular Power Systems, Ann Arbor, MI (United States)

    1997-12-31

    Alkali Metal Thermal to Electric Conversion (AMTEC) is under consideration for a range of applications from solar and radioisotope spacecraft power systems to micro-cogeneration in residential furnaces. AMTEC cells designed for many applications require series connection of individual beta-alumina solid electrolyte (BASE) tubes. In order to prevent short circuit conditions due to liquid sodium bridging to the metallic cell structure, this generally demands cell operation in a vapor-anode mode. The authors report here the results of a series of AMTC experiments carried out in a simple vapor-vapor mini-electrode test cell (METC). The cell provides for a once-through sodium supply, in order to provide rapid turnaround and avoid the assembly complications of providing for Na recirculation. This test cell design also provides a simple method to allow for operating a given electrode and current collector combination in both vapor-vapor and liquid-vapor states in a single experimental run. This capability allows a direct comparison between the larger body of historical data on liquid-vapor cells and the vapor-vapor systems now required.

  20. SiC nanofibers grown by high power microwave plasma chemical vapor deposition

    Microsoft Academic Search

    Shin-ichi Honda; Yang-Gyu Baek; Takashi Ikuno; Hidekazu Kohara; Mitsuhiro Katayama; Kenjiro Oura; Takashi Hirao

    2003-01-01

    Silicon carbide (SiC) nanofibers have been synthesized on Si substrates covered by Ni thin films using high power microwave chemical vapor deposition (CVD). Characterization using transmission electron microscopy (TEM) combined with electron energy-dispersive X-ray spectroscopy (EDX) revealed that the resultant fibrous nanostructures were assigned to ?-SiC with high crystallinity. The formation of SiC nanofibers can be explained by the vapor

  1. Vapor-Liquid Equilibria for Some Concentrated Aqueous PolymerSolutions

    SciTech Connect

    Striolo, Alberto; Prausnitz, John M.

    1999-07-01

    Vapor-liquid-equilibrium data were obtained for binary aqueous solutions of six water-soluble linear polymers in the range 70-95 C. A classical gravimetric sorption method was used to measure the amount of solvent absorbed as a function of vapor-phase water pressure. Polymers studied were polyvinylpyrrolidone, polyethyleneoxide, polyvinylalcohol, hydroxyethylcellulose, polyethylenimine, polymethylvinylether. The experimental data were reduced with Hino's lattice model that distinguished the interactions due to London dispersion forces and those due to hydrogen bonding.

  2. Water Vapor Circulation on Earth

    NSDL National Science Digital Library

    Water vapor plays an important role in the water cycle and in the distribution of heat around the planet. By observing the movement of water vapor, scientists can study global wind patterns and the development of cyclonic storms. This simulation from the National Center for Atmospheric Research shows the circulation of water vapor around the Earth over the course of a year. The segment is four minutes fifty-two seconds in length. Quicktime is required to view the clip.

  3. Tunable alkali metallic vapor laser

    Microsoft Academic Search

    I. Itzkan; R. T. V. Kung

    1979-01-01

    A tunable alkali metallic vapor laser system is disclosed. Stimulated Raman scattering (SRS) in a low pressure atomic alkali metallic vapor of potassium or cesium is utilized wherein the atomic vapor is provided and then primed to populate an intermediate level such as the 4Pââ level for potassium and the 6Pââ level for cesium from which the desired upper laser

  4. The design of an optical sensor arrangement for the detection of oil contamination in an adhesively bonded structure of a liquefied natural gas (LNG) ship

    Microsoft Academic Search

    Bu Gi Kim; Dai Gil Lee

    2009-01-01

    Liquefied natural gas (LNG) has been widely used as a substitute fuel for commercial purposes. It is transported mainly by LNG ships which have primary and secondary leakage barriers. The former is composed of welded thin stainless steel or invar plates, while the latter is composed of adhesively bonded glass composite or aluminum foil sheets. The role of the secondary

  5. Particle Transport by Rapid Vaporization of Superheated Liquid.

    NASA Astrophysics Data System (ADS)

    Sugioka, Ichiro

    Superheated liquid vaporizing explosively in a particle bed inside a cylindrical test cell has been studied using a rapid depressurization apparatus. The experiments provide insights into the explosive vaporization phenomenon and the multiphase flow which is generated by the rapid production of vapor. Inside the sealed test cell, spherical glass particles are immersed in a volatile liquid, Refrigerant 12 or 114 at 300K. When the diaphragm at the upper end of the test cell is ruptured, the liquid pressure is reduced to a predetermined pressure within milliseconds. Since the liquid temperature is higher than the boiling temperature at reduced pressure, the liquid achieves a superheated state and nucleate boiling begins among the particles. The particle-liquid-vapor flow produced by the rapid release of vapor has been found to differ depending on whether the pressure is reduced below a critical level, which is 55% of the vapor pressure in the experiments conducted. When the final pressure is greater than critical, vapor pockets continue to grow throughout the particle bed and displace a liquid-particles mixture out from the test cell. When the final pressure is below critical, the particles are dispersed by a wave -like phenomenon (disruption front) where explosive vaporization appears to be localized in a narrow region. A disruption front in R12 travels at about 380 cm/s, and at about 200 cm/s in R114. Experiments have been performed at various conditions to study the vaporization and transport process. High -speed cinematography and fast-response pressure gauges have provided data on the particle acceleration process. The inertial effect on particle acceleration has been studied by conducting similar experiments in a centrifuge. Using this data, the transport process associated with the disruption front has been examined in detail. An empirical relationship between the particle weight and viscous drag is presented for this particular case. This study concludes with discussions based on analytical models of the disruption front to approximate flows properties which are intractable experimentally. It is suggested that a disruption front is an expansion process which maximizes vaporization and entropy.

  6. Particle transport by rapid vaporization of superheated liquid

    NASA Astrophysics Data System (ADS)

    Sugioka, Ichiro

    Superheated liquid vaporizing explosively in a particle bed inside a cylindrical test cell has been studied using a rapid depressurization apparatus. The experiments provide insights into the explosive vaporization phenomenon and the multiphase flow which is generated by the rapid production of vapor.Inside the sealed test cell, spherical glass particles are immersed in a volatile liquid, Refrigerant 12 or 114 at 300K. When the diaphragm at the upper end of the test cell is ruptured, the liquid pressure is reduced to a predetermined pressure within milliseconds. Since the liquid temperature is higher than the boiling temperature at reduced pressure, the liquid achieves a superheated state and nucleate boiling begins among the particles. The particle-liquid-vapor flow produced by the rapid release of vapor has been found to differ depending on whether the pressure is reduced below a critical level, which is 55% of the vapor pressure in the experiments conducted. When the final pressure is greater than critical, vapor pockets continue to grow throughout the particle bed and displace a liquid-particles mixture out from the test cell. When the final pressure is below critical, the particles are dispersed by a wave-like phenomenon (disruption front) where explosive vaporization appears to be localized in a narrow region. A disruption front in R12 travels at about 380 cm/s, and at about 200 cm/s in R114.Experiments have been performed at various conditions to study the vaporization and transport process. High-speed cinematography and fast response pressure gauges have provided data on the particle acceleration process. The inertial effect on particle acceleration has been studied by conducting similar experiments in a centrifuge. Using this data, the transport process associated with the disruption front has been examined in detail. An empirical relationship between the particle weight and viscous drag is presented for this particular case. This study concludes with discussions based on analytical models of the disruption front to approximate flows properties which are intractable experimentally. It is suggested that a disruption front is an expansion process which maximizes vaporization and entropy.

  7. The Vaporization Enthalpies and Vapor Pressures of Some Primary Amines of Pharmaceutical Importance by Correlation Gas

    E-print Network

    Chickos, James S.

    The Vaporization Enthalpies and Vapor Pressures of Some Primary Amines of Pharmaceutical Importance Information ABSTRACT: Vapor pressures, vaporization, and sublimation enthalpies of several pharmaceuticals.5 ± 2.1); p(cr)/Pa = 0.12 ± 0.04]. Vapor pressure equations also derived from vapor pressureretention

  8. The atmospheric water vapor line

    Microsoft Academic Search

    M. Strong; Z. D. Sharp; D. S. Gutzler

    2008-01-01

    We have measured the hydrogen and oxygen isotope composition of atmospheric water vapor periodically across the American Southwest through most of 2007. Samples were primarily collected over Albuquerque, NM on the roof of the 3-story UNM geology building on a near-daily basis with occasional sampling in southern Arizona and southern Texas. Water vapor was captured by pumping ~60 to ~600

  9. DISPERSAL IN FRESHWATER INVERTEBRATES

    Microsoft Academic Search

    David T. Bilton; Joanna R. Freeland; Beth Okamura

    2001-01-01

    ? Abstract Movement between discrete habitat patches can present significant challenges to organisms. Freshwater invertebrates achieve dispersal using a variety of mechanisms that can be broadly categorized as active or passive, and which have important consequences for processes of colonization, gene flow, and evolutionary divergence. Apart from flight in adult freshwater insects, active dispersal appears rela- tively uncommon. Passive dispersal

  10. FIELD DISPERSANT EFFECTIVENESS TEST

    EPA Science Inventory

    The EPA's OHMSETT facility has developed a rapid field test that includes some of the theoretical aspects and conditions of dispersion at sea. This Field Dispersant Effectiveness Test (FDET) has been used to evaluate the dispersibility of various commonly-transported oils and mak...

  11. Simulations and studies of heavy-gas dispersion using the SLAB model

    SciTech Connect

    Morgan, D.L. Jr.; Kansa, E.J.; Morris, L.K.

    1982-11-01

    The SLAB model is a one-dimensional (1-D), time-dependent model suitable for computer simulations which describes the diffusion and gravity flow of a heavy gas released into the atmosphere. The properties of the air-gas cloud are treated explicitly in their dependence on the downwind direction. When strong turbulent mixing occurs within the cloud, the properties are sufficiently constant in the crosswind directions to justify the 1-D simulation. The SLAB model has successfully simulated four large-scale 40-m/sup 3/ experimental spills of liquefied natural gas (LNG). In particular, the calculated positions of the lower flammability limits (LFL) in the resultant vapor cloud agreed very well with the experimental measurements. The model is now being used to simulate other LNG spills. In addition, parameter studies are being conducted to determine the dependence of gas concentration, distance to the LFL, and the cloud dimensions on various quantities. These quantities include source rate, wind speed, atmospheric stability, type of source gas, and source duration. Sensitivity studies are also being conducted to assess the effect of uncertainties in the submodels.

  12. Generation of ultrahigh pressure using single-crystal chemical-vapor-deposition diamond anvils

    NASA Astrophysics Data System (ADS)

    Mao, Wendy L.; Mao, Ho-kwang; Yan, Chih-shiue; Shu, Jinfu; Hu, Jingzhu; Hemley, Russell J.

    2003-12-01

    Two experiments were conducted compressing Ta, Re, Pt, and an Fe-Si alloy to ultrahigh pressures using single-crystal chemical vapor deposition (CVD) and natural diamonds. In situ energy-dispersive and angle-dispersive x-ray diffraction were used to determine pressure from known equations of state. We demonstrate that CVD diamonds can be used in diamond anvil cells to reach pressures of nearly 200 GPa.

  13. Chemical vapor deposition growth

    NASA Technical Reports Server (NTRS)

    Ruth, R. P.; Manasevit, H. M.; Kenty, J. L.; Moudy, L. A.; Simpson, W. I.; Yang, J. J.

    1976-01-01

    The chemical vapor deposition (CVD) method for the growth of Si sheet on inexpensive substrate materials is investigated. The objective is to develop CVD techniques for producing large areas of Si sheet on inexpensive substrate materials, with sheet properties suitable for fabricating solar cells meeting the technical goals of the Low Cost Silicon Solar Array Project. Specific areas covered include: (1) modification and test of existing CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using standard and near-standard processing techniques.

  14. Vapor compression distillation module

    NASA Technical Reports Server (NTRS)

    Nuccio, P. P.

    1975-01-01

    A Vapor Compression Distillation (VCD) module was developed and evaluated as part of a Space Station Prototype (SSP) environmental control and life support system. The VCD module includes the waste tankage, pumps, post-treatment cells, automatic controls and fault detection instrumentation. Development problems were encountered with two components: the liquid pumps, and the waste tank and quantity gauge. Peristaltic pumps were selected instead of gear pumps, and a sub-program of materials and design optimization was undertaken leading to a projected life greater than 10,000 hours of continuous operation. A bladder tank was designed and built to contain the waste liquids and deliver it to the processor. A detrimental pressure pattern imposed upon the bladder by a force-operated quantity gauge was corrected by rearranging the force application, and design goals were achieved. System testing has demonstrated that all performance goals have been fulfilled.

  15. Constrained Vapor Bubble

    NASA Technical Reports Server (NTRS)

    Huang, J.; Karthikeyan, M.; Plawsky, J.; Wayner, P. C., Jr.

    1999-01-01

    The nonisothermal Constrained Vapor Bubble, CVB, is being studied to enhance the understanding of passive systems controlled by interfacial phenomena. The study is multifaceted: 1) it is a basic scientific study in interfacial phenomena, fluid physics and thermodynamics; 2) it is a basic study in thermal transport; and 3) it is a study of a heat exchanger. The research is synergistic in that CVB research requires a microgravity environment and the space program needs thermal control systems like the CVB. Ground based studies are being done as a precursor to flight experiment. The results demonstrate that experimental techniques for the direct measurement of the fundamental operating parameters (temperature, pressure, and interfacial curvature fields) have been developed. Fluid flow and change-of-phase heat transfer are a function of the temperature field and the vapor bubble shape, which can be measured using an Image Analyzing Interferometer. The CVB for a microgravity environment, has various thin film regions that are of both basic and applied interest. Generically, a CVB is formed by underfilling an evacuated enclosure with a liquid. Classification depends on shape and Bond number. The specific CVB discussed herein was formed in a fused silica cell with inside dimensions of 3x3x40 mm and, therefore, can be viewed as a large version of a micro heat pipe. Since the dimensions are relatively large for a passive system, most of the liquid flow occurs under a small capillary pressure difference. Therefore, we can classify the discussed system as a low capillary pressure system. The studies discussed herein were done in a 1-g environment (Bond Number = 3.6) to obtain experience to design a microgravity experiment for a future NASA flight where low capillary pressure systems should prove more useful. The flight experiment is tentatively scheduled for the year 2000. The SCR was passed on September 16, 1997. The RDR is tentatively scheduled for October, 1998.

  16. Rapid response calculation of LNG cargo containment system under sloshing load using wavelet transformation

    NASA Astrophysics Data System (ADS)

    Kim, Yooil

    2013-06-01

    Reliable strength assessment of the Liquefied Natural Gas (LNG) cargo containment system under the sloshing impact load is very difficult task due to the complexity of the physics involved in, both in terms of the hydrodynamics and structural mechanics. Out of all those complexities, the proper selection of the design sloshing load which is applied to the structural model of the LNG cargo containment system, is one of the most challenging one due to its inherent randomness as well as the statistical analysis which is tightly linked to the design sloshing load selection. In this study, the response based strength assessment procedure of LNG cargo containment system has been developed and proposed as an alternative design methodology. Sloshing pressure time history, measured from the model test, is decomposed into wavelet basis function targeting the minimization of the number of the basis function together with the maximization of the numerical efficiency. Then the response of the structure is obtained using the finite element method under each wavelet basis function of different scale. Finally, the response of the structure under entire sloshing impact time history is rapidly calculated by synthesizing the structural response under wavelet basis function. Through this analysis, more realistic response of the system under sloshing impact pressure can be obtained without missing the details of pressure time history such as rising pattern, oscillation due to air entrapment and decay pattern and so on. The strength assessment of the cargo containment system is then performed based on the statistical analysis of the stress peaks selected out of the obtained stress time history.

  17. Thermally induced dispersion mechanisms for aluminum-based plate-type fuels under rapid transient energy deposition

    SciTech Connect

    Georgevich, V.; Taleyarkham, R.P.; Navarro-Valenti, S.; Kim, S.H.

    1995-12-31

    A thermally induced dispersion model was developed to analyze for dispersive potential and determine onset of fuel plate dispersion for Al-based research and test reactor fuels. Effect of rapid energy deposition in a fuel plate was simulated. Several data types for Al-based fuels tested in the Nuclear Safety Research Reactor in Japan and in the Transient Reactor Test in Idaho were reviewed. Analyses of experiments show that onset of fuel dispersion is linked to a sharp rise in predicted strain rate, which futher coincides with onset of Al vaporization. Analysis also shows that Al oxidation and exothermal chemical reaction between the fuel and Al can significantly affect the energy deposition characteristics, and therefore dispersion onset connected with Al vaporization, and affect onset of vaporization.

  18. Price discrimination and limits to arbitrage: An analysis of global LNG markets

    E-print Network

    Ritz, Robert A.

    2014-07-31

    for years, and have become more pronounced since the Fukushima accident of March 2011 (IGU, 2013). The 2012 average natural gas price was roughly US$16/MMBtu in Japan, $9 in Europe but only $3 in the US. Some expect large price disparities to persist... conditions. The Fukushima accident, for instance, e¤ectively switched o¤ large parts of Japanese nuclear power, leading to an increase in demand for imported LNG to ??ll the gap?. (Local demand conditions play no role in the competitive model, in which price...

  19. Seed Dispersal: Animals

    NSDL National Science Digital Library

    Pulse of the Planet

    2007-08-02

    The guest scientist in this two-minute radio program discusses seed dispersal in plants. He first explains why it is important for seeds to be distributed away from the mother plant. Then he contrasts wind-dispersed seeds with animal-dispersed seeds, pointing out that animals can disperse larger seeds that contain more nutrients for an emerging seedling. The program, which is available here in audio and text, is part of a Pulse of the Planet series on seed dispersal. Copyright 2005 Eisenhower National Clearinghouse

  20. MODIFICATION OF SPILL FACTORS AFFECTING AIR POLLUTION. VOLUME I. AN EVALUATION OF COOLING AS A VAPOR MITIGATION PROCEDURE FOR SPILLED VOLATILE CHEMICALS

    EPA Science Inventory

    Spilled chemicals that pose a hazard to the land and water ecosystems can also provide a significant vapor hazard. Although the vapors released by such chemicals may ultimately be dispersed in the environment with little long-term effects, they do pose a hazard to life and proper...

  1. Passive vapor extraction feasibility study

    SciTech Connect

    Rohay, V.J.

    1994-06-30

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft{sup 3}/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft{sup 3}/min air flow rates, passive vapor extraction is more cost effective below 100 ppm.

  2. Carbon nanotube synthesis using a magnetic fluid via thermal chemical vapor deposition

    Microsoft Academic Search

    Yu-Suk Cho; Gyu-Seok Choi; Sang-Young Hong; Dojin Kim

    2002-01-01

    A new approach to synthesizing carbon nanotubes (CNTs) using dispersed magnetic fluids, instead of conventional metallic catalyst nanoparticles of Ni, Co, or Fe, was proposed. A magnetic fluid of surfactant-coated magnetite nanoparticles has been successfully applied for CNT synthesis in chemical vapor deposition by a simple spin coating method. Using the method dense and aligned CNTs were successfully grown on

  3. Design, fabrication and testing of porous tungsten vaporizers for mercury ion thrusters

    NASA Technical Reports Server (NTRS)

    Zavesky, R.; Kroeger, E.; Kami, S.

    1983-01-01

    The dispersions in the characteristics, performance and reliability of vaporizers for early model 30-cm thrusters were investigated. The purpose of the paper is to explore the findings and to discuss the approaches that were taken to reduce the observed dispersion and present the results of a program which validated those approaches. The information that is presented includes porous tungsten materials specifications, a discussion of assembly procedures, and a description of a test program which screens both material and fabrication processes. There are five appendices providing additional detail in the areas of vaporizer contamination, nitrogen flow testing, bubble testing, porosimeter testing, and mercury purity. Four neutralizers, seven cathodes and five main vaporizers were successfully fabricated, tested, and operated on thrusters. Performance data from those devices is presented and indicates extremely repeatable results from using the design and fabrication procedures.

  4. Comparative Life-cycle Air Emissions of Coal, Domestic Natural Gas, LNG, and SNG for Electricity Generation

    E-print Network

    Jaramillo, Paulina

    , natural gas used by electricity generators is bought directly from the transmission system, so1 Comparative Life-cycle Air Emissions of Coal, Domestic Natural Gas, LNG, and SNG for Electricity Generation Supporting Information 1. Graphical Representation of the Fuel Life-cycles Figure 1S and Figure 2S

  5. Understanding Latent Heat of Vaporization.

    ERIC Educational Resources Information Center

    Linz, Ed

    1995-01-01

    Presents a simple exercise for students to do in the kitchen at home to determine the latent heat of vaporization of water using typical household materials. Designed to stress understanding by sacrificing precision for simplicity. (JRH)

  6. Pre-heat vaporization system

    SciTech Connect

    Gartside, R.J.

    1981-11-17

    A process and system ar disclosed for vaporizing heavy oil prior to thermal cracking in a TRC system having low residence time on the order of 0.05 to 2 seconds, and at a temperature between 1300* and 2500

  7. Portable vapor diffusion coefficient meter

    DOEpatents

    Ho, Clifford K. (Albuquerque, NM)

    2007-06-12

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  8. Vapor detection using resonating microcantilevers

    SciTech Connect

    Thundat, T.; Chen, G.Y.; Warmack, R.J.; Allison, D.P.; Wachter, E.A. (Oak Ridge National Lab., TN (United States))

    1995-02-01

    Changes in the resonance frequency of microcantilevers due to adsorption of analyte vapor on exposed surfaces is shown to provide a novel means for detection of the analyte. Frequency changes can be due to mass loading or adsorption-induced changes in cantilever spring constant. Sensitization to water vapor is demonstrated by coating cantilever surfaces with hygroscopic materials, such as phosphoric acid. Cantilevers coated with a thin gelatin film exhibit high sensitivity and a linear response with changes in relative humidity, apparently due to changes in the spring constant of the coated cantilever. In addition to frequency response, static cantilever deflection also changes with vapor adsorption. Both phenomena can be used to detect adsorbed vapors with picogram mass resolution. 19 refs., 2 figs.

  9. Water vapor diffusion membranes, 2

    NASA Technical Reports Server (NTRS)

    Holland, F. F.; Klein, E.; Smith, J. K.; Eyer, C.

    1976-01-01

    Transport mechanisms were investigated for the three different types of water vapor diffusion membranes. Membranes representing porous wetting and porous nonwetting structures as well as dense diffusive membrane structures were investigated for water permeation rate as a function of: (1) temperature, (2) solids composition in solution, and (3) such hydrodynamic parameters as sweep gas flow rate, solution flow rate and cell geometry. These properties were measured using nitrogen sweep gas to collect the effluent. In addition, the chemical stability to chromic acid-stabilized urine was measured for several of each type of membrane. A technology based on the mechanism of vapor transport was developed, whereby the vapor diffusion rates and relative susceptibility of membranes to fouling and failure could be projected for long-term vapor recovery trials using natural chromic acid-stabilized urine.

  10. TROPOSPHERIC WATER VAPOR, CONVECTION, AND CLIMATE

    E-print Network

    Sherwood, Steven

    Click Here for Full Article TROPOSPHERIC WATER VAPOR, CONVECTION, AND CLIMATE S. C. Sherwood,1 R with water vapor and changes associated with water vapor in warmer climates. Progress includes new observing the anticipated water vapor feedback on climate, though key uncertainties remain connected to atmospheric dynamics

  11. Vapor deposition of hardened niobium

    DOEpatents

    Blocher, Jr., John M. (Columbus, OH); Veigel, Neil D. (Columbus, OH); Landrigan, Richard B. (Columbus, OH)

    1983-04-19

    A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

  12. Packed Alumina Absorbs Hypergolic Vapors

    NASA Technical Reports Server (NTRS)

    Thomas, J. J.; Mauro, D. M.

    1984-01-01

    Beds of activated alumina effective as filters to remove hypergolic vapors from gas streams. Beds absorb such substances as nitrogen oxides and hydrazines and may also absorb acetylene, ethylene, hydrogen sulfide, benzene, butadiene, butene, styrene, toluene, and xoylene. Bed has no moving parts such as pumps, blowers and mixers. Reliable and energy-conservative. Bed readily adapted to any size from small portable units for use where little vapor release is expected to large stationary units for extensive transfer operations.

  13. Vapor pressure of germanium precursors

    Microsoft Academic Search

    J. Pangrác; M. Fulem; E. Hulicius; K. Melichar; T. Šime?ek; K. Ruzicka; P. Morávek; V. R?ži?ka; S. A. Rushworth

    2008-01-01

    The vapor pressure of two germanium precursors tetrakis(methoxy)germanium (Ge(OCH3)4, CASRN 992-91-6) and tetrakis(ethoxy)germanium (Ge(OC2H5)4, CASRN 14165-55-0) was determined using a static method in the temperature range 259–303K. The experimental vapor pressure data were fit with the Antoine equation. The mass spectra before and after degassing by vacuum distillation at low temperature are also reported and discussed.

  14. Dispersible carbon nanotubes.

    PubMed

    Soulié-Ziakovic, Corinne; Nicolaÿ, Renaud; Prevoteau, Alexandre; Leibler, Ludwik

    2014-01-27

    A method is proposed to produce nanoparticles dispersible and recyclable in any class of solvents, and the concept is illustrated with the carbon nanotubes. Classically, dispersions of CNTs can be achieved through steric stabilization induced by adsorbed or grafted polymer chains. Yet, the surface modification of CNTs surfaces is irreversible, and the chemical nature of the polymer chains imposes the range of solvents in which CNTs can be dispersed. To address this limitation, supramolecular bonds can be used to attach and to detach polymer chains from the surface of CNTs. The reversibility of supramolecular bonds offers an easy way to recycle CNTs as well as the possibility to disperse the same functional CNTs in any type of solvent, by simply adapting the chemical nature of the stabilizing chains to the dispersing medium. The concept of supramolecular functionalization can be applied to other particles, for example, silica or metal oxides, as well as to dispersing in polymer melts, films or coatings. PMID:24458908

  15. Vapor passage fuel blockage removal

    SciTech Connect

    Faeth, W.P.

    1993-08-31

    In a method of making a system for dispensing gasoline fuel into a vehicle fuel tank, said system is described comprising a dispenser pump, a nozzle, a fuel hose connecting said dispenser pump to said nozzle for dispensing said fuel from said pump to said tank, a vapor recovery hose surrounding said fuel hose for conducting fuel vapors from the fuel tank to a storage reservoir, said fuel hose and vapor recovery hose adapted to form at least one looped low portion during dispensing of fuel into a fuel tank whereat condensed fuel vapors tend to collect in said vapor recovery passage, and a venturi means having inlet means disposed in said vapor recovery passage so as to be at said one looped low portion during said dispensing of fuel, said venturi means being so arranged that said fuel being dispensed from said pump to said tank will flow through said venturi means and create a suction at said inlet means, the improvement comprising the step of forming said inlet means to comprise a plurality of separate inlets disposed in a spaced apart relation.

  16. Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures of Polyaromatic Heterocycles and Related Compounds

    E-print Network

    Chickos, James S.

    Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures The vaporization enthalpies and vapor pressures of the liqiud phase from T ) 298.15 K to T ) 500 K of a series. The vaporization enthalpies at T ) 298.15 K measured in kilojoules per mole include: tri-n-butylamine (62.7 ( 1

  17. Infrared absorption bands of alkali saturated vapors

    Microsoft Academic Search

    A. Vasilakis

    1981-01-01

    A region of absorption was observed and measured in the near infrared region of the spectrum for saturated sodium vapor and for saturated rubidium vapor (absorption beyond 0.83 microns for saturated sodium vapor, and beyond 1.20 microns in rubidium saturated vapor). In addition, earlier data taken on near infrared absorption by cesium saturated vapor beyond 1.30 microns was reexamined in

  18. Structure of a zinc sulfide film prepared by molecular stratification on the surface of disperse silica

    Microsoft Academic Search

    N. A. Stepanova; V. D. Kupriyanov; A. A. Malygin

    1987-01-01

    The authors report the physicochemical study of the surface structures formed in successive and alternate treatment of highly disperse silicon(IV) oxide with ZnClâ and HâS vapors. The results of the study can be used in creating coating pigments and inorganic luminophors with controllable properties. The zinc sulfide film was synthesized by treating it with ZnClâ and HâS vapors by the

  19. Advection-condensation paradigm for stratospheric water vapor

    NASA Astrophysics Data System (ADS)

    Liu, Y. S.; Fueglistaler, S.; Haynes, P. H.

    2010-12-01

    The advection-condensation (A-C) paradigm is a starting point for a theoretical framework for analysis of atmospheric water vapor distributions and changes therein in a changing climate. It postulates that water vapor concentrations are governed to leading order by the transport through the full four-dimensional temperature (and hence saturation mixing ratio) field. Brewer's (1949) qualitative deduction of the stratospheric circulation based on water vapor measurements was a first and prominently successful application of this paradigm. Here we examine the quantitative validity of the A-C paradigm by predicting stratospheric water vapor based on the saturation mixing ratio at the Lagrangian dry point of trajectories calculated using data from the European Centre for Medium-range Weather Forecasts. Using different data sets for the calculation, we show that results are sensitive to seemingly small differences in temperatures and wind fields and that interpretation of results (in terms of identification of effects of processes deliberately neglected by the advection-condensation paradigm) requires a careful error calculation. We introduce a semiempirical approach to analyze errors in the Lagrangian predictions of water vapor. We show that persistent (in time and space) errors in the temperature fields lead to similar errors in the Lagrangian model predictions. Conversely, biases in the variance of the temperature fields introduces a systematic bias in the model prediction. Further, model predictions are affected by dispersion and the time scale of troposphere-to-stratosphere transport. Our conclusion is that water vapor predictions for the stratospheric overworld based on the A-C paradigm have a dry bias of -40% ± 10% and -50% ± 10% when small-space-scale and short-time-scale temperature fluctuations not resolved by the ECMWF reanalyses are taken into account. We suggest that the correction to the A-C paradigm most likely to remove this dry bias is the inclusion of cloud microphysical processes (such as incomplete sedimentation of particles allowing reevaporation), which relax the assumption of instantaneous dehydration to the saturation mixing ratio. Interestingly, the bias attributed to the A-C paradigm in terms of water vapor concentration is found to be proportional to the measured water concentration, and a constant offset in terms of frost point temperature can account for much of the bias and its variability in water vapor mixing ratios.

  20. Thermogravity system designed for use in dispersion strengthening studies

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.

    1972-01-01

    A thermogravimetry system designed to study the reduction of oxides in metal and alloy powders to be used in dispersion strengthened materials is described. The apparatus was devised for use at high temperatures with controlled atmospheres. Experimental weight change and moisture evolution results for the thermal decomposition of calcium oxalate monohydrate in dry helium, and experimental weight change results for the reduction of nickel oxide in dry hydrogen and hydrogen containing 15,000 PPM water vapor are presented. The system is currently being successfully applied to the evaluation of the reduction characteristics and the removal of impurities from metals and alloys to be used for dispersion strengthening.

  1. Thermogravimetry system designed for use in dispersion strengthening studies.

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.

    1972-01-01

    A thermogravimetry system, designed to study the reduction of oxides in metal and alloy powders to be used in dispersion strengthened materials, is described. The apparatus was devised for use at high temperatures with controlled atmospheres. Experimental weight change and moisture evolution results for the thermal decomposition of calcium oxalate monohydrate in dry helium, and experimental weight change results for the reduction of nickel oxide in dry hydrogen and hydrogen containing 15,000 p.p.m. water vapor are presented. The system is currently being successfully applied to the evaluation of the reduction characteristics and the removal of impurities from metals and alloys to be used for dispersion strengthening.

  2. Landfill Gas Conversion to LNG and LCO{sub 2}. Phase II Final Report for January 25, 1999 - April 30, 2000

    SciTech Connect

    Brown, W. R.; Cook, W. J.; Siwajek, L. A.

    2000-10-20

    This report summarizes work on the development of a process to produce LNG (liquefied methane) for heavy vehicle use from landfill gas (LFG) using Acrion's CO{sub 2} wash process for contaminant removal and CO{sub 2} recovery.

  3. Visualizing Dispersion Interactions

    ERIC Educational Resources Information Center

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  4. Dispersive ionospheric Alfvén resonator

    Microsoft Academic Search

    Oleg A. Pokhotelov; D. Pokhotelov; A. Streltsov; V. Khruschev; M. Parrot

    2000-01-01

    A new model of the ionospheric Alfvén resonator (IAR) including the effect of wave frequency dispersion is presented. It is shown that the shear Alfvén waves in the IAR are coupled to the compressional mode through the boundary conditions at the ionosphere. This coupling results in the appearance of the Hall dispersion and subsequent shift of the IAR frequency spectrum.

  5. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  6. Spores Disperse, Too!

    ERIC Educational Resources Information Center

    Schumann, Donna N.

    1981-01-01

    Suggests the use of spores and spore-producing structures to show adaptations facilitating spore dispersal and dispersal to favorable environments. Describes several activities using horsetails, ferns, and mosses. Lists five safety factors related to use of mold spores in the classroom. (DS)

  7. Almost Optimal Dispersers

    Microsoft Academic Search

    Amnon Ta-shma

    2002-01-01

      A disperser is a bipartite graph with the property that every subset A of of cardinality at least K, has at least fraction of the vertices of as neighbors. Such graphs have many applications in derandomization. Saks, Srinivasan and Zhou presented an explicit construction\\u000a of a disperser with an almost optimal degree , for every . We extend their result

  8. Near-infrared spectroscopy with a dispersive waveguide device

    Microsoft Academic Search

    Brian R. Stallard; R. K. Rowe; Arnold J. Howard; G. Ronald Hadley; Gregory A. Vawter; Joel R. Wendt; Ian J. Fritz

    1997-01-01

    Miniature, low-cost sensors are in demand for a variety of applications in industry, medicine, and environmental sciences. As a first step in developing such a sensor, we have etched a grating into a GaAs rib waveguide to serve as a wavelength-dispersive element. The device was fabricated with the techniques of metal-organic chemical vapor deposition, electron-beam lithography, optical lithography, and reactive

  9. An AMTEC vapor-vapor, series connected cell

    NASA Astrophysics Data System (ADS)

    Underwood, Mark L.; Williams, Roger M.; Ryan, Margaret A.; Jefferies-Nakamura, Barbara; O'Connor, Dennis

    1992-01-01

    The alkali metal thermal-to-electric converter (AMTEC) converts heat energy to electrical energy with efficiencies up to 3 to 4 times the state of the art static converters. However, the high current, low voltage output of a single module requires difficult series connecting of cells, and several life limiting concerns may reduce the achievable efficiency. A concept is proposed that incorporates internal series connecting of cells and sodium supply as a vapor without condensation. This concept overcomes many of the long term materials concerns in liquid anode systems and results in a module with about the same power density, but at a higher voltage and lower current. The vapor-vapor AMTEC concept is described and its performance predicted for typical AMTEC operating conditions.

  10. Dispersion and space charge

    SciTech Connect

    Venturini, Marco [Department of Physics and Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States); Kishek, Rami A.; Reiser, Martin [Department of Electrical Engeneering and Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States)

    1998-11-05

    The presence of space charge affects the value of the dispersion function. On the other hand dispersion has a role in shaping the beam distribution and therefore in determining the resulting forces due to space charge. In this paper we present a framework where the interplay between space charge and dispersion for a continuous beam can be simultaneously treated. We revise the derivation of a new set of rms envelope-dispersion equations we have recently proposed. The new equations generalize the standard rms envelope equations currently used for matching to the case where bends and a longitudinal momentum spread are present. We report a comparison between the solutions of the rms envelope-dispersion equations and the results obtained using WARP, a Particle in Cell (PIC) code, in the modeling of the Maryland Electron Ring.

  11. Vaporization Enthalpies and Vapor Pressures of Two Insecticide Components, Muscalure and Empenthrin, by Correlation Gas

    E-print Network

    Chickos, James S.

    Vaporization Enthalpies and Vapor Pressures of Two Insecticide Components, Muscalure and Empenthrin: The vaporization enthalpies at T/K = 298.15 and vapor pressures from T/K = (298.15 to Tnb (normal boiling. Vaporization enthalpies of [(114.4 ± 1.0) and (114.5 ± 1.0)] kJ·mol-1 and vapor pressures, p/Pa = [(1.2 ± 0

  12. Series-Connected Vapor/Vapor AMTEC Cells

    NASA Technical Reports Server (NTRS)

    Underwood, Mark L.; Williams, Roger M.; Ryan, Margaret A.; Jeffries-Nakamura, Barbara; Oconnor, Dennis

    1993-01-01

    Size and weight reduced; operating lifetime increased. Developmental alkali-metal thermal-to-electric converter (AMTEC) in which cells fed from common supply of high-pressure sodium vapor and connected electrically in series. No liquid sodium makes contact with any part of AMTEC cells. Sodium vapor supplied to solid electrolyte of each cell through porous metal anode on upstream side. Proposed design reduces need for high-temperature feedthroughs in that cells internally connected. Power withdrawn through feedthrough at lower temperature without significant thermal loss.

  13. Atmospheric Dispersion Lecture Atmospheric Local-Scale Dispersion Modelling.

    E-print Network

    pressure centers (its the opposite on the #12;Southern Hemisphere.) Atmospheric boundary layerAtmospheric Dispersion Lecture Atmospheric Local-Scale Dispersion Modelling. Lecturer: Dr Torben) Learning aims ! To understand the basic phenomena of atmospheric dispersion and deposition. ! To understand

  14. Experimental study on flow boiling heat transfer of LNG in a vertical smooth tube

    NASA Astrophysics Data System (ADS)

    Chen, Dongsheng; Shi, Yumei

    2013-10-01

    An experimental apparatus is set up in this work to study the upward flow boiling heat transfer characteristics of LNG (liquefied natural gas) in vertical smooth tubes with inner diameters of 8 mm and 14 mm. The experiments were performed at various inlet pressures from 0.3 to 0.7 MPa. The results were obtained over the mass flux range from 16 to 200 kg m-2 s-1 and heat fluxes ranging from 8.0 to 32 kW m-2. The influences of quality, heat flux and mass flux, tube diameter on the heat transfer characteristic are examined and discussed. The comparisons of the experimental heat transfer coefficients with the predicted values from the existing correlations are analyzed. The correlation by Zou et al. [16] shows the best accuracy with the RMS deviation of 31.7% in comparison with the experimental data.

  15. LNG combined cycle power plant for stable power supply for Kiheung semiconductor plant

    SciTech Connect

    Chang, Choong Koo [Samsung Electronic, Seoul (Korea, Republic of); Park, Hyo Jeong [Samsung Electronics, Kiheung (Korea, Republic of); Kim, In Chool [Samsung Heavy Industries, Seoul (Korea, Republic of)

    1995-12-31

    Reserve margins of Korea Electric Power Corporation (KEPCO) was 12% in 1993, however it was reduced to less than 3% in the summer of 1994 due to increase of electric power consumption caused by life style change based on economic growth. Therefore stable supply of electric power to industrial plant was threatened during last summer`s peak. The process of semiconductor manufacturing is very precious and full processing time reaches several months. Furthermore interruption of power supply to the process causes abortion of every product in the process. Therefore, power failure of less than one (1) second, may result in enormous loss of capital. In order to protect disaster caused by power shortage during summer peaks. Samsung Electronics Co., Ltd (SEC) planned to construct LNG combined cycle power plant for the Klheung semiconductor plant which is the world`s leading maker of dynamic random access memory (DRAM) chips.

  16. Numerical study on mixing of sprayed liquid in an LNG storage tank

    NASA Technical Reports Server (NTRS)

    Uchida, Hiroyuki; Arai, Tatsuya; Sugihara, Makoto; Nakayama, Mariko

    1992-01-01

    This paper presents a numerical method to simulate the mixing of heavier LNG sprayed on lighter layer. Numerical results for evolutions of flow field and density field are obtained in a rectangular computational domain which includes the vicinity of the liquid surface. At the surface boundary, uniform distributions of the fluid velocity and the density are assumed. Detail structure of flow caused by impingements of liquid drops are neglected. But, to trigger a realistic motion, a series of random numbers is employed. It is used as an initial distribution of the density near the surface. This method successfully gives a realistic simulation of the mixing process. Numerical results for mixing velocity shows good agreement with experimental data.

  17. Electrical Breakdown in Water Vapor

    SciTech Connect

    Skoro, N.; Maric, D.; Malovic, G.; Petrovic, Z. Lj. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Graham, W. G. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, BT7 1NN (United Kingdom)

    2011-11-15

    In this paper investigations of the voltage required to break down water vapor are reported for the region around the Paschen minimum and to the left of it. In spite of numerous applications of discharges in biomedicine, and recent studies of discharges in water and vapor bubbles and discharges with liquid water electrodes, studies of the basic parameters of breakdown are lacking. Paschen curves have been measured by recording voltages and currents in the low-current Townsend regime and extrapolating them to zero current. The minimum electrical breakdown voltage for water vapor was found to be 480 V at a pressure times electrode distance (pd) value of around 0.6 Torr cm ({approx}0.8 Pa m). The present measurements are also interpreted using (and add additional insight into) the developing understanding of relevant atomic and particularly surface processes associated with electrical breakdown.

  18. Low level vapor verification of monomethyl hydrazine

    NASA Technical Reports Server (NTRS)

    Mehta, Narinder

    1990-01-01

    The vapor scrubbing system and the coulometric test procedure for the low level vapor verification of monomethyl hydrazine (MMH) are evaluated. Experimental data on precision, efficiency of the scrubbing liquid, instrument response, detection and reliable quantitation limits, stability of the vapor scrubbed solution, and interference were obtained to assess the applicability of the method for the low ppb level detection of the analyte vapor in air. The results indicated that the analyte vapor scrubbing system and the coulometric test procedure can be utilized for the quantitative detection of low ppb level vapor of MMH in air.

  19. Image Storage in Hot Vapors

    E-print Network

    L. Zhao; T. Wang; Y. Xiao; S. F. Yelin

    2007-10-22

    We theoretically investigate image propagation and storage in hot atomic vapor. A $4f$ system is adopted for imaging and an atomic vapor cell is placed over the transform plane. The Fraunhofer diffraction pattern of an object in the object plane can thus be transformed into atomic Raman coherence according to the idea of ``light storage''. We investigate how the stored diffraction pattern evolves under diffusion. Our result indicates, under appropriate conditions, that an image can be reconstructed with high fidelity. The main reason for this procedure to work is the fact that diffusion of opposite-phase components of the diffraction pattern interfere destructively.

  20. Vapor deposition of thin films

    DOEpatents

    Smith, David C. (Los Alamos, NM); Pattillo, Stevan G. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Sattelberger, Alfred P. (Los Alamos, NM)

    1992-01-01

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  1. Efficiency of vaporization cutting by copper vapor laser

    Microsoft Academic Search

    Michail O. Nikonchuk; Igor V. Polyakov

    1992-01-01

    The copper vapor laser (CVL) can be a very suitable tool for cutting and drilling with minimum roughness and maximum accuracy. Visible range of irradiation, perfect quality of output beam, high pulse power, and pulse repetition frequency favor this application. However, there is no data on productivity of cutting, which defines the economic benefit of using CVL technology. In the

  2. Vapor generation methods for explosives detection research

    SciTech Connect

    Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

    2012-12-01

    The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

  3. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM); Meek, Thomas T. (Knoxville, TN); Blake, Rodger D. (Santa Fe, NM)

    1990-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  4. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM); Meek, Thomas T. (Knoxville, TN); Blake, Rodger D. (Santa Fe, NM)

    1989-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  5. Chapter 6--Dispersal Introduction

    E-print Network

    del Moral, Roger

    in the Early morning on the Pumice Plain (July 29, 2001). Seeds dispersed onto this surface from several the Pumice Plain. Backlit in the late afternoon, the view was inspiring. Happily for the future course of suc

  6. Boiler for generating high quality vapor

    NASA Technical Reports Server (NTRS)

    Gray, V. H.; Marto, P. J.; Joslyn, A. W.

    1972-01-01

    Boiler supplies vapor for use in turbines by imparting a high angular velocity to the liquid annulus in heated rotating drum. Drum boiler provides a sharp interface between boiling liquid and vapor, thereby, inhibiting the formation of unwanted liquid droplets.

  7. Nanocrystal dispersed amorphous alloys

    NASA Technical Reports Server (NTRS)

    Perepezko, John H. (Inventor); Allen, Donald R. (Inventor); Foley, James C. (Inventor)

    2001-01-01

    Compositions and methods for obtaining nanocrystal dispersed amorphous alloys are described. A composition includes an amorphous matrix forming element (e.g., Al or Fe); at least one transition metal element; and at least one crystallizing agent that is insoluble in the resulting amorphous matrix. During devitrification, the crystallizing agent causes the formation of a high density nanocrystal dispersion. The compositions and methods provide advantages in that materials with superior properties are provided.

  8. Synthesis and properties of magnetic fluid based on iron nanoparticles prepared by a vapor-phase condensation process

    Microsoft Academic Search

    Ji-Hun Yu; Dong-Won Lee; Byoung-Kee Kim; Taesuk Jang

    2006-01-01

    Magnetic fluid containing metallic iron nanoparticles was successfully fabricated in this work. The iron nanoparticles were synthesized by chemical vapor condensation process and then dispersed in water-base solution (pH 11) with oleic acid as surfactant. More than 80% of iron nanoparticles were fully dispersed in the fluid and remained stable without any further oxidation over 200h. Both the iron nanoparticles

  9. Organometallic vapor phase epitaxy (OMVPE)

    Microsoft Academic Search

    William G. Breiland; Michael E. Coltrin; J. Randall Creighton; Hong Q. Hou; Harry K. Moffat; Jeffrey Y. Tsao

    1999-01-01

    Organometallic vapor phase epitaxy (OMVPE) has emerged in this past decade as a flexible and powerful epitaxial materials synthesis technology for a wide range of compound–semiconductor materials and devices. Despite its capabilities and rapidly growing importance, OMVPE is far from being well understood: it is exceedingly complex, involving the chemically reacting flow of mixtures of organometallic, hydride and carrier-gas precursors.

  10. Physical vapor deposition tool coatings

    Microsoft Academic Search

    William D. Sproul

    1996-01-01

    Physical vapor deposition (PVD) of hard coatings such as titanium nitride have been an industrial reality since the beginning of the 1980s. Two PVD processes, low voltage electron beam and cathodic arc deposition, were responsible for the early commercial success of hard coatings on high speed steel tooling. Since that time, two other PVD processes have also been prosperous in

  11. Simple Chemical Vapor Deposition Experiment

    ERIC Educational Resources Information Center

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  12. Final OSWER Vapor Intrusion Guidance

    EPA Science Inventory

    EPA is preparing to finalize its guidance on assessing and addressing vapor intrusion, which is defined as migration of volatile constituents from contaminated media in the subsurface (soil or groundwater) into the indoor environment. In November 2002, EPA issued draft guidance o...

  13. Vacuum vapor deposition gun assembly

    DOEpatents

    Zeren, Joseph D. (Boulder, CO)

    1985-01-01

    A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  14. Remote sensing of water vapor features

    NASA Technical Reports Server (NTRS)

    Fuelberg, Henry E.

    1991-01-01

    The three major objectives of the project are outlined: (1) to describe atmospheric water vapor features as functions of space and time; (2) to evaluate remotely sensed measurements of water vapor content; and (3) to study relations between fine-scale water vapor fields and convective activity. Data from several remote sensors were used. The studies used the GOES/VAS, HIS, and MAMS instruments have provided a progressively finer scale view of water vapor features.

  15. Thermoeconomic optimization of a cryogenic refrigeration cycle for re-liquefaction of the LNG boil-off gas

    Microsoft Academic Search

    Hoseyn Sayyaadi; M. Babaelahi

    2010-01-01

    The development of the liquefaction process for the Liquefied Natural Gas (LNG) boil-off re-liquefaction plants will be addressed to provide an environmentally friendly and cost effective solution for the gas transportation. In this manner, onboard boil-off gas (BOG) re-liquefaction system as a cryogenic refrigeration cycle is utilized in order to re-liquefy the BOG and returns it to the cargo tanks

  16. Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures of Polyaromatic Hydrocarbons

    E-print Network

    Chickos, James S.

    Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures and Biochemistry, University of MissourisSt. Louis, St. Louis, Missouri 63121 The vaporization enthalpies and liquid vapor pressures from T ) 298.15 K to T ) 510 K of a series of polyaromatic hydrocarbons have been

  17. Nuclear vapor thermal reactor propulsion technology

    Microsoft Academic Search

    Isaac Maya; Nils J. Diaz; Edward T. Dugan; Yoichi Watanabe; James A. McClanahan; Wen-Hsiung Tu; Robert L. Carman

    1993-01-01

    The conceptual design of a nuclear rocket based on the vapor core reactor is presented. The Nuclear Vapor Thermal Rocket (NVTR) offers the potential for a specific impulse of 1000 to 1200 s at thrust-to-weight ratios of 1 to 2. The design is based on NERVA geometry and systems with the solid fuel replaced by uranium tetrafluoride (UF4) vapor. The

  18. 6, 80698095, 2006 Water vapor in Asian

    E-print Network

    Paris-Sud XI, Université de

    ACPD 6, 8069­8095, 2006 Water vapor in Asian summer monsoon region R. Zhan et al. Title Page Chemistry and Physics Discussions Intraseasonal variations of upper tropospheric water vapor in Asian;ACPD 6, 8069­8095, 2006 Water vapor in Asian summer monsoon region R. Zhan et al. Title Page Abstract

  19. Efficient copper-vapor pulsed laser

    NASA Technical Reports Server (NTRS)

    Russell, G. R.; Nerheim, N. M.; Pivirotto, T. J.

    1977-01-01

    High velocity flow is attained within system by expanding heated mixture of copper vapor, argon, and helium through supersonic nozzle. Arc heater, operated on argon/helium mixture, supplies energy to vaporize copper and to produce high temperature supersonic flow of gas/vapor mixture.

  20. Inert gas: Vapor mixtures in thermoacoustics

    Microsoft Academic Search

    William Victor Slaton

    2001-01-01

    An analytic solution of sound propagation in wet-walled tubes with a temperature gradient will be presented. The tube contains an inert gas-vapor mixture with a thin layer of condensed vapor coating the tube wall. The vapor phase condenses and evaporates from this layer during an acoustic cycle. This phased evaporation and condensation modifies traditional energy density and wave number equations.

  1. Reductive Dehalogenation of Trichloroethene Vapors in an

    E-print Network

    Reductive Dehalogenation of Trichloroethene Vapors in an Anaerobic Biotrickling Filter S U D E E P to treat trichloroethene (TCE) from waste gases generated by soil vapor extraction or dual-phase extraction biotreatment of TCE vapors. The vision is that nitrogen sparging could be substituted for air sparging

  2. WATER VAPOR FEEDBACK AND GLOBAL WARMING1

    Microsoft Academic Search

    Isaac M. Held; Brian J. Soden

    2000-01-01

    Abstract Water vapor is the dominant greenhouse gas, the most important gaseous source of infrared opacity in the atmosphere. As the concentrations of other greenhouse gases, particularly carbon dioxide, increase because of human activity, it is centrally important to predict how the water vapor distribution will be affected. To the extent that water vapor concentrations increase in a warmer world,

  3. Mechanisms, models and methods of vapor deposition

    E-print Network

    Wadley, Haydn

    Mechanisms, models and methods of vapor deposition H.N.G. Wadley a, *, X. Zhou a , R.A. Johnson during its growth by vapor deposition is complex. Mediating the growth process by varying the ¯ux for high performance ®lms. A multiscale modeling method for ana- lyzing the growth of vapor deposited thin

  4. Operators Manual Tec 3 Continuous Flow Vaporizer

    E-print Network

    Kleinfeld, David

    hmeda Operators Manual Tec 3 Continuous Flow Vaporizer Beciienungsanleitung Tec 3 of Variables Principle of Operation Vaporizer Sump and Valve Assembly Installation Back Bar Selectatec Manifold Reparations #12;Warnings DO NOT FILL THE VAPORIZER WITH ANY ANAESTHETIC AGENT OTHER THAN THE ONE SPECIFIED

  5. Vapor Pressure Measurements in a Closed System

    ERIC Educational Resources Information Center

    Iannone, Mark

    2006-01-01

    An alternative method that uses a simple apparatus to measure vapor pressure versus temperature in a closed system, in which the total pressure is the vapor pressure of the liquid sample, is described. The use of this apparatus gives students a more direct picture of vapor pressure than the isoteniscope method and results have generally been quite…

  6. Vapor-Resistant Heat-Pipe Artery

    NASA Technical Reports Server (NTRS)

    Dussinger, Peter M.; Shaubach, Robert M.; Buchko, Matt

    1991-01-01

    Vapor lock in heat pipe delayed or prevented. Modifications of wick prevent flow of vapor into, or formation of vapor in, liquid-return artery. Small pores of fine-grained sintered wick help to prevent formation of large bubbles. Slotted tube offers few nucleation sites for bubbles. Improves return of liquid in heat pipe.

  7. Dispersal characteristics of swift foxes

    Microsoft Academic Search

    Jan F. Kamler; Warren B. Ballard; Eric M. Gese; Robert L. Harrison; Seija M. Karki

    2004-01-01

    From 1997 to 2001, we monitored movements of 109 adult and 114 juvenile swift foxes, Vulpes velox (Say, 1823), at study sites in Colorado, New Mexico, and Texas to determine patterns of dispersal. Significantly more male (93%) than female (58%) juveniles dispersed, and both sexes had similar bimodal dispersal patterns with peaks in September-October and January-February. Adult dispersal occurred more

  8. Peculiar features of curing epoxy oligomers in water-dispersible painting materials

    Microsoft Academic Search

    A. Yu. Filipovich; V. K. Grishchenko; A. V. Barantsova; Yu. P. Gomza

    2011-01-01

    The article discusses the properties of water emulsions\\/dispersions of epoxy resins, investigates peculiar features of their\\u000a curing, and determines the physicochemical and structural parameters. In addition, the studied substances, which possess improved\\u000a environmental properties and adhesion to fresh concrete, are characterized by significant vapor permeability.

  9. When Seed Dispersal Matters

    NSDL National Science Digital Library

    HENRY F. HOWE and MARIA N. MIRITI (; )

    2004-07-01

    This peer-reviewed resource from Bioscience journal is about the varying importance of seed dispersal within plant communities. A profusion of fruit forms implies that seed dispersal plays a central role in plant ecology, yet the chance that an individual seed will ultimately produce a reproductive adult is low to infinitesimal. Extremely high variance in survival implies that variations in fruit production or transitions from seed to seedling will contribute little to population growth. The key issue is that variance in survival of plant life-history stages, and therefore the importance of dispersal, differs greatly among and within plant communities. In stable communities of a few species of long-lived plants, variances in seed and seedling survival are immense, so seed-to-seedling transitions have little influence on overall population dynamics. However, when seedlings in different circumstances have very different chances of survival--in ecological succession, for example, or when dispersed seeds escape density-dependent mortality near parent trees--the biased survival of dispersed seeds or seedlings in some places rather than others results in pervasive demographic impacts.

  10. Means and method for vapor generation

    DOEpatents

    Carlson, Larry W. (Oswego, IL)

    1984-01-01

    A liquid, in heat transfer contact with a surface heated to a temperature well above the vaporization temperature of the liquid, will undergo a multiphase (liquid-vapor) transformation from 0% vapor to 100% vapor. During this transition, the temperature driving force or heat flux and the coefficients of heat transfer across the fluid-solid interface, and the vapor percentage influence the type of heating of the fluid--starting as "feedwater" heating where no vapors are present, progressing to "nucleate" heating where vaporization begins and some vapors are present, and concluding with "film" heating where only vapors are present. Unstable heating between nucleate and film heating can occur, accompanied by possibly large and rapid temperature shifts in the structures. This invention provides for injecting into the region of potential unstable heating and proximate the heated surface superheated vapors in sufficient quantities operable to rapidly increase the vapor percentage of the multiphase mixture by perhaps 10-30% and thereby effectively shift the multiphase mixture beyond the unstable heating region and up to the stable film heating region.

  11. Vapor stabilizing surfaces for superhydrophobicity

    NASA Astrophysics Data System (ADS)

    Patankar, Neelesh

    2010-11-01

    The success of rough substrates designed for superhydrophobicity relies crucially on the presence of air pockets in the roughness grooves. This air is supplied by the surrounding environment. However, if the rough substrates are used in enclosed configurations, such as in fluidic networks, the air pockets may not be sustained in the roughness grooves. In this work a design approach based on sustaining a vapor phase of the liquid in the roughness grooves, instead of relying on the presence of air, is explored. The resulting surfaces, referred to as vapor stabilizing substrates, are deemed to be robust against wetting transition even if no air is present. Applications of this approach include low drag surfaces, nucleate boiling, and dropwise condensation heat transfer, among others.

  12. Studies on Vapor Adsorption Systems

    NASA Technical Reports Server (NTRS)

    Shamsundar, N.; Ramotowski, M.

    1998-01-01

    The project consisted of performing experiments on single and dual bed vapor adsorption systems, thermodynamic cycle optimization, and thermal modeling. The work was described in a technical paper that appeared in conference proceedings and a Master's thesis, which were previously submitted to NASA. The present report describes some additional thermal modeling work done subsequently, and includes listings of computer codes developed during the project. Recommendations for future work are provided.

  13. Seed Dispersal: Lemurs

    NSDL National Science Digital Library

    Pulse of the Planet

    2007-09-20

    Trees in Madagascar's forests have evolved traits that promote the dispersal of their seeds by lemurs. This two-minute radio program focuses on the interaction between forest plants and lemurs--the main seed dispersers in the forests. A guest scientist explains why lemurs ingest seeds that are large relative to their body size. He also notes that the fruits of Madagascar's trees have evolved to be strong smelling but drably colored in accordance with lemurs' keen sense of smell and poor vision. The program is available in text and audio formats. The latter includes audio of ring-tailed lemurs. Copyright 2005 Eisenhower National Clearinghouse

  14. Dispersion strengthened cemented carbides

    SciTech Connect

    Cutler, R.A.; Alexander, G.B.; Plichta, M.R.

    1983-09-01

    The research studied the feasibility of strengthening WC-CO cermets by adding refractory oxides to the binder phase. Cemented carbides containing 0.06 to 1.5 vol. % finely dispersed oxide particles in cobalt powder, prior to liquid phase sintering, were densified and compared to undoped control powders. Three different processes for dispersing refractory oxides in cobalt metal were investigated. Results suggest that the oxide particles coalesced and/or segregated to WC-CO interfaces during the liquid-phase sintering process.

  15. Measurement of the Molecular Weights of Vapors at High Temperature. II. The Vapor Pressure of Germanium and the Molecular Weight of Germanium Vapor

    Microsoft Academic Search

    Alan W. Searcy; Robert D. Freeman

    1955-01-01

    The vapor pressure of germanium and the molecular weight of germanium vapor have been determined by use of an apparatus for the simultaneous measurement of the weight of vapor effusing through two small orifices and of the force exerted by the effusing vapor. The molecular weight of germanium vapor at 1750°K was found to be 58±16 compared to the atomic

  16. Self-assembly of gold nanoparticles at the oil-vapor interface: from mono- to multilayers.

    PubMed

    Born, Philip; Schön, Volker; Blum, Susanne; Gerstner, Dominik; Huber, Patrick; Kraus, Tobias

    2014-11-11

    Alkylthiol-coated gold nanoparticles spontaneously segregate from dispersion in toluene to the toluene-vapor interface. We show that surface tension drops during segregation with a rate that depends on particle concentration. Mono- and multilayers of particles form depending on particle concentration, time, and temperature. X-ray reflectometry indicates fast monolayer formation and slow multilayer formation. A model that combines diffusion-limited segregation driven by surface energy and heterogeneous agglomeration driven by dispersive van der Waals particle interactions is proposed to describe film formation. PMID:25317984

  17. Sound Propagation in Gas-Vapor-Droplet Suspensions with Evaporation and Nonlinear Particle Relaxation

    NASA Technical Reports Server (NTRS)

    Kandula, Max

    2012-01-01

    The Sound attenuation and dispersion in saturated gas-vapor-droplet mixture in the presence of evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson to accommodate the effects of nonlinear particle relaxation processes of mass, momentum and energy transfer on sound attenuation and dispersion. The results indicate the existence of a spectral broadening effect in the attenuation coefficient (scaled with respect to the peak value) with a decrease in droplet mass concentration. It is further shown that for large values of the droplet concentration the scaled attenuation coefficient is characterized by a universal spectrum independent of droplet mass concentration.

  18. Metallorganic chemical vapor deposition and characterization of TiO 2 nanoparticles

    Microsoft Academic Search

    W Li; S Ismat Shah; C.-P Huang; O Jung; C Ni

    2002-01-01

    TiO2 nanoparticles were synthesized using metallorganic chemical vapor deposition process. Particles with and without metal ion dopants were obtained. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy measurements confirmed the stoichiometry of the TiO2 nanoparticles. X-ray diffraction patterns showed a polycrystalline anatase structure of TiO2. Transmission electron microscopy revealed that these particles are of nanoscale dimensions. Exact particle size and

  19. Metallorganic Chemical Vapor Deposition and Characterization of TiO2 Nanoparticles

    Microsoft Academic Search

    Oh-Jin Jung; Sam-Hyeok Kim; Kyung-Hoon Cheong; W. Li; S. Ismat Saha

    2002-01-01

    TiO2 nanoparticles were synthesized using the metallorganic chemical vapor deposition process. Particles with and without metal ion dopants were obtained. X-ray photoelectron and energy dispersive X-ray spectroscopic measurements confirmed the stoichiometry of the TiO 2 nanoparticles. X-ray diffraction patterns showed a polycrystalline anatase structure of TiO 2. Transmission electron microscopy revealed that these particles are of nanoscale dimensions. Exact particle

  20. Observations of micrometer BCN rods by bias-assisted hot-filament chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Yu, Jie; Wang, E. G.; Xu, Guichang

    1998-08-01

    The largest boron carbonitride (BCN) rods of about 20 ?m in diameter and 100 ?m in length are synthesized on molybdenum substrates by bias-assisted hot-filament chemical vapor deposition. These rods with full-hollow or part-solid insides are composed of many small crystalline particles shown by scanning electron microscopy. X-ray photoelectron spectroscopy and energy dispersive X-ray analysis are used to confirm their chemical composition and atomic-level hybrid.

  1. Sintering behavior of ultrafine silicon carbide powders obtained by vapor phase reaction

    NASA Technical Reports Server (NTRS)

    Okabe, Y.; Miyachi, K.; Hojo, J.; Kato, A.

    1984-01-01

    The sintering behavior of ultrafine SiC powder with average particle size of about 0.01-0.06 microns produced by a vapor phase reaction of the Me4Si-H2 system was studied at the temperature range of 1400-2050 deg. It was found that the homogeneous dispersion of C on SiC particles is important to remove the surface oxide layer effectively. B and C and inhibitive effect on SiC grain growth.

  2. Characterization and optimization of absorbing plasma-enhanced chemical vapor deposited antireflection coatings for silicon photovoltaics

    Microsoft Academic Search

    Parag Doshi; Gerald E. Jellison Jr.; Ajeet Rohatgi

    1997-01-01

    We have optimized plasma-enhanced chemical vapor deposition (PECVD) of SiN-based antireflection (AR) coatings with special consideration for the short-wavelength ( 600 nm) parasitic absorption in SiN. Spectroscopic ellipsometry was used to measure the dispersion relation for both the refractive index n and the extinction coefficient k , allowing a precise analysis of the trade-off between reflection and absorption in SiN-based

  3. Oxide dispersion strengthened superalloy

    NASA Technical Reports Server (NTRS)

    Glasgow, T. K.; Kim, Y. G.; Curwick, L. R.; Merrick, H. F.

    1981-01-01

    MA6000E alloy is strengthened at high temperatures by dispersion of yttrium oxide. Strength properties are about twice those of conventional nickel base alloys. Good thermal fatigue, intermediate temperature strength, and good oxidation resistance give alloy unique combination of benefits. Application in aircraft gas turbine is improved.

  4. BIODEGRADABILITY OF DISPERSED OIL.

    EPA Science Inventory

    The program office is concerned about the fate of dispersed oil once it is in the water column due to the perceived toxic effects it may have on intertidal, subtidal, and benthic zone flora and fauna. This project is an in-house experiment that was conducted during the summer and...

  5. Nonlinear dispersion relations

    Microsoft Academic Search

    A. Ludu; P. G. Kevrekidis

    2007-01-01

    We examine how nonlinear dispersion relations (NLDR) can be used as a simple, universal algebraic tool to provide information for the localized, nonlinear solutions of PDE that model physical systems. Such scaling relations between width, amplitude and velocity are of great help for numerical investigations of nonlinear solutions. The methodology is applied to a variety of examples from diverse branches

  6. Universally dispersible carbon nanotubes.

    PubMed

    Prevoteau, Alexandre; Soulié-Ziakovic, Corinne; Leibler, Ludwik

    2012-12-12

    We show that supramolecular chemistry provides a convenient tool to prepare carbone nanotubes (CNTs) that can be dispersed in solvents of any chemical nature, easily recovered and redispersed. Thymine-modified CNTs (CNT-Thy) can be dispersed in solution in the presence of diaminotriazine (DAT) end-functionalized polymers, through supramolecular Thy/DAT association. DAT-polymer chains are selected according to the solvent chemical nature: polystyrene (PS) for hydrophobic/low polarity solvents and a propylene oxide/ethylene oxide copolymer (predominantly propylene oxide based, PPO/PEO) for polar solvents or water. Long-term stable supramolecular CNT dispersions are reversibly aggregated by adding a few droplets of a selective dissociating agent of the Thy/DAT association (DMSO). CNT-Thy, simply recycled by centrifugation or filtration, can be redispersed in another solvent in presence of a suitable soluble DAT-polymer. Dispersion and aggregation can also be switched on and off by choosing a polymer for which a given solvent is close to ?-conditions, e.g., PS in cyclohexane or PPO/PEO in water. PMID:23171241

  7. Process for recovering organic vapors from air

    DOEpatents

    Baker, Richard W. (Mountain View, CA)

    1985-01-01

    A process for recovering and concentrating organic vapor from a feed stream of air having an organic vapor content of no more than 20,000 ppm by volume. A thin semipermeable membrane is provided which has a feed side and a permeate side, a selectivity for organic vapor over air of at least 50, as measured by the ratio of organic vapor permeability to nitrogen permeability, and a permeability of organic vapor of at least 3.times.10.sup.-7 cm.sup.3 (STP) cm/cm.sup.2 sec.cm Hg. The feed stream is passed across the feed side of the thin semipermeable membrane while providing a pressure on the permeate side which is lower than the feed side by creating a partial vacuum on the permeate side so that organic vapor passes preferentially through the membrane to form an organic vapor depleted air stream on the feed side and an organic vapor enriched stream on the permeate side. The organic vapor which has passed through the membrane is compressed and condensed to recover the vapor as a liquid.

  8. LNG (liquefied natural gas) as a fuel and refrigerant for diesel powered shrimp boats

    SciTech Connect

    Acker, G. Jr.; Brett, C.E.; Schaetzle, W.J.; Song, Y.K.

    1988-01-01

    A 3406-B Caterpillar and a 4.236 Perkins have been converted from their standard diesel configuration to dual-fuel engines. These engines operate using an aspirated charge of natural gas and a pilot charge of diesel fuel. The pilot is injected for combustion initiation, performing the same task as a spark plug in a spark ignition engine. Natural gas supplies 80% of the total heat addition at full load for both engines. The diesel fuel provides ignition, performs the function of idling the engine, and acts as a coolant for the injector tips. The diesel pilot setting remains constant throughout the operating range and provides a regular repeatable idle for the engine during no-load operation. A shrimp boat is being used to evaluate the dual-fuel system. The vessel normally carries 16000 1 of diesel fuel giving it a trip length of 14-21 days. To operate on natural gas with similar trip length requires liquification and cryogenic storage at -163/sup 0/C. This type of storage provides the necessary energy density needed for on board fuel storage. A 22 m shrimp boat will carry approximately 17000 1 of LNG in insulated tanks. Urethane insulation is used as both an insulator against heat leak and as a partial tank support structure.

  9. Meals, quarters for 8,200 needed at peak in LNG project

    SciTech Connect

    Aalund, L.R.

    1998-04-27

    It has everything a real town has except women, children, schools, bars, and old people. It is the huge camp built at Ras Laffan, Qatar, on the shores of the Persian Gulf to lodge and feed over 5,000 workers as they build the first plant in the emirate for liquefying millions of tons of natural gas yearly. Japan`s Chiyoda Corp. is the top contractor for the Qatar Liquefied Gas Co. (QatarGas) project, which is owned by a Qatari, French, American, and Japanese consortium. As part of the plant construction contract, Chiyoda built the camp, which Teyseer Services Co., the Qatar affiliate of the French company, Sodexho Alliance, now runs and maintains. Sodexho is the world`s largest catering/remote site management organization. It has had all its expertise in those fields put to the test for nearly 4 years supporting this world-scale LNG project which will be completed this summer. This project is described.

  10. Control of flow through a vapor generator

    DOEpatents

    Radcliff, Thomas D.

    2005-11-08

    In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.

  11. Profiling atmospheric water vapor by microwave radiometry

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Wilheit, T. T.; Szejwach, G.; Gesell, L. H.; Nieman, R. A.; Niver, D. S.; Krupp, B. M.; Gagliano, J. A.; King, J. L.

    1983-01-01

    High-altitude microwave radiometric observations at frequencies near 92 and 183.3 GHz were used to study the potential of retrieving atmospheric water vapor profiles over both land and water. An algorithm based on an extended kalman-Bucy filter was implemented and applied for the water vapor retrieval. The results show great promise in atmospheric water vapor profiling by microwave radiometry heretofore not attainable at lower frequencies.

  12. Coupling apparatus for a metal vapor laser

    DOEpatents

    Ball, D.G.; Miller, J.L.

    1993-02-23

    Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

  13. Dual frequency water vapor radiometer

    NASA Astrophysics Data System (ADS)

    Xu, Peiyuan; Jin, Peiyu; Yao, Zhunliang; Fang, Zhenhe; Li, Mingxiang

    A steerable dual frequency water vapor radiometer (DFWVR) is developed. A pair of optimum frequencies, 20.60 and 31.65 GHz, is adopted. Each frequency channel has its own offset parabola antenna and Dicke switched receiver, but both channels are mounted on one rotatable pedestal and controlled by one microcomputer system. This DFWVR is capable of continuous, unattended operation. The sensitivity at 1 second time constant and the accuracy of the brightness temperature are 0.2 and 0.5 K, respectively, at both frequencies. It is expected to promote the excess path length corrections to be better than 1 cm for geodetic VLBI and GPS measurements.

  14. Advanced Raman water vapor lidar

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Melfi, S. Harvey; Ferrare, Richard A.; Evans, Keith A.; Ramos-Izquierdo, Luis; Staley, O. Glenn; Disilvestre, Raymond W.; Gorin, Inna; Kirks, Kenneth R.; Mamakos, William A.

    1992-01-01

    Water vapor and aerosols are important atmospheric constituents. Knowledge of the structure of water vapor is important in understanding convective development, atmospheric stability, the interaction of the atmosphere with the surface, and energy feedback mechanisms and how they relate to global warming calculations. The Raman Lidar group at the NASA Goddard Space Flight Center (GSFC) developed an advanced Raman Lidar for use in measuring water vapor and aerosols in the earth's atmosphere. Drawing on the experience gained through the development and use of our previous Nd:YAG based system, we have developed a completely new lidar system which uses a XeF excimer laser and a large scanning mirror. The additional power of the excimer and the considerably improved optical throughput of the system have resulted in approximately a factor of 25 improvement in system performance for nighttime measurements. Every component of the current system has new design concepts incorporated. The lidar system consists of two mobile trailers; the first (13m x 2.4m) houses the lidar instrument, the other (9.75m x 2.4m) is for system control, realtime data display, and analysis. The laser transmitter is a Lambda Physik LPX 240 iCC operating at 400 Hz with a XeF gas mixture (351 nm). The telescope is a .75m horizontally mounted Dall-Kirkham system which is bore sited with a .8m x 1.1m elliptical flat which has a full 180 degree scan capability - horizon to horizon within a plane perpendicular to the long axis of the trailer. The telescope and scan mirror assembly are mounted on a 3.65m x .9m optical table which deploys out the rear of the trailer through the use of a motor driven slide rail system. The Raman returns from water vapor (403 nm), nitrogen (383 nm) and oxygen (372 nm) are measured in addition to the direct Rayleigh/Mie backscatter (351). The signal from each of these is split at about a 5/95 ratio between two photomultiplier detectors. The 5 percent detector is used for measurements below about 4.0 km, while the 95 percent detector provides the information above this level.

  15. Water vapor in protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Banzatti, Andrea

    2013-03-01

    This thesis is devoted to a study of the conditions and evolution of the planet formation region in young circumstellar disks, by means of spectroscopic observations of molecular gas emission. The main focus of this work is the infrared spectrum of water (H2O), which provides thousands of emission lines tracing the warm and dense gas inward of the water snow line in disks. The analysis includes also emission from some organic molecules that trace the carbon chemistry, C2H2, HCN, and CO2, as well as emission from OH that is connected to the formation and destruction of the water molecule. Two are the main directions explored in this work, for which we used spectra from the Spitzer Space Telescope (IRS) and the Very Large Telescope (VISIR and X-shooter). The first is to investigate how variable accretion phenomena occurring during the T Tauri phase affect the molecular environments in the planet formation region of disks. By monitoring T Tauri stars in different phases of accretion, we found that outbursts can remarkably affect their mid-infrared molecular emission. We propose a scenario where accretion flares trigger a recession of the water snow line, increasing water emission from the disk, when the accretion luminosity keeps higher over long enough timescales for the thermal structure of the disk to change (at least a few weeks, as observed in the strongly variable EX Lupi). In addition, enhanced UV radiation is found to produce OH from photodissociation of water in the disk. Organic molecules instead disappear during a strong outburst, and we are currently investigating the long-term evolution of these effects. A second direction was taken to tackle another fundamental problem: the origin of water vapor in inner disks. Some models predict that water is produced by evaporation of icy solids migrating inward of the snow line. One way to probe this scenario is by measuring the abundance of water vapor in the inner disk, and compare it to the oxygen abundance available to form water in situ. In this thesis, for the first time, a systematic rotation diagram analysis has been applied to infrared water emission. This analysis established a link between the spread of the rotational scatter and the water abundance in the inner disk, where a large rotational scatter would provide evidence for the migration scenario. Large rotational scatters are indeed tentatively observed in some disks, supporting water vapor enrichment from evaporation of icy migrators. Future higher-resolution observations will provide important answers on the origin of water vapor and its connection to disk evolution and planet formation processes.

  16. Pulsed copper halide vapor lasers

    NASA Astrophysics Data System (ADS)

    Kazarian, M. A.; Petrash, G. G.; Trofimov, A. N.

    The theory and the performance characteristics of copper halide lasers are examined with reference to recent theoretical and experimental research in the field of metal vapor lasers. The discussion covers gas discharge tubes, comparative characteristics of copper halide lasers, determination of the metastable level decomposition rates in copper chloride and copper bromide lasers, and spectroscopic measurements of the discharge plasma in copper halide lasers. Attention is also given to the kinetics of copper atoms formation in copper halide lasers and calculation of the kinetic characteristics of copper halide lasers.

  17. Microwave assisted chemical vapor infiltration

    SciTech Connect

    Devlin, D.J.; Currier, R.P.; Barbero, R.S.; Espinoza, B.F.; Elliott, N.

    1991-01-01

    A microwave assisted process for production of continuous fiber reinforced ceramic matrix composites is described. A simple apparatus combining a chemical vapor infiltration reactor with a conventional 700 W multimode oven is described. Microwave induced inverted thermal gradients are exploited with the ultimate goal of reducing processing times on complex shapes. Thermal gradients in stacks of SiC (Nicalon) cloths have been measured using optical thermometry. Initial results on the inside out'' deposition of SiC via decomposition of methyltrichlorosilane in hydrogen are presented. Several key processing issues are identified and discussed. 5 refs.

  18. Microwave assisted chemical vapor infiltration

    SciTech Connect

    Devlin, D.J.; Currier, R.P.; Barbero, R.S.; Espinoza, B.F.; Elliott, N.

    1991-12-31

    A microwave assisted process for production of continuous fiber reinforced ceramic matrix composites is described. A simple apparatus combining a chemical vapor infiltration reactor with a conventional 700 W multimode oven is described. Microwave induced inverted thermal gradients are exploited with the ultimate goal of reducing processing times on complex shapes. Thermal gradients in stacks of SiC (Nicalon) cloths have been measured using optical thermometry. Initial results on the ``inside out`` deposition of SiC via decomposition of methyltrichlorosilane in hydrogen are presented. Several key processing issues are identified and discussed. 5 refs.

  19. DENSE GAS DISPERSION MODEL (DEGADIS)

    EPA Science Inventory

    The Dense Gas Dispersion Model (DEGADIS) is a mathematical dispersion model that can be used to model the transport of toxic chemical releases into the atmosphere. Its range of applicability includes continuous, instantaneous, finite duration, and time- variant releases; negative...

  20. IMPROVED LABORATORY DISPERSANT EFFECTIVENESS TEST

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) initiated a program to evaluate an Improved Laboratory Dispersant Effectiveness Test (ILDET) which was developed to replace EPA's Revised Standard Dispersant Effectiveness Test (RSDET). The report summarizes the development of the IL...

  1. X-ray-induced water vaporization

    SciTech Connect

    Weon, B. M.; Lee, J. S.; Je, J. H. [X-ray Imaging Center, Department of Materials Science and Engineering,Pohang University of Science and Technology, San 31, Pohang 790-784 (Korea, Republic of); Fezzaa, K. [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

    2011-09-15

    We present quantitative evidence for x-ray-induced water vaporization: water is vaporized at a rate of 5.5 pL/s with the 1-A-wavelength x-ray irradiation of {approx}0.1 photons per A{sup 2}; moreover, water vapor is reversibly condensed during pauses in irradiation. This result fundamentally suggests that photoionization induces vaporization. This phenomenon is attributed to surface-tension reduction by ionization and would be universally important in radiological and electrohydrodynamic situations.

  2. Chemistry of vaporization of refractory materials

    NASA Technical Reports Server (NTRS)

    Gilles, P. W.

    1975-01-01

    A discussion is given of the principles of physical chemistry important in vaporization studies, notably the concepts of equilibrium, phase behavior, thermodynamics, solid solution, and kinetics. The important factors influencing equilibrium vaporization phenomena are discussed and illustrated. A proper course of a vaporization study consisting of 9 stages is proposed. The important experimental techniques of Knudsen effusion, Langmuir vaporization and mass spectrometry are discussed. The principles, the factors, the course of a study and the experimental techniques and procedures are illustrated by recent work on the Ti-O system.

  3. A vapor generator for transonic flow visualization

    NASA Technical Reports Server (NTRS)

    Bruce, Robert A.; Hess, Robert W.; Rivera, Jose A., Jr.

    1989-01-01

    A vapor generator was developed for use in the NASA Langley Transonic Dynamics Tunnel (TDT). Propylene glycol was used as the vapor material. The vapor generator system was evaluated in a laboratory setting and then used in the TDT as part of a laser light sheet flow visualization system. The vapor generator provided satisfactory seeding of the air flow with visible condensate particles, smoke, for tests ranging from low subsonic through transonic speeds for tunnel total pressures from atmospheric pressure down to less than 0.1 atmospheric pressure.

  4. Seed Dispersal by Japanese Macaques

    Microsoft Academic Search

    Tatsuya Otani

    \\u000a Seed dispersal is a crucial process in recruitment of plant populations, as well as for pollen dispersal. The location of\\u000a dispersed seeds affects the survival of seedlings and the spatial distribution pattern of plants. Plants employ various strategies\\u000a for effective seed dispersal, and diaspores have unique structures that utilize biotic and\\/or abiotic factors such as fleshy\\u000a arils for endozoochory, thorny

  5. Near real time vapor detection and enhancement using aerosol adsorption

    DOEpatents

    Novick, Vincent J. (Downers Grove, IL); Johnson, Stanley A. (Countryside, IL)

    1999-01-01

    A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

  6. Near real time vapor detection and enhancement using aerosol adsorption

    DOEpatents

    Novick, V.J.; Johnson, S.A.

    1999-08-03

    A vapor sample detection method is described where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample. 13 figs.

  7. Vapor Phase Transport Synthesis of Zeolites from Sol-Gel Precursors

    SciTech Connect

    THOMA,STEVEN G.; NENOFF,TINA M.

    2000-07-14

    A study of zeolite crystallization from sol-gel precursors using the vapor phase transport synthesis method has been performed. Zeolites (ZSM-5, ZSM-48, Zeolite P, and Sodalite) were crystallized by contacting vapor phase organic or organic-water mixtures with dried sodium silicate and dried sodium alumino-silicate gels. For each precursor gel, a ternary phase system of vapor phase organic reactant molecules was explored. The vapor phase reactant mixtures ranged from pure ethylene diamene, triethylamine, or water, to an equimolar mixture of each. In addition, a series of gels with varied physical and chemical properties were crystallized using the same vapor phase solvent mixture for each gel. The precursor gels and the crystalline products were analyzed via Scanning Electron Microscopy, Electron Dispersive Spectroscopy, X-ray mapping, X-ray powder diffraction, nitrogen surface area, Fourier Transform Infrared Spectroscopy, and thermal analyses. The product phase and purity as a function of the solvent mixture, precursor gel structure, and precursor gel chemistry is discussed.

  8. Ascent trajectory dispersion analysis

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The results of a Space Transportation System ascent trajectory dispersion analysis are documented. Critical trajectory parameter values useful for the definition of lightweight external tank insulation requirements are provided. This analysis was conducted using two of the critical missions specified for the Space Transportation System: a 28.5 deg inclination trajectory launched from the Eastern Test Range (ETR) and a Western Test Range (WTR) trajectory launched into a 104 deg orbital inclination.

  9. Dispersive analysis of ? /? ?3 ? ,? ?*

    NASA Astrophysics Data System (ADS)

    Danilkin, I. V.; Fernández-Ramírez, C.; Guo, P.; Mathieu, V.; Schott, D.; Shi, M.; Szczepaniak, A. P.

    2015-05-01

    The decays ? /? ?3 ? are considered in the dispersive framework that is based on the isobar decomposition and subenergy unitarity. The inelastic contributions are parametrized by the power series in a suitably chosen conformal variable that properly accounts for the analytic properties of the amplitude. The Dalitz plot distributions and integrated decay widths are presented. Our results indicate that the final-state interactions may be sizable. As a further application of the formalism we also compute the electromagnetic transition form factors of ? /? ??0?*.

  10. Dispersive analysis of ?/? ? 3?, ??*

    DOE PAGESBeta

    Danilkin, Igor V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Fernandez Ramirez, Cesar [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)JLAB; Guo, Peng [Indiana Univ., Bloomington, IN (United States); Mathieu, Vincent [Indiana Univ., Bloomington, IN (United States); Schott, Diane M. [George Washington Univ., Washington, DC (United States); Shi, Meng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Peking Univ., Beijing (China); Szczepaniak, Adam P. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Indiana Univ., Bloomington, IN (United States)

    2015-05-01

    The decays ?/? ? 3? are considered in the dispersive framework that is based on the isobar decomposition and subenergy unitarity. The inelastic contributions are parametrized by the power series in a suitably chosen conformal variable that properly accounts for the analytic properties of the amplitude. The Dalitz plot distributions and integrated decay widths are presented. Our results indicate that the final- state interactions may be sizable. As a further application of the formalism we also compute the electromagnetic transition form factors of ?/? ? ???*.

  11. Almost optimal dispersers

    Microsoft Academic Search

    Amnon Ta-Shma

    1998-01-01

    A (K, E) disperser graph G = (VI, V2, E) is a bipartite graph wit.h the property that for any subset A E VI of cardmality K, the neighbors of A cover at least 1 - E fraction of t,he vertices of V2. Such graphs have many applicat.ions in derandomization. Saks, Srinivasan and Zhou presented an explicit construction of (K

  12. Coal-water dispersion

    SciTech Connect

    Stigsson, L.L.; Lindman, B.

    1986-07-08

    A dispersion is described comprising water, pulverized coal and stabilizing additives, the coal content ranging from 60 to 80% by weight and the additives comprising a combination of (a) sufficient lecithin adsorbed on surfaces of coal particles to provide repulsion between the coal particles by hydration forces and (b) polymer cooperating with the lecithin and comprising at least one polymer having segments of hydrophobic as well as segments of hydrophilic character.

  13. Disabling Radiological Dispersal Terror

    SciTech Connect

    Hart, M

    2002-11-08

    Terror resulting from the use of a radiological dispersal device (RDD) relies upon an individual's lack of knowledge and understanding regarding its significance. Disabling this terror will depend upon realistic reviews of the current conservative radiation protection regulatory standards. It will also depend upon individuals being able to make their own informed decisions merging perceived risks with reality. Preparation in these areas will reduce the effectiveness of the RDD and may even reduce the possibility of its use.

  14. Dispersion Compensating Fibers

    NASA Astrophysics Data System (ADS)

    Grüner-Nielsen, Lars; Knudsen, Stig Nissen; Edvold, Bent; Veng, Torben; Magnussen, Dorte; Larsen, C. Christian; Damsgaard, Hans

    2000-04-01

    The basic principles for use of dispersion compensating fibers (DCF) are reviewed, including definition of figure of merit and condition for dispersion slope compensation. The main design features of a triple-cladding index profile design are examined theoretically and experimentally. Production results are presented for three types of DCF. It is shown that polarization-mode dispersion can be reduced by introducing oscillatory twist into the fiber. The splice loss between DCF and standard fibers is shown to be reducible by use of a special intermediate fiber. Two methods for measuring the nonlinear effective area of DCF are compared and good agreement is found. Measurement results for the nonlinear refractive index n2 are reported. The nonlinear coefficient n2/ Aeff of DCF is found to be a factor of 5 higher than that on standard single-made fibers. The macrobending resistance of DCF is examined and found to be comparable with that of standard fibers. The microbending resistance of DCF is found to be better than that of standard fibers. Finally, positive results from a cabling experiment with DCF are reported.

  15. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

    1998-06-02

    A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.

  16. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, W.G.; Basaran, O.A.; Harris, M.T.

    1998-04-14

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

  17. Optimal dispersion and central places

    Microsoft Academic Search

    Kevin M. Curtin; Richard L. Church

    2007-01-01

    This paper presents research into optimal dispersion models as applied to central places. The literature regarding location optimization and central places is reviewed and the motivation for employing dispersion models is identified. Models that employ the objective of maximal dispersion in the context of central places are formulated and solved in the context of both single- and multiple-good systems. Two

  18. Characteristics of dispersal in wolverines

    Microsoft Academic Search

    Knut Morten Vangen; Jens Persson; Arild Landa; Roy Andersen; Peter Segerström

    2001-01-01

    We studied patterns of dispersal and sizes of home ranges of juvenile wolverines (Gulo gulo). Mean dis- persal age was 13 months for both male (n = 11) and female (n = 9) wolverines. Females displayed more variation in dispersal age (7-26 months) than males (7-18 months). Of the animals used in the dispersal analyses, all males and 69% of

  19. Optical sensor for diverse organic vapors at ppm concentration ranges.

    PubMed

    Thomas, J Christopher; Trend, John E; Rakow, Neal A; Wendland, Michael S; Poirier, Richard J; Paolucci, Dora M

    2011-01-01

    A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index) and sensor response are discussed. PMID:22163798

  20. G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product

    SciTech Connect

    Koontz, A; Cadeddu, M

    2012-12-05

    The G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) value-added product (VAP) computes precipitable water vapor using neural network techniques from data measured by the GVR. The GVR reports time-series measurements of brightness temperatures for four channels located at 183.3 ± 1, 3, 7, and 14 GHz.

  1. Transpiration method: Vapor pressures and enthalpies of vaporization of some low-boiling esters

    Microsoft Academic Search

    Sergey P. Verevkin; Vladimir N. Emel’yanenko

    2008-01-01

    This investigation was undertaken to reveal the upper limit of vapor pressures which could be measured by using the transpiration method accurately. Molar enthalpies of vaporization of 10 esters of monocarboxylic acids were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. The measured data sets were successfully checked for internal consistency. A large number

  2. Vapor passage fuel blockage removal

    SciTech Connect

    Faeth, W.P.

    1988-06-07

    In a liquid dispensing hose for distributing liquid fuel from a pump to a valved nozzle adapted to be inserted into the fill pipe of a vehicle fuel tank, the hose having an inner tube defining a fuel conduit and a tubular outer sleeve that defines with the inner tube an annular passage for recovering fuel vapors from the fuel tank, the improvement is described comprising: a venturi section adapted for serial connection with the inner tube within the outer sleeve and comprising a cylindrical block having connecting means at each end for connection to end portions of the inner tube and defining a venturi having a throat which forms a part of the fuel conduit; aspirator means defining at least two radial ports in the venturi section for communicating between the venturi throat and the annular vapor passage; and a check valve means associated with each radial port for blocking fuel flow from the fuel conduit to the annular passage, the check valve means respectively having inlet openings directed radially outwardly of the venturi section and facing the tubular outer sleeve, whereby liquid fuel collected in the annular passage adjacent the venturi section is drawn through the aspirator means due to suction produced in the venturi throat.

  3. Characterization of Carbon Nanotubes Grown by Chemical Vapor Deposition

    NASA Technical Reports Server (NTRS)

    Cochrane, J. C.; Zhu, Shen; Su, Ching-Hua; Lehoczky, S. L.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Since the superior properties of multi-wall carbon nanotubes (MWCNT) could improve numerous devices such as electronics and sensors, many efforts have been made in investigating the growth mechanism of MWCNT to synthesize high quality MWCNT. Chemical vapor deposition (CVD) is widely used for MWCNT synthesis, and scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) are useful methods for analyzing the structure, morphology and composition of MWCNT. Temperature and pressure are two important growth parameters for fabricating carbon nanotubes. In MWCNT growth by CVD, the plasma assisted method is normally used for low temperature growth. However a high temperature environment is required for thermal CVD. A systematic study of temperature and pressure-dependence is very helpful to understanding MWCNT growth. Transition metal particles are commonly used as catalysis in carbon nanotube growth. It is also interesting to know how temperature and pressure affect the interface of carbon species and catalyst particles

  4. Interfacial Force Field Characterization in a Constrained Vapor Bubble Thermosyphon

    NASA Technical Reports Server (NTRS)

    DasGupta, Sunando; Plawsky, Joel L.; Wayner, Peter C., Jr.

    1995-01-01

    Isothermal profiles of the extended meniscus in a quartz cuvette were measured in the earth's gravitational field using an image-analyzing interferometer that is based on computer-enhanced video microscopy of the naturally occurring interference fringes. These profiles are a function of the stress field. Experimentally, the augmented Young-Laplace equation is an excellent model for the force field at the solid-liquid-vapor interfaces for heptane and pentane menisci on quartz and tetradecane on SFL6. The effects of refractive indices of the solid and liquid on the measurement techniques were demonstrated. Experimentally obtained values of the disjoining pressure and dispersion constants were compared to those predicted from the Dzyaloshinskii - Lifshitz - Pilaevskii theory for an ideal surface and reasonable agreements were obtained. A parameter introduced gives a quantitative measurement of the closeness of the system to equilibrium. The nonequilibrium behavior of this parameter is also presented

  5. Synthesis of silicon carbide nanotubes by chemical vapor deposition.

    PubMed

    Xie, Zhengfang; Tao, Deliang; Wang, Jiqing

    2007-02-01

    Silicon carbide nanotubes (SiCNTs) were directly synthesized by chemical vapor deposition (CVD) in the paper. Methyltrichlorosilane (MTS) was selected as the SiC gaseous source and, ferrocence and thiophene as the catalyst and the cocatalyst, respectively. The influences of reaction temperature, contents of catalyst and cocatalyst, and content of gaseous source on the morphologies of the products were investigated, respectively. The products were identified by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX), respectively. The synthesis of SiCNTs by CVD suggested a condition-dependent process. Novel SiCNTs, with 20 approximately 80 nm in outer diameter and 15 approximately 35 nm in inner diameter, respectively, were observed. The wall structure similar to that of carbon nanotubes was not found for the SiCNTs. PMID:17450808

  6. Experimental study of flash boiling spray vaporization through quantitative vapor concentration and liquid temperature measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Gaoming; Hung, David L. S.; Xu, Min

    2014-08-01

    Flash boiling sprays of liquid injection under superheated conditions provide the novel solutions of fast vaporization and better air-fuel mixture formation for internal combustion engines. However, the physical mechanisms of flash boiling spray vaporization are more complicated than the droplet surface vaporization due to the unique bubble generation and boiling process inside a superheated bulk liquid, which are not well understood. In this study, the vaporization of flash boiling sprays was investigated experimentally through the quantitative measurements of vapor concentration and liquid temperature. Specifically, the laser-induced exciplex fluorescence technique was applied to distinguish the liquid and vapor distributions. Quantitative vapor concentration was obtained by correlating the intensity of vapor-phase fluorescence with vapor concentration through systematic corrections and calibrations. The intensities of two wavelengths were captured simultaneously from the liquid-phase fluorescence spectra, and their intensity ratios were correlated with liquid temperature. The results show that both liquid and vapor phase of multi-hole sprays collapse toward the centerline of the spray with different mass distributions under the flash boiling conditions. Large amount of vapor aggregates along the centerline of the spray to form a "gas jet" structure, whereas the liquid distributes more uniformly with large vortexes formed in the vicinity of the spray tip. The vaporization process under the flash boiling condition is greatly enhanced due to the intense bubble generation and burst. The liquid temperature measurements show strong temperature variations inside the flash boiling sprays with hot zones present in the "gas jet" structure and vortex region. In addition, high vapor concentration and closed vortex motion seem to have inhibited the heat and mass transfer in these regions. In summary, the vapor concentration and liquid temperature provide detailed information concerning the heat and mass transfer inside flash boiling sprays, which is important for the understanding of its unique vaporization process.

  7. Vapor phase mediated cellular uptake of sub 5 nm nanoparticles

    PubMed Central

    2012-01-01

    Nanoparticles became an important and wide-used tool for cell imaging because of their unique optical properties. Although the potential of nanoparticles (NPs) in biology is promising, a number of questions concerning the safety of nanomaterials and the risk/benefit ratio of their usage are open. Here, we have shown that nanoparticles produced from silicon carbide (NPs) dispersed in colloidal suspensions are able to penetrate into surrounding air environment during the natural evaporation of the colloids and label biological cells via vapor phase. Natural gradual size-tuning of NPs in dependence to the distance from the NP liquid source allows progressive shift of the fluorescence color of labeled cells in the blue region according to the increase of the distance from the NP suspension. This effect may be used for the soft vapor labeling of biological cells with the possibility of controlling the color of fluorescence. However, scientists dealing with the colloidal NPs have to seriously consider such a NP's natural transfer in order to protect their own health as well as to avoid any contamination of the control samples. PMID:22494848

  8. Vapor phase lubrication of a Ni-based superalloy

    SciTech Connect

    Hanyaloglu, B.; Fedor, D.C.; Graham, E.E. [Cleveland State Univ., OH (United States)

    1995-03-01

    In addition to ceramics, alloys such as tool steel and nickel- and iron-based superalloys are being considered for high temperature applications such as missile bearings and low heat rejection engines. Studies were made to lubricate a nickel-based superalloy at 500{degrees}C, by using a vaporized aryl phosphate ester, at a concentration of 0.1% in air. From deposition and wear studies it was found that it was impossible to form a good polymeric coating on the superalloy surface. Energy dispersive X-ray analyzer (EDXA) analysis showed that this was due to minute quantities of aluminum in the alloy segregating to the surface, upon being heated to 500{degrees}C, forming a passive oxide coating. It was necessary to activate the surface, in order to lubricate the material successfully. A method of activation by electrodepositing the surface with a layer of iron oxide was developed. Once activated, a good lubricous polymer was formed on the superalloy surface. Tests performed under dynamic conditions and 1 MPa pressure, using an activated specimen surface showed no wear and a coefficient of friction ({mu}) of 0.05. These results stress the importance of material selection for high temperature vapor phase lubrication. 15 refs., 13 figs., 2 tabs.

  9. Nonequilibrium vapor-generation model for flashing flows

    SciTech Connect

    Saha, P.; Abuaf, N.; Wu, B. J.C.

    1981-01-01

    A nonequilibrium vapor generation model for flashing flows is presented. The model consists of a flashing inception point, a bubbly flow regime followed by a bubbly-slug regime, an annular or annular-mist regime, and finally a dispersed-droplet regime. Existence of superheated liquid at the inception point and beyond is recognized. The vapor generation rate in each flow regime is calculated from the estimates for interfacial area density and net interfacial heat flux. However, the bubble number density at the flashing inception point was varied to obtain optimum fits with the void fraction data taken in a vertical converging-diverging nozzle. The interfacial area density at the inception point, thus determined, showed a rapid increase with the decrease in the liquid superheat at that point. This trend is correct since in the limit of thermal equilibrium flow where the liquid superheat approaches zero, the interfacial area for heat and mass transfer should approach infinity. 32 refs., 7 figs., 1 tab.

  10. Atmospheric sugar alcohols: evaporation rates and saturation vapor pressures

    NASA Astrophysics Data System (ADS)

    Bilde, M.; Zardini, A. A.; Hong, J.; Tschiskale, M.; Emanuelsson, E.

    2014-12-01

    The atmospheric partitioning between gas and condensed phase of organic molecules is poorly understood, and discrepancies exist between predicted and observed concentrations of secondary organic aerosols. A key problem is the lack of information about thermodynamic properties of semi- and low volatile organic molecules. Saturation vapor pressure and the associated temperature dependence (dH) are key parameters for improving predictive atmospheric models. In this work we combine experiments and thermodynamic modeling to investigate these parameters for a series of polyols, so-called sugar alcohols. These polyols are common in the water soluble fraction of atmospheric aerosols. In our experimental system sub-micron particles are generated by nebulization from aqueous solution, and a mono disperse fraction of the aerosol is selected using a differential mobility analyzer. The particles are allowed to evaporate in a laminar flow reactor, and changes in particle size as function of evaporation time are determined using a scanning mobility particle sizer system. In this work saturation vapor pressures of sugar alcohols at several temperatures have been inferred from such measurements using thermodynamic modeling. Results are presented and discussed in context of atmospheric gas to particle partitioning.

  11. Dispersal dynamics in food webs.

    PubMed

    Melián, Carlos J; K?ivan, Vlastimil; Altermatt, Florian; Starý, Petr; Pellissier, Loïc; De Laender, Frederik

    2015-02-01

    Studies of food webs suggest that limited nonrandom dispersal can play an important role in structuring food webs. It is not clear, however, whether density-dependent dispersal fits empirical patterns of food webs better than density-independent dispersal. Here, we study a spatially distributed food web, using a series of population-dispersal models that contrast density-independent and density-dependent dispersal in landscapes where sampled sites are either homogeneously or heterogeneously distributed. These models are fitted to empirical data, allowing us to infer mechanisms that are consistent with the data. Our results show that models with density-dependent dispersal fit the ?, ?, and ? tritrophic richness observed in empirical data best. Our results also show that density-dependent dispersal leads to a critical distance threshold beyond which site similarity (i.e., ? tritrophic richness) starts to decrease much faster. Such a threshold can also be detected in the empirical data. In contrast, models with density-independent dispersal do not predict such a threshold. Moreover, preferential dispersal from more centrally located sites to peripheral sites does not provide a better fit to empirical data when compared with symmetric dispersal between sites. Our results suggest that nonrandom dispersal in heterogeneous landscapes is an important driver that shapes local and regional richness (i.e., ? and ? tritrophic richness, respectively) as well as the distance-decay relationship (i.e., ? tritrophic richness) in food webs. PMID:25616136

  12. 75 FR 65151 - Marine Vapor Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ...VAPOR'' painted in black letters at least 50...625 inch) diameter holes in the flange...VAPOR'' painted in black letters at least 50...625 inch) diameter hole(s) located midway between...High-level Alarm'' in black letters at least...

  13. Risk assessment of metal vapor arcing

    NASA Technical Reports Server (NTRS)

    Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

    2009-01-01

    A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

  14. Vapor Wall Deposition in Chambers: Theoretical Considerations

    NASA Astrophysics Data System (ADS)

    McVay, R.; Cappa, C. D.; Seinfeld, J.

    2014-12-01

    In order to constrain the effects of vapor wall deposition on measured secondary organic aerosol (SOA) yields in laboratory chambers, Zhang et al. (2014) varied the seed aerosol surface area in toluene oxidation and observed a clear increase in the SOA yield with increasing seed surface area. Using a coupled vapor-particle dynamics model, we examine the extent to which this increase is the result of vapor wall deposition versus kinetic limitations arising from imperfect accommodation of organic species into the particle phase. We show that a seed surface area dependence of the SOA yield is present only when condensation of vapors onto particles is kinetically limited. The existence of kinetic limitation can be predicted by comparing the characteristic timescales of gas-phase reaction, vapor wall deposition, and gas-particle equilibration. The gas-particle equilibration timescale depends on the gas-particle accommodation coefficient ?p. Regardless of the extent of kinetic limitation, vapor wall deposition depresses the SOA yield from that in its absence since vapor molecules that might otherwise condense on particles deposit on the walls. To accurately extrapolate chamber-derived yields to atmospheric conditions, both vapor wall deposition and kinetic limitations must be taken into account.

  15. An application of oil vaporization evaluation methods

    SciTech Connect

    Fleckenstein, W.W. [Bechtel Petroleum Operations, Inc., Tupman, CA (United States); Bouck, L.S.; Hudgens, D. [Scientific Software-Intercomp, Inc., Denver, CO (United States); Querin, M. [USDOE, Washington, DC (United States); Williams, L. [Chevron U.S.A., Inc., San Francisco, CA (United States)

    1992-02-01

    This paper describes and quantifies the benefits of residual oil vaporization in an enhanced recovery gas injection project. Vaporized oil is recovered as natural gas liquid (NGL) when the injected gas is produced. In the reservoir application studied, 20% of the liquid hydrocarbons produced were being recovered as NGL. (VC)

  16. An application of oil vaporization evaluation methods

    SciTech Connect

    Fleckenstein, W.W. (Bechtel Petroleum Operations, Inc., Tupman, CA (United States)); Bouck, L.S.; Hudgens, D. (Scientific Software-Intercomp, Inc., Denver, CO (United States)); Querin, M. (USDOE, Washington, DC (United States)); Williams, L. (Chevron U.S.A., Inc., San Francisco, CA (United States))

    1992-01-01

    This paper describes and quantifies the benefits of residual oil vaporization in an enhanced recovery gas injection project. Vaporized oil is recovered as natural gas liquid (NGL) when the injected gas is produced. In the reservoir application studied, 20% of the liquid hydrocarbons produced were being recovered as NGL. (VC)

  17. Vapor sensitivity of thin porous silicon layers

    Microsoft Academic Search

    S. Zangooie; R. Bjorklund; H. Arwin

    1997-01-01

    Spectroscopic ellipsometry has been used to study optical changes in thin porous silicon layers due to exposure to vapors from different liquids. The changes in the ellipsometric parameters ? and ? were caused by changes in the total refractive index of the layers. The detection limit threshold for acetone vapors by the layers was 12 ppm. Using a 4-layer optical

  18. SOIL VAPOR EXTRACTION TECHNOLOGY: REFERENCE HANDBOOK

    EPA Science Inventory

    Soil vapor extraction (SVE) systems are being used in Increasing numbers because of the many advantages these systems hold over other soil treatment technologies. SVE systems appear to be simple in design and operation, yet the fundamentals governing subsurface vapor transport ar...

  19. SOIL VAPOR EXTRACTION TECHNOLOGY: REFERENCE HANDBOOK

    EPA Science Inventory

    Soil vapor extraction (SVE) systems are being used in increasing numbers due to many advantages these systems hold over other soil treatment technologies. VE systems appear to be simple in design and operation, yet the fundamentals governing subsurface vapor transport are quite c...

  20. ON-LINE CALCULATOR: VAPOR INTRUSION MODELING

    EPA Science Inventory

    Migration of volatile chemicals from the subsurface into overlying buildings is called vapor intrusion (VI). Volatile organic chemicals in contaminated soils or groundwater can emit vapors, which may migrate through subsurface soils and may enter the indoor air of overlying build...

  1. Groundbased detection of middle atmospheric water vapor

    Microsoft Academic Search

    Paul Hartogh; Christopher Jarchow

    1995-01-01

    Groundbased microwave measurements are well suited for the intercomparison and validation of satellite data. A microwave heterodyne spectrometer, which can be used for this purpose has been developed at our institute. It measures the 22.235 GHz water vapor spectral emission and supplies water vapor profiles in the altitude range from 35 to 85 km with a time resolution of one

  2. Thermophilic Biotrickling Filtration of Ethanol Vapors

    E-print Network

    Thermophilic Biotrickling Filtration of Ethanol Vapors H U U B H . J . C O X , T H O M A S S E X of ethanol vapors in biotrickling filters for air pollution control was investigated. Two reactors were adaptation phase, the removal of ethanol was similar in both reactors. At a bed contact time of 57 s

  3. Structure of a zinc sulfide film prepared by molecular stratification on the surface of disperse silica

    SciTech Connect

    Stepanova, N.A.; Kupriyanov, V.D.; Malygin, A.A.

    1987-08-01

    The authors report the physicochemical study of the surface structures formed in successive and alternate treatment of highly disperse silicon(IV) oxide with ZnCl/sub 2/ and H/sub 2/S vapors. The results of the study can be used in creating coating pigments and inorganic luminophors with controllable properties. The zinc sulfide film was synthesized by treating it with ZnCl/sub 2/ and H/sub 2/S vapors by the method of molecular stratification. It was found that after two treatment cycles at 673/sup 0/K a film of wurtzite formed on the surface of the silica.

  4. Phonon dispersion in graphene

    E-print Network

    L. A. Falkovsky

    2007-08-11

    Taking into account the constraints imposed by the lattice symmetry, the phonon dispersion is calculated for graphene with interactions between the first and second nearest neighbors in the framework of the Born-von Karman model. Analytical expressions are obtained for the out-of-plane (bending) modes determined only by two force constants as well as for the in-plane modes with four force constants. Values of the force constants are found in fitting to elastic constants and Raman frequencies observed in graphite.

  5. Fatigue crack growth properties of the base metal and weld metal of a 9% Ni steel for LNG storage tank

    NASA Astrophysics Data System (ADS)

    Kim, Young-Kyun; Shim, Kyu-Taek; Kim, Jae-Hoon

    2009-07-01

    Newly developed heavy thick plates of 9% Ni steel for large capacity of LNG tank were fabricated to conduct a fatigue crack growth test. The weld metal specimens were also fabricated by taking the same weld procedures which are applied to actual LNG storage tank inner shell. The effect of changes in load ratio, R, and test temperature on the fatigue crack growth rate has been investigated. Separate fatigue crack growth experiments were performed at load ratio of 0.1 and 0.5 at -162°C and compared to the behavior at room temperature. The fatigue crack growth rates of weld metal were nearly the same as those of the base metal irrespective of load ratio change at room temperature. A decrease in temperature decreased the fatigue crack growth rates of base metal but in the case of weld metal only small scatters appeared in the fatigue crack growth rate compared with those of base metals. The fatigue crack growth rates were dominated by residual stress due to welding processes rather than temperature effects.

  6. Eyeing the Sky's Water Vapor

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image, and many like it, are one way NASA's Phoenix Mars Lander is measuring trace amounts of water vapor in the atmosphere over far-northern Mars. Phoenix's Surface Stereo Imager (SSI) uses solar filters, or filters designed to image the sun, to make these images. The camera is aimed at the sky for long exposures.

    SSI took this image as a test on June 9, 2008, which was the Phoenix mission's 15th Martian day, or sol, since landing, at 5:20 p.m. local solar time. The camera was pointed about 38 degrees above the horizon. The white dots in the sky are detector dark current that will be removed during image processing and analysis.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space

  7. Stacked vapor fed AMTEC modules

    SciTech Connect

    Sievers, R.K.

    1989-02-28

    The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta -alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta -alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta -alumina solid electrolyte of the tubular member.

  8. Vapor Phase Catalytic Ammonia Reduction

    NASA Technical Reports Server (NTRS)

    Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

  9. The impact of vaporized nanoemulsions on ultrasound-mediated ablation

    PubMed Central

    2013-01-01

    Background The clinical feasibility of using high-intensity focused ultrasound (HIFU) for ablation of solid tumors is limited by the high acoustic pressures and long treatment times required. The presence of microbubbles during sonication can increase the absorption of acoustic energy and accelerate heating. However, formation of microbubbles within the tumor tissue remains a challenge. Phase-shift nanoemulsions (PSNE) have been developed as a means for producing microbubbles within tumors. PSNE are emulsions of submicron-sized, lipid-coated, and liquid perfluorocarbon droplets that can be vaporized into microbubbles using short (<1 ms), high-amplitude (>5 MPa) acoustic pulses. In this study, the impact of vaporized phase-shift nanoemulsions on the time and acoustic power required for HIFU-mediated thermal lesion formation was investigated in vitro. Methods PSNE containing dodecafluoropentane were produced with narrow size distributions and mean diameters below 200 nm using a combination of sonication and extrusion. PSNE was dispersed in albumin-containing polyacrylamide gel phantoms for experimental tests. Albumin denatures and becomes opaque at temperatures above 58°C, enabling visual detection of lesions formed from denatured albumin. PSNE were vaporized using a 30-cycle, 3.2-MHz, at an acoustic power of 6.4 W (free-field intensity of 4,586 W/cm2) pulse from a single-element, focused high-power transducer. The vaporization pulse was immediately followed by a 15-s continuous wave, 3.2-MHz signal to induce ultrasound-mediated heating. Control experiments were conducted using an identical procedure without the vaporization pulse. Lesion formation was detected by acquiring video frames during sonication and post-processing the images for analysis. Broadband emissions from inertial cavitation (IC) were passively detected with a focused, 2-MHz transducer. Temperature measurements were acquired using a needle thermocouple. Results Bubbles formed at the HIFU focus via PSNE vaporization enhanced HIFU-mediated heating. Broadband emissions detected during HIFU exposure coincided in time with measured accelerated heating, which suggested that IC played an important role in bubble-enhanced heating. In the presence of bubbles, the acoustic power required for the formation of a 9-mm3 lesion was reduced by 72% and the exposure time required for the onset of albumin denaturation was significantly reduced (by 4 s), provided that the PSNE volume fraction in the polyacrylamide gel was at least 0.008%. Conclusions The time or acoustic power required for lesion formation in gel phantoms was dramatically reduced by vaporizing PSNE into bubbles. These results suggest that PSNE may improve the efficiency of HIFU-mediated thermal ablation of solid tumors; thus, further investigation is warranted to determine whether bubble-enhanced HIFU may potentially become a viable option for cancer therapy. PMID:24761223

  10. Stacked vapor fed amtec modules

    DOEpatents

    Sievers, Robert K. (North Huntingdon, PA)

    1989-01-01

    The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta"-alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta"-alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta"-alumina solid electrolyte of the tubular member. A transition piece is positioned about the interior of the member and contacts the transporting means. The transition piece divides the member into a first cell and a second cell such that each first and second cell has a beta"-alumina solid electrolyte, a first and second porous electrode and a grid. The transition piece conducts electrons from the interior of the tubular member. There is supply means for supplying sodium to the transporting means. Preferably the supply means is a shell which surrounds the tubular member and is operated at a temperature such that the vaporized sodium condenses thereon. Returning means for returning the condensed sodium from the shell to the transporting means provides a continuous supply of liquid sodium to the transporting means. Also, there are first conducting means for conducting electric current from the transition piece which extends through the shell, and second conducting means for conducting electric current to the grid of the first cell which extends through the shell.

  11. Thermal Plasma Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Lu, Zhipeng

    Diamond has many unrivaled properties and has great application potentials in modern industry. Among various metastable chemical vapor deposition methods for producing diamond, thermal plasma chemical vapor deposition has shown advantages of offering high growth rates and high quality. However, systematic parametric studies are needed for optimization of the process. This study investigates the effects of substrate materials, substrate temperatures, substrate pre-treatment methods, precursor concentrations, and process pressures on the initial nucleation, growth rate, morphology, and quality of the diamond films under thermal plasma conditions. X-ray diffraction, optical microscopy, scanning electron microscopy, and Raman spectroscopy have been used for the diamond film characterization. Thermal plasmas have been also used to deposit homoepitaxial diamond films at high growth rates. High quality macro-sized diamond crystals have been grown on {100} and {110} oriented natural type IIa diamond seeds. Raman spectra reveal that the diamond deposit is of high quality. Laue X-ray diffraction patterns show that the diamond grown on the seed is single crystal and oriented epitaxially with the underlying seed crystal. The gas phase chemistry has been calculated using computer code SOLGASMIX to determine the equilibrium gaseous composition in thermal plasmas. Key species concentrations have been obtained under various pressure conditions. Although kinetic factors have not been taken into account, equilibrium conditions offer an estimation of the process justified by the "frozen chemistry" associated with the fast quenching in the boundary layer. Due to the strong emission of the highly luminous plasma plumes, it has been difficult to measure the in -situ substrate temperature distribution with conventional infrared optical pyrometers. A new technique has been developed to obtain the surface temperature distribution of the substrate by combining the experimental temperature measurements of an array of thermocouples imbedded in the substrate and analytical solutions of the two-dimensional heat conduction equation. This method enables an indirect determination of the substrate temperature distribution.

  12. Determination of dispersivities from a natural-gradient dispersion test

    E-print Network

    Hoover, Caroline Marie

    1985-01-01

    Conceptual chloride concentration contours based on measured concentrations at observa- tion points in the field. 23 Predicted chloride concentration contours using input parameters of source si ze and dispersivity as determined by Sudicky et al . (1983... of these variables are in err, determ1nations of the dispersion parameters are likely to be affected. Thus physically-based dispersion parameters must be ex- tracted from contam1nation studies in the absence of as- sumptions regarding these other variables...

  13. General relationships between consumer dispersal, resource dispersal and metacommunity diversity.

    PubMed

    Haegeman, Bart; Loreau, Michel

    2014-02-01

    One of the central questions of metacommunity theory is how dispersal of organisms affects species diversity. Here, we show that the diversity-dispersal relationship should not be studied in isolation of other abiotic and biotic flows in the metacommunity. We study a mechanistic metacommunity model in which consumer species compete for an abiotic or biotic resource. We consider both consumer species specialised to a habitat patch, and generalist species capable of using the resource throughout the metacommunity. We present analytical results for different limiting values of consumer dispersal and resource dispersal, and complement these results with simulations for intermediate dispersal values. Our analysis reveals generic patterns for the combined effects of consumer and resource dispersal on the metacommunity diversity of consumer species, and shows that hump-shaped relationships between local diversity and dispersal are not universal. Diversity-dispersal relationships can also be monotonically increasing or multimodal. Our work is a new step towards a general theory of metacommunity diversity integrating dispersal at multiple trophic levels. PMID:24304725

  14. Atmospheric chemistry of propellant vapors.

    PubMed

    Stone, D A

    1989-12-01

    Hydrazine fuels are used as examples of the relatively rapid chemical processes which may occur when propellants are released into the atmosphere from normal handling or during accidents. The experimental procedures used to study these processes are reviewed along with postulated chemical reaction mechanisms and measured reaction rates and products. Results show that chemical processes which occur on a time scale comparable with meteorological processes must be considered in the development of dispersion models. These models must also account for the potential formation of toxic reaction products. PMID:2603168

  15. LANDFILL GAS CONVERSION TO LNG AND LCO{sub 2}. PHASE 1, FINAL REPORT FOR THE PERIOD MARCH 1998-FEBRUARY 1999

    SciTech Connect

    COOK,W.J.; NEYMAN,M.; SIWAJEK,L.A.; BROWN,W.R.; VAN HAUWAERT,P.M.; CURREN,E.D.

    1998-02-25

    Process designs and economics were developed to produce LNG and liquid carbon dioxide (CO{sub 2}) from landfill gas (LFG) using the Acrion CO{sub 2} wash process. The patented Acrion CO{sub 2} wash process uses liquid CO{sub 2} to absorb contaminants from the LFG. The process steps are compression, drying, CO{sub 2} wash contaminant removal and CO{sub 2} recovery, residual CO{sub 2} removal and methane liquefaction. Three flowsheets were developed using different residual CO{sub 2} removal schemes. These included physical solvent absorption (methanol), membranes and molecular sieves. The capital and operating costs of the flowsheets were very similar. The LNG production cost was around ten cents per gallon. In parallel with process flowsheet development, the business aspects of an eventual commercial project have been explored. The process was found to have significant potential commercial application. The business plan effort investigated the economics of LNG transportation, fueling, vehicle conversion, and markets. The commercial value of liquid CO{sub 2} was also investigated. This Phase 1 work, March 1998 through February 1999, was funded under Brookhaven National laboratory contract 725089 under the research program entitled ``Liquefied Natural Gas as a Heavy Vehicle Fuel.'' The Phase 2 effort will develop flowsheets for the following: (1) CO{sub 2} and pipeline gas production, with the pipeline methane being liquefied at a peak shaving site, (2) sewage digester gas as an alternate feedstock to LFG and (3) the use of mixed refrigerants for process cooling. Phase 2 will also study the modification of Acrion's process demonstration unit for the production of LNG and a market site for LNG production.

  16. CO2 DIAL measurements of water vapor

    NASA Technical Reports Server (NTRS)

    Grant, William B.; Margolis, Jack S.; Brothers, Alan M.; Tratt, David M.

    1987-01-01

    CO2 lidars have heretofore been used to measure water vapor concentrations primarily using the 10R(20) line at 10.247 microns, which has a strong overlap with a water vapor absorption line. This paper discusses the use of that line as well as other CO2 laser lines for which the absorption coefficients are weaker. The literature on measurement of water vapor absorption coefficients using CO2 lasers is reviewed, and the results from four laboratories are shown to be generally consistent with each other after they are normalized to the same partial pressure, temperature, and ethylene absorption coefficent for the 10P(14) CO2 laser line; however, the agreement with the Air Force Geophysics Laboratory's HITRAN and FASCOD 2 spectral data tapes is not good either for the water vapor absorption lines or for the water vapor continuum. Demonstration measurements of atmospheric water vapor have been conducted using the Mobile Atmospheric Pollutant Mapping System, a dual CO2 lidar system using heterodyne detection. Results are discussed for measurements using three sets of laser line pairs covering a wide range of water vapor partial pressures.

  17. Automated Test Systems for Toxic Vapor Detectors

    NASA Technical Reports Server (NTRS)

    Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

    1997-01-01

    The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/ temperature / humidity (FTH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy Space Center.

  18. Automated Test Systems for Toxic Vapor Detectors

    NASA Technical Reports Server (NTRS)

    Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

    1997-01-01

    The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/temperature/humidity (FIFH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy Space Center.

  19. Optimal dispersion and central places

    Microsoft Academic Search

    Kevin M. Curtin; Richard L. Church

    2007-01-01

    This paper presents research into optimal dispersion models as applied to central places. The literature regarding location\\u000a optimization and central places is reviewed and the motivation for employing dispersion models is identified. Models that\\u000a employ the objective of maximal dispersion in the context of central places are formulated and solved in the context of both\\u000a single- and multiple-good systems. Two

  20. Water vapor radiometry research and development phase

    NASA Technical Reports Server (NTRS)

    Resch, G. M.; Chavez, M. C.; Yamane, N. L.; Barbier, K. M.; Chandlee, R. C.

    1985-01-01

    This report describes the research and development phase for eight dual-channel water vapor radiometers constructed for the Crustal Dynamics Project at the Goddard Space Flight Center, Greenbelt, Maryland, and for the NASA Deep Space Network. These instruments were developed to demonstrate that the variable path delay imposed on microwave radio transmissions by atmospheric water vapor can be calibrated, particularly as this phenomenon affects very long baseline interferometry measurement systems. Water vapor radiometry technology can also be used in systems that involve moist air meteorology and propagation studies.

  1. Recovering hydrocarbons from hydrocarbon-containing vapors

    DOEpatents

    Mirza, Zia I. (La Verne, CA); Knell, Everett W. (Los Alamitos, CA); Winter, Bruce L. (Danville, CA)

    1980-09-30

    Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

  2. Process for vaporizing a liquid hydrocarbon fuel

    DOEpatents

    Szydlowski, Donald F. (East Hartford, CT); Kuzminskas, Vaidotas (Glastonbury, CT); Bittner, Joseph E. (East Hartford, CT)

    1981-01-01

    The object of the invention is to provide a process for vaporizing liquid hydrocarbon fuels efficiently and without the formation of carbon residue on the apparatus used. The process includes simultaneously passing the liquid fuel and an inert hot gas downwardly through a plurality of vertically spaed apart regions of high surface area packing material. The liquid thinly coats the packing surface, and the sensible heat of the hot gas vaporizes this coating of liquid. Unvaporized liquid passing through one region of packing is uniformly redistributed over the top surface of the next region until all fuel has been vaporized using only the sensible heat of the hot gas stream.

  3. Amplified Dispersive Optical Tomography

    E-print Network

    Goda, Keisuke; Jalali, Bahram

    2008-01-01

    Optical coherence tomography (OCT) has proven to be a powerful technique for studying tissue morphology in ophthalmology, cardiology, and endomicroscopy. Its performance is limited by the fundamental trade-off between the imaging sensitivity and acquisition speed -- a predicament common in virtually all imaging systems. In this paper, we circumvent this limit by using distributed Raman post-amplification of the reflection from the sample. We combine the amplification with simultaneously performed dispersive Fourier transformation, a process that maps the optical spectrum into an easily measured time-domain waveform. The Raman amplification enables measurement of weak signals which are otherwise buried in noise. It extends the depth range without sacrificing the acquisition speed or causing damage to the sample. As proof of concept, single-shot imaging with 15 dB improvement in sensitivity at an axial scan rate of 36.6 MHz is demonstrated.

  4. Natural dispersion revisited.

    PubMed

    Johansen, Øistein; Reed, Mark; Bodsberg, Nils Rune

    2015-04-15

    This paper presents a new semi-empirical model for oil droplet size distributions generated by single breaking wave events. Empirical data was obtained from laboratory experiments with different crude oils at different stages of weathering. The paper starts with a review of the most commonly used model for natural dispersion, which is followed by a presentation of the laboratory study on oil droplet size distributions formed by breaking waves conducted by SINTEF on behalf of the NOAA/UNH Coastal Response Research Center. The next section presents the theoretical and empirical foundation for the new model. The model is based on dimensional analysis and contains two non-dimensional groups; the Weber and Reynolds number. The model was validated with data from a full scale experimental oil spill conducted in the Haltenbanken area offshore Norway in July 1982, as described in the last section of the paper. PMID:25752537

  5. Probe for measurement of velocity and density of vapor in vapor plume

    DOEpatents

    Berzins, L.V.; Bratton, B.A.; Fuhrman, P.W.

    1997-03-11

    A probe is disclosed which directs a light beam through a vapor plume in a first direction at a first angle ranging from greater than 0{degree} to less than 90{degree}, reflecting the light beam back through the vapor plume at a 90{degree} angle, and then reflecting the light beam through the vapor plume a third time at a second angle equal to the first angle, using a series of mirrors to deflect the light beam while protecting the mirrors from the vapor plume with shields. The velocity, density, temperature and flow direction of the vapor plume may be determined by a comparison of the energy from a reference portion of the beam with the energy of the beam after it has passed through the vapor plume. 10 figs.

  6. Probe for measurement of velocity and density of vapor in vapor plume

    DOEpatents

    Berzins, Leon V. (Livermore, CA); Bratton, Bradford A. (Bethel Island, CA); Fuhrman, Paul W. (Livermore, CA)

    1997-01-01

    A probe which directs a light beam through a vapor plume in a first direction at a first angle ranging from greater than 0.degree. to less than 90.degree., reflecting the light beam back through the vapor plume at a 90.degree. angle, and then reflecting the light beam through the vapor plume a third time at a second angle equal to the first angle, using a series of mirrors to deflect the light beam while protecting the mirrors from the vapor plume with shields. The velocity, density, temperature and flow direction of the vapor plume may be determined by a comparison of the energy from a reference portion of the beam with the energy of the beam after it has passed through the vapor plume.

  7. Phase refractive index dispersions of organic oligomer crystals with different molecular alignments

    NASA Astrophysics Data System (ADS)

    Sakurai, Yusaku; Hayashi, Waka; Yamao, Takeshi; Hotta, Shu

    2014-02-01

    We grew slab crystals of end-capped oligothiophenes with phenyl, biphenyl, or methyl groups and unsubstituted oligophenyls. These crystals were grown in the vapor and liquid phases. We determined their dispersions and anisotropic refractive indices from interference fringes in the emission and reflectance spectra. To do this, we used pairs of parallel facets, which were naturally formed during the crystal growth or cleaved from wide crystals, as optical resonators. The unsubstituted oligophenyls indicated blue-shifted dispersions compared with the end-capped oligothiophenes. We discussed refractive indices in connection with molecular alignments in the crystals and compared them with computational results.

  8. A spectroscopic study of mercury vapor adsorption on gold nanoparticle films.

    PubMed

    Morris, Todd; Kloepper, Kathy; Wilson, Scott; Szulczewski, Greg

    2002-10-01

    We have modified the surfaces of glass and Si(100) with 3-aminopropyltrimethoxy silane, a fourth generation amine-terminated poly(amidoamine) dendrimer, and poly(diallydimethyl ammonium chloride) to facilitate adsorption onto colloidal gold particles (average diameter 3, 5, 12, and 22 nm). UV-vis absorption spectroscopy and atomic force microscopy monitored the adsorption process, which is governed by particle diffusion to the surface. The differences in adsorption to the three adhesion layers as a function of pH are discussed. Mercury vapor was exposed to the gold particle films and quantified by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy. The surface plasmon oscillation of 5-, 12-, and 22-nm particles blue-shifts after exposure to parts-per-million levels of mercury vapor in air. Particle films prepared from the 3-nm gold particles develop a broad peak centered near 530 nm after exposure to mercury vapor. The results demonstrate a novel "litmus" film for mercury vapor. PMID:12702424

  9. Comparison between Normal and HeII Two-phase Flows at High Vapor Velocities

    NASA Astrophysics Data System (ADS)

    Perraud, S.; Rousset, B.; Thibault, P.; van Weelderen, R.; Wolf, P. E.

    2006-04-01

    We present results on helium co-current two-phase flow experiments at high vapor velocity obtained with the use of the new CEA/SBT 400 W/1.8 K refrigerator. For vapor velocities larger than typically 4 m/s, a mist of droplets develops from the bulk liquid interface accompanied by an increase in heat transfer at the wall. Experiments were conducted in a 10 m long, 40 mm I.D. straight pipe, both in helium II and in helium I to compare these two situations. The respective roles of vapor density, vapor velocity and liquid level on atomization were systematically investigated. Light scattering experiments were performed to measure sizes, velocities and interfacial areas of droplets in a complete cross section. In-house-made heat transfer sensors located in the mist allowed us to deduce an upper value of the extra cooling power of the dispersed phase. The practical interest of atomized flow for cooling large cryogenic facilities is discussed by considering the balance between increase in heat transfer and pressure drops it induces.

  10. Chemical vapor deposition of functionalized isobenzofuran polymers

    E-print Network

    Olsson, Ylva Kristina

    2007-01-01

    This thesis develops a platform for deposition of polymer thin films that can be further tailored by chemical surface modification. First, we explore chemical vapor deposition of functionalized isobenzofuran films using ...

  11. Isolating the Ricochet-induced Vaporization Process

    NASA Astrophysics Data System (ADS)

    Schultz, P. H.; Sugita, S.; Eberhardy, C. A.; Ernst, C. M.

    2004-03-01

    Experiments were designed to isolate the ricochet contribution to impact-generated vaporization of calcium carbonate. High-speed spectroscopy reveals that downrange impacts by the ricocheting projectile play a significant role.

  12. Vapor purification with self-cleaning filter

    DOEpatents

    Josephson, Gary B.; Heath, William O.; Aardahl, Christopher L.

    2003-12-09

    A vapor filtration device including a first electrode, a second electrode, and a filter between the first and second electrodes is disclosed. The filter is formed of dielectric material and the device is operated by applying a first electric potential between the electrodes to polarize the dielectric material such that upon passing a vapor stream through the filter, particles from the vapor stream are deposited onto the filter. After depositing the particles a second higher voltage is applied between the electrodes to form a nonthermal plasma around the filter to vaporize the collected particles thereby cleaning the filter. The filter can be a packed bed or serpentine filter mat, and an optional upstream corona wire can be utilized to charge airborne particles prior to their deposition on the filter.

  13. Chemical vapor infiltration using microwave energy

    SciTech Connect

    Devlin, D.J.; Currier, R.P.; Laia, J.R.; Barbero, R.S.

    1992-12-31

    This invention is comprised of a method for producing reinforced ceramic composite articles by means of chemical vapor infiltration and deposition in which an inverted temperature gradient is utilized. Microwave energy is the source of heat for the process.

  14. Designing polymer surfaces via vapor deposition

    E-print Network

    Asatekin, Ayse

    Chemical Vapor Deposition (CVD) methods significantly augment the capabilities of traditional surface modification techniques for designing polymeric surfaces. In CVD polymerization, the monomer(s) are delivered to the ...

  15. External fuel vaporization study, phase 1

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.

    1980-01-01

    A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

  16. Silicon doping techniques using chemical vapor dopant

    E-print Network

    Technische Universiteit Delft

    Silicon doping techniques using chemical vapor dopant deposition s üMilos Popadic #12;#12;Silicon Semiconductors Dr. ir. W. D. van Noort National Semiconductor, USA s üMilos Popadic, Silicon doping techniques

  17. Test and evaluation of water vapor radiometers

    NASA Technical Reports Server (NTRS)

    Moran, J.

    1980-01-01

    The accuracy of very long baseline interferometry in geodetic and astrometric applications is primarily limited by the propagation delays through the troposphere. The part of this delay that is most difficult to predict is due to atmospheric water vapor which can contribute up to about 40 cm of excess propagation path at microwave frequencies. The water vapor content in the atmosphere is variable and is not well correlated with surface meteorological variables. The brightness temperature measured near the transition of water vapor at 22.2 GHz and the propagation delay due to water vapor, or wet path length, are well correlated. This correlation is not perfect because the absorption coefficient and index of refraction do not have the same dependence on temperature and pressure.

  18. Vapor Cavitation in Dynamically Loaded Journal Bearings

    NASA Technical Reports Server (NTRS)

    Jacobson, B. O.; Hamrock, B. J.

    1983-01-01

    High speed motion camera experiments were performed on dynamically loaded journal bearings. The length to diameter ratio of the bearing, the speed of the roller and the tube, the surface material of the roller, and the static and dynamic eccentricity of the bearing were varied. One hundred and thirty-four cases were filmed. The occurrence of vapor cavitation was clearly evident in the films and figures presented. Vapor cavitation was found to occur when the tensile stress applied to the oil exceeded the tensile strength of the oil or the binding of the oil to the surface. The physical situation in which vapor cavitation occurs is during the squeezing and sliding motion within a bearing. Besides being able to accurately capture the vapor cavitation on film, an analysis of the formation and collapse of the cavitation bubbles and characteristics of the bubble content are presented.

  19. Water vapor recovery from plant growth chambers

    NASA Technical Reports Server (NTRS)

    Ray, R. J.; Newbold, D. D.; Colton, R. H.; Mccray, S. B.

    1991-01-01

    NASA is investigating the use of plant growth chambers (PGCs) for space missions and for bases on the moon and Mars. Key to successful development of PGCs is a system to recover and reuse the water vapor that is transpired from the leaves of the plants. A design is presented for a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in PGCs. The system is based on two membrane technologies: (1) dehumidification membrane modules to remove water vapor from the air, and (2) membrane contactors to return water vapor to the PGC (and, in doing so, to control the humidity and temperature within the PGC). The membrane-based system promises to provide an ideal, stable growth environment for a variety of plants, through a design that minimizes energy usage, volume, and mass, while maximizing simplicity and reliability.

  20. Multiscale modeling strategies for chemical vapor deposition

    E-print Network

    Nemirovskaya, Maria A., 1972-

    2002-01-01

    In order to predict the quality of the fabricated devices as a function of growth conditions in chemical vapor deposition (CVD) reactors, a model should describe multiple time and length scales. These scales include the ...

  1. Chemical vapor infiltration using microwave energy

    DOEpatents

    Devlin, David J. (Los Alamos, NM); Currier, Robert P. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Barbero, Robert S. (Santa Cruz, NM)

    1993-01-01

    A method for producing reinforced ceramic composite articles by means of chemical vapor infiltration and deposition in which an inverted temperature gradient is utilized. Microwave energy is the source of heat for the process.

  2. Shock-induced vaporization of zinc -- Experiments and numerical simulations

    Microsoft Academic Search

    L. C. Chhabildas; R. M. Brannon

    1996-01-01

    Prediction of the interaction between expanded vaporized debris and target materials for applications such as meteorite impact on space vehicles, ballistic penetration of armors, debris shield design, etc. demands an accurate treatment of the melting and vaporization process and the kinetics of liquid-vapor propagation. Historically, experimental efforts to understand high-pressure melting and vaporization have been hindered by unavailability of experimental

  3. The Enceladus Torus: Saturn's Vaporous Ring T. A. Cassidy

    E-print Network

    The Enceladus Torus: Saturn's Vaporous Ring T. A. Cassidy Top-down view of water vapor ejected from) eject water vapor with escape speed, into Saturn orbit. (similar to how E-ring is formed) Most of this talk will be about what happens to the vapor as it orbits Saturn. 2 #12;3 Enceladus' torus is one

  4. Vapor flammability above aqueous solutions of flammable liquids

    Microsoft Academic Search

    Mark R. Brooks; Daniel A. Crowl

    2007-01-01

    The flammability of vapors above aqueous solutions of ethanol and acetonitrile was studied experimentally in a 20-L combustion apparatus. No liquid was present in the apparatus, but the vapor concentrations were adjusted to correspond to the vapor in equilibrium with a specified aqueous solution. The experimental results for these two systems show that•As water is added to the vapor, the

  5. Holographic studies of the vapor explosion of vaporizing water-in-fuel emulsion droplets

    NASA Technical Reports Server (NTRS)

    Sheffield, S. A.; Hess, C. F.; Trolinger, J. D.

    1982-01-01

    Holographic studies were performed which examined the fragmentation process during vapor explosion of a water-in-fuel (hexadecane/water) emulsion droplet. Holograms were taken at 700 to 1000 microseconds after the vapor explosion. Photographs of the reconstructed holograms reveal a wide range of fragment droplet sizes created during the explosion process. Fragment droplet diameters range from below 10 microns to over 100 microns. It is estimated that between ten thousand and a million fragment droplets can result from this extremely violent vapor explosion process. This enhanced atomization is thus expected to have a pronounced effect on vaporization processes which are present during combustion of emulsified fuels.

  6. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    PubMed

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude. PMID:17902946

  7. Solar-powered alkali metal vapor lasers

    NASA Technical Reports Server (NTRS)

    Blount, Charles E.

    1989-01-01

    The emission spectrum of the A(1 Sigma u +) - X(1 Sigma g +) band of Na2 has been recorded following excitation by monochromatic radiation in the region of X-A and X-B absorption. The spectral profile has been investigated as a function of excitation wavelength, sodium vapor temperature and buffer gas pressure. Additionally, gain measurements were made for the satellite of the A-X band as a function of the sodium vapor temperature and buffer gas pressure.

  8. Anthropogenic water vapor emissions in Tokyo

    NASA Astrophysics Data System (ADS)

    Moriwaki, Ryo; Kanda, Manabu; Senoo, Hiroshi; Hagishima, Aya; Kinouchi, Tsuyoshi

    2008-11-01

    Temporal and spatial variations in anthropogenic water vapor (AWV) emissions and anthropogenic heat (AH) in Tokyo were estimated using data from a geographic information system (GIS) and an energy-consumption database. The maximum value of AWV exceeded 500 W m-2 in summer in central Tokyo. Estimations of AWV were validated with field-measured data. The estimated and measured data agreed well, indicating that anthropogenic sources such as district cooling systems release large amounts of water vapor into the atmosphere.

  9. Multicomponent fuel vaporization at high pressures.

    SciTech Connect

    Torres, D. J. (David J.); O'Rourke, P. J. (Peter J.)

    2002-01-01

    We extend our multicomponent fuel model to high pressures using a Peng-Robinson equation of state, and implement the model into KIVA-3V. Phase equilibrium is achieved by equating liquid and vapor fugacities. The latent heat of vaporization and fuel enthalpies are also corrected for at high pressures. Numerical simulations of multicomponent evaporation are performed for single droplets for a diesel fuel surrogate at different pressures.

  10. Optical NOR gate using cesium vapor.

    PubMed

    Knize, R J

    1992-02-15

    The transmission of light at the S((1/2))-P((1/2)) resonance in an alkali vapor is strongly dependent on the laser polarization. This polarization dependence can cause a nonlinear interaction between different lasers so that one laser can be used to control the transmission of another laser. An optical NOR gate is demonstrated by using this nonlinearity in a cesium vapor cell. PMID:19784289

  11. Diode pumped alkali vapor fiber laser

    Microsoft Academic Search

    Stephen A. Payne; Raymond J. Beach; Jay W. Dawson; William F. Krupke

    2007-01-01

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into

  12. Diode pumped alkali vapor fiber laser

    Microsoft Academic Search

    Stephen A. Payne; Raymond J. Beach; Jay W. Dawson; William F. Krupke

    2006-01-01

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into

  13. Soil vapor extraction: Radio frequency heating

    SciTech Connect

    Lowe, D.F.; Oubre, C.L.; Ward, C.H. [eds.; Daniel, D.E.; Loehr, R.C.; Webster, M.T.; Kasevich, R.S.

    2000-07-01

    One of the most widely used techniques for treating soils contaminated with volatile organic compounds, soil vapor extraction (SVE) can also be applied to semi-volatile organic compounds (SVOCs) if the soil is heated, by applying electromagnetic energy in the radio frequency (FR) range, to increase the vapor pressure of the contaminants. However, questions remain concerning its viability and cost-effectiveness. This book presents detailed scientific and engineering information that answers these questions and more.

  14. Vapor Power Systems MAE 4263 Final Exam

    E-print Network

    Vapor Power Systems MAE 4263 Final Exam Wednesday, May 5, 2004 Prof. P.M. Moretti Key Instructions, then think, then write! 1. What is the dewpoint of the exhaust of your car, if the gasoline consists2 so that the mole fraction of water vapor is yH2 O = 9 9 + 8 + 47 = 0:14063 pH2 O = 0:14063 14

  15. An overview: Vapor phase corrosion inhibitors

    SciTech Connect

    Subramanian, A.; Natesan, M.; Muralidharan, V.S.; Balakrishnan, K.; Vasudevan, T.

    2000-02-01

    When present as vapors, certain organic compounds offer inhibition against the corrosion of ferrous and nonferrous materials. The inhibitors include aliphatic, aromatic, cyclohexylamines, aminonitrobenzoates, heteroalkylated lower amines, etc. The mechanism of inhibition offered by these compounds was discussed and an unified mechanism was presented. Various methods of evaluating inhibition efficiency were discussed with a special reference to surface film characterization techniques. Methods of application of the vapor phase inhibitors and their industrial uses also were presented.

  16. Vapor wall deposition in Teflon chambers

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

    2015-04-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be underestimated, owing to deposition of SOA-forming vapors to the chamber wall. We present here an experimental protocol and a model framework to constrain the vapor-wall interactions in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, ?-pinene, and dodecane in two chambers that had been extensively used and in two new unused chambers. We found that the extent of prior use of the chamber did not significantly affect the sorption behavior of the Teflon films. Among the 25 compounds studied, the maximum wall deposition rate is exhibited by the most highly oxygenated and least volatile compounds. By optimizing the model output to the observed vapor decay profiles, we identified that the dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (?wi), which can be correlated through its volatility with the number of carbons and oxygens in the molecule. By doing so, the wall-induced deposition rate of intermediate/semi-volatile organic vapors can be reasonably predicted based on their molecular constituency. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and the chamber wall. The timescale associated with vapor wall deposition can vary from minutes to hours depending on the value of ?w,i. For volatile and intermediate volatility organic compounds (small ?w,i), gas-particle partitioning will dominate wall deposition for typical particle number concentrations in chamber experiments. For compounds characterized by relatively large ?w,i, vapor transport to particles is suppressed by competition with the chamber wall even with perfect particle accommodation.

  17. Water Vapor Distribution in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Du, Fujun; Bergin, Edwin A.

    2014-09-01

    Water vapor has been detected in protoplanetary disks. In this work, we model the distribution of water vapor in protoplanetary disks with a thermo-chemical code. For a set of parameterized disk models, we calculate the distribution of dust temperature and radiation field of the disk with a Monte Carlo method, and then solve the gas temperature distribution and chemical composition. The radiative transfer includes detailed treatment of scattering by atomic hydrogen and absorption by water of Ly? photons, since the Ly? line dominates the UV spectrum of accreting young stars. In a fiducial model, we find that warm water vapor with temperature around 300 K is mainly distributed in a small and well-confined region in the inner disk. The inner boundary of the warm water region is where the shielding of UV field due to dust and water itself become significant. The outer boundary is where the dust temperature drops below the water condensation temperature. A more luminous central star leads to a more extended distribution of warm water vapor, while dust growth and settling tends to reduce the amount of warm water vapor. Based on typical assumptions regarding the elemental oxygen abundance and the water chemistry, the column density of warm water vapor can be as high as 1022 cm-2. A small amount of hot water vapor with temperature higher than ~300 K exists in a more extended region in the upper atmosphere of the disk. Cold water vapor with temperature lower than 100 K is distributed over the entire disk, produced by photodesorption of the water ice.

  18. Experimental and analytical analyses of the mechanisms governing the dispersion of flammable clouds formed by liquid hydrogen spills

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.; Chirivella, J. E.

    1984-01-01

    This paper presents the initial findings of hydrogen vapor cloud dispersion experiments conducted by NASA. The experiments were performed to obtain basic information regarding the physical phenomena governing the dispersion of flammable clouds formed as the result of spills of large quantities of liquid hydrogen. The experiments consisted of ground spills of up to 5.7 cu m of liquid hydrogen with spill durations of approx. 35 s. Instrumented towers, located downwind of the spill site, gathered data on the temperature, hydrogen concentration and turbulence levels as the hydrogen vapor cloud drifted downwind. Preliminary results of the experiments indicate that, for rapid spills, thermal and momentum-induced turbulences cause the cloud to disperse to safe concentration levels and become positively buoyant long before mixing due to normal atmospheric turbulence becomes a major factor. An adiabatic mixing model has been developed to deduce hydrogen-air mixture ratios for temperature measurements obtained within the cloud formed by liquid hydrogen spills.

  19. Fermion dispersion in axion medium

    E-print Network

    N. V. Mikheev; E. N. Narynskaya

    2008-12-02

    The interaction of a fermion with the dense axion medium is investigated for the purpose of finding an axion medium effect on the fermion dispersion. It is shown that axion medium influence on the fermion dispersion under astrophysical conditions is negligible small if the correct Lagrangian of the axion-fermion interaction is used.

  20. Procedure for dispersing fiber bundles

    NASA Technical Reports Server (NTRS)

    Padilla, D.

    1974-01-01

    Fiber bundles are dispersed and fibers are cleaned within enclosed container; therefore, safety clothing, masks, and eye protection are not required. Procedure also could be used wherever materials, such as fiberglass or insulation, require dispersion, fluffing, or cleaning. Process could be automated into continuous operation for handling large quantities of fiber.